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Lu QB, Ding Y, Liu Y, Wang ZC, Wu YJ, Niu KM, Li KX, Zhang JR, Sun HJ. Metrnl ameliorates diabetic cardiomyopathy via inactivation of cGAS/STING signaling dependent on LKB1/AMPK/ULK1-mediated autophagy. J Adv Res 2023; 51:161-179. [PMID: 36334887 PMCID: PMC10491969 DOI: 10.1016/j.jare.2022.10.014] [Citation(s) in RCA: 25] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 10/25/2022] [Accepted: 10/28/2022] [Indexed: 11/11/2022] Open
Abstract
INTRODUCTION Meteorin-like hormone (Metrnl) is ubiquitously expressed in skeletal muscle, heart, and adipose with beneficial roles in obesity, insulin resistance, and inflammation. Metrnl is found to protect against cardiac hypertrophy and doxorubicin-induced cardiotoxicity. However, its role in diabetic cardiomyopathy (DCM) is undefined. OBJECTIVES We aimed to elucidate the potential roles of Metrnl in DCM. METHODS Gain- andloss-of-function experimentswere utilized to determine the roles of Metrnl in the pathological processes of DCM. RESULTS We found that plasma Metrnl levels, myocardial Metrnl protein and mRNA expressions were significantly downregulated in both streptozotocin (STZ)-induced (T1D) mice and leptin receptor deficiency (db/db) (T2D) mice. Cardiac-specific overexpression (OE) of Metrnl markedly ameliorated cardiac injury and dysfunction in both T1D and T2D mice. In sharp contrast, specific deletion of Metrnl in the heart had the opposite phenotypes. In parallel, Metrnl OE ameliorated, whereas Metrnl downregulation exacerbated high glucose (HG)-elicited hypertrophy, apoptosis and oxidative damage in primary neonatal rat cardiomyocytes. Antibody-induced blockade of Metrnl eliminated the effects of benefits of Metrnl in vitro and in vivo. Mechanistically, Metrnl activated the autophagy pathway and inhibited the cGAS/STING signaling in a LKB1/AMPK/ULK1-dependent mechanism in cardiomyocytes. Besides, Metrnl-induced ULK1 phosphorylation facilitated the dephosphorylation and mitochondrial translocation of STING where it interacted with tumor necrosis factor receptor-associated factor 2 (TRAF2), a scaffold protein and E3 ubiquitin ligase that was responsible for ubiquitination and degradation of STING, rendering cardiomyocytes sensitive to autophagy activation. CONCLUSION Thus, Metrnl may be an attractive therapeutic target or regimen for treating DCM.
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Affiliation(s)
- Qing-Bo Lu
- Department of Basic Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi 214122, China; Department of Endocrine, Affiliated Hospital of Jiangnan University, Jiangnan University, Wuxi 214125, China
| | - Yi Ding
- Department of Anesthesiology, Affiliated Hospital of Jiangnan University, Jiangnan University, Wuxi 214125, China
| | - Yao Liu
- Department of Cardiac Ultrasound, The Fourth Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210000, China
| | - Zi-Chao Wang
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, No. 24 Tongjia Lane, Nanjing 210009, China
| | - Yu-Jie Wu
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, No. 24 Tongjia Lane, Nanjing 210009, China
| | - Kai-Ming Niu
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, No. 24 Tongjia Lane, Nanjing 210009, China
| | - Ke-Xue Li
- Department of Physiology, Xuzhou Medical University, Xuzhou 221004, China.
| | - Ji-Ru Zhang
- Department of Anesthesiology, Affiliated Hospital of Jiangnan University, Jiangnan University, Wuxi 214125, China.
| | - Hai-Jian Sun
- Department of Basic Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi 214122, China; State Key Laboratory of Natural Medicines, China Pharmaceutical University, No. 24 Tongjia Lane, Nanjing 210009, China; Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, 117600 Singapore, Singapore.
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Qiu Z, Li Y, Fu Y, Yang Y. Research progress of AMP-activated protein kinase and cardiac aging. Open Life Sci 2023; 18:20220710. [PMID: 37671091 PMCID: PMC10476487 DOI: 10.1515/biol-2022-0710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 07/27/2023] [Accepted: 08/05/2023] [Indexed: 09/07/2023] Open
Abstract
The process of aging is marked by a gradual deterioration in the physiological functions and functional reserves of various tissues and organs, leading to an increased susceptibility to diseases and even death. Aging manifests in a tissue- and organ-specific manner, and is characterized by varying rates and direct and indirect interactions among different tissues and organs. Cardiovascular disease (CVD) is the leading cause of death globally, with older adults (aged >70 years) accounting for approximately two-thirds of CVD-related deaths. The prevalence of CVD increases exponentially with an individual's age. Aging is a critical independent risk factor for the development of CVD. AMP-activated protein kinase (AMPK) activation exerts cardioprotective effects in the heart and restores cellular metabolic functions by modulating gene expression and regulating protein levels through its interaction with multiple target proteins. Additionally, AMPK enhances mitochondrial function and cellular energy status by facilitating the utilization of energy substrates. This review focuses on the role of AMPK in the process of cardiac aging and maintaining normal metabolic levels and redox homeostasis in the heart, particularly in the presence of oxidative stress and the invasion of inflammatory factors.
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Affiliation(s)
- Zhengqi Qiu
- Faculty of Medicine, Macau University of Science and Technology, Taipa, Macao SAR 999078, China
| | - Yufei Li
- Faculty of Medicine, Macau University of Science and Technology, Taipa, Macao SAR 999078, China
| | - Yancheng Fu
- Guangdong Key Laboratory of Genome Stability and Human Disease Prevention, Carson International Cancer Center, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Health Science Center, Shenzhen University, Shenzhen518060, China
| | - Yanru Yang
- Guangdong Key Laboratory of Genome Stability and Human Disease Prevention, Carson International Cancer Center, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Health Science Center, Shenzhen University, Shenzhen518060, China
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Jiang B, Zhou X, Yang T, Wang L, Feng L, Wang Z, Xu J, Jing W, Wang T, Su H, Yang G, Zhang Z. The role of autophagy in cardiovascular disease: Cross-interference of signaling pathways and underlying therapeutic targets. Front Cardiovasc Med 2023; 10:1088575. [PMID: 37063954 PMCID: PMC10090687 DOI: 10.3389/fcvm.2023.1088575] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 03/13/2023] [Indexed: 03/31/2023] Open
Abstract
Autophagy is a conserved lysosomal pathway for the degradation of cytoplasmic proteins and organelles, which realizes the metabolic needs of cells and the renewal of organelles. Autophagy-related genes (ATGs) are the main molecular mechanisms controlling autophagy, and their functions can coordinate the whole autophagic process. Autophagy can also play a role in cardiovascular disease through several key signaling pathways, including PI3K/Akt/mTOR, IGF/EGF, AMPK/mTOR, MAPKs, p53, Nrf2/p62, Wnt/β-catenin and NF-κB pathways. In this paper, we reviewed the signaling pathway of cross-interference between autophagy and cardiovascular diseases, and analyzed the development status of novel cardiovascular disease treatment by targeting the core molecular mechanism of autophagy as well as the critical signaling pathway. Induction or inhibition of autophagy through molecular mechanisms and signaling pathways can provide therapeutic benefits for patients. Meanwhile, we hope to provide a unique insight into cardiovascular treatment strategies by understanding the molecular mechanism and signaling pathway of crosstalk between autophagy and cardiovascular diseases.
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Affiliation(s)
- Bing Jiang
- Department of Integrated Chinese and Western Medicine, Gansu University of Traditional Chinese Medicine, Lanzhou, China
| | - Xuan Zhou
- Department of First Clinical Medicine, Gansu University of Traditional Chinese Medicine, Lanzhou, China
| | - Tao Yang
- Department of Basic Medicine, Gansu University of Traditional Chinese Medicine, Lanzhou, China
| | - Linlin Wang
- Department of First Clinical Medicine, Gansu University of Traditional Chinese Medicine, Lanzhou, China
| | - Longfei Feng
- Department of Basic Medicine, Gansu University of Traditional Chinese Medicine, Lanzhou, China
| | - Zheng Wang
- Department of Integrated Chinese and Western Medicine, Gansu University of Traditional Chinese Medicine, Lanzhou, China
| | - Jin Xu
- Department of First Clinical Medicine, Lanzhou University, Lanzhou, China
| | - Weiyao Jing
- Department of Acupuncture-Moxibustion and Tuina, Gansu University of Traditional Chinese Medicine, Lanzhou, China
| | - Tao Wang
- Research Center for Translational Medicine, Gansu Province Academic Institute for Medical Research, Gansu Provincial Cancer Hospital, Lanzhou, China
| | - Haixiang Su
- Research Center for Translational Medicine, Gansu Province Academic Institute for Medical Research, Gansu Provincial Cancer Hospital, Lanzhou, China
| | - GuoWei Yang
- Center for Heart, First Hospital of Lanzhou University, Lanzhou, China
| | - Zheng Zhang
- Department of Integrated Chinese and Western Medicine, Gansu University of Traditional Chinese Medicine, Lanzhou, China
- Center for Heart, First Hospital of Lanzhou University, Lanzhou, China
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Evans AM. Of Mice and Men and Plethysmography Systems: Does LKB1 Determine the Set Point of Carotid Body Chemosensitivity and the Hypoxic Ventilatory Response? ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1427:163-173. [PMID: 37322347 DOI: 10.1007/978-3-031-32371-3_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Our recent studies suggest that the level of liver kinase B1 (LKB1) expression in some way determines carotid body afferent discharge during hypoxia and to a lesser extent during hypercapnia. In short, phosphorylation by LKB1 of an as yet unidentified target(s) determines a set point for carotid body chemosensitivity. LKB1 is the principal kinase that activates the AMP-activated protein kinase (AMPK) during metabolic stresses, but conditional deletion of AMPK in catecholaminergic cells, including therein carotid body type I cells, has little or no effect on carotid body responses to hypoxia or hypercapnia. With AMPK excluded, the most likely target of LKB1 is one or other of the 12 AMPK-related kinases, which are constitutively phosphorylated by LKB1 and, in general, regulate gene expression. By contrast, the hypoxic ventilatory response is attenuated by either LKB1 or AMPK deletion in catecholaminergic cells, precipitating hypoventilation and apnea during hypoxia rather than hyperventilation. Moreover, LKB1, but not AMPK, deficiency causes Cheyne-Stokes-like breathing. This chapter will explore further the possible mechanisms that determine these outcomes.
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Affiliation(s)
- A Mark Evans
- Centre for Discovery Brain Sciences, Hugh Robson Building, University of Edinburgh, Edinburgh, UK.
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Molaei A, Molaei E, Sadeghnia H, Hayes AW, Karimi G. LKB1: An emerging therapeutic target for cardiovascular diseases. Life Sci 2022; 306:120844. [PMID: 35907495 DOI: 10.1016/j.lfs.2022.120844] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 07/22/2022] [Accepted: 07/24/2022] [Indexed: 10/16/2022]
Abstract
Cardiovascular diseases (CVDs) are currently the most common cause of morbidity and mortality worldwide. Experimental studies suggest that liver kinase B1 (LKB1) plays an important role in the heart. Several studies have shown that cardiomyocyte-specific LKB1 deletion leads to hypertrophic cardiomyopathy, left ventricular contractile dysfunction, and an increased risk of atrial fibrillation. In addition, the cardioprotective effects of several medicines and natural compounds, including metformin, empagliflozin, bexarotene, and resveratrol, have been reported to be associated with LKB1 activity. LKB1 limits the size of the damaged myocardial area by modifying cellular metabolism, enhancing the antioxidant system, suppressing hypertrophic signals, and inducing mild autophagy, which are all primarily mediated by the AMP-activated protein kinase (AMPK) energy sensor. LKB1 also improves myocardial efficiency by modulating the function of contractile proteins, regulating the expression of electrical channels, and increasing vascular dilatation. Considering these properties, stimulation of LKB1 signaling offers a promising approach in the prevention and treatment of heart diseases.
