1
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Chun YW, Miyamoto M, Williams CH, Neitzel LR, Silver-Isenstadt M, Cadar AG, Fuller DT, Fong DC, Liu H, Lease R, Kim S, Katagiri M, Durbin MD, Wang KC, Feaster TK, Sheng CC, Neely MD, Sreenivasan U, Cortes-Gutierrez M, Finn AV, Schot R, Mancini GMS, Ament SA, Ess KC, Bowman AB, Han Z, Bichell DP, Su YR, Hong CC. Impaired Reorganization of Centrosome Structure Underlies Human Infantile Dilated Cardiomyopathy. Circulation 2023; 147:1291-1303. [PMID: 36970983 PMCID: PMC10133173 DOI: 10.1161/circulationaha.122.060985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 02/22/2023] [Indexed: 03/29/2023]
Abstract
BACKGROUND During cardiomyocyte maturation, the centrosome, which functions as a microtubule organizing center in cardiomyocytes, undergoes dramatic structural reorganization where its components reorganize from being localized at the centriole to the nuclear envelope. This developmentally programmed process, referred to as centrosome reduction, has been previously associated with cell cycle exit. However, understanding of how this process influences cardiomyocyte cell biology, and whether its disruption results in human cardiac disease, remains unknown. We studied this phenomenon in an infant with a rare case of infantile dilated cardiomyopathy (iDCM) who presented with left ventricular ejection fraction of 18% and disrupted sarcomere and mitochondria structure. METHODS We performed an analysis beginning with an infant who presented with a rare case of iDCM. We derived induced pluripotent stem cells from the patient to model iDCM in vitro. We performed whole exome sequencing on the patient and his parents for causal gene analysis. CRISPR/Cas9-mediated gene knockout and correction in vitro were used to confirm whole exome sequencing results. Zebrafish and Drosophila models were used for in vivo validation of the causal gene. Matrigel mattress technology and single-cell RNA sequencing were used to characterize iDCM cardiomyocytes further. RESULTS Whole exome sequencing and CRISPR/Cas9 gene knockout/correction identified RTTN, the gene encoding the centrosomal protein RTTN (rotatin), as the causal gene underlying the patient's condition, representing the first time a centrosome defect has been implicated in a nonsyndromic dilated cardiomyopathy. Genetic knockdowns in zebrafish and Drosophila confirmed an evolutionarily conserved requirement of RTTN for cardiac structure and function. Single-cell RNA sequencing of iDCM cardiomyocytes showed impaired maturation of iDCM cardiomyocytes, which underlie the observed cardiomyocyte structural and functional deficits. We also observed persistent localization of the centrosome at the centriole, contrasting with expected programmed perinuclear reorganization, which led to subsequent global microtubule network defects. In addition, we identified a small molecule that restored centrosome reorganization and improved the structure and contractility of iDCM cardiomyocytes. CONCLUSIONS This study is the first to demonstrate a case of human disease caused by a defect in centrosome reduction. We also uncovered a novel role for RTTN in perinatal cardiac development and identified a potential therapeutic strategy for centrosome-related iDCM. Future study aimed at identifying variants in centrosome components may uncover additional contributors to human cardiac disease.
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Affiliation(s)
- Young Wook Chun
- Division of Cardiovascular Medicine, Department of Medicine, University of Maryland Medical Center, Baltimore, MD 21201
| | - Matthew Miyamoto
- Division of Cardiovascular Medicine, Department of Medicine, University of Maryland Medical Center, Baltimore, MD 21201
| | - Charles H. Williams
- Division of Cardiovascular Medicine, Department of Medicine, University of Maryland Medical Center, Baltimore, MD 21201
| | - Leif R. Neitzel
- Division of Cardiovascular Medicine, Department of Medicine, University of Maryland Medical Center, Baltimore, MD 21201
| | - Maya Silver-Isenstadt
- Division of Cardiovascular Medicine, Department of Medicine, University of Maryland Medical Center, Baltimore, MD 21201
| | - Adrian G. Cadar
- Division of Cardiovascular Medicine, Vanderbilt University Medical Center, Nashville, TN 37201
| | - Daniela T. Fuller
- Division of Cardiovascular Medicine, Department of Medicine, University of Maryland Medical Center, Baltimore, MD 21201
| | - Daniel C. Fong
- Division of Cardiovascular Medicine, Department of Medicine, University of Maryland Medical Center, Baltimore, MD 21201
| | - Hanhan Liu
- Division of Cardiovascular Medicine, Department of Medicine, University of Maryland Medical Center, Baltimore, MD 21201
| | - Robert Lease
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Sungseek Kim
- Division of Cardiovascular Medicine, Vanderbilt University Medical Center, Nashville, TN 37201
| | - Mikako Katagiri
- Division of Cardiovascular Medicine, Vanderbilt University Medical Center, Nashville, TN 37201
| | - Matthew D. Durbin
- Division of Neonatology-Perinatology, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN 26202
| | - Kuo-Chen Wang
- Division of Cardiovascular Medicine, Department of Medicine, University of Maryland Medical Center, Baltimore, MD 21201
| | - Tromondae K. Feaster
- Division of Cardiovascular Medicine, Vanderbilt University Medical Center, Nashville, TN 37201
| | - Calvin C. Sheng
- Division of Cardiovascular Medicine, Vanderbilt University Medical Center, Nashville, TN 37201
| | - M. Diana Neely
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37201
| | - Urmila Sreenivasan
- Division of Cardiovascular Medicine, Department of Medicine, University of Maryland Medical Center, Baltimore, MD 21201
| | - Marcia Cortes-Gutierrez
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Aloke V. Finn
- Division of Cardiovascular Medicine, Department of Medicine, University of Maryland Medical Center, Baltimore, MD 21201
| | - Rachel Schot
- Division of Neonatology-Perinatology, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN 26202
| | - Grazia M. S. Mancini
- Department of Clinical Genetics, Erasmus University Medical Center (Erasmus MC), P.O. Box 2040, 3000 CA Rotterdam, The Netherlands
| | - Seth A. Ament
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Kevin C. Ess
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN37201
| | - Aaron B. Bowman
- School of Health Sciences, Purdue University, West Lafayette, IN 47906
| | - Zhe Han
- Division of Cardiovascular Medicine, Department of Medicine, University of Maryland Medical Center, Baltimore, MD 21201
| | - David P. Bichell
- Department of Pediatric Cardiac Surgery, Vanderbilt University Medical Center, Nashville, TN 37201
| | - Yan Ru Su
- Division of Cardiovascular Medicine, Vanderbilt University Medical Center, Nashville, TN 37201
| | - Charles C. Hong
- Division of Cardiovascular Medicine, Department of Medicine, University of Maryland Medical Center, Baltimore, MD 21201
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Gu W, Li Q, Ding M, Cao Y, Wang T, Zhang S, Feng J, Li H, Zheng L. Regular Exercise Rescues Heart Function Defects and Shortens the Lifespan of Drosophila Caused by dMnM Downregulation. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:16554. [PMID: 36554435 PMCID: PMC9779684 DOI: 10.3390/ijerph192416554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 12/06/2022] [Accepted: 12/07/2022] [Indexed: 06/17/2023]
Abstract
Although studies have shown that myomesin 2 (MYOM2) mutations can lead to hypertrophic cardiomyopathy (HCM), a common cardiovascular disease that has a serious impact on human life, the effect of MYOM2 on cardiac function and lifespan in humans is unknown. In this study, dMnM (MYOM2 homologs) knockdown in cardiomyocytes resulted in diastolic cardiac defects (diastolic dysfunction and arrhythmias) and increased cardiac oxidative stress. Furthermore, the knockdown of dMnM in indirect flight muscle (IFM) reduced climbing ability and shortened lifespan. However, regular exercise significantly ameliorated diastolic cardiac dysfunction, arrhythmias, and oxidative stress triggered by dMnM knockdown in cardiac myocytes and also reversed the reduction in climbing ability and shortening of lifespan caused by dMnM knockdown in Drosophila IFM. In conclusion, these results suggest that Drosophila cardiomyocyte dMnM knockdown leads to cardiac functional defects, while dMnM knockdown in IFM affects climbing ability and lifespan. Furthermore, regular exercise effectively upregulates cardiomyocyte dMnM expression levels and ameliorates cardiac functional defects caused by Drosophila cardiomyocyte dMnM knockdown by increasing cardiac antioxidant capacity. Importantly, regular exercise ameliorates the shortened lifespan caused by dMnM knockdown in IFM.
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3
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Trujillo AS, Hsu KH, Viswanathan MC, Cammarato A, Bernstein SI. The R369 Myosin Residue within Loop 4 Is Critical for Actin Binding and Muscle Function in Drosophila. Int J Mol Sci 2022; 23:ijms23052533. [PMID: 35269675 PMCID: PMC8910226 DOI: 10.3390/ijms23052533] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 02/16/2022] [Accepted: 02/17/2022] [Indexed: 02/06/2023] Open
Abstract
The myosin molecular motor interacts with actin filaments in an ATP-dependent manner to yield muscle contraction. Myosin heavy chain residue R369 is located within loop 4 at the actin-tropomyosin interface of myosin's upper 50 kDa subdomain. To probe the importance of R369, we introduced a histidine mutation of that residue into Drosophila myosin and implemented an integrative approach to determine effects at the biochemical, cellular, and whole organism levels. Substituting the similarly charged but bulkier histidine residue reduces maximal actin binding in vitro without affecting myosin ATPase activity. R369H mutants exhibit impaired flight ability that is dominant in heterozygotes and progressive with age in homozygotes. Indirect flight muscle ultrastructure is normal in mutant homozygotes, suggesting that assembly defects or structural deterioration of myofibrils are not causative of reduced flight. Jump ability is also reduced in homozygotes. In contrast to these skeletal muscle defects, R369H mutants show normal heart ultrastructure and function, suggesting that this residue is differentially sensitive to perturbation in different myosin isoforms or muscle types. Overall, our findings indicate that R369 is an actin binding residue that is critical for myosin function in skeletal muscles, and suggest that more severe perturbations at this residue may cause human myopathies through a similar mechanism.
