Low sputum MMP-9/TIMP ratio is associated with airway narrowing in smokers with asthma

Role of IL-5 in asthma and airway remodelling

Asthma is a common and burdensome chronic inflammatory airway disease that affects both children and adults. One of the main concerns with asthma is the manifestation of irreversible tissue remodelling of the airways due to the chronic inflammatory environment that eventually disrupts the whole structure of the airways. Most people with troublesome asthma are treated with inhaled corticosteroids. However, the development of steroid resistance is a commonly encountered issue, necessitating other treatment options for these patients. Biological therapies are a promising therapeutic approach for people with steroid-resistant asthma. Interleukin 5 is recently gaining a lot of attention as a biological target relevant to the tissue remodelling process. Since IL-5-neutralizing monoclonal antibodies (mepolizumab, reslizumab and benralizumab) are currently available for clinical use, this review aims to revisit the role of IL-5 in asthma pathogenesis at large and airway remodelling in particular, in addition to exploring its role as a target for biological treatments.

Melia azedarach L. reduces pulmonary inflammation and mucus hypersecretion on a murine model of ovalbumin exposed asthma

ETHNOPHARMACOLOGICAL RELEVANCE

Melia azedarach L. is a traditional medicinal plant used to control pain, pyrexia, inflammation and bacterial infections that possesses several pharmacological activities, including anti-inflammatory and antioxidant activities. Particularly, the root of M. azedarach was used as expectorant and anti-cough and asthma treatment. Based its properties, M. azedarach is expected to have a potential to treat allergic asthma, chronic inflammatory respiratory disease. However, there is no study on anti-asthmatic effects of M. azedarach and its mechanism of action until now.

AIM OF THE STUDY

We investigated the active ingredient of M. azedarach fruit extract (MAE) using high-performance liquid chromatography (HPLC) and explored the therapeutic effects of MAE on pulmonary inflammation and mucus hypersecretion using a murine model of ovalbumin (OVA) exposed asthma.

MATERIALS AND METHODS

The ingredients of MAE were analyzed using HPLC. To develop allergic asthma model, the animals were sensitized (days 1 and 14) and the airway was challenged (from day 21-23) using OVA. MAE was administered by oral gavage once a day from day 18-23 at doses of 30 and 100 mg/kg.

RESULTS

HPLC analysis revealed the presence of toosendanin in MAE. In asthmatic mice, MAE administration effectively suppressed the inflammatory cell counts in bronchoalveolar lavage fluid (BALF) along with a reduction in airway hyperresponsiveness. Moreover, MAE administration inhibited the production of proinflammatory cytokines and immunoglobulin E in BALF and serum of asthmatic mice, respectively. These results were similar to the results of histological examination showing a reduction in pulmonary inflammation and mucus hypersecretion. MAE elevated the expression of nuclear factor erythroid 2-related factor 2, heme oxygenase-1, and superoxide dismutase 2, which in turn resulted in the suppression of matrix metallopeptidase-9 expression in lung tissue of asthmatic mice.

CONCLUSIONS

Altogether, MAE successfully inhibited allergic asthma in OVA-exposed mice. Thus, MAE could be a potential therapeutic remedy for treating allergic asthma.

Tissue Inhibitor of Metalloproteinase-1 Enhances Eosinophilic Airway Inflammation in Severe Asthma

PURPOSE

Severe asthma (SA) is characterized by persistent airway inflammation and remodeling, followed by lung function decline. The present study aimed to evaluate the role of tissue inhibitor of metalloproteinase-1 (TIMP-1) in the pathogenesis of SA.

METHODS

We enrolled 250 adult asthmatics (54 with SA and 196 with non-SA) and 140 healthy controls (HCs). Serum TIMP-1 levels were determined by enzyme-linked immunosorbent assay. The release of TIMP-1 from airway epithelial cells (AECs) in response to stimuli as well as the effects of TIMP-1 on the activations of eosinophils and macrophages were evaluated in vitro and in vivo.

RESULTS

Significantly higher levels of serum TIMP-1 were noted in asthmatics than in HCs, in the SA group than in non-SA group, and in the type 2 SA group than in non-type 2 SA group (P < 0.01 for all). A negative correlation between serum TIMP-1 and FEV₁% values (r = -0.400, P = 0.003) was noted in the SA group. In vitro study demonstrated that TIMP-1 was released from AECs in response to poly I:C, IL-13, eosinophil extracellular traps (EETs) and in coculture with eosinophils. TIMP-1-stimulated mice showed eosinophilic airway inflammation, which was not completely suppressed by steroid treatment. In vitro and in vivo functional studies showed that TIMP-1 directly activated eosinophils and macrophages, and induced the release of EETs and macrophages to polarize toward M2 subset, which was suppressed by anti-TIMP-1 antibody.

CONCLUSIONS

These findings suggest that TIMP-1 enhances eosinophilic airway inflammation and that serum TIMP-1 may be a potential biomarker and/or therapeutic target for type 2 SA.

Airway epithelial ITGB4 deficiency induces airway remodeling in a mouse model

BACKGROUND

Airway epithelial cells (AECs) with impaired barrier function contribute to airway remodeling through the activation of epithelial-mesenchymal trophic units (EMTUs). Although the decreased expression of ITGB4 in AECs is implicated in the pathogenesis of asthma, how ITGB4 deficiency impacts airway remodeling remains obscure.

OBJECTIVE

This study aims to determine the effect of epithelial ITGB4 deficiency on the barrier function of AECs, asthma susceptibility, airway remodeling, and EMTU activation.

METHODS

AEC-specific ITGB4 conditional knockout mice (ITGB4^-/-) were generated and an asthma model was employed by the sensitization and challenge of house dust mite (HDM). EMTU activation-related growth factors were examined in ITGB4-silenced primary human bronchial epithelial cells of healthy subjects after HDM stimulation. Dexamethasone, the inhibitors of JNK phosphorylation or FGF2 were administered for the identification of the molecular mechanisms of airway remodeling in HDM-exposed ITGB4^-/- mice.

