祛毒颗粒对5/6肾切除大鼠肾脏皮质MMP-2、TIMP-2、ECM及足细胞超微结构的影响

Effect of Qudu Granules on the MMP-2、TIMP-2、ECM and Ultrastructur of Podocyte in Renal Cortex of 5/6 Nephrectomized Rats

目的:观察祛毒颗粒对5/6肾切除大鼠肾皮质基质金属蛋白-2(matrix metalloproteinase-2,MMP-2)和金属蛋白酶组织抑制物-2(tissue inhibitor of metalloproteinase-2,TIMP-2)蛋白表达、细胞外基质(extracellular matrix,ECM)积聚和足细胞超微结构的影响。方法:将55只Wistar大鼠随机取10只为正常对照组,余用5/6肾切除法建立慢性肾衰竭(CRF)动物模型,将造模成功后的大鼠随机分为模型组、尿毒清颗粒组(简称对照组)、祛毒颗粒低剂量组(简称低剂量组)、祛毒颗粒高剂量组(简称高剂量组),每组10只,分别给与相应浓度和剂量的药物,实验期间测定大鼠的尿蛋白、肾功能,治疗12周后观察其肾脏病理改变,PAS染色评价肾小球硬化程度,免疫组化法检测肾小球Ⅳ型胶原(ColⅣ)、纤连蛋白(FN)和MMP-2、TIMP-2蛋白表达,电镜观察足细胞超微结构。结果:祛毒颗粒能明显减少5/6肾切除大鼠尿蛋白量(P<0.05),改善肾功能;减轻肾脏病理损害;PAS染色显示,祛毒颗粒治疗后肾小球阳性面积与肾小球总面积比值、肾小球硬化指数明显下降(P<0.01);免疫组化检查显示祛毒颗粒能抑制了FN、ColⅣ在肾组织的表达(P<0.01),下调TIMP-2蛋白表达,增加MMP-2活性,减轻ECM积聚;电镜观察显示,祛毒颗粒能减少足细胞脱落,减轻足突融合,保护足细胞形态。结论:祛毒颗粒通过调整5/6肾切除大鼠肾皮质MMP-2、TIMP-2的表达,促进ECM降解,减轻ECM集聚,保护足细胞,起到减轻肾小球硬化的作用。

Objective：To observe the effect of Qudu Granules on the MMP-2、TIMP-2、ECM and podocyte ultrastructur in renal cortex of nephrectomized rats（NXR）.Methods：10 Wistar rats served as the sham operation group,others 5/6 NX rats were randomly divided into 4 groups：the model group,Niao Duqing granules group（control group）,the low-dosage of Qudu granules group（low dosage group）and high dosage of Qudu granules group（high dosage group）.Medicine was given to each group according to the designed concentration and dosage.The therapeutic course was 12 weeks.Proteinuria、renal function were measured,renal tissues were examined routinedly by light microscope.The level of glomerular sclerosis was evaluated by PAS staining.The protein expression of type Ⅳ collagen（ColⅣ）and fibronectin（FN）in glomeruli were detected by ELISA,and MMP-2 activity and expression of TIMP-2 protein in cortex were assessed with same methods respectively.Podocyte ultrastructur was observed by electron microscopy.Results：The proteinuria of the 5/6 NX rats was significantly reduced by Qudu granules.The creatinine and urea nitrogen were improved.Glomerulosclerosis index was mitigated.The protein expression of ColⅣ and FN were significantly inhibited.Expression of TIMP-2 protein was markedly down-regulated,while MMP-2 activity was higher than that of the model group.Qudu granules can improve podocytes ultrastructure,lessen the fusion of foot process.Conclusion：Through the activation of MMP-2 and the down-regulation of expression of TIMP-2 protein in 5/6 NX rats,promotting the degradation of ECM and ameliorating ECM accumulation in glomeruli,and protecting the podocytes,Qudu granules may mitigate glomerular sclerosis.