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Su C, Ma J, Yao X, Hao W, Gan S, Gao Y, He J, Ren Y, Gao X, Zhu Y, Yang J, Wei M. Tudor-SN promotes cardiomyocyte proliferation and neonatal heart regeneration through regulating the phosphorylation of YAP. Cell Commun Signal 2024; 22:345. [PMID: 38943195 PMCID: PMC11212424 DOI: 10.1186/s12964-024-01715-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Accepted: 06/14/2024] [Indexed: 07/01/2024] Open
Abstract
BACKGROUND The neonatal mammalian heart exhibits considerable regenerative potential following injury through cardiomyocyte proliferation, whereas mature cardiomyocytes withdraw from the cell cycle and lose regenerative capacities. Therefore, investigating the mechanisms underlying neonatal cardiomyocyte proliferation and regeneration is crucial for unlocking the regenerative potential of adult mammalian heart to repair damage and restore contractile function following myocardial injury. METHODS The Tudor staphylococcal nuclease (Tudor-SN) transgenic (TG) or cardiomyocyte-specific knockout mice (Myh6-Tudor-SN -/-) were generated to investigate the role of Tudor-SN in cardiomyocyte proliferation and heart regeneration following apical resection (AR) surgery. Primary cardiomyocytes isolated from neonatal mice were used to assess the influence of Tudor-SN on cardiomyocyte proliferation in vitro. Affinity purification and mass spectrometry were employed to elucidate the underlying mechanism. H9c2 cells and mouse myocardia with either overexpression or knockout of Tudor-SN were utilized to assess its impact on the phosphorylation of Yes-associated protein (YAP), both in vitro and in vivo. RESULTS We previously identified Tudor-SN as a cell cycle regulator that is highly expressed in neonatal mice myocardia but downregulated in adults. Our present study demonstrates that sustained expression of Tudor-SN promotes and prolongs the proliferation of neonatal cardiomyocytes, improves cardiac function, and enhances the ability to repair the left ventricular apex resection in neonatal mice. Consistently, cardiomyocyte-specific knockout of Tudor-SN impairs cardiac function and retards recovery after injury. Tudor-SN associates with YAP, which plays important roles in heart development and regeneration, inhibiting phosphorylation at Ser 127 and Ser 397 residues by preventing the association between Large Tumor Suppressor 1 (LATS1) and YAP, correspondingly maintaining stability and promoting nuclear translocation of YAP to enhance the proliferation-related genes transcription. CONCLUSION Tudor-SN regulates the phosphorylation of YAP, consequently enhancing and prolonging neonatal cardiomyocyte proliferation under physiological conditions and promoting neonatal heart regeneration after injury.
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Affiliation(s)
- Chao Su
- Division of Cardiovascular Surgery, Cardiac and Vascular Center, the University of Hong Kong-Shenzhen Hospital, Shenzhen, China
| | - Jinzheng Ma
- Tianjin Key Laboratory of Cellular and Molecular Immunology, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), State Key Laboratory of Experimental Hematology, Tianjin Key Laboratory of Metabolic Diseases, The Province and Ministry Co-Sponsored Collaborative Innovation Center for Medical Epigenetics, Tianjin Medical University, Tianjin, China
| | - Xuyang Yao
- Tianjin Key Laboratory of Cellular and Molecular Immunology, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), State Key Laboratory of Experimental Hematology, Tianjin Key Laboratory of Metabolic Diseases, The Province and Ministry Co-Sponsored Collaborative Innovation Center for Medical Epigenetics, Tianjin Medical University, Tianjin, China
- Department of Ophthalmology, Tianjin Medical University General Hospital, Tianjin, China
| | - Wei Hao
- Tianjin Key Laboratory of Cellular and Molecular Immunology, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), State Key Laboratory of Experimental Hematology, Tianjin Key Laboratory of Metabolic Diseases, The Province and Ministry Co-Sponsored Collaborative Innovation Center for Medical Epigenetics, Tianjin Medical University, Tianjin, China
| | - Shihu Gan
- Tianjin Key Laboratory of Cellular and Molecular Immunology, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), State Key Laboratory of Experimental Hematology, Tianjin Key Laboratory of Metabolic Diseases, The Province and Ministry Co-Sponsored Collaborative Innovation Center for Medical Epigenetics, Tianjin Medical University, Tianjin, China
| | - Yixiang Gao
- Tianjin Key Laboratory of Cellular and Molecular Immunology, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), State Key Laboratory of Experimental Hematology, Tianjin Key Laboratory of Metabolic Diseases, The Province and Ministry Co-Sponsored Collaborative Innovation Center for Medical Epigenetics, Tianjin Medical University, Tianjin, China
| | - Jinlong He
- Tianjin Key Laboratory of Cellular and Molecular Immunology, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), State Key Laboratory of Experimental Hematology, Tianjin Key Laboratory of Metabolic Diseases, The Province and Ministry Co-Sponsored Collaborative Innovation Center for Medical Epigenetics, Tianjin Medical University, Tianjin, China
| | - Yuanyuan Ren
- Tianjin Key Laboratory of Cellular and Molecular Immunology, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), State Key Laboratory of Experimental Hematology, Tianjin Key Laboratory of Metabolic Diseases, The Province and Ministry Co-Sponsored Collaborative Innovation Center for Medical Epigenetics, Tianjin Medical University, Tianjin, China
| | - Xingjie Gao
- Tianjin Key Laboratory of Cellular and Molecular Immunology, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), State Key Laboratory of Experimental Hematology, Tianjin Key Laboratory of Metabolic Diseases, The Province and Ministry Co-Sponsored Collaborative Innovation Center for Medical Epigenetics, Tianjin Medical University, Tianjin, China
| | - Yi Zhu
- Tianjin Key Laboratory of Cellular and Molecular Immunology, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), State Key Laboratory of Experimental Hematology, Tianjin Key Laboratory of Metabolic Diseases, The Province and Ministry Co-Sponsored Collaborative Innovation Center for Medical Epigenetics, Tianjin Medical University, Tianjin, China
| | - Jie Yang
- Tianjin Key Laboratory of Cellular and Molecular Immunology, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), State Key Laboratory of Experimental Hematology, Tianjin Key Laboratory of Metabolic Diseases, The Province and Ministry Co-Sponsored Collaborative Innovation Center for Medical Epigenetics, Tianjin Medical University, Tianjin, China.
| | - Minxin Wei
- Division of Cardiovascular Surgery, Cardiac and Vascular Center, the University of Hong Kong-Shenzhen Hospital, Shenzhen, China.
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Paltzer WG, Aballo TJ, Bae J, Flynn CGK, Wanless KN, Hubert KA, Nuttall DJ, Perry C, Nahlawi R, Ge Y, Mahmoud AI. mTORC1 regulates the metabolic switch of postnatal cardiomyocytes during regeneration. J Mol Cell Cardiol 2024; 187:15-25. [PMID: 38141532 PMCID: PMC10922357 DOI: 10.1016/j.yjmcc.2023.12.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 12/06/2023] [Accepted: 12/14/2023] [Indexed: 12/25/2023]
Abstract
The metabolic switch from glycolysis to fatty acid oxidation in postnatal cardiomyocytes contributes to the loss of the cardiac regenerative potential of the mammalian heart. However, the mechanisms that regulate this metabolic switch remain unclear. The protein kinase complex mechanistic target of rapamycin complex 1 (mTORC1) is a central signaling hub that regulates cellular metabolism and protein synthesis, yet its role during mammalian heart regeneration and postnatal metabolic maturation is undefined. Here, we use immunoblotting, rapamycin treatment, myocardial infarction, and global proteomics to define the role of mTORC1 in postnatal heart development and regeneration. Our results demonstrate that the activity of mTORC1 is dynamically regulated between the regenerating and the non-regenerating hearts. Acute inhibition of mTORC1 by rapamycin or everolimus reduces cardiomyocyte proliferation and inhibits neonatal heart regeneration following injury. Our quantitative proteomic analysis demonstrates that transient inhibition of mTORC1 during neonatal heart injury did not reduce protein synthesis, but rather shifts the cardiac proteome of the neonatal injured heart from glycolysis towards fatty acid oxidation. This indicates that mTORC1 inhibition following injury accelerates the postnatal metabolic switch, which promotes metabolic maturation and impedes cardiomyocyte proliferation and heart regeneration. Taken together, our results define an important role for mTORC1 in regulating postnatal cardiac metabolism and may represent a novel target to modulate cardiac metabolism and promote heart regeneration.
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Affiliation(s)
- Wyatt G Paltzer
- Department of Cell and Regenerative Biology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53705, United States
| | - Timothy J Aballo
- Department of Cell and Regenerative Biology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53705, United States
| | - Jiyoung Bae
- Department of Nutritional Sciences, Oklahoma State University, Stillwater, OK 74078, United States
| | - Corey G K Flynn
- Department of Cell and Regenerative Biology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53705, United States
| | - Kayla N Wanless
- Department of Cell and Regenerative Biology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53705, United States
| | - Katharine A Hubert
- Department of Cell and Regenerative Biology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53705, United States
| | - Dakota J Nuttall
- Department of Cell and Regenerative Biology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53705, United States
| | - Cassidy Perry
- Department of Cell and Regenerative Biology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53705, United States
| | - Raya Nahlawi
- Department of Cell and Regenerative Biology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53705, United States
| | - Ying Ge
- Department of Cell and Regenerative Biology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53705, United States; Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, United States; Human Proteomics Program, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53705, United States
| | - Ahmed I Mahmoud
- Department of Cell and Regenerative Biology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53705, United States.