RESULTS

ITGB4 deficiency in AECs enhanced asthma susceptibility and airway remodeling by disrupting airway epithelial barrier function. Aggravated airway remodeling in HDM-exposed ITGB4^-/- mice was induced through the enhanced activation of EMTU mediated by Src homology domain 2-containing protein tyrosine phosphatase 2/c-Jun N-terminal kinase/Jun N-terminal kinase-dependent transcription factor/FGF2 (SHP2/JNK/c-Jun/FGF2) signaling pathway, which was partially independent of airway inflammation. Both JNK and FGF2 inhibitors significantly inhibited the aggravated airway remodeling and EMTU activation in HDM-exposed ITGB4^-/- mice.

CONCLUSIONS

Airway epithelial ITGB4 deficiency induces airway remodeling in a mouse model of asthma through enhanced EMTU activation that is regulated by the SHP2/JNK/c-Jun/FGF2 pathway.

Determination of the effects of advanced glycation end products receptor polymorphisms and its activation on structural cell responses and inflammation in asthma

BACKGROUND

Advanced glycation end products receptor (RAGE) is a pattern recognition receptor which attracted attention in chronic airway diseases recently. This study aimed to determine the association of RAGE with asthma and the cellular responses resulting from RAGE signaling pathway activation.

METHODS

Asthmatic (n = 362) and healthy (n = 134) children were genotyped by PCR-RFLP. Plasma sRAGE levels were determined by ELISA. Lung structural cells were stimulated with AGEs (advanced glycation end products) and control BSA. Expressions of cytokines and protein levels were determined by real-time PCR and ELISA.

RESULTS

: Gly82Ser and -374 T/A polymorphisms in RAGE gene were associated with lower plasma sRAGE levels (p < 0.001 and p < 0.025, respectively). AGE stimulation increased the expression of RAGE (p = 0.002), ICAM-1 (p = 0.010) and VCAM-1 (p = 0.002) in endothelial cells; TIMP-1 (p = 0.003) and MCP-1 (p = 0.005) in fibroblasts. AGE stimulation increased protein levels of IL-6 (p < 0.001) in endothelial cells; VEGF (p = 0.025) and IL-8 (p < 0.001) in fibroblasts; IL-1b (p < 0.001) and VEGF (p = 0.007) in epithelial cells.

DISCUSSION

Activation of RAGE pathway may contribute to asthma pathogenesis by increasing the expression of several asthmarelated genes. These findings suggest that suppression of RAGE signaling may be an alternative candidate for treating asthma.

Exploration of the Pharmacological Mechanism of Bufei Nashen Pill in Treating Chronic Obstructive Pulmonary Disease Using Network Pharmacology Integrated Molecular Docking

Objective: Based on network pharmacological analysis and molecular docking verification, the therapeutic mechanism of Bufei Nashen Pill (BFNSP) in treating chronic obstructive pulmonary disease (COPD) is discussed. Methods: First, the active ingredients and therapeutic targets of BFNSP were determined based on literature and the Chinese medicine system pharmacology database. Relevant targets of COPD were determined using GeneCard, Therapeutic Target Database and Online Mendelian Inheritance in Man (OMIM). The con-targets of BFNSP and COPD were then obtained through the Veen platform, which were implemented in Cytoscape to build “Drug-Ingredients-Potential Target network.” Target gene function enrichment analysis and signal pathway analysis were performed based on STRING database, Database for Annotation, Visualization, and Integrated Discovery, and Kyoto Encyclopedia of Genes and Genomes Pathway database. Finally, SYBYL 2.2.1 software was used to finish docking. Results: In the Drug-Ingredients-Potential Targets network, 172 active ingredients and 183 potential targets were found. Enrichment analysis showed that potential targets mainly involve biological functions such as inflammation, reactive oxygen, and immunity. Molecular docking showed that the active ingredients of BFNSP had preferential interaction with interleukin 6, mitogen-activated protein kinase 1, SRC, epidermal growth factor receptor, and matrix metalloproteinase-9. Conclusion: BFNSP can be used to treat COPD by the regulation of inflammation, immunity, and hypoxia tolerance.

Epithelial cell responses to rhinovirus identify an early-life-onset asthma phenotype in adults

BACKGROUND

The study of pathogenic mechanisms in adult asthma is often marred by a lack of precise information about the natural history of the disease. Children who have persistent wheezing (PW) during the first 6 years of life and whose symptoms start before age 3 years (PW+) are much more likely to have wheezing illnesses due to rhinovirus (RV) in infancy and to have asthma into adult life than are those who do not have PW (PW-).

OBJECTIVE

Our aim was to determine whether nasal epithelial cells from PW+ asthmatic adults as compared with cells from PW- asthmatic adults show distinct biomechanistic processes activated by RV exposure.

METHODS

Air-liquid interface cultures derived from nasal epithelial cells of 36-year old participants with active asthma with and without a history of PW in childhood (10 PW+ participants and 20 PW- participants) from the Tucson Children's Respiratory Study were challenged with a human RV-A strain (RV-A16) or control, and their RNA was sequenced.

RESULTS

A total of 35 differentially expressed genes involved in extracellular remodeling and angiogenesis distinguished the PW+ group from the PW- group at baseline and after RV-A stimulation. Notably, 22 transcriptomic pathways showed PW-by-RV interactions; the pathways were invariably overactivated in PW+ patients, and were involved in Toll-like receptor- and cytokine-mediated responses, remodeling, and angiogenic processes.

