Figure 4.

ACTZ treatment partially restores PASMC phenotype in the SU/Hx model. (A) Relative expression of PASMC markers representative of a contractile (MYOCD, TAGLN, SMTN, ACTA2, CNN1, MYH11), synthetic (RBP1), and proliferative (CCND1) phenotype in pulmonary arteries from patients with IPAH compared with failed donor control pulmonary arteries (Donor; set as 1). n = 13 donor samples (10 male, 3 female) and n = 10 IPAH samples (6 male, 4 female). Statistical analysis by Mann-Whitney U test. (B) Vascular smooth muscle cell markers in pulmonary artery samples from SU/Hx rats showed a similar pattern of dedifferentiation expression profiles seen in human IPAH. Significant reduction in all contractile markers in SU/Hx animals compared with Ctrl and partial reversal by ACTZ treatment. Upregulation of CCND1 is ameliorated by ACTZ treatment. n = 9–15 per experimental group. Statistical analysis by one-way ANOVA and Tukey’s post hoc test. (C) Primary PASMCs from control, SU/Hx, and SU/Hx + ACTZ animals retained their phenotype in vitro. PASMCs at passage 1 were grown to subconfluence and kept in 0.5% FBS for 48 hours. n = 3–8 cell cultures per group. Significant differences from control (#) and SU/Hx (*) are noted. (D) PASMCs from SU/Hx animals showed a higher rate of proliferation than PASMCs from control or SU/Hx + ACTZ animals. Proliferation was induced after 48 hours in 0.5% FBS by media supplemented with 20% FBS, and cell numbers were determined. n = 6 cell cultures per group. Significant differences on Days 4 and 5 between control and SU/Hx (*) and SU/Hx + ACTZ and SU/Hx (#) are indicated. (A–D) Data are presented as mean ± SEM. (C and D) Statistical analysis by one-way ANOVA and Tukey’s post hoc test (*P < 0.05, **P < 0.01, ***P < 0.001, ^#P < 0.05, ^##P < 0.01, and ^###P < 0.001).