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Affiliation(s)
- Adriana S. Trujillo
- Department of Biology, Molecular Biology Institute, Heart Institute, San Diego State University, San Diego, CA 92182, USA; (A.S.T.); (K.H.H.)
| | - Karen H. Hsu
- Department of Biology, Molecular Biology Institute, Heart Institute, San Diego State University, San Diego, CA 92182, USA; (A.S.T.); (K.H.H.)
| | - Meera C. Viswanathan
- Department of Medicine, Division of Cardiology, Johns Hopkins University, Baltimore, MD 21205, USA; (M.C.V.); (A.C.)
| | - Anthony Cammarato
- Department of Medicine, Division of Cardiology, Johns Hopkins University, Baltimore, MD 21205, USA; (M.C.V.); (A.C.)
| | - Sanford I. Bernstein
- Department of Biology, Molecular Biology Institute, Heart Institute, San Diego State University, San Diego, CA 92182, USA; (A.S.T.); (K.H.H.)
- Correspondence:
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4
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Drosophila Heart as a Model for Cardiac Development and Diseases. Cells 2021; 10:cells10113078. [PMID: 34831301 PMCID: PMC8623483 DOI: 10.3390/cells10113078] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 11/04/2021] [Accepted: 11/05/2021] [Indexed: 01/26/2023] Open
Abstract
The Drosophila heart, also referred to as the dorsal vessel, pumps the insect blood, the hemolymph. The bilateral heart primordia develop from the most dorsally located mesodermal cells, migrate coordinately, and fuse to form the cardiac tube. Though much simpler, the fruit fly heart displays several developmental and functional similarities to the vertebrate heart and, as we discuss here, represents an attractive model system for dissecting mechanisms of cardiac aging and heart failure and identifying genes causing congenital heart diseases. Fast imaging technologies allow for the characterization of heartbeat parameters in the adult fly and there is growing evidence that cardiac dysfunction in human diseases could be reproduced and analyzed in Drosophila, as discussed here for heart defects associated with the myotonic dystrophy type 1. Overall, the power of genetics and unsuspected conservation of genes and pathways puts Drosophila at the heart of fundamental and applied cardiac research.
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Tuthill II BF, Quaglia CJ, O'Hara E, Musselman LP. Loss of Stearoyl-CoA desaturase 1 leads to cardiac dysfunction and lipotoxicity. J Exp Biol 2021; 224:jeb240432. [PMID: 34423827 PMCID: PMC8502255 DOI: 10.1242/jeb.240432] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 08/16/2021] [Indexed: 12/28/2022]
Abstract
Diets high in carbohydrates are associated with type 2 diabetes and its co-morbidities, including hyperglycemia, hyperlipidemia, obesity, hepatic steatosis and cardiovascular disease. We used a high-sugar diet to study the pathophysiology of diet-induced metabolic disease in Drosophila melanogaster. High-sugar diets produce hyperglycemia, obesity, insulin resistance and cardiomyopathy in flies, along with ectopic accumulation of toxic lipids, or lipotoxicity. Stearoyl-CoA desaturase 1 is an enzyme that contributes to long-chain fatty acid metabolism by introducing a double bond into the acyl chain. Knockdown of stearoyl-CoA desaturase 1 in the fat body reduced lipogenesis and exacerbated pathophysiology in flies reared on high-sucrose diets. These flies exhibited dyslipidemia and growth deficiency in addition to defects in cardiac and gut function. We assessed the lipidome of these flies using tandem mass spectrometry to provide insight into the relationship between potentially lipotoxic species and type 2 diabetes-like pathophysiology. Oleic acid supplementation is able to rescue a variety of phenotypes produced by stearoyl-CoA desaturase 1 RNAi, including fly mass, triglyceride storage, gut development and cardiac failure. Taken together, these data suggest a protective role for monounsaturated fatty acids in diet-induced metabolic disease phenotypes.
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6
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Wüst RCI, Coolen BF, Held NM, Daal MRR, Alizadeh Tazehkandi V, Baks-te Bulte L, Wiersma M, Kuster DWD, Brundel BJJM, van Weeghel M, Strijkers GJ, Houtkooper RH. The Antibiotic Doxycycline Impairs Cardiac Mitochondrial and Contractile Function. Int J Mol Sci 2021; 22:4100. [PMID: 33921053 PMCID: PMC8071362 DOI: 10.3390/ijms22084100] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 04/08/2021] [Accepted: 04/08/2021] [Indexed: 12/22/2022] Open
Abstract
Tetracycline antibiotics act by inhibiting bacterial protein translation. Given the bacterial ancestry of mitochondria, we tested the hypothesis that doxycycline-which belongs to the tetracycline class-reduces mitochondrial function, and results in cardiac contractile dysfunction in cultured H9C2 cardiomyoblasts, adult rat cardiomyocytes, in Drosophila and in mice. Ampicillin and carbenicillin were used as control antibiotics since these do not interfere with mitochondrial translation. In line with its specific inhibitory effect on mitochondrial translation, doxycycline caused a mitonuclear protein imbalance in doxycycline-treated H9C2 cells, reduced maximal mitochondrial respiration, particularly with complex I substrates, and mitochondria appeared fragmented. Flux measurements using stable isotope tracers showed a shift away from OXPHOS towards glycolysis after doxycycline exposure. Cardiac contractility measurements in adult cardiomyocytes and Drosophila melanogaster hearts showed an increased diastolic calcium concentration, and a higher arrhythmicity index. Systolic and diastolic dysfunction were observed after exposure to doxycycline. Mice treated with doxycycline showed mitochondrial complex I dysfunction, reduced OXPHOS capacity and impaired diastolic function. Doxycycline exacerbated diastolic dysfunction and reduced ejection fraction in a diabetes mouse model vulnerable for metabolic derangements. We therefore conclude that doxycycline impairs mitochondrial function and causes cardiac dysfunction.
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Affiliation(s)
- Rob C. I. Wüst
- Laboratory Genetic Metabolic Diseases, Amsterdam Gastroenterology, Endocrinology, and Metabolism, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands; (N.M.H.); (V.A.T.); (M.v.W.)
- Biomedical Engineering and Physics, Amsterdam Cardiovascular Sciences, University of Amsterdam, Amsterdam UMC, 1105 AZ Amsterdam, The Netherlands; (B.F.C.); (M.R.R.D.); (G.J.S.)
- Laboratory for Myology, Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Amsterdam Movement Sciences, Vrije University Amsterdam, 1081 BT Amsterdam, The Netherlands
| | - Bram F. Coolen
- Biomedical Engineering and Physics, Amsterdam Cardiovascular Sciences, University of Amsterdam, Amsterdam UMC, 1105 AZ Amsterdam, The Netherlands; (B.F.C.); (M.R.R.D.); (G.J.S.)
| | - Ntsiki M. Held
- Laboratory Genetic Metabolic Diseases, Amsterdam Gastroenterology, Endocrinology, and Metabolism, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands; (N.M.H.); (V.A.T.); (M.v.W.)
| | - Mariah R. R. Daal
- Biomedical Engineering and Physics, Amsterdam Cardiovascular Sciences, University of Amsterdam, Amsterdam UMC, 1105 AZ Amsterdam, The Netherlands; (B.F.C.); (M.R.R.D.); (G.J.S.)
| | - Vida Alizadeh Tazehkandi
- Laboratory Genetic Metabolic Diseases, Amsterdam Gastroenterology, Endocrinology, and Metabolism, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands; (N.M.H.); (V.A.T.); (M.v.W.)
| | - Luciënne Baks-te Bulte
- Department of Physiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, VU University Medical Center, 1081 HZ Amsterdam, The Netherlands; (L.B.-t.B.); (M.W.); (D.W.D.K.); (B.J.J.M.B.)
| | - Marit Wiersma
- Department of Physiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, VU University Medical Center, 1081 HZ Amsterdam, The Netherlands; (L.B.-t.B.); (M.W.); (D.W.D.K.); (B.J.J.M.B.)
| | - Diederik W. D. Kuster
- Department of Physiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, VU University Medical Center, 1081 HZ Amsterdam, The Netherlands; (L.B.-t.B.); (M.W.); (D.W.D.K.); (B.J.J.M.B.)
| | - Bianca J. J. M. Brundel
- Department of Physiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, VU University Medical Center, 1081 HZ Amsterdam, The Netherlands; (L.B.-t.B.); (M.W.); (D.W.D.K.); (B.J.J.M.B.)
| | - Michel van Weeghel
- Laboratory Genetic Metabolic Diseases, Amsterdam Gastroenterology, Endocrinology, and Metabolism, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands; (N.M.H.); (V.A.T.); (M.v.W.)
| | - Gustav J. Strijkers
- Biomedical Engineering and Physics, Amsterdam Cardiovascular Sciences, University of Amsterdam, Amsterdam UMC, 1105 AZ Amsterdam, The Netherlands; (B.F.C.); (M.R.R.D.); (G.J.S.)
- Department of Radiology, Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Riekelt H. Houtkooper
- Laboratory Genetic Metabolic Diseases, Amsterdam Gastroenterology, Endocrinology, and Metabolism, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands; (N.M.H.); (V.A.T.); (M.v.W.)
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7
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Walls S, Diop S, Birse R, Elmen L, Gan Z, Kalvakuri S, Pineda S, Reddy C, Taylor E, Trinh B, Vogler G, Zarndt R, McCulloch A, Lee P, Bhattacharya S, Bodmer R, Ocorr K. Prolonged Exposure to Microgravity Reduces Cardiac Contractility and Initiates Remodeling in Drosophila. Cell Rep 2020; 33:108445. [PMID: 33242407 PMCID: PMC7787258 DOI: 10.1016/j.celrep.2020.108445] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 11/01/2020] [Accepted: 11/06/2020] [Indexed: 01/08/2023] Open
Abstract
Understanding the effects of microgravity on human organs is crucial to exploration of low-earth orbit, the moon, and beyond. Drosophila can be sent to space in large numbers to examine the effects of microgravity on heart structure and function, which is fundamentally conserved from flies to humans. Flies reared in microgravity exhibit cardiac constriction with myofibrillar remodeling and diminished output. RNA sequencing (RNA-seq) in isolated hearts revealed reduced expression of sarcomeric/extracellular matrix (ECM) genes and dramatically increased proteasomal gene expression, consistent with the observed compromised, smaller hearts and suggesting abnormal proteostasis. This was examined further on a second flight in which we found dramatically elevated proteasome aggregates co-localizing with increased amyloid and polyQ deposits. Remarkably, in long-QT causing sei/hERG mutants, proteasomal gene expression at 1g, although less than the wild-type expression, was nevertheless increased in microgravity. Therefore, cardiac remodeling and proteostatic stress may be a fundamental response of heart muscle to microgravity.
