Airway Remodeling In Asthmatic Mice Research Articles

Yunpi Xiefei Huatan Tang decoction reduces airway inflammation and airway remodeling in asthmatic mice through Wnt/β-catenin signaling pathway.

Asthma is one of the most prevalent chronic respiratory diseases among children, markedly impairing patient's health and imposing an increasing burden on the healthcare system. Several traditional Chinese medicines have demonstrated efficacy in alleviating asthma symptoms through studies conducted on animal models. Recent studies have shown that the Yunpi Xiefei Huatan Tang decoction (YPD) exhibits significant therapeutic outcomes in treating phlegm-obstructed pulmonary asthma. However, the precise regulatory effects of YPD on the progression of asthma require additional investigation. To explore the functions of YPD in asthma progression. The asthma rat model triggered by ovalbumin (OVA) was established successfully. The pathological changes of lung tissues were examined through Hematoxylin and Eosin (H&E) staining. The levels of Interleukin 6 (IL-6) and IL-1β were tested through Enzyme-Linked-Immunosorbent Serologic Assay (ELISA). The number of total cells or eosinophils in bronchoalveolar lavage fluid was confirmed through cell counter. The collagen deposition in bronchi was assessed through Masson staining. The protein expressions were measured through western blot. This study demonstrated that YPD could mitigate airway inflammation in an OVA-triggered asthma rat model. Furthermore, YPD was found to decrease the production of inflammatory cytokines in the lungs and suppress the infiltration of inflammatory cells into bronchoalveolar lavage fluid. Additionally, the airway remodeling stimulated by OVA could be suppressed following YPD treatment. Finally, it was disclosed that YPD inhibited the wingless-related integration site-beta-catenin (Wnt/β-catenin) signaling pathway in the OVA-stimulated asthma rat model. YPD alleviated airway inflammation and remodeling in asthmatic mice via the Wnt/β-catenin signaling pathway. This research offers significant insights into the potential application of YPD in the treatment of asthma.

Fisetin reduces ovalbumin-triggered airway remodeling by preventing phenotypic switching of airway smooth muscle cells

BackgroundThe transformation of airway smooth muscle cells (ASMCs) from a quiescent phenotype to a hypersecretory and hypercontractile phenotype is a defining feature of asthmatic airway remodeling. Fisetin, a flavonoid compound, possesses anti-inflammatory characteristics in asthma; yet, its impact on airway remodeling and ASMCs phenotype transition has not been investigated.ObjectivesThis research seeked to assess the impact of fisetin on ovalbumin (OVA) induced asthmatic airway remodeling and ASMCs phenotype transition, and clarify the mechanisms through network pharmacology predictions as well as in vivo and in vitro validation.MethodsFirst, a fisetin-asthma-ASMCs network was constructed to identify potential targets. Subsequently, cellular and animal studies were carried out to examine the inhibitory effects of fisetin on airway remodeling in asthmatic mice, and to detemine how fisetin impacts the phenotypic transition of ASMCs.ResultsNetwork analysis indicated that fisetin might affect asthma via mediating the phosphatidylinositol 3-kinase (PI3K)/ protein kinase B (AKT) pathway. Intraperitoneal administration of fisetin in vivo reduced airway inflammation and remodeling, as shown by reduced inflammatory cells, decreased T helper type 2 (Th2) cytokine release, diminished collagen accumulation, mitigated airway smooth muscle thickening, and decreased expression of osteopontin (OPN), collagen-I and α-smooth muscle actin (α-SMA). Moreover, fisetin suppressed the PI3K/AKT pathway in asthmatic lung tissue. According to the in vitro data, fisetin downregulated the expression of the synthetic phenotypic proteins OPN and collagen-I, contractile protein α-SMA, and inhibited cellular migration, potentially through the PI3K/AKT pathway.ConclusionThese results suggest that fisetin inhibits airway remodeling in asthma by regulating ASMCs phenotypic shift, emphasizing that fisetin is a promising candidate for the treatment of airway smooth muscle remodeling.

Total alkaloids in Fritillaria cirrhosa D. Don alleviate OVA-induced allergic asthma by inhibiting M2 macrophage polarization

