Professor Phil Hansbro

Non-communicable, chronic respiratory diseases (CRDs) affect millions of individuals worldwide. The course of these CRDs (asthma, chronic obstructive pulmonary disease, and cystic fibrosis) are often punctuated by microbial infections that may result in hospitalization and are associated with increased risk of morbidity and mortality, as well as reduced quality of life. Interleukin-13 (IL-13) is a key protein that regulates airway inflammation and mucus hypersecretion. There has been much interest in IL-13 from the last two decades. This cytokine is believed to play a decisive role in the exacerbation of inflammation during the course of viral infections, especially, in those with pre-existing CRDs. Here, we discuss the common viral infections in CRDs, as well as the potential role that IL-13 plays in the virus-induced disease pathogenesis of CRDs. We also discuss, in detail, the immune-modulation potential of IL-13 that could be translated to in-depth studies to develop IL-13-based therapeutic entities.

Nuclear factor ¿B (NF¿B) is a unique protein complex that plays a major role in lung inflammation and respiratory dysfunction. The NF¿B signaling pathway, therefore becomes an avenue for the development of potential pharmacological interventions, especially in situations where chronic inflammation is often constitutively active and plays a key role in the pathogenesis and progression of the disease. NF¿B decoy oligodeoxynucleotides (ODNs) are double-stranded and carry NF¿B binding sequences. They prevent the formation of NF¿B-mediated inflammatory cytokines and thus have been employed in the treatment of a variety of chronic inflammatory diseases. However, the systemic administration of naked decoy ODNs restricts their therapeutic effectiveness because of their poor pharmacokinetic profile, instability, degradation by cellular enzymes and their low cellular uptake. Both structural modification and nanotechnology have shown promising results in enhancing the pharmacokinetic profiles of potent therapeutic substances and have also shown great potential in the treatment of respiratory diseases such as asthma, chronic obstructive pulmonary disease and cystic fibrosis. In this review, we examine the contribution of NF¿B activation in respiratory diseases and recent advancements in the therapeutic use of decoy ODNs. In addition, we also highlight the limitations and challenges in use of decoy ODNs as therapeutic molecules, cellular uptake of decoy ODNs, and the current need for novel delivery systems to provide efficient delivery of decoy ODNs. Furthermore, this review provides a common platform for discussion on the existence of decoy ODNs, as well as outlining perspectives on the latest generation of delivery systems that encapsulate decoy ODNs and target NF¿B in respiratory diseases.

Background: Ubiquitin ligases or E3 ligases are well programmed to regulate molecular interactions that operate at a post-translational level. Skp, Cullin, F-box containing complex (or SCF complex) is a multidomain E3 ligase known to mediate the degradation of a wide range of proteins through the proteasomal pathway. The three-dimensional domain architecture of SCF family proteins suggests that it operates through a novel and adaptable ¿super-enzymatic¿ process that might respond to targeted therapeutic modalities in cancer. Recent findings: Several F-box containing proteins have been characterized either as tumor suppressors (FBXW8, FBXL3, FBXW8, FBXL3, FBXO1, FBXO4, and FBXO18) or as oncogenes (FBXO5, FBXO9, and SKP2). Besides, F-box members like ßTrcP1 and ßTrcP2, the ones with context-dependent functionality, have also been studied and reported. FBXW7 is a well-studied F-box protein and is a tumor suppressor. FBXW7 regulates the activity of a range of substrates, such as c-Myc, cyclin E, mTOR, c-Jun, NOTCH, myeloid cell leukemia sequence-1 (MCL1), AURKA, NOTCH through the well-known ubiquitin-proteasome system (UPS)-mediated degradation pathway. NOTCH signaling is a primitive pathway that plays a crucial role in maintaining normal tissue homeostasis. FBXW7 regulates NOTCH protein activity by controlling its half-life, thereby maintaining optimum protein levels in tissue. However, aberrations in the FBXW7 or NOTCH expression levels can lead to poor prognosis and detrimental outcomes in patients. Therefore, the FBXW7-NOTCH axis has been a subject of intense study and research over the years, especially around the interactome's role in driving cancer development and progression. Several studies have reported the effect of FBXW7 and NOTCH mutations on normal tissue behavior. The current review attempts to critically analyze these mutations prognostic value in a wide range of tumors. Furthermore, the review summarizes the recent findings pertaining to the FBXW7 and NOTCH interactome and its involvement in phosphorylation-related events, cell cycle, proliferation, apoptosis, and metastasis. Conclusion: The review concludes by positioning FBXW7 as an effective diagnostic marker in tumors and by listing out recent advancements made in cancer therapeutics in identifying protocols targeting the FBXW7-NOTCH aberrations in tumors.

Background: Macrophages control innate and acquired immunity, but their role in severe asthma remains ill-defined. We investigated gene signatures of macrophage subtypes in the sputum of 104 asthmatics and 16 healthy volunteers from the U-BIOPRED cohort. Methods: Forty-nine gene signatures (modules) for differentially stimulated macrophages, one to assess lung tissue-resident cells (TR-Mf) and two for their polarization (classically and alternatively activated macrophages: M1 and M2, respectively) were studied using gene set variation analysis. We calculated enrichment scores (ES) across severity and previously identified asthma transcriptome-associated clusters (TACs). Results: Macrophage numbers were significantly decreased in severe asthma compared to mild-moderate asthma and healthy volunteers. The ES for most modules were also significantly reduced in severe asthma except for 3 associated with inflammatory responses driven by TNF and Toll-like receptors via NF-¿B, eicosanoid biosynthesis via the lipoxygenase pathway and IL-2 biosynthesis (all P¿<.01). Sputum macrophage number and the ES for most macrophage signatures were higher in the TAC3 group compared to TAC1 and TAC2 asthmatics. However, a high enrichment was found in TAC1 for 3 modules showing inflammatory pathways linked to Toll-like and TNF receptor activation and arachidonic acid metabolism (P¿<.001) and in TAC2 for the inflammasome and interferon signalling pathways (P¿<.001). Data were validated in the ADEPT cohort. Module analysis provides additional information compared to conventional M1 and M2 classification. TR-Mf were enriched in TAC3 and associated with mitochondrial function. Conclusions: Macrophage activation is attenuated in severe granulocytic asthma highlighting defective innate immunity except for specific subsets characterized by distinct inflammatory pathways.

Curcumin is a major curcuminoid present in turmeric. The compound is attributed to various therapeutic properties, which include anti-oxidant, anti-inflammatory, anti-bacterial, anti-malarial, and neuroprotection. Due to its therapeutic potential, curcumin has been employed for centuries in treating different ailments. Curcu-min has been investigated lately as a novel therapeutic agent in the treatment of cancer. However, the mechanisms by which curcumin exerts its cytotoxic effects on malignant cells are still not fully understood. One of the main limiting factors in the clinical use of curcumin is its poor bioavailability and rapid elimination. Advancements in drug delivery systems such as nanoparticle-based vesicular drug delivery platforms have improved several parameters, namely, drug bioavailability, solubility, stability, and controlled release properties. The use of curcumin-encapsulated niosomes to improve the physical and pharmacokinetic properties of curcumin is one such approach. This review provides an up-to-date summary of nanoparticle-based vesicular drug carriers and their therapeutic applications. Specifically, we focus on niosomes as novel drug delivery formulations and their potential in improving the delivery of challenging small molecules, including curcumin. Overall, the applications of such carriers will provide a new direction for novel pharmaceutical drug delivery, as well as for biotechnology, nutraceutical, and functional food industries.

Background: Asthma, a heterogeneous disease, can be divided into 4 inflammatory phenotypes using induced sputum cell counts¿eosinophilic asthma (EA), neutrophilic asthma (NA), mixed granulocytic asthma, and paucigranulocytic asthma (PGA). Although research has focused on EA and NA, there is little known about PGA. Objective: To study the heterogeneity of PGA and identify possible PGA clusters to guide clinical treatment. Methods: Patients with PGA were grouped by hierarchical cluster analysis and enrolled into a prospective cohort study to validate the clusters, relative to future risk of asthma exacerbations in a real-world setting. Clusters were validated by tree analysis in a separate population. Finally, we explored PGA stability. Results: Cluster analysis of 145 patients with PGA identified 3 clusters: cluster 1 (n = 110, 75.9%) was ¿mild PGA,¿ cluster 2 (n = 20, 13.8%) was ¿PGA with psychological dysfunction and rhinoconjunctivitis and other allergic diseases,¿ and cluster 3 (n = 15, 10.3%) was ¿smoking-associated PGA.¿ Cluster 3 had significantly increased risk of severe exacerbation (relative risk [RR] = 6.43, P =.01), emergency visit (RR = 8.61, P =.03), and hospitalization (RR = 12.94, P <.01). Results of the cluster analysis were successfully validated in an independent PGA population classified using decision tree analysis. Although PGA can transform into or develop from other phenotypes, 70% were stable over time. Conclusions: Among 3 identified PGA clusters, cluster 3 had a higher risk of severe exacerbation. PGA heterogeneity indicates the requirement of novel targeted interventions.

Inflammation is the result of a complex network of cellular and molecular interactions and mechanisms that facilitate immune protection against intrinsic and extrinsic stimuli, particularly pathogens, to maintain homeostasis and promote tissue healing. However, dysregulation in the immune system elicits excess/abnormal inflammation resulting in unintended tissue damage and causes major inflammatory diseases including asthma, chronic obstructive pulmonary disease, atherosclerosis, inflammatory bowel diseases, sarcoidosis and rheumatoid arthritis. It is now widely accepted that both endoplasmic reticulum (ER) stress and inflammasomes play critical roles in activating inflammatory signalling cascades. Notably, evidence is mounting for the involvement of ER stress in exacerbating inflammasome-induced inflammatory cascades, which may provide a new axis for therapeutic targeting in a range of inflammatory disorders. Here, we comprehensively review the roles, mechanisms and interactions of both ER stress and inflammasomes, as well as their interconnected relationships in inflammatory signalling cascades. We also discuss novel therapeutic strategies that are being developed to treat ER stress- and inflammasome-related inflammatory disorders.

Background and objective: COVID-19 is complicated by acute lung injury, and death in some individuals. It is caused by SARS-CoV-2 that requires the ACE2 receptor and serine proteases to enter AEC. We determined what factors are associated with ACE2 expression particularly in patients with asthma and COPD. Methods: We obtained lower AEC from 145 people from two independent cohorts, aged 2¿89 years, Newcastle (n = 115) and Perth (n = 30), Australia. The Newcastle cohort was enriched with people with asthma (n = 37) and COPD (n = 38). Gene expression for ACE2 and other genes potentially associated with SARS-CoV-2 cell entry was assessed by qPCR, and protein expression was confirmed with immunohistochemistry on endobronchial biopsies and cultured AEC. Results: Increased gene expression of ACE2 was associated with older age (P = 0.03) and male sex (P = 0.03), but not with pack-years smoked. When we compared gene expression between adults with asthma, COPD and healthy controls, mean ACE2 expression was lower in asthma patients (P = 0.01). Gene expression of furin, a protease that facilitates viral endocytosis, was also lower in patients with asthma (P = 0.02), while ADAM-17, a disintegrin that cleaves ACE2 from the surface, was increased (P = 0.02). ACE2 protein expression was also reduced in endobronchial biopsies from asthma patients. Conclusion: Increased ACE2 expression occurs in older people and males. Asthma patients have reduced expression. Altered ACE2 expression in the lower airway may be an important factor in virus tropism and may in part explain susceptibility factors and why asthma patients are not over-represented in those with COVID-19 complications.

Air pollution exposure during pregnancy may be a risk factor for altered immune maturation in the offspring. We investigated the association between ambient air pollutants during pregnancy and cell populations in cord blood from babies born to mothers with asthma enrolled in the Breathing for Life Trial. For each patient (n = 91), daily mean ambient air pollutant levels were extracted during their entire pregnancy for sulfur dioxide (SO2), nitric oxide, nitrogen dioxide, carbon monoxide, ozone, particulate matter <10 µm (PM10) or <2.5 µm (PM2.5), humidity, and temperature. Ninety-one cord blood samples were collected, stained, and assessed using fluorescence-activated cell sorting (FACS). Principal Component (PC) analyses of both air pollutants and cell types with linear regression were employed to define associations. Considering risk factors and correlations between PCs, only one PC from air pollutants and two from cell types were statistically significant. PCs from air pollutants were characterized by higher PM2.5 and lower SO2 levels. PCs from cell types were characterized by high numbers of CD8 T cells, low numbers of CD4 T cells, and by high numbers of plasmacytoid dendritic cells (pDC) and low numbers of myeloid DCs (mDCs). PM2.5 levels during pregnancy were significantly associated with high numbers of pDCs (p = 0.006), and SO2 with high numbers of CD8 T cells (p = 0.002) and low numbers of CD4 T cells (p = 0.011) and mDCs (p = 4.43 × 10-6) in cord blood. These data suggest that ambient SO2 and PM2.5 exposure are associated with shifts in cord blood cell types that are known to play significant roles in inflammatory respiratory disease in childhood.

Alzheimer's disease, the most common form of dementia, was first formally described in 1907 yet its etiology has remained elusive. Recent proposals that Aß peptide may be part of the brain immune response have revived longstanding contention about the possibility of causal relationships between brain pathogens and Alzheimer's disease. Research has focused on infectious pathogens that may colonize the brain such as herpes simplex type I. Some researchers have proposed the respiratory bacteria Chlamydia pneumoniae may also be implicated in Alzheimer's disease, however this remains controversial. This review aims to provide a balanced overview of the current evidence and its limitations and future approaches that may resolve controversies. We discuss the evidence from in vitro, animal and human studies proposed to implicate Chlamydia pneumoniae in Alzheimer's disease and other neurological conditions, the potential mechanisms by which the bacterium may contribute to pathogenesis and limitations of previous studies that may explain the inconsistencies in the literature.

Estrogen, a major female sex steroid hormone, has been shown to promote the selection of mucoid Pseudomonas aeruginosa in the airways of patients with chronic respiratory diseases, including cystic fibrosis. This results in long-term persistence, poorer clinical outcomes, and limited therapeutic options. In this study, we demonstrate that at physiological concentrations, sex steroids, including testosterone and estriol, induce membrane stress responses in P. aeruginosa. This is characterized by increased virulence and consequent inflammation and release of proinflammatory outer membrane vesicles promoting in vivo persistence of the bacteria. The steroid-induced P. aeruginosa response correlates with the molecular polarity of the hormones and membrane fluidic properties of the bacteria. This novel mechanism of interaction between sex steroids and P. aeruginosa explicates the reported increased disease severity observed in females with cystic fibrosis and provides evidence for the therapeutic potential of the modulation of sex steroids to achieve better clinical outcomes in patients with hormone-responsive strains. IMPORTANCE Molecular mechanisms by which sex steroids interact with P. aeruginosa to modulate its virulence have yet to be reported. Our work provides the first characterization of a steroid-induced membrane stress mechanism promoting P. aeruginosa virulence, which includes the release of proinflammatory outer membrane vesicles, resulting in inflammation, host tissue damage, and reduced bacterial clearance. We further demonstrate that at nanomolar (physiological) concentrations, male and female sex steroids promote virulence in clinical strains of P. aeruginosa based on their dynamic membrane fluidic properties. This work provides, for the first-time, mechanistic insight to better understand and predict the P. aeruginosa related response to sex steroids and explain the interindividual patient variability observed in respiratory diseases such as cystic fibrosis that are complicated by gender differences and chronic P. aeruginosa infection.

In asthma, goblet cell numbers are increased within the airway epithelium, perpetuating the production of mucus that is more difficult to clear and results in airway mucus plugging. Notch1, Notch2, or Notch3, or a combination of these has been shown to influence the differentiation of airway epithelial cells. How the expression of specific Notch isoforms differs in fully differentiated adult asthmatic epithelium and whether Notch influences mucin production after differentiation is currently unknown. We aimed to quantify different Notch isoforms in the airway epithelium of individuals with severe asthma and to examine the impact of Notch signaling on mucin MUC5AC. Human lung sections and primary bronchial epithelial cells from individuals with and without asthma were used in this study. Primary bronchial epithelial cells were differentiated at the air-liquid interface for 28 days. Notch isoform expression was analyzed by Taqman quantitative PCR. Immunohistochemistry was used to localize and quantify Notch isoforms in human airway sections. Notch signaling was inhibited in vitro using dibenzazepine or Notch3-specific siRNA, followed by analysis of MUC5AC. NOTCH3 was highly expressed in asthmatic airway epithelium compared with nonasthmatic epithelium. Dibenzazepine significantly reduced MUC5AC production in air-liquid interface cultures of primary bronchial epithelial cells concomitantly with suppression of NOTCH3 intracellular domain protein. Specific knockdown using NOTCH3 siRNA recapitulated the dibenzazepine-induced reduction in MUC5AC. We demonstrate that NOTCH3 is a regulator of MUC5AC production. Increased NOTCH3 signaling in the asthmatic airway epithelium may therefore be an underlying driver of excess MUC5AC production.