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Affiliation(s)
- Ali Molaei
- Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | | | - Hamidreza Sadeghnia
- Pharmacological Research Center of Medicinal Plants, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Pharmacology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - A Wallace Hayes
- University of South Florida College of Public Health, Tampa, FL, USA
| | - Gholamreza Karimi
- Pharmaceutical Research Center, Institute of Pharmaceutical Technology, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Pharmacodynamics and Toxicology, Faculty of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran..
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LKB1 is the gatekeeper of carotid body chemosensing and the hypoxic ventilatory response. Commun Biol 2022; 5:642. [PMID: 35768580 PMCID: PMC9243028 DOI: 10.1038/s42003-022-03583-7] [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: 01/26/2022] [Accepted: 06/14/2022] [Indexed: 11/08/2022] Open
Abstract
The hypoxic ventilatory response (HVR) is critical to breathing and thus oxygen supply to the body and is primarily mediated by the carotid bodies. Here we reveal that carotid body afferent discharge during hypoxia and hypercapnia is determined by the expression of Liver Kinase B1 (LKB1), the principal kinase that activates the AMP-activated protein kinase (AMPK) during metabolic stresses. Conversely, conditional deletion in catecholaminergic cells of AMPK had no effect on carotid body responses to hypoxia or hypercapnia. By contrast, the HVR was attenuated by LKB1 and AMPK deletion. However, in LKB1 knockouts hypoxia evoked hypoventilation, apnoea and Cheyne-Stokes-like breathing, while only hypoventilation and apnoea were observed after AMPK deletion. We therefore identify LKB1 as an essential regulator of carotid body chemosensing and uncover a divergence in dependency on LKB1 and AMPK between the carotid body on one hand and the HVR on the other.
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Aiyasiding X, Liao HH, Feng H, Zhang N, Lin Z, Ding W, Yan H, Zhou ZY, Tang QZ. Liquiritin Attenuates Pathological Cardiac Hypertrophy by Activating the PKA/LKB1/AMPK Pathway. Front Pharmacol 2022; 13:870699. [PMID: 35592411 PMCID: PMC9110825 DOI: 10.3389/fphar.2022.870699] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 04/05/2022] [Indexed: 12/11/2022] Open
Abstract
Background: Liquiritin (LQ) is one of the main flavonoids extracted from the roots of Glycyrrhiza spp., which are widely used in traditional Chinese medicine. Studies in both cellular and animal disease models have shown that LQ attenuates or prevents oxidative stress, inflammation, and apoptosis. However, the potential therapeutic effects of LQ on pressure overload-induced cardiac hypertrophy have not been so far explored. Therefore, we investigated the cardioprotective role of LQ and its underlying mechanisms in the aortic banding (AB)-induced cardiac hypertrophy mouse model. Methods and Results: Starting 3 days after AB surgery, LQ (80 mg/kg/day) was administered daily over 4 weeks. Echocardiography and pressure-volume loop analysis indicated that LQ treatment markedly improved hypertrophy-related cardiac dysfunction. Moreover, hematoxylin and eosin, picrosirius red, and TUNEL staining showed that LQ significantly inhibited cardiomyocyte hypertrophy, interstitial fibrosis, and apoptosis. Western blot assays further showed that LQ activated LKB1/AMPKα2/ACC signaling and inhibited mTORC1 phosphorylation in cardiomyocytes. Notably, LQ treatment failed to prevent cardiac dysfunction, hypertrophy, and fibrosis in AMPKα2 knockout (AMPKα2−/−) mice. However, LQ still induced LKB1 phosphorylation in AMPKα2−/− mouse hearts. In vitro experiments further demonstrated that LQ inhibited Ang II-induced hypertrophy in neonatal rat cardiomyocytes (NRCMs) by increasing cAMP levels and PKA activity. Supporting the central involvement of the cAMP/PKA/LKB1/AMPKα2 signaling pathway in the cardioprotective effects of LQ, inhibition of Ang II-induced hypertrophy and induction of LKB1 and AMPKα phosphorylation were no longer observed after inhibiting PKA activity. Conclusion: This study revealed that LQ alleviates pressure overload-induced cardiac hypertrophy in vivo and inhibits Ang II-induced cardiomyocyte hypertrophy in vitro via activating cAMP/PKA/LKB1/AMPKα2 signaling. These findings suggest that LQ might be a valuable adjunct to therapeutic approaches for treating pathological cardiac remodeling.
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Affiliation(s)
- Xiahenazi Aiyasiding
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Hubei Key Laboratory of Metabolic and Chronic Diseases, Wuhan, China
| | - Hai-Han Liao
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Hubei Key Laboratory of Metabolic and Chronic Diseases, Wuhan, China
| | - Hong Feng
- Department of Geriatrics, Renmin Hospital of Wuhan University, Wuhan, China
| | - Nan Zhang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Hubei Key Laboratory of Metabolic and Chronic Diseases, Wuhan, China
| | - Zheng Lin
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Hubei Key Laboratory of Metabolic and Chronic Diseases, Wuhan, China
| | - Wen Ding
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Hubei Key Laboratory of Metabolic and Chronic Diseases, Wuhan, China
| | - Han Yan
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Hubei Key Laboratory of Metabolic and Chronic Diseases, Wuhan, China
| | - Zi-Ying Zhou
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Hubei Key Laboratory of Metabolic and Chronic Diseases, Wuhan, China
| | - Qi-Zhu Tang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Hubei Key Laboratory of Metabolic and Chronic Diseases, Wuhan, China
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Hu Z, Li M, Cao Y, Akan OD, Guo T, Luo F. Targeting AMPK Signaling by Dietary Polyphenols in Cancer Prevention. Mol Nutr Food Res 2021; 66:e2100732. [PMID: 34802178 DOI: 10.1002/mnfr.202100732] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 11/03/2021] [Indexed: 12/14/2022]
Abstract
Cancer is a serious public health problem in the world and a major disease affecting human health. Dietary polyphenols have shown good potential in the treatment of various cancers. It is worth noting that cancer cells usually exhibit metabolic abnormalities of high glucose intake and inefficient utilization. AMPK is the key molecule in the regulation of energy metabolism and is closely related with obesity and diabetes. Recent studies indicate that AMPK also plays an important role in cancer prevention and regulating cancer-related genes and pathways, and dietary polyphenols can significantly regulate AMPK activity. In this review, the progress of dietary polyphenols preventing carcinogenesis via AMPK pathway is systemically summarized. From the viewpoint of interfering energy metabolism, the anti-cancer effects of dietary polyphenols are explained. AMPK pathway modulated by different dietary polyphenols affects pathways and target genes are summarized. Dietary polyphenols exert anti-cancer effect through the target molecules regulated by AMPK, which broadens the understanding of polyphenols anti-cancer mechanisms and provides value reference for the investigators of the novel field.
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Affiliation(s)
- Zuomin Hu
- Hunan Key Laboratory of Processed Food for Special Medical Purpose, Hunan Key Laboratory of Deeply Processing and Quality Control of Cereals and Oils, Hunan Key Laboratory of Forestry Edible Resources Safety and Processing, Central South University of Forestry and Technology, Changsha, Hunan, 410004, China
| | - Mengyuan Li
- Hunan Key Laboratory of Processed Food for Special Medical Purpose, Hunan Key Laboratory of Deeply Processing and Quality Control of Cereals and Oils, Hunan Key Laboratory of Forestry Edible Resources Safety and Processing, Central South University of Forestry and Technology, Changsha, Hunan, 410004, China
| | - Yunyun Cao
- Hunan Key Laboratory of Processed Food for Special Medical Purpose, Hunan Key Laboratory of Deeply Processing and Quality Control of Cereals and Oils, Hunan Key Laboratory of Forestry Edible Resources Safety and Processing, Central South University of Forestry and Technology, Changsha, Hunan, 410004, China
| | - Otobong Donald Akan
- Hunan Key Laboratory of Processed Food for Special Medical Purpose, Hunan Key Laboratory of Deeply Processing and Quality Control of Cereals and Oils, Hunan Key Laboratory of Forestry Edible Resources Safety and Processing, Central South University of Forestry and Technology, Changsha, Hunan, 410004, China
| | - Tianyi Guo
- Hunan Key Laboratory of Processed Food for Special Medical Purpose, Hunan Key Laboratory of Deeply Processing and Quality Control of Cereals and Oils, Hunan Key Laboratory of Forestry Edible Resources Safety and Processing, Central South University of Forestry and Technology, Changsha, Hunan, 410004, China
| | - Feijun Luo
- Hunan Key Laboratory of Processed Food for Special Medical Purpose, Hunan Key Laboratory of Deeply Processing and Quality Control of Cereals and Oils, Hunan Key Laboratory of Forestry Edible Resources Safety and Processing, Central South University of Forestry and Technology, Changsha, Hunan, 410004, China
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Dynamic Regulation of Cysteine Oxidation and Phosphorylation in Myocardial Ischemia-Reperfusion Injury. Cells 2021; 10:cells10092388. [PMID: 34572037 PMCID: PMC8469016 DOI: 10.3390/cells10092388] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 09/06/2021] [Accepted: 09/07/2021] [Indexed: 02/02/2023] Open
Abstract
Myocardial ischemia-reperfusion (I/R) injury significantly alters heart function following infarct and increases the risk of heart failure. Many studies have sought to preserve irreplaceable myocardium, termed cardioprotection, but few, if any, treatments have yielded a substantial reduction in clinical I/R injury. More research is needed to fully understand the molecular pathways that govern cardioprotection. Redox mechanisms, specifically cysteine oxidations, are acute and key regulators of molecular signaling cascades mediated by kinases. Here, we review the role of reactive oxygen species in modifying cysteine residues and how these modifications affect kinase function to impact cardioprotection. This exciting area of research may provide novel insight into mechanisms and likely lead to new treatments for I/R injury.
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Mao JY, Su LX, Li DK, Zhang HM, Wang XT, Liu DW. The effects of UCP2 on autophagy through the AMPK signaling pathway in septic cardiomyopathy and the underlying mechanism. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:259. [PMID: 33708886 PMCID: PMC7940903 DOI: 10.21037/atm-20-4819] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Background Mitochondrial dysfunction plays an important role in the development of septic cardiomyopathy. This study aimed to reveal the protective role of uncoupling protein 2 (UCP2) in mitochondria through AMP-activated protein kinase (AMPK) on autophagy during septic cardiomyopathy. Methods UCP2 knockout mice via a cecal ligation and puncture (CLP) model and the H9C2 cardiomyocyte cell line in response to lipopolysaccharide (LPS) in vitro were used to study the effect. The myocardial morphological alterations, indicators of mitochondrial injury and levels of autophagy-associated proteins (pAMPK, pmTOR, pULK1, pTSC2, Beclin-1, and LC3-I/II) were assessed. In addition, the mechanism of the interaction between UCP2 and AMPK was further studied through gain- and loss-of-function studies. Results Compared with the wild-type mice, the UCP2 knockout mice exhibited more severe cardiomyocyte injury after CLP, and the AMPK agonist AICAR protected against such injury. Consistent with this result, silencing UCP2 augmented the LPS-induced pathological damage and mitochondrial injury in the H9C2 cells, limited the upregulation of autophagy proteins and reduced AMPK phosphorylation. AICAR protected the cells from morphological changes and mitochondrial membrane potential loss and promoted autophagy. The silencing and overexpression of UCP2 led to correlated changes in the AMPK upstream kinases pLKB1 and CAMKK2. Conclusions UCP2 exerts cardioprotective effects on mitochondrial dysfunction during sepsis via the action of AMPK on autophagy.