Fritillaria cirrhosa D. Don (FCD) is a traditional Chinese medicine used to treat respiratory disorders, known for its effects in clearing heat, moistening the lungs, resolving phlegm, and relieving cough. Additionally, the total alkaloids extracted from FCD can alleviate asthma symptoms and reduce airway inflammation. However, no studies have investigated the effects of total alkaloids on lung macrophages. This study explored whether the total alkaloids of FCD (TAs-FCD) reduce M2 macrophage polarization and, consequently, attenuate airway remodeling in asthmatic mice. This study further elucidated its mechanism of action in treating allergic asthma. The extracted TAs-FCD was analyzed for its composition using UPLC-Q-TOF/MS. Network pharmacology was employed to identify the active ingredients and potential mechanisms of TAs-FCD in the treatment of allergic asthma. A mouse model of ovalbumin-induced allergic asthma was established, adopted, and validated through in vivo experiments. Hematoxylin-eosin staining (H&E), immunohistochemistry (IHC), immunofluorescence staining (IF), enzyme-linked immunosorbent assay (ELISA), Western blotting (WB), and real-time fluorescence quantitative polymerase chain reaction (q-PCR) were used to investigate the role of TAs-FCD in inhibiting M2 macrophage polarization in the context of allergic asthma. A total of 66 active ingredients were screened from 116 compounds using SWISSADME. The targets of these 66 compounds were predicted by SwissTargetPrediction, resulting in 808 unique drug targets after excluding duplicates. Additionally, 1,756 targets related to allergic asthma were identified from the DisGeNET, Genecard, and OMIM databases. This led to 267 cross-targets between the active ingredient targets and allergic asthma targets, including interleukin (IL)-1β, tumor necrosis factor (TNF), and STAT3. Animal experiments demonstrated that TAs-FCD improved histopathological injury in mouse lungs, reduced peri-airway collagen fiber accumulation, airway mucus secretion, and airway smooth muscle proliferation. TAs-FCD also lowered IL-1β, TNF-α and IL-4 levels in lung tissues and alleviated airway inflammation. Furthermore, TAs-FCD significantly reduced levels of Arg1 and CD206, which are closely associated with M2 macrophages, and downregulated the expression of p-STAT3 and p-JAK2. TAs-FCD may inhibit M2 macrophage polarization by regulating the JAK2/STAT3 pathway, thereby alleviating airway remodeling and inflammation in allergic asthmatic mice.

Allergo-immunopathology mechanism of thymol-inhibiting airway remodeling in asthmatic mice by regulating TGF-β/Smad3 pathway.

Allergic asthma is an important public health problem and is a complicated respiratory sickness that is characterized by bronchial inflammation, bronchoconstriction, and breathlessness. Asthma is orchestrated by type 2 immune response and remodeling is one of the important outputted problem in chronic asthma. Thymol is a naturally occurring monocyclic phenolic, it has a series of biological properties, and its immunomodulatory and anti-remodeling effects on allergic asthma were evaluated. The OVA-LPS-induced asthmatic mice were treated with thymol. Methacholine challenge test, eosinophil count, and levels of IL-4, IL-5, IL-13, and IL-33 in bronchoalveolar lavage fluid, total and OVA-specific IgE levels in serum, remodeling factors, gene expression of TGF-β, Smad2, Smad3, and lung histopathology were done. Treatment with thymol could control AHR, eosinophil percentage levels of Th2 cytokines and Igs, remodeling factors, expression of TGF-β, Smad2 and Smad3 genes, inflammation, goblet cell hyperplasia, and mucus production in asthmatic mice. Thymol can control asthma pathogens and related remodeling and fibrosis bio-factors and can be a potential treatment of asthma.

Jolkinolide B attenuates allergic airway inflammation and airway remodeling in asthmatic mice.

Asthma is a widely prevalent chronic disease that brings great suffering to patients and may result in death if it turns severe. Jolkinolide B (JB) is one diterpenoid component separated from the dried roots of Euphorbia fischeriana Steud (Euphorbiaceae), and has anti--inflammatory, antioxidative, and antitumor properties. However, the detailed regulatory role and associated regulatory mechanism in the progression of asthma remain elusive. In this work, it was demonstrated that the extensive infiltration of bronchial inflammatory cells and the thickening of airway wall were observed in ovalbumin (OVA)-induced mice, but these impacts were reversed by JB (10 mg/kg) treatment, indicating that JB relieved the provocative symptoms in OVA-induced asthma mice. In addition, JB can control OVA-triggered lung function and pulmonary resistance. Moreover, JB attenuated OVA-evoked inflammation by lowering the levels of interleukin (IL)-4, IL-5, and IL-13. Besides, the activated nuclear factor kappa B (NF-κB) and transforming growth factor-beta-mothers against decapentaplegic homolog 3 (TGFβ/smad3) pathways in OVA-induced mice are rescued by JB treatment. In conclusion, it was disclosed that JB reduced allergic airway inflammation and airway remodeling in asthmatic mice by modulating the NF-κB and TGFβ/smad3 pathways. This work could offer new opinions on JB for lessening progression of asthma.

The effects and mechanisms of Gefitinib on airway inflammation and airway remodeling in C57BL/6 mice with asthma

