1
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Fenwick AJ, Jani VP, Foster DB, Sharp TE, Goodchild TT, LaPenna K, Doiron JE, Lefer DJ, Hill JA, Kass DA, Cammarato A. Common Heart Failure With Preserved Ejection Fraction Animal Models Yield Disparate Myofibril Mechanics. J Am Heart Assoc 2024; 13:e032037. [PMID: 38193306 PMCID: PMC10926808 DOI: 10.1161/jaha.123.032037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 11/27/2023] [Indexed: 01/10/2024]
Affiliation(s)
- Axel J. Fenwick
- Division of Cardiology, Department of MedicineJohns Hopkins UniversityBaltimoreMDUSA
| | - Vivek P. Jani
- Division of Cardiology, Department of MedicineJohns Hopkins UniversityBaltimoreMDUSA
- Department of Biomedical EngineeringJohns Hopkins UniversityBaltimoreMDUSA
| | - D. Brian Foster
- Division of Cardiology, Department of MedicineJohns Hopkins UniversityBaltimoreMDUSA
| | - Thomas E. Sharp
- Department of Molecular Pharmacology and PhysiologyUniversity of South FloridaTampaFLUSA
| | - Traci T. Goodchild
- Department of Cardiac SurgerySmidt Heart Institute, Cedars‐Sinai Medical CenterLos AngelesCAUSA
| | - Kyle LaPenna
- Department of Medicine, Cardiovascular Center of ExcellenceLouisiana State University Health Sciences CenterNew OrleansLAUSA
| | - Jake E. Doiron
- Department of Medicine, Cardiovascular Center of ExcellenceLouisiana State University Health Sciences CenterNew OrleansLAUSA
| | - David J. Lefer
- Department of Cardiac SurgerySmidt Heart Institute, Cedars‐Sinai Medical CenterLos AngelesCAUSA
| | - Joseph A. Hill
- Department of MedicineUT Southwestern Medical CenterDallasTXUSA
- Department of Molecular BiologyUT Southwestern Medical CenterDallasTXUSA
| | - David A. Kass
- Division of Cardiology, Department of MedicineJohns Hopkins UniversityBaltimoreMDUSA
- Department of Biomedical EngineeringJohns Hopkins UniversityBaltimoreMDUSA
| | - Anthony Cammarato
- Division of Cardiology, Department of MedicineJohns Hopkins UniversityBaltimoreMDUSA
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2
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Fenwick AJ, Jani VP, Kass DA, Cammarato A. HFpEF animal models display differences in myofibril mechanics. Biophys J 2023; 122:122a. [PMID: 36782539 DOI: 10.1016/j.bpj.2022.11.830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Affiliation(s)
- Axel J Fenwick
- Division of Cardiology, Department of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Vivek P Jani
- Division of Cardiology, Department of Medicine, Johns Hopkins University, Baltimore, MD, USA; Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - David A Kass
- Division of Cardiology, Department of Medicine, Johns Hopkins University, Baltimore, MD, USA; Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Anthony Cammarato
- Division of Cardiology, Department of Medicine, Johns Hopkins University, Baltimore, MD, USA
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3
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Kronert WA, Hsu KH, Madan A, Sarsoza F, Cammarato A, Bernstein SI. Myosin Transducer Inter-Strand Communication Is Critical for Normal ATPase Activity and Myofibril Structure. Biology (Basel) 2022; 11:biology11081137. [PMID: 36009764 PMCID: PMC9404822 DOI: 10.3390/biology11081137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 07/21/2022] [Accepted: 07/25/2022] [Indexed: 02/07/2023]
Abstract
The R249Q mutation in human β-cardiac myosin results in hypertrophic cardiomyopathy. We previously showed that inserting this mutation into Drosophila melanogaster indirect flight muscle myosin yields mechanical and locomotory defects. Here, we use transgenic Drosophila mutants to demonstrate that residue R249 serves as a critical communication link within myosin that controls both ATPase activity and myofibril integrity. R249 is located on a β-strand of the central transducer of myosin, and our molecular modeling shows that it interacts via a salt bridge with D262 on the adjacent β-strand. We find that disrupting this interaction via R249Q, R249D or D262R mutations reduces basal and actin-activated ATPase activity, actin in vitro motility and flight muscle function. Further, the R249D mutation dramatically affects myofibril assembly, yielding abnormalities in sarcomere lengths, increased Z-line thickness and split myofibrils. These defects are exacerbated during aging. Re-establishing the β-strand interaction via a R249D/D262R double mutation restores both basal ATPase activity and myofibril assembly, indicating that these properties are dependent upon transducer inter-strand communication. Thus, the transducer plays an important role in myosin function and myofibril architecture.
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Affiliation(s)
- William A. Kronert
- Department of Biology, Molecular Biology Institute, Heart Institute, San Diego State University, San Diego, CA 92182, USA; (W.A.K.); (K.H.H.); (F.S.)
| | - Karen H. Hsu
- Department of Biology, Molecular Biology Institute, Heart Institute, San Diego State University, San Diego, CA 92182, USA; (W.A.K.); (K.H.H.); (F.S.)
| | - Aditi Madan
- Department of Medicine, Division of Cardiology, Johns Hopkins University, Baltimore, MD 21205, USA; (A.M.); (A.C.)
| | - Floyd Sarsoza
- Department of Biology, Molecular Biology Institute, Heart Institute, San Diego State University, San Diego, CA 92182, USA; (W.A.K.); (K.H.H.); (F.S.)
| | - Anthony Cammarato
- Department of Medicine, Division of Cardiology, Johns Hopkins University, Baltimore, MD 21205, USA; (A.M.); (A.C.)
| | - Sanford I. Bernstein
- Department of Biology, Molecular Biology Institute, Heart Institute, San Diego State University, San Diego, CA 92182, USA; (W.A.K.); (K.H.H.); (F.S.)
- Correspondence:
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4
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Lopez A, Romanick S, Stewart T, Madan A, Baker J, Cammarato A, Ferguson B. Skeletal muscle alpha actin (ACTA1) acetylation negatively regulates muscle function in response to obesity. FASEB J 2022. [DOI: 10.1096/fasebj.2022.36.s1.r4315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Adrian Lopez
- Cell and Molecular BiologyUniversity of Nevada‐RenoRenoNV
- Cellular Signal Transduction in the Cardiovascular SystemUniversity of Nevada‐RenoRenoNV
| | | | - Travis Stewart
- Cellular and Molecular Pharmacology and PhysiologyUniversity of Nevada‐RenoRenoNV
| | | | - Josh Baker
- Cellular and Molecular Pharmacology and PhysiologyUniversity of Nevada‐RenoRenoNV
| | | | - Bradley Ferguson
- Cellular Signal Transduction in the Cardiovascular SystemUniversity of Nevada‐RenoRenoNV
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5
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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6
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Ma W, Gong H, Jani V, Lee KH, Landim-Vieira M, Papadaki M, Pinto JR, Aslam MI, Cammarato A, Irving T. Myofibril orientation as a metric for characterizing heart disease. Biophys J 2022; 121:565-574. [PMID: 35032456 PMCID: PMC8874025 DOI: 10.1016/j.bpj.2022.01.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 12/28/2021] [Accepted: 01/11/2022] [Indexed: 11/17/2022] Open
Abstract
Myocyte disarray is a hallmark of many cardiac disorders. However, the relationship between alterations in the orientation of individual myofibrils and myofilaments to disease progression has been largely underexplored. This oversight has predominantly been because of a paucity of methods for objective and quantitative analysis. Here, we introduce a novel, less-biased approach to quantify myofibrillar and myofilament orientation in cardiac muscle under near-physiological conditions and demonstrate its superiority as compared with conventional histological assessments. Using small-angle x-ray diffraction, we first investigated changes in myofibrillar orientation at increasing sarcomere lengths in permeabilized, relaxed, wild-type mouse myocardium from the left ventricle by assessing the angular spread of the 1,0 equatorial reflection (angle σ). At a sarcomere length of 1.9 μm, the angle σ was 0.23 ± 0.01 rad, decreased to 0.19 ± 0.01 rad at a sarcomere length of 2.1 μm, and further decreased to 0.15 ± 0.01 rad at a sarcomere length of 2.3 μm (p < 0.0001). Angle σ was significantly larger in R403Q, a MYH7 hypertrophic cardiomyopathy model, porcine myocardium (0.24 ± 0.01 rad) compared with wild-type myocardium (0.14 ± 0.005 rad; p < 0.0001), as well as in human heart failure tissue (0.19 ± 0.006 rad) when compared with nonfailing samples (0.17 ± 0.007 rad; p = 0.01). These data indicate that diseased myocardium suffers from greater myofibrillar disorientation compared with healthy controls. Finally, we showed that conventional, histology-based analysis of disarray can be subject to user bias and/or sampling error and lead to false positives. Our method for directly assessing myofibrillar orientation avoids the artifacts introduced by conventional histological approaches that assess myocyte orientation and only indirectly evaluate myofibrillar orientation, and provides a precise and objective metric for phenotypically characterizing myocardium. The ability to obtain excellent x-ray diffraction patterns from frozen human myocardium provides a new tool for investigating structural anomalies associated with cardiac diseases.
