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Li J, Xie Y, Zheng S, He H, Wang Z, Li X, Jiao S, Liu D, Yang F, Zhao H, Li P, Sun Y. Targeting autophagy in diabetic cardiomyopathy: From molecular mechanisms to pharmacotherapy. Biomed Pharmacother 2024; 175:116790. [PMID: 38776677 DOI: 10.1016/j.biopha.2024.116790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Revised: 05/13/2024] [Accepted: 05/17/2024] [Indexed: 05/25/2024] Open
Abstract
Diabetic cardiomyopathy (DCM) is a cardiac microvascular complication caused by metabolic disorders. It is characterized by myocardial remodeling and dysfunction. The pathogenesis of DCM is associated with abnormal cellular metabolism and organelle accumulation. Autophagy is thought to play a key role in the diabetic heart, and a growing body of research suggests that modulating autophagy may be a potential therapeutic strategy for DCM. Here, we have summarized the major signaling pathways involved in the regulation of autophagy in DCM, including Adenosine 5'-monophosphate-activated protein kinase (AMPK), mechanistic target of rapamycin (mTOR), Forkhead box subfamily O proteins (FOXOs), Sirtuins (SIRTs), and PTEN-inducible kinase 1 (PINK1)/Parkin. Given the significant role of autophagy in DCM, we further identified natural products and chemical drugs as regulators of autophagy in the treatment of DCM. This review may help to better understand the autophagy mechanism of drugs for DCM and promote their clinical application.
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Affiliation(s)
- Jie Li
- China-Japan Friendship Hospital (Institute of Clinical Medical Sciences), Beijing, China
| | - Yingying Xie
- Department of Cardiology, China-Japan Friendship Hospital (Institute of Clinical Medical Sciences), Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Shuwen Zheng
- Beijing University of Chinese Medicine School of Traditional Chinese Medicine, Beijing, China
| | - Haoming He
- Department of Cardiology, China-Japan Friendship Hospital (Institute of Clinical Medical Sciences), Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Zhe Wang
- Department of Cardiology, China-Japan Friendship Hospital (Institute of Clinical Medical Sciences), Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Xuexi Li
- Department of Cardiology, China-Japan Friendship Hospital (Institute of Clinical Medical Sciences), Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Siqi Jiao
- Peking University China-Japan Friendship School of Clinical Medicine, Beijing, China
| | - Dong Liu
- Peking University China-Japan Friendship School of Clinical Medicine, Beijing, China
| | - Furong Yang
- Beijing University of Chinese Medicine School of Traditional Chinese Medicine, Beijing, China
| | - Hailing Zhao
- Beijing Key Laboratory for Immune-Mediated Inflammatory Diseases, Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing, China.
| | - Ping Li
- Beijing Key Laboratory for Immune-Mediated Inflammatory Diseases, Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing, China.
| | - Yihong Sun
- Department of Cardiology, China-Japan Friendship Hospital (Institute of Clinical Medical Sciences), Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China; Peking University China-Japan Friendship School of Clinical Medicine, Beijing, China.
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Lv M, Zhu X, You Y, Fan S, Chai R, Cheng T, Xue W, Shi S, Hu Y. Knowledge domain and emerging trends of autophagy in cardiovascular research: A bibliometric analysis. Medicine (Baltimore) 2024; 103:e36811. [PMID: 38215119 PMCID: PMC10783360 DOI: 10.1097/md.0000000000036811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 12/07/2023] [Indexed: 01/14/2024] Open
Abstract
BACKGROUND Autophagy is essential for the homeostasis and function of the cardiovascular system. Citespace is a visual analysis software developed in the context of scientometrics and data visualization. The purpose of this study is to use Citespace software to conduct bibliometric and visual analysis of the research on autophagy in cardiovascular diseases, identify the current status, hot spots and trends in this field, help researchers clarify the future research focus and direction of autophagy in cardiovascular diseases, and provide more positive and broader ideas for the treatment and drug development of cardiovascular diseases. METHODS In the Web of Science Core Collection database to download the data from 2004 to 2022 regarding autophagy in cardiovascular research. CitespaceV was used to collect the research status, hotspots and development trends for visual analysis. RESULTS The 3568 articles were published by 547 authors from 397 institutions in 75 countries. From 2004 to 2021, the annual publications increased over time. The top 3 productive nations were China, the United States, and Germany. The leading institution was China's Fudan University. The most cited paper is Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition). The research hotpots include monitoring methods for autophagy activity, changes in autophagy levels in different types of cardiovascular diseases, autophagy signal transduction mechanism in cardiovascular diseases, etc. CONCLUSION Bibliometric analysis provided valuable information for autophagy research in cardiovascular disease, which is full of opportunities and challenges. The research of autophagy in the field of cardiovascular diseases is still worthy of in-depth exploration. A challenge with autophagy-targeted therapies is their dichotomy in which the goal is to target maladaptive autophagy while maintaining a baseline level of cell survival to optimize a beneficial outcome. It is necessary for scientists to develop new methods to evaluate the level of autophagy from basic application to human body and reveal the signaling mechanism of autophagy in different types of cardiovascular diseases.
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Affiliation(s)
- Meng Lv
- Guang’anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Xueping Zhu
- Guang’anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Yaping You
- Guang’anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Shaowei Fan
- Guang’anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Ruoning Chai
- Guang’anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Tao Cheng
- Guang’anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Wenjing Xue
- Guang’anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Shuai Shi
- Guang’anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Yuanhui Hu
- Guang’anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
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Zhang Z, Dalan R, Hu Z, Wang JW, Chew NW, Poh KK, Tan RS, Soong TW, Dai Y, Ye L, Chen X. Reactive Oxygen Species Scavenging Nanomedicine for the Treatment of Ischemic Heart Disease. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2202169. [PMID: 35470476 DOI: 10.1002/adma.202202169] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 04/08/2022] [Indexed: 06/14/2023]
Abstract
Ischemic heart disease (IHD) is the leading cause of disability and mortality worldwide. Reactive oxygen species (ROS) have been shown to play key roles in the progression of diabetes, hypertension, and hypercholesterolemia, which are independent risk factors that lead to atherosclerosis and the development of IHD. Engineered biomaterial-based nanomedicines are under extensive investigation and exploration, serving as smart and multifunctional nanocarriers for synergistic therapeutic effect. Capitalizing on cell/molecule-targeting drug delivery, nanomedicines present enhanced specificity and safety with favorable pharmacokinetics and pharmacodynamics. Herein, the roles of ROS in both IHD and its risk factors are discussed, highlighting cardiovascular medications that have antioxidant properties, and summarizing the advantages, properties, and recent achievements of nanomedicines that have ROS scavenging capacity for the treatment of diabetes, hypertension, hypercholesterolemia, atherosclerosis, ischemia/reperfusion, and myocardial infarction. Finally, the current challenges of nanomedicines for ROS-scavenging treatment of IHD and possible future directions are discussed from a clinical perspective.
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Affiliation(s)
- Zhan Zhang
- Cancer Centre and Institute of Translational Medicine, Faculty of Health Sciences, University of Macau, Taipa, Macau SAR, 999078, China
| | - Rinkoo Dalan
- Department of Endocrinology, Tan Tock Seng Hospital, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 408433, Singapore
| | - Zhenyu Hu
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore
| | - Jiong-Wei Wang
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore
- Cardiovascular Research Institute, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore
- Department of Diagnostic Radiology and Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore
- Nanomedicine Translational Research Programme, Centre for NanoMedicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore
| | - Nicholas Ws Chew
- Department of Cardiology, National University Heart Centre, National University Hospital, Singapore, 119074, Singapore
| | - Kian-Keong Poh
- Department of Cardiology, National University Heart Centre, National University Hospital, Singapore, 119074, Singapore
| | - Ru-San Tan
- Department of Cardiology, National Heart Centre Singapore, Singapore, 119609, Singapore
| | - Tuck Wah Soong
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore
| | - Yunlu Dai
- Cancer Centre and Institute of Translational Medicine, Faculty of Health Sciences, University of Macau, Taipa, Macau SAR, 999078, China
- MoE Frontiers Science Center for Precision Oncology, University of Macao, Taipa, Macau SAR, 999078, China
| | - Lei Ye
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Xiaoyuan Chen
- Department of Diagnostic Radiology and Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore
- Nanomedicine Translational Research Programme, Centre for NanoMedicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore
- Department of Chemical and Biomolecular Engineering and Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, Singapore, 117597, Singapore
- Clinical Imaging Research Centre, Centre for Translational Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore
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Yuan S, Cai Z, Luan X, Wang H, Zhong Y, Deng L, Feng J. Gut microbiota: A new therapeutic target for diabetic cardiomyopathy. Front Pharmacol 2022; 13:963672. [PMID: 36091756 PMCID: PMC9461091 DOI: 10.3389/fphar.2022.963672] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 08/04/2022] [Indexed: 11/17/2022] Open
Abstract
Diabetic cardiomyopathy seriously affects quality of life and even threatens life safety of patients. The pathogenesis of diabetic cardiomyopathy is complex and multifactorial, and it is widely accepted that its mechanisms include oxidative stress, inflammation, insulin resistance, apoptosis, and autophagy. Some studies have shown that gut microbiota plays an important role in cardiovascular diseases. Gut microbiota and its metabolites can affect the development of diabetic cardiomyopathy by regulating oxidative stress, inflammation, insulin resistance, apoptosis, and autophagy. Here, the mechanisms of gut microbiota and its metabolites resulting in diabetic cardiomyopathy are reviewed. Gut microbiota may be a new therapeutic target for diabetic cardiomyopathy.
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Affiliation(s)
- Suxin Yuan
- Department of Cardiology, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China
| | - Zhengyao Cai
- Department of Cardiology, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China
| | - Xingzhao Luan
- Department of Neurosurgery, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China
| | - Haibo Wang
- Department of Cardiology, Gulin People’s Hospital, Luzhou, Sichuan, China
| | - Yi Zhong
- Department of Cardiology, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China
| | - Li Deng
- Department of Rheumatology, The Affiliated, Hospital of Southwest Medical University, Luzhou, Sichaun, China
| | - Jian Feng
- Department of Cardiology, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China
- *Correspondence: Jian Feng,
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Aromolaran KA, Do J, Bernardi J, Aromolaran AS. mTOR Modulation of IKr through hERG1b-Dependent Mechanisms in Lipotoxic Heart. Int J Mol Sci 2022; 23:8061. [PMID: 35897638 PMCID: PMC9329916 DOI: 10.3390/ijms23158061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 07/17/2022] [Accepted: 07/20/2022] [Indexed: 12/04/2022] Open
Abstract
In the atria, the rapid delayed rectifier channel (IKr) is a critical contributor to repolarization. In lipotoxic atria, increased activity of the serine/threonine mammalian target of rapamycin (mTOR) may remodel IKr and predispose patients to arrhythmias. To investigate whether mTOR produced defects in IKr channel function (protein expression and gating mechanisms), electrophysiology and biochemical assays in HEK293 cells stably expressing hERG1a/1b, and adult guinea pig atrial myocytes were used. Feeding with the saturated fatty acid palmitic acid high-fat diet (HFD) was used to induce lipotoxicity. Lipotoxicity-challenged HEK293 cells displayed an increased density of hERG1a/1b currents due to a targeted and significant increase in hERG1b protein expression. Furthermore, lipotoxicity significantly slowed the hERG1a/1b inactivation kinetics, while the activation and deactivation remained essentially unchanged. mTOR complex 1 (mTORC1) inhibition with rapamycin (RAP) reversed the increase in hERG1a/1b density and inactivation. Compared to lipotoxic myocytes, RAP-treated cells displayed action potential durations (APDs) and IKr densities similar to those of controls. HFD feeding triggered arrhythmogenic changes (increased the IKr density and shortened the APD) in the atria, but this was not observed in low-fat-fed controls. The data are the first to show the modulation of IKr by mTORC1, possibly through the remodeling of hERG1b, in lipotoxic atrial myocytes. These results offer mechanistic insights with implications for targeted therapeutic options for the therapy of acquired supraventricular arrhythmias in obesity and associated pathologies.