Objective: To investigate the effects of the epidermal growth factor receptor(EGFR) inhibitor Gefitinib on airway inflammation and airway remodelling in asthmatic C57BL/6 mice, and to analyze its possible mechanisms. Methods: Male C57BL/6 mice, aged 6-8 weeks, were randomly assigned into five groups: Group A (control group), Group B (asthma group), Group C (asthma+20 mg/kg gefitinib group), Group D (asthma+40 mg/kg gefitinib group), and Group E (40 mg/kg gefitinib group), with seven mice per group. Mice were sensitized by intraperitoneal injection of a mixture of 0.2 ml solution containing OVA and Al(OH)3 [20 μg OVA+2 mg Al(OH)3 dissolved in 0.2 ml of physiological saline] at Day 0 and 14. Starting from Day 25 to 31, Group B, C, and D were challenged with nebulization of 1% OVA solution (8 ml) to induce asthma, once a day for approximately 40 minutes, with continuous aerosolization for 7 days. Group C and D were given 0.2 ml of Gefitinib dissolved in 0.5% carboxymethylcellulose sodium (CMCNa) by gavage half an hour before challenging, and Group E was simultaneously given with 0.2 ml of Gefitinib dissolved in 0.5% CMCNa only. Group A and B were given an equivalent volume of 0.5% CMCNa by gavage. After 24 h of final challenge, the bronchoalveolar lavage fluid (BALF) was prepared for the determination of total cell count and eosinophil count. The levels of total immune globulin E (IgE) in serum and interleukin (IL)-4, IL-5 and IL-13 in BALF and lung tissue homogenates were measured by ELISA. The mRNA expression levels of IL-4, IL-5, IL-13 in lung were measured. Immunohistochemistry and Western blot experiments were used to detect the expression levels of EGFR in lung tissues. Results: In Group B, the level of total IgE in serum, total cell count, eosinophil count, the levels of IL-4, IL-5, IL-13 in BALF and the phosphorylation of EGFR and its downstream activation in lung were higher than those in Group A (all P<0.05). The levels of total IgE in serum [(261.32±44.38) ng/ml, (194.09±52.39) ng/ml vs (1 023.70±105.51) ng/ml], total cell count [(23.70±4.08)×105/ml, (14.92±4.06)×105/ml vs (35.36±6.30)×105/ml], eosinophil count [(108.00±13.69)×104/ml, (67.00±17.28)×104/ml vs (147.86±20.06)×104/ml], IL-4 [(36.42±4.48) pg/ml, (30.45±8.12) pg/ml vs (58.72±7.17) pg/ml], IL-5 [(16.20±4.62) pg/ml, (13.38±5.14) pg/ml vs (23.46±5.38) pg/ml], IL-13 [(18.45±7.28) pg/ml, (14.33±7.70) pg/ml vs (104.12±24.66) pg/ml] in BALF of Group C and D were lower than those in Group B (all P<0.05). The levels of IL-4, IL-5, and IL-13 as well as their mRNA levels in the lung tissue of Group C and D were lower than those in Group B (all P<0.05). In Group C and D, the positive expression rate of phosphorylated epidermal growth factor receptor (p-EGFR) in lung tissue [(40.53±6.80)%, (23.60±4.42)% vs (70.78±5.36)%], p-EGFR/EGFR (61.68±7.48, 51.13±5.19 vs 105.90±11.66), phosphorylated extracellular regulated protein kinase (p-Erk)/extracellular regulated protein kinase (Erk) (75.28±7.11, 47.54±4.83 vs 98.76±4.71), and phosphorylated protein kinase B (p-Akt)/protein kinase B (Akt) (96.24±5.40, 68.52±2.73 vs 103.30±4.52) was lower than those of Group B (all P<0.05). There was no statistically significant difference in the relevant indicators between Group A and E (all P>0.05). Conclusion: Gefitinib may alleviate airway inflammation and airway remodeling in asthmatic mice by inhibiting EGFR phosphorylation and affecting the activation of downstream Erk and Akt.

Atomized inhalation of Icaritin reduces airway inflammation and remodeling in asthmatic mice

Background Asthma is a disease characterized by airway hyperresponsiveness and airway inflammation. Icaritin (ICT) is a plant hormone with various pharmacological activities such as anti-inflammatory, immune regulation, and anti-tumor. This study mainly explored the effects of nebulized inhalation of ICT on airway inflammation and airway remodeling in asthmatic mice. Method Different groups of ovalbumin (OVA)-induced asthma mice with acute and chronic airway inflammation received ICT. Asthmatic mice received budesonide (BDND) aerosol inhalation as a positive control, while normal control and asthma model mice received the same volume of saline. Following finishing of the study, analyses were conducted on behavioral tests, biochemical indices, and histological structures of lung tissues. Results Aerosol inhalation of ICT can notably reduce inflammatory cells infiltration around the airways and pulmonary vessels, and suppressed goblet cell hyperplasia in asthmatic mice. Long-term inhalation of ICT can decrease airway collagen deposition and airway smooth muscle hyperplasia, and alleviate airway hyperresponsiveness, mirroring the effects observed with hormone employed in clinical practice. Conclusion Nebulized inhalation of ICT can effectively inhibit airway inflammation in asthmatic mice, improve airway remodeling, and reduce airway hyperresponsiveness, with effects similar to those of hormones. It may serve as a potential candidate used as a hormone replacement asthma treatment.