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Affiliation(s)
- Jia-Yu Mao
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Science, Beijing 100730, China
| | - Long-Xiang Su
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Science, Beijing 100730, China
| | - Dong-Kai Li
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Science, Beijing 100730, China
| | - Hong-Min Zhang
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Science, Beijing 100730, China
| | - Xiao-Ting Wang
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Science, Beijing 100730, China
| | - Da-Wei Liu
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Science, Beijing 100730, China
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Chen T, Hill JT, Moore TM, Cheung ECK, Olsen ZE, Piorczynski TB, Marriott TD, Tessem JS, Walton CM, Bikman BT, Hansen JM, Thomson DM. Lack of skeletal muscle liver kinase B1 alters gene expression, mitochondrial content, inflammation and oxidative stress without affecting high-fat diet-induced obesity or insulin resistance. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165805. [PMID: 32339642 DOI: 10.1016/j.bbadis.2020.165805] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 04/02/2020] [Accepted: 04/16/2020] [Indexed: 12/28/2022]
Abstract
Ad libitum high-fat diet (HFD) induces obesity and skeletal muscle metabolic dysfunction. Liver kinase B1 (LKB1) regulates skeletal muscle metabolism by controlling the AMP-activated protein kinase family, but its importance in regulating muscle gene expression and glucose tolerance in obese mice has not been established. The purpose of this study was to determine how the lack of LKB1 in skeletal muscle (KO) affects gene expression and glucose tolerance in HFD-fed, obese mice. KO and littermate control wild-type (WT) mice were fed a standard diet or HFD for 14 weeks. RNA sequencing, and subsequent analysis were performed to assess mitochondrial content and respiration, inflammatory status, glucose and insulin tolerance, and muscle anabolic signaling. KO did not affect body weight gain on HFD, but heavily impacted mitochondria-, oxidative stress-, and inflammation-related gene expression. Accordingly, mitochondrial protein content and respiration were suppressed while inflammatory signaling and markers of oxidative stress were elevated in obese KO muscles. KO did not affect glucose or insulin tolerance. However, fasting serum insulin and skeletal muscle insulin signaling were higher in the KO mice. Furthermore, decreased muscle fiber size in skmLKB1-KO mice was associated with increased general protein ubiquitination and increased expression of several ubiquitin ligases, but not muscle ring finger 1 or atrogin-1. Taken together, these data suggest that the lack of LKB1 in skeletal muscle does not exacerbate obesity or insulin resistance in mice on a HFD, despite impaired mitochondrial content and function and elevated inflammatory signaling and oxidative stress.
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Affiliation(s)
- Ting Chen
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT 84602, USA
| | - Jonathon T Hill
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT 84602, USA
| | - Timothy M Moore
- David Geffen School of Medicine, Department of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Eric C K Cheung
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT 84602, USA
| | - Zachary E Olsen
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT 84602, USA
| | - Ted B Piorczynski
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT 84602, USA
| | - Tanner D Marriott
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT 84602, USA
| | - Jeffery S Tessem
- Department of Nutrition, Dietetics and Food Science, Brigham Young University, Provo, UT 84602, USA
| | - Chase M Walton
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT 84602, USA
| | - Benjamin T Bikman
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT 84602, USA
| | - Jason M Hansen
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT 84602, USA
| | - David M Thomson
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT 84602, USA; Department of Nutrition, Dietetics and Food Science, Brigham Young University, Provo, UT 84602, USA.
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Ma L, Wang R, Wang H, Zhang Y, Zhao Z. Long-term caloric restriction activates the myocardial SIRT1/AMPK/PGC-1α pathway in C57BL/6J male mice. Food Nutr Res 2020; 64:3668. [PMID: 32082101 PMCID: PMC7007760 DOI: 10.29219/fnr.v64.3668] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Revised: 12/22/2019] [Accepted: 01/07/2020] [Indexed: 01/23/2023] Open
Abstract
Background Caloric restriction (CR) can help in improving heart function. There is as yet no consensus on the mechanism of the effect of CR. Silent mating-type information regulation 1 (SIRT1), adenosine monophosphate-activated protein kinase (AMPK), and mTOR are key players in metabolic stress management. We aimed to explore the effect of CR on the myocardial SIRT1/AMPK/mTOR pathway in mice. Methods Thirty-six 6-week-old male C57BL/6J mice were randomly divided into three groups: normal control group (NC group, n = 12), high-energy group (HE group, n = 12) and CR group (n = 12) according to different diets. After 11 months, western blot was used to examine proteins such as p-AMPK, peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), SIRT1, and p-mTOR, whereas real-time PCR was used to examine the expression of AMPK, PGC-1α, and SIRT1 transcripts. Results Compared to the HE group, the CR group displayed increased expression of myocardial p-AMPK protein, SIRT1 protein and mRNA, and PGC-1a mRNA. However, no difference was observed in the expression of p-mTOR protein and mTOR mRNA in the myocardium among the three groups. Conclusions CR improves the SIRT1/AMPK/PGC-1α pathway in mice myocardium with no effect on the mTOR pathway.
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Affiliation(s)
- Lina Ma
- Department of Geriatrics, Xuanwu Hospital Capital Medical University, National Clinical Research Center for Geriatric Diseases, Beijing, China.,Central Laboratory, Xuanwu Hospital Capital Medical University, Key Laboratory for Neurodegenerative Disease of Ministry of Education, Center of Alzheimer's Disease, Beijing Institute for Brain Disorders, Beijing, China
| | - Rong Wang
- Central Laboratory, Xuanwu Hospital Capital Medical University, Key Laboratory for Neurodegenerative Disease of Ministry of Education, Center of Alzheimer's Disease, Beijing Institute for Brain Disorders, Beijing, China
| | - Hongjuan Wang
- Department of Biochemistry and Molecular Biology, Yanjing Medical College, Capital Medical University, Beijing, China
| | - Yaxin Zhang
- Department of Geriatrics, Xuanwu Hospital Capital Medical University, National Clinical Research Center for Geriatric Diseases, Beijing, China
| | - Zhiwei Zhao
- Central Laboratory, Xuanwu Hospital Capital Medical University, Key Laboratory for Neurodegenerative Disease of Ministry of Education, Center of Alzheimer's Disease, Beijing Institute for Brain Disorders, Beijing, China
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13
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Visnjic D, Dembitz V, Lalic H. The Role of AMPK/mTOR Modulators in the Therapy of Acute Myeloid Leukemia. Curr Med Chem 2019; 26:2208-2229. [PMID: 29345570 DOI: 10.2174/0929867325666180117105522] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 01/01/2018] [Accepted: 01/11/2018] [Indexed: 12/13/2022]
Abstract
Differentiation therapy of acute promyelocytic leukemia with all-trans retinoic acid represents the most successful pharmacological therapy of acute myeloid leukemia (AML). Numerous studies demonstrate that drugs that inhibit mechanistic target of rapamycin (mTOR) and activate AMP-kinase (AMPK) have beneficial effects in promoting differentiation and blocking proliferation of AML. Most of these drugs are already in use for other purposes; rapalogs as immunosuppressants, biguanides as oral antidiabetics, and 5-amino-4-imidazolecarboxamide ribonucleoside (AICAr, acadesine) as an exercise mimetic. Although most of these pharmacological modulators have been widely used for decades, their mechanism of action is only partially understood. In this review, we summarize the role of AMPK and mTOR in hematological malignancies and discuss the possible role of pharmacological modulators in proliferation and differentiation of leukemia cells.
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Affiliation(s)
- Dora Visnjic
- Department of Physiology and Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Salata 12, 10 000 Zagreb, Croatia
| | - Vilma Dembitz
- Department of Physiology and Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Salata 12, 10 000 Zagreb, Croatia
| | - Hrvoje Lalic
- Department of Physiology and Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Salata 12, 10 000 Zagreb, Croatia
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14
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Ren Y, Shen HM. Critical role of AMPK in redox regulation under glucose starvation. Redox Biol 2019; 25:101154. [PMID: 30853530 PMCID: PMC6859544 DOI: 10.1016/j.redox.2019.101154] [Citation(s) in RCA: 119] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Revised: 02/09/2019] [Accepted: 02/27/2019] [Indexed: 12/24/2022] Open
Abstract
Glucose starvation is one of the major forms of metabolic stress in cancer cells. Deprivation of glucose impairs glycolysis and the pentose phosphate pathway, which elicits oxidative stress due to enhanced production of reactive oxygen species (ROS) and impaired antioxidant system, leading to redox imbalance and cell death. Under glucose starvation, the 5' AMP-activated protein kinase (AMPK) plays a critical role in maintaining redox homeostasis and cell survival via multiple pathways, such as regulation of fatty acid metabolism and antioxidant response. Convergence of ROS and the glucose metabolic pathway reveals novel molecular targets for the development of effective cancer therapeutic strategies. Interestingly, AMPK, along with its upstream kinase liver kinase B1 (LKB1), has been regarded to play a tumor suppressor role. However, emerging studies have provided novel insights into the pro-tumor survival function of the LKB1-AMPK pathway. Therefore, targeting metabolic and oxidative stress in cancer cells, with manipulation of AMPK activity, is a promising strategy in developing novel cancer therapeutic agents.
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Affiliation(s)
- Yi Ren
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 117593, Singapore
| | - Han-Ming Shen
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 117593, Singapore.
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15
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Cathepsin K Knockout Exacerbates Haemorrhagic Transformation Induced by Recombinant Tissue Plasminogen Activator After Focal Cerebral Ischaemia in Mice. Cell Mol Neurobiol 2019; 39:823-831. [PMID: 31065924 DOI: 10.1007/s10571-019-00682-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Accepted: 04/29/2019] [Indexed: 12/19/2022]
Abstract
Severe haemorrhagic transformation (HT), a common complication of recombinant tissue plasminogen activator (rtPA) treatment, predicts poor clinical outcomes in acute ischaemic stroke. The search for agents to mitigate this effect includes investigating biomolecules involved in neovascularization. This study examines the role of Cathepsin K (Ctsk) in rtPA-induced HT after focal cerebral ischaemia in mice. After knockout of Ctsk, the gene encoding Ctsk, the outcomes of Ctsk+/+ and Ctsk-/- mice were compared 24 h after rtPA-treated cerebral ischaemia with respect to HT severity, neurological deficits, brain oedema, infarct volume, number of apoptotic neurons and activated microglia/macrophage, blood-brain barrier integrity, vascular endothelial growth factor (VEGF) expression and Akt-mTOR pathway activation. We observed that haemoglobin levels, brain oedema and infarct volume were significantly greater and resulted in more severe neurological deficits in Ctsk-/- than in Ctsk+/+ mice. Consistent with our hypothesis, the number of NeuN-positive neurons was lower and the number of TUNEL-positive apoptotic neurons and activated microglia/macrophage was higher in Ctsk-/- than in Ctsk+/+ mice. Ctsk knockout mice exhibited more severe blood-brain barrier (BBB) disruption, with microvascular endothelial cells exhibiting greater VEGF expression and lower ratios of phospo-Akt/Akt and phospo-mTOR/mTOR than in Ctsk+/+ mice. This study is the first to provide molecular insights into Ctsk-regulated HT after cerebral ischaemia, suggesting that Ctsk deficiency may disrupt the BBB via Akt/mTOR/VEGF signalling, resulting in neurological deficits and neuron apoptosis. Ctsk administration has the potential as a novel modality for improving the safety of rtPA treatment following stroke.