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Affiliation(s)
- Kelly A. Aromolaran
- Nora Eccles Harrison Cardiovascular Research and Training Institute (CVRTI), University of Utah School of Medicine, Salt Lake City, UT 84112, USA;
| | - Jenny Do
- Masonic Medical Research Institute, Utica, NY 13501, USA; (J.D.); (J.B.)
| | - Joyce Bernardi
- Masonic Medical Research Institute, Utica, NY 13501, USA; (J.D.); (J.B.)
| | - Ademuyiwa S. Aromolaran
- Nora Eccles Harrison Cardiovascular Research and Training Institute (CVRTI), University of Utah School of Medicine, Salt Lake City, UT 84112, USA;
- Masonic Medical Research Institute, Utica, NY 13501, USA; (J.D.); (J.B.)
- Department of Surgery, Division of Cardiothoracic Surgery, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
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Muthuramu I, Mishra M, De Geest B. Increased Remnant Lipoproteins in Apo E Deficient Mice Induce Coronary Atherosclerosis following Transverse Aortic Constriction and Aggravate the Development of Pressure Overload-Induced Cardiac Hypertrophy and Heart Failure. Biomedicines 2022; 10:biomedicines10071592. [PMID: 35884897 PMCID: PMC9312863 DOI: 10.3390/biomedicines10071592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 06/27/2022] [Accepted: 06/29/2022] [Indexed: 11/16/2022] Open
Abstract
Murine coronary arteries are very resistant to the development of atherosclerosis, which may be related to their intramyocardial course. Blood pressure promotes atherosclerotic plaque formation by acting as a physical force that potentiates the migration of pro-atherogenic lipoproteins across the endothelium. C57BL/6N apolipoprotein (apo) E deficient mice have increased remnant lipoproteins that are a risk factor for coronary atherosclerosis. In this study, our aim was to quantify coronary atherosclerosis and artery remodeling following transverse aortic constriction (TAC) in C57BL/6N apo E−/− mice and to evaluate the impact of increased remnant lipoproteins on the development of pressure overload-induced cardiac hypertrophy and heart failure. Advanced atherosclerotic lesions were observed in the left coronary artery of C57BL/6N apo E−/− TAC mice but not in C57BL/6N TAC mice. Pressure overload resulted in markedly increased cardiac hypertrophy and more pronounced heart failure in C57BL/6N apo E−/− TAC mice in comparison to C57BL/6N TAC mice. Pathological hypertrophy, as evidenced by increased myocardial fibrosis and capillary rarefaction, was more prominent in C57BL/6N TAC apo E−/− than in C57BL/6N TAC mice and led to more marked cardiac dysfunction. In conclusion, TAC in apo E deficient mice induces coronary atherosclerosis and aggravates the development of pathological cardiac hypertrophy and heart failure.
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Affiliation(s)
- Ilayaraja Muthuramu
- Centre for Molecular and Vascular Biology, Catholic University of Leuven, 3000 Leuven, Belgium; (I.M.); (M.M.)
- Gene Therapy Program, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Mudit Mishra
- Centre for Molecular and Vascular Biology, Catholic University of Leuven, 3000 Leuven, Belgium; (I.M.); (M.M.)
- Department of Cardiothoracic Surgery, University Medical Center Utrecht, 3508 GA Utrecht, The Netherlands
- Laboratory of Experimental Cardiology, Department of Cardiology, University Medical Center Utrecht, University Utrecht, 3508 GA Utrecht, The Netherlands
| | - Bart De Geest
- Centre for Molecular and Vascular Biology, Catholic University of Leuven, 3000 Leuven, Belgium; (I.M.); (M.M.)
- Correspondence: ; Tel.: +32-16-372059; Fax: +32-16-345990
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Lipid metabolism, inflammation, and foam cell formation in health and metabolic disorders: targeting mTORC1. J Mol Med (Berl) 2021; 99:1497-1509. [PMID: 34312684 DOI: 10.1007/s00109-021-02117-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Revised: 07/12/2021] [Accepted: 07/14/2021] [Indexed: 02/07/2023]
Abstract
Metabolic homeostasis is important for maintaining a healthy lifespan. Lipid metabolism is particularly necessary for the maintenance of metabolic energy sources and their storage, and the structure and function of cell membranes, as well as for the regulation of nutrition through lipogenesis, lipolysis, and lipophagy. Dysfunctional lipid metabolism leads to the development of metabolic disorders, such as atherosclerosis, diabetes mellitus, and non-alcoholic fatty liver disease (NAFLD). Furthermore, dyslipidaemia causes inflammatory responses and foam cell formation. Mechanistic target of rapamycin (mTOR) signalling is a key regulator of diverse cellular processes, including cell metabolism and cell fate. mTOR complex 1 (mTORC1) is involved in lipid metabolism and immune responses in the body. Therefore, the mTORC1 signalling pathway has been suggested as a potential therapeutic target for the treatment of metabolic disorders. In this review, we focus on the roles of mTORC1 in lipid metabolism and inflammation, and present current evidence on its involvement in the development and progression of metabolic disorders.
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Dewanjee S, Vallamkondu J, Kalra RS, John A, Reddy PH, Kandimalla R. Autophagy in the diabetic heart: A potential pharmacotherapeutic target in diabetic cardiomyopathy. Ageing Res Rev 2021; 68:101338. [PMID: 33838320 DOI: 10.1016/j.arr.2021.101338] [Citation(s) in RCA: 80] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 02/24/2021] [Accepted: 03/29/2021] [Indexed: 12/20/2022]
Abstract
Association of diabetes with an elevated risk of cardiac failure has been clinically evident. Diabetes potentiates diastolic and systolic cardiac failure following the myocardial infarction that produces the cardiac muscle-specific microvascular complication, clinically termed as diabetic cardiomyopathy. Elevated susceptibility of diabetic cardiomyopathy is primarily caused by the generation of free radicals in the hyperglycemic milieu, compromising the myocardial contractility and normal cardiac functions with increasing redox insult, impaired mitochondria, damaged organelles, apoptosis, and cardiomyocytes fibrosis. Autophagy is essentially involved in the recycling/clearing the damaged organelles, cytoplasmic contents, and aggregates, which are frequently produced in cardiomyocytes. Although autophagy plays a vital role in maintaining the cellular homeostasis in diligent cardiac tissues, this process is frequently impaired in the diabetic heart. Given its clinical significance, accumulating evidence largely showed the functional aspects of autophagy in diabetic cardiomyopathy, elucidating its intricate protective and pathogenic outcomes. However, etiology and molecular readouts of these contrary autophagy activities in diabetic cardiomyopathy are not yet comprehensively assessed and translated. In this review, we attempted to assess the role of autophagy and its adaptations in the diabetic heart. To delineate the molecular consequences of these events, we provided detailed insights into the autophagy regulation pieces of machinery including the mTOR/AMPK, TFEB/ZNSCAN3, FOXOs, SIRTs, PINK1/Parkin, Nrf2, miRNAs, and others in the diabetic cardiomyopathy. Given the clinical significance of autophagy in the diabetic heart, we further discussed the potential pharmacotherapeutic strategies towards targeting autophagy. Taken together, the present report meticulously assessed autophagy, its adaptations, and molecular regulations in diabetic cardiomyopathy and reviewed the current autophagy-targeting strategies.
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Affiliation(s)
- Saikat Dewanjee
- Advanced Pharmacognosy Research Laboratory, Department of Pharmaceutical Technology, Jadavpur University, Kolkata, 700032, India.
| | | | - Rajkumar Singh Kalra
- AIST-INDIA DAILAB, National Institute of Advanced Industrial Science & Technology (AIST), Higashi 1-1-1, Tsukuba, 305 8565, Japan.
| | - Albin John
- Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - P Hemachandra Reddy
- Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA; Neuroscience & Pharmacology, Texas Tech University Health Sciences Center, Lubbock, TX, USA; Neurology, Departments of School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA; Public Health Department of Graduate School of Biomedical Sciences, Texas Tech University Health Sciences Center, Lubbock, TX, USA; Department of Speech, Language and Hearing Sciences, School Health Professions, Texas Tech University Health Sciences Center, Lubbock, TX, USA.
| | - Ramesh Kandimalla
- Department of Biochemistry, Kakatiya Medical College, Warangal, 506007, Telangana, India; Applied Biology, CSIR-Indian Institute of Technology, Uppal Road, Tarnaka, Hyderabad, 50000, Telangana, India.
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Al-Shamma G. Serum lipids .. again, and always! BAGHDAD JOURNAL OF BIOCHEMISTRY AND APPLIED BIOLOGICAL SCIENCES 2020. [DOI: 10.47419/bjbabs.v1i01.26] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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Autophagy, Hyperlipidemia, and Atherosclerosis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1207:237-264. [PMID: 32671753 DOI: 10.1007/978-981-15-4272-5_18] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Autophagy is an evolutionarily conserved process in eukaryotes that processes the turnover of intracellular substances. Atherosclerosis is a disease caused by multiple factors, it mainly occurs on the walls of large and medium blood vessels and atherosclerotic plaques form in the intima of the blood vessels. Hyperlipidemia is considered to be a very dangerous factor leading to cardiovascular and cerebrovascular diseases, especially atherosclerosis. This chapter mainly introduces the key role of autophagy in hyperlipidemia and atherosclerosis, that is, impaired lipophagy affects the degradation of triacylglycerol, cholesterol, etc., leading to hyperlipidemia in atherosclerosis. In patients, excessive levels of autophagy accelerate the rupture of atherosclerotic plaque. This chapter also describes the advances in the treatment of atherosclerosis and hyperlipidemia by targeted autophagy.
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Yao YS, Li TD, Zeng ZH. Mechanisms underlying direct actions of hyperlipidemia on myocardium: an updated review. Lipids Health Dis 2020; 19:23. [PMID: 32035485 PMCID: PMC7007679 DOI: 10.1186/s12944-019-1171-8] [Citation(s) in RCA: 84] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 12/09/2019] [Indexed: 02/02/2023] Open
Abstract
Hyperlipidemia is a common metabolic disorder and one of risk factors for cardiovascular disease. Clinical studies have shown that hyperlipidemia increases the risk of non-ischemic heart failure, while decreasing serum lipids can reverse heart dysfunction. Apart from indirectly affecting the function of the heart by promoting the development of atherosclerosis, hyperlipidemia also affects the systolic function and cardiac electrophysiological response of the heart directly, which may be related to gradual accumulation of cardiac lipids and consequent systemic oxidative stress, proinflammatory state and mitochondrial dysfunction. However, the mechanism underlying direct effects of hyperlipidemia on the heart are not fully understood. In this review, we provide an updated summary of recent experimental and clinical studies that focus on elucidating the mechanisms of the action of hyperlipidemia on cardiac function, the relationship between heart failure and serum lipids, and protective effects of lipid-lowering drugs on the heart. The exciting progress in this field supports the prospect of guiding early protection of the heart to benefit the patients with chronic hyperlipidemia and familial hyperlipidemia.
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Affiliation(s)
- Yu Si Yao
- Department of Cardiovascular Diseases, The First Affiliated Hospital of Guangdong Pharmaceutical University, Guangzhou, Guangdong 510080 People’s Republic of China
| | - Tu Di Li
- Department of Cardiovascular Diseases, The First Affiliated Hospital of Guangdong Pharmaceutical University, Guangzhou, Guangdong 510080 People’s Republic of China
| | - Zhi Huan Zeng
- Department of Cardiovascular Diseases, The First Affiliated Hospital of Guangdong Pharmaceutical University, Guangzhou, Guangdong 510080 People’s Republic of China
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Protective Role of mTOR in Liver Ischemia/Reperfusion Injury: Involvement of Inflammation and Autophagy. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:7861290. [PMID: 31827701 PMCID: PMC6885218 DOI: 10.1155/2019/7861290] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 08/24/2019] [Accepted: 10/14/2019] [Indexed: 02/06/2023]
Abstract
Liver ischemia/reperfusion (IR) injury is a common phenomenon after liver resection and transplantation, which often results in liver graft dysfunction such as delayed graft function and primary nonfunction. The mammalian target of rapamycin (mTOR) is an evolutionarily highly conserved serine/threonine protein kinase, which coordinates cell growth and metabolism through sensing environmental inputs under physiological or pathological conditions, involved in the pathophysiological process of IR injury. In this review, we mainly present current evidence of the beneficial role of mTOR in modulating inflammation and autophagy under liver IR to provide some evidence for the potential therapies for liver IR injury.