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Affiliation(s)
- Weikang Ma
- BioCAT, Department of Biology, Illinois Institute of Technology, Chicago, Illinois.
| | - Henry Gong
- BioCAT, Department of Biology, Illinois Institute of Technology, Chicago, Illinois
| | - Vivek Jani
- Department of Biomedical Engineering, The Johns Hopkins School of Medicine, The Johns Hopkins University, Baltimore, Maryland; Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Kyoung Hwan Lee
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Maicon Landim-Vieira
- Department of Biomedical Sciences, Florida State University, Tallahassee, Florida
| | - Maria Papadaki
- Department of Cell and Molecular Physiology, Loyola University Chicago, Chicago, Illinois
| | - Jose R Pinto
- Department of Biomedical Sciences, Florida State University, Tallahassee, Florida
| | - M Imran Aslam
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Anthony Cammarato
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Thomas Irving
- BioCAT, Department of Biology, Illinois Institute of Technology, Chicago, Illinois
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7
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Doran M, Despond E, Viswanathan M, Madan A, Cossentino J, Rynkiewicz MJ, Sousa D, Lehman W, Dawson J, Cammarato A. The ACTC A331P hypertrophic cardiomyopathy mutation enhances basal contractile activity and causes resting muscle dysfunction. Biophys J 2022. [DOI: 10.1016/j.bpj.2021.11.2187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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8
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Jani VP, Aslam I, Ma W, Cubero Salazar I, Gong HM, Cammarato A, Irving TC, Kass DA, Hsu S. Increased super-relaxed myosin underlies the tension deficit in RV myocytes from hfref patients. Biophys J 2022. [DOI: 10.1016/j.bpj.2021.11.598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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9
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Fenwick A, Jani VP, Madan A, Cammarato A. Pseudo-acetylation of actin K326 and K328 increases duration and force of contraction in mouse cardiomyocytes. Biophys J 2022. [DOI: 10.1016/j.bpj.2021.11.772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
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10
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Jani V, Aslam MI, Ma W, Gong H, Cammarato A, Irving T, Kass DA, Hsu S. Abstract P505: Rv Sarcomeres From Lv-hfref Patients With Low Papi Have Abnormal Rv Thick Filament Structure. Circ Res 2021. [DOI: 10.1161/res.129.suppl_1.p505] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Patients with left heart failure and reduced ejection fraction (HFrEF) have variable RV failure that, if present, drastically worsens outcomes. In a cohort of 21 HFrEF patients from two hospital sites, we have previously shown (Aslam et al, Eur J HF; 2020: volume 23, pages 339-341) that like global function, RV myocyte maximum calcium-activated myocyte tension (T
max
) is quite variable (COV 27%). To determine if a relationship between RV myocyte function and indices of RV chamber function exists, we trained a random forest classifier based on 41 clinical variables, including hemodynamic, laboratory, and echocardiographic data, and queried the importance of each. This revealed that the most predictive model for reduced T
max
was based on the pulmonary artery pulsatility index (PAPi), an established clinical index of RV failure. To gain insight into potential mechanisms for depressed T
max
in HFrEF patients with a low PAPi, we obtained small angle x-ray diffraction patterns in 5 HFrEF patients with depressed PAPi and T
max
and compared this to 5 non-failing (NF) controls. The equatorial intensity ratio I(1,1)/I(1,0) was reduced in low T
max
RV muscle fibers vs. controls (0.250.06 vs. 0.180.02, P<0.0001), suggesting myosin heads are more associated with the thick filament backbone. In meridional reflections, we find a significant decrease in M3 band spacing (14.340.03 nm in NF vs. 14.300.01 nm in HFrEF; P=0.0013) suggesting more myosin heads are in the “OFF” configuration. The latter may underly tension reduction in RV myocytes from failing RV HFrEF patients. Ongoing studies will examine these structural changes in HFrEF patients with a broader range of PAPi and T
max
to test if this association applies. These findings focus attention on thick filament structural and configuration abnormalities as potential culprits underlying RV disease in HFrEF. Further studies using novel sarcomere enhancers will test if these changes can be remedied, and if so, in which patients.
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Affiliation(s)
| | | | - Weikang Ma
- Illinois Institute of Technology, Lemont, IL
| | | | | | | | | | - Steven Hsu
- Johns Hopkins Sch of Medicine, Baltimore, MD
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11
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Trujillo AS, Hsu KH, Puthawala J, Viswanathan MC, Loya A, Irving TC, Cammarato A, Swank DM, Bernstein SI. Myosin dilated cardiomyopathy mutation S532P disrupts actomyosin interactions, leading to altered muscle kinetics, reduced locomotion, and cardiac dilation in Drosophila. Mol Biol Cell 2021; 32:1690-1706. [PMID: 34081531 PMCID: PMC8684735 DOI: 10.1091/mbc.e21-02-0088] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Dilated cardiomyopathy (DCM), a life-threatening disease characterized by pathological heart enlargement, can be caused by myosin mutations that reduce contractile function. To better define the mechanistic basis of this disease, we employed the powerful genetic and integrative approaches available in Drosophila melanogaster. To this end, we generated and analyzed the first fly model of human myosin-induced DCM. The model reproduces the S532P human β-cardiac myosin heavy chain DCM mutation, which is located within an actin-binding region of the motor domain. In concordance with the mutation's location at the actomyosin interface, steady-state ATPase and muscle mechanics experiments revealed that the S532P mutation reduces the rates of actin-dependent ATPase activity and actin binding and increases the rate of actin detachment. The depressed function of this myosin form reduces the number of cross-bridges during active wing beating, the power output of indirect flight muscles, and flight ability. Further, S532P mutant hearts exhibit cardiac dilation that is mutant gene dose-dependent. Our study shows that Drosophila can faithfully model various aspects of human DCM phenotypes and suggests that impaired actomyosin interactions in S532P myosin induce contractile deficits that trigger the disease.
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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
| | - Karen H Hsu
- Department of Biology, Molecular Biology Institute, Heart Institute, San Diego State University, San Diego, CA 92182
| | - Joy Puthawala
- Department of Biological Sciences and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180
| | - Meera C Viswanathan
- Division of Cardiology, Department of Medicine, Johns Hopkins University, Baltimore, MD 21205
| | - Amy Loya
- Department of Biological Sciences and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180
| | - Thomas C Irving
- Center for Synchrotron Radiation Research and Instrumentation and Department of Biological Sciences, Illinois Institute of Technology, Chicago, IL 60616
| | - Anthony Cammarato
- Division of Cardiology, Department of Medicine, Johns Hopkins University, Baltimore, MD 21205
| | - Douglas M Swank
- Department of Biological Sciences and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180
| | - Sanford I Bernstein
- Department of Biology, Molecular Biology Institute, Heart Institute, San Diego State University, San Diego, CA 92182
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12
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Tobacman LS, Cammarato A. Cardiomyopathic troponin mutations predominantly occur at its interface with actin and tropomyosin. J Gen Physiol 2021; 153:e202012815. [PMID: 33492345 PMCID: PMC7836260 DOI: 10.1085/jgp.202012815] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Accepted: 12/23/2020] [Indexed: 01/09/2023] Open
Abstract
Reversible Ca2+ binding to troponin is the primary on-off switch of the contractile apparatus of striated muscles, including the heart. Dominant missense mutations in human cardiac troponin genes are among the causes of hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy. Structural understanding of troponin action has recently advanced considerably via electron microscopy and molecular dynamics studies of the thin filament. As a result, it is now possible to examine cardiomyopathy-inducing troponin mutations in thin-filament structural context, and from that to seek new insight into pathogenesis and into the troponin regulatory mechanism. We compiled from consortium reports a representative set of troponin mutation sites whose pathogenicity was determined using standardized clinical genetics criteria. Another set of sites, apparently tolerant of amino acid substitutions, was compiled from the gnomAD v2 database. Pathogenic substitutions occurred predominantly in the areas of troponin that contact actin or tropomyosin, including, but not limited to, two regions of newly proposed structure and long-known implication in cardiomyopathy: the C-terminal third of troponin I and a part of the troponin T N terminus. The pathogenic mutations were located in troponin regions that prevent contraction under low Ca2+ concentration conditions. These regions contribute to Ca2+-regulated steric hindrance of myosin by the combined effects of troponin and tropomyosin. Loss-of-function mutations within these parts of troponin result in loss of inhibition, consistent with the hypercontractile phenotype characteristic of HCM. Notably, pathogenic mutations are absent in our dataset from the Ca2+-binding, activation-producing troponin C (TnC) N-lobe, which controls contraction by a multi-faceted mechanism. Apparently benign mutations are also diminished in the TnC N-lobe, suggesting mutations are poorly tolerated in that critical domain.
