电针预处理对高血糖小鼠肾损伤的保护效应研究

Electroacupuncture preconditioning alleviates kidney injury in hyperglycemic mice

目的:探讨电针预处理对链脲佐菌素(STZ)诱导的高血糖小鼠肾损伤的保护效应及分子机制。方法:将C57BL/6小鼠随机分为对照组、模型组、假电针组和电针组,每组20只。模型组、假电针组和电针组小鼠连续5 d腹腔注射STZ(50 mg·kg^(-1)·d^(-1))进行造模,电针组在造模前于"足三里"及"肾俞"行电针预处理7 d(2 Hz/15 Hz,梯度电流,30 min/次)。各组小鼠在造模完成3 d后,禁食6 h后测血糖值;HE染色法、PAS染色法观察肾脏组织损伤程度;免疫组织化学法检测肾小球瞬时受体电位阳离子通道蛋白6(TRPC6)及Nephrin蛋白阳性表达;Western blot法检测肾皮质TRPC6及Nephrin蛋白表达。结果:与对照组比较,模型组血糖水平明显升高(P<0.01),肾小球切面面积明显增大(P<0.0001),肾小球毛细血管明显扩张、基质增生,肾小管刷状缘消失,异常肾小管比例升高(P<0.0001),肾小球及肾组织TRPC6、Nephrin表达明显增加(P<0.01)。与模型组、假电针组比较,电针组血糖明显降低(P<0.01),肾组织损伤不明显,肾小球切面面积缩小(P<0.05),肾小管刷状缘消失较少,异常肾小管比例降低(P<0.0001),肾小球及肾组织TRPC6、Nephrin表达降低(P<0.05)。结论:电针预处理可减轻高血糖小鼠肾脏损伤,其保护效应可能是通过抑制高血糖,减少肾脏TRPC6和Nephrin的表达,抑制足细胞活化实现的。

Objective To explore the protective effect and molecular mechanism of electroacupuncture(EA) preconditioning on renal injury induced by streptozotocin(STZ) in hyperglycemic mice. Methods Eighty male C57 BL/6 mice were randomly divided into 4 groups: control, model, EA and sham EA groups, n=20 in each group. The hyperglycemic model was established by intraperitoneal injection of 0.1% STZ solution(50 mg/kg) for 5 days. EA preconditioning or sham EA was applied at "Zusanli"(ST36) and "Shenshu"(BL23), once daily for 7 successive days in the EA or sham EA group. Three days after mode-ling, the blood glucose was measured after fasting for 6 hours. The degree of renal injury was observed by HE staining and PAS staining;the expressions of transient receptor potential cation channel 6(TRPC6) and Nephrin protein in glomerulus were observed by immunohistochemistry;the expressions of TRPC6 and Nephrin protein in renal cortex were detected by Western blot. Results Compared with the control group, the blood glucose level was significantly increased(P<0.01), the glomerular cross-sectional area was apparently increased(P<0.000 1), the glomerular capillaries dilated, the matrix proliferated, the brush edge of renal tubules disappeared, the proportion of abnormal renal tubules increased(P<0.000 1), and the expressions of TRPC6 and Nephrin in glomeruli and renal tissue were significantly increased(P<0.01) in the model group. Following EA treatment and compared with the model and sham EA groups, the blood glucose was significantly down-regulated(P<0.01), the renal tissue injury was apparently alleviate, the cross-sectional area of glomerulus was reduced(P<0.05), the brush edge of renal tubules changes were obviously improved, the proportion of abnormal renal tubules decreased(P<0.000 1), and the expressions of TRPC6 and Nephrin in glomerulus and renal tissue decreased(P<0.05) in the EA group. Conclusion EA preconditioning can alleviate renal injury in hyperglycemic mice, which is closely related to its effects in reducing renal TRPC6 and Nephrin expressions and inhibiting podocyte activation.