Introduction: Chronic obstructive pulmonary disease (COPD) is a lung disease characterized by chronic bronchitis, emphysema, and remodeling. Its prevalence is increasing worldwide; however, there are few effective therapies, and none of the treatments currently available prevent the progression of the disease or target all of the hallmark features. The development and progression of COPD are heterogeneous, which has hampered the development of new therapies. Areas covered: In this review, we cover the emergence of the improvement of existing classes of drugs including glucocorticoids, ß2-adrenoceptor agonists, phosphodiesterase inhibitors, PDE4 selective inhibitors, PDE3/PDE4 inhibitors, protease inhibitors, recombinant a1-antitrypsin and neutrophil elastase inhibitors. We also highlight new compounds that target recently identified mechanisms of COPD, new dual-action muscarinic antagonists, and ß2-agonists, kinase inhibitors, cytokine modifiers, chemokines modifiers, NF-¿B inhibitors, senolytics, antioxidants, inhaled antiviral agents, anti-fibrotic compounds, and compounds stimulating lung regeneration. Expert opinion: Given the myriad of potential therapeutic avenues that can be pursued, careful consideration of the phenotypes/endotypes of COPD patients will be important for personalized treatment options in the future, and a full understanding of disease mechanisms in patient subsets will ensure these emerging therapies are targeted appropriately.

Aim: In this study, curcumin was encapsulated in niosomes (Nio-Curc) to increase its effectiveness for the treatment of asthma. Materials & methods: The formulation underwent various physicochemical characterization experiments, an in vitro release study, molecular simulations and was evaluated for in vitro anti-inflammatory activity. Results: Results showed that Nio-Curc had a mean particle size of 284.93 ± 14.27 nm, zeta potential of -46.93 and encapsulation efficacy of 99.62%, which demonstrates optimized physicochemical characteristics. Curcumin release in vitro could be sustained for up to 24 h. Additionally, Nio-Curc effectively reduced mRNA transcript expression of pro-inflammatory markers; IL-6, IL-8, IL-1ß and TNF-a in immortalized human airway basal cell line (BCi-NS1.1). Conclusion: In this study, we have demonstrated that Nio-Curc mitigated the mRNA expression of pro-inflammatory markers in an in vitro study, which could be applied to treatment of asthma with further studies.

Conspicuous coloured displays from ultraviolet to bright red have been documented in many species throughout the animal kingdom. These colours often occur as sexual signals and can be incorporated into different types of integuments (e.g. scales, feathers, skin). Two main mechanisms are known to produce coloured integuments: pigmentation and tissue structure. Although pigmental and structural coloration are separate mechanisms and can occur independently, some coloured displays might emerge from a combination of both. Here, we demonstrate, using biochemical, optical and morphological methodologies, that the yellow coloration of the skin located around the eye of Common (Indian) Mynas (Acridotheres tristis) is produced by both light-reflecting nanostructures and light-absorbing carotenoid pigments. Our analysis confirms that nanostructured collagen in the avian dermis work in combination with carotenoid pigments to produce vivid integumentary colours. Identifying the mechanisms behind the production of a coloured signal provides a basis for predicting how a signal¿s function might be influenced by environmental factors such as fledgling nutrition.

Neutrophils are essential effector cells of immune system for clearing the extracellular pathogens during inflammation and immune reactions. Neutrophils play a major role in chronic respiratory diseases. In respiratory diseases such as asthma, chronic obstructive pulmonary disease, cystic fibrosis, lung cancer and others, there occurs extreme infiltration and activation of neutrophils followed by a cascade of events like oxidative stress and dysregulated cellular proteins that eventually result in apoptosis and tissue damage. Dysregulation of neutrophil effector functions including delayed neutropil apoptosis, increased neutrophil extracellular traps in the pathogenesis of asthma, and chronic obstructive pulmonary disease enable neutrophils as a potential therapeutic target. Accounting to their role in pathogenesis, neutrophils present as an excellent therapeutic target for the treatment of chronic respiratory diseases. This review highlights the current status and the emerging trends in novel drug delivery systems such as nanoparticles, liposomes, microspheres, and other newer nanosystems that can target neutrophils and their molecular pathways, in the airways against infections, inflammation, and cancer. These drug delivery systems are promising in providing sustained drug delivery, reduced therapeutic dose, improved patient compliance, and reduced drug toxicity. In addition, the review also discusses emerging strategies and the future perspectives in neutrophil-based therapy.

Lee JM, Mayall JR, Chevalier A, McCarthy H, Van Helden D, Hansbro PM, Horvat JC, Jobling P. Chlamydia muridarum infection differentially alters smooth muscle function in mouse uterine horn and cervix. Am J Physiol Endocrinol Metab 318: E981 E994, 2020. First published April 21, 2020; doi:10.1152/ajpendo.00513. 2019. Chlamydia trachomatis infection is a primary cause of reproductive tract diseases including infertility. Previous studies showed that this infection alters physiological activities in mouse oviducts. Whether this occurs in the uterus and cervix has never been investigated. This study characterized the physiological activities of the uterine horn and the cervix in a Chlamydia muridarum (Cmu)-infected mouse model at three infection time points of 7, 14, and 21 days postinfection (dpi). Cmu infection significantly decreased contractile force of spontaneous contraction in the cervix (7 and 14 dpi; P < 0.001 and P < 0.05, respectively), but this effect was not observed in the uterine horn. The responses of the uterine horn and cervix to oxytocin were significantly altered by Cmu infection at 7 dpi (P < 0.0001), but such responses were attenuated at 14 and 21 dpi. Cmu infection increased contractile force to prostaglandin (PGF2_) by 53 83% in the uterine horn. This corresponded with the increased messenger ribonucleic acid (mRNA) expression of Ptgfr that encodes for its receptor. However, Cmu infection did not affect contractions of the uterine horn and cervix to PGE2 and histamine. The mRNA expression of Otr and Ptger4 was inversely correlated with the mRNA expression of Il1b, Il6 in the uterine horn of Cmu-inoculated mice (P < 0.01 to P < 0.001), suggesting that the changes in the Otr and Ptger4 mRNA expression might be linked to the changes in inflammatory cytokines. Lastly, this study also showed a novel physiological finding of the differential response to PGE2 in mouse uterine horn and cervix.

The application of medicinal plants has captured the interest of researchers in recent times due to their potent therapeutic properties and a better safety profile. The prominent role of herbal products in treating and preventing multiple diseases dates back to ancient history and most of the modern drugs today originated from their significant sources owing to their ability to control multiple targets via different signalling pathways. Among them, flavonoids consist of a large group of polyphenols, which are well known for their various therapeutic benefits. Rutin is considered one of the attractive phytochemicals and important flavonoids in the pharmaceutical industry due to its diverse pharmacological activities via various underlying molecular mechanisms. It is usually prescribed for various disease conditions such as varicosities, haemorrhoids and internal haemorrhage. In this review, we have discussed and highlighted the different molecular mechanisms attributed to the various pharmacological activities of rutin, such as antioxidant, anti-inflammatory, anticancer, anti-allergic and anti-diabetic. This review will be beneficial to herbal, biological and molecular scientists in understanding the pharmacological relevance of rutin at the molecular level.

Olfactory receptors (ORs) are a group of G protein coupled receptors (GPCRs) that initiate chemical odorant signals. Although ORs are predominantly located in nasal epithelia to detect smell, these receptors are also present in peripherally in non-nasal organs/tissues. Since the quality of life and cognitive and sensorial features of sense of smell are worsened in multiple chemical sensitivity due to the interaction of ORs with offending compounds, it is important to not only differentiate these receptors from other GPCRs but also characterize these organelles to understand the underlying mechanisms of smelling disorders. The aim of this study was develop computerized programs to differentiate ORs from GPCRs. The computer program was developed on the basis of widely accepted basic algorithms. It is noteworthy that an accuracy of 95.5% was attained, a level not achieved using other established techniques for screening of ORs from GPCRs. The high accuracy rate indicates that this method of differential identification appears reliable. Our findings indicate that this novel method may be considered as a tool for identification and characterization of receptors which might aid in therapeutic approaches to human chemical-mediated sensitization.

Biomass smoke exposure is associated with a heightened risk of development of respiratory diseases that include chronic obstructive pulmonary disease (COPD). The aim of this study was to increase our understanding of how biomass smoke could contribute to an increased susceptibility to respiratory infection. We investigated the effects of cow dung and wood smoke exposure on human bronchial epithelial cells with respect to adherence of a major respiratory bacterial pathogen in COPD, nontypeable Haemophilus influenzae (NTHi), using immunofluorescence microscopy. In addition, expression of a known receptor of NTHi, platelet-activating factor receptor (PAFR), and two pro-inflammatory cytokines, interleukin 6 (IL-6) and interleukin-8 (IL-8), were determined using quantitative polymerase chain reaction. We observed a dose-dependent increase in NTHi adhesion to human bronchial epithelial cells following exposure to cow dung but not wood smoke extracts. Pre-treatment with PAFR antagonists, WEB-2086 and its analogue, C17, decreased adherence by NTHi to airway epithelial cells exposed to cow dung smoke. Both cow dung and wood smoke-induced expression of PAFR, as well as of IL-6 and IL-8, which was inhibited by WEB-2086 and C17. In conclusion, biomass smoke from combustion of cow dung and wood-induced expression of PAFR and airway inflammatory markers in human bronchial epithelial cells. Cow dung exposure, but not wood smoke exposure, mediated a measurable increase in NTHi adhesion to airway epithelial cells that was inhibited by PAFR antagonists. This work highlights the potential of PAFR as a therapeutic target for reducing the impact of hazardous biomass smoke exposure on respiratory health.

Tobacco smoke is not only a leading cause for chronic obstructive pulmonary disease, cardiovascular disorders, and lung and oral cancers, but also causes neurological disorders such as Alzheimer ¿s disease. Tobacco smoke consists of more than 4500 toxic chemicals, which form free radicals and can cross blood-brain barrier resulting in oxidative stress, an extracellular amyloid plaque from the aggregation of amyloid ß (Aß) peptide deposition in the brain. Further, respiratory infections such as Chlamydia pneumoniae, respiratory syncytial virus have also been involved in the induction and development of the disease. The necessary information collated on this review has been gathered from various literature published from 1995 to 2019. The review article sheds light on the role of smoking and respiratory infections in causing oxidative stress and neuroinflammation, resulting in Alzheimer's disease (AD). This review will be of interest to scientists and researchers from biological and medical science disciplines, including microbiology, pharmaceutical sciences and the translational researchers, etc. The increasing understanding of the relationship between chronic lung disease and neurological disease is two-fold. First, this would help to identify the risk factors and possible therapeutic interventions to reduce the development and progression of both diseases. Second, this would help to reduce the probable risk of development of AD in the population prone to chronic lung diseases.

COVID-19 is causing a major once-in-a-century global pandemic. The scientific and clinical community is in a race to define and develop effective preventions and treatments. The major features of disease are described but clinical trials have been hampered by competing interests, small scale, lack of defined patient cohorts and defined readouts. What is needed now is head-to-head comparison of existing drugs, testing of safety including in the background of predisposing chronic diseases, and the development of new and targeted preventions and treatments. This is most efficiently achieved using representative animal models of primary infection including in the background of chronic disease with validation of findings in primary human cells and tissues. We explore and discuss the diverse animal, cell and tissue models that are being used and developed and collectively recapitulate many critical aspects of disease manifestation in humans to develop and test new preventions and treatments.

The nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) family, pyrin domain-containing protein 3 (NLRP3) inflammasome, is one of the most well-characterized inflammasomes, activated by pathogen-associated molecular patterns and damage-associated molecular patterns, including from commensal or pathogenic bacterial and viral infections. The NLRP3 inflammasome promotes inflammatory cell recruitment and regulates immune responses in tissues such as the gastrointestinal tract and the lung, and is involved in many diseases that affect the gut and lung. Recently, the microbiome in the gut and the lung, and the crosstalk between these organs (gut¿lung axis), has been identified as a potential mechanism that may influence disease in a bidirectional manner. In this review, we focus on themes presented in this area at the 2019 World Congress on Inflammation. We discuss recent evidence on how the microbiome can affect NLRP3 inflammasome responses in the gut and lung, the role of this inflammasome in regulating gut and lung inflammation in disease, and its potential role in the gut¿lung axis. We highlight the exponential increase in our understanding of the NLRP3 inflammasome due to the synthesis of the NLRP3 inflammasome inhibitor, MCC950, and propose future studies that may further elucidate the roles of the NLRP3 inflammasome in gut and lung diseases.

IL-33 has been deorphanized as a member of the IL-1 family and has key roles as an alarmin and cytokine with potent capacity to drive type 2 inflammation. This has led to a plethora of studies surrounding its role in chronic diseases with a type 2 inflammatory component. Here, we review the roles of IL-33 in two chronic respiratory diseases, asthma and chronic obstructive pulmonary disease (COPD). We discuss the hallmark and paradigm-shifting studies that have contributed to our understanding of IL-33 biology. We cover animal studies that have elucidated the mechanisms of IL-33 and assessed the role of anti-IL-33 treatment and immunization against IL-33. We highlight key clinical evidence for the potential of targeting increased IL-33 in respiratory diseases including exacerbations, and we outline current clinical trials using an anti-IL-33 monoclonal antibody in asthma patients. Finally, we discuss some of the challenges that have arisen in IL-33 biology and highlight potential future directions in targeting this cytokine in chronic respiratory diseases.

Background: Acute exacerbations of asthma represent a major burden of disease and are often caused by respiratory infections. Viral infections are recognized as significant triggers of exacerbations; however, less is understood about the how microbial bioproducts such as the endotoxin (lipopolysaccharide (LPS)) trigger episodes. Indeed, increased levels of LPS have been linked to asthma onset, severity and steroid resistance. Objective: The goal of this study was to identify mechanisms underlying bacterial-induced exacerbations by employing LPS as a surrogate for infection. Methods: We developed a mouse model of LPS-induced exacerbation on the background of pre-existing type-2 allergic airway disease (AAD). Results: LPS-induced exacerbation was characterized by steroid-resistant airway hyperresponsiveness (AHR) and an exaggerated inflammatory response distinguished by increased numbers of infiltrating neutrophils/macrophages and elevated production of lung inflammatory cytokines, including TNFa, IFN¿, IL-27 and MCP-1. Expression of the type-2 associated inflammatory factors such as IL-5 and IL-13 were elevated in AAD but not altered by LPS exposure. Furthermore, AHR and airway inflammation were no longer suppressed by corticosteroid (dexamethasone) treatment after LPS exposure. Depletion of pulmonary macrophages by administration of 2-chloroadenosine into the lungs suppressed AHR and reduced IL-13, TNFa and IFN¿ expression. Blocking IL-13 function, through either IL-13-deficiency or administration of specific blocking antibodies, also suppressed AHR and airway inflammation. Conclusions & Clinical Relevance: We present evidence that IL-13 and innate immune pathways (in particular pulmonary macrophages) contribute to LPS-induced exacerbation of pre-existing AAD and provide insight into the complex molecular processes potentially underlying microbial-induced exacerbations.