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Packer M. Foetal recapitulation of nutrient surplus signalling by O-GlcNAcylation and the failing heart. Eur J Heart Fail 2023; 25:1199-1212. [PMID: 37434410 DOI: 10.1002/ejhf.2972] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 07/02/2023] [Accepted: 07/09/2023] [Indexed: 07/13/2023] Open
Abstract
The development of the foetal heart is driven by increased glucose uptake and activation of mammalian target of rapamycin (mTOR) and hypoxia-inducible factor-1α (HIF-1α), which drives glycolysis. In contrast, the healthy adult heart is governed by sirtuin-1 (SIRT1) and adenosine monophosphate-activated protein kinase (AMPK), which promote fatty-acid oxidation and the substantial mitochondrial ATP production required for survival in a high-workload normoxic environment. During cardiac injury, the heart recapitulates the foetal signalling programme, which (although adaptive in the short term) is highly deleterious if sustained for long periods of time. Prolonged increases in glucose uptake in cardiomyocytes under stress leads to increased flux through the hexosamine biosynthesis pathway; its endproduct - uridine diphosphate N-acetylglucosamine (UDP-GlcNAc) - functions as a critical nutrient surplus sensor. UDP-GlcNAc drives the post-translational protein modification known as O-GlcNAcylation, which rapidly and reversibly modifies thousands of intracellular proteins. Both O-GlcNAcylation and phosphorylation act at serine/threonine residues, but whereas phosphorylation is regulated by hundreds of specific kinases and phosphatases, O-GlcNAcylation is regulated by only two enzymes, O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), which adds or removes GlcNAc (N-acetylglucosamine), respectively, from target proteins. Recapitulation of foetal programming in heart failure (regardless of diabetes) is accompanied by marked increases in O-GlcNAcylation, both experimentally and clinically. Heightened O-GlcNAcylation in the heart leads to impaired calcium kinetics and contractile derangements, arrhythmias related to activation of voltage-gated sodium channels and Ca2+ /calmodulin-dependent protein kinase II, mitochondrial dysfunction, and maladaptive hypertrophy, microvascular dysfunction, fibrosis and cardiomyopathy. These deleterious effects can be prevented by suppression of O-GlcNAcylation, which can be achieved experimentally by upregulation of AMPK and SIRT1 or by pharmacological inhibition of OGT or stimulation of OGA. The effects of sodium-glucose cotransporter 2 (SGLT2) inhibitors on the heart are accompanied by reduced O-GlcNAcylation, and their cytoprotective effects are reportedly abrogated if their action to suppress O-GlcNAcylation is blocked. Such an action may represent one of the many mechanisms by which enhanced AMPK and SIRT1 signalling following SGLT2 inhibition leads to cardiovascular benefits. These observations, taken collectively, suggest that UDP-GlcNAc functions as a critical nutrient surplus sensor (which acting in concert with mTOR and HIF-1α) can promote the development of cardiomyopathy.
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Affiliation(s)
- Milton Packer
- Baylor Heart and Vascular Institute, Dallas, TX, USA
- Imperial College, London, UK
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Packer M. SGLT2 inhibitors: role in protective reprogramming of cardiac nutrient transport and metabolism. Nat Rev Cardiol 2023; 20:443-462. [PMID: 36609604 DOI: 10.1038/s41569-022-00824-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/29/2022] [Indexed: 01/09/2023]
Abstract
Sodium-glucose cotransporter 2 (SGLT2) inhibitors reduce heart failure events by direct action on the failing heart that is independent of changes in renal tubular function. In the failing heart, nutrient transport into cardiomyocytes is increased, but nutrient utilization is impaired, leading to deficient ATP production and the cytosolic accumulation of deleterious glucose and lipid by-products. These by-products trigger downregulation of cytoprotective nutrient-deprivation pathways, thereby promoting cellular stress and undermining cellular survival. SGLT2 inhibitors restore cellular homeostasis through three complementary mechanisms: they might bind directly to nutrient-deprivation and nutrient-surplus sensors to promote their cytoprotective actions; they can increase the synthesis of ATP by promoting mitochondrial health (mediated by increasing autophagic flux) and potentially by alleviating the cytosolic deficiency in ferrous iron; and they might directly inhibit glucose transporter type 1, thereby diminishing the cytosolic accumulation of toxic metabolic by-products and promoting the oxidation of long-chain fatty acids. The increase in autophagic flux mediated by SGLT2 inhibitors also promotes the clearance of harmful glucose and lipid by-products and the disposal of dysfunctional mitochondria, allowing for mitochondrial renewal through mitochondrial biogenesis. This Review describes the orchestrated interplay between nutrient transport and metabolism and nutrient-deprivation and nutrient-surplus signalling, to explain how SGLT2 inhibitors reverse the profound nutrient, metabolic and cellular abnormalities observed in heart failure, thereby restoring the myocardium to a healthy molecular and cellular phenotype.
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Affiliation(s)
- Milton Packer
- Baylor Heart and Vascular Institute, Dallas, TX, USA.
- Imperial College London, London, UK.
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Jiang Y, Zhao X, Chen J, Aniagu S, Chen T. PM2.5 induces cardiac malformations via PI3K/akt2/mTORC1 signaling pathway in zebrafish larvae. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 323:121306. [PMID: 36804889 DOI: 10.1016/j.envpol.2023.121306] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 01/12/2023] [Accepted: 02/15/2023] [Indexed: 06/18/2023]
Abstract
Growing evidence indicates that maternal fine particulate matter (PM2.5) exposure is linked with congenital heart diseases in the offspring. To explore the underlying molecular mechanisms, we tested the effects of a number of pharmaceutical inhibitors, and found that suppressing the PI3K/akt signaling pathway had a protective effect against cardiac defects in zebrafish larvae exposed to extractable organic matter (EOM) from PM2.5. Using genetic knockdown and a specific akt2 pharmacological inhibitor, CCT128930, we demonstrated that akt2 activation is essential to EOM-induced heart malformations. Next, we found that the EOM-induced akt2 overactivation enhances intracellular reactive oxygen species (ROS)/mitochondrial ROS production, decreases mitochondrial membrane potential levels, and elicits intrinsic apoptosis in the heart of zebrafish embryos. In addition, EOM-induced akt2 activation decreased active β-catenin levels and inhibited the expression of Wnt target genes axin2 and nkx2.5. We further demonstrated that mTORC1 phosphorylation mediates the adverse effects of akt2 on intrinsic apoptosis and canonical Wnt signaling in the heart of zebrafish larvae exposed to EOM. Moreover, EOM-induced akt2 activation is mediated via aryl hydrocarbon receptor (AHR)/ROS-induced PTEN inhibition. In conclusion, our results indicate that PM2.5 activates PI3K/akt2/mTORC1 signaling via AHR/ROS-induced PTEN suppression, which leads to mitochondrial-mediated intrinsic apoptosis and Wnt signaling suppression, resulting in cardiac defects in zebrafish larvae.
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Affiliation(s)
- Yan Jiang
- Suzhou Medical College of Soochow University, Suzhou, China
| | - Xiahao Zhao
- Suzhou Medical College of Soochow University, Suzhou, China
| | - Jin Chen
- Suzhou Medical College of Soochow University, Suzhou, China
| | - Stanley Aniagu
- Toxicology, Risk Assessment, and Research Division, Texas Commission on Environmental Quality, 12015 Park 35 Cir, Austin, TX, USA
| | - Tao Chen
- Suzhou Medical College of Soochow University, Suzhou, China; Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases, Soochow University, Suzhou, China.
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Gholipour A, Zahedmehr A, Shakerian F, Irani S, Oveisee M, Mowla SJ, Malakootian M. Significance of microRNA-targeted ErbB signaling pathway genes in cardiomyocyte differentiation. Mol Cell Probes 2023; 69:101912. [PMID: 37019292 DOI: 10.1016/j.mcp.2023.101912] [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: 09/13/2022] [Revised: 03/31/2023] [Accepted: 03/31/2023] [Indexed: 04/07/2023]
Abstract
OBJECTIVE(S) Cardiomyocyte differentiation is a complex process that follows the progression of gene expression alterations. The ErbB signaling pathway is necessary for various stages of cardiac development. We aimed to identify potential microRNAs targeting the ErbB signaling pathway genes by in silico approaches. METHODS Small RNA-sequencing data were obtained from GSE108021 for cardiomyocyte differentiation. Differentially expressed miRNAs were acquired via the DESeq2 package. Signaling pathways and gene ontology processes for the identified miRNAs were determined and the targeted genes of those miRNAs affecting the ErbB signaling pathway were determined. RESULTS Results revealed highly differentially expressed miRNAs were common between the differentiation stages and they targeted the genes involved in the ErbB signaling pathway as follows: let-7g-5p targets both CDKN1A and NRAS, while let-7c-5p and let-7d-5p hit CDKN1A and NRAS exclusively. let-7 family members targeted MAPK8 and ABL2. GSK3B was targeted by miR-199a-5p and miR-214-3p, and ERBB4 was targeted by miR-199b-3p and miR-653-5p. miR-214-3p, miR-199b-3p, miR-1277-5p, miR-21-5p, and miR-21-3p targeted CBL, mTOR, Jun, JNKK, and GRB1, respectively. MAPK8 was targeted by miR-214-3p, and ABL2 was targeted by miR-125b-5p and miR-1277-5p, too. CONCLUSION We determined miRNAs and their target genes in the ErbB signaling pathway in cardiomyocyte development and consequently heart pathophysiology progression.
