1
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Fowler JL, Zheng SL, Nguyen A, Chen A, Xiong X, Chai T, Chen JY, Karigane D, Banuelos AM, Niizuma K, Kayamori K, Nishimura T, Cromer MK, Gonzalez-Perez D, Mason C, Liu DD, Yilmaz L, Miquerol L, Porteus MH, Luca VC, Majeti R, Nakauchi H, Red-Horse K, Weissman IL, Ang LT, Loh KM. Lineage-tracing hematopoietic stem cell origins in vivo to efficiently make human HLF+ HOXA+ hematopoietic progenitors from pluripotent stem cells. Dev Cell 2024; 59:1110-1131.e22. [PMID: 38569552 PMCID: PMC11072092 DOI: 10.1016/j.devcel.2024.03.003] [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: 08/21/2023] [Revised: 12/05/2023] [Accepted: 03/01/2024] [Indexed: 04/05/2024]
Abstract
The developmental origin of blood-forming hematopoietic stem cells (HSCs) is a longstanding question. Here, our non-invasive genetic lineage tracing in mouse embryos pinpoints that artery endothelial cells generate HSCs. Arteries are transiently competent to generate HSCs for 2.5 days (∼E8.5-E11) but subsequently cease, delimiting a narrow time frame for HSC formation in vivo. Guided by the arterial origins of blood, we efficiently and rapidly differentiate human pluripotent stem cells (hPSCs) into posterior primitive streak, lateral mesoderm, artery endothelium, hemogenic endothelium, and >90% pure hematopoietic progenitors within 10 days. hPSC-derived hematopoietic progenitors generate T, B, NK, erythroid, and myeloid cells in vitro and, critically, express hallmark HSC transcription factors HLF and HOXA5-HOXA10, which were previously challenging to upregulate. We differentiated hPSCs into highly enriched HLF+ HOXA+ hematopoietic progenitors with near-stoichiometric efficiency by blocking formation of unwanted lineages at each differentiation step. hPSC-derived HLF+ HOXA+ hematopoietic progenitors could avail both basic research and cellular therapies.
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Affiliation(s)
- Jonas L Fowler
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University, Stanford, CA 94305, USA; Department of Developmental Biology, Stanford University, Stanford, CA 94305, USA
| | - Sherry Li Zheng
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University, Stanford, CA 94305, USA; Department of Developmental Biology, Stanford University, Stanford, CA 94305, USA
| | - Alana Nguyen
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University, Stanford, CA 94305, USA; Department of Developmental Biology, Stanford University, Stanford, CA 94305, USA
| | - Angela Chen
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University, Stanford, CA 94305, USA; Department of Developmental Biology, Stanford University, Stanford, CA 94305, USA
| | - Xiaochen Xiong
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University, Stanford, CA 94305, USA; Department of Developmental Biology, Stanford University, Stanford, CA 94305, USA
| | - Timothy Chai
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University, Stanford, CA 94305, USA; Department of Developmental Biology, Stanford University, Stanford, CA 94305, USA
| | - Julie Y Chen
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University, Stanford, CA 94305, USA; Department of Developmental Biology, Stanford University, Stanford, CA 94305, USA
| | - Daiki Karigane
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University, Stanford, CA 94305, USA; Division of Hematology, Department of Medicine, Stanford University, Stanford, CA 94305, USA
| | - Allison M Banuelos
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University, Stanford, CA 94305, USA; Department of Pathology, Stanford University, Stanford, CA 94305, USA
| | - Kouta Niizuma
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University, Stanford, CA 94305, USA; Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Kensuke Kayamori
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University, Stanford, CA 94305, USA; Division of Hematology, Department of Medicine, Stanford University, Stanford, CA 94305, USA
| | - Toshinobu Nishimura
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University, Stanford, CA 94305, USA; Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - M Kyle Cromer
- Department of Surgery, University of California, San Francisco, San Francisco, CA 94143, USA
| | | | - Charlotte Mason
- Department of Drug Discovery, Moffitt Cancer Center, Tampa, FL 33612, USA
| | - Daniel Dan Liu
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University, Stanford, CA 94305, USA; Department of Pathology, Stanford University, Stanford, CA 94305, USA
| | - Leyla Yilmaz
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University, Stanford, CA 94305, USA; Department of Pathology, Stanford University, Stanford, CA 94305, USA
| | - Lucile Miquerol
- Aix-Marseille Université, CNRS UMR 7288, IBDM, Marseille 13288, France
| | - Matthew H Porteus
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University, Stanford, CA 94305, USA; Department of Pediatrics, Stanford University, Stanford, CA 94305, USA
| | - Vincent C Luca
- Department of Drug Discovery, Moffitt Cancer Center, Tampa, FL 33612, USA
| | - Ravindra Majeti
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University, Stanford, CA 94305, USA; Division of Hematology, Department of Medicine, Stanford University, Stanford, CA 94305, USA
| | - Hiromitsu Nakauchi
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University, Stanford, CA 94305, USA; Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Kristy Red-Horse
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University, Stanford, CA 94305, USA; Department of Biology, Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Irving L Weissman
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University, Stanford, CA 94305, USA; Department of Pathology, Stanford University, Stanford, CA 94305, USA
| | - Lay Teng Ang
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University, Stanford, CA 94305, USA.
| | - Kyle M Loh
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University, Stanford, CA 94305, USA; Department of Developmental Biology, Stanford University, Stanford, CA 94305, USA.
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2
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Lee C, Xu S, Samad T, Goodyer WR, Raissadati A, Heinrich P, Wu SM. The cardiac conduction system: History, development, and disease. Curr Top Dev Biol 2024; 156:157-200. [PMID: 38556422 DOI: 10.1016/bs.ctdb.2024.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/02/2024]
Abstract
The heart is the first organ to form during embryonic development, establishing the circulatory infrastructure necessary to sustain life and enable downstream organogenesis. Critical to the heart's function is its ability to initiate and propagate electrical impulses that allow for the coordinated contraction and relaxation of its chambers, and thus, the movement of blood and nutrients. Several specialized structures within the heart, collectively known as the cardiac conduction system (CCS), are responsible for this phenomenon. In this review, we discuss the discovery and scientific history of the mammalian cardiac conduction system as well as the key genes and transcription factors implicated in the formation of its major structures. We also describe known human diseases related to CCS development and explore existing challenges in the clinical context.
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Affiliation(s)
- Carissa Lee
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, United States
| | - Sidra Xu
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, United States
| | - Tahmina Samad
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, United States; Division of Pediatric Cardiology, Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, United States; Department of Pediatrics, Stanford University, Stanford, CA, United States
| | - William R Goodyer
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, United States; Division of Pediatric Cardiology, Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, United States
| | - Alireza Raissadati
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, United States; Division of Pediatric Cardiology, Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, United States
| | - Paul Heinrich
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, United States; Regenerative Medicine in Cardiovascular Diseases, First Department of Medicine, Cardiology, Klinikum Rechts der Isar, Technical University of Munich, School of Medicine and Health, Munich, Germany
| | - Sean M Wu
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, United States; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, CA, United States; Division of Cardiovascular Medicine, Department of Medicine, Stanford University, Stanford, CA, United States.
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3
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Pun R, Kim MH, North BJ. Role of Connexin 43 phosphorylation on Serine-368 by PKC in cardiac function and disease. Front Cardiovasc Med 2023; 9:1080131. [PMID: 36712244 PMCID: PMC9877470 DOI: 10.3389/fcvm.2022.1080131] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 12/19/2022] [Indexed: 01/13/2023] Open
Abstract
Intercellular communication mediated by gap junction channels and hemichannels composed of Connexin 43 (Cx43) is vital for the propagation of electrical impulses through cardiomyocytes. The carboxyl terminal tail of Cx43 undergoes various post-translational modifications including phosphorylation of its Serine-368 (S368) residue. Protein Kinase C isozymes directly phosphorylate S368 to alter Cx43 function and stability through inducing conformational changes affecting channel permeability or promoting internalization and degradation to reduce intercellular communication between cardiomyocytes. Recent studies have implicated this PKC/Cx43-pS368 circuit in several cardiac-associated diseases. In this review, we describe the molecular and cellular basis of PKC-mediated Cx43 phosphorylation and discuss the implications of Cx43 S368 phosphorylation in the context of various cardiac diseases, such as cardiomyopathy, as well as the therapeutic potential of targeting this pathway.
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Affiliation(s)
- Renju Pun
- Department of Biomedical Sciences, School of Medicine, Creighton University, Omaha, NE, United States
| | - Michael H. Kim
- CHI Health Heart Institute, School of Medicine, Creighton University, Omaha, NE, United States
| | - Brian J. North
- Department of Biomedical Sciences, School of Medicine, Creighton University, Omaha, NE, United States,*Correspondence: Brian J. North,
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4
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Fang JS, Burt JM. Connexin37 Regulates Cell Cycle in the Vasculature. J Vasc Res 2022; 60:73-86. [PMID: 36067749 DOI: 10.1159/000525619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 06/08/2022] [Indexed: 11/19/2022] Open
Abstract
Control of vascular cell growth responses is critical for development and maintenance of a healthy vasculature. Connexins - the proteins comprising gap junction channels - are key regulators of cell growth in diseases such as cancer, but their involvement in controlling cell growth in the vasculature is less well appreciated. Connexin37 (Cx37) is one of four connexin isotypes expressed in the vessel wall. Its primary role in blood vessels relies on its unique ability to transduce flow-sensitive signals into changes in cell cycle status of endothelial (and perhaps, mural) cells. Here, we review available evidence for Cx37's role in the regulation of vascular growth, vessel organization, and vascular tone in healthy and diseased vasculature. We propose a novel mechanism whereby Cx37 accomplishes this with a phosphorylation-dependent transition between closed (growth-suppressive) and multiple open (growth-permissive) channel conformations that result from interactions of the C-terminus with cell-cycle regulators to limit or support cell cycle progression. Lastly, we discuss Cx37 and its downstream signaling as a novel potential target in the treatment of cardiovascular disease, and we address outstanding research questions that still challenge the development of such therapies.
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Affiliation(s)
- Jennifer S Fang
- Department of Cell and Molecular Biology, Tulane University, New Orleans, Louisiana, USA
| | - Janis M Burt
- Department of Physiology, University of Arizona, Tucson, Arizona, USA
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5
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p38 MAPK priming boosts VSMC proliferation and arteriogenesis by promoting PGC1α-dependent mitochondrial dynamics. Sci Rep 2022; 12:5938. [PMID: 35396524 PMCID: PMC8994030 DOI: 10.1038/s41598-022-09757-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 03/28/2022] [Indexed: 12/05/2022] Open
Abstract
Vascular smooth muscle cell (VSMC) proliferation is essential for arteriogenesis to restore blood flow after artery occlusion, but the mechanisms underlying this response remain unclear. Based on our previous findings showing increased VSMC proliferation in the neonatal aorta of mice lacking the protease MT4-MMP, we aimed at discovering new players in this process. We demonstrate that MT4-MMP absence boosted VSMC proliferation in vitro in response to PDGF-BB in a cell-autonomous manner through enhanced p38 MAPK activity. Increased phospho-p38 in basal MT4-MMP-null VSMCs augmented the rate of mitochondrial degradation by promoting mitochondrial morphological changes through the co-activator PGC1α as demonstrated in PGC1α−/− VSMCs. We tested the in vivo implications of this pathway in a novel conditional mouse line for selective MT4-MMP deletion in VSMCs and in mice pre-treated with the p38 MAPK activator anisomycin. Priming of p38 MAPK activity in vivo by the absence of the protease MT4-MMP or by anisomycin treatment led to enhanced arteriogenesis and improved flow recovery after femoral artery occlusion. These findings may open new therapeutic opportunities for peripheral vascular diseases.