Acute asthma remains an important medical emergency, the most frequent cause of acute admissions in children and a major source of morbidity for adults with asthma. In all ages with asthma, the presence of exacerbations is an important defining characteristic of asthma severity. In this review, we assess the epidemiology of acute asthma, the triggers of acute exacerbations, and the mechanisms that underlie these exacerbations. We also assess current treatments that prevent exacerbations, with an emphasis on the role of type 2 airway inflammation in the context of acute exacerbations and the novel treatments that effectively target this. Finally we review current mana ement strate ies of the exacerbations themselves

Lung diseases are the leading cause of mortality worldwide. The currently available therapies are not sufficient, leading to the urgent need for new therapies with sustained anti-inflammatory effects. Small/short or silencing interfering RNA (siRNA) has potential therapeutic implications through post-transcriptional downregulation of the target gene expression. siRNA is essential in gene regulation, so is more favorable over other gene therapies due to its small size, high specificity, potency, and no or low immune response. In chronic respiratory diseases, local and targeted delivery of siRNA is achieved via inhalation. The effectual delivery can be attained by the generation of aerosols via inhalers and nebulizers, which overcomes anatomical barriers, alveolar macrophage clearance and mucociliary clearance. In this review, we discuss the different siRNA nanocarrier systems for chronic respiratory diseases, for safe and effective delivery. siRNA mediated pro-inflammatory gene or miRNA targeting approach can be a useful approach in combating chronic respiratory inflammatory conditions and thus providing sustained drug delivery, reduced therapeutic dose, and improved patient compliance. This review will be of high relevance to the formulation, biological and translational scientists working in the area of respiratory diseases.

The innate immune system is our first line of defense against viral pathogens. Host cell pattern recognition receptors sense viral components and initiate immune signaling cascades that result in the production of an array of cytokines to combat infection. Retinoic acid¿inducible gene-I (RIG-I) is a pattern recognition receptor that recognizes viral RNA and, when activated, results in the production of type I and III interferons (IFNs) and the upregulation of IFN-stimulated genes. Ubiquitination of RIG-I by the E3 ligases tripartite motif-containing 25 (TRIM25) and Riplet is thought to be requisite for RIG-I activation; however, recent studies have questioned the relative importance of these two enzymes for RIG-I signaling. In this study, we show that deletion of Trim25 does not affect the IFN response to either influenza A virus (IAV), influenza B virus, Sendai virus or several RIG-I agonists. This is in contrast to deletion of either Rig-i or Riplet, which completely abrogated RIG-I-dependent IFN responses. This was consistent in both mouse and human cell lines, as well as in normal human bronchial cells. With most of the current TRIM25 literature based on exogenous expression, these findings provide critical evidence that Riplet, and not TRIM25, is required endogenously for the ubiquitination of RIG-I. Despite this, loss of TRIM25 results in greater susceptibility to IAV infection in¿vivo, suggesting that it may have an alternative role in host antiviral defense. This study refines our understanding of RIG-I signaling in viral infections and will inform future studies in the field.

Short-chain fatty acids (SCFAs), produced as by-products of dietary fiber metabolism by gut bacteria, have anti-inflammatory properties and could potentially be used for the treatment of inflammatory diseases, including asthma. The direct effects of SCFAs on inflammatory responses in primary human lung mesenchymal cells have not been assessed. We investigated whether SCFAs can protect against tumor necrosis factor (TNF) a-induced inflammation in primary human lung fibroblasts (HLFs) and airway smooth muscle (ASM) cells in vitro. HLFs and ASM cells were exposed to SCFAs, acetate (C2:0), propionate (C3:0), and butyrate (C4:0) (0.01¿25 mM) with or without TNFa, and the release of proinflammatory cytokines, IL-6, and CXCL8 was measured using ELISA. We found that none of the SCFAs suppressed TNFa-induced cytokine release. On the contrary, challenge with supraphysiological concentrations (10 ¿25 mM), as might be used therapeutically, of propionate or butyrate in combination with TNFa resulted in substantially greater IL-6 and CXCL8 release from HLFs and ASM cells than challenge with TNFa alone, demonstrating synergistic effects. In ASM cells, challenge with acetate also enhanced TNFa-induced IL-6, but not CXCL8 release. Synergistic upregulation of IL-6 and CXCL8 was mediated through the activation of free fatty acid receptor (FFAR)3, but not FFAR2. The signaling pathways involved were further examined using specific inhibitors and immunoblotting, and responses were found to be mediated through p38 MAPK signaling. This study demonstrates that proinflammatory, rather than anti-inflammatory effects of SCFAs are evident in lung mesenchymal cells.

COPD is a common and highly destructive disease with huge impacts on people and health services throughout the world. It is mainly caused by cigarette smoking though environmental pollution is also significant. There are no current treatments that affect the overall course of COPD; current drugs focus on symptomatic relief and to some extent reducing exacerbation rates. There is an urgent need for in-depth studies of the fundamental pathogenic mechanisms that underpin COPD. This is vital, given the fact that nearly 40%¿ 60% of the small airway and alveolar damage occurs in COPD well before the first measurable changes in lung function are detected. These individuals are also at a high risk of lung cancer. Current COPD research is mostly centered around late disease and/or innate immune activation within the airway lumen, but the actual damage to the airway wall has early onset. COPD is the end result of complex mechanisms, possibly triggered through initial epithelial activation. To change the disease trajectory, it is crucial to understand the mechanisms in the epithelium that are switched on early in smokers. One such mechanism we believe is the process of epithelial to mesenchymal transition. This article highlights the importance of this profound epithelial cell plasticity in COPD and also its regulation. We consider that understanding early changes in COPD will open new windows for therapy.

Pulmonary inflammation in chronic obstructive pulmonary disease (COPD) is characterized by both innate and adaptive immune responses; however, their specific roles in the pathogenesis of COPD are unclear. Therefore, we investigated the roles of T and B lymphocytes and group 2 innate lymphoid cells (ILC2s) in airway inflammation and remodelling, and lung function in an experimental model of COPD using mice that specifically lack these cells (Rag1 -/- and Rora fl/fl Il7r Cre [ILC2-deficient] mice). Wild-type (WT) C57BL/6 mice, Rag1 -/- , and Rora fl/fl Il7r Cre mice were exposed to cigarette smoke (CS; 12 cigarettes twice a day, 5 days a week) for up to 12¿weeks, and airway inflammation, airway remodelling (collagen deposition and alveolar enlargement), and lung function were assessed. WT, Rag1 -/- , and ILC2-deficient mice exposed to CS had similar levels of airway inflammation and impaired lung function. CS exposure increased small airway collagen deposition in WT mice. Rag1 -/- normal air- and CS-exposed mice had significantly increased collagen deposition compared to similarly exposed WT mice, which was associated with increases in IL-33, IL-13, and ILC2 numbers. CS-exposed Rora fl/fl Il7r Cre mice were protected from emphysema, but had increased IL-33/IL-13 expression and collagen deposition compared to WT CS-exposed mice. T/B lymphocytes and ILC2s play roles in airway collagen deposition/fibrosis, but not inflammation, in experimental COPD.

Oxidative stress is intensely involved in enhancing the severity of various chronic respiratory diseases (CRDs) including asthma, chronic obstructive pulmonary disease (COPD), infections and lung cancer. Even though there are various existing anti-inflammatory therapies, which are not enough to control the inflammation caused due to various contributing factors such as anti-inflammatory genes and antioxidant enzymes. This leads to an urgent need of novel drug delivery systems to combat the oxidative stress. This review gives a brief insight into the biological factors involved in causing oxidative stress, one of the emerging hallmark feature in CRDs and particularly, highlighting recent trends in various novel drug delivery carriers including microparticles, microemulsions, microspheres, nanoparticles, liposomes, dendrimers, solid lipid nanocarriers etc which can help in combating the oxidative stress in CRDs and ultimately reducing the disease burden and improving the quality of life with CRDs patients. These carriers improve the pharmacokinetics and bioavailability to the target site. However, there is an urgent need for translational studies to validate the drug delivery carriers for clinical administration in the pulmonary clinic.

Introduction: COPD and lung cancer are leading causes of morbidity and mortality worldwide, and they share a common environmental risk factor in cigarette smoke exposure and a genetic predisposition represented by their incidence in only a fraction of smokers. This reflects the ability of cigarette smoke to induce an inflammatory response in the airways of susceptible smokers. Moreover, COPD could be a driving factor in lung cancer, by increasing oxidative stress and the resulting DNA damage and repression of the DNA repair mechanisms, chronic exposure to pro-inflammatory cytokines, repression of innate immunity and increased cellular proliferation. Areas covered: We have focused our review on the potential pathogenic molecular links between tobacco smoking-related COPD and lung cancer and the potential molecular targets for new drug development by understanding the common signaling pathways involved in COPD and lung cancer. Expert commentary: Research in this field is mostly limited to animal models or small clinical trials. Large clinical trials are needed but mostly combined models of COPD and lung cancer are necessary to investigate the processes caused by chronic inflammation, including genetic and epigenetic alteration, and the expression of inflammatory mediators that link COPD and lung cancer, to identify new molecular therapeutic targets.

Chronic obstructive pulmonary disease (COPD) is a progressive and devastating chronic lung condition that has a significant global burden, both medically and financially. Currently there are no medications that can alter the course of disease. At best, the drugs in clinical practice provide symptomatic relief to suffering patients by alleviating acute exacerbations. Most of current clinical research activities are in late severe disease with lesser attention given to early disease manifestations. There is as yet, a lack of understanding of the underlying mechanisms of disease progression and the molecular switches that are involved in their manifestation. Small airway fibrosis and obliteration are known to cause fixed airflow obstruction in COPD, and the consequential damage to the lung has an early onset. So far, there is little evidence of the mechanisms that underlie this aspect of pathology. However, emerging research confirms that airway epithelial reprogramming or epithelial to mesenchymal transition (EMT) is a key mechanism that drives fibrotic remodelling changes in smokers and patients with COPD. A recent study by Lai et al. further highlights the importance of EMT in smoking-related COPD pathology. The authors identify HB-EGF, an EGFR ligand, as a key driver of EMT and a potential new therapeutic target for the amelioration of EMT and airway remodelling. There are also wider implications in lung cancer prophylaxis, which is another major comorbidity associated with COPD. We consider that improved molecular understanding of the intricate pathways associated with epithelial cell plasticity in smokers and patients with COPD will have major therapeutic implications.

Macrophages are considered as the most flexible cells of the hematopoietic system that are distributed in the tissues to act against pathogens and foreign particles. Macrophages are essential in maintaining homeostatic tissue processes, repair and immunity. Also, play important role in cytokine secretion and signal transduction of the infection so as to develop acquired immunity. Accounting to their involvement in pathogenesis, macrophages present a therapeutic target for the treatment of inflammatory respiratory diseases. This review focuses on novel drug delivery systems (NDDS) including nanoparticles, liposomes, dendrimers, microspheres etc that can target alveolar macrophage associated with inflammation, intracellular infection and lung cancer. The physiochemical properties and functional moieties of the NDDS attributes to enhanced macrophage targeting and uptake. The NDDS are promising for sustained drug delivery, reduced therapeutic dose, improved patient compliance and reduce drug toxicity. Further, the review also discuss about modified NDDS for specificity to the target and molecular targeting via anti-microbial peptides, kinases, NRF-2 and phosphodiesterase.

Objectives: To examine the effectiveness of different strategies for recruiting participants for a large Australian randomised controlled trial (RCT), the Australian Study for the Prevention through Immunisation of Cardiovascular Events (AUSPICE). Design, setting, participants: Men and women aged 55¿60 years with at least two cardiovascular risk factors (hypertension, hypercholesterolaemia, overweight/obesity) were recruited for a multicentre placebo-controlled RCT assessing the effectiveness of 23-valent pneumococcal polysaccharide vaccine (23vPPV) for preventing cardiovascular events. Methods: Invitations were mailed by the Australian Department of Human Services to people in the Medicare database aged 55¿60 years; reminders were sent 2 weeks later. Invitees could respond in hard copy or electronically. Direct recruitment was supplemented by asking invitees to extend the invitation to friends and family (snowball sampling) and by Facebook advertising. Main outcome: Proportions of invitees completing screening questionnaire and recruited for participation in the RCT. Results: 21¿526 of 154¿992 invited people (14%) responded by completing the screening questionnaire, of whom 4725 people were eligible and recruited for the study. Despite the minimal study burden (one questionnaire, one clinic visit), the overall participation rate was 3%, or an estimated 10% of eligible persons. Only 16% of eventual participants had responded within 2 weeks of the initial invitation letter (early responders); early and late responders did not differ in their demographic or medical characteristics. Socio-economic disadvantage did not markedly influence response rates. Facebook advertising and snowball sampling did not increase recruitment. Conclusions: Trial participation rates are low, and multiple concurrent methods are needed to maximise recruitment. Social media strategies may not be successful in older age groups. Trial registration: Australian New Zealand Clinical Trials Registry, ACTRN12615000536561.

Asthma is a common, heterogeneous and serious disease with high prevalence globally. Poorly controlled, steroid-resistant asthma is particularly important as there are no effective therapies and it exerts substantial healthcare and societal burden. The role of microbiomes, particularly in chronic diseases has generated considerable interest in recent times. Existing evidence clearly demonstrates an association between asthma initiation and the microbiome, both respiratory and gastro-intestinal, although its¿ roles are poorly understood when assessing the asthma progression or heterogeneity (i.e. phenotypes/endotypes) across different geographical locations. Moreover, modulating microbiomes could be preventive and/or therapeutic in patients with asthma warrants urgent attention. Here, we review recent advances in assessing the role of microbiomes in asthma and present the challenges associated with the potential therapeutic utility of modifying microbiomes in management.

Introduction The prevalence of heart failure increases in the aging population and following myocardial infarction (MI), yet the extracellular matrix (ECM) remodeling underpinning the development of aging- and MI-associated cardiac fibrosis remains poorly understood. A link between inflammation and fibrosis in the heart has long been appreciated, but has mechanistically remained undefined. We investigated the expression of a novel protein, extracellular matrix protein 1 (ECM1) in the aging and infarcted heart. Methods Young adult (3-month old) and aging (18-month old) C57BL/6 mice were assessed. Young mice were subjected to left anterior descending artery-ligation to induce MI, or transverse aortic constriction (TAC) surgery to induce pressure-overload cardiomyopathy. Left ventricle (LV) tissue was collected early and late post-MI/TAC. Bone marrow cells (BMCs) were isolated from young healthy mice, and subject to flow cytometry. Human cardiac fibroblast (CFb), myocyte, and coronary artery endothelial & smooth muscle cell lines were cultured; human CFbs were treated with recombinant ECM1. Primary mouse CFbs were cultured and treated with recombinant angiotensin-II or TGF-ß1. Immunoblotting, qPCR and mRNA fluorescent in-situ hybridization (mRNA-FISH) were conducted on LV tissue and cells. Results ECM1 expression was upregulated in the aging LV, and in the infarct zone of the LV early post-MI. No significant differences in ECM1 expression were found late post-MI or at any time-point post-TAC. ECM1 was not expressed in any resident cardiac cells, but ECM1 was highly expressed in BMCs, with high ECM1 expression in granulocytes. Flow cytometry of bone marrow revealed ECM1 expression in large granular leucocytes. mRNA-FISH revealed that ECM1 was indeed expressed by inflammatory cells in the infarct zone at day-3 post-MI. ECM1 stimulation of CFbs induced ERK1/2 and AKT activation and collagen-I expression, suggesting a pro-fibrotic role. Conclusions ECM1 expression is increased in ageing and infarcted hearts but is not expressed by resident cardiac cells. Instead it is expressed by bone marrow-derived granulocytes. ECM1 is sufficient to induce cardiac fibroblast stimulation in vitro. Our findings suggest ECM1 is released from infiltrating inflammatory cells, which leads to cardiac fibroblast stimulation and fibrosis in aging and MI. ECM1 may be a novel intermediary between inflammation and fibrosis.

The composition of the lung microbiome is increasingly well characterised, with changes in microbial diversity or abundance observed in association with several chronic respiratory diseases such as asthma, cystic fibrosis, bronchiectasis, and chronic obstructive pulmonary disease. However, the precise effects of the microbiome on pulmonary health and the functional mechanisms by which it regulates host immunity are only now beginning to be elucidated. Bacteria, viruses, and fungi from both the upper and lower respiratory tract produce structural ligands and metabolites that interact with the host and alter the development and progression of chronic respiratory diseases. Here, we review recent advances in our understanding of the composition of the lung microbiome, including the virome and mycobiome, the mechanisms by which these microbes interact with host immunity, and their functional effects on the pathogenesis, exacerbations, and comorbidities of chronic respiratory diseases. We also describe the present understanding of how respiratory microbiota can influence the efficacy of common therapies for chronic respiratory disease, and the potential of manipulation of the microbiome as a therapeutic strategy. Finally, we highlight some of the limitations in the field and propose how these could be addressed in future research.

