Figure 6.

Effect of hypoxia (1% O₂, 24 hr) on HIF‐1α abundance (a, b), total protein phosphatase activity (c, d), PP2Ac abundance (e, f), and PPP2CA mRNA expression (g, h) following HIF‐1α silencing in HASMC and AC16 ventricular cardiomyocytes. Normoxia, non‐target siRNA, and mock transfection were included as controls. HIF‐1α abundance was determined by ELISA, while total phosphatase activity, PP2Ac abundance, and PPP2CA mRNA expression were determined using a phosphatase activity assay, immunoblotting, and semi‐quantitative PCR respectively. HIF‐1α abundance is expressed in pg·ml⁻¹. All other data are expressed relative to normoxia and where appropriate were normalized to β‐actin or geometric mean of the housekeeping genes (GPI and GAPDH). Data are presented as mean ± SEM (n = 5) and were analysed using one‐way ANOVA with Dunnett's post hoc test. *P < 0.05, significantly different as indicated. HIF‐1α, hypoxia inducible factor‐1 α; NT, non‐target siRNA; PP2Ac, catalytic subunit of protein phosphatase 2A; PPP2CA, gene coding PP2Ac; UnTx, untreated cells