High sugar intake and development of skeletal muscle insulin resistance and inflammation in mice: a protective role for PPAR- δ agonism

Mediators Inflamm. 2013:2013:509502. doi: 10.1155/2013/509502. Epub 2013 Jun 18.

Abstract

Peroxisome Proliferator Activated Receptor (PPAR)- δ agonists may serve for treating metabolic diseases. However, the effects of PPAR- δ agonism within the skeletal muscle, which plays a key role in whole-body glucose metabolism, remain unclear. This study aimed to investigate the signaling pathways activated in the gastrocnemius muscle by chronic administration of the selective PPAR- δ agonist, GW0742 (1 mg/kg/day for 16 weeks), in male C57Bl6/J mice treated for 30 weeks with high-fructose corn syrup (HFCS), the major sweetener in foods and soft-drinks (15% wt/vol in drinking water). Mice fed with the HFCS diet exhibited hyperlipidemia, hyperinsulinemia, hyperleptinemia, and hypoadiponectinemia. In the gastrocnemius muscle, HFCS impaired insulin and AMP-activated protein kinase signaling pathways and reduced GLUT-4 and GLUT-5 expression and membrane translocation. GW0742 administration induced PPAR- δ upregulation and improvement in glucose and lipid metabolism. Diet-induced activation of nuclear factor-κB and expression of inducible-nitric-oxide-synthase and intercellular-adhesion-molecule-1 were attenuated by drug treatment. These effects were accompanied by reduction in the serum concentration of interleukin-6 and increase in muscular expression of fibroblast growth factor-21. Overall, here we show that PPAR- δ activation protects the skeletal muscle against the metabolic abnormalities caused by chronic HFCS exposure by affecting multiple levels of the insulin and inflammatory cascades.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Carbohydrates / administration & dosage*
  • Fibroblast Growth Factors / metabolism
  • Gene Expression Regulation*
  • Glucose / metabolism
  • Glucose Tolerance Test
  • Immunohistochemistry
  • Inflammation / metabolism*
  • Insulin / metabolism
  • Insulin Resistance*
  • Interleukin-6 / metabolism
  • Lipid Metabolism
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Muscle, Skeletal / metabolism*
  • Nutritive Sweeteners / administration & dosage
  • PPAR delta / agonists
  • PPAR delta / metabolism*
  • Signal Transduction
  • Thiazoles / pharmacology

Substances

  • Carbohydrates
  • Insulin
  • Interleukin-6
  • Nutritive Sweeteners
  • PPAR delta
  • Thiazoles
  • fibroblast growth factor 21
  • (4-(((2-(3-fluoro-4-(trifluoromethyl)phenyl)-4-methyl-1,3-thiazol-5-yl)methyl)sulfanyl)-2-methylphenoxy)acetic acid
  • Fibroblast Growth Factors
  • Glucose