缬沙坦抑制高糖培养的大鼠肾小球系膜细胞细胞外基质及CTGF的表达

Valsartan inhibits the expression of connective tissue growth factor in rat glomerular mesangial cells incubated with high concentration glucose

目的探讨高糖状态下体外培养的肾小球系膜细胞中结缔组织生长因子(CTGF)的表达以及缬沙坦的影响。方法体外培养大鼠系膜细胞,分别给予高糖和缬沙坦干预,采用Western blot检测CTGF、P38丝裂原活化蛋白激酶(P38MAPK)、cAMP反应元件结合蛋白1(CREB1)及各自磷酸化蛋白的表达,RT-PCR检测CTGF mRNA和纤维黏连蛋白(FN)mRNA的表达。放免法测定细胞上清液中层黏连蛋白(LN)和IV型胶原的含量。结果与低糖组相比,高糖组系膜细胞CTGF、p-P38 MAPK、p-CREB1表达明显上调,CTGF mRNA和FN mRNA表达增加,细胞上清中LN和IV型胶原含量增加。缬沙坦组CTGF、p-P38 MAPK、p-CREB1的表达明显下调,CTGF mRNA和FN mRNA表达降低,LN和IV型胶原的含量减少。结论缬沙坦抑制高糖状态系膜细胞CTGF表达和细胞外基质的分泌可能部分是通过影响P38 MAPK及其下游核因子CREB1的激活而实现。

Objective To investigate the effects of valsartan on the expression （CTGF） in rat glomerular mesangial cells incubated with high concentration of of connective tissue growth factor glucose. Methods We used high concentration glucose and valsartan to stimulate the cultured rat glomerular mesangial cells in vitro. The protein expressions of CTGF and the activation of P38 mitogen-activated protein kinase（ P38 MAPK） and cAMP response element binding protein 1 （CREB1）were tested by Western blot. CTGF and fibronectin（FN） mRNA were measured by reverse transcription and polymerase chain reaction （RT-PCR）. The protein synthesis of lamanin （LN） and type Ⅳ collagen in the supernatants of the GMCs were detected by radioimmunoassay. Results Compared with low glucose control group, the expression of CTGF,p-P38 MAPK, p-CREB1 ,CTGF mRNA, FN mRNA, LN and type Ⅳ collagen in the supernatants were significantly increased in GMCs incubated with high concentration of glucose medium. The expression levels of CTGF,p-P38 MAPK,p-CREBI ,CTGF mRNA and FN mRNA were significantly lower in the valsartan group than those in the high concentration glucose group. The concentrations of LN and type Ⅳ collagen in the supernatantsin the valsartan group were also lower than those in the high concentration glucose group. Conclusion Valsartan can inhibit expression of CTGF and ECM proteins in rat glomerular mesangial cells incubated with high concentration of glucose, partly by regulating the phosphorylation of P38 MAPK and CREB1.