CONCLUSIONS

Asthmatic adults with a history of persistent wheeze in the first 6 years of life have specific biomolecular alterations in response to RV-A that are not present in patients without such a history. Targeting these mechanisms may slow the progression of asthma in these patients.

Network-based integrated analysis for toxic effects of high-concentration formaldehyde inhalation exposure through the toxicogenomic approach

Formaldehyde is a colorless, pungent, highly reactive, and toxic environmental pollutant used in various industries and products. Inhaled formaldehyde is a human and animal carcinogen that causes genotoxicity, such as reactive oxygen species formation and DNA damage. This study aimed to identify the toxic effects of inhaled formaldehyde through an integrated toxicogenomic approach utilizing database information. Microarray datasets (GSE7002 and GSE23179) were collected from the Gene Expression Omnibus database, and differentially expressed genes were identified. The network analyses led to the construction of the respiratory system-related biological network associated with formaldehyde exposure, and six upregulated hub genes (AREG, CXCL2, HMOX1, PLAUR, PTGS2, and TIMP1) were identified. The expression levels of these genes were verified via qRT-PCR in 3D reconstructed human airway tissues exposed to aerosolized formaldehyde. Furthermore, NRARP was newly found as a potential gene associated with the respiratory and carcinogenic effects of formaldehyde by comparison with human in vivo and in vitro formaldehyde-exposure data. This study improves the understanding of the toxic mechanism of formaldehyde and suggests a more applicable analytic pipeline for predicting the toxic effects of inhaled toxicants.

Theory of the exterior-interior relationship between the lungs and the large intestine to explore the mechanism of Eriobotrya japonica leaf water extract in the treatment of cough variant asthma

ETHNOPHARMACOLOGICAL RELEVANCE

Eriobotrya japonica (Thunb.) Lindl leaf (EJL) is used as a traditional Chinese medicine. E. japonica is a member of the Rosaceae family. EJL suppresses cough and relieves asthma and is widely used to treat lung diseases. In the present study, guided by the traditional Chinese medicine theory of the exterior-interior relationship between the lungs and the large intestine, the pathogenesis of cough variant asthma (CVA) and the treatment mechanism of EJL on CVA were explored.

AIM OF THE STUDY

This study aimed to explore the airway remodeling effects of EJL in CVA from the perspective of the intestinal flora and the matrix metallopeptidase 9/tissue inhibitor of metalloproteinases-1 (MMP-9/TIMP-1) pathway.

MATERIALS AND METHODS

The oleanolic acid and ursolic acid contents in EJL were measured by high-performance liquid chromatography (HPLC) to ensure the quality of EJL. BALB/c mice were used to establish a CVA model through ovalbumin (OVA) sensitization and atomization. EJL (at 5, 10, or 20 g/kg/day) was intragastrically administered. The body weight, ratio of total bronchial wall area (WAt) to bronchial basement membrane perimeter (Pbm) (WAt/Pbm), the number of coughs, and cough latency were measured. The pathological changes of the lung tissue were analyzed by hematoxylin and eosin (HE) staining. The expression of α-smooth muscle actin (α-SMA) was measured by immunohistochemistry (IHC). The expressions of MMP-9 and TIMP-1 were detected in the lung tissue by reverse transcription quantitative polymerase chain reaction (RT-PCR) and Western blot analysis. Additionally, an Illumina Hiseq platform was used for 16S ribosomal DNA (16S rDNA) high-throughput sequencing to detect the intestinal flora in feces samples.

RESULTS

The results confirmed the positive effects of EJL on CVA. After administration of EJL, the number of coughs and the WAt/Pbm ratio decreased, the cough latency was prolonged, body weight was increased, and the general status was better than that of the CVA model mice. HE staining revealed that EJL decreased inflammatory cell infiltration and improved the histopathological structure of the lung tissue. EJL also showed significant inhibitory effects on the expression of α-SMA, MMP-9, and TIMP-1 and normalized the intestinal flora to a certain extent.

CONCLUSIONS

The results demonstrated that EJL alleviated airway remodeling of CVA mice, which might be related to the inhibition of the MMP-P/TIMP-1 pathway and the regulation of intestinal flora.

Therapeutic effect of statins on airway remodeling during asthma

INTRODUCTION

Asthma is a chronic inflammatory disease of the airways, which is usually characterized by remodeling, hyperresponsiveness and episodic obstruction of the airways. The underlying chronic airway inflammation leads to pathological restructuring of both the large and small airways. Since the effects of current asthma medications on airway remodeling have been met with contradictions, many therapeutic agents have been redirected from their primary use for the treatment of asthma. Such treatments, which could target several signaling molecules implicated in the inflammatory and airway remodeling processes of asthma, would be an ideal choice.

AREAS COVERED

Statins are effective serum cholesterol-lowering agents that were found to have potential anti-inflammatory and anti-remodeling properties. Literature search was done for the past 10 years to include research and review articles in the field of statins and asthma complications. In this review, we discuss the role of statins in airway tissue remodeling and their potential therapeutic modalities in asthma.

EXPERT OPINION

With improved understanding of the role of statins in airway remodeling and inflammation, statins represent a potential therapeutic option for various asthma phenotypes. Further research is warranted to optimize statins for asthma therapy through inhalation as a possible route of administration.

