中文摘要：

目的：探讨人组织型激肽释放酶基因（human tissue kallikrein,HK）对糖尿病肾病（diabetic nephropathy,DN）的影响及其机制。方法：48只雄性Wistar大鼠随机分为普通饲料组（即正常组）和高脂高糖饲料组。高脂高糖饲料组以小剂量链脲佐菌素加高脂高糖饮食诱导2型糖尿病（diabete mellitus,DM）模型,造模后随机分为两组,分别经尾静脉导入重组腺相关病毒（recombinant adeno-associated viruses,rAAV）介导的HK基因（HK组）以及报告基因beta-半乳糖苷酶（beta-galac-tosidase,LacZ）（LacZ组）,观察12周后处死实验动物,留取心、肝、肾等组织。Western blot检测HK在各组织的表达。PAS染色观察肾小球硬化情况,天狼猩红染色观察肾脏纤维化情况。24h尿微量白蛋白（microalbuminuria,mAlb）与尿渗透压检测评定肾功能,免疫组织化学以及Western blot检测肾脏转化生长因子-β1（transforming growth factor-β1,TGF-β1）的表达。结果：rAAV介导的HK可在2型DM大鼠的肝脏、肾脏、心脏表达,而且相较于LacZ组且表达增强;PAS染色显示：LacZ组肾脏出现中度的肾小球系膜细胞及基质增生,血管周围间质细胞浸润,血管壁增厚,以及肾小囊滴状病变和毛细血管纤维帽。另外肾小管大量的空泡变性,肾小管腔内出现较多蛋白质管型,HK组较LacZ组明显好转;天狼星红染色显示：LacZ组肾脏间质、血管壁胶原沉积,肾小球细动脉管壁增厚,而HK组病变较轻（P〈0.05）;24hmAlb排泄量LacZ组比正常组明显增加（P〈0.05）,HK组较LacZ组排泄量显著下降（P〈0.05）。LacZ组与正常组比较,尿渗透压明显下降（P〈0.05）,HK组较LacZ组显著上升（P〈0.05）;TGF-β1主要表达于LacZ组的肾小管上皮细胞,HK组较LacZ组TGF-β1明显下调（P〈0.05）。结论：HK基因明显改善DN,保护肾功能,原因可能与下调肾脏TGF-β1的表达有关。

英文摘要：

Objective：To investigate the effect and mechanism of human tissue kallikrein on diabetic nephropathy.Methods：Forty-eight male Wistar rats were randomly divided into the control group and the experimental group.Rats of experimental group were injected with low dose streptozotocin and were fed with diets enriched in both glucose and fat to establish type 2 diabetic models.Recombinant adeno-associated viruses vector expressing HK gene（HK group） or Lacz gene（Lacz group） were injected into diabetic rats through tail veins,then all rats were killed after 12 weeks.The expressions of HK in rats and TGF-β1 were determined by Western blot.Four 3 m renal paraffin sections were randomly chosen from one kidney from each animal and stained with periodic acid Schiff（PAS） reagent to evaluate morphological changes and with Sirius red to evaluate collagen deposition.Twenty four hours urinary microalbumin and urine osmolarity were measured to evaluate renal function.TGF-β1 was stained by immunohistochemical method in kidneys.Results：The expression of HK in HK group increased significantly compared with that in LacZ group.The stain of PAS of kidneys revealed moderate mesangial cellular proliferation,severe interstitial lymphocyte infiltration,renal tubular vacuolation,and protein casts in renal tubules.Hyaline caps were observed in rats of LacZ group,and HK can significantly attenuate these changes in rats of HK group.Moderate collagen deposition and blood capillary thrombosis were also observed in rats of LacZ group.In contrast,HK can significantly attenuate these changes in rats of HK group（P〈0.05）.24 h urinary microalbumin increased significantly in LacZ group,compared with that of normal group（P〈0.05）,and Hk can reverse this change in HK group（P〈0.05）.Urine osmolarity decreased significantly in LacZ group,compared with that of normal group（P〈0.05）,and HK can reverse this change in HK group（P〈0.05）.TGF-β1 level measured by immunological histochemistry and western blot were signif