CD147 induces asthmatic airway remodeling and activation of circulating fibrocytes in a mouse model of asthma

BackgroundAirway remodeling is a poorly reversible feature of asthma which lacks effective therapeutic interventions. CD147 can regulate extracellular matrix (ECM) remodeling and tissue fibrosis, and participate in the pathogenesis of asthma. In this study, the role of CD147 in airway remodeling and activation of circulating fibrocytes was investigated in asthmatic mice.MethodsAsthmatic mouse model was established by sensitizing and challenging mice with ovalbumin (OVA), and treated with anti-CD147 or Isotype antibody. The number of eosinophils in bronchoalveolar lavage fluid (BALF) was examined by microscope, and the levels of interleukin-4 (IL-4), IL-5 and IL-13 in BALF were detected by enzyme-linked immunosorbent assay (ELISA). The number of CD45+ and collagen I (COL-I)+ circulating fibrocytes in BALF was detected by flow cytometry. Lung tissue sections were respectively stained with hematoxylin and eosin (HE), periodic acid-Schiff (PAS) or Masson trichrome staining, or used for immunohistochemistry of CD31 and immunohistofluorescence of α-smooth muscle actin (α-SMA), CD45 and COL-I. The protein expression of α-SMA, vascular endothelial growth factor (VEGF), transforming growth factor-β1 (TGF-β1), Fibronectin, and COL-I was determined by western blotting.ResultsAnti-CD147 treatment significantly reduced the number of eosinophils and the levels of IL-4, IL-13, and IL-5 in BALF, and repressed airway inflammatory infiltration and airway wall thickening in asthmatic mice. Anti-CD147 treatment also reduced airway goblet cell metaplasia, collagen deposition, and angiogenesis in asthmatic mice, accompanied by inhibition of VEGF and α-SMA expression. The number of CD45+COL-I+ circulating fibrocytes was increased in BALF and lung tissues of OVA-induced asthmatic mice, but was decreased by anti-CD147 treatment. In addition, anti-CD147 treatment also reduced the protein expression of COL-I, fibronectin, and TGF-β1 in lung tissues of asthmatic mice.ConclusionOVA-triggered airway inflammation and airway remodeling in asthmatic mice can be repressed by anti-CD147 treatment, along with inhibiting the accumulation and activation of circulating fibrocytes.

DPP4 Regulates the Th17/IL-17 Axis and Accelerates Epithelial Mesenchymal Transition to Promote Ovalbumin-Induced Asthma in Female C57BL/6J Mice.

Dipeptidyl peptidase-4 (DPP4) is a transmembrane glycoprotein, prevalent across a variety of tissues and cells and can be foundin a solubilised in peripheral blood. This paper aims at determining the role of sCD26/sDPP4 in Th17 cell polarization and airway epithelial cell to epithelial mesenchymal transition (EMT) in asthma. Female C57BL/6J mice were treated with ovalbumin to constructed asthma mice. The CD4+ T cell, and bronchial epithelial cells (BECs) were purified from the spleens and bronchus of mice. The KRT8 expression in BECs were identified by immunofluorescence (IF). Th17 cells were differentiated from a CD4+ T cell. Flow cytometry was usewd to identify and calculate the Th17 and Treg cells. Mice woth asthma were treated by DPP4 overexpressing lentivirus or DPP4 inhibitor. Histopathological modifications were assessed by hematoxylin-eosin (HE), periodic acid Schiff (PAS), and Masson staining. The total number of leucocytes was detected using a hemocytometer. For detection, quantitative Real-time PCR (qRT-PCR), western blotting (WB), and IF were used to evaluate the expression of E-cadherin and alpha-smooth muscle actin (α-SMA). Enzyme-linked immunosorbent assay (ELISA) was performed to analyze the DPP4, IL-4, IL-5, IL-13 and IL-17 levels. The findings suggest that sCD26/sDPP4 promote CD4+ T cells differentiation into Th17 cells in a depending on the applied dose. sCD26/sDPP4 up-regulated the expression of α-SMA and down-regulated the expression of E-cadherin in TGF-β1-induced mouse BECs, which was reversed by DPP4 inhibitor. Co-culture induced a synergic effect between Th17 cells and sCD26/sDPP4 on the formation of airway EMT in BECs. Furthermore, DPP4 inhibitor prevented lung-bronchial inflammatory infiltration, mucus secretion, goblet cell hyperplasia and collagen deposition in asthma mice. Meanwhile, DPP4 inhibitor decreased the levels of DPP4, IL-4, IL-5, IL-13, IL-17 and increased the total number of leukocytes in bronchoalveolar lavage fluid of asthma mice. In addition, DPP4 inhibitor also inhibited airway EMT and Th17 cell polarization in asthma mice. The results in this paper show that up-regulation of DPP4 enabled airway inflammation and airway remodeling in asthmatic mice by modulating the Th17/IL-17 axis and accelerating the airway EMT, which isa therapeutic target in asthma.