The systemic inflammatory landscape of COVID-19 in pregnancy: Extensive serum proteomic profiling of mother-infant dyads with in utero SARS-CoV-2

While pregnancy increases the risk for severe COVID-19, the clinical and immunological implications of COVID-19 on maternal-fetal health remain unknown. Here, we present the clinical and immunological landscapes of 93 COVID-19 mothers and 45 of their SARS-CoV-2-exposed infants through comprehensive serum proteomics profiling for >1,400 cytokines of their peripheral and cord blood specimens. Prenatal SARS-CoV-2 infection triggers NF-κB-dependent proinflammatory immune activation. Pregnant women with severe COVID-19 show increased inflammation and unique IFN-λ antiviral signaling, with elevated levels of IFNL1 and IFNLR1. Furthermore, SARS-CoV-2 infection re-shapes maternal immunity at delivery, altering the expression of pregnancy complication-associated cytokines, inducing MMP7, MDK, and ESM1 and reducing BGN and CD209. Finally, COVID-19-exposed infants exhibit induction of T cell-associated cytokines (IL33, NFATC3, and CCL21), while some undergo IL-1β/IL-18/CASP1 axis-driven neonatal respiratory distress despite birth at term. Our findings demonstrate COVID-19-induced immune rewiring in both mothers and neonates, warranting long-term clinical follow-up to mitigate potential health risks.

A dynamic nomogram for predicting the risk of asthma: Development and validation in a database study

Background

Asthma remains a serious health problem with increasing prevalence and incidence. This study was to develop and validate a dynamic nomogram for predicting asthma risk.

Methods

Totally 597 subjects whose age ≥18 years old with asthma, an accurate age at first cigarette, and clear smoking status were selected from the National Health and Nutrition Examination Survey (NHANES) database (2013–2018). The dataset was randomly split into the training set and the testing set at a ratio of 4:6. Simple and multiple logistic regressions were used for identifying independent predictors. Then the nomogram was developed and internally validated using data from the testing set. The receiver operator characteristic (ROC) curve was used for assessing the performance of the nomogram.

Results

According to the simple and multiple logistic regressions, smoking ≥40 years, female gender, the age for the first smoking, having close relative with asthma were independently associated with the risk of an asthma attack. The nomogram was thereby developed with the link of https://yanglifen.shinyapps.io/Dynamic_Nomogram_for_Asthma/. The ROC analyses showed an AUC of 0.726 (0.724–0.728) with a sensitivity of 0.887 (0.847–0.928) in the training set, and an AUC of 0.702 (0.700–0.703) with a sensitivity of 0.860 (0.804–0.916) in the testing set, fitting well in calibration curves. Decision curve analysis further confirmed the clinical usefulness of the nomogram.

Conclusion

Our dynamic nomogram could help clinicians to assess the individual probability of asthma attack, which was helpful for improving the treatment and prognosis of asthma.

Airway Remodeling Factors During Early-Life Rhinovirus Infection and the Effect of Premature Birth

Background: Early rhinovirus (RV) infection is a strong risk factor for asthma development. Airway remodeling factors play a key role in the progression of the asthmatic condition. We hypothesized that RV infection in young children elicits the secretion of growth factors implicated in airway remodeling and asthma progression. Methods: We examined the nasal airway production of remodeling factors in children ( ≤ 2 years old) hospitalized due to PCR-confirmed RV infection. Airway remodeling proteins included: MMP-1, MMP-2, MMP-7, MMP-9, MMP-10, TIMP-1, TIMP-2, EGF, Angiopoietin-2, G-CSF, BMP-9, Endoglin, Endothelin-1, Leptin, FGF-1, Follistatin, HGF, HB-EGF, PLGF, VEGF-A, VEGF-C, VEGF-D, FGF-2, TGF-β1, TGF-β2, TGF-β3, PDGF AA, PDGF BB, SPARC, Periostin, OPN, and TGF-α. Results: A total of 43 young children comprising RV cases (n = 26) and uninfected controls (n = 17) were included. Early RV infection was linked to (1) enhanced production of several remodeling factors (e.g., HGF, TGFα), (2) lower MMP-9/TIMP-2 and MMP-2/TIMP-2 ratios, and (3) increased MMP-10/TIMP-1 ratios. We also found that relative to term infants, severely premature children had reduced MMP-9/TIMP-2 ratios at baseline. Conclusion: RV infection in young children elicits the airway secretion of growth factors implicated in angiogenesis, fibrosis, and extracellular matrix deposition. Our results highlight the potential of investigating virus-induced airway remodeling growth factors during early infancy to monitor and potentially prevent chronic progression of respiratory disorders in all ages.

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.

An association between MMP-9 and impaired T cell migration in ethanol-fed BALB/c mice infected with respiratory syncytial virus-2A

Matrix metalloproteinases are important for proper airway matrix structure and wound healing. These enzymes are also implicated in many airway diseases. Previously, chronic ethanol consumption was shown to prolong inflammation and delay viral clearance in respiratory syncytial virus (RSV)-infected mice. We hypothesize that alcohol alters anti-viral immunity by disrupting immune cell chemotaxis in the lung. BALB/c mice were randomly selected to consume 18% alcohol ad libitum for 8 weeks prior to infection with RSV-2A. Bronchoalveolar lavage (BAL) cell populations were measured by flow cytometry, and chemokines were detected by Western blot or ELISA. MMP-9 levels were determined by polymerase chain reaction (PCR) in mouse lungs and in BAL fluid by ELISA. T cells were acquired from the spleens of water-fed, non-infected control mice (CTRL); alcohol-fed, non-infected (ETOH); water-fed, RSV-infected (RSV); or ethanol-fed, RSV-infected (ETOH-RSV) 4 days after RSV infection. T cells were placed in a transmigration system where chemokines had been treated with and without activated MMP-9. Lymphocyte recruitment was significantly reduced in the BAL 4 days after RSV infection in ETOH-RSV mice, whereas chemokine levels were the highest in this group at all experimental time points examined in comparison to RSV (p < 0.05). MMP-9 mRNA and protein were detected at high levels in ETOH-RSV mice compared to RSV. Using ex vivo transmigration to CCL2 and CXCL10, T cell migration was not impaired between any of the treatment groups, yet when CCL2 and CXCL10 were treated with activated MMP-9, significantly fewer T cells migrated across collagen-coated 5-μm membranes (p < 0.05). Immune cell recruitment is necessary for viral clearance. We show that immune cells are decreased in the lungs of ETOH-RSV mice. In contrast to decreased cell recruitment, key inflammatory chemokines were elevated in the lungs of ETOH-RSV mice. These proteins may be prematurely degraded by MMP-9 in the lung, leading to defective immunity and reduced viral clearance.