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Affiliation(s)
- Larry S. Tobacman
- Departments of Medicine and of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL
| | - Anthony Cammarato
- Departments of Medicine and of Physiology, Johns Hopkins University, Baltimore, MD
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13
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Konstantinidis K, Bezzerides VJ, Lai L, Isbell HM, Wei AC, Wu Y, Viswanathan MC, Blum ID, Granger JM, Heims-Waldron D, Zhang D, Luczak ED, Murphy KR, Lu F, Gratz DH, Manta B, Wang Q, Wang Q, Kolodkin AL, Gladyshev VN, Hund TJ, Pu WT, Wu MN, Cammarato A, Bianchet MA, Shea MA, Levine RL, Anderson ME. MICAL1 constrains cardiac stress responses and protects against disease by oxidizing CaMKII. J Clin Invest 2021; 130:4663-4678. [PMID: 32749237 PMCID: PMC7456244 DOI: 10.1172/jci133181] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 05/29/2020] [Indexed: 01/22/2023] Open
Abstract
Oxidant stress can contribute to health and disease. Here we show that invertebrates and vertebrates share a common stereospecific redox pathway that protects against pathological responses to stress, at the cost of reduced physiological performance, by constraining Ca2+/calmodulin-dependent protein kinase II (CaMKII) activity. MICAL1, a methionine monooxygenase thought to exclusively target actin, and MSRB, a methionine reductase, control the stereospecific redox status of M308, a highly conserved residue in the calmodulin-binding (CaM-binding) domain of CaMKII. Oxidized or mutant M308 (M308V) decreased CaM binding and CaMKII activity, while absence of MICAL1 in mice caused cardiac arrhythmias and premature death due to CaMKII hyperactivation. Mimicking the effects of M308 oxidation decreased fight-or-flight responses in mice, strikingly impaired heart function in Drosophila melanogaster, and caused disease protection in human induced pluripotent stem cell-derived cardiomyocytes with catecholaminergic polymorphic ventricular tachycardia, a CaMKII-sensitive genetic arrhythmia syndrome. Our studies identify a stereospecific redox pathway that regulates cardiac physiological and pathological responses to stress across species.
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Affiliation(s)
- Klitos Konstantinidis
- Division of Cardiology.,Department of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | | | - Lo Lai
- Laboratory of Biochemistry, National Heart, Lung, and Blood Institute, Bethesda, Maryland, USA
| | - Holly M Isbell
- Department of Biochemistry, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - An-Chi Wei
- Department of Electrical Engineering, Graduate Institute of Biomedical and Bioinformatics, National Taiwan University, Taipei City, Taiwan
| | - Yuejin Wu
- Department of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Meera C Viswanathan
- Division of Cardiology.,Department of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Ian D Blum
- Department of Neurology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Jonathan M Granger
- Department of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | | | - Donghui Zhang
- Department of Cardiology, Boston Children's Hospital, Boston, Massachusetts, USA.,State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Science, Hubei University, Wuhan, China
| | - Elizabeth D Luczak
- Department of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Kevin R Murphy
- Department of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Fujian Lu
- Department of Cardiology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Daniel H Gratz
- Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio, USA
| | - Bruno Manta
- Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Qiang Wang
- Department of Neurology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Qinchuan Wang
- Department of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Alex L Kolodkin
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Maryland, USA
| | - Vadim N Gladyshev
- Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Thomas J Hund
- Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio, USA
| | - William T Pu
- Department of Cardiology, Boston Children's Hospital, Boston, Massachusetts, USA.,Harvard Stem Cell Institute, Cambridge, Massachusetts, USA
| | - Mark N Wu
- Department of Medicine, Johns Hopkins University, Baltimore, Maryland, USA.,Department of Neurology, Johns Hopkins University, Baltimore, Maryland, USA.,Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Maryland, USA.,Department of Genetic Medicine
| | - Anthony Cammarato
- Division of Cardiology.,Department of Medicine, Johns Hopkins University, Baltimore, Maryland, USA.,Department of Physiology, and
| | - Mario A Bianchet
- Department of Neurology, Johns Hopkins University, Baltimore, Maryland, USA.,Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, Baltimore, Maryland, USA
| | - Madeline A Shea
- Department of Biochemistry, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Rodney L Levine
- Laboratory of Biochemistry, National Heart, Lung, and Blood Institute, Bethesda, Maryland, USA
| | - Mark E Anderson
- Division of Cardiology.,Department of Medicine, Johns Hopkins University, Baltimore, Maryland, USA.,Department of Physiology, and
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14
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Dou Z, Madan A, Carlson JS, Chung J, Spoleti T, Dimopoulos G, Cammarato A, Mittal R. Acoustotactic response of mosquitoes in untethered flight to incidental sound. Sci Rep 2021; 11:1884. [PMID: 33479423 PMCID: PMC7820424 DOI: 10.1038/s41598-021-81456-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2020] [Accepted: 01/04/2021] [Indexed: 11/29/2022] Open
Abstract
Mosquitoes are vectors for some of the most devastating diseases on the planet. Given the centrality of acoustic sensing in the precopulatory behavior of these vectors, the use of an exogenous acoustic stimulus offers the potential of interfering with the courtship behavior of these insects. Previous research on the acoustotactic response of mosquitoes has been conducted on tethered preparations using low-intensity sound stimuli. To quantify differences in acoustotactic responses between mosquitos of distinct sex and species, we examined the effects of incidental sound stimuli on the flight behavior of free-flying male vs. female Aedes aegypti and Anopheles gambiae mosquitoes. The key variables were sound frequency (100–1000 Hz) and intensity (67–103 dB, measured at 12.5 cm from the source), and the acoustotactic response was measured in terms of the relative increase in flight speed in response to the stimulus. The data show, for the first time, significant sex- and species-specific differences in acoustotactic responses. A. aegypti exhibited a greater response to sound stimulus compared to An. gambiae, and the response also extended over a larger range of frequencies. Furthermore, the males of both species displayed a greater acoustotactic response than females, with An. gambiae females exhibiting minimal response to sound.
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Affiliation(s)
- Zhongwang Dou
- Department of Mechanical Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Aditi Madan
- Division of Cardiology, Department of Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Jenny S Carlson
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Joseph Chung
- Department of Mechanical Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Tyler Spoleti
- Department of Mechanical Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - George Dimopoulos
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Anthony Cammarato
- Division of Cardiology, Department of Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Rajat Mittal
- Department of Mechanical Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, MD, USA.
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15
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Schmidt W, Madan A, Foster DB, Cammarato A. Lysine acetylation of F-actin decreases tropomyosin-based inhibition of actomyosin activity. J Biol Chem 2020; 295:15527-15539. [PMID: 32873710 DOI: 10.1074/jbc.ra120.015277] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/18/2020] [Indexed: 12/17/2022] Open
Abstract
Recent proteomics studies of vertebrate striated muscle have identified lysine acetylation at several sites on actin. Acetylation is a reversible post-translational modification that neutralizes lysine's positive charge. Positively charged residues on actin, particularly Lys326 and Lys328, are predicted to form critical electrostatic interactions with tropomyosin (Tpm) that promote its binding to filamentous (F)-actin and bias Tpm to an azimuthal location where it impedes myosin attachment. The troponin (Tn) complex also influences Tpm's position along F-actin as a function of Ca2+ to regulate exposure of myosin-binding sites and, thus, myosin cross-bridge recruitment and force production. Interestingly, Lys326 and Lys328 are among the documented acetylated residues. Using an acetic anhydride-based labeling approach, we showed that excessive, nonspecific actin acetylation did not disrupt characteristic F-actin-Tpm binding. However, it significantly reduced Tpm-mediated inhibition of myosin attachment, as reflected by increased F-actin-Tpm motility that persisted in the presence of Tn and submaximal Ca2+ Furthermore, decreasing the extent of chemical acetylation, to presumptively target highly reactive Lys326 and Lys328, also resulted in less inhibited F-actin-Tpm, implying that modifying only these residues influences Tpm's location and, potentially, thin filament regulation. To unequivocally determine the residue-specific consequences of acetylation on Tn-Tpm-based regulation of actomyosin activity, we assessed the effects of K326Q and K328Q acetyl (Ac)-mimetic actin on Ca2+-dependent, in vitro motility parameters of reconstituted thin filaments (RTFs). Incorporation of K328Q actin significantly enhanced Ca2+ sensitivity of RTF activation relative to control. Together, our findings suggest that actin acetylation, especially Lys328, modulates muscle contraction via disrupting inhibitory Tpm positioning.
