Ling Charlotte, Vavakova Magdalena, Ahmad Mir Bilal, Säll Johanna, Perfilyev Alexander, Martin Melina, Jansson Per-Anders, Davegårdh Cajsa, Asplund Olof, Hansson Ola, Vaag Allan, Nilsson Emma
Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, Scania University Hospital, Malmö, 205 02, Sweden.
Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark.
BMC Med. 2024 Dec 2;22(1):572. doi: 10.1186/s12916-024-03789-y.
A large proportion of skeletal muscle insulin resistance in type 2 diabetes (T2D) is caused by environmental factors.
By applying multiomics mRNA, microRNA (miRNA), and DNA methylation platforms in biopsies from 20 monozygotic twin pairs discordant for T2D, we aimed to delineate the epigenetic and transcriptional machinery underlying non-genetic muscle insulin resistance in T2D.
Using gene set enrichment analysis (GSEA), we found decreased mRNA expression of genes involved in extracellular matrix organization, branched-chain amino acid catabolism, metabolism of vitamins and cofactors, lipid metabolism, muscle contraction, signaling by receptor tyrosine kinases pathways, and translocation of glucose transporter 4 (GLUT4) to the plasma membrane in muscle from twins with T2D. Differential expression levels of one or more predicted target relevant miRNA(s) were identified for approximately 35% of the dysregulated GSEA pathways. These include miRNAs with a significant overrepresentation of targets involved in GLUT4 translocation (miR-4643 and miR-548z), signaling by receptor tyrosine kinases pathways (miR-607), and muscle contraction (miR-4658). Acquired DNA methylation changes in skeletal muscle were quantitatively small in twins with T2D compared with the co-twins without T2D. Key methylation and expression results were validated in muscle, myotubes, and/or myoblasts from unrelated subjects with T2D and controls. Finally, mimicking T2D-associated changes by overexpressing miR-548 and miR-607 in cultured myotubes decreased expression of target genes, GLUT4 and FGFR4, respectively, and impaired insulin-stimulated phosphorylation of Akt (Ser473) and TBC1D4.
Together, we show that T2D is associated with non- and epigenetically determined differential transcriptional regulation of pathways regulating skeletal muscle metabolism and contraction.
2型糖尿病（T2D）中很大一部分骨骼肌胰岛素抵抗是由环境因素引起的。
通过在20对T2D不一致的同卵双胞胎的活检组织中应用多组学mRNA、微小RNA（miRNA）和DNA甲基化平台，我们旨在描绘T2D中非遗传肌肉胰岛素抵抗背后的表观遗传和转录机制。
使用基因集富集分析（GSEA），我们发现T2D双胞胎肌肉中参与细胞外基质组织、支链氨基酸分解代谢、维生素和辅因子代谢、脂质代谢、肌肉收缩、受体酪氨酸激酶信号通路以及葡萄糖转运蛋白4（GLUT4）向质膜转位的基因的mRNA表达降低。对于约35%失调的GSEA通路，鉴定出一种或多种预测的相关靶miRNA的差异表达水平。这些包括在GLUT4转位（miR-4643和miR-548z）、受体酪氨酸激酶信号通路（miR-607）和肌肉收缩（miR-4658）中靶标显著富集的miRNA。与无T2D的双胞胎相比，T2D双胞胎骨骼肌中获得的DNA甲基化变化在数量上较小。关键的甲基化和表达结果在来自不相关的T2D受试者和对照的肌肉、肌管和/或成肌细胞中得到验证。最后，在培养的肌管中过表达miR-548和miR-607模拟T2D相关变化，分别降低了靶基因GLUT4和FGFR4的表达，并损害了胰岛素刺激的Akt（Ser473）和TBC1D4的磷酸化。
总之，我们表明T2D与调节骨骼肌代谢和收缩的通路的非遗传和表观遗传决定的差异转录调控有关。
