title: FGF-2 enhances intestinal stem cell survival and its expression is induced after radiation injury.
abstract: Fibroblast growth factors (FGFs) have mitogenic activity toward a wide variety of cells of mesenchymal, neuronal, and epithelial origin and regulate events in normal embryonic development, angiogenesis, wound repair, and neoplasia. FGF-2 is expressed in many normal adult tissues and can regulate migration and replication of intestinal epithelial cells in culture. However, little is known about the effects of FGF-2 on intestinal epithelial stem cells during either normal epithelial renewal or regeneration of a functional epithelium after injury. In this study, we investigated the expression of FGF-2 in the mouse small intestine after irradiation and determined the effect of exogenous FGF-2 on crypt stem cell survival after radiation injury. Expression of FGF-2 mRNA and protein began to increase at 12 h after gamma-irradiation, and peak levels were observed from 48 to 120 h after irradiation. At all times after irradiation, the higher molecular mass isoform ( approximately 24 kDa) of FGF-2 was the predominant form expressed in the small intestine. Immunohistochemical analysis of FGF-2 expression after radiation injury demonstrated that FGF-2 was predominantly found in the mesenchyme surrounding regenerating crypts. Exogenous recombinant human FGF-2 (rhFGF-2) markedly enhanced crypt stem cell survival when given before irradiation. We conclude that expression of FGF-2 is induced by radiation injury and that rhFGF-2 can enhance crypt stem cell survival after subsequent injury.
authors.affiliation: Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
authors.forename: C W
authors.initials: CW
authors.lastname: Houchen
authors.forename: R J
authors.initials: RJ
authors.lastname: George
authors.forename: M A
authors.initials: MA
authors.lastname: Sturmoski
authors.forename: S M
authors.initials: SM
authors.lastname: Cohn
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology*; D006801:Humans; D007422:Intestines / Q000187:drug effects* / Q000473:pathology / Q000528:radiation effects*; D051379:Mice; D008815:Mice, Inbred Strains; D012333:RNA, Messenger / Q000378:metabolism; D011833:Radiation Injuries, Experimental / Q000378:metabolism*; D011994:Recombinant Proteins; D013234:Stem Cells / Q000187:drug effects* / Q000502:physiology; D014018:Tissue Distribution
chemical_list: D012333:RNA, Messenger; D011994:Recombinant Proteins; D016222:Fibroblast Growth Factor 2