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Affiliation(s)
- Akram Gholipour
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran; Cardiogenetic Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Ali Zahedmehr
- Cardiovascular Intervention Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Farshad Shakerian
- Cardiovascular Intervention Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran; Cardiogenetic Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Shiva Irani
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | | | - Seyed Javad Mowla
- Department of Molecular Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Mahshid Malakootian
- Cardiogenetic Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran.
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Genes involved in paediatric apnoea and death based on knockout animal models: Implications for sudden infant death syndrome (SIDS). Paediatr Respir Rev 2022; 44:53-60. [PMID: 34750067 DOI: 10.1016/j.prrv.2021.09.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 09/14/2021] [Indexed: 12/14/2022]
Abstract
The mechanism of death in Sudden infant death syndrome (SIDS) remains unknown but it is hypothesised that cardiorespiratory failure of brainstem origin results in early post-natal death. For a subset of SIDS infants, an underlying genetic cause may be present, and genetic abnormalities affecting brainstem respiratory control may result in abnormalities that are detectable before death. Genetic knockout mice models were developed in the 1990s and have since helped to elucidate the physiological roles of a number of genes. This systematic review aimed to identify which genes, when knocked out, result in the phenotypes of abnormal cardiorespiratory control and/or early post-natal death. Three major genes were identified: Pet1- a serotonin transcription factor, the neurotrophin pituitary adenylate cyclase activating polypeptide (PACAP) and its receptor (PAC1). Knockouts targeting these genes had blunted hypercapnic and/or hypoxic responses and early post-natal death. The hypothesis that these genes have a role in SIDS is supported by their being identified as abnormal in SIDS cohorts. Future research in SIDS cohorts will be important to determine whether these genetic abnormalities coexist and their potential applicability as biomarkers.
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Duan X, Liu X, Zhan Z. Metabolic Regulation of Cardiac Regeneration. Front Cardiovasc Med 2022; 9:933060. [PMID: 35872916 PMCID: PMC9304552 DOI: 10.3389/fcvm.2022.933060] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Accepted: 06/13/2022] [Indexed: 12/16/2022] Open
Abstract
The mortality due to heart diseases remains highest in the world every year, with ischemic cardiomyopathy being the prime cause. The irreversible loss of cardiomyocytes following myocardial injury leads to compromised contractility of the remaining myocardium, adverse cardiac remodeling, and ultimately heart failure. The hearts of adult mammals can hardly regenerate after cardiac injury since adult cardiomyocytes exit the cell cycle. Nonetheless, the hearts of early neonatal mammals possess a stronger capacity for regeneration. To improve the prognosis of patients with heart failure and to find the effective therapeutic strategies for it, it is essential to promote endogenous regeneration of adult mammalian cardiomyocytes. Mitochondrial metabolism maintains normal physiological functions of the heart and compensates for heart failure. In recent decades, the focus is on the changes in myocardial energy metabolism, including glucose, fatty acid, and amino acid metabolism, in cardiac physiological and pathological states. In addition to being a source of energy, metabolites are becoming key regulators of gene expression and epigenetic patterns, which may affect heart regeneration. However, the myocardial energy metabolism during heart regeneration is majorly unknown. This review focuses on the role of energy metabolism in cardiac regeneration, intending to shed light on the strategies for manipulating heart regeneration and promoting heart repair after cardiac injury.
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Affiliation(s)
- Xuewen Duan
- Key Laboratory of Arrhythmias of the Ministry of Education of China, Institute of Heart Failure, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Xingguang Liu
- Department of Pathogen Biology, Naval Medical University, Shanghai, China
- Xingguang Liu,
| | - Zhenzhen Zhan
- Key Laboratory of Arrhythmias of the Ministry of Education of China, Institute of Heart Failure, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
- *Correspondence: Zhenzhen Zhan,
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Bae J, Paltzer WG, Mahmoud AI. The Role of Metabolism in Heart Failure and Regeneration. Front Cardiovasc Med 2021; 8:702920. [PMID: 34336958 PMCID: PMC8322239 DOI: 10.3389/fcvm.2021.702920] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 06/23/2021] [Indexed: 12/25/2022] Open
Abstract
Heart failure is the leading cause of death worldwide. The inability of the adult mammalian heart to regenerate following injury results in the development of systolic heart failure. Thus, identifying novel approaches toward regenerating the adult heart has enormous therapeutic potential for adult heart failure. Mitochondrial metabolism is an essential homeostatic process for maintaining growth and survival. The emerging role of mitochondrial metabolism in controlling cell fate and function is beginning to be appreciated. Recent evidence suggests that metabolism controls biological processes including cell proliferation and differentiation, which has profound implications during development and regeneration. The regenerative potential of the mammalian heart is lost by the first week of postnatal development when cardiomyocytes exit the cell cycle and become terminally differentiated. This inability to regenerate following injury is correlated with the metabolic shift from glycolysis to fatty acid oxidation that occurs during heart maturation in the postnatal heart. Thus, understanding the mechanisms that regulate cardiac metabolism is key to unlocking metabolic interventions during development, disease, and regeneration. In this review, we will focus on the emerging role of metabolism in cardiac development and regeneration and discuss the potential of targeting metabolism for treatment of heart failure.
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Affiliation(s)
- Jiyoung Bae
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, United States
| | - Wyatt G Paltzer
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, United States
| | - Ahmed I Mahmoud
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, United States
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Derous D, Sahu J, Douglas A, Lusseau D, Wenzel M. Comparative genomics of cetartiodactyla: energy metabolism underpins the transition to an aquatic lifestyle. CONSERVATION PHYSIOLOGY 2021; 9:coaa136. [PMID: 33505701 PMCID: PMC7816800 DOI: 10.1093/conphys/coaa136] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 11/09/2020] [Accepted: 12/19/2020] [Indexed: 05/28/2023]
Abstract
Foraging disruption caused by human activities is emerging as a key issue in cetacean conservation because it can affect nutrient levels and the amount of energy available to individuals to invest into reproduction. Our ability to predict how anthropogenic stressors affect these ecological processes and ultimately population trajectory depends crucially on our understanding of the complex physiological mechanisms that detect nutrient availability and regulate energy metabolism, foraging behavior and life-history decisions. These physiological mechanisms are likely to differ considerably from terrestrial mammalian model systems. Here, we examine nucleotide substitution rates in cetacean and other artiodactyl genomes to identify signatures of selection in genes associated with nutrient sensing pathways. We also estimated the likely physiological consequences of adaptive amino acid substitutions for pathway functions. Our results highlight that genes involved in the insulin, mTOR and NF-ĸB pathways are subject to significant positive selection in cetaceans compared to terrestrial artiodactyla. These genes may have been positively selected to enable cetaceans to adapt to a glucose-poor diet, to overcome deleterious effects caused by hypoxia during diving (e.g. oxidative stress and inflammation) and to modify fat-depot signaling functions in a manner different to terrestrial mammals. We thus show that adaptation in cetaceans to an aquatic lifestyle significantly affected functions in nutrient sensing pathways. The use of fat stores as a condition index in cetaceans may be confounded by the multiple and critical roles fat has in regulating cetacean metabolism, foraging behavior and diving physiology.
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Affiliation(s)
- Davina Derous
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK
| | - Jagajjit Sahu
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK
| | - Alex Douglas
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK
| | - David Lusseau
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK
- National Institute of Aquatic Resources, Technical University of Denmark, Kgs. Lyngby, Copenhagen, Denmark
| | - Marius Wenzel
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK
- Centre for Genome Enabled Biology and Medicine, University of Aberdeen, Aberdeen, UK
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11
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Chen Q, Chen L, Jian J, Li J, Zhang X. The mechanism of BAF60c in myocardial metabolism through the PGC1α/PPARα/mTOR signaling pathway in rats with heart failure. Biochem Cell Biol 2020; 100:93-103. [PMID: 33245682 DOI: 10.1139/bcb-2019-0450] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
BRM-associated factor (BAF) 60c promotes muscle glycolysis and improves glucose homeostasis. This study explored the mechanism of BAF60c in heart failure (HF). Fetal/adult rat models of HF were established, and the levels of cardiac contractile proteins and energy metabolism-, oxidative metabolism- and glycolysis-related factors were detected. Overexpression/siRNA BAF60c plasmids were injected into adult HF rats to estimate myocardial glucose uptake, high-energy phosphate contents, mitochondrial function, and cell proliferation and apoptosis. The overexpression/siRNA BAF60c plasmids were transfected into cardiac hypertrophic H9C2 cells to explore the in vitro effects. The interaction of BAF60c and PGC1α was detected. The results suggested that adult HF rats presented increased levels of fetal proteins (ssTnI and fTnT), BAF60c and glycolysis-related factors, and reduced levels of cardiac contractile proteins, PGC1α, PPARα, and oxidative metabolism-related factors. BAF60c knockdown improved glucose uptake, maintained the oxidative metabolism/glycolysis balance, promoted H9C2 cell proliferation, and inhibited apoptosis. PGC1α interacted with BAF60c. Knocking down BAF60c also activated the PGC1α/PPARα/mTOR pathway. Overexpression of PGC1α decreased the damage to H9C2 cells caused by BAF60c. Altogether, BAF60c downregulation activated the PGC1α/PPARα/mTOR pathway, maintained the oxidative metabolism/glycolysis balance and improved mitochondrial function in rat models of HF. This study may offer novel insights into HF treatment.
