糖尿病大鼠肾小球蛋白激酶Cα表达与肾病发病关系的研究

目的:观察四氧嘧啶诱发的糖尿病大鼠肾小球中蛋白激酶Cα(PKCα)、转化生长因子-β₁(TGF-β₁)和α-平滑肌肌动蛋白(α-SMA)表达的动态变化, 探讨3者之间相互关系以及与肾损害之间的关系。方法:将大鼠随机分为正常对照组(A组), 糖尿病1周组(B组), 糖尿病1月组(C组)和糖尿病2月组(D组)。用免疫组化和Western印迹法检查PKCα, TGF-β₁和α-SMA在肾小球的表达情况。光镜观察肾组织的形态改变, 生化法测定大鼠血糖, 血脂, 血尿肌酐以及尿蛋白。结果:糖尿病各组肾小球PKCα和TGF-β₁的表达多于正常组(P<0.05), 糖尿病各组PKCα, TGF-β₁和α-SMA3者间呈正相关, 并且与肾脏病变程度呈正相关。结论:糖尿病早期肾组织PKCα表达持续增加, 可使肾小球滤过率和滤过膜通透性增加, 参与了肾病早期蛋白尿的发生机制, 使TGF-β₁增多并诱导α-SMA的表达, 标志着肾脏固有细胞激活及表型转变和肾脏组织学改变。

Study on relationship between expression of PKCα in glomeruli and development of nephropathy in diabetic rats

AIM:To observe the dynamic changes of expression of PKCα, TGF-β₁ and α-SMA in glomeruli of diabetic rats induced by the alloxon and to invesitigate their roles in the diabetic nephropathy(DN).METHODS:Rats were randomly divided into four groups: normal control group (group A), diabetic group of one week (group B), diabetic group of one month (group C), diabetic group of two months (group D). Immunohistochemistry and Western blotting were used to detect the expression of PKCα, TGF-β₁ and α-SMA in renal tissue of all groups. Blood glucose, triglycerides, cholesterol, creatinine and urine protein were analysed by chemical methods. The morphological changes of renal tissue were checked through microscopy.RESULTS:The expression of PKCα and TGF-β₁ in renal tissue of diabetic groups were increased comparing with those of nomal control group(P<0.05). The mesangial cells expressed α-SMA in two months group. Chronologically the expression of PKCα, TGF-β₁ and α-SMA were positively correlative with each other and the impairment of kidney was also observed.CONCLUSIONS: During the DN process the expression of PKCα increased. PKCα raised GFR and the permeability of glomerular filtration membrane which enhanced urinary albumin excretion. PKCα also increased expression of TGF-β and therefore to induce the expression of α-SMA. The appearance of α-SMA was a marker of the phenotypic transform of renal cells.