Fig. 1: Increased vascular calcification in PAH.

a Von Kossa staining revealed obvious deposits of calcium mineral in the medial vessels from the PAH rat model induced by chronic hypoxia or MCT. All panels are at × 20 magnification except for the zoomed ones. Scale bars = 50 μm; n = 10. b Chronic hypoxia or MCT administration increased activity of ALP in pulmonary arteries, n = 10. c Immunohistochemical analysis of cellular expression of Runx2 at the medial layer in lung tissues from normoxia, chronic hypoxia, and MCT-treated rats. All panels are at 20 × magnification. Scale bars = 50 μm; n = 10. d Western blotting of Runx2, MSX2, BMP2, SOX9, and SM22α expression in lung tissues from normoxia, chronic hypoxia, and MCT-treated rats. β-Actin served as the standard; n = 10. e PASMCs were exposed to hypoxia for 24 h and expression of Runx2, MSX2, BMP2, SOX9, and SM22α was evaluated with western blotting and real-time PCR. β-Actin served as the standard for western blotting; 18 s served as the standard for real-time PCR; n = 6. f PASMCs were cultured under hypoxia for 7 days upon treatment with procalcifying media containing 2.5 mM inorganic phosphate. Deposits of calcium mineral were assessed by Alizarin Red S staining f and determination of calcium content g; n = 6. Data are represented as mean ± SEM. *P < 0.05 and **P < 0.01 versus normoxia group. HYP, hypoxia, MCT, monocrotaline; NOR, normoxia