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Affiliation(s)
- William Schmidt
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Aditi Madan
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - D Brian Foster
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Anthony Cammarato
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
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16
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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17
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Elmén L, Volpato CB, Kervadec A, Pineda S, Kalvakuri S, Alayari NN, Foco L, Pramstaller PP, Ocorr K, Rossini A, Cammarato A, Colas AR, Hicks AA, Bodmer R. Silencing of CCR4-NOT complex subunits affects heart structure and function. Dis Model Mech 2020; 13:dmm044727. [PMID: 32471864 PMCID: PMC7390626 DOI: 10.1242/dmm.044727] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 05/19/2020] [Indexed: 12/12/2022] Open
Abstract
The identification of genetic variants that predispose individuals to cardiovascular disease and a better understanding of their targets would be highly advantageous. Genome-wide association studies have identified variants that associate with QT-interval length (a measure of myocardial repolarization). Three of the strongest associating variants (single-nucleotide polymorphisms) are located in the putative promotor region of CNOT1, a gene encoding the central CNOT1 subunit of CCR4-NOT: a multifunctional, conserved complex regulating gene expression and mRNA stability and turnover. We isolated the minimum fragment of the CNOT1 promoter containing all three variants from individuals homozygous for the QT risk alleles and demonstrated that the haplotype associating with longer QT interval caused reduced reporter expression in a cardiac cell line, suggesting that reduced CNOT1 expression might contribute to abnormal QT intervals. Systematic siRNA-mediated knockdown of CCR4-NOT components in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) revealed that silencing CNOT1 and other CCR4-NOT genes reduced their proliferative capacity. Silencing CNOT7 also shortened action potential duration. Furthermore, the cardiac-specific knockdown of Drosophila orthologs of CCR4-NOT genes in vivo (CNOT1/Not1 and CNOT7/8/Pop2) was either lethal or resulted in dilated cardiomyopathy, reduced contractility or a propensity for arrhythmia. Silencing CNOT2/Not2, CNOT4/Not4 and CNOT6/6L/twin also affected cardiac chamber size and contractility. Developmental studies suggested that CNOT1/Not1 and CNOT7/8/Pop2 are required during cardiac remodeling from larval to adult stages. To summarize, we have demonstrated how disease-associated genes identified by GWAS can be investigated by combining human cardiomyocyte cell-based and whole-organism in vivo heart models. Our results also suggest a potential link of CNOT1 and CNOT7/8 to QT alterations and further establish a crucial role of the CCR4-NOT complex in heart development and function.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Lisa Elmén
- Development Aging and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Claudia B Volpato
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, Via Galvani 31, 39100 Bolzano, Italy
| | - Anaïs Kervadec
- Development Aging and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Santiago Pineda
- Development Aging and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Sreehari Kalvakuri
- Development Aging and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Nakissa N Alayari
- Development Aging and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Luisa Foco
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, Via Galvani 31, 39100 Bolzano, Italy
| | - Peter P Pramstaller
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, Via Galvani 31, 39100 Bolzano, Italy
| | - Karen Ocorr
- Development Aging and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Alessandra Rossini
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, Via Galvani 31, 39100 Bolzano, Italy
| | - Anthony Cammarato
- Johns Hopkins University, Division of Cardiology, 720 Rutland Ave., Baltimore, MD 21205, USA
| | - Alexandre R Colas
- Development Aging and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Andrew A Hicks
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, Via Galvani 31, 39100 Bolzano, Italy
| | - Rolf Bodmer
- Development Aging and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 N Torrey Pines Rd, La Jolla, CA 92037, USA
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18
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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19
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Madan A, Viswanathan MC, Woulfe KC, Schmidt WM, Vogler G, Wilson C, Madathil S, Biesiadecki BJ, Trinh B, Sidor A, Liu T, O'Rourke B, Tobacman LS, Cammarato A. Mutations in the TnT1 Tropomyosin-Binding Element of Troponin-T Alter Its Inhibitory Properties and Stimulate Myocardial Dysfunction. Biophys J 2020. [DOI: 10.1016/j.bpj.2019.11.2384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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20
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Lin YH, Schmidt W, Fritz KS, Jeong MY, Cammarato A, Foster DB, Biesiadecki BJ, McKinsey TA, Woulfe KC. Site-specific acetyl-mimetic modification of cardiac troponin I modulates myofilament relaxation and calcium sensitivity. J Mol Cell Cardiol 2020; 139:135-147. [PMID: 31981571 DOI: 10.1016/j.yjmcc.2020.01.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 01/20/2020] [Accepted: 01/21/2020] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Cardiac troponin I (cTnI) is an essential physiological and pathological regulator of cardiac relaxation. Significant to this regulation, the post-translational modification of cTnI through phosphorylation functions as a key mechanism to accelerate myofibril relaxation. Similar to phosphorylation, post-translational modification by acetylation alters amino acid charge and protein function. Recent studies have demonstrated that the acetylation of cardiac myofibril proteins accelerates relaxation and that cTnI is acetylated in the heart. These findings highlight the potential significance of myofilament acetylation; however, it is not known if site-specific acetylation of cTnI can lead to changes in myofilament, myofibril, and/or cellular mechanics. The objective of this study was to determine the effects of mimicking acetylation at a single site of cTnI (lysine-132; K132) on myofilament, myofibril, and cellular mechanics and elucidate its influence on molecular function. METHODS To determine if pseudo-acetylation of cTnI at 132 modulates thin filament regulation of the acto-myosin interaction, we reconstituted thin filaments containing WT or K132Q (to mimic acetylation) cTnI and assessed in vitro motility. To test if mimicking acetylation at K132 alters cellular relaxation, adult rat ventricular cardiomyocytes were infected with adenoviral constructs expressing either cTnI K132Q or K132 replaced with arginine (K132R; to prevent acetylation) and cell shortening and isolated myofibril mechanics were measured. Finally, to confirm that changes in cell shortening and myofibril mechanics were directly due to pseudo-acetylation of cTnI at K132, we exchanged troponin containing WT or K132Q cTnI into isolated myofibrils and measured myofibril mechanical properties. RESULTS Reconstituted thin filaments containing K132Q cTnI exhibited decreased calcium sensitivity compared to thin filaments reconstituted with WT cTnI. Cardiomyocytes expressing K132Q cTnI had faster relengthening and myofibrils isolated from these cells had faster relaxation along with decreased calcium sensitivity compared to cardiomyocytes expressing WT or K132R cTnI. Myofibrils exchanged with K132Q cTnI ex vivo demonstrated faster relaxation and decreased calcium sensitivity. CONCLUSIONS Our results indicate for the first time that mimicking acetylation of a specific cTnI lysine accelerates myofilament, myofibril, and myocyte relaxation. This work underscores the importance of understanding how acetylation of specific sarcomeric proteins affects cardiac homeostasis and disease and suggests that modulation of myofilament lysine acetylation may represent a novel therapeutic target to alter cardiac relaxation.
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Affiliation(s)
- Ying H Lin
- Division of Cardiology, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States of America
| | - William Schmidt
- Division of Cardiology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Kristofer S Fritz
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, United States of America
| | - Mark Y Jeong
- Division of Cardiology, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States of America
| | - Anthony Cammarato
- Division of Cardiology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - D Brian Foster
- Division of Cardiology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Brandon J Biesiadecki
- Department of Physiology and Cell Biology, The Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States of America
| | - Timothy A McKinsey
- Division of Cardiology, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States of America; Consortium for Fibrosis Research & Translation, University of Colorado Anschutz Medical Campus, Aurora, CO, United States of America.
| | - Kathleen C Woulfe
- Division of Cardiology, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States of America.