Expressions of TOLL-like receptor 4 (TLR-4) and matrix metalloproteinase 9 (MMP-9)/Tissue inhibitor of metalloproteinase 1 (TIMP-1) in pulmonary blood vessels with chronic obstructive pulmonary diseases and their relationships with pulmonary vascular remodelling

OBJECTIVE

This study aims at investigating the expressions of TOLL-like receptor 4 (TLR-4) and matrix metalloproteinase 9 (MMP-9)/ tissue inhibitor of metalloproteinase 1 (TIMP-1) in pulmonary blood vessels with chronic obstructive pulmonary disease (COPD) and their relationships with pulmonary vascular remodelling (PVR).

METHODS

60 para-tumour tissues were divided into the COPD group and the control group (n=30); the inflammations, pulmonary artery wall area/total artery area (WA%), and wall thickness/vascular outer diameter (WT%) were compared. The expressions of TLR-4, MMP-9/TIMP-1, and PCNA in pulmonary vascular smooth muscle cells were detected, and their relationships with PVR were then analysed.

RESULTS

The inflammations (1.6±0.8), WA% (44.0±6.4), and WT% (27.3±3.3) in the COPD group were higher than in the control group (0.3±0.5, 26.1±2.8, 15.6±1.8), and the expressions of TLR-4 (31.4±147) and MMP-9/TIMP-1 (2.2±2.6) were increased compared to the control group (4.7±4.5, 1.9±12). Correlation analysis: TLR-4 and MMP-9/TIMP-1 were positively correlated with the inflammations (r=0.18, P<0.01), WA% (r=0.68, P<0.01), and WT% (r=0.73, P<0.01), as well as positively correlated with the expression of PCNA (r=0.44, P<0.01); the upregulation of TLR-4 was positively correlated with the expressions of MMP-9 and TIMP-1.

CONCLUSIONS

The upregulation of TLR-4 in the pulmonary arterial smooth muscle cells of COPD patients could promote the inflammations and the MMP-9 expression, thus causing abnormal degradation of extracellular matrix, so it played an important role in the process of PVR.

Low-molecular-mass hyaluronan induces pulmonary inflammation by up-regulation of Mcl-1 to inhibit neutrophil apoptosis via PI3K/Akt1 pathway

Although low-molecular-mass hyaluronan (LMMHA) has been implicated in pulmonary inflammatory diseases, the signalling pathway of LMMHA (200 000 molecular weight) that initiates the inflammatory response in lung is still unknown. In this study, we evaluate the role of phosphoinositide 3-kinase (PI3K) and its downstream signalling pathway in LMMHA-induced lung inflammatory responses. Our results indicate that pharmacological inhibition of PI3K or genetic deletion of Akt1 enhances neutrophil apoptosis, attenuates neutrophil influx into the lungs of mice and diminishes the expression of pro-inflammatory factors such as interleukin-6, keratinocyte cell-derived chemokine and pro-matrix metalloproteinase-9 in bronchoalveolar lavage fluid after intratracheal administration of LMMHA. More importantly, we found that PI3K/Akt1 participates in LMMHA-induced inflammatory responses, which are mainly mediated by the myeloid leukaemia cell differentiation protein (Mcl-1). Our study suggests that LMMHA induced significantly increased levels of inflammatory factors in bronchoalveolar lavage fluid and activation of the PI3K/Akt1 pathway, which up-regulates the expression of the anti-apoptotic protein Mcl-1 and inhibits the activation of caspase-3, thereby suppressing neutrophil apoptosis to trigger lung inflammation. These findings reveal a novel molecular mechanism underlying sterile inflammation and provides a new potential target for the treatment of pulmonary disease.

Active and passive smoking impacts on asthma with quantitative and temporal relations: A Korean Community Health Survey

This study aimed to evaluate the relations of smoking with asthma and asthma-related symptoms, considering quantitative and temporal influences. The 820,710 Korean adults in the Korean Community Health Survey in 2009, 2010, 2011, and 2013 were included and classified as non-smoker, past smoker or current smoker. Total smoking years, total pack-years, and age at smoking onset were assessed. Information on wheezing, exercise wheezing, and aggravation of asthma in the past 12 months and asthma diagnosis history and current treatment was collected. Multiple logistic regression analysis with complex sampling was used. Current and former smokers showed significant positive relations with wheezing, exercise wheezing, asthma ever, current asthma, and asthma aggravation. Current smokers demonstrated higher adjusted odd ratios (AORs) for wheezing, exercise wheezing, and asthma aggravation than former smokers. Former smokers showed higher AORs than current smokers for current asthma treatment. Longer passive smoking was related to wheezing and exercise wheezing. Greater age at smoking onset and duration since cessation were negatively related to wheezing, exercise wheezing, and current asthma; total pack-years demonstrated proportional associations with these symptoms. Former, current, and passive smoking was positively correlated with wheezing and exercise wheezing. Total pack-years and early initiation were increasingly related to asthma.

Impaired response of the bronchial epithelium to inflammation characterizes severe equine asthma

BACKGROUND

Severe equine asthma is a naturally occurring lung inflammatory disease of mature animals characterized by neutrophilic inflammation, bronchoconstriction, mucus hypersecretion and airway remodeling. Exacerbations are triggered by inhalation of dust and microbial components. Affected animals eventually are unable of aerobic performance. In this study transcriptomic differences between asthmatic and non-asthmatic animals in the response of the bronchial epithelium to an inhaled challenge were determined.