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Muthuramu I, Mishra M, Aboumsallem JP, Postnov A, Gheysens O, De Geest B. Cholesterol lowering attenuates pressure overload-induced heart failure in mice with mild hypercholesterolemia. Aging (Albany NY) 2019; 11:6872-6891. [PMID: 31484164 PMCID: PMC6756886 DOI: 10.18632/aging.102218] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 08/13/2019] [Indexed: 01/19/2023]
Abstract
Epidemiological studies support a strong association between non-high-density lipoprotein cholesterol levels and heart failure incidence. The objective of the current study was to evaluate the effect of selective cholesterol lowering adeno-associated viral serotype 8 (AAV8)-mediated low-density lipoprotein receptor (LDLr) gene transfer on cardiac remodelling and myocardial oxidative stress following transverse aortic constriction (TAC) in female C57BL/6 LDLr-/- mice with mild hypercholesterolemia. Cholesterol lowering gene transfer resulted in a 65.9% (p<0.0001) reduction of plasma cholesterol levels (51.2 ± 2.2 mg/dl) compared to controls (150 ± 7 mg/dl). Left ventricular wall area was 11.2% (p<0.05) lower in AAV8-LDLr TAC mice than in control TAC mice. In agreement, pro-hypertrophic myocardial proteins were potently decreased in AAV8-LDLr TAC mice. The degree of interstitial fibrosis and perivascular fibrosis was 31.0% (p<0.001) and 29.8% (p<0.001) lower, respectively, in AAV8-LDLr TAC mice compared to control TAC mice. These structural differences were associated with improved systolic and diastolic function and decreased lung congestion in AAV8-LDLr TAC mice compared to control TAC mice. Cholesterol lowering gene therapy counteracted myocardial oxidative stress and preserved the potential for myocardial fatty acid oxidation in TAC mice. In conclusion, cholesterol lowering gene therapy attenuates pressure overload-induced heart failure in mice with mild hypercholesterolemia.
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Affiliation(s)
- Ilayaraja Muthuramu
- Centre for Molecular and Vascular Biology, Department of Cardiovascular Sciences, Catholic University of Leuven, Leuven 3000, Belgium
| | - Mudit Mishra
- Centre for Molecular and Vascular Biology, Department of Cardiovascular Sciences, Catholic University of Leuven, Leuven 3000, Belgium
| | - Joseph Pierre Aboumsallem
- Centre for Molecular and Vascular Biology, Department of Cardiovascular Sciences, Catholic University of Leuven, Leuven 3000, Belgium
| | - Andrey Postnov
- Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, Catholic University of Leuven, Leuven 3000, Belgium
| | - Olivier Gheysens
- Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, Catholic University of Leuven, Leuven 3000, Belgium
| | - Bart De Geest
- Centre for Molecular and Vascular Biology, Department of Cardiovascular Sciences, Catholic University of Leuven, Leuven 3000, Belgium
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Chen X, Miller NM, Afghah Z, Geiger JD. Development of AD-Like Pathology in Skeletal Muscle. JOURNAL OF PARKINSON'S DISEASE AND ALZHEIMER'S DISEASE 2019; 6:10.13188/2376-922x.1000028. [PMID: 32190732 PMCID: PMC7079679 DOI: 10.13188/2376-922x.1000028] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Effective therapeutic strategy against Alzheimer's disease (AD) requires early detection of AD; however, clinical diagnosis of Alzheimer's disease (AD) is not precise and a definitive diagnosis of AD is only possible via postmortem examination for AD pathological hallmarks including senile plaques composed of Aβ and neuro fibrillary tangles composed of phosphorylated tau. Although a variety of biomarker has been developed and used in clinical setting, none of them robustly predicts subsequent clinical course of AD. Thus, it is essential to identify new biomarkers that may facilitate the diagnosis of early stages of AD, prediction of subsequent clinical course, and development of new therapeutic strategies. Given that pathological hallmarks of AD including Aβaccumulation and the presence of phosphorylated tau are also detected in peripheral tissues, AD is considered a systemic disease. Without the protection of blood-brain barrier, systemic factors can affect peripheral tissues much earlier than neurons in brain. Here, we will discuss the development of AD-like pathology in skeletal muscle and the potential use of skeletal muscle biopsy (examination for Aβaccumulation and phosphorylated tau) as a biomarker for AD.
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Affiliation(s)
- X Chen
- Department of Biomedical Sciences, University of North Dakota, USA
| | - NM Miller
- Department of Biomedical Sciences, University of North Dakota, USA
| | - Z Afghah
- Department of Biomedical Sciences, University of North Dakota, USA
| | - JD Geiger
- Department of Biomedical Sciences, University of North Dakota, USA
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Zhang X, Liu H, Hao Y, Xu L, Zhang T, Liu Y, Guo L, Zhu L, Pei Z. Coenzyme Q10 protects against hyperlipidemia-induced cardiac damage in apolipoprotein E-deficient mice. Lipids Health Dis 2018; 17:279. [PMID: 30526612 PMCID: PMC6286539 DOI: 10.1186/s12944-018-0928-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 11/26/2018] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Hyperlipidemia is a well-established risk factor for cardiac damage, which can lead to cardiovascular diseases. Many studies have shown that Coenzyme Q10(CoQ10) protects against cardiac damage in vivo. The aim of this study was to investigate the possible protective effects of CoQ10 against cardiac damage in apolipoprotein E-deficient (ApoE-/-) mice. METHODS Eight-week-old male C57BL/6 and ApoE-/- mice were randomly divided into four groups: C57BL/6 mice fed a normal diet (C57BL/6 group); C57BL/6 mice fed a normal diet + CoQ10 (C57BL/6 + CoQ10 group); ApoE-/- mice fed a high-fat diet (ApoE-/- HD group), and ApoE-/- mice fed a high-fat diet + CoQ10 (ApoE-/- HD + CoQ10 group). All groups were fed the different diets for 16 weeks. Blood samples were obtained from the inferior vena cava and collected in serum tubes. The samples were then stored at - 80 °C until used. Coronal sections of heart tissues were fixed in 10% formalin and then embedded in paraffin for histological evaluation. The remainder of the heart tissues was snap-frozen in liquid nitrogen for mRNA or immunohistochemical analysis. RESULTS The metabolic parameters such as total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-c), and triglycerides (TG) levels were lower in ApoE-/-HD + CoQ10 mice than in ApoE-/- HD mice. There were significant pathophysiological changes (H&E, PAS, Masson and CD68 staining) in ApoE-/- mice in the HD group compared with those in the HD + CoQ10 group. CoQ10 reduced HD-induced cardiac tissue damage via autophagy (p62 and LC3), as evidenced by immunoblotting, immunohistochemistry, and RT-qPCR. CoQ10 also inhibited inflammation (IL-6 and TNF-α) gene expression in ApoE-/- mice. CONCLUSIONS These results indicate that CoQ10 is a potential therapeutic target for cardiac damage caused by hyperlipidemia.
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Affiliation(s)
- Xiaoqing Zhang
- Department of Infection, Affiliated Zhongshan Hospital of Dalian University, No. 6 Jiefang Street, Dalian, China
| | - Hongyang Liu
- Department of Heart Intensive Care Unit, the First Affiliated Hospital of Dalian Medical University, No.193 Lianhe Road, Dalian, China
| | - Yuhua Hao
- Department of Infection, Affiliated Zhongshan Hospital of Dalian University, No. 6 Jiefang Street, Dalian, China
| | - Lulu Xu
- Department of Infection, Affiliated Zhongshan Hospital of Dalian University, No. 6 Jiefang Street, Dalian, China
| | - Tiemei Zhang
- Department of Infection, Affiliated Zhongshan Hospital of Dalian University, No. 6 Jiefang Street, Dalian, China
| | - Yingshu Liu
- Department of Endocrinology, Dalian Municipal Central Hospital, 42 Xuegong Road, Dalian, China
| | - Lipeng Guo
- Department of Cardiology, Dalian Third People' Hospital Affiliated to Dalian Medical University, No.40 Qianshan Road, Dalian, China
| | - Liyue Zhu
- Rehabilitation Center, Zhejiang Hospital, 12 Lingyin Road, Hangzhou, Zhejiang, China
| | - Zuowei Pei
- Department of Cardiology, Affiliated Zhongshan Hospital of Dalian University, No. 6 Jiefang Street, Dalian, China.
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Zhang Y, Whaley-Connell AT, Sowers JR, Ren J. Autophagy as an emerging target in cardiorenal metabolic disease: From pathophysiology to management. Pharmacol Ther 2018; 191:1-22. [PMID: 29909238 PMCID: PMC6195437 DOI: 10.1016/j.pharmthera.2018.06.004] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 06/05/2018] [Indexed: 12/16/2022]
Abstract
Although advances in medical technology and health care have improved the early diagnosis and management for cardiorenal metabolic disorders, the prevalence of obesity, insulin resistance, diabetes, hypertension, dyslipidemia, and kidney disease remains high. Findings from numerous population-based studies, clinical trials, and experimental evidence have consolidated a number of theories for the pathogenesis of cardiorenal metabolic anomalies including resistance to the metabolic action of insulin, abnormal glucose and lipid metabolism, oxidative and nitrosative stress, endoplasmic reticulum (ER) stress, apoptosis, mitochondrial damage, and inflammation. Accumulating evidence has recently suggested a pivotal role for proteotoxicity, the unfavorable effects of poor protein quality control, in the pathophysiology of metabolic dysregulation and related cardiovascular complications. The ubiquitin-proteasome system (UPS) and autophagy-lysosomal pathways, two major although distinct cellular clearance machineries, govern protein quality control by degradation and clearance of long-lived or damaged proteins and organelles. Ample evidence has depicted an important role for protein quality control, particularly autophagy, in the maintenance of metabolic homeostasis. To this end, autophagy offers promising targets for novel strategies to prevent and treat cardiorenal metabolic diseases. Targeting autophagy using pharmacological or natural agents exhibits exciting new strategies for the growing problem of cardiorenal metabolic disorders.
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Affiliation(s)
- Yingmei Zhang
- Shanghai Institute of Cardiovascular Diseases, Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai 200032, China; Center for Cardiovascular Research and Alternative Medicine, University of Wyoming College of Health Sciences, Laramie, WY 82071, USA.
| | - Adam T Whaley-Connell
- Research Service, Harry S Truman Memorial Veterans' Hospital, University of Missouri-Columbia School of Medicine, Columbia, MO, USA; Diabetes and Cardiovascular Center, Department of Medicine, University of Missouri-Columbia School of Medicine, Columbia, MO, USA
| | - James R Sowers
- Research Service, Harry S Truman Memorial Veterans' Hospital, University of Missouri-Columbia School of Medicine, Columbia, MO, USA; Diabetes and Cardiovascular Center, Department of Medicine, University of Missouri-Columbia School of Medicine, Columbia, MO, USA
| | - Jun Ren
- Shanghai Institute of Cardiovascular Diseases, Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai 200032, China; Center for Cardiovascular Research and Alternative Medicine, University of Wyoming College of Health Sciences, Laramie, WY 82071, USA.
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Tan Y, Gong Y, Dong M, Pei Z, Ren J. Role of autophagy in inherited metabolic and endocrine myopathies. Biochim Biophys Acta Mol Basis Dis 2018; 1865:48-55. [PMID: 30343140 DOI: 10.1016/j.bbadis.2018.10.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 10/11/2018] [Accepted: 10/17/2018] [Indexed: 12/11/2022]
Abstract
The prevalence of cardiometabolic disease has reached an exponential rate of rise over the last decades owing to high fat/high caloric diet intake and satiety life style. Although the presence of dyslipidemia, insulin resistance, hypertension and obesity mainly contributes to the increased incidence of cardiometabolic diseases, population-based, clinical and genetic studies have revealed a rather important role for inherited myopathies and endocrine disorders in the ever-rising metabolic anomalies. Inherited metabolic and endocrine diseases such as glycogen storage and lysosomal disorders have greatly contributed to the overall prevalence of cardiometabolic diseases. Recent evidence has demonstrated an essential role for proteotoxicity due to autophagy failure and/or dysregulation in the onset of inherited metabolic and endocrine disorders. Given the key role for autophagy in the degradation and removal of long-lived or injured proteins and organelles for the maintenance of cellular and organismal homeostasis, this mini-review will discuss the potential contribution of autophagy dysregulation in the pathogenesis of inherited myopathies and endocrine disorders, which greatly contribute to an overall rise in prevalence of cardiometabolic disorders. Molecular, clinical, and epidemiological aspects will be covered as well as the potential link between autophagy and metabolic anomalies thus target therapy may be engaged for these comorbidities.
