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

ABSTRACT

Objective To study the effect of astragaloside on TGF-β1,SMAD2/3,and α-SMA expression in the kidney tissue of diabetic KKAy mice,and evaluate its potential role in renal interstitial fibrosis.Methods 20 type 2 diabetic KKAy mice were randomly divided into model group and astragaloside group,while 10 male C57BL/6J mice were selected as the control.Astragaloside at 40 mg · 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 40 mg · kg-1 · d-1.Blood glucose meter was used to detect the blood glucose value of each mice at 16th,20th and 24th 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 valuecmpared 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 16th,20th and 24th week (P＜0.05);the blood glucose value of astragaloside group decreased compared with control group (P＜0.05).(2) Morphology of kidneyin 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 increaised.In astragaloside group,there were few renal tubular epithelial cell cytoplasm,and there was no obvious fibrosis.(3)TGF-β1,SMAD2/3,and α-SMA expression levels of the kidney issusecompared with control group,mice in model group up-regulated TGF-β1,SMAD2/3 and α-SMA expression (P＜ 0.05).TGF-β1,SMAD2/3,and α-SMA expression levels in astragaloside group were significantly lower than those in the model group (P＜0.05).There was few phosphorylated SMAD2/3 expression 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-β1 and α-SMA expression,thus to relieve renal fibrosis in diabetic mice.