1
|
Lickiss B, Hunker J, Bhagwan J, Linder P, Thomas U, Lotay H, Broadbent S, Dragicevic E, Stoelzle-Feix S, Turner J, Gossmann M. Chamber-specific contractile responses of atrial and ventricular hiPSC-cardiomyocytes to GPCR and ion channel targeting compounds: A microphysiological system for cardiac drug development. J Pharmacol Toxicol Methods 2024; 128:107529. [PMID: 38857637 DOI: 10.1016/j.vascn.2024.107529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 05/15/2024] [Accepted: 06/05/2024] [Indexed: 06/12/2024]
Abstract
Human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes (CMs) have found utility for conducting in vitro drug screening and disease modelling to gain crucial insights into pharmacology or disease phenotype. However, diseases such as atrial fibrillation, affecting >33 M people worldwide, demonstrate the need for cardiac subtype-specific cells. Here, we sought to investigate the base characteristics and pharmacological differences between commercially available chamber-specific atrial or ventricular hiPSC-CMs seeded onto ultra-thin, flexible PDMS membranes to simultaneously measure contractility in a 96 multi-well format. We investigated the effects of GPCR agonists (acetylcholine and carbachol), a Ca2+ channel agonist (S-Bay K8644), an HCN channel antagonist (ivabradine) and K+ channel antagonists (4-AP and vernakalant). We observed differential effects between atrial and ventricular hiPSC-CMs on contractile properties including beat rate, beat duration, contractile force and evidence of arrhythmias at a range of concentrations. As an excerpt of the compound analysis, S-Bay K8644 treatment showed an induced concentration-dependent transient increase in beat duration of atrial hiPSC-CMs, whereas ventricular cells showed a physiological increase in beat rate over time. Carbachol treatment produced marked effects on atrial cells, such as increased beat duration alongside a decrease in beat rate over time, but only minimal effects on ventricular cardiomyocytes. In the context of this chamber-specific pharmacology, we not only add to contractile characterization of hiPSC-CMs but propose a multi-well platform for medium-throughput early compound screening. Overall, these insights illustrate the key pharmacological differences between chamber-specific cardiomyocytes and their application on a multi-well contractility platform to gain insights for in vitro cardiac liability studies and disease modelling.
Collapse
Affiliation(s)
| | - Jan Hunker
- innoVitro GmbH, Artilleriestr 2, 52428 Jülich, Germany
| | - Jamie Bhagwan
- Axol Bioscience Ltd, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Peter Linder
- innoVitro GmbH, Artilleriestr 2, 52428 Jülich, Germany
| | - Ulrich Thomas
- Nanion Technologies GmbH, Ganghoferstr 70A, 80339 Munich, Germany
| | - Hardeep Lotay
- Axol Bioscience Ltd, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Steven Broadbent
- Axol Bioscience Ltd, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Elena Dragicevic
- Nanion Technologies GmbH, Ganghoferstr 70A, 80339 Munich, Germany
| | | | - Jan Turner
- Axol Bioscience Ltd, Babraham Research Campus, Cambridge CB22 3AT, UK
| | | |
Collapse
|
2
|
Tran P, Linekar A, Dandekar U, Barker T, Balasubramanian S, Bhaskara-Pillai J, Shelley S, Maddock H, Banerjee P. Profiling the Biomechanical Responses to Workload on the Human Myocyte to Explore the Concept of Myocardial Fatigue and Reversibility: Rationale and Design of the POWER Heart Failure Study. J Cardiovasc Transl Res 2024; 17:275-286. [PMID: 37126208 PMCID: PMC10150683 DOI: 10.1007/s12265-023-10391-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 04/20/2023] [Indexed: 05/02/2023]
Abstract
It remains unclear why some patients develop heart failure without evidence of structural damage. One theory relates to impaired myocardial energetics and ventricular-arterial decoupling as the heart works against adverse mechanical load. In this original study, we propose the novel concept of myocardial fatigue to capture this phenomenon and aim to investigate this using human cardiomyocytes subjected to a modern work-loop contractility model that closely mimics in vivo cardiac cycles. This proof-of-concept study (NCT04899635) will use human myocardial tissue samples from patients undergoing cardiac surgery to develop a reproducible protocol to isolate robust calcium-tolerant cardiomyocytes. Thereafter, work-loop contractility experiments will be performed over a range of preload, afterload and cycle frequency as a function of time to elicit any reversible reduction in contractile performance (i.e. fatigue). This will provide novel insight into mechanisms behind heart failure and myocardial recovery and serve as a valuable research platform in translational cardiovascular research.