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Affiliation(s)
- Qiang Chen
- The First Affiliated Hospital of Baotou Medical College, Inner Mongolia Baotou Medical University, Department of Cardiology, The First Affiliated Hospital of Baotou Medical College, Inner Mongolia Baotou Medical University, Baotou, China, 014010;
| | - Lizhu Chen
- The First Affiliated Hospital of Baotou Medical College, Inner Mongolia Baotou Medical University, Baotou, China;
| | - Jianguo Jian
- The First Affiliated Hospital of Baotou Medical College, Inner Mongolia Baotou Medical University, Department of Cardiology, Baotou, China;
| | - Junping Li
- The First Affiliated Hospital of Baotou Medical College, Inner Mongolia Baotou Medical University, Department of Cardiology, Baotou, China;
| | - Xiaomiao Zhang
- The First Affiliated Hospital of Baotou Medical College, Inner Mongolia Baotou Medical University, Baotou, China;
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12
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Affiliation(s)
- Francesco Perone
- Department of Angiocardioneurology and Translational Medicine, IRCCS Neuromed, Via dell'Elettronica, 86077 Pozzilli (IS), Italy
| | - Giuseppe Lembo
- Department of Angiocardioneurology and Translational Medicine, IRCCS Neuromed, Via dell'Elettronica, 86077 Pozzilli (IS), Italy.,Department of Molecular Medicine, "Sapienza" University of Rome, Rome, Italy
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13
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Oka SI, Chin A, Park JY, Ikeda S, Mizushima W, Ralda G, Zhai P, Tong M, Byun J, Tang F, Einaga Y, Huang CY, Kashihara T, Zhao M, Nah J, Tian B, Hirabayashi Y, Yodoi J, Sadoshima J. Thioredoxin-1 maintains mitochondrial function via mechanistic target of rapamycin signalling in the heart. Cardiovasc Res 2020; 116:1742-1755. [PMID: 31584633 PMCID: PMC7825501 DOI: 10.1093/cvr/cvz251] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 08/29/2019] [Accepted: 09/26/2019] [Indexed: 12/12/2022] Open
Abstract
AIMS Thioredoxin 1 (Trx1) is an evolutionarily conserved oxidoreductase that cleaves disulphide bonds in oxidized substrate proteins such as mechanistic target of rapamycin (mTOR) and maintains nuclear-encoded mitochondrial gene expression. The cardioprotective effect of Trx1 has been demonstrated via cardiac-specific overexpression of Trx1 and dominant negative Trx1. However, the pathophysiological role of endogenous Trx1 has not been defined with a loss-of-function model. To address this, we have generated cardiac-specific Trx1 knockout (Trx1cKO) mice. METHODS AND RESULTS Trx1cKO mice were viable but died with a median survival age of 25.5 days. They developed heart failure, evidenced by contractile dysfunction, hypertrophy, and increased fibrosis and apoptotic cell death. Multiple markers consistently indicated increased oxidative stress and RNA-sequencing revealed downregulation of genes involved in energy production in Trx1cKO mice. Mitochondrial morphological abnormality was evident in these mice. Although heterozygous Trx1cKO mice did not show any significant baseline phenotype, pressure-overload-induced cardiac dysfunction, and downregulation of metabolic genes were exacerbated in these mice. mTOR was more oxidized and phosphorylation of mTOR substrates such as S6K and 4EBP1 was impaired in Trx1cKO mice. In cultured cardiomyocytes, Trx1 knockdown inhibited mitochondrial respiration and metabolic gene promoter activity, suggesting that Trx1 maintains mitochondrial function in a cell autonomous manner. Importantly, mTOR-C1483F, an oxidation-resistant mutation, prevented Trx1 knockdown-induced mTOR oxidation and inhibition and attenuated suppression of metabolic gene promoter activity. CONCLUSION Endogenous Trx1 is essential for maintaining cardiac function and metabolism, partly through mTOR regulation via Cys1483.
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Affiliation(s)
- Shin-Ichi Oka
- Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, NJ 07101, USA
| | - Adave Chin
- Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, NJ 07101, USA
| | - Ji Yeon Park
- Seoul National University Biomedical Informatics, Division of Biomedical Informatics, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Shohei Ikeda
- Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, NJ 07101, USA
| | - Wataru Mizushima
- Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, NJ 07101, USA
| | - Guersom Ralda
- Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, NJ 07101, USA
| | - Peiyong Zhai
- Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, NJ 07101, USA
| | - Mingming Tong
- Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, NJ 07101, USA
| | - Jaemin Byun
- Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, NJ 07101, USA
| | - Fan Tang
- Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, NJ 07101, USA
| | - Yudai Einaga
- Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, NJ 07101, USA
| | - Chun-Yang Huang
- Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, NJ 07101, USA
- Division of Cardiovascular Surgery, Department of Surgery, Taipei Veterans General Hospital, Taipei, Taiwan
- Institute of Clinical Medicine, School of Medicine National Yang-Ming University, Taipei, Taiwan
| | - Toshihide Kashihara
- Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, NJ 07101, USA
| | - Mengyuan Zhao
- Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, NJ 07101, USA
| | - Jihoon Nah
- Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, NJ 07101, USA
| | - Bin Tian
- Department of Biochemistry & Molecular Biology, Rutgers New Jersey Medical School, Newark, NJ 07101, USA
| | - Yoko Hirabayashi
- Division of Cellular and Molecular Toxicology, Center for Biological Safety and Research, National Institute of Health Sciences, Tokyo 158-8501, Japan
| | - Junji Yodoi
- Department of Biological Responses, Laboratory of Infection and Prevention, Institute for Virus Research, Kyoto University, Sakyo-ku, Kyoto, 606-8397, Japan
| | - Junichi Sadoshima
- Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, NJ 07101, USA
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14
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Chávez MN, Morales RA, López-Crisosto C, Roa JC, Allende ML, Lavandero S. Autophagy Activation in Zebrafish Heart Regeneration. Sci Rep 2020; 10:2191. [PMID: 32042056 PMCID: PMC7010704 DOI: 10.1038/s41598-020-59106-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 01/23/2020] [Indexed: 02/06/2023] Open
Abstract
Autophagy is an evolutionarily conserved process that plays a key role in the maintenance of overall cellular health. While it has been suggested that autophagy may elicit cardioprotective and pro-survival modulating functions, excessive activation of autophagy can also be detrimental. In this regard, the zebrafish is considered a hallmark model for vertebrate regeneration, since contrary to adult mammals, it is able to faithfully regenerate cardiac tissue. Interestingly, the role that autophagy may play in zebrafish heart regeneration has not been studied yet. In the present work, we hypothesize that, in the context of a well-established injury model of ventricular apex resection, autophagy plays a critical role during cardiac regeneration and its regulation can directly affect the zebrafish regenerative potential. We studied the autophagy events occurring upon injury using electron microscopy, in vivo tracking of autophagy markers, and protein analysis. Additionally, using pharmacological tools, we investigated how rapamycin, an inducer of autophagy, affects regeneration relevant processes. Our results show that a tightly regulated autophagic response is triggered upon injury and during the early stages of the regeneration process. Furthermore, treatment with rapamycin caused an impairment in the cardiac regeneration outcome. These findings are reminiscent of the pathophysiological description of an injured human heart and hence put forward the zebrafish as a model to study the poorly understood double-sword effect that autophagy has in cardiac homeostasis.
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Affiliation(s)
- Myra N Chávez
- Advanced Center for Chronic Diseases (ACCDiS) & Corporación Centro de Estudios Científicos de las Enfermedades Crónicas (CECEC), Faculty of Chemical and Pharmaceutical Sciences & Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Center for Genome Regulation (CGR), Department of Biology, Faculty of Sciences, University of Chile, Santiago, Chile
| | - Rodrigo A Morales
- Center for Genome Regulation (CGR), Department of Biology, Faculty of Sciences, University of Chile, Santiago, Chile
| | - Camila López-Crisosto
- Advanced Center for Chronic Diseases (ACCDiS) & Corporación Centro de Estudios Científicos de las Enfermedades Crónicas (CECEC), Faculty of Chemical and Pharmaceutical Sciences & Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Juan Carlos Roa
- Department of Pathology, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Miguel L Allende
- Center for Genome Regulation (CGR), Department of Biology, Faculty of Sciences, University of Chile, Santiago, Chile.
| | - Sergio Lavandero
- Advanced Center for Chronic Diseases (ACCDiS) & Corporación Centro de Estudios Científicos de las Enfermedades Crónicas (CECEC), Faculty of Chemical and Pharmaceutical Sciences & Faculty of Medicine, Universidad de Chile, Santiago, Chile. .,Department of Internal Medicine (Cardiology Division), University of Texas Southwestern Medical Center, Dallas, USA.
