학술논문
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 PancreaticβCell Apoptosis by MicroRNA-32 in Type 2 Diabetes of Mice
Document Type
Academic Journal
Author
Source
南昌大学学报（医学版）. 56(6):9-12
Subject
Language
Chinese
ISSN
2095-4727
Abstract
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≥11．1 mmol· 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-32 mimic）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-32 agomir），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-32 agomir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。
ABSTRACT:Objective To investigate the effect of microRNA-32(miR-32)on the apoptosis of pancreaticβcells and its mechanism of action in type 2 diabetes.Methods A total of 70 C57BL/KsJ-db/db mice were used in this study.Among them,40 mice were randomly divided into diabe-tes group and negative control group,with 20 mice in each group.Blood glucose concentration ≥11.1 mmol·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 pancre-aticβcells was determined by TUNEL staining,and the expression of Apaf-1 and caspase-3 was measured by Western blot.In addition,the other 30 mice were randomly divided into random con-trol group,NC group(model mice were injected with miR-NC)and miR-32 group(model mice were injected with miR-32 agomir),with 10 mice in each group.The effect of miR-32 overexpres-sion 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).Further-more,the overexpression of miR-32 inhibited the apoptosis of pancreaticβcells(P<0.01).Bioin-formatic prediction showed that Apaf-1 is the downstream target gene of miR-32.The overexpres-sion of miR-32 significantly down-regulated the expression of Apaf-1.Compared with random con-trol 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 4 after treatment,suggesting that miR-32 can re-duce the levels of FBG in mice with type 2 diabetes.Conclusion MiR-32 can inhibit pancreaticβcell apoptosis through inhibiting the expression of Apaf-1 in diabetic mice,and thereby improve the occurrence and development of type 2 diabetes.
ABSTRACT:Objective To investigate the effect of microRNA-32(miR-32)on the apoptosis of pancreaticβcells and its mechanism of action in type 2 diabetes.Methods A total of 70 C57BL/KsJ-db/db mice were used in this study.Among them,40 mice were randomly divided into diabe-tes group and negative control group,with 20 mice in each group.Blood glucose concentration ≥11.1 mmol·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 pancre-aticβcells was determined by TUNEL staining,and the expression of Apaf-1 and caspase-3 was measured by Western blot.In addition,the other 30 mice were randomly divided into random con-trol group,NC group(model mice were injected with miR-NC)and miR-32 group(model mice were injected with miR-32 agomir),with 10 mice in each group.The effect of miR-32 overexpres-sion 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).Further-more,the overexpression of miR-32 inhibited the apoptosis of pancreaticβcells(P<0.01).Bioin-formatic prediction showed that Apaf-1 is the downstream target gene of miR-32.The overexpres-sion of miR-32 significantly down-regulated the expression of Apaf-1.Compared with random con-trol 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 4 after treatment,suggesting that miR-32 can re-duce the levels of FBG in mice with type 2 diabetes.Conclusion MiR-32 can inhibit pancreaticβcell apoptosis through inhibiting the expression of Apaf-1 in diabetic mice,and thereby improve the occurrence and development of type 2 diabetes.