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Weng LC, Khurshid S, Hall AW, Nauffal V, Morrill VN, Sun YV, Rämö JT, Beer D, Lee S, Nadkarni G, Johnson R, Andreasen L, Clayton A, Pullinger CR, Yoneda ZT, Friedman DJ, Hyman MC, Judy RL, Skanes AC, Orland KM, Jordà P, Treu TM, Oetjens MT, Subbiah R, Hartmann JP, May HT, Kane JP, Issa TZ, Nafissi NA, Leong-Sit P, Dubé MP, Roselli C, Choi SH, Tardif JC, Khan HR, Knight S, Svendsen JH, Walker B, Linnér RK, Gaziano JM, Tadros R, Fatkin D, Rader DJ, Shah SH, Roden DM, Marcus GM, Loos RJ, Damrauer SM, Haggerty CM, Cho K, Palotie A, Olesen MS, Eckhardt LL, Roberts JD, Cutler MJ, Shoemaker MB, Wilson PW, Ellinor PT, Lubitz SA. Meta-Analysis of Genome-Wide Association Studies Reveals Genetic Mechanisms of Supraventricular Arrhythmias. CIRCULATION. GENOMIC AND PRECISION MEDICINE 2024; 17:e004320. [PMID: 38804128 PMCID: PMC11187659 DOI: 10.1161/circgen.123.004320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 03/31/2024] [Indexed: 05/29/2024]
Abstract
BACKGROUND Substantial data support a heritable basis for supraventricular tachycardias, but the genetic determinants and molecular mechanisms of these arrhythmias are poorly understood. We sought to identify genetic loci associated with atrioventricular nodal reentrant tachycardia (AVNRT) and atrioventricular accessory pathways or atrioventricular reciprocating tachycardia (AVAPs/AVRT). METHODS We performed multiancestry meta-analyses of genome-wide association studies to identify genetic loci for AVNRT (4 studies) and AVAP/AVRT (7 studies). We assessed evidence supporting the potential causal effects of candidate genes by analyzing relations between associated variants and cardiac gene expression, performing transcriptome-wide analyses, and examining prior genome-wide association studies. RESULTS Analyses comprised 2384 AVNRT cases and 106 489 referents, and 2811 AVAP/AVRT cases and 1,483 093 referents. We identified 2 significant loci for AVNRT, which implicate NKX2-5 and TTN as disease susceptibility genes. A transcriptome-wide association analysis supported an association between reduced predicted cardiac expression of NKX2-5 and AVNRT. We identified 3 significant loci for AVAP/AVRT, which implicate SCN5A, SCN10A, and TTN/CCDC141. Variant associations at several loci have been previously reported for cardiac phenotypes, including atrial fibrillation, stroke, Brugada syndrome, and electrocardiographic intervals. CONCLUSIONS Our findings highlight gene regions associated with ion channel function (AVAP/AVRT), as well as cardiac development and the sarcomere (AVAP/AVRT and AVNRT) as important potential effectors of supraventricular tachycardia susceptibility.
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Affiliation(s)
- Lu-Chen Weng
- Cardiovascular Rsrch Ctr, Dept of Medicine, Dept of Neurology & Dept of Psychiatry, MGH, Boston
- Cardiovascular Disease Initiative, The Broad Institute of MIT & Harvard, Cambridge
- VA Boston Healthcare System
| | - Shaan Khurshid
- Cardiovascular Disease Initiative, The Broad Institute of MIT & Harvard, Cambridge
- Demoulas Ctr for Cardiac Arrhythmias, Dept of Medicine, Dept of Neurology & Dept of Psychiatry, MGH, Boston
| | - Amelia Weber Hall
- Gene Regulation Observatory, The Broad Institute of MIT & Harvard, Cambridge
| | - Victor Nauffal
- Cardiovascular Disease Initiative, The Broad Institute of MIT & Harvard, Cambridge
- VA Boston Healthcare System
- Cardiovascular Medicine Division, Brigham and Women’s Hospital, Boston, MA
| | - Valerie N. Morrill
- Cardiovascular Disease Initiative, The Broad Institute of MIT & Harvard, Cambridge
| | - Yan V. Sun
- Dept of Epidemiology, Emory Univ Rollins School of Public Health, Atlanta
- VA Atlanta Healthcare System, Decatur, GA
| | - Joel T. Rämö
- Inst for Molecular Medicine Finland (FIMM), Helsinki Inst of Life Science (HiLIFE), Univ of Helsinki, Helsinki, Finland
- The Broad Inst of MIT & Harvard, Cambridge, MA
| | | | - Simon Lee
- Icahn School of Medicine at Mount Sinai, New York, NY
| | | | - Renee Johnson
- Victor Chang Cardiac Rsrch Inst, Darlinghurst
- School of Clinical Medicine, Faculty of Medicine & Health, UNSW Sydney, Kensington, NSW, Australia
| | - Laura Andreasen
- Laboratory for Molecular Cardiology, Dept of Cardiology, Copenhagen Univ Hospital, Rigshospitalet
- Dept of Biomedical Sciences, Univ of Copenhagen, Copenhagen, Denmark
| | - Anne Clayton
- Intermountain Heart Inst, Intermountain Medical Ctr, Murray, UT
| | - Clive R. Pullinger
- Cardiovascular Rsrch Inst & Dept of Physiological Nursing, Univ of California, San Francisco, CA
| | - Zachary T. Yoneda
- Dept of Medicine, Division of Cardiovascular Medicine, Vanderbilt Univ Medical Ctr, Nashville, TN
| | - Daniel J. Friedman
- Division of Cardiology, Dept of Medicine, Duke Univ School of Medicine, Durham, NC
| | - Matthew C. Hyman
- Division of Cardiac Electrophysiology, Hospital of the Univ of Pennsylvania
| | - Renae L. Judy
- Dept of Surgery, Perelman School of Medicine, Univ of Pennsylvania, Philadelphia, PA
| | - Allan C. Skanes
- Section of Cardiac Electrophysiology, Division of Cardiology, Dept of Medicine, Western Univ, London, ON, Canada
| | - Kate M. Orland
- Dept of Medicine, Division of Cardiovascular Medicine, Univ of Wisconsin–Madison, Madison, WI
| | - Paloma Jordà
- Montreal Heart Inst Rsrch Ctr & Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | | | | | - Rajesh Subbiah
- Victor Chang Cardiac Rsrch Inst, Darlinghurst
- School of Clinical Medicine, Faculty of Medicine & Health, UNSW Sydney, Kensington, NSW, Australia
- St Vincent’s Hospital, Darlinghurst
| | - Jacob P. Hartmann
- Laboratory for Molecular Cardiology, Dept of Cardiology, Copenhagen Univ Hospital, Rigshospitalet
| | - Heidi T. May
- Intermountain Heart Inst, Intermountain Medical Ctr, Murray, UT
| | - John P. Kane
- Cardiovascular Rsrch Inst, Univ of California, San Francisco, CA
- Dept of Medicine, Univ of California, San Francisco, CA
- Dept of Biochemistry & Biophysics, Univ of California, San Francisco, CA
| | - Tariq Z. Issa
- Feinberg School of Medicine, Northwestern Univ, Chicago, IL
| | - Navid A. Nafissi
- Division of Cardiology, Dept of Medicine, Duke Univ School of Medicine, Durham, NC
| | - Peter Leong-Sit
- Section of Cardiac Electrophysiology, Division of Cardiology, Dept of Medicine, Western Univ, London, ON, Canada
| | - Marie-Pierre Dubé
- Montreal Heart Inst Rsrch Ctr & Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
- Beaulieu-Saucier Pharmacogenomics Ctr, Montreal, Canada
| | - Carolina Roselli
- Cardiovascular Disease Initiative, The Broad Institute of MIT & Harvard, Cambridge
- Dept of Cardiology, Univ of Groningen, University Medical Ctr Groningen, the Netherlands
| | - Seung Hoan Choi
- Cardiovascular Disease Initiative, The Broad Institute of MIT & Harvard, Cambridge
| | | | | | | | - Jean-Claude Tardif
- Montreal Heart Inst Rsrch Ctr & Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Habib R. Khan
- Section of Cardiac Electrophysiology, Division of Cardiology, Dept of Medicine, Western Univ, London, ON, Canada
| | - Stacey Knight
- Intermountain Heart Inst, Intermountain Medical Ctr, Murray, UT
- Dept of Medicine, Univ of Utah, Salt Lake City, UT
| | - Jesper H. Svendsen
- Laboratory for Molecular Cardiology, Dept of Cardiology, Copenhagen Univ Hospital, Rigshospitalet
- Dept of Clinical Medicine, Univ of Copenhagen, Copenhagen, Denmark
| | - Bruce Walker
- School of Clinical Medicine, Faculty of Medicine & Health, UNSW Sydney, Kensington, NSW, Australia
- St Vincent’s Hospital, Darlinghurst
| | - Richard Karlsson Linnér
- Autism & Developmental Medicine Inst, Geisinger, Lewisburg, PA
- Dept of Economics, Leiden Law School, Leiden Univ, Leiden, the Netherlands
| | - J. Michael Gaziano
- VA Boston Healthcare System
- Cardiovascular Medicine Division, Brigham and Women’s Hospital, Boston, MA
- Harvard Medical School, Boston, MA
| | - Rafik Tadros
- Montreal Heart Inst Rsrch Ctr & Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Diane Fatkin
- Victor Chang Cardiac Rsrch Inst, Darlinghurst
- School of Clinical Medicine, Faculty of Medicine & Health, UNSW Sydney, Kensington, NSW, Australia
- St Vincent’s Hospital, Darlinghurst
| | - Daniel J. Rader
- Division of Cardiovascular Medicine, Dept of Medicine, Perelman School of Medicine, Univ of Pennsylvania, Philadelphia, PA
| | - Svati H. Shah
- Division of Cardiology, Dept of Medicine, Duke Univ School of Medicine, Durham, NC
- Duke Molecular Physiology Inst, Duke Univ School of Medicine, Durham, NC
| | | | | | - Ruth J.F. Loos
- Charles Bronfman Institute for Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, NY & Novo Nordisk Foundation Ctr for Basic Metabolic Rsrch, Dept of Health & Medical Sciences, Univ of Copenhagen, Copenhagen, Denmark
| | - Scott M. Damrauer
- Dept of Surgery & Dept of Genetics, Perelman School of Medicine, Univ of Pennsylvania, Philadelphia, PA
- Corporal Michael Crescenz VA Medical Ctr, Philadelphia
| | - Christopher M. Haggerty
- Heart Inst, Geisinger, Danville, PA
- Dept of Translational Data Science & Informatics, Geisinger, Danville, PA
| | - Kelly Cho
- VA Boston Healthcare System
- Cardiovascular Medicine Division, Brigham and Women’s Hospital, Boston, MA
| | - Aarno Palotie
- Inst for Molecular Medicine Finland (FIMM), Helsinki Inst of Life Science (HiLIFE), Univ of Helsinki, Helsinki, Finland
- The Stanley Center for Psychiatric Rsrch & Program in Medical & Population Genetics, The Broad Institute of MIT & Harvard, Cambridge
- Analytic & Translational Genetics Unit, Dept of Medicine, Dept of Neurology & Dept of Psychiatry, MGH, Boston
| | - Morten S. Olesen
- Laboratory for Molecular Cardiology, Dept of Cardiology, Copenhagen Univ Hospital, Rigshospitalet
- Dept of Biomedical Sciences, Univ of Copenhagen, Copenhagen, Denmark
| | - Lee L. Eckhardt
- Dept of Medicine, Division of Cardiovascular Medicine, Univ of Wisconsin–Madison, Madison, WI
| | - Jason D. Roberts
- Section of Cardiac Electrophysiology, Division of Cardiology, Dept of Medicine, Western Univ, London, ON, Canada
| | | | - M. Benjamin Shoemaker
- Dept of Medicine, Division of Cardiovascular Medicine, Vanderbilt Univ Medical Ctr, Nashville, TN
| | - Peter W.F. Wilson
- VA Atlanta Healthcare System, Decatur, GA
- Dept of Medicine, Emory Univ School of Medicine, Atlanta, GA
| | - Patrick T. Ellinor
- Cardiovascular Disease Initiative, The Broad Institute of MIT & Harvard, Cambridge
- Demoulas Ctr for Cardiac Arrhythmias, Dept of Medicine, Dept of Neurology & Dept of Psychiatry, MGH, Boston
| | - Steven A. Lubitz
- Cardiovascular Disease Initiative, The Broad Institute of MIT & Harvard, Cambridge
- Demoulas Ctr for Cardiac Arrhythmias, Dept of Medicine, Dept of Neurology & Dept of Psychiatry, MGH, Boston
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Targeting parvalbumin promotes M2 macrophage polarization and energy expenditure in mice. Nat Commun 2022; 13:3301. [PMID: 35676256 PMCID: PMC9177846 DOI: 10.1038/s41467-022-30757-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 05/17/2022] [Indexed: 11/08/2022] Open
Abstract
Exercise benefits M2 macrophage polarization, energy homeostasis and protects against obesity partially through exercise-induced circulating factors. Here, by unbiased quantitative proteomics on serum samples from sedentary and exercised mice, we identify parvalbumin as a circulating factor suppressed by exercise. Parvalbumin functions as a non-competitive CSF1R antagonist to inhibit M2 macrophage activation and energy expenditure in adipose tissue. More importantly, serum concentrations of parvalbumin positively correlate with obesity in mouse and human, while treating mice with a recombinant parvalbumin blocker prevents its interaction with CSF1R and promotes M2 macrophage polarization and ameliorates diet-induced obesity. Thus, although further studies are required to assess the significance of parvalbumin in mediating the effects of exercise, our results implicate parvalbumin as a potential therapeutic strategy against obesity in mice.
