Altered response of skeletal muscle to IL-6 in type 2 diabetic patients

Diabetes. 2013 Feb;62(2):355-61. doi: 10.2337/db11-1790. Epub 2012 Oct 18.

Abstract

Interleukin-6 (IL-6) has a dual role in modulating insulin sensitivity, with evidence for this cytokine as both an enhancer and inhibitor of insulin action. We determined the effect of IL-6 exposure on glucose and lipid metabolism in cultured myotubes established from people with normal glucose tolerance or type 2 diabetes. Acute IL-6 exposure increased glycogen synthesis, glucose uptake, and signal transducer and activator of transcription 3 (STAT3) phosphorylation in cultured myotubes from normal glucose tolerant subjects. However, in type 2 diabetic patients, IL-6 was without effect on glucose metabolism and STAT3 signaling, concomitant with increased suppressor of cytokine signaling 3 (SOCS3) expression. IL-6 increased fatty acid oxidation in myotubes from type 2 diabetic and normal glucose tolerant subjects. Expression of IL-6, IL-6 receptor (IL-6R), or glycoprotein 130, as well as IL-6 secretion, was unaltered between cultured myotubes from normal glucose tolerant or type 2 diabetic subjects. Circulating serum IL-6 concentration was unaltered between normal glucose tolerant and type 2 diabetic subjects. In summary, skeletal muscle cells from type 2 diabetic patients display selective IL-6 resistance for glucose rather than lipid metabolism. In conclusion, IL-6 appears to play a differential role in regulating metabolism in type 2 diabetic patients compared with normal glucose tolerant subjects.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cells, Cultured
  • Diabetes Mellitus, Type 2 / metabolism*
  • Fatty Acids / metabolism
  • Female
  • Glucose / metabolism*
  • Glycogen / biosynthesis
  • Glycoproteins / biosynthesis
  • Humans
  • Insulin Resistance / physiology
  • Interleukin-6 / analysis
  • Interleukin-6 / pharmacology
  • Interleukin-6 / physiology*
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Middle Aged
  • Muscle Fibers, Skeletal / drug effects
  • Muscle, Skeletal / drug effects
  • Muscle, Skeletal / metabolism*
  • Phosphorylation
  • Receptors, Interleukin-6 / metabolism
  • STAT3 Transcription Factor / metabolism
  • Suppressor of Cytokine Signaling 3 Protein
  • Suppressor of Cytokine Signaling Proteins / biosynthesis

Substances

  • Fatty Acids
  • Glycoproteins
  • Interleukin-6
  • Receptors, Interleukin-6
  • SOCS3 protein, human
  • STAT3 Transcription Factor
  • STAT3 protein, human
  • Suppressor of Cytokine Signaling 3 Protein
  • Suppressor of Cytokine Signaling Proteins
  • glycoprotein 130, human
  • Glycogen
  • Glucose