Transgenic mice rich in endogenous omega-3 fatty acids are protected from colitis

Proc Natl Acad Sci U S A. 2006 Jul 25;103(30):11276-81. doi: 10.1073/pnas.0601280103. Epub 2006 Jul 17.

Abstract

Omega-6 (n-6) and omega-3 (n-3) polyunsaturated fatty acids (PUFA) are the precursors of potent lipid mediators and play an important role in regulation of inflammation. Generally, n-6 PUFA promote inflammation whereas n-3 PUFA have antiinflammatory properties, traditionally attributed to their ability to inhibit the formation of n-6 PUFA-derived proinflammatory eicosanoids. Newly discovered resolvins and protectins are potent antiinflammatory lipid mediators derived directly from n-3 PUFA with distinct pathways of action. However, the role of the n-3 PUFA tissue status in the formation of these antiinflammatory mediators has not been addressed. Here we show that an increased n-3 PUFA tissue status in transgenic mice that endogenously biosynthesize n-3 PUFA from n-6 PUFA leads to significant formation of antiinflammatory resolvins and effective reduction in inflammation and tissue injury in colitis. The endogenous increase in n-3 PUFA and related products did not decrease n-6 PUFA-derived lipid mediators such as leukotriene B4 and prostaglandin E2. The observed inflammation protection might result from decreased NF-kappaB activity and expression of TNFalpha, inducible NO synthase, and IL-1beta, with enhanced mucoprotection probably because of the higher expression of trefoil factor 3, Toll-interacting protein, and zonula occludens-1. These results thus establish the fat-1 transgenic mouse as a new experimental model for the study of n-3 PUFA-derived lipid mediators. They add insight into the molecular mechanisms of inflammation protection afforded by n-3 PUFA through formation of resolvins and protectins other than inhibition of n-6 PUFA-derived eicosanoid formation.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Colitis / genetics*
  • Colitis / pathology
  • Colitis / prevention & control*
  • Dinoprostone / metabolism
  • Eicosanoids / metabolism
  • Fatty Acids, Omega-3 / metabolism*
  • Inflammation / prevention & control
  • Leukotriene B4 / metabolism
  • Lipids / chemistry
  • Mass Spectrometry
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic*
  • Models, Chemical
  • NF-kappa B / metabolism
  • Ultraviolet Rays

Substances

  • Eicosanoids
  • Fatty Acids, Omega-3
  • Lipids
  • NF-kappa B
  • Leukotriene B4
  • Dinoprostone