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16
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Ginkgo Biloba Leaf Extract Attenuates Atherosclerosis in Streptozotocin-Induced Diabetic ApoE-/- Mice by Inhibiting Endoplasmic Reticulum Stress via Restoration of Autophagy through the mTOR Signaling Pathway. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:8134678. [PMID: 31080547 PMCID: PMC6442448 DOI: 10.1155/2019/8134678] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Revised: 12/03/2018] [Accepted: 12/13/2018] [Indexed: 12/26/2022]
Abstract
Background There is a crosstalk between endoplasmic reticulum stress (ERS) and autophagy, and autophagy could attenuate endoplasmic reticulum stress-mediated apoptosis. Ginkgo biloba leaf extract (GBE) exerts vascular protection functions. The purpose of the present study is to investigate the role of autophagy in diabetic atherosclerosis (AS) and the effect of GBE on autophagy and ERS. Methods Network pharmacology was utilized to predict the targets and pathways of the active chemical compounds of Gingko biloba leaf to attenuate AS. ApoE−/− mice were rendered diabetic by intraperitoneal ingestion with streptozotocin combined with a high-fat diet. The diabetic mice were divided into five groups: model group, atorvastatin group, rapamycin group, and low- and high-dose GBE groups. Serum and tissue markers of autophagy or ERS markers, including the protein expression, were examined. Results The mammalian target of rapamycin (mTOR) and NF-κB signaling pathways were targeted by the active chemical compounds of GBE to attenuate AS predicted by network pharmacology. GBE reduced the plaque area/lumen area and the plaque lipid deposition area/intimal area and inhibited the expressions of CD68, MMP2, and MMP9. Rapamycin and GBE inhibited the expression of mTOR and SQSTM1/p62 which increased in the aorta of diabetic mice. In addition, GBE reduced the expression of ERS markers in diabetic mice. GBE reduced the serum lipid metabolism levels, blood glucose, and inflammatory cytokines. Conclusion Impaired autophagy and overactive endoplasmic reticulum stress contributed to diabetic atherosclerosis. mTOR inhibitor rapamycin and GBE attenuated diabetic atherosclerosis by inhibiting ERS via restoration of autophagy through inhibition of mTOR.
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17
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The Role of AMPK in the Regulation of Skeletal Muscle Size, Hypertrophy, and Regeneration. Int J Mol Sci 2018; 19:ijms19103125. [PMID: 30314396 PMCID: PMC6212977 DOI: 10.3390/ijms19103125] [Citation(s) in RCA: 127] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 10/08/2018] [Accepted: 10/09/2018] [Indexed: 12/22/2022] Open
Abstract
AMPK (5’-adenosine monophosphate-activated protein kinase) is heavily involved in skeletal muscle metabolic control through its regulation of many downstream targets. Because of their effects on anabolic and catabolic cellular processes, AMPK plays an important role in the control of skeletal muscle development and growth. In this review, the effects of AMPK signaling, and those of its upstream activator, liver kinase B1 (LKB1), on skeletal muscle growth and atrophy are reviewed. The effect of AMPK activity on satellite cell-mediated muscle growth and regeneration after injury is also reviewed. Together, the current data indicate that AMPK does play an important role in regulating muscle mass and regeneration, with AMPKα1 playing a prominent role in stimulating anabolism and in regulating satellite cell dynamics during regeneration, and AMPKα2 playing a potentially more important role in regulating muscle degradation during atrophy.
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18
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Multiple recycling routes: Canonical vs. non-canonical mitophagy in the heart. Biochim Biophys Acta Mol Basis Dis 2018; 1865:797-809. [PMID: 30290272 DOI: 10.1016/j.bbadis.2018.09.034] [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: 06/26/2018] [Revised: 09/13/2018] [Accepted: 09/27/2018] [Indexed: 12/14/2022]
Abstract
The heart is composed of cardiomyocytes that require large amounts of energy to sustain contraction. Mitochondria are distinctive organelles of bacterial origin that generate most of the energy for the heart via oxidative phosphorylation. To ensure a healthy population of mitochondria that efficiently produce ATP, myocytes quickly eliminate any unhealthy or unwanted mitochondria via a process known as mitochondrial autophagy, or mitophagy. It is especially important to selectively remove damaged or aged mitochondria since they can become excessive producers of reactive oxygen species and release pro-death proteins. Because this is such a crucial cellular process, cells have several mechanisms in place to deal with potentially harmful mitochondria. Here, we review the various pathways identified to date and how they are regulated. We also discuss the importance of these canonical and non-canonical pathways in the heart and their link to cardiovascular health, disease and aging.
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19
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Sun XL, Lessard SJ, An D, Koh HJ, Esumi H, Hirshman MF, Goodyear LJ. Sucrose nonfermenting AMPK-related kinase (SNARK) regulates exercise-stimulated and ischemia-stimulated glucose transport in the heart. J Cell Biochem 2018; 120:685-696. [PMID: 30256437 DOI: 10.1002/jcb.27425] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 07/12/2018] [Indexed: 01/15/2023]
Abstract
The signaling mechanisms mediating myocardial glucose transport are not fully understood. Sucrose nonfermenting AMP-activated protein kinase (AMPK)-related kinase (SNARK) is an AMPK-related protein kinase that is expressed in the heart and has been implicated in contraction-stimulated glucose transport in mouse skeletal muscle. We first determined if SNARK is phosphorylated on Thr208 , a site critical for SNARK activity. Mice were treated with exercise, ischemia, submaximal insulin, or maximal insulin. Treadmill exercise slightly, but significantly increased SNARK Thr208 phosphorylation. Ischemia also increased SNARK Thr208 phosphorylation, but there was no effect of submaximal or maximal insulin. HL1 cardiomyocytes were used to overexpress wild-type (WT) SNARK and to knockdown endogenous SNARK. Overexpression of WT SNARK had no effect on ischemia-stimulated glucose transport; however, SNARK knockdown significantly decreased ischemia-stimulated glucose transport. SNARK overexpression or knockdown did not alter insulin-stimulated glucose transport or glycogen concentrations. To study SNARK function in vivo, SNARK heterozygous knockout mice (SNARK+/- ) and WT littermates performed treadmill exercise. Exercise-stimulated glucose transport was decreased by ~50% in hearts from SNARK+/- mice. In summary, exercise and ischemia increase SNARK Thr208 phosphorylation in the heart and SNARK regulates exercise-stimulated and ischemia-stimulated glucose transport. SNARK is a novel mediator of insulin-independent glucose transport in the heart.
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Affiliation(s)
- Xiang-Lan Sun
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China.,Integrative Physiology and Metabolism Section, Joslin Diabetes Center and Department of Medicine, Harvard Medical School, Boston, Massachusetts
| | - Sarah J Lessard
- Integrative Physiology and Metabolism Section, Joslin Diabetes Center and Department of Medicine, Harvard Medical School, Boston, Massachusetts
| | - Ding An
- Integrative Physiology and Metabolism Section, Joslin Diabetes Center and Department of Medicine, Harvard Medical School, Boston, Massachusetts
| | - Ho-Jin Koh
- Integrative Physiology and Metabolism Section, Joslin Diabetes Center and Department of Medicine, Harvard Medical School, Boston, Massachusetts
| | - Hiroyasu Esumi
- Cancer Physiology Project, Research Center for Innovative Oncology, National Cancer Center Hospital East, Kashiwa, Japan
| | - Michael F Hirshman
- Integrative Physiology and Metabolism Section, Joslin Diabetes Center and Department of Medicine, Harvard Medical School, Boston, Massachusetts
| | - Laurie J Goodyear
- Integrative Physiology and Metabolism Section, Joslin Diabetes Center and Department of Medicine, Harvard Medical School, Boston, Massachusetts
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20
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Abstract
Cells constantly adapt their metabolism to meet their energy needs and respond to nutrient availability. Eukaryotes have evolved a very sophisticated system to sense low cellular ATP levels via the serine/threonine kinase AMP-activated protein kinase (AMPK) complex. Under conditions of low energy, AMPK phosphorylates specific enzymes and growth control nodes to increase ATP generation and decrease ATP consumption. In the past decade, the discovery of numerous new AMPK substrates has led to a more complete understanding of the minimal number of steps required to reprogramme cellular metabolism from anabolism to catabolism. This energy switch controls cell growth and several other cellular processes, including lipid and glucose metabolism and autophagy. Recent studies have revealed that one ancestral function of AMPK is to promote mitochondrial health, and multiple newly discovered targets of AMPK are involved in various aspects of mitochondrial homeostasis, including mitophagy. This Review discusses how AMPK functions as a central mediator of the cellular response to energetic stress and mitochondrial insults and coordinates multiple features of autophagy and mitochondrial biology.
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21
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Peterzan MA, Lygate CA, Neubauer S, Rider OJ. Metabolic remodeling in hypertrophied and failing myocardium: a review. Am J Physiol Heart Circ Physiol 2017. [PMID: 28646030 DOI: 10.1152/ajpheart.00731.2016] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The energy starvation hypothesis proposes that maladaptive metabolic remodeling antedates, initiates, and maintains adverse contractile dysfunction in heart failure (HF). Better understanding of the cardiac metabolic phenotype and metabolic signaling could help identify the role metabolic remodeling plays within HF and the conditions known to transition toward HF, including "pathological" hypertrophy. In this review, we discuss metabolic phenotype and metabolic signaling in the contexts of pathological hypertrophy and HF. We discuss the significance of alterations in energy supply (substrate utilization, oxidative capacity, and phosphotransfer) and energy sensing using observations from human and animal disease models and models of manipulated energy supply/sensing. We aim to provide ways of thinking about metabolic remodeling that center around metabolic flexibility, capacity (reserve), and efficiency rather than around particular substrate preferences or transcriptomic profiles. We show that maladaptive metabolic remodeling takes multiple forms across multiple energy-handling domains. We suggest that lack of metabolic flexibility and reserve (substrate, oxidative, and phosphotransfer) represents a final common denominator ultimately compromising efficiency and contractile reserve in stressful contexts.
