黄芪甲苷对糖尿病KKAy小鼠肾组织TGF-β1、SMAD2/3及α-SMA表达的影响

The effect of astragaloside on TGF-β1,SMAD2/3,and α-SMA expression in the kidney tissues of diabetic KKAy mice

目的观察黄芪甲苷对糖尿病KKAy小鼠肾组织转化生长因子β1(TGF-β1)、SMAD2/3、α-平滑肌肌动蛋白(α-SMA)表达的影响,探讨其延缓肾脏纤维化的可能机制。方法雄性C57BL/6J小鼠10只作为对照组,20只2型糖尿病模型KKAy小鼠予以高脂饮食至14周,随机数字法分为模型组和黄芪甲苷组,每组10只,黄芪甲苷组给予黄芪甲苷40mg·kg-1·d-1,模型组与对照组给予等量生理盐水。实验期间,各组动物自由饮食、饮水。血糖仪测量16、20、24周龄时各组小鼠的血糖水平。24周时处死,观察各组小鼠肾的病理学变化,免疫组织化学法测定TGF-β1、SMAD2/3、α-SMA的表达。结果 (1)血糖:与对照组相比,14周龄的KKAy小鼠血糖明显升高,模型组血糖在16、20、24周时血糖明显升高(P<0.05),黄芪甲苷组与其相比,血糖下降(P<0.05)。(2)肾组织形态学:对照组肾小球及肾小管结构清晰,未出现肾间质纤维化,模型组肾小球系膜基质增宽,系膜细胞增多,肾小管上皮细胞细胞质空泡样变性,肾间质炎性细胞增多,黄芪甲苷组肾小管上皮细胞细胞质较少,未呈现明显的纤维化。(3)肾组织TGF-β1、SMAD2/3、α-SMA的表达:对照组TGF-β1表达微弱,而模型组TGF-β1显著表达于肾小管上皮细胞细胞质(P<0.01);与模型组相比,黄芪甲苷组TGF-β1、α-SMA表达明显下调(P<0.05);对照组肾小管与肾小球细胞核有少量磷酸化的SMAD2/3表达,模型组表达增加(P<0.01),与模型组相比,黄芪甲苷组表达减少(P<0.05)。结论黄芪甲苷通过影响TGF-β/SMADS信号通路,下调TGF-β1、α-SMA表达,改善糖尿病小鼠肾脏纤维化。

Objective To study the effect of astragaloside on TGF-β1,SMAD2/3,andα-SMA expression in the kidney tissue of diabetic KKAy mice,and evaluate its potential role in renal interstitial fibrosis.Methods 20 type 2diabetic KKAy mice were randomly divided into model group and astragaloside group,while 10 male C57BL/6Jmice were selected as the control.Astragaloside at 40mg·kg-1·d-1 was given when the KKAy mice fed with high-fat diet to 14 weeks old.The mice in the control and model group received normal saline at 40mg·kg-1·d-1.Blood glucose meter was used to detect the blood glucose value of each mice at16 th,20th and 24 th week.The mice were killed at 24 weeks old and the kidney tissue samples were collected.Pathology morphological changes were observed.Results（1）blood glucose value：cmpared with the control group,the blood glucose value of KKAy mice at 14 week increased significantly,and that of model group also increased significantly at 16 th,20th and 24 th week（P〈0.05）;the blood glucose value of astragaloside group decreased compared with control group（P〈0.05）.（2）Morphology of kidney：in the control group,the glomerular and tubular had clear structure,there was no renal interstitial fibrosis;in the model group,the renal glomerular mesangial matrix had broaden,mesangial cell had increased,renal tubular epithelial cell cytoplasm showed vacuole degeneration,renal interstitial inflammatory cell had increased.In astragaloside group,there were few renal tubular epithelial cell cytoplasm,and there was no obvious fibrosis.（3）TGF-β1,SMAD2/3,andα-SMA expression levels of the kidney issuse：compared with control group,mice in model group up-regulated TGF-β1,SMAD2/3andα-SMA expression（P〈0.05）.TGF-β1,SMAD2/3,andα-SMA expression levels in astragaloside group were significantly lower than those in the model group（P〈0.05）.There was few phosphorylated SMAD2/3expression in renal tubular and glomerular nuclei,while that of model group increased（P〈0.01）,and compared with model group,that of the astragaloside group decreased（P〈0.05）.Conclusion Astragaloside can delay the renal fibrosis process in diabetic mice by influencing the TGF-β/SMADS signaling pathway and down-regulating TGF-β1andα-SMA expression,thus to relieve renal fibrosis in diabetic mice.