GRP75 overexpression inhibits apoptosis induced by glucose deprivation via Raf/Mek/Erk1/2 signaling pathway.
- Author:
Hong-yan LI
1
;
Ling YANG
;
Wen LIU
;
Ji ZUO
Author Information
1. Department of Cellular and Genetic Medicine, Shanghai Medical College, Fudan University, Shanghai 200032, China.
- Publication Type:Journal Article
- MeSH:
Animals;
Apoptosis;
physiology;
Butadienes;
pharmacology;
Cells, Cultured;
Culture Media;
Glucose;
pharmacology;
HSP70 Heat-Shock Proteins;
genetics;
metabolism;
MAP Kinase Signaling System;
physiology;
Membrane Proteins;
genetics;
metabolism;
Mitogen-Activated Protein Kinase 3;
metabolism;
Nitriles;
pharmacology;
PC12 Cells;
Phosphorylation;
Rats;
raf Kinases;
metabolism
- From:
Acta Physiologica Sinica
2011;63(1):69-74
- CountryChina
- Language:Chinese
-
Abstract:
The purpose of the present study is to investigate whether glucose-regulated protein 75 (GRP75) overexpression inhibits apoptosis induced by glucose deprivation through Raf/Mek/Erk1/2 signaling pathway. After pretreatment with Mek-specific inhibitor U0126, GRP75 overexpressing PC12 cells were incubated in glucose-free DMEM medium for indicated time (6, 12 and 24 h). And DMSO-treated GRP75 overexpressing PC12 cells were applied as control. Western blot was used to determine the expression and phosphorylation level of Erk1/2. MTT assay was used to measure cell viability. Hoechst 33258 staining and flow cytometry using propidium iodide (PI) staining was used to analysis apoptosis. Immunofluorescence with antibody against cytochrome c (Cyt c) was used to detect Cyt c release from mitochondrion. The results showed U0126 prevented the activation of Erk1/2 maintained by GRP75, but the total Erk1/2 expression was not affected. U0126-treated group showed lower cell viability and higher apoptotic rate compared with control group. Immunofluorescence indicated the delay in release of Cyt c was blocked by U0126. These results suggest U0126 prevents protective effect of GRP75 on PC12 cells by inhibiting Erk1/2 phosphorylation, which certifies that GRP75 can inhibit the mitochondria-dependent apoptotic pathway through Raf/Mek/Erk1/2 signaling cascade.
