Interleukin-13 induces collagen type-1 expression through matrix metalloproteinase-2 and transforming growth factor-β1 in airway fibroblasts in asthma

The role of IL-2 cytokine family in asthma

BACKGROUND

The interleukin-2 (IL-2) family of cytokines, including IL-2, IL-4, IL-7, IL-9, IL-15, and IL-21, are pivotal regulators of the immune response, impacting both innate and adaptive immunity. Understanding their molecular characteristics, receptor interactions, and signalling pathways is essential for elucidating their roles in health and disease.

OBJECTIVES

This review provides a comprehensive overview of the IL-2 family of cytokines, highlighting their molecular biology, receptor interactions, and signalling mechanisms. Furthermore, it explores the involvement of IL-2 family cytokines in the pathogenesis of chronic respiratory diseases, with a specific focus on chronic obstructive pulmonary disease (COPD) and asthma.

METHODS

A thorough literature review was conducted to gather insights into the molecular biology, receptor interactions, and signalling pathways of IL-2 family cytokines. Additionally, studies investigating the roles of these cytokines in chronic respiratory diseases, particularly COPD and asthma, were analysed to discern their implications in wider pathophysiology of disease.

RESULTS

IL-2 family cytokines exert pleiotropic effects on immune cells, modulating cellular proliferation, differentiation, and survival. Dysregulation of IL-2 family cytokines has been implicated in the pathogenesis of chronic respiratory illnesses, including COPD and asthma. Elevated levels of IL-2 and IL-9 have been associated with disease severity in COPD, while IL-4 and IL-9 play crucial roles in asthma pathogenesis by promoting airway inflammation and remodelling.

CONCLUSION

Understanding the intricate roles of IL-2 family cytokines in chronic respiratory diseases provides valuable insights into potential therapeutic targets for these conditions. Targeting specific cytokines or their receptors may offer novel treatment modalities to attenuate disease progression and improve clinical outcomes in patients with COPD and asthma.

Type 2 severe asthma: pathophysiology and treatment with biologics

INTRODUCTION

The hallmark of most patients with severe asthma is type 2 inflammation, driven by innate and adaptive immune responses leading to either allergic or non-allergic eosinophilic infiltration of airways. The cellular and molecular pathways underlying severe type 2 asthma can be successfully targeted by specific monoclonal antibodies.

AREAS COVERED

This review article provides a concise overview of the pathophysiology of type 2 asthma, followed by an updated appraisal of the mechanisms of action and therapeutic efficacy of currently available biologic treatments used for management of severe type 2 asthma. Therefore, all reported information arises from a wide literature search performed on PubMed.

EXPERT OPINION

The main result of the recent advances in the field of anti-asthma biologic therapies is the implementation of a personalized medicine approach, aimed to achieve clinical remission of severe asthma. Today this accomplishment is made possible by the right choice of the most beneficial biologic drug for the pathologic traits characterizing each patient, including type 2 severe asthma and its comorbidities.

Role of Mast Cells in Eosinophilic Gastrointestinal Diseases

Mast cells play a central role in the pathogenesis of eosinophilic gastrointestinal disorders (EGIDs), including eosinophilic esophagitis. Their interactions with immune and structural cells, involvement in tissue remodeling, and contribution to symptoms make them attractive targets for therapeutic intervention. More is being discovered regarding the intricate interplay of mast cells and eosinophils. Recent studies demonstrating that depletion of eosinophils is insufficient to improve symptoms of EGIDs have raised the question of whether other cells may play a role in symptomatology and pathogenesis of EGIDs.

Immunosuppressive tumor microenvironment and uterine fibroids: Role in collagen synthesis

Uterine fibroids (UF), also called uterine leiomyoma, is one of the most prevalent uterine tumors. UF represents a serious women's health global problem with a significant physical, emotional, and socioeconomic impact. Risk factors for UF include racial disparities, age, race, hormonal factors, obesity, and lifestyle (diet, physical activity, and stress. There are several biological contributors to UF pathogenesis such as cellular proliferation, angiogenesis, and extracellular matrix (ECM) accumulation. This review addresses tumor immune microenvironment as a novel mediator of ECM deposition. Polarization of immune microenvironment towards the immunosuppressive phenotype has been associated with ECM deposition. Immunosuppressive cells include M2 macrophage, myeloid-derived suppressor cells (MDSCs), and Th17 cells, and their secretomes include interleukin 4 (IL-4), IL-10, IL-13, IL-17, IL-22, arginase 1, and transforming growth factor-beta (TGF-β1). The change in the immune microenvironment not only increase tumor growth but also aids in collagen synthesis and ECM disposition, which is one of the main hallmarks of UF pathogenesis. This review invites further investigations on the change in the UF immune microenvironment as well as a novel targeting approach instead of the traditional UF hormonal and supportive treatment.

Mast Cells in Aspirin-Exacerbated Respiratory Disease

PURPOSE OF REVIEW

Aspirin-exacerbated respiratory disease (AERD) is a syndrome of high type 2 inflammation and is known to critically involve mast cell activation. The mast cell is an important cell in the baseline inflammatory processes in the upper and lower airway by maintaining and amplifying type 2 inflammation. But it also is prominent in the hypersensitivity reaction to COX-1 inhibition which defines this condition.

RECENT FINDINGS

Recent work highlights the mast cell as a focal point in AERD pathogenesis. Using AERD as a specific model of both high type 2 asthma and chronic sinusitis, the role of mast cell activity can be better understood in other aspects of airway inflammation. Further dissecting out the mechanism of COX-1-mediated mast cell activation in AERD will be an important next phase in our understanding of NSAID-induced hypersensitivity as well as AERD pathophysiology.

Bronchial Asthma, Airway Remodeling and Lung Fibrosis as Successive Steps of One Process

Bronchial asthma is a heterogeneous disease characterized by persistent respiratory system inflammation, airway hyperreactivity, and airflow obstruction. Airway remodeling, defined as changes in airway wall structure such as extensive epithelial damage, airway smooth muscle hypertrophy, collagen deposition, and subepithelial fibrosis, is a key feature of asthma. Lung fibrosis is a common occurrence in the pathogenesis of fatal and long-term asthma, and it is associated with disease severity and resistance to therapy. It can thus be regarded as an irreversible consequence of asthma-induced airway inflammation and remodeling. Asthma heterogeneity presents several diagnostic challenges, particularly in distinguishing between chronic asthma and other pulmonary diseases characterized by disruption of normal lung architecture and functions, such as chronic obstructive pulmonary disease. The search for instruments that can predict the development of irreversible structural changes in the lungs, such as chronic components of airway remodeling and fibrosis, is particularly difficult. To overcome these challenges, significant efforts are being directed toward the discovery and investigation of molecular characteristics and biomarkers capable of distinguishing between different types of asthma as well as between asthma and other pulmonary disorders with similar structural characteristics. The main features of bronchial asthma etiology, pathogenesis, and morphological characteristics as well as asthma-associated airway remodeling and lung fibrosis as successive stages of one process will be discussed in this review. The most common murine models and biomarkers of asthma progression and post-asthmatic fibrosis will also be covered. The molecular mechanisms and key cellular players of the asthmatic process described and systematized in this review are intended to help in the search for new molecular markers and promising therapeutic targets for asthma prediction and therapy.

Lactobacillus rhamnosus Modulates Lung Inflammation and Mitigates Gut Dysbiosis in a Murine Model of Asthma-COPD Overlap Syndrome

The asthma-COPD overlap syndrome (ACOS) presents lung inflammation similar to both asthma and chronic obstructive pulmonary disease (COPD). Due to the immune response between the lung and gut, it is possible that ACOS individuals present gut dysbiosis. Due to therapeutic limitations in ACOS, Lactobacillus rhamnosus (Lr) have received attention once Lr has been effective in asthma and COPD. However, there is no data about the Lr effect on both lung inflammation and gut dysbiosis in ACOS. Thus, our study investigated the Lr effect on lung inflammation, bronchoconstriction, airway remodeling, and gut dysbiosis in the murine ACOS model. Treated mice with Lr were exposed to HDM and cigarette smoke to induce ACOS. Sixty days after ACOS induction, mice were euthanized. Lung inflammation was evaluated in leukocytes in bronchoalveolar lavage fluid (BALF), airway remodeling, cytokine secretion, and transcription factor expression in the lung. The gut microbiota was assayed by 16S mRNA sequencing from a fecal sample. Leukocyte population, bronchial hyperreactivity, pro-inflammatory cytokines, and airway remodeling were attenuated in Lr-treated ACOS mice. Likewise, IL-4, IL-5, and IL-13, STAT6 and GATA3, as well as IL-17, IL-21, IL-22, STAT3, and RORɣt were reduced after Lr. In addition, IL-2, IL-12, IFN-γ, STAT1, and T-bet as well as IL-10, TGF-β, STAT5, and Foxp3 were restored after the Lr. Firmicutes was reduced, while Deferribacteres was increased after Lr. Likewise, Lr decreased Staphylococcus and increased Mucispirillum in ACOS mice. Lr improves fecal bacterial β-diversity. Our findings show for the first time the Lr effect on lung inflammation and gut dysbiosis in murine ACOS.

