Pathogenic Role of mTORC1 and mTORC2 in Pulmonary Hypertension
Haiyang Tang, Kang Wu, Jian Wang, Sujana Vinjamuri, Yali Gu, Shanshan Song, Ziyi Wang, Qian Zhang, Angela Balistrieri, Ramon J. Ayon, Franz Rischard, Rebecca Vanderpool, Jiwang Chen, Guofei Zhou, Ankit A. Desai, Stephen M. Black, Joe G.N. Garcia, Jason X.-J. Yuan and Ayako Makino
mTORC2 Regulates PDGFR Expression in Smooth Muscle Cells
Pharmacological inhibition of mammalian target of rapamycin complex 2 (mTORC2) up-regulates the protein expression of PDGFRα and PDGFRβ in pulmonary arterial smooth muscle cells (PASMCs). Reverse transcription polymerase chain reaction analyses on (A) mTOR, Raptor, Rictor, GβL, and Sin1 as well as (B) PDGFRα and PDGFRβ (a) in human PASMCs and pulmonary arterial endothelial cells (PAECs). Summarized data (mean ± SE) (b) showing the levels of PDGFRα and PDGFRβ in human PASMCs (n = 6) and PAECs (n = 6). Welch’s t-test, ***p < 0.001 vs PASMC. (C) Western blot analyses on PDGFRα and PDGFRβ in human PASMCs and PAECs treated with vehicle (Cont), 50-nM rapamycin (Rap), and 200-nM KU 0063794 (KU) for 24 h. (D) Western blot analyses on PDGFRα, PDGFRβ, pAKT (T308), pAKT (S473), and AKT in PASMCs treated with vehicle (Cont), Rap, and KU (for 24 h) (a). Summarized data (mean ± SE) showing the levels of PDGFRα (Kruskal-Wallis test, p < 0.001; n = 9), PDGFRβ (Kruskal-Wallis test, p = 0.01; n = 7), pAKT (T308) (Kruskal-Wallis test, p < 0.001; n = 9), and pAKT (S473) (Kruskal-Wallis test, p < 0.001; n = 7) in control PASMC and PASMC-treated Rap and KU (b). Dunn test, *p < 0.05, **p < 0.01 versus Control. (E) Representative record of RVP in control rats and hypoxia/Sugen (Hyp/Su) rats treated with vehicle, Rap (5 mg/kg body weight, intraperitoneally), imatinib (Imat, 20 mg/kg body weight, intraperitoneally), or combination of Rap and Imat (Rap/Imat) (a). Summarized data (mean ± SE) (b–d) in control rats (Cont) and Hyp/Su rats treated with vehicle (V), Rap (R), Imat (I), or Rap and Imat (R + I) showing peak RVSP (b) (Kruskal-Wallis test, p < 0.001), the Fulton index (c) (Kruskal-Wallis test, p < 0.001), and the ratio of right ventricle weight to body weight (RV/BW) (d) (Kruskal-Wallis test, p < 0.001). Dunn test, *p < 0.05, **p < 0.01, ***p < 0.001 versus Control; Student’s t-test, #p < 0.05, ##p < 0.01, ###p<0.001 versus Hyp/Su with Vehicle (V) and Hyp/Su with Imatinib (I). Abbreviations as in Figures 1 and 6.