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21
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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22
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Woulfe KC, Lin YH, Schmidt W, Cammarato A, Foster DB, Biesiadecki BJ, McKinsey TA. Abstract 109: Site-specific Acetylation of Cardiac Troponin I Regulates Myofilament Relaxation and Calcium Sensitivity. Circ Res 2019. [DOI: 10.1161/res.125.suppl_1.109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Objective:
Cardiac troponin I (cTnI) is an essential regulator of cardiac contractility and relaxation. Mutations within key regions of this regulator lead to cardiomyopathies. Further, post-translational modification of cTnI through phosphorylation impacts myofibril relaxation and calcium sensitivity. Recent studies have also demonstrated that myofibril proteins are acetylated leading to faster relaxation. These studies highlight the potential significance of myofilament acetylation; however, it is not known if site-specific acetylation of cTnI can lead to mechanical changes in the myofibril. The objective of this study was to determine if acetylation at a single site of cTnI (lysine-132; K132) is sufficient to alter myofibril protein mechanics.
Methods:
Adult rat ventricular cardiomyocytes infected with adenoviral constructs expressing either cTnI K132 replaced with glutamine (K132Q; to mimic acetylation) or K132 replaced with arginine (K132R; to prevent acetylation) were subjected to cell contractility and isolated myofibril mechanic measurements. Additionally, skinned myofibrils were exchanged with troponin containing wildtype (WT) or K132Q cTnI and mechanics assessed. Finally, dynamics of reconstituted thin filaments containing WT or K132Q cTnI were assessed by in vitro motility assay.
Results:
Cardiomyocytes expressing cTnI K132Q relaxed faster and had decreased calcium sensitivity compared to WT cTnI at the whole cell and myofibril level. Relaxation or calcium sensitivity did not differ between cardiomyocytes infected with WT cTnI and cTnI K132R. Myofibrils with cTnI K132Q exchanged ex vivo demonstrate faster relaxation and decreased calcium sensitivity as well as decreased motility.
Conclusions:
Our results indicate for the first time that acetylation at a specific cTnI lysine can alter myofibril relaxation and calcium sensitivity. This work underscores the importance of understanding how acetylation affects specific sarcomeric proteins in the context of cardiac disease, and suggests that modulation of myofilament lysine acetylation may represent a novel therapeutic target to alter cardiac relaxation.
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Affiliation(s)
| | | | | | | | - D B Foster
- Johns Hopkins Univ Sch of Medicine, Baltimore, MD
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Blice-Baum AC, Guida MC, Hartley PS, Adams PD, Bodmer R, Cammarato A. As time flies by: Investigating cardiac aging in the short-lived Drosophila model. Biochim Biophys Acta Mol Basis Dis 2019; 1865:1831-1844. [PMID: 30496794 PMCID: PMC6527462 DOI: 10.1016/j.bbadis.2018.11.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 11/05/2018] [Accepted: 11/13/2018] [Indexed: 02/06/2023]
Abstract
Aging is associated with a decline in heart function across the tissue, cellular, and molecular levels. The risk of cardiovascular disease grows significantly over time, and as developed countries continue to see an increase in lifespan, the cost of cardiovascular healthcare for the elderly will undoubtedly rise. The molecular basis for cardiac function deterioration with age is multifaceted and not entirely clear, and there is a limit to what investigations can be performed on human subjects or mammalian models. Drosophila melanogaster has emerged as a useful model organism for studying aging in a short timeframe, benefitting from a suite of molecular and genetic tools and displaying highly conserved traits of cardiac senescence. Here, we discuss recent advances in our understanding of cardiac aging and how the fruit fly has aided in these developments.
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Affiliation(s)
| | - Maria Clara Guida
- Development, Aging and Regeneration Program, Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, CA, USA.
| | - Paul S Hartley
- Bournemouth University, Department of Life and Environmental Science, Talbot Campus, Fern Barrow, Poole, Dorset BH12 5BB, UK.
| | - Peter D Adams
- Development, Aging and Regeneration Program, Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, CA, USA.
| | - Rolf Bodmer
- Development, Aging and Regeneration Program, Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, CA, 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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24
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Abstract
Lipotoxic cardiomyopathy (LCM) is characterized by abnormal myocardial accumulation of lipids, including ceramide; however, the contribution of ceramide to the etiology of LCM is unclear. Here, we investigated the association of ceramide metabolism and ceramide-interacting proteins (CIPs) in LCM in the Drosophila heart model. We find that ceramide feeding or ceramide-elevating genetic manipulations are strongly associated with cardiac dilation and defects in contractility. High ceramide-associated LCM is prevented by inhibiting ceramide synthesis, establishing a robust model of direct ceramide-associated LCM, corroborating previous indirect evidence in mammals. We identified several CIPs from mouse heart and Drosophila extracts, including caspase activator Annexin-X, myosin chaperone Unc-45, and lipogenic enzyme FASN1, and remarkably, their cardiac-specific manipulation can prevent LCM. Collectively, these data suggest that high ceramide-associated lipotoxicity is mediated, in part, through altering caspase activation, sarcomeric maintenance, and lipogenesis, thus providing evidence for conserved mechanisms in LCM pathogenesis in mammals.
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Affiliation(s)
- Stanley M Walls
- Development, Aging and Regeneration Program, Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, CA, USA; Department of Cellular and Molecular Biology, San Diego State University, San Diego, CA, USA
| | - Anthony Cammarato
- Development, Aging and Regeneration Program, Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Dale A Chatfield
- Department of Cellular and Molecular Biology, San Diego State University, San Diego, CA, USA
| | - Karen Ocorr
- Development, Aging and Regeneration Program, Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Greg L Harris
- Department of Cellular and Molecular Biology, San Diego State University, San Diego, CA, USA.
| | - Rolf Bodmer
- Development, Aging and Regeneration Program, Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, CA, USA.
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25
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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26
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Limpitikul WB, Viswanathan MC, O'Rourke B, Yue DT, Cammarato A. L-Type Calcium Channels are a Major Source of Plasmalemmel Calcium Influx for Drosophila Cardiomyocytes. Biophys J 2019. [DOI: 10.1016/j.bpj.2018.11.848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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27
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Madan A, Viswanathan MC, Vogler G, Woulfe KC, Schmidt W, Trinh B, Madathil S, Wilson C, Tobacman LS, Cammarato A. Troponin-T Cardiomyopathy Mutations Depress its Inhibitory Properties, In Vitro, and Stimulate Myocardial Dysfunction, In Vivo. Biophys J 2019. [DOI: 10.1016/j.bpj.2018.11.643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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28
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Schmidt WM, Foster DB, Cammarato A. Acetylation of Actin K328 Contributes to a Loss in Tropomyosin-Mediated Inhibition of Myosin Binding. Biophys J 2019. [DOI: 10.1016/j.bpj.2018.11.2467] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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29
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Blice-Baum AC, Vogler G, Viswanathan MC, Trinh B, Limpitikul WB, Cammarato A. Quantifying Tissue-Specific Overexpression of FOXO in Drosophila via mRNA Fluorescence In Situ Hybridization Using Branched DNA Probe Technology. Methods Mol Biol 2019; 1890:171-190. [PMID: 30414154 PMCID: PMC7906431 DOI: 10.1007/978-1-4939-8900-3_15] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
While the highly conserved FOXO transcription factors have been studied in Drosophila melanogaster for decades, the ability to accurately control and measure their tissue-specific expression is often cumbersome due to a lack of reagents and to limited, nonhomogeneous samples. The need for quantitation within a distinct cell type is particularly important because transcription factors must be expressed in specific amounts to perform their functions properly. However, the inherent heterogeneity of many samples can make evaluating cell-specific FOXO and/or FOXO load difficult. Here, we describe an extremely sensitive fluorescence in situ hybridization (FISH) approach for visualizing and quantifying multiple mRNAs with single-cell resolution in adult Drosophila cardiomyocytes. The procedure relies upon branched DNA technology, which allows several fluorescent molecules to label an individual transcript, drastically increasing the signal-to-noise ratio compared to other FISH assays. This protocol can be modified for use in various small animal models, tissue types, and for assorted nucleic acids.