Pathobiology of Type 2 Inflammation in Asthma and Nasal Polyposis

Asthma and nasal polyposis often coexist and are frequently intertwined by tight pathogenic links, mainly consisting of the cellular and molecular pathways underpinning type 2 airway inflammation. The latter is characterized by a structural and functional impairment of the epithelial barrier, associated with the eosinophilic infiltration of both the lower and upper airways, which can be driven by either allergic or non-allergic mechanisms. Type 2 inflammatory changes are predominantly due to the biological actions exerted by interleukins 4 (IL-4), 13 (IL-13), and 5 (IL-5), produced by T helper 2 (Th2) lymphocytes and group 2 innate lymphoid cells (ILC2). In addition to the above cytokines, other proinflammatory mediators involved in the pathobiology of asthma and nasal polyposis include prostaglandin D₂ and cysteinyl leukotrienes. Within this context of 'united airway diseases', nasal polyposis encompasses several nosological entities such as chronic rhinosinusitis with nasal polyps (CRSwNP) and aspirin-exacerbated respiratory disease (AERD). Because of the common pathogenic origins of asthma and nasal polyposis, it is not surprising that the more severe forms of both these disorders can be successfully treated by the same biologic drugs, targeting many molecular components (IgE, IL-5 and its receptor, IL-4/IL-13 receptors) of the type 2 inflammatory trait.

Real-life effects of dupilumab in patients with severe type 2 asthma, according to atopic trait and presence of chronic rhinosinusitis with nasal polyps

Background

The efficacy of dupilumab as biological treatment of severe asthma and chronic rhinosinusitis with nasal polyps (CRSwNP) depends on its ability to inhibit the pathophysiologic mechanisms involved in type 2 inflammation.

Objective

To assess in a large sample of subjects with severe asthma, the therapeutic impact of dupilumab in real-life, with regard to positive or negative skin prick test (SPT) and CRSwNP presence or absence.

Methods

Clinical, functional, and laboratory parameters were measured at baseline and 24 weeks after the first dupilumab administration. Moreover, a comparative evaluation was carried out in relation to the presence or absence of SPT positivity and CRSwNP.

Results

Among the 127 recruited patients with severe asthma, 90 had positive SPT, while 78 reported CRSwNP. Compared with the 6 months preceding the first dupilumab injection, asthma exacerbations decreased from 4.0 (2.0-5.0) to 0.0 (0.0-0.0) (p < 0.0001), as well as the daily prednisone intake fell from 12.50 mg (0.00-25.00) to 0.00 mg (0.00-0.00) (p < 0.0001). In the same period, asthma control test (ACT) score increased from 14 (10-18) to 22 (20-24) (p < 0.0001), and sino-nasal outcome test (SNOT-22) score dropped from 55.84 ± 20.32 to 19.76 ± 12.76 (p < 0.0001). Moreover, we observed relevant increases in forced expiratory volume in one second (FEV1) from the baseline value of 2.13 L (1.62-2.81) to 2.39 L (1.89-3.06) (p < 0.0001). Fractional exhaled nitric oxide (FeNO) values decreased from 27.0 ppb (18.0-37.5) to 13.0 ppb (5.0-20.0) (p < 0.0001). These improvements were quite similar in subgroups of patients characterized by SPT negativity or positivity, and CRSwNP absence or presence. No statistically significant correlations were detected between serum IgE levels, baseline blood eosinophils or FeNO levels and dupilumab-induced changes, with the exception of FEV1 increase, which was shown to be positively correlated with FeNO values (r = 0.3147; p < 0.01).

Conclusion

Our results consolidate the strategic position of dupilumab in its role as an excellent therapeutic option currently available within the context of modern biological treatments of severe asthma and CRSwNP, frequently driven by type 2 airway inflammation.

Development of Adaptive Immunity and Its Role in Lung Remodeling

Asthma is characterized by airflow limitations resulting from bronchial closure, which can be either reversible or fixed due to changes in airway tissue composition and structure, also known as remodeling. Airway remodeling is defined as increased presence of mucins-producing epithelial cells, increased thickness of airway smooth muscle cells, angiogenesis, increased number and activation state of fibroblasts, and extracellular matrix (ECM) deposition. Airway inflammation is believed to be the main cause of the development of airway remodeling in asthma. In this chapter, we will review the development of the adaptive immune response and the impact of its mediators and cells on the elements defining airway remodeling in asthma.

A Deficiency in the Cytokine TNFSF14/LIGHT Limits Inflammation and Remodeling in Murine Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is a chronic type 2 allergic disease, with esophageal tissue remodeling as the mechanism behind clinical dysphagia and strictures. IL-13 is thought to be a central driver of disease, but other inflammatory factors, such as IFNs and TNF superfamily members, have been hypothesized to play a role in disease pathogenesis. We recently found that the cytokine TNFSF14/LIGHT is upregulated in the esophagus of patients with EoE and that LIGHT promotes inflammatory activity in esophageal fibroblasts. However, the global effects of LIGHT on EoE pathogenesis in vivo remain unknown. We investigated the impact of a LIGHT deficiency in a murine model of EoE driven by house dust mite allergen. Chronic intranasal challenge with house dust mite promoted esophageal eosinophilia and increased CD4+ T cell numbers and IL-13 and CCL11 production in wild-type mice. Esophageal remodeling was reflected by submucosal collagen accumulation, increased muscle density, and greater numbers of fibroblasts. LIGHT-/- mice displayed normal esophageal eosinophilia, but exhibited reduced frequencies of CD4 T cells, IL-13 expression, submucosal collagen, and muscle density and a decrease in esophageal accumulation of fibroblasts. In vitro, LIGHT increased division of human esophageal fibroblasts and selectively enhanced IL-13-mediated expression of a subset of inflammatory and fibrotic genes. These results show that LIGHT contributes to various features of murine EoE, impacting the accumulation of CD4 T cells, IL-13 production, fibroblast proliferation, and esophagus remodeling. These findings suggest that LIGHT may be, to our knowledge, a novel therapeutic target for the treatment of EoE.

A novel iridoid glycoside leonuride (ajugol) attenuates airway inflammation and remodeling through inhibiting type-2 high cytokine/chemokine activity in OVA-induced asthmatic mice

BACKGROUND

Asthma is a chronic airway disorder with a hallmark feature of airflow obstruction that associated with the remodeling and inflammation in the airway wall. Effective therapy for controlling both remodeling and inflammation is still urgently needed. Leonuride is the main pharmacological component identified from Bu-Shen-Yi-Qi-Tang (BSYQT) which has been traditionally used in treatment of lung diseases. However, no pharmacological effects of leonuride in asthma were reported.

PURPOSE

Here we aimed to investigated whether leonuride provided a therapeutic efficacy in reversing asthma airway remodeling and inflammation and uncover the underlying mechanisms.

STUDY DESIGN AND METHODS

Mouse models of chronic asthma were developed with ovalbumin (OVA) exposure for 8 weeks. Respiratory mechanics, lung histopathology and asthma-related cytokines were examined. Lung tissues were analyzed using RNA sequencing to reveal the transcriptional profiling changes.

RESULTS

After oral administration with leonuride (15 mg/kg or 30 mg/kg), mice exhibited a lower airway hyperresponsiveness in comparison to asthmatic mice. Leonuride suppressed airway inflammation evidenced by the significant reductions in accumulation of inflammatory cells around bronchi and vessels, leukocyte population counts and the abundance of type 2 inflammatory mediators (OVA specific IgE, IL-4, IL-5 and IL-13) in bronchoalveolar lavage fluid (BALF). On the other hand, leonuride slowed down the process of active remodeling as demonstrated by weaker goblet cell metaplasia and subepithelial fibrosis in lung histopathology and lower transforming growth factor (TGF)-β1 levels in serum and BALF in comparison to mice treated with OVA only. Furthermore, we uncovered transcriptional profiling alternations in lung tissue of mice after OVA exposure and leonuride treatment. Gene sets belonging to type-2 cytokine/chemokine activity stood out in leonuride target transcripts. Those upregulated (Bmp10, Ccl12, Ccl22, Ccl8, Ccl9, Cxcl15, Il13, Il33, Tnfrsf9, Il31ra, Il5ra, Il13ra2 and Ccl24) or downregulated (Acvr1c and Il18) genes in asthmatic mice, were all reversely regulated by leonuride treatment.

CONCLUSIONS

Our results revealed the therapeutic efficacy of leonuride in experimental chronic asthma for the first time, and implied that its anti-inflammatory and antifibrotic properties might be mediated by regulation of type-2 high cytokine/chemokines responses.