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6
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Cairns M, Joseph D, Essop MF. The dual role of the hexosamine biosynthetic pathway in cardiac physiology and pathophysiology. Front Endocrinol (Lausanne) 2022; 13:984342. [PMID: 36353238 PMCID: PMC9637655 DOI: 10.3389/fendo.2022.984342] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 10/10/2022] [Indexed: 11/20/2022] Open
Abstract
The heart is a highly metabolic organ with extensive energy demands and hence relies on numerous fuel substrates including fatty acids and glucose. However, oxidative stress is a natural by-product of metabolism that, in excess, can contribute towards DNA damage and poly-ADP-ribose polymerase activation. This activation inhibits key glycolytic enzymes, subsequently shunting glycolytic intermediates into non-oxidative glucose pathways such as the hexosamine biosynthetic pathway (HBP). In this review we provide evidence supporting the dual role of the HBP, i.e. playing a unique role in cardiac physiology and pathophysiology where acute upregulation confers cardioprotection while chronic activation contributes to the onset and progression of cardio-metabolic diseases such as diabetes, hypertrophy, ischemic heart disease, and heart failure. Thus although the HBP has emerged as a novel therapeutic target for such conditions, proposed interventions need to be applied in a context- and pathology-specific manner to avoid any potential drawbacks of relatively low cardiac HBP activity.
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Affiliation(s)
- Megan Cairns
- Centre for Cardio-Metabolic Research in Africa, Division of Medical Physiology, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Danzil Joseph
- Centre for Cardio-Metabolic Research in Africa, Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, South Africa
| | - M. Faadiel Essop
- Centre for Cardio-Metabolic Research in Africa, Division of Medical Physiology, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
- *Correspondence: M. Faadiel Essop,
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7
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New Insights into the Development and Morphogenesis of the Cardiac Purkinje Fiber Network: Linking Architecture and Function. J Cardiovasc Dev Dis 2021; 8:jcdd8080095. [PMID: 34436237 PMCID: PMC8397066 DOI: 10.3390/jcdd8080095] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 07/30/2021] [Accepted: 08/03/2021] [Indexed: 12/30/2022] Open
Abstract
The rapid propagation of electrical activity through the ventricular conduction system (VCS) controls spatiotemporal contraction of the ventricles. Cardiac conduction defects or arrhythmias in humans are often associated with mutations in key cardiac transcription factors that have been shown to play important roles in VCS morphogenesis in mice. Understanding of the mechanisms of VCS development is thus crucial to decipher the etiology of conduction disturbances in adults. During embryogenesis, the VCS, consisting of the His bundle, bundle branches, and the distal Purkinje network, originates from two independent progenitor populations in the primary ring and the ventricular trabeculae. Differentiation into fast-conducting cardiomyocytes occurs progressively as ventricles develop to form a unique electrical pathway at late fetal stages. The objectives of this review are to highlight the structure–function relationship between VCS morphogenesis and conduction defects and to discuss recent data on the origin and development of the VCS with a focus on the distal Purkinje fiber network.
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8
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Mantri S, Wu SM, Goodyer WR. Molecular Profiling of the Cardiac Conduction System: the Dawn of a New Era. Curr Cardiol Rep 2021; 23:103. [PMID: 34196831 DOI: 10.1007/s11886-021-01536-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/17/2021] [Indexed: 11/28/2022]
Abstract
PURPOSE OF REVIEW Recent technological advances have led to an increased ability to define the gene expression profile of the cardiac conduction system (CCS). Here, we review the most salient studies to emerge in recent years and discuss existing gaps in our knowledge as well as future areas of investigation. RECENT FINDINGS Molecular profiling of the CCS spans several decades. However, the advent of high-throughput sequencing strategies has allowed for the discovery of unique transcriptional programs of the many diverse CCS cell types. The CCS, a diverse structure with significant inter- and intra-component cellular heterogeneity, is essential to the normal function of the heart. Progress in transcriptomic profiling has improved the resolution and depth of characterization of these unique and clinically relevant CCS cell types. Future studies leveraging this big data will play a crucial role in improving our understanding of CCS development and function as well as translating these findings into tangible translational tools for the improved detection, prevention, and treatment of cardiac arrhythmias.
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Affiliation(s)
- Sruthi Mantri
- Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Sean M Wu
- Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, 94305, USA.,Division of Pediatric Cardiology, Department of Pediatrics, Stanford University, Stanford, CA, 94305, USA.,Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - William R Goodyer
- Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, 94305, USA. .,Division of Pediatric Cardiology, Department of Pediatrics, Stanford University, Stanford, CA, 94305, USA. .,Division of Pediatric Cardiology, Electrophysiology, Department of Pediatrics, Lucile Packard Children's Hospital, Stanford University School of Medicine, Room G1105 Lokey Stem Cell Research Building, 265 Campus Drive, Stanford, CA, 94305, USA.
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9
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Lauschke K, Volpini L, Liu Y, Vinggaard AM, Hall VJ. A Comparative Assessment of Marker Expression Between Cardiomyocyte Differentiation of Human Induced Pluripotent Stem Cells and the Developing Pig Heart. Stem Cells Dev 2021; 30:374-385. [PMID: 33599158 DOI: 10.1089/scd.2020.0184] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The course of differentiation of pluripotent stem cells into cardiomyocytes and the intermediate cell types are characterized using molecular markers for different stages of development. These markers have been selected primarily from studies in the mouse and from a limited number of human studies. However, it is not clear how well mouse cardiogenesis compares with human cardiogenesis at the molecular level. We tackle this issue by analyzing and comparing the expression of common cardiomyogenesis markers [platelet-derived growth factor receptor, alpha polypeptide (PDGFR-α), fetal liver kinase 1 (FLK1), ISL1, NK2 homeobox 5 (NKX2.5), cardiac troponin T (CTNT), connexin43 (CX43), and myosin heavy chain 7 (MYHC-B)] in the developing pig heart at embryonic day (E)15, E16, E18, E20, E22, and E24 and in differentiating cardiomyocytes from human induced pluripotent stem cells (hiPSCs). We found that porcine expression of the mesoderm marker FLK1 and the cardiac progenitor marker ISL1 was in line with our differentiating hiPSC and reported murine expression. The cardiac lineage marker NKX2.5 was expressed at almost all stages in the pig and hiPSC, with an earlier onset in the hiPSC compared with reported murine expression. Markers of immature cardiomyocytes, CTNT, and MYHC-B were consistently expressed throughout E16-E70 in the pig, which is comparable with mouse development, whereas the markers increased over time in the hiPSC. However, the commonly used mature cardiomyocyte marker, CX43, should be used with caution, as it was also expressed in the pig mesoderm, as well as hiPSC immature cardiomyocytes, while this has not been reported in mice. Based on our observations in the various species, we suggest to use FLK1/PDGFR-α for identifying cardiac mesoderm and ISL1/NKX2.5 for cardiac progenitors. Furthermore, a combination of two or more of the following, CTNT+/MYHC-B+/ISL1+ could mark immature cardiomyocytes and CTNT+/ISL1- mature cardiomyocytes. CX43 should be used together with sarcomeric proteins. This knowledge may help improving differentiation of hiPSC into more in vivo-like cardiac tissue in the future.
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Affiliation(s)
- Karin Lauschke
- National Food Institute, Technical University of Denmark, Kongens Lyngby, Denmark.,Department for Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Luca Volpini
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Yong Liu
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Anne Marie Vinggaard
- National Food Institute, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Vanessa Jane Hall
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, Denmark
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10
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Zhao Y, Iyer S, Tavanaei M, Nguyen NT, Lin A, Nguyen TP. Proarrhythmic Electrical Remodeling by Noncardiomyocytes at Interfaces With Cardiomyocytes Under Oxidative Stress. Front Physiol 2021; 11:622613. [PMID: 33603677 PMCID: PMC7884825 DOI: 10.3389/fphys.2020.622613] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 12/17/2020] [Indexed: 12/11/2022] Open
Abstract
Life-threatening ventricular arrhythmias, typically arising from interfaces between fibrosis and surviving cardiomyocytes, are feared sequelae of structurally remodeled hearts under oxidative stress. Incomplete understanding of the proarrhythmic electrical remodeling by fibrosis limits the development of novel antiarrhythmic strategies. To define the mechanistic determinants of the proarrhythmia in electrical crosstalk between cardiomyocytes and noncardiomyocytes, we developed a novel in vitro model of interface between neonatal rat ventricular cardiomyocytes (NRVMs) and controls [NRVMs or connexin43 (Cx43)-deficient HeLa cells] vs. Cx43+ noncardiomyocytes [aged rat ventricular myofibroblasts (ARVFs) or HeLaCx43 cells]. We performed high-speed voltage-sensitive optical imaging at baseline and following acute H2O2 exposure. In NRVM-NRVM and NRVM-HeLa controls, no arrhythmias occurred under either experimental condition. In the NRVM-ARVF and NRVM-HeLaCx43 groups, Cx43+ noncardiomyocytes enabled passive decremental propagation of electrical impulses and impaired NRVM activation and repolarization, thereby slowing conduction and prolonging action potential duration. Following H2O2 exposure, arrhythmia triggers, automaticity, and non-reentrant and reentrant arrhythmias emerged. This study reveals that myofibroblasts (which generate cardiac fibrosis) and other noncardiomyocytes can induce not only structural remodeling but also electrical remodeling and that electrical remodeling by noncardiomyocytes can be particularly arrhythmogenic in the presence of an oxidative burst. Synergistic electrical remodeling between H2O2 and noncardiomyocytes may account for the clinical arrhythmogenicity of myofibroblasts at fibrotic interfaces with cardiomyocytes in ischemic/non-ischemic cardiomyopathies. Understanding the enhanced arrhythmogenicity of synergistic electrical remodeling by H2O2 and noncardiomyocytes may guide novel safe-by-design antiarrhythmic strategies for next-generation iatrogenic interfaces between surviving native cardiomyocytes and exogenous stem cells or engineered tissues in cardiac regenerative therapies.
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Affiliation(s)
- Yali Zhao
- Division of Cardiology, Department of Medicine, The Cardiovascular Research Laboratory, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States
| | - Shankar Iyer
- Division of Cardiology, Department of Medicine, The Cardiovascular Research Laboratory, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States
| | - Maryam Tavanaei
- Division of Cardiology, Department of Medicine, The Cardiovascular Research Laboratory, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States
| | - Nicole T Nguyen
- Division of Cardiology, Department of Medicine, The Cardiovascular Research Laboratory, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States
| | - Andrew Lin
- Division of Cardiology, Department of Medicine, The Cardiovascular Research Laboratory, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States
| | - Thao P Nguyen
- Division of Cardiology, Department of Medicine, The Cardiovascular Research Laboratory, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States
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11
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Xiao S, Shimura D, Baum R, Hernandez DM, Agvanian S, Nagaoka Y, Katsumata M, Lampe PD, Kleber AG, Hong T, Shaw RM. Auxiliary trafficking subunit GJA1-20k protects connexin-43 from degradation and limits ventricular arrhythmias. J Clin Invest 2021; 130:4858-4870. [PMID: 32525845 DOI: 10.1172/jci134682] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 06/03/2020] [Indexed: 12/31/2022] Open
Abstract
Connexin-43 (Cx43) gap junctions provide intercellular coupling, which ensures rapid action potential propagation and synchronized heart contraction. Alterations in Cx43 localization and reductions in gap junction coupling occur in failing hearts, contributing to ventricular arrhythmias and sudden cardiac death. Recent reports have found that an internally translated Cx43 isoform, GJA1-20k, is an auxiliary subunit for the trafficking of Cx43 in heterologous expression systems. Here, we have created a mouse model by using CRISPR technology to mutate a single internal translation initiation site in Cx43 (M213L mutation), which generates full-length Cx43, but not GJA1-20k. We found that GJA1M213L/M213L mice had severely abnormal electrocardiograms despite preserved contractile function, reduced total Cx43, and reduced gap junctions, and they died suddenly at 2 to 4 weeks of age. Heterozygous GJA1M213L/WT mice survived to adulthood with increased ventricular ectopy. Biochemical experiments indicated that cytoplasmic Cx43 had a half-life that was 50% shorter than membrane-associated Cx43. Without GJA1-20k, poorly trafficked Cx43 was degraded. The data support that GJA1-20k, an endogenous entity translated independently of Cx43, is critical for Cx43 gap junction trafficking, maintenance of Cx43 protein, and normal electrical function of the mammalian heart.