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Affiliation(s)
- Anna C Blice-Baum
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Science Department, Iadarola Center for Science, Education and Technology, Cabrini University, Radnor, PA, USA.
| | - Georg Vogler
- Development, Aging and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA.
| | - Meera C Viswanathan
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Bosco Trinh
- Development, Aging and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Worawan B Limpitikul
- Department of Biomedical Engineering, 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
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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30
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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31
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Brody MJ, Vanhoutte D, Viswanathan MC, Nguyen T, Maillet M, York AJ, Sargent MA, Cammarato A, Molkentin JD. Abstract 548: Evolutionarily Conserved Functions for Valosin Containing Protein (VCP) in Cardiac and Skeletal Muscle Reveal Mechanistic Insights into Multisystem Proteinopathy. Circ Res 2018. [DOI: 10.1161/res.123.suppl_1.548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Valosin Containing Protein (VCP)/p97 is a AAA-ATPase with functions in vast cellular protein quality control processes, including targeting of misfolded or aggregated proteins for degradation by the ubiquitin proteasome system and autophagy. Mutations in VCP cause a multisystem degenerative proteinopathy disorder that includes pathologies of the nervous system, skeletal muscle, bone, and heart. However, the molecular function of VCP in myocytes is unknown. We generated cardiomyocyte-specific transgenic mice overexpressing wildtype VCP or a VCP
K524A
mutant with deficient ATPase activity. Mice overexpressing wildtype VCP exhibit normal cardiac structure and function while mutant VCP overexpressing mice develop cardiomyopathy and have elevated levels of ubiquitinated proteins in the heart. Additionally, we generated transgenic flies overexpressing wildtype VCP or VCP
K524A
in muscle. Flies overexpressing the VCP ATPase-deficient mutant have reduced flight ability at two days of age and are unable to fly at seven days of age, suggesting conserved indispensable homeostatic functions for VCP in heart and skeletal muscle. Moreover, mouse hearts and
Drosophila
indirect flight muscle overexpressing the ATPase-deficient VCP mutant exhibit profound ultrastructural abnormalities consistent with dysregulation of proteostasis. Extensive proteomics in
Drosophila
and in mouse heart identified conserved interactions of VCP with protein complexes that suggest unique functions for VCP in regulating novel quality control pathways in muscle. These data and novel regulatory relationships will be presented, which implicate important and evolutionarily conserved functions for VCP and suggest molecular mechanisms that underlie the molecular etiology of multisystem proteinopathy disorders.
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Affiliation(s)
| | | | | | | | | | - Allen J York
- Cincinnati Childrens Hosp, Howard Hughes Med Institute, Cincinnati, OH
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Viswanathan MC, Tham RC, Kronert WA, Sarsoza F, Trujillo AS, Cammarato A, Bernstein SI. Myosin storage myopathy mutations yield defective myosin filament assembly in vitro and disrupted myofibrillar structure and function in vivo. Hum Mol Genet 2018; 26:4799-4813. [PMID: 28973424 DOI: 10.1093/hmg/ddx359] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 09/11/2017] [Indexed: 12/19/2022] Open
Abstract
Myosin storage myopathy (MSM) is a congenital skeletal muscle disorder caused by missense mutations in the β-cardiac/slow skeletal muscle myosin heavy chain rod. It is characterized by subsarcolemmal accumulations of myosin that have a hyaline appearance. MSM mutations map near or within the assembly competence domain known to be crucial for thick filament formation. Drosophila MSM models were generated for comprehensive physiological, structural, and biochemical assessment of the mutations' consequences on muscle and myosin structure and function. L1793P, R1845W, and E1883K MSM mutant myosins were expressed in an indirect flight (IFM) and jump muscle myosin null background to study the effects of these variants without confounding influences from wild-type myosin. Mutant animals displayed highly compromised jump and flight ability, disrupted muscle proteostasis, and severely perturbed IFM structure. Electron microscopy revealed myofibrillar disarray and degeneration with hyaline-like inclusions. In vitro assembly assays demonstrated a decreased ability of mutant myosin to polymerize, with L1793P filaments exhibiting shorter lengths. In addition, limited proteolysis experiments showed a reduced stability of L1793P and E1883K filaments. We conclude that the disrupted hydropathy or charge of residues in the heptad repeat of the mutant myosin rods likely alters interactions that stabilize coiled-coil dimers and thick filaments, causing disruption in ordered myofibrillogenesis and/or myofibrillar integrity, and the consequent myosin aggregation. Our Drosophila models are the first to recapitulate the human MSM phenotype with ultrastructural inclusions, suggesting that the diminished ability of the mutant myosin to form stable thick filaments contributes to the dystrophic phenotype observed in afflicted subjects.
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Affiliation(s)
- Meera C Viswanathan
- Department of Biology, Molecular Biology Institute and Heart Institute, San Diego State University, San Diego, CA 92182-4614, USA.,Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Rick C Tham
- Department of Biology, Molecular Biology Institute and Heart Institute, San Diego State University, San Diego, CA 92182-4614, USA
| | - William A Kronert
- Department of Biology, Molecular Biology Institute and Heart Institute, San Diego State University, San Diego, CA 92182-4614, USA
| | - Floyd Sarsoza
- Department of Biology, Molecular Biology Institute and Heart Institute, San Diego State University, San Diego, CA 92182-4614, USA
| | - Adriana S Trujillo
- Department of Biology, Molecular Biology Institute and Heart Institute, San Diego State University, San Diego, CA 92182-4614, USA
| | - Anthony Cammarato
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Sanford I Bernstein
- Department of Biology, Molecular Biology Institute and Heart Institute, San Diego State University, San Diego, CA 92182-4614, USA
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Limpitikul WB, Viswanathan MC, O'Rourke B, Yue DT, Cammarato A. Conservation of cardiac L-type Ca 2+ channels and their regulation in Drosophila: A novel genetically-pliable channelopathic model. J Mol Cell Cardiol 2018; 119:64-74. [PMID: 29684406 DOI: 10.1016/j.yjmcc.2018.04.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 04/08/2018] [Accepted: 04/11/2018] [Indexed: 01/28/2023]
Abstract
Dysregulation of L-type Ca2+ channels (LTCCs) underlies numerous cardiac pathologies. Understanding their modulation with high fidelity relies on investigating LTCCs in their native environment with intact interacting proteins. Such studies benefit from genetic manipulation of endogenous channels in cardiomyocytes, which often proves cumbersome in mammalian models. Drosophila melanogaster, however, offers a potentially efficient alternative as it possesses a relatively simple heart, is genetically pliable, and expresses well-conserved genes. Fluorescence in situ hybridization confirmed an abundance of Ca-α1D and Ca-α1T mRNA in fly myocardium, which encode subunits that specify hetero-oligomeric channels homologous to mammalian LTCCs and T-type Ca2+ channels, respectively. Cardiac-specific knockdown of Ca-α1D via interfering RNA abolished cardiac contraction, suggesting Ca-α1D (i.e. A1D) represents the primary functioning Ca2+ channel in Drosophila hearts. Moreover, we successfully isolated viable single cardiomyocytes and recorded Ca2+ currents via patch clamping, a feat never before accomplished with the fly model. The profile of Ca2+ currents recorded in individual cells when Ca2+ channels were hypomorphic, absent, or under selective LTCC blockage by nifedipine, additionally confirmed the predominance of A1D current across all activation voltages. T-type current, activated at more negative voltages, was also detected. Lastly, A1D channels displayed Ca2+-dependent inactivation, a critical negative feedback mechanism of LTCCs, and the current through them was augmented by forskolin, an activator of the protein kinase A pathway. In sum, the Drosophila heart possesses a conserved compendium of Ca2+ channels, suggesting that the fly may serve as a robust and effective platform for studying cardiac channelopathies.
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Affiliation(s)
- Worawan B Limpitikul
- Calcium Signals Laboratory, Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Ross Research Building, 720 Rutland Avenue, Baltimore, MD 21205, United States
| | - Meera C Viswanathan
- Institute of CardioScience, Division of Cardiology, Department of Medicine, The Johns Hopkins University School of Medicine, Ross Research Building, 720 Rutland Avenue, Baltimore, MD 21205, United States
| | - Brian O'Rourke
- Institute of CardioScience, Division of Cardiology, Department of Medicine, The Johns Hopkins University School of Medicine, Ross Research Building, 720 Rutland Avenue, Baltimore, MD 21205, United States
| | - David T Yue
- Calcium Signals Laboratory, Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Ross Research Building, 720 Rutland Avenue, Baltimore, MD 21205, United States
| | - Anthony Cammarato
- Institute of CardioScience, Division of Cardiology, Department of Medicine, The Johns Hopkins University School of Medicine, Ross Research Building, 720 Rutland Avenue, Baltimore, MD 21205, United States; Department of Physiology, The Johns Hopkins University School of Medicine, Ross Research Building, 720 Rutland Avenue, Baltimore, MD 21205, United States.
