糖基化终末产物对大鼠肾皮质基质金属蛋白酶2活性和表达的影响

的　研究糖基化终末产物 (AGEs)对肾皮质基质金属蛋白酶 2 (MMP 2 )活性及其mRNA表达的影响。方法　用链脲佐菌素制备大鼠糖尿病模型。大鼠血清蛋白与 0 .5mol/L葡萄糖孵育制备AGEs,分静脉注射AGEs(AGEs组 )、静脉注射大鼠正常血清 (阴性对照组 )和未注射大鼠 (对照组 ) 3组进行观察。ELISA测定肾皮质和血清AGEs含量 ,RT PCR检测MMP 2、金属蛋白酶组织抑制物 2 (TIMP 2 )mRNA表达水平 ,酶谱法测定MMP 2活性。结果　糖尿病大鼠肾皮质AGEs含量明显升高 ,MMP 2mRNA表达下降 ,TIMP 2mRNA表达上调 (均P <0 .0 1)。AGEs处理组大鼠肾皮质AGEs含量明显升高 (P <0 .0 1) ,MMP 2活性也明显下降 (均P <0 .0 5)。结论　AGEs通过降低大鼠肾皮质MMP 2的活性及其mRNA表达及增加TIMP 2mRNA表达 ,由此减少肾小球细胞外基质 (ECM )降解 ,可能是导致糖尿病肾病ECM积聚的原因之一

Effects of advanced glycation end products on activity and expression of matrix metalloproteinase-2 in renal cortex of rats

Objective To in ve stigate the effects of advanced glycation end products (AGEs) on matrix metallop roteinase-2 (MMP-2) activity and its mRNA expression in renal cortex of rats. Methods Diabetic model of rats was induced by s treptozotocin. AGEs were prepared by incubation of rat serum protein with 0.5 mo l/L glucose. AGEs was administered intravenously to normal rats (AGEs group), an d native rat serum protein was given as negative control (negative group) and no rmal rats without treatment were as control (control group). AGEs content in ren al cortex and serum was quantified by ELISA, MMP-2 and TIMP-2 mRNA expressions were examined by RT-PCR and MMP-2 activity was measured by zymography. Results AGEs content increased significantly, MMP-2 mRNA expression descended and TIMP-2 mRNA expression ascended in renal cortex o f diabetic rats (all P<0.01). In AGEs-treated group, AGEs content of renal cortex was markedly increased (P<0.01)andtheactivityofactiveformMMP-2 (62 KD) was signifi cantly reduced in AGEs-treated group (P<0.05) as compared with that in negatvie group or in control group. Conclusion AGEs inhibit MMP-2 activity and mRNA expression, and enhance TIMP -2 mRNA expression in renal cortex, suggesting that decreased degradation of gl omerular extracellular matrix may contribute to the development of diabetic neph ropathy.