Fig. 4

Hypoxia and HIF1α are involved in the regulation of 5’tiRNA-His-GTG expression. a HIF1α is overexpressed under hypoxic conditions, as determined using western blotting. b The level of ANG increased with prolonged hypoxia time. c The expression of 5’tiRNA-His-GTG is upregulated with prolonged hypoxia time, as determined using qRT-PCR. d ANG knockdown significantly reduced the level of the ANG protein (left) and the level of 5’tiRNA-His-GTG (right) e HIF1α inhibitors (LW6, 2-ME) significantly reduced the levels of HIF1α and ANG (left), as well as the 5’tiRNA-His-GTG expression level (right). f ANG is upregulated under hypoxic conditions and is mainly located in the cytoplasm of the indicated cells, as shown using immunofluorescence (IF). g The binding sites of HIF1α to the ANG promoter were obtained from JASPAR. h A luciferase reporter assay was used to measure the direct binding between HIF-1α and the ANG promoter region under a hypoxic environment. *p < 0.05, **p < 0.01, ns: not significant. All data are representative of at least three independent experiments and are presented as the means ± SD. ANG, angiogenin; HIF-1α, hypoxia inducible factor 1 subunit alpha; qRT-PCR, quantitative real-time reverse transcription PCR