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Cheng Z, Fang T, Huang J, Guo Y, Alam M, Qian H. Hypertrophic Cardiomyopathy: From Phenotype and Pathogenesis to Treatment. Front Cardiovasc Med 2021; 8:722340. [PMID: 34760939 PMCID: PMC8572854 DOI: 10.3389/fcvm.2021.722340] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 09/17/2021] [Indexed: 02/05/2023] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is a very common inherited cardiovascular disease (CAD) and the incidence is about 1/500 of the common population. It is caused by more than 1,400 mutations in 11 or more genes encoding the proteins of the cardiac sarcomere. HCM presents a heterogeneous clinical profile and complex pathophysiology and HCM is the most important cause of sudden cardiac death (SCD) in young people. HCM also contributes to functional disability from heart failure and stroke (caused by atrial fibrillation). Current treatments for HCM (medication, myectomy, and alcohol septal ablation) are geared toward slowing down the disease progression and symptom relief and implanted cardiac defibrillator (ICD) to prevent SCD. HCM is, however, entering a period of tight translational research that holds promise for the major advances in disease-specific therapy. Main insights into the genetic landscape of HCM have improved our understanding of molecular pathogenesis and pointed the potential targets for the development of therapeutic agents. We reviewed the critical discoveries about the treatments, mechanism of HCM, and their implications for future research.
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Affiliation(s)
- Zeyi Cheng
- Department of Cardiovascular Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Tingting Fang
- Department of Cardiology, West China Hospital, Sichuan University, Chengdu, China
| | - Jinglei Huang
- School of Medicine, Lanzhou University, Lanzhou, China
| | - Yingqiang Guo
- Department of Cardiovascular Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Mahboob Alam
- Division of Cardiovascular Medicine, Department of Medicine, Baylor College of Medicine, Houston, TX, United States
| | - Hong Qian
- Department of Cardiovascular Surgery, West China Hospital, Sichuan University, Chengdu, China
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Shahvaran SA, Menyhárt O, Csedrik L, Patai ÁV. Diagnosis and Prevalence of Cirrhotic Cardiomyopathy: A Systematic Review and Meta-analysis. Curr Probl Cardiol 2021; 46:100821. [PMID: 34016482 DOI: 10.1016/j.cpcardiol.2021.100821] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 02/17/2021] [Indexed: 01/26/2023]
Abstract
The proposed diagnostic criteria for cirrhotic cardiomyopathy (CCM), defines it as documented echocardiographic findings of systolic or diastolic dysfunction (using conventional 2D echocardiogram), with or without electrophysiological abnormalities or elevated biomarkers in cirrhotic patients. In comparison to 2D echocardiogram, tissue Doppler imaging (TDI) has better sensitivity and specificity, when evaluating for cardiac dysfunction. This meta-analysis of 12 selected cohort studies attempted to estimate the pooled prevalence of CCM using either conventional echocardiography or TDI. Using the 2005 criteria, the pooled prevalence of CCM is 61% (P = 0.106). When TDI is used, the prevalence of CCM is at 45% (P = 0.088). Analyzing data of 615 cirrhotic patients, this study estimates the mean population-specific echocardiographic values of cirrhotic patients, including left ventricle ejection fraction (63.52%), deceleration time (229.04 ms), isovolumetric relaxation time (87.71 ms) and E/A ratio (1.04). In comparison to TDI, using standard 2D echocardiography leads to overdiagnosis of CCM.
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Affiliation(s)
| | - Orsolya Menyhárt
- Department of Internal Medicine and Hematology, Semmelweis University, Budapest, Hungary; Buda Health Center
| | | | - Árpád V Patai
- Interdisciplinary Gastroenterology Working Group, Semmelweis University, Budapest, Hungary; Department of Internal Medicine and Hematology, Semmelweis University, Budapest, Hungary.
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Huang H, Huang X, Luo S, Zhang H, Hu F, Chen R, Huang C, Su Z. The MicroRNA MiR-29c Alleviates Renal Fibrosis via TPM1-Mediated Suppression of the Wnt/β-Catenin Pathway. Front Physiol 2020; 11:331. [PMID: 32346368 PMCID: PMC7171049 DOI: 10.3389/fphys.2020.00331] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 03/23/2020] [Indexed: 01/14/2023] Open
Abstract
Purpose This study aimed to evaluate the mechanism by which miR-29c expression in fibroblasts regulates renal interstitial fibrosis. Methods We stimulated NRK-49F cells with TGF-β1 to mimic the effects of fibrosis in vitro, while unilateral ureteral obstruction (UUO) was performed to obstruct the mid-ureter in mice. MiR-29c mimic or miR-29c inhibitor was used to mediate genes expressions in vitro. The recombinant adeno associated virus (rAAV) vectors carrying a FSP1 promoter that encodes miR-29c precursor or miR-29c inhibitor was used to mediate genes expressions in vivo, and a flank incision was made to expose the left kidney of each animal. Results In the present study, TGF-β1 was demonstrated to regulate miR-29c expression through Wnt/β-catenin signaling. In contrast, miR-29c appears to inhibit the Wnt/β-catenin pathway by suppressing TPM1 expression. As suggested by this feedback mechanism, miR-29c may be a key fibrosis-related microRNA expressed by fibroblasts in TGF-β1/Wnt/β-catenin-driven renal fibrosis, and manipulation of miR-29c action may accordingly offer a potential therapeutic pathway for renal fibrosis treatment. Conclusion MiR-29c expression was downregulated in UUO mouse kidneys as well as TGF-β1-treated NRK-49F cells, which thus inhibits myofibroblast formation via targeting of TPM1. Additionally, the production of extracellular matrix (ECM) in renal fibroblasts appears to be controlled by the reciprocal regulation of miR-29c action and the Wnt/β-catenin pathway.
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Affiliation(s)
- Huiya Huang
- Department of Nephrology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.,Department of Intensive Care Unit, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Xiaozhong Huang
- Department of Pediatric Surgery, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Shengnan Luo
- Department of Nephrology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Huidi Zhang
- Department of Nephrology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Feifei Hu
- Department of Nephrology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Ruyi Chen
- Department of Nephrology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Chaoxing Huang
- Department of Nephrology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Zhen Su
- Department of Nephrology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
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Chowdhury SAK, Warren CM, Simon JN, Ryba DM, Batra A, Varga P, Kranias EG, Tardiff JC, Solaro RJ, Wolska BM. Modifications of Sarcoplasmic Reticulum Function Prevent Progression of Sarcomere-Linked Hypertrophic Cardiomyopathy Despite a Persistent Increase in Myofilament Calcium Response. Front Physiol 2020; 11:107. [PMID: 32210830 PMCID: PMC7075858 DOI: 10.3389/fphys.2020.00107] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 01/30/2020] [Indexed: 01/12/2023] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is a genetic disorder caused by mutations in different genes mainly encoding myofilament proteins and therefore called a “disease of the sarcomere.” Despite the discovery of sarcomere protein mutations linked to HCM almost 30 years ago, the cellular mechanisms responsible for the development of this disease are not completely understood and likely vary among different mutations. Moreover, despite many efforts to develop effective treatments for HCM, these have largely been unsuccessful, and more studies are needed to better understand the cellular mechanisms of the disease. In experiments reported here, we investigated a mouse model expressing the mutant cTnT-R92Q, which is linked to HCM and induces an increase in myofilament Ca2+ sensitivity and diastolic dysfunction. We found that early correction of the diastolic dysfunction by phospholamban knockout (PLNKO) was able to prevent the development of the HCM phenotype in troponin T (TnT)-R92Q transgenic (TG) mice. Four groups of mice in FVB/N background were generated and used for the experiments: (1) non-transgenic (NTG)/PLN mice, which express wild-type TnT and normal level of PLN; (2) NTG/PLNKO mice, which express wild-type TnT and no PLN; (3) TG/PLN mice, which express TnT-R92Q and normal level of PLN; (4) TG/PLNKO mice, which express TnT-R92Q and no PLN. Cardiac function was determined using both standard echocardiographic parameters and speckle tracking strain measurements. We found that both atrial morphology and diastolic function were altered in TG/PLN mice but normal in TG/PLNKO mice. Histological analysis showed a disarray of myocytes and increased collagen deposition only in TG/PLN hearts. We also observed increased Ca2+/calmodulin-dependent protein kinase II (CaMKII) phosphorylation only in TG/PLN hearts but not in TG/PLNKO hearts. The rescue of the HCM phenotype was not associated with differences in myofilament Ca2+ sensitivity between TG/PLN and TG/PLNKO mice. Moreover, compared to standard systolic echo parameters, such as ejection fraction (EF), speckle strain measurements provided a more sensitive approach to detect early systolic dysfunction in TG/PLN mice. In summary, our results indicate that targeting diastolic dysfunction through altering Ca2+ fluxes with no change in myofilament response to Ca2+ was able to prevent the development of the HCM phenotype and should be considered as a potential additional treatment for HCM patients.
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Affiliation(s)
- Shamim A K Chowdhury
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - Chad M Warren
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - Jillian N Simon
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - David M Ryba
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - Ashley Batra
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - Peter Varga
- Department of Pediatrics, Section of Cardiology, University of Illinois at Chicago, Chicago, IL, United States
| | - Evangelia G Kranias
- Department of Pharmacology and Systems Physiology, University of Cincinnati, Cincinnati, OH, United States
| | - Jil C Tardiff
- Department of Medicine, Division of Cardiology, The University of Arizona, Tucson, AZ, United States
| | - R John Solaro
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - Beata M Wolska
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States.,Department of Medicine, Division of Cardiology, University of Illinois at Chicago, Chicago, IL, United States
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Heizmann CW. S100 proteins: Diagnostic and prognostic biomarkers in laboratory medicine. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2019; 1866:1197-1206. [DOI: 10.1016/j.bbamcr.2018.10.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 10/12/2018] [Indexed: 01/04/2023]
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Heizmann CW. Ca 2+-Binding Proteins of the EF-Hand Superfamily: Diagnostic and Prognostic Biomarkers and Novel Therapeutic Targets. Methods Mol Biol 2019; 1929:157-186. [PMID: 30710273 DOI: 10.1007/978-1-4939-9030-6_11] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
A multitude of Ca2+-sensor proteins containing the specific Ca2+-binding motif (helix-loop-helix, called EF-hand) are of major clinical relevance in a many human diseases. Measurements of troponin, the first intracellular Ca-sensor protein to be discovered, is nowadays the "gold standard" in the diagnosis of patients with acute coronary syndrome (ACS). Mutations have been identified in calmodulin and linked to inherited ventricular tachycardia and in patients affected by severe cardiac arrhythmias. Parvalbumin, when introduced into the diseased heart by gene therapy to increase contraction and relaxation speed, is considered to be a novel therapeutic strategy to combat heart failure. S100 proteins, the largest subgroup with the EF-hand protein family, are closely associated with cardiovascular diseases, various types of cancer, inflammation, and autoimmune pathologies. The intention of this review is to summarize the clinical importance of this protein family and their use as biomarkers and potential drug targets, which could help to improve the diagnosis of human diseases and identification of more selective therapeutic interventions.
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Affiliation(s)
- Claus W Heizmann
- Department of Pediatrics, Division of Clinical Chemistry and Biochemistry, University of Zürich, Zürich, Switzerland.
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Thompson BR, Cohen H, Angulski ABB, Metzger JM. Gene Transfer of Calcium-Binding Proteins into Adult Cardiac Myocytes. Methods Mol Biol 2019; 1929:187-205. [PMID: 30710274 PMCID: PMC6507422 DOI: 10.1007/978-1-4939-9030-6_12] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Heart failure is the leading cause of combined morbidity and mortality in the USA with 50% of cases being diastolic heart failure. Diastolic heart failure results from poor myocardial relaxation and inadequate filling of the left ventricular chamber caused in part by calcium-handling dysregulation. In this chapter we describe methods to investigate new approaches of novel human Ca2+ binding protein motifs to restore normal Ca2+ handling function to diseased myocardium. Gene transfer of parvalbumin into adult cardiac myocytes has been studied as a potential therapeutic, specifically as a strategic Ca2+ buffer to correct cardiac mechanical dysfunction in disease. This chapter provides protocols for studying wild-type parvalbumin isoforms and parvalbumins with strategically designed EF-hand motifs in adult cardiac myocytes via acute adenoviral gene transfer. These protocols have been used extensively to optimize parvalbumin function as a potential therapeutic for failing heart muscle.
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Affiliation(s)
- Brian R Thompson
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Houda Cohen
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Addeli Bez Batti Angulski
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Joseph M Metzger
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN, USA.
