Brief Article
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World J Gastroenterol. Jul 7, 2012; 18(25): 3254-3259
Published online Jul 7, 2012. doi: 10.3748/wjg.v18.i25.3254
Intestinal alkaline phosphatase in the colonic mucosa of children with inflammatory bowel disease
Kriszta Molnár, Ádám Vannay, Beáta Szebeni, Nóra Fanni Bánki, Erna Sziksz, Áron Cseh, Hajnalka Győrffy, Péter László Lakatos, Mária Papp, András Arató, Gábor Veres
Kriszta Molnár, Áron Cseh, András Arató, Gábor Veres, First Department of Pediatrics, Semmelweis University, H-1083 Budapest, Hungary
Ádám Vannay, Beáta Szebeni, Erna Sziksz, Research Group for Pediatrics and Nephrology, Semmelweis University and Hungarian Academy of Sciences, H-1083 Budapest, Hungary
Nóra Fanni Bánki, SE-MTA “Lendulet” Diabetes Research Group, H-1083 Budapest, Hungary
Hajnalka Győrffy, Second Department of Pathology, Semmelweis University, H-1091 Budapest, Hungary
Péter László Lakatos, First Department of Medicine, Semmelweis University, H-1083 Budapest, Hungary
Mária Papp, Second Department of Medicine, University of Debrecen, H-4032 Debrecen, Hungary
Author contributions: Veres G, Vannay Á and Molnár K designed the research; Arató A and Veres G included the patients; Molnár K, Szebeni B, Bánki NF and Cseh Á performed the analyses; Sziksz E and Győrffy H analyzed the histological data; Molnár K, Vannay Á and Veres G wrote the paper; Lakatos PL, Papp M and Arató A critically reviewed the paper.
Supported by Grants OTKA-76316, OTKA-K81117, and ETT-028-02 (Veres G and Vannay Á are holders of the János Bolyai Research grant); János Bolyai Research Scholarship of the Hungarian Academy of Sciences
Correspondence to: Gábor Veres, MD, PhD, First Department of Pediatrics, Semmelweis University, H-1083 Budapest, Hungary.
Telephone: +36-208-258163 Fax: +36-1-3036077
Received: November 2, 2011
Revised: April 17, 2012
Accepted: April 21, 2012
Published online: July 7, 2012

AIM: To investigate intestinal alkaline phosphatase (iAP) in the intestinal mucosa of children with inflammatory bowel disease (IBD).

METHODS: Colonic biopsy samples were taken from 15 newly diagnosed IBD patients and from 10 healthy controls. In IBD patients, specimens were obtained both from inflamed and non-inflamed areas. The iAP mRNA and protein expression was determined by reverse transcription-polymerase chain reaction and Western blotting analysis, respectively. Tissue localization of iAP and Toll-like receptor (TLR) 4 was investigated by immunofluorescent staining.

RESULTS: The iAP protein level in the inflamed mucosa of children with Crohn’s disease (CD) and ulcerative colitis (UC) was significantly decreased when compared with controls (both P < 0.05). Similarly, we found a significantly decreased level of iAP protein in the inflamed mucosa in CD compared with non-inflamed mucosa in CD (P < 0.05). In addition, the iAP protein level in inflamed colonic mucosa in patients with UC was decreased compared with non-inflamed mucosa in patients with CD (P < 0.05). iAP protein levels in the non-inflamed mucosa of patients with CD were similar to controls. iAP mRNA expression in inflamed colonic mucosa of children with CD and UC was not significantly different from that in non-inflamed colonic mucosa with CD. Expression of iAP mRNA in patients with non-inflamed mucosa and in controls were similar. Co-localization of iAP with TLR4 showed intense staining with a dotted-like pattern. iAP was present in the inflamed and non-inflamed mucosa of patients with CD, UC, and in control biopsy specimens, irrespective of whether it was present in the terminal ileum or in the colon. However, the fluorescent signal of TLR4 was more pronounced in the colon compared with the terminal ileum in all groups studied.

CONCLUSION: Lower than normal iAP protein levels in inflamed mucosa of IBD patients may indicate a role for iAP in inflammatory lesions in IBD. Based on our results, administration of exogenous iAP enzyme to patients with the active form of IBD may be a therapeutic option.

Keywords: Intestinal alkaline phosphatase, Toll-like receptor, Colonic biopsy, Children, Inflammatory bowel disease