Figure 5. HIF-1α activated the VEGFA transcriptional level in HUVECs. (A) Western blot revealed the VEGFA protein expression in HUVECs transfected with HIF-1α overexpression plasmids (OE) or controls. (B) Bioinformatics analysis illustrated that there were two hypoxia response elements (HRE) in the promoter region of VEGFA gene. (C) The plasmid vectors containing HRE-1 and/or HRE-2 were constructed for luciferase assay. (D) Luciferase assay showed the Luciferase activity in the transfection with HRE-1 or HRE-2 vectors and HIF-1α. (E) Chromatin immunoprecipitation (ChIP) and qPCR showed the abundance of HRE-1 region in HIF-1α antibody immunoprecipitation. (F) RT-PCR showed the VEGFA mRNA level in HUVECs with HIF-1α overexpression or controls. **P < 0.01.