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Abstract
PURPOSE OF REVIEW Cardiomyopathies due to genetic mutations are a heterogeneous group of disorders that comprise diseases of contractility, myocardial relaxation, and arrhythmias. Our goal here is to discuss a limited list of genetically inherited cardiomyopathies and the specific therapeutic strategies used to treat them. RECENT FINDINGS Research into the molecular pathophysiology of the development of these cardiomyopathies is leading to the development of novel treatment approaches. Therapies targeting these specific mutations with gene therapy vectors are on the horizon, while other therapies which indirectly affect the physiologic derangements of the mutations are currently being studied and used clinically. Many of these therapies are older medications being given new roles such as mexiletine for Brugada syndrome and diflunisal for transthyretin amyloid cardiomyopathy. A newer targeted therapy, the inhibitor of myosin ATPase MYK-461, has been shown to suppress the development of ventricular hypertrophy, fibrosis, and myocyte disarray and is being studied as a potential therapy in patients with hypertrophic cardiomyopathy. While this field is too large to be completely contained in a single review, we present a large cross section of recent developments in the field of therapeutics for inherited cardiomyopathies. New therapies are on the horizon, and their development will likely result in improved outcomes for patients inflicted by these conditions.
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Affiliation(s)
- Kenneth Varian
- Department of Cardiovascular Medicine, Heart and Vascular Institute, Cleveland Clinic, 9500 Euclid Avenue, Desk J3-4, Cleveland, OH, 44195, USA
| | - W H Wilson Tang
- Department of Cardiovascular Medicine, Heart and Vascular Institute, Cleveland Clinic, 9500 Euclid Avenue, Desk J3-4, Cleveland, OH, 44195, USA. .,Center for Clinical Genomics, Cleveland Clinic, Cleveland, OH, USA.
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11
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The heart matters when the liver shatters! Cirrhotic cardiomyopathy: frequency, comparison, and correlation with severity of disease. GASTROENTEROLOGY REVIEW 2016; 11:247-256. [PMID: 28053679 PMCID: PMC5209462 DOI: 10.5114/pg.2016.57962] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 11/08/2015] [Indexed: 01/01/2023]
Abstract
Introduction Cirrhotic cardiomyopathy is a visor complication among patients with cirrhosis of the liver, manifesting during stress, exertion, transjuglar intrahepatic portosystemic shunt (TIPS), or liver transplantation. Cirrhotic cardiomyopathy is reported to be most common cause of post transplant mortality after rejection of 7% to 21%. Aim To determine the frequency of cirrhotic cardiomyopathy and was further designed to compare parameters of cardiac dysfunction in patients with or without cirrhotic cardiomyopathy. Material and methods All confirmed cases of cirrhosis with various aetiologies were enrolled. Resting ejection fraction (EF) was determined in all patients. Patients were grouped with resting EF < 55% (suspected cardiomyopathy) or > 55% (without cardiomyopathy). Stress echocardiography with dobutamine infusion in both groups yielded an increase of less than 10% in left ventricular (LV) EF at peak dobutamine infusion confirming systolic dysfunction. The diastolic dysfunction (E/A ratio), electrocardiographic parameter (prolong QT interval), and cardiac biomarker (NT-proBNP) were also determined in both the groups to confirm cirrhotic cardiomyopathy. Results Among 89 patients with cirrhosis, 35 (39.32%) had cirrhotic cardiomyopathy. All components of cirrhotic cardiomyopathy, like systolic dysfunction, diastolic dysfunction, prolong QT interval, and cardiac biomarkers, were found to be statistically significant (p = 0.001) when compared with patients without cardiomyopathy. Cirrhotic cardiomyopathy parameters were positively correlated with advancing liver disease. Conclusions Cirrhotic cardiomyopathy is a frequent but unmasked complication in cirrhosis of the liver. All components of cardiac dysfunction, such as systolic, diastolic, and electrocardiographic changes, are present in patients with cirrhotic cardiomyopathy. Cirrhotic cardiomyopathy is positively correlated to severity of liver disease.
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12
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Leviner DB, Hochhauser E, Arad M. Inherited cardiomyopathies--Novel therapies. Pharmacol Ther 2015; 155:36-48. [PMID: 26297672 DOI: 10.1016/j.pharmthera.2015.08.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/10/2015] [Indexed: 01/10/2023]
Abstract
Cardiomyopathies arising due to a single gene defect represent various pathways that evoke adverse remodeling and cardiac dysfunction. While the gene therapy approach is slowly evolving and has not yet reached clinical "prime time" and gene correction approaches are applicable at the bench but not at the bedside, major advances are being made with molecular and drug therapies. This review summarizes the contemporary drugs introduced or being tested to help manage these unique disorders bearing a major impact on the quality of life and survival of the affected individuals. The restoration of the RNA reading frame facilitates the expression of partly functional protein to salvage or alleviate the disease phenotype. Chaperones are used to prevent the degradation of abnormal but still functional proteins, while other molecules are given for pathogen silencing, to prevent aggregation or to enhance clearance of protein deposits. The absence of protein may be managed by viral gene delivery or protein therapy. Enzyme replacement therapy is already a clinical reality for a series of metabolic diseases. The progress in molecular biology, based on the knowledge of the gene defect, helps generate small molecules and pharmaceuticals targeting the key events occurring in the malfunctioning element of the sick organ. Cumulatively, these tools augment the existing armamentarium of phenotype oriented symptomatic and evidence-based therapies for patients with inherited cardiomyopathies.
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Affiliation(s)
- Dror B Leviner
- Department of Cardiothoracic Surgery, Rabin Medical Center, Petah Tikva, Israel; Cardiac Research Laboratory, Felsenstein Medical Research Center, Petah Tikva and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Edith Hochhauser
- Cardiac Research Laboratory, Felsenstein Medical Research Center, Petah Tikva and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Michael Arad
- Leviev Heart Center, Sheba Medical Center, Tel Hashomer and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
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13
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Strakova J, Dean JD, Sharpe KM, Meyers TA, Odom GL, Townsend D. Dystrobrevin increases dystrophin's binding to the dystrophin-glycoprotein complex and provides protection during cardiac stress. J Mol Cell Cardiol 2014; 76:106-15. [PMID: 25158611 DOI: 10.1016/j.yjmcc.2014.08.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Revised: 08/14/2014] [Accepted: 08/16/2014] [Indexed: 01/05/2023]
Abstract
Duchenne muscular dystrophy is a fatal progressive disease of both cardiac and skeletal muscle resulting from the mutations in the DMD gene and loss of the protein dystrophin. Alpha-dystrobrevin (α-DB) tightly associates with dystrophin but the significance of this interaction within cardiac myocytes is poorly understood. In the current study, the functional role of α-DB in cardiomyocytes and its implications for dystrophin function are examined. Cardiac stress testing demonstrated significant heart disease in α-DB null (adbn(-/-)) mice, which displayed mortality and lesion sizes that were equivalent to those seen in dystrophin-deficient mdx mice. Despite normal expression and subcellular localization of dystrophin in the adbn(-/-) heart, there is a significant decrease in the strength of dystrophin's interaction with the membrane-bound dystrophin-associated glycoprotein complex (DGC). A similar weakening of the dystrophin-membrane interface was observed in mice lacking the sarcoglycan complex. Cardiomyocytes from adbn(-/-) mice were smaller and responded less to adrenergic receptor induced hypertrophy. The basal decrease in size could not be attributed to aberrant Akt activation. In addition, the organization of the microtubule network was significantly altered in adbn(-/-) cardiac myocytes, while the total expression of tubulin was unchanged in adbn(-/-) hearts. These studies demonstrate that α-DB is a multifunctional protein that increases dystrophin's binding to the dystrophin-glycoprotein complex, and is critical for the full functionality of dystrophin.
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Affiliation(s)
- Jana Strakova
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, USA
| | - Jon D Dean
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, USA
| | - Katharine M Sharpe
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, USA
| | - Tatyana A Meyers
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, USA
| | - Guy L Odom
- Department of Neurology, University of Washington, Seattle, WA, USA
| | - DeWayne Townsend
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, USA.
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14
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Scimia MC, Cannavo A, Koch WJ. Gene therapy for heart disease: molecular targets, vectors and modes of delivery to myocardium. Expert Rev Cardiovasc Ther 2014; 11:999-1013. [PMID: 23984926 DOI: 10.1586/14779072.2013.818813] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Despite the numerous hurdles that gene therapy has encountered along the way, clinical trials over the last few years are showing promising results in many fields of medicine, including cardiology, where many targets are moving toward clinical development. In this review, the authors discuss the current state of the art in terms of clinical and preclinical development. They also examine vector technology and available vector-delivery strategies.
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Affiliation(s)
- Maria Cecilia Scimia
- Department of Pharmacology, Center for Translational Medicine, Temple University School of Medicine, 3500 N Broad St, MERB 941, Philadelphia, PA 19140, USA
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15
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Alves ML, Dias FAL, Gaffin RD, Simon JN, Montminy EM, Biesiadecki BJ, Hinken AC, Warren CM, Utter MS, Davis RT, Sakthivel S, Robbins J, Wieczorek DF, Solaro RJ, Wolska BM. Desensitization of myofilaments to Ca2+ as a therapeutic target for hypertrophic cardiomyopathy with mutations in thin filament proteins. ACTA ACUST UNITED AC 2014; 7:132-143. [PMID: 24585742 DOI: 10.1161/circgenetics.113.000324] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
BACKGROUND Hypertrophic cardiomyopathy (HCM) is a common genetic disorder caused mainly by mutations in sarcomeric proteins and is characterized by maladaptive myocardial hypertrophy, diastolic heart failure, increased myofilament Ca(2+) sensitivity, and high susceptibility to sudden death. We tested the following hypothesis: correction of the increased myofilament sensitivity can delay or prevent the development of the HCM phenotype. METHODS AND RESULTS We used an HCM mouse model with an E180G mutation in α-tropomyosin (Tm180) that demonstrates increased myofilament Ca(2+) sensitivity, severe hypertrophy, and diastolic dysfunction. To test our hypothesis, we reduced myofilament Ca(2+) sensitivity in Tm180 mice by generating a double transgenic mouse line. We crossed Tm180 mice with mice expressing a pseudophosphorylated cardiac troponin I (S23D and S24D; TnI-PP). TnI-PP mice demonstrated a reduced myofilament Ca(2+) sensitivity compared with wild-type mice. The development of pathological hypertrophy did not occur in mice expressing both Tm180 and TnI-PP. Left ventricle performance was improved in double transgenic compared with their Tm180 littermates, which express wild-type cardiac troponin I. Hearts of double transgenic mice demonstrated no changes in expression of phospholamban and sarcoplasmic reticulum Ca(2+) ATPase, increased levels of phospholamban and troponin T phosphorylation, and reduced phosphorylation of TnI compared with Tm180 mice. Moreover, expression of TnI-PP in Tm180 hearts inhibited modifications in the activity of extracellular signal-regulated kinase and zinc finger-containing transcription factor GATA in Tm180 hearts. CONCLUSIONS Our data strongly indicate that reduction of myofilament sensitivity to Ca(2+) and associated correction of abnormal relaxation can delay or prevent development of HCM and should be considered as a therapeutic target for HCM.
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Affiliation(s)
- Marco L Alves
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois, Chicago, IL.,Department of Physiology and Department of Cell Biology, Federal University of Parana, Curitiba, Brazil
| | - Fernando A L Dias
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois, Chicago, IL.,Department of Physiology and Department of Cell Biology, Federal University of Parana, Curitiba, Brazil
| | - Robert D Gaffin
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois, Chicago, IL
| | - Jillian N Simon
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois, Chicago, IL
| | - Eric M Montminy
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois, Chicago, IL
| | - Brandon J Biesiadecki
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois, Chicago, IL.,Department of Physiology and Cell Biology, The Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH
| | - Aaron C Hinken
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois, Chicago, IL
| | - Chad M Warren
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois, Chicago, IL
| | - Megan S Utter
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois, Chicago, IL
| | - Robert T Davis
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois, Chicago, IL
| | - Sadayappan Sakthivel
- Division of Molecular Cardiovascular Biology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati
| | - Jeffrey Robbins
- Division of Molecular Cardiovascular Biology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati
| | - David F Wieczorek
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, College of Medicine
| | - R John Solaro
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois, Chicago, IL
| | - Beata M Wolska
- Department of Medicine, Section of Cardiology, University of Illinois, Chicago, IL.,Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois, Chicago, IL
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16
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Abstract
INTRODUCTION Cardiovascular gene therapy is the third most popular application for gene therapy, representing 8.4% of all gene therapy trials as reported in 2012 estimates. Gene therapy in cardiovascular disease is aiming to treat heart failure from ischemic and non-ischemic causes, peripheral artery disease, venous ulcer, pulmonary hypertension, atherosclerosis and monogenic diseases, such as Fabry disease. AREAS COVERED In this review, we will focus on elucidating current molecular targets for the treatment of ventricular dysfunction following myocardial infarction (MI). In particular, we will focus on the treatment of i) the clinical consequences of it, such as heart failure and residual myocardial ischemia and ii) etiological causes of MI (coronary vessels atherosclerosis, bypass venous graft disease, in-stent restenosis). EXPERT OPINION We summarise the scheme of the review and the molecular targets either already at the gene therapy clinical trial phase or in the pipeline. These targets will be discussed below. Following this, we will focus on what we believe are the 4 prerequisites of success of any gene target therapy: safety, expression, specificity and efficacy (SESE).
