Interplay between Intravitreal RvD1 and Local Endogenous Sirtuin-1 in the Protection from Endotoxin-Induced Uveitis in Rats

Mediators Inflamm. 2015:2015:126408. doi: 10.1155/2015/126408. Epub 2015 Jun 9.

Abstract

Rat endotoxin-induced uveitis (EIU) is a well-established model of human uveitis. In this model, intravitreal injection of resolvin D1 (RvD1, 10-100-1000 ng/kg) 1 hour after subcutaneous treatment of Sprague-Dawley rats with lipopolysaccharide (LPS, 200 μg/rat) significantly prevented the development of uveitis into the eye. RvD1 dose-dependently increased the expression of sirtuin-1 (SIRT1) within the eye, while it decreased the expression of acetyl-p53 and acetyl-FOXO1. These effects were accompanied by local downregulation of some microRNAs related to the expression and activity of SIRT1. These were miR-195-5p, miR-200a-3p, miR-34a-5p, and miR-145-5p. An increase of manganese superoxide dismutase and decrease of caspase 3 were evident after RvD1 treatment. In another set of experiments, the protective effects of RvD1 (1000 ng/kg) were partly abolished by the pretreatment of the rats with EX527 (10 mg/kg/day, i.p.), a specific inhibitor of SIRT1 activity, for 7 days prior to the induction of EIU in rats. Similarly, the effects of RvD1 (1000 ng/kg) on the SIRT1 protein expression were abolished by Boc2, N-t-butoxycarbonyl-PLPLP, a specific formyl-peptide receptor type 2/lipoxin A receptor antagonist. Therefore, an interplay of the SIRT1 activity on the RvD1 mediated resolution of EIU is argued.

MeSH terms

  • Animals
  • Caspase 3 / analysis
  • Docosahexaenoic Acids / pharmacology*
  • Endotoxins / toxicity
  • Forkhead Transcription Factors / physiology
  • Intravitreal Injections
  • Nerve Tissue Proteins / physiology
  • Rats
  • Rats, Sprague-Dawley
  • Sirtuin 1 / antagonists & inhibitors
  • Sirtuin 1 / physiology*
  • Superoxide Dismutase / analysis
  • Tumor Suppressor Protein p53 / physiology
  • Uveitis / prevention & control*

Substances

  • Endotoxins
  • Forkhead Transcription Factors
  • Nerve Tissue Proteins
  • Tumor Suppressor Protein p53
  • resolvin D1
  • Foxo1 protein, rat
  • Docosahexaenoic Acids
  • Superoxide Dismutase
  • Caspase 3
  • Sirt1 protein, rat
  • Sirtuin 1