Published online Mar 15, 2023. doi: 10.4239/wjd.v14.i3.209
Peer-review started: August 17, 2022
First decision: December 12, 2022
Revised: January 5, 2023
Accepted: February 15, 2023
Article in press: February 15, 2023
Published online: March 15, 2023
Processing time: 210 Days and 10.4 Hours
Diabetes is a metabolic disorder disease characterized by chronic hyperglycemia. The pathological features of diabetes include insulin resistance and a secretory deficiency in pancreatic islets β-cell. In clinical studies, a variety of miRNA are involved in the occurrence and development of diabetes. And miR-124 is highly expressed in the serum of patients with diabetes and in pancreatic islet β-cells. So, the role and mechanism of action of miR-124 in diabetes was explored in the diabetes mellitus type 2 (T2DM) mice and high glucose (HG) -induced Min6 cells.
A variety of miRNAs were abnormally expressed in patients with diabetes and affected insulin secretion by regulating the differentiation of islet β-cells, or affecting insulin synthesis and secretion. So, what is the role and mechanism of miR-124 in diabetes.
The present study aimed to investigate the expression of miR-124 in diabetic mice and the potential mechanism of action in islet β-cells.
Mice were fed with a high sucrose/high-fat diet combined with a low-dose streptozotocin injection to establish the mouse model of T2DM. The expression levels of miR-124 and enhancer of zeste homolog 2 (EZH2) in pancreatic tissues of diabetic mice were detected. The targeted relationship between miR-124 and EZH2 was predicted by Targetscan software and verified by a double luciferase reporter assay. To model diabetic mouse islets β-cells, Min6 cells were grown in HG medium to mimic glucolipotoxicity. The insulin secretion, proliferation, cell cycle and apoptosis of HG-induced Min6 cells were detected after interference of miR-124a and/or EZH2.
The expression of miR-124 was upregulated and EZH2 was downregulated in the pancreatic tissue of diabetic mice compared with control mice, and the expression of miR-124 was negatively correlated with that of EZH2. miR-124 was highly expressed in HG-induced Min6 cells. Inhibition of miR-124 promoted insulin secretion and cell proliferation, induced the transition from the G0/G1 phase to the S phase of the cell cycle, and inhibited cell apoptosis in HG-induced Min6 cells. EZH2 was one of the targets of miR-124. Co-transfection of miR-124 inhibitor and siRNA-EZH2 could reverse the effects of the miR-124 inhibitor in HG-induced Min6 cells.
miR-124 is highly expressed in diabetic mice and HG-induced Min6 cells and regulates insulin secretion, proliferation and apoptosis of islet β-cells by targeting EZH2.
miR-124-EZH2 axis might be one of the pathogenesis mechanisms of diabetes, providing a new target for the treatment of diabetes.