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Affiliation(s)
- Maria C Scimia
- Temple University, Translational Medicine/Pharmacology , 3500 N. Broad Street, Philadelphia, 19140 , USA
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17
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Schulz EM, Wilder T, Chowdhury SAK, Sheikh HN, Wolska BM, Solaro RJ, Wieczorek DF. Decreasing tropomyosin phosphorylation rescues tropomyosin-induced familial hypertrophic cardiomyopathy. J Biol Chem 2013; 288:28925-35. [PMID: 23960072 DOI: 10.1074/jbc.m113.466466] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Studies indicate that tropomyosin (Tm) phosphorylation status varies in different mouse models of cardiac disease. Investigation of basal and acute cardiac function utilizing a mouse model expressing an α-Tm protein that cannot be phosphorylated (S283A) shows a compensated hypertrophic phenotype with significant increases in SERCA2a expression and phosphorylation of phospholamban Ser-16 (Schulz, E. M., Correll, R. N., Sheikh, H. N., Lofrano-Alves, M. S., Engel, P. L., Newman, G., Schultz Jel, J., Molkentin, J. D., Wolska, B. M., Solaro, R. J., and Wieczorek, D. F. (2012) J. Biol. Chem. 287, 44478-44489). With these results, we hypothesized that decreasing α-Tm phosphorylation may be beneficial in the context of a chronic, intrinsic stressor. To test this hypothesis, we utilized the familial hypertrophic cardiomyopathy (FHC) α-Tm E180G model (Prabhakar, R., Boivin, G. P., Grupp, I. L., Hoit, B., Arteaga, G., Solaro, R. J., and Wieczorek, D. F. (2001) J. Mol. Cell. Cardiol. 33, 1815-1828). These FHC hearts are characterized by increased heart:body weight ratios, fibrosis, increased myofilament Ca(2+) sensitivity, and contractile defects. The FHC mice die by 6-8 months of age. We generated mice expressing both the E180G and S283A mutations and found that the hypertrophic phenotype was rescued in the α-Tm E180G/S283A double mutant transgenic animals; these mice exhibited no signs of cardiac hypertrophy and displayed improved cardiac function. These double mutant transgenic hearts showed increased phosphorylation of phospholamban Ser-16 and Thr-17 compared with the α-Tm E180G mice. This is the first study to demonstrate that decreasing phosphorylation of tropomyosin can rescue a hypertrophic cardiomyopathic phenotype.
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Affiliation(s)
- Emily M Schulz
- From the Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267
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18
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Licata A, Corrao S, Petta S, Genco C, Cardillo M, Calvaruso V, Cabibbo G, Massenti F, Cammà C, Licata G, Craxì A. NT pro BNP plasma level and atrial volume are linked to the severity of liver cirrhosis. PLoS One 2013; 8:e68364. [PMID: 23940514 PMCID: PMC3734231 DOI: 10.1371/journal.pone.0068364] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Accepted: 05/29/2013] [Indexed: 02/06/2023] Open
Abstract
Background and Aims Plasma levels of NT-pro-BNP, a natriuretic peptide precursor, are raised in the presence of fluid retention of cardiac origin and can be used as markers of cardiac dysfunction. Recent studies showed high levels of NT pro BNP in patients with cirrhosis. We assessed NT pro-BNP and other parameters of cardiac dysfunction in patients with cirrhosis, with or without ascites, in order to determine whether the behaviour of NT pro BNP is linked to the stage of liver disease or to secondary cardiac dysfunction. Methods Fifty eight consecutive hospitalized patients mostly with viral or NAFLD-related cirrhosis were studied. All underwent abdominal ultrasound and upper GI endoscopy. Cardiac morpho-functional changes were evaluated by echocardiography and NT-pro-BNP plasma levels determined upon admission. Twenty-eight hypertensive patients, without evidence of liver disease served as controls. Results Fifty eight cirrhotic patients (72% men) with a median age of 62 years (11% with mild arterial hypertension and 31% with type 2 diabetes) had a normal renal function (mean creatinine 0.9 mg/dl, range 0.7–1.06). As compared to controls, cirrhotic patients had higher NT pro-BNP plasma levels (365.2±365.2 vs 70.8±70.6 pg/ml; p<0.001). Left atrial volume (LAV) (61.8±26.3 vs 43.5±14.1 ml; p = 0.001), and left ventricular ejection fraction (62.7±6.9 vs. 65.5±4%,; p = 0.05) were also altered in cirrhotic patients that in controls. Patients with F2-F3 oesophageal varices as compared to F0/F1, showed higher e' velocity (0.91±0.23 vs 0.66±0.19 m/s, p<0.001), and accordingly a higher E/A ratio (1.21±0.46 vs 0.89±0.33 m/s., p = 0.006). Conclusion NT-pro-BNP plasma levels are increased proportionally to the stage of chronic liver disease. Advanced cirrhosis and high NT-pro-BNP levels are significantly associated to increased LAV and to signs of cardiac diastolic dysfunction. NT pro-BNP levels could hence be an useful prognostic indicators of early decompensation of cirrhosis.
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Affiliation(s)
- Anna Licata
- Sezione di Gastroenterologia, Dipartimento Biomedico di Medicina Interna e Specialistica, DI.BI.M.I.S, University of Palermo, Palermo, Italy.
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19
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Rajan S, Pena JR, Jegga AG, Aronow BJ, Wolska BM, Wieczorek DF. Microarray analysis of active cardiac remodeling genes in a familial hypertrophic cardiomyopathy mouse model rescued by a phospholamban knockout. Physiol Genomics 2013; 45:764-73. [PMID: 23800848 DOI: 10.1152/physiolgenomics.00023.2013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Familial hypertrophic cardiomyopathy (FHC) is a disease characterized by ventricular hypertrophy, fibrosis, and aberrant systolic and/or diastolic function. Our laboratories have previously developed two mouse models that affect cardiac performance. One mouse model encodes an FHC-associated mutation in α-tropomyosin: Glu → Gly at amino acid 180, designated as Tm180. These mice display a phenotype that is characteristic of FHC, including severe cardiac hypertrophy with fibrosis and impaired physiological performance. The other model was a gene knockout of phospholamban (PLN KO), a regulator of calcium uptake in the sarcoplasmic reticulum of cardiomyocytes; these hearts exhibit hypercontractility with no pathological abnormalities. Previous work in our laboratories shows that when mice were genetically crossed between the PLN KO and Tm180, the progeny (PLN KO/Tm180) display a rescued hypertrophic phenotype with improved morphology and cardiac function. To understand the changes in gene expression that occur in these models undergoing cardiac remodeling (Tm180, PLN KO, PLN KO/Tm180, and nontransgenic control mice), we conducted microarray analyses of left ventricular tissue at 4 and 12 mo of age. Expression profiling reveals that 1,187 genes changed expression in direct response to the three genetic models. With these 1,187 genes, 11 clusters emerged showing normalization of transcript expression in the PLN KO/Tm180 hearts. In addition, 62 transcripts are highly involved in suppression of the hypertrophic phenotype. Confirmation of the microarray analysis was conducted by quantitative RT-PCR. These results provide insight into genes that alter expression during cardiac remodeling and are active during modulation of the cardiomyopathic phenotype.
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Affiliation(s)
- Sudarsan Rajan
- Department of Molecular Genetics, Biochemistry, & Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0524, USA
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20
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Fang Y, Yu X, Liu Y, Kriegel AJ, Heng Y, Xu X, Liang M, Ding X. miR-29c is downregulated in renal interstitial fibrosis in humans and rats and restored by HIF-α activation. Am J Physiol Renal Physiol 2013; 304:F1274-82. [PMID: 23467423 DOI: 10.1152/ajprenal.00287.2012] [Citation(s) in RCA: 103] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Treatment with L-mimosine, which activates hypoxia-inducible factor-α (HIF-α), attenuates renal tubulointerstitial injury and improves renal function in a rat remnant kidney model. The miR-29 family of microRNAs directly targets a large number of extracellular matrix genes and reduces renal interstitial fibrosis. We analyzed microRNA expression profiles in rat remnant kidneys with or without treatment with L-mimosine. The expression of miR-29c was downregulated in rat remnant kidneys compared with sham control and significantly restored by the L-mimosine treatment. In cultured human kidney epithelial HK2 cells, cobalt chloride activated HIF-α and upregulated miR-29c expression. The upregulation of miR-29c expression was significantly attenuated by knockdown of HIF-1α or HIF-2α. Downregulation of miR-29c was associated with significant increases in interstitial fibrosis, collagen type II α1 (COL2A1) protein, and tropomyosin 1α (TPM1) protein in rat remnant kidneys and in kidneys from IgA nephropathy patients. The increases in rat remnant kidneys were attenuated by the L-mimosine treatment. COL2A1 and TPM1 were confirmed to be new, direct targets of miR-29c. In conclusion, miR-29c, an antifibrotic microRNA, is upregulated by HIF-α activation. MiR-29c is downregulated in renal interstitial fibrosis in humans and rats and restored by activation of HIF-α that attenuates fibrosis.
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Affiliation(s)
- Yi Fang
- Department of Nephrology, Zhongshan Hospital, Fudan University, Shanghai, China
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21
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Wang W, Barnabei MS, Asp ML, Heinis FI, Arden E, Davis J, Braunlin E, Li Q, Davis JP, Potter JD, Metzger JM. Noncanonical EF-hand motif strategically delays Ca2+ buffering to enhance cardiac performance. Nat Med 2013; 19:305-12. [PMID: 23396207 DOI: 10.1038/nm.3079] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Accepted: 12/21/2012] [Indexed: 12/26/2022]
Abstract
EF-hand proteins are ubiquitous in cell signaling. Parvalbumin (Parv), the archetypal EF-hand protein, is a high-affinity Ca(2+) buffer in many biological systems. Given the centrality of Ca(2+) signaling in health and disease, EF-hand motifs designed to have new biological activities may have widespread utility. Here, an EF-hand motif substitution that had been presumed to destroy EF-hand function, that of glutamine for glutamate at position 12 of the second cation binding loop domain of Parv (ParvE101Q), markedly inverted relative cation affinities: Mg(2+) affinity increased, whereas Ca(2+) affinity decreased, forming a new ultra-delayed Ca(2+) buffer with favorable properties for promoting cardiac relaxation. In therapeutic testing, expression of ParvE101Q fully reversed the severe myocyte intrinsic contractile defect inherent to expression of native Parv and corrected abnormal myocardial relaxation in diastolic dysfunction disease models in vitro and in vivo. Strategic design of new EF-hand motif domains to modulate intracellular Ca(2+) signaling could benefit many biological systems with abnormal Ca(2+) handling, including the diseased heart.
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Affiliation(s)
- Wang Wang
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, Minnesota, USA
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22
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Asp ML, Martindale JJ, Heinis FI, Wang W, Metzger JM. Calcium mishandling in diastolic dysfunction: mechanisms and potential therapies. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1833:895-900. [PMID: 23022395 DOI: 10.1016/j.bbamcr.2012.09.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Revised: 09/18/2012] [Accepted: 09/20/2012] [Indexed: 01/11/2023]
Abstract
Diastolic dysfunction is characterized by slow or incomplete relaxation of the ventricles during diastole, and is an important contributor to heart failure pathophysiology. Clinical symptoms include fatigue, shortness of breath, and pulmonary and peripheral edema, all contributing to decreased quality of life and poor prognosis. There are currently no therapies available that directly target the heart pump defects in diastolic function. Calcium mishandling is a hallmark of heart disease and has been the subject of a large body of research. Efforts are ongoing in a number of gene therapy approaches to normalize the function of calcium handling proteins such as sarcoplasmic reticulum calcium ATPase. An alternative approach to address calcium mishandling in diastolic dysfunction is to introduce calcium buffers to facilitate relaxation of the heart. Parvalbumin is a calcium binding protein found in fast-twitch skeletal muscle and not normally expressed in the heart. Gene transfer of parvalbumin into normal and diseased cardiac myocytes increases relaxation rate but also markedly decreases contraction amplitude. Although parvalbumin binds calcium in a delayed manner, it is not delayed enough to preserve full contractility. Factors contributing to the temporal nature of calcium buffering by parvalbumin are discussed in relation to remediation of diastolic dysfunction. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Cardiac Pathways of Differentiation, Metabolism and Contraction.