RESULTS

Paired endobronchial biopsies were obtained pre- and post-challenge from asthmatic and non-asthmatic animals. The transcriptome, determined by RNA-seq and analyzed with edgeR, contained 111 genes differentially expressed (DE) after challenge between horses with and without asthma, and 81 of these were upregulated. Genes involved in neutrophil migration and activation were in central location in interaction networks, and related gene ontology terms were significantly overrepresented. Relative abundance of specific gene products as determined by immunohistochemistry was correlated with differential gene expression. Gene sets involved in neutrophil chemotaxis, immune and inflammatory response, secretion, blood coagulation and apoptosis were overrepresented among up-regulated genes, while the rhythmic process gene set was overrepresented among down-regulated genes. MMP1, IL8, TLR4 and MMP9 appeared to be the most important proteins in connecting the STRING protein network of DE genes.

CONCLUSIONS

Several differentially expressed genes and networks in horses with asthma also contribute to human asthma, highlighting similarities between severe human adult and equine asthma. Neutrophil activation by the bronchial epithelium is suggested as the trigger of the inflammatory cascade in equine asthma, followed by epithelial injury and impaired repair and differentiation. Circadian rhythm dysregulation and the sonic Hedgehog pathway were identified as potential novel contributory factors in equine asthma.

Plasma MMP2/TIMP4 Ratio at Follow-up Assessment Predicts Disease Progression of Idiopathic Pulmonary Arterial Hypertension

PURPOSE

Matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) are of particular interest in the remodeling processes of pulmonary hypertension. The aim of this study was to investigate MMP/TIMP ratios of selected biomarkers (MMP2, MMP9, TIMP1, TIMP4) at follow-up examination (V2) and their prognostic value in patients with idiopathic pulmonary arterial hypertension (iPAH).

METHODS

Blood samples were taken from iPAH patients during right heart catheterization at diagnosis (V1, from 2003 to 2012) and first follow-up examination (V2). MMP2, MMP9, TIMP1, and TIMP4 plasma levels at V2 were determined by ELISA. Coincident with sample collection hemodynamic, laboratory, and clinical parameters were acquired. Additionally, death and clinical worsening (CW) events were listed until July 2015.

RESULTS

MMP2/TIMP1 and MMP9/TIMP1 did not correlate with hemodynamic and clinical parameters. MMP2/TIMP4 showed a good correlation with mean pulmonary arterial pressure (mPAP), pulmonary vascular resistance, estimated glomerular filtration rate (eGFR), and tricuspid annular plain systolic excursion (TAPSE). MMP9/TIMP4 shows good correlation with mPAP and eGFR. MMP2/TIMP4 showed significant results in the receiver operating characteristics analysis predicting death (AUC = 0.922; p = 0.005) and CW event (AUC = 0.818; p = 0.026). Patients above the cut-off values had a significantly higher probability to die or experience CW, respectively, estimated by log-rank test (p = 0.010 for death; p = 0.032 for CW).

CONCLUSIONS

MMP2/TIMP4 ratio was detected as a marker of disease severity and right ventricular function as well as a predictor for survival and time to clinical worsening and therefore might help for guidance of disease progression in iPAH patients at V2.

Brain-derived neurotrophic factor and airway fibrosis in asthma

Airway remodeling in asthma driven by inflammation involves proliferation of epithelial cells and airway smooth muscle (ASM), as well as enhanced extracellular matrix (ECM) generation and deposition, i.e., fibrosis. Accordingly, understanding profibrotic mechanisms is important for developing novel therapeutic strategies in asthma. Recent studies, including our own, have suggested a role for locally produced growth factors such as brain-derived neurotrophic factor (BDNF) in mediating and modulating inflammation effects. In this study, we explored the profibrotic influence of BDNF in the context of asthma by examining expression, activity, and deposition of ECM proteins in primary ASM cells isolated from asthmatic vs. nonasthmatic patients. Basal BDNF expression and secretion, and levels of the high-affinity BDNF receptor TrkB, were higher in asthmatic ASM. Exogenous BDNF significantly increased ECM production and deposition, especially of collagen-1 and collagen-3 (less so fibronectin) and the activity of matrix metalloproteinases (MMP-2, MMP-9). Exposure to the proinflammatory cytokine TNFα significantly increased BDNF secretion, particularly in asthmatic ASM, whereas no significant changes were observed with IL-13. Chelation of BDNF using TrkB-Fc reversed TNFα-induced increase in ECM deposition. Conditioned media from asthmatic ASM enhanced ECM generation in nonasthmatic ASM, which was blunted by BDNF chelation. Inflammation-induced changes in MMP-2, MMP-9, and tissue inhibitor metalloproteinases (TIMP-1, TIMP-2) were reversed in the presence of TrkB-Fc. These novel data suggest ASM as an inflammation-sensitive source of BDNF within human airways, with autocrine effects on fibrosis relevant to asthma.

Thymic stromal lymphopoietin and apocynin alter the expression of airway remodeling factors in human rhinovirus-infected cells

Airway remodeling is a characteristic of bronchial asthma. The process involves the expression of many genes, such as transforming growth factor-beta (TGF-β), tissue inhibitors of metalloproteinases (TIMP-1), MMP and arginase. Human rhinovirus (HRV) is known to cause asthma exacerbations, and viral infections might be involved in the development of airway remodeling. Therefore, the aim of this study was to determine the influence of HRV on the genes involved in airway remodeling and to examine the impact of thymic stromal lymphopoietin (TSLP) and contribution of oxidative stress on airway remodeling in the context of HRV infection. Peripheral blood mononuclear cells, isolated from blood collected from 10 healthy volunteers, and human lung fibroblasts were infected with HRV-16. The cells were treated with apocynin or TSLP 48h after infection. The expression of TGF-β1, TIMP-1 and arginase I mRNA and protein were determined by real-time PCR, immunoblotting and ELISA, respectively. Rhinovirus infection significantly increased the expression of TGF-β1 and arginase I, on the mRNA and protein levels. This effect was inhibited by apocynin, though only on the mRNA level. TIMP-1 expression was not influenced by HRV; however, apocynin caused a significant increase of TIMP-1 mRNA expression. TSLP increased the expression of TGF-β1 and arginase I mRNA in fibroblasts, but not in PBMC.