Lysyl oxidase-like 2 (LOXL2) is a secreted enzyme that catalyzes the formation of cross-links in extracellular matrix proteins, namely, collagen and elastin, and is indicated in fibrotic diseases. Herein, we report the identification and subsequent optimization of a series of indole-based fluoroallylamine inhibitors of LOXL2. The result of this medicinal chemistry campaign is PXS-5120A (12k), a potent, irreversible inhibitor that is >300-fold selective for LOXL2 over LOX. PXS-5120A also shows potent inhibition of LOXL3, an emerging therapeutic target for lung fibrosis. Key to the development of this compound was the utilization of a compound oxidation assay. PXS-5120A was optimized to show negligible substrate activity in vitro for related amine oxidase family members, leading to metabolic stability. PXS-5120A, in a pro-drug form (PXS-5129A, 12o), displayed anti-fibrotic activity in models of liver and lung fibrosis, thus confirming LOXL2 as an important target in diseases where collagen cross-linking is implicated.

Chronic respiratory diseases are among the leading causes of mortality worldwide, with the major contributor, chronic obstructive pulmonary disease (COPD) accounting for approximately 3 million deaths annually. Frequent acute exacerbations (AEs) of COPD (AECOPD) drive clinical and functional decline in COPD and are associated with accelerated loss of lung function, increased mortality, decreased health-related quality of life and significant economic costs. Infections with a small subgroup of pathogens precipitate the majority of AEs and consequently constitute a significant comorbidity in COPD. However, current pharmacological interventions are ineffective in preventing infectious exacerbations and their treatment is compromised by the rapid development of antibiotic resistance. Thus, alternative preventative therapies need to be considered. Pathogen adherence to the pulmonary epithelium through host receptors is the prerequisite step for invasion and subsequent infection of surrounding structures. Thus, disruption of bacterial-host cell interactions with receptor antagonists or modulation of the ensuing inflammatory profile present attractive avenues for therapeutic development. This review explores key mediators of pathogen-host interactions that may offer new therapeutic targets with the potential to prevent viral/bacterial-mediated AECOPD. There are several conceptual and methodological hurdles hampering the development of new therapies that require further research and resolution.

In the recent years, much attention has been focused on identifying bioactive compounds from medicinal plants that could be employed in therapeutics, which is attributed to their potent pharmacological actions and better toxicological profile. One such example that has come into the light with considerable interest is the pentacyclic triterpenoid, celastrol, which has been found to provide substantial therapeutic properties in a variety of diseases. In an effort to further accelerate its potential to be utilized in clinical practice in the future; along with advancing technologies in the field of drug discovery and development, different researchers have been investigating on the various mechanisms and immunological targets of celastrol that underlie its broad spectrum of pharmacological properties. In this review, we have collated the various research findings related to the molecular modulators responsible for different pharmacological activities shown by celastrol. Our review will be of interest to the herbal, biological, molecular scientist and by providing a quick snapshot about celastrol giving a new direction in the area of herbal drug discovery and development.

Oligonucleotide-based therapies are advanced novel interventions used in the management of various respiratory diseases such as asthma and Chronic Obstructive Pulmonary Disease (COPD). These agents primarily act by gene silencing or RNA interference. Better methodologies and techniques are the need of the hour that can deliver these agents to tissues and cells in a target specific manner by which their maximum potential can be reached in the management of chronic inflammatory diseases. Nanoparticles play an important role in the target-specific delivery of drugs. In addition, oligonucleotides also are extensively used for gene transfer in the form of polymeric, liposomal and inorganic carrier materials. Therefore, the current review focuses on various novel dosage forms like nanoparticles, liposomes that can be used efficiently for the delivery of various oligonucleotides such as siRNA and miRNA. We also discuss the future perspectives and targets for oligonucleotides in the management of respiratory diseases.

Acute kidney injury (AKI) remains a global challenge and, despite the availability of dialysis and transplantation, can be fatal. Those that survive an AKI are at increased risk of developing chronic kidney disease and end stage renal failure. Understanding the fundamental mechanisms underpinning the pathophysiology of AKI is critical for developing novel strategies for diagnosis and treatment. A growing body of evidence indicates that amplifying type 2 immunity may have therapeutic potential in kidney injury and disease. Of particular interest are the recently described subset of innate immune cells, termed group 2 innate lymphoid cells (ILCs). Group 2 ILCs are crucial tissue-resident immune cells that maintain homeostasis and regulate tissue repair at multiple organ sites, including the kidney. They are critical mediators of type 2 immune responses following infection and injury. The existing literature suggests that activation of group 2 ILCs and production of a local type 2 immune milieu is protective against renal injury and associated pathology. In this review, we describe the emerging role for group 2 ILCs in renal homeostasis and repair. We provide an in-depth discussion of the most recent literature that use preclinical models of AKI and assess the therapeutic effect of modulating group 2 ILC function. We debate the potential for targeting these cells as novel cellular therapies in AKI and discuss the implications for future studies and translation. Copyright © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Artemisia vulgaris is a traditional Chinese herb believed to have a wide range of healing properties; it is traditionally used to treat numerous health ailments. The plant is commonly called mugwort or riverside wormwood. The plant is edible, and in addition to its medicinal properties, it is also used as a culinary herb in Asian cooking in the form of a vegetable or in soup. The plant has garnered the attention of researchers in the past few decades, and several research studies have investigated its biological effects, including antioxidant, anti-inflammatory, anticancer, hypolipidemic, and antimicrobial properties. In this review, various studies on these biological effects are discussed along with the tests conducted, compounds involved, and proposed mechanisms of action. This review will be of interest to the researchers working in the field of herbal medicine, pharmacology, medical sciences, and immunology.

Group 2 innate lymphoid cells (ILC2s) are a recently described subset of innate lymphocytes with important immune and homeostatic functions at multiple tissue sites, especially the lung. These cells expand locally after birth and during postnatal lung maturation and are present in the lung and other peripheral organs. They are modified by a variety of processes and mediate inflammatory responses to respiratory pathogens, inhaled allergens and noxious particles. Here, we review the emerging roles of ILC2s in pulmonary homeostasis and discuss recent and surprising advances in our understanding of how hormones, age, neurotransmitters, environmental challenges, and infection influence ILC2s. We also review how these responses may underpin the development, progression and severity of pulmonary inflammation and chronic lung diseases and highlight some of the remaining challenges for ILC2 biology.

Lung development is a complex process mediated through the interaction of multiple cell types, factors and mediators. In mice, it starts as early as embryonic day 9 and continues into early adulthood. The process can be separated into five different developmental stages: embryonic, pseudoglandular, canalicular, saccular, and alveolar. Whilst lung bud formation and branching morphogenesis have been studied extensively, the mechanisms of alveolarisation are incompletely understood. Aberrant lung development can lead to deleterious consequences for respiratory health such as bronchopulmonary dysplasia (BPD), a disease primarily affecting preterm neonates, which is characterised by increased pulmonary inflammation and disturbed alveolarisation. While the deleterious effects of type 1-mediated inflammatory responses on lung development have been well established, the role of type 2 responses in postnatal lung development remains poorly understood. Recent studies indicate that type 2-associated immune cells, such as group 2 innate lymphoid cells and alveolar macrophages, are increased in number during postnatal alveolarisation. Here, we present the current state of understanding of the postnatal stages of lung development and the key cell types and mediators known to be involved. We also provide an overview of how stem cells are involved in lung development and regeneration, and the negative influences of respiratory infections. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Extra-intestinal manifestations (EIM) are common in inflammatory bowel disease (IBD). One such EIM is sub-clinical pulmonary inflammation, which occurs in up to 50% of IBD patients. In animal models of colitis, pulmonary inflammation is driven by neutrophilic infiltrations, primarily in response to the systemic bacteraemia and increased bacterial load in the lungs. Platelet activating factor receptor (PAFR) plays a critical role in regulating pulmonary responses to infection in conditions, such as chronic obstructive pulmonary disease and asthma. We investigated the role of PAFR in pulmonary EIMs of IBD, using dextran sulfate sodium (DSS) and anti-CD40 murine models of colitis. Both models induced neutrophilic inflammation, with increased TNF and IL-1ß levels, bacterial load and PAFR protein expression in mouse lungs. Antagonism of PAFR decreased lung neutrophilia, TNF, and IL-1ß in an NLRP3 inflammasome-dependent manner. Lipopolysaccharide from phosphorylcholine (ChoP)-positive bacteria induced NLRP3 and caspase-1 proteins in human alveolar epithelial cells, however antagonism of PAFR prevented NLRP3 activation by ChoP. Amoxicillin reduced bacterial populations in the lungs and reduced NLRP3 inflammasome protein levels, but did not reduce PAFR. These data suggest a role for PAFR in microbial pattern recognition and NLRP3 inflammasome signaling in the lung.

Dysregulated induction of goblet cell differentiation results in excessive production and retention of mucus and is a common feature of several chronic airways diseases. To date, therapeutic strategies to reduce mucus accumulation have focused primarily on altering the properties of the mucus itself, or have aimed to limit the production of mucus-stimulating cytokines. Here we review the current knowledge of key molecular pathways that are dysregulated during persistent goblet cell differentiation and highlights both pre-existing and novel therapeutic strategies to combat this pathology.

The Special AT-rich Sequence Binding Protein 1 (SATB1) is a chromatin organiser and transcription factor which regulates numerous cellular processes such as differentiation, proliferation and apoptosis through effects on gene expression. SATB1 undergoes various post-translational modifications, which determine its interaction with co-activators and co-repressors to induce regulation of gene transcription. SATB1 is an identified oncogene, its increased expression is associated with poor prognosis in many cancers. This paper provides a review on SATB1-mediated immune responses and on its target genes in the context of tumorigenesis and tumour progression. Specifically, we discuss the role of SATB1 in tumour immunity, Epithelial to Mesenchymal Transition (EMT), metastasis and multidrug resistance. Therapeutic targeting of aberrant SATB1 may be an important strategy in the treatment of cancer.

Tuberculosis (caused by Mycobacterium tuberculosis, Mtb) treatment involves multiple drug regimens for a prolonged period. However, the therapeutic benefit is often limited by poor patient compliance, subsequently leading to treatment failure and development of antibiotic resistance. Notably, oxidative stress is a crucial underlying factor that adversely influences the various treatment regimens in tuberculosis. Little information is available with advanced drug delivery systems that could be effectively utilized, in particular, for targeting the oxidative stress in tuberculosis. Thus, this presents an opportunity to review the utility of various available, controlled-release drug delivery systems (e.g., microspheres, liposomes, niosomes, solid lipid nanoparticles, dendrimers) that could be beneficial in tuberculosis treatments. This will help the biological and formulation scientists to pave a new path in formulating a treatment regimen for multi-drug resistant Mtb.

Inflammatory bowel disease (IBD) is associated with several immune-mediated extraintestinal manifestations. More than half of all IBD patients have some form of respiratory pathology, most commonly neutrophil-mediated diseases, such as bronchiectasis and chronic bronchitis. Using murine models of colitis, we aimed to identify the immune mechanisms driving pulmonary manifestations of IBD. We found increased neutrophil numbers in lung tissue associated with the pulmonary vasculature in both trinitrobenzenesulfonic acid¿ and dextran sulfate sodium¿induced models of colitis. Analysis of systemic inflammation identified that neutrophilia was associated with bacteremia and pyrexia in animal models of colitis. We further identified IL-6 as a systemic mediator of neutrophil recruitment from the bone marrow of dextran sulfate sodium animals. Functional inhibition of IL-6 led to reduced systemic and pulmonary neutrophilia, but it did not attenuate established colitis pathology. These data suggest that systemic bacteremia and pyrexia drive IL-6 secretion, which is a critical driver for pulmonary manifestation of IBD. Targeting IL-6 may reduce neutrophil-associated extraintestinal manifestations in IBD patients.

Background: Type 1 diabetes mellitus (T1DM) is an autoimmune disorder characterized by T cell-mediated self-destruction of insulin-secreting islet ß cells. Management of T1DM is challenging and complicated especially with conventional medications. Gene therapy has emerged as one of the potential therapeutic alternatives to treat T1DM. This review primarily focuses on the current status and the future perspectives of gene therapy in the management of T1DM. A vast number of the studies which are reported on gene therapy for the management of T1DM are done in animal models and in preclinical studies. In addition, the safety of such therapies is yet to be established in humans. Currently, there are several gene level interventions that are being investigated, notably, overexpression of genes and proteins needed against T1DM, transplantation of cells that express the genes against T1DM, stem-cells mediated gene therapy, genetic vaccination, immunological precursor cell-mediated gene therapy and vectors. Methods: We searched the current literature through searchable online databases, journals and other library sources using relevant keywords and search parameters. Only relevant publications in English, between the years 2000 and 2018, with evidences and proper citations, were considered. The publications were then analyzed and segregated into several subtopics based on common words and content. A total of 126 studies were found suitable for this review. Findings: Generally, the pros and cons of each of the gene-based therapies have been discussed based on the results collected from the literature. However, there are certain interventions that require further detailed studies to ensure their effectiveness. We have also highlighted the future direction and perspectives in gene therapy, which, researchers could benefit from.

Curcumin a component of turmeric, which is derived from Curcuma longa is used as a colouring agent and as a dietary spice for centuries. Extensive studies have been done on the anti-inflammatory activity of curcumin along with its molecular mechanism involving different signalling pathways. However, the physicochemical and biological properties such as poor solubility and rapid metabolism of curcumin have led to low bioavailability and hence limits its application. Current therapies for asthma such as bronchodilators and inhaled corticosteroids (ICS) are aimed at controlling disease symptoms and prevent asthma exacerbation. However, this approach requires lifetime therapy and is associated with a constellation of side effects. This creates a clear unmet medical need and there is an urgent demand for new and more-effective treatments. The present study is aimed to formulate liposomes containing curcumin and evaluate for its anti-inflammatory effects on lipopolysaccharide (LPS)-induced inflammation on BCi-NS1.1 cell line. Curcumin and salbutamol liposomes were formulated using lipid hydration method. The prepared liposomes were characterized in terms of particle size, zeta potential, encapsulation efficiency and in-vitro release profile. The liposomes were tested on BCI-NS1.1 cell line to evaluate its anti-inflammatory properties. The various pro-inflammatory markers studied were Interleukin-6 (IL-6), Interleukin-8 (IL-8), Interleukin-1ß (IL-1ß) and Tumour Necrosis Factor-a (TNF-a). Additionally, molecular mechanics simulations were used to elucidate the positioning, energy minimization, and aqueous dispersion of the liposomal architecture involving lecithin and curcumin. The prepared curcumin formulation showed an average size and zeta potential of 271.3 ± 3.06 nm and -61.0 mV, respectively. The drug encapsulation efficiency of liposomal curcumin is 81.1%. Both curcumin-loaded liposomes formulation (1 µg/mL, 5 µg/mL) resulted in significant (p < 0.05) reduction in the level of pro-inflammatory marker expression such as IL-6, IL-8, IL-1ß and TNF-a compared to positive control group. Liposomal curcumin with the dose of 1 µg/mL reduced the inflammatory markers more effectively compared to that of 5 µg/mL. Liposomal curcumin could be a promising intervention for asthma therapy showing their efficacy in suppressing the important pro-inflammatory markers involved in the pathogenesis of asthma.

Microbiome refers to an ecological community of various symbiotic and pathogenic microorganisms, which plays a crucial role in human health and disease. The concept of novel drug delivery systems particularly the vesicular drug delivery systems is gaining massive attention. This emerging technology has started expanding its horizons in the area of microbiome delivery. This mini-review highlights the role of vesicular systems such as nanoparticles, liposomes etc. as a host/carrier for the microbiome in targeting various diseases. This review will be of interest for both the biological and formulation scientists to understand and explore the new vistas in the area of vesicular delivery system as carrier for microbiome delivery.