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Affiliation(s)
- Shaohua Xiao
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, Utah, USA.,Department of Neurology, UCLA, Los Angeles, California, USA
| | - Daisuke Shimura
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, Utah, USA
| | - Rachel Baum
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, Utah, USA.,Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Diana M Hernandez
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Sosse Agvanian
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Yoshiko Nagaoka
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA.,Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Makoto Katsumata
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Paul D Lampe
- Translational Research Program, Public Health Sciences and Human Biology Divisions, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - Andre G Kleber
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - TingTing Hong
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, Utah, USA.,Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Robin M Shaw
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, Utah, USA
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12
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Boengler K, Rohrbach S, Weissmann N, Schulz R. Importance of Cx43 for Right Ventricular Function. Int J Mol Sci 2021; 22:ijms22030987. [PMID: 33498172 PMCID: PMC7863922 DOI: 10.3390/ijms22030987] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/13/2021] [Accepted: 01/18/2021] [Indexed: 11/16/2022] Open
Abstract
In the heart, connexins form gap junctions, hemichannels, and are also present within mitochondria, with connexin 43 (Cx43) being the most prominent connexin in the ventricles. Whereas the role of Cx43 is well established for the healthy and diseased left ventricle, less is known about the importance of Cx43 for the development of right ventricular (RV) dysfunction. The present article focusses on the importance of Cx43 for the developing heart. Furthermore, we discuss the expression and localization of Cx43 in the diseased RV, i.e., in the tetralogy of Fallot and in pulmonary hypertension, in which the RV is affected, and RV hypertrophy and failure occur. We will also introduce other Cx molecules that are expressed in RV and surrounding tissues and have been reported to be involved in RV pathophysiology. Finally, we highlight therapeutic strategies aiming to improve RV function in pulmonary hypertension that are associated with alterations of Cx43 expression and function.
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13
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Bhattacharyya S, Munshi NV. Development of the Cardiac Conduction System. Cold Spring Harb Perspect Biol 2020; 12:cshperspect.a037408. [PMID: 31988140 DOI: 10.1101/cshperspect.a037408] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The cardiac conduction system initiates and propagates each heartbeat. Specialized conducting cells are a well-conserved phenomenon across vertebrate evolution, although mammalian and avian species harbor specific components unique to organisms with four-chamber hearts. Early histological studies in mammals provided evidence for a dominant pacemaker within the right atrium and clarified the existence of the specialized muscular axis responsible for atrioventricular conduction. Building on these seminal observations, contemporary genetic techniques in a multitude of model organisms has characterized the developmental ontogeny, gene regulatory networks, and functional importance of individual anatomical compartments within the cardiac conduction system. This review describes in detail the transcriptional and regulatory networks that act during cardiac conduction system development and homeostasis with a particular emphasis on networks implicated in human electrical variation by large genome-wide association studies. We conclude with a discussion of the clinical implications of these studies and describe some future directions.
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Affiliation(s)
| | - Nikhil V Munshi
- Department of Internal Medicine, Division of Cardiology.,McDermott Center for Human Growth and Development.,Department of Molecular Biology, UT Southwestern Medical Center, Dallas, Texas 75390, USA.,Hamon Center for Regenerative Science and Medicine, Dallas, Texas 75390, USA
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14
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Nkx2-5 defines distinct scaffold and recruitment phases during formation of the murine cardiac Purkinje fiber network. Nat Commun 2020; 11:5300. [PMID: 33082351 PMCID: PMC7575572 DOI: 10.1038/s41467-020-19150-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 09/29/2020] [Indexed: 01/24/2023] Open
Abstract
The ventricular conduction system coordinates heartbeats by rapid propagation of electrical activity through the Purkinje fiber (PF) network. PFs share common progenitors with contractile cardiomyocytes, yet the mechanisms of segregation and network morphogenesis are poorly understood. Here, we apply genetic fate mapping and temporal clonal analysis to identify murine cardiomyocytes committed to the PF lineage as early as E7.5. We find that a polyclonal PF network emerges by progressive recruitment of conductive precursors to this scaffold from a pool of bipotent progenitors. At late fetal stages, the segregation of conductive cells increases during a phase of rapid recruitment to build the definitive PF network through a non-cell autonomous mechanism. We also show that PF differentiation is impaired in Nkx2-5 haploinsufficient embryos leading to failure to extend the scaffold. In particular, late fetal recruitment fails, resulting in PF hypoplasia and persistence of bipotent progenitors. Our results identify how transcription factor dosage regulates cell fate divergence during distinct phases of PF network morphogenesis. Here, the authors apply genetic fate mapping and temporal clonal analysis to study progenitor recruitment and network morphogenesis of murine cardiac Purkinje fibers. Additionally, they characterize how transcription factor dosage regulates cell fate divergence during distinct phases of this process.
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15
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Maroli G, Braun T. The long and winding road of cardiomyocyte maturation. Cardiovasc Res 2020; 117:712-726. [PMID: 32514522 DOI: 10.1093/cvr/cvaa159] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 05/15/2020] [Accepted: 06/02/2020] [Indexed: 12/13/2022] Open
Abstract
Knowledge about the molecular mechanisms regulating cardiomyocyte (CM) proliferation and differentiation has increased exponentially in recent years. Such insights together with the availability of more efficient protocols for generation of CMs from induced pluripotent stem cells (iPSCs) have raised expectations for new therapeutic strategies to treat congenital and non-congenital heart diseases. However, the poor regenerative potential of the postnatal heart and the incomplete maturation of iPSC-derived CMs represent important bottlenecks for such therapies in future years. CMs undergo dramatic changes at the doorstep between prenatal and postnatal life, including terminal cell cycle withdrawal, change in metabolism, and further specialization of the cellular machinery required for high-performance contraction. Here, we review recent insights into pre- and early postnatal developmental processes that regulate CM maturation, laying specific focus on genetic and metabolic pathways that control transition of CMs from the embryonic and perinatal to the fully mature adult CM state. We recapitulate the intrinsic features of CM maturation and highlight the importance of external factors, such as energy substrate availability and endocrine regulation in shaping postnatal CM development. We also address recent approaches to enhance maturation of iPSC-derived CMs in vitro, and summarize new discoveries that might provide useful tools for translational research on repair of the injured human heart.
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Affiliation(s)
- Giovanni Maroli
- Department of Cardiac Development and Remodeling, Max Planck Institute for Heart and Lung Research, Ludwigstrasse 43, 61231 Bad Nauheim, Germany
| | - Thomas Braun
- Department of Cardiac Development and Remodeling, Max Planck Institute for Heart and Lung Research, Ludwigstrasse 43, 61231 Bad Nauheim, Germany.,German Centre for Cardiovascular Research (DZHK), partner site Rhein-Main, Ludwigstrasse 43, 61231 Bad Nauheim, Germany
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16
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Khan SF, Damerell V, Omar R, Du Toit M, Khan M, Maranyane HM, Mlaza M, Bleloch J, Bellis C, Sahm BDB, Peres J, ArulJothi KN, Prince S. The roles and regulation of TBX3 in development and disease. Gene 2020; 726:144223. [PMID: 31669645 PMCID: PMC7108957 DOI: 10.1016/j.gene.2019.144223] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 10/18/2019] [Accepted: 10/22/2019] [Indexed: 12/18/2022]
Abstract
TBX3, a member of the ancient and evolutionary conserved T-box transcription factor family, is a critical developmental regulator of several structures including the heart, mammary glands, limbs and lungs. Indeed, mutations in the human TBX3 lead to ulnar mammary syndrome which is characterized by several clinical malformations including hypoplasia of the mammary and apocrine glands, defects of the upper limb, areola, dental structures, heart and genitalia. In contrast, TBX3 has no known function in adult tissues but is frequently overexpressed in a wide range of epithelial and mesenchymal derived cancers. This overexpression greatly impacts several hallmarks of cancer including bypass of senescence, apoptosis and anoikis, promotion of proliferation, tumour formation, angiogenesis, invasion and metastatic capabilities as well as cancer stem cell expansion. The debilitating consequences of having too little or too much TBX3 suggest that its expression levels need to be tightly regulated. While we have a reasonable understanding of the mutations that result in low levels of functional TBX3 during development, very little is known about the factors responsible for the overexpression of TBX3 in cancer. Furthermore, given the plethora of oncogenic processes that TBX3 impacts, it must be regulating several target genes but to date only a few have been identified and characterised. Interestingly, while there is compelling evidence to support oncogenic roles for TBX3, a few studies have indicated that it may also have tumour suppressor functions in certain contexts. Together, the diverse functional elasticity of TBX3 in development and cancer is thought to involve, in part, the protein partners that it interacts with and this area of research has recently received some attention. This review provides an insight into the significance of TBX3 in development and cancer and identifies research gaps that need to be explored to shed more light on this transcription factor.
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Affiliation(s)
- Saif F Khan
- Division of Cell Biology, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Observatory, 7925, Cape Town, South Africa
| | - Victoria Damerell
- Division of Cell Biology, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Observatory, 7925, Cape Town, South Africa
| | - Rehana Omar
- Division of Cell Biology, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Observatory, 7925, Cape Town, South Africa
| | - Michelle Du Toit
- Division of Cell Biology, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Observatory, 7925, Cape Town, South Africa
| | - Mohsin Khan
- Division of Cell Biology, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Observatory, 7925, Cape Town, South Africa
| | - Hapiloe Mabaruti Maranyane
- Division of Cell Biology, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Observatory, 7925, Cape Town, South Africa
| | - Mihlali Mlaza
- Division of Cell Biology, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Observatory, 7925, Cape Town, South Africa
| | - Jenna Bleloch
- Division of Cell Biology, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Observatory, 7925, Cape Town, South Africa
| | - Claire Bellis
- Division of Cell Biology, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Observatory, 7925, Cape Town, South Africa
| | - Bianca D B Sahm
- Division of Cell Biology, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Observatory, 7925, Cape Town, South Africa; Department of Pharmacology, Institute of Biomedical Science, University of São Paulo, São Paulo, SP 11030-400, Brazil
| | - Jade Peres
- Division of Cell Biology, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Observatory, 7925, Cape Town, South Africa
| | - K N ArulJothi
- Division of Cell Biology, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Observatory, 7925, Cape Town, South Africa
| | - Sharon Prince
- Division of Cell Biology, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Observatory, 7925, Cape Town, South Africa.
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17
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Wu X, Zhang W, Li Y, Lin X. Structure and Function of Cochlear Gap Junctions and Implications for the Translation of Cochlear Gene Therapies. Front Cell Neurosci 2019; 13:529. [PMID: 31827424 PMCID: PMC6892400 DOI: 10.3389/fncel.2019.00529] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 11/13/2019] [Indexed: 12/23/2022] Open
Abstract
Connexins (Cxs) are ubiquitous membrane proteins that are found throughout vertebrate organs, acting as building blocks of the gap junctions (GJs) known to play vital roles in the normal function of many organs. Mutations in Cx genes (particularly GJB2, which encodes Cx26) cause approximately half of all cases of congenital hearing loss in newborns. Great progress has been made in understanding GJ function and the molecular mechanisms for the role of Cxs in the cochlea. Data reveal that multiple types of Cxs work together to ensure normal development and function of the cochlea. These findings include many aspects not proposed in the classic K+ recycling theory, such as the formation of normal cochlear morphology (e.g., the opening of the tunnel of Corti), the fine-tuning of the innervation of nerve fibers to the hair cells (HCs), the maturation of the ribbon synapses, and the initiation of the endocochlear potential (EP). New data, especially those collected from targeted modification of major Cx genes in the mouse cochlea, have demonstrated that Cx26 plays an essential role in the postnatal maturation of the cochlea. Studies also show that Cx26 and Cx30 assume very different roles in the EP generation, given that only Cx26 is required for normal hearing. This article will review our current understanding of the molecular structure, cellular distribution, and major functions of cochlear GJs. Potential implications of the knowledge of cochlear GJs on the design and implementation of translational studies of cochlear gene therapies for Cx mutations are also discussed.