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Affiliation(s)
- Mark A Peterzan
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
| | - Craig A Lygate
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
| | - Stefan Neubauer
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
| | - Oliver J Rider
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
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22
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Ma X, Bai G, Lu D, Huang L, Zhang J, Deng R, Ding S, Gu N, Guo X. Association between STK11 Gene Polymorphisms and Coronary Artery Disease in Type 2 Diabetes in Han Population in China. J Diabetes Res 2017; 2017:6297087. [PMID: 28349069 PMCID: PMC5350304 DOI: 10.1155/2017/6297087] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2016] [Accepted: 01/24/2017] [Indexed: 11/18/2022] Open
Abstract
Background. Recent studies indicated that the Serine threonine kinase 11 (STK11), which is a key regulator of the AMP-activated protein kinase (AMPK), plays a crucial role in cardiovascular system. This study aimed to investigate whether genetic variations in the STK11 gene affect the risk of coronary artery disease (CAD) in Chinese type 2 diabetics. Methods. 5 haplotype-tagging single nucleotide polymorphisms (SNPs) were selected, and 288 CAD-positive cases and 159 CAD-negative controls with type 2 diabetes were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. Results. The carriers of minor allele A at rs12977689 had a higher risk of CAD compared to the homozygotes of CC (OR = 1.572, 95% CI = 1.039-2.376, p = 0.035), and the difference was still significant after adjustment for the other known CAD risk factors (OR' = 1.184, 95% CI' = 1.036-1.353, p' = 0.013). Conclusion. Genetic variability at STK11 locus is associated with CAD risk in type 2 diabetes in the Chinese population.
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Affiliation(s)
- Xiaowei Ma
- Department of Endocrinology, Peking University First Hospital, Beijing, China
- *Xiaowei Ma:
| | - Ge Bai
- Department of Endocrinology, Peking University First Hospital, Beijing, China
| | - Difei Lu
- Department of Endocrinology, Peking University First Hospital, Beijing, China
| | - Linjuan Huang
- Department of Endocrinology, Peking University First Hospital, Beijing, China
| | - Jianwei Zhang
- Department of Endocrinology, Peking University First Hospital, Beijing, China
| | - Ruifen Deng
- Department of Endocrinology, Peking University First Hospital, Beijing, China
| | - Shan Ding
- Department of Endocrinology, Peking University First Hospital, Beijing, China
| | - Nan Gu
- Department of Endocrinology, Peking University First Hospital, Beijing, China
| | - Xiaohui Guo
- Department of Endocrinology, Peking University First Hospital, Beijing, China
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23
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Miller EJ, Calamaras T, Elezaby A, Sverdlov A, Qin F, Luptak I, Wang K, Sun X, Vijay A, Croteau D, Bachschmid M, Cohen RA, Walsh K, Colucci WS. Partial Liver Kinase B1 (LKB1) Deficiency Promotes Diastolic Dysfunction, De Novo Systolic Dysfunction, Apoptosis, and Mitochondrial Dysfunction With Dietary Metabolic Challenge. J Am Heart Assoc 2015; 5:e002277. [PMID: 26722122 PMCID: PMC4859355 DOI: 10.1161/jaha.115.002277] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 11/04/2015] [Indexed: 11/24/2022]
Abstract
BACKGROUND Myocardial hypertrophy and dysfunction are key features of metabolic heart disease due to dietary excess. Metabolic heart disease manifests primarily as diastolic dysfunction but may progress to systolic dysfunction, although the mechanism is poorly understood. Liver kinase B1 (LKB1) is a key activator of AMP-activated protein kinase and possibly other signaling pathways that oppose myocardial hypertrophy and failure. We hypothesized that LKB1 is essential to the heart's ability to withstand the metabolic stress of dietary excess. METHODS AND RESULTS Mice heterozygous for cardiac LKB1 were fed a control diet or a high-fat, high-sucrose diet for 4 months. On the control diet, cardiac LKB1 hearts had normal structure and function. After 4 months of the high-fat, high-sucrose diet, there was left ventricular hypertrophy and diastolic dysfunction in wild-type mice. In cardiac LKB1 (versus wild-type) mice, high-fat, high-sucrose feeding caused more hypertrophy (619 versus 553 μm(2), P<0.05), the de novo appearance of systolic dysfunction (left ventricular ejection fraction; 41% versus 59%, P<0.01) with left ventricular dilation (3.6 versus 3.2 mm, P<0.05), and more severe diastolic dysfunction with progression to a restrictive filling pattern (E/A ratio; 5.5 versus 1.3, P=0.05). Myocardial dysfunction in hearts of cardiac LKB1 mice fed the high-fat, high-sucrose diet was associated with evidence of increased apoptosis and apoptotic signaling via caspase 3 and p53/PUMA (p53 upregulated modulator of apoptosis) and more severe mitochondrial dysfunction. CONCLUSIONS Partial deficiency of cardiac LKB1 promotes the adverse effects of a high-fat, high-sucrose diet on the myocardium, leading to worsening of diastolic function and the de novo appearance of systolic dysfunction. LKB1 plays a key role in protecting the heart from the consequences of metabolic stress.
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MESH Headings
- AMP-Activated Protein Kinases/metabolism
- Animals
- Apoptosis
- Apoptosis Regulatory Proteins/metabolism
- Caspase 3/metabolism
- Diastole
- Diet, High-Fat
- Dietary Sucrose
- Disease Models, Animal
- Genetic Predisposition to Disease
- Heterozygote
- Hypertrophy, Left Ventricular/genetics
- Hypertrophy, Left Ventricular/metabolism
- Hypertrophy, Left Ventricular/pathology
- Hypertrophy, Left Ventricular/physiopathology
- Mice, Knockout
- Mitochondria, Heart/enzymology
- Mitochondria, Heart/pathology
- Myocardium/enzymology
- Myocardium/pathology
- Phenotype
- Protein Serine-Threonine Kinases/deficiency
- Protein Serine-Threonine Kinases/genetics
- Signal Transduction
- Systole
- Time Factors
- Tumor Suppressor Protein p53/metabolism
- Tumor Suppressor Proteins/metabolism
- Ventricular Dysfunction, Left/genetics
- Ventricular Dysfunction, Left/metabolism
- Ventricular Dysfunction, Left/pathology
- Ventricular Dysfunction, Left/physiopathology
- Ventricular Function, Left
- Ventricular Remodeling
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Affiliation(s)
- Edward J. Miller
- Myocardial Biology UnitBoston Medical Center and Boston University School of MedicineBostonMA
- Whitaker Cardiovascular InstituteBoston Medical Center and Boston University School of MedicineBostonMA
| | - Timothy Calamaras
- Myocardial Biology UnitBoston Medical Center and Boston University School of MedicineBostonMA
| | - Aly Elezaby
- Myocardial Biology UnitBoston Medical Center and Boston University School of MedicineBostonMA
| | - Aaron Sverdlov
- Myocardial Biology UnitBoston Medical Center and Boston University School of MedicineBostonMA
| | - Fuzhong Qin
- Myocardial Biology UnitBoston Medical Center and Boston University School of MedicineBostonMA
- Whitaker Cardiovascular InstituteBoston Medical Center and Boston University School of MedicineBostonMA
| | - Ivan Luptak
- Myocardial Biology UnitBoston Medical Center and Boston University School of MedicineBostonMA
| | - Ke Wang
- Myocardial Biology UnitBoston Medical Center and Boston University School of MedicineBostonMA
| | - Xinxin Sun
- Myocardial Biology UnitBoston Medical Center and Boston University School of MedicineBostonMA
| | - Andrea Vijay
- Myocardial Biology UnitBoston Medical Center and Boston University School of MedicineBostonMA
| | - Dominique Croteau
- Myocardial Biology UnitBoston Medical Center and Boston University School of MedicineBostonMA
| | - Markus Bachschmid
- Vascular Biology UnitBoston Medical Center and Boston University School of MedicineBostonMA
- Whitaker Cardiovascular InstituteBoston Medical Center and Boston University School of MedicineBostonMA
| | - Richard A. Cohen
- Vascular Biology UnitBoston Medical Center and Boston University School of MedicineBostonMA
- Whitaker Cardiovascular InstituteBoston Medical Center and Boston University School of MedicineBostonMA
| | - Kenneth Walsh
- Whitaker Cardiovascular InstituteBoston Medical Center and Boston University School of MedicineBostonMA
| | - Wilson S. Colucci
- Myocardial Biology UnitBoston Medical Center and Boston University School of MedicineBostonMA
- Whitaker Cardiovascular InstituteBoston Medical Center and Boston University School of MedicineBostonMA
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24
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Maiese K. Erythropoietin and diabetes mellitus. World J Diabetes 2015; 6:1259-1273. [PMID: 26516410 PMCID: PMC4620106 DOI: 10.4239/wjd.v6.i14.1259] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 08/25/2015] [Accepted: 09/28/2015] [Indexed: 02/05/2023] Open
Abstract
Erythropoietin (EPO) is a 30.4 kDa growth factor and cytokine that governs cell proliferation, immune modulation, metabolic homeostasis, vascular function, and cytoprotection. EPO is under investigation for the treatment of variety of diseases, but appears especially suited for the treatment of disorders of metabolism that include diabetes mellitus (DM). DM and the complications of this disease impact a significant portion of the global population leading to disability and death with currently limited therapeutic options. In addition to its utility for the treatment of anemia, EPO can improve cardiac function, reduce fatigue, and improve cognition in patients with DM as well as regulate cellular energy metabolism, obesity, tissue repair and regeneration, apoptosis, and autophagy in experimental models of DM. Yet, EPO can have adverse effects that involve the vasculature system and unchecked cellular proliferation. Critical to the cytoprotective capacity and the potential for a positive clinical outcome with EPO are the control of signal transduction pathways that include protein kinase B, the mechanistic target of rapamycin, Wnt signaling, mammalian forkhead transcription factors of the O class, silent mating type information regulation 2 homolog 1 (Saccharomyces cerevisiae), and AMP activated protein kinase. Therapeutic strategies that can specifically target and control EPO and its signaling pathways hold great promise for the development of new and effective clinical treatments for DM and the complications of this disorder.
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25
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Kim GE, Ross JL, Xie C, Su KN, Zaha VG, Wu X, Palmeri M, Ashraf M, Akar JG, Russell KS, Akar FG, Young LH. LKB1 deletion causes early changes in atrial channel expression and electrophysiology prior to atrial fibrillation. Cardiovasc Res 2015; 108:197-208. [PMID: 26378152 PMCID: PMC4571838 DOI: 10.1093/cvr/cvv212] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 07/09/2015] [Accepted: 07/14/2015] [Indexed: 12/19/2022] Open
Abstract
AIMS Liver kinase B1 (LKB1) is a protein kinase that activates the metabolic regulator AMP-activated protein kinase (AMPK) and other related kinases. Deletion of LKB1 in mice leads to cardiomyopathy and atrial fibrillation (AF). However, the specific role of the LKB1 pathway in early atrial biology remains unknown. Thus, we investigated whether LKB1 deletion altered atrial channel expression and electrophysiological function in a cardiomyocyte-specific knockout mouse model. METHODS AND RESULTS We performed a systematic comparison of αMHC-Cre LKB1(fl/fl) and littermate LKB1(fl/fl) male mice. This included analysis of gene expression, histology, and echocardiography, as well as cellular and tissue-level electrophysiology using patch-clamp recordings in vitro, optical mapping ex vivo, and ECG recordings in vivo. At postnatal day 1, atrial depolarization was prolonged, and Nav1.5 and Cx40 expression were markedly down-regulated in MHC-Cre LKB1(fl/fl) mice. Inward sodium current density was significantly decreased in MHC-Cre LKB1(fl/fl) neonatal atrial myocytes. Subsequently, additional alterations in atrial channel expression, atrial fibrosis, and spontaneous onset of AF developed by 2 weeks of age. In adult mice, abnormalities of interatrial conduction and bi-atrial electrical coupling were observed, likely promoting the perpetuation of AF. Mice with AMPK-inactivated hearts demonstrated modest overlap in channel expression with MHC-Cre LKB1(fl/fl) hearts, but retained normal structure, electrophysiological function and contractility. CONCLUSIONS Deletion of LKB1 causes early defects in atrial channel expression, action potential generation and conduction, which precede widespread atrial remodelling, fibrosis and AF. LKB1 is critical for normal atrial growth and electrophysiological function.