Mechanosensitive transient receptor potential vanilloid 4 regulates Dermatophagoides farinae-induced airway remodeling via 2 distinct pathways modulating matrix synthesis and degradation

Contributions of mechanical signals to airway remodeling during asthma are poorly understood. Transient receptor potential vanilloid 4 (TRPV4), a mechanosensitive ion channel, has been implicated in cardiac and pulmonary fibrosis; however, its role in asthma remains elusive. Employing a Dermatophagoides farinae-induced asthma model, we report here that TRPV4-knockout mice were protected from D. farinae-induced airway remodeling. Furthermore, lung fibroblasts that were isolated from TRPV4-knockout mice showed diminished differentiation potential compared with wild-type mice. Fibroblasts from asthmatic lung exhibited increased TRPV4 activity and enhanced differentiation potential compared with normal human lung fibroblasts. Of interest, TGF-β1 treatment enhanced TRPV4 activation in a PI3K-dependent manner in normal human lung fibroblasts in vitro Mechanistically, TRPV4 modulated matrix remodeling in the lung via 2 distinct but dependent pathways: one enhances matrix deposition by fibrotic gene activation, whereas the other slows down matrix degradation by increased plasminogen activator inhibitor 1. Of importance, both pathways are regulated by Rho/myocardin-related transcription factor-A and contribute to fibroblast differentiation and matrix remodeling in the lung. Thus, our results support a unique role for TRPV4 in D. farinae-induced airway remodeling and warrant further studies in humans for it to be used as a novel therapeutic target in the treatment of asthma.-Gombedza, F., Kondeti, V., Al-Azzam, N., Koppes, S., Duah, E., Patil, P., Hexter, M., Phillips, D., Thodeti, C. K., Paruchuri, S. Mechanosensitive transient receptor potential vanilloid 4 regulates Dermatophagoides farinae-induced airway remodeling via 2 distinct pathways modulating matrix synthesis and degradation.

Theophylline action on primary human bronchial epithelial cells under proinflammatory stimuli and steroidal drugs: a therapeutic rationale approach

Theophylline is a natural compound present in tea. Because of its property to relax smooth muscle it is used in pharmacology for the treatment of airway diseases (ie, chronic obstructive pulmonary disease, asthma). However, this effect on smooth muscle is dose dependent and it is related to the development of side effects. Recently, an increasing body of evidence suggests that theophylline, at low concentrations, also has anti-inflammatory effects related to the activation of histone deacetylases. In this study, we evaluated the effects of theophylline alone and in combination with corticosteroids on human bronchial epithelial cells under inflammatory stimuli. Theophylline administrated alone was not able to reduce growth-stimulating signaling via extracellular signal-regulated kinases activation and matrix metalloproteases release, whereas it strongly counteracts this biochemical behavior when administered in the presence of corticosteroids. These data provide scientific evidence for supporting the rationale for the pharmacological use of theophylline and corticosteroid combined drug.

Expression of MMP and TIMP mRNA in Peripheral Blood Leukocytes of Patients with Invasive Ductal Carcinoma of the Breast

Purpose

An imbalance between matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) appears critical for tumor progression and metastasis. This study aimed to determine whether gene expression of MMP1, MMP2, MMP9, TIMP1 and TIMP3 and the MMP/TIMP expression ratio in peripheral blood leukocytes (PBLs) and the MMP1 and TIMP1 contents or MMP1/TIMP1 ratio in plasma were associated with clinicopathological characteristics in invasive ductal carcinoma (IDC) of the breast.

Materials and methods

Blood samples were collected from women newly diagnosed with IDC who had not received prior treatment (n = 102). Gene expression in PBLs was analyzed by quantitative real-time polymerase chain reaction. Concentrations of MMP1 and TIMP1 in plasma were measured using ELISA.

Results

In univariate analysis the expression levels of MMP2 and TIMP1 mRNA were significantly higher in premenopausal compared to postmenopausal patients (p<0.001 and p = 0.014, respectively). MMP2 mRNA expression negatively correlated with age (p<0.001, r = -0.43). We found that the MMP2/TIMP3 expression ratio was significantly higher in women after menopause (p = 0.007). The MMP2/TIMP1 expression ratio was higher in human epidermal growth factor receptor 2 (HER2)-positive patients (p = 0.022). Low-grade tumors had significantly lower MMP1/TIMP1 and MMP2/TIMP1 expression ratios (p = 0.047 and p = 0.048, respectively). TIMP1 plasma concentration was significantly higher in small tumors compared with T2-T3 tumors (p = 0.013).

Conclusions

These findings reveal an important association between tumor characteristics and expression ratios of MMP1/TIMP1 and MMP2/TIMP1 in PBLs and TIMP1 concentration in plasma. Menopausal status may influence the mRNA expression levels of MMP2 and TIMP1 as well as the MMP2/TIMP3 expression ratio in IDC of the breast.

[Airway inflammation induced by Poly(I:C) stimulation in the late stage of respiratory syncytial virus infection in mice and its mechanism]

OBJECTIVE

To investigate the pathogenic mechanisms of airway inflammation and recurrent wheezing induced by recurrent respiratory virus infection after respiratory syncytial virus (RSV) infection.

