二甲双胍对大鼠肾缺血再灌注损伤后纤维化的影响

苏娟

[摘要] 目的 探讨二甲双胍对大鼠肾脏缺血再灌注后纤维化改变的保护作用。 方法 采用随机数字表法将24只SD雄性成年大鼠分为假手术（Sham）组、缺血再灌注（I/R）组和二甲双胍（Metformin）处理组，每组8只。再灌注12周后，检测各组大鼠血清肌酐（Cr）、尿素氮（BUN）水平，苏木精-伊红（HE）染色和Masson染色观察肾组织结构变化和纤维化改变；免疫组织化学观察α-平滑肌肌动蛋（α-SMA）和转化生长因子-β1（TGF-β1）分布；Western blot进一步检测α-SMA和TGF-β1的表达水平。 结果 Sham组、I/R组和Metformin组间Cr和BUN比较差异无统计学意义（P > 0.05）。与Sham组比较，I/R组和Metformin组大鼠肾脏出现了明显间质纤维化，但是Metformin组与I/R组比较肾脏间质纤维化明显减轻；与Sham组比较，I/R组和Metformin组大鼠肾脏α-SMA和TGF-β1的表达水平显著升高，Metformin组与I/R组比较，大鼠肾脏α-SMA和TGF-β1的表达水平显著降低；差异均有高度统计学意义（P < 0.01）。 结论 肾脏缺血再灌注损伤可以引起小管间质纤维化，二甲双胍处理可以减轻此病理改变，其作用可能与二甲双胍能够抑制α-SMA和TGF-β1表达相关。

[关键词] 缺血再灌注损伤；二甲双胍；肾；纤维化

[中图分类号] R692.6 [文献标识码] A [文章编号] 1673-7210（2018）08（a）-0022-05

[Abstract] Objective To assess the potential effects of Metformin on the development of tubulointerstitial fibrosis after acute renal ischemia-reperfusion. Methods Twenty-four male Sprague Dawley rats were randomly assigned to three groups： Sham group， I/R group and Metformin group （n = 8）. Twelve weeks after reperfusion， levels of serum urea nitrogen （BUN） and creatinine （Cr） were assessed； Hematoxylin-eosin （H&E;） and Masson′s trichrome staining were used to assess renal fibrosis； the expression spot and protein levels of α-smooth muscle actin （α-SMA） and transforming growth factor-β1 （TGF-β1） were analyzed by immunohistochemistry （IHC） and Western blot. Results There was no statistically significant difference in levels of Cr and BUN among Sham group， I/R group and Metformin group （P > 0.05）. Compared with the Sham group， tubulointerstitial fibrosis was more obvious in the I/R group and the Metformin group； however， the level of tubulointerstitial fibrosis in the Metformin group was less than that of the I/R group. Compared with the Sham group， the levels of α-SMA and TGF-β1 were significantly increased in the I/R group and the Metformin group， the expression of α-SMA and TGF-β1 in the Metformin group were significantly decreased compared with those in the I/R group； the differences were statistically significant （P < 0.01）. Conclusion Administration of metformin significantly attenuated tubuleinterstitial fibrosis following I/R in rats， potentially via down-regulating expressions of α-SMA and TGF-β1.

[Key words] Ischemia-reperfusion injury； Metformin； Renal； Fibrosis

缺血再灌注損伤（ischemia/reperfusion injury，I/R）在肾移植、肾部分切除手术、肾动脉狭窄、主动脉搭桥手术、栓塞性疾病、意外或医源性损伤等过程中不可避免，是临床诊疗过程中常见的一种病理生理改变[1-2]。肾缺血可导致急性再灌注损伤，从而导致肾功能延迟恢复，并可能导致肾脏纤维化改变，进而产生慢性肾功能损害[3-4]。二甲双胍（Metformin）是一种常用的口服降糖药，用于治疗2型糖尿病。单磷酸腺苷活化蛋白激酶（AMP-activated protein kinase，AMPK）可以通过抑制合成代谢，促进分解代谢，增加ATP的合成，并降低ATP的利用，从而满足缺血组织的能量需求，参与脂肪酸氧化、葡萄糖转运、糖酵解、三酰甘油合成和蛋白质合成等一系列生物过程[5-9]。二……