Asthma

Exercise Reduces Airway Smooth Muscle Contraction in Asthmatic Rats via Inhibition of IL-4 Secretion and Store-Operated Ca2+ Entry Pathway

PURPOSE

Increased evidence has shown that aerobic exercise reduces airway hyperresponsiveness in asthmatic individuals. However, the underlying mechanisms of action remain elusive. This study aimed to investigate the effect of exercise on airway smooth muscle (ASM) contractile function in asthmatic rats, and uncover the possible involvement of interleukin 4 (IL-4) and the store-operated Ca²⁺ entry (SOCE) pathway.

METHODS

In this study, chicken ovalbumin was used to induce asthma in male Sprague-Dawley rats. The exercise group received moderate-intensity aerobic exercise training for 4 weeks. IL-4 concentrations in bronchoalveolar lavage fluid (BALF) samples were evaluated by enzyme linked immunosorbent assay. The contractile function of the ASM was investigated using tracheal ring tension experiments and intracellular Ca²⁺ imaging techniques. Western blot analysis was used to evaluate expression levels of calcium-release activated calcium (CRAC) channel protein (Orai) and stromal interaction molecule 1 (STIM1) in ASM.

RESULTS

Our data showed that the carbachol-stimulated, SOCE-mediated contraction of rat ASM was significantly increased in asthmatic rats, which could be abolished by exercise. Pharmacological studies revealed that GSK5498A and BTP-2, selective blockers of CRAC channels significantly inhibited SOCE-induced ASM contraction. In addition, exercise inhibited the up-regulation of IL-4 in BALF as well as STIM1 and Orai expression in the ASM of asthmatic rats. In line with these observations, we demonstrated that pretreatment of the ASM with IL-4 up-regulated the expression level of STIM1, Orai1 and Orai2, thereby promoting SOCE-mediated ASM contraction.

CONCLUSIONS

The data in this study reveal that aerobic exercise may improve the ASM contractile function in asthmatic rats by inhibiting IL-4 secretion and by down-regulating the expression of STIM1, Orai1 and Orai2, thus decreasing excessive SOCE-mediated ASM contraction in asthmatic rats.

Berberine and its derivatives represent as the promising therapeutic agents for inflammatory disorders

Berberine, with the skeleton of quaternary ammonium, has been considered as the well-defined natural product in treating multiple diseases, including inflammation, acute and chronic infection, autoimmune diseases, and diabetes. However, due to the low bioavailability and systemic exposure, broad clinical applications of berberine have been largely impeded. Numerous studies have been conducted to further explore the therapeutic capacities of berberine in preclinical and clinical trials. Over the past, berberine and its derivatives have been shown to possess numerous pharmacological activities, as evidenced in intestinal, pulmonary, skin, and bone inflammatory disorders. In the present review, the pharmacological impact of berberine on inflammatory diseases are fully discussed, with indication that berberine and its potential derivatives represent promising natural therapeutic agents with anti-inflammatory properties.

Schisandrin B Attenuates Airway Inflammation and Airway Remodeling in Asthma by Inhibiting NLRP3 Inflammasome Activation and Reducing Pyroptosis

Asthma is a chronic inflammatory disorder of the airways. Schisandrin B (SB) is the main effective component. This study investigated the effects of SB on airway inflammation and airway remodeling in asthma. The rat model of asthma was established. The rats were treated with SB to evaluate the effects of SB on airway inflammation, airway remodeling, NLRP3 inflammasome activation, and pyroptosis. Alveolar macrophages of rats were isolated, and the macrophage inflammatory model was established by lipopolysaccharide (LPS) induction. The LPS-induced macrophages were treated with SB. The binding relationship between miR-135a-5p and TPRC1 was analyzed. LPS + SB-treated macrophages were transfected with miR-135a-5p inhibitor. The expressions of key factors of the STAT3/NF-κB pathway were detected. SB reduced airway inflammation and airway remodeling in asthmatic rats. SB inhibited NLRP3 inflammasome activation and reduced pyroptosis in asthmatic rats and LPS-induced macrophages. SB reversely regulated the miR-135a-5p/TRPC1 axis. Downregulation of miR-135a-5p attenuated the inhibitory effect of SB on NLRP3 inflammasome activation. SB inhibited the STAT3/NF-κB pathway via the miR-135a-5p/TRPC1 axis. In conclusion, SB inhibited NLRP3 inflammasome activation and reduced pyroptosis via the miR-135a-5p/TRPC1/STAT3/NF-κB axis, thus alleviating airway inflammation and airway remodeling in asthma. This study may confer novel insights for the management of asthma.

