Chronic endothelin-1 treatment leads to heterologous desensitization of insulin signaling in 3T3-L1 adipocytes

J Clin Invest. 2001 May;107(9):1193-202. doi: 10.1172/JCI11753.

Abstract

We recently reported that insulin and endothelin-1 (ET-1) can stimulate GLUT4 translocation via the heterotrimeric G protein G alpha q/11 and through PI3-kinase--mediated pathways in 3T3-L1 adipocytes. Because both hormones stimulate glucose transport through a common downstream pathway, we determined whether chronic ET-1 pretreatment would desensitize these cells to acute insulin signaling. We found that ET-1 pretreatment substantially inhibited insulin-stimulated 2-deoxyglucose uptake and GLUT4 translocation. Cotreatment with the ETA receptor antagonist BQ 610 prevented these effects, whereas inhibitors of G alpha i or G beta gamma were without effect. Chronic ET-1 treatment inhibited insulin-stimulated tyrosine phosphorylation of G alpha q/11 and IRS-1, as well as their association with PI3-kinase and blocked the activation of PI3-kinase activity and phosphorylation of AKT: In addition, chronic ET-1 treatment caused IRS-1 degradation, which could be blocked by inhibitors of PI3-kinase or p70 S6-kinase. Similarly, expression of a constitutively active G alpha q mutant, but not the wild-type G alpha q, led to IRS-1 degradation and inhibited insulin-stimulated phosphorylation of IRS-1, suggesting that the ET-1-induced decrease in IRS-1 depends on G alpha q/11 and PI3-kinase. Insulin-stimulated tyrosine phosphorylation of SHC was also reduced in ET-1 treated cells, resulting in inhibition of the MAPK pathway. In conclusion, chronic ET-1 treatment of 3T3-L1 adipocytes leads to heterologous desensitization of metabolic and mitogenic actions of insulin, most likely through the decreased tyrosine phosphorylation of the insulin receptor substrates IRS-1, SHC, and G alpha q/11.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • 3T3 Cells
  • Adaptor Proteins, Signal Transducing
  • Adipocytes / drug effects*
  • Adipocytes / metabolism
  • Animals
  • Biological Transport / drug effects
  • Deoxyglucose / metabolism
  • Drug Interactions
  • Endothelin Receptor Antagonists
  • Endothelin-1 / pharmacology*
  • GTP-Binding Protein alpha Subunit, Gi2
  • GTP-Binding Protein alpha Subunits, Gi-Go / antagonists & inhibitors
  • GTP-Binding Protein alpha Subunits, Gi-Go / metabolism
  • GTP-Binding Protein alpha Subunits, Gq-G11
  • Glucose Transporter Type 4
  • Heterotrimeric GTP-Binding Proteins / antagonists & inhibitors
  • Heterotrimeric GTP-Binding Proteins / metabolism
  • Insulin / pharmacology*
  • Insulin Receptor Substrate Proteins
  • Intracellular Signaling Peptides and Proteins
  • Intramolecular Transferases / metabolism
  • Mice
  • Mitogen-Activated Protein Kinases / metabolism
  • Monosaccharide Transport Proteins / metabolism
  • Muscle Proteins*
  • Oligopeptides / pharmacology
  • Phosphatidylinositol 3-Kinases / metabolism
  • Phosphoproteins / metabolism
  • Phosphorylation / drug effects
  • Protein-Serine-Threonine Kinases*
  • Proto-Oncogene Proteins / antagonists & inhibitors
  • Proto-Oncogene Proteins / metabolism
  • Proto-Oncogene Proteins c-akt
  • Proto-Oncogene Proteins c-cbl
  • Receptor, Endothelin A
  • Signal Transduction / drug effects
  • Tyrosine / metabolism
  • Ubiquitin-Protein Ligases*

Substances

  • Adaptor Proteins, Signal Transducing
  • Endothelin Receptor Antagonists
  • Endothelin-1
  • Gab1 protein, mouse
  • Glucose Transporter Type 4
  • Insulin
  • Insulin Receptor Substrate Proteins
  • Intracellular Signaling Peptides and Proteins
  • Irs1 protein, mouse
  • Irs2 protein, mouse
  • Monosaccharide Transport Proteins
  • Muscle Proteins
  • Oligopeptides
  • Phosphoproteins
  • Proto-Oncogene Proteins
  • Receptor, Endothelin A
  • Slc2a4 protein, mouse
  • BQ 610
  • Tyrosine
  • Deoxyglucose
  • Proto-Oncogene Proteins c-cbl
  • Ubiquitin-Protein Ligases
  • Protein-Serine-Threonine Kinases
  • Proto-Oncogene Proteins c-akt
  • Mitogen-Activated Protein Kinases
  • GTP-Binding Protein alpha Subunit, Gi2
  • GTP-Binding Protein alpha Subunits, Gi-Go
  • GTP-Binding Protein alpha Subunits, Gq-G11
  • Gnai2 protein, mouse
  • Heterotrimeric GTP-Binding Proteins
  • Intramolecular Transferases
  • squalene-hopene cyclase
  • CBL protein, human
  • Cbl protein, mouse