Obesity is an important risk factor for developing severe asthma. Dietary fatty acids, which are increased in sera of obese individuals and after high-fat meals, activate the innate immune system and induce inflammation. This study investigated whether dietary fatty acids directly cause inflammation and/or synergize with obesity-induced cytokines in primary human pulmonary fibroblasts in vitro. Fibroblasts were challenged with BSA-conjugated fatty acids [¿-6 polyunsaturated fatty acids (PUFAs) and ¿-3 PUFAs or saturated fatty acids (SFAs)], with or without TNF-a, and release of the proinflammatory cytokines, IL-6 and CXCL8, was measured. We found that the ¿-6 PUFA arachidonic acid (AA), but not ¿-3 PUFAs or SFAs, upregulates IL-6 and CXCL8 release. Combined AA and TNF-a challenge resulted in substantially greater cytokine release than either alone, demonstrating synergy. Synergistic upregulation of IL-6, but not CXCL8, was mainly mediated via cyclooxygenase (COX). Inhibition of p38 MAPK reduced CXCL8 release, induced by AA and TNF-a alone, but not in combination. Synergistic CXCL8 release, following AA and TNF-a challenge, was not medicated via a single signaling pathway (MEK1, JNK, phosphoinositide 3-kinase, and NF-¿B) nor by hyperactivation of NF-¿B or p38. To investigate if these findings occur in other airway cells, effects of AA in primary human airway smooth muscle (ASM) cells and human bronchial epithelial cells were also investigated. We found proinflammatory effects in ASM cells but not epithelial cells. This study suggests that diets rich in ¿-6 PUFAs might promote airway inflammation via multiple pathways, including COX-depen-dent and-independent pathways, and in an obese person, may lead to more severe airway inflammation.

MicroRNAs (miRNAs) represent a new class of diagnostic and prognostic biomarker as well as new therapeutic targets in cancer therapy. miRNAs are gaining significant interest due to extensive advancements in knowledge since their discovery and, more recently, their translational application as therapeutic moieties and targets in the management of disease. miRNAs used in the treatment of cancer would position them as a new class of emerging therapeutic agents. Indeed, numerous candidate miRNAs have been identified as having therapeutic application in the treatment of cancer, but there is still much to learn about how to transform these into effective, patient-compliant, and targeted drug delivery systems. In this mini review, we discuss the utility and potential of nanotechnology in miRNA formulation and delivery with particular emphasis on cancer, including their role in conferring multidrug resistance and metastatic capacity. This review benefits both the formulation and biological scientists in understanding and exploring the new vistas of miRNA delivery using nanotechnology in the cancer clinically.

Several vesicular systems loaded with curcumin have found their way in the therapeutic applications of several diseases, primarily acting through their immunological pathways. Such systems use particles at a nanoscale range, bringing about their intended use through a range of complex mechanisms. Apart from delivering drug substances into target tissues, these vesicular systems also effectively overcome problems like insolubility and unequal drug distribution. Several mechanisms are explored lately by different workers, and interest over vesicular curcumin has been renewed in the past decade. This commentary discusses several immunological targets in which curcumin is employed in a vesicular form.

Severe, steroid-resistant asthma is clinically and economically important since affected individuals do not respond to mainstay corticosteroid treatments for asthma. Patients with this disease experience more frequent exacerbations of asthma, are more likely to be hospitalized, and have a poorer quality of life. Effective therapies are urgently required, however, their development has been hampered by a lack of understanding of the pathological processes that underpin disease. A major obstacle to understanding the processes that drive severe, steroid-resistant asthma is that the several endotypes of the disease have been described that are characterized by different inflammatory and immunological phenotypes. This heterogeneity makes pinpointing processes that drive disease difficult in humans. Clinical studies strongly associate specific respiratory infections with severe, steroid-resistant asthma. In this review, we discuss key findings from our studies where we describe the development of representative experimental models to improve our understanding of the links between infection and severe, steroid-resistant forms of this disease. We also discuss their use in elucidating the mechanisms, and their potential for developing effective therapeutic strategies, for severe, steroid-resistant asthma. Finally, we highlight how the immune mechanisms and therapeutic targets we have identified may be applicable to obesity-or pollution-associated asthma.

Rationale: Aberrant expression of microRNAs (miRNAs) can have a detrimental role in disease pathogenesis. Objectives: To identify dysregulated miRNAs in lung tissue of patients with chronic obstructive pulmonary disease (COPD). Methods: We performed miRNA and mRNA profiling using high throughput stem-loop reverse-transcriptase quantitative polymerase chain reaction and mRNA microarray, respectively, on lung tissue of 30 patients (screening cohort) encompassing 8 never-smokers, 10 smokers without airflow limitation, and 12 smokers with COPD. Differential expression of miRNA-218-5p (miR-218-5p) was validated by reverse-transcriptase quantitative polymerase chain reaction in an independent cohort of 71 patients, an in vivo murine model of COPD, and primary human bronchial epithelial cells. Localization of miR-218-5p was assessed by in situ hybridization. In vitro and in vivo perturbation of miR-218-5p combined with RNA sequencing and gene set enrichment analysis was used to elucidate its functional role in COPD pathogenesis. Measurements and Main Results: Several miRNAs were differentially expressed among the different patient groups. Interestingly, miR-218-5p was significantly down-regulated in smokers without airflow limitation and in patients with COPD compared with never-smokers. Decreased pulmonary expression of miR-218-5p was validated in an independent validation cohort, in cigarette smoke-exposed mice, and in human bronchial epithelial cells. Importantly, expression of miR-218-5p strongly correlated with airway obstruction. Furthermore, cellular localization of miR-218-5p in human and murine lung revealed highest expression of miR-218-5p in the bronchial airway epithelium. Perturbation experiments with a miR-218-5p mimic or inhibitor demonstrated a protective role of miR-218-5p in cigarette smoke-induced inflammation and COPD. Conclusions: We highlight a role for miR-218-5p in the pathogenesis of COPD.

Chronic obstructive pulmonary disease (COPD) patients are at increased risk of developing nonsmall cell lung carcinoma, irrespective of their smoking history. Although the mechanisms behind this observation are not clear, established drivers of carcinogenesis in COPD include oxidative stress and sustained chronic inflammation. Mitochondria are critical in these two processes and recent evidence links increased oxidative stress in COPD patients to mitochondrial damage. We therefore postulate that mitochondrial damage in COPD patients leads to increased oxidative stress and chronic inflammation, thereby increasing the risk of carcinogenesis. The functional state of the mitochondrion is dependent on the balance between its biogenesis and degradation (mitophagy). Dysfunctional mitochondria are a source of oxidative stress and inflammasome activation. In COPD, there is impaired translocation of the ubiquitin-related degradation molecule Parkin following activation of the Pink1 mitophagy pathway, resulting in excessive dysfunctional mitochondria. We hypothesise that deranged pathways in mitochondrial biogenesis and mitophagy in COPD can account for the increased risk in carcinogenesis. To test this hypothesis, animal models exposed to cigarette smoke and developing emphysema and lung cancer should be developed. In the future, the use of mitochondria-based antioxidants should be studied as an adjunct with the aim of reducing the risk of COPD-associated cancer.

There is currently enormous interest in studying the role of the microbiome in health and disease. Microbiome's role is increasingly being applied to respiratory diseases, in particular COPD, asthma, cystic fibrosis and bronchiectasis. The changes in respiratory microbiomes that occur in these diseases and how they are modified by environmental challenges such as cigarette smoke, air pollution and infection are being elucidated. There is also emerging evidence that gut microbiomes play a role in lung diseases through the modulation of systemic immune responses and can be modified by diet and antibiotic treatment. There are issues that are particular to the Asia-Pacific region involving diet and prevalence of specific respiratory diseases. Each of these issues is further complicated by the effects of ageing. The challenges now are to elucidate the cause and effect relationships between changes in microbiomes and respiratory diseases and how to translate these into new treatments and clinical care. Here we review the current understanding and progression in these areas.

The microbiota is vital for the development of the immune system and homeostasis. Changes in microbial composition and function, termed dysbiosis, in the respiratory tract and the gut have recently been linked to alterations in immune responses and to disease development in the lungs. In this Opinion article, we review the microbial species that are usually found in healthy gastrointestinal and respiratory tracts, their dysbiosis in disease and interactions with the gut-lung axis. Although the gut-lung axis is only beginning to be understood, emerging evidence indicates that there is potential for manipulation of the gut microbiota in the treatment of lung diseases.

Background: Asthma is an allergic airway disease (AAD) caused by aberrant immune responses to allergens. Protein phosphatase-2A (PP2A) is an abundant serine/threonine phosphatase with anti-inflammatory activity. The ubiquitin proteasome system (UPS) controls many cellular processes, including the initiation of inflammatory responses by protein degradation. We assessed whether enhancing PP2A activity with fingolimod (FTY720) or 2-amino-4-(4-(heptyloxy) phenyl)-2-methylbutan-1-ol (AAL (S) ), or inhibiting proteasome activity with bortezomib (BORT), could suppress experimental AAD. Methods: Acute AAD was induced in C57BL/6 mice by intraperitoneal sensitization with ovalbumin (OVA) in combination with intranasal (i.n) exposure to OVA. Chronic AAD was induced in mice with prolonged i.n exposure to crude house dust mite (HDM) extract. Mice were treated with vehicle, FTY720, AAL (S) , BORT or AAL (S) +BORT and hallmark features of AAD assessed. Results: AAL (S) reduced the severity of acute AAD by suppressing tissue eosinophils and inflammation, mucus-secreting cell (MSC) numbers, type 2-associated cytokines (interleukin (IL)-33, thymic stromal lymphopoietin, IL-5 and IL-13), serum immunoglobulin (Ig)E and airway hyper-responsiveness (AHR). FTY720 only suppressed tissue inflammation and IgE. BORT reduced bronchoalveolar lavage fluid (BALF) and tissue eosinophils and inflammation, IL-5, IL-13 and AHR. Combined treatment with AAL (S) +BORT had complementary effects and suppressed BALF and tissue eosinophils and inflammation, MSC numbers, reduced the production of type 2 cytokines and AHR. AAL (S) , BORT and AAL (S) +BORT also reduced airway remodelling in chronic AAD. Conclusion: These findings highlight the potential of combination therapies that enhance PP2A and inhibit proteasome activity as novel therapeutic strategies for asthma.

Innate immune responses act as first line defences upon exposure to potentially noxious stimuli. The innate immune system has evolved numerous intracellular and extracellular receptors that undertake surveillance for potentially damaging particulates. Inflammasomes are intracellular innate immune multiprotein complexes that form and are activated following interaction with these stimuli. Inflammasome activation leads to the cleavage of pro-IL-1ß and release of the pro-inflammatory cytokine, IL-1ß, which initiates acute phase pro-inflammatory responses, and other responses are also involved (IL-18, pyroptosis). However, excessive activation of inflammasomes can result in chronic inflammation, which has been implicated in a range of chronic inflammatory diseases. The airways are constantly exposed to a wide variety of stimuli. Inflammasome activation and downstream responses clears these stimuli. However, excessive activation may drive the pathogenesis of chronic respiratory diseases such as severe asthma and chronic obstructive pulmonary disease. Thus, there is currently intense interest in the role of inflammasomes in chronic inflammatory lung diseases and in their potential for therapeutic targeting. Here we review the known associations between inflammasome-mediated responses and the development and exacerbation of chronic lung diseases.

Background Severe steroid-insensitive asthma is a substantial clinical problem. Effective treatments are urgently required, however, their development is hampered by a lack of understanding of the mechanisms of disease pathogenesis. Steroid-insensitive asthma is associated with respiratory tract infections and noneosinophilic endotypes, including neutrophilic forms of disease. However, steroid-insensitive patients with eosinophil-enriched inflammation have also been described. The¿mechanisms that underpin infection-induced, severe steroid-insensitive asthma can be elucidated by using mouse models of disease. Objective We sought to develop representative mouse models of severe, steroid-insensitive asthma and to use them to identify pathogenic mechanisms and investigate new treatment approaches. Methods Novel mouse models of Chlamydia, Haemophilus influenzae, influenza, and respiratory syncytial virus respiratory¿tract infections and ovalbumin-induced, severe, steroid-insensitive allergic airway disease (SSIAAD) in BALB/c mice were developed and interrogated. Results Infection induced increases in the levels of microRNA (miRNA)-21 (miR-21) expression in the lung during SSIAAD, whereas expression of the miR-21 target phosphatase and tensin homolog was reduced. This was associated with an increase in levels of phosphorylated Akt, an indicator of phosphoinositide 3-kinase (PI3K) activity, and decreased nuclear histone deacetylase (HDAC)2 levels. Treatment with an miR-21¿specific antagomir (Ant-21) increased phosphatase and tensin homolog levels. Treatment with Ant-21, or the pan-PI3K inhibitor LY294002, reduced PI3K activity and restored HDAC2 levels. This led to suppression of airway hyperresponsiveness and restored steroid sensitivity to allergic airway disease. These observations were replicated with SSIAAD associated with 4 different pathogens. Conclusion We identify a previously unrecognized role for an¿miR-21/PI3K/HDAC2 axis in SSIAAD. Our data highlight miR-21 as a novel therapeutic target for the treatment of this form of asthma.

COPD is a major cause of global mortality and morbidity but current treatments are poorly effective. This is because the underlying mechanisms that drive the development and progression of COPD are incompletely understood. Animal models of disease provide a valuable, ethically and economically viable experimental platform to examine these mechanisms and identify biomarkers that may be therapeutic targets that would facilitate the development of improved standard of care. Here, we review the different established animal models of COPD and the various aspects of disease pathophysiology that have been successfully recapitulated in these models including chronic lung inflammation, airway remodelling, emphysema and impaired lung function. Furthermore, some of the mechanistic features, and thus biomarkers and therapeutic targets of COPD identified in animal models are outlined. Some of the existing therapies that suppress some disease symptoms that were identified in animal models and are progressing towards therapeutic development have been outlined. Further studies of representative animal models of human COPD have the strong potential to identify new and effective therapeutic approaches for COPD.

The aim of this study is to elucidate the role of TRAIL during rhinovirus (RV) infection in vivo. Naïve wild-type and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-deficient (Tnfsf10-/-) BALB/c mice were infected intranasally with RV1B. In separate experiments, Tnfsf10-/-mice were sensitized and challenged via the airway route with house dust mite (HDM) to induce allergic airways disease and then challenged with RVIB or UV-RVIB. Airway hyperreactivity (AHR) was invasively assessed as total airways resistance in response to increasing methacholine challenge and inflammation was assessed in bronchoalveolar lavage fluid at multiple time points postinfection. Chemokines were quantified by ELISA of whole lung lysates and viral load was determined by quantitative RT-PCR and tissue culture infective dose (TCID50). Human airway epithelial cells (BEAS2B) were infected with RV1B and stimulated with recombinant TRAIL or neutralizing anti-TRAIL antibodies and viral titer assessed by TCID50. HDM-challenged Tnfsf10-/-mice were protected against RV-induced AHR and had suppressed cellular infiltration in the airways upon RV infection. Chemokine C-X-C-motif ligand 2 (CXCL2) production was suppressed in naïve Tnfsf10-/-mice infected with RV1B, with less RV1B detected 24 h postinfection. This was associated with reduced apoptotic cell death and a reduction of interferon (IFN)-¿2/3 but not IFN-a or IFN-ß. TRAIL stimulation increased, whereas anti-TRAIL antibodies reduced viral replication in RV1B-infected BEAS2B cells in vitro. In conclusion, TRAIL promotes RV-induced AHR, inflammation and RV1B replication, implicating this molecule and its downstream signaling pathways as a possible target for the amelioration of RV1B-induced allergic and nonallergic lung inflammation and AHR.

The rapid advancement in the area of microRNAs (miRNAs) from discovery to their translation into therapeutic moieties reflects their significance as important regulators in the management of disease pathology. The miRNAs can potentially be a new class of drugs in the near future for the treatment of various lung diseases, but it lacks the current knowledge how these identified therapeutic moieties can be designed into an effective, patient complaint and targeted drug delivery system. miRNAs have characteristic features like small size and low molecular weight which makes them easily translated into an effective drug delivery system. In this review, we have summarised the concept of miRNAs and different approaches which can be employed to deliver miRNAs effectively and safely to the target cells including the challenges associated with their development in particular emphasis on pulmonary diseases. Such approaches will be of interest for both the biological and formulation scientists to understand and explore the new vistas in the area of miRNA delivery for pulmonary inflammatory diseases.