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Affiliation(s)
- Grace E Kim
- Department of Cellular and Molecular Physiology, Yale University, New Haven, CT 06520, USA
| | - Jenna L Ross
- Yale Cardiovascular Research Center, Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - Chaoqin Xie
- Cardiovascular Research Center, Mt. Sinai School of Medicine, New York, NY 10029, USA
| | - Kevin N Su
- Department of Cellular and Molecular Physiology, Yale University, New Haven, CT 06520, USA
| | - Vlad G Zaha
- Yale Cardiovascular Research Center, Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - Xiaohong Wu
- Yale Cardiovascular Research Center, Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - Monica Palmeri
- Yale Cardiovascular Research Center, Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - Mohammed Ashraf
- Yale Cardiovascular Research Center, Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - Joseph G Akar
- Yale Cardiovascular Research Center, Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - Kerry S Russell
- Yale Cardiovascular Research Center, Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - Fadi G Akar
- Cardiovascular Research Center, Mt. Sinai School of Medicine, New York, NY 10029, USA
| | - Lawrence H Young
- Department of Cellular and Molecular Physiology, Yale University, New Haven, CT 06520, USA Yale Cardiovascular Research Center, Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
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Liu B, Wu Z, Li Y, Ou C, Huang Z, Zhang J, Liu P, Luo C, Chen M. Puerarin prevents cardiac hypertrophy induced by pressure overload through activation of autophagy. Biochem Biophys Res Commun 2015; 464:908-15. [PMID: 26188094 DOI: 10.1016/j.bbrc.2015.07.065] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Accepted: 07/14/2015] [Indexed: 11/28/2022]
Abstract
This study aimed to explore the effects of puerarin on autophagy in cardiac hypertrophy. Decreased 5'-adenosine monophosphate kinase (AMPK) activity alone with inhibited autophagy could be detected in rats within 3 weeks after aortic banding (AB). Puerarin treatment for 3 weeks in AB rats significantly restored autophagy. Administration of puerarin for 6 weeks effectively restricted cardiomyocyte hypertrophy and apoptosis. In an in vitro study, similar anti-hypertrophy and anti-apoptosis effects of puerarin on isoprenaline-induced H9c2 cells were also observed. After inhibition of autophagy by pretreatment with 3-methyladenine, the protective effects of puerarin were blocked. Further in vivo study demonstrated that puerarin significantly enabled phosphorylation of 5'-AMPK to be activated, subsequently inhibiting expression of the mammalian target of rapamycin (mTOR) target proteins S6 ribosomal protein and 4E-binding protein 1. All these data indicate that puerarin exerts protective effects against cardiomyocyte hypertrophy and apoptosis, partly by restoration of autophagy through AMPK/mTOR-mediated signaling.
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Affiliation(s)
- Bei Liu
- Department of Cardiology, Zhu Jiang Hospital of Southern Medical University, China
| | - Zhiye Wu
- Department of Cardiology, Zhu Jiang Hospital of Southern Medical University, China
| | - Yunpeng Li
- Department of Cardiology, Zhu Jiang Hospital of Southern Medical University, China
| | - Caiwen Ou
- Department of Cardiology, Zhu Jiang Hospital of Southern Medical University, China
| | - Zhenjun Huang
- Department of Cardiology, The Second Affiliated Hospital of Guangzhou Medical University, China
| | - Jianwu Zhang
- Department of Cardiology, Zhu Jiang Hospital of Southern Medical University, China
| | - Peng Liu
- Department of Cardiology, Zhu Jiang Hospital of Southern Medical University, China
| | - Chengfeng Luo
- Department of Cardiology, The Second Affiliated Hospital of Guangzhou Medical University, China.
| | - Minsheng Chen
- Department of Cardiology, Zhu Jiang Hospital of Southern Medical University, China.
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27
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Sung MM, Zordoky BN, Bujak AL, Lally JSV, Fung D, Young ME, Horman S, Miller EJ, Light PE, Kemp BE, Steinberg GR, Dyck JRB. AMPK deficiency in cardiac muscle results in dilated cardiomyopathy in the absence of changes in energy metabolism. Cardiovasc Res 2015; 107:235-45. [PMID: 26023060 DOI: 10.1093/cvr/cvv166] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 05/21/2015] [Indexed: 12/25/2022] Open
Abstract
AIMS AMP-activated protein kinase (AMPK) is thought to be a central player in regulating myocardial metabolism and its activation has been shown to inhibit cardiac hypertrophy. Recently, mice with muscle-specific deletion of AMPK β1/β2 subunits (AMPKβ1β2-deficient mice, β1β2M-KO) have been generated and possess <10% of normal AMPK activity in muscle. However, how/if dramatic AMPK deficiency alters cardiac metabolism, function, or morphology has not been investigated. Therefore, the aim of this study was to determine whether a significant loss of AMPK activity alters cardiac function, metabolism, and hypertrophy, and whether this may play a role in the pathogenesis of heart failure. METHODS AND RESULTS β1β2M-KO mice exhibit an approximate 25% reduction in systolic and diastolic function compared with wild-type (WT) littermates. Despite the well-documented role of AMPK in controlling myocardial energy metabolism, there was no difference in basal glucose and fatty acid oxidation rates between β1β2M-KO and WT mice. However, there was reduced AMPK-mediated phosphorylation of troponin I in β1β2M-KO and reduced ventricular cell shortening in the presence of low Ca(2+), which may explain the impaired cardiac function in these mice. Interestingly, β1β2M-KO mice did not display any signs of compensatory cardiac hypertrophy, which could be attributed to impaired activation of p38 MAPK. CONCLUSIONS β1β2M-KO mice display evidence of dilated cardiomyopathy. This is the first mouse model of AMPK deficiency that demonstrates cardiac dysfunction in the absence of pathological stress and provides insights into the role of AMPK in regulating myocardial function, metabolism, hypertrophy, and the progression to heart failure.
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Affiliation(s)
- Miranda M Sung
- Cardiovascular Research Centre, Department of Pediatrics, Mazankowski Alberta Heart Institute, Faculty of Medicine and Dentistry, University of Alberta, 458 Heritage Medical Research Centre, Edmonton, AB, Canada T6G 2S2
| | - Beshay N Zordoky
- Cardiovascular Research Centre, Department of Pediatrics, Mazankowski Alberta Heart Institute, Faculty of Medicine and Dentistry, University of Alberta, 458 Heritage Medical Research Centre, Edmonton, AB, Canada T6G 2S2
| | - Adam L Bujak
- Department of Medicine, McMaster University, Hamilton, ON, Canada
| | - James S V Lally
- Department of Medicine, McMaster University, Hamilton, ON, Canada
| | - David Fung
- Cardiovascular Research Centre, Department of Pediatrics, Mazankowski Alberta Heart Institute, Faculty of Medicine and Dentistry, University of Alberta, 458 Heritage Medical Research Centre, Edmonton, AB, Canada T6G 2S2
| | - Martin E Young
- Division of Cardiovascular Disease, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Sandrine Horman
- Institut de Recherche Expérimentale et Clinique, Pôle de Recherche Cardio-Vasculaire, Université catholique de Louvain, Brussels, Belgium
| | | | - Peter E Light
- Alberta Diabetes Institute, Department of Pharmacology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Bruce E Kemp
- Department of Medicine, St Vincent's Institute of Medical Research, University of Melbourne, Melbourne, Australia
| | | | - Jason R B Dyck
- Cardiovascular Research Centre, Department of Pediatrics, Mazankowski Alberta Heart Institute, Faculty of Medicine and Dentistry, University of Alberta, 458 Heritage Medical Research Centre, Edmonton, AB, Canada T6G 2S2
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New Insights for Oxidative Stress and Diabetes Mellitus. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015; 2015:875961. [PMID: 26064426 PMCID: PMC4443788 DOI: 10.1155/2015/875961] [Citation(s) in RCA: 145] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Accepted: 04/15/2015] [Indexed: 12/12/2022]
Abstract
The release of reactive oxygen species (ROS) and the generation of oxidative stress are considered critical factors for the pathogenesis of diabetes mellitus (DM), a disorder that is growing in prevalence and results in significant economic loss. New therapeutic directions that address the detrimental effects of oxidative stress may be especially warranted to develop effective care for the millions of individuals that currently suffer from DM. The mechanistic target of rapamycin (mTOR), silent mating type information regulation 2 homolog 1 (S. cerevisiae) (SIRT1), and Wnt1 inducible signaling pathway protein 1 (WISP1) are especially justified to be considered treatment targets for DM since these pathways can address the complex relationship between stem cells, trophic factors, impaired glucose tolerance, programmed cell death pathways of apoptosis and autophagy, tissue remodeling, cellular energy homeostasis, and vascular biology that greatly impact the biology and disease progression of DM. The translation and development of these pathways into viable therapies will require detailed understanding of their proliferative nature to maximize clinical efficacy and limit adverse effects that have the potential to lead to unintended consequences.
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Maiese K. Novel applications of trophic factors, Wnt and WISP for neuronal repair and regeneration in metabolic disease. Neural Regen Res 2015; 10:518-28. [PMID: 26170801 PMCID: PMC4424733 DOI: 10.4103/1673-5374.155427] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/02/2015] [Indexed: 12/13/2022] Open
Abstract
Diabetes mellitus affects almost 350 million individuals throughout the globe resulting in significant morbidity and mortality. Of further concern is the growing population of individuals that remain undiagnosed but are susceptible to the detrimental outcomes of this disorder. Diabetes mellitus leads to multiple complications in the central and peripheral nervous systems that include cognitive impairment, retinal disease, neuropsychiatric disease, cerebral ischemia, and peripheral nerve degeneration. Although multiple strategies are being considered, novel targeting of trophic factors, Wnt signaling, Wnt1 inducible signaling pathway protein 1, and stem cell tissue regeneration are considered to be exciting prospects to overcome the cellular mechanisms that lead to neuronal injury in diabetes mellitus involving oxidative stress, apoptosis, and autophagy. Pathways that involve insulin-like growth factor-1, fibroblast growth factor, epidermal growth factor, and erythropoietin can govern glucose homeostasis and are intimately tied to Wnt signaling that involves Wnt1 and Wnt1 inducible signaling pathway protein 1 (CCN4) to foster control over stem cell proliferation, wound repair, cognitive decline, β-cell proliferation, vascular regeneration, and programmed cell death. Ultimately, cellular metabolism through Wnt signaling is driven by primary metabolic pathways of the mechanistic target of rapamycin and AMP activated protein kinase. These pathways offer precise biological control of cellular metabolism, but are exquisitely sensitive to the different components of Wnt signaling. As a result, unexpected clinical outcomes can ensue and therefore demand careful translation of the mechanisms that govern neural repair and regeneration in diabetes mellitus.