Collapse
Affiliation(s)
- Patrick Tran
- Centre for Sport, Exercise & Life Sciences, Faculty of Health & Life Sciences, Coventry University, Coventry, UK.
- Cardiology Department, University Hospitals Coventry and Warwickshire NHS Trust, Clifford Bridge Road, Coventry, UK.
| | - Adam Linekar
- Centre for Sport, Exercise & Life Sciences, Faculty of Health & Life Sciences, Coventry University, Coventry, UK
- InoCardia Ltd, TechnoCentre, Puma Way, Coventry, UK
| | - Uday Dandekar
- Cardiology Department, University Hospitals Coventry and Warwickshire NHS Trust, Clifford Bridge Road, Coventry, UK
- Warwick Medical School, University of Warwick, Coventry, UK
| | - Thomas Barker
- Centre for Sport, Exercise & Life Sciences, Faculty of Health & Life Sciences, Coventry University, Coventry, UK
- Cardiology Department, University Hospitals Coventry and Warwickshire NHS Trust, Clifford Bridge Road, Coventry, UK
- Warwick Medical School, University of Warwick, Coventry, UK
| | - Sendhil Balasubramanian
- Cardiology Department, University Hospitals Coventry and Warwickshire NHS Trust, Clifford Bridge Road, Coventry, UK
- Warwick Medical School, University of Warwick, Coventry, UK
| | - Jain Bhaskara-Pillai
- Cardiology Department, University Hospitals Coventry and Warwickshire NHS Trust, Clifford Bridge Road, Coventry, UK
- Warwick Medical School, University of Warwick, Coventry, UK
| | - Sharn Shelley
- Centre for Sport, Exercise & Life Sciences, Faculty of Health & Life Sciences, Coventry University, Coventry, UK
- InoCardia Ltd, TechnoCentre, Puma Way, Coventry, UK
| | - Helen Maddock
- Centre for Sport, Exercise & Life Sciences, Faculty of Health & Life Sciences, Coventry University, Coventry, UK
- InoCardia Ltd, TechnoCentre, Puma Way, Coventry, UK
| | - Prithwish Banerjee
- Centre for Sport, Exercise & Life Sciences, Faculty of Health & Life Sciences, Coventry University, Coventry, UK
- Cardiology Department, University Hospitals Coventry and Warwickshire NHS Trust, Clifford Bridge Road, Coventry, UK
- Warwick Medical School, University of Warwick, Coventry, UK
| |
Collapse
|
3
|
Jani V, Aslam MI, Fenwick AJ, Ma W, Gong H, Milburn G, Nissen D, Cubero Salazar IM, Hanselman O, Mukherjee M, Halushka MK, Margulies KB, Campbell KS, Irving TC, Kass DA, Hsu S. Right Ventricular Sarcomere Contractile Depression and the Role of Thick Filament Activation in Human Heart Failure With Pulmonary Hypertension. Circulation 2023; 147:1919-1932. [PMID: 37194598 PMCID: PMC10270283 DOI: 10.1161/circulationaha.123.064717] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 04/17/2023] [Indexed: 05/18/2023]
Abstract
BACKGROUND Right ventricular (RV) contractile dysfunction commonly occurs and worsens outcomes in patients with heart failure with reduced ejection fraction and pulmonary hypertension (HFrEF-PH). However, such dysfunction often goes undetected by standard clinical RV indices, raising concerns that they may not reflect aspects of underlying myocyte dysfunction. We thus sought to characterize RV myocyte contractile depression in HFrEF-PH, identify those components reflected by clinical RV indices, and uncover underlying biophysical mechanisms. METHODS Resting, calcium-, and load-dependent mechanics were prospectively studied in permeabilized RV cardiomyocytes isolated from explanted hearts from 