Beta-7 integrin controls enterocyte migration in the small intestine

AIM:To hypothesize that beta-7 integrin affects cellularmigration of both,lymphocytes and enterocytes.METHODS:The nucleoside analog Brd U was ip injected in beta-7-deficient mice(C57BL/6-Itgbtmlcgn/J)of male gender and age-matched male C57BL/J J mice(wild type)4,20,or 40 h before analysis.The total small intestine was isolated,dissected,and used for morphometrical studies.Brd U-positive epithelial cells were numbered in at least 15 hemi-crypts per duodenum,jejunum,and ileum of each animal.The outer most Brd U-positive cell(cellmax)was determined per hemi-crypt,numerically documented,and statistically analysed.RESULTS:Integrins containing the beta-7-chain were exclusively expressed on leukocytes.In the small intestinal mucosa of beta-7 integrin-deficient mice the number of intraepithelial lymphocytes was drastically decreased.Moreover,the Peyer’s patches of beta-7integrin-deficient mice appeared hypoplastic.In beta-7integrin-deficient mice the location of cellmax was found in a higher position than it was the case for the controls.The difference was already detected at 4 h after Brd U application,but significantly increased with time(40 h after Brd U injection)in all small intestinal segments investigated,i.e.,duodenum,jejunum,and ileum.Migration of small intestinal enterocytes was different between the experimental groups measured by cellmax locations.CONCLUSION:The E-cadherin beta-7 integrin pathway probably controls migration of enterocytes within the small intestinal surface lining epithelial layer.