Ruxolitinib Ameliorates Airway Hyperresponsiveness and Lung Inflammation in a Corticosteroid-Resistant Murine Model of Severe Asthma

Asthma prevalence has increased considerably over the decades and it is now considered as one of the most common chronic disorders in the world. While the current anti-asthmatic therapies are effective for most asthma patients, there are 5-10% subjects whose disease is not controlled by such agents and they account for about 50% of the asthma-associated healthcare costs. Such patients develop severe asthma (SA), a condition characterized by a dominant Th1/Th17 cytokine response that is accompanied by Type 2 (T2)-low endotype. As JAK (Janus Kinase) signaling is very important for the activation of several cytokine pathways, we examined whether inhibition of JAKs might lessen the clinical and laboratory manifestations of SA. To that end, we employed a recently described murine model that recapitulates the complex immune response identified in the airways of human SA patients. To induce SA, mice were sensitized with house dust mite extract (HDME) and cyclic (c)-di-GMP and then subsequently challenged with HDME and a lower dose of c-di-GMP. In this model, treatment with the JAK inhibitor, Ruxolitinib, significantly ameliorated all the features of SA, including airway hyperresponsiveness and lung inflammation as well as total IgE antibody titers. Thus, these studies highlight JAKs as critical targets for mitigating the hyper-inflammation that occurs in SA and provide the framework for their incorporation into future clinical trials for patients that have severe or difficult-to manage asthma.

LncRNA CRNDE correlates negatively with miR-33a and miR-495 and positively with inflammatory cytokines in asthmatic children

Objectives

It is reported that long non‐coding RNA (lncRNA) colorectal neoplasia differentially expressed (CRNDE) targets microRNA (miR)‐33a, miR‐181a and miR‐495 to regulate inflammation process, while few studies report their clinical application for paediatric asthma management. Therefore, this study aimed to explore the interaction of lncRNA CRNDE with miR‐33a, miR‐181a and miR‐495, as well as their correlation with inflammation, exacerbation risk and severity in paediatric patients with asthma.

Methods

Asthmatic exacerbation children (N = 65), asthmatic controlled children (N = 65) and controls (N = 65) were recruited. LncRNA CRNDE, miR‐33a, miR‐181a and miR‐495 expressions in peripheral blood mononuclear cells were detected by RT‐qPCR. Besides, serum inflammatory cytokines (including TNF‐α, IL‐1β, IL‐6 and IL‐17) were determined by enzyme‐linked immunosorbent assay (ELISA).

Results

LncRNA CRNDE, miR‐33a and miR‐495 expressions were different, while miR‐181a expression was similar among asthmatic exacerbation children, asthmatic controlled children and controls. Moreover, lncRNA CRNDE negatively correlated with miR‐33a and miR‐495 in asthmatic exacerbation children and asthmatic controlled children, but not in controls. Further analyses showed that lncRNA CRNDE positively correlated with TNF‐α, IL‐1β, IL‐17 and exacerbation severity, while it negatively correlated with FEV₁/FVC in asthmatic exacerbation children. Meanwhile, miR‐33a, miR‐181a and miR‐495 all negatively correlated with some individual inflammatory cytokines, while only miR‐33a negatively correlated with exacerbation severity in asthmatic exacerbation children.

Conclusion

LncRNA CRNDE correlates negatively with miR‐33a and miR‐495 and positively with inflammatory cytokines in asthmatic children.

Potential Association Between Asthma, Helicobacter pylori Infection, and Gastric Cancer

Background: The prevalence of Helicobacter pylori infection (HPI) is still high around the world, which induces gastric diseases, such as gastric cancer (GC). The epidemiological investigation showed that there was an association between HPI and asthma (AST). Coptidis rhizoma (CR) has been reported as an herbal medicine with anti-inflammatory and anti-bacterial effects.

Purpose: The present study was aimed to investigate the protective mechanism of HPI on AST and its adverse effects on the development of GC. Coptis chinensis was used to neutralize the damage of HPI in GC and to hopefully intensify certain protective pathways for AST.

Method: The information about HPI was obtained from the public database Comparative Toxicogenomics Database (CTD). The related targets in AST and GC were obtained from the public database GeneCards. The ingredients of CR were obtained from the public database Traditional Chinese Medicine Systems Pharmacology (TCMSP). The network pharmacology including gene ontology (GO) enrichment analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, and molecular docking were utilized. Protein–protein interaction was constructed to analyze the functional link of target genes. The molecular docking was employed to study the potential effects of active ingredients from CR on key target genes.

Result: The top 10 key targets of HPI for AST were CXCL9, CX3CL1, CCL20, CCL4, PF4, CCL27, C5AR1, PPBP, KNG1, and ADORA1. The GO biological process involved mainly leukocyte migration, which responded to bacterium. The (R)-canadine and quercetin were selected from C. chinensis, which were employed to explore if they inhibited the HPI synchronously and protect against AST. The targets of (R)-canadine were SLC6A4 and OPRM1. For ingredient quercetin, the targets were AKR1B1 and VCAM1.

Conclusion: CXCL9 and VCAM1 were the common targets of AST and HPI, which might be one of the imported targets of HPI for AST. Quercetin could be an effective ingredient to suppress HPI and help prevent AST.