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Affiliation(s)
- Xuewen Wu
- Department of Otolaryngology, Head-Neck and Surgery, Xiangya Hospital of Central South University, Changsha, China
- Department of Otolaryngology, Emory University School of Medicine, Atlanta, GA, United States
| | - Wenjuan Zhang
- Department of Otolaryngology, Wuhan Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yihui Li
- Department of Pharmacy, Changsha Hospital of Traditional Medicine, Changsha, China
| | - Xi Lin
- Department of Otolaryngology, Emory University School of Medicine, Atlanta, GA, United States
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18
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Ivanova E, Kovacs-Oller T, Sagdullaev BT. Domain-specific distribution of gap junctions defines cellular coupling to establish a vascular relay in the retina. J Comp Neurol 2019; 527:2675-2693. [PMID: 30950036 PMCID: PMC6721971 DOI: 10.1002/cne.24699] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 04/02/2019] [Accepted: 04/02/2019] [Indexed: 12/22/2022]
Abstract
In the retina, diverse functions of neuronal gap junctions (GJs) have been established. However, the distribution and function of vascular GJs are less clear. Here in the mouse retina whole mounts, we combined structural immunohistochemical analysis and a functional assessment of cellular coupling with a GJ-permeable tracer Neurobiotin to determine distribution patterns of three major vascular connexins. We found that Cx43 was expressed in punctate fashion on astroglia, surrounding all types of blood vessels and in continuous string-like structures along endothelial cell contacts in specialized regions of the vascular tree. Specifically, these Cx43-positive strings originated at the finest capillaries and extended toward the feeding artery. As this structural arrangement promoted strong and exclusive coupling of pericytes and endothelial cells along the corresponding branch, we termed this region a "vascular relay." Cx40 expression was found predominantly along the endothelial cell contacts of the primary arteries and did not overlap with Cx43-positive strings. At their occupied territories, Cx43 and Cx40 clustered with tight junctions and, to a lesser extent, with adhesion contacts, both key elements of the blood-retina barrier. Finally, Cx37 puncta were associated with the entire surface of both mural and endothelial cells across all regions of the vascular tree. This combinatorial analysis of vascular connexins and identification of the vascular relay region will serve as a structural foundation for future studies of neurovascular signaling in health and disease.
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Affiliation(s)
- Elena Ivanova
- Burke Neurological Institute, Department of Ophthalmology, Weill Cornell Medicine, White Plains, New York
| | - Tamas Kovacs-Oller
- Burke Neurological Institute, Department of Ophthalmology, Weill Cornell Medicine, White Plains, New York
| | - Botir T Sagdullaev
- Burke Neurological Institute, Department of Ophthalmology, Weill Cornell Medicine, White Plains, New York
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19
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Rotenone and 3-bromopyruvate toxicity impacts electrical and structural cardiac remodeling in rats. Toxicol Lett 2019; 318:57-64. [PMID: 31585160 DOI: 10.1016/j.toxlet.2019.09.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 09/06/2019] [Accepted: 09/29/2019] [Indexed: 12/14/2022]
Abstract
3-Bromopyruvate (3-BrPA) is a promising agent that has been widely studied in the treatment of cancer and pulmonary hypertension. Rotenone is a pesticide commonly used on farms and was shown to have anti-cancer activity and delay fibrosis progression in chronic kidney disease in a recent study. However, there are few studies showing the toxicity of rotenone and 3-BrPA in the myocardium. To support further medical exploration, it is necessary to clarify the side effects of these compounds on the heart. This study was designed to examine the cardiotoxicity of 3-BrPA and rotenone by investigating electrical and structural cardiac remodeling in rats. Forty male rats were divided into 4 groups (n = 10 in each group) and injected intraperitoneally with 3-BrPA, rotenone or a combination of 3-BrPA and rotenone. The ventricular effective refractory period (VERP), corrected QT interval (QTc), and ventricular tachycardia/ventricular fibrillation (VT/VF) inducibility were measured. The expression of Cx43, Kir2.1, Kir6.2, DHPRα1, KCNH2, caspase3, caspase9, Bax, Bcl2, and P53 was detected. Masson's trichrome, TUNEL, HE, and PAS staining and transmission electron microscopy were used to detect pathological and ultrastructural changes. Our results showed that rotenone alone and rotenone combined with 3-BrPA significantly increased the risk of ventricular arrhythmias. Rotenone combined with 3-BrPA caused myocardial apoptosis, and rotenone alone and rotenone combined with 3-BrPA caused electrical and structural cardiac remodeling in rats.
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20
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Mroß C, Marko M, Munck M, Glöckner G, Motameny S, Altmüller J, Noegel AA, Eichinger L, Peche VS, Neumann S. Depletion of Nesprin-2 is associated with an embryonic lethal phenotype in mice. Nucleus 2019; 9:503-515. [PMID: 30220251 PMCID: PMC6244730 DOI: 10.1080/19491034.2018.1523664] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Nesprin-2 is a nuclear envelope component and provides a link between cytoskeletal components of the cytoplasm and the nucleoplasm. Several isoforms are generated from its gene Syne2. Loss of the largest isoform Nesprin-2 Giant in mice is associated with a skin phenotype and altered wound healing, loss of C-terminal isoforms in mice leads to cardiomyopathies and neurological defects. Here we attempted to establish mice with an inducible knockout of all Nesprin-2 isoforms by inserting shRNA encoding sequences targeting the N- and C-terminus into the ROSA26 locus of mice. This caused early embryonic death of the animals harboring the mutant allele, which was presumably due to leaky expression of the shRNAs. Mutant embryos were only observed before E13. They had an altered appearance and were smaller in size than their wild type littermates. From this we conclude that the Nesprin-2 gene function is crucial during embryonic growth, differentiation and organogenesis.
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Affiliation(s)
- Carmen Mroß
- a Institute of Biochemistry I, Medical Faculty , University Hospital Cologne; Center for Molecular Medicine Cologne (CMMC) and Cologne Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) , Koeln , Germany
| | - Marija Marko
- a Institute of Biochemistry I, Medical Faculty , University Hospital Cologne; Center for Molecular Medicine Cologne (CMMC) and Cologne Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) , Koeln , Germany
| | - Martina Munck
- a Institute of Biochemistry I, Medical Faculty , University Hospital Cologne; Center for Molecular Medicine Cologne (CMMC) and Cologne Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) , Koeln , Germany
| | - Gernot Glöckner
- a Institute of Biochemistry I, Medical Faculty , University Hospital Cologne; Center for Molecular Medicine Cologne (CMMC) and Cologne Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) , Koeln , Germany
| | - Susanne Motameny
- b Cologne Center for Genomics (CCG) , University of Cologne , Koeln , Germany
| | - Janine Altmüller
- b Cologne Center for Genomics (CCG) , University of Cologne , Koeln , Germany
| | - Angelika A Noegel
- a Institute of Biochemistry I, Medical Faculty , University Hospital Cologne; Center for Molecular Medicine Cologne (CMMC) and Cologne Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) , Koeln , Germany
| | - Ludwig Eichinger
- a Institute of Biochemistry I, Medical Faculty , University Hospital Cologne; Center for Molecular Medicine Cologne (CMMC) and Cologne Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) , Koeln , Germany
| | - Vivek S Peche
- a Institute of Biochemistry I, Medical Faculty , University Hospital Cologne; Center for Molecular Medicine Cologne (CMMC) and Cologne Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) , Koeln , Germany
| | - Sascha Neumann
- a Institute of Biochemistry I, Medical Faculty , University Hospital Cologne; Center for Molecular Medicine Cologne (CMMC) and Cologne Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) , Koeln , Germany
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21
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Abstract
The rate and rhythm of heart muscle contractions are coordinated by the cardiac conduction system (CCS), a generic term for a collection of different specialized muscular tissues within the heart. The CCS components initiate the electrical impulse at the sinoatrial node, propagate it from atria to ventricles via the atrioventricular node and bundle branches, and distribute it to the ventricular muscle mass via the Purkinje fibre network. The CCS thereby controls the rate and rhythm of alternating contractions of the atria and ventricles. CCS function is well conserved across vertebrates from fish to mammals, although particular specialized aspects of CCS function are found only in endotherms (mammals and birds). The development and homeostasis of the CCS involves transcriptional and regulatory networks that act in an embryonic-stage-dependent, tissue-dependent, and dose-dependent manner. This Review describes emerging data from animal studies, stem cell models, and genome-wide association studies that have provided novel insights into the transcriptional networks underlying CCS formation and function. How these insights can be applied to develop disease models and therapies is also discussed.
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22
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Goodyer W, Wu SM. Fates Aligned: Origins and Mechanisms of Ventricular Conduction System and Ventricular Wall Development. Pediatr Cardiol 2018; 39:1090-1098. [PMID: 29594502 PMCID: PMC6093793 DOI: 10.1007/s00246-018-1869-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 03/14/2018] [Indexed: 12/19/2022]
Abstract
The cardiac conduction system is a network of distinct cell types necessary for the coordinated contraction of the cardiac chambers. The distal portion, known as the ventricular conduction system, allows for the rapid transmission of impulses from the atrio-ventricular node to the ventricular myocardium and plays a central role in cardiac function as well as disease when perturbed. Notably, its patterning during embryogenesis is intimately linked to that of ventricular wall formation, including trabeculation and compaction. Here, we review our current understanding of the underlying mechanisms responsible for the development and maturation of these interdependent processes.
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Affiliation(s)
- William Goodyer
- Cardiovascular Institute, Stanford University, Stanford, CA 94305, USA,Division of Pediatric Cardiology, Department of Pediatrics, Lucille Packard Children’s Hospital, Stanford, CA 94305, USA
| | - Sean M. Wu
- Cardiovascular Institute, Stanford University, Stanford, CA 94305, USA,Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA,Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA,Correspondence: Sean M. Wu, M.D. PhD., Lokey Stem Cell Building, Room G1120A, 265 Campus Drive, Stanford, CA 94305, Phone No. 650-724-4498, Fax No. 650-726-4689,
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23
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Fang JS, Coon BG, Gillis N, Chen Z, Qiu J, Chittenden TW, Burt JM, Schwartz MA, Hirschi KK. Shear-induced Notch-Cx37-p27 axis arrests endothelial cell cycle to enable arterial specification. Nat Commun 2017; 8:2149. [PMID: 29247167 PMCID: PMC5732288 DOI: 10.1038/s41467-017-01742-7] [Citation(s) in RCA: 159] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 10/13/2017] [Indexed: 01/26/2023] Open
Abstract
Establishment of a functional vascular network is rate-limiting in embryonic development, tissue repair and engineering. During blood vessel formation, newly generated endothelial cells rapidly expand into primitive plexi that undergo vascular remodeling into circulatory networks, requiring coordinated growth inhibition and arterial-venous specification. Whether the mechanisms controlling endothelial cell cycle arrest and acquisition of specialized phenotypes are interdependent is unknown. Here we demonstrate that fluid shear stress, at arterial flow magnitudes, maximally activates NOTCH signaling, which upregulates GJA4 (commonly, Cx37) and downstream cell cycle inhibitor CDKN1B (p27). Blockade of any of these steps causes hyperproliferation and loss of arterial specification. Re-expression of GJA4 or CDKN1B, or chemical cell cycle inhibition, restores endothelial growth control and arterial gene expression. Thus, we elucidate a mechanochemical pathway in which arterial shear activates a NOTCH-GJA4-CDKN1B axis that promotes endothelial cell cycle arrest to enable arterial gene expression. These insights will guide vascular regeneration and engineering.
