Aliskiren‐attenuated myocardium apoptosis via regulation of autophagy and connexin‐43 in aged spontaneously hypertensive rats |
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| Authors: | Wenbin Zhang Gang Zhao Xiaona Hu Min Wang Hua Li Yong Ye Qijun Du Jin Yao Zhijun Bao Wei Hong Guosheng Fu Junbo Ge Zhaohui Qiu |
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| Institution: | 1. Department of Cardiology, Biomedical Research (Therapy) Center, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, , Hangzhou, Zhejiang, China;2. Shanghai Institute of Cardiovascular Diseases of Zhongshan Hospital, Fudan University, , Shanghai, China;3. Gastroenterology Department, Huadong Hospital, Fudan University, , Shanghai, China;4. Shanghai Key Laboratory of Clinical Geriatric Medicine, , Shanghai, China;5. Institute of Biomedical Science, Fudan University, , Shanghai, China;6. Cardiovascular Department, Huadong Hospital, Fudan University, , Shanghai, China;7. Geriatrics Department, Huadong Hospital, Fudan University, , Shanghai, China |
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| Abstract: | There are controversies about the mechanism of myocardium apoptosis in hypertensive heart disease. The aim of this study was to investigate the relationship among autophagy, Cx43 and apoptosis in aged spontaneously hypertensive rats (SHRs) and establish whether Aliskiren is effective or not for the treatment of myocardium apoptosis. Twenty‐one SHRs aged 52 weeks were randomly divided into three groups, the first two receiving Aliskiren at a dose of 10 and 25 mg/kg/day respectively; the third, placebo for comparison with seven Wistar‐Kyoto (WKY) as controls. After a 2‐month treatment, systolic blood pressure (SBP), heart to bw ratios (HW/BW%) and angiotensin II (AngII) concentration were significantly enhanced in SHRs respectively. Apoptotic cardiomyocytes detected with TUNEL and immunofluorescent labelling for active caspase‐3 increased nearly fourfolds in SHRs, with a decline in the expression of survivin and AKT activation, and an increase in caspase‐3 activation and the ratio of Bax/Bcl‐2. Myocardium autophagy, detected with immunofluorescent labelling for LC3‐II, increased nearly threefolds in SHRs, with the up‐regulation of Atg5, Atg16L1, Beclin‐1 and LC3‐II. The expression of Cx43 plaque was found to be down‐regulated in SHRs. Aliskiren significantly reduced SBP, HW/BW%, AngII concentration and the expression of AT1R. Thus, Aliskiren protects myocardium against apoptosis by decreasing autophagy, up‐regulating Cx43. These effects showed a dose‐dependent tendency, but no significance. In conclusion, the myocardium apoptosis developed during the hypertensive end‐stage of SHRs could be ameliorated by Aliskiren via the regulation of myocardium autophagy and maladaptive remodelling of Cx43. |
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| Keywords: | connexin‐43 aged spontaneously hypertensive rats apoptosis autophagy Aliskiren Survivin
AKT
Caspase3 |
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