Trend of self-reported asthma prevalence in Brazil from 2003 to 2013 in adults and factors associated with prevalence

Objectives:

To determine the trend of self-reported asthma diagnosed prevalence and to describe the factors associated with asthma in Brazilian adults.

Method:

Epidemiological cross-sectional study based on databases analysis from three national household surveys: Pesquisa Nacional por Amostra de Domicílios (PNAD) 2003, PNAD 2008 and Pesquisa Nacional de Saúde (PNS) 2013. Participants between 18-45 years old were included. Trend analysis of asthma diagnosed prevalence was conducted using a logistic general linear model. A hierarchical logistic regression model was used to select factors significantly associated with asthma prevalence.

Results:

Asthma diagnosed prevalence was 3.6% (2003), 3.7% (2008) and 4.5% (2013), showing a statistically significant increased trend. Asthma diagnosed prevalence also increased when analysed by gender (annual change for men: 2.47%, p < 0.003; women: 2.16%, p < 0.001), urban area (annual change for urban: 2.15%, p < 0.001; rural: 2.69%, p = 0.072), healthcare insurance status (annual change without healthcare insurance: 2.18%, p < 0.001; with healthcare insurance: 1.84%, p = 0.014), and geographic regions (annual change North: 4.68%, p < 0.001; Northeast: 4.14%, p < 0.001; and Southeast: 1.84%, p = 0.025). Female gender, obesity, living in urban areas and depression were associated with asthma diagnosed prevalence.

Discussion:

PNAD and PNS surveys allow for a very large, representative community-based sample of the Brazilian adults to investigate the asthma prevalence. From 2003 to 2013, the prevalence of self-reported physician diagnosis of asthma increased, especially in the North and Northeast regions. Gender, region of residence, household location (urban/rural), obesity, and depression diagnosis seem to play significant roles in the epidemiology of asthma in Brazil.

Curcumin suppresses MUC5AC production via interfering with the EGFR signaling pathway

Excessive mucin production in the airway may contribute to airway inflammatory diseases. Curcumin has been reported to prevent mucin 5AC (MUC5AC) production in human airway epithelial cells; however, the molecular targets of curcumin involved in regulating MUC5AC expression have remained elusive. The present study aimed to elucidate the molecular mechanisms by which curcumin regulates MUC5AC production, utilizing the NCI‑H292 human airway epithelial cell line featuring MUC5AC hypersecretion. Curcumin was able to counteract the endothelial growth factor (EGF)‑stimulated mRNA and protein expression of MUC5AC. In addition, curcumin treatment prevented EGF‑induced phosphorylation of EGF receptor (EGFR) as well as the downstream AKT and signal transducer and activator of transcription 3 (STAT3), while inhibition of PI3K and STAT3 signaling significantly attenuated the expression of MUC5AC that was induced by EGF. Furthermore, EGF‑induced increases in the levels of phosphorylated STAT3 in the nuclear fraction were inhibited by curcumin and PI3K inhibitors. In addition, treatment with curcumin significantly decreased MUC5AC and EGFR expression in a time‑dependent manner under basal conditions. These results demonstrated that curcumin inhibited MUC5AC protein expression in NCI‑H292 cells under basal conditions as well under EGF stimulation. This inhibition was accompanied by decreased activation of the EGFR/AKT/STAT3 pathway and reduced EGFR expression, which indicated that curcumin may have a dual role in interfering with the EGFR signaling pathway and inhibiting mucin expression in human airway epithelial cells.

Activation of the mTOR signaling pathway is required for asthma onset

The mTOR pathway has been implicated in immune functions; however, its role in asthma is not well understood. We found that patients experiencing an asthma attack, when compared with patients in asthma remission, showed significantly elevated serum mTOR pathway activation, increased Th17 cells and IL-4, and decreased Treg cells and IFN-γ. In patients experiencing asthma, mTOR activation was positively correlated with the loss of Th17/Treg and Th1/Th2 balance. The role of mTOR in asthma was further confirmed using an ovalbumin-induced asthmatic mouse model. The mTOR pathway was activated in asthmatic mice, demonstrated by elevated levels of p-PI3K, p-Akt, p-mTOR, and p-p70S6k, and this activation was significantly reduced by treatment with budenoside or mTOR pathway inhibitors. Moreover, mTOR pathway inhibitor treatment reduced asthmatic markers and reversed the Th17/Treg and Th1/Th2 imbalances in asthmatic mice. Finally, different mTOR pathway inhibitor treatments have different inhibitory effects on signaling molecules in asthmatic mice. In summary, mTOR is activated during asthma onset and suppressed during asthma remission, and inhibiting the mTOR pathway in asthmatic mice alleviates asthmatic markers and restores the balances of Th17/Treg and Th1/Th2 cytokines. These data strongly suggest a critical requirement for mTOR pathway activation in asthma onset, suggesting potential targets for asthma treatments.