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Affiliation(s)
- Jennifer S Fang
- Department of Medicine, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA
- Yale Cardiovascular Research Center, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA
- Vascular Biology and Therapeutics Program, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA
- Yale Stem Cell Center, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA
| | - Brian G Coon
- Department of Medicine, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA
- Yale Cardiovascular Research Center, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA
- Vascular Biology and Therapeutics Program, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA
| | - Noelle Gillis
- Department of Medicine, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA
- Yale Cardiovascular Research Center, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA
- Vascular Biology and Therapeutics Program, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA
- Yale Stem Cell Center, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA
| | - Zehua Chen
- Computational Statistics and Bioinformatics Group, Advanced Artificial Intelligence Research Laboratory, WuXi NextCODE 55 Cambridge Parkway, 8th Floor, Cambridge, MA, 02142, USA
| | - Jingyao Qiu
- Department of Medicine, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA
- Yale Cardiovascular Research Center, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA
- Vascular Biology and Therapeutics Program, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA
- Yale Stem Cell Center, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA
- Department of Genetics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA
| | - Thomas W Chittenden
- Computational Statistics and Bioinformatics Group, Advanced Artificial Intelligence Research Laboratory, WuXi NextCODE 55 Cambridge Parkway, 8th Floor, Cambridge, MA, 02142, USA
- Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, A-111, 25 Shattuck Street, Boston, MA, 02115, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, 21 Ames Street #56-651, Cambridge, MA, 02142, USA
| | - Janis M Burt
- Department of Physiology, College of Medicine, The University of Arizona, 1501 N. Campbell Road, Tucson, AZ, 85724, USA
| | - Martin A Schwartz
- Department of Medicine, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA
- Yale Cardiovascular Research Center, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA
- Vascular Biology and Therapeutics Program, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA
- Department of Cell Biology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA
- Department of Biomedical Engineering, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA
| | - Karen K Hirschi
- Department of Medicine, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA.
- Yale Cardiovascular Research Center, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA.
- Vascular Biology and Therapeutics Program, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA.
- Yale Stem Cell Center, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA.
- Department of Genetics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA.
- Department of Biomedical Engineering, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA.
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Meng T, Cheng G, Wei Y, Ma S, Jiang Y, Wu J, Zhou X, Sun C. Exposure to a chronic high-fat diet promotes atrial structure and gap junction remodeling in rats. Int J Mol Med 2017; 40:217-225. [DOI: 10.3892/ijmm.2017.2982] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2016] [Accepted: 05/05/2017] [Indexed: 11/05/2022] Open
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25
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Crist AM, Young C, Meadows SM. Characterization of arteriovenous identity in the developing neonate mouse retina. Gene Expr Patterns 2017; 23-24:22-31. [PMID: 28167138 DOI: 10.1016/j.gep.2017.01.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Revised: 12/14/2016] [Accepted: 01/31/2017] [Indexed: 12/26/2022]
Abstract
The murine retina has become an ideal model to study blood vessel formation. Blood vessels in the retina undergo various processes, including remodeling and differentiation, to form a stereotypical network that consists of precisely patterned arteries and veins. This model presents a powerful tool for understanding many different aspects of angiogenesis including artery and vein (AV) cell fate acquisition and differentiation. However, characterization of AV differentiation has been largely unexplored in the mouse retinal model. In this study, we describe the expression of previously established AV markers and assess arteriovenous acquisition and identity in the murine neonatal retina. Using in situ hybridization and immunofluorescent antibody staining techniques, we analyzed numerous AV differentiation markers such as EphB4-EphrinB2 and members of the Notch pathway. We find that at postnatal day 3 (P3), when blood vessels are beginning to populate the retina, AV identity is not immediately established. However, by P5 expression of many molecular identifiers of arteries and veins become restricted to their respective vessel types. This molecular distinction is more obvious at P7 and remains unchanged through P9. Overall, these studies indicate that, similar to the embryo, acquisition of AV identity occurs in a step-wise process and is largely established by P7 during retina development.
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Affiliation(s)
- Angela M Crist
- Department of Cell and Molecular Biology, Tulane University, USA
| | - Chandler Young
- Department of Cell and Molecular Biology, Tulane University, USA
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26
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Abstract
TBX5 is a member of the T-box transcription factor family and is primarily known for its role in cardiac and forelimb development. Human patients with dominant mutations in TBX5 are characterized by Holt-Oram syndrome, and show defects of the cardiac septa, cardiac conduction system, and the anterior forelimb. The range of cardiac defects associated with TBX5 mutations in humans suggests multiple roles for the transcription factor in cardiac development and function. Animal models demonstrate similar defects and have provided a useful platform for investigating the roles of TBX5 during embryonic development. During early cardiac development, TBX5 appears to act primarily as a transcriptional activator of genes associated with cardiomyocyte maturation and upstream of morphological signals for septation. During later cardiac development, TBX5 is required for patterning of the cardiac conduction system and maintenance of mature cardiomyocyte function. A comprehensive understanding of the integral roles of TBX5 throughout cardiac development and adult life will be critical for understanding human cardiac morphology and function.
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Affiliation(s)
- J D Steimle
- University of Chicago, Chicago, IL, United States
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27
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Ahir BK, Pratten MK. The impact of caffeine on connexin expression in the embryonic chick cardiomyocyte micromass culture system. J Appl Toxicol 2016; 36:903-13. [PMID: 26304238 DOI: 10.1002/jat.3219] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2014] [Revised: 07/03/2015] [Accepted: 07/06/2015] [Indexed: 12/19/2022]
Abstract
Cardiomyocytes are electrically coupled by gap junctions, defined as clusters of low-resistance multisubunit transmembrane channels composed of connexins (Cxs). The expression of Cx40, Cx43 and Cx45, which are present in cardiomyocytes, is known to be developmentally regulated. This study investigates the premise that alterations in gap junction proteins are one of the mechanisms by which teratogens may act. Specifically, those molecules known to be teratogenic in humans could cause their effects via disruption of cell-to-cell communication pathways, resulting in an inability to co-ordinate tissue development. Caffeine significantly inhibited contractile activity at concentrations above and including 1500 μm (P < 0.05), while not affecting cell viability and total protein, in the embryonic chick cardiomyocyte micromass culture system. The effects of caffeine on key cardiac gap junction protein (Cx40, Cx43 and Cx45) expression were analysed using immunocytochemistry and in-cell Western blotting. The results indicated that caffeine altered the expression pattern of Cx40, Cx43 and Cx45 at non-cytotoxic concentrations (≥2000 μm), i.e., at concentrations that did not affect total cell protein and cell viability. In addition the effects of caffeine on cardiomyocyte formation and function (contractile activity score) were correlated with modulation of Cxs (Cx40, Cx43 and Cx45) expression, at above and including 2000 μm caffeine concentrations (P < 0.05). These experiments provide evidence that embryonic chick cardiomyocyte micromass culture may be a useful in vitro method for mechanistic studies of perturbation of embryonic heart development. Copyright © 2015 John Wiley & Sons, Ltd.
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Affiliation(s)
- Bhavesh K Ahir
- National Center for Computational Toxicology (B205-01), US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Margaret K Pratten
- School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham, UK
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28
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Nishii K, Seki A, Kumai M, Morimoto S, Miwa T, Hagiwara N, Shibata Y, Kobayashi Y. Connexin45 contributes to global cardiovascular development by establishing myocardial impulse propagation. Mech Dev 2016; 140:41-52. [DOI: 10.1016/j.mod.2016.02.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Revised: 02/19/2016] [Accepted: 02/20/2016] [Indexed: 11/15/2022]
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29
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Zafir A, Bradley JA, Long BW, Muthusamy S, Li Q, Hill BG, Wysoczynski M, Prabhu SD, Bhatnagar A, Bolli R, Jones SP. O-GlcNAcylation Negatively Regulates Cardiomyogenic Fate in Adult Mouse Cardiac Mesenchymal Stromal Cells. PLoS One 2015; 10:e0142939. [PMID: 26565625 PMCID: PMC4643874 DOI: 10.1371/journal.pone.0142939] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 10/28/2015] [Indexed: 11/25/2022] Open
Abstract
In both preclinical and clinical studies, cell transplantation of several cell types is used to promote repair of damaged organs and tissues. Nevertheless, despite the widespread use of such strategies, there remains little understanding of how the efficacy of cell therapy is regulated. We showed previously that augmentation of a unique, metabolically derived stress signal (i.e., O-GlcNAc) improves survival of cardiac mesenchymal stromal cells; however, it is not known whether enhancing O-GlcNAcylation affects lineage commitment or other aspects of cell competency. In this study, we assessed the role of O-GlcNAc in differentiation of cardiac mesenchymal stromal cells. Exposure of these cells to routine differentiation protocols in culture increased markers of the cardiomyogenic lineage such as Nkx2.5 and connexin 40, and augmented the abundance of transcripts associated with endothelial and fibroblast cell fates. Differentiation significantly decreased the abundance of O-GlcNAcylated proteins. To determine if O-GlcNAc is involved in stromal cell differentiation, O-GlcNAcylation was increased pharmacologically during the differentiation protocol. Although elevated O-GlcNAc levels did not significantly affect fibroblast and endothelial marker expression, acquisition of cardiomyocyte markers was limited. In addition, increasing O-GlcNAcylation further elevated smooth muscle actin expression. In addition to lineage commitment, we also evaluated proliferation and migration, and found that increasing O-GlcNAcylation did not significantly affect either; however, we found that O-GlcNAc transferase--the protein responsible for adding O-GlcNAc to proteins--is at least partially required for maintaining cellular proliferative and migratory capacities. We conclude that O-GlcNAcylation contributes significantly to cardiac mesenchymal stromal cell lineage and function. O-GlcNAcylation and pathological conditions that may affect O-GlcNAc levels (such as diabetes) should be considered carefully in the context of cardiac cell therapy.
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Affiliation(s)
- Ayesha Zafir
- Institute of Molecular Cardiology; Diabetes and Obesity Center, Department of Medicine, Division of Cardiovascular Medicine, University of Louisville, Louisville, Kentucky, United States of America
| | - James A. Bradley
- Institute of Molecular Cardiology; Diabetes and Obesity Center, Department of Medicine, Division of Cardiovascular Medicine, University of Louisville, Louisville, Kentucky, United States of America
| | - Bethany W. Long
- Institute of Molecular Cardiology; Diabetes and Obesity Center, Department of Medicine, Division of Cardiovascular Medicine, University of Louisville, Louisville, Kentucky, United States of America
| | - Senthilkumar Muthusamy
- Institute of Molecular Cardiology; Diabetes and Obesity Center, Department of Medicine, Division of Cardiovascular Medicine, University of Louisville, Louisville, Kentucky, United States of America
| | - Qianhong Li
- Institute of Molecular Cardiology; Diabetes and Obesity Center, Department of Medicine, Division of Cardiovascular Medicine, University of Louisville, Louisville, Kentucky, United States of America
| | - Bradford G. Hill
- Institute of Molecular Cardiology; Diabetes and Obesity Center, Department of Medicine, Division of Cardiovascular Medicine, University of Louisville, Louisville, Kentucky, United States of America
| | - Marcin Wysoczynski
- Institute of Molecular Cardiology; Diabetes and Obesity Center, Department of Medicine, Division of Cardiovascular Medicine, University of Louisville, Louisville, Kentucky, United States of America
| | - Sumanth D. Prabhu
- Institute of Molecular Cardiology; Diabetes and Obesity Center, Department of Medicine, Division of Cardiovascular Medicine, University of Louisville, Louisville, Kentucky, United States of America
| | - Aruni Bhatnagar
- Institute of Molecular Cardiology; Diabetes and Obesity Center, Department of Medicine, Division of Cardiovascular Medicine, University of Louisville, Louisville, Kentucky, United States of America
| | - Roberto Bolli
- Institute of Molecular Cardiology; Diabetes and Obesity Center, Department of Medicine, Division of Cardiovascular Medicine, University of Louisville, Louisville, Kentucky, United States of America
| | - Steven P. Jones
- Institute of Molecular Cardiology; Diabetes and Obesity Center, Department of Medicine, Division of Cardiovascular Medicine, University of Louisville, Louisville, Kentucky, United States of America
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30
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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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31
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Barbuti A, Robinson RB. Stem Cell–Derived Nodal-Like Cardiomyocytes as a Novel Pharmacologic Tool: Insights from Sinoatrial Node Development and Function. Pharmacol Rev 2015; 67:368-88. [DOI: 10.1124/pr.114.009597] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
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32
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Meilhac SM, Lescroart F, Blanpain C, Buckingham ME. Cardiac cell lineages that form the heart. Cold Spring Harb Perspect Med 2014; 4:a013888. [PMID: 25183852 DOI: 10.1101/cshperspect.a013888] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Myocardial cells ensure the contractility of the heart, which also depends on other mesodermal cell types for its function. Embryological experiments had identified the sources of cardiac precursor cells. With the advent of genetic engineering, novel tools have been used to reconstruct the lineage tree of cardiac cells that contribute to different parts of the heart, map the development of cardiac regions, and characterize their genetic signature. Such knowledge is of fundamental importance for our understanding of cardiogenesis and also for the diagnosis and treatment of heart malformations.