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15
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Tang Z, Shi B, Sun W, Yin Y, Chen Q, Mohamed T, Lu C, Sun Z. Tryptophan promoted β-defensin-2 expressionviathe mTOR pathway and its metabolites: kynurenine banding to aryl hydrocarbon receptor in rat intestine. RSC Adv 2020; 10:3371-3379. [PMID: 35497743 PMCID: PMC9049194 DOI: 10.1039/c9ra10477a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 01/04/2020] [Indexed: 12/20/2022] Open
Abstract
In this study, we investigated the signalling pathways mediating tryptophan (Trp)-promoted β-defensin-2 (BD-2) expression in rat intestinal mucosa. Sprague Dawley rats were administered with l-Trp and treated with rapamycin (RAPA), 1-methyltryptophan (1-MT), or para-chlorophenyl-amine (PCPA) to inhibit mammalian target of rapamycin (mTOR), indoleamine-2,3-dioxygenase (IDO), or tryptophan hydroxylase (TPH), respectively. The mRNA and protein levels of BD-2 in the jejunal and ileal mucosa of rats increased with administration of l-Trp. Intraperitoneal injection of RAPA significantly decreased the mRNA level of BD-2 and the concentrations of p-mTORC1 and BD-2 in the jejunal and ileal mucosa of rats with administration of l-Trp (P < 0.05). Oral administration of 1-MT decreased the IDO activity and the mRNA and protein levels of BD-2, and increased the concentrations of tumour necrosis factor (TNF-α), interleukin (IL)-17, and IL-22 in the jejunal and ileal mucosa of rats with administration of l-Trp (P < 0.05). Intraperitoneal injection of PCPA decreased the TPH activity and increased the mRNA and protein levels of BD-2, but did not change the concentrations of TNF-α, IL-17, or IL-22 in the jejunal and ileal mucosa of rats with administration of l-Trp. The results indicate the Trp-promoted BD-2 expression in the jejunum and ileum via the mTOR pathway and its metabolites: kynurenine banding to aryl hydrocarbon receptor in rat intestine. In this study, we investigated the signalling pathways mediating tryptophan (Trp)-promoted β-defensin-2 (BD-2) expression in rat intestinal mucosa.![]()
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Affiliation(s)
- Zhiru Tang
- Laboratory for Bio-feed and Molecular Nutrition
- College of Animal Science and Technology
- Southwest University
- Chongqing 400715
- China
| | - Baoshi Shi
- Laboratory for Bio-feed and Molecular Nutrition
- College of Animal Science and Technology
- Southwest University
- Chongqing 400715
- China
| | - Weizhong Sun
- Laboratory for Bio-feed and Molecular Nutrition
- College of Animal Science and Technology
- Southwest University
- Chongqing 400715
- China
| | - Yulong Yin
- Institute of Subtropical Agriculture
- The Chinese Academy of Sciences
- Changsha 410125
- P. R. China
| | - Qingju Chen
- Laboratory for Bio-feed and Molecular Nutrition
- College of Animal Science and Technology
- Southwest University
- Chongqing 400715
- China
| | - Taha Mohamed
- Laboratory for Bio-feed and Molecular Nutrition
- College of Animal Science and Technology
- Southwest University
- Chongqing 400715
- China
| | - Changwen Lu
- Laboratory for Bio-feed and Molecular Nutrition
- College of Animal Science and Technology
- Southwest University
- Chongqing 400715
- China
| | - Zhihong Sun
- Laboratory for Bio-feed and Molecular Nutrition
- College of Animal Science and Technology
- Southwest University
- Chongqing 400715
- China
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16
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Garbern JC, Helman A, Sereda R, Sarikhani M, Ahmed A, Escalante GO, Ogurlu R, Kim SL, Zimmerman JF, Cho A, MacQueen L, Bezzerides VJ, Parker KK, Melton DA, Lee RT. Inhibition of mTOR Signaling Enhances Maturation of Cardiomyocytes Derived From Human-Induced Pluripotent Stem Cells via p53-Induced Quiescence. Circulation 2019; 141:285-300. [PMID: 31707831 PMCID: PMC7009740 DOI: 10.1161/circulationaha.119.044205] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND Current differentiation protocols to produce cardiomyocytes from human induced pluripotent stem cells (iPSCs) are capable of generating highly pure cardiomyocyte populations as determined by expression of cardiac troponin T. However, these cardiomyocytes remain immature, more closely resembling the fetal state, with a lower maximum contractile force, slower upstroke velocity, and immature mitochondrial function compared with adult cardiomyocytes. Immaturity of iPSC-derived cardiomyocytes may be a significant barrier to clinical translation of cardiomyocyte cell therapies for heart disease. During development, cardiomyocytes undergo a shift from a proliferative state in the fetus to a more mature but quiescent state after birth. The mechanistic target of rapamycin (mTOR)-signaling pathway plays a key role in nutrient sensing and growth. We hypothesized that transient inhibition of the mTOR-signaling pathway could lead cardiomyocytes to a quiescent state and enhance cardiomyocyte maturation. METHODS Cardiomyocytes were differentiated from 3 human iPSC lines using small molecules to modulate the Wnt pathway. Torin1 (0 to 200 nmol/L) was used to inhibit the mTOR pathway at various time points. We quantified contractile, metabolic, and electrophysiological properties of matured iPSC-derived cardiomyocytes. We utilized the small molecule inhibitor, pifithrin-α, to inhibit p53 signaling, and nutlin-3a, a small molecule inhibitor of MDM2 (mouse double minute 2 homolog) to upregulate and increase activation of p53. RESULTS Torin1 (200 nmol/L) increased the percentage of quiescent cells (G0 phase) from 24% to 48% compared with vehicle control (P<0.05). Torin1 significantly increased expression of selected sarcomere proteins (including TNNI3 [troponin I, cardiac muscle]) and ion channels (including Kir2.1) in a dose-dependent manner when Torin1 was initiated after onset of cardiomyocyte beating. Torin1-treated cells had an increased relative maximum force of contraction, increased maximum oxygen consumption rate, decreased peak rise time, and increased downstroke velocity. Torin1 treatment increased protein expression of p53, and these effects were inhibited by pifithrin-α. In contrast, nutlin-3a independently upregulated p53, led to an increase in TNNI3 expression and worked synergistically with Torin1 to further increase expression of both p53 and TNNI3. CONCLUSIONS Transient treatment of human iPSC-derived cardiomyocytes with Torin1 shifts cells to a quiescent state and enhances cardiomyocyte maturity.
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Affiliation(s)
- Jessica C Garbern
- Department of Stem Cell and Regenerative Biology and the Harvard Stem Cell Institute (J.C.G., A.H., R.S., M.S., A.A., G.O.E., D.A.M., R.T.L.), Harvard University, Cambridge, MA.,Department of Cardiology, Boston Children's Hospital, MA (J.C.G., R.O., V.J.B.)
| | - Aharon Helman
- Department of Stem Cell and Regenerative Biology and the Harvard Stem Cell Institute (J.C.G., A.H., R.S., M.S., A.A., G.O.E., D.A.M., R.T.L.), Harvard University, Cambridge, MA
| | - Rebecca Sereda
- Department of Stem Cell and Regenerative Biology and the Harvard Stem Cell Institute (J.C.G., A.H., R.S., M.S., A.A., G.O.E., D.A.M., R.T.L.), Harvard University, Cambridge, MA
| | - Mohsen Sarikhani
- Department of Stem Cell and Regenerative Biology and the Harvard Stem Cell Institute (J.C.G., A.H., R.S., M.S., A.A., G.O.E., D.A.M., R.T.L.), Harvard University, Cambridge, MA
| | - Aishah Ahmed
- Department of Stem Cell and Regenerative Biology and the Harvard Stem Cell Institute (J.C.G., A.H., R.S., M.S., A.A., G.O.E., D.A.M., R.T.L.), Harvard University, Cambridge, MA
| | - Gabriela O Escalante
- Department of Stem Cell and Regenerative Biology and the Harvard Stem Cell Institute (J.C.G., A.H., R.S., M.S., A.A., G.O.E., D.A.M., R.T.L.), Harvard University, Cambridge, MA
| | - Roza Ogurlu
- Department of Cardiology, Boston Children's Hospital, MA (J.C.G., R.O., V.J.B.)
| | - Sean L Kim
- Department of Stem Cell and Regenerative Biology and the Harvard Stem Cell Institute (J.C.G., A.H., R.S., M.S., A.A., G.O.E., D.A.M., R.T.L.), Harvard University, Cambridge, MA.,Disease Biophysics Group, Wyss Institute for Biologically Inspired Engineering, School of Engineering and Applied Sciences (S.L.K., J.F.Z., A.C., L.M., K.K.P.), Harvard University, Cambridge, MA
| | - John F Zimmerman
- Disease Biophysics Group, Wyss Institute for Biologically Inspired Engineering, School of Engineering and Applied Sciences (S.L.K., J.F.Z., A.C., L.M., K.K.P.), Harvard University, Cambridge, MA
| | - Alexander Cho
- Disease Biophysics Group, Wyss Institute for Biologically Inspired Engineering, School of Engineering and Applied Sciences (S.L.K., J.F.Z., A.C., L.M., K.K.P.), Harvard University, Cambridge, MA
| | - Luke MacQueen
- Disease Biophysics Group, Wyss Institute for Biologically Inspired Engineering, School of Engineering and Applied Sciences (S.L.K., J.F.Z., A.C., L.M., K.K.P.), Harvard University, Cambridge, MA
| | | | - Kevin Kit Parker
- Disease Biophysics Group, Wyss Institute for Biologically Inspired Engineering, School of Engineering and Applied Sciences (S.L.K., J.F.Z., A.C., L.M., K.K.P.), Harvard University, Cambridge, MA
| | - Douglas A Melton
- Department of Stem Cell and Regenerative Biology and the Harvard Stem Cell Institute (J.C.G., A.H., R.S., M.S., A.A., G.O.E., D.A.M., R.T.L.), Harvard University, Cambridge, MA
| | - Richard T Lee
- Department of Stem Cell and Regenerative Biology and the Harvard Stem Cell Institute (J.C.G., A.H., R.S., M.S., A.A., G.O.E., D.A.M., R.T.L.), Harvard University, Cambridge, MA.,Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA (R.T.L.)