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Abstract
Supranormal contractile properties are frequently associated with cardiac diseases. Anesthetic agents, including propofol, can depress myocardial contraction. We tested the hypothesis that fropofol, a propofol derivative, reduces force development in cardiac muscles via inhibition of cross-bridge cycling and may therefore have therapeutic potential. Force and intracellular Ca2+ concentration ([Ca2+]i) transients of rat trabecular muscles were determined. Myofilament ATPase, actin-activated myosin ATPase, and velocity of actin filaments propelled by myosin were also measured. Fropofol dose dependently decreased force without altering [Ca2+]i in normal and pressure-induced hypertrophied-hypercontractile muscles. Similarly, fropofol depressed maximum Ca2+-activated force ( Fmax) and increased the [Ca2+]i required for 50% of Fmax (Ca50) at steady state without affecting the Hill coefficient in both intact and skinned cardiac fibers. The drug also depressed cardiac myofibrillar and actin-activated myosin ATPase activity. In vitro actin sliding velocity was significantly reduced when fropofol was introduced during rigor binding of cross-bridges. The data suggest that the depressing effects of fropofol on cardiac contractility are likely to be related to direct targeting of actomyosin interactions. From a clinical standpoint, these findings are particularly significant, given that fropofol is a nonanesthetic small molecule that decreases myocardial contractility specifically and thus may be useful in the treatment of hypercontractile cardiac disorders.-Ren, X., Schmidt, W., Huang, Y., Lu, H., Liu, W., Bu, W., Eckenhoff, R., Cammarato, A., Gao, W. D. Fropofol decreases force development in cardiac muscle.
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Affiliation(s)
- Xianfeng Ren
- Department of Anesthesiology, China-Japan Friendship Hospital, Beijing, China
| | - William Schmidt
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Yiyuan Huang
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Haisong Lu
- Department of Anesthesiology, Fuwai Hospital, Beijing, China
| | - Wenjie Liu
- Department of Anesthesiology, South China University School of Medicine, China
| | - Weiming Bu
- Department of Anesthesiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Roderic Eckenhoff
- Department of Anesthesiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Anthony Cammarato
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Wei Dong Gao
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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36
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Viswanathan MC, Schmidt W, Madan A, Sullivan LC, Newhard CS, Rynkiewicz MJ, Lehman W, Swank DM, Cammarato A. The ACTC M305L Hypertrophic Cardiomyopathy Mutation Results in Hypercontractility and Impaired Relaxation of Drosophila Muscles. Biophys J 2018. [DOI: 10.1016/j.bpj.2017.11.1776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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37
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Madan A, Madathil S, Schmidt W, Tobacman LS, Cammarato A. TNNT2 Restrictive and Hypertrophic Cardiomyopathy Mutations Depress the Inhibitory Properties of the Troponin-T1 Fragment, In Vitro. Biophys J 2018. [DOI: 10.1016/j.bpj.2017.11.2735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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38
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Wang Q, Luczak E, Viswanathan M, Wu Y, Wei AC, Gupta A, Corradini E, Heck A, Cammarato A, Weiss R, Anderson M. Abstract 128: Mitochondrial CaMKII Plays Important Physiological and Pathological Roles. Circ Res 2017. [DOI: 10.1161/res.121.suppl_1.128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Calcium/calmodulin-dependent protein kinase II (CaMKII) is known for its roles in fight-or-flight responses, where it mobilizes ATP-consuming processes to maximize power output by regulating cellular Ca
2+
. We hypothesized that CaMKII may also influence ATP-generating processes in a feedforward mechanism to match ATP consumption with demand. Most cellular ATP is produced by oxidative phosphorylation (OXPHOS) in mitochondria; therefore, we generated transgenic animals whose mitochondrial CaMKII activity is boosted or inhibited by overexpressing mitochondrial targeted CaMKII (mtCaMKII), or a specific CaMKII inhibitor (mtCaMKII
N
). We found that mitochondria from mtCaMKII mice have increased activity of pyruvate dehydrogenase and various TCA cycle enzymes. However, these mitochondria failed to provide sufficient ATP for cardiac function, likely due to detrimental remodeling of electron transport chain complex I. As a result, mtCaMKII mice develop a unique dilated cardiomyopathy soon after birth, which could be rescued by overexpressing the mitochondrial but not the myofibrillar form of creatine kinase. mtCaMKII
N
mice are protected against lipopolysaccharides (LPS)-induced mortality, ischemia/reperfusion injury, adverse cardiac remodeling after myocardial infarction and asthma. Furthermore,
Drosophila melanogaster
overexpressing mtCaMKII
N
have longer lifespan under heat stress (29
o
C) and are resistant to paraquat, an ROS-inducing agent. However, in the mice, inhibiting mitochondrial CaMKII reduces metabolic fitness required to sustain the isoproterenol-induced fight-or-flight response, leading to elevated utilization of the cardiac glycogen store and increased lactate production. mtCaMKII
N
mice have reduced spontaneous activity and a higher tendency to gain fat mass when fed a high-fat diet; mtCaMKII
N
flies have a shorter lifespan in the absence of thermal stress (25
o
C). We are using phosphoproteomics, metabolomics and
in silico
modeling approaches to determine the mechanisms by which mtCaMKII regulates energy metabolism and stress responses. Our results have provided important insights into the physiological and pathological roles of mitochondrial CaMKII.
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Trujillo AS, Kronert WA, Bell K, Viswanathan MC, Melkani GC, Melkani A, Cammarato A, Swank DM, Bernstein SI. A R146N Hypertrophic Cardiomyopathy Myosin Mutation Disrupts Myosin Function, Myofibrillar Structure, and Cardiac Contraction in Drosophila. Biophys J 2017. [DOI: 10.1016/j.bpj.2016.11.1435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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40
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Madan A, Viswanathan MC, Lavorato M, Schmidt W, Ochala J, Cammarato A. ACTA1-Related Nemaline Myopathy Mutations Engender a Range of Structural and Functional Phenotypes in Drosophila Indirect Flight Muscles. Biophys J 2017. [DOI: 10.1016/j.bpj.2016.11.1010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Blice-Baum AC, Viswanathan MC, Sang TK, Cammarato A. Cardiac-Specific Expression of VCP/TER94 RNAi or Disease Alleles Disrupts Drosophila Heart Structure and Impairs Function. Biophys J 2017. [DOI: 10.1016/j.bpj.2016.11.3014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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42
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Blice-Baum AC, Zambon AC, Kaushik G, Viswanathan MC, Engler AJ, Bodmer R, Cammarato A. Modest overexpression of FOXO maintains cardiac proteostasis and ameliorates age-associated functional decline. Aging Cell 2017; 16:93-103. [PMID: 28090761 PMCID: PMC5242305 DOI: 10.1111/acel.12543] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/11/2016] [Indexed: 11/27/2022] Open
Abstract
Heart performance declines with age. Impaired protein quality control (PQC), due to reduced ubiquitin‐proteasome system (UPS) activity, autophagic function, and/or chaperone‐mediated protein refolding, contributes to cardiac deterioration. The transcription factor FOXO participates in regulating genes involved in PQC, senescence, and numerous other processes. Here, a comprehensive approach, involving molecular genetics, novel assays to probe insect cardiac physiology, and bioinformatics, was utilized to investigate the influence of heart‐restricted manipulation of dFOXO expression in the rapidly aging Drosophila melanogaster model. Modest dFOXO overexpression was cardioprotective, ameliorating nonpathological functional decline with age. This was accompanied by increased expression of genes associated predominantly with the UPS, relative to other PQC components, which was validated by a significant decrease in ubiquitinated proteins. RNAi knockdown of UPS candidates accordingly compromised myocardial physiology in young flies. Conversely, excessive dFOXO overexpression or suppression proved detrimental to heart function and/or organismal development. This study highlights D. melanogaster as a model of cardiac aging and FOXO as a tightly regulated mediator of proteostasis and heart performance over time.
