Objective: To study the role and mechanism of Kcnq1ot1 by targeting to regulate miR-92a-1-5p to effect insulin secretion in pancreatic β cells.
Methods: The qRT-PCR was used to detect the expression of Kcnq1ot1 in different tissues of C57BL/6J mice, Min6 with PA intervention, islets of T2D model mice and the serum of T2D patients. The biological information website was used to predict that Kcnq1ot1 had complementary binding sites with miR-92a-1-5p, which was verified by the luciferase reporting gene system. The si-Kcnq1ot1, miR-92a-1-5p mimics, miR-92a-1-5p inhibitors and their respective controls were respectively transfected into Min6, and the effect of Ins1, Ins2, Insr, Nkx6.1, Irs1 and Ngn3 were detected by qRT-PCR, the Western blot method was used to detect the expression of insulin and Insr, and the GSIS experiment was used to detect its effect on insulin secretion.
Results: The expression of Kcnq1ot1 in pancreas was significantly higher than that in other tissues. Compared with the control group, the expression of Kcnq1ot1 in T2D patients' serum, Min6 after PA treatment and the islets of T2D model mice were lower. And the expression of Kcnq1ot1 in serum is negatively correlated with FBG or HbA1c. Low expression of Kcnq1ot1 led to remarkable reduction of insulin secretion in Min6 cells. Down-regulation of Kcnq1ot1 or overexpression of miR-92a-1-5p reduced the mRNA expression levels of Ins1, Ins2, Insr, Nkx6.1, Irs1 and Ngn3, and the protein levels of insulin and Insr. We screened miR-92a-1-5p as targets of Kcnq1ot1, and their interaction was validated with dual luciferase reporter gene experiment. After knocking down Kcnq1ot1, the expression of miR-92a-1-5p was found to increase. Further rescue experiments showed that down-regulation of miR-92a-1-5p could reverse the effect of low Kcnq1ot1 expression on the function of pancreatic β-cells.
Conclusion: Kcnq1ot1 may regulate the function of pancreatic β cells by targeting to negatively regulate miR-92a-1-5p.
Y.Chen: None. Y.Li: None. W.Xu: None. B.Lin: None. X.Mai: None. Y.Peng: None. D.Chen: None. Y.Su: None. W.Li: n/a.
Science & Technology Project of Guangzhou（202102010175）