METHODS

Sixty-four female BALB/c mice (aged 6-8 weeks) were randomly divided into four groups: control, RSV, Poly(I:C), and RSV+Poly(I:C) (n=16 each). The bronchoalveolar lavage fluid (BALF) was collected on the 3rd day after Poly(I:C) administration, and the total cell number and differential counts in BALF were determined. Hematoxylin-eosin staining was used to observe pulmonary pathological changes. The airway responsiveness was detected. ELISA was used to measure the levels of interferon-γ (IFN-γ), interleukin-4 (IL-4), interleukin-13 (IL-13), matrix metallopeptidase-9 (MMP-9), and tissue inhibitor of metalloproteinase-1 (TIMP-1) in BALF.

RESULTS

Compared with the other three groups, the RSV+Poly(I:C) group had significant increases in the total number of inflammatory infiltrating cells in the airway, airway responsiveness, and MMP-9 level in BALF (P<0.05). The RSV+Poly(I:C) group showed more severe pulmonary tissue injuries compared with the control and RSV groups (P<0.01). Compared with the RSV group, the RSV+Poly(I:C) group showed significant reductions in the levels of IL-4 and TIMP-1 in BALF (P<0.01).

CONCLUSIONS

Viral re-infection in the late stage of RSV infection may cause an imbalance of MMP-9/TIMP-1 expression and thus contribute to aggravated airway inflammation.

Novel concepts in airway inflammation and remodelling in asthma

The hallmark pathological features of asthma include airway eosinophilic inflammation and structural changes (remodelling) which are associated with an irreversible loss in lung function that tracks from childhood to adulthood. In parallel with changes in function, pathological abnormalities occur early, during the pre-school years, are established by school age and subsequently remain (even though symptoms may remit for periods during adulthood). Given the equal importance of inflammation and remodelling in asthma pathogenesis, there is a significant disparity in studies undertaken to investigate the contribution of each. The majority focus on the role of inflammation, and although novel therapeutics such as those targeted against T-helper cell type 2 (Th2) mediators have arisen, it is apparent that targeting inflammation alone has not allowed disease modification. Therefore, unless airway remodelling is addressed for future therapeutic strategies, it is unlikely that we will progress towards a cure for asthma. Having acknowledged these limitations, the focus of this review is to highlight the gaps in our current knowledge about the mechanisms underlying airway remodelling, the relationships between remodelling, inflammation and function, remodelling and clinical phenotypes, and the importance of utilising innovative and realistic pre-clinical models to uncover effective, disease-modifying therapeutic strategies.

Effect of diosmetin on airway remodeling in a murine model of chronic asthma

Bronchial asthma, one of the most common allergic diseases, is characterized by airway hyperresponsiveness (AHR), inflammation, and remodeling. The anti-oxidant flavone aglycone diosmetin ameliorates the inflammation in pancreatitis, but little is known about its impact on asthma. In this study, the effects of diosmetin on chronic asthma were investigated with an emphasis on the modulation of airway remodeling in BALB/c mice challenged with ovalbumin (OVA). It was found that diosmetin significantly relieved inflammatory cell infiltration, goblet cell hyperplasia, and collagen deposition in the lungs of asthmatic mice and notably reduced AHR in these animals. The OVA-induced increases in total cell and eosinophil counts in bronchoalveolar lavage fluid were reversed, and the level of OVA-specific immunoglobulin E in serum was attenuated by diosmetin administration, implying an anti-Th2 activity of diosmetin. Furthermore, diosmetin remarkably suppressed the expression of smooth muscle actin alpha chain, indicating a potent anti-proliferative effect of diosmetin on airway smooth muscle cells (ASMCs). Matrix metallopeptidase-9, transforming growth factor-β1, and vascular endothelial growth factor levels were also alleviated by diosmetin, suggesting that the remission of airway remodeling might be attributed to the decline of these proteins. Taken together, our findings provided a novel profile of diosmetin with anti-remodeling therapeutic benefits, highlighting a new potential of diosmetin in remitting the ASMC proliferation in chronic asthma.

Atorvastatin in combination with inhaled beclometasone modulates inflammatory sputum mediators in smokers with asthma

BACKGROUND

Statins have pleiotropic immunomodulatory effects that may be beneficial in the treatment of asthma. We previously reported that treatment with atorvastatin improved asthma symptoms in smokers with asthma in the absence of a change in the concentration of a selection of sputum inflammatory mediators.

OBJECTIVE

To determine the effects of atorvastatin alone and in combination with inhaled corticosteroid on a range of sputum cytokines, chemokines and growth factors implicated in the pathogenesis of asthma, and their association with asthma control questionnaire (ACQ) and/or asthma quality of life questionnaire (AQLQ) scores.

METHODS

Sputum samples were analysed from a sub-group of 39 smokers with mild to moderate asthma recruited to a randomised controlled trial comparing atorvastatin (40 mg/day) versus placebo for four weeks, followed by inhaled beclometasone (400 μg/day) for a further four weeks. Induced sputum supernatant fluid was analysed (Luminex or biochemical analyses) for concentrations of 35 mediators.

RESULTS

Sputum mediator concentrations were not reduced by inhaled beclometasone alone. Atorvastatin significantly reduced sputum concentrations of CCL7, IL-12p70, sCD40L, FGF-2, CCL4, TGF-α and MMP-8 compared with placebo and, when combined with inhaled beclometasone, reduced sputum concentrations of MMP-8, IL-1β, IL-10, MMP-9, sCD40L, FGF-2, IL-7, G-CSF and CCL7 compared to ICS alone. Improvements in ACQ and/or AQLQ scores with atorvastatin and ICS were associated with decreases in G-CSF, IL-7, CCL2 and CXCL8.

CONCLUSION

Short-term treatment with atorvastatin alone or in combination with inhaled beclometasone reduces several sputum cytokines, chemokines and growth factors concentrations unresponsive to inhaled corticosteroids alone, in smokers with asthma.