罗格列酮、胰岛素对Ⅱ型糖尿病大鼠脑内TIPE2的表达和细胞凋亡的影响

Effects of rosiglitazone and insulin on the expression of TIPE2 and cell apoptosis in the brain of type 2 diabetic GK rats

目的探讨罗格列酮、胰岛素干预下Ⅱ型糖尿病大鼠脑内肿瘤坏死因子α诱导蛋白8样因子2(TIPE2)表达与细胞凋亡的变化,以及它们之间的相关性。方法选取3月龄Wistar大鼠(n=5,3Wistar组)和3月龄GK大鼠(n=5,3GK组);4月龄GK大鼠喂养至6月龄,根据期间的不同处理分为6月龄GK大鼠(n=5,6GK组)、罗格列酮干预6月龄GK大鼠(n=5,RSG+6GK组)、胰岛素干预6月龄GK大鼠(n=5,INS+6GK组)。采用免疫组化法检测各组大鼠脑内TIPE2的表达部位及特征,运用RT-PCR法和Western blotting法检测各组大鼠脑内TIPE2 mRNA和蛋白的表达,采用免疫荧光法检测各组大鼠脑内细胞凋亡的情况。结果 3GK组在染色强度、阳染细胞数、阳染血管数、mRNA、蛋白水平均较3 Wistar组有明显增加(P<0.05),6GK组较3GK组有明显增加(P<0.05),RSG+6GK组、INS+6GK组均较6GK组有明显减少(P<0.05)。大鼠脑内细胞凋亡数目与TIPE2的表达呈正相关性(r=0.981 6,P<0.05)。结论Ⅱ型糖尿病可促进大鼠脑内TIPE2的表达和细胞凋亡,随年龄的增长和糖尿病病程的进展,TIPE2的表达和细胞凋亡数目相应增加,罗格列酮、胰岛素干预可减少糖尿病大鼠脑内TIPE2的表达并抑制细胞凋亡。在糖尿病大鼠脑内细胞凋亡的进程中,TIPE2能够发挥促凋亡作用。

Objective To explore the effects of rosiglitazone and insulin on the expression of tumor necrosis factor-αinduced protein 8 like-2 （TIPE2）and cell apoptosis in the brain of type 2 diabetic GK rats,and to investigate the mech-anism involved.Methods A total of 25 rats were enrolled and divided into 5 groups,including 3-month-old Wistar rats in the 3Wistar group,3-month-old GK rats in the 3GK group,6-month-old GK rats in the 6GK group,rosiglita-zone treated 6-month-old GK rats in the RSG ＋6GK group,and insulin treated 6-month-old GK rats in the INS ＋6GK group,with 5 rats in each group.Immunohistochemistry （IHC）was used to observe the quantity and features of TIPE2＆amp;nbsp;expression in different rats’brains.RT-PCR and Western blotting were adopted respectively to detect the mRNA and protein level of TIPE2 in different rats’brains.Immunofluorescence （IH）was applied to observe the numbers of apop-totic cells in different rats’brains.Results There were significant differences among the groups in the staining intensi-ty,numbers of positively-stained cells and positively-stained vessels,level of mRNA and protein,and expression of TIPE2.The above indexes were highest in the 6GK group,followed by the 3GK group,3Wistar group,RSG ＋6GK group and INS ＋6GK group （all P 〈0.05）.The number of apoptotic cells was positively associated with the expression of TIPE2 （r =0.981 6,P 〈0.05）.Conclusion Type 2 diabetes can promote the expression of TIPE2 and cell apop-tosis.With age and progression of diabetes mellitus,expression of TIPE2 and the number of apoptotic cells gradually increase.After rosiglitazone and insulin treatment,the expression of TIPE2 reduces and cell apoptosis is inhibited.In the course of diabetes mellitus,TIPE2 accelerates the cell apoptosis.