Biological Therapy of Severe Asthma with Dupilumab, a Dual Receptor Antagonist of Interleukins 4 and 13

Interleukin-4 (IL-4) and interleukin-13 (IL-13) are key cytokines involved in the pathophysiology of both immune-inflammatory and structural changes underlying type 2 asthma. IL-4 plays a pivotal role in Th2 cell polarization, immunoglobulin E (IgE) synthesis and eosinophil recruitment into the airways. IL-13 synergizes with IL-4 in inducing IgE production and also promotes nitric oxide (NO) synthesis, eosinophil chemotaxis, bronchial hyperresponsiveness and mucus secretion, as well as the proliferation of airway resident cells such as fibroblasts and smooth muscle cells. The biological effects of IL-4 and IL-13 are mediated by complex signaling mechanisms activated by receptor dimerization triggered by cytokine binding to the α-subunit of the IL-4 receptor (IL-4Rα). The fully human IgG4 monoclonal antibody dupilumab binds to IL-4Rα, thereby preventing its interactions with both IL-4 and IL-13. This mechanism of action makes it possible for dupilumab to effectively inhibit type 2 inflammation, thus significantly reducing the exacerbation of severe asthma, the consumption of oral corticosteroids (OCS) and the levels of fractional exhaled NO (FeNO). Dupilumab has been approved not only for the add-on therapy of severe asthma, but also for the biological treatment of atopic dermatitis and nasal polyposis.

Novel Biological Therapies for Severe Asthma Endotypes

Severe asthma comprises several heterogeneous phenotypes, underpinned by complex pathomechanisms known as endotypes. The latter are driven by intercellular networks mediated by molecular components which can be targeted by specific monoclonal antibodies. With regard to the biological treatments of either allergic or non-allergic eosinophilic type 2 asthma, currently available antibodies are directed against immunoglobulins E (IgE), interleukin-5 (IL-5) and its receptor, the receptors of interleukins-4 (IL-4) and 13 (IL-13), as well as thymic stromal lymphopoietin (TSLP) and other alarmins. Among these therapeutic strategies, the best choice should be made according to the phenotypic/endotypic features of each patient with severe asthma, who can thus respond with significant clinical and functional improvements. Conversely, very poor options so far characterize the experimental pipelines referring to the perspective biological management of non-type 2 severe asthma, which thereby needs to be the focus of future thorough research.

Interleukins 4 and 13 in Asthma: Key Pathophysiologic Cytokines and Druggable Molecular Targets

Interleukins (IL)-4 and -13 play a pivotal role in the pathobiology of type-2 asthma. Indeed, IL-4 is crucially involved in Th2 cell differentiation, immunoglobulin (Ig) class switching and eosinophil trafficking. IL-13 cooperates with IL-4 in promoting IgE synthesis, and also induces nitric oxide (NO) production, goblet cell metaplasia and fibroblast proliferation, as well as elicits contractile responses and hyperplasia of airway smooth muscle cells.

IL-4 and IL-13 share common signaling pathways, activated by the binding of both cytokines to receptor complexes including the α-subunit of the IL-4 receptor (IL-4Rα). Therefore, the subsequent receptor dimerization is responsible for the pathophysiologic effects of IL-4 and IL-13. By selectively blocking IL-4Rα, the fully human IgG4 monoclonal antibody dupilumab behaves as a dual receptor antagonist of both IL-4 and IL-13. Through this mechanism of action, dupilumab exerts effective therapeutic actions in type-2 inflammation, thus decreasing asthma exacerbations, FeNO (fractional exhaled NO) levels, and the intake of oral corticosteroids (OCS). In addition to being approved for the add-on biological therapy of severe asthma, dupilumab has also been licensed for the treatment of nasal polyposis and atopic dermatitis.

Interrelationships between the extracellular matrix and the immune microenvironment that govern epithelial tumour progression

Solid tumours are composed of cancer cells characterised by genetic mutations that underpin the disease, but also contain a suite of genetically normal cells and the extracellular matrix (ECM). These two latter components are constituents of the tumour microenvironment (TME), and are key determinants of tumour biology and thereby the outcomes for patients. The tumour ECM has been the subject of intense research over the past two decades, revealing key biochemical and mechanobiological principles that underpin its role in tumour cell proliferation and survival. However, the ECM also strongly influences the genetically normal immune cells within the microenvironment, regulating not only their proliferation and survival, but also their differentiation and access to tumour cells. Here we review recent advances in our knowledge of how the ECM regulates the tumour immune microenvironment and vice versa, comparing normal skin wound healing to the pathological condition of tumour progression.

Prenatal and Postnatal Cigarette Smoke Exposure Is Associated With Increased Risk of Exacerbated Allergic Airway Immune Responses: A Preclinical Mouse Model

Increased exposure to household air pollution and ambient air pollution has become one of the world’s major environmental health threats. In developing and developed countries, environmental cigarette smoke (CS) exposure is one of the main sources of household air pollution (HAP). Moreover, results from different epidemiological and experimental studies indicate that there is a strong association between HAP, specifically CS exposure, and the development of allergic diseases that often persists into later life. Here, we investigated the impact of prenatal and postnatal CS exposure on offspring susceptibility to the development of allergic airway responses by using a preclinical mouse model. Pregnant BALB/c mice were exposed to either CS or air during pregnancy and lactation and in order to induce allergic asthma the offspring were sensitized and challenged with house dust mite (HDM). Decreased lung function parameters, like dynamic compliance and pleural pressure, were observed in PBS-treated offspring born to CS-exposed mothers compared to offspring from air-exposed mothers. Maternal CS exposure significantly increased the HDM-induced airway eosinophilia and neutrophilia in the offspring. Prenatal and postnatal CS exposure increased the frequency of Th2 cells in the lungs of HDM-treated offspring compared to offspring born to air-exposed mothers. Offspring born to CS-exposed mothers showed increased levels of IL-4, IL-5 and IL-13 in bronchoalveolar lavage fluid compared to offspring from air-exposed mothers. Ex-vivo restimulation of lung cells isolated from HDM-treated offspring born to CS-exposed mothers also resulted in increased IL-4 production. Finally, serum immunoglobulins levels of HDM-specific IgE and HDM-specific IgG1 were significantly increased upon a HDM challenge in offspring born to CS-exposed mothers compared to offspring from air-exposed mothers. In summary, our results reveal a biological plausibility for the epidemiological studies indicating that prenatal and postnatal CS exposure increases the susceptibility of offspring to allergic immune responses.

Angiotensin-(1-7)/Mas receptor modulates anti-inflammatory effects of exercise training in a model of chronic allergic lung inflammation

AIMS

Exercise training increases circulating and tissue levels of angiotensin-(1-7) [Ang-(1-7)], which was shown to attenuate inflammation and fibrosis in different diseases. Here, we evaluated whether Ang-(1-7)/Mas receptor is involved in the beneficial effects of aerobic training in a chronic model of asthma.

MATERIAL AND METHODS

BALB/c mice were subjected to a protocol of asthma induced by ovalbumin sensitization (OVA; 4 i.p. injections) and OVA challenge (3 times/week for 4 weeks). Simultaneously to the challenge period, part of the animals was continuously treated with Mas receptor antagonist (A779, 1 μg/h; for 28 days) and trained in a treadmill (TRE; 60% of the maximal capacity, 1 h/day, 5 days/week during 4 weeks). PGC1-α mRNA expression (qRT-PCR), plasma IgE and lung cytokines (ELISA), inflammatory cells infiltration (enzymatic activity assay) and airway remodeling (by histology) were evaluated.

KEY FINDINGS

Blocking the Mas receptor with A779 increased IgE and IL-13 levels and prevented the reduction in extracellular matrix deposition in airways in OVA-TRE mice. Mas receptor blockade prevented the reduction of myeloperoxidase activity, as well as, prevented exercise-induced IL-10 increase. These data show that activation of Ang-(1-7)/Mas receptor pathway is involved in the anti-inflammatory and anti-fibrotic effects of aerobic training in an experimental model of chronic asthma.

SIGNIFICANCE

Our results support exercise training as a non-pharmacological tool to defeat lung remodeling induced by chronic pulmonary inflammation. Further, our result also supports development of new therapy based on Ang-(1-7) or Mas agonists as important tool for asthma treatment in those patients that cannot perform aerobic training.

Understanding the key issues in the treatment of uncontrolled persistent asthma with type 2 inflammation

Asthma is a complex respiratory disease that varies in severity and response to treatment. Several asthma phenotypes with unique clinical and inflammatory characteristics have been identified. Endotypes, based on distinct molecular profiles, help to further elucidate the heterogeneity within asthma. Type 2 inflammation, involving both the innate (type 2 innate lymphoid cell) and adaptive (T-helper type 2 cells) immune systems, underpins the complex pathophysiology of chronic inflammation in asthma, as well as the presence of comorbid disease (e.g. chronic rhinosinusitis with nasal polyps, allergic rhinitis and atopic dermatitis). Type 2 inflammation is characterised by upregulation of the type 2 cytokines interleukin (IL)-4, IL-5 and IL-13, IgE-mediated release of immune mediators and dysfunction of epithelial or epidermal barriers. Targeting these key proximal type 2 cytokines has shown efficacy in recent studies adopting a personalised approach to treatment using targeted biologics. Elevated levels of biomarkers downstream of type 2 cytokines, including fractional exhaled nitric oxide, serum IgE and blood and sputum eosinophils, have been linked to mechanisms involved in type 2 inflammation. They have the potential to aid diagnosis, and to predict and monitor response to treatment. The objective of this review is to summarise the current understanding of the biology of type 2 inflammation in asthma, examine its influence on type 2 inflammatory comorbidities, and discuss how type 2 inflammatory biomarkers can be harnessed to further personalise treatments in the age of biologic medicines.