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Affiliation(s)
- Michelle L Asp
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN 55455, USA
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23
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Ducreux S, Gregory P, Schwaller B. Inverse regulation of the cytosolic Ca²⁺ buffer parvalbumin and mitochondrial volume in muscle cells via SIRT1/PGC-1α axis. PLoS One 2012; 7:e44837. [PMID: 23028640 PMCID: PMC3441610 DOI: 10.1371/journal.pone.0044837] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Accepted: 08/09/2012] [Indexed: 12/16/2022] Open
Abstract
Skeletal muscles show a high plasticity to cope with various physiological demands. Different muscle types can be distinguished by the force, endurance, contraction/relaxation kinetics (fast-twitch vs. slow-twitch muscles), oxidative/glycolytic capacity, and also with respect to Ca²⁺-signaling components. Changes in Ca²⁺ signaling and associated Ca²⁺-dependent processes are thought to underlie the high adaptive capacity of muscle fibers. Here we investigated the consequences and the involved mechanisms caused by the ectopic expression of the Ca²⁺-binding protein parvalbumin (PV) in C2C12 myotubes in vitro, and conversely, the effects caused by its absence in in fast-twitch muscles of parvalbumin null-mutant (PV⁻/⁻) mice in vivo. The absence of PV in fast-twitch muscle tibialis anterior (TA) resulted in an increase in the peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) and of its positive regulator, the deacetylase sirtuin 1 (SIRT1). TA muscles from PV⁻/⁻ mice also have an increased mitochondrial volume. Mild ionophore treatment of control (PV-devoid) C2C12 myotubes causing a moderate elevation in [Ca²⁺](c) resulted in an increase in mitochondrial volume, together with elevated PGC-1α and SIRT1 expression levels, whilst it increased PV expression levels in myotubes stably transfected with PV. In PV-expressing myotubes the mitochondrial volume, PGC-1α and SIRT1 were significantly lower than in control C2C12 myotubes already at basal conditions and application of ionophore had no effect on either one. SIRT1 activation causes a down-regulation of PV in transfected myotubes, whilst SIRT1 inhibition has the opposite effect. We conclude that PV expression and mitochondrial volume in muscle cells are inversely regulated via a SIRT1/PGC-1α signaling axis.
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Affiliation(s)
- Sylvie Ducreux
- Unit of Anatomy, Department of Medicine, University of Fribourg, Fribourg, Switzerland
| | - Patrick Gregory
- Unit of Anatomy, Department of Medicine, University of Fribourg, Fribourg, Switzerland
| | - Beat Schwaller
- Unit of Anatomy, Department of Medicine, University of Fribourg, Fribourg, Switzerland
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Insights into restrictive cardiomyopathy from clinical and animal studies. J Geriatr Cardiol 2012; 8:168-83. [PMID: 22783303 PMCID: PMC3390071 DOI: 10.3724/sp.j.1263.2011.00168] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2011] [Revised: 08/24/2011] [Accepted: 08/31/2011] [Indexed: 01/13/2023] Open
Abstract
Cardiomyopathies are diseases that primarily affect the myocardium, leading to serious cardiac dysfunction and heart failure. Out of the three major categories of cardiomyopathies (hypertrophic, dilated and restrictive), restrictive cardiomyopathy (RCM) is less common and also the least studied. However, the prognosis for RCM is poor as some patients dying in their childhood. The molecular mechanisms behind the disease development and progression are not very clear and the treatment of RCM is very difficult and often ineffective. In this article, we reviewed the recent progress in RCM research from the clinical studies and the translational studies done on diseased transgenic animal models. This will help for a better understanding of the mechanisms underlying the etiology and development of RCM and for the design of better treatments for the disease.
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Davis J, Yasuda S, Palpant NJ, Martindale J, Stevenson T, Converso K, Metzger JM. Diastolic dysfunction and thin filament dysregulation resulting from excitation-contraction uncoupling in a mouse model of restrictive cardiomyopathy. J Mol Cell Cardiol 2012; 53:446-57. [PMID: 22683325 DOI: 10.1016/j.yjmcc.2012.05.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Revised: 05/22/2012] [Accepted: 05/29/2012] [Indexed: 10/28/2022]
Abstract
Restrictive cardiomyopathy (RCM) has been linked to mutations in the thin filament regulatory protein cardiac troponin I (cTnI). As the pathogenesis of RCM from genotype to clinical phenotype is not fully understood, transgenic (Tg) mice were generated with cardiac specific expression of an RCM-linked missense mutation (R193H) in cTnI. R193H Tg mouse hearts with 15% stoichiometric replacement had smaller hearts and significantly elevated end diastolic pressures (EDP) in vivo. Using a unique carbon microfiber-based assay, membrane intact R193H adult cardiac myocytes generated higher passive tensions across a range of physiologic sarcomere lengths resulting in significant Ca(2+) independent cellular diastolic tone that was manifest in vivo as elevated organ-level EDP. Sarcomere relaxation and Ca(2+) decay was uncoupled in isolated R193H Tg adult myocytes due to the increase in myofilament Ca(2+) sensitivity of tension, decreased passive compliance of the sarcomere, and adaptive in vivo changes in which phospholamban (PLN) content was decreased. Further evidence of Ca(2+) and mechanical uncoupling in R193H Tg myocytes was demonstrated by the biphasic response of relaxation to increased pacing frequency versus the negative staircase seen with Ca(2+) decay. In comparison, non-transgenic myocyte relaxation closely paralleled the accelerated Ca(2+) decay. Ca(2+) transient amplitude was also significantly blunted in R193H Tg myocytes despite normal mechanical shortening resulting in myocyte hypercontractility when compared to non-transgenics. These results identify for the first time that a single point mutation in cTnI, R193H, directly causes elevated EDP due to a myocyte intrinsic loss of compliance independent of Ca(2+) cycling or altered cardiac morphology. The compound influence of impaired relaxation and elevated EDP represents a clinically severe form of diastolic dysfunction similar to the hemodynamic state documented in RCM patients.
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Affiliation(s)
- Jennifer Davis
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN 55455, USA
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26
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Knöll R. Myosin binding protein C: implications for signal-transduction. J Muscle Res Cell Motil 2011; 33:31-42. [PMID: 22173300 PMCID: PMC3351598 DOI: 10.1007/s10974-011-9281-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Accepted: 11/28/2011] [Indexed: 12/29/2022]
Abstract
Myosin binding protein C (MYBPC) is a crucial component of the sarcomere and an important regulator of muscle function. While mutations in different myosin binding protein C (MYBPC) genes are well known causes of various human diseases, such as hypertrophic (HCM) and dilated (DCM) forms of cardiomyopathy as well as skeletal muscular disorders, the underlying molecular mechanisms remain not well understood. A variety of MYBPC3 (cardiac isoform) mutations have been studied in great detail and several corresponding genetically altered mouse models have been generated. Most MYBPC3 mutations may cause haploinsufficiency and with it they may cause a primary increase in calcium sensitivity which is potentially able to explain major features observed in HCM patients such as the hypercontractile phenotype and the well known secondary effects such as myofibrillar disarray, fibrosis, myocardial hypertrophy and remodelling including arrhythmogenesis. However the presence of poison peptides in some cases cannot be fully excluded and most probably other mechanisms are also at play. Here we shall discuss MYBPC interacting proteins and possible pathways linked to cardiomyopathy and heart failure.
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Affiliation(s)
- Ralph Knöll
- Imperial College, National Heart and Lung Institute, British Heart Foundation-Centre for Research Excellence, Myocardial Genetics, London, UK.
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27
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Serizawa T, Terui T, Kagemoto T, Mizuno A, Shimozawa T, Kobirumaki F, Ishiwata S, Kurihara S, Fukuda N. Real-time measurement of the length of a single sarcomere in rat ventricular myocytes: a novel analysis with quantum dots. Am J Physiol Cell Physiol 2011; 301:C1116-27. [DOI: 10.1152/ajpcell.00161.2011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
As the dynamic properties of cardiac sarcomeres are markedly changed in response to a length change of even ∼0.1 μm, it is imperative to quantitatively measure sarcomere length (SL). Here we show a novel system using quantum dots (QDs) that enables a real-time measurement of the length of a single sarcomere in cardiomyocytes. First, QDs were conjugated with anti-α-actinin antibody and applied to the sarcomeric Z disks in isolated skinned cardiomyocytes of the rat. At partial activation, spontaneous sarcomeric oscillations (SPOC) occurred, and QDs provided a quantitative measurement of the length of a single sarcomere over the broad range (i.e., from ∼1.7 to ∼2.3 μm). It was found that the SPOC amplitude was inversely related to SL, but the period showed no correlation with SL. We then treated intact cardiomyocytes with the mixture of the antibody-QDs and FuGENE HD, and visualized the movement of the Z lines/T tubules. At a low frequency of 1 Hz, the cycle of the motion of a single sarcomere consisted of fast shortening followed by slow relengthening. However, an increase in stimulation frequency to 3–5 Hz caused a phase shift of shortening and relengthening due to acceleration of relengthening, and the waveform became similar to that observed during SPOC. Finally, the anti-α-actinin antibody-QDs were transfected from the surface of the beating heart in vivo. The striated patterns with ∼1.96-μm intervals were observed after perfusion under fluorescence microscopy, and an electron microscopic observation confirmed the presence of QDs in and around the T tubules and Z disks, but primarily in the T tubules, within the first layer of cardiomyocytes of the left ventricular wall. Therefore, QDs are a useful tool to quantitatively analyze the movement of single sarcomeres in cardiomyocytes, under various experimental settings.
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Affiliation(s)
- Takahiro Serizawa
- Department of Cell Physiology, The Jikei University School of Medicine,
- Department of Physics, Waseda University, and
| | - Takako Terui
- Department of Cell Physiology, The Jikei University School of Medicine,
| | - Tatsuya Kagemoto
- Department of Cell Physiology, The Jikei University School of Medicine,
- Department of Physics, Waseda University, and
| | - Akari Mizuno
- Department of Cell Physiology, The Jikei University School of Medicine,
- Department of Physics, Waseda University, and
| | | | - Fuyu Kobirumaki
- Department of Cell Physiology, The Jikei University School of Medicine,
| | | | - Satoshi Kurihara
- Department of Cell Physiology, The Jikei University School of Medicine,
| | - Norio Fukuda
- Department of Cell Physiology, The Jikei University School of Medicine,
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28
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Ashrafian H, McKenna WJ, Watkins H. Disease pathways and novel therapeutic targets in hypertrophic cardiomyopathy. Circ Res 2011; 109:86-96. [PMID: 21700950 DOI: 10.1161/circresaha.111.242974] [Citation(s) in RCA: 136] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
As described in earlier reviews in this series on the molecular basis of hypertrophic cardiomyopathy (HCM), HCM is one of the archetypal monogenic cardiovascular disorders to be understood at the molecular level. Twenty years after the discovery of the first HCM disease gene, genetic studies still confirm that HCM is principally a disease of the sarcomere. At the biophysical level, myofilament mutations generally enhance Ca(2+) sensitivity, maximal force production, and ATPase activity. These defects ultimately appear to converge on energy deficiency and altered Ca(2+) handling as major common paths leading to the anatomic (hypertrophy, myofiber disarray, and fibrosis) and functional features (pathological signaling and diastolic dysfunction) characteristic of HCM. In this review, we provide an account of the consequences of HCM mutations and describe how specifically targeting these molecular features has already yielded early promise for novel therapies for HCM. Although substantial efforts are still required to understand the molecular link between HCM mutations and their clinical consequences, HCM endures as an exemplar of how novel insights derived from molecular characterization of Mendelian disorders can inform the understanding of biological processes and translate into rational therapies.
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Affiliation(s)
- Houman Ashrafian
- Department of Cardiovascular Medicine, University of Oxford, Oxford, United Kingdom
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29
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Gaffin RD, Peña JR, Alves MSL, Dias FAL, Chowdhury SAK, Heinrich LS, Goldspink PH, Kranias EG, Wieczorek DF, Wolska BM. Long-term rescue of a familial hypertrophic cardiomyopathy caused by a mutation in the thin filament protein, tropomyosin, via modulation of a calcium cycling protein. J Mol Cell Cardiol 2011; 51:812-20. [PMID: 21840315 DOI: 10.1016/j.yjmcc.2011.07.026] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2011] [Revised: 07/05/2011] [Accepted: 07/28/2011] [Indexed: 11/17/2022]
Abstract
We have recently shown that a temporary increase in sarcoplasmic reticulum (SR) cycling via adenovirus-mediated overexpression of sarcoplasmic reticulum ATPase (SERCA2) transiently improves relaxation and delays hypertrophic remodeling in a familial hypertrophic cardiomyopathy (FHC) caused by a mutation in the thin filament protein, tropomyosin (i.e., α-TmE180G or Tm180). In this study, we sought to permanently alter calcium fluxes via phospholamban (PLN) gene deletion in Tm180 mice in order to sustain long-term improvements in cardiac function and adverse cardiac remodeling/hypertrophy. While similar work has been done in FHCs resulting from mutations in thick myofilament proteins, no one has studied these effects in an FHC resulting from a thin filament protein mutation. Tm180 transgenic (TG) mice were crossbred with PLN knockout (KO) mice and four groups were studied in parallel: 1) non-TG (NTG), 2) Tm180, 3) PLNKO/NTG and 4) PLNKO/Tm180. Tm180 mice exhibit increased heart weight/body weight and hypertrophic gene markers compared to NTG mice, but levels in PLNKO/Tm180 mice were similar to NTG. Tm180 mice also displayed altered function as assessed via in situ pressure-volume analysis and echocardiography at 3-6 months and one year; however, altered function in Tm180 mice was rescued back to NTG levels in PLNKO/Tm180 mice. Collagen deposition, as assessed by Picrosirius Red staining, was increased in Tm180 mice but was similar in NTG and in PLNKO/Tm180 mice. Extracellular signal-regulated kinase (ERK1/2) phosphorylation increased in Tm180 mice while levels in PLNKO/Tm180 mice were similar to NTGs. The present study shows that by modulating SR calcium cycling, we were able to rescue many of the deleterious aspects of FHC caused by a mutation in the thin filament protein, Tm.
