A role for AMPK in increased insulin action after serum starvation

Am J Physiol Cell Physiol. 2010 Nov;299(5):C1171-9. doi: 10.1152/ajpcell.00514.2009. Epub 2010 Sep 1.

Abstract

Serum starvation is a common cell culture procedure for increasing cellular response to insulin, though the mechanism for the serum starvation effect is not understood. We hypothesized that factors known to potentiate insulin action [e.g., AMP-activated protein kinase (AMPK) and p38] or to be involved in insulin signaling leading to glucose transport [e.g., Akt, PKCζ, AS160, and ataxia telangiectasia mutated (ATM)] would be phosphorylated during serum starvation and would be responsible for increased insulin action after serum starvation. L6 myotubes were incubated in serum-containing or serum-free medium for 3 h. Levels of phosphorylated AMPK, Akt, and ATM were greater in serum-starved cells than in control cells. Serum starvation did not affect p38, PKCζ, or AS160 phosphorylation or insulin-stimulated Akt or AS160 phosphorylation. Insulin had no effect on glucose transport in control cells but caused an increase in glucose uptake for serum-starved cells that was preventable by compound C (an AMPK inhibitor), by expression of dominant negative AMPK (AMPK-DN), and by KU55933 (an ATM inhibitor). ATM protein levels increased during serum starvation, and this increase in ATM was prevented by compound C and AMPK-DN. Thus, it appears that AMPK is required for the serum starvation-related increase in insulin-stimulated glucose transport, with ATM as a possible downstream effector.

Publication types

  • Research Support, American Recovery and Reinvestment Act
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • AMP-Activated Protein Kinases / antagonists & inhibitors
  • AMP-Activated Protein Kinases / metabolism*
  • Animals
  • Ataxia Telangiectasia Mutated Proteins
  • Biological Transport / physiology
  • Cell Culture Techniques*
  • Cell Cycle Proteins / antagonists & inhibitors
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism
  • Cell Line
  • DNA-Binding Proteins / antagonists & inhibitors
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • Glucose / metabolism
  • Insulin / metabolism*
  • Isoenzymes / genetics
  • Isoenzymes / metabolism
  • Mice
  • Mice, Knockout
  • Muscle Fibers, Skeletal / cytology
  • Muscle Fibers, Skeletal / drug effects
  • Muscle Fibers, Skeletal / metabolism
  • Protein-Serine-Threonine Kinases / antagonists & inhibitors
  • Protein-Serine-Threonine Kinases / genetics
  • Protein-Serine-Threonine Kinases / metabolism
  • Pyrazoles / pharmacology
  • Pyrimidines / pharmacology
  • Starvation / metabolism*
  • Tumor Suppressor Proteins / antagonists & inhibitors
  • Tumor Suppressor Proteins / genetics
  • Tumor Suppressor Proteins / metabolism

Substances

  • Cell Cycle Proteins
  • DNA-Binding Proteins
  • Insulin
  • Isoenzymes
  • Pyrazoles
  • Pyrimidines
  • Tumor Suppressor Proteins
  • dorsomorphin
  • Ataxia Telangiectasia Mutated Proteins
  • Atm protein, mouse
  • Protein-Serine-Threonine Kinases
  • AMP-Activated Protein Kinases
  • Glucose