The Function Of NOD2 In Colonic Epithelial Cells

Main Category: GastroIntestinal / Gastroenterology
Also Included In: Infectious Diseases / Bacteria / Viruses;  Biology / Biochemistry;  Colorectal Cancer
Article Date: 24 Oct 2008 - 3:00 PDT

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NOD2 is a cytosolic pattern recognition receptor similar in structure and function to Toll like receptors (TLRs). It can recognize and respond to a component found in the cell wall of bacteria, muramyl dipeptide (MDP), and has been shown to play an important role in the innate immune response of macrophages to bacterial infections. However, the function of NOD2 in the gastrointestinal tract and the colon and its contribution of mutant NOD2 alleles to the pathogenesis of CD is still unclear.

A research article to be published in the World Journal of Gastroenterology refers. The research team led by Professor Simon Carding from the University of Leeds used in vivo and in vitro studies to analyse the specific function of NOD2 in colonic epithelial cells.

They found that NOD2 was predominantly expressed in epithelial cells at the base of colonic crypts, where the majority of cells are undergoing proliferation. In addition, NOD2's ligand, MDP, stimulated the growth of in vitro cultures of colonic epithelial cells. Further evidence for the role of NOD2 in cell growth and survival was obtained using NOD2-deficient mice and RNA interference. In the absence of NOD2 colonic epithelial cells proliferation was reduced and apoptosis increased, which were exacerbated when challenged with the enteric pathogen, Salmonella typhimurium. Surprisingly the ability of NOD2 to promote cell growth and survival was also apparent in the colorectal cancer cells as the introduction of siRNAs specific for NOD2 resulted in an 80% decrease in survival compared to cells treated with control NOD2 siRNA.

These results highlight for the first time the importance of NOD2 in the regulation of epithelial cell growth and survival and consequently the integrity of the intestinal epithelial cell barrier, that is required for protection against pathogenic and opportunistic bacterial infections. further investigation is needed to assess if these receptors work alongside each other in the regulation of epithelial cell homeostasis.

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Article adapted by Medical News Today from original press release.
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Reference: Cruickshank SM, Wakenshaw L, Cardone J, Howdle PD, Murray PJ, Carding SR. Evidence for the involvement of NOD2 in regulating colonic epithelial cell growth and survival. World J Gastroenterol 2008; 14(38): 5834-5841 http://www.wjgnet.com/1007-9327/14/5834.asp

Correspondence to: Simon R Carding, Professor, The Institute of Food Research, Norwich Research Park, Norwich NR4 7UA, United Kingdom.

About World Journal of Gastroenterology

World Journal of Gastroenterology (WJG), a leading international journal in gastroenterology and hepatology, has established a reputation for publishing first class research on esophageal cancer, gastric cancer, liver cancer, viral hepatitis, colorectal cancer, and H pylori infection and provides a forum for both clinicians and scientists. WJG has been indexed and abstracted in Current Contents/Clinical Medicine, Science Citation Index Expanded (also known as SciSearch) and Journal Citation Reports/Science Edition, Index Medicus, MEDLINE and PubMed, Chemical Abstracts, EMBASE/Excerpta Medica, Abstracts Journals, Nature Clinical Practice Gastroenterology and Hepatology, CAB Abstracts and Global Health. ISI JCR 2003-2000 IF: 3.318, 2.532, 1.445 and 0.993. WJG is a weekly journal published by WJG Press. The publication dates are the 7th, 14th, 21st, and 28th day of every month. WJG is supported by The National Natural Science Foundation of China, No. 30224801 and No. 30424812, and was founded with the name of China National Journal of New Gastroenterology on October 1, 1995, and renamed WJG on January 25, 1998.

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Source: Lai-Fu Li
World Journal of Gastroenterology