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Affiliation(s)
- Ying Tan
- Department of Emergency Medicine, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China; Center for Cardiovascular Research and Alternative Medicine, University of Wyoming College of Health Sciences, Laramie, WY 82071, USA
| | - Yan Gong
- The Second Department of Cardiology, The Third Hospital of Nanchang, Nanchang, Jiangxi 330009, China
| | - Maolong Dong
- Department of Emergency Medicine, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China; Center for Cardiovascular Research and Alternative Medicine, University of Wyoming College of Health Sciences, Laramie, WY 82071, USA; Department of Burns, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Zhaohui Pei
- The Second Department of Cardiology, The Third Hospital of Nanchang, Nanchang, Jiangxi 330009, China.
| | - Jun Ren
- Center for Cardiovascular Research and Alternative Medicine, University of Wyoming College of Health Sciences, Laramie, WY 82071, USA.
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Muthuramu I, Amin R, Postnov A, Mishra M, Aboumsallem JP, Dresselaers T, Himmelreich U, Van Veldhoven PP, Gheysens O, Jacobs F, De Geest B. Cholesterol-Lowering Gene Therapy Counteracts the Development of Non-ischemic Cardiomyopathy in Mice. Mol Ther 2017; 25:2513-2525. [PMID: 28822689 DOI: 10.1016/j.ymthe.2017.07.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 07/20/2017] [Accepted: 07/27/2017] [Indexed: 02/02/2023] Open
Abstract
A causal role of hypercholesterolemia in non-ischemic heart failure has never been demonstrated. Adeno-associated viral serotype 8 (AAV8)-low-density lipoprotein receptor (AAV8-LDLr) gene transfer was performed in LDLr-deficient mice without and with pressure overload induced by transverse aortic constriction (TAC). AAV8-LDLr gene therapy resulted in an 82.8% (p < 0.0001) reduction of plasma cholesterol compared with controls. Mortality rate was lower (p < 0.05) in AAV8-LDLr TAC mice compared with control TAC mice (hazard ratio for mortality 0.457, 95% confidence interval [CI] 0.237-0.882) during 8 weeks of follow-up. AAV8-LDLr gene therapy attenuated cardiac hypertrophy, reduced interstitial and perivascular fibrosis, and decreased lung congestion in TAC mice. Cardiac function, quantified by invasive hemodynamic measurements and magnetic resonance imaging, was significantly improved 8 weeks after sham operation or after TAC in AAV8-LDLr mice compared with respective control groups. Myocardial protein levels of mammalian target of rapamycin and of acetyl-coenzyme A carboxylase were strikingly decreased following cholesterol lowering in mice without and with pressure overload. AAV8-LDLr therapy potently reduced cardiac glucose uptake and counteracted metabolic remodeling following pressure overload. Furthermore, oxidative stress and myocardial apoptosis were decreased following AAV8-LDLr therapy in mice with pressure overload. In conclusion, cholesterol-lowering gene therapy potently counteracts structural and metabolic remodeling, and enhances cardiac function.
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Affiliation(s)
- Ilayaraja Muthuramu
- Centre for Molecular and Vascular Biology, Department of Cardiovascular Sciences, Catholic University of Leuven, 3000 Leuven, Belgium
| | - Ruhul Amin
- Centre for Molecular and Vascular Biology, Department of Cardiovascular Sciences, Catholic University of Leuven, 3000 Leuven, Belgium
| | - Andrey Postnov
- Nuclear Medicine & Molecular Imaging, Department of Imaging & Pathology, Catholic University of Leuven, 3000 Leuven, Belgium
| | - Mudit Mishra
- Centre for Molecular and Vascular Biology, Department of Cardiovascular Sciences, Catholic University of Leuven, 3000 Leuven, Belgium
| | - Joseph Pierre Aboumsallem
- Centre for Molecular and Vascular Biology, Department of Cardiovascular Sciences, Catholic University of Leuven, 3000 Leuven, Belgium
| | - Tom Dresselaers
- Biomedical MRI, Department of Imaging & Pathology, Catholic University of Leuven, 3000 Leuven, Belgium; Department of Radiology, University Hospitals Leuven, 3000 Leuven, Belgium
| | - Uwe Himmelreich
- Biomedical MRI, Department of Imaging & Pathology, Catholic University of Leuven, 3000 Leuven, Belgium
| | - Paul P Van Veldhoven
- Laboratory of Lipid Biochemistry and Protein Interactions, Department of Cellular and Molecular Medicine, Catholic University of Leuven, 3000 Leuven, Belgium
| | - Olivier Gheysens
- Nuclear Medicine & Molecular Imaging, Department of Imaging & Pathology, Catholic University of Leuven, 3000 Leuven, Belgium
| | - Frank Jacobs
- Centre for Molecular and Vascular Biology, Department of Cardiovascular Sciences, Catholic University of Leuven, 3000 Leuven, Belgium
| | - Bart De Geest
- Centre for Molecular and Vascular Biology, Department of Cardiovascular Sciences, Catholic University of Leuven, 3000 Leuven, Belgium.
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Wong VKW, Zeng W, Chen J, Yao XJ, Leung ELH, Wang QQ, Chiu P, Ko BCB, Law BYK. Tetrandrine, an Activator of Autophagy, Induces Autophagic Cell Death via PKC-α Inhibition and mTOR-Dependent Mechanisms. Front Pharmacol 2017. [PMID: 28642707 PMCID: PMC5462963 DOI: 10.3389/fphar.2017.00351] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Emerging evidence suggests the therapeutic role of autophagic modulators in cancer therapy. This study aims to identify novel traditional Chinese medicinal herbs as potential anti-tumor agents through autophagic induction, which finally lead to autophagy mediated-cell death in apoptosis-resistant cancer cells. Using bioactivity-guided purification, we identified tetrandrine (Tet) from herbal plant, Radix stephaniae tetrandrae, as an inducer of autophagy. Across a number of cancer cell lines, we found that breast cancer cells treated with tetrandrine show an increase autophagic flux and formation of autophagosomes. In addition, tetrandrine induces cell death in a panel of apoptosis-resistant cell lines that are deficient for caspase 3, caspase 7, caspase 3 and 7, or Bax-Bak respectively. We also showed that tetrandrine-induced cell death is independent of necrotic cell death. Mechanistically, tetrandrine induces autophagy that depends on mTOR inactivation. Furthermore, tetrandrine induces autophagy in a calcium/calmodulin-dependent protein kinase kinase-β (CaMKK-β), 5' AMP-activated protein kinase (AMPK) independent manner. Finally, by kinase profiling against 300 WT kinases and computational molecular docking analysis, we showed that tetrandrine is a novel PKC-α inhibitor, which lead to autophagic induction through PKC-α inactivation. This study provides detailed insights into the novel cytotoxic mechanism of an anti-tumor compound originated from the herbal plant, which may be useful in promoting autophagy mediated- cell death in cancer cell that is resistant to apoptosis.
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Affiliation(s)
- Vincent Kam Wai Wong
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and TechnologyMacau, China
| | - Wu Zeng
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and TechnologyMacau, China
| | - Juan Chen
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, The Second Affiliated Hospital of Chongqing Medical University, Chongqing Medical UniversityChongqing, China
| | - Xiao Jun Yao
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and TechnologyMacau, China
| | - Elaine Lai Han Leung
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and TechnologyMacau, China
| | - Qian Qian Wang
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and TechnologyMacau, China
| | - Pauline Chiu
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, University of Hong KongHong Kong, China
| | - Ben C B Ko
- Department of Applied Biology and Chemical Technology, and State Key Laboratory of Chirosciences, The Hong Kong Polytechnic UniversityHong Kong, China
| | - Betty Yuen Kwan Law
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and TechnologyMacau, China
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20
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Giricz Z, Koncsos G, Rajtík T, Varga ZV, Baranyai T, Csonka C, Szobi A, Adameová A, Gottlieb RA, Ferdinandy P. Hypercholesterolemia downregulates autophagy in the rat heart. Lipids Health Dis 2017; 16:60. [PMID: 28330474 PMCID: PMC5363032 DOI: 10.1186/s12944-017-0455-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 03/14/2017] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND We have previously shown that efficiency of ischemic conditioning is diminished in hypercholesterolemia and that autophagy is necessary for cardioprotection. However, it is unknown whether isolated hypercholesterolemia disturbs autophagy or the mammalian target of rapamycin (mTOR) pathways. Therefore, we investigated whether isolated hypercholesterolemia modulates cardiac autophagy-related pathways or programmed cell death mechanisms such as apoptosis and necroptosis in rat heart. METHODS Male Wistar rats were fed either normal chow (NORM; n = 9) or with 2% cholesterol and 0.25% cholic acid-enriched diet (CHOL; n = 9) for 12 weeks. CHOL rats exhibited a 41% increase in plasma total cholesterol level over that of NORM rats (4.09 mmol/L vs. 2.89 mmol/L) at the end of diet period. Animals were sacrificed, hearts were excised and briefly washed out. Left ventricles were snap-frozen for determination of markers of autophagy, mTOR pathway, apoptosis, and necroptosis by Western blot. RESULTS Isolated hypercholesterolemia was associated with a significant reduction in expression of cardiac autophagy markers such as LC3-II, Beclin-1, Rubicon and RAB7 as compared to controls. Phosphorylation of ribosomal S6, a surrogate marker for mTOR activity, was increased in CHOL samples. Cleaved caspase-3, a marker of apoptosis, increased in CHOL hearts, while no difference in the expression of necroptotic marker RIP1, RIP3 and MLKL was detected between treatments. CONCLUSIONS This is the first comprehensive analysis of autophagy and programmed cell death pathways of apoptosis and necroptosis in hearts of hypercholesterolemic rats. Our data show that isolated hypercholesterolemia suppresses basal cardiac autophagy and that the decrease in autophagy may be a result of an activated mTOR pathway. Reduced autophagy was accompanied by increased apoptosis, while cardiac necroptosis was not modulated by isolated hypercholesterolemia. Decreased basal autophagy and elevated apoptosis may be responsible for the loss of cardioprotection reported in hypercholesterolemic animals.
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Affiliation(s)
- Zoltán Giricz
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvárad tér 4, H-1089 Budapest, Hungary
- Pharmahungary Group, Szeged, Hungary
| | - Gábor Koncsos
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvárad tér 4, H-1089 Budapest, Hungary
| | - Tomáš Rajtík
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Comenius University, Odbojárov 10, 83232 Bratislava, Slovakia
| | - Zoltán V. Varga
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvárad tér 4, H-1089 Budapest, Hungary
- Department of Biochemistry, Faculty of Medicine, University of Szeged, Dóm tér 9, H-6720 Szeged, Hungary
| | - Tamás Baranyai
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvárad tér 4, H-1089 Budapest, Hungary
| | - Csaba Csonka
- Department of Biochemistry, Faculty of Medicine, University of Szeged, Dóm tér 9, H-6720 Szeged, Hungary
| | - Adrián Szobi
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Comenius University, Odbojárov 10, 83232 Bratislava, Slovakia
| | - Adriana Adameová
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Comenius University, Odbojárov 10, 83232 Bratislava, Slovakia
| | - Roberta A. Gottlieb
- Heart Institute, Cedars-Sinai Medical Center, 127 S. San Vicente Blvd., Los Angeles, CA 90048 USA
| | - Péter Ferdinandy
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvárad tér 4, H-1089 Budapest, Hungary
- Pharmahungary Group, Szeged, Hungary
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Insights for Oxidative Stress and mTOR Signaling in Myocardial Ischemia/Reperfusion Injury under Diabetes. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:6437467. [PMID: 28298952 PMCID: PMC5337354 DOI: 10.1155/2017/6437467] [Citation(s) in RCA: 119] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 12/01/2016] [Accepted: 01/04/2017] [Indexed: 12/31/2022]
Abstract
Diabetes mellitus (DM) displays a high morbidity. The diabetic heart is susceptible to myocardial ischemia/reperfusion (MI/R) injury. Impaired activation of prosurvival pathways, endoplasmic reticulum (ER) stress, increased basal oxidative state, and decreased antioxidant defense and autophagy may render diabetic hearts more vulnerable to MI/R injury. Oxidative stress and mTOR signaling crucially regulate cardiometabolism, affecting MI/R injury under diabetes. Producing reactive oxygen species (ROS) and reactive nitrogen species (RNS), uncoupling nitric oxide synthase (NOS), and disturbing the mitochondrial quality control may be three major mechanisms of oxidative stress. mTOR signaling presents both cardioprotective and cardiotoxic effects on the diabetic heart, which interplays with oxidative stress directly or indirectly. Antihyperglycemic agent metformin and newly found free radicals scavengers, Sirt1 and CTRP9, may serve as promising pharmacological therapeutic targets. In this review, we will focus on the role of oxidative stress and mTOR signaling in the pathophysiology of MI/R injury in diabetes and discuss potential mechanisms and their interactions in an effort to provide some evidence for cardiometabolic targeted therapies for ischemic heart disease (IHD).