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Affiliation(s)
- Stanley Walls
- Development, Aging & Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92037, USA
| | - Soda Diop
- Development, Aging & Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92037, USA
| | - Ryan Birse
- Development, Aging & Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92037, USA
| | - Lisa Elmen
- Development, Aging & Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92037, USA
| | - Zhuohui Gan
- Department of Bioengineering, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Sreehari Kalvakuri
- Development, Aging & Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92037, USA
| | - Santiago Pineda
- Development, Aging & Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92037, USA
| | - Curran Reddy
- Space Biosciences Division, NASA Ames Research Center, Mailstop 236-5, Moffett Field, CA 94035, USA
| | - Erika Taylor
- Development, Aging & Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92037, USA
| | - Bosco Trinh
- Development, Aging & Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92037, USA
| | - Georg Vogler
- Development, Aging & Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92037, USA
| | - Rachel Zarndt
- Development, Aging & Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92037, USA
| | - Andrew McCulloch
- Department of Bioengineering, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Peter Lee
- Department of Pathology and Laboratory Medicine, Brown University, 69 Brown Street, Providence, RI 02912, USA
| | - Sharmila Bhattacharya
- Space Biosciences Division, NASA Ames Research Center, Mailstop 236-5, Moffett Field, CA 94035, USA
| | - Rolf Bodmer
- Development, Aging & Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92037, USA.
| | - Karen Ocorr
- Development, Aging & Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92037, USA.
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8
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Madan A, Viswanathan MC, Woulfe KC, Schmidt W, Sidor A, Liu T, Nguyen TH, Trinh B, Wilson C, Madathil S, Vogler G, O'Rourke B, Biesiadecki BJ, Tobacman LS, Cammarato A. TNNT2 mutations in the tropomyosin binding region of TNT1 disrupt its role in contractile inhibition and stimulate cardiac dysfunction. Proc Natl Acad Sci U S A 2020; 117:18822-18831. [PMID: 32690703 PMCID: PMC7414051 DOI: 10.1073/pnas.2001692117] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Muscle contraction is regulated by the movement of end-to-end-linked troponin-tropomyosin complexes over the thin filament surface, which uncovers or blocks myosin binding sites along F-actin. The N-terminal half of troponin T (TnT), TNT1, independently promotes tropomyosin-based, steric inhibition of acto-myosin associations, in vitro. Recent structural models additionally suggest TNT1 may restrain the uniform, regulatory translocation of tropomyosin. Therefore, TnT potentially contributes to striated muscle relaxation; however, the in vivo functional relevance and molecular basis of this noncanonical role remain unclear. Impaired relaxation is a hallmark of hypertrophic and restrictive cardiomyopathies (HCM and RCM). Investigating the effects of cardiomyopathy-causing mutations could help clarify TNT1's enigmatic inhibitory property. We tested the hypothesis that coupling of TNT1 with tropomyosin's end-to-end overlap region helps anchor tropomyosin to an inhibitory position on F-actin, where it deters myosin binding at rest, and that, correspondingly, cross-bridge cycling is defectively suppressed under diastolic/low Ca2+ conditions in the presence of HCM/RCM lesions. The impact of TNT1 mutations on Drosophila cardiac performance, rat myofibrillar and cardiomyocyte properties, and human TNT1's propensity to inhibit myosin-driven, F-actin-tropomyosin motility were evaluated. Our data collectively demonstrate that removing conserved, charged residues in TNT1's tropomyosin-binding domain impairs TnT's contribution to inhibitory tropomyosin positioning and relaxation. Thus, TNT1 may modulate acto-myosin activity by optimizing F-actin-tropomyosin interfacial contacts and by binding to actin, which restrict tropomyosin's movement to activating configurations. HCM/RCM mutations, therefore, highlight TNT1's essential role in contractile regulation by diminishing its tropomyosin-anchoring effects, potentially serving as the initial trigger of pathology in our animal models and humans.
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Affiliation(s)
- Aditi Madan
- Department of Medicine, Division of Cardiology, Johns Hopkins University, Baltimore, MD 21205
| | - Meera C Viswanathan
- Department of Medicine, Division of Cardiology, Johns Hopkins University, Baltimore, MD 21205
| | - Kathleen C Woulfe
- Department of Medicine, Division of Cardiology, University of Colorado Denver, Aurora, CO 80045
| | - William Schmidt
- Department of Medicine, Division of Cardiology, Johns Hopkins University, Baltimore, MD 21205
| | - Agnes Sidor
- Department of Medicine, Division of Cardiology, Johns Hopkins University, Baltimore, MD 21205
| | - Ting Liu
- Department of Medicine, Division of Cardiology, Johns Hopkins University, Baltimore, MD 21205
| | - Tran H Nguyen
- Department of Medicine, Division of Cardiology, Johns Hopkins University, Baltimore, MD 21205
| | - Bosco Trinh
- Development, Aging and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037
| | - Cortney Wilson
- Department of Medicine, Division of Cardiology, University of Colorado Denver, Aurora, CO 80045
| | - Sineej Madathil
- Department of Medicine, University of Illinois College of Medicine, Chicago, IL 60612
| | - Georg Vogler
- Development, Aging and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037
| | - Brian O'Rourke
- Department of Medicine, Division of Cardiology, Johns Hopkins University, Baltimore, MD 21205
| | - Brandon J Biesiadecki
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH 43210
- The Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210
| | - Larry S Tobacman
- Department of Medicine, University of Illinois College of Medicine, Chicago, IL 60612
| | - Anthony Cammarato
- Department of Medicine, Division of Cardiology, Johns Hopkins University, Baltimore, MD 21205;
- Department of Physiology, Johns Hopkins University, Baltimore, MD 21205
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9
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Viswanathan MC, Schmidt W, Franz P, Rynkiewicz MJ, Newhard CS, Madan A, Lehman W, Swank DM, Preller M, Cammarato A. A role for actin flexibility in thin filament-mediated contractile regulation and myopathy. Nat Commun 2020; 11:2417. [PMID: 32415060 PMCID: PMC7229152 DOI: 10.1038/s41467-020-15922-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 03/30/2020] [Indexed: 12/20/2022] Open
Abstract
Striated muscle contraction is regulated by the translocation of troponin-tropomyosin strands over the thin filament surface. Relaxation relies partly on highly-favorable, conformation-dependent electrostatic contacts between actin and tropomyosin, which position tropomyosin such that it impedes actomyosin associations. Impaired relaxation and hypercontractile properties are hallmarks of various muscle disorders. The α-cardiac actin M305L hypertrophic cardiomyopathy-causing mutation lies near residues that help confine tropomyosin to an inhibitory position along thin filaments. Here, we investigate M305L actin in vivo, in vitro, and in silico to resolve emergent pathological properties and disease mechanisms. Our data suggest the mutation reduces actin flexibility and distorts the actin-tropomyosin electrostatic energy landscape that, in muscle, result in aberrant contractile inhibition and excessive force. Thus, actin flexibility may be required to establish and maintain interfacial contacts with tropomyosin as well as facilitate its movement over distinct actin surface features and is, therefore, likely necessary for proper regulation of contraction. The α-cardiac actin M305L hypertrophic cardiomyopathy-causing mutation is located near residues that help confine tropomyosin to an inhibitory position along thin filaments. Here the authors assessed M305L actin in vivo, in vitro, and in silico to characterize emergent pathological properties and define the mechanistic basis of disease.
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Affiliation(s)
- Meera C Viswanathan
- Department of Medicine, Division of Cardiology, Johns Hopkins University, 720 Rutland Avenue, Baltimore, MD, 21205, USA
| | - William Schmidt
- Department of Medicine, Division of Cardiology, Johns Hopkins University, 720 Rutland Avenue, Baltimore, MD, 21205, USA
| | - Peter Franz
- Institute for Biophysical Chemistry, Hannover Medical School, Carl-Neuberg-Straße 1, 30625, Hannover, Germany
| | - Michael J Rynkiewicz
- Department of Physiology and Biophysics, Boston University School of Medicine, 700 Albany Street St, Boston, MA, 02118, USA
| | - Christopher S Newhard
- Department of Biological Sciences and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY, 12180-3590, USA
| | - Aditi Madan
- Department of Medicine, Division of Cardiology, Johns Hopkins University, 720 Rutland Avenue, Baltimore, MD, 21205, USA
| | - William Lehman
- Department of Physiology and Biophysics, Boston University School of Medicine, 700 Albany Street St, Boston, MA, 02118, USA
| | - Douglas M Swank
- Department of Biological Sciences and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY, 12180-3590, USA
| | - Matthias Preller
- Institute for Biophysical Chemistry, Hannover Medical School, Carl-Neuberg-Straße 1, 30625, Hannover, Germany.
| | - Anthony Cammarato
- Department of Medicine, Division of Cardiology, Johns Hopkins University, 720 Rutland Avenue, Baltimore, MD, 21205, USA. .,Department of Physiology, Johns Hopkins University School of Medicine, 720 Rutland Avenue, Baltimore, MD, 21205, USA.
