表没食子儿茶素没食子酸酯对高糖培养的系膜细胞糖原合成酶激酶-3β和细胞外基质合成的影响

Effects of Epigallocatechin-3-gallate on Glycogen Synthase Kinase-3β and Extracellar Matrix Production Induced by High Glucose in Mesangial Cells

目的观察高糖对大鼠肾小球系膜细胞(GMCs)糖原合成酶激酶-3β(GSK-3β)及细胞外基质成分(ECM)的影响及表没食子儿茶素没食子酸酯(EGCG)的干预效果。方法以大鼠GMCs为实验对象,培养48h后,用四甲基偶氮唑蓝(MTT)测定GMCs增殖情况,Western blot法测定GSK-3β蛋白表达,酶联免疫吸附实验(ELISA)检测高糖条件下细胞培养液中细胞外基质成分纤维连接蛋白(FN)、Ⅳ型胶原(ColⅣ)及层粘连蛋白(LN)的含量。结果高糖明显诱导GMCs增殖并抑制GSK-3β磷酸化,EGCG和GSK-3β特异性的抑制剂TDZD-8均能抑制高糖诱导的细胞增生,并增加GSK-3β磷酸化水平。高糖环境下系膜细胞分泌的FN、ColⅣ及LN明显增加(P<0.05),EGCG能抑制上述作用。结论EGCG通过GSK-3β信号通路抑制高糖诱导的GMCs增殖,并能抑制GMCs细胞外基质的合成,从而延缓糖尿病肾小球肥大和肾小球硬化。

Objective To observe the changes of glycogen synthase kinase-3β and extracellar matrix production of glomerular mesangial cells（GMCs） induced by high glucose（HG） and the inhibitory effect of epigallocatechin-3-gallate（EGCG）.Methods The rat mesangial cells were divided into five groups： normal glucose（NG,5mmol·L-1） control group,high glucose（HG,25mmol·L-1） group,HG＋EGCG（400μg·L-1）,HG＋TDZD-8（50 μg·L-1）,and mannitol groups.The proliferation activity of GMCs was observed by MTT assay,the expression of GSK-3β and pGSK-3β protein was examined by Western blot,and the levels of fibronection（FN）,collagen Ⅳ（ColⅣ）,laminin（LN） in the supernatant of cultured GMCs were detected by ELISA.Results Compared with normal glucose group,high glucose significantly inhibited the expression of pGSK-3β protein.EGCG could significantly increase the expression of pGSK-3β,ameliorate the levels of FN,ColⅣ and LN of the rat mesangial cells cultured in high glucose,inhibite the proliferation and ECM synthesis of GMCs induced by high glucose via GSK-3β.Conclusion EGCG may be used in the prevention and treatment of diabetic nephropathy.