The non-coding RNA gadd7 is a regulator of lipid-induced oxidative and endoplasmic reticulum stress

J Biol Chem. 2009 Mar 20;284(12):7446-54. doi: 10.1074/jbc.M806209200. Epub 2009 Jan 15.

Abstract

In obesity and diabetes, an imbalance in fatty acid uptake and fatty acid utilization leads to excess accumulation of lipid in non-adipose tissues. This lipid overload is associated with cellular dysfunction and cell death, which contribute to organ failure, a phenomenon termed lipotoxicity. To elucidate the molecular mechanism of lipid-mediated cell death, we generated and characterized a mutant Chinese hamster ovary cell line that is resistant to palmitate-induced cell death. In this mutant, random insertion of a retroviral promoter trap has disrupted the gene for the non-coding RNA, growth arrested DNA-damage inducible gene 7 (gadd7). Here we report that gadd7 is induced by lipotoxic stress in a reactive oxygen species (ROS)-dependent fashion and is necessary for both lipid- and general oxidative stress-mediated cell death. Depletion of gadd7 by mutagenesis or short hairpin RNA knockdown significantly reduces lipid and non-lipid induced ROS. Furthermore, depletion of gadd7 delays and diminishes ROS-induced endoplasmic reticulum stress. Together these data are the first to implicate a non-coding RNA in a feed-forward loop with oxidative stress and its induction of the endoplasmic reticulum stress response.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CHO Cells
  • Cricetinae
  • Cricetulus
  • Diabetes Mellitus / genetics
  • Diabetes Mellitus / metabolism
  • Diabetes Mellitus / pathology
  • Endoplasmic Reticulum / genetics
  • Endoplasmic Reticulum / metabolism*
  • Endoplasmic Reticulum / pathology
  • Fatty Acids / genetics
  • Fatty Acids / metabolism*
  • Mutagenesis
  • Mutation
  • Obesity / genetics
  • Obesity / metabolism
  • Obesity / pathology
  • Oxidative Stress*
  • RNA, Untranslated / genetics
  • RNA, Untranslated / metabolism*
  • Reactive Oxygen Species / metabolism*

Substances

  • Fatty Acids
  • RNA, Untranslated
  • Reactive Oxygen Species