Fig. 7

Rassf1a knockout protects mice against Hypoxia induced PH. a Real time PCR measurement of Rassf1a mRNA in lungs from WT mice exposed to normoxia (n = 9) or hypoxia for 1 week (n = 5), 2 weeks (n = 5), 3 weeks (n = 9), and 5 weeks (n = 9). b–i Rassf1a KO mice (Rassf1a^+/−, Rassf1a^−/−) and wildtype littermates (WT) were exposed to Hypoxia (10% O₂) for 28 days or maintained under normoxic conditions. b, c Physiological measurements were carried out on all groups of mice exposed to hypoxia and normoxia to determine b right ventricle systolic pressure (RVSP) and c RV hypertrophy (RV/tibia length). d All three groups of mice exposed to hypoxia were subjected to magnetic resonance imaging (MRI) pre- and post-hypoxia to determine right heart function presented as d, left end diastolic volume (EDV), d, middle, end systolic volume (ESV) and d, right end systolic (ES) mass. e Representative end diastolic and systolic images for each experimental group are shown. (n = 4–5 mice each group). f, g Lung sections were subjected to H&E staining, followed by morphometric analysis of pulmonary vessels (n = 4–5 each group). f Medial wall thickness of pulmonary arteries (20- to 70-μm in diameter) and representative photomicrographs (g) are shown. h, i Immunohistochemical analysis of PCNA in small (20- to 70-μm in diameter) pulmonary vessels from the groups described above was carried out (n = 3 each group). h Percentage of PCNA positive cells and i representative photomicrographs for PCNA staining (green) are shown. Nuclei are counterstained with DAPI (blue). Scale bar: 20 μm. *P < 0.05, **P < 0.01, ***P < 0.001 compared to a hypoxia 0 weeks or b–d, f, h hypoxic WT, one-way ANOVA followed by SNK multiple comparison test. Data represent mean ± s.e.m.