Astragalus Polysaccharide Regulates miR-182/Bcl-2 Axis to Relieve Metabolic Memory through Suppressing Mitochondrial Damage-Mediated Apoptosis in Retinal Pigment Epithelial Cells

Pharmacology. 2021;106(9-10):520-533. doi: 10.1159/000515901. Epub 2021 Aug 5.

Abstract

Introduction: Metabolic memory is one of the causes of diabetic retinopathy, and astragalus polysaccharide (APS) has great advantages in the treatment of diabetes. However, the effect of APS on metabolic memory remains to be investigated.

Methods: Retinal pigment epithelial cell line ARPE-19 and primary retinal pigment epithelial cells were used to verify the effect of APS on mitochondria damage and apoptosis induced by high glucose-induced metabolic memory. The relationship between miR-182 and Bcl-2 was confirmed by a luciferase activity assay. Western blotting and quantitative reverse-transcriptase polymerase chain reaction were conducted to investigate the changes in mitochondrial damage- and apoptosis-associated markers. The cell mitochondrial membrane potential was assessed by JC-1 fluorescence. Terminal deoxynucleotidyl transferase dUTP nick end labelling staining and flow cytometry assays were performed to determine the occurrence of apoptosis.

Results: Treatment with high glucose followed by normal glucose significantly upregulated the expression of miR-182 and downregulated the expression of its target Bcl-2, and APS treatment reversed the above effects. Additionally, APS treatment restored mitochondrial function and inhibited apoptosis in cells in a state of metabolic memory. The effects of APS against mitochondrial damage and apoptosis were partially inhibited after miR-182 overexpression.

Conclusion: APS alleviated mitochondrial damage and apoptosis induced by metabolic memory by regulating the miR-182/Bcl-2 axis, which might serve as a new strategy for the treatment of diabetic retinopathy.

Keywords: Astragalus polysaccharides; Diabetic retinopathy; Metabolic memory; Mitochondrial damage; miR-182.

MeSH terms

  • Animals
  • Apoptosis / drug effects*
  • Astragalus Plant / chemistry*
  • Cell Line
  • Diabetic Retinopathy / pathology
  • Down-Regulation
  • Epithelial Cells / drug effects*
  • Genes, bcl-2 / drug effects*
  • Humans
  • Membrane Potential, Mitochondrial / drug effects*
  • MicroRNAs / drug effects*
  • Rats
  • Retinal Pigments / metabolism

Substances

  • MicroRNAs
  • Mirn182 microRNA, human
  • Retinal Pigments