Stearidonic and eicosapentaenoic acids inhibit interleukin-6 expression in ob/ob mouse adipose stem cells via Toll-like receptor-2-mediated pathways

J Nutr. 2011 Jul;141(7):1260-6. doi: 10.3945/jn.110.132571. Epub 2011 May 11.

Abstract

Increased adipose tissue positively correlates with circulating inflammatory cytokines such as IL-6. We previously reported that adipose stem cells from genetically obese ob/ob mice produce significantly higher levels of IL-6 compared with other cell types such as adipocytes and macrophages within adipose tissue. We also demonstrated that (n-3) PUFA have antiinflammatory effects on adipocyte IL-6 secretion. Based on these findings, we hypothesized that EPA [20:5 (n-3)] and stearidonic acid [SDA, 18:4 (n-3)] would decrease LPS (200 μg/L)-induced IL-6 secretion and IL-6 mRNA content in the adipose stem cells. SDA (100 μmol/L) and EPA (100 μmol/L) significantly reduced LPS-induced IL-6 secretion and decreased IL-6 mRNA expression. To determine the underlying intracellular mechanisms, we tested whether LPS-induced Toll-like-receptor (TLR) 4 and TLR2 expression were modulated by these fatty acids using Western-blot analysis. EPA and SDA suppressed LPS-induced TLR2 but not TLR4 protein expression in the adipose stem cells. Furthermore, SDA and EPA significantly lowered the activation and translocation of NF-κB, a TLR2 downstream signaling target, while protein expression of extracellular signal-regulated kinases-1/2 were unaffected. Collectively, our results suggest that EPA and SDA inhibit LPS-induced IL-6 secretion and IL-6 mRNA expression in the adipose stem cells by decreasing TRL2-mediated signaling pathways.

Publication types

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

MeSH terms

  • Adipocytes / drug effects*
  • Adipocytes / metabolism*
  • Animals
  • Biological Transport, Active / drug effects
  • Eicosapentaenoic Acid / pharmacology*
  • Fatty Acids, Omega-3 / pharmacology*
  • Gene Expression / drug effects
  • Interleukin-1 Receptor-Associated Kinases / metabolism
  • Interleukin-6 / genetics*
  • Interleukin-6 / metabolism*
  • Lipopolysaccharides / pharmacology
  • MAP Kinase Signaling System / drug effects
  • Mice
  • Mice, Inbred C57BL
  • Mice, Obese
  • Models, Biological
  • NF-kappa B / metabolism
  • Obesity / diet therapy
  • Obesity / genetics
  • Obesity / metabolism
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Signal Transduction / drug effects
  • Stem Cells / drug effects*
  • Stem Cells / metabolism*
  • Toll-Like Receptor 2 / genetics*
  • Toll-Like Receptor 2 / metabolism*

Substances

  • Fatty Acids, Omega-3
  • Interleukin-6
  • Lipopolysaccharides
  • NF-kappa B
  • RNA, Messenger
  • Tlr2 protein, mouse
  • Toll-Like Receptor 2
  • Eicosapentaenoic Acid
  • Interleukin-1 Receptor-Associated Kinases
  • Irak1 protein, mouse
  • stearidonic acid