Fig. 4

Hypercholesterolemia activates hypoxia signaling to upregulate NOS expression. A Representative immunofluorescence images of HIF-1α staining in CRC samples from WT and ApoE^−/− mice. B Correlation between LOX-1 mRNA expression and the hypoxia signature in CRC patients from the TCGA-CRC dataset. C Intracellular levels of ROS were measured by DCFH-DA staining in indicated cells treated with oxLDL. D HIF-1 pathway activity was measured by HIF-1 luciferase reporter assay in indicated cells treated with oxLDL. E Correlation between mRNA expression of NOSs and HIF target genes in CRC samples from TCGA-CRC datasets. F RT-qPCR analysis of the mRNA expression of NOSs and HIF target genes in indicated cells treated with oxLDL. G Western blot analysis of the protein expression of NOSs and HIF-1α in indicated cells treated with oxLDL for 24 h. H RT-qPCR analysis of the mRNA expression of NOSs in indicated oxLDL-treated cells incubated with or without digoxin. Pearson’s correlation (B and E), Two-tailed Student’s t-test (C, D, and H). Error bars represent ± SD. *p < 0.05, **p < 0.01, ***p < 0.001. Data represent mean ± SD of at least three independent experiments