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Affiliation(s)
- Kenneth Maiese
- Cellular and Molecular Signaling, Newark, New Jersey 07101, USA
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30
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Maiese K. mTOR: Driving apoptosis and autophagy for neurocardiac complications of diabetes mellitus. World J Diabetes 2015; 6:217-224. [PMID: 25789103 PMCID: PMC4360415 DOI: 10.4239/wjd.v6.i2.217] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2014] [Revised: 12/10/2014] [Accepted: 01/19/2015] [Indexed: 02/05/2023] Open
Abstract
The World Health Organization estimates that diabetes mellitus (DM) will become the seventh leading cause of death during the next two decades. DM affects approximately 350 million individuals worldwide and additional millions that remain undiagnosed are estimated to suffer from the complications of DM. Although the complications of DM can be seen throughout the body, the nervous, cardiac, and vascular systems can be significantly affected and lead to disorders that include cognitive loss, stroke, atherosclerosis, cardiac failure, and endothelial stem cell impairment. At the cellular level, oxidative stress is a significant determinant of cell fate during DM and leads to endoplasmic reticulum stress, mitochondrial dysfunction, apoptosis, and autophagy. Multiple strategies are being developed to combat the complications of DM, but it is the mechanistic target of rapamycin (mTOR) that is gaining interest in drug development circles especially for protective therapies that involve cytokines and growth factors such as erythropoietin. The pathways of mTOR linked to mTOR complex 1, mTOR complex 2, AMP activated protein kinase, and the hamartin (tuberous sclerosis 1)/tuberin (tuberous sclerosis 2) complex can ultimately influence neuronal, cardiac, and vascular cell survival during oxidant stress in DM through a fine interplay between apoptosis and autophagy. Further understanding of these mTOR regulated pathways should foster novel strategies for the complications of DM that impact millions of individuals with death and disability.
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Maiese K. Programming apoptosis and autophagy with novel approaches for diabetes mellitus. Curr Neurovasc Res 2015; 12:173-88. [PMID: 25742566 PMCID: PMC4380829 DOI: 10.2174/1567202612666150305110929] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 02/16/2015] [Accepted: 02/19/2015] [Indexed: 12/13/2022]
Abstract
According to the World Health Organization, diabetes mellitus (DM) in the year 2030 will be ranked the seventh leading cause of death in the world. DM impacts all systems of the body with oxidant stress controlling cell fate through endoplasmic reticulum stress, mitochondrial dysfunction, alterations in uncoupling proteins, and the induction of apoptosis and autophagy. Multiple treatment approaches are being entertained for DM with Wnt1 inducible signaling pathway protein 1 (WISP1), mechanistic target of rapamycin (mTOR), and silent mating type information regulation 2 homolog) 1 (S. cerevisiae) (SIRT1) generating significant interest as target pathways that can address maintenance of glucose homeostasis as well as prevention of cellular pathology by controlling insulin resistance, stem cell proliferation, and the programmed cell death pathways of apoptosis and autophagy. WISP1, mTOR, and SIRT1 can rely upon similar pathways such as AMP activated protein kinase as well as govern cellular metabolism through cytokines such as EPO and oral hypoglycemics such as metformin. Yet, these pathways require precise biological control to exclude potentially detrimental clinical outcomes. Further elucidation of the ability to translate the roles of WISP1, mTOR, and SIRT1 into effective clinical avenues offers compelling prospects for new therapies against DM that can benefit hundreds of millions of individuals throughout the globe.
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Affiliation(s)
- Kenneth Maiese
- MD, Cellular and Molecular Signaling, Newark, New Jersey 07101, USA.
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32
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Maiese K. Cutting through the complexities of mTOR for the treatment of stroke. Curr Neurovasc Res 2014; 11:177-86. [PMID: 24712647 DOI: 10.2174/1567202611666140408104831] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Revised: 03/17/2014] [Accepted: 03/19/2014] [Indexed: 01/06/2023]
Abstract
On a global basis, at least 15 million individuals suffer some form of a stroke every year. Of these individuals, approximately 800,000 of these cerebrovascular events occur in the United States (US) alone. The incidence of stroke in the US has declined from the third leading cause of death to the fourth, a result that can be attributed to multiple factors that include improved vascular disease management, reduced tobacco use, and more rapid time to treatment in patients that are clinically appropriate to receive recombinant tissue plasminogen activator. However, treatment strategies for the majority of stroke patients are extremely limited and represent a critical void for care. A number of new therapeutic considerations for stroke are under consideration, but it is the mammalian target of rapamycin (mTOR) that is receiving intense focus as a potential new target for cerebrovascular disease. As part of the phosphoinositide 3-kinase (PI 3-K) and protein kinase B (Akt) cascade, mTOR is an essential component of mTOR Complex 1 (mTORC1) and mTOR Complex 2 (mTORC2) to govern cell death involving apoptosis, autophagy, and necroptosis, cellular metabolism, and gene transcription. Vital for the consideration of new therapeutic strategies for stroke is the ability to understand how the intricate and complex pathways of mTOR signaling sometimes lead to disparate clinical outcomes.
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Affiliation(s)
- Kenneth Maiese
- Cellular and Molecular Signaling, Newark, New Jersey 07101, USA.
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Abstract
A significant portion of the world's population suffers from sporadic Alzheimer's disease (AD) with available present therapies limited to symptomatic care that does not alter disease progression. Over the next decade, advancing age of the global population will dramatically increase the incidence of AD and severely impact health care resources, necessitating novel, safe, and efficacious strategies for AD. The mammalian target of rapamycin (mTOR) and its protein complexes mTOR Complex 1 (mTORC1) and mTOR Complex 2 (mTORC2) offer exciting and unique avenues of intervention for AD through the oversight of programmed cell death pathways of apoptosis, autophagy, and necroptosis. mTOR modulates multi-faceted signal transduction pathways that involve phosphoinositide 3-kinase (PI 3-K), protein kinase B (Akt), hamartin (tuberous sclerosis 1)/ tuberin (tuberous sclerosis 2) (TSC1/TSC2) complex, proline-rich Akt substrate 40 kDa (PRAS40), and p70 ribosomal S6 kinase (p70S6K) and can interface with the neuroprotective pathways of growth factors, sirtuins, wingless, forkhead transcription factors, and glycogen synthase kinase-3β. With the ability of mTOR to broadly impact cellular function, clinical strategies for AD that implement mTOR must achieve parallel objectives of protecting neuronal, vascular, and immune cell survival in conjunction with preserving networks that determine memory and cognitive function.
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Affiliation(s)
- Kenneth Maiese
- Cellular and Molecular Signaling , Newark, New Jersey 07101 , USA
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34
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Beirowski B, Babetto E, Golden JP, Chen YJ, Yang K, Gross RW, Patti GJ, Milbrandt J. Metabolic regulator LKB1 is crucial for Schwann cell-mediated axon maintenance. Nat Neurosci 2014; 17:1351-61. [PMID: 25195104 DOI: 10.1038/nn.3809] [Citation(s) in RCA: 143] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 08/15/2014] [Indexed: 02/06/2023]
Abstract
Schwann cells (SCs) promote axonal integrity independently of myelination by poorly understood mechanisms. Current models suggest that SC metabolism is critical for this support function and that SC metabolic deficits may lead to axonal demise. The LKB1-AMP-activated protein kinase (AMPK) kinase pathway targets several downstream effectors, including mammalian target of rapamycin (mTOR), and is a key metabolic regulator implicated in metabolic diseases. We found through molecular, structural and behavioral characterization of SC-specific mutant mice that LKB1 activity is central to axon stability, whereas AMPK and mTOR in SCs are largely dispensable. The degeneration of axons in LKB1 mutants was most dramatic in unmyelinated small sensory fibers, whereas motor axons were comparatively spared. LKB1 deletion in SCs led to abnormalities in nerve energy and lipid homeostasis and to increased lactate release. The latter acts in a compensatory manner to support distressed axons. LKB1 signaling is essential for SC-mediated axon support, a function that may be dysregulated in diabetic neuropathy.
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Affiliation(s)
- Bogdan Beirowski
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Elisabetta Babetto
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Judith P Golden
- Department of Anesthesiology, Washington University Pain Center, St. Louis, Missouri, USA
| | - Ying-Jr Chen
- Department of Chemistry, Washington University, St. Louis, Missouri, USA
| | - Kui Yang
- Department of Internal Medicine, Division of Bioorganic Chemistry and Molecular Pharmacology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Richard W Gross
- Department of Internal Medicine, Division of Bioorganic Chemistry and Molecular Pharmacology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Gary J Patti
- 1] Department of Genetics, Washington University School of Medicine, St. Louis, Missouri, USA. [2] Department of Chemistry, Washington University, St. Louis, Missouri, USA. [3] Department of Internal Medicine, Division of Bioorganic Chemistry and Molecular Pharmacology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Jeffrey Milbrandt
- 1] Department of Genetics, Washington University School of Medicine, St. Louis, Missouri, USA. [2] Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, Missouri, USA
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35
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Jessen N, Sundelin EI, Møller AB. AMP kinase in exercise adaptation of skeletal muscle. Drug Discov Today 2014; 19:999-1002. [DOI: 10.1016/j.drudis.2014.03.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Accepted: 03/07/2014] [Indexed: 11/25/2022]
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36
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Tanner CB, Madsen SR, Hallowell DM, Goring DMJ, Moore TM, Hardman SE, Heninger MR, Atwood DR, Thomson DM. Mitochondrial and performance adaptations to exercise training in mice lacking skeletal muscle LKB1. Am J Physiol Endocrinol Metab 2013; 305:E1018-29. [PMID: 23982155 PMCID: PMC3798697 DOI: 10.1152/ajpendo.00227.2013] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
LKB1 and its downstream targets of the AMP-activated protein kinase family are important regulators of many aspects of skeletal muscle cell function, including control of mitochondrial content and capillarity. LKB1 deficiency in skeletal and cardiac muscle (mLKB1-KO) greatly impairs exercise capacity. However, cardiac dysfunction in that genetic model prevents a clear assessment of the role of skeletal muscle LKB1 in the observed effects. Our purposes here were to determine whether skeletal muscle-specific knockout of LKB1 (skmLKB1-KO) decreases exercise capacity and mitochondrial protein content, impairs accretion of mitochondrial proteins after exercise training, and attenuates improvement in running performance after exercise training. We found that treadmill and voluntary wheel running capacity was reduced in skmLKB1-KO vs. control (CON) mice. Citrate synthase activity, succinate dehydrogenase activity, and pyruvate dehydrogenase kinase content were lower in KO vs. CON muscles. Three weeks of treadmill training resulted in significantly increased treadmill running performance in both CON and skmLKB1-KO mice. Citrate synthase activity increased significantly with training in both genotypes, but protein content and activity for components of the mitochondrial electron transport chain increased only in CON mice. Capillarity and VEGF protein was lower in skmLKB1-KO vs. CON muscles, but VEGF increased with training only in skmLKB1-KO. Three hours after an acute bout of muscle contractions, PGC-1α, cytochrome c, and VEGF gene expression all increased in CON but not skmLKB1-KO muscles. Our findings indicate that skeletal muscle LKB1 is required for accretion of some mitochondrial proteins but not for early exercise capacity improvements with exercise training.