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17
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Zhang Y, Wu Q, Zhang L, Wang Q, Yang Z, Liu J, Feng L. Caffeic acid reduces A53T α-synuclein by activating JNK/Bcl-2-mediated autophagy in vitro and improves behaviour and protects dopaminergic neurons in a mouse model of Parkinson's disease. Pharmacol Res 2019; 150:104538. [PMID: 31707034 DOI: 10.1016/j.phrs.2019.104538] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 10/30/2019] [Accepted: 11/05/2019] [Indexed: 01/08/2023]
Abstract
The human A53T mutant of α-synuclein tends to aggregate and leads to neurotoxicity in familial Parkinson's disease (PD). The aggregation of α-synuclein is also found in sporadic PD. Thus, targeting α-synuclein clearance could be used as a drug-discovery strategy for PD treatment. Caffeic acid (CA) has shown neuroprotection in Alzheimer's disease or cerebral ischaemia; however, it is unclear whether CA confers neuroprotection in α-synuclein-induced PD models. Here we focus on whether and how A53T α-synuclein is affected by CA. We assessed the effect of CA on cell viability in SH-SY5Y cells overexpressing A53T α-synuclein. Pathway-related inhibitors were used to identify the autophagy mechanisms. Seven-month-old A53T α-synuclein transgenic mice (A53T Tg mice) received CA daily for eight consecutive weeks. Behaviour tests including the buried food pellet test, the pole test, the Rotarod test, open field analysis, and gait analysis were used to evaluate the neuroprotective effect of CA. Tyrosine hydroxylase and α-synuclein were assessed by immunohistochemistry or western blot in the substantia nigra (SN). We found that CA alleviated the cell damage induced by overexpressing A53T α-synuclein and that CA reduced A53T α-synuclein by activating the JNK/Bcl-2-mediated autophagy pathway. The efficacy of CA on A53T α-synuclein degradation was reversed by the autophagy inhibitor bafilomycin A1 and the JNK inhibitor SP600125. In A53T Tg mice, CA improved behavioural impairments, attenuated loss of dopaminergic neurons, enhanced autophagy and reduced α-synuclein in the SN. Thus, the results provide scientific evidence for the neuroprotective effect of CA in PD. Our work lays the foundation for CA clinical trials to treat PD in the future.
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Affiliation(s)
- Yu Zhang
- CAS Key Laboratory of Receptor Research, Department of Neuropharmacology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai, 201203, China; School of Pharmacy, University of Chinese Academy of Sciences, No.19A Yuquan road, Beijing, 100049, China
| | - Qimei Wu
- CAS Key Laboratory of Receptor Research, Department of Neuropharmacology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai, 201203, China; School of Pharmacy, University of Chinese Academy of Sciences, No.19A Yuquan road, Beijing, 100049, China
| | - Lei Zhang
- CAS Key Laboratory of Receptor Research, Department of Neuropharmacology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai, 201203, China; School of Pharmacy, University of Chinese Academy of Sciences, No.19A Yuquan road, Beijing, 100049, China
| | - Qing Wang
- CAS Key Laboratory of Receptor Research, Department of Neuropharmacology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai, 201203, China; School of Pharmacy, University of Chinese Academy of Sciences, No.19A Yuquan road, Beijing, 100049, China
| | - Zexian Yang
- CAS Key Laboratory of Receptor Research, Department of Neuropharmacology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai, 201203, China; School of Pharmacy, University of Chinese Academy of Sciences, No.19A Yuquan road, Beijing, 100049, China
| | - Jia Liu
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai, 201203, China
| | - Linyin Feng
- CAS Key Laboratory of Receptor Research, Department of Neuropharmacology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai, 201203, China; School of Pharmacy, University of Chinese Academy of Sciences, No.19A Yuquan road, Beijing, 100049, China.
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18
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Emerging Role of mTOR Signaling-Related miRNAs in Cardiovascular Diseases. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:6141902. [PMID: 30305865 PMCID: PMC6165581 DOI: 10.1155/2018/6141902] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Accepted: 07/04/2018] [Indexed: 12/21/2022]
Abstract
Mechanistic/mammalian target of rapamycin (mTOR), an atypical serine/threonine kinase of the phosphoinositide 3-kinase- (PI3K-) related kinase family, elicits a vital role in diverse cellular processes, including cellular growth, proliferation, survival, protein synthesis, autophagy, and metabolism. In the cardiovascular system, the mTOR signaling pathway integrates both intracellular and extracellular signals and serves as a central regulator of both physiological and pathological processes. MicroRNAs (miRs), a class of short noncoding RNA, are an emerging intricate posttranscriptional modulator of critical gene expression for the development and maintenance of homeostasis across a wide array of tissues, including the cardiovascular system. Over the last decade, numerous studies have revealed an interplay between miRNAs and the mTOR signaling circuit in the different cardiovascular pathophysiology, like myocardial infarction, hypertrophy, fibrosis, heart failure, arrhythmia, inflammation, and atherosclerosis. In this review, we provide a comprehensive state of the current knowledge regarding the mechanisms of interactions between the mTOR signaling pathway and miRs. We have also highlighted the latest advances on mTOR-targeted therapy in clinical trials and the new perspective therapeutic strategies with mTOR-targeting miRs in cardiovascular diseases.
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19
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Liu TY, Chen YC, Jong YJ, Tsai HJ, Lee CC, Chang YS, Chang JG, Chang YF. Muscle developmental defects in heterogeneous nuclear Ribonucleoprotein A1 knockout mice. Open Biol 2017; 7:rsob.160303. [PMID: 28077597 PMCID: PMC5303281 DOI: 10.1098/rsob.160303] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 12/05/2016] [Indexed: 01/18/2023] Open
Abstract
Heterogeneous ribonucleoprotein A1 (hnRNP A1) is crucial for regulating alternative splicing. Its integrated function within an organism has not, however, been identified. We generated hnRNP A1 knockout mice to study the role of hnRNP A1 in vivo. The knockout mice, hnRNP A1−/−, showed embryonic lethality because of muscle developmental defects. The blood pressure and heart rate of the heterozygous mice were higher than those of the wild-type mice, indicating heart function defects. We performed mouse exon arrays to study the muscle development mechanism. The processes regulated by hnRNP A1 included cell adhesion and muscle contraction. The expression levels of muscle development-related genes in hnRNP A1+/− mice were significantly different from those in wild-type mice, as detected using qRT-PCR. We further confirmed the alternative splicing patterns of muscle development-related genes including mef2c, lrrfip1, usp28 and abcc9. Alternative mRNA isoforms of these genes were increased in hnRNP A1+/− mice compared with wild-type mice. Furthermore, we revealed that the functionally similar hnRNP A2/B1 did not compensate for the expression of hnRNP A1 in organisms. In summary, our study demonstrated that hnRNP A1 plays a critical and irreplaceable role in embryonic muscle development by regulating the expression and alternative splicing of muscle-related genes.