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Wang F, Jia J, Rodrigues B. Autophagy, Metabolic Disease, and Pathogenesis of Heart Dysfunction. Can J Cardiol 2017; 33:850-859. [PMID: 28389131 DOI: 10.1016/j.cjca.2017.01.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 12/29/2016] [Accepted: 01/04/2017] [Indexed: 12/12/2022] Open
Abstract
In normal physiology, autophagy is recognized as a protective housekeeping mechanism that enables elimination of unhealthy organelles, protein aggregates, and invading pathogens, as well as recycling cell components and producing new building blocks and energy for cellular renovation and homeostasis. However, overactive or depressed autophagy is often associated with the pathogenesis of multiple disorders, including cardiac disease. During metabolic disorders, such as diabetes and obesity, dysregulation of autophagy frequently leads to cell death, cardiomyopathy, and cardiac dysfunction. In this article, we summarize the current understanding of autophagy-its classification, progression, and regulation; its roles in both physiological and pathophysiological conditions; and the balance between autophagy and apoptosis. We also explore how dysregulation of autophagy leads to cell death in models of metabolic disease and its contributing factors-including nutrient state, hyperglycemia, dyslipidemia, insulin inefficiency, and oxidative stress-and outline some recent efforts to restore normal autophagy in pathophysiological states. This information could provide potential targets for the prevention of, or intervention in, cardiac failure in metabolic disorders such as diabetes and obesity.
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Affiliation(s)
- Fulong Wang
- Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Jocelyn Jia
- Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Brian Rodrigues
- Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, British Columbia, Canada.
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Sciarretta S, Boppana VS, Umapathi M, Frati G, Sadoshima J. Boosting autophagy in the diabetic heart: a translational perspective. Cardiovasc Diagn Ther 2015; 5:394-402. [PMID: 26543826 DOI: 10.3978/j.issn.2223-3652.2015.07.02] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Diabetes, obesity, and dyslipidemia are main risk factors that promote the development of cardiovascular diseases. These metabolic abnormalities are frequently found to be associated together in a highly morbid clinical condition called metabolic syndrome. Metabolic derangements promote endothelial dysfunction, atherosclerotic plaque formation and rupture, cardiac remodeling and dysfunction. This evidence strongly encourages the elucidation of the mechanisms through which obesity, diabetes, and metabolic syndrome induce cellular abnormalities and dysfunction in order to discover new therapeutic targets and strategies for their prevention and treatment. Numerous studies employing both dietary and genetic animal models of obesity and diabetes have demonstrated that autophagy, an intracellular system for protein degradation, is impaired in the heart under these conditions. This suggests that autophagy reactivation may represent a future potential therapeutic intervention to reduce cardiac maladaptive alterations in patients with metabolic derangements. In fact, autophagy is a critical mechanism to preserve cellular homeostasis and survival. In addition, the physiological activation of autophagy protects the heart during stress, such as acute ischemia, starvation, chronic myocardial infarction, pressure overload, and proteotoxic stress. All these aspects will be discussed in our review article together with the potential ways to reactivate autophagy in the context of obesity, metabolic syndrome, and diabetes.
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Affiliation(s)
- Sebastiano Sciarretta
- 1 Cardiovascular Research Institute, Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, New Jersey 07103, USA ; 2 IRCCS Neuromed, Pozzilli (IS) 86077, Italy ; 3 Department of Medical-Surgical Sciences and Biotechnologies, University of Rome "Sapienza", Latina 04100, Italy
| | - V Subbarao Boppana
- 1 Cardiovascular Research Institute, Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, New Jersey 07103, USA ; 2 IRCCS Neuromed, Pozzilli (IS) 86077, Italy ; 3 Department of Medical-Surgical Sciences and Biotechnologies, University of Rome "Sapienza", Latina 04100, Italy
| | - Mahaa Umapathi
- 1 Cardiovascular Research Institute, Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, New Jersey 07103, USA ; 2 IRCCS Neuromed, Pozzilli (IS) 86077, Italy ; 3 Department of Medical-Surgical Sciences and Biotechnologies, University of Rome "Sapienza", Latina 04100, Italy
| | - Giacomo Frati
- 1 Cardiovascular Research Institute, Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, New Jersey 07103, USA ; 2 IRCCS Neuromed, Pozzilli (IS) 86077, Italy ; 3 Department of Medical-Surgical Sciences and Biotechnologies, University of Rome "Sapienza", Latina 04100, Italy
| | - Junichi Sadoshima
- 1 Cardiovascular Research Institute, Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, New Jersey 07103, USA ; 2 IRCCS Neuromed, Pozzilli (IS) 86077, Italy ; 3 Department of Medical-Surgical Sciences and Biotechnologies, University of Rome "Sapienza", Latina 04100, Italy
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Sabe AA, Elmadhun NY, Sadek AA, Chu LM, Bianchi C, Sellke FW. Differential effects of atorvastatin on autophagy in ischemic and nonischemic myocardium in Ossabaw swine with metabolic syndrome. J Thorac Cardiovasc Surg 2014; 148:3172-8. [PMID: 25240527 DOI: 10.1016/j.jtcvs.2014.07.104] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 07/26/2014] [Accepted: 07/29/2014] [Indexed: 11/28/2022]
Abstract
OBJECTIVES The perioperative administration of pleomorphic statin drugs has been implicated in improving outcomes after cardiac surgery. Adaptive autophagy is a highly conserved cellular process that allows for the elimination of dysfunctional cell components in response to stress and survival under starving conditions. We sought to investigate the effects of the statin drug atorvastatin on autophagy in ischemic and nonischemic myocardia using a clinically relevant porcine model of metabolic syndrome. METHODS Male Ossabaw swine were fed a regular diet (n = 8), a high-cholesterol diet (n = 8), or a high-cholesterol diet with supplemental atorvastatin (1.5 mg/kg/d) (n = 8). After 14 weeks, all animals underwent surgical placement of an ameroid constrictor to the circumflex coronary artery to induce chronic ischemia. Nonischemic and ischemic myocardia were harvested 6 months after initiation of the diet and processed for Western blotting. RESULTS In the nonischemic myocardium, Western blot results demonstrate that a high cholesterol diet resulted in a statistically significant decrease in autophagy as indicated by an increase in mammalian target of rapamycin and the accumulation of several essential autophagy markers, including Beclin-1, light chain 3B-I, and light chain 3B-II. Atorvastatin supplementation prevented these changes and resulted in an increase in autophagy as indicated by a decrease in autophagy flux marker P62. In the ischemic myocardium, atorvastatin had the opposite effect, with a decrease in autophagy flux as indicated by an increase in p62 and an accumulation of light chain 3B-I, light chain B-II, and lysosome-associated membrane protein 2. CONCLUSIONS Atorvastatin administration has differential effects on autophagy in ischemic and nonischemic myocardia. In the setting of metabolic syndrome, atorvastatin stimulates autophagy in nonischemic myocardium while partly inhibiting autophagy in ischemic myocardium. The differential regulation on autophagy may, in part, explain the cardioprotective effect of statins in both ischemic and nonischemic myocardia, and these findings may have implications in the setting of cardiac surgery.
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Affiliation(s)
- Ashraf A Sabe
- Division of Cardiothoracic Surgery, Cardiovascular Research Center, Warren Alpert School of Medicine, Brown University, Providence, RI
| | - Nassrene Y Elmadhun
- Division of Cardiothoracic Surgery, Cardiovascular Research Center, Warren Alpert School of Medicine, Brown University, Providence, RI
| | - Ahmed A Sadek
- Division of Cardiothoracic Surgery, Cardiovascular Research Center, Warren Alpert School of Medicine, Brown University, Providence, RI
| | - Louis M Chu
- Division of Cardiothoracic Surgery, Cardiovascular Research Center, Warren Alpert School of Medicine, Brown University, Providence, RI
| | - Cesario Bianchi
- Division of Cardiothoracic Surgery, Cardiovascular Research Center, Warren Alpert School of Medicine, Brown University, Providence, RI
| | - Frank W Sellke
- Division of Cardiothoracic Surgery, Cardiovascular Research Center, Warren Alpert School of Medicine, Brown University, Providence, RI.
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Li ZL, Ebrahimi B, Zhang X, Eirin A, Woollard JR, Tang H, Lerman A, Wang SM, Lerman LO. Obesity-metabolic derangement exacerbates cardiomyocyte loss distal to moderate coronary artery stenosis in pigs without affecting global cardiac function. Am J Physiol Heart Circ Physiol 2014; 306:H1087-101. [PMID: 24508639 DOI: 10.1152/ajpheart.00052.2013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Obesity associated with metabolic derangements (ObM) worsens the prognosis of patients with coronary artery stenosis (CAS), but the underlying cardiac pathophysiologic mechanisms remain elusive. We tested the hypothesis that ObM exacerbates cardiomyocyte loss distal to moderate CAS. Obesity-prone pigs were randomized to four groups (n = 6 each): lean-sham, ObM-sham, lean-CAS, and ObM-CAS. Lean and ObM pigs were maintained on a 12-wk standard or atherogenic diet, respectively, and left circumflex CAS was then induced by placing local-irritant coils. Cardiac structure, function, and myocardial oxygenation were assessed 4 wk later by computed-tomography and blood oxygenation level dependent (BOLD) MRI, the microcirculation with micro-computed-tomography, and injury mechanisms by immunoblotting and histology. ObM pigs showed obesity, dyslipidemia, and insulin resistance. The degree of CAS (range, 50-70%) was similar in lean and ObM pigs, and resting myocardial perfusion and global cardiac function remained unchanged. Increased angiogenesis distal to the moderate CAS observed in lean was attenuated in ObM pigs, which also showed microvascular dysfunction and increased inflammation (M1-macrophages, TNF-α expression), oxidative stress (gp91), hypoxia (BOLD-MRI), and fibrosis (Sirius-red and trichrome). Furthermore, lean-CAS showed increased myocardial autophagy, which was blunted in ObM pigs (downregulated expression of unc-51-like kinase-1 and autophagy-related gene-12; P < 0.05 vs. lean CAS) and associated with marked apoptosis. The interaction diet xstenosis synergistically inhibited angiogenic, autophagic, and fibrogenic activities. ObM exacerbates structural and functional myocardial injury distal to moderate CAS with preserved myocardial perfusion, possibly due to impaired cardiomyocyte turnover.
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Affiliation(s)
- Zi-Lun Li
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
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Sabe AA, Elmadhun NY, Dalal RS, Robich MP, Sellke FW. Resveratrol regulates autophagy signaling in chronically ischemic myocardium. J Thorac Cardiovasc Surg 2014; 147:792-8; Discussion 798-9. [PMID: 24267781 PMCID: PMC3947125 DOI: 10.1016/j.jtcvs.2013.06.062] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 06/06/2013] [Accepted: 06/18/2013] [Indexed: 01/05/2023]
Abstract
OBJECTIVE Autophagy is a cellular process by which damaged components are removed. Although autophagy can result in cell death, when optimally regulated, it might be cardioprotective. Resveratrol is a naturally occurring polyphenol also believed to be cardioprotective. Using a clinically relevant swine model of metabolic syndrome, we investigated the effects of resveratrol on autophagy in the chronically ischemic myocardium. METHODS Yorkshire swine were fed a regular diet (n = 7), a high cholesterol diet (n = 7), or a high cholesterol diet with supplemental resveratrol (n = 6). After 4 weeks, an ameroid constrictor was surgically placed on the left circumflex artery to induce chronic myocardial ischemia. The diets were continued another 7 weeks, and then the ischemic and nonischemic myocardium were harvested for protein analysis. RESULTS In the ischemic myocardium, a high cholesterol diet partly attenuated the autophagy, as determined by an increase in phosphorylated mammalian target of rapamycin (p-mTOR) and a decrease in p70 S6 kinase (P70S6K), lysosome-associated membrane protein (LAMP)-2, and autophagy-related gene 12-5 conjugate (ATG 12-5; P < .05). The addition of resveratrol blunted many of these changes, because the p-mTOR, P70S6K, and LAMP-2 levels were not significantly altered from those of the pigs fed a regular diet. Other autophagy markers were increased with a high cholesterol diet, including light chain 3A-II and beclin 1 (P < .05). In the nonischemic myocardium, beclin 1 was decreased in the high cholesterol-fed pigs (P < .05); otherwise no significant changes in protein expression were noted among the 3 groups. CONCLUSIONS In the chronically ischemic myocardium, resveratrol partly reversed the effects of a high cholesterol diet on autophagy. This might be a mechanism by which resveratrol exerts its cardioprotective effects.
