Fig. 4

Effect of HFD on pulmonary artery remodeling. A Representative microphotographs of pulmonary arteries after EM staining. The smooth muscle area was calculated (n = 7 in each group). After immunostaining with α-SMA, the peripheral pulmonary arteries were classified into non-muscular (NM), partially muscular (PM), and fully muscular (FM) based on the degree of muscularization. The results are expressed as mean ± SEM in 4–5 animals. B Active caspase-3 expression in the lung tissues was determined by western blotting. Representative immunoblots (top panels) and bar graph (bottom panel) are shown (n = 5 in each group). C Representative microphotographs of TUNEL-stained pulmonary arteries of mice from the ND and HFD group. TUNEL-positive cells are indicated by a red arrow. The graph represents  the percentage of TUNEL-positive nuclei in the medial smooth muscle layer (n = 5 in each group). D PPAR-γ expression in the lung tissues was determined by western blotting. Representative immunoblots (top panels) and bar graph (bottom panel) are shown (n = 5 in each group). E Apelin expression in the lung tissues was determined by western blotting. Representative immunoblots (top panels) and bar graph (bottom panel) are shown (ND, n = 3; HFD, n = 4). F, G The expressions of HO-1 (F) and HIF-1 (G) in the lung tissues were determined by western blotting. Representative immunoblots (top panels) and bar graphs (bottom panel) are shown (n = 3 in each group). The results are expressed as mean ± SEM. *P < 0.05 versus ND group, **P < 0.01 versus ND group, †P < 0.01 versus normoxia-exposed mice. ND normal diet, HFD high-fat diet