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10
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Large-Scale Transgenic Drosophila Resource Collections for Loss- and Gain-of-Function Studies. Genetics 2020; 214:755-767. [PMID: 32071193 DOI: 10.1534/genetics.119.302964] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 02/11/2020] [Indexed: 01/20/2023] Open
Abstract
The Transgenic RNAi Project (TRiP), a Drosophila melanogaster functional genomics platform at Harvard Medical School, was initiated in 2008 to generate and distribute a genome-scale collection of RNA interference (RNAi) fly stocks. To date, it has generated >15,000 RNAi fly stocks. As this covers most Drosophila genes, we have largely transitioned to development of new resources based on CRISPR technology. Here, we present an update on our libraries of publicly available RNAi and CRISPR fly stocks, and focus on the TRiP-CRISPR overexpression (TRiP-OE) and TRiP-CRISPR knockout (TRiP-KO) collections. TRiP-OE stocks express single guide RNAs targeting upstream of a gene transcription start site. Gene activation is triggered by coexpression of catalytically dead Cas9 fused to an activator domain, either VP64-p65-Rta or Synergistic Activation Mediator. TRiP-KO stocks express one or two single guide RNAs targeting the coding sequence of a gene or genes. Cutting is triggered by coexpression of Cas9, allowing for generation of indels in both germline and somatic tissue. To date, we have generated >5000 TRiP-OE or TRiP-KO stocks for the community. These resources provide versatile, transformative tools for gene activation, gene repression, and genome engineering.
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11
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Pavadai E, Rynkiewicz MJ, Ghosh A, Lehman W. Docking Troponin T onto the Tropomyosin Overlapping Domain of Thin Filaments. Biophys J 2019; 118:325-336. [PMID: 31864661 DOI: 10.1016/j.bpj.2019.11.3393] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 11/14/2019] [Accepted: 11/26/2019] [Indexed: 01/02/2023] Open
Abstract
Complete description of thin filament conformational transitions accompanying muscle regulation requires ready access to atomic structures of actin-bound tropomyosin-troponin. To date, several molecular-docking protocols have been employed to identify troponin interactions on actin-tropomyosin because high-resolution experimentally determined structures of filament-associated troponin are not available. However, previously published all-atom models of the thin filament show chain separation and corruption of components during our molecular dynamics simulations of the models, implying artifactual subunit organization, possibly due to incorporation of unorthodox tropomyosin-TnT crystal structures and complex FRET measurements during model construction. For example, the recent Williams et al. (2016) atomistic model of the thin filament displays a paucity of salt bridges and hydrophobic complementarity between the TnT tail (TnT1) and tropomyosin, which is difficult to reconcile with the high, 20 nM Kd binding of TnT onto tropomyosin. Indeed, our molecular dynamics simulations show the TnT1 component in their model partially dissociates from tropomyosin in under 100 ns, whereas actin-tropomyosin and TnT1 models themselves remain intact. We therefore revisited computational work aiming to improve TnT1-thin filament models by employing unbiased docking methodologies, which test billions of trial rotations and translations of TnT1 over three-dimensional grids covering end-to-end bonded tropomyosin alone or tropomyosin on F-actin. We limited conformational searches to the association of well-characterized TnT1 helical domains and either isolated tropomyosin or actin-tropomyosin yet avoided docking TnT domains that lack known or predicted structure. The docking programs PIPER and ClusPro were used, followed by interaction energy optimization and extensive molecular dynamics. TnT1 docked to either side of isolated tropomyosin but uniquely onto one location of actin-bound tropomyosin. The antiparallel interaction with tropomyosin contained abundant salt bridges and intimately integrated hydrophobic networks joining TnT1 and the tropomyosin N-/C-terminal overlapping domain. The TnT1-tropomyosin linkage yields well-defined molecular crevices. Interaction energy measurements strongly favor this TnT1-tropomyosin design over previously proposed models.
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Affiliation(s)
- Elumalai Pavadai
- Department of Physiology and Biophysics, Boston University School of Medicine, Boston, Massachusetts
| | - Michael J Rynkiewicz
- Department of Physiology and Biophysics, Boston University School of Medicine, Boston, Massachusetts
| | - Anita Ghosh
- Department of Physiology and Biophysics, Boston University School of Medicine, Boston, Massachusetts
| | - William Lehman
- Department of Physiology and Biophysics, Boston University School of Medicine, Boston, Massachusetts.
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12
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Weismann CG, Blice-Baum A, Tong T, Li J, Huang BK, Jonas SM, Cammarato A, Choma MA. Multi-modal and multiscale imaging approaches reveal novel cardiovascular pathophysiology in Drosophila melanogaster. Biol Open 2019; 8:bio.044339. [PMID: 31455664 PMCID: PMC6737974 DOI: 10.1242/bio.044339] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Establishing connections between changes in linear DNA sequences and complex downstream mesoscopic pathology remains a major challenge in biology. Herein, we report a novel, multi-modal and multiscale imaging approach for comprehensive assessment of cardiovascular physiology in Drosophila melanogaster We employed high-speed angiography, optical coherence tomography (OCT) and confocal microscopy to reveal functional and structural abnormalities in the hdp2 mutant, pre-pupal heart tube and aorta relative to controls. hdp2 harbor a mutation in wupA, which encodes an ortholog of human troponin I (TNNI3). TNNI3 variants frequently engender cardiomyopathy. We demonstrate that the hdp2 aortic and cardiac muscle walls are disrupted and that shorter sarcomeres are associated with smaller, stiffer aortas, which consequently result in increased flow and pulse wave velocities. The mutant hearts also displayed diastolic and latent systolic dysfunction. We conclude that hdp2 pre-pupal hearts are exposed to increased afterload due to aortic hypoplasia. This may in turn contribute to diastolic and subtle systolic dysfunction via vascular-heart tube interaction, which describes the effect of the arterial loading system on cardiac function. Ultimately, the cardiovascular pathophysiology caused by a point mutation in a sarcomeric protein demonstrates that complex and dynamic micro- and mesoscopic phenotypes can be mechanistically explained in a gene sequence- and molecular-specific manner.
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Affiliation(s)
- Constance G Weismann
- Yale School of Medicine, Department of Pediatrics, Division of Pediatric Cardiology, New Haven, CT 06510, USA .,Lund University, Skane University Hospital, Department of Clinical Sciences Lund, Pediatric Cardiology, 22184 Lund, Sweden
| | - Anna Blice-Baum
- Johns Hopkins University School of Medicine, Division of Cardiology, Department of Medicine, Department of Physiology, Baltimore, MD 21205, USA
| | - Tangji Tong
- Yale Departments of Diagnostic Radiology, Pediatrics, Biomedical Engineering, and Applied Physics, New Haven, CT 06510, USA
| | - Joyce Li
- Yale Departments of Diagnostic Radiology, Pediatrics, Biomedical Engineering, and Applied Physics, New Haven, CT 06510, USA
| | - Brendan K Huang
- Yale Departments of Diagnostic Radiology, Pediatrics, Biomedical Engineering, and Applied Physics, New Haven, CT 06510, USA
| | - Stephan M Jonas
- Yale Departments of Diagnostic Radiology, Pediatrics, Biomedical Engineering, and Applied Physics, New Haven, CT 06510, USA.,Department of Informatics, Technical University of Munich, 85748 Garching, Germany
| | - Anthony Cammarato
- Johns Hopkins University School of Medicine, Division of Cardiology, Department of Medicine, Department of Physiology, Baltimore, MD 21205, USA
| | - Michael A Choma
- Yale Departments of Diagnostic Radiology, Pediatrics, Biomedical Engineering, and Applied Physics, New Haven, CT 06510, USA
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13
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Schmidt W, Cammarato A. The actin 'A-triad's' role in contractile regulation in health and disease. J Physiol 2019; 598:2897-2908. [PMID: 30770548 DOI: 10.1113/jp276741] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 01/30/2019] [Indexed: 12/15/2022] Open
Abstract
Striated muscle contraction is regulated by Ca2+ -dependent modulation of myosin cross-bridge binding to F-actin by the thin filament troponin (Tn)-tropomyosin (Tm) complex. In the absence of Ca2+ , Tn binds to actin and constrains Tm to an azimuthal location where it sterically occludes myosin binding sites along the thin filament surface. This limits force production and promotes muscle relaxation. In addition to Tn-actin interactions, inhibitory Tm positioning requires associations between other thin filament constituents. For example, the actin 'A-triad', composed of residues K326, K328 and R147, forms numerous, highly favourable electrostatic contacts with Tm that are critical for establishing its inhibitory azimuthal binding position. Here, we review recent findings, including the identification and interrogation of modifications within and proximal to the A-triad that are associated with disease and/or altered muscle behaviour, which highlight the surface feature's role in F-actin-Tm interactions and contractile regulation.
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Affiliation(s)
- William Schmidt
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, 733 N Broadway, 21205, Baltimore, MD, USA
| | - Anthony Cammarato
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, 733 N Broadway, 21205, Baltimore, MD, USA.,Department of Physiology, Johns Hopkins University School of Medicine, 733 N Broadway, 21205, Baltimore, MD, USA
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14
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Kronert WA, Bell KM, Viswanathan MC, Melkani GC, Trujillo AS, Huang A, Melkani A, Cammarato A, Swank DM, Bernstein SI. Prolonged cross-bridge binding triggers muscle dysfunction in a Drosophila model of myosin-based hypertrophic cardiomyopathy. eLife 2018; 7:38064. [PMID: 30102150 PMCID: PMC6141233 DOI: 10.7554/elife.38064] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 08/10/2018] [Indexed: 01/08/2023] Open
Abstract
K146N is a dominant mutation in human β-cardiac myosin heavy chain, which causes hypertrophic cardiomyopathy. We examined how Drosophila muscle responds to this mutation and integratively analyzed the biochemical, physiological and mechanical foundations of the disease. ATPase assays, actin motility, and indirect flight muscle mechanics suggest at least two rate constants of the cross-bridge cycle are altered by the mutation: increased myosin attachment to actin and decreased detachment, yielding prolonged binding. This increases isometric force generation, but also resistive force and work absorption during cyclical contractions, resulting in decreased work, power output, flight ability and degeneration of flight muscle sarcomere morphology. Consistent with prolonged cross-bridge binding serving as the mechanistic basis of the disease and with human phenotypes, 146N/+ hearts are hypercontractile with increased tension generation periods, decreased diastolic/systolic diameters and myofibrillar disarray. This suggests that screening mutated Drosophila hearts could rapidly identify hypertrophic cardiomyopathy alleles and treatments. Myosin is a motor protein that drives the contraction of muscles. Filaments made from myosin molecules slide between filaments of another protein called actin, tugging the edges of the muscle cell inwards. To achieve this, part of each motor protein – called the 'head' – grabs hold of actin and uses energy to pull on the filaments. Small genetic mutations in the gene for myosin can change the shape of the protein. This can change the way that it interacts with actin, altering the molecular machinery that makes muscles contract. In some cases, gene errors can cause the heart muscle wall to thicken, a condition called hypertrophic cardiomyopathy. Mapping the locations of known mutations revealed 'hot spots' on the myosin protein where these errors are likely to cause disease. These include the part of the molecule that swings the myosin heads, and the heads themselves. It only takes a change to a single letter in the DNA code to thicken the heart wall, but the impact of each possible change is not yet known. Kronert et al. have now genetically modified fruit flies to give them one of the mutations that causes thickening of the heart wall in humans. The mutation, known as K146N, does not appear in one of the well-known 'hot spots'. The experiments revealed that the mutation causes myosin to remain attached to actin for longer than normal. This increased the amount of force the myosin generated, but slowed down actin movement, causing muscle stiffness. This resulted in less power for every cycle of muscle movement, and caused the muscles to degenerate over time. As a result, the flies were less able to use their wings, and their hearts pumped less well. Hypertrophic cardiomyopathy can cause death in young adults, particularly competitive athletes. Yet studying the disease in humans is challenging. Recreating myosin mutations in fruit flies provides a way to study hypertrophic cardiomyopathy in the laboratory. In the future, extensions to this technique could allow researchers to examine the impact of other mutations. Models like this one could also allow early testing of new drugs or genetic treatments to repair faulty myosin molecules.