Repetitive aeroallergen challenges elucidate maladaptive epithelial and inflammatory traits that underpin allergic airway diseases

BACKGROUND

Signifying the 2-compartments/1-disease paradigm, allergic rhinoconjunctivitis (ARC) and asthma (AA) are prevalent, comorbid conditions triggered by environmental factors (eg, house dust mites [HDMs]). However, despite the ubiquity of triggers, progression to severe ARC/AA is infrequent, suggesting either resilience or adaptation.

OBJECTIVE

We sought to determine whether ARC/AA severity relates to maladaptive responses to disease triggers.

METHODS

Adults with HDM-associated ARC were challenged repetitively with HDMs in an aeroallergen challenge chamber. Mechanistic traits associated with disease severity were identified.

RESULTS

HDM challenges evoked maladaptive (persistently higher ARC symptoms), adaptive (progressive symptom reduction), and resilient (resistance to symptom induction) phenotypes. Symptom severity in the natural environment was an imprecise correlate of the phenotypes. Nasal airway traits, defined by low inflammation-effectual epithelial integrity, moderate inflammation-effectual epithelial integrity, and higher inflammation-ineffectual epithelial integrity, were hallmarks of the resilient, adaptive, and maladaptive evoked phenotypes, respectively. Highlighting a crosstalk mechanism, peripheral blood inflammatory tone calibrated these traits: ineffectual epithelial integrity associated with CD8⁺ T cells, whereas airway inflammation associated with both CD8⁺ T cells and eosinophils. Hallmark peripheral blood maladaptive traits were increased natural killer and CD8⁺ T cells, lower CD4⁺ mucosal-associated invariant T cells, and deficiencies along the TLR-IRF-IFN antiviral pathway. Maladaptive traits tracking HDM-associated ARC also contributed to AA risk and severity models.

CONCLUSIONS

Repetitive challenges with HDMs revealed that maladaptation to disease triggers may underpin ARC/AA disease severity. A combinatorial therapeutic approach may involve reversal of loss-of-beneficial-function traits (ineffectual epithelial integrity, TLR-IRF-IFN deficiencies), mitigation of gain-of-adverse-function traits (inflammation), and blocking of a detrimental crosstalk between the peripheral blood and airway compartments.

Abundant TNF-LIGHT expression in the airways of patients with asthma with persistent airflow limitation: Association with nitrative and inflammatory profiles

BACKGROUND

The role of the inflammatory secretory protein TNF-LIGHT (LIGHT) in the molecular mechanisms underlying persistent airflow limitation (PAL) in asthma remains unclear. We hypothesized that high airway LIGHT expression may be a feature of asthma with PAL associated with specific expression patterns of inflammatory molecules.

METHODS

This hypothesis was tested in 16 patients with asthma on inhaled corticosteroid treatment. Induced sputum was collected, the expression of LIGHT and 3-nitrotyrosine (NT), which reflects the footprint of reactive nitrogen species content, was measured using immunohistochemical staining, and the inflammatory molecules in the sputum supernatant were analyzed using a magnetic bead array.

RESULTS

LIGHT staining in the cells had a significantly higher intensity in participants with PAL than in participants without PAL (47.9 × 10⁴/ml vs. 5.4 × 10⁴/ml; p < 0.05). The array analysis indicated that IL-8, IL-19, matrix metalloproteinase 2, and osteopontin, were associated with high LIGHT immunoreactivity. The fractionation of 3-NT-positive cells was positively correlated with that of LIGHT-positive cells (r = 0.57, p < 0.05) and the TGF-β1 level (r = 0.61, p < 0.05). LIGHT- and 3-NT-positive cells showed significant positive correlation with the differential cell counts of neutrophils, macrophages, and eosinophils in the induced sputum. Intense immunoreactivities of LIGHT (r = -0.54, p < 0.05) and 3-NT (r = -0.42, p = 0.1) were negatively associated with decreased forced expiratory volume in 1/forced vital capacity ratio.

CONCLUSIONS

The findings suggest that LIGHT is a key component in the association between airway inflammation and airflow limitation in patients with asthma, and its expression may be persistently correlated with the abundance of inflammatory cells and inflammatory and profibrogenic radical/molecules.

IL-13 Augments Histone Demethylase JMJD2B/KDM4B Expression Levels, Activity, and Nuclear Translocation in Airway Fibroblasts in Asthma

Purpose

Asthma is one of the most common obstructive pulmonary diseases worldwide. Epigenetic alterations, including DNA methylation and histone modifications, have been reported to contribute to asthma pathogenesis. Since the inflammation mediator and remodeling trigger, IL-13, is known to play a central role in the pathophysiology of asthma, this study was aimed to identify novel IL-13-regulated epigenetic modifiers in asthma that may contribute to subepithelial fibrosis.

Methods

Publicly available transcriptomic datasets from Gene Expression Omnibus (GEO) were used to identify differentially expressed genes on an epigenetic level upon IL-13 exposure in lung fibroblasts. Bronchial fibroblasts isolated from healthy and asthmatic individuals were assessed for the gene and protein expression levels of the identified gene at baseline and upon IL-13 treatment using qRT-PCR and western blotting, respectively. Its subcellular localization and tissue distribution were examined in bronchial fibroblasts as well as bronchial biopsies by immunofluorescence and immunohistochemical analysis, respectively.

Results

Bioinformatic analysis revealed the differential expression of the histone demethylase JMJD2B/KDM4B, a well-known epigenetic modulator that leads to the demethylation of different lysine residues on histones, in IL-13-treated lung fibroblasts. The baseline expression levels of JMJD2B were higher in asthmatic fibroblasts and in bronchial biopsies in comparison to healthy ones. There was also an increase in JMJD2B activity as evidenced by the demethylation of its downstream target, H3K36me3. Furthermore, IL-13 stimulation induced JMJD2B expression and further demethylation of H3K36me3 in asthmatic fibroblasts. This was accompanied by increased translocation of JMJD2B into the nucleus.

Conclusion

This study highlights the novel pathological involvement of the histone demethylase JMJD2B/KDM4B in asthmatic airway fibroblasts that are regulated by IL-13. Clinical implications. Given that there is no single therapeutic medicine to effectively treat the various subtypes of asthma, this study provides promising insights into JMJD2B as a new therapeutic target that could potentially improve the treatment and management of asthma.

Role of Matrix Metalloproteinases in Angiogenesis and Its Implications in Asthma

Asthma is a chronic airway disorder associated with aberrant inflammatory and remodeling responses. Angiogenesis and associated vascular remodeling are one of the pathological hallmarks of asthma. The mechanisms underlying angiogenesis in asthmatic airways and its clinical relevance represent a relatively nascent field in asthma when compared to other airway remodeling features. Matrix metalloproteinases (MMPs) are proteases that play an important role in both physiological and pathological conditions. In addition to facilitating extracellular matrix turnover, these proteolytic enzymes cleave bioactive molecules, thereby regulating cell signaling. MMPs have been implicated in the pathogenesis of asthma by interacting with both the airway inflammatory cells and the resident structural cells. MMPs also cover a broad range of angiogenic functions, from the degradation of the vascular basement membrane and extracellular matrix remodeling to the release of a variety of angiogenic mediators and growth factors. This review focuses on the contribution of MMPs and the regulatory role exerted by them in angiogenesis and vascular remodeling in asthma as well as addresses their potential as therapeutic targets in ameliorating angiogenesis in asthma.

Active smoking effect in allergic rhinitis

Background

Tobacco smoke has been described as causing increased prevalence of rhinitis symptoms and decreased atopy. Furthermore, these nasal symptoms and quality of life in smokers with Allergic Rhinitis (AR) were not significantly different to non-smokers. As a result of this duality, a comparison study between the quality of life and inflammatory markers of atopy among active smokers and non-smokers having AR was put forward.

Material and methods

Cross-sectional study in adult smokers and non-smokers, with a clinical diagnosis of AR and positive Skin Prick Test (SPT). Smoking status was confirmed by salivary cotinine measurements. Functional respiratory evaluation was performed, and quality of life between groups was compared using Mini-RQLQ questionnaire. Immunological markers in serum and nasal washes (IgE, IL-4, IL 5, IL 13, IL 17, IL 33) were evaluated, while samples from a third group of passive smokers was incorporated for serological comparison exclusively. The statistical analysis included Student T test, x2, Mann Whitney U (Anova 2-way), and Kruskal Wallis for 3 groups analysis. Values of P < 0.05 were considered significant.

Results

Twenty-two patients per group with similar demographics and allergen sensitivity were studied. Regarding inflammatory markers, a reduction of IL 33 in the serum of smokers (P < 0.001) was the only statistically significant different parameter revealed, showing a remarkable trend in nasal lavage. Salivary cotinine levels were absolutely different (P < 0.0001), but pulmonary function evaluations were not statistically significant after multiple adjusting. There were no significant differences in quality of life parameters.