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Affiliation(s)
- Ashraf A Sabe
- Division of Cardiothoracic Surgery, Cardiovascular Research Center, Brown University Warren Alpert School of Medicine, Providence, RI
| | - Nassrene Y Elmadhun
- Division of Cardiothoracic Surgery, Cardiovascular Research Center, Brown University Warren Alpert School of Medicine, Providence, RI
| | - Rahul S Dalal
- Division of Cardiothoracic Surgery, Cardiovascular Research Center, Brown University Warren Alpert School of Medicine, Providence, RI
| | - Michael P Robich
- Division of Cardiothoracic Surgery, Cardiovascular Research Center, Brown University Warren Alpert School of Medicine, Providence, RI
| | - Frank W Sellke
- Division of Cardiothoracic Surgery, Cardiovascular Research Center, Brown University Warren Alpert School of Medicine, Providence, RI.
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Lassaletta AD, Elmadhun NY, Zanetti AVD, Feng J, Anduaga J, Gohh RY, Sellke FW, Bianchi C. Rapamycin treatment of healthy pigs subjected to acute myocardial ischemia-reperfusion injury attenuates cardiac functions and increases myocardial necrosis. Ann Thorac Surg 2013; 97:901-7. [PMID: 24266948 DOI: 10.1016/j.athoracsur.2013.09.059] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 09/18/2013] [Accepted: 09/23/2013] [Indexed: 01/22/2023]
Abstract
BACKGROUND The mammalian target of rapamycin (mTOR) pathway is a major regulator of cell immunity and metabolism. mTOR is a well-known suppressor of tissue rejection in organ transplantation. However, it has other nonimmune functions: in the cardiovascular system, it is a regulator of heart hypertrophy and locally, in coated vascular stents, it inhibits vascular wall cell growth and hence neointimal formation/restenosis. Because the mTOR pathway plays major roles in normal cell growth, metabolism, and survival, we hypothesized that inhibiting it with rapamycin before an acute myocardial ischemia-reperfusion injury (IRI) would confer cardioprotection by virtue of slowing down cardiac function and metabolism. METHODS Yorkshire pigs received either placebo or 4 mg/d rapamycin orally for 7 days before the IRI. All animals underwent median sternotomy, and the mid-left anterior descending coronary artery was occluded for 60 minutes followed by 120 minutes of reperfusion. Left ventricular pressure-volume data were collected throughout the operation. The ischemic and infarcted areas were determined by monastral blue and triphenyltetrazolium chloride staining, respectively, and plasma cardiac troponin I concentration. mTOR kinase activities were monitored in remote cardiac tissue by Western blotting with specific antibodies against mTOR substrates phosphorylating sites. RESULTS Rapamycin before treatment impaired endothelial-dependent vasorelaxation, attenuated cardiac function during IRI, and increased myocardial necrosis. Western blotting confirmed effective inhibition of myocardial mTOR kinase activities. CONCLUSIONS Acute myocardial IRI, in healthy pigs treated with rapamycin, is associated with decreased cardiac function and higher myocardial necrosis.
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Affiliation(s)
- Antonio D Lassaletta
- Rhode Island Hospital Division of Cardiothoracic Surgery, Warren Alpert Medical School of Brown University, Providence, Rhode Island
| | - Nassrene Y Elmadhun
- Rhode Island Hospital Division of Cardiothoracic Surgery, Warren Alpert Medical School of Brown University, Providence, Rhode Island
| | - Arthus V D Zanetti
- Rhode Island Hospital Division of Cardiothoracic Surgery, Warren Alpert Medical School of Brown University, Providence, Rhode Island; Faculdade de Ciencias Medicas da Santa Casa de Sao Paulo, Sao Paulo, Brazil
| | - Jun Feng
- Rhode Island Hospital Division of Cardiothoracic Surgery, Warren Alpert Medical School of Brown University, Providence, Rhode Island
| | - Javier Anduaga
- Rhode Island Hospital Division of Cardiothoracic Surgery, Warren Alpert Medical School of Brown University, Providence, Rhode Island
| | - Reginald Y Gohh
- Organ Transplantation, and Cardiovascular Research Center, Warren Alpert Medical School of Brown University, Providence, Rhode Island
| | - Frank W Sellke
- Rhode Island Hospital Division of Cardiothoracic Surgery, Warren Alpert Medical School of Brown University, Providence, Rhode Island
| | - Cesario Bianchi
- Rhode Island Hospital Division of Cardiothoracic Surgery, Warren Alpert Medical School of Brown University, Providence, Rhode Island.
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Blagosklonny MV. Aging is not programmed: genetic pseudo-program is a shadow of developmental growth. Cell Cycle 2013; 12:3736-42. [PMID: 24240128 PMCID: PMC3905065 DOI: 10.4161/cc.27188] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Aging is not and cannot be programmed. Instead, aging is a continuation of developmental growth, driven by genetic pathways such as mTOR. Ironically, this is often misunderstood as a sort of programmed aging. In contrast, aging is a purposeless quasi-program or, figuratively, a shadow of actual programs. “The brightest flame casts the darkest shadow.” -George Martin
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Lee H, Yoo YS, Lee D, Song EJ. Cholesterol induces cardiac hypertrophy by activating the AKT pathway. J Steroid Biochem Mol Biol 2013; 138:307-13. [PMID: 23907017 DOI: 10.1016/j.jsbmb.2013.07.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Revised: 06/27/2013] [Accepted: 07/22/2013] [Indexed: 01/01/2023]
Abstract
Cardiac hypertrophy leads to decompensated heart function, predisposition to heart failure, and sudden death due to physiological and pathological stimuli. Although high cholesterol is considered a principal risk factor for atherosclerosis and heart disease, it has not been shown whether cholesterol itself is sufficient to cause cardiac hypertrophy. In this study, we investigated whether cholesterol induces cardiac hypertrophy, and identified cellular mechanisms underlying hypertrophic responses using H9c2 cells as a model system. Here we show that cholesterol loading significantly increased the cellular surface area and upregulated hypertrophy marker gene, β-myosin-heavy chain (β-MHC). Cholesterol loading alone activated the extracellular signal-regulated kinase (ERK)/mitogen activated protein kinase (MAPK) and phosphatidylinositol-3-kinase (PI3K)/AKT pathways. Conversely, cholesterol induced hypertrophic characteristic features such as increase in cellular surface area, and the expression of β-MHC mRNA is markedly inhibited by LY294002, a PI3K kinase inhibitor. These results suggest that cholesterol may play a key role in the development of cardiac hypertrophy through the activation of the PI3K/AKT pathway activation.
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Affiliation(s)
- Hyunjung Lee
- Molecular Recognition Research Center, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791, Republic of Korea; Department of Life & Pharmaceutical Sciences Ewha Womans University, Daehyun-dong, Seodaemun-gu, Seoul 120-750, Republic of Korea
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Ouyang C, You J, Xie Z. The interplay between autophagy and apoptosis in the diabetic heart. J Mol Cell Cardiol 2013; 71:71-80. [PMID: 24513079 DOI: 10.1016/j.yjmcc.2013.10.014] [Citation(s) in RCA: 112] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Revised: 10/07/2013] [Accepted: 10/21/2013] [Indexed: 11/19/2022]
Abstract
Diabetic cardiomyopathy is characterized by ventricular dysfunction that occurs in diabetic patients independent of coronary artery disease, hypertension, and any other cardiovascular diseases. Diabetic cardiomyopathy has become a major cause of diabetes-related mortality. Thus, an urgent need exists to clarify the mechanism of pathogenesis. Emerging evidence demonstrates that diabetes induces cardiomyocyte apoptosis and suppresses cardiac autophagy, indicating that the interplay between the autophagy and apoptotic cell death pathways is important in the pathogenesis of diabetic cardiomyopathy. This review highlights recent advances in the crosstalk between autophagy and apoptosis and its importance in the development of diabetic cardiomyopathy. This article is part of a Special Issue entitled "Protein Quality Control, the Ubiquitin Proteasome System, and Autophagy".
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Affiliation(s)
- Changhan Ouyang
- Section of Molecular Medicine, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Jieyun You
- Section of Molecular Medicine, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Zhonglin Xie
- Section of Molecular Medicine, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
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Shiu SWM, Wong Y, Tan KCB. Effect of advanced glycation end products on lectin-like oxidized low density lipoprotein receptor-1 expression in endothelial cells. J Atheroscler Thromb 2013; 19:1083-92. [PMID: 22863784 DOI: 10.5551/jat.11742] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
AIM Lectin-like oxidized LDL receptor-1 (LOX-1) is a class E oxidized LDL specific scavenger receptor that recognizes multiple ligands. Advanced glycation end products (AGEs) have been recently identified as other ligands to LOX-1 and shown to increase LOX-1 expressions in diabetes; therefore, we investigated the underlying mechanism involved. METHODS Confluent human aortic endothelial cells were treated with a fixed concentration of AGE-BSA or BSA as a control in the presence or absence of either antibody of the receptor for advanced glycation end products, mammalian target of rapamycin (mTOR) inhibitor rapamycin, NF-kB inhibitor, phosphoinositide 3-kinases (PI3K) inhibitor or anti-diabetic drug metformin. After stimulation, cells were lysed and Western blot protein expression on LOX-1, rapamycin-insensitive companion of mTOR (RICTOR), the phosphorylation status of p-mTOR, p-P70S6 kinase and p-Akt were determined. RESULTS AGEs induced LOX-1 expression in endothelial cells. Pretreatment either with anti-RAGE antibody or LY294002 prior to AGE-BSA decreases LOX-1 and p-mTOR expressions. Incubating endothelial cells with AGE-BSA in the presence of rapamycin down-regulated the protein expression-level of p-mTOR by 41% (p<0.05) and LOX-1 expression by 61.5% (p<0.01). Knockdown of RICTOR by RNA silencing showed a 41.5% (p<0.01) and 71.2% (p<0.01) reduction in LOX-1 and p-Akt expressions, respectively. Preincubation of endothelial cells with AGE-BSA and metformin, an anti-diabetic drug known to have an mTOR inhibition effect, significantly reduced AGE-stimulated LOX-1 expression. CONCLUSION Our results indicated that LOX-1 up-regulation induced by AGE-BSA was a receptor mediated through RAGE and is via the PI3K/PDK1/mTORC2 pathway. Metformincan reduce AGE-stimulated LOX-1 expression in endothelial cells in vitro.
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Affiliation(s)
- Sammy W M Shiu
- Department of Medicine, University of Hong Kong, Hong Kong
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Abstract
Autophagy is a housekeeping process that helps to maintain cellular energy homeostasis and remove damaged organelles. In the heart, autophagy is an adaptive process that is activated in response to stress including acute and chronic ischemia. Given the evidence that autophagy is suppressed in energy-rich conditions, the objective of this review is to examine autophagy and cardioprotection in the setting of the metabolic syndrome. Clinical approaches that involve the induction of cardiac autophagy pharmacologically to enhance the heart's tolerance to ischemia are also discussed.