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Affiliation(s)
- Sigolène M Meilhac
- Institut Pasteur, Department of Developmental and Stem Cell Biology, CNRS URA2578, 75015 Paris, France
| | | | - Cédric Blanpain
- Université Libre de Bruxelles, IRIBHM, Brussels B-1070, Belgium WELBIO, Université Libre de Bruxelles, Brussels B-1070, Belgium
| | - Margaret E Buckingham
- Institut Pasteur, Department of Developmental and Stem Cell Biology, CNRS URA2578, 75015 Paris, France
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33
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Clowes C, Boylan MGS, Ridge LA, Barnes E, Wright JA, Hentges KE. The functional diversity of essential genes required for mammalian cardiac development. Genesis 2014; 52:713-37. [PMID: 24866031 PMCID: PMC4141749 DOI: 10.1002/dvg.22794] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 05/22/2014] [Accepted: 05/23/2014] [Indexed: 01/04/2023]
Abstract
Genes required for an organism to develop to maturity (for which no other gene can compensate) are considered essential. The continuing functional annotation of the mouse genome has enabled the identification of many essential genes required for specific developmental processes including cardiac development. Patterns are now emerging regarding the functional nature of genes required at specific points throughout gestation. Essential genes required for development beyond cardiac progenitor cell migration and induction include a small and functionally homogenous group encoding transcription factors, ligands and receptors. Actions of core cardiogenic transcription factors from the Gata, Nkx, Mef, Hand, and Tbx families trigger a marked expansion in the functional diversity of essential genes from midgestation onwards. As the embryo grows in size and complexity, genes required to maintain a functional heartbeat and to provide muscular strength and regulate blood flow are well represented. These essential genes regulate further specialization and polarization of cell types along with proliferative, migratory, adhesive, contractile, and structural processes. The identification of patterns regarding the functional nature of essential genes across numerous developmental systems may aid prediction of further essential genes and those important to development and/or progression of disease. genesis 52:713–737, 2014.
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Affiliation(s)
- Christopher Clowes
- Faculty of Life Sciences, University of Manchester, Michael Smith Building, Oxford Road, Manchester, United Kingdom
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34
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Benes J, Ammirabile G, Sankova B, Campione M, Krejci E, Kvasilova A, Sedmera D. The role of connexin40 in developing atrial conduction. FEBS Lett 2014; 588:1465-9. [PMID: 24486905 DOI: 10.1016/j.febslet.2014.01.032] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2013] [Revised: 01/22/2014] [Accepted: 01/22/2014] [Indexed: 11/28/2022]
Abstract
Connexin40 (Cx40) is the main connexin expressed in the murine atria and ventricular conduction system. We assess here the developmental role of Cx40 in atrial conduction of the mouse. Cx40 deficiency significantly prolonged activation times in embryonic day 10.5, 12.5 and 14.5 atria during spontaneous activation; the severity decreased with increasing age. In a majority of Cx40 deficient mice the impulse originated from an ectopic focus in the right atrial appendage; in such a case the activation time was even longer due to prolonged activation. Cx40 has thus an important physiological role in the developing atria.
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Affiliation(s)
- Jiri Benes
- Department of Cardiovascular Morphogenesis, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic; Charles University in Prague, First Faculty of Medicine, Institute of Anatomy, U Nemocnice 3, Prague, Czech Republic; Charles University in Prague, First Faculty of Medicine, Department of Radiology of the First Faculty of Medicine and General Teaching Hospital, U Nemocnice 2, Prague, Czech Republic.
| | - Grazia Ammirabile
- CNR Institute of Neurosciences, Department of Biomedical Sciences, University of Padova, Viale G. Colombo 3, Padova 35121, Italy
| | - Barbora Sankova
- Department of Cardiovascular Morphogenesis, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic; Charles University in Prague, First Faculty of Medicine, Institute of Anatomy, U Nemocnice 3, Prague, Czech Republic
| | - Marina Campione
- CNR Institute of Neurosciences, Department of Biomedical Sciences, University of Padova, Viale G. Colombo 3, Padova 35121, Italy
| | - Eliska Krejci
- Department of Cardiovascular Morphogenesis, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic; Charles University in Prague, First Faculty of Medicine, Institute of Anatomy, U Nemocnice 3, Prague, Czech Republic
| | - Alena Kvasilova
- Charles University in Prague, First Faculty of Medicine, Institute of Anatomy, U Nemocnice 3, Prague, Czech Republic
| | - David Sedmera
- Department of Cardiovascular Morphogenesis, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic; Charles University in Prague, First Faculty of Medicine, Institute of Anatomy, U Nemocnice 3, Prague, Czech Republic
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35
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van den Boogaard M, Smemo S, Burnicka-Turek O, Arnolds DE, van de Werken HJG, Klous P, McKean D, Muehlschlegel JD, Moosmann J, Toka O, Yang XH, Koopmann TT, Adriaens ME, Bezzina CR, de Laat W, Seidman C, Seidman JG, Christoffels VM, Nobrega MA, Barnett P, Moskowitz IP. A common genetic variant within SCN10A modulates cardiac SCN5A expression. J Clin Invest 2014; 124:1844-52. [PMID: 24642470 DOI: 10.1172/jci73140] [Citation(s) in RCA: 136] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Accepted: 01/09/2014] [Indexed: 12/19/2022] Open
Abstract
Variants in SCN10A, which encodes a voltage-gated sodium channel, are associated with alterations of cardiac conduction parameters and the cardiac rhythm disorder Brugada syndrome; however, it is unclear how SCN10A variants promote dysfunctional cardiac conduction. Here we showed by high-resolution 4C-seq analysis of the Scn10a-Scn5a locus in murine heart tissue that a cardiac enhancer located in Scn10a, encompassing SCN10A functional variant rs6801957, interacts with the promoter of Scn5a, a sodium channel-encoding gene that is critical for cardiac conduction. We observed that SCN5A transcript levels were several orders of magnitude higher than SCN10A transcript levels in both adult human and mouse heart tissue. Analysis of BAC transgenic mouse strains harboring an engineered deletion of the enhancer within Scn10a revealed that the enhancer was essential for Scn5a expression in cardiac tissue. Furthermore, the common SCN10A variant rs6801957 modulated Scn5a expression in the heart. In humans, the SCN10A variant rs6801957, which correlated with slowed conduction, was associated with reduced SCN5A expression. These observations establish a genomic mechanism for how a common genetic variation at SCN10A influences cardiac physiology and predisposes to arrhythmia.
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36
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Jamsheer A, Sowińska-Seidler A, Socha M, Stembalska A, Kiraly-Borri C, Latos-Bieleńska A. Three novel GJA1 missense substitutions resulting in oculo-dento-digital dysplasia (ODDD) - further extension of the mutational spectrum. Gene 2014; 539:157-61. [PMID: 24508941 DOI: 10.1016/j.gene.2014.01.066] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Revised: 01/26/2014] [Accepted: 01/29/2014] [Indexed: 11/30/2022]
Abstract
Oculodentodigital dysplasia (ODDD) is a clinically variable genetic disorder caused by mutations of the GJA1 gene, predominantly inherited in an autosomal dominant fashion. In rare cases ODDD can also exhibit autosomal recessive mode of inheritance. The phenotype of ODDD comprises craniofacial (short and narrow palpebral fissure, thin, narrow nose with hypoplastic alae nasi), dental (oligodontia, hypoplastic enamel), and digital abnormalities (syndactyly of finger 4/5, hypoplastic phalanges). Ocular manifestation is typical and involves microphthalmia, microcornea, glaucoma, congenital malformations of iris or vitreous, ectopic pupils or strabismus. To date, only 67 GJA1 mutations have been described to underlie ODDD and most of them (i.e. 97%) represent missense substitutions. In this report, we describe three (two familial and one sporadic) non-consanguineous cases presenting with ODDD features in whom we identified novel missense heterozygous mutations of the GJA1 gene: c.317T>G (p. L106R), c.G139C (p.D47H), and c.C257A (p.S86Y). The first two mutations were inherited from an affected parent, whereas the latter one occurred de novo. The mutations affect highly conserved amino acid residues located in the different portions of the GJA1 protein. Our report broadens the spectrum of probably pathogenic mutations associated with ODDD phenotype and demonstrates that the amino acid substitutions at highly conserved positions 47, 86, 106 may affect protein functioning and lead to the development of this syndrome. Together with molecular data, we provide a brief clinical description of the affected individuals.
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Affiliation(s)
- Aleksander Jamsheer
- Department of Medical Genetics, Poznan University of Medical Sciences, Poznan, Poland; NZOZ Center for Medical Genetics GENESIS, Poznan, Poland.
| | - Anna Sowińska-Seidler
- Department of Medical Genetics, Poznan University of Medical Sciences, Poznan, Poland
| | - Magdalena Socha
- Department of Medical Genetics, Poznan University of Medical Sciences, Poznan, Poland
| | | | - Cathy Kiraly-Borri
- Genetic Services of Western Australia, King Edward Memorial Hospital for Women, Subiaco, Australia
| | - Anna Latos-Bieleńska
- Department of Medical Genetics, Poznan University of Medical Sciences, Poznan, Poland; NZOZ Center for Medical Genetics GENESIS, Poznan, Poland
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37
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Reyskens KMSE, Essop MF. HIV protease inhibitors and onset of cardiovascular diseases: a central role for oxidative stress and dysregulation of the ubiquitin-proteasome system. Biochim Biophys Acta Mol Basis Dis 2013; 1842:256-68. [PMID: 24275553 DOI: 10.1016/j.bbadis.2013.11.019] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Revised: 11/09/2013] [Accepted: 11/18/2013] [Indexed: 12/18/2022]
Abstract
The successful roll-out of highly active antiretroviral therapy (HAART) has extended life expectancy and enhanced the overall well-being of HIV-positive individuals. There are, however, increased concerns regarding HAART-mediated metabolic derangements and its potential risk for cardiovascular diseases (CVD) in the long-term. Here certain classes of antiretroviral drugs such as the HIV protease inhibitors (PIs) are strongly implicated in this process. This article largely focuses on the direct PI-linked development of cardio-metabolic complications, and reviews the inter-linked roles of oxidative stress and the ubiquitin-proteasome system (UPS) as key mediators driving this process. It is proposed that PIs trigger reactive oxygen species (ROS) production that leads to serious downstream consequences such as cell death, impaired mitochondrial function, and UPS dysregulation. Moreover, we advocate that HIV PIs may also directly lower myocardial UPS function. The attenuation of cardiac UPS can initiate transcriptional changes that contribute to perturbed lipid metabolism, thereby fueling a pro-atherogenic milieu. It may also directly alter ionic channels and interfere with electrical signaling in the myocardium. Therefore HIV PI-induced ROS together with a dysfunctional UPS elicit detrimental effects on the cardiovascular system that will eventually result in the onset of heart diseases. Thus while HIV PIs substantially improve life expectancy and quality of life in HIV-positive patients, its longer-term side-effects on the cardiovascular system should lead to a) greater clinical awareness regarding its benefit-harm paradigm, and b) the development and evaluation of novel co-treatment strategies.
