Annexin A1 regulates intestinal mucosal injury, inflammation, and repair

J Immunol. 2008 Oct 1;181(7):5035-44. doi: 10.4049/jimmunol.181.7.5035.

Abstract

During mucosal inflammation, a complex array of proinflammatory and protective mechanisms regulates inflammation and severity of injury. Secretion of anti-inflammatory mediators is a mechanism that is critical in controlling inflammatory responses and promoting epithelial restitution and barrier recovery. AnxA1 is a potent anti-inflammatory protein that has been implicated to play a critical immune regulatory role in models of inflammation. Although AnxA1 has been shown to be secreted in intestinal mucosal tissues during inflammation, its potential role in modulating the injury/inflammatory response is not understood. In this study, we demonstrate that AnxA1-deficient animals exhibit increased susceptibility to dextran sulfate sodium (DSS)-induced colitis with greater clinical morbidity and histopathologic mucosal injury. Furthermore, impaired recovery following withdrawal of DSS administration was observed in AnxA1 (-/-) animals compared with wild-type (WT) control mice that was independent of inflammatory cell infiltration. Since AnxA1 exerts its anti-inflammatory properties through stimulation of ALX/FPRL-1, we explored the role of this receptor-ligand interaction in regulating DSS-induced colitis. Interestingly, treatment with an ALX/FPRL-1 agonist, 15-epi-lipoxin A4 reversed the enhanced sensitivity of AnxA1 (-/-) mice to DSS colitis. In contrast, 15-epi-lipoxin A4 did not significantly improve the severity of disease in WT animals. Additionally, differential expression of ALX/FPLR-1 in control and DSS-treated WT and AnxA1-deficient animals suggested a potential role for AnxA1 in regulating ALX/FPRL-1 expression under pathophysiological conditions. Together, these results support a role of endogenous AnxA1 in the protective and reparative properties of the intestinal mucosal epithelium.

Publication types

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

MeSH terms

  • Animals
  • Annexin A1 / biosynthesis
  • Annexin A1 / deficiency
  • Annexin A1 / genetics
  • Annexin A1 / physiology*
  • Colitis / chemically induced
  • Colitis / metabolism
  • Colitis / pathology
  • Dextran Sulfate / toxicity
  • Female
  • Genetic Predisposition to Disease
  • Inflammation Mediators / metabolism
  • Inflammation Mediators / physiology*
  • Intestinal Mucosa / drug effects
  • Intestinal Mucosa / metabolism*
  • Intestinal Mucosa / pathology*
  • Mice
  • Mice, Inbred BALB C
  • Mice, Knockout
  • Severity of Illness Index
  • Wound Healing / drug effects
  • Wound Healing / immunology*

Substances

  • Annexin A1
  • Inflammation Mediators
  • Dextran Sulfate