Biofilm comprises a community of microorganisms which form on medical devices and can lead to various threatening infections. It is a major concern in various respiratory diseases like cystic fibrosis, chronic obstructive pulmonary disease, etc. The treatment strategies for such infections are difficult due to the resistance of the microflora existing in the biofilms against various antimicrobial agents, thus posing threats to the patient population. The present era witnesses the beginning of research to understand the biofilm physiology and the associated microfloral diversity by applying -omics approaches. There is very limited information about how the deposition of biofilm on the respiratory devices and lung itself affects the drug delivered, the delivery system, and other implications. The present mini review summarizes the basic introduction to the biofilms and its avoidance using various drug delivery systems with special emphasis on the respiratory diseases. Understanding the approaches, principles, and modes of drug delivery involved in preventing biofilm deposition will be of interest to both biological and formulation scientists, thereby opening avenues to explore the new vistas in biofilm research for identifying better treatments for pulmonary infectious diseases.

The constitutive heparin+ (HP) mast cells (MCs) in mice express mouseMCprotease (mMCP)-5 and carboxypeptidaseA (mMC-CPA). The amino acid sequence ofmMCP-5is most similar to that of human chymase-1, as are the nucleotide sequences of their genes and transcripts. Using a homologous recombination approach, a C57BL/6 mouse line was created that possessed a disrupted mMCP-5 gene. The resulting mice were fertile and had no obvious developmental abnormality. Lack of mMCP-5 protein did not alter the granulation of the IL-3/IL-9-dependent mMCP-2+ MCs in the jejunal mucosa of Trichinella spiralisinfected mice. In contrast, the constitutive HP+ MCs in the tongues of mMCP-5-null mice were poorly granulated and lacked mMC-CPA protein. Bone marrow-derived MCs were readily developed from the transgenic mice using IL-3. Although these MCs contained high levels of mMC-CPA mRNA, they also lacked the latter exopeptidase. mMCP-5 protein is therefore needed to target translated mMC-CPA to the secretory granule along with HP-containing serglycin proteoglycans. Alternately, mMCP-5 is needed to protect mMC-CPA from autolysis in the cell's granules. Fibronectin was identified as a target of mMCP-5, and the exocytosis ofmMCP-5from theMCs in the mouse's peritoneal cavity resulted in the expression of metalloproteinase protease-9, which has been implicated in arthritis. In support of the latter finding, experimental arthritis was markedly reduced in mMCP-5-null mice relative to wildtype mice in two disease models.

Rationale: Severe, steroid-resistant asthma is the major unmet need in asthma therapy. Disease heterogeneity and poor understanding of pathogenic mechanisms hampers the identification of therapeutic targets. Excessive nucleotide-binding oligomerization domain-like receptor family, pyrin domain-containing 3 (NLRP3) inflammasome and concomitant IL-1ß responses occur in chronic obstructive pulmonary disease, respiratory infections, and neutrophilic asthma. However, the direct contributions to pathogenesis, mechanisms involved, and potential for therapeutic targeting remain poorly understood, and are unknown in severe, steroid-resistant asthma. Objectives: To investigate the roles and therapeutic targeting of the NLRP3 inflammasome and IL-1ß in severe, steroid-resistant asthma. Methods: We developed mouse models of Chlamydia and Haemophilus respiratory infection-mediated, ovalbumin-induced severe, steroid-resistant allergic airway disease. These models share the hallmark features of human disease, including elevated airway neutrophils, and NLRP3 inflammasome and IL-1ß responses. The roles and potential for targeting of NLRP3 inflammasome, caspase-1, and IL-1ß responses in experimental severe, steroid-resistant asthma were examined using a highly selective NLRP3 inhibitor, MCC950; the specific caspase-1 inhibitor Ac-YVAD-cho; and neutralizing anti-IL-1ß antibody. Roles for IL-1ß-induced neutrophilic inflammation were examined using IL-1ß and anti-Ly6G. Measurements and Main Results: Chlamydia and Haemophilus infections increase NLRP3, caspase-1, IL-1ß responses that drive steroid-resistant neutrophilic inflammation and airway hyperresponsiveness. Neutrophilic airway inflammation, disease severity, and steroid resistance in human asthma correlate with NLRP3 and IL-1ß expression. Treatment with anti-IL-1ß, Ac- YVAD-cho, and MCC950 suppressed IL-1ß responses and the important steroid-resistant features of disease in mice, whereas IL-1ß administration recapitulated these features. Neutrophil depletion suppressed IL-1ß-induced steroid-resistant airway hyperresponsiveness. Conclusions: NLRP3 inflammasome responses drive experimental severe, steroid-resistant asthma and are potential therapeutic targets in this disease.

Background: Disseminated metastatic cancer requires insistent management owing to its reduced responsiveness for chemotherapeutic agents, toxicity to normal cells consequently lower survival rate and hampered quality of life of patients. Methods: Dendrimer mediated cancer therapy is advantageous over conventional chemotherapy, radiotherapy and surgical resection due to reduced systemic toxicity, and molecular level cell injury to cancerous mass, for an appreciable survival of the subject. Recently used dendrimer mediated nanotechnology for oncology aims to conquer these challenges. Dendrimers based nano-constructs are having architectures comparable to that of biological vesicles present in the human body. Results: Operating with dendrimer technology, proffers the exclusive and novel strategies with numerous applications in cancer management involving diagnostics, therapeutics, imaging, and prognostics by sub-molecular interactions. Dendrimers are designed to acquire the benefits of the malignant tumor morphology and characteristics, i.e. leaky vasculature of tumor, expression of specific cell surface antigen, and rapid proliferation. Conclusion: Dendrimers mediated targeted therapy recommends innovatory function equally in diagnostics (imaging, immune-detection) as well as chemotherapy. Currently, dendrimers as nanomedicine has offered a strong assurance and advancement in drastically varying approaches towards cancer imaging and treatment. The present review discusses different approaches for cancer diagnosis and treatment such as, targeted and control therapy, photodynamic therapy, photo-thermal therapy, gene therapy, antiangiogenics therapy, radiotherapy etc.

Food antigens are common inflammatory triggers in pediatric eosinophilic esophagitis (EoE). TNFrelated apoptosis-inducing ligand (TRAIL) promotes eosinophilic inflammation through the upregulation of the E3 ubiquitin ligase Midline (MID)-1 and subsequent downregulation of protein phosphatase 2A (PP2A), but the role of this pathway in EoE that is experimentally induced by repeated food antigen challenges has not been investigated. Esophageal mucosal biopsies were collected from children with EoE and controls and assessed for TRAIL and MID-1 protein and mRNA transcript levels. Wild-type and TRAIL-deficient (Tnfsf10-/-) mice were administered subcutaneous ovalbumin (OVA) followed by oral OVA challenges. In separate experiments, OVA-challenged mice were intraperitoneally administered salmeterol or dexamethasone. Esophageal biopsies from children with EoE revealed increased levels of TRAIL and MID-1 and reduced PP2A activation compared with controls. Tnfsf10-/- mice were largely protected from esophageal fibrosis, eosinophilic inflammation, and the upregulation of TSLP, IL-5, IL-13, and CCL11 when compared with wild-type mice. Salmeterol administration to wild-type mice with experimental EoE restored PP2A activity and also prevented esophageal eosinophilia, inflammatory cytokine expression, and remodeling, which was comparable to the treatment effect of dexamethasone. TRAIL and PP2A regulate inflammation and fibrosis in experimental EoE, which can be therapeutically modulated by salmeterol.

Introduction. Macrophage migration inhibitory factor (MIF) is an inflammatory cytokine associated with acute and chronic inflammatory disorders and corticosteroid insensitivity. Its expression in the airways of patients with chronic obstructive pulmonary disease (COPD), a relatively steroid insensitive inflammatory disease is unclear, however. Methods. Sputum, bronchoalveolar lavage (BAL) macrophages and serum were obtained from nonsmokers, smokers and COPD patients. To mimic oxidative stress-induced COPD, mice were exposed to ozone for six-weeks and treated with ISO-1, a MIF inhibitor, and/or dexamethasone before each exposure. BAL fluid and lung tissue were collected after the final exposure. Airway hyperresponsiveness (AHR) and lung function were measured using whole body plethysmography. HIF-1a binding to the Mif promoter was determined by Chromatin Immunoprecipitation assays. Results. MIF levels in sputum and BAL macrophages from COPD patients were higher than those from non-smokers, with healthy smokers having intermediate levels. MIF expression correlated with that of HIF-1a in all patients groups and in ozone-exposed mice. BAL cell counts, cytokine mRNA and protein expression in lungs and BAL, including MIF, were elevated in ozone-exposed mice and had increased AHR. Dexamethasone had no effect on these parameters in the mouse but ISO-1 attenuated cell recruitment, cytokine release and AHR. Conclusion MIF and HIF-1a levels are elevated in COPD BAL macrophages and inhibition of MIF function blocks corticosteroid-insensitive lung inflammation and AHR. Inhibition of MIF may provide a novel anti-inflammatory approach in COPD.

Background and objective Chronic obstructive pulmonary disease (COPD) is characterized by progressive airflow limitation and inflammation. Airway bacterial colonization is increased in COPD; however, the role of potentially pathogenic and non-pathogenic bacteria in the pathogenesis of disease is unclear. This study characterized the presence of bacteria in a well-characterized cohort of adults with COPD and healthy controls. Methods Adults with COPD (n = 70) and healthy controls (n = 51) underwent clinical assessment and sputum induction. Sputum was dispersed, and total and differential cell counts were performed. Bacteria were cultured, identified and enumerated. Supernatants were assessed for neutrophil elastase (NE) and IL-1ß. Common respiratory pathogens were also determined using real-time PCR. Results Participants with COPD had a typical neutrophilic inflammatory profile. The total load of bacteria was increased in COPD and was associated with poorer respiratory health status, as measured by the St George's Respiratory Questionnaire (Spearman's r = 0.336, P = 0.013). Significantly lower levels of culturable Bacillus species were identified compared with healthy controls. PCR analyses revealed increased rates of detection of potentially pathogenic bacteria with Haemophilus influenzae detection associated with higher sputum levels of NE and IL-1ß, while Streptococcus pneumoniae was more common in male ex-smokers with emphysema and a deficit in diffusion capacity. Conclusion Non-pathogenic and pathogenic bacteria were altered in the sputum of patients with COPD. These observations highlight the potential to identify treatment and management strategies that both target specific bacterial pathogens and restore the microbial balance, which may lead to reductions in inflammation and subsequent improvements in lung health.

Chronic obstructive pulmonary disease (COPD) is a life-Threatening inflammatory respiratory disorder, often induced by cigarette smoke (CS) exposure. The development of effective therapies is impaired by a lack of understanding of the underlining mechanisms. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a cytokine with inflammatory and apoptotic properties. We interrogated a mouse model of CS-induced experimental COPD and human tissues to identify a novel role for TRAIL in COPD pathogenesis. CS exposure of wild-Type mice increased TRAIL and its receptor messenger RNA (mRNA) expression and protein levels, as well as the number of TRAIL + CD11b + monocytes in the lung. TRAIL and its receptor mRNA were also increased in human COPD. CS-exposed TRAIL-deficient mice had decreased pulmonary inflammation, pro-inflammatory mediators, emphysema-like alveolar enlargement, and improved lung function. TRAIL-deficient mice also developed spontaneous small airway changes with increased epithelial cell thickness and collagen deposition, independent of CS exposure. Importantly, therapeutic neutralization of TRAIL, after the establishment of early-stage experimental COPD, reduced pulmonary inflammation, emphysema-like alveolar enlargement, and small airway changes. These data provide further evidence for TRAIL being a pivotal inflammatory factor in respiratory diseases, and the first preclinical evidence to suggest that therapeutic agents that target TRAIL may be effective in COPD therapy.

Background Rhinovirus (RV) infections are the major precipitant of asthma exacerbations. While neutrophilic lung inflammation occurs during such infections, its role remains unclear. Neutrophilic inflammation is associated with increased asthma severity and steroid refractory disease. Neutrophils are vital for controlling infections but also have immunomodulatory functions. Previously, we found that neutrophils respond to viral mimetics but not replication competent RV. We aimed to investigate if neutrophils are activated and/or modulate immune responses of monocytes during RV16 infection. Methods Primary human monocytes and autologous neutrophils were cocultured with or without RV16, in direct contact or separated by transwells. RV16-stimulated monocytes were also exposed to lysed neutrophils, neutrophil membrane components or soluble neutrophil intracellular components. Interleukin 6 (IL-6) and C-X-C motif (CXC)L8 mRNA and proteins were measured by quantitative PCR and ELISA at 24â ¿..hours. Results RV16 induced IL-6 and CXCL8 in monocytes, but not neutrophils. RV16-induced IL-6 and CXCL8 from monocytes was reduced in the presence of live neutrophils. Transwell separation abolished the inhibitory effects. Lysed neutrophils inhibited RV16-induced IL-6 and CXCL8 from monocytes. Neutrophil intracellular components alone effectively inhibited RV16-induced monocyte-derived IL-6 and CXCL8. Neutrophil intracellular components reduced RV16-induced IL-6 and CXCL8 mRNA in monocytes. Conclusions Cell contact between monocytes and neutrophils is required, and preformed neutrophil mediator(s) are likely to be involved in the suppression of cytokine mRNA and protein production. This study demonstrates a novel regulatory function of neutrophils on RV-Activated monocytes in vitro, challenging the paradigm that neutrophils are predominantly proinflammatory.

Chronic respiratory diseases are driven by inflammation, but some clinical conditions (severe asthma, COPD) are refractory to conventional anti-inflammatory therapies. Thus, novel anti-inflammatory strategies are necessary. The mRNA destabilizing protein, tristetraprolin (TTP), is an anti-inflammatory molecule that functions to induce mRNA decay of cytokines that drive pathogenesis of respiratory disorders. TTP is regulated by phosphorylation and protein phosphatase 2A (PP2A) is responsible for dephosphorylating (and hence activating) TTP, amongst other targets. PP2A is activated by small molecules, FTY720 and AAL(S), and in this study we examine whether these compounds repress cytokine production in a cellular model of airway inflammation using A549 lung epithelial cells stimulated with tumor necrosis factor a (TNFa) in vitro. PP2A activators significantly increase TNFa-induced PP2A activity and inhibit mRNA expression and protein secretion of interleukin 8 (IL-8) and IL-6; two key pro-inflammatory cytokines implicated in respiratory disease and TTP targets. The effect of PP2A activators is not via an increase in TNFa-induced TTP mRNA expression; instead we demonstrate a link between PP2A activation and TTP anti-inflammatory function by showing that specific knockdown of TTP with siRNA reversed the repression of TNFa-induced IL-8 and IL-6 mRNA expression and protein secretion by FTY720. Therefore we propose that PP2A activators affect the dynamic equilibrium regulating TTP; shifting the equilibrium from phosphorylated (inactive) towards unphosphorylated (active) but unstable TTP. PP2A activators boost the anti-inflammatory function of TTP and have implications for future pharmacotherapeutic strategies to combat inflammation in respiratory disease.

Exposure to particulate matter (PM), a major component of air pollution, contributes to increased morbidity and mortality worldwide. PM induces innate immune responses and contributes to allergic sensitization, although the mechanisms governing this process remain unclear. Lung mucosal uric acid has also been linked to allergic sensitization. The links among PM exposure, uric acid, and allergic sensitization remain unexplored. We therefore investigated the mechanisms behind PM-induced allergic sensitization in the context of lung mucosal uric acid. PM 10 and house dust mite exposure selectively induced lung mucosal uric acid production and secretion in vivo, which did not occur with other challenges (lipopolysaccharide, virus, bacteria, or inflammatory/fibrotic stimuli). PM 10 -induced uric acid mediates allergic sensitization and augments antigen-specific T-cell proliferation, which is inhibited by uricase. We then demonstrate that human airway epithelial cells secrete uric acid basally and after stimulation through a previously unidentified mucosal secretion system. Our work discovers a previously unknown mechanism of air pollution-induced, uric acid-mediated, allergic sensitization that may be important in the pathogenesis of asthma.

