STIM1 promotes arterial smooth muscle cells proliferation by regulating Akt/mTOR pathway / 中国药理学通报

ABSTRACT

Aim To investigate the expression of stro-mal interaction molecule 1 (STIM1) in rat pulmonary arterial hypertension ( PAH ) tissues and effects of STIM1 on arterial muscle cells proliferation. Methods PAH was induced by a single intraperitoneal injec-tion of MCT at a dose of 60 mg·kg - 1 . The mRNA or protein expressions of STIM1 in monocrotaline-induced pulmonary hypertensive rats were measured by real-time PCR or Western blot, respectively. The arterial smooth muscle cells A7R5 were transiently transfected with STIM1 plasmids to prepare STIM1 overexpressed cells. Cell proliferations were detected by using CCK-8 kits. The expressions of Akt/ mTOR pathway molecules of A7R5 were measured by Western blot. Results The right ventricular systolic blood pressure ( RVSP) and right ventricular mass index ( RVMI ) were markedly elevated in MCT-treated rats (P < 0. 01) in comparison to control rats. The mRNA and protein ex-pression levels of STIM1 in monocrotaline-induced pul-monary hypertensive rats were 2. 19 and 1. 66 folds of control rats, respectively. STIM1 were transiently over-expressed in cultured A7R5. Cells transfected with STIM1 grew more quickly than non-transfected control. Overexpression of STIM1 significantly increased the phosphorylation of Akt, mTOR, p70-S6K, and 4E-BP1, but did not change their protein expression lev-els. Conclusion STIM1 are over-expressed in rat PAH tissues. Overexpression of STIM1 can promote ar-terial smooth muscle cells proliferation by regulating Akt/ mTOR pathway.