Hypoxia promotes apoptosis of neuronal cells through hypoxia-inducible factor-1α-microRNA-204-B-cell lymphoma-2 pathway

X Wang, J Li, D Wu, X Bu… - Experimental Biology and …, 2016 - journals.sagepub.com
X Wang, J Li, D Wu, X Bu, Y Qiao
Experimental Biology and Medicine, 2016journals.sagepub.com
Neuronal cells are highly sensitive to hypoxia and may be subjected to apoptosis when
exposed to hypoxia. Several apoptosis-related genes and miRNAs involve in hypoxia-
induced apoptosis. This study aimed to examine the role of HIF1α-miR-204-BCL-2 pathway
in hypoxia-induced apoptosis in neuronal cells. Annexin V/propidium iodide assay was
performed to analyze cell apoptosis in AGE1. HN and PC12 cells under hypoxic or normoxic
conditions. The expression of BCL-2 and miR-204 were determined by Western blot and …
Neuronal cells are highly sensitive to hypoxia and may be subjected to apoptosis when exposed to hypoxia. Several apoptosis-related genes and miRNAs involve in hypoxia-induced apoptosis. This study aimed to examine the role of HIF1α-miR-204-BCL-2 pathway in hypoxia-induced apoptosis in neuronal cells. Annexin V/propidium iodide assay was performed to analyze cell apoptosis in AGE1.HN and PC12 cells under hypoxic or normoxic conditions. The expression of BCL-2 and miR-204 were determined by Western blot and qRT-PCR. The effects of miR-204 overexpression or knockdown on the expression of BCL-2 were evaluated by luciferase assay and Western blot under hypoxic or normoxic conditions. HIF-1α inhibitor YC-1 and siHIF-1α were employed to determine the effect of HIF-1α on the up-regulation of miR-204 and down-regulation of BCL-2 induced by hypoxia. Apoptosis assay showed the presence of apoptosis induced by hypoxia in neuronal cells. Moreover, we found that hypoxia significantly down-regulated the expression of BCL-2, and increased the mRNA level of miR-204 in neuronal cells than that in control. Bioinformatic analysis and luciferase reporter assay demonstrated that miR-204 directly targeted and regulated the expression of BCL-2. Specifically, the expression of BCL-2 was inhibited by miR-204 mimic and enhanced by miR-204 inhibitor. Furthermore, we detected that hypoxia induced cell apoptosis via HIF-1α/miR-204/BCL-2 in neuronal cells. This study demonstrated that HIF-1α-miR-204-BCL-2 pathway contributed to apoptosis of neuronal cells induced by hypoxia, which could potentially be exploited to prevent spinal cord ischemia–reperfusion injury.
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