Relief of ovalbumin-induced airway remodeling by the glycyl-l-histidyl-l-lysine-Cu2+ tripeptide complex via activation of SIRT1 in airway epithelial cells

Fixed airflow limitation (FAO), prevalent in patients with severe or difficult-to-treat asthma, is mainly caused by airway remodeling. Airway remodeling is initiated by inflammation and involves subsequent pathological changes. Glycyl-l-histidyl-l-lysine (GHK) is a matrikine with anti-inflammatory and antioxidant effects, naturally existing in human tissue. At present, the GHK level in human plasma and whether it is related to airway remodeling of asthma remain unclear. This study was conducted to determine how GHK is involved in airway remodeling in asthma. Our result showed that the plasma GHK levels of patients with asthma were significantly lower than those of age-matched healthy controls. In asthma patients, plasma GHK levels display a moderate correlation with FEF25–75%, and patients with FAO had significantly lower GHK levels. Ovalbumin-induced mice of asthma model treated with PBS or GHK-Cu (a form of GHK with higher bioavailability) were used to evaluate the effect of exogenous GHK supplement on airway remodeling. GHK-Cu administration alleviated airway remodeling, as reflected by decreased peribronchial collagen deposition and airway mucus secretion, and suppressed epithelial-mesenchymal transition. The therapeutical effect related to decreased TGF-β1 level. Successively, network pharmacology and the validation data of experiments in vivo and vitro demonstrated that GHK-Cu decreased TGF-β1 level by increasing SIRT1 expression and activating SIRT1 deacetylation in airway epithelial cells, thereby alleviating airway remodeling. Collectively, decreased plasma GHK levels were related to FAO in asthma patients. Through the direct binding and activation of SIRT1, exogenous GHK-Cu administration alleviated airway remodeling in asthmatic mice.

Dexmedetomidine Protects against Airway Inflammation and Airway Remodeling in a Murine Model of Chronic Asthma through TLR4/NF-κB Signaling Pathway.

Asthma is a common respiratory disease characterized by chronic airway inflammation. Dexmedetomidine (DEX), a highly selective α2 adrenergic receptor agonist, has been shown to participate in regulating inflammatory states and thus exert organ protective actions. However, the potential of DEX in asthma is still unknown. This study is aimed at investigating the role of DEX in a mouse model of house dust mite- (HDM-) induced asthma and exploring its underlying mechanism. Here, we found that DEX treatment significantly ameliorated airway hyperresponsiveness, airway inflammation, and airway remodeling in the asthmatic mice, which were similar to the efficacy of the reference anti-inflammatory drug dexamethasone. In addition, DEX reversed the increased expression of toll-like receptor 4 (TLR4) and its downstream signaling adaptor molecule nuclear factor-κB (NF-κB) in the lung tissue of asthmatic mice. Furthermore, these protective effects of DEX were abolished by yohimbine, an α2 adrenergic receptor antagonist. These results indicate that DEX is capable of ameliorating airway inflammation and remodeling in asthmatic mice, and this protective effect is associated with the inhibition of the TLR4/NF-κB signaling pathway.

Effect of roflumilast on airway remodeling in asthmatic mice exposed to or not exposed to cigarette smoke: Comparison with the effect of dexamethasone

Cigarette smoking constitutes a risk factor for severe asthma, which is frequently linked to remodeling of the airways. Appropriate drug treatment for smokers with asthma is uncertain because many smokers with asthma are less sensitive to glucocorticoid treatment than non-smokers with asthma. The purpose of this study was to compare the anti-airway remodeling effects of dexamethasone (Dex) and roflumilast (Rof), a selective phosphodiesterases-4 inhibitor, in smoking and non-smoking mice with asthma. BALB/c mice were sensitized with ovalbumin (OVA) and then challenged with OVA for two weeks, either with or without concurrent exposure to cigarette smoke (CS). Dex (1 mg/kg body weight), Rof (5 mg/kg body weight), or vehicle alone was given orally to the mice once daily. To assess the histopathological effects of airway remodeling, lung tissue sections were obtained. Repeated OVA challenges resulted in fibrosis, goblet cell hyperplasia, and thickening of the airway but not the smooth muscle layer. The presence of CS did not have an impact on the degree of airway remodeling brought on by repeated OVA challenges. In mice repeatedly exposed to OVA either with or without CS, Dex treatment reduced the remodeling alterations. In these mice group, the Rof Treatment had a less significant impact than the Dex treatment. Dex was still more effective than Rof at reducing airway remodeling in asthmatic smoking mice. According to the current study's findings, Dex effectively prevented airway remodeling in a two-week asthma model in mice exposed to CS or not. In contrast, we found that Rof had little to no inhibitory effect of Rof on the airway in our mouse model of asthma, whether or not it had been exposed to CS. We were unable to find solid proof to support CS-induced steroid resistance to treat airway remodeling.

Study of the Regulatory Mechanism of miR-26a-5p in Allergic Asthma.

