Airway Remodeling In Asthmatic Rats Research Articles

Combined Epimedii Folium and Ligustri Lucidi Fructus with dexamethasone alleviate the proliferation of airway smooth muscle cells by regulating apoptosis/autophagy

Ethnopharmacological relevanceTraditional Chinese medicine (TCM) theory believes kidney deficiency is the root cause of chronic refractory asthma with pathological changes of airway remodeling. Our previous experiments confirmed that the combination of Epimedii Folium and Ligustri Lucidi Fructus (ELL) with the effect of nourishing Yin and Yang of the kidney could improve the pathological changes of airway remodeling in asthmatic rats, but the specific mechanism remains unclear. Aim of the studyThis research was designed to reveal the synergy of ELL and dexamethasone (Dex) in the proliferation, apoptosis, and autophagy of airway smooth muscle cells (ASMCs). Materials and methodsPrimary cultures of ASMCs from rats were prepared and induced with histamine (Hist), Z-DEVD-FMK (ZDF), rapamycin (Rap), or 3-Methyladenine (3-MA) at generation 3–7 for 24 or 48 h. Subsequently, the cells were treated with Dex, ELL, and ELL&Dex for 24 or 48 h. The effect of various concentrations of inducers and drugs on cell viability was detected by Methyl Thiazolyl Tetrazolium (MTT) assay, cell proliferation was tested using immunocytochemistry (ICC) by detecting Ki67 protein, cell apoptosis was measured by Annexin V-FITC/PI assay and Hoechst nuclear staining, cell ultrastructure was observed by transmission electron microscopy (TEM), and immunofluorescence (IF), Western blot (WB) combined with quantitative real-time PCR (qPCR) were used for measuring autophagy and apoptosis-related genes including protein 53 (P53), cysteinyl aspartate-specific proteinase (Caspase)-3, microtubule-associated protein 1 light chain 3 (LC3), Beclin-1, mammalian target of rapamycin (mTOR) and p-mTOR. ResultsIn ASMCs, Hist and ZDF promoted cell proliferation, significantly decreased Caspase-3 protein expression, and up-regulated Beclin-1 levels; Dex alone and in combination with ELL promoted Beclin-1, Caspase-3, and P53 expression, enhancing autophagy activity and apoptosis in Hist and ZDF-induced AMSCs. In contrast, Rap inhibited cell viability, increased Caspase-3, P53, Beclin-1, and LC3-II/I and decreased the levels of mTOR and p-mTOR with promoting apoptosis and autophagy; ELL or ELL&Dex reduced P53, Beclin-1, and LC3-II/I to down-regulate apoptosis and the excessive autophagic state of ASMCs induced by Rap. In the 3-MA model, cell viability and autophagy were reduced; ELL&Dex significantly upgraded the expression of Beclin-1, P53, and Caspase-3 and promoted apoptosis and autophagy of ASMCs. ConclusionsThese results suggest that ELL combined with Dex may regulate the proliferation of ASMCs by promoting apoptosis and autophagy and be a potential medicine for the treatment of asthma.

Meta-Analysis of Preventive and Therapeutic Effects of Ligustrazine on Airway Remodeling in Asthmatic Rats

Objective To assess the effect of ligustrazine on airway remodeling in asthmatic rats. Methods To collect studies on the effects of ligustrazine on airway remodeling in asthmatic rat models, PubMed, Embase, CBM, Cochrane, Chinese Knowledge Infrastructure (CNKI), VIP, and Wanfang data (WANFANG) were searched using a computer. Two investigators independently screened the literature, extracted the data, and assessed the methodological quality by complying with the inclusion criteria. Moreover, a meta-analysis was conducted by adopting Stata 11.0. Results On the whole, 10 articles were included. As indicated from the meta-analysis, we have the following: ① ligustrazine was capable of reducing the thickness of the airway smooth muscle and inhibiting the proliferation of smooth muscle (WMD = −5.98, 95% CI (−7.75, −4.42), P ≤ 0.001); ② ligustrazine could reduce the thickness of the airway wall and mitigate tracheal stenosis (WMD = 0.12, 95% CI (0.05, 0.20), P ≤ 0.001); ③ ligustrazine could decrease the number of eosinophils in the lung tissue and reduce airway inflammation (WMD = −14.47, 95% CI (−18.09, −10.86), P ≤ 0.001). Conclusion Ligustrazine was demonstrated to be an effective therapeutic drug in asthmatic rats by preventing and treating airway remodeling. Further high-quality experimental studies should be conducted to investigate the mechanism of ligustrazine action in depth.

