Zhao Y.,Zhejiang University |
Zhao Y.,Key Laboratory of Medical Neurobiology of the Ministry of Health |
Wang M.-Y.,Zhejiang University |
Wang M.-Y.,Key Laboratory of Medical Neurobiology of the Ministry of Health |
And 8 more authors.
Peptides | Year: 2013
We have previously reported that hypoxia activates corticotrophin-releasing hormone (CRH) and the expression of its type-1 receptor (CRHR1) and induces disorders of the brain-endocrine-immune network. p53 is activated by hypoxia and involved in tumorigenesis and apoptosis. Whether CRHR1 regulates p53 transactivation to further influence apoptotic genes remains unclear. Here, we showed that hypoxia at a simulated altitude of 5 km or 7 km for 8 and 24 h increased p53 protein and mRNA, and reduced apoptotic bax and IGFBP3 gene expression while upregulating the cell-arrest gene p21 for 8 h in rat liver cells. The upregulation of p53 mRNA and downregulation of bax mRNA induced by hypoxia were blocked by pretreatment with the specific CRHR1 antagonist CP-154,526, but the downregulation of IGFBP3 and upregulation of p21 mRNA were not. Furthermore, CRH stimulated p53 mRNA via the ERK 1/2 pathway in the BRL-3A cell line and this was blocked by the ERK 1/2 antagonist U0126. These data provide novel evidence that the CRHR1-triggered ERK 1/2 pathway is involved in the activation of p53 and suppression of the apoptotic bax gene by hypoxia in rat liver. © 2013 Elsevier Inc. All rights reserved.