Allergic asthma is a growing burden on national public health services due to its high prevalence. The aim of this experiment was to investigate whether miR-26a-5p affects cellular fibrosis and thus airway remodeling in asthmatic mice through the regulation of target genes. Screening for differentially expressed miRNAs in asthma model mice was carried out by constructing a mouse model of allergic asthma. qRT-PCR was performed to determine candidate miRNAs in each group of bronchial tissues. Western blot detection of the expression levels of predicted candidate target genes in each group of bronchial tissues was conducted. A dual luciferase assay was performed to validate the binding of miR-26a-5p to target genes. Fibronectin, a marker of cellular fibrosis, was detected via flow cytometry. CCK8 and BrdU staining were used to detect the proliferation ability of each group of cells. miR-26a-5p is able to target and bind to ABL2 3'-UTR, MMP16 3'-UTR and PDE7A 3'-UTR sequences. After interference with miR-26a-5p, improved bronchial histopathology and reduced peribronchial collagen deposition were found. Compared with the model group, interference with miR-26a-5p reduced lung fibrosis, decreased fibroblasts and increased apoptosis in mouse bronchial tissues; overexpression of miR-26a-5p decreased apoptosis in mouse bronchial tissues. Compared with the model group, the serum levels of IL-4, IL-5, IL-13 and I IFN-γ were decreased in the miR-26a-5p inhibitor group and increased in the miR-26a-5p mimic group. The immunohistochemical results showed that the expression of ABL2, MMP16 and PDE7A was significantly reduced after intervention with miR-26a-5p. Compared with the model group, the apoptosis rate of cells in the miR-26a-5p inhibitor group of the allergic asthma model was upregulated, the levels of IL-4, IL-5, IL-13, IFN-γ and ROS were decreased, the expression of the miRNA and proteins of ABL2, MMP16 and PDE7A was decreased, the expression of LC3A and P62 was significantly increased and the expression of LC3B, Beclin1, Atg5 and fibrosis markers collagen I and α-SMA was decreased. miR-26a-5p affects cellular fibrosis and thus airway remodeling in asthmatic mice by regulating target genes.

Qufeng Xuanbi Formula Ameliorates Airway Remodeling in Asthmatic Mice by Suppressing Airway Smooth Muscle Cell Proliferation through MEK/ERK Signaling Pathway.

Asthma is a common chronic respiratory disease. The Qufeng Xuanbi formula (QFXBF), a Chinese herbal decoction, has shown efficacy in the management of asthma. The purpose of this study was to investigate the potential therapeutic effects of QFXBF in the treatment of asthma both in vitro and in vivo. Platelet-derived growth factor (PDGF)-induced airway smooth muscle cell (ASMC) proliferation and MTT assays were used to explore the effects of QFXBF on the proliferation of ASMCs. Moreover, 40 female BALB/c mice were randomly divided into five groups: control group, ovalbumin (OVA) group, high QFXBF group, low QFXBF group, and dexamethasone (DEX) group (n = 8 per group). A mouse allergic asthma model was established using the intranasally administered OVA sensitization method. Morphological changes in the lung tissue were examined by hematoxylin and eosin (H&E) staining and Masson's trichrome staining. Finally, the protein expression of alpha-smooth muscle actin (α-SMA), proliferating cell nuclear antigen (PCNA), phospho-mitogen-activated protein kinase (p-MEK1/2), mitogen-activated protein kinase (MEK1/2), phospho-extracellular signal-regulated kinases (p-ERK1/2), and extracellular signal-regulated kinases (ERK1/2) in ASMCs and lung tissue were determined by western blotting and immunofluorescent staining assays. PDGF significantly increased the viability of ASMCs. Compared with mice in the control group, the airway walls and airway smooth muscle of mice in the OVA group were thickened, and the number of inflammatory cells around the bronchus significantly increased. Moreover, the administration of QFXBF markedly inhibited the proliferation of ASMCs and alleviated the pathological changes induced by OVA. Furthermore, the protein expressions of p-ERK1/2, p-MEK1/2, PCNA, and α-SMA were significantly increased in OVA-treated mice and PDGF-treated ASMCs. Finally, treatment with QFXBF also significantly decreased the protein expression of p-ERK1/2, p-MEK1/2, α-SMA, and PCNA. QFXBF inhibited the proliferation of ASMCs by suppressing MEK/ERK signaling in PDGF-induced ASMCs and OVA-induced mice.

Glycyrrhizic acid restrains airway inflammation and remodeling in asthma via the TGF-β1/Smad signaling pathway.