Retraction Statement.

Retraction Statement.

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.

Vitamin D supplementation decreases the expression of TGF-β1 in rats with asthma and thereby suppressing airway remodeling

Objective To investigate the preventive and therapeutic effects of 1, 25-(OH)2D3 on airway remodeling in asthmatic rats, and to explore the effect of 1, 25-(OH)2D3 on the expression of transforming growth factor-β1 (TGF-β1) and the related mechanism between them. Methods Seventy male Sprague Dawley (SD) rats were randomly divided into seven groups: normal control group (group A, n=10), asthmatic group (group B, n=10), dexamethasone group (group C, n=10), 1, 25-(OH)2D3 2 μg/(kg·d) group (group D, n=10), 1, 25-(OH)2D3 4 μg/(kg·d) group (group E, n=10), 1, 25-(OH)2D3 8 μg/(kg·d) group (group F, n=10), 1, 25(OH)2D3 16 μg/(kg·d) group (group G, n=10). Rats were sensitized and challenged with ovalbumin (OVA) to establish the asthmatic model in B, C, D, E, F, G group respectively. Rats in group B and group C were fed with normal saline 10 ml/(kg·d) and dexamethasone 2 mg/(kg·d) before atomization. While group D-G was 1, 25- (OH)2D3 intervention group, rats were fed with vitamin D 2, 4, 8, 16 μg/(kg·d) before atomization. The number of total and different cells of the bronchoalveolar lavage fluid (BALF) from the 7 groups was counted for analysis; The change of the thickness, the area of airway wall and the number of ASMC nucleus and pulmonary tissue changes were observed by microscope. The protein and mRNA expression of TGF-β1 in the lung tissue was measured by immunochemistry and real-time polymerase chain reaction (RT-PCR). Results ⑴ The airway remodeling and pulmonary inflammatory exudation in the B group were significantly heavier than those in the A, C and G groups (P<0.01); and the difference between groups of different doses of vitamin D [D group (minimum dose) and G group(the maximum dose) ] was statistically significant (P<0.01). ⑵ The results of TGF-β1 mRNA and protein levels in rats of each group showed that the expression level of TGF-β1 mRNA and integrated option density (IOD) value in A group were significantly lower than those in other groups (P<0.01); the expression level of TGF-β1 mRNA and IOD value in B group was higher than the other groups (P<0.01); Compared with the B group, the expression level of TGF-β1 mRNA and IOD value in G group (large dose vitamin D group) was decreased, with statistically difference. Conclusions In the rat model of asthma, 1, 25-(OH)2D3 may alleviate airway remodeling by regulating the expression of TGF- beta 1 and play its opposite biological effect in the prevention and treatment of asthma. Key words: Asthma; Rats; Transforming growth factor beta1; Vitamin D; Airway remodeling

Effect of Xiaochuanping powder on the inflammatory response and airway remodeling in asthmatic rats

OBJECTIVETo observe the effect of Xiaochuanping powder (XP), a traditional Chinese prescription for the treatment of cough and asthma, on serum concentrations of eosinophil cationic protein (ECP), tumor necrosis factor (TNF)-α, and interleukin (IL)-4, eosinophil counts, as well as expression of matrix metalloproteinase (MMP)-9, tissue inhibitor of metalloproteinase (TIMP)-1 in the lung tissues of asthmatic rats. METHODSSixty clean-grade Sprague–Dawley rats were divided randomly into six groups: normal control (NC), asthma model, Guilong Kechuanning (GK) group, as well as high-, intermediate-, and low-dose XP groups. Rats were sensitized with ovalbumin (OVA) to trigger asthma. Serum concentrations of ECP, TNF-α and IL-4, eosinophil counts, as well as expression of MMP-9 and TIMP-1 in lung tissues were evaluated using an immunofluorescence method. mRNA expression of MMP-9 and TIMP-1 was determined using real-time quantitative polymerase chain reaction. RESULTSCompared with the asthma-model group, serum concentrations of ECP, TNF-α, and IL-4, and eosinophil counts decreased significantly in the high- and intermediate-dose XP groups and GK group (all P < 0.01). Protein expression of MMP-9 and TIMP-1 decreased significantly in the high- and intermediate-dose XP groups and GK group (all P < 0.01). Transcription of MMP-9 and TIMP-1 mRNA and the ratio of expression of MMP-9: TIMP-1 in lung tissue were significantly lower (P < 0.01). CONCLUSIONXP can reduce TNF-α secretion, suppress the infiltration / activation of eosinophils, reduce serum concentrations of ECP and IL-4, reduce the protein and mRNA expression of MMP-9 and TIMP-1 in lung tissue, and regulate the balance between expression of MMP-9 and TIMP-1. In these ways, XP alleviated the inflammation and remodeling of the airways.