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Affiliation(s)
- William A Kronert
- Department of Biology, Molecular Biology Institute and Heart Institute, San Diego State University, San Diego, United States
| | - Kaylyn M Bell
- Department of Biology and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, New York, United States
| | - Meera C Viswanathan
- Department of Medicine, Division of Cardiology, Johns Hopkins University, Baltimore, United States
| | - Girish C Melkani
- Department of Biology, Molecular Biology Institute and Heart Institute, San Diego State University, San Diego, United States
| | - Adriana S Trujillo
- Department of Biology, Molecular Biology Institute and Heart Institute, San Diego State University, San Diego, United States
| | - Alice Huang
- Department of Biology and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, New York, United States
| | - Anju Melkani
- Department of Biology, Molecular Biology Institute and Heart Institute, San Diego State University, San Diego, United States
| | - Anthony Cammarato
- Department of Medicine, Division of Cardiology, Johns Hopkins University, Baltimore, United States
| | - Douglas M Swank
- Department of Biology and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, New York, United States.,Department of Biomedical Engineering, Rensselaer Polytechnic Institute, New York, United States
| | - Sanford I Bernstein
- Department of Biology, Molecular Biology Institute and Heart Institute, San Diego State University, San Diego, United States
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15
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Viswanathan MC, Schmidt W, Rynkiewicz MJ, Agarwal K, Gao J, Katz J, Lehman W, Cammarato A. Distortion of the Actin A-Triad Results in Contractile Disinhibition and Cardiomyopathy. Cell Rep 2018; 20:2612-2625. [PMID: 28903042 PMCID: PMC5902318 DOI: 10.1016/j.celrep.2017.08.070] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 07/25/2017] [Accepted: 08/21/2017] [Indexed: 12/20/2022] Open
Abstract
Striated muscle contraction is regulated by the movement of tropomyosin over the thin filament surface, which blocks or exposes myosin binding sites on actin. Findings suggest that electrostatic contacts, particularly those between K326, K328, and R147 on actin and tropomyosin, establish an energetically favorable F-actin-tropomyosin configuration, with tropomyosin positioned in a location that impedes actomyosin associations and promotes relaxation. Here, we provide data that directly support a vital role for these actin residues, termed the A-triad, in tropomyosin positioning in intact functioning muscle. By examining the effects of an A295S α-cardiac actin hypertrophic cardiomyopathy-causing mutation, over a range of increasingly complex in silico, in vitro, and in vivo Drosophila muscle models, we propose that subtle A-triad-tropomyosin perturbation can destabilize thin filament regulation, which leads to hypercontractility and triggers disease. Our efforts increase understanding of basic thin filament biology and help unravel the mechanistic basis of a complex cardiac disorder.
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Affiliation(s)
- Meera C Viswanathan
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - William Schmidt
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Michael J Rynkiewicz
- Department of Physiology and Biophysics, Boston University School of Medicine, Boston, MA 02118, USA
| | - Karuna Agarwal
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Jian Gao
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Joseph Katz
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - William Lehman
- Department of Physiology and Biophysics, Boston University School of Medicine, Boston, MA 02118, USA
| | - Anthony Cammarato
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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16
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Overexpression of miRNA-9 Generates Muscle Hypercontraction Through Translational Repression of Troponin-T in Drosophila melanogaster Indirect Flight Muscles. G3-GENES GENOMES GENETICS 2017; 7:3521-3531. [PMID: 28866639 PMCID: PMC5633399 DOI: 10.1534/g3.117.300232] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
MicroRNAs (miRNAs) are small noncoding endogenous RNAs, typically 21-23 nucleotides long, that regulate gene expression, usually post-transcriptionally, by binding to the 3'-UTR of target mRNA, thus blocking translation. The expression of several miRNAs is significantly altered during cardiac hypertrophy, myocardial ischemia, fibrosis, heart failure, and other cardiac myopathies. Recent studies have implicated miRNA-9 (miR-9) in myocardial hypertrophy. However, a detailed mechanism remains obscure. In this study, we have addressed the roles of miR-9 in muscle development and function using a genetically tractable model system, the indirect flight muscles (IFMs) of Drosophila melanogaster Bioinformatics analysis identified 135 potential miR-9a targets, of which 27 genes were associated with Drosophila muscle development. Troponin-T (TnT) was identified as major structural gene target of miR-9a. We show that flies overexpressing miR-9a in the IFMs have abnormal wing position and are flightless. These flies also exhibit a loss of muscle integrity and sarcomeric organization causing an abnormal muscle condition known as "hypercontraction." Additionally, miR-9a overexpression resulted in the reduction of TnT protein levels while transcript levels were unaffected. Furthermore, muscle abnormalities associated with miR-9a overexpression were completely rescued by overexpression of TnT transgenes which lacked the miR-9a binding site. These findings indicate that miR-9a interacts with the 3'-UTR of the TnT mRNA and downregulates the TnT protein levels by translational repression. The reduction in TnT levels leads to a cooperative downregulation of other thin filament structural proteins. Our findings have implications for understanding the cellular pathophysiology of cardiomyopathies associated with miR-9 overexpression.
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17
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Dissecting the Role of the Extracellular Matrix in Heart Disease: Lessons from the Drosophila Genetic Model. Vet Sci 2017; 4:vetsci4020024. [PMID: 29056683 PMCID: PMC5606597 DOI: 10.3390/vetsci4020024] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 02/15/2017] [Accepted: 04/20/2017] [Indexed: 12/16/2022] Open
Abstract
The extracellular matrix (ECM) is a dynamic scaffold within organs and tissues that enables cell morphogenesis and provides structural support. Changes in the composition and organisation of the cardiac ECM are required for normal development. Congenital and age-related cardiac diseases can arise from mis-regulation of structural ECM proteins (Collagen, Laminin) or their receptors (Integrin). Key regulators of ECM turnover include matrix metalloproteinases (MMPs) and their inhibitors, tissue inhibitors of matrix metalloproteinases (TIMPs). MMP expression is increased in mice, pigs, and dogs with cardiomyopathy. The complexity and longevity of vertebrate animals makes a short-lived, genetically tractable model organism, such as Drosophila melanogaster, an attractive candidate for study. We survey ECM macromolecules and their role in heart development and growth, which are conserved between Drosophila and vertebrates, with focus upon the consequences of altered expression or distribution. The Drosophila heart resembles that of vertebrates during early development, and is amenable to in vivo analysis. Experimental manipulation of gene function in a tissue- or temporally-regulated manner can reveal the function of adhesion or ECM genes in the heart. Perturbation of the function of ECM proteins, or of the MMPs that facilitate ECM remodelling, induces cardiomyopathies in Drosophila, including cardiodilation, arrhythmia, and cardia bifida, that provide mechanistic insight into cardiac disease in mammals.
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18
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Shahrestani P, Burke MK, Birse R, Kezos JN, Ocorr K, Mueller LD, Rose MR, Bodmer R. Experimental Evolution and Heart Function in Drosophila. Physiol Biochem Zool 2017; 90:281-293. [PMID: 28277957 DOI: 10.1086/689288] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Drosophila melanogaster is a good model species for the study of heart function. However, most previous work on D. melanogaster heart function has focused on the effects of large-effect genetic variants. We compare heart function among 18 D. melanogaster populations that have been selected for altered development time, aging, or stress resistance. We find that populations with faster development and faster aging have increased heart dysfunction, measured as percentage heart failure after electrical pacing. Experimental evolution of different triglyceride levels, by contrast, has little effect on heart function. Evolved differences in heart function correlate with allele frequency changes at many loci of small effect. Genomic analysis of these populations produces a list of candidate loci that might affect cardiac function at the intersection of development, aging, and metabolic control mechanisms.
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19
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Kaushik G, Leijten J, Khademhosseini A. Concise Review: Organ Engineering: Design, Technology, and Integration. Stem Cells 2016; 35:51-60. [PMID: 27641724 DOI: 10.1002/stem.2502] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2015] [Revised: 08/30/2016] [Accepted: 09/06/2016] [Indexed: 01/19/2023]
Abstract
Engineering complex tissues and whole organs has the potential to dramatically impact translational medicine in several avenues. Organ engineering is a discipline that integrates biological knowledge of embryological development, anatomy, physiology, and cellular interactions with enabling technologies including biocompatible biomaterials and biofabrication platforms such as three-dimensional bioprinting. When engineering complex tissues and organs, core design principles must be taken into account, such as the structure-function relationship, biochemical signaling, mechanics, gradients, and spatial constraints. Technological advances in biomaterials, biofabrication, and biomedical imaging allow for in vitro control of these factors to recreate in vivo phenomena. Finally, organ engineering emerges as an integration of biological design and technical rigor. An overall workflow for organ engineering and guiding technology to advance biology as well as a perspective on necessary future iterations in the field is discussed. Stem Cells 2017;35:51-60.