The anti-inflammatory effects of glycyrrhizic acid (GA) against asthma have previously been reported; however, the underlying molecular mechanism of GA in asthma has not yet been elucidated. Thus, the present study aimed to determine the function and potential molecular mechanism of GA for modulating the transforming growth factor-β1 (TGF-β1)/Smad signaling pathway in asthma-associated airway inflammation and remodeling. In order to study the mechanism of GA on airway inflammation and airway remodeling in asthmatic mice, a mouse model of chronic asthma was constructed. A total of 50 female mice were randomly assigned into five groups (10 mice/group), as follows: Blank group, asthma group, GA group, dexamethasone group and GA + TGF-β1 group. Hematoxylin and eosin, and Masson staining were performed to assess the airway inflammation and remodeling in mice with ovalbumin (OVA)-induced asthma. The serum levels of interleukin (IL)-4, IL-5, IL-13 and IL-17 in mice were assessed via the enzyme-linked immunosorbent assay. Reverse transcription-quantitative PCR and western blot analyses were performed to detect the levels of TGF-β1 and Smads in lung tissues of each group of mice. The results demonstrated that GA and dexamethasone treatment mitigated airway inflammation, inflammatory cell infiltration and airway remolding, with a concomitant decrease in the expression levels of IL-4, IL-5, IL-13 and IL-17, in mice with OVA-induced asthma. In addition, the levels of TGF-β1 and Smad2 notably decreased, while Smad7 expression increased in the GA and dexamethasone groups compared with the asthma group. Furthermore, histopathological morphometry exhibited significantly elevated inflammatory cell infiltration, airway wall and smooth muscle, collagen secretion and inflammatory cytokines in the serum of mice in the GA + TGF-β1 group compared with the GA group. Taken together, the results of the present study suggest that GA ameliorates airway inflammation and remodeling via the TGF-β1/Smad signaling pathway in mice with asthma.

Long non-coding RNA TUG1 promotes airway remodeling and mucus production in asthmatic mice through the microRNA-181b/HMGB1 axis

MicroRNA-181b (miR-181b) has been well noted with anti-inflammatory properties in several pathological conditions. It has also been suggested to be downregulated in patients with asthma. In this study, we explored the function of miR-181b in airway remodeling in asthmatic mice and the molecular mechanism. A mouse model with asthma was induced by ovalbumin (OVA) challenge, and miR-181b was found to be downregulated in lung tissues in the OVA-challenged mice. Overexpression of miR-181b was introduced in mice, after which the respiratory resistance, inflammatory infiltration, mucus production, and epithelial-mesenchymal transition (EMT) and fibrosis in mouse airway tissues were decreased. The integrated bioinformatics analysis suggested long non-coding RNA (lncRNA) TUG1 as a sponge for miR-181b. miR-181 directly targeted high mobility group box 1 (HMGB1) mRNA. HMGB1 was suggested to enhance activation of the nuclear factor kappa B (NF-κB) signaling. Further upregulation of lncRNA TUG1 blocked the protective functions of miR-181b in asthmatic mice. To conclude, this study evidenced that lncRNA TUG1 reinforces HMGB1 expression through sequestering microRNA-181b, which activates the NF-κB signaling pathway and promotes airway remodeling in asthmatic mice. This study may provide novel ideas in asthma management.

Exchange protein directly activated by cAMP (Epac) protects against airway inflammation and airway remodeling in asthmatic mice

Backgroundβ2 receptor agonists induce airway smooth muscle relaxation by increasing intracellular cAMP production. PKA is the traditional downstream signaling pathway of cAMP. Exchange protein directly activated by cAMP (Epac) was identified as another important signaling molecule of cAMP recently. The role of Epac in asthmatic airway inflammation and airway remodeling is unclear.MethodsWe established OVA-sensitized and -challenged acute and chronic asthma mice models to explore the expression of Epac at first. Then, airway inflammation and airway hyperresponsiveness in acute asthma mice model and airway remodeling in chronic asthma mice model were observed respectively after treatment with Epac-selective cAMP analogue 8-pCPT-2′-O-Me-cAMP (8pCPT) and Epac inhibitor ESI-09. Next, the effects of 8pCPT and ESI-09 on the proliferation and apoptosis of in vitro cultured mouse airway smooth muscle cells (ASMCs) were detected with CCK-8 assays and Annexin-V staining. Lastly, the effects of 8pCPT and ESI-09 on store-operated Ca2+ entry (SOCE) of ASMCs were examined by confocal Ca2+ fluorescence measurement.ResultsWe found that in lung tissues of acute and chronic asthma mice models, both mRNA and protein expression of Epac1 and Epac2, two isoforms of Epac, were lower than that of control mice. In acute asthma mice model, the airway inflammatory cell infiltration, Th2 cytokines secretion and airway hyperresponsiveness were significantly attenuated by 8pCPT and aggravated by ESI-09. In chronic asthma mice model, 8pCPT decreased airway inflammatory cell infiltration and airway remodeling indexes such as collagen deposition and airway smooth muscle cell proliferation, while ESI-09 increased airway inflammation and airway remodeling. In vitro cultured mice ASMCs, 8pCPT dose-dependently inhibited, whereas ESI-09 promoted ASMCs proliferation. Interestingly, 8pCPT promoted the apoptosis of ASMCs, whereas ESI-09 had no effect on ASMCs apoptosis. Lastly, confocal Ca2+ fluorescence examination found that 8pCPT could inhibit SOCE in ASMCs at 100 μM, and ESI-09 promoted SOCE of ASMCs at 10 μM and 100 μM. In addition, the promoting effect of ESI-09 on ASMCs proliferation was inhibited by store-operated Ca2+ channel blocker, SKF-96365.ConclusionsOur results suggest that Epac has a protecting effect on asthmatic airway inflammation and airway remodeling, and Epac reduces ASMCs proliferation by inhibiting SOCE in part.

