基于TGF-β1/Smad3信号通路调控的温阳益气方对心梗后结构重塑的干预作用

Effect of Wenyang Yiqi Decoction on Regulating Lung Structure Remodeling in Rats with Heart Failure After Myocardial Infarction Through Regulating TGF-β1/Smad3 Signaling Pathway

目的：探讨温阳益气方改善心梗后心力衰竭大鼠肺结构重塑的作用和机制。方法：建立大鼠心力衰竭模型,分成6组,温阳益气方高、中、低（2.0,1.0,0.5 g·kg-1·d-1）剂量组,强的松组（0.1 g·kg-1·d-1）,模型组和假手术组（以同等体积的蒸馏水灌胃）,连续灌胃8周。灌胃结束后,彩色多普勒超声诊断仪测定左心室舒张末期内径（left ventricular end diastolic diameter,LVIDd）,左心室收缩末期内径（left ventricular end systolic diameter,LVIDs）,短轴缩短分数（fractional shortening,FS）和射血分数（ejection fraction,EF）;测定湿肺/体质量和干肺/体质量,肺组织苏木素-伊红（HE）染色切片,酶联免疫吸附法（ELISA）测定大鼠肺组织转化生长因子-β1（transforming growth factor-β1,TGF-β1）,胶原蛋白（Collagen）,α-平滑肌肌动蛋白（α-smooth muscle actin,α-SMA）,p-Smad3蛋白家族（drosophila mothers against decapentaplegic,p-Smad3）蛋白表达量。结果：与模型组比较,温阳益气方高、中剂量组LVIDd,LVIDs明显升高,FS,EF明显降低（P〈0.05）;与假手术组及强的松组比较,温阳益气方低剂量组LVIDd,LVIDs明显降低,FS,EF明显升高（P〈0.05）;与模型组比较,温阳益气方高、中剂量组湿肺/体质量、干肺/体质量明显升高（P〈0.05）;与假手术组及强的松组比较,温阳益气方低剂量湿肺/体质量、干肺/体质量明显降低（P〈0.05）,模型组肺泡严重破化,淋巴细胞浸润明显;假手术组及强的松组未见明显肺泡破化,无淋巴细胞浸润,无胶原蛋白沉淀;温阳益气方高、中剂量组肺泡破化轻,胶原蛋白沉淀也较少;温阳益气方低剂量组淋巴细胞浸润明显,肺泡壁明显增厚;与模型组比较,温阳益气方高、中剂量组α-SMA,Collagen,TGF-β1,p-Smad3明显降低（P〈0.05）,TGF-β1,p-Smad3 mRNA明显降低（P〈0.05）;与假手术组及强的松组比较,温阳益气方低剂量组α-SMA,Collagen,TGF-β1,p-Smad3明显升高（P〈0.05）。TGF-β1mRNA与TGF-β1,p-Smad3 mRNA,α-SMA,Collagen;p-Smad3 mRNA与p-Smad3,α-SMA,Collagen正相关关系明显（P〈0.05）。结论：温阳益气方能阻断TGF-β1/Smad3通路信号传导,抑制α-SMA,Collagen,TGF-β1,p-Smad3蛋白的表达,进而抑制成纤维细胞的活化增殖,降低肺部胶原蛋白的沉淀,最终达到抑制肺部组织重塑的作用。

Objective： To explore the role and mechanism of Wenyang Yiqi decoction on regulating lung structure remodeling in rats with heart failure after myocardial infarction. Method： The heart failure rat model was set up and the rats were divided into 6 groups： Wenyang Yiqi decoction high,middle,and low（ 2. 0,1. 0,0. 5 g·kg-1·d-1） dose groups,positive control group（ prednisone 0. 1 g·kg-1·d-1）,model group and sham operation group（ gavage administration of the same volume of distilled water）. All the groups were treated for eight weeks. After gavage administration,the color Doppler ultrasonic diagnostic instrument was used to measure left ventricular end-diastolic diameter（ LVIDd）,left ventricular end systolic diameter（ LVIDs）,short axial shortening fraction（ FS） and ejection fraction（ EF）. The wet lung/body weight,dry lung/body weight were determined,and HE staining was used for lung tissue slice. The enzyme-linked immunosorbent assay（ ELISA） was used to determinate the tissue growth factor-β_1（ TGF-β_1）,Collagen and α-smooth muscle actin（ α-SMA）,p-Smad3 protein family（ p-Smad3） protein expression. Result： As compared with the model group,the LVIDd and LVIDs of Wenyang Yiqi decoction high dose group and medium dose group were significantly increased; the FS and EF levels were significantly decreased（ P〈0. 05）; the wet lung/body weight and dry lung/body weight were significantly increased（ P〈0. 05）. The alveolar was seriously damaged and the wall of alveolar was thickened in the model group. There was no obvious alveolar rupture,no lymphocytic infiltration,and no collagen deposition in the sham operation group and prednisone group. There was light alveolar rupture and less collagen deposition in Wenyang Yiqi decoction high dose group and middle dose group; while in low dose group, there was obvious lymphocyte infiltration and thickened alveolar wall. As compared with the model group,the expression levels of α-SMA,Collagen,TGF-β_1,and p-Smad3 of Wenyang Yiqi decoction high dose group and middle dose group were significantly decreased（ P〈0. 05）; and the mRNA of TGF-β_1 and mRNA of p-Smad3 were also significantly decreased in the high dose and middle dose group（ P〈0. 05）. As compared with the sham operation group and prednisone group,the α-SMA,Collagen,TGF-β_1,and p-Smad3 levels were significantly increased in Wenyang Yiqi decoction low dose group（ P〈0. 05）,and there was an positive relationship between TGF-β_1 mRNA and TGF-β_1,p-Smad3 mRNA,α-SMA,Collagen（ P〈0. 05）. Conclusion： Wenyang Yiqi decoction can block TGF-β_1/Smad3 pathway signal transduction,inhibit the expression of protein including α-SMA,Collagen,TGF-β_1 and p-Smad3,and then inhibit the activation of fibroblast proliferation,reduce the sedimentation of lung Collagen,and finally reach the role of inhibition of lung tissue remodeling.