PCNA及Caspase-3在2型糖尿病模型小鼠胰岛细胞中的表达及意义

目的：：观察和分析自发性2型糖尿病动物模型小鼠病程进展中增殖细胞核抗原(PCNA)和半胱天冬蛋白酶-3(Caspase-3)在胰岛细胞中的表达情况,探讨其临床意义。方法：选取 db/db 小鼠为糖尿病组,按3,5,8,10和12月龄分为5组,空腹血糖>10.0 mmol/L,肥胖；对照组为 db/+m 表型正常小鼠,按相应月龄分为5组,空腹血糖<6.0 mmol/L,体重正常。于相应年龄段取胰尾,用于 HE染色,免疫组织化学观察和比较。结果：(1)各月龄糖尿病组胰岛Caspase-3阳性细胞(凋亡细胞)的阳性率高于对照组(P<0.05),且糖尿病组胰岛凋亡细胞阳性率随病程进展呈增高趋势(P <0.05)；各月龄对照组胰岛Caspase-3阳性细胞(凋亡细胞)的阳性率无变化(P >0.05)。(2)各月龄糖尿病组胰岛细胞 PCNA 阳性细胞的阳性率与对照组比较无明显变化(P>0.05),且糖尿病组胰岛细胞PCNA阳性细胞的阳性率不随病程进展而变化(P>0.05)。结论：db/db 自发性糖尿病小鼠在其发病的过程中,胰岛 B 细胞增殖和凋亡同时存在。随着病情的进展,B细胞凋亡增加,数量减少与2型糖尿病的病因相关。

Expression and Significance of PCNA and Caspase-3 in Pancreatic Islet Cells of Mice with Spontaneous Type 2 Diabetes Mellitus

Obj ective:To observe and analyse the expression and relationship of proliferating cell nuciear antigen (PCNA)and Caspase-3 in pancreatic islet cells of mice with spontaneous type 2 diabetes mellitus.Methods:3,5,8,10 and 12 month-old obese db/db mice with fasting blood glucose(FBG)more than 10.0 mmol/L were selected as the test group(DM group),the age-matched normal weight db/+m mice with FBG less than 6.0 mmol/L served as the control group.Each group included 5 mice.The tails of pancreas were excised at 3,5,8, 10 and 12 months,and was observed by HE and immunohistochemical staining.Results:(1)The rate of positive cells of Caspase-3 increased in each age phase of DM group than in the control group(P<0.05).And the percentage of positive cells of Caspase-3 presented a rising tendency as the disease progressed in DW group(P<0.05).The rate of positive cells of Caspase-3 had no changes in the control group (P>0.05).(2)The rate of positive cells of PCNA had no changes in DM group and the control group(P>0.05),and also had no changes as the disease progressed in DW group(P>0.05).Conclusion:Insular B cells in db/db mice were varying as the disease progressed.B cell apoptosis increasing and quantities decreasing played an important role in causing type 2 diabetes mellitus.