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MESH Headings
- AMP-Activated Protein Kinases
- Adaptation, Physiological
- Animals
- Capillaries/physiology
- Citrate (si)-Synthase/metabolism
- Citric Acid Cycle
- Female
- Gene Expression Regulation, Enzymologic
- Male
- Mice
- Mice, Knockout
- Mitochondria, Muscle/enzymology
- Mitochondria, Muscle/metabolism
- Motor Activity
- Motor Skills
- Muscle, Skeletal/blood supply
- Muscle, Skeletal/cytology
- Muscle, Skeletal/enzymology
- Muscle, Skeletal/metabolism
- Protein Serine-Threonine Kinases/genetics
- Protein Serine-Threonine Kinases/metabolism
- Pyruvate Dehydrogenase Acetyl-Transferring Kinase
- RNA, Messenger/metabolism
- Succinate Dehydrogenase/metabolism
- Vascular Endothelial Growth Factor A/metabolism
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Affiliation(s)
- Colby B Tanner
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, Utah
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37
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Miura S, Kai Y, Tadaishi M, Tokutake Y, Sakamoto K, Bruce CR, Febbraio MA, Kita K, Chohnan S, Ezaki O. Marked phenotypic differences of endurance performance and exercise-induced oxygen consumption between AMPK and LKB1 deficiency in mouse skeletal muscle: changes occurring in the diaphragm. Am J Physiol Endocrinol Metab 2013; 305:E213-29. [PMID: 23695215 DOI: 10.1152/ajpendo.00114.2013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
LKB1 phosphorylates members of the AMP-activated protein kinase (AMPK) family. LKB1 and AMPK in the skeletal muscle are believed to regulate not only fuel oxidation during exercise but also exercise capacity. LKB1 was also required to prevent diaphragm fatigue, which was shown to affect exercise performance. Using mice expressing dominant negative (DN) mutants of LKB1 and AMPK, specifically in the skeletal muscle but not in the heart, we investigated the roles of LKB1 and AMPK activity in exercise performance and the effects of these kinases on the characteristics of respiratory and locomotive muscles. In the diaphragm and gastrocnemius, both AMPK-DN and LKB1-DN mice showed complete loss of AMPKα2 activity, and LKB1-DN mice showed a reduction in LKB1 activity. Exercise capacity was significantly reduced in LKB1-DN mice, with a marked reduction in oxygen consumption and carbon dioxide production during exercise. The diaphragm from LKB1-DN mice showed an increase in myosin heavy chain IIB and glycolytic enzyme expression. Normal respiratory chain function and CPT I activity were shown in the isolated mitochondria from LKB1-DN locomotive muscle, and the expression of genes related to fiber type, mitochondria function, glucose and lipid metabolism, and capillarization in locomotive muscle was not different between LKB1-DN and AMPK-DN mice. We concluded that LKB1 in the skeletal muscle contributes significantly to exercise capacity and oxygen uptake during exercise. LKB1 mediated the change of fiber-type distribution in the diaphragm independently of AMPK and might be responsible for the phenotypes we observed.
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Affiliation(s)
- Shinji Miura
- Laboratory of Nutritional Biochemistry, Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka, Japan.
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Koczor CA, Lee EK, Torres RA, Boyd A, Vega JD, Uppal K, Yuan F, Fields EJ, Samarel AM, Lewis W. Detection of differentially methylated gene promoters in failing and nonfailing human left ventricle myocardium using computation analysis. Physiol Genomics 2013; 45:597-605. [PMID: 23695888 DOI: 10.1152/physiolgenomics.00013.2013] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Human dilated cardiomyopathy (DCM) is characterized by congestive heart failure and altered myocardial gene expression. Epigenetic changes, including DNA methylation, are implicated in the development of DCM but have not been studied extensively. Clinical human DCM and nonfailing control left ventricle samples were individually analyzed for DNA methylation and expressional changes. Expression microarrays were used to identify 393 overexpressed and 349 underexpressed genes in DCM (GEO accession number: GSE43435). Gene promoter microarrays were utilized for DNA methylation analysis, and the resulting data were analyzed by two different computational methods. In the first method, we utilized subtractive analysis of DNA methylation peak data to identify 158 gene promoters exhibiting DNA methylation changes that correlated with expression changes. In the second method, a two-stage approach combined a particle swarm optimization feature selection algorithm and a discriminant analysis via mixed integer programming classifier to identify differentially methylated gene promoters. This analysis identified 51 hypermethylated promoters and six hypomethylated promoters in DCM with 100% cross-validation accuracy in the group assignment. Generation of a composite list of genes identified by subtractive analysis and two-stage computation analysis revealed four genes that exhibited differential DNA methylation by both methods in addition to altered gene expression. Computationally identified genes (AURKB, BTNL9, CLDN5, and TK1) define a central set of differentially methylated gene promoters that are important in classifying DCM. These genes have no previously reported role in DCM. This study documents that rigorous computational analysis applied to microarray analysis of healthy and diseased human heart samples helps to define clinically relevant DNA methylation and expressional changes in DCM.
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Niemann B, Pan R, Teschner M, Boening A, Silber RE, Rohrbach S. Age and obesity-associated changes in the expression and activation of components of the AMPK signaling pathway in human right atrial tissue. Exp Gerontol 2013; 48:55-63. [DOI: 10.1016/j.exger.2012.04.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2011] [Revised: 04/05/2012] [Accepted: 04/16/2012] [Indexed: 11/25/2022]
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Sun C, Tian L, Nie J, Zhang H, Han X, Shi Y. Inactivation of MARK4, an AMP-activated protein kinase (AMPK)-related kinase, leads to insulin hypersensitivity and resistance to diet-induced obesity. J Biol Chem 2012; 287:38305-15. [PMID: 22992738 DOI: 10.1074/jbc.m112.388934] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
MARK4, also known as Par-1d/MarkL1, is a member of the AMP-activated protein kinase (AMPK)-related family of kinases, which are implicated in the regulation of dynamic biological functions, including glucose and energy homeostasis. However, the physiological function of MARK4 in mammals remains elusive. Here, we investigated a role for MARK4 in regulating energy homeostasis by generating mice with targeted inactivation of the mark4 gene. We show that MARK4 deficiency in mice caused hyperphagia, hyperactivity, and hypermetabolism, leading to protection from diet-induced obesity and its related metabolic complications through up-regulation of brown fat activity. Consequently, MARK4 deficiency mitigated insulin resistance associated with diet-induced obesity by dramatically enhancing insulin-stimulated AKT phosphorylation in major metabolic tissues. Ablation of MARK4 also significantly improved glucose homeostasis by up-regulating the activity and expression of AMPK kinase in key metabolic tissues. Taken together, these data identify a key role of MARK4 in energy metabolism, implicating the kinase as a novel drug target for the treatment of obesity and type 2 diabetes.
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Affiliation(s)
- Chao Sun
- College of Animal Science and Technology, Northwest A&F University, Yangling 712100, China
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Chong ZZ, Maiese K. Mammalian target of rapamycin signaling in diabetic cardiovascular disease. Cardiovasc Diabetol 2012; 11:45. [PMID: 22545721 PMCID: PMC3398846 DOI: 10.1186/1475-2840-11-45] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 04/30/2012] [Indexed: 12/15/2022] Open
Abstract
Diabetes mellitus currently affects more than 170 million individuals worldwide and is expected to afflict another 200 million individuals in the next 30 years. Complications of diabetes as a result of oxidant stress affect multiple systems throughout the body, but involvement of the cardiovascular system may be one of the most severe in light of the impact upon cardiac and vascular function that can result in rapid morbidity and mortality for individuals. Given these concerns, the signaling pathways of the mammalian target of rapamycin (mTOR) offer exciting prospects for the development of novel therapies for the cardiovascular complications of diabetes. In the cardiovascular and metabolic systems, mTOR and its multi-protein complexes of TORC1 and TORC2 regulate insulin release and signaling, endothelial cell survival and growth, cardiomyocyte proliferation, resistance to β-cell injury, and cell longevity. Yet, mTOR can, at times, alter insulin signaling and lead to insulin resistance in the cardiovascular system during diabetes mellitus. It is therefore vital to understand the complex relationship mTOR and its downstream pathways hold during metabolic disease in order to develop novel strategies for the complications of diabetes mellitus in the cardiovascular system.
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Bessi VL, Labbé SM, Huynh DN, Ménard L, Jossart C, Febbraio M, Guérin B, Bentourkia M, Lecomte R, Carpentier AC, Ong H, Marleau S. EP 80317, a selective CD36 ligand, shows cardioprotective effects against post-ischaemic myocardial damage in mice. Cardiovasc Res 2012; 96:99-108. [DOI: 10.1093/cvr/cvs225] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Horman S, Beauloye C, Vanoverschelde JL, Bertrand L. AMP-activated Protein Kinase in the Control of Cardiac Metabolism and Remodeling. Curr Heart Fail Rep 2012; 9:164-73. [DOI: 10.1007/s11897-012-0102-z] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Ollila S, Mäkelä TP. The tumor suppressor kinase LKB1: lessons from mouse models. J Mol Cell Biol 2011; 3:330-40. [PMID: 21926085 DOI: 10.1093/jmcb/mjr016] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Mutations in the tumor suppressor gene LKB1 are important in hereditary Peutz-Jeghers syndrome, as well as in sporadic cancers including lung and cervical cancer. LKB1 is a kinase-activating kinase, and a number of LKB1-dependent phosphorylation cascades regulate fundamental cellular and organismal processes in at least metabolism, polarity, cytoskeleton organization, and proliferation. Conditional targeting approaches are beginning to demonstrate the relevance and specificity of these signaling pathways in development and homeostasis of multiple organs. More than one of the pathways also appear to contribute to tumor growth following Lkb1 deficiencies based on a number of mouse tumor models. Lkb1-dependent activation of AMPK and subsequent inactivation of mammalian target of rapamycin signaling are implicated in several of the models, and other less well characterized pathways are also involved. Conditional targeting studies of Lkb1 also point an important role of LKB1 in epithelial-mesenchymal interactions, significantly expanding knowledge on the relevance of LKB1 in human disease.
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Affiliation(s)
- Saara Ollila
- Institute of Biotechnology, University of Helsinki, Viikki Biocenter, Viikinkaari 9B, FIN-00014, Helsinki, Finland
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Beauloye C, Bertrand L, Horman S, Hue L. AMPK activation, a preventive therapeutic target in the transition from cardiac injury to heart failure. Cardiovasc Res 2011; 90:224-33. [PMID: 21285292 DOI: 10.1093/cvr/cvr034] [Citation(s) in RCA: 148] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Heart failure is a progressive muscular disorder leading to a deterioration of the heart characterized by a contractile dysfunction and a chronic energy deficit. As a consequence, the failing heart is unable to meet the normal metabolic and energy needs of the body. The transition between compensated left ventricular hypertrophy and the de-compensated heart is multifactorial, although metabolic disturbances are considered to play a significant role. In this respect, the AMP-activated protein kinase (AMPK) could be a potential target in heart failure development. AMPK senses the energy state of the cell and orchestrates a global metabolic response to energy deprivation. We briefly review here the current knowledge about the chronic energy deficit of the failing heart, as well as the role of AMPK in energy homeostasis and in the control of non-metabolic targets in relation to cardiac hypertrophy and heart failure. The relative importance of energetic and non-metabolic effects in the potential cardioprotective action of AMPK is discussed.
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Affiliation(s)
- Christophe Beauloye
- Institut de Recherche Expérimentale et Clinique, Pôle de Recherche Cardio-Vasculaire, Université catholique de Louvain, Brussels, Belgium
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Shorning BY, Clarke AR. LKB1 loss of function studied in vivo. FEBS Lett 2011; 585:958-66. [DOI: 10.1016/j.febslet.2011.01.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Revised: 01/10/2011] [Accepted: 01/11/2011] [Indexed: 12/12/2022]
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