CHEN Xing1 CHENG Chuanfang2 FANG Yanling1 GONG Ya′nan1 XU Miqing1
1.Department of Geriatrics, the Second Affiliated Hospital, Guangzhou Medical University, Guangdong Province, Guangzhou 510260, China;
2.Department of Cardiovascular Disease, the Second Affiliated Hospital, Guangzhou Medical University, Guangdong Province, Guangzhou 510260, China
Abstract：Objective To detect protein the expression of mammalian target of rapamycin (mTOR) signaling in pressure-overloaded cardiac hypertrophy and H9c2 cardiomyocyte hypertrophy, and investigate effect of mTOR signaling on cardiac hypertrophy. Methods Sixteen SD rats were randomly grouped as the abdominal aorta coarctation (AAC) group and the sham group, with 8 rats for each group. Two weeks after AAC, echocardiography and histological analysis were performed. Norepinephrine (NE) was used to induce H9c2 cardiomyocyte hypertrophy in vitro. Relative protein expressions were detected for mTOR signaling by western blot. Results Compared with the sham group, rats in the ACC group showed a significant increase in left ventricular posterior wall end-diastolic thickness (LVPWd), interventricular septal end-diastolic thickness (IVSd) and heart weight index (HWI) (all P ＜ 0.05). Western blot showed that there was a significant increased ratio of P-mTOR and mTOR protein expression in the AAC group compared with the sham group (P ＜ 0.05). NE treatment significantly increased the ratio of P-mTOR and mTOR protein expression in vitro, with a significant difference compared with the control group (P ＜ 0.05). Conclusion Protein expressions in mTOR signaling can be significantly increased in pressure-overloaded cardiac hypertrophy and H9c2 cardiomyocyte hypertrophy. mTOR signaling may play a key role in the pathogenesis of cardiac hypertrophy.
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2018, Vol. 15 
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