O-GlcNAc Signaling Augmentation Protects Human Corneal Endothelial Cells from Oxidative Stress via AKT Pathway Activation

Curr Eye Res. 2020 May;45(5):556-562. doi: 10.1080/02713683.2019.1686154. Epub 2020 Jan 10.

Abstract

Purpose: To investigate the effect of inhibitor of O-glycosylation on human corneal endothelial cells (HCECs) under oxidative stress.Methods: HCECs were cultured and treated with 10 mM tert-butyl hydroperoxide (tBHP) with or without PUGNAc, a known inhibitor of OGA. Cell viability was assessed. Mitochondrial membrane potential (ΔΨm) was measured. Intracellular Ca2+ levels and mitochondrial Ca2+ levels were measured. Intracellular reactive oxygen species formation was measured. Levels of O-linked β-N-acetylglucosamine (O-GlcNAc), AKT, and pAKT were evaluated by Western blotting.Results: O-GlcNAc augmentation by PUGNAc increased cell viability, attenuated the loss of ΔΨm, and intracellular ROS against tBHP-induced oxidative stress (p < .05). O-GlcNAc augmentation reduced tBHP-induced mitochondrial calcium overload (p < .05) while it did not have any effect on intracellular calcium overload with tBHP. Furthermore, AKT signaling was activated in the cells with O-GlcNAc augmentation.Conclusions: O-GlcNAc signaling augmentation protects HCECs from oxidative stress via activation of AKT pathways.

Keywords: AKT pathway; Corneal endothelial cells; O-linked β-N-acetylglucosamine; corneal endothelial wound healing; oxidative stress.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylglucosamine / analogs & derivatives
  • Acetylglucosamine / metabolism*
  • Acetylglucosamine / pharmacology
  • Apoptosis / drug effects
  • Blotting, Western
  • Calcium / metabolism
  • Cell Survival
  • Cells, Cultured
  • Cytoplasm / metabolism
  • Cytoprotection / physiology
  • Endothelium, Corneal / drug effects
  • Endothelium, Corneal / metabolism*
  • Humans
  • Membrane Potential, Mitochondrial / physiology
  • Mitochondria / metabolism
  • Oxidative Stress*
  • Oximes / pharmacology
  • Phenylcarbamates / pharmacology
  • Proto-Oncogene Proteins c-akt / metabolism*
  • Reactive Oxygen Species / metabolism
  • Signal Transduction / physiology*
  • tert-Butylhydroperoxide / toxicity

Substances

  • Oximes
  • Phenylcarbamates
  • Reactive Oxygen Species
  • N-acetylglucosaminono-1,5-lactone O-(phenylcarbamoyl)oxime
  • tert-Butylhydroperoxide
  • Proto-Oncogene Proteins c-akt
  • Calcium
  • Acetylglucosamine