α-Lipoic acid ameliorates impaired glucose uptake in LYRM1 overexpressing 3T3-L1 adipocytes through the IRS-1/Akt signaling pathway

J Bioenerg Biomembr. 2012 Oct;44(5):579-86. doi: 10.1007/s10863-012-9460-1. Epub 2012 Jul 22.

Abstract

Overexpression of the Homo sapiens LYR motif containing 1 (LYRM1) causes mitochondrial dysfunction and induces insulin resistance in 3T3-L1 adipocytes. α-Lipoic acid (α-LA), a dithiol compound with antioxidant properties, improves glucose transport and utilization in 3T3-L1 adipocytes. The aim of this study was to investigate the direct effects of α-LA on reactive oxygen species (ROS) production and insulin sensitivity in LYRM1 overexpressing 3T3-L1 adipocytes and to explore the underlying mechanism. Pretreatment with α-LA significantly increased both basal and insulin-stimulated glucose uptake and insulin-stimulated GLUT4 translocation, while intracellular ROS levels in LYRM1 overexpressing 3T3-L1 adipocytes were decreased. These changes were accompanied by a marked upregulation in expression of insulin-stimulated tyrosine phosphorylation of IRS-1 and serine phosphorylation of Akt following treatment with α-LA. These results indicated that α-LA protects 3T3-L1 adipocytes from LYRM1-induced insulin resistance partially via its capacity to restore mitochondrial function and/or increase phosphorylation of IRS-1 and Akt.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3T3-L1 Cells
  • Animals
  • Antioxidants / pharmacology*
  • Apoptosis Regulatory Proteins / biosynthesis*
  • Apoptosis Regulatory Proteins / genetics
  • Gene Expression
  • Glucose / genetics
  • Glucose / metabolism*
  • Glucose Transporter Type 4 / genetics
  • Glucose Transporter Type 4 / metabolism
  • Humans
  • Insulin Receptor Substrate Proteins / genetics
  • Insulin Receptor Substrate Proteins / metabolism*
  • Insulin Resistance / genetics
  • Mice
  • Phosphorylation / drug effects
  • Phosphorylation / genetics
  • Protein Transport / drug effects
  • Protein Transport / genetics
  • Proto-Oncogene Proteins c-akt / genetics
  • Proto-Oncogene Proteins c-akt / metabolism*
  • Reactive Oxygen Species
  • Signal Transduction / drug effects*
  • Signal Transduction / genetics
  • Thioctic Acid / pharmacology*

Substances

  • Antioxidants
  • Apoptosis Regulatory Proteins
  • Glucose Transporter Type 4
  • Insulin Receptor Substrate Proteins
  • Irs1 protein, mouse
  • LYR motif containing 1 protein, mouse
  • LYRM1 protein, human
  • Reactive Oxygen Species
  • Slc2a4 protein, mouse
  • Thioctic Acid
  • Proto-Oncogene Proteins c-akt
  • Glucose