Lipoxin A₄ and benzo-lipoxin A₄ attenuate experimental renal fibrosis

FASEB J. 2011 Sep;25(9):2967-79. doi: 10.1096/fj.11-185017. Epub 2011 May 31.

Abstract

Unresolved inflammation underlies the development of fibrosis and organ failure. Here, we investigate the potential of the proresolving eicosanoid lipoxinA₄ (LXA₄) and its synthetic analog benzo-LXA₄ to prophylactically modulate fibrotic and inflammatory responses in a model of early renal fibrosis, unilateral ureteric obstruction (UUO). Male Wistar rats (Animalia, Chordata, Rattus norvegicus) were injected intravenously with vehicle (0.1% ethanol), LXA₄ (45 μg/250-g rat), or benzo-LXA₄ (15 μg/250-g rat) 15 min prior to surgery and sacrificed 3 d postligation. Renal gene and protein expression, collagen deposition, macrophage infiltration, and apoptosis were analyzed using manipulated kidneys from sham operations as control. Lipoxins (LXs) attenuated collagen deposition and renal apoptosis (P<0.05) and shifted the inflammatory milieu toward resolution, inhibiting TNF-α and IFN-γ expression, while stimulating proresolving IL-10. LXs attenuated UUO-induced activation of MAP kinases, Akt, and Smads (P<0.05) in injured kidneys. We explored whether the underlying mechanism reflected LX-induced modulation of fibroblast activation. Using cultured rat renal NRK-49F fibroblasts, we report that LXA₄ (1 nM) inhibits TGF-β1 (10 ng/ml)-induced activation of Smad2 and MAP-kinases (P<0.05), and furthermore, LXA₄ reduced TGF-β1-stimulated PAI-1 luciferase activation (P<0.05) relative to vehicle-stimulated cells. We propose that LXs may represent a potentially useful and novel therapeutic strategy for consideration in the context of renal fibrosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Inflammatory Agents, Non-Steroidal / therapeutic use*
  • Apoptosis / drug effects
  • Collagen / genetics
  • Collagen / metabolism
  • Disease Models, Animal
  • Fibrosis / drug therapy
  • Fibrosis / prevention & control
  • Gene Expression Regulation
  • Kidney / drug effects
  • Kidney / pathology*
  • Kidney Diseases / drug therapy*
  • Kidney Diseases / pathology
  • Kidney Diseases / prevention & control
  • Ligation
  • Lipoxins / chemistry
  • Lipoxins / therapeutic use*
  • Male
  • Rats
  • Rats, Wistar
  • Transforming Growth Factor beta1 / genetics
  • Transforming Growth Factor beta1 / metabolism

Substances

  • Anti-Inflammatory Agents, Non-Steroidal
  • Lipoxins
  • Transforming Growth Factor beta1
  • lipoxin A4
  • Collagen
  • benzo-lipoxin A4