Fig 1: SIK1 levels were decreased in hypoxia-stimulated PASMCs and PAH model mice. hPASMCs were cultured under normoxia (21% O2) or hypoxia (3% O2) for 24 h. Male C57/BL6 mice were raised in normoxic (21% O2) or hypoxic (10% O2) chambers and given a subcutaneous injection of 20 mg/kg Sugen 5416 (SU5416) dissolved in DMSO weekly for 4 weeks. (A–D) Western blot analysis of SIK1, SIK2 and SIK3 protein expression in hPASMCs stimulated with hypoxia or cultured under normoxia at multiple time points (n = 4). (E–H) Western blot analysis of SIK1, SIK2 and SIK3 protein expression in lung tissues of hypoxia-induced PAH mice and normoxia control mice at weeks 1–4 (n = 4). The original blots were shown in the supplementary material (Figure SM1). Quantification of the proteins is shown in the bar graphs. Data were normalized to ß-actin. All values are presented as the mean ± SD; *p < 0.05, **p < 0.01, ***p < 0.005; NS, no significance.