Conclusions

In our study of AR, active smokers do not demonstrate impaired nasal related quality of life or impact on atopic inflammatory parameters, compared to non-smokers. Reduced levels of IL33 could explain a lack of symptoms alerting smokers of the harmful consequences of smoking.

The Effect of MMP-2 Inhibitor 1 on Osteogenesis and Angiogenesis During Bone Regeneration

Bone regeneration is a popular research focus around the world. Recent studies have suggested that the formation of a vascular network as well as intrinsic osteogenic ability is important for bone regeneration. Here, we show for the first time that matrix metalloproteinase (MMP) 2 inhibitor 1 (MMP2-I1) has a positive role in the osteogenesis of human bone marrow mesenchymal stem cells (hBMSCs) and angiogenesis of human vascular endothelial cells (HUVECs). MMP2-I1 activated the p38/mitogen-activated protein kinase signaling pathway to promote the osteogenesis of hBMSCs, and promoted the angiogenesis of HUVECs via the hypoxia-inducible factor-1α signaling pathway. We also found that MMP2-I1 enhanced bone formation using a rat tibial defect model and prevented bone loss using an ovariectomy-induced mouse model of osteoporosis. Data from the mouse model demonstrated that MMP2-I1 generated more type H vessels (CD31^hiEmcn^hi) when preventing bone loss. These results provide important insights into the regulatory effects of MMP2-I1 on bone regeneration.

MicroRNA-98 reduces nerve growth factor expression in nicotine-induced airway remodeling

Evolving evidence suggests that nicotine may contribute to impaired asthma control by stimulating expression of nerve growth factor (NGF), a neurotrophin associated with airway remodeling and airway hyperresponsiveness. We explored the hypothesis that nicotine increases NGF by reducing lung fibroblast (LF) microRNA-98 (miR-98) and PPARγ levels, thus promoting airway remodeling. Levels of NGF, miR-98, PPARγ, fibronectin 1 (FN1), endothelin-1 (EDN1, herein referred to as ET-1), and collagen (COL1A1 and COL3A1) were measured in human LFs isolated from smoking donors, in mouse primary LFs exposed to nicotine (50 μg/ml), and in whole lung homogenates from mice chronically exposed to nicotine (100 μg/ml) in the drinking water. In selected studies, these pathways were manipulated in LFs with miR-98 inhibitor (anti-miR-98), miR-98 overexpression (miR-98 mimic), or the PPARγ agonist rosiglitazone. Compared with unexposed controls, nicotine increased NGF, FN1, ET-1, COL1A1, and COL3A1 expression in human and mouse LFs and mouse lung homogenates. In contrast, nicotine reduced miR-98 levels in LFs in vitro and in lung homogenates in vivo Treatment with anti-miR-98 alone was sufficient to recapitulate increases in NGF, FN1, and ET-1, whereas treatment with a miR-98 mimic significantly suppressed luciferase expression in cells transfected with a luciferase reporter linked to the putative seed sequence in the NGF 3'UTR and also abrogated nicotine-induced increases in NGF, FN1, and ET-1 in LFs. Similarly, rosiglitazone increased miR-98 and reversed nicotine-induced increases in NGF, FN1, and ET-1. Taken together, these findings demonstrate that nicotine-induced increases in NGF and other markers of airway remodeling are negatively regulated by miR-98.

Mabs for treating asthma: omalizumab, mepolizumab, reslizumab, benralizumab, dupilumab

The introduction of biologics for the treatment of patients with refractory asthma represented a marked therapeutic advance. For more than 10 y, the only biologic available has been the monoclonal anti-IgE antibody omalizumab, reserved for patients with asthma caused by perennial allergen. In recent years, other biologics have been licensed for the treatment of severe eosinophilic asthma. They include monoclonal antibodies that target the Th2-pathway cytokines, such as IL-5 (mepolizumab and reslizumab) or its receptor (benralizumab) and the IL-4 and IL-13 receptor (dupilumab). The effectiveness of these biologics was demonstrated in several placebo controlled trials, the main outcomes being the significant reduction of the rate of asthma exacerbation and the improvement of respiratory function in actively treated patients. Based on the further understanding of the pathogenesis of asthma, new cytokines network and new targets are emerging, such as thymic stromal lymphopoietin, which can activate Th2 cells, innate lymphoid cells, or both, or prostaglandin D2 (PGD2), to develop additional biologics.

Hypersensitivity pneumonitis

Hypersensitivity pneumonitis (HP) is a complex syndrome caused by the inhalation of a variety of antigens in susceptible and sensitized individuals. These antigens are found in the environment, mostly derived from bird proteins and fungi. The prevalence and incidence of HP vary widely depending on the intensity of exposure, the geographical area and the local climate. Immunopathologically, HP is characterized by an exaggerated humoral and cellular immune response affecting the small airways and lung parenchyma. A complex interplay of genetic, host and environmental factors underlies the development and progression of HP. HP can be classified into acute, chronic non-fibrotic and chronic fibrotic forms. Acute HP results from intermittent, high-level exposure to the inducing antigen, usually within a few hours of exposure, whereas chronic HP mostly originates from long-term, low-level exposure (usually to birds or moulds in the home), is not easy to define in terms of time, and may occur within weeks, months or even years of exposure. Some patients with fibrotic HP may evolve to a progressive phenotype, even with complete exposure avoidance. Diagnosis is based on an accurate exposure history, clinical presentation, characteristic high-resolution CT findings, specific IgG antibodies to the offending antigen, bronchoalveolar lavage and pathological features. Complete antigen avoidance is the mainstay of treatment. The pharmacotherapy of chronic HP consists of immunosuppressive drugs such as corticosteroids, with antifibrotic therapy being a potential therapy for patients with progressive disease.

Identification of the collagen family as prognostic biomarkers and immune-associated targets in gastric cancer

BACKGROUND

Gastric cancer has extremely high morbidity and mortality. Currently, it is lack of effective biomarkers and therapeutic targets for guiding clinical treatment. In this study, we aimed to identify novel biomarkers and therapeutic targets for gastric cancer.

METHODS

Differentially expressed genes (DEGs) between gastric cancer and normal tissues were obtained from Gene Expression Omnibus (GEO). Core genes were identified by constructing protein-protein interaction network of DEGs. The expression of core genes was verified in Gene Expression Profiling Interactive Analysis (GEPIA), UALCAN and clinical samples. Further, the mutation, DNA methylation, prognostic value, and immune infiltration of core genes were validated by cBioPortal, MethSurv, Kaplan-Meier plotter, and Tumor Immune Estimation Resource (TIMER) databases. Additionally, drug response analysis was performed by Cancer Therapy Response Portal (CTRP).

RESULTS

A total of seven collagen family members were identified as core genes among upregulated genes. And copy number amplification may be involved in the upregulation of COL1A1 and COL1A2. Importantly, the collagen family was associated with the poor prognosis of patients with metastasis. Among them, COL1A1 had a higher hazard ratio (HR) for overall survival than other members (HR = 2.33). The correlation between DNA methylation levels at CpG sites of collagen family members and the prognosis was verified in gastric cancer. Besides, collagen family expression was positively correlated with macrophages infiltration and the expression of M2 macrophages markers. Further, collagen expression was related to the sensitivity and resistance of gastric cancer cell lines to certain drugs.

CONCLUSIONS

The collagen family, especially COL1A1, COL1A2, and COL12A1, may act as potential prognostic biomarkers and immune-associated therapeutic targets in gastric cancer.

Targeting interleukin 4 receptor α: A new approach to the treatment of cutaneous autoimmune bullous diseases?

Bullous pemphigoid, mucous membrane pemphigoid, and pemphigus vulgaris are different cutaneous autoimmune blistering diseases, with complex pathogenic mechanisms. In all of them, a type-2 response is thought to have a central role. Interleukin 4 and Interleukin 13 are crucial cytokines in type-2 response. Treatment of these conditions is often challenging. Dupilumab, a recombinant fully human IgG4 monoclonal antibody with binding specificity to human interleukin-4 receptor IL-4Rα, has the potential to inhibit both IL-4 and IL-13. We propose IL-4Rα as a theoretical drug target for cutaneous autoimmune bullous diseases.