Background and Purpose: Chronic obstructive pulmonary disease (COPD) is a major cause of illness and death, often induced by cigarette smoking (CS). It is characterized by pulmonary inflammation and fibrosis that impairs lung function. Existing treatments aim to control symptoms but have low efficacy, and there are no broadly effective treatments. A new potential target is the ectoenzyme, semicarbazide-sensitive mono-amine oxidase (SSAO; also known as vascular adhesion protein-1). SSAO is elevated in smokers¿ serum and is a pro-inflammatory enzyme facilitating adhesion and transmigration of leukocytes from the vasculature to sites of inflammation. Experimental Approach: PXS-4728A was developed as a low MW inhibitor of SSAO. A model of COPD induced by CS in mice reproduces key aspects of human COPD, including chronic airway inflammation, fibrosis and impaired lung function. This model was used to assess suppression of SSAO activity and amelioration of inflammation and other characteristic features of COPD. Key Results: Treatment with PXS-4728A completely inhibited lung and systemic SSAO activity induced by acute and chronic CS-exposure. Daily oral treatment inhibited airway inflammation (immune cell influx and inflammatory factors) induced by acute CS-exposure. Therapeutic treatment during chronic CS-exposure, when the key features of experimental COPD develop and progress, substantially suppressed inflammatory cell influx and fibrosis in the airways and improved lung function. Conclusions and Implications: Treatment with a low MW inhibitor of SSAO, PXS-4728A, suppressed airway inflammation and fibrosis and improved lung function in experimental COPD, demonstrating the therapeutic potential of PXS-4728A for this debilitating disease.

Chronic obstructive pulmonary disease (COPD) is a serious lung disease that progressively worsens lung function. Those affected are highly susceptible to influenza virus infections that result in exacerbations with exaggerated symptoms with increased mortality. The mechanisms underpinning this increased susceptibility to infection in COPD are unclear. In this study, we show that primary bronchial epithelial cells (pBECs) from subjects with COPD have impaired induction of type I IFN (IFN-ß) and lead to heightened viral replication after influenza viral infection. COPD pBECs have reduced protein levels of protein kinase (PK) R and decreased formation of PKR-mediated antiviral stress granules, which are critical in initiating type I IFNinductions. In addition, reduced protein expression of p300 resulted in decreased activation of IFN regulatory factor 3 and subsequent formation of IFN-ß enhanceosome in COPD pBECs. The decreased p300 induction was the result of enhanced levels of microRNA (miR)-132. Ectopic expression of PKR or miR-132 antagomiR alone failed to restore IFN-ß induction, whereas cotreatment increased antiviral stress granule formation, induction of p300, and IFN-ß in COPD pBECs. This study reveals that decreased induction of both PKR and p300 proteins contribute to impaired induction of IFN-ß in COPD pBECs upon influenza infection.

Corticosteroids are effective anti-inflammatory therapies widely utilized in chronic respiratory diseases. But these medicines can lose their efficacy during respiratory infection resulting in disease exacerbation. Further in vitro research is required to understand how infection worsens lung function control in order to advance therapeutic options to treat infectious exacerbation in the future. In this study, we utilize a cellular model of bacterial exacerbation where we pretreat A549 lung epithelial cells with the synthetic bacterial lipoprotein Pam3CSK4 (a TLR2 ligand) to mimic bacterial infection and tumor necrosis factor a (TNFa) to simulate inflammation. Under these conditions, Pam3CSK4 induces corticosteroid insensitivity; demonstrated by substantially reduced ability of the corticosteroid dexamethasone to repress TNFa-induced interleukin 6 secretion. We then explored the molecular mechanism responsible and found that corticosteroid insensitivity induced by bacterial mimics was not due to altered translocation of the glucocorticoid receptor into the nucleus, nor an impact on the NF-¿B pathway. Moreover, Pam3CSK4 did not affect corticosteroid-induced upregulation of anti-inflammatory MAPK deactivating phosphatase¿MKP-1. However, Pam3CSK4 can induce oxidative stress and we show that a proportion of the MKP-1 produced in response to corticosteroid in the context of TLR2 ligation was rendered inactive by oxidation. Thus to combat inflammation in the context of bacterial exacerbation we sought to discover effective strategies that bypassed this road-block. We show for the first time that known (FTY720) and novel (theophylline) activators of the phosphatase PP2A can serve as non-steroidal anti-inflammatory alternatives and/or corticosteroid-sparing approaches in respiratory inflammation where corticosteroid insensitivity exists.

Saemangeum, in the Republic of Korea (ROK, commonly called South Korea) was one of the most important shorebird staging sites in the Yellow Sea. It supported at least 330000 shorebirds annually between 1997 and 2001, including ~30% of the world population of Great Knots (Calidris tenuirostris) during both northward and southward migration. Construction of a 33-km long sea-wall was completed in April 2006. We show that shorebird numbers at Saemangeum and two adjacent wetlands decreased by 130000 during northward migration in the next two years and that all species have declined at Saemangeum since completion of the sea-wall. Great Knots were among the most rapidly affected species. Fewer than 5000 shorebirds were recorded at Saemangeum during northward migration in 2014. We found no evidence to suggest that most shorebirds of any species displaced from Saemangeum successfully relocated to other sites in the ROK. Instead, by 2011-13 nearly all species had declined substantially in the ROK since previous national surveys in 1998 and 2008, especially at more heavily reclaimed sites. It is likely that these declines were driven by increased mortality rather than movement to alternate staging sites given that other studies have shown concurrent declines in numbers and survival on the non-breeding grounds. This is the first study in the East Asian-Australasian Flyway to confirm declines of shorebirds at a range of geographical scales following a single reclamation project. The results indicate that if migratory shorebirds are displaced from major staging sites by reclamation they are probably unable to relocate successfully to alternate sites.

Pregnancy provides a unique challenge for maternal immunity, requiring the ability to tolerate the presence of a semi-allogeneic foetus, and yet still being capable of inducing an immune response against invading pathogens. To achieve this, numerous changes must occur in the activity and function of maternal immune cells throughout the course of pregnancy. Respiratory viruses take advantage of these changes, altering the sensitive balance of maternal immunity, leaving the mother with increased susceptibility to viral infections and increased disease severity. Influenza virus is one of the most common respiratory virus infections during pregnancy, leading to an increased risk of ICU hospitalisations, pneumonia, acute respiratory distress syndrome and even death. Whilst much research has been performed to understand the changes that must take place in maternal immunity during pregnancy, considerable work is still needed to fully comprehend this tremendous feat. To date, few studies have focused on the alterations that occur in maternal immunity during respiratory virus infections. This review highlights the role of dendritic cells (DCs) and CD8 T cells during pregnancy, and the changes that occur in these antiviral cells following influenza virus infections.

The immune and nociceptive systems are shaped during the neonatal period where they undergo fine-tuning and maturation. Painful experiences during this sensitive period of development are known to produce long-lasting effects on the immune and nociceptive responses. It is less clear, however, whether inflammatory pain responses are primed by neonatal exposure to mild immunological stimuli, such as with lipopolysaccharide (LPS). Here, we examine the impact of neonatal LPS exposure on inflammatory pain responses, peripheral and hippocampal interleukin-1ß (IL-1ß), as well as mast cell number and degranulation in preadolescent and adult rats. Wistar rats were injected with LPS (0.05 mg/kg IP, Salmonella enteritidis) or saline on postnatal days (PNDs) 3 and 5 and later subjected to the formalin test at PNDs 22 and 80-97. At both time-points, and one-hour after formalin injection, blood and hippocampus were collected for measuring circulating and central IL-1ß levels using ELISA and Western blot, respectively. Paw tissue was also isolated to assess mast cell number and degree of degranulation using Toluidine Blue staining. Behavioural analyses indicate that at PND 22, LPS-challenged rats displayed enhanced flinching (p<.01) and licking (p<.01) in response to formalin injection. At PNDs 80-97, LPS-challenged rats exhibited increased flinching (p<.05), an effect observed in males only. Furthermore, neonatal LPS exposure enhanced circulating IL-1ß and mast cell degranulation in preadolescent but not adult rats following formalin injection. Hippocampal IL-1ß levels were increased in LPS-treated adult but not preadolescent rats in response to formalin injection. These data suggest neonatal LPS exposure produces developmentally regulated changes in formalin-induced behavioural responses, peripheral and central IL-1ß levels, as well as mast cell degranulation following noxious stimulation later in life. These findings highlight the importance of immune activation during the neonatal period in shaping immune response and pain sensitivity later in life. This is of clinical relevance given the high prevalence of bacterial infection during the neonatal period, particularly in the vulnerable population of preterm infants admitted to neonatal intensive care units.

The epithelium of asthmatics is characterized by reduced expression of E-cadherin and increased expression of the basal cell markers ck-5 and p63 that is indicative of a relatively undifferentiated repairing epithelium. This phenotype correlates with increased proliferation, compromised wound healing and an enhanced capacity to undergo epithelial-mesenchymal transition (EMT). The transcription factor ß-catenin plays a vital role in epithelial cell differentiation and regeneration, depending on the co-factor recruited. Transcriptional programs driven by the ß-catenin/CBP axis are critical for maintaining an undifferentiated and proliferative state, whereas the ß-catenin/p300 axis is associated with cell differentiation. We hypothesized that disrupting the ß-catenin/CBP signaling axis would promote epithelial differentiation and inhibit EMT. We treated monolayer cultures of human airway epithelial cells with TGFß1 in the presence or absence of the selective small molecule ICG-001 to inhibit ß-catenin/CBP signaling. We used western blots to assess expression of an EMT signature, CBP, p300, ß-catenin, fibronectin and ITGß1 and scratch wound assays to assess epithelial cell migration. Snai-1 and -2 expressions were determined using q-PCR. Exposure to TGFß1 induced EMT, characterized by reduced E-cadherin expression with increased expression of a-smooth muscle actin and EDA-fibronectin. Either co-treatment or therapeutic administration of ICG-001 completely inhibited TGFß1-induced EMT. ICG-001 also reduced the expression of ck-5 and -19 independent of TGFß1. Exposure to ICG-001 significantly inhibited epithelial cell proliferation and migration, coincident with a down regulation of ITGß1 and fibronectin expression. These data support our hypothesis that modulating the ß-catenin/CBP signaling axis plays a key role in epithelial plasticity and function.

Rationale: Chronic obstructive pulmonary disease (COPD) and influenza virus infections are major global health issues. Patients with COPD are more susceptible to infection, which exacerbates their condition and increases morbidity and mortality. The mechanisms of increased susceptibility remain poorly understood, and current preventions and treatments have substantial limitations. Objectives: To characterize the mechanisms of increased susceptibility to influenza virus infection in COPD and the potential for therapeutic targeting. Methods: We used a combination of primary bronchial epithelial cells (pBECs) from COPD and healthy control subjects, a mouse model of cigarette smoke-induced experimental COPD, and influenza infection. The role of the phosphoinositide-3-kinase (PI3K) pathway was characterized using molecular methods, and its potential for targeting assessed using inhibitors. Measurements and Main Results: COPDpBECs were susceptible to increased viral entry and replication. Infected mice with experimental COPD also had more severe infection (increased viral titer and pulmonary inflammation, and compromised lung function). These processes were associated with impaired antiviral immunity, reduced retinoic acid-inducible gene-I, and IFN/cytokine and chemokine responses. Increased PI3K-p110a levels and activity inCOPDpBECs and/or mice were responsible for increased infection and reduced antiviral responses. Global PI3K, specific therapeutic p110a inhibitors, or exogenous IFN-b restored protective antiviral responses, suppressed infection, and improved lung function. Conclusions: The increased susceptibility of individuals with COPD to influenza likely results from impaired antiviral responses, which are mediated by increased PI3K-p110a activity. This pathway may be targeted therapeutically in COPD, or in healthy individuals, during seasonal or pandemic outbreaks to prevent and/or treat influenza.

Background: Avian influenza viruses (AIVs) are found worldwide in numerous bird species, causing significant disease in gallinaceous poultry and occasionally other species. Surveillance of wild bird reservoirs provides an opportunity to add to the understanding of the epidemiology of AIVs. Methods: This study examined key findings from the National Avian Influenza Wild Bird Surveillance Program over a 5-year period (July 2007-June 2012), the main source of information on AIVs circulating in Australia. Results: The overall proportion of birds that tested positive for influenza A via PCR was 1.9±0.1%, with evidence of widespread exposure of Australian wild birds to most low pathogenic avian influenza (LPAI) subtypes (H1-13, H16). LPAI H5 subtypes were found to be dominant and widespread during this 5-year period. Conclusion: Given Australia's isolation, both geographically and ecologically, it is important for Australia not to assume that the epidemiology of AIV from other geographic regions applies here. Despite all previous highly pathogenic avian influenza outbreaks in Australian poultry being attributed to H7 subtypes, widespread detection of H5 subtypes in wild birds may represent an ongoing risk to the Australian poultry industry.

Background Pregnancy increases susceptibility to influenza. The placenta releases an immunosuppressive endogenous retroviral protein syncytin-1.We hypothesised that exposure of peripheral monocytes (PBMCs) to syncytin-1 would impair responses to H1N1pdm09 influenza. Methods and Findings Recombinant syncytin-1 was produced. PBMCs from non-pregnant women (n=10) were exposed to H1N1pdm09 in the presence and absence of syncytin-1 and compared to responses of PBMCs from pregnant women (n=12). PBMCs were characterised using flow cytometry, release of interferon (IFN)-a, IFN-¿, IFN-¿, IL-10, IL-2, IL-6 and IL-1ß were measured by cytometric bead array or ELISA. Exposure of PBMCs to H1N1pdm09 resulted in the release of IFN-a, (14,787 pg/mL, 95% CI 7311-22,264 pg/mL) IFN-¿ (1486 pg/mL, 95% CI 756-2216 pg/mL) and IFN-¿ (852 pg/mL, 95% CI 193-1511 pg/mL) after 48 hours. This was significantly impaired in pregnant women (IFN-a; p<0.0001 and IFN-¿; p<0.001). Furthermore, in the presence of syncytin-1, PBMCs demonstrated marked reductions in IFN-a and IFN-¿, while enhanced release of IL-10 as well as IL-6 and IL-1ß. Conclusions Our data indicates that a placental derived protein, syncytin-1 may be responsible for the heightened vulnerability of pregnant women to influenza.

Pathogenic bacterial infections of the lung are life threatening and underpin chronic lung diseases. Current treatments are often ineffective potentially due to increasing antibiotic resistance and impairment of innate immunity by disease processes and steroid therapy. Manipulation miRNA directly regulating anti-microbial machinery of the innate immune system may boost host defence responses. Here we demonstrate that miR-328 is a key element of the host response to pulmonary infection with non-typeable haemophilus influenzae and pharmacological inhibition in mouse and human macrophages augments phagocytosis, the production of reactive oxygen species, and microbicidal activity. Moreover, inhibition of miR-328 in respiratory models of infection, steroid-induced immunosuppression, and smoke-induced emphysema enhances bacterial clearance. Thus, miRNA pathways can be targeted in the lung to enhance host defence against a clinically relevant microbial infection and offer a potential new anti-microbial approach for the treatment of respiratory diseases.

Mononuclear molybdenum enzymes of the dimethylsulfoxide (DMSO) reductase family occur exclusively in prokaryotes, and a loss of some these enzymes has been linked to a loss of bacterial virulence in several cases. The MobA protein catalyzes the final step in the synthesis of the molybdenum guanine dinucleotide (MGD) cofactor that is exclusive to enzymes of the DMSO reductase family. MobA has been proposed as a potential target for control of virulence since its inhibition would affect the activities of all molybdoenzymes dependent upon MGD. Here, we have studied the phenotype of a mobA mutant of the host-adapted human pathogen Haemophilus influenzae. H. influenzae causes and contributes to a variety of acute and chronic diseases of the respiratory tract, and several enzymes of the DMSO reductase family are conserved and highly expressed in this bacterium. The mobA mutation caused a significant decrease in the activities of all Mo-enzymes present, and also resulted in a small defect in anaerobic growth. However, we did not detect a defect in in vitro biofilm formation nor in invasion and adherence to human epithelial cells in tissue culture compared to the wild-type. In a murine in vivo model, the mobA mutant showed only a mild attenuation compared to the wild-type. In summary, our data show that MobA is essential for the activities of molybdenum enzymes, but does not appear to affect the fitness of H. influenzae. These results suggest that MobA is unlikely to be a useful target for antimicrobials, at least for the purpose of treating H. influenzae infections.

