Article thumbnail
Location of Repository

Intestinal Epithelial Serum Amyloid A Modulates Bacterial Growth In Vitro and Pro-Inflammatory Responses in Mouse Experimental Colitis

By Wang Yu, Arsenescu Violeta, Arsenescu Razvan, Zhong Jian, Witta Jassir, Eckhardt Erik RM, Ghoshal Sarbani, de Beer Marcielle C, de Beer Frederick C and de Villiers Willem JS

Abstract

<p>Abstract</p> <p>Background</p> <p>Serum Amyloid A (SAA) is a major acute phase protein of unknown function. SAA is mostly expressed in the liver, but also in other tissues including the intestinal epithelium. SAA reportedly has anti-bacterial effects, and because inflammatory bowel diseases (IBD) result from a breakdown in homeostatic interactions between intestinal epithelia and bacteria, we hypothesized that SAA is protective during experimental colitis.</p> <p>Methods</p> <p>Intestinal SAA expression was measured in mouse and human samples. Dextran sodium sulfate (DSS) colitis was induced in SAA 1/2 double knockout (DKO) mice and in wildtype controls. Anti-bacterial effects of SAA1/2 were tested in intestinal epithelial cell lines transduced with adenoviral vectors encoding the CE/J SAA isoform or control vectors prior to exposure to live <it>Escherichia coli</it>.</p> <p>Results</p> <p>Significant levels of SAA1/SAA2 RNA and SAA protein were detected by in situ hybridization and immunohistochemistry in mouse colonic epithelium. SAA3 expression was weaker, but similarly distributed. SAA1/2 RNA was present in the ileum and colon of conventional mice and in the colon of germfree mice. Expression of SAA3 was strongly regulated by bacterial lipopolysaccharides in cultured epithelial cell lines, whereas SAA1/2 expression was constitutive and not LPS inducible. Overexpression of SAA1/2 in cultured epithelial cell lines reduced the viability of co-cultured <it>E. coli</it>. This might partially explain the observed increase in susceptibility of DKO mice to DSS colitis. SAA1/2 expression was increased in colon samples obtained from Crohn's Disease patients compared to controls.</p> <p>Conclusions</p> <p>Intestinal epithelial SAA displays bactericidal properties in vitro and could play a protective role in experimental mouse colitis. Altered expression of SAA in intestinal biopsies from Crohn's Disease patients suggests that SAA is involved in the disease process..</p

Topics: Diseases of the digestive system. Gastroenterology, RC799-869
Publisher: BMC
Year: 2010
DOI identifier: 10.1186/1471-230X-10-133
OAI identifier: oai:doaj.org/article:2d1201e2e1c645a6af48368e556c3e22
Journal:
Download PDF:
Sorry, we are unable to provide the full text but you may find it at the following location(s):
  • https://doaj.org/toc/1471-230X (external link)
  • http://www.biomedcentral.com/1... (external link)
  • https://doaj.org/article/2d120... (external link)
  • Suggested articles


    To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.