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Affiliation(s)
- Gaurav Kaushik
- Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Medicine, Biomaterials Innovation Research Center, Brigham and Women's Hospital, Harvard Medical School, Cambridge, Massachusetts, USA
| | - Jeroen Leijten
- Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Medicine, Biomaterials Innovation Research Center, Brigham and Women's Hospital, Harvard Medical School, Cambridge, Massachusetts, USA.,Department of Developmental BioEngineering, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands
| | - Ali Khademhosseini
- Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Medicine, Biomaterials Innovation Research Center, Brigham and Women's Hospital, Harvard Medical School, Cambridge, Massachusetts, USA.,Department of Physics, King Abdulaziz University, Jeddah, 21569, Saudi Arabia, USA.,Department of Bioindustrial Technologies, College of Animal Bioscience and Technology, Konkuk University, Hwayang-dong, Gwangjin-gu, Seoul, Republic of Korea.,Department of Physics, King Abdulaziz University, Jeddah, Saudi Arabia
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20
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Sessions AO, Kaushik G, Parker S, Raedschelders K, Bodmer R, Van Eyk JE, Engler AJ. Extracellular matrix downregulation in the Drosophila heart preserves contractile function and improves lifespan. Matrix Biol 2016; 62:15-27. [PMID: 27793636 DOI: 10.1016/j.matbio.2016.10.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 10/19/2016] [Accepted: 10/22/2016] [Indexed: 02/01/2023]
Abstract
Aging is associated with extensive remodeling of the heart, including basement membrane (BM) components that surround cardiomyocytes. Remodeling is thought to impair cardiac mechanotransduction, but the contribution of specific BM components to age-related lateral communication between cardiomyocytes is unclear. Using a genetically tractable, rapidly aging model with sufficient cardiac genetic homology and morphology, e.g. Drosophila melanogaster, we observed differential regulation of BM collagens between laboratory strains, correlating with changes in muscle physiology leading to cardiac dysfunction. Therefore, we sought to understand the extent to which BM proteins modulate contractile function during aging. Cardiac-restricted knockdown of ECM genes Pericardin, Laminin A, and Viking in Drosophila prevented age-associated heart tube restriction and increased contractility, even under viscous load. Most notably, reduction of Laminin A expression correlated with an overall preservation of contractile velocity with age and extension of organismal lifespan. Global heterozygous knockdown confirmed these data, which provides new evidence of a direct link between BM homeostasis, contractility, and maintenance of lifespan.
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Affiliation(s)
- Ayla O Sessions
- Biomedical Sciences Program, UC, San Diego; La Jolla, CA 92093, USA
| | - Gaurav Kaushik
- Department of Bioengineering, UC, San Diego; La Jolla, CA 92093, USA
| | - Sarah Parker
- Advanced Clinical Biosystems Research Institute; Barbra Streisand Women's Heart Center; Cedars-Sinai Heart Institute; Cedars-Sinai Medical Center; Los Angeles, CA 90048, USA
| | - Koen Raedschelders
- Advanced Clinical Biosystems Research Institute; Barbra Streisand Women's Heart Center; Cedars-Sinai Heart Institute; Cedars-Sinai Medical Center; Los Angeles, CA 90048, USA
| | - Rolf Bodmer
- Development, Aging, and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute; La Jolla, CA 92037, USA
| | - Jennifer E Van Eyk
- Advanced Clinical Biosystems Research Institute; Barbra Streisand Women's Heart Center; Cedars-Sinai Heart Institute; Cedars-Sinai Medical Center; Los Angeles, CA 90048, USA
| | - Adam J Engler
- Biomedical Sciences Program, UC, San Diego; La Jolla, CA 92093, USA; Department of Bioengineering, UC, San Diego; La Jolla, CA 92093, USA; Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA.
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21
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Abstract
The high level of conservation of the cardiogenic gene regulatory network as well as of the cellular and physiological characteristics of the cardiomyocytes between fly and human, makes the small heart of this invertebrate the simplest and most flexible genetic system to dissect the fundamental molecular mechanisms that are brought into play during the development, the establishment and the maintenance of the cardiac function. The recent improvements in techniques of measurements of cardiac function made it possible to validate Drosophila as a model of cardiomyopathies and arrhythmias of genetic and metabolic origin or dependent of ageing. The heart of the fly thus represents a model of choice to identify genes and their interactions implicated in cardiac pathologies.
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Affiliation(s)
- Laurent Perrin
- Inserm UMR_S 1090, Technological advances for genomics and clinics (TAGC), parc scientifique de Luminy, case 908, 13288 Marseille Cedex 9, France - CNRS, Marseille, France - Aix-Marseille université, UMR_S 1090, TAGC, parc scientifique de Luminy, 13288 Marseille, France
| | - Laurence Röder
- Inserm UMR_S 1090, Technological advances for genomics and clinics (TAGC), parc scientifique de Luminy, case 908, 13288 Marseille Cedex 9, France - Aix-Marseille université, UMR_S 1090, TAGC, parc scientifique de Luminy, 13288 Marseille, France
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22
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Viswanathan MC, Blice-Baum AC, Sang TK, Cammarato A. Cardiac-Restricted Expression of VCP/TER94 RNAi or Disease Alleles Perturbs Drosophila Heart Structure and Impairs Function. J Cardiovasc Dev Dis 2016; 3. [PMID: 27500162 PMCID: PMC4973812 DOI: 10.3390/jcdd3020019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Valosin-containing protein (VCP) is a highly conserved mechanoenzyme that helps maintain protein homeostasis in all cells and serves specialized functions in distinct cell types. In skeletal muscle, it is critical for myofibrillogenesis and atrophy. However, little is known about VCP’s role(s) in the heart. Its functional diversity is determined by differential binding of distinct cofactors/adapters, which is likely disrupted during disease. VCP mutations cause multisystem proteinopathy (MSP), a pleiotropic degenerative disorder that involves inclusion body myopathy. MSP patients display progressive muscle weakness. They also exhibit cardiomyopathy and die from cardiac and respiratory failure, which are consistent with critical myocardial roles for the enzyme. Nonetheless, efficient models to interrogate VCP in cardiac muscle remain underdeveloped and poorly studied. Here, we investigated the significance of VCP and mutant VCP in the Drosophila heart. Cardiac-restricted RNAi-mediated knockdown of TER94, the Drosophila VCP homolog, severely perturbed myofibrillar organization and heart function in adult flies. Furthermore, expression of MSP disease-causing alleles engendered cardiomyopathy in adults and structural defects in embryonic hearts. Drosophila may therefore serve as a valuable model for examining role(s) of VCP in cardiogenesis and for identifying novel heart-specific VCP interactions, which when disrupted via mutation, contribute to or elicit cardiac pathology.
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Affiliation(s)
- Meera C. Viswanathan
- Division of Cardiology, Department of Medicine, Johns Hopkins University, Ross 1050, 720 Rutland Avenue, Baltimore, MD 21205, USA; (M.C.V.); (A.C.B.-B.)
| | - Anna C. Blice-Baum
- Division of Cardiology, Department of Medicine, Johns Hopkins University, Ross 1050, 720 Rutland Avenue, Baltimore, MD 21205, USA; (M.C.V.); (A.C.B.-B.)
| | - Tzu-Kang Sang
- Institute of Biotechnology & Department of Life Science, National Tsing Hua University, Hsinchu City 30013, Taiwan;
| | - Anthony Cammarato
- Division of Cardiology, Department of Medicine, Johns Hopkins University, Ross 1050, 720 Rutland Avenue, Baltimore, MD 21205, USA; (M.C.V.); (A.C.B.-B.)
- Department of Physiology, Johns Hopkins University, Ross 1050, 720 Rutland Avenue, Baltimore, MD 21205, USA
- Correspondence: ; Tel.: +1-410-955-1807; Fax: +1-410-502-2558
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23
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Abstract
Unlike diet and exercise, which individuals can modulate according to their lifestyle, aging is unavoidable. With normal or healthy aging, the heart undergoes extensive vascular, cellular, and interstitial molecular changes that result in stiffer less compliant hearts that experience a general decline in organ function. Although these molecular changes deemed cardiac remodeling were once thought to be concomitant with advanced cardiovascular disease, they can be found in patients without manifestation of clinical disease. It is now mostly acknowledged that these age-related mechanical changes confer vulnerability of the heart to cardiovascular stresses associated with disease, such as hypertension and atherosclerosis. However, recent studies have aimed at differentiating the initial compensatory changes that occur within the heart with age to maintain contractile function from the maladaptive responses associated with disease. This work has identified new targets to improve cardiac function during aging. Spanning invertebrate to vertebrate models, we use this review to delineate some hallmarks of physiological versus pathological remodeling that occur in the cardiomyocyte and its microenvironment, focusing especially on the mechanical changes that occur within the sarcomere, intercalated disc, costamere, and extracellular matrix.
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Affiliation(s)
- Ayla O Sessions
- From the Biomedical Sciences Program (A.O.S., A.J.E.) and Department of Bioengineering, University of California, San Diego, La Jolla (A.J.E.); and Sanford Consortium for Regenerative Medicine, La Jolla, CA (A.J.E.)
| | - Adam J Engler
- From the Biomedical Sciences Program (A.O.S., A.J.E.) and Department of Bioengineering, University of California, San Diego, La Jolla (A.J.E.); and Sanford Consortium for Regenerative Medicine, La Jolla, CA (A.J.E.).