ORMDL3 knockdown in the lungs alleviates airway inflammation and airway remodeling in asthmatic mice via JNK1/2-MMP-9 pathway

Orosomucoid-like protein 3 (ORMDL3) is a common mutation in many asthma patients and its effects on the specific pathogenesis of asthma are still unclear. Therefore, in this study, we used a mouse that specifically knockout the mouse ORDML3 gene to further study the mechanism. We used ovalbumin (OVA) to induce asthma in wild-type mice and ORMDL3 knockout mice. Lung ventilation resistance, airway inflammation, mucus hypersecretion, collagen deposition, the levels of inflammatory factors and the expression of ORDML3 and JNK1/2-MMP-9 pathway were detected. The results showed that ORMDL3 gene was highly expressed in clinical asthmatic children and mouse asthma model. Knocking down the ORMDL3 gene in the lung tissue of asthmatic mice can reduce airway hyperresponsiveness, airway inflammation, mucus secretion, and collagen deposition around the airway. After knocking down the lung tissue of mice, the IL-4, IL-5 and IL-13 concentrations in broncho alveolar lavage fluid of asthmatic mice were significantly decreased, and the activation of JNK1/2-MMP-9 pathway was inhibited in mouse lung tissue. Collectively, our results demonstrate that the ORMDL3 gene may aggravate asthma symptoms by activating the JNK1/2-MMP-9 pathway, which indicates that the ORMDL3 gene may be the key molecule for the next step of asthma targeted therapy.

Budesonide up-regulates vitamin D receptor expression in human bronchial fibroblasts and enhances the inhibitory effect of calcitriol on airway remodeling

Introduction and objectivesTransforming growth factor β1 (TGFβ1) and dysregulated microRNA-21 (miR-21) expression is associated with TGFβ/Smad signaling pathway activation and fibrosis. While calcitriol has been shown to improve airway remodeling in asthmatic mice, its mechanism remains unknown. In this study, the effect of calcitriol on the TGFβ/Smad signaling pathway and miR-21 expression in human bronchial fibroblasts was investigated to explore the mechanism of action of calcitriol and the inhaled glucocorticoid, budesonide, in airway remodeling. Materials and methodsHuman bronchial fibroblasts were pretreated with budesonide, calcitriol, or budesonide plus calcitriol, and stimulated with TGFβ1 for 48h. Quantitative real-time PCR was used to determine the expression of miR-21. Western blot was used to determine airway remodeling-related proteins, TGFβ/Smad signaling pathway-related proteins, glucocorticoid receptor, and vitamin D receptor (VDR) expression. ResultsBoth budesonide and calcitriol down-regulated miR-21 expression in human bronchial fibroblasts, up-regulated Smad7 expression, and inhibited the expression of airway remodeling-related proteins. Both budesonide and calcitriol up-regulated the low expression of VDR induced by TGFβ1 in human bronchial fibroblasts. The expression of VDR in the combined treatment group (budesonide plus calcitriol) was significantly higher than that in the calcitriol treatment group. The expression of collagen type I in the combined treatment group was significantly lower than that in the calcitriol treatment group. ConclusionsCalcitriol can up-regulate the expression of VDR in human bronchial fibroblasts and exert an anti-airway remodeling effect. Budesonide can up-regulate the expression of VDR in human bronchial fibroblasts and enhance the inhibitory effect of calcitriol on airway remodeling.

Role of microRNA-21 in airway remodeling in asthmatic mice

Objective Airway remodeling is an important pathological feature of asthma.This study is to investigate the role of microRNA-21 (miR-21) in airway remodeling in asthmatic mice. Methods A total of 16 female BALB/c mice were randomly divided into control group and asthma model group.Mice were sensitized and challenged by ovalbumin to establish a murine model of asthma.The mice in the normal control group were intraperitoneally injected with phosphate buffered saline for sensitization and given a phosphate buffered saline inhalation for the challenge.Twenty-four hours after the last aerosol inhalation, lung tissues of mice were sampled and subjectd to Western blot for testing expression of TGFβ type Ⅱ receptor, Smad7, and Collagen Type Ⅰ (COL Ⅰ) in lung tissue of mice of each group.Quantitative real-time PCR was used to test miR-21 expression in lung tissue of mice of each group.Target gene prediction software (TargetScan) was used to predict target gene of miR-21.293T cell was used to conduct dual-luciferase reporter gene assay for verification of miR-21 target gene. Results Compared with control group, asthma group had increased expression of COL Ⅰ protein and miR-21 in lung tissue (t=11.94, P<0.05; t=23.05, P<0.05). Smad7 and TGF-βRⅡ were target genes of miR-21. Conclusion miR-21 down-regulates Smad7, a target gene of miR-21, activates the TGFβ/Smad signaling pathway, and promotes airway remodeling, indicating that miR-21 may be a therapeutic target for the treatment of airway remodeling in asthma. Key words: MicroRNA-21; Target gene; Asthma; Airway remodeling; Mice