水蛭素对糖尿病大鼠肾脏的保护作用及其分子机制

Protective Effect and Molecular Mechanism of Hirudin on Kidney of Diabetic Rats

目的探究水蛭素对糖尿病大鼠肾脏的保护作用及其分子机制。方法18只SD大鼠随机分为对照组(n=5)和造模组(n=13)。造模组予以腹腔注射链脲佐菌素制备糖尿病大鼠模型。8周后,取造模成功的糖尿病大鼠(n=11)随机分为糖尿病模型组(n=6,后因血糖过高死亡1只)和水蛭素组(n=5)。水蛭素组皮下注射水蛭素5 U/只,连续6周;对照组和糖尿病模型组皮下注射等体积磷酸盐缓冲液。实验期间每2周记录1次大鼠的随机血糖和体质量。给药6周后,测定3组大鼠肾功能指标,肾脏组织肿瘤坏死因子α(tumor necrosis factorα,TNF⁃α)、转化生长因子β1(transforming growth factorβ1,TGF⁃β1)、白细胞介素⁃6(interleukin 6,IL⁃6)、纤连蛋白(fibronectin,FN)、nephrin、Ⅳ型胶原纤维(collagen typeⅣ,COL⁃Ⅳ)及酪氨酸激酶2(Janus kinase 2,JAK2)/信号转导与转录激活因子3(signal transduction and transcriptional activator 3,STAT3)信号通路相关蛋白表达水平,并观察肾脏病理改变。结果与对照组比较,糖尿病模型组实验期间随机血糖及给药6周内肾功能指标均升高(P均<0.05),体质量明显降低(P均<0.05),且肾脏出现病理损伤。与糖尿病模型组比较,水蛭素组肾功能指标降低(P<0.05),肾脏病理损伤减轻。与对照组比较,糖尿病模型组肾脏组织FN、COL⁃Ⅳ、TNF⁃α、TGF⁃β1、IL⁃6、p⁃JAK2、p⁃STAT3表达水平均明显升高(P均<0.05),nephrin表达水平降低(P<0.05)。与糖尿病模型组比较,水蛭素组肾脏组织FN、COL⁃Ⅳ、TNF⁃α、TGF⁃β1、IL⁃6、p⁃JAK2、p⁃STAT3表达水平均降低(P均<0.05),nephrin表达水平升高(P<0.05)。结论水蛭素可减轻糖尿病大鼠肾脏病理损伤,其作用机制可能与降低纤维化相关因子水平、抑制JAK2/STAT3通路活化相关。

Objective To investigate the protective effect of hirudin on kidneys of diabetic rats and its molecular mechanism.Methods Eighteen Sprague⁃Dawley rats were randomly divided into control group(n=5)and model group(n=13).The model group was injected intraperitoneally with streptozotocin(STZ)to establish a diabetic rat model.Eight weeks after STZ injection,successfully modeled diabetic rats were randomly divided into diabetic model group(n=6,with 1 rat dead due to hyperglycemia)and hirudin treatment group(n=5).The hirudin treatment group was administered 5 U hirudin while the control group and diabetic model group were injected subcutaneously with equal volume of phosphate buffered saline once daily for six weeks.During the experiment,the ratsbody weight and random blood glucose levels were monitored every two weeks.After 6 weeks of treatment,renal function parameters were measured,and the levels of tumor necrosis factorα(TNF⁃α),trans⁃forming growth factorβ1(TGF⁃β1),interleukin 6(IL⁃6),fibronectin(FN),nephrin,collagen⁃Ⅳ(COL⁃Ⅳ),and proteins related to the Janus kinase 2(JAK2)/signal transduction and transcriptional activator 3(STAT3)signaling pathway were assessed.Renal histopathological changes were also observed.Results Compared with the control group,the diabetic model group showed significantly elevated random blood glucose and renal function pa⁃rameters during the 6⁃week treatment(both P<0.05),along with a significant decrease in body weight(P<0.05)and renal pathological damage.Compared with the diabetic model group,the renal function parameters of hirudin treatment group were significantly decreased(P<0.05),the renal pathological damage was ameliorated.Compared with the control group,the expression levels of FN,COL⁃Ⅳ,TNF⁃α,TGF⁃β1,IL⁃6,p⁃JAK2,and p⁃STAT3 in the kidneys of diabetic model group were significantly increased(all P<0.05),while the expression of nephrin was reduced(P<0.05).Compared with the diabetic group,the expression level of FN,COL⁃Ⅳ,TNF⁃α,TGF⁃β1,IL⁃6,p⁃JAK2,and p⁃STAT3 in hirudin treatment group were significantly reduced(all P<0.05),while the nephrin expression increased(P<0.05).Conclusion Hirudin improved renal pathological changes in diabetic rats,and its mechanism may be related to the decrease of fibrosis⁃related factors and inhibition of the activation of the JAK2/STAT3 pathway.