Higd1a Protects Cells from Lipotoxicity under High-Fat Exposure

Oxid Med Cell Longev. 2019 Apr 8:2019:6051262. doi: 10.1155/2019/6051262. eCollection 2019.

Abstract

Hypoxia-inducible gene domain family member 1A (Higd1a) has recently been reported to protect cells from hypoxia by helping to maintain normal mitochondrial function. The potential induction of Higd1a under high-fat exposure and whether it could protect cells from oxidative stress attracted our attention. Initially, 0.4 mM oleic acid and 0.2 mM palmitate were added to the growth media of HepG2 and LO2 cells for 72 hours. We discovered increased Higd1a expression, and knocking down Higd1a impaired mitochondrial transmembrane potential and induced cell apoptosis. We then identified that elevated reactive oxygen species (ROS) is responsible for increased Higd1a expression. Furthermore, we found that ROS promoted Higd1a expression by upregulating HIF-1a and PGC-1a expressions, and these two proteins could exert synergistic effects in inducing Higd1a expression. Taken together, these data suggest that Higd1a plays positive roles in protecting cells from oxidative stress, and ROS could induce Higd1a expression by upregulating PGC-1a and HIF-1a expressions.

MeSH terms

  • Animals
  • Apoptosis Regulatory Proteins / metabolism*
  • Cytoprotection* / drug effects
  • Diet, High-Fat*
  • Hep G2 Cells
  • Humans
  • Hypoxia-Inducible Factor 1, alpha Subunit / metabolism
  • Intracellular Signaling Peptides and Proteins / metabolism*
  • Lipids / toxicity*
  • Membrane Potential, Mitochondrial / drug effects
  • Mice, Inbred C57BL
  • Mitochondrial Proteins / metabolism*
  • Neoplasm Proteins / metabolism*
  • Non-alcoholic Fatty Liver Disease / metabolism
  • Non-alcoholic Fatty Liver Disease / pathology
  • Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha / metabolism
  • Reactive Oxygen Species / metabolism
  • Up-Regulation / drug effects

Substances

  • Apoptosis Regulatory Proteins
  • HIGD1A protein, human
  • Higd1a protein, mouse
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Intracellular Signaling Peptides and Proteins
  • Lipids
  • Mitochondrial Proteins
  • Neoplasm Proteins
  • Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha
  • Reactive Oxygen Species