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Affiliation(s)
- Anna C. Blice-Baum
- Division of Cardiology; Department of Medicine; Johns Hopkins University; Baltimore MD 21205 USA
| | - Alexander C. Zambon
- Department of Biopharmaceutical Sciences; Keck Graduate Institute; Claremont CA 91711 USA
- Sanford Burnham Prebys Medical Discovery Institute, Development, Aging and Regeneration Program; La Jolla CA 92037 USA
| | - Gaurav Kaushik
- Department of Bioengineering; University of California, San Diego; La Jolla CA 92093 USA
| | - Meera C. Viswanathan
- 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
| | - Rolf Bodmer
- Sanford Burnham Prebys Medical Discovery Institute, Development, Aging and Regeneration Program; La Jolla CA 92037 USA
| | - Anthony Cammarato
- Division of Cardiology; Department of Medicine; Johns Hopkins University; Baltimore MD 21205 USA
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Viswanathan MC, Tham R, Kronert WA, Schmidt W, Sarsoza F, Trujillo AS, Bernstein SI, Cammarato A. Expression of Myosin Storage Myopathy Mutations in Drosophila Disrupts Muscle Function, Myofibrillar Structure and Causes Defects in Thick Filament Assembly. Biophys J 2017. [DOI: 10.1016/j.bpj.2016.11.660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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44
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Cannon L, Zambon AC, Cammarato A, Zhang Z, Vogler G, Munoz M, Taylor E, Cartry J, Bernstein SI, Melov S, Bodmer R. Expression patterns of cardiac aging in Drosophila. Aging Cell 2017; 16:82-92. [PMID: 28090760 PMCID: PMC5242310 DOI: 10.1111/acel.12559] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/11/2016] [Indexed: 11/27/2022] Open
Abstract
Aging causes cardiac dysfunction, often leading to heart failure and death. The molecular basis of age-associated changes in cardiac structure and function is largely unknown. The fruit fly, Drosophila melanogaster, is well-suited to investigate the genetics of cardiac aging. Flies age rapidly over the course of weeks, benefit from many tools to easily manipulate their genome, and their heart has significant genetic and phenotypic similarities to the human heart. Here, we performed a cardiac-specific gene expression study on aging Drosophila and carried out a comparative meta-analysis with published rodent data. Pathway level transcriptome comparisons suggest that age-related, extra-cellular matrix remodeling and alterations in mitochondrial metabolism, protein handling, and contractile functions are conserved between Drosophila and rodent hearts. However, expression of only a few individual genes similarly changed over time between and even within species. We also examined gene expression in single fly hearts and found significant variability as has been reported in rodents. We propose that individuals may arrive at similar cardiac aging phenotypes via dissimilar transcriptional changes, including those in transcription factors and micro-RNAs. Finally, our data suggest the transcription factor Odd-skipped, which is essential for normal heart development, is also a crucial regulator of cardiac aging.
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Affiliation(s)
- Leah Cannon
- Development, Aging and Regeneration Program; Sanford-Burnham-Prebys Medical Discovery Institute; La Jolla CA USA
| | - Alexander C. Zambon
- Development, Aging and Regeneration Program; Sanford-Burnham-Prebys Medical Discovery Institute; La Jolla CA USA
- Department of Biopharmaceutical Sciences; Keck Graduate Institute; Claremont CA USA
| | - Anthony Cammarato
- Division of Cardiology; Department of Medicine; Johns Hopkins University; Baltimore MD USA
| | - Zhi Zhang
- Development, Aging and Regeneration Program; Sanford-Burnham-Prebys Medical Discovery Institute; La Jolla CA USA
| | - Georg Vogler
- Development, Aging and Regeneration Program; Sanford-Burnham-Prebys Medical Discovery Institute; La Jolla CA USA
| | - Matthew Munoz
- Department of Biopharmaceutical Sciences; Keck Graduate Institute; Claremont CA USA
| | - Erika Taylor
- Development, Aging and Regeneration Program; Sanford-Burnham-Prebys Medical Discovery Institute; La Jolla CA USA
| | - Jérôme Cartry
- Development, Aging and Regeneration Program; Sanford-Burnham-Prebys Medical Discovery Institute; La Jolla CA USA
| | - Sanford I. Bernstein
- Department of Biology, Molecular Biology Institute, and The Heart Institute; San Diego State University; San Diego CA USA
| | - Simon Melov
- Buck Institute for Research on Aging; Novato CA USA
| | - Rolf Bodmer
- Development, Aging and Regeneration Program; Sanford-Burnham-Prebys Medical Discovery Institute; La Jolla CA USA
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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. Abstract 419: Conserved Age-associated Cytoskeletal Remodeling Improves Cardiac Function and Lifespan. Circ Res 2016. [DOI: 10.1161/res.119.suppl_1.419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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 myosindeficient fly hearts. Moreover, cardiac-specific vinculin overexpression increased median life span by more than 150% in flies and preserved their physical activity. A broad array of potential therapeutic targets and regulators of age-associated modifications, specifically for vinculin, are presented and suggest altered metabolism as a system mechanism for lifespan extension. 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)
| | | | | | | | | | | | | | | | | | | | | | - Karen Ocorr
- Sanford-Burnham-Prebys Med Discovery Institute, La Jolla, CA
| | - Rolf Bodmer
- Sanford-Burnham-Prebys Med Discovery Institute, La Jolla, CA
| | | | | | | | | |
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Achal M, Trujillo AS, Melkani GC, Farman GP, Ocorr K, Viswanathan MC, Kaushik G, Newhard CS, Glasheen BM, Melkani A, Suggs JA, Moore JR, Swank DM, Bodmer R, Cammarato A, Bernstein SI. A Restrictive Cardiomyopathy Mutation in an Invariant Proline at the Myosin Head/Rod Junction Enhances Head Flexibility and Function, Yielding Muscle Defects in Drosophila. J Mol Biol 2016; 428:2446-2461. [PMID: 27107639 PMCID: PMC4884507 DOI: 10.1016/j.jmb.2016.04.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 04/12/2016] [Accepted: 04/13/2016] [Indexed: 11/27/2022]
Abstract
An "invariant proline" separates the myosin S1 head from its S2 tail and is proposed to be critical for orienting S1 during its interaction with actin, a process that leads to muscle contraction. Mutation of the invariant proline to leucine (P838L) caused dominant restrictive cardiomyopathy in a pediatric patient (Karam et al., Congenit. Heart Dis. 3:138-43, 2008). Here, we use Drosophila melanogaster to model this mutation and dissect its effects on the biochemical and biophysical properties of myosin, as well as on the structure and physiology of skeletal and cardiac muscles. P838L mutant myosin isolated from indirect flight muscles of transgenic Drosophila showed elevated ATPase and actin sliding velocity in vitro. Furthermore, the mutant heads exhibited increased rotational flexibility, and there was an increase in the average angle between the two heads. Indirect flight muscle myofibril assembly was minimally affected in mutant homozygotes, and isolated fibers displayed normal mechanical properties. However, myofibrils degraded during aging, correlating with reduced flight abilities. In contrast, hearts from homozygotes and heterozygotes showed normal morphology, myofibrillar arrays, and contractile parameters. When P838L was placed in trans to Mhc(5), an allele known to cause cardiac restriction in flies, it did not yield the constricted phenotype. Overall, our studies suggest that increased rotational flexibility of myosin S1 enhances myosin ATPase and actin sliding. Moreover, instability of P838L myofibrils leads to decreased function during aging of Drosophila skeletal muscle, but not cardiac muscle, despite the strong evolutionary conservation of the P838 residue.
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Affiliation(s)
- Madhulika Achal
- Biology Department, Molecular Biology Institute, Heart Institute, San Diego State University, San Diego, CA 92182-4614, USA
| | - Adriana S Trujillo
- Biology Department, Molecular Biology Institute, Heart Institute, San Diego State University, San Diego, CA 92182-4614, USA
| | - Girish C Melkani
- Biology Department, Molecular Biology Institute, Heart Institute, San Diego State University, San Diego, CA 92182-4614, USA
| | - Gerrie P Farman
- Department of Biological Sciences, University of Massachusetts, Lowell, MA 01854, USA
| | - Karen Ocorr
- Development, Aging and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Meera C Viswanathan
- Department of Medicine, Division of Cardiology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Gaurav Kaushik
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Christopher S Newhard
- Department of Biological Sciences and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180-3590, USA
| | - Bernadette M Glasheen
- Department of Biological Sciences and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180-3590, USA
| | - Anju Melkani
- Biology Department, Molecular Biology Institute, Heart Institute, San Diego State University, San Diego, CA 92182-4614, USA
| | - Jennifer A Suggs
- Biology Department, Molecular Biology Institute, Heart Institute, San Diego State University, San Diego, CA 92182-4614, USA
| | - Jeffrey R Moore
- Department of Biological Sciences, University of Massachusetts, Lowell, MA 01854, USA
| | - Douglas M Swank
- Department of Biological Sciences and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180-3590, USA
| | - Rolf Bodmer
- Development, Aging and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Anthony Cammarato
- Department of Medicine, Division of Cardiology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Sanford I Bernstein
- Biology Department, Molecular Biology Institute, Heart Institute, San Diego State University, San Diego, CA 92182-4614, USA.
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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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] [What about the content of this article? (0)] [Affiliation(s)] [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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49
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Lavorato M, Schmidt W, Viswanathan MC, Ochala J, Franzini-Armstrong C, Cammarato A. The Actin F352S Nemaline Myopathy Mutation Disrupts Indirect Flight Muscle Structure and Function in Drosophila. Biophys J 2016. [DOI: 10.1016/j.bpj.2015.11.734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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50
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Kaushik G, Van Eyk J, Cammarato A, Engler A. Vinculin Remodeling of the Sarcomere Lattice Regulates Contractile Function. Biophys J 2016. [DOI: 10.1016/j.bpj.2015.11.567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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