Gene expression of activin, activin receptors, and follistatin in intestinal epithelial cells.
Gene expression of activin, activin receptors, and follistatin was investigated in vivo and in vitro using semiquantitative RT-PCR in intestinal epithelial cells. Rat jejunum and the intestinal epithelial cell line IEC-6 expressed mRNA encoding the betaA-subunit of activin, alpha-subunit of inhibin, activin receptors IB and IIA, and follistatin. An epithelial cell isolation study focused along the crypt-villus axis in rat jejunum showed that betaA mRNA levels were eight- to tenfold higher in villus cells than in crypt cells. Immunohistochemistry revealed the expression of activin A in upper villus cells. The human intestinal cell line Caco-2 was used as a differentiation model of enterocytes. Four- to fivefold induction of betaA mRNA was observed in postconfluent Caco-2 cells grown on filter but not in those cells grown on plastic. In contrast, follistatin mRNA was seen to be reduced after reaching confluence. Exogenous activin A dose-dependently suppressed the proliferation and stimulated the expression of apolipoprotein A-IV gene, a differentiation marker, in IEC-6 cells. These results suggest that the activin system is involved in the regulation of such cellular functions as proliferation and differentiation in intestinal epithelial cells.
Sonoyama
K
K
Laboratory of Food Biochemistry, Department of Bioscience and Chemistry, Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan. ksnym@chem.agr.hokudai.ac.jp
Rutatip
S
S
Kasai
T
T
D029404:Activin Receptors; D028341:Activins; D000818:Animals; D000943:Antigens, Differentiation / Q000235:genetics; D001054:Apolipoproteins A / Q000235:genetics; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D038681:Follistatin; D015870:Gene Expression / Q000187:drug effects; D006023:Glycoproteins / Q000235:genetics*; D006801:Humans; D007265:Inhibins / Q000235:genetics* / Q000494:pharmacology; D007413:Intestinal Mucosa / Q000166:cytology / Q000502:physiology*; D008297:Male; D020033:Protein Isoforms / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D017978:Receptors, Growth Factor / Q000235:genetics*
D000943:Antigens, Differentiation; D001054:Apolipoproteins A; D038681:Follistatin; D006023:Glycoproteins; D020033:Protein Isoforms; D012333:RNA, Messenger; D017978:Receptors, Growth Factor; C022205:apolipoprotein A-IV; D028341:Activins; D007265:Inhibins; D029404:Activin Receptors