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MESH Headings
- Animals
- Biomarkers/metabolism
- Body Weight
- Calcium/metabolism
- Calcium-Binding Proteins/deficiency
- Calcium-Binding Proteins/genetics
- Calcium-Binding Proteins/therapeutic use
- Cardiomyopathy, Hypertrophic, Familial/diagnostic imaging
- Cardiomyopathy, Hypertrophic, Familial/genetics
- Cardiomyopathy, Hypertrophic, Familial/metabolism
- Cardiomyopathy, Hypertrophic, Familial/physiopathology
- Cardiomyopathy, Hypertrophic, Familial/therapy
- Disease Models, Animal
- Echocardiography
- Extracellular Signal-Regulated MAP Kinases/genetics
- Extracellular Signal-Regulated MAP Kinases/metabolism
- Gene Expression
- Humans
- Mice
- Mice, Transgenic
- Mutation
- Myocardial Contraction/genetics
- Myocardium/cytology
- Myocardium/metabolism
- Organ Size
- Phosphorylation
- Real-Time Polymerase Chain Reaction
- Sarcoplasmic Reticulum/genetics
- Sarcoplasmic Reticulum/metabolism
- Tropomyosin/genetics
- Tropomyosin/metabolism
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Affiliation(s)
- Robert D Gaffin
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, IL 60612, USA
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30
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Peña JR, Szkudlarek AC, Warren CM, Heinrich LS, Gaffin RD, Jagatheesan G, del Monte F, Hajjar RJ, Goldspink PH, Solaro RJ, Wieczorek DF, Wolska BM. Neonatal gene transfer of Serca2a delays onset of hypertrophic remodeling and improves function in familial hypertrophic cardiomyopathy. J Mol Cell Cardiol 2010; 49:993-1002. [PMID: 20854827 DOI: 10.1016/j.yjmcc.2010.09.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Revised: 08/25/2010] [Accepted: 09/10/2010] [Indexed: 10/19/2022]
Abstract
Familial hypertrophic cardiomyopathy (FHC) is an autosomal dominant genetic disorder linked to numerous mutations in the sarcomeric proteins. The clinical presentation of FHC is highly variable, but it is a major cause of sudden cardiac death in young adults with no specific treatments. We tested the hypothesis that early intervention in Ca(2+) regulation may prevent pathological hypertrophy and improve cardiac function in a FHC displaying increased myofilament sensitivity to Ca(2+) and diastolic dysfunction. A transgenic (TG) mouse model of FHC with a mutation in tropomyosin at position 180 was employed. Adenoviral-Serca2a (Ad.Ser) was injected into the left ventricle of 1-day-old non-transgenic (NTG) and TG mice. Ad.LacZ was injected as a control. Serca2a protein expression was significantly increased in NTG and TG hearts injected with Ad.Ser for up to 6 weeks. Compared to TG-Ad.LacZ hearts, the TG-Ad.Ser hearts showed improved whole heart morphology. Moreover, there was a significant decline in ANF and β-MHC expression. Developed force in isolated papillary muscle from 2- to 3-week-old TG-Ad.Ser hearts was higher and the response to isoproterenol (ISO) improved compared to TG-Ad.LacZ muscles. In situ hemodynamic measurements showed that by 3 months the TG-Ad.Ser hearts also had a significantly improved response to ISO compared to TG-Ad.LacZ hearts. The present study strongly suggests that Serca2a expression should be considered as a potential target for gene therapy in FHC. Moreover, our data imply that development of FHC can be successfully delayed if therapies are started shortly after birth.
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Affiliation(s)
- James R Peña
- Department of Medicine, Section of Cardiology, University of Illinois at Chicago, Chicago, IL 60612, USA
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31
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Abstract
Cirrhotic cardiomyopathy is a clinical syndrome in patients with liver cirrhosis characterized by an abnormal and blunted response to physiologic, pathologic, or pharmacologic stress but normal to increased cardiac output and contractility at rest. As many as 50% of cirrhotic patients undergoing liver transplantation show signs of cardiac dysfunction, and 7% to 21% of deaths after orthotopic liver transplantation result from overt heart failure. In this review, we critically evaluate the existing literature on the pathophysiology and clinical implications of cirrhotic cardiomyopathy.
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32
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Jagatheesan G, Rajan S, Ahmed RPH, Petrashevskaya N, Boivin G, Arteaga GM, Tae HJ, Liggett SB, Solaro RJ, Wieczorek DF. Striated muscle tropomyosin isoforms differentially regulate cardiac performance and myofilament calcium sensitivity. J Muscle Res Cell Motil 2010; 31:227-39. [PMID: 20803058 DOI: 10.1007/s10974-010-9228-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2010] [Accepted: 08/16/2010] [Indexed: 11/28/2022]
Abstract
Tropomyosin (TM) plays a central role in calcium mediated striated muscle contraction. There are three muscle TM isoforms: alpha-TM, beta-TM, and gamma-TM. alpha-TM is the predominant cardiac and skeletal muscle isoform. beta-TM is expressed in skeletal and embryonic cardiac muscle. gamma-TM is expressed in slow-twitch musculature, but is not found in the heart. Our previous work established that muscle TM isoforms confer different physiological properties to the cardiac sarcomere. To determine whether one of these isoforms is dominant in dictating its functional properties, we generated single and double transgenic mice expressing beta-TM and/or gamma-TM in the heart, in addition to the endogenously expressed alpha-TM. Results show significant TM protein expression in the betagamma-DTG hearts: alpha-TM: 36%, beta-TM: 32%, and gamma-TM: 32%. These betagamma-DTG mice do not develop pathological abnormalities; however, they exhibit a hyper contractile phenotype with decreased myofilament calcium sensitivity, similar to gamma-TM transgenic hearts. Biophysical studies indicate that gamma-TM is more rigid than either alpha-TM or beta-TM. This is the first report showing that with approximately equivalent levels of expression within the same tissue, there is a functional dominance of gamma-TM over alpha-TM or beta-TM in regulating physiological performance of the striated muscle sarcomere. In addition to the effect expression of gamma-TM has on Ca(2+) activation of the cardiac myofilaments, our data demonstrates an effect on cooperative activation of the thin filament by strongly bound rigor cross-bridges. This is significant in relation to current ideas on the control mechanism of the steep relation between Ca(2+) and tension.
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Affiliation(s)
- Ganapathy Jagatheesan
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, 231 Albert B. Sabin Way, Cincinnati, OH 45267-0524, USA
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33
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Davis J, Metzger JM. Combinatorial effects of double cardiomyopathy mutant alleles in rodent myocytes: a predictive cellular model of myofilament dysregulation in disease. PLoS One 2010; 5:e9140. [PMID: 20161772 PMCID: PMC2818843 DOI: 10.1371/journal.pone.0009140] [Citation(s) in RCA: 9] [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: 11/16/2009] [Accepted: 01/19/2010] [Indexed: 12/05/2022] Open
Abstract
Inherited cardiomyopathy (CM) represents a diverse group of cardiac muscle diseases that present with a broad spectrum of symptoms ranging from benign to highly malignant. Contributing to this genetic complexity and clinical heterogeneity is the emergence of a cohort of patients that are double or compound heterozygotes who have inherited two different CM mutant alleles in the same or different sarcomeric gene. These patients typically have early disease onset with worse clinical outcomes. Little experimental attention has been directed towards elucidating the physiologic basis of double CM mutations at the cellular-molecular level. Here, dual gene transfer to isolated adult rat cardiac myocytes was used to determine the primary effects of co-expressing two different CM-linked mutant proteins on intact cardiac myocyte contractile physiology. Dual expression of two CM mutants, that alone moderately increase myofilament activation, tropomyosin mutant A63V and cardiac troponin mutant R146G, were shown to additively slow myocyte relaxation beyond either mutant studied in isolation. These results were qualitatively similar to a combination of moderate and strong activating CM mutant alleles alphaTmA63V and cTnI R193H, which approached a functional threshold. Interestingly, a combination of a CM myofilament deactivating mutant, troponin C G159D, together with an activating mutant, cTnIR193H, produced a hybrid phenotype that blunted the strong activating phenotype of cTnIR193H alone. This is evidence of neutralizing effects of activating/deactivating mutant alleles in combination. Taken together, this combinatorial mutant allele functional analysis lends molecular insight into disease severity and forms the foundation for a predictive model to deconstruct the myriad of possible CM double mutations in presenting patients.
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Affiliation(s)
- Jennifer Davis
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Joseph M. Metzger
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, Minnesota, United States of America
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34
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Rescue of familial cardiomyopathies by modifications at the level of sarcomere and Ca2+ fluxes. J Mol Cell Cardiol 2010; 48:834-42. [PMID: 20079744 DOI: 10.1016/j.yjmcc.2010.01.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Revised: 12/30/2009] [Accepted: 01/06/2010] [Indexed: 12/21/2022]
Abstract
Cardiomyopathies are a heterogeneous group of diseases of the myocardium associated with mechanical and/or electrical dysfunction that frequently show inappropriate ventricular hypertrophy or dilation. Current data suggest that numerous mutations in several genes can cause cardiomyopathies, and the severity of their phenotypes is also influenced by modifier genes. Two major types of inherited cardiomyopathies include familial hypertrophic cardiomyopathy (FHC) and dilated cardiomyopathy (DCM). FHC typically involves increased myofilament Ca(2+) sensitivity associated with diastolic dysfunction, whereas DCM often results in decreased myofilament Ca(2+) sensitivity and systolic dysfunction. Besides alterations in myofilament Ca(2+) sensitivity, alterations in the levels of Ca(2+)-handling proteins have also been described in both diseases. Recent work in animal models has attempted to rescue FHC and DCM via modifications at the myofilament level, altering Ca(2+) homeostasis by targeting Ca(2+)-handling proteins, such as the sarcoplasmic reticulum ATPase and phospholamban, or by interfering with the products of different modifiers genes. Although attempts to rescue cardiomyopathies in animal models have shown great promise, further studies are needed to validate these strategies in order to provide more effective and specific treatments.
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35
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Rajan S, Jagatheesan G, Karam CN, Alves ML, Bodi I, Schwartz A, Bulcao CF, D'Souza KM, Akhter SA, Boivin GP, Dube DK, Petrashevskaya N, Herr AB, Hullin R, Liggett SB, Wolska BM, Solaro RJ, Wieczorek DF. Molecular and functional characterization of a novel cardiac-specific human tropomyosin isoform. Circulation 2010; 121:410-8. [PMID: 20065163 DOI: 10.1161/circulationaha.109.889725] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Tropomyosin (TM), an essential actin-binding protein, is central to the control of calcium-regulated striated muscle contraction. Although TPM1alpha (also called alpha-TM) is the predominant TM isoform in human hearts, the precise TM isoform composition remains unclear. METHODS AND RESULTS In this study, we quantified for the first time the levels of striated muscle TM isoforms in human heart, including a novel isoform called TPM1kappa. By developing a TPM1kappa-specific antibody, we found that the TPM1kappa protein is expressed and incorporated into organized myofibrils in hearts and that its level is increased in human dilated cardiomyopathy and heart failure. To investigate the role of TPM1kappa in sarcomeric function, we generated transgenic mice overexpressing cardiac-specific TPM1kappa. Incorporation of increased levels of TPM1kappa protein in myofilaments leads to dilated cardiomyopathy. Physiological alterations include decreased fractional shortening, systolic and diastolic dysfunction, and decreased myofilament calcium sensitivity with no change in maximum developed tension. Additional biophysical studies demonstrate less structural stability and weaker actin-binding affinity of TPM1kappa compared with TPM1alpha. CONCLUSIONS This functional analysis of TPM1kappa provides a possible mechanism for the consequences of the TM isoform switch observed in dilated cardiomyopathy and heart failure patients.
