氟伐他汀对高糖培养大鼠肾小球系膜细胞CTGF mRNA的影响及其作用机制的研究

Effect and Functional Mechanisms of Fluvastatin on the Expressions of Connective Tissue Growth Factor mRNA in Glomerular Mesangial Cells Cultivated with High Concentration of Glucose in Rats

目的探讨高糖状态下肾小球系膜细胞中结缔组织生长因子(CTGF)mRNA的表达以及HMG-CoA还原酶抑制剂氟伐他汀对其的影响及作用机制。方法体外培养大鼠肾小球系膜细胞,实验分为4组:低糖组(LG组,5.5 mmol/L葡萄糖);低糖+甘露醇组(LG+M组,5.5 mmol/L葡萄糖+24.5 mmol/L甘露醇);高糖组(HG组,30 mmol/L葡萄糖);高糖+氟伐他汀组(HG+Flu组,30 mmol/L葡萄糖+10μmol/L氟伐他汀)。采用逆转录-聚合酶链反应(RT-PCR)检测CTGF和纤维粘连蛋白(FN)mRNA的表达,Western印迹检测磷酸化p38丝裂原活化蛋白激酶(p-p38 MAPK)及其下游因子cAMP反应元件结合蛋白1(p-CREB1)。结果与LG+M组相比,HG组系膜细胞增殖明显,p-p38 MAPK、p-CREB1表达明显上调,CTGF和FN mRNA的表达增加。与HG组比较,HG+Flu组可抑制系膜细胞增殖,p-p38 MAPK、p-CREB1的表达明显下调,CTGF和FN mRNA的表达降低。结论高糖状态下肾小球系膜细胞CTGF mRNA表达增强,p-p38 MAPK和p-CREB1表达明显升高,氟伐他汀抑制肾小球系膜细胞CTGF mRNA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 effect and functional mechanisms of Fluvastatin on the expression of connective tissue growth factor（ CTGF） mRNA and the activation of p38 mitogen-activated protein Kinase（ p38 MAPK） and cAMP response element- bingding protein1（ CREB1） in glomerular mesangial cells cultivated with high concentration of glucose in rats. Methods Glomerular mesangial cells in Wistar rats were cultured in vitro and divided into four groups： low glucose group（ group LG,5. 5 mmol /L glucose）,low glucose with mannitol group（ group LG ＋ M,5. 5 mmol /L glucose ＋ 24. 5mmol / L mannitol）,high glucose group（ group HG,30mmol /L glucose） and high glucose with Fluvastatin group（ group HG ＋ Flu, 30 mmol /L glucose ＋ 10 μmol /L Fluvastatin）. Expressions of mRNA in CTGF and fibronectin（ FN） were detected by reverse transcription and polymerase chain reaction（ RT-PCR）. Expressions of phosphorylated p38（ p-p38） mitogen activated protein kinase（ MAPK） and p-CREB1 were detected by Western blotting. Results The intercapillary cell multiplication and expressions of p-p38 MAPK,p-CREB1 and mRNA of CTGF and FN were significantly increased in group HG,compared with those in group LG ＋ M. The intercapillary cell multiplication could be inhibited,and expressions of p-p38 MAPK,p-CREB1 and mRNA of CTGF and FN were significantly lower in group HG ＋ Flu,compared with those in group HG. Conclusion The expressions of CTGF mRNA,p-p38 MAPK and p-CREB1 may be significantly increased in glomerular mesangial cells under high concentration of glucose,and Fluvastatin can inhibit production of CTGF and extracellular matrix（ ECM） proteins partly by regulating the phosphorylation of p38 MAPK and CREB1.