title: Decreased mucosal expression of intestinal alkaline phosphatase in children with coeliac disease.
abstract: A major function of the enzyme intestinal alkaline phosphatase (iAP) is the detoxification of lipopolysaccharide (LPS), the ligand of Toll-like receptor 4 (TLR4). Hence, iAP has a role in the defence of maintaining intestinal barrier integrity. As intestinal barrier integrity is impaired in coeliac disease (CD), we tested the expression and localization of iAP in duodenal mucosa specimens from children with newly diagnosed CD (n = 10), with CD on gluten-free diet (GFD) (n = 5) and compared to those from ten healthy children. The mRNA and protein expression was determined by RT-PCR and Western blot analysis, respectively. Tissue localization of iAP and TLR4 was determined by immunofluorescence staining. iAP protein expression level was significantly lower than normal in newly diagnosed CD, while it was normalised in children on GFD. iAP and TLR4 colocalized at the epithelial surface of duodenal mucosa in each group of subjects enrolled. The finding of decreased iAP protein levels in newly diagnosed CD is consistent with its role in decreased intestinal barrier integrity. The latter may be the result of decreased LPS-detoxifying ability.
authors.affiliation: 1st Department of Paediatrics, Semmelweis University, Bókay u. 53, H-1083 Budapest, Hungary.
authors.forename: Kriszta
authors.initials: K
authors.lastname: Molnár
authors.forename: Adám
authors.initials: A
authors.lastname: Vannay
authors.forename: Erna
authors.initials: E
authors.lastname: Sziksz
authors.forename: Nóra Fanni
authors.initials: NF
authors.lastname: Bánki
authors.forename: Hajnalka
authors.initials: H
authors.lastname: Győrffy
authors.forename: András
authors.initials: A
authors.lastname: Arató
authors.forename: Antal
authors.initials: A
authors.lastname: Dezsőfi
authors.forename: Gabor
authors.initials: G
authors.lastname: Veres
mesh_terms: D000293:Adolescent; D000469:Alkaline Phosphatase / Q000096:biosynthesis*; D015153:Blotting, Western; D002446:Celiac Disease / Q000201:enzymology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D007223:Infant; D007413:Intestinal Mucosa / Q000201:enzymology*; D008297:Male; D012333:RNA, Messenger / Q000032:analysis; D060888:Real-Time Polymerase Chain Reaction; D051197:Toll-Like Receptor 4 / Q000096:biosynthesis*
chemical_list: D012333:RNA, Messenger; C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4; D000469:Alkaline Phosphatase