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Pietka TA, Sulkin MS, Kuda O, Wang W, Zhou D, Yamada KA, Yang K, Su X, Gross RW, Nerbonne JM, Efimov IR, Abumrad NA. CD36 protein influences myocardial Ca2+ homeostasis and phospholipid metabolism: conduction anomalies in CD36-deficient mice during fasting. J Biol Chem 2012; 287:38901-12. [PMID: 23019328 DOI: 10.1074/jbc.m112.413609] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Sarcolemmal CD36 facilitates myocardial fatty acid (FA) uptake, which is markedly reduced in CD36-deficient rodents and humans. CD36 also mediates signal transduction events involving a number of cellular pathways. In taste cells and macrophages, CD36 signaling was recently shown to regulate store-responsive Ca(2+) flux and activation of Ca(2+)-dependent phospholipases A(2) that cycle polyunsaturated FA into phospholipids. It is unknown whether CD36 deficiency influences myocardial Ca(2+) handling and phospholipid metabolism, which could compromise the heart, typically during stresses. Myocardial function was examined in fed or fasted (18-22 h) CD36(-/-) and WT mice. Echocardiography and telemetry identified conduction anomalies that were associated with the incidence of sudden death in fasted CD36(-/-) mice. No anomalies or death occurred in WT mice during fasting. Optical imaging of perfused hearts from fasted CD36(-/-) mice documented prolongation of Ca(2+) transients. Consistent with this, knockdown of CD36 in cardiomyocytes delayed clearance of cytosolic Ca(2+). Hearts of CD36(-/-) mice (fed or fasted) had 3-fold higher SERCA2a and 40% lower phospholamban levels. Phospholamban phosphorylation by protein kinase A (PKA) was enhanced after fasting reflecting increased PKA activity and cAMP levels in CD36(-/-) hearts. Abnormal Ca(2+) homeostasis in the CD36(-/-) myocardium associated with increased lysophospholipid content and a higher proportion of 22:6 FA in phospholipids suggests altered phospholipase A(2) activity and changes in membrane dynamics. The data support the role of CD36 in coordinating Ca(2+) homeostasis and lipid metabolism and the importance of this role during myocardial adaptation to fasting. Potential relevance of the findings to CD36-deficient humans would need to be determined.
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Affiliation(s)
- Terri A Pietka
- Center for Human Nutrition, Washington University, St. Louis, Missouri 63110, USA
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Xu X, Ren J. Unmasking the janus faces of autophagy in obesity-associated insulin resistance and cardiac dysfunction. Clin Exp Pharmacol Physiol 2012; 39:200-8. [PMID: 22053892 DOI: 10.1111/j.1440-1681.2011.05638.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Autophagy is an intracellular, lysosomal-dependent process involved in the turnover of long-lived proteins, damaged organelles and other subcellular structures. The autophagic process is known to play an essential role in the maintenance of cellular homeostasis. Results from recent studies also indicate an important role for the autophagic process in the pathogenesis of human diseases, including cancer, cardiovascular diseases, obesity, diabetes mellitus and ageing. Because of the pivotal role of autophagy in the regulation of adipogenesis, obesity and insulin sensitization, research efforts have focused on elucidating the role of autophagy in metabolic syndrome. Mammalian target of rapamycin (mTOR) is a key regulator of cell growth and is characterized by a complex signalling mechanism that affects protein synthesis and autophagy. Results from experimental and clinical studies reveal some interesting, but conflicting, findings regarding the mTOR signalling pathway and autophagy in adipocytes in metabolic syndrome. Although the pivotal role of autophagy in obesity and other metabolic diseases has been established, its involvement in obesity-induced cardiac dysfunction remains unknown, as do the upstream signalling regulators of autophagy. The present minireview discusses the molecular mechanisms of autophagy in the regulation of cardiac function in overweight and obesity. Further studies using appropriate models are needed to better unravel the complex intracellular mechanisms involved in the regulation of autophagy in obesity-induced cardiac dysfunction.
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Affiliation(s)
- Xihui Xu
- Center for Cardiovascular Research and Alternative Medicine, University of Wyoming College of Health Sciences, Laramie, WY, USA
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Nair S, Ren J. Autophagy and cardiovascular aging: lesson learned from rapamycin. Cell Cycle 2012; 11:2092-9. [PMID: 22580468 DOI: 10.4161/cc.20317] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The biological aging process is commonly associated with increased risk of cardiovascular diseases. Several theories have been put forward for aging-associated deterioration in ventricular function, including attenuation of growth hormone (insulin-like growth factors and insulin) signaling, loss of DNA replication and repair, histone acetylation and accumulation of reactive oxygen species. Recent evidence has depicted a rather unique role of autophagy as another important pathway in the regulation of longevity and senescence. Autophagy is a predominant cytoprotective (rather than self-destructive) process. It carries a prominent role in determination of lifespan. Reduced autophagy has been associated with aging, leading to accumulation of dysfunctional or damaged proteins and organelles. To the contrary, measures such as caloric restriction and exercise may promote autophagy to delay aging and associated comorbidities. Stimulation of autophagy using rapamycin may represent a novel strategy to prolong lifespan and combat aging-associated diseases. Rapamycin regulates autophagy through inhibition of the nutrient-sensing molecule mammalian target of rapamycin (mTOR). Inhibition of mTOR through rapamycin and caloric restriction promotes longevity. The purpose of this review is to recapitulate some of the recent advances in an effort to better understand the interplay between rapamycin-induced autophagy and decelerating cardiovascular aging.
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Affiliation(s)
- Sreejayan Nair
- Division of Pharmaceutical Sciences and Center for Cardiovascular Research and Alternative Medicine, University of Wyoming, Laramie, WY USA.
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36
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Effect of everolimus on pre-existing atherosclerosis in LDL-receptor deficient mice. Atherosclerosis 2012; 222:337-43. [DOI: 10.1016/j.atherosclerosis.2012.03.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Revised: 02/27/2012] [Accepted: 03/02/2012] [Indexed: 01/11/2023]
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Abstract
Weak stresses (including weak oxidative stress, cytostatic agents, heat shock, hypoxia, calorie restriction) may extend lifespan. Known as hormesis, this is the most controversial notion in gerontology. For one, it is believed that aging is caused by accumulation of molecular damage. If so, hormetic stresses (by causing damage) must shorten lifespan. To solve the paradox, it was suggested that, by activating repair, hormetic stresses eventually decrease damage. Similarly, Baron Munchausen escaped from a swamp by pulling himself up by his own hair. Instead, I discuss that aging is not caused by accumulation of molecular damage. Although molecular damage accumulates, organisms do not live long enough to age from this accumulation. Instead, aging is driven by overactivated signal-transduction pathways including the TOR (Target of Rapamycin) pathway. A diverse group of hormetic conditions can be divided into two groups. "Hormesis A" inhibits the TOR pathway. "Hormesis B" increases aging-tolerance, defined as the ability to survive catastrophic complications of aging. Hormesis A includes calorie restriction, resveratrol, rapamycin, p53-inducing agents and, in part, physical exercise, heat shock and hypoxia. Hormesis B includes ischemic preconditioning and, in part, physical exercise, heat shock, hypoxia and medical interventions.
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Affiliation(s)
- Mikhail V Blagosklonny
- Department of Cell Stress Biology, Roswell Park Cancer Institute, Buffalo, NY 14263, USA.
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Li ZL, Woollard JR, Ebrahimi B, Crane JA, Jordan KL, Lerman A, Wang SM, Lerman LO. Transition from obesity to metabolic syndrome is associated with altered myocardial autophagy and apoptosis. Arterioscler Thromb Vasc Biol 2012; 32:1132-41. [PMID: 22383702 DOI: 10.1161/atvbaha.111.244061] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
OBJECTIVE Transition from obesity to metabolic-syndrome (MetS) promotes cardiovascular diseases, but the underlying cardiac pathophysiological mechanisms are incompletely understood. We tested the hypothesis that development of insulin resistance and MetS is associated with impaired myocardial cellular turnover. METHODS AND RESULTS MetS-prone Ossabaw pigs were randomized to 10 weeks of standard chow (lean) or to 10 (obese) or 14 (MetS) weeks of atherogenic diet (n=6 each). Cardiac structure, function, and myocardial oxygenation were assessed by multidetector computed-tomography and Blood Oxygen Level-Dependent-MRI, the microcirculation with microcomputed-tomography, and injury mechanisms by immunoblotting and histology. Both obese and MetS showed obesity and dyslipidemia, whereas only MetS showed insulin resistance. Cardiac output and myocardial perfusion increased only in MetS, yet Blood Oxygen Level-Dependent-MRI showed hypoxia. Inflammation, oxidative stress, mitochondrial dysfunction, and fibrosis also increased in both obese and MetS, but more pronouncedly in MetS. Furthermore, autophagy in MetS was decreased and accompanied by marked apoptosis. CONCLUSIONS Development of insulin resistance characterizing a transition from obesity to MetS is associated with progressive changes of myocardial autophagy, apoptosis, inflammation, mitochondrial dysfunction, and fibrosis. Restoring myocardial cellular turnover may represent a novel therapeutic target for preserving myocardial structure and function in obesity and MetS.
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Affiliation(s)
- Zi-Lun Li
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN 55905, USA
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Sciarretta S, Zhai P, Shao D, Maejima Y, Robbins J, Volpe M, Condorelli G, Sadoshima J. Rheb is a critical regulator of autophagy during myocardial ischemia: pathophysiological implications in obesity and metabolic syndrome. Circulation 2012; 125:1134-46. [PMID: 22294621 DOI: 10.1161/circulationaha.111.078212] [Citation(s) in RCA: 235] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
BACKGROUND Rheb is a GTP-binding protein that promotes cell survival and mediates the cellular response to energy deprivation (ED). The role of Rheb in the regulation of cell survival during ED has not been investigated in the heart. METHODS AND RESULTS Rheb is inactivated during cardiomyocyte (CM) glucose deprivation (GD) in vitro, and during acute myocardial ischemia in vivo. Rheb inhibition causes mTORC1 inhibition, because forced activation of Rheb, through Rheb overexpression in vitro and through inducible cardiac-specific Rheb overexpression in vivo, restored mTORC1 activity. Restoration of mTORC1 activity reduced CM survival during GD and increased infarct size after ischemia, both of which were accompanied by inhibition of autophagy, whereas Rheb knockdown increased autophagy and CM survival. Rheb inhibits autophagy mostly through Atg7 depletion. Restoration of autophagy, through Atg7 reexpression and inhibition of mTORC1, increased cellular ATP content and reduced endoplasmic reticulum stress, thereby reducing CM death induced by Rheb activation. Mice with high-fat diet-induced obesity and metabolic syndrome (HFD mice) exhibited deregulated cardiac activation of Rheb and mTORC1, particularly during ischemia. HFD mice presented inhibition of cardiac autophagy and displayed increased ischemic injury. Pharmacological and genetic inhibition of mTORC1 restored autophagy and abrogated the increase in infarct size observed in HFD mice, but they failed to protect HFD mice in the presence of genetic disruption of autophagy. CONCLUSIONS Inactivation of Rheb protects CMs during ED through activation of autophagy. Rheb and mTORC1 may represent therapeutic targets to reduce myocardial damage during ischemia, particularly in obese patients.
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Affiliation(s)
- Sebastiano Sciarretta
- Cardiovascular Research Institute, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Medical Science Building, Newark, NJ 07103, USA
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Ming XF, Montani JP, Yang Z. Perspectives of Targeting mTORC1-S6K1 in Cardiovascular Aging. Front Physiol 2012; 3:5. [PMID: 22291661 PMCID: PMC3265748 DOI: 10.3389/fphys.2012.00005] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Accepted: 01/09/2012] [Indexed: 01/10/2023] Open
Abstract
The global population aging is accelerating and age-associated diseases including cardiovascular diseases become more challenging. The underlying mechanisms of aging and age-associated cardiovascular dysfunction remain elusive. There are substantial evidences demonstrating a pivotal role of the mammalian target of rapamycin complex 1 (mTORC1) and its down-stream effector S6K1 signaling in mammalian lifespan regulation and age-related diseases such as type II diabetes mellitus and cancer. The role of mTORC1–S6K1 in age-related cardiovascular diseases is, however, largely unknown and the available experimental results are controversial. This review article primarily summarizes the most recent advances toward understanding the role of mTORC1–S6K1 in cardiovascular aging and discusses the future perspectives of targeting mTORC1–S6K1 signaling as a healthy lifespan extension modality in anti-aging and anti-cardiovascular aging.
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Affiliation(s)
- Xiu-Fen Ming
- Laboratory of Vascular Biology, Division of Physiology, Department of Medicine, Faculty of Science, University of Fribourg Fribourg, Switzerland
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Lipids in autophagy: constituents, signaling molecules and cargo with relevance to disease. Biochim Biophys Acta Mol Cell Biol Lipids 2012; 1821:1133-45. [PMID: 22269166 DOI: 10.1016/j.bbalip.2012.01.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Revised: 12/29/2011] [Accepted: 01/02/2012] [Indexed: 01/12/2023]
Abstract
The balance between protein and lipid biosynthesis and their eventual degradation is a critical component of cellular health. Autophagy, the catabolic process by which cytoplasmic material becomes degraded in lysosomes, can be induced by various physiological stimuli to maintain cellular homeostasis. Autophagy was for a long time considered a non-selective bulk process, but recent data have shown that unwanted components such as aberrant protein aggregates, dysfunctional organelles and invading pathogens can be selectively eliminated by autophagy. Recently, also intracellular lipid droplets were described as specific autophagic cargo, indicating that autophagy plays a role in lipid metabolism and storage (Singh et al., 2009 [1]). Moreover, over the past several years, it has become increasingly evident that lipids and lipid-modifying enzymes play important roles in the autophagy process itself, both at the level of regulation of autophagy and as membrane constituents required for formation of autophagic vesicles. In this review, we will discuss the interplay between lipids and autophagy, as well as the role of lipid-binding proteins in autophagy. We also comment on the possible implications of this mutual interaction in the context of disease. This article is part of a Special Issue entitled Lipids and Vesicular Transport.
