Regulation of Insulin Resistance by Multiple MiRNAs via Targeting the GLUT4 Signalling Pathway

Abstract

Background/Aims: Type 2 Diabetes Mellitus (T2DM) is characterized by insulin resistance (IR), but the underlying molecular mechanisms are incompletely understood. MicroRNAs (miRNAs) have been demonstrated to participate in the signalling pathways relevant to glucose metabolism in IR. The purpose of this study was to test whether the multiple-target anti-miRNA antisense oligonucleotides (MTg-AMO) technology, an innovative miRNA knockdown strategy, can be used to interfere with multiple miRNAs that play critical roles in regulating IR. Methods: An MTg-AMO carrying the antisense sequences targeting miR-106b, miR-27a and miR-30d was constructed (MTg-AMO_106b/27a/30d). Protein levels were determined by Western blot analysis, and transcript levels were detected by real-time RT-PCR (qRT-PCR). Insulin resistance was analysed with glucose consumption and glucose uptake assays. Results: We found that the protein level of glucose transporter 4 (GLUT4), Mitogen-activated protein kinase 14 (MAPK 14), Phosphatidylinositol 3-kinase regulatory subunit beta (PI3K regulatory subunit beta) and mRNA level of Slc2a4 (encode GLUT4), Mapk14 (encode MAPK 14) and Pik3r2 (encode PI3K regulatory subunit beta) were all significantly down-regulated in the skeletal muscle of diabetic rats and in insulin-resistant L6 cells. Overexpression of miR-106b, miR-27a and miR-30d in L6 cells decreased glucose consumption and glucose uptake, and reduced the expression of GLUT4, MAPK 14 and PI3K regulatory subunit beta. Conversely, silencing of endogenous miR-106b, miR-27a and miR-30d in insulin-resistant L6 cells enhanced glucose consumption and glucose uptake, and increased the expression of GLUT4, MAPK 14 and PI3K regulatory subunit beta. MTg-AMO_106b/27a/30d up-regulated the protein levels of GLUT4, MAPK 14 and PI3K regulatory subunit beta, enhanced glucose consumption and glucose uptake. Conclusion: Our data suggested that miR-106b, miR-27a and miR-30d play crucial roles in the regulation of glucose metabolism by targeting the GLUT4 signalling pathway in L6 cells. Moreover, MTg-AMO_106b/27a/30d offers more potent effects than regular singular AMOs.

MicroRNAs-Mediated Regulation of Skeletal Muscle GLUT4 Expression and Translocation in Insulin Resistance

“…Confirmed direct modulations of Slc2a4 /GLUT4 expression were demonstrated for miR-93-5p, miR-223-3p, and miR-106b-5p [111–114]. …”

“…In these cells, overexpression of miR-106b-5p downregulated the GLUT4 content and decreased the glucose consumption and uptake; and, conversely, knockdown of miR-106b-5p increased the levels of GLUT4 and glucose consumption in this cell [114]. …”

Protective Effects of 2-Dodecyl-6-Methoxycyclohexa-2,5 -Diene-1,4-Dione Isolated from Averrhoa Carambola L. (Oxalidaceae) Roots on High-Fat Diet-Induced Obesity and Insulin Resistance in Mice

“…Insulin resistance is a prominent feature that is central to the development of T2DM. It decreases the ability of insulin to interact with insulin-sensitive tissues (especially muscle, liver, and fat), impairs glucose utilization, and induces hepatic glucose output [31,32].…”

Regulation of Gene Expression by Exercise-Related Micrornas

“…MiR-7 has been suggested to be involved in the pathogenesis of myocardial infarction and heart failure [59], miR-155 in the inflammatory process of the atherosclerosis via SOCS-1 activation in macrophages [60], and miR-378 in the cytokine-induced inflammation through SREBP and C/EBP pathaway in adipose tissue [61]. MiR-103 and miR-107 negatively regulate insulin sensitivity in liver from animal experimental models and patients with insulin resistance [62,63], whereas miR-1 has been positively related to the insulin sensitivity and miR-106b, -27a, and -30d negatively to the GLUT-4 expression in skeletal muscle cells from animal and cellular models [64,65]. MiRs also play an important role in skeletal muscle function [66,67].…”