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Affiliation(s)
- Kathleen M S E Reyskens
- Cardio-Metabolic Research Group (CMRG), Department of Physiological Sciences, Stellenbosch University, Stellenbosch 7600, South Africa
| | - M Faadiel Essop
- Cardio-Metabolic Research Group (CMRG), Department of Physiological Sciences, Stellenbosch University, Stellenbosch 7600, South Africa.
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38
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Dai X, Jiang W, Zhang Q, Xu L, Geng P, Zhuang S, Petrich BG, Jiang C, Peng L, Bhattacharya S, Evans SM, Sun Y, Chen J, Liang X. Requirement for integrin-linked kinase in neural crest migration and differentiation and outflow tract morphogenesis. BMC Biol 2013; 11:107. [PMID: 24131868 PMCID: PMC3906977 DOI: 10.1186/1741-7007-11-107] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Accepted: 10/07/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Neural crest defects lead to congenital heart disease involving outflow tract malformation. Integrin-linked-kinase (ILK) plays important roles in multiple cellular processes and embryogenesis. ILK is expressed in the neural crest, but its role in neural crest and outflow tract morphogenesis remains unknown. RESULTS We ablated ILK specifically in the neural crest using the Wnt1-Cre transgene. ILK ablation resulted in abnormal migration and overpopulation of neural crest cells in the pharyngeal arches and outflow tract and a significant reduction in the expression of neural cell adhesion molecule (NCAM) and extracellular matrix components. ILK mutant embryos exhibited an enlarged common arterial trunk and ventricular septal defect. Reduced smooth muscle differentiation, but increased ossification and neurogenesis/innervation were observed in ILK mutant outflow tract that may partly be due to reduced transforming growth factor β2 (TGFβ2) but increased bone morphogenetic protein (BMP) signaling. Consistent with these observations, microarray analysis of fluorescence-activated cell sorting (FACS)-sorted neural crest cells revealed reduced expression of genes associated with muscle differentiation, but increased expression of genes of neurogenesis and osteogenesis. CONCLUSIONS Our results demonstrate that ILK plays essential roles in neural crest and outflow tract development by mediating complex crosstalk between cell matrix and multiple signaling pathways. Changes in these pathways may collectively result in the unique neural crest and outflow tract phenotypes observed in ILK mutants.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | - Yunfu Sun
- Key Laboratory of Arrhythmia, Ministry of Education, East Hospital, Tongji University School of Medicine, 150 Jimo Road, Shanghai 200120, China.
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39
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Abstract
The establishment and maintenance of the vascular system is critical for embryonic development and postnatal life. Defects in endothelial cell development and vessel formation and function lead to embryonic lethality and are important in the pathogenesis of vascular diseases. Here, we review the underlying molecular mechanisms of endothelial cell differentiation, plasticity, and the development of the vasculature. This review focuses on the interplay among transcription factors and signaling molecules that specify the differentiation of vascular endothelial cells. We also discuss recent progress on reprogramming of somatic cells toward distinct endothelial cell lineages and its promise in regenerative vascular medicine.
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Affiliation(s)
- Changwon Park
- Department of Pharmacology, Center for Lung and Vascular Biology, The University of Illinois College of Medicine, Chicago, IL 60612, USA
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40
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Verheule S, Kaese S. Connexin diversity in the heart: insights from transgenic mouse models. Front Pharmacol 2013; 4:81. [PMID: 23818881 PMCID: PMC3694209 DOI: 10.3389/fphar.2013.00081] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Accepted: 06/04/2013] [Indexed: 11/13/2022] Open
Abstract
Cardiac conduction is mediated by gap junction channels that are formed by connexin (Cx) protein subunits. The connexin family of proteins consists of more than 20 members varying in their biophysical properties and ability to combine with other connexins into heteromeric gap junction channels. The mammalian heart shows regional differences both in connexin expression profile and in degree of electrical coupling. The latter reflects functional requirements for conduction velocity which needs to be low in the sinoatrial and atrioventricular nodes and high in the ventricular conduction system. Over the past 20 years knowledge of the biology of gap junction channels and their role in the genesis of cardiac arrhythmias has increased enormously. This review focuses on the insights gained from transgenic mouse models. The mouse heart expresses Cx30, 30.2, 37, 40, 43, 45, and 46. For these connexins a variety of knock-outs, heart-specific knock-outs, conditional knock-outs, double knock-outs, knock-ins and overexpressors has been studied. We discuss the cardiac phenotype in these models and compare Cx expression between mice and men. Mouse models have enhanced our understanding of (patho)-physiological implications of Cx diversity in the heart. In principle connexin-specific modulation of electrical coupling in the heart represents an interesting treatment strategy for cardiac arrhythmias and conduction disorders.
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Affiliation(s)
- Sander Verheule
- Department of Physiology, Faculty of Medicine, Maastricht University Maastricht, Netherlands
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41
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Salameh A, Blanke K, Daehnert I. Role of connexins in human congenital heart disease: the chicken and egg problem. Front Pharmacol 2013; 4:70. [PMID: 23760510 PMCID: PMC3669755 DOI: 10.3389/fphar.2013.00070] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Accepted: 05/15/2013] [Indexed: 01/15/2023] Open
Abstract
Inborn cardiac diseases are among the most frequent congenital anomalies and are the main cause of death in infants within the first year of age in industrialized countries when not adequately treated. They can be divided into simple and complex cardiac malformations. The former ones, for instance atrial and ventricular septal defects, valvular or subvalvular stenosis or insufficiency account for up to 80% of cardiac abnormalities. The latter ones, for example transposition of the great vessels, Tetralogy of Fallot or Shone’s anomaly often do not involve only the heart, but also the great vessels and although occurring less frequently, these severe cardiac malformations will become symptomatic within the first months of age and have a high risk of mortality if the patients remain untreated. In the last decade, there is increasing evidence that cardiac gap junction proteins, the connexins (Cx), might have an impact on cardiac anomalies. In the heart, mainly three of them (Cx40, Cx43, and Cx45) are differentially expressed with regard to temporal organogenesis and to their spatial distribution in the heart. These proteins, forming gap junction channels, are most important for a normal electrical conduction and coordinated synchronous heart muscle contraction and also for the normal embryonic development of the heart. Animal and also some human studies revealed that at least in some cardiac malformations alterations in certain gap junction proteins are present but until today no particular gap junction mutation could be assigned to a specific cardiac anomaly. As gap junctions have often been supposed to transmit growth and differentiation signals from cell to cell it is reasonable to assume that they are somehow involved in misdirected growth present in many inborn heart diseases playing a primary or contributory role. This review addresses the potentional role of gap junctions in the development of inborn heart anomalies like the conotruncal heart defects.
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Affiliation(s)
- Aida Salameh
- Clinic for Pediatric Cardiology, Heart Centre, University of Leipzig Leipzig, Germany
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42
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Seidl S, Braun U, Roos N, Li S, Lüdtke THW, Kispert A, Leitges M. Phenotypical analysis of atypical PKCs in vivo function display a compensatory system at mouse embryonic day 7.5. PLoS One 2013; 8:e62756. [PMID: 23690951 PMCID: PMC3653893 DOI: 10.1371/journal.pone.0062756] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Accepted: 03/25/2013] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND The atypical protein kinases C (PKC) isoforms ι/λ and ζ play crucial roles in many cellular processes including development, cell proliferation, differentiation and cell survival. Possible redundancy between the two isoforms has always been an issue since most biochemical tools do not differentiate between the two proteins. Thus, much effort has been made during the last decades to characterize the functions of aPKCs using gene targeting approaches and depletion studies. However, little is known about the specific roles of each isoform in mouse development. METHODOLOGY/PRINCIPAL FINDINGS To evaluate the importance of PKCι in mouse development we designed PKCι deletion mutants using the gene targeting approach. We show that the deletion of PKCι, results in a reduced size of the amniotic cavity at E7.5 and impaired growth of the embryo at E8.5 with subsequent absorption of the embryo. Our data also indicate an impaired localization of ZO-1 and disorganized structure of the epithelial tissue in the embryo. Importantly, using electron microscopy, embryoid body formation and immunofluorescence analysis, we found, that in the absence of PKCι, tight junctions and apico-basal polarity were still established. Finally, our study points to a non-redundant PKCι function at E9.5, since expression of PKCζ is able to rescue the E7.5 phenotype, but could not prevent embryonic lethality at a later time-point (E9.5). CONCLUSION Our data show that PKCι is crucial for mouse embryogenesis but is dispensable for the establishment of polarity and tight junction formation. We present a compensatory function of PKCζ at E7.5, rescuing the phenotype. Furthermore, this study indicates at least one specific, yet unknown, PKCι function that cannot be compensated by the overexpression of PKCζ at E9.5.
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Affiliation(s)
- Sebastian Seidl
- The Biotechnology Centre of Oslo, University of Oslo, Oslo, Norway
| | - Ursula Braun
- The Biotechnology Centre of Oslo, University of Oslo, Oslo, Norway
| | - Norbert Roos
- Department of Molecular Biosciences, University of Oslo, Oslo, Norway
| | - Shaohua Li
- Department of Surgery, University of Medicine and Dentistry of New Jersey–Robert Wood Johnson Medical School, New Brunswick, New Jersey, United States of America
| | - Timo H.-W. Lüdtke
- Institute for Molecular Biology, Medizinische Hochschule Hannover, Hannover, Germany
| | - Andreas Kispert
- Institute for Molecular Biology, Medizinische Hochschule Hannover, Hannover, Germany
| | - Michael Leitges
- The Biotechnology Centre of Oslo, University of Oslo, Oslo, Norway
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43
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Baker C, Taylor DG, Osuala K, Natarajan A, Molnar PJ, Hickman J, Alam S, Moscato B, Weinshenker D, Ebert SN. Adrenergic deficiency leads to impaired electrical conduction and increased arrhythmic potential in the embryonic mouse heart. Biochem Biophys Res Commun 2012; 423:536-41. [PMID: 22683331 DOI: 10.1016/j.bbrc.2012.05.163] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Accepted: 05/31/2012] [Indexed: 11/30/2022]
Abstract
To determine if adrenergic hormones play a critical role in the functional development of the cardiac pacemaking and conduction system, we employed a mouse model where adrenergic hormone production was blocked due to targeted disruption of the dopamine β-hydroxylase (Dbh) gene. Immunofluorescent histochemical evaluation of the major gap junction protein, connexin 43, revealed that its expression was substantially decreased in adrenergic-deficient (Dbh-/-) relative to adrenergic-competent (Dbh+/+ and Dbh+/-) mouse hearts at embryonic day 10.5 (E10.5), whereas pacemaker and structural protein staining appeared similar. To evaluate cardiac electrical conduction in these hearts, we cultured them on microelectrode arrays (8×8, 200 μm apart). Our results show a significant slowing of atrioventricular conduction in adrenergic-deficient hearts compared to controls (31.4±6.4 vs. 15.4±1.7 ms, respectively, p<0.05). To determine if the absence of adrenergic hormones affected heart rate and rhythm, mouse hearts from adrenergic-competent and deficient embryos were cultured ex vivo at E10.5, and heart rates were measured before and after challenge with the β-adrenergic receptor agonist, isoproterenol (0.5 μM). On average, all hearts showed increased heart rate responses following isoproterenol challenge, but a significant (p<0.05) 225% increase in the arrhythmic index (AI) was observed only in adrenergic-deficient hearts. These results show that adrenergic hormones may influence heart development by stimulating connexin 43 expression, facilitating atrioventricular conduction, and helping to maintain cardiac rhythm during a critical phase of embryonic development.
