[Effect of palmitate on proliferation and apoptosis of INS-1 pancreatic beta-cell].
OBJECTIVE
To investigate the effect of saturated fatty acid palmitate (PA) on cell viability of MIN6 beta-cell and the possible cell cycle pathways affected by PA.


METHODS
MIN6 cells were synchronized at G(0); phase by serum deprivation for 36 h, and further MIN6 cells were exposed to different concentrations of PA(0.25-1.0 mmol/L, 45 min-24 h)compared with control cell treated with BSA.Cell viability was assessed by MTT colorimetric assay. The cell cycle was measured by FACS analysis, and cell cycle proteins were further detected using Western blot.


RESULTS
(1)PA significantly affected the cell viability of MIN6 cells. (2)The G(0);/G(1); cell cycle arrest (n=6, P<0.05) also induced by PA, whereas MIN6 cells in S and G(2);/M phase were decreased. (3) For cell cycle proteins, PA treatment caused significant reductions in cyclin D1 and CDK4 levels, which was consistent to the cell cycle delay.


CONCLUSIONS
The findings thus suggest that increased PA directly affects pancreatic beta-cell proliferation, possibly by reducing the levels of cyclin D1/CDK4 in the cells, which results in arresting in progression through the G(1); phase to the S phase of the cell cycle.
Cui
Wei
W
Department of Endocrinology, the First Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, China. doctorweiwei.cui@126.com
Huang
Ting
T
Liu
Jun-li
JL
Shi
Bing-yin
BY
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D002453:Cell Cycle / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D019938:Cyclin D1 / Q000378:metabolism; D051358:Cyclin-Dependent Kinase 4 / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005434:Flow Cytometry; D016195:G2 Phase / Q000187:drug effects; D050417:Insulin-Secreting Cells / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D010168:Palmitates / Q000494:pharmacology*; D016196:S Phase / Q000187:drug effects; D013997:Time Factors
D010168:Palmitates; D019938:Cyclin D1; C495902:Cdk4 protein, mouse; D051358:Cyclin-Dependent Kinase 4