Figure 2.

GTF2H4 mitigates the reduction in HMEC-1 cell viability under hypoxic conditions and facilitates hypoxia-induced partial EndMT

(A) The transcription of GTF2H4 in peripheral blood samples from patients with STEMI before and after PCI was evaluated using the published GSE61144 dataset. The x axis shows 24 blood samples divided into the normal, STEMI, and 7-day post-PCI groups. The y axis shows the log2-transformed expression of GTF2H4 normalized by quantile normalization.

(B) The expression of GTF2H4 in different tissues (left ventricle myocardium, ascending coronary aorta, and ascending aorta) from 50- to 59-year-old donors based on data obtained from the GTEx database. The x axis shows the tissue from which the 273 samples were derived, and the y axis shows the log2 (TPM + 1) value. TPM, transcript count per million.

(C) Western blot analysis of GTF2H4 protein expression relative to GAPDH in HEMC-1 cells and MCMECs exposed to hypoxia. HMEC-1 and MCMECs were cultured under normoxic or hypoxic conditions for 1, 2, 4, 6, 8, 12, 24, 48, and 72 h.

(D and E) The viability of HMEC-1 cells exposed to hypoxia for 1, 2, or 3 days in each group was determined by a CCK-8 assay (n = 7).

(F and G) Western blot analysis of Bax, Bcl-xL, and cleaved caspase-3 protein expression relative to GAPDH in each group under normoxic or hypoxic conditions for 3 days (n = 3).

(H and I) Double immunofluorescence staining of CD31 (green) and α-SMA (red) in each group after exposure to hypoxia for 3 days. Nuclei were counterstained with DAPI (blue) (n = 8, scale bars, 50 μm).

(J and K) Western blot analysis of fibronectin, α-SMA, FSP-1, VE-cadherin, CD31, and GTF2H4 protein expression relative to GAPDH in each group under normoxic or hypoxic conditions for 3 days (n = 3).

The data are presented as means ± SEMs. p values were calculated by 1-way ANOVA (A and B) or 2-tailed t tests (D and E).