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Affiliation(s)
- Sudarsan Rajan
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati Medical Center, Cincinnati, OH 45267-0524, USA
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36
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Jagatheesan G, Rajan S, Wieczorek DF. Investigations into tropomyosin function using mouse models. J Mol Cell Cardiol 2009; 48:893-8. [PMID: 19835881 DOI: 10.1016/j.yjmcc.2009.10.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2009] [Revised: 09/30/2009] [Accepted: 10/01/2009] [Indexed: 01/13/2023]
Abstract
Tropomyosin plays a key role in controlling calcium regulated sarcomeric contraction through its interactions with actin and the troponin complex. The focus of this review is on striated muscle tropomyosin isoforms and the in vivo approach we have taken to define the functional differences among these isoforms in regulating cardiac physiology. In addition, we address specific regions within tropomyosin that differ among the isoforms to impart differences in the physiological performance of muscle and the sarcomere itself. There is a high degree of amino acid identity among the three striated muscle alpha-, beta-, and gamma-tropomyosin isoforms; this identity ranges from 86% to 91%. We employ transgenic mouse model systems that express the different tropomyosin isoforms or chimeric tropomyosin molecules specifically in the myocardium. Results show that the three isoforms differentially regulate the rates of cardiac contraction and relaxation, along with conferring differences in myofilament calcium sensitivity and sarcomere tension development. We also found the putative troponin T binding regions of tropomyosin (amino acids 175-190 and 258-284) appear to a play significant role in imparting these physiological differences that are observed during cardiac and sarcomeric contraction/relaxation. In addition, we have successfully used chimeric tropomyosin molecules to rescue cardiomyopathic diseased mice by normalizing sarcomeric performance. These studies illustrate not only the importance of tropomyosin structure and function for understanding muscle physiology, but also demonstrate how this information can potentially be used for gene therapy.
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Affiliation(s)
- Ganapathy Jagatheesan
- Department of Molecular Genetics, Biochemistry & Microbiology, University of Cincinnati Medical Center, Cincinnati, OH 45267-0524, USA
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37
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Arif SH. A Ca(2+)-binding protein with numerous roles and uses: parvalbumin in molecular biology and physiology. Bioessays 2009; 31:410-21. [PMID: 19274659 DOI: 10.1002/bies.200800170] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Parvalbumins (PVs) are acidic, intracellular Ca(2+)-binding proteins of low molecular weight. They are associated with several Ca(2+)-mediated cellular activities and physiological processes. It has been suggested that PV might function as a "Ca2+ shuttle" transporting Ca2+ from troponin-C (TnC) to the sarcoplasmic reticulum (SR) Ca2+ pump during muscle relaxation. Thus, PV may contribute to the performance of rapid, phasic movements by accelerating the contraction-relaxation cycle of fast-twitch muscle fibers. Interestingly, PVs promote the generation of power stroke in fish by speeding up the rate of relaxation and thus provide impetus to attain maximal sustainable speeds. However, immunological monitoring of diverse tissues demonstrated that PVs are also present in non-muscle cells. The axoplasmic transport and various intracellular secretory mechanisms including the endocrine secretions seem to be controlled by the Ca2+ regulation machinery. Any defect in the Ca2+ handling apparatus may cause several clinical problems; for instance, PV deficiency alters the neuronal activity, a key mechanism leading to epileptic seizures. Moreover, atypical relaxation of the heart results in diastolic dysfunction, which is a major cause of heart failure predominantly among the aged people. PV may offer a unique potential to correct defective relaxation in energetically compromised failing hearts through PV gene transfer. Consequently, PV gene transfer may present a new therapeutic approach to correct cellular disturbances in Ca2+ signaling pathways of diseased organs. Hence, PVs appear to be amazingly useful candidate proteins regulating a variety of cellular functions through action on Ca2+ flux management.
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Affiliation(s)
- Syed Hasan Arif
- Section of Genetics, Department of Zoology, Aligarh Muslim University, Aligarh, UP, India.
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38
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Guinto PJ, Haim TE, Dowell-Martino CC, Sibinga N, Tardiff JC. Temporal and mutation-specific alterations in Ca2+ homeostasis differentially determine the progression of cTnT-related cardiomyopathies in murine models. Am J Physiol Heart Circ Physiol 2009; 297:H614-26. [PMID: 19502551 DOI: 10.1152/ajpheart.01143.2008] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Naturally occurring mutations in cardiac troponin T (cTnT) result in a clinical subset of familial hypertrophic cardiomyopathy. To determine the mechanistic links between thin-filament mutations and cardiovascular phenotypes, we have generated and characterized several transgenic mouse models carrying cTnT mutations. We address two central questions regarding the previously observed changes in myocellular mechanics and Ca(2+) homeostasis: 1) are they characteristic of all severe cTnT mutations, and 2) are they primary (early) or secondary (late) components of the myocellular response? Adult left ventricular myocytes were isolated from 2- and 6-mo-old transgenic mice carrying missense mutations at residue 92, flanking the TNT1 NH(2)-terminal tail domain. Results from R92L and R92W myocytes showed mutation-specific alterations in contraction and relaxation indexes at 2 mo with improvements by 6 mo. Alterations in Ca(2+) kinetics remained consistent with mechanical data in which R92L and R92W exhibited severe diastolic impairments at the early time point that improved with increasing age. A normal regulation of Ca(2+) kinetics in the context of an altered baseline cTnI phosphorylation suggested a pathogenic mechanism at the myofilament level taking precedence for R92L. The quantitation of Ca(2+)-handling proteins in R92W mice revealed a synergistic compensatory mechanism involving an increased Ser16 and Thr17 phosphorylation of phospholamban, contributing to the temporal onset of improved cellular mechanics and Ca(2+) homeostasis. Therefore, independent cTnT mutations in the TNT1 domain result in primary mutation-specific effects and a differential temporal onset of altered myocellular mechanics, Ca(2+) kinetics, and Ca(2+) homeostasis, complex mechanisms which may contribute to the clinical variability in cTnT-related familial hypertrophic cardiomyopathy mutations.
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Affiliation(s)
- Pia J Guinto
- Department of Physiology and Biophysics, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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Davis J, Westfall MV, Townsend D, Blankinship M, Herron TJ, Guerrero-Serna G, Wang W, Devaney E, Metzger JM. Designing heart performance by gene transfer. Physiol Rev 2008; 88:1567-651. [PMID: 18923190 DOI: 10.1152/physrev.00039.2007] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The birth of molecular cardiology can be traced to the development and implementation of high-fidelity genetic approaches for manipulating the heart. Recombinant viral vector-based technology offers a highly effective approach to genetically engineer cardiac muscle in vitro and in vivo. This review highlights discoveries made in cardiac muscle physiology through the use of targeted viral-mediated genetic modification. Here the history of cardiac gene transfer technology and the strengths and limitations of viral and nonviral vectors for gene delivery are reviewed. A comprehensive account is given of the application of gene transfer technology for studying key cardiac muscle targets including Ca(2+) handling, the sarcomere, the cytoskeleton, and signaling molecules and their posttranslational modifications. The primary objective of this review is to provide a thorough analysis of gene transfer studies for understanding cardiac physiology in health and disease. By comparing results obtained from gene transfer with those obtained from transgenesis and biophysical and biochemical methodologies, this review provides a global view of cardiac structure-function with an eye towards future areas of research. The data presented here serve as a basis for discovery of new therapeutic targets for remediation of acquired and inherited cardiac diseases.
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Affiliation(s)
- Jennifer Davis
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA
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40
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Abstract
With increasing knowledge of basic molecular mechanisms governing the development of heart failure (HF), the possibility of specifically targeting key pathological players is evolving. Technology allowing for efficient in vivo transduction of myocardial tissue with long-term expression of a transgene enables translation of basic mechanistic knowledge into potential gene therapy approaches. Gene therapy in HF is in its infancy clinically with the predominant amount of experience being from animal models. Nevertheless, this challenging and promising field is gaining momentum as recent preclinical studies in larger animals have been carried out and, importantly, there are 2 newly initiated phase I clinical trials for HF gene therapy. To put it simply, 2 parameters are needed for achieving success with HF gene therapy: (1) clearly identified detrimental/beneficial molecular targets; and (2) the means to manipulate these targets at a molecular level in a sufficient number of cardiac cells. However, several obstacles do exist on our way to efficient and safe gene transfer to human myocardium. Some of these obstacles are discussed in this review; however, it primarily focuses on the molecular target systems that have been subjected to intense investigation over the last decade in an attempt to make gene therapy for human HF a reality.
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Affiliation(s)
- Leif Erik Vinge
- Center for Translational Medicine, George Zallie and Family Laboratory for Cardiovascular Gene Therapy, Thomas Jefferson University, Philadelphia, PA 19107, USA
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41
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Palpant NJ, Day SM, Herron TJ, Converso KL, Metzger JM. Single histidine-substituted cardiac troponin I confers protection from age-related systolic and diastolic dysfunction. Cardiovasc Res 2008; 80:209-18. [PMID: 18635554 DOI: 10.1093/cvr/cvn198] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
AIMS Contractile dysfunction associated with myocardial ischaemia is a significant cause of morbidity and mortality in the elderly. Strategies to protect the aged heart from ischaemia-mediated pump failure are needed. We hypothesized that troponin I-mediated augmentation of myofilament calcium sensitivity would protect cardiac function in aged mice. METHODS AND RESULTS To address this, we investigated transgenic (Tg) mice expressing a histidine-substituted form of adult cardiac troponin I (cTnI A164H), which increases myofilament calcium sensitivity in a pH-dependent manner. Serial echocardiography revealed that Tg hearts showed significantly improved systolic function at 4 months, which was sustained for 2 years based on ejection fraction and velocity of circumferential fibre shortening. Age-related diastolic dysfunction was also attenuated in Tg mice as assessed by Doppler measurements of the mitral valve inflow and lateral annulus Doppler tissue imaging. During acute hypoxia, cardiac contractility significantly improved in aged Tg mice made evident by increased stroke volume, end systolic pressure, and +dP/dt compared with non-transgenic mice. CONCLUSION This study shows that increasing myofilament function by means of a pH-responsive histidine button engineered into cTnI results in enhanced baseline heart function in Tg mice over their lifetime, and during acute hypoxia improves survival in aged mice by maintaining cardiac contractility.
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Affiliation(s)
- Nathan J Palpant
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, 1301 E. Catherine Street, 7727 Medical Science II, Ann Arbor, MI 48109-0622, USA
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42
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Wang W, Metzger JM. Parvalbumin isoforms for enhancing cardiac diastolic function. Cell Biochem Biophys 2008; 51:1-8. [PMID: 18458829 DOI: 10.1007/s12013-008-9011-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2008] [Accepted: 04/04/2008] [Indexed: 11/28/2022]
Abstract
Diastolic heart failure (DHF), characterized by depressed myocardial relaxation performance and poor ventricular filling, is a distinct form of heart failure accounting for nearly half of the heart failure patients with otherwise normal systolic performance. Defective intracellular calcium (Ca2+) cycling is an important mechanism underlying impaired relaxation in DHF. Recently, genetic manipulation of Ca2+ handling proteins in cardiac myocytes has been explored for its potential therapeutic application in DHF. Specifically, ectopic expression of the skeletal muscle Ca2+ binding protein parvalbumin (Parv) has been shown to accelerate myocardial relaxation in vitro and in vivo. Parv acts as a unique "delayed" Ca2+ buffer during diastole by promoting Ca2+ transient decay and sequestration and corrects diastolic dysfunction in an energy-independent manner. This brief review summarizes the rationale and development of Parv gene transfer approaches for DHF, and in particular, discusses the divergent effects of Parv isoforms on cardiac myocyte Ca2+ handling and contractile function with the long-range goal of alleviating diastolic dysfunction in DHF.
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Affiliation(s)
- Wang Wang
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, 1301 E. Catherine St., 7727 Medical Science II, Ann Arbor, MI 48109-0622, USA
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Day SM, Coutu P, Wang W, Herron T, Turner I, Shillingford M, Lacross NC, Converso KL, Piao L, Li J, Lopatin AN, Metzger JM. Cardiac-directed parvalbumin transgene expression in mice shows marked heart rate dependence of delayed Ca2+ buffering action. Physiol Genomics 2008; 33:312-22. [PMID: 18334547 DOI: 10.1152/physiolgenomics.00302.2007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Relaxation abnormalities are prevalent in heart failure and contribute to clinical outcomes. Disruption of Ca2+ homeostasis in heart failure delays relaxation by prolonging the intracellular Ca2+ transient. We sought to speed cardiac relaxation in vivo by cardiac-directed transgene expression of parvalbumin (Parv), a cytosolic Ca2+ buffer normally expressed in fast-twitch skeletal muscle. A key feature of Parv's function resides in its Ca2+/Mg2+ binding affinities that account for delayed Ca2+ buffering in response to the intracellular Ca2+ transient. Cardiac Parv expression decreased sarcoplasmic reticulum Ca2+ content without otherwise altering intracellular Ca2+ homeostasis. At high physiological mouse heart rates in vivo, Parv modestly accelerated relaxation without affecting cardiac morphology or systolic function. Ex vivo pacing of the isolated heart revealed a marked heart rate dependence of Parv's delayed Ca2+ buffering effects on myocardial performance. As the pacing frequency was lowered (7 to 2.5 Hz), the relaxation rates increased in Parv hearts. However, as pacing rates approached the dynamic range in humans, Parv hearts demonstrated decreased contractility, consistent with Parv buffering systolic Ca2+. Mathematical modeling and in vitro studies provide the underlying mechanism responsible for the frequency-dependent fractional Ca2+ buffering action of Parv. Future studies directed toward refining the dose and frequency-response relationships of Parv in the heart or engineering novel Parv-based Ca2+ buffers with modified Mg2+ and Ca2+ affinities to limit systolic Ca2+ buffering may hold promise for the development of new therapies to remediate relaxation abnormalities in heart failure.