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Affiliation(s)
- Ting-Yuan Liu
- Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan, Republic of China
| | - Yu-Chia Chen
- Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan, Republic of China
| | - Yuh-Jyh Jong
- Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan, Republic of China.,Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan, Republic of China.,Departments of Pediatrics and Clinical Laboratory, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan, Republic of China.,Department of Biological Science and Technology, Institute of Molecular Medicine and Bioengineering, College of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan, Republic of China
| | - Huai-Jen Tsai
- Institute of Biomedical Sciences, Mackay Medical College, New Taipei City, Taiwan, Republic of China
| | - Chien-Chin Lee
- Epigenome Research Center, China Medical University, Taichung, Taiwan, Republic of China
| | - Ya-Sian Chang
- Epigenome Research Center, China Medical University, Taichung, Taiwan, Republic of China.,Department of Laboratory Medicine, China Medical University, Taichung, Taiwan, Republic of China.,Department of Medical Laboratory Science and Biotechnology, China Medical University, Taichung, Taiwan, Republic of China
| | - Jan-Gowth Chang
- Epigenome Research Center, China Medical University, Taichung, Taiwan, Republic of China .,Department of Laboratory Medicine, China Medical University, Taichung, Taiwan, Republic of China.,School of Medicine, China Medical University, Taichung, Taiwan, Republic of China
| | - Yung-Fu Chang
- Department of Biomedical Science and Environmental Biology, College of Life Science, Kaohsiung Medical University, Kaohsiung, Taiwan, Republic of China
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20
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Hennig M, Fiedler S, Jux C, Thierfelder L, Drenckhahn JD. Prenatal Mechanistic Target of Rapamycin Complex 1 (m TORC1) Inhibition by Rapamycin Treatment of Pregnant Mice Causes Intrauterine Growth Restriction and Alters Postnatal Cardiac Growth, Morphology, and Function. J Am Heart Assoc 2017; 6:JAHA.117.005506. [PMID: 28778941 PMCID: PMC5586418 DOI: 10.1161/jaha.117.005506] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Background Fetal growth impacts cardiovascular health throughout postnatal life in humans. Various animal models of intrauterine growth restriction exhibit reduced heart size at birth, which negatively influences cardiac function in adulthood. The mechanistic target of rapamycin complex 1 (mTORC1) integrates nutrient and growth factor availability with cell growth, thereby regulating organ size. This study aimed at elucidating a possible involvement of mTORC1 in intrauterine growth restriction and prenatal heart growth. Methods and Results We inhibited mTORC1 in fetal mice by rapamycin treatment of pregnant dams in late gestation. Prenatal rapamycin treatment reduces mTORC1 activity in various organs at birth, which is fully restored by postnatal day 3. Rapamycin‐treated neonates exhibit a 16% reduction in body weight compared with vehicle‐treated controls. Heart weight decreases by 35%, resulting in a significantly reduced heart weight/body weight ratio, smaller left ventricular dimensions, and reduced cardiac output in rapamycin‐ versus vehicle‐treated mice at birth. Although proliferation rates in neonatal rapamycin‐treated hearts are unaffected, cardiomyocyte size is reduced, and apoptosis increased compared with vehicle‐treated neonates. Rapamycin‐treated mice exhibit postnatal catch‐up growth, but body weight and left ventricular mass remain reduced in adulthood. Prenatal mTORC1 inhibition causes a reduction in cardiomyocyte number in adult hearts compared with controls, which is partially compensated for by an increased cardiomyocyte volume, resulting in normal cardiac function without maladaptive left ventricular remodeling. Conclusions Prenatal rapamycin treatment of pregnant dams represents a new mouse model of intrauterine growth restriction and identifies an important role of mTORC1 in perinatal cardiac growth.
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Affiliation(s)
- Maria Hennig
- Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - Saskia Fiedler
- Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - Christian Jux
- Department of Pediatric Cardiology, University Hospital Münster, Münster, Germany
| | | | - Jörg-Detlef Drenckhahn
- Max-Delbrück-Center for Molecular Medicine, Berlin, Germany .,Department of Pediatric Cardiology, University Hospital Münster, Münster, Germany
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21
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Tan P, Tiong IS, Fleming S, Pomilio G, Cummings N, Droogleever M, McManus J, Schwarer A, Catalano J, Patil S, Avery S, Spencer A, Wei A. The mTOR inhibitor everolimus in combination with azacitidine in patients with relapsed/refractory acute myeloid leukemia: a phase Ib/II study. Oncotarget 2016; 8:52269-52280. [PMID: 28881728 PMCID: PMC5581027 DOI: 10.18632/oncotarget.13699] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 11/20/2016] [Indexed: 12/11/2022] Open
Abstract
Therapeutic options are limited in relapsed/refractory acute myeloid leukemia (AML). We evaluated the maximum tolerated dose (MTD) and preliminary efficacy of mammalian target of rapamycin (mTOR) inhibitor, everolimus (days 5–21) in combination with azacitidine 75 mg/m2 subcutaneously (days 1–5 and 8–9 every 28 days) in 40 patients with relapsed (n = 27), primary refractory (n = 11) or elderly patients unfit for intensive chemotherapy (n = 2). MTD was not reached following everolimus dose escalation (2.5, 5 or 10 mg; n = 19) to the 10 mg dose level which was expanded (n = 21). Major adverse events (grade > 2) were mostly disease-related: neutropenia (73%), thrombocytopenia (67%), mucositis (24%) and febrile neutropenia (19%). Overall survival (OS) of the entire cohort was 8.5 months, and overall response rate (ORR; including CR/CRi/PR/MLFS) was 22.5%. Furthermore, a landmark analysis beyond cycle 1 revealed superior OS and ORR in patients receiving 2.5 mg everolimus with azoles, compared to those without azoles (median OS 12.8 vs. 6.0 months, P = 0.049, and ORR 50% vs. 16%, P = 0.056), potentially due to achievement of higher everolimus blood levels. This study demonstrates that everolimus in combination with azacitidine is tolerable, with promising clinical activity in advanced AML.
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Affiliation(s)
- Peter Tan
- Malignant Haematology and Stem Cell Transplantation Service, Alfred Hospital, Melbourne, Australia
| | - Ing Soo Tiong
- Malignant Haematology and Stem Cell Transplantation Service, Alfred Hospital, Melbourne, Australia.,Australian Centre for Blood Diseases, Monash University, Melbourne, Australia
| | - Shaun Fleming
- Malignant Haematology and Stem Cell Transplantation Service, Alfred Hospital, Melbourne, Australia
| | - Giovanna Pomilio
- Australian Centre for Blood Diseases, Monash University, Melbourne, Australia
| | - Nik Cummings
- Department of Pathology, Alfred Hospital, Melbourne, Australia
| | - Mark Droogleever
- Faculty of Medicine, University of Amsterdam, Amsterdam, The Netherlands
| | - Julie McManus
- Department of Pathology, Alfred Hospital, Melbourne, Australia
| | - Anthony Schwarer
- Eastern Health Clinical School, Monash University, Box Hill, Australia
| | - John Catalano
- Clinical Haematology, Frankston Hospital, Frankston, Australia
| | - Sushrut Patil
- Malignant Haematology and Stem Cell Transplantation Service, Alfred Hospital, Melbourne, Australia
| | - Sharon Avery
- Malignant Haematology and Stem Cell Transplantation Service, Alfred Hospital, Melbourne, Australia
| | - Andrew Spencer
- Malignant Haematology and Stem Cell Transplantation Service, Alfred Hospital, Melbourne, Australia.,Australian Centre for Blood Diseases, Monash University, Melbourne, Australia
| | - Andrew Wei
- Malignant Haematology and Stem Cell Transplantation Service, Alfred Hospital, Melbourne, Australia.,Australian Centre for Blood Diseases, Monash University, Melbourne, Australia
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22
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Guo X, Huang C, Lian K, Wang S, Zhao H, Yan F, Zhang X, Zhang J, Xie H, An R, Tao L. BCKA down-regulates mTORC2-Akt signal and enhances apoptosis susceptibility in cardiomyocytes. Biochem Biophys Res Commun 2016; 480:106-113. [PMID: 27697526 DOI: 10.1016/j.bbrc.2016.09.162] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 09/29/2016] [Indexed: 12/15/2022]
Abstract
Diabetic mellitus (DM) portends poor prognosis concerning pressure overloaded heart disease. Branched-chain amino acids (BCAAs), elements of essential amino acids, have been found altered in its catabolism in diabetes decades ago. However, the relationship between BCAAs and DM induced deterioration of pressure overloaded heart disease remains controversial. This study is aimed to investigate the particular effect of BCKA, a metabolite of BCAA, on myocardial injury induced by pressure overloaded. Primary cardiomyocytes were incubated with or without BCKA and followed by treatment with isoproterenol (ISO); then cell viability was detected by CCK8 and apoptosis was examined by TUNNEL stain and caspase-3 activity analysis. Compared to non-BCKA incubated group, BCKA incubation decreased cell survival and increased apoptosis concentration dependently. Furthermore, Western blot assay showed that mTORC2-Akt pathway was significantly inactivated by BCKA incubation. Moreover, overexpression of rictor, a vital component of mTORC2, significantly abolished the adverse effects of BCKA on apoptosis susceptibility of cardiomyocytes. These results indicate that BCKA contribute to vulnerability of cardiomyocytes in stimulated stress via inactivation of mTORC2-Akt pathway.
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Affiliation(s)
- Xiong Guo
- Department of Cardiology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China
| | - Chong Huang
- Department of Cardiology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China
| | - Kun Lian
- Department of Cardiology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China
| | - Shan Wang
- Department of Cardiology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China
| | - Huishou Zhao
- Department of Cardiology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China
| | - Feng Yan
- Department of Cardiology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China
| | - Xiaomeng Zhang
- Department of Cardiology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China
| | - Jinglong Zhang
- Department of Cardiology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China
| | - Huaning Xie
- Department of Cardiology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China
| | - Rui An
- Department of Radiology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China
| | - Ling Tao
- Department of Cardiology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China.