Sevoflurane Prevents Airway Remodeling via Downregulation of VEGF and TGF-β1 in Mice with OVA-Induced Chronic Airway Inflammation

Asthma is characterized by chronic airway inflammation, which is the underlying cause of airway remodeling featured by goblet cell hyperplasia, subepithelial fibrosis, and proliferation of smooth muscle. Sevoflurane has been used to treat life-threatening asthma and our previous study shows that sevoflurane inhibits acute lung inflammation in ovalbumin (OVA)-induced allergic mice. However, the effect of sevoflurane on airway remodeling in the context of chronic airway inflammation and the underlying mechanism are still unknown. Here, female C57BL/6 mice were used to establish chronic airway inflammation model. Hematoxylin and eosin (H&E), periodic acid-Schiff (PAS), and Sirius red (SR) staining were used to evaluate airway remodeling. Protein levels of α-SMA, VEGF, and TGF-β1 in lung tissues were detected by western blotting analyses and immunohistochemistry staining. Results showed that inhalation of sevoflurane inhibited chronic airway inflammation including inflammatory cell infiltration and pro-inflammatory cytokine production in BALF of the OVA-challenged mice. Meanwhile, sevoflurane suppressed airway thickening, goblet cell hyperplasia, smooth muscle hyperplasia, collagen deposition, and fiber hyperplasia in the lung tissues of the mice with airway remodeling. Most notably, sevoflurane inhibited the OVA-induced expressions of VEGF and TGF-β1. These results suggested that sevoflurane effectively inhibits airway remodeling in mouse model of chronic airway inflammation, which may be due to the downregulation of VEGF and TGF-β1in lung tissues. Therefore, our results indicate a potential role of sevoflurane in inhibiting airway remodeling besides its known suppression effect on airway inflammation, and support the use of sevoflurane in treating severe asthma in ICU.

Maternal Obesity in Mice Exacerbates the Allergic Inflammatory Response in the Airways of Male Offspring

It was previously demonstrated that non-allergen-sensitized rodents born to mothers exposed to a high-fat diet (HFD) spontaneously develop lower respiratory compliance and higher respiratory resistance. In the present study, we sought to determine if mice born to mothers consuming HFD would exhibit changes in inflammatory response and lung remodeling when subjected to ovalbumin (OVA) sensitization/challenge in adult life. Mice born to dams consuming either HFD or standard chow had increased bronchoalveolar lavage (BAL) levels of IL-1β, IL-4, IL-5, IL-10, IL-13, TNF-α and TGF-β1 after challenge with OVA. IL-4, IL-13, TNF-α and TGF-β1 levels were further increased in the offspring of HFD-fed mothers. Mice born to obese dams also had exacerbated values of leukocyte infiltration in lung parenchyma, eosinophil and neutrophil counts in BAL, mucus overproduction and collagen deposition. The programming induced by maternal obesity was accompanied by increased expression of miR-155 in peripheral-blood mononuclear cells and reduced miR-133b in trachea and lung tissue in adult life. Altogether, the present data support the unprecedented notion that the progeny of obese mice display exacerbated responses to sensitization/challenge with OVA, leading to the intensification of the morphological changes of lung remodeling. Such changes are likely to result from long-lasting changes in miR-155 and miR-133b expression.

Immune induction of airway remodeling

Airway remodeling is accepted to be a determining component within the natural history of asthma. It is a phenomenon characterized by changes in the airways structures that marches in parallel with and can be influenced by airway inflammation, floating at the interface between both natural and adaptive immunity and physical and mechanical cells behavior. In this review we aimed to highlight the comprehensive, yet not exhaustive, evidences of how immune cells induce, regulate and adapt to the recognized markers of airway remodeling. Mucous cell hyperplasia, epithelial dysfunction and mesenchymal transition, extracellular matrix protein synthesis and restructuration, fibroblast to myofibroblast transition, airway smooth muscle proliferation, bioactive and contractile properties, and vascular remodeling encompass complex physiopathological mechanisms that can be induced, suppressed or regulated by different cellular and molecular pathways. Growth factors, cytokines, chemokines and adhesion molecules expressed or derived either from the immune network of cells infiltrating the asthmatic airways and involving T helper lymphocytes, immune lymphoid cells, dendritic cells, eosinophils, neutrophils, mast cells or by the structural components such as epithelial cells, fibroblasts, myocytes, airway smooth muscle cells concur with protein cellular matrix component and metalloproteases in modifying the airway structure in a detrimental way. The consequences in lung function decline, fixed airway obstruction and clinical severity of the disease suggest the possibility of identify among the immune molecular pathway of remodeling some biological parameters or signal pathway to be either a good tracer for monitoring the disease evolution or a target for hypothetical phenotypes and endotypes. In the era of personalized medicine, a biomarker of remodeling might predict a response to small-molecule inhibitors or biologicals potentially targeting a fundamental aspect of asthma pathogenesis that impacts on the low responsiveness to airway inflammation directed treatments.

MMP2 Polymorphism Affects Plasma Matrix Metalloproteinase (MMP)-2 Levels, and Correlates with the Decline in Lung Function in Hypersensitivity Pneumonitis Positive to Autoantibodies Patients

Among hypersensitivity pneumonitis (HP) patients have been identified who develop autoantibodies with and without clinical manifestations of autoimmune disease. Genetic factors involved in this process and the effect of these autoantibodies on the clinical phenotype are unknown. Matrix metalloproteinases (MMPs) have an important role in architecture and pulmonary remodeling. The aim of our study was to identify polymorphisms in the MMP1, MMP2, MMP9 and MMP12 genes associated with susceptibility to HP with the presence of autoantibodies (HPAbs+). Using the dominant model of genetic association, comparisons were made between three groups. For rs7125062 in MMP1 (CC vs. CT+TT), we found an association when comparing groups of patients with healthy controls: HPAbs+ vs. HC (p < 0.001, OR = 10.62, CI 95% = 4.34–25.96); HP vs. HC (p < 0.001, OR = 7.85, 95% CI 95% = 4.54–13.57). This rs11646643 in MMP2 shows a difference in the HPAbs+ group by the dominant genetic model GG vs. GA+AA, (p = 0.001, OR = 8.11, CI 95% = 1.83–35.84). In the linear regression analysis, rs11646643 was associated with a difference in basal forced vital capacity (FVC)/12 months (p = 0.013, β = 0.228, 95% CI95% = 1.97–16.72). We identified single-nucleotide polymorphisms (SNPs) associated with the risk of developing HP, and with the evolution towards the phenotype with the presence of autoantibodies. Also, to the decrease in plasma MMP-2 levels.

miR-29b Reverses T helper 1 cells/T helper 2 cells Imbalance and Alleviates Airway Eosinophils Recruitment in OVA-Induced Murine Asthma by Targeting Inducible Co-Stimulator

Asthma is a complex chronic disease and the pathogenesis is still not entirely clear. In this study, we aimed to clarify the role and mechanism of miR-29b in the development of asthma. We observed that miR-29b levels were decreased in the lung and spleen of OVA-induced asthmatic mice. Reverse transcription-quantitative polymerase chain reaction and flow cytometry demonstrated that the inducible co-stimulator (ICOS) expression at mRNA and protein levels was elevated in the lung of asthmatic mice, and miR-29b expression in the lung of asthmatic mice was negatively associated with ICOS mRNA levels by Pearson Correlation analysis. Additional, flow cytometry showed that the percentage of CD4+ICOS+ T cells in the lung and spleen was regulated by miR-29b, and dual luciferase reporter assay confirmed ICOS was a target gene of miR-29b. Furthermore, miR-29b overexpression in asthmatic mice was induced with miR-29b agomir by intranasal administration; miR-29b alleviated total inflammatory cell infiltration and CCL24 levels, decreased IL-5 levels in bronchoalveolar lavage fluid and serum, and upregulated IFN-γ expression in serum. This study demonstrates that miR-29b targets ICOS, thereby reverses the imbalance of T helper 1 cells (Th1)/Th2 responses and decreases eosinophils recruitment in the airway, which are key features of allergic airway inflammation. Therefore, miR-29b might be an attractive candidate target for asthma treatment.

Protective Role of Matrix Metalloproteinase-2 in Allergic Bronchial Asthma

Inflammation, reversible obstruction, and hyperresponsiveness of the airways are characteristic findings of bronchial asthma. Several evidence has demonstrated the involvement of matrix metalloproteinase-2 in allergic airway inflammation. Matrix metalloproteinase-2 may promote aberrant tissue remodeling in late stages of allergic airway inflammation. However, whether matrix metalloproteinase-2 is detrimental or protective in early stages of allergic airway inflammation remains unclear. To evaluate this here we compared the severity of allergic bronchial asthma between mice overexpressing human matrix metalloproteinase-2 and wild type mice. After sensitization and challenge with an allergen, mice overexpressing the human matrix metalloproteinase-2 showed a significant reduction in airway hyperresponsiveness and in the expression of Th2 cytokines and IgE compared to their wild type counterparts. An inhibitor of matrix metalloproteinases abolished this beneficial effect of human matrix metalloproteinase-2 overexpression. Allergen-sensitized and challenged human matrix metalloproteinase-2 transgenic mice had enhanced percentage of M1 macrophages with increased expression of inducible nitric oxide synthase and STAT1 activation in the lungs compared to their wild type counterparts. There was no difference in the percentage of regulatory T cells between mouse groups. The results of this study showed that matrix metalloproteinase-2 is protective in allergic bronchial asthma by promoting polarization of macrophages to M1 phenotype.

