霉酚酸对高糖环境下肾小球系膜细胞外基质的影响

目的：通过检测霉酚酸酯（MMF）的代谢产物霉酚酸（mycophenolic acid,MPA）对高糖环境下大鼠肾小球系膜细胞（mesangial cells,MCs）增殖、转化生长因子-β1（transformation growth factor-β1,TGF-β1）和细胞外基质的主要成分：纤维连接蛋白（fibrin,FN）、层黏连蛋白（laminin,LN）和胶原Ⅳ（typeⅣ collagen,ColⅣ）分泌的影响,探讨MPA对糖尿病肾病（diabetic nephropathy,DN）的保护机制。方法：四甲基偶氮唑盐微量酶反应比色法测定高糖及高糖加入不同浓度MPA（1～10μmol/L）后对大鼠MCs增殖的影响,ELASE的方法测定各组24h、48h、72hFN、LN、ColⅣ的表达,荧光定量多聚酶链反应的方法检测各组标本中TGF-β1 mRNA的表达,并进行统计学分析。结果：高糖可以诱导MCs增殖及TGF-β1、FN、LN、ColⅣ的表达,MPA抑制高糖环境下MCs增殖和FN、LN和ColⅣ分泌并呈剂量时间依赖性,MPA可以呈剂量依赖性抑制高糖环境下MCs分泌TGF-β1,各组之间有统计学差异（P〈0.05）。结论：MPA可以通过抑制高糖环境下MCs的增殖和TGF-β1的分泌,从而抑制系膜外基质增多、系膜区扩张,有效阻止细胞外基质积聚,从而防止肾小球硬化,延缓DN的发展。

The Effect of Mycophenolic Acid on Extracelular Material of Glomerular Mesangial Induced by High Glucose

Objective： This study is to investigate effects of MPA （Mycophenolic acid） which is the metabolic product of MMF in vivo on proliferation and expressions of transformation growth factor （TGF - β1 ）, Fibrin （FN）, Laminin （LN）, Type IV collagen （Col Ⅳ ） induced by high glucose in rat Mesangial cells （MCs）. Methods： （ 1 ） The MCs proliferative rate within 6,12 and 24 hours were detected by MTT colorimetry. （2） FN, LN, ColⅣ in supernatant contents of medium were detected by radioimmunoassay method at 24, 48 and 72h respectively. （3） TGF -β1 was detected by fluorescent quantitation polymerase chain reaction at 72 h. All the indexs were detected as MPA at different doses （1- 10 μmol/L） added to high glucose medium （30 mmol/L）, high glucose group and normal control group （5 mmol/L）. Results：The expressions of TGF-β1 ,FN,LN and ColIg arid the proliferation of MCs induced by high glucose were significantly high compared to normal control group （ P 〈 0.05 ）, but minimal dose MPA can depress the proliferation and the expressions of TGF - β1, FN, LN and CollV of MCs induced by high glucose effectivly （ P 〈 0.05）. Not only the proliferation and the expressions of FN,LN and ColⅣ showing time and dose dependence but also the expression of TGF- β1 by dose - dependence were down regulated by MPA （P〈 0.05）. Conclusion：Increased mesangial extracellular matrix and mesangial expansion can be inhibited by MPA through suppressing MCs proliferation and secretion of TGF- β1 induced by the high sugar environment. It can also prevent glomerulosclerosis, delaying the development of Diabetic Nephropathy （DN）.