microRNA-32抑制小鼠2型糖尿病胰岛β细胞凋亡的机制研究  

Mechanism of Inhibition of Pancreatic β Cell Apoptosis by MicroRNA-32 in Type 2 Diabetes of Mice

作　　者：聂俊刚[1] 宋志芳[1] 施国祥[1] 章燕[2] 郑泽琪[1] 

机构地区：[1]南昌大学第一附属医院心内科,南昌330006 [2]南昌大学第一附属医院内分泌科,南昌330006

出　　处：《南昌大学学报（医学版）》2016年第6期9-12,共4页Journal of Nanchang University：Medical Sciences

基　　金：江西省自然科学基金(20142BAB205058);江西省卫生计生委课题(20151039)

摘　　要：目的探讨2型糖尿病中microRNA-32(miR-32)对胰岛β细胞凋亡的影响及其机制。方法以70只C57BL/KsJ-db/db小鼠为研究对象,将其中40只小鼠按随机数字表法分为糖尿病组及阴性对照组,每组20只,以血糖浓度≥11.1mmol·L-1时判为建模成功,并测定体质量;采用实时荧光定量PCR(qRT-PCR)检测糖尿病组及阴性对照组中胰腺组织miR-32的表达;脂质体法转染miR-32的模拟物(miR-32mimic)至胰岛β细胞,使其在细胞中呈过表达状态,进行TUNEL染色对比转染前后胰岛β细胞的凋亡情况;并利用蛋白质印迹技术(Western blot)检测miR-32过表达胰岛β细胞中Apaf-1和Caspase-3蛋白的表达。再选择30只C57BL/KsJ-db/db小鼠,按随机数字表法分为随机对照组(n=10)、NC组(n=10,建模成功后在小鼠体内注射miR-NC)和miR-32组(n=10,建模成功后在小鼠体内注射miR-32agomir),观察体内过表达miR-32对糖尿病小鼠空腹血糖的影响。结果糖尿病组小鼠胰腺组织中miR-32的表达量较阴性对照组明显减少(P<0.01);过表达miR-32的胰岛β细胞的细胞凋亡率明显下降(P<0.01);生物信息学预测显示Apaf-1为miR-32的下游靶基因,过表达miR-32后,Apaf-1显著下调。与随机对照组相比,NC组、miR-32组小鼠空腹血糖明显升高,NC组、miR-32组小鼠体内分别注射miR-NC和miR-32agomir后第4周,miR-32组小鼠空腹血糖较NC组明显降低(均P<0.01),提示miR-32可显著降低2型糖尿病小鼠的空腹血糖。结论 miR-32可以通过抑制Apaf-1的表达减少糖尿病小鼠中胰岛β细胞的凋亡,进而改善2型糖尿病的发生和发展进程。Objective To investigate the effect of microRNA-32（miR-32）on the apoptosis of pancreaticβcells and its mechanism of action in type 2diabetes.Methods A total of 70C57BL/KsJ-db/db mice were used in this study.Among them,40 mice were randomly divided into diabetes group and negative control group,with 20 mice in each group.Blood glucose concentration ≥11.1mmol·L^-1 was judged as a successful modeling,and the body weight was measured.The expression of miR-32 in pancreatic tissue was detected by qRT-PCR.The miR-32 mimics were transfected into pancreaticβcells by lipidosome to overexpress miR-32.The apoptosis of pancreaticβcells was determined by TUNEL staining,and the expression of Apaf-1and caspase-3was measured by Western blot.In addition,the other 30 mice were randomly divided into random control group,NC group（model mice were injected with miR-NC）and miR-32group（model mice were injected with miR-32agomir）,with 10 mice in each group.The effect of miR-32 overexpression on fasting blood glucose（FBG）levels was observed in diabetes mice.Results Compared with negative control group,the expression of miR-32 decreased in diabetes group（P〈0.01）.Furthermore,the overexpression of miR-32 inhibited the apoptosis of pancreaticβcells（P〈0.01）.Bioinformatic prediction showed that Apaf-1is the downstream target gene of miR-32.The overexpression of miR-32 significantly down-regulated the expression of Apaf-1.Compared with random control group,FBG levels increased in both NC group and miR-32 group.Compared with NC group,FBG levels decreased in miR-32 group at week 4after treatment,suggesting that miR-32 can reduce the levels of FBG in mice with type 2diabetes.Conclusion MiR-32 can inhibit pancreaticβcell apoptosis through inhibiting the expression of Apaf-1in diabetic mice,and thereby improve the occurrence and development of type 2diabetes.

关 键 词：糖尿病 胰岛Β细胞 细胞凋亡 microRNA-32 动物 实验 小鼠 

分 类 号：R332[医药卫生—人体生理学]