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23
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Mazelin L, Panthu B, Nicot AS, Belotti E, Tintignac L, Teixeira G, Zhang Q, Risson V, Baas D, Delaune E, Derumeaux G, Taillandier D, Ohlmann T, Ovize M, Gangloff YG, Schaeffer L. mTOR inactivation in myocardium from infant mice rapidly leads to dilated cardiomyopathy due to translation defects and p53/JNK-mediated apoptosis. J Mol Cell Cardiol 2016; 97:213-25. [DOI: 10.1016/j.yjmcc.2016.04.011] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 04/05/2016] [Accepted: 04/12/2016] [Indexed: 10/21/2022]
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24
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MiR-28 inhibits cardiomyocyte survival through suppressing PDK1/Akt/mTOR signaling. In Vitro Cell Dev Biol Anim 2016; 52:1020-1025. [DOI: 10.1007/s11626-016-0065-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 06/03/2016] [Indexed: 02/01/2023]
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25
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De novo RRAGC mutation activates mTORC1 signaling in syndromic fetal dilated cardiomyopathy. Hum Genet 2016; 135:909-917. [PMID: 27234373 DOI: 10.1007/s00439-016-1685-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 05/14/2016] [Indexed: 12/30/2022]
Abstract
Idiopathic dilated cardiomyopathy (DCM) is a heritable, genetically heterogeneous disorder with variable age-dependent penetrance. We sought to identify the genetic underpinnings of syndromic, sporadic DCM in a newborn female diagnosed in utero. Postnatal evaluation revealed ventricular dilation and systolic dysfunction, bilateral cataracts, and mild facial dysmorphisms. Comprehensive metabolic and genetic testing, including chromosomal microarray, mitochondrial DNA and targeted RASopathy gene sequencing, and clinical whole exome sequencing for known cardiomyopathy genes was non-diagnostic. Following exclusion of asymptomatic DCM in the parents, trio-based whole exome sequencing was carried out on a research basis, filtering for rare, predicted deleterious de novo and recessive variants. An unreported de novo S75Y mutation was discovered in RRAGC, encoding Ras-related GTP binding C, an essential GTPase in nutrient-activated mechanistic target of rapamycin complex 1 (mTORC1) signaling. In silico protein modeling and molecular dynamics simulation predicted the mutation to disrupt ligand interactions and increase the GDP-bound state. Overexpression of RagC(S75Y) rendered AD293 cells partially insensitive to amino acid deprivation, resulting in increased mTORC1 signaling compared to wild-type RagC. These findings implicate mTORC1 dysregulation through a gain-of-function mutation in RagC as a novel molecular basis for syndromic forms of pediatric heart failure, and expand genotype-phenotype correlation in RASopathy-related syndromes.
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26
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Pascual F, Coleman RA. Fuel availability and fate in cardiac metabolism: A tale of two substrates. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:1425-33. [PMID: 26993579 DOI: 10.1016/j.bbalip.2016.03.014] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 03/10/2016] [Accepted: 03/11/2016] [Indexed: 12/12/2022]
Abstract
The heart's extraordinary metabolic flexibility allows it to adapt to normal changes in physiology in order to preserve its function. Alterations in the metabolic profile of the heart have also been attributed to pathological conditions such as ischemia and hypertrophy; however, research during the past decade has established that cardiac metabolic adaptations can precede the onset of pathologies. It is therefore critical to understand how changes in cardiac substrate availability and use trigger events that ultimately result in heart dysfunction. This review examines the mechanisms by which the heart obtains fuels from the circulation or from mobilization of intracellular stores. We next describe experimental models that exhibit either an increase in glucose use or a decrease in FA oxidation, and how these aberrant conditions affect cardiac metabolism and function. Finally, we highlight the importance of alternative, relatively under-investigated strategies for the treatment of heart failure. This article is part of a Special Issue entitled: Heart Lipid Metabolism edited by G.D. Lopaschuk.
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Affiliation(s)
- Florencia Pascual
- Department of Nutrition, University of North Carolina at Chapel Hill, 27599, USA.
| | - Rosalind A Coleman
- Department of Nutrition, University of North Carolina at Chapel Hill, 27599, USA.
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27
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Tan VP, Miyamoto S. Nutrient-sensing mTORC1: Integration of metabolic and autophagic signals. J Mol Cell Cardiol 2016; 95:31-41. [PMID: 26773603 DOI: 10.1016/j.yjmcc.2016.01.005] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 12/11/2015] [Accepted: 01/04/2016] [Indexed: 12/26/2022]
Abstract
The ability of adult cardiomyocytes to regenerate is limited, and irreversible loss by cell death plays a crucial role in heart diseases. Autophagy is an evolutionarily conserved cellular catabolic process through which long-lived proteins and damaged organelles are targeted for lysosomal degradation. Autophagy is important in cardiac homeostasis and can serve as a protective mechanism by providing an energy source, especially in the face of sustained starvation. Cellular metabolism is closely associated with cell survival, and recent evidence suggests that metabolic and autophagic signaling pathways exhibit a high degree of crosstalk and are functionally interdependent. In this review, we discuss recent progress in our understanding of regulation of autophagy and its crosstalk with metabolic signaling, with a focus on the nutrient-sensing mTOR complex 1 (mTORC1) pathway.
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Affiliation(s)
- Valerie P Tan
- Department of Pharmacology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0636, USA
| | - Shigeki Miyamoto
- Department of Pharmacology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0636, USA.
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28
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A Critical Role of the mTOR/eIF2α Pathway in Hypoxia-Induced Pulmonary Hypertension. PLoS One 2015; 10:e0130806. [PMID: 26120832 PMCID: PMC4487252 DOI: 10.1371/journal.pone.0130806] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 05/25/2015] [Indexed: 11/28/2022] Open
Abstract
Enhanced proliferation of pulmonary arterial vascular smooth muscle cells (PASMCs) is a key pathological component of vascular remodeling in hypoxia-induced pulmonary hypertension (HPH). Mammalian targeting of rapamycin (mTOR) signaling has been shown to play a role in protein translation and participate in the progression of pulmonary hypertension. Eukaryotic translation initiation factor-2α (eIF2α) is a key factor in regulation of cell growth and cell cycle, but its role in mTOR signaling and PASMCs proliferation remains unknown. Pulmonary hypertension (PH) rat model was established by hypoxia. Rapamycin was used to treat rats as an mTOR inhibitor. Proliferation of primarily cultured rat PASMCs was induced by hypoxia, rapamycin and siRNA of mTOR and eIF2α were used in loss-of-function studies. The expression and activation of eIF2α, mTOR and c-myc were analyzed. Results showed that mTOR/eIF2α signaling was significantly activated in pulmonary arteries from hypoxia exposed rats and PASMCs cultured under hypoxia condition. Treatment with mTOR inhibitor for 21 days attenuated vascular remodeling, suppressed mTOR and eIF2α activation, inhibited c-myc expression in HPH rats. In hypoxia-induced PASMCs, rapamycin and knockdown of mTOR and eIF2α by siRNA significantly abolished proliferation and increased c-myc expression. These results suggest a critical role of the mTOR/eIF2αpathway in hypoxic vascular remodeling and PASMCs proliferation of HPH.
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29
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Zhang P, Liang X, Shan T, Jiang Q, Deng C, Zheng R, Kuang S. mTOR is necessary for proper satellite cell activity and skeletal muscle regeneration. Biochem Biophys Res Commun 2015; 463:102-8. [PMID: 25998386 DOI: 10.1016/j.bbrc.2015.05.032] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 05/09/2015] [Indexed: 12/14/2022]
Abstract
The serine/threonine kinase mammalian target of rapamycin (mTOR) is a key regulator of protein synthesis, cell proliferation and energy metabolism. As constitutive deletion of Mtor gene results in embryonic lethality, the function of mTOR in muscle stem cells (satellite cells) and skeletal muscle regeneration remains to be determined. In this study, we established a satellite cell specific Mtor conditional knockout (cKO) mouse model by crossing Pax7(CreER) and Mtor(flox/flox) mice. Skeletal muscle regeneration after injury was severely compromised in the absence of Mtor, indicated by increased number of necrotic myofibers infiltrated by Evans blue dye, and reduced number and size of regenerated myofibers in the Mtor cKO mice compared to wild type (WT) littermates. To dissect the cellular mechanism, we analyzed satellite cell-derived primary myoblasts grown on single myofibers or adhered to culture plates. The Mtor cKO myoblasts exhibited defective proliferation and differentiation kinetics when compared to myoblasts derived from WT littermates. At the mRNA and protein levels, the Mtor cKO myoblasts expressed lower levels of key myogenic determinant genes Pax7, Myf5, Myod, Myog than did the WT myoblasts. These results suggest that mTOR is essential for satellite cell function and skeletal muscle regeneration through controlling the expression of myogenic genes.
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Affiliation(s)
- Pengpeng Zhang
- Key Laboratory of Swine Genetics and Breeding of Agricultural Ministry & Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; Department of Animal Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Xinrong Liang
- Department of Animal Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Tizhong Shan
- Department of Animal Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Qinyang Jiang
- Department of Animal Sciences, Purdue University, West Lafayette, IN 47907, USA; College of Animal Science and Technology, Guangxi University, Nanning 530004, China
| | - Changyan Deng
- Key Laboratory of Swine Genetics and Breeding of Agricultural Ministry & Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Rong Zheng
- Key Laboratory of Swine Genetics and Breeding of Agricultural Ministry & Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
| | - Shihuan Kuang
- Department of Animal Sciences, Purdue University, West Lafayette, IN 47907, USA.
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