MicroRNA-142 Inhibits Proliferation and Promotes Apoptosis in Airway Smooth Muscle Cells During Airway Remodeling in Asthmatic Rats via the Inhibition of TGF-β -Dependent EGFR Signaling Pathway

Asthma is a heterogeneous disease characterized by chronic airway inflammation resulting from airway hyper-responsiveness to diverse stimuli. In this study, we investigated whether microRNA-142 (miR-142) expression affects proliferation and apoptosis in airway smooth muscle cells (ASMCs) during airway remodeling in asthmatic rats. Thirty six Wistar rats were randomly classified into a control group and an model group. miR-142 mimics and inhibitors were constructed, and ASMCs were transfected using liposomes according to the following groups: blank, negative control (NC), miR-142 mimics, miR-142 inhibitors, si-TGF-β and miR-142 inhibitors + si-TGF-β. We verified that miR-142 targets TGF-β using a dual-luciferase reporter assay. The expression levels of miR-142, TGF-β, EGFR and apoptosis signaling pathway-related genes were determined using RT-qPCR and western blotting. Changes in cell proliferation, cell cycle progression and apoptosis were analyzed using MTT assays and flow cytometry. Rats with asthma had higher expression levels of EGFR and Akt and lower miR-142 levels. miR-142 was negatively correlated with TGF-β expression. In ASMCs, the expression of TGF-β, EGFR, Akt, phosphorylated-Akt (p-Akt), Bcl-2 and Bcl-xl and the rate of early apoptosis were decreased while expression of Bax and p21 and the proliferation rate were elevated with the upregulation of miR-142. The opposite results were observed with the downregulation of miR-142. Finally, the proliferative rate was decreased while the apoptosis rate was increased and expression levels of EGFR, Akt, p-Akt, Bcl-2 and Bcl-xl were reduced while Bax and p21 were elevated in the ASMCs transfected with miR-142 inhibitors and si-TGF-β. The results of our study suggest that miR-142 inhibits proliferation and promotes apoptosis in ASMCs during airway remodeling in asthmatic rats by inhibiting TGF-β expression via a mechanism involving the EGFR signaling pathway.

Influence of Three Kinds of Traditional Chinese Therapies on Airway Remodeling in Asthmatic Rats

Abstract This paper was aimed at observing the protective effects of traditional Chinese medicine (TCM) varying in therapeutic methods on airway remodeling in bronchial asthma. Three TCM decoctions, representing body resistance-strengthening therapy, lung-diffusing therapy, and combination therapy, were prepared and administrated peroral to asthmatic rats induced by ovalbumin. Eosinophils (EOS) were counted in bronchoalveolar lavage fluid (BALF), and levels of matrix metalloproteinase (MMP-9) and tissue inhibitors of metalloproteinase (TIMP)-1 were detected in serum by ELISA. The results showed that compared with the control group administration of TCM recipes is significantly effective in reducing EOS infiltration into BALF; there was a drop in MMP-1 level and a rise in TIMP-1 level. It was concluded that the three TCM therapies exerted similar protective effects against bronchial asthma. The improvement in airway remodeling can be attributed in part to the inhibiting infiltration of EOS, down-regulating MMP-9 expression and up-regulating TIMP-1 expression.

