Fig. 1

Oxidative stress and mitochondrial disorganization are associated with increased apoptosis in the right ventricular tissue of RVF rats. A Schematic diagram of the pulmonary hypertension-induced RVF rat model established by intraperitoneal injection of MCT. Transthoracic echocardiography was carried out as indicated. The right ventricular tissues were harvested on day 28 for analysis. B–C Right ventricular function was determined by measuring the fractional area change (FAC). Results are expressed as mean ± SEM, n = 6 rats per group. D Pulmonary artery pressure was measured using right heart catheterization. Results are expressed as mean ± SEM, n = 4–5 rats per group. E–F Paraffin-embedded sections of heart tissue were subjected to HE or Masson staining. The boxed area was further enlarged. Scale bar (left panel) = 100 μm; scale bar (right panel) = 2000 μm. G Apoptosis was measured by TUNEL staining (green) at paraffin-embedded sections. Nuclei were stained with DAPI in blue. Scale bar (left panel) = 100 μm; scale bar (right panel) = 50 μm. H The quantification of G. Data was collected from ten random fields from the right ventricular tissue section of two rats per group. I–J Lysates from right ventricle of control and RVF rats were analyzed by western blotting with indicated antibodies. Relative protein level was quantified and expressed as mean ± SEM, n = 3 rats per group. K Relative ROS level in right ventricular tissue was measured by AOPP test. Results are expressed as mean ± SEM, n = 6–7 rats per group. L TEM of right ventricle from control and RVF rats (scale bar = 1 μm). Damaged mitochondria were marked with black arrow head, ruptured mitochondria were marked with red arrow head. M The total count of mitochondria in field were calculated according to representative transmission electron micrographs of right ventricular tissues of rat in control and RVF group. Results are expressed as mean ± SEM, n = 10 micrographs per group. N The ratio of damaged mitochondria to total mitochondria (black arrows) in field were calculated according to representative transmission electron micrographs of right ventricular tissues of rat in control and RVF group. Results are expressed as mean ± SEM, n = 10 micrographs per group. O The ratio of ruptured mitochondria to total mitochondria (red arrows) in field were calculated according to representative transmission electron micrographs of right ventricular tissues of rat in control and RVF group. Results are expressed as mean ± SEM, n = 10 micrographs per group