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Blagosklonny MV. Molecular damage in cancer: an argument for mTOR-driven aging. Aging (Albany NY) 2011; 3:1130-41. [PMID: 22246147 PMCID: PMC3273893 DOI: 10.18632/aging.100422] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Accepted: 12/31/2011] [Indexed: 12/12/2022]
Abstract
Despite common belief, accumulation of molecular damage does not play a key role in aging. Still, cancer (an age-related disease) is initiated by molecular damage. Cancer and aging share a lot in common including the activation of the TOR pathway. But the role of molecular damage distinguishes cancer and aging. Furthermore, an analysis of the role of both damage and aging in cancer argues against "a decline, caused by accumulation of molecular damage" as a cause of aging. I also discuss how random molecular damage, via rounds of multiplication and selection, brings about non-random hallmarks of cancer.
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Affiliation(s)
- Mikhail V Blagosklonny
- Department of Cell Stress Biology, Roswell Park Cancer Institute, Buffalo, NY 14263, USA.
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Ogura Y, Iemitsu M, Naito H, Kakigi R, Kakehashi C, Maeda S, Akema T. Single bout of running exercise changes LC3-II expression in rat cardiac muscle. Biochem Biophys Res Commun 2011; 414:756-60. [PMID: 22005460 DOI: 10.1016/j.bbrc.2011.09.152] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Accepted: 09/30/2011] [Indexed: 11/25/2022]
Abstract
Macroautophagy (autophagy) is an intracellular catalytic process. We examined the effect of running exercise, which stimulates cardiac work physiologically, on the expression of microtubule-associated protein 1 light chain 3 (LC3)-II, an indicator of autophagy, as well as some autophagy-related proteins in rat cardiac muscle. The left ventricles were taken from rats immediately (0 h), and at 0.5h, 1h or 3h after a single bout of running exercise on a treadmill for 30 min and also from rats in a rest condition. In these samples, we evaluated the level of LC3-II and p62, and the phosphorylation level of mammalian target of rapamycin (mTOR), Akt and AMP-activated protein kinase alpha (AMPKα) by Western blotting. The exercise produced a biphasic change in LC3-II, with an initial decrease observed immediately after the exercise and a subsequent increase 1h thereafter. LC3-II then returned to the rest level at 3h after the exercise. A negative correlation was found between the LC3-II expression and mTOR phosphorylation, which plays a role in inhibiting autophagy. The exercise increased phosphorylation of AMPKα, which stimulates autophagy via suppression of mTOR phosphorylation, immediately after exercise. The level of p62 and phosphorylated Akt was not altered significantly by the exercise. These results suggest for the first time that a single bout of running exercise induces a biphasic change in autophagy in the cardiac muscle. The exercise-induced change in autophagy might be partially mediated by mTOR in the cardiac muscle.
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Affiliation(s)
- Yuji Ogura
- Department of Physiology, St. Marianna University School of Medicine, Kawasaki, Kanagawa 216-8511, Japan
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Abstract
The mechanistic target of rapamycin (mTOR) plays a central role in cellular growth and metabolism. mTOR forms two distinct protein complexes, mTORC1 and mTORC2. Much is known about the regulation and functions of mTORC1 due to availability of a natural compound, rapamycin, that inhibits this complex. Studies that define mTORC2 cellular functions and signaling have lagged behind. The development of pharmacological inhibitors that block mTOR kinase activity, and thereby inhibit both mTOR complexes, along with availability of mice with genetic knockouts in mTOR complex components have now provided new insights on mTORC2 function and regulation. Since prolonged effects of rapamycin can also disrupt mTORC2, it is worth re-evaluating the contribution of this less-studied mTOR complex in cancer, metabolic disorders and aging. In this review, we focus on recent developments on mammalian mTORC2 signaling mechanisms and its cellular and tissue-specific functions.
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Affiliation(s)
- Won Jun Oh
- Department of Physiology and Biophysics, UMDNJ-Robert Wood Johnson Medical School, Piscataway, NJ, USA
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Sussman MA, Völkers M, Fischer K, Bailey B, Cottage CT, Din S, Gude N, Avitabile D, Alvarez R, Sundararaman B, Quijada P, Mason M, Konstandin MH, Malhowski A, Cheng Z, Khan M, McGregor M. Myocardial AKT: the omnipresent nexus. Physiol Rev 2011; 91:1023-70. [PMID: 21742795 PMCID: PMC3674828 DOI: 10.1152/physrev.00024.2010] [Citation(s) in RCA: 180] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
One of the greatest examples of integrated signal transduction is revealed by examination of effects mediated by AKT kinase in myocardial biology. Positioned at the intersection of multiple afferent and efferent signals, AKT exemplifies a molecular sensing node that coordinates dynamic responses of the cell in literally every aspect of biological responses. The balanced and nuanced nature of homeostatic signaling is particularly essential within the myocardial context, where regulation of survival, energy production, contractility, and response to pathological stress all flow through the nexus of AKT activation or repression. Equally important, the loss of regulated AKT activity is primarily the cause or consequence of pathological conditions leading to remodeling of the heart and eventual decompensation. This review presents an overview compendium of the complex world of myocardial AKT biology gleaned from more than a decade of research. Summarization of the widespread influence that AKT exerts upon myocardial responses leaves no doubt that the participation of AKT in molecular signaling will need to be reckoned with as a seemingly omnipresent regulator of myocardial molecular biological responses.
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Affiliation(s)
- Mark A Sussman
- Department of Biology, San Diego State University, SDSU Heart Institute, San Diego, California 92182, USA.
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Jayakumar S, Guillot S, Argo C, Redick J, Caldwell S. Ultrastructural findings in human nonalcoholic steatohepatitis. Expert Rev Gastroenterol Hepatol 2011; 5:141-5. [PMID: 21476907 DOI: 10.1586/egh.11.9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Sciarretta S, Zablocki D, Sadoshima J. New Insights into the Role and Regulation of Autophagy during Myocardial Ischaemia. High Blood Press Cardiovasc Prev 2010. [DOI: 10.2165/11587970-000000000-00000] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
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Abstract
IMPORTANCE OF THE FIELD Life expectancy has increased across the globe and the number of aged people is increasing rapidly. With the rise in the average age of people, the prevalence of age related pathologies has also increased and thus the strategies to find anti-aging molecules assume significance. Anti-aging basically concerns the prevention or delaying the alterations taking place as a function of age which are manifested as age-associated illnesses. AREAS COVERED IN THIS REVIEW This review covers anti-aging strategies involving supplementation of dietary antioxidants such as polyphenols, vitamins E and C, lipoic acid, acetyl carnitine, carnosine and cysteine along with the application of mammalian target of rapamycin inhibitors and plasma membrane redox system activators. It also presents the use of different hormone supplementation, for example, melatonin, dehydroepiandrosterone, growth hormone and sex hormones as a tool against aging. The use of caloric restriction and calorie restriction mimetics as an anti-aging intervention is also reviewed. WHAT THE READER WILL GAIN The concept, use and efficacy of different anti-aging approaches. TAKE HOME MESSAGE Despite a lot of research and sustained ongoing efforts, finding a viable anti-aging therapy which can extend the maximum human lifespan remains elusive. However, several interventions aimed towards a longer healthy life seem promising.
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Nazarewicz RR, Salazar G, Patrushev N, San Martin A, Hilenski L, Xiong S, Alexander RW. Early endosomal antigen 1 (EEA1) is an obligate scaffold for angiotensin II-induced, PKC-alpha-dependent Akt activation in endosomes. J Biol Chem 2010; 286:2886-95. [PMID: 21097843 DOI: 10.1074/jbc.m110.141499] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Akt/protein kinase B (PKB) activation/phosphorylation by angiotensin II (Ang II) is a critical signaling event in hypertrophy of vascular smooth muscle cells (VSMCs). Conventional wisdom asserts that Akt activation occurs mainly in plasma membrane domains. Recent evidence that Akt activation may take place within intracellular compartments challenges this dogma. The spatial identity and mechanistic features of these putative signaling domains have not been defined. Using cell fractionation and fluorescence methods, we demonstrate that the early endosomal antigen-1 (EEA1)-positive endosomes are a major site of Ang II-induced Akt activation. Akt moves to and is activated in EEA1 endosomes. The expression of EEA1 is required for phosphorylation of Akt at both Thr-308 and Ser-473 as well as for phosphorylation of its downstream targets mTOR and S6 kinase, but not for Erk1/2 activation. Both Akt and phosphorylated Akt (p-Akt) interact with EEA1. We also found that PKC-α is required for organizing Ang II-induced, EEA1-dependent Akt phosphorylation in VSMC early endosomes. EEA1 expression enables PKC-α phosphorylation, which in turn regulates Akt upstream signaling kinases, PDK1 and p38 MAPK. Our results indicate that PKC-α is a necessary regulator of EEA1-dependent Akt signaling in early endosomes. Finally, EEA1 down-regulation or expression of a dominant negative mutant of PKC-α blunts Ang II-induced leucine incorporation in VSMCs. Thus, EEA1 serves a novel function as an obligate scaffold for Ang II-induced Akt activation in early endosomes.
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Affiliation(s)
- Rafal Robert Nazarewicz
- Division of Cardiology, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia 30322, USA
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Drake JC, Alway SE, Hollander JM, Williamson DL. AICAR treatment for 14 days normalizes obesity-induced dysregulation of TORC1 signaling and translational capacity in fasted skeletal muscle. Am J Physiol Regul Integr Comp Physiol 2010; 299:R1546-54. [PMID: 20844264 DOI: 10.1152/ajpregu.00337.2010] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The aim of this study was to determine the effect of 14 days of 5-aminoimidazole-4-carboxamide-1β-4-ribofuranoside (AICAR) treatment on mammalian target of rapamycin (mTOR) signaling and mTOR-regulated processes (i.e., translation initiation) in obese mouse skeletal muscle. Our hypothesis was that daily treatment (14 days) with AICAR would normalize obesity-induced alterations in skeletal muscle mTOR signaling and mTOR-regulated processes to lean levels and positively affect muscle mass. Fourteen-week-old male, lean (L; 31.3 g body wt) wild-type and ob/ob (O; 59.6 g body wt) mice were injected with the AMP-activated kinase (AMPK) activator AICAR (A) at 0.5 mg·g body wt(-1)·day(-1) or saline control (C) for 14 days. At 24 h after the last injection (including a 12-h fast), all mice were killed, and the plantar flexor complex muscle (gastrocnemius, soleus, and plantaris) was excised for analysis. Muscle mass was lower in OC (159 ± 12 mg) than LC, LA, and OA (176 ± 10, 178 ± 9, and 166 ± 16 mg, respectively) mice, independent of a body weight change. A decrease in obese muscle mass corresponded with higher muscle cross section staining intensity for lipid and glycogen, higher blood glucose and insulin levels, and lower nuclear-enriched fractions for peroxisome proliferator-activated receptor-γ coactivator-1α protein expression in OC skeletal muscle, which was normalized with AICAR treatment. AMPK and acetyl-cocarboxylase phosphorylation was reduced in OC mice and augmented by AICAR treatment in OA mice. Conversely, OC mice displayed higher activation of downstream targets (S6 kinase-1 and ribosomal protein S6) of mTOR and lower raptor-associated mTOR than LC mice, which were reciprocally altered after 14 days of AICAR treatment. Dysregulation of translational capacity was improved in OA mice, as assessed by sucrose density gradient fractionation of ribosomes, total and ribosome-associated RNA content, eukaryotic initiation factor 4F complex formation, and eukaryotic initiation factor 4G phosphorylation. These data show that short-term (14 days) AMPK agonist treatment augments regulatory processes in atrophic obese mouse skeletal muscle through the normalization of mTOR signaling and mRNA translation closer to lean levels.
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Affiliation(s)
- Joshua C Drake
- Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, West Virginia, USA
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