Regulated expression of the integrin α9β1 in the epithelium of the developing human gut and in intestinal cell lines: Relation with cell proliferation

✍ Scribed by Nathalie Desloges; Nuria Basora; Nathalie Perreault; Yamina Bouatrouss; Dean Sheppard; Jean-François Beaulieu

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 275 KB
• Volume: 71
• Category: Article
• ISSN: 0730-2312
• DOI: 10.1002/(sici)1097-4644(19981215)71:4<536::aid-jcb8>3.0.co;2-1

✦ Synopsis

The integrin ␣9␤1 is one of the recently identified integrins whose expression is restricted to specialized tissues. Its exact function is still unknown. In the present study, we have analyzed the expression of the ␣9 subunit in human fetal and adult small intestinal and colonic epithelia as well as in intestinal cell lines by indirect immunofluorescence, immunoprecipitation, Western blot, and Northern blot. In intact tissues, the antigen was restricted to the basolateral domain of epithelial cells in intestinal crypts at the fetal stage and was absent in the adult. The ␣9␤1 integrin was also detected in the intestinal cell lines HIEC-6 and Caco-2/15. The presence of ␣9␤1 in HIEC-6 was found to be consistent with their proliferative crypt-like status. In Caco-2/15 cells, the integrin was present at high levels in proliferating cells but was downregulated when cells cease to grow and undertake their differentiation. EGF treatment, which is known to maintain Caco-2/15 cells in a proliferative state, resulted in higher levels of ␣9 as compared to control cells. Taken together, these observations suggest a relation between integrin ␣9␤1 expression and proliferation in human intestinal cells.