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24
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Kooij V, Viswanathan MC, Lee DI, Rainer PP, Schmidt W, Kronert WA, Harding SE, Kass DA, Bernstein SI, Van Eyk JE, Cammarato A. Profilin modulates sarcomeric organization and mediates cardiomyocyte hypertrophy. Cardiovasc Res 2016; 110:238-48. [PMID: 26956799 PMCID: PMC4836629 DOI: 10.1093/cvr/cvw050] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2015] [Accepted: 02/28/2016] [Indexed: 11/17/2022] Open
Abstract
Aims Heart failure is often preceded by cardiac hypertrophy, which is characterized by increased cell size, altered protein abundance, and actin cytoskeletal reorganization. Profilin is a well-conserved, ubiquitously expressed, multifunctional actin-binding protein, and its role in cardiomyocytes is largely unknown. Given its involvement in vascular hypertrophy, we aimed to test the hypothesis that profilin-1 is a key mediator of cardiomyocyte-specific hypertrophic remodelling. Methods and results Profilin-1 was elevated in multiple mouse models of hypertrophy, and a cardiomyocyte-specific increase of profilin in Drosophila resulted in significantly larger heart tube dimensions. Moreover, adenovirus-mediated overexpression of profilin-1 in neonatal rat ventricular myocytes (NRVMs) induced a hypertrophic response, measured by increased myocyte size and gene expression. Profilin-1 silencing suppressed the response in NRVMs stimulated with phenylephrine or endothelin-1. Mechanistically, we found that profilin-1 regulates hypertrophy, in part, through activation of the ERK1/2 signalling cascade. Confocal microscopy showed that profilin localized to the Z-line of Drosophila myofibrils under normal conditions and accumulated near the M-line when overexpressed. Elevated profilin levels resulted in elongated sarcomeres, myofibrillar disorganization, and sarcomeric disarray, which correlated with impaired muscle function. Conclusion Our results identify novel roles for profilin as an important mediator of cardiomyocyte hypertrophy. We show that overexpression of profilin is sufficient to induce cardiomyocyte hypertrophy and sarcomeric remodelling, and silencing of profilin attenuates the hypertrophic response.
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Affiliation(s)
- Viola Kooij
- Department of Medicine, Division of Cardiology, The Johns Hopkins University, Baltimore, MD, USA National Heart and Lung Institute, Imperial College London, 4th floor, ICTEM, Hammersmith Campus, Du Cane Road, London W12 0NN, UK
| | - Meera C Viswanathan
- Department of Medicine, Division of Cardiology, The Johns Hopkins University, Baltimore, MD, USA
| | - Dong I Lee
- Department of Medicine, Division of Cardiology, The Johns Hopkins University, Baltimore, MD, USA
| | - Peter P Rainer
- Department of Medicine, Division of Cardiology, The Johns Hopkins University, Baltimore, MD, USA Division of Cardiology, Medical University of Graz, Graz, Austria
| | - William Schmidt
- Department of Medicine, Division of Cardiology, The Johns Hopkins University, Baltimore, MD, USA
| | - William A Kronert
- Department of Biology, San Diego State University, San Diego, CA, USA
| | - Sian E Harding
- National Heart and Lung Institute, Imperial College London, 4th floor, ICTEM, Hammersmith Campus, Du Cane Road, London W12 0NN, UK
| | - David A Kass
- Department of Medicine, Division of Cardiology, The Johns Hopkins University, Baltimore, MD, USA
| | | | - Jennifer E Van Eyk
- Department of Medicine, Division of Cardiology, The Johns Hopkins University, Baltimore, MD, USA Advanced Clinical Biosystems Research Institute, Heart Institute and Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Anthony Cammarato
- Department of Medicine, Division of Cardiology, The Johns Hopkins University, Baltimore, MD, USA
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25
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Taghli-Lamallem O, Plantié E, Jagla K. Drosophila in the Heart of Understanding Cardiac Diseases: Modeling Channelopathies and Cardiomyopathies in the Fruitfly. J Cardiovasc Dev Dis 2016; 3:jcdd3010007. [PMID: 29367558 PMCID: PMC5715700 DOI: 10.3390/jcdd3010007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Revised: 01/23/2016] [Accepted: 02/06/2016] [Indexed: 12/16/2022] Open
Abstract
Cardiovascular diseases and, among them, channelopathies and cardiomyopathies are a major cause of death worldwide. The molecular and genetic defects underlying these cardiac disorders are complex, leading to a large range of structural and functional heart phenotypes. Identification of molecular and functional mechanisms disrupted by mutations causing channelopathies and cardiomyopathies is essential to understanding the link between an altered gene and clinical phenotype. The development of animal models has been proven to be efficient for functional studies in channelopathies and cardiomyopathies. In particular, the Drosophila model has been largely applied for deciphering the molecular and cellular pathways affected in these inherited cardiac disorders and for identifying their genetic modifiers. Here we review the utility and the main contributions of the fruitfly models for the better understanding of channelopathies and cardiomyopathies. We also discuss the investigated pathological mechanisms and the discoveries of evolutionarily conserved pathways which reinforce the value of Drosophila in modeling human cardiac diseases.
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Affiliation(s)
- Ouarda Taghli-Lamallem
- GReD (Genetics, Reproduction and Development laboratory), INSERM U1103, CNRS UMR6293, University of Clermont-Ferrand, 28 place Henri-Dunant, 63000 Clermont-Ferrand, France.
| | - Emilie Plantié
- GReD (Genetics, Reproduction and Development laboratory), INSERM U1103, CNRS UMR6293, University of Clermont-Ferrand, 28 place Henri-Dunant, 63000 Clermont-Ferrand, France.
| | - Krzysztof Jagla
- GReD (Genetics, Reproduction and Development laboratory), INSERM U1103, CNRS UMR6293, University of Clermont-Ferrand, 28 place Henri-Dunant, 63000 Clermont-Ferrand, France.
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26
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Hartley PS, Motamedchaboki K, Bodmer R, Ocorr K. SPARC-Dependent Cardiomyopathy in Drosophila. ACTA ACUST UNITED AC 2016; 9:119-29. [PMID: 26839388 PMCID: PMC4838489 DOI: 10.1161/circgenetics.115.001254] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 01/27/2016] [Indexed: 12/17/2022]
Abstract
Supplemental Digital Content is available in the text. Background— The Drosophila heart is an important model for studying the genetics underpinning mammalian cardiac function. The system comprises contractile cardiomyocytes, adjacent to which are pairs of highly endocytic pericardial nephrocytes that modulate cardiac function by uncharacterized mechanisms. Identifying these mechanisms and the molecules involved is important because they may be relevant to human cardiac physiology. Methods and Results— This work aimed to identify circulating cardiomodulatory factors of potential relevance to humans using the Drosophila nephrocyte–cardiomyocyte system. A Kruppel-like factor 15 (dKlf15) loss-of-function strategy was used to ablate nephrocytes and then heart function and the hemolymph proteome were analyzed. Ablation of nephrocytes led to a severe cardiomyopathy characterized by a lengthening of diastolic interval. Rendering adult nephrocytes dysfunctional by disrupting their endocytic function or temporally conditional knockdown of dKlf15 led to a similar cardiomyopathy. Proteomics revealed that nephrocytes regulate the circulating levels of many secreted proteins, the most notable of which was the evolutionarily conserved matricellular protein Secreted Protein Acidic and Rich in Cysteine (SPARC), a protein involved in mammalian cardiac function. Finally, reducing SPARC gene dosage ameliorated the cardiomyopathy that developed in the absence of nephrocytes. Conclusions— The data implicate SPARC in the noncell autonomous control of cardiac function in Drosophila and suggest that modulation of SPARC gene expression may ameliorate cardiac dysfunction in humans.
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Affiliation(s)
- Paul S Hartley
- From the Department of Life and Environmental Science, University of Bournemouth, Dorset, United Kingdom (P.S.H.); and Proteomics Facility (K.M.) and Development, Aging, and Regeneration Program (R.B., K.O.), Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA.
| | - Khatereh Motamedchaboki
- From the Department of Life and Environmental Science, University of Bournemouth, Dorset, United Kingdom (P.S.H.); and Proteomics Facility (K.M.) and Development, Aging, and Regeneration Program (R.B., K.O.), Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA
| | - Rolf Bodmer
- From the Department of Life and Environmental Science, University of Bournemouth, Dorset, United Kingdom (P.S.H.); and Proteomics Facility (K.M.) and Development, Aging, and Regeneration Program (R.B., K.O.), Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA
| | - Karen Ocorr
- From the Department of Life and Environmental Science, University of Bournemouth, Dorset, United Kingdom (P.S.H.); and Proteomics Facility (K.M.) and Development, Aging, and Regeneration Program (R.B., K.O.), Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA.
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27
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Kaushik G, Spenlehauer A, Sessions AO, Trujillo AS, Fuhrmann A, Fu Z, Venkatraman V, Pohl D, Tuler J, Wang M, Lakatta EG, Ocorr K, Bodmer R, Bernstein SI, Van Eyk JE, Cammarato A, Engler AJ. Vinculin network-mediated cytoskeletal remodeling regulates contractile function in the aging heart. Sci Transl Med 2015; 7:292ra99. [PMID: 26084806 PMCID: PMC4507505 DOI: 10.1126/scitranslmed.aaa5843] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The human heart is capable of functioning for decades despite minimal cell turnover or regeneration, suggesting that molecular alterations help sustain heart function with age. However, identification of compensatory remodeling events in the aging heart remains elusive. We present the cardiac proteomes of young and old rhesus monkeys and rats, from which we show that certain age-associated remodeling events within the cardiomyocyte cytoskeleton are highly conserved and beneficial rather than deleterious. Targeted transcriptomic analysis in Drosophila confirmed conservation and implicated vinculin as a unique molecular regulator of cardiac function during aging. Cardiac-restricted vinculin overexpression reinforced the cortical cytoskeleton and enhanced myofilament organization, leading to improved contractility and hemodynamic stress tolerance in healthy and myosin-deficient fly hearts. Moreover, cardiac-specific vinculin overexpression increased median life span by more than 150% in flies. A broad array of potential therapeutic targets and regulators of age-associated modifications, specifically for vinculin, are presented. These findings suggest that the heart has molecular mechanisms to sustain performance and promote longevity, which may be assisted by therapeutic intervention to ameliorate the decline of function in aging patient hearts.