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Affiliation(s)
- Sharlene M Day
- Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0644, USA
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The role of tropomyosin in heart disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2008; 644:132-42. [PMID: 19209819 DOI: 10.1007/978-0-387-85766-4_11] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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45
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Iorga B, Blaudeck N, Solzin J, Neulen A, Stehle I, Lopez Davila AJ, Pfitzer G, Stehle R. Lys184 deletion in troponin I impairs relaxation kinetics and induces hypercontractility in murine cardiac myofibrils. Cardiovasc Res 2007; 77:676-86. [PMID: 18096573 DOI: 10.1093/cvr/cvm113] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
AIMS To understand the functional consequences of the Lys184 deletion in murine cardiac troponin I (mcTnI(DeltaK184)), we have studied the primary effects of this mutation linked to familial hypertrophic cardiomyopathy (FHC) at the sarcomeric level. METHODS AND RESULTS Ca(2+) sensitivity and kinetics of force development and relaxation were investigated in cardiac myofibrils from transgenic mice expressing mcTnI(DeltaK184), as a model which co-segregates with FHC. Ca(2+)-dependent conformational changes (switch-on/off) of the fluorescence-labelled human troponin complex, containing either wild-type hcTnI or mutant hcTnI(DeltaK183), were investigated in myofibrils prepared from the guinea pig left ventricle. Ca(2+) sensitivity and maximum Ca(2+)-activated and passive forces were significantly enhanced and cooperativity was reduced in mutant myofibrils. At partial Ca(2+) activation, mutant but not wild-type myofibrils displayed spontaneous oscillatory contraction of sarcomeres. Both conformational switch-off rates of the incorporated troponin complex and the myofibrillar relaxation kinetics were slowed down by the mutation. Impaired relaxation kinetics and increased force at low [Ca(2+)] were reversed by 2,3-butanedione monoxime (BDM), which traps cross-bridges in non-force-generating states. CONCLUSION We conclude that these changes are not due to alterations of the intrinsic cross-bridge kinetics. The molecular mechanism of sarcomeric diastolic dysfunction in this FHC model is based on the impaired regulatory switch-off kinetics of cTnI, which induces incomplete inhibition of force-generating cross-bridges at low [Ca(2+)] and thereby slows down relaxation of sarcomeres. Ca(2+) sensitization and impairment of the relaxation of sarcomeres induced by this mutation may underlie the enhanced systolic function and diastolic dysfunction at the sarcomeric level.
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Affiliation(s)
- Bogdan Iorga
- Institute of Vegetative Physiology, University of Cologne, Robert-Koch-Strasse 39, Cologne, Germany.
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46
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Rodenbaugh DW, Wang W, Davis J, Edwards T, Potter JD, Metzger JM. Parvalbumin isoforms differentially accelerate cardiac myocyte relaxation kinetics in an animal model of diastolic dysfunction. Am J Physiol Heart Circ Physiol 2007; 293:H1705-13. [PMID: 17545482 DOI: 10.1152/ajpheart.00232.2007] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The cytosolic Ca(2+)/Mg(2+)-binding protein alpha-parvalbumin (alpha-Parv) has been shown to accelerate cardiac relaxation; however, beyond an optimal concentration range, alpha-Parv can also diminish contractility. Mathematical modeling suggests that increasing Parv's Mg(2+) affinity may lower the effective concentration of Parv ([Parv]) to speed relaxation and, thus, limit Parv-mediated depressed contraction. Naturally occurring alpha/beta-Parv isoforms show divergence in amino acid primary structure (57% homology) and cation-binding affinities, with beta-Parv having an estimated 16% greater Mg(2+) affinity and approximately 200% greater Ca(2+) affinity than alpha-Parv. We tested the hypothesis that, at the same or lower estimated [Parv], mechanical relaxation rate would be more significantly accelerated by beta-Parv than by alpha-Parv. Dahl salt-sensitive (DS) rats were used as an experimental model of diastolic dysfunction. Relaxation properties were significantly slowed in adult cardiac myocytes isolated from DS rats compared with controls: time from peak contraction to 50% relaxation was 57 +/- 2 vs. 49 +/- 2 (SE) ms (P < 0.05), validating this model system. DS cardiac myocytes were subsequently transduced with alpha- or beta-Parv adenoviral vectors. Upon Parv gene transfer, beta-Parv caused significantly faster relaxation than alpha-Parv (P < 0.05), even though estimated [beta-Parv] was approximately 10% of [alpha-Parv]. This comparative analysis showing distinct functional outcomes raises the prospect of utilizing naturally occurring Parv variants to address disease-associated slowed cardiac relaxation.
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Affiliation(s)
- David W Rodenbaugh
- Department of Molecular and Integrative Physiology, University of Michigan, 1301 E. Catherine St., Ann Arbor, MI 48109-0622, USA
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47
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Frazier A, Murphy AM. Repairing the myofilaments to heal the heart. Am J Physiol Heart Circ Physiol 2007; 293:H907-8. [PMID: 17416606 DOI: 10.1152/ajpheart.00272.2007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
MESH Headings
- Actin Cytoskeleton/drug effects
- Actin Cytoskeleton/metabolism
- Animals
- Calcium/metabolism
- Cardiomyopathy, Hypertrophic, Familial/genetics
- Cardiomyopathy, Hypertrophic, Familial/metabolism
- Cardiomyopathy, Hypertrophic, Familial/pathology
- Cardiomyopathy, Hypertrophic, Familial/physiopathology
- Cardiomyopathy, Hypertrophic, Familial/therapy
- Disease Models, Animal
- Gene Transfer Techniques
- Genetic Therapy/methods
- Genotype
- Mice
- Mice, Transgenic
- Mutation
- Myocardial Contraction/drug effects
- Myocardium/metabolism
- Myocardium/pathology
- Phenotype
- RNA, Messenger/metabolism
- Recombinant Fusion Proteins/metabolism
- Severity of Illness Index
- Tropomyosin/genetics
- Tropomyosin/metabolism
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Affiliation(s)
- Aisha Frazier
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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48
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Jagatheesan G, Rajan S, Petrashevskaya N, Schwartz A, Boivin G, Arteaga GM, Solaro RJ, Liggett SB, Wieczorek DF. Rescue of tropomyosin-induced familial hypertrophic cardiomyopathy mice by transgenesis. Am J Physiol Heart Circ Physiol 2007; 293:H949-58. [PMID: 17416600 DOI: 10.1152/ajpheart.01341.2006] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Familial hypertrophic cardiomyopathy (FHC) is a disease caused by mutations in contractile proteins of the sarcomere. Our laboratory developed a mouse model of FHC with a mutation in the thin filament protein alpha-tropomyosin (TM) at amino acid 180 (Glu180Gly). The hearts of these mice exhibit dramatic systolic and diastolic dysfunction, and their myofilaments demonstrate increased calcium sensitivity. The mice also develop severe cardiac hypertrophy, with death ensuing by 6 mo. In an attempt to normalize calcium sensitivity in the cardiomyofilaments of the hypertrophic mice, we generated a chimeric alpha-/beta-TM protein that decreases calcium sensitivity in transgenic mouse cardiac myofilaments. By mating mice from these two models together, we tested the hypothesis that an attenuation of myofilament calcium sensitivity would modulate the severe physiological and pathological consequences of the FHC mutation. These double-transgenic mice "rescue" the hypertrophic phenotype by exhibiting a normal morphology with no pathological abnormalities. Physiological analyses of these rescued mice show improved cardiac function and normal myofilament calcium sensitivity. These results demonstrate that alterations in calcium response by modification of contractile proteins can prevent the pathological and physiological effects of this disease.
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MESH Headings
- Actin Cytoskeleton/drug effects
- Actin Cytoskeleton/metabolism
- Adrenergic beta-Agonists/pharmacology
- Animals
- Calcium/metabolism
- Cardiomyopathy, Hypertrophic, Familial/genetics
- Cardiomyopathy, Hypertrophic, Familial/metabolism
- Cardiomyopathy, Hypertrophic, Familial/pathology
- Cardiomyopathy, Hypertrophic, Familial/physiopathology
- Cardiomyopathy, Hypertrophic, Familial/therapy
- Disease Models, Animal
- Dose-Response Relationship, Drug
- Gene Transfer Techniques
- Genetic Therapy/methods
- Genotype
- Heart Rate
- Isoproterenol/pharmacology
- Mice
- Mice, Transgenic
- Mutation
- Myocardial Contraction/drug effects
- Myocardium/metabolism
- Myocardium/pathology
- Phenotype
- RNA, Messenger/metabolism
- Recombinant Fusion Proteins/metabolism
- Sarcomeres/metabolism
- Severity of Illness Index
- Time Factors
- Tropomyosin/genetics
- Tropomyosin/metabolism
- Ventricular Pressure
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Affiliation(s)
- Ganapathy Jagatheesan
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0524, USA
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49
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Haim TE, Dowell C, Diamanti T, Scheuer J, Tardiff JC. Independent FHC-related cardiac troponin T mutations exhibit specific alterations in myocellular contractility and calcium kinetics. J Mol Cell Cardiol 2007; 42:1098-110. [PMID: 17490679 DOI: 10.1016/j.yjmcc.2007.03.906] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2006] [Revised: 03/19/2007] [Accepted: 03/26/2007] [Indexed: 10/23/2022]
Abstract
Mutations in cardiac troponin T (cTnT) are linked to a severe form of Familial Hypertrophic Cardiomyopathy. Patients carrying mutations flanking the tropomyosin-binding domain of cTnT (R92L and Delta160E) develop distinct clinical syndromes. In order to better understand the cellular pathophysiology underlying these clinically relevant differences, we studied isolated adult left ventricular myocytes from independent transgenic cTnT mouse lines carrying either a 35% (Delta160E) or 50% (R92L) replacement of the endogenous cTnT with the mutant forms. Measurement of baseline myocellular contraction revealed that the Delta160E cells had significant decreases in the peak rate of contraction and percent shortening as compared to either R92L or Non-TG myocytes. In addition, while both Delta160E and R92L myocytes demonstrated a decrease in the peak rate of relaxation as compared to Non-TG, the magnitude of the difference was significantly greater in Delta160E cells. Concurrent myocyte [Ca2+](i) transient measurements revealed that while the alterations in the peak rates and times of the rise and decline of the [Ca2+](i) transient were similar to the changes in the respective measures of sarcomeric mechanics, R92L cells also exhibited reduced rates of the rise and decline of the [Ca2+](i) transient but did not exhibit these reductions in terms of sarcomeric mechanics. Of note, only Delta160E, and not R92L myocytes, demonstrated significant reductions in SR Ca2+ load and uptake, corresponding to the impairments seen in the [Ca2+](i) and mechanical transients. Finally, Western analysis revealed a significant Delta160E-specific reduction in the SERCA2a/PLB ratio, which may well underlie the observed alterations in Ca2+ homeostasis. Therefore, independent cTnT mutations result in significant mutation-specific effects in Ca2+ handling that may, in part, contribute to the observed clinical variability in cTnT-related FHC.
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Affiliation(s)
- Todd E Haim
- Department of Physiology and Biophysics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
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50
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Wilwert JL, Madhoun NM, Coughlin DJ. Parvalbumin correlates with relaxation rate in the swimming muscle of sheepshead and kingfish. ACTA ACUST UNITED AC 2006; 209:227-37. [PMID: 16391345 DOI: 10.1242/jeb.01987] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Parvalbumin is a muscle protein that aids in relaxation from contraction. Parvalbumin binds myoplasmic Ca(2+) during contractions, reducing calcium concentration and enhancing relaxation. Different isoforms of parvalbumin have varying affinities for calcium, and relaxation rates in skeletal muscle may be affected by variations in the isoforms of parvalbumin expressed. This study examines the effect of expression levels of parvalbumin isoforms on relaxation rate in the sheepshead, Archosargus probatocephalus (Pisces, F. Sparidae). We measured relaxation rate of each of the three fiber types, white (fast-twitch), red (slow-twitch) and pink (intermediate), from three longitudinal body positions. Sheepshead show a significant longitudinal shift in relaxation rate in red muscle, with anterior muscle displaying faster rates of relaxation than posterior, but this pattern was not significant in the pink and white muscle. We hypothesized that patterns of parvalbumin expression determine relaxation rate along the length of the fish. The prediction is that total parvalbumin content and the relative expression of parvalbumin isoforms will differ between the anterior and posterior red muscle, but little longitudinal variation will be observed in parvalbumin expression in white and pink muscle. We successfully employed protein electrophoresis (SDS-PAGE) with western blots to identify two parvalbumin isoforms in each muscle fiber type. SDS-PAGE and densitometry were used to determine the relative expression levels of the two parvalbumin isoforms and total parvalbumin expression. Red muscle displays a significant shift, from anterior to posterior, in the relative expression of the two isoforms, both in their relative contribution and in total parvalbumin content, but white and pink muscle did not. The red muscle of southern kingfish, Menticirrhus americanus (Pisces, F. Scianidae) showed a pattern similar to the red muscle of sheepshead.
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Affiliation(s)
- Jennifer L Wilwert
- Widener University, Department of Biology, One University Place, Chester, PA 19013, USA
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