大鼠肾组织中组织型转谷氨酰胺酶和结缔组织生长因子表达的研究

目的观察依那普利对单侧输尿管梗阻(UUO)大鼠肾组织内组织型转谷氨酰胺酶(tTG)、结缔组织生长因子(CTGF)介导的肾间质纤维化的作用。方法采用UUO致肾间质纤维化大鼠模型。将大鼠随机分为假手术组(8只)、模型组(8只)、依那普利治疗组(8只)。术后第4周,处死各组大鼠,用苏木素-伊红(HE)、Masson染色评定肾小管间质纤维化程度;用免疫组织化学方法检测肾组织内tTG、CTGF和Ⅰ型胶原(ColⅠ)的表达部位及蛋白表达水平。结果与假手术组相比,模型组大鼠BUN水平显著增加(P<0.01),肾间质纤维组织相对面积显著扩大(P<0.01),肾组织内tTG、CTGF及ColⅠ蛋白质表达均显著上调(P<0.01或P<0.05)。依那普利干预后,上述上调指标都被显著抑制(P<0.01或P<0.05)。结论依那普利具有抗肾纤维化的作用,其机制可能与下调肾组织tTG和CTGF表达有关。

Study of the expression of tissue transglutaminase and connective tissue growth factor in kidneys from UUO rats

Objective To investigate the effect of enalapril on the expression of tTG,CTGF and its mechanism on renal interstitial fibrosis following unilateral ureteral obstruction(UUO) in rat kidney.Methods Unilateral ureteral obstruction(UUO) rat animal models were used.Male wistar rats were randomly divided into three groups with 8 rats in each:sham-operated group(0.9% saline solution),model group(0.9% saline solution),enalapril treatment group(enalapril 10 mg·kg-1·d-1).Sham-operated rats had their ureters exposed and manipulated but not ligated and snipping.Medicines were given intraperitoneally daily two days after the operation.All rats were killed 4 weeks after surgery,and the kidneys were removed.One part of the kidneys was fixed in 10% phosphate-buffered formalin for pathological and immunohistochemical studies after paraffin embedding.Firstly,renal function was examined in each rat by heart puncture.Secondly,the sites and levels of protein expression of tTG,CTGF and ColⅠwere detected by immunohistochemistry staining.Lastly,the degree of tubulointerstitial fibrosis was scored by HE and Masson staining.Results Compared with sham-operated group,the blood uria nitrogen level was significantly increased in model group [(10.6±1.5)mmol/Lvs (7.1±0.5)mmol/L](P<0.01),but serum creatinine was normal in each group.Furthermore,the relative area of interstitial fibrosis was also significantly enlarged in the model group (0.319±0.104 vs 0.039±0.007)(P<0.01).Meanwhile,compared with sham-operated group,the expression of tTG,CTGF and Col Ⅰ protein was significantly up-regulated in their kidney tissue(0.243±0.036 vs 0.098±0.003;0.314±0.044 vs 0.004±0.001;0.062±0.015 vs 0.012±0.002)(P<0.01或0.05).After intervention with enalapril,the upregulation of the above-mentioned parameters were all significantly inhibited,and there was significant difference between model group and treatment group(P<0.01或0.05).Conclusion The effect of enalapril on ameliorating renal interstitial fibrosis may be correlated with its inhibition on over-expression of tTG and CTGF in kidney tissue.