Downregulation of miR-637 promotes vascular smooth muscle cell proliferation and migration via regulation of insulin-like growth factor-2

Cell Mol Biol Lett. 2020 May 7:25:30. doi: 10.1186/s11658-020-00222-z. eCollection 2020.

Abstract

Background: Dysregulation of the proliferation and migration of vascular smooth muscle cells (VSMCs) is a crucial cause of atherosclerosis. MiR-637 exerts an antiproliferative effect on multiple human cells. Its impact on atherosclerosis remains largely unexplored.

Methods: Real-time PCR was used to determine miR-637 expression in samples from atherosclerosis patients and animal models. Its expression in VSMC dysfunction models (induced by ox-LDL) was also measured. The proliferation and migration of VSMCs were respectively tested using CCK-8 and Transwell assays, and apoptosis was measured using flow cytometry. The Targetscan database was used to predict the target genes of miR-637. Interaction between miR-637 and the potential target gene was validated via real-time PCR, western blotting and a luciferase reporter assay.

Results: MiR-637 expression was significantly lower in atherosclerosis patient and animal model samples. It also decreased in a dose- and time-dependent manner in animal models with ox-LDL-induced atherosclerosis. Transfection with miR-637 mimics suppressed the proliferation and migration of VSMCs while promoting apoptosis, while transfection with miR-637 inhibitors had the opposite effects. We also validated that insulin-like growth factor-2 (IGF-2), a crucial factor in the pathogenesis of atherosclerosis, serves as a target gene for miR-637.

Conclusion: MiR-637 targeting IGF-2 contributes to atherosclerosis inhibition and could be a potential target for this disease.

Keywords: Atherosclerosis; IGF-2; VSMC; miR-637.

MeSH terms

  • Animals
  • Atherosclerosis / genetics
  • Cell Movement / genetics
  • Cell Proliferation / genetics
  • Cells, Cultured
  • Disease Models, Animal
  • Down-Regulation
  • Gene Expression Regulation
  • Humans
  • Insulin-Like Growth Factor II / genetics*
  • Lipoproteins, LDL / pharmacology
  • Mice, Inbred C57BL
  • Mice, Knockout, ApoE
  • MicroRNAs / blood
  • MicroRNAs / genetics*
  • Muscle, Smooth, Vascular / cytology*
  • Muscle, Smooth, Vascular / drug effects
  • Muscle, Smooth, Vascular / pathology
  • Muscle, Smooth, Vascular / physiology
  • Plaque, Atherosclerotic / genetics*
  • Plaque, Atherosclerotic / pathology

Substances

  • Lipoproteins, LDL
  • MIRN637 microRNA, human
  • MicroRNAs
  • oxidized low density lipoprotein
  • Insulin-Like Growth Factor II