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Rapamycin inhibits growth factor-induced cell cycle regulation in pancreatic beta cells.
- Source :
-
Journal of investigative medicine : the official publication of the American Federation for Clinical Research [J Investig Med] 2008 Dec; Vol. 56 (8), pp. 985-96. - Publication Year :
- 2008
-
Abstract
- A progressive decline in islet function is a major obstacle to success of islet transplantation. The cause of this decline is islet function is unclear, but immunosuppressive agents may contribute. Insulin-like growth factor-I (IGF-I) and betacellulin are important for islet cell survival and/or proliferation. In the present study, we performed studies of IGF-I and betacellulin on progression of islet cells through the cell cycle and the impact of immunosuppressive agents. Treatment of INS-1 cells for 24 hours with 20 ng/mL betacellulin or 50 ng/mL IGF-1 increased cells in S phase by ~2-fold. Treatment of INS-1 cells with IGF-I or betacellulin also increased cyclin D1 expression and nuclear exclusion of the cyclindependent kinase inhibitors p21(Cip1) and p27(Kip1). In INS-1 cells and islets, betacellulin- and IGF-I increased the increase in p70(s6 kinase) phosphorylation stimulated by betacellulin- and IGF-I in INS-1 cells. Rapamycin also inhibited betacellulin- and IGF-I IN IGF-1 cells. Rapamycin also inhibited betacellulin- and IGF-I-induced entry of cells into S phase and 5'-Bromo-2'-deoxyuridine incorporation as well as the effect of betacellulin and IGF-I on cyclin D1 expression and nuclear exclusion of p21(Cip1) and p(27Kip1). Together, these data suggest that the effect of betacellulin and IGF-I on islet cell growth and proliferation is mediated, in part, via signaling through mammalian target of rapamycin. As rapamycin is used to treat islet transplant recipients, these results suggest that rapamycin could have deleterious effects on islet proliferation and function over time.
- Subjects :
- Animals
Betacellulin
Cell Proliferation drug effects
Cells, Cultured
Cyclin D1 analysis
Cyclin-Dependent Kinase Inhibitor p21 analysis
Cyclin-Dependent Kinase Inhibitor p27 analysis
Insulin-Secreting Cells cytology
Male
Mice
Mice, Inbred C57BL
Rats
Signal Transduction drug effects
Cell Cycle drug effects
Insulin-Like Growth Factor I pharmacology
Insulin-Secreting Cells drug effects
Intercellular Signaling Peptides and Proteins pharmacology
Sirolimus pharmacology
Subjects
Details
- Language :
- English
- ISSN :
- 1081-5589
- Volume :
- 56
- Issue :
- 8
- Database :
- MEDLINE
- Journal :
- Journal of investigative medicine : the official publication of the American Federation for Clinical Research
- Publication Type :
- Academic Journal
- Accession number :
- 19105244
- Full Text :
- https://doi.org/10.2310/JIM.0b013e31818ce763