Insulin-like growth factor-1 modulation of intestinal epithelial cell restitution.
After superficial intestinal injury, the mucosal integrity is reestablished by rapid migration of epithelial cells from the adjacent area in a process called restitution. Our previous study suggested that growth hormone improves intestinal healing in an experimental small bowel ulceration, mediated by insulin-like growth factor-1 (IGF-1). The aim of the present study was to assess the role of IGF-1 in mucosal epithelial restitution using an in vitro epithelial wound model. Wounds were established in confluent monolayers of the intestinal cell line, IEC-6. Migration was quantitated in the presence or absence of IGF-1 as the number of cells migrating across the wound edge. Proliferation was assessed by thymidine incorporation. IGF-1-enhanced epithelial cell migration by 2- to 2.5-fold after 12- and 24-hour treatment, respectively, the first step involved in gastrointestinal wound healing. Cell proliferation was significantly stimulated by IGF-1 as well. In addition, expression of transforming growth factor-beta (TGF-beta) mRNA was significantly enhanced in the wounded monolayers treated with IGF-1. IGF-1 receptor mRNA was found to be detectable throughout the gastrointestinal mucosa and in the intestinal epithelial cells. In conclusion, these findings suggest that IGF-1 plays an important role in reconstitution of intestinal epithelial integrity after mucosal injury.
Chen
K
K
Department of Biochemistry and Biophysics, University of Rochester Medical Center, New York, USA.
Nezu
R
R
Wasa
M
M
Sando
K
K
Kamata
S
S
Takagi
Y
Y
Okada
A
A
D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000502:physiology*; D007413:Intestinal Mucosa / Q000187:drug effects*; D007422:Intestines / Q000293:injuries; D012333:RNA, Messenger / Q000302:isolation & purification; D014945:Wound Healing / Q000187:drug effects
D012333:RNA, Messenger; D007334:Insulin-Like Growth Factor I