Fibroblast-to-myofibroblast transition in bronchial asthma

Bronchial asthma is a chronic inflammatory disease in which bronchial wall remodelling plays a significant role. This phenomenon is related to enhanced proliferation of airway smooth muscle cells, elevated extracellular matrix protein secretion and an increased number of myofibroblasts. Phenotypic fibroblast-to-myofibroblast transition represents one of the primary mechanisms by which myofibroblasts arise in fibrotic lung tissue. Fibroblast-to-myofibroblast transition requires a combination of several types of factors, the most important of which are divided into humoural and mechanical factors, as well as certain extracellular matrix proteins. Despite intensive research on the nature of this process, its underlying mechanisms during bronchial airway wall remodelling in asthma are not yet fully clarified. This review focuses on what is known about the nature of fibroblast-to-myofibroblast transition in asthma. We aim to consider possible mechanisms and conditions that may play an important role in fibroblast-to-myofibroblast transition but have not yet been discussed in this context. Recent studies have shown that some inherent and previously undescribed features of fibroblasts can also play a significant role in fibroblast-to-myofibroblast transition. Differences observed between asthmatic and non-asthmatic bronchial fibroblasts (e.g., response to transforming growth factor β, cell shape, elasticity, and protein expression profile) may have a crucial influence on this phenomenon. An accurate understanding and recognition of all factors affecting fibroblast-to-myofibroblast transition might provide an opportunity to discover efficient methods of counteracting this phenomenon.

The role of miR-29c/B7-H3 axis in children with allergic asthma

Background

MicroRNAs play roles in the pathogenesis of bronchial asthma. However, the mechanism of miR-29c in allergic asthma remains unclear. This study is to elucidate the regulation of Th cell differentiation by miR-29c in mononuclear macrophages.

Methods

A total of 52 children with asthma exacerbation and 26 children as controls were enrolled in the study. CD14⁺ monocytes were isolated from the peripheral blood. Differential expressions of microRNAs were evaluated using microarray analysis and miR-29c expression in monocytes was determined by qRT-PCR. The plasma B7-H3 was determined by ELISA. Transfection studies and luciferase reporter assay were performed to confirm target gene of miR-29c and its function.

Results

Compared to controls, 88 miRNAs in blood monocytes were up-regulated and 41 miRNAs down-regulated including miR-29c in asthma children. Children with asthma exacerbation had significantly lower level of miR-29c and higher level of plasma B7-H3 compared to controls (both P < 0.05). Functional studies based on luciferase reporter assay and immunofluorescence staining suggest that B7-H3 is the direct target of miR-29c and transfection anti-miR-29c into macrophages could enhance ROR-γt and GATA-3 expression in co-cultured CD4⁺ T cells and increase levels of IL-4 and IL-17 in supernatants.

Conclusion

The axis of miR-29c/B7-H3 plays an important role in children with asthma through regulating Th2/Th17 cell differentiation and may provide new targets for treatment of asthma.

Tralokinumab for severe, uncontrolled asthma (STRATOS 1 and STRATOS 2): two randomised, double-blind, placebo-controlled, phase 3 clinical trials

BACKGROUND

Tralokinumab is an anti-interleukin-13 human monoclonal antibody developed for the treatment of severe, uncontrolled asthma. These clinical trials aimed to assess the efficacy and safety of tralokinumab in this population.

METHODS

STRATOS 1 and STRATOS 2 were randomised, double-blind, parallel-group, placebo-controlled, phase 3 clinical trials that enrolled participants aged 12-75 years with severe asthma that was inadequately controlled despite use of inhaled corticosteroids (≥500 μg per day fluticasone or equivalent) and a long-acting β₂ agonist (but not oral corticosteroids). STRATOS 1 was done at 246 sites in 14 countries, and STRATOS 2 was done at 242 sites in 13 countries. In STRATOS 1, participants were randomly assigned (2:1) to receive tralokinumab 300 mg or matching placebo subcutaneously every 2 weeks or every 4 weeks for 52 weeks. In STRATOS 2, participants were randomly assigned (1:1) to receive tralokinumab 300 mg or matching placebo subcutaneously every 2 weeks for 52 weeks. STRATOS 1 attempted to identify a biomarker-positive population with enhanced tralokinumab benefit, which was then tested in STRATOS 2. The primary endpoint was the annualised asthma exacerbation rate (AAER) reduction at week 52 in the all-comers population for STRATOS 1 and in the biomarker-positive population for STRATOS 2. All efficacy analyses for both trials were done on the full analysis set by an intention-to-treat approach. The safety analysis set comprised any participant who received the investigational drug and was categorised by treatment received. These trials are registered with ClinicalTrials.gov, numbers NCT02161757 (STRATOS 1) and NCT02194699 (STRATOS 2), and with the EU Clinical Trials Register, EudraCT 2013-005614-35 (STRATOS 1) and EudraCT 2013-005615-27 (STRATOS 2).

FINDINGS

STRATOS 1 was done between June 13, 2014, and Feb 28, 2017. 1207 participants were randomly assigned and 1202 treated as follows: tralokinumab every 2 weeks (n=398), tralokinumab every 4 weeks (n=404), or placebo (n=400). STRATOS 2 was done between Oct 30, 2014, and Sept 21, 2017. 856 participants were randomly assigned and 849 treated as follows: tralokinumab every 2 weeks (n=427) and placebo every 2 weeks (n=422). In the STRATOS 1 all-comers population, tralokinumab every 2 weeks did not significantly reduce AAER compared with placebo (7·0% reduction [95% CI -20·8 to 28·4]; rate ratio 0·93 [95% CI 0·72 to 1·21]; p=0·59). Baseline fractional exhaled nitric oxide (FENO) 37 ppb or greater was identified as the preferred biomarker in STRATOS 1; in FENO-high participants, tralokinumab every 2 weeks (n=97) reduced AAER by 44·0% (95% CI 6·0 to 66·0; rate ratio 0·56 [95% CI 0·34 to 0·94]; p=0·028) compared with placebo (n=102). In the STRATOS 2 FENO-high population, tralokinumab every 2 weeks (n=108) did not significantly improve AAER (15·8% reduction [95% CI -33·7 to 47·0]; rate ratio 0·84 [95% CI 0·53 to 1·34]; p=0·47) compared with placebo (n=121). The safety profile was consistent with that of previous tralokinumab trials.

INTERPRETATION

Tralokinumab reduced AAER in participants with severe asthma with baseline FENO 37 ppb or higher in STRATOS 1, but not in STRATOS 2. These inconsistent effects on AAER do not support a key role for interleukin 13 in severe asthma exacerbations.

FUNDING

AstraZeneca.

March1 E3 Ubiquitin Ligase Modulates Features of Allergic Asthma in an Ovalbumin-Induced Mouse Model of Lung Inflammation

Membrane-associated RING-CH-1 (March1) is a member of the March family of E3 ubiquitin ligases. March1 downregulates cell surface expression of MHC II and CD86 by targeting them to lysosomal degradation. Given the key roles of MHC class II and CD86 in T cell activation and to get further insights into the development of allergic inflammation, we asked whether March1 deficiency exacerbates or attenuates features of allergic asthma in mice. Herein, we used an acute model of allergy to compare the asthmatic phenotype of March1-deficient and -sufficient mice immunized with ovalbumin (OVA) and later challenged by intranasal instillation of OVA in the lungs. We found that eosinophilic inflammation in airways and lung tissue was similar between WT and March1^-/- allergic mice, whereas neutrophilic inflammation was significant only in March1^-/- mice. Airway hyperresponsiveness as well as levels of IFN-γ, IL-13, IL-6, and IL-10 was lower in the lungs of asthmatic March1^-/- mice compared to WT, whereas lung levels of TNF-α, IL-4, and IL-5 were not significantly different. Interestingly, in the serum, levels of total and ova-specific IgE were reduced in March1-deficient mice as compared to WT mice. Taken together, our results demonstrate a role of March1 E3 ubiquitin ligase in modulating allergic responses.

TGF-β1 Signaling and Tissue Fibrosis

Activation of TGF-β1 initiates a program of temporary collagen accumulation important to wound repair in many organs. However, the outcome of temporary extracellular matrix strengthening all too frequently morphs into progressive fibrosis, contributing to morbidity and mortality worldwide. To avoid this maladaptive outcome, TGF-β1 signaling is regulated at numerous levels and intimately connected to feedback signals that limit accumulation. Here, we examine the current understanding of the core functions of TGF-β1 in promoting collagen accumulation, parallel pathways that promote physiological repair, and pathological triggers that tip the balance toward progressive fibrosis. Implicit in better understanding of these processes is the identification of therapeutic opportunities that will need to be further advanced to limit or reverse organ fibrosis.