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Affiliation(s)
- Gaurav Kaushik
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Alice Spenlehauer
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Ayla O Sessions
- Biomedical Sciences Program, University of California, San Diego, La Jolla, CA 92093, USA
| | - Adriana S Trujillo
- Department of Biology, Heart Institute, and Molecular Biology Institute, San Diego State University, San Diego, CA 92182, USA
| | - Alexander Fuhrmann
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Zongming Fu
- Division of Cardiology, Department of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Vidya Venkatraman
- Advanced Clinical Biosystems Research Institute, Barbra Streisand Women's Heart Center, Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Danielle Pohl
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jeremy Tuler
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Mingyi Wang
- Laboratory of Cardiovascular Science, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Edward G Lakatta
- Laboratory of Cardiovascular Science, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Karen Ocorr
- Development and Aging Program, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA
| | - Rolf Bodmer
- Development and Aging Program, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA
| | - Sanford I Bernstein
- Department of Biology, Heart Institute, and Molecular Biology Institute, San Diego State University, San Diego, CA 92182, USA
| | - Jennifer E Van Eyk
- Division of Cardiology, Department of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA. Advanced Clinical Biosystems Research Institute, Barbra Streisand Women's Heart Center, Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Anthony Cammarato
- Division of Cardiology, Department of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA.
| | - Adam J Engler
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA. Biomedical Sciences Program, University of California, San Diego, La Jolla, CA 92093, USA. Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA.
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28
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Viswanathan MC, Blice-Baum AC, Schmidt W, Foster DB, Cammarato A. Pseudo-acetylation of K326 and K328 of actin disrupts Drosophila melanogaster indirect flight muscle structure and performance. Front Physiol 2015; 6:116. [PMID: 25972811 PMCID: PMC4412121 DOI: 10.3389/fphys.2015.00116] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 03/26/2015] [Indexed: 01/13/2023] Open
Abstract
In striated muscle tropomyosin (Tm) extends along the length of F-actin-containing thin filaments. Its location governs access of myosin binding sites on actin and, hence, force production. Intermolecular electrostatic associations are believed to mediate critical interactions between the proteins. For example, actin residues K326, K328, and R147 were predicted to establish contacts with E181 of Tm. Moreover, K328 also potentially forms direct interactions with E286 of myosin when the motor is strongly bound. Recently, LC-MS/MS analysis of the cardiac acetyl-lysine proteome revealed K326 and K328 of actin were acetylated, a post-translational modification (PTM) that masks the residues' inherent positive charges. Here, we tested the hypothesis that by removing the vital actin charges at residues 326 and 328, the PTM would perturb Tm positioning and/or strong myosin binding as manifested by altered skeletal muscle function and structure in the Drosophila melanogaster model system. Transgenic flies were created that permit tissue-specific expression of K326Q, K328Q, or K326Q/K328Q acetyl-mimetic actin and of wild-type actin via the UAS-GAL4 bipartite expression system. Compared to wild-type actin, muscle-restricted expression of mutant actin had a dose-dependent effect on flight ability. Moreover, excessive K328Q and K326Q/K328Q actin overexpression induced indirect flight muscle degeneration, a phenotype consistent with hypercontraction observed in other Drosophila myofibrillar mutants. Based on F-actin-Tm and F-actin-Tm-myosin models and on our physiological data, we conclude that acetylating K326 and K328 of actin alters electrostatic associations with Tm and/or myosin and thereby augments contractile properties. Our findings highlight the utility of Drosophila as a model that permits efficient targeted design and assessment of molecular and tissue-specific responses to muscle protein modifications, in vivo.
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Affiliation(s)
- Meera C Viswanathan
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine Baltimore, MD, USA
| | - Anna C Blice-Baum
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine Baltimore, MD, USA
| | - William Schmidt
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine Baltimore, MD, USA
| | - D Brian Foster
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine Baltimore, MD, USA
| | - Anthony Cammarato
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine Baltimore, MD, USA
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29
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Enhanced assessment of contractile dynamics in Drosophila hearts. Biotechniques 2015; 58:77-80. [PMID: 25652030 DOI: 10.2144/000114255] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 11/21/2014] [Indexed: 11/23/2022] Open
Abstract
The Drosophila heart has gained considerable traction as a model of cardiac development and physiology. Previously we described a semiautomatic optical heartbeat analysis (SOHA) method for quantifying functional parameters from the fly heart that facilitated its use as an organ system and disease model. Here we present an extensively rewritten version of the original SOHA program that takes advantage of additional information contained in high-speed videos of beating hearts. Program updates allow more precise quantification of cardiac contractions, increase the signal-to-noise ratio, and reduce the overall cost and time required to analyze recordings. This new SOHA version permits relatively rapid and highly accurate determination of subphases of contraction and relaxation. Importantly, the improved functionality enables the calculation of novel physiological data, suggesting that the fly model system may also be practical for screening drugs and alleles that modulate cardiac repolarization and force production.
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30
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Duncker DJ, Bakkers J, Brundel BJ, Robbins J, Tardiff JC, Carrier L. Animal and in silico models for the study of sarcomeric cardiomyopathies. Cardiovasc Res 2015; 105:439-48. [PMID: 25600962 DOI: 10.1093/cvr/cvv006] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Over the past decade, our understanding of cardiomyopathies has improved dramatically, due to improvements in screening and detection of gene defects in the human genome as well as a variety of novel animal models (mouse, zebrafish, and drosophila) and in silico computational models. These novel experimental tools have created a platform that is highly complementary to the naturally occurring cardiomyopathies in cats and dogs that had been available for some time. A fully integrative approach, which incorporates all these modalities, is likely required for significant steps forward in understanding the molecular underpinnings and pathogenesis of cardiomyopathies. Finally, novel technologies, including CRISPR/Cas9, which have already been proved to work in zebrafish, are currently being employed to engineer sarcomeric cardiomyopathy in larger animals, including pigs and non-human primates. In the mouse, the increased speed with which these techniques can be employed to engineer precise 'knock-in' models that previously took years to make via multiple rounds of homologous recombination-based gene targeting promises multiple and precise models of human cardiac disease for future study. Such novel genetically engineered animal models recapitulating human sarcomeric protein defects will help bridging the gap to translate therapeutic targets from small animal and in silico models to the human patient with sarcomeric cardiomyopathy.
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Affiliation(s)
- Dirk J Duncker
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Jeroen Bakkers
- Hubrecht Institute-KNAW and University Medical Center Utrecht, Utrecht, The Netherlands
| | - Bianca J Brundel
- Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Jeff Robbins
- Division of Molecular Cardiovascular Biology, Cincinnati Children's Hospital, Cincinnati, OH, USA
| | - Jil C Tardiff
- Department of Medicine and Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ, USA
| | - Lucie Carrier
- Department of Experimental Pharmacology and Toxicology, Cardiovascular Research Center, University Medical Center Hamburg-Eppendorf, Hamburg, Germany DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
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31
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Kooij V, Venkatraman V, Tra J, Kirk JA, Rowell J, Blice-Baum A, Cammarato A, Van Eyk JE. Sizing up models of heart failure: Proteomics from flies to humans. Proteomics Clin Appl 2014; 8:653-64. [PMID: 24723306 PMCID: PMC4282793 DOI: 10.1002/prca.201300123] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Revised: 01/31/2014] [Accepted: 04/03/2014] [Indexed: 12/25/2022]
Abstract
Cardiovascular disease is the leading cause of death in the western world. Heart failure is a heterogeneous and complex syndrome, arising from various etiologies, which result in cellular phenotypes that vary from patient to patient. The ability to utilize genetic manipulation and biochemical experimentation in animal models has made them indispensable in the study of this chronic condition. Similarly, proteomics has been helpful for elucidating complicated cellular and molecular phenotypes and has the potential to identify circulating biomarkers and drug targets for therapeutic intervention. In this review, the use of human samples and animal model systems (pig, dog, rat, mouse, zebrafish, and fruit fly) in cardiac research is discussed. Additionally, the protein sequence homology between these species and the extent of conservation at the level of the phospho-proteome in major kinase signaling cascades involved in heart failure are investigated.
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Affiliation(s)
- Viola Kooij
- Department of Medicine, Division of Cardiology, The Johns Hopkins University, Baltimore, MD, USA
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32
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Methods to assess Drosophila heart development, function and aging. Methods 2014; 68:265-72. [PMID: 24727147 DOI: 10.1016/j.ymeth.2014.03.031] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Accepted: 03/26/2014] [Indexed: 12/11/2022] Open
Abstract
In recent years the Drosophila heart has become an established model for many different aspects of human cardiac disease. This model has allowed identification of disease-causing mechanisms underlying congenital heart disease and cardiomyopathies and has permitted the study of underlying genetic, metabolic and age-related contributions to heart function. In this review we discuss methods currently employed in the analysis of the Drosophila heart structure and function, such as optical methods to infer heart function and performance, electrophysiological and mechanical approaches to characterize cardiac tissue properties, and conclude with histological techniques used in the study of heart development and adult structure.
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33
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Kaushik G, Engler AJ. From stem cells to cardiomyocytes: the role of forces in cardiac maturation, aging, and disease. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2014; 126:219-42. [PMID: 25081620 DOI: 10.1016/b978-0-12-394624-9.00009-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Stem cell differentiation into a variety of lineages is known to involve signaling from the extracellular niche, including from the physical properties of that environment. What regulates stem cell responses to these cues is there ability to activate different mechanotransductive pathways. Here, we will review the structures and pathways that regulate stem cell commitment to a cardiomyocyte lineage, specifically examining proteins within muscle sarcomeres, costameres, and intercalated discs. Proteins within these structures stretch, inducing a change in their phosphorylated state or in their localization to initiate different signals. We will also put these changes in the context of stem cell differentiation into cardiomyocytes, their subsequent formation of the chambered heart, and explore negative signaling that occurs during disease.
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Affiliation(s)
- Gaurav Kaushik
- Department of Bioengineering, University of California, San Diego, La Jolla, California, USA
| | - Adam J Engler
- Department of Bioengineering, University of California, San Diego, La Jolla, California, USA
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