Functional mechanism of Pingchuanning Decoction on adjustment of clara cell secretory protein in airway remodeling of asthmatic rats

ObjectiveTo study the functional mechanism of Pingchuanning Decoction in treatment of airway remodeling in asthmatic rats. MethodsEighty healthy Wistar male rats were randomized into eight groups (n=10 rats each): Normal group, Asthma model group, Dexamethasone group, Guilong Kechuanning group, Xiaoqinglong Decoction group, and Pingchuanning Decoction low-, middle-, and high-dose groups. The rats of all but the Normal group were made into asthma models through intraperitoneal injection and aerosol inhalation of ovalbumin. All treatments were administered at the first stimulation of asthma onset (third week of modeling), and the rats were killed after stimulating asthma attacks for 4 weeks. The general conditions of rats and pathomorphological changes of the lung tissues were observed. The expression of nerve growth factor (NGF) of the lung tissues was measured with immunohistochemical methods, and the content of Clara cell secretory protein (CCSP) mRNA was determined with RT-PCR. ResultsCompared with the Normal group, the contents of NGF and CCSP mRNA in the lung tissues of the Model group were significantly changed (P<0.01). Compared with the Model group, the indices of Pingchuanning Decoction and other treatment groups were improved to some extent (P<0.05 or P<0.01). ConclusionSPathological changes of airway inflammation and remodeling were present in these rat asthma models. Pingchuanning Decoction had an intervention effect on these experimental models. Its functional mechanism may be related to multiple factors, including alleviation of airway inflammation, relief of bronchial smooth muscle spasm, and inhibition of airway remodeling.

Effect of nuclear factor-kappaB on airway remodeling in asthmatic rats.

In order to investigate the effect of nuclear factor-kappaB (NF-kappaB) on airway remodeling in asthmatic rats, 18 Wistar rats were divided into three groups: asthmatic group; pyrrolidine dithiocarbamate (PDTC) group, in which rats were injected intraperitoneally with NF-kappaB specific inhibitor PDTC (100 mg/kg) before ovalbumin (OVA) challenge; control group. The NF-kappaB activity and the expression of inhibitory protein kappaBalpha (I-kappaBalpha) in airway were detected by electrophoretic mobility shift assay (EMSA), Western blot and immunohistochemistry respectively. The infiltration of inflammatory cells, the number of Goblet cells, the area of collagen and smooth muscle in airway were measured by means of image analysis system. The results showed that with the up-regulation of airway NF-kappaB activity in asthmatic group, the number of goblet cells (3.084 +/- 0.86/100 microm basement membrane (BM)), the area of collagen (24.71 +/- 4.24 microm2/microm BM) and smooth muscle (13.81 +/- 2.11 microm2/microm BM) in airway were significantly increased (P<0.05) as compared with control group (0.14 +/- 0.05/100 microm BM, 14.31 +/- 3.16 microm2/microm BM and 7.67 +/- 2.35 microm2/microm BM respectively) and PDTC group (0.33 +/- 0.14/100 microm BM, 18.16 +/- 2.85 microm/microm BM and 8.95 +/- 2.16 microm2/microm BM respectively). However, there was no significant difference between PDTC group and control group (P>0.05). It was concluded that the activity of NF-kappaB is increased in airway of asthmatic rats. Inhibition of NF-kappaB activation can attenuate constructional changes in asthma airway, suggesting NF-kappaB may contribute to asthmatic airway remodeling.

Morphological changes following airway remodeling in asthmatic rats

To explore the establishment of an asthmatic model with airway remodeling in rats by observing the morphological changes of the airway in different stages. Animals were divided into two groups: asthmatic group and control group. The subjects were observed at 5 phases: before activation and 2, 4, 6, 8 weeks after activation. General histological changes were observed using hematoxylin and eosin stained sections. Being standardized by internal perimeter (Pi), the wall thickness (d), internal area (Ai), outer area (Ao) and wall area (WA) of the airway were quantified by computer-assisted image analysis system. And the membrane airways were divided into 3 grades (large, media and small airways) to be analyzed. The changes of small airway appeared earlier and greater than the others. The changes of media airway appeared later than the small one. The changes of large airway appeared as later as the 4th week after activation. There were no differences before and after activation in control group (P>0.05). (1) Prolonged, repeated and low density Ag activation could establish asthmatic model with airway remodeling. (2) The morphological changes of the airways increased following airway remodeling, and the greatest increase occurred at small airway. (3)The morphological changes in the model rats were similar to that in human beings.