Exendin-4 regulates endoplasmic reticulum stress to protect endothelial progenitor cells from high-glucose damage

Mol Cell Probes. 2020 Jun:51:101527. doi: 10.1016/j.mcp.2020.101527. Epub 2020 Jan 26.

Abstract

Background: High glucose affects the function of endothelial cells by increasing oxidative stress. Studies have found that exendin-4 can improve wound healing in diabetic mice and mice with normal blood glucose. However, the mechanism of exendin-4 in endothelial progenitor cells under high-glucose condition has not been fully elucidated.

Methods: Diabetic mouse models were established to investigate the effects of exendin-4 on endothelial progenitor cells in diabetic mice. Serum superoxide dismutase (SOD) and malondialdehyde (MDA) were determined by WST-8 and thiobarbituric acid (TBA) colorimetry, respectively. Cell viability, apoptosis and reactive oxygen species (ROS) were detected by 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) and flow cytometry. Gene and protein expressions were determined by Quantitative reverse transcription PCR (qRT-PCR) assay and Western blot (WB).

Results: The results showed that in diabetic mice, exendin-4 did not affect blood glucose or body weight, moreover, it improved aortic diastolic function, increased SOD activity and down-regulated malondialdehyde (MDA) level in the mice. In addition, exendin-4 also increased endothelial progenitor cell (EPCs) viability and reduced cell apoptosis through inhibiting p38 MAPK pathway and reducing endoplasmic reticulum stress and ROS.

Conclusion: Exndin-4 can alleviate diabetes-caused damage to mice, moreover, it reduced endoplasmic reticulum stress and ROS through inhibiting p38 MAPK pathway in MPCs cells under high-glucose condition, thus increasing cell viability and reducing cell apoptosis.

Keywords: Diabetes mellitus; Endoplasmic reticulum stress; Endothelial progenitor cells; Exendin-4.

MeSH terms

  • Animals
  • Apoptosis / drug effects*
  • Body Weight / drug effects
  • Cell Survival / drug effects
  • Cells, Cultured
  • Diabetes Mellitus, Experimental
  • Endoplasmic Reticulum Stress / drug effects*
  • Endothelial Progenitor Cells / drug effects*
  • Endothelial Progenitor Cells / metabolism
  • Exenatide / pharmacology*
  • Glucose / pharmacology*
  • MAP Kinase Signaling System / drug effects
  • Male
  • Malondialdehyde / blood
  • Mice
  • Mice, Inbred C57BL
  • Reactive Oxygen Species / metabolism
  • Superoxide Dismutase / blood
  • Superoxide Dismutase / genetics

Substances

  • Reactive Oxygen Species
  • Malondialdehyde
  • Exenatide
  • Superoxide Dismutase
  • Glucose