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Affiliation(s)
- Candice Baker
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, 6900 Lake Nona Blvd, Orlando, FL 32827, USA
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44
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Gemel J, Nelson TK, Burt JM, Beyer EC. Inducible coexpression of connexin37 or connexin40 with connexin43 selectively affects intercellular molecular transfer. J Membr Biol 2012; 245:231-41. [PMID: 22729648 PMCID: PMC3501935 DOI: 10.1007/s00232-012-9444-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Accepted: 06/01/2012] [Indexed: 12/17/2022]
Abstract
Many tissues express multiple gap junction proteins, or connexins (Cx); for example, Cx43, Cx40, and Cx37 are coexpressed in vascular cells. This study was undertaken to elucidate the consequences of coexpression of Cx40 or Cx37 with Cx43 at different ratios. EcR-293 cells (which endogenously produce Cx43) were transfected with ecdysone-inducible plasmids encoding Cx37 or Cx40. Immmunoblotting showed a ponasterone dose-dependent induction of Cx37 or Cx40 while constant levels of Cx43 were maintained. The coexpressed connexins colocalized at appositional membranes. Double whole-cell patch clamp recordings showed no significant change in total junctional conductances in cells treated with 0, 0.5, or 4 μM ponasterone; however, they did show a diversity of unitary channel sizes consistent with the induced connexin expression. In cells with induced expression of either Cx40 or Cx37, intercellular transfer of microinjected Lucifer yellow was reduced, but transfer of NBD-TMA (2-(4-nitro-2,1,3-benzoxadiol-7-yl)[aminoethyl]trimethylammonium) was not affected. In cocultures containing uninduced EcR cells together with cells induced to coexpress Cx37 or Cx40, Lucifer yellow transfer was observed only between the cells expressing Cx43 alone. These data show that induced expression of either Cx37 or Cx40 in Cx43-expressing cells can selectively alter the intercellular exchange of some molecules without affecting the transfer of others.
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Affiliation(s)
- Joanna Gemel
- Department of Pediatrics, University of Chicago, Chicago, IL, USA
| | - Tasha K. Nelson
- Department of Physiology, University of Arizona, Tucson, AZ, USA
| | - Janis M. Burt
- Department of Physiology, University of Arizona, Tucson, AZ, USA
| | - Eric C. Beyer
- Department of Pediatrics, University of Chicago, Chicago, IL, USA
- Section of Pediatric Hematology/Oncology, University of Chicago, 900 E 57th St., KCBD 5152, Chicago, IL 60637, USA
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45
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Ye J, Boyle A, Shih H, Sievers RE, Zhang Y, Prasad M, Su H, Zhou Y, Grossman W, Bernstein HS, Yeghiazarians Y. Sca-1+ cardiosphere-derived cells are enriched for Isl1-expressing cardiac precursors and improve cardiac function after myocardial injury. PLoS One 2012; 7:e30329. [PMID: 22272337 PMCID: PMC3260268 DOI: 10.1371/journal.pone.0030329] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2011] [Accepted: 12/13/2011] [Indexed: 12/28/2022] Open
Abstract
Background Endogenous cardiac progenitor cells are a promising option for cell-therapy for myocardial infarction (MI). However, obtaining adequate numbers of cardiac progenitors after MI remains a challenge. Cardiospheres (CSs) have been proposed to have cardiac regenerative properties; however, their cellular composition and how they may be influenced by the tissue milieu remains unclear. Methodology/Principal Finding Using “middle aged” mice as CSs donors, we found that acute MI induced a dramatic increase in the number of CSs in a mouse model of MI, and this increase was attenuated back to baseline over time. We also observed that CSs from post-MI hearts engrafted in ischemic myocardium induced angiogenesis and restored cardiac function. To determine the role of Sca-1+CD45- cells within CSs, we cloned these from single cell isolates. Expression of Islet-1 (Isl1) in Sca-1+CD45- cells from CSs was 3-fold higher than in whole CSs. Cloned Sca-1+CD45- cells had the ability to differentiate into cardiomyocytes, endothelial cells and smooth muscle cells in vitro. We also observed that cloned cells engrafted in ischemic myocardium induced angiogenesis, differentiated into endothelial and smooth muscle cells and improved cardiac function in post-MI hearts. Conclusions/Significance These studies demonstrate that cloned Sca-1+CD45- cells derived from CSs from infarcted “middle aged” hearts are enriched for second heart field (i.e., Isl-1+) precursors that give rise to both myocardial and vascular tissues, and may be an appropriate source of progenitor cells for autologous cell-therapy post-MI.
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Affiliation(s)
- Jianqin Ye
- Division of Cardiology, Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Andrew Boyle
- Division of Cardiology, Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, San Francisco, California, United States of America
| | - Henry Shih
- Division of Cardiology, Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Richard E. Sievers
- Division of Cardiology, Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Yan Zhang
- Division of Cardiology, Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Megha Prasad
- Division of Cardiology, Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Hua Su
- Department of Anesthesia and Perioperative Care, University of California San Francisco, San Francisco, California, United States of America
| | - Yan Zhou
- Department of Cell and Tissue Biology, University of California San Francisco, San Francisco, California, United States of America
| | - William Grossman
- Division of Cardiology, Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, California, United States of America
| | - Harold S. Bernstein
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, California, United States of America
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, San Francisco, California, United States of America
- Department of Pediatrics, University of California San Francisco, San Francisco, California, United States of America
| | - Yerem Yeghiazarians
- Division of Cardiology, Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, San Francisco, California, United States of America
- * E-mail:
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46
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Iroquois homeobox gene 3 establishes fast conduction in the cardiac His-Purkinje network. Proc Natl Acad Sci U S A 2011; 108:13576-81. [PMID: 21825130 DOI: 10.1073/pnas.1106911108] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Rapid electrical conduction in the His-Purkinje system tightly controls spatiotemporal activation of the ventricles. Although recent work has shed much light on the regulation of early specification and morphogenesis of the His-Purkinje system, less is known about how transcriptional regulation establishes impulse conduction properties of the constituent cells. Here we show that Iroquois homeobox gene 3 (Irx3) is critical for efficient conduction in this specialized tissue by antithetically regulating two gap junction-forming connexins (Cxs). Loss of Irx3 resulted in disruption of the rapid coordinated spread of ventricular excitation, reduced levels of Cx40, and ectopic Cx43 expression in the proximal bundle branches. Irx3 directly represses Cx43 transcription and indirectly activates Cx40 transcription. Our results reveal a critical role for Irx3 in the precise regulation of intercellular gap junction coupling and impulse propagation in the heart.
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47
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Fontes MSC, van Veen TAB, de Bakker JMT, van Rijen HVM. Functional consequences of abnormal Cx43 expression in the heart. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2011; 1818:2020-9. [PMID: 21839722 DOI: 10.1016/j.bbamem.2011.07.039] [Citation(s) in RCA: 110] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Revised: 07/23/2011] [Accepted: 07/28/2011] [Indexed: 11/26/2022]
Abstract
The major gap junction protein expressed in the heart, connexin43 (Cx43), is highly remodeled in the diseased heart. Usually, Cx43 is down-regulated and heterogeneously redistributed to the lateral sides of cardiomyocytes. Reverse remodeling of the impaired Cx43 expression could restore normal cardiac function and normalize electrical stability. In this review, the reduced and heterogeneous Cx43 expression in the heart will be addressed in hypertrophic, dilated and ischemic cardiomyopathy together with its functional consequences of conduction velocity slowing, dispersed impulse conduction, its interaction with fibrosis and propensity to generate arrhythmias. Finally, different therapies are discussed. Treatments aimed to improve the Cx43 expression levels show new potentially anti-arrhythmic therapies during heart failure, but those in the context of acute ischemia can be anti-arrhythmogenic at the cost of larger infarct sizes. This article is part of a Special Issue entitled: The Communicating junctions, composition, structure and characteristics.
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Affiliation(s)
- Magda S C Fontes
- Department of Medical Physiology, University Medical Center, Utrecht, The Netherlands
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48
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Hahurij ND, Kolditz DP, Bökenkamp R, Markwald RR, Schalij MJ, Poelmann RE, Gittenberger-De Groot AC, Blom NA. Accessory atrioventricular myocardial pathways in mouse heart development: substrate for supraventricular tachycardias. Pediatr Res 2011; 70:37-43. [PMID: 21399557 DOI: 10.1203/pdr.0b013e3182192bfa] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Atrioventricular reentry tachycardia (AVRT) requiring an accessory atrioventricular pathway (AP) is the most common type of arrhythmia in the perinatal period. The etiology of these arrhythmias is not fully understood as well as their capability to dissipate spontaneously in the first year of life. Temporary presence of APs during annulus fibrosus development might cause this specific type of arrhythmias. To study the presence of APs, electrophysiological recordings of ventricular activation patterns and immunohistochemical analyses with antibodies specifically against atrial myosin light chain 2 (MLC-2a), Periostin, Nkx2.5, and Connexin-43 were performed in embryonic mouse hearts ranging from 11.5 to 18.5 days post-conception (dpc). The electrophysiological recordings revealed the presence of functional APs in early (13.5-15.5 dpc) and late (16.5-18.5 dpc) postseptated stages of mouse heart development. These APs stained positive for MLC-2a and Nkx2.5 and negative for Periostin and Connexin-43. Longitudinal analyses showed that APs gradually decreased in number (p = 0.003) and size (p = 0.035) at subsequent developmental stages (13.5-18.5 dpc). Expression of periostin was observed in the developing annulus fibrosus, adjacent to APs and other locations where formation of fibrous tissue is essential. We conclude that functional APs are present during normal mouse heart development. These APs can serve as transient substrate for AVRTs in the perinatal period of development.
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Affiliation(s)
- Nathan D Hahurij
- Department of Pediatric Cardiology, Leiden University Medical Center, Leiden, 2300 RC, The Netherlands
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49
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Lozano-Velasco E, Chinchilla A, Martínez-Fernández S, Hernández-Torres F, Navarro F, Lyons GE, Franco D, Aránega AE. Pitx2c modulates cardiac-specific transcription factors networks in differentiating cardiomyocytes from murine embryonic stem cells. Cells Tissues Organs 2011; 194:349-62. [PMID: 21389672 DOI: 10.1159/000323533] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/13/2010] [Indexed: 02/02/2023] Open
Abstract
AIM The knowledge of the molecular signals that control cell differentiation into cardiomyocytes is critical to apply cell-based therapies and repair an injured heart. The transcription factor Pitx2 has essential roles in the development of different organs including the heart. Although a direct role of Pitx2 in the developing myocardium has recently been reported, the molecular pathways driven by Pitx2 as well as its cardiac target genes remain largely unexplored. The aim of this study was to unravel the molecular mechanisms driven by Pitx2 during the process of cardiomyocyte differentiation in vitro in mouse embryonic stem cell-derived cardiomyocytes. METHODS AND RESULTS Pitx2c was overexpressed in the R1-embryonic stem cell line. mRNA levels and protein distribution of several specific cardiac genes were analyzed by real-time PCR and immunohistochemistry experiments in R1-embryonic stem cell-derived beating areas at different stages of in vitro differentiation. Our results show that overexpression of Pitx2c in embryonic stem cell-derived cardiomyocytes is able to dynamically upregulate several cardiac-enriched transcription factors such as Isl1, Mef2c and Gata4. Additionally, Pitx2c induces the expression of chamber-specific cardiac genes such as Tbx5, Nppa and Cx40. These data were validated in an in vivo model of Pitx2 loss of function. CONCLUSION Taken together, these results demonstrate that Pitx2 plays a major role reinforcing the transcriptional program of cardiac differentiation.
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50
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Miquerol L, Beyer S, Kelly RG. Establishment of the mouse ventricular conduction system. Cardiovasc Res 2011; 91:232-42. [DOI: 10.1093/cvr/cvr069] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
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