TNFSF14 (LIGHT) Exhibits Inflammatory Activities in Lung Fibroblasts Complementary to IL-13 and TGF-β

The cytokine TNFSF14 [homologous to Lymphotoxin, exhibits Inducible expression and competes with HSV Glycoprotein D for binding to HVEM, a receptor expressed on T lymphocytes (LIGHT)] has been shown in mouse models to be important for development of lung tissue remodeling that is characteristic of asthma, idiopathic pulmonary fibrosis (IPF), and systemic sclerosis (SSc). However, its cellular targets are not fully delineated. In the present report, we show that LTβR and HVEM, the receptors for LIGHT, are constitutively expressed in primary human lung fibroblasts (HLFs). We asked whether LIGHT could promote inflammatory and remodeling-relevant activity in HLFs and how this was similar to, or distinct from, IL-13 or TGF-β, two cytokines strongly implicated in the pathogenesis of asthma, IPF, and SSc. Accumulation of myofibroblasts expressing alpha smooth muscle actin is a feature of lung inflammatory diseases. LIGHT promoted cell cycle progression and proliferation of HLFs, but not alpha smooth muscle actin expression. In contrast, TGF-β upregulated alpha smooth muscle actin but did not drive their proliferation. LIGHT also increased the gene or protein expression of a number of proinflammatory mediators, including ICAM-1 and VCAM-1, IL-6 and GM-CSF, the chemokines CCL5 and 20, and CXCL5, 11, and 12, and lung remodeling-associated proteinases MMP-9 and ADAM8. These were dependent on LTβR but not HVEM. LIGHT displayed overlapping and synergistic activities with IL-13 for a number of the activities, but LIGHT additionally enhanced the gene expression of several molecules, including the innate cytokines IL-33 and TSLP, which were not upregulated by IL-13. Our results highlight the varied and pleiotropic effects of LIGHT in HLFs. LIGHT might then be a therapeutic target for modulation of inflammation and remodeling associated with asthma and other similar diseases of the lung that involve fibroblasts.

Tralokinumab for the treatment of severe, uncontrolled asthma: the ATMOSPHERE clinical development program

Tralokinumab, a fully human IgG₄ monoclonal antibody, specifically neutralizes IL-13. The ATMOSPHERE clinical development program comprised four randomized, placebo-controlled clinical trials and an open-label study that aimed to assess the efficacy and safety of tralokinumab for the treatment of severe, uncontrolled asthma. The two pivotal trials (STRATOS 1 and STRATOS 2; NCT02161757 and NCT02194699) evaluated the efficacy and safety of tralokinumab, with STRATOS 1 identifying a subgroup most likely to demonstrate enhanced response to treatment. Further trials have assessed the ability of tralokinumab to reduce oral corticosteroid use (TROPOS; NCT02281357) and determined its mechanistic effects (MESOS; NCT02449473). An open-label study in Japanese individuals (NCT02902809) assessed the long-term safety and tolerability of tralokinumab in this population.

CD34 Differentially Regulates Contractile and Noncontractile Elements of Airway Reactivity

Airway hyperresponsiveness (AHR), a major hallmark of asthma, results from alterations of contractile and noncontractile elements of airway reactivity. CD34 is a sialomucin that is expressed on various cells involved in asthma, such as eosinophils and airway smooth muscle precursors, highlighting its potential influence in AHR. To study the role of CD34 in regulating the contractile and noncontractile elements of AHR, AHR was induced by chronic exposure to house dust mite (HDM) antigen. To assess the role of CD34 on the contractile elements of AHR, airway reactivity and airway smooth muscle contractility in response to methacholine were measured. To assess CD34's role in regulating the noncontractile elements of AHR, a chimeric mouse model was used to determine the impact of CD34 expression on inflammatory versus microenvironmental cells in AHR development. Extracellular matrix production, mucus production, and mast cell degranulation were also measured. Whereas wild-type mice developed AHR in response to HDM, a loss of airway reactivity was observed in Cd34^-/- mice 24 hours after the last exposure to HDM compared with naive controls. This was reversed when airway reactivity was measured 1 week after the last HDM exposure. Additionally, mast cell degranulation and mucus production were altered in the absence of CD34 expression. Importantly, simultaneous expression of CD34 on cells originating from the hematopoietic compartment and the microenvironment was needed for expression of this phenotype. These results provide evidence that CD34 is required for AHR and airway reactivity maintenance in the early days after an inflammatory episode in asthma.

Imbalanced Expression of Th2 and Treg Cell-related Parameters in Peripheral Blood Mononuclear Cells in Patients with Allergic Asthma

BACKGROUND

The imbalance between Th2 and Treg cells plays fundamental role in the pathogenesis of allergic asthma. The current study aimed at assessing the expression of some Th2 and Treg cell-related parameters in patients with allergic asthma.

MATERIAL AND METHODS

The serum and peripheral blood mononuclear cell (PBMC) samples were collected from 30 patients with asthma and 36 healthy subjects. The serum levels of transforming growth factor (TGF)-β, interleukin (IL)-4, as well as the expression levels of GATA3 and FOXP3 genes in PBMCs were determined by the enzyme-linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (PCR), respectively. The PBMCs were cultured for 48 hours with/without phytohemagglutinin (PHA) stimulation. The TGF-β and IL-4 levels in supernatants were also determined.

RESULTS

The serum levels of IL-4, the expression level of GATA3, and GATA3/FOXP3 ratio in patients with asthma were significantly higher than healthy subjects (P <0.002, P <0.001, and P <0.004, respectively). The FOXP3 expression did no differ between the two groups. The serum level of TGF-β as well as its secretion profile in non-stimulated and stimulated PBMCs isolated from patients with asthma were significantly higher than those of the controls (P <0.03, P <0.001, and P <0.001, respectively). The serum TGF-β levels in severe asthma were significantly higher than moderate asthma; whereas the TGF-β secretion by PHA-stimulated PBMCs isolated from moderate asthma was higher than that of severe pattern of the disease (P <0.001 and P <0.05, respectively). The GTAT3/FOXP3 expression ratio in moderate asthma was significantly higher than severe form (P <0.04).

CONCLUSION

The results confirmed a Th2 cell-biased pattern and possible contribution of TGF-β in allergic asthma. TGF-β may have different expression patterns in moderate and severe asthma and the two forms of the disease may have differences in some main immunological parameters.

ICOS protects against mortality from acute lung injury through activation of IL-5+ ILC2s

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease causing irreversible lung scarring and loss of pulmonary function. IPF Patients suffer from a high rate of pulmonary infections and acute exacerbations of disease that further contribute to pulmonary decline. Low expression of the inducible T-cell costimulatory molecule (ICOS) in peripheral blood mononuclear cells predicts decreased survival of IPF patients, but the mechanisms by which ICOS protects are unclear. Using a model of bleomycin-induced lung injury and fibrosis, we now demonstrate that ICOS expression enhances survival from lung injury rather than regulating fibrogenesis. Of ICOS-expressing cells, type 2 innate lymphocytes (ILC2s) are the first to respond to bleomycin-induced injury, and this expansion is ICOS dependent. Interestingly, a similar decrease in ICOS⁺ ILCs was found in lung tissue from IPF patients. Interleukin (IL)-5, produced primarily by ILC2s, was significantly reduced after lung injury in ICOS^-/- mice, and strikingly, treatment with IL-5 protected both ICOS^-/- and wild-type mice from mortality. These results imply that low ICOS expression and decreased lung ILC2s in IPF patients may contribute to poor recovery from infections and acute exacerbation and that IL-5 treatment may be a novel therapeutic strategy to overcome these defects and protect against lung injury.

Overexpression of miR-155-5p Inhibits the Proliferation and Migration of IL-13-Induced Human Bronchial Smooth Muscle Cells by Suppressing TGF-β-Activated Kinase 1/MAP3K7-Binding Protein 2

Purpose

Molecular mechanisms leading to asthma is still ill-defined. Though the function of microRNAs (miRNAs) in asthma was previously reported, the involvement of miR-155 in important features of this disease remains unknown. The present study was designed to uncover the probable involvement of miR-155-5p in the proliferation and migration of IL-13-induced human bronchial smooth muscle cells (BSMCs) and the intrinsic regulatory mechanism.

Methods

The effects of different concentrations of IL-13 on the proliferation and migration of BSMCs as well as the expression of miR-155-5p and its predicted target transforming growth factor (TGF)-β-activated kinase 1/MAP3K7-binding protein 2 (TAB2) were investigated. The effects of miR-155-5p on the proliferation and migration of interleukin (IL)-13-induced BSMCs was determined in vitro using BSMCs transfected with miR-155 mimic/inhibitor and induced by a high concentration of IL-13. The quantitative real-time polymerase chain reaction (qRTPCR) was employed for determining the expression of miR-155-5p and TAB2. Western blotting was applied to analyze the expression of TAB2 at the protein level. Cell proliferation and migration were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and Transwell assays, respectively.

Results

The proliferation and migration of BSMCs were dose-dependently increased with IL-13 treatment. Contrariwise, IL-13 dose-dependently inhibited the expression of miR-155-5p in BSMCs. Mechanistic studies showed that inhibition of miR-155-5p further promoted the stimulatory effects of IL-13, whereas overexpression of miR-155 significantly inhibited these effects. In silico studies and luciferase reporter assays indicated that TAB2 was a negatively regulated miR-155-5p target.

Conclusions

These results suggested that miR-155-5p-inhibit the IL-13-induced proliferation and migration of BSMCs by targeting TAB2 and that the IL-13/miR-155/TAB2 pathway could serve as a therapeutic target for pulmonary diseases, especially asthma.