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
Rictor (mTORC2) in Smooth Muscle Cells and Pulmonary Hypertension
SM-specific conditional and inducible KO of Rictor increases basal RVSP and negligibly affects the development of hypoxia-induced pulmonary hypertension in RictorSM−/− mice. (A) Schematic strategy for the generation of RictorSM−/− mice (a); Western blot analysis of Rictor (rapamycin insensitive companion of mammalian target of rapamycin) in isolated PA from WT and RictorSM−/− mice (b); and the timeline indicating the time for Tam injection (to induce Rictor KO), hypoxic exposure (to induce PH) and experimental measurements (c). (B) Representative immunofluorescence images (a) and summarized data (mean ± SE; n = 5 in each group) (b) showing cell nuclei (DAPI; blue), smooth muscle cells (SMA; red), and Rictor (dark green) in the cross-section of small PA in lung tissues from WT (Rictor-Oil) and RictorSM−/− (Rictor-Tam) mice. Student’s t-test, ***p < 0.001 versus Rictor-Oil. (C) Representative record of RVP (a) and summarized data (mean ± SE) showing the peak value of RVSP (b) (Kruskal-Wallis test, p < 0.001) and the Fulton index (RV/[LV + S]) ratio (c) (Kruskal-Wallis test, p < 0.001) in WT and RictorSM−/− mice exposed to normoxia and hypoxia (for 3 weeks). Dunn test, *p < 0.05, ***p < 0.001 versus Normoxia-WT. (D) Representative hematoxylin and eosin images of the cross-section of small PA (a) and summarized data (mean ± SE) showing the PA wall thickness in WT and RictorSM−/− mice under normoxic and hypoxic conditions (b). (c) Hypoxia-induced increase in PA wall thickness in WT and RictorSM−/− mice. The numbers of experiments (n) for each group are indicated in each bar. Abbreviations as in Figure 1.