β-catenin和WISP-1在糖尿病大鼠心肌中的表达

目的观察Wnt信号通路中β-catenin及其下游靶基因WISP～1在糖尿病大鼠心肌组织中的表达，分析Wnt/β-catenin信号通路在糖尿病大鼠心肌损伤中的作用。方法雄性SD大鼠随机分为正常对照组（Control Group）和糖尿病模型组（DMGroup），腹腔注射STZ55mg／kg诱导糖尿病大鼠模型，喂养至8周。测定大鼠的空腹血糖、心体比和心肌羟脯氨酸含量；电镜观察心肌超微结构变化，免疫组化法观察心肌组织β-catenin和WISP-1的表达。结果与对照组相比，糖尿病组大鼠空腹血糖水平明显增加，心体比增加，心肌羟脯氨酸含量增高。心肌超微结构显示肌纤维断裂，线粒体呈空泡样改变。心肌β-catenin和WISP-1蛋白表达增加。结论糖尿病大鼠心肌组织β-catenin和其下游靶基因WISP-1表达增加，提示Wnt／β-catenin信号通路的激活参与糖尿病所致的心肌损伤。

Expressions of myocardial I$-catenin and WISP-1 in diabetic rats

Objective To observe the expressions of myocardial-catenin and Wnt-induced secreted protein 1 （WISP-1） in diabetic rat, and analyze the role of Wnt/β-catenin signaling pathway in diabetes-in- duced myocardial injury. Methods Male SD rats were divided into control group and diabetes group. The diabetic rats were injected with STZ at 55mg/kg intraperitoneally and fed to 8th week. The plasma fasting blood glucose （FBG） level, heart weight/body weight （HW/BW） and myocardial hydroxyproline （Hp） content were measured. Myocardium ultrastructure was observed by electron microscopy. The expressions of myocardial β-catenin and WISP-1 protein were measured by immunohistochemical staining. Results In contrast to those of the control group, FBG level, HW/BW and myocardial Hp content were increased in the diabetes group. The breakage of myofibrils and mitochondria injury were aggravated. The expressions of myocardial t3 catenin and WISP-1 were higher than in the control group. Conclusion The protein expres- sions of myocardial β catenin and the downstream gene WISP-1 were increased in diabetic rat, which suggests that the activation of the Wnt/β-catenin signaling pathway participated in diabetes-induced myocardial injury.