Dexamethasone-induced apoptosis of murine MIN6 pancreatic beta-cells and its effect on AKT phosphorylation.
- Author:
Lin-xi WANG
1
;
Yan-ping WANG
;
Xiao-ying LIU
;
Liang LIU
;
Li-jing WANG
;
Wen-jia CHEN
;
Xiao-hong LIU
;
Li-bin LIU
Author Information
1. Fujian Endocrinology Institute, Affiliated Union Hospital, Fujian Medical University, Fuzhou 350001, China.
- Publication Type:Journal Article
- MeSH:
Animals;
Antineoplastic Agents, Hormonal;
pharmacology;
Apoptosis;
drug effects;
Caspase 3;
metabolism;
Cell Line;
Cytochromes c;
metabolism;
Dexamethasone;
pharmacology;
Down-Regulation;
Insulin-Secreting Cells;
metabolism;
pathology;
Mice;
Phosphorylation;
Proto-Oncogene Proteins c-akt;
metabolism;
Proto-Oncogene Proteins c-bcl-2;
metabolism;
bcl-2-Associated X Protein;
metabolism
- From:
Acta Pharmaceutica Sinica
2009;44(11):1216-1220
- CountryChina
- Language:Chinese
-
Abstract:
This study is to investigate the effect of dexamethasone on cell apoptosis of murine MIN6 pancreatic beta-cells, and to investigate the mechanism of dexamethasone-dependent cell apoptosis. The cell apoptosis model was established by choosing the murine MIN6 pancreatic beta-cells, which was cultured in vitro and induced by dexamethasone. The morphology of the cell apoptosis was observed through fluorescence microscopic analysis after Hochest/PI staining and flow cytometric assay after Annexin-V/PI staining. The expression of caspase-3 was detected with caspase-3 activity assay kit. The expressions of Cyt-c, Bcl-2, Bax, AKT and p-AKT were observed with Western blotting. The results indicated that after exposure to dexamethasone at a concentration ranging from 50-800 nmol x L(-1) for 48 h, the percentage of cell apoptosis was significantly increased with the concentration over 100 nmol x L(-1) of dexamethasone; after exposure to dexamethasone (100 nmol x L(-1)) for 72 h, the activity of caspase-3 increased significantly; after exposure to dexamethasone at a concentration ranging from 50-800 nmol x L(-1) for 48 h, the expression of Cyt-c increased, Bcl-2 and AKT phosphorylation decreased while Bax and T-AKT remained unchanged. It could be concluded that the effect of dexamethasone on murine MIN6 pancreatic beta-cells apoptosis is significant. The mechanism of dexamethasone-dependent cell apoptosis is probably related to down regulation of the Bcl-2 expression and reduction of AKT phosphorylation.
