Leptin decreases apoptosis and alters BCL-2 : Bax ratio in clonal rodent pancreatic beta-cells.
Abstract
AIMS/HYPOTHESIS: The adipocyte derived peptide hormone leptin is known to regulate apoptosis and cell viability in several cells and tissues, as well as having several pancreatic islet beta-cell specific effects such as inhibition of glucose-stimulated insulin secretion. This study investigated the effects of leptin upon apoptosis induced by serum depletion and on expression of the apoptotic regulators B-cell leukaemia 2 gene product (BCL-2) and BCL2-associated X protein (Bax) in the glucose-responsive BRIN-BD11 beta-cell line. METHODS: BRIN-BD11 cells were cultured in RPMI 1640 and subsequently serum depleted +/- leptin (10 and 50 ng/mL) for 24 h. Cell viability and apoptosis were measured using a modified MTS assay and TUNEL/YO-PRO-1 assays, respectively. BCL-2 and Bax expression were measured by real-time PCR and Western blotting. RESULTS: Leptin caused a reduction in serum-depleted apoptosis, although it failed to have any effect on the overall cell viability, causing a 68% shift from apoptosis to necrosis. Leptin significantly increased the level of BCL-2 mRNA expression (150% compared to serum depletion alone), without altering Bax mRNA expression. At the protein level, leptin increased BCL-2 and decreased Bax, altering the BCL-2 : Bax ratio. CONCLUSIONS: We conclude that leptin reduces apoptosis in beta-cells at physiological concentrations, possibly via its ability to up-regulate BCL-2 and Bax expression.Citation
Diabetes/Metabolism Research Reviews, 23(6): 497-502Publisher
Wiley InterscienceDOI
10.1002/dmrr.726PubMed ID
17318810Additional Links
http://www3.interscience.wiley.com/cgi-bin/abstract/114123262/Type
Journal articleLanguage
enISSN
1520-7552ae974a485f413a2113503eed53cd6c53
10.1002/dmrr.726