Effect of α-linolenic acid on endoplasmic reticulum stress-mediated apoptosis of palmitic acid lipotoxicity in primary rat hepatocytes

Lipids Health Dis. 2011 Jul 25:10:122. doi: 10.1186/1476-511X-10-122.

Abstract

Background: Hepatic inflammation and degeneration induced by lipid depositions may be the major cause of nonalcoholic fatty liver disease (NAFLD). In this study, we investigated the effects of saturated and unsaturated fatty acids (FA) on apoptosis in primary rat hepatocytes.

Methods: The primary rat hepatocytes were treated with palmitic acid and/or α-linolenic acid in vitro. The expression of proteins associated with endoplasmic reticulum (ER) stress, apoptosis, caspase-3 levels were detected after the treatment.

Results: The treatment with palmitic acid produced a significant increase in cell death. The unfolded protein response (UPR)-associated genes CHOP, GRP78, and GRP94 were induced to higher expression levels by palmitic acid. Co-treatment with α-linolenic acid reversed the apoptotic effect and levels of all three indicators of ER stress exerted by palmitic acid. Tunicamycin, which induces ER stress produced similar effects to those obtained using palmitic acid; its effects were also reversed by α-linolenic acid.

Conclusions: α-Linolenic acid may provide a useful strategy to avoid the lipotoxicity of dietary palmitic acid and nutrient overload accompanied with obesity and NAFLD.

MeSH terms

  • Animals
  • Apoptosis / drug effects*
  • Cell Survival
  • Cells, Cultured
  • Drug Evaluation, Preclinical
  • Endoplasmic Reticulum / drug effects*
  • Endoplasmic Reticulum / physiology
  • Fatty Liver / physiopathology
  • Gene Expression
  • Heat-Shock Proteins / genetics
  • Heat-Shock Proteins / metabolism
  • Hepatocytes / drug effects*
  • Hepatocytes / physiology
  • Non-alcoholic Fatty Liver Disease
  • Palmitic Acid / toxicity*
  • Primary Cell Culture
  • Rats
  • Rats, Sprague-Dawley
  • Stress, Physiological / drug effects*
  • Transcription Factor CHOP / genetics
  • Transcription Factor CHOP / metabolism
  • Tunicamycin / pharmacology
  • Unfolded Protein Response / drug effects
  • alpha-Linolenic Acid / pharmacology*

Substances

  • Ddit3 protein, rat
  • GRP78 protein, rat
  • Heat-Shock Proteins
  • alpha-Linolenic Acid
  • Tunicamycin
  • Transcription Factor CHOP
  • Palmitic Acid