Relationship between the expression of HIF-1α and apoptosis related genes P53,Bcl-2 in cortex of hypoxia ischemia brain damage in neonatal rat

Abstract

Objective: To investigate the expression of HIF-1α and explore the relationship between expression of HIF-1α and apoptosis related genes P53,Bcl-2 in hypoxia ischemia brain damage in neonatal rats.Methods: Postnatal day 7 SD rats were divided into three groups: sham group,the hypoxia group and the hypoxia-ischemia group.Rats′ brain tissue were collected at 3,6,12,24,72 h after hypoxia or hypoxia-ischemia from each group.The histopathological damage was detected by HE staining.Immunohistochemistry was used to detect the expression of HIF-1 α,P53 and Bcl-2.Results: HE staining showed that neuronal degeneration and edema became prominent at 24 h in both hypoxia group and hypoxia-ischemia group.The expression of HIF-1 α protein was significantly upregulated at 3 h,peak at 12 h,and then decreased in both hypoxia and hypoxia-ischemia group.The expression of P53 protein was upregulated at 3 h,peak at 24 h,and then decreased in both hypoxia and hypoxia-ischemia group.The expression of Bcl-2 protein was similar with HIF-1 α in hypoxia and hypoxia-ischemia group.The ratio of P53 and Bcl-2 was almost 1 in sham group,less than 1 at 3 h,6 h,12 h,and more than 1 at 24 h and 72 h in both hypoxia and hypoxia-ischemia groups.Conclusion: The HIF-1 α participates in the regulation of P53 and Bcl-2 in hypoxia ischemia brain damage in neonatal rats.HIF-1α may have protective role in the onset of hypoxia.