Wild aquatic birds are recognized as the natural reservoir of avian influenza A viruses (AIV), but across high and low pathogenic AIV strains, scientists have yet to rigorously identify most competent hosts for the various subtypes. We examined 11,870 GenBank records to provide a baseline inventory and insight into patterns of global AIV subtype diversity and richness. Further, we conducted an extensive literature review and communicated directly with scientists to accumulate data from 50 non-overlapping studies and over 250,000 birds to assess the status of historic sampling effort. We then built virus subtype sample-based accumulation curves to better estimate sample size targets that capture a specific percentage of virus subtype richness at seven sampling locations. Our study identifies a sampling methodology that will detect an estimated 75% of circulating virus subtypes from a targeted bird population and outlines future surveillance and research priorities that are needed to explore the influence of host and virus biodiversity on emergence and transmission.

Background: Tumstatin is a segment of the collagen-IV protein that is markedly reduced in the airways of asthmatics. Tumstatin can play an important role in the development of airway remodelling associated with asthma due to its antiangiogenic properties. This study assessed the anti-angiogenic properties of smaller peptides derived from tumstatin, which contain the interface tumstatin uses to interact with the aVb3 integrin. Methods: Primary human lung endothelial cells were exposed to the LF-15, T3 and T7 tumstatin-derived peptides and assessed for cell viability and tube formation in vitro. The impact of the anti-angiogenic properties on airways hyperresponsiveness (AHR) was then examined using a murine model of chronic OVA-induced allergic airways disease. Results: The LF-15 and T7 peptides significantly reduced endothelial cell viability and attenuated tube formation in vitro. Mice exposed to OVA+ LF-15 or OVA+T7 also had reduced total lung vascularity and AHR was attenuated compared to mice exposed to OVA alone. T3 peptides reduced cell viability but had no effect on any other parameters. Conclusion: The LF-15 and T7 peptides may be appropriate candidates for use as novel pharmacotherapies due to their small size and anti-angiogenic properties observed in vitro and in vivo. © 2014 Grafton et al.

Objective The spondyloarthritides share genetic susceptibility, interleukin-23 (IL-23) dependence, and the involvement of microbiota. The aim of the current study was to elucidate how host genetics influence gut microbiota and the relationship between microbiota and organ inflammation in spondyloarthritides.

Protease serine member S31 (Prss31)/transmembrane tryptase/tryptase-¿ is a mast cell (MC)-restricted protease of unknown function that is retained on the outer leaflet of the plasma membrane when MCs are activated. We determined the nucleotide sequences of the Prss31 gene in different mouse strains and then used a Cre/loxP homologous recombination approach to create a novel Prss31 -/- C57BL/6 mouse line. The resulting animals exhibited no obvious developmental abnormality, contained normal numbers of granulated MCs in their tissues, and did not compensate for their loss of the membrane tryptase by increasing their expression of other granule proteases. When Prss31-null MCs were activated with a calcium ionophore or by their high affinity IgE receptors, they degranulated in a pattern similar to that of WT MCs. Prss31-null mice had increased baseline airway reactivity to methacholine but markedly reduced experimental chronic obstructive pulmonary disease and colitis, thereby indicating both beneficial and adverse functional roles for the tryptase. In a cigarette smokeinduced model of chronic obstructive pulmonary disease, WT mice had more pulmonary macrophages, higher histopathology scores, and more fibrosis in their small airways than similarly treated Prss31-null mice. In a dextran sodium sulfate-induced acute colitis model, WT mice lost more weight, had higher histopathology scores, and contained more Cxcl-2 and IL-6 mRNA in their colons than similarly treated Prss31-null mice. The accumulated data raise the possibility that inhibitors of this membrane tryptase may provide additional therapeutic benefit in the treatment of humans with these MC-dependent inflammatory diseases. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

The dynamic interplay between regulatory T cells (Tregs) and effector T cells (Teffs) governs the balance between tolerance and effector immune responses. Perturbations of Treg frequency and function or imbalances in Treg/Teff levels are associated with the development of autoimmunity. The factors that mediate these changes remain poorly understood and were investigated in this study in murine autoimmune arthritis. Tregs displayed a stable phenotype in arthritic mice and were fully functional in in vitro suppression assays. However, their expansion was delayed relative to Teffs (T follicular helper cells and Th17 cells) during the early stages of autoimmune reactivity. This imbalance is likely to have led to insufficient Treg control of Teffs and induced autoimmunity. Moreover, a counterregulatory and probably IL-7-driven increase in thymic Treg production and recruitment to inflamed tissues was too slow for disease prevention. Increased Teff over Treg expansion was further aggravated by inflammation and lymphopenia. Both these conditions contribute to autoimmune pathogenesis and were accompanied by decreases in the availability of IL-2 and increases in levels of IL-21. IL-2 neutralization or supplementation was used to show that Treg expansion mainly depended on this cytokine. IL-21R2/2 cells were used to demonstrate that IL-21 promoted the maintenance of Teffs. Thus, at inflammatory sites in experimental arthritis, a deficit in IL-2 hampers Treg proliferation, whereas exaggerated IL-21 levels overwhelm Treg control by supporting Teff expansion. This identifies IL-2 and IL-21 as targets for manipulation in therapies for autoimmunity.

Introduction: Neutrophil extracellular traps (NETs) have not been demonstrated after trauma and subsequent surgery. Neutrophil extracellular traps are formed from pure mitochondrial DNA (mtDNA) under certain conditions, which is potently proinflammatory. We hypothesized that injury and orthopedic trauma surgery would induce NET production with mtDNA as a structural component. Methods: Neutrophils were isolated 8 trauma patients requiring orthopedic surgery postinjury and up to 5 days postoperatively. Four healthy volunteers provided positive and negative controls. Total hip replacement patients acted as an uninjured surgical control group. Neutrophil extracellular traps were visualized with DNA (Hoechst 33342TM/Sytox Green/MitoSox/MitoTracker) stains using live cell fluorescence microscopy with downstream quantitative polymerase chain reaction analysis of DNA composition. Results: Neutrophil extracellular traps were present after injury in all 8 trauma patients. They persisted for 5 days postoperatively. Delayed surgery resulted in NET resolution, but they reformed postoperatively. Total hip replacement patients developed NETs postoperatively, which resolved by day 5. Quantitative polymerase chain reaction analysis of NET-DNA composition revealed that NETs formed after injury and surgery were made of mtDNA with no detectable nuclear DNA component. Conclusions: Neutrophil extracellular traps formed after major trauma and subsequent surgery contain mtDNA and represent a novel marker of heightened innate immune activation. They could be considered when timing surgery after trauma to prevent systemic NET-induced inflammatory complications.

Tetramer-forming tryptase (hTryptase-ß) was recently discovered to have a prominent role in preventing the internal accumulation of life-threatening fibrin deposits and fibrin-platelet clots. The anticoagulant activity of hTryptase-ß is an explanation for the presence of hemorrhagic disorders in some patients with anaphylaxis or mastocytosis. The fragments of hFibrinogen formed by the proteolysis of this prominent protein by hTryptase-ß could be used as biomarkers in the blood and/or urine for the identification and monitoring of patients with mast cell-dependent disorders. Recombinant hTryptase-ß has potential to be used in clinical settings where it is desirable to inhibit blood coagulation. © 2014 Elsevier Inc.

Recent genetic, structural and functional studies have identified the airway and lung epithelium as a key orchestrator of the immune response. Further, there is now strong evidence that epithelium dysfunction is involved in the development of inflammatory disorders of the lung. Here we review the characteristic immune responses that are orchestrated by the epithelium in response to diverse triggers such as pollutants, cigarette smoke, bacterial peptides, and viruses. We focus in part on the role of epithelium-derived interleukin (IL)-25, IL-33 and thymic stromal lymphopoietin (TSLP), as well as CC family chemokines as critical regulators of the immune response. We cite examples of the function of the epithelium in host defense and the role of epithelium dysfunction in the development of inflammatory diseases. © 2013 Elsevier Inc.

Background and objective Airway epithelial cells represent the first line of defence against inhaled insults, including air pollution. Air pollution can activate innate immune signalling in airway epithelial cells leading to the production of soluble mediators that can influence downstream inflammatory cells. Our objective was to develop and validate a model of dendritic cell exposure to airway epithelial cell-conditioned media. After establishing the model, we explored how soluble mediators released from airway epithelial cells in response to air pollution influenced the phenotype of dendritic cells. Methods Human airway epithelial cells were cultured under control and urban particulate matter (PM10) exposure conditions with or without pharmacological inhibitors of the uric acid pathway. Culture supernatants were collected for conditioned media experiments with peripheral blood mononuclear cell-derived dendritic cells analysed by flow cytometry. Results Monocytes derived from peripheral blood mononuclear cells cultured in interleukin-4 and granulocyte macrophage colony stimulating factor differentiated into immature dendritic cells that phenotypically differentiated into mature dendritic cells in response to conditioned media from phorbol myristate acetate-activated THP-1 monocytes. Exposure of immature dendritic cells to conditioned media from airway epithelial cells exposed to PM10 resulted in dendritic cell maturation that was independent of uric acid. Conclusions We present a conditioned media model useful for interrogating the contribution of soluble mediators produced by airway epithelial cells to dendritic cell phenotype and function. Furthermore, we demonstrate that PM10 exposure induces airway epithelial cell production of soluble mediators that induce maturation of dendritic cells independent of uric acid. We developed and validated a model of airway epithelial cell conditioned media exposure to primary human dendritic cells. Using this model, we then tested the hypothesis that urban particulate matter exposure to airway epithelial cells resulted in production of soluble mediators capable of inducing dendritic cell maturation. © 2014 Asian Pacific Society of Respirology.

Introduction: Chronic obstructive pulmonary disease (COPD) is a leading global cause of mortality and chronic morbidity. Inhalation of cigarette smoke is the principal risk factor for development of this disease. COPD is a progressive disease that is typically characterised by chronic pulmonary inflammation, mucus hypersecretion, airway remodelling and emphysema that collectively reduce lung function. There are currently no therapies that effectively halt or reverse disease progression. It is hoped that the development of animal models that develop the hallmark features of COPD, in a short time frame, will aid in the identifying and testing of new therapeutic approaches. Areas covered: The authors review the recent developments in mouse models of chronic cigarette smoke-induced COPD as well as the principal findings. Furthermore, the authors discuss the use of mouse models to understand the pathogenesis and the contribution of infectious exacerbations. They also discuss the investigations of the systemic co-morbidities of COPD (pulmonary hypertension, cachexia and osteoporosis). Expert opinion: Recent advances in the field mark a point where animal models recapitulate the pathologies of COPD patients in a short time frame. They also reveal novel insights into the pathogenesis and potential treatment of this debilitating disease. © 2014 Informa UK, Ltd.

Preterm infants who receive supplemental oxygen for prolonged periods are at increased risk of impaired lung function later in life. This suggests that neonatal hyperoxia induces persistent changes in small conducting airways (bronchioles). Although the effects of neonatal hyperoxia on alveolarization are well documented, little is known about its effects on developing bronchioles. We hypothesized that neonatal hyperoxia would remodel the bronchiolar walls, contributing to altered lung function in adulthood. We studied three groups of mice (C57BL/6J) to postnatal day 56 (P56; adulthood) when they either underwent lung function testing or necropsy for histological analysis of the bronchiolar wall. One group inhaled 65% O2 from birth until P7, after which they breathed room air; this group experienced growth restriction (HE+GR group). We also used a group in which hyperoxia-induced GR was prevented by dam rotation (HE group). A control group inhaled room air from birth. At P56, the bronchiolar epithelium of HE mice contained fewer Clara cells and more ciliated cells, and the bronchiolar wall contained ~25% less collagen than controls; in HE+GR mice the bronchiolar walls had ~13% more collagen than controls. Male HE and HE+GR mice had significantly thicker bronchiolar epithelium than control males and altered lung function (HE males: greater dynamic compliance; HE+GR males: lower dynamic compliance). We conclude that neonatal hyperoxia remodels the bronchiolar wall and, in adult males, affects lung function, but effects are altered by concomitant growth restriction. Our findings may partly explain the reports of poor lung function in ex-preterm children and adults. Anat Rec, 297:758-769, 2014. © 2014 Wiley Periodicals, Inc.

Pharmacological stabilization of hypoxia-inducible factor (HIF) through prolyl hydroxylase (PHD) inhibition limits mucosal damage associated with models of murine colitis. However, little is known about how PHD inhibitors (PHDi) influence systemic immune function during mucosal inflammation or the relative importance of immunological changes to mucosal protection. We hypothesized that PHDi enhances systemic innate immune responses to colitis-associated bacteremia. Mice with colitis induced by trinitrobenzene sulfonic acid were treated with AKB-4924, a new HIF-1 isoform-predominant PHDi, and clinical, immunological, and biochemical endpoints were assessed. Administration of AKB-4924 led to significantly reduced weight loss and disease activity compared with vehicle controls. Treated groups were pyrexic but did not become subsequently hypothermic. PHDi treatment augmented epithelial barrier function and led to an approximately 50-fold reduction in serum endotoxin during colitis. AKB-4924 also decreased cytokines involved in pyrogenesis and hypothermia, significantly reducing serum levels of interleukin (IL)-1ß, IL-6, and tumor necrosis factor (TNF)-a while increasing IL-10. Treatment offered no protection against colitis in epithelial-specific HIF-1a-deficient mice, strongly implicating epithelial HIF-1a as the tissue target for AKB-4924-mediated protection. Taken together, these results indicate that inhibition of prolyl hydroxylase with AKB-4924 enhances innate immunity and identifies that the epithelium is a central site of inflammatory protection afforded by PHDi in murine colitis. © 2014 Society for Mucosal Immunology.

The pathogenesis of chronic obstructive pulmonary disease (COPD) and its exacerbations, are intricately linked to colonisation and infection with bacteria and other microbes. Despite their undeniable importance, we have a poor understanding of the complex relationships between COPD phenotypes, physiology, cellular and molecular biology and the roles of colonising microbe or infecting pathogens. The management algorithms for the care of patients with COPD that include microbial influences, have almost exclusively been developed using microbial methods that were entirely dependent on the ability to grow bacteria on suitable media. The shortcomings of this approach are becoming clear now that it is possible to completely and accurately define the microbial ecology of ecosystems using genomic methods, which do not rely on the ability to cultivate the organisms present. Whilst our appreciation of the relationships between some bacterial ecosystems and the organ in which they reside in humans is now relatively advanced, this is not true for lung. This perspective serves to highlight the growing importance of including an accurate description of bacterial ecology in any attempt to decipher the pathobiology of COPD. While this field is in its infancy, there is significant potential to gain new insights which will translate into more rational and effective treatment algorithms for patients with COPD.

Asthma affects 10% of the population in Westernized countries, being most common in children. It is a heterogeneous condition characterized by chronic allergic airway inflammation, mucus hypersecretion, and airway hyperresponsiveness (AHR) to normally innocuous antigens. Combination therapies with inhaled corticosteroids and bronchodilators effectively manage mild to moderate asthma, but there are no cures, and patients with severe asthma do not respond to these treatments. The inception of asthma is linked to respiratory viral (respiratory syncytial virus, rhinovirus) and bacterial (Chlamydia, Mycoplasma) infections. The examination of mouse models of early-life infections and allergic airway disease (AAD) provides valuable insights into the mechanisms of disease inception that may lead to the development of more effective therapeutics. For example, early-life, but not adult, Chlamydia respiratory infections in mice permanently modify immunity and lung physiology. This increases the severity of AAD by promoting IL-13 expression, mucus hypersecretion, and AHR. We have identified novel roles for tumor necrosis factor-related apoptosisinducing ligand (TRAIL) and IL-13 in promoting infection-induced pathology in early life and subsequent chronic lung disease. Genetic deletion of TRAIL or IL-13 variously protected against neonatal infection-induced inflammation, mucus hypersecretion, altered lung structure, AHR, and impaired lung function. Therapeutic neutralization of these factors prevented infection-induced severe AAD. Other novel mechanisms and avenues for intervention are also being explored. Such studies indicate the immunological mechanisms that may underpin the association between early-life respiratory infections and the development of more severe asthma and may facilitate the development of tailored preventions and treatments.