23 patients with HFrEF-PH undergoing cardiac transplantation and 9 organ donor controls. RESULTS Unsupervised machine learning using myocyte mechanical data with the highest variance yielded 2 HFrEF-PH subgroups that in turn mapped to patients with decompensated or compensated clinical RV function. This correspondence was driven by reduced calcium-activated isometric tension in decompensated clinical RV function, whereas surprisingly, many other major myocyte contractile measures including peak power and myocyte active stiffness were similarly depressed in both groups. Similar results were obtained when subgroups were first defined by clinical indices, and then myocyte mechanical properties in each group compared. To test the role of thick filament defects, myofibrillar structure was assessed by x-ray diffraction of muscle fibers. This revealed more myosin heads associated with the thick filament backbone in decompensated clinical RV function, but not compensated clinical RV function, as compared with controls. This corresponded to reduced myosin ATP turnover in decompensated clinical RV function myocytes, indicating less myosin in a crossbridge-ready disordered-relaxed (DRX) state. Altering DRX proportion (%DRX) affected peak calcium-activated tension in the patient groups differently, depending on their basal %DRX, highlighting potential roles for precision-guided therapeutics. Last, increasing myocyte preload (sarcomere length) increased %DRX 1.5-fold in controls but only 1.2-fold in both HFrEF-PH groups, revealing a novel mechanism for reduced myocyte active stiffness and by extension Frank-Starling reserve in human heart failure. CONCLUSIONS Although there are many RV myocyte contractile deficits in HFrEF-PH, commonly used clinical indices only detect reduced isometric calcium-stimulated force, which is related to deficits in basal and recruitable %DRX myosin. Our results support use of therapies to increase %DRX and enhance length-dependent recruitment of DRX myosin heads in such patients.
Collapse
Affiliation(s)
- Vivek Jani
- Department of Biomedical Engineering (V.J., O.H., D.A.K.), Johns Hopkins School of Medicine, Baltimore, MD
- Division of Cardiology, Department of Medicine (V.J., A.J.F., I.M.C.S., M.M., D.A.K., S.H.), Johns Hopkins School of Medicine, Baltimore, MD
| | - M. Imran Aslam
- Division of Cardiology, Department of Medicine, University of Texas San Antonio School of Medicine (M.I.A.)
| | - Axel J. Fenwick
- Division of Cardiology, Department of Medicine (V.J., A.J.F., I.M.C.S., M.M., D.A.K., S.H.), Johns Hopkins School of Medicine, Baltimore, MD
| | - Weikang Ma
- Biophysics Collaborative Access Team (BioCAT), Department of Biology, Illinois Institute of Technology, Chicago (W.M., H.G., D.N., T.C.I.)
| | - Henry Gong
- Biophysics Collaborative Access Team (BioCAT), Department of Biology, Illinois Institute of Technology, Chicago (W.M., H.G., D.N., T.C.I.)
| | - Gregory Milburn
- Division of Cardiovascular Medicine, Department of Medicine, University of Kentucky, Lexington (G.M., K.S.C.)
| | - Devin Nissen
- Biophysics Collaborative Access Team (BioCAT), Department of Biology, Illinois Institute of Technology, Chicago (W.M., H.G., D.N., T.C.I.)
| | - Ilton M. Cubero Salazar
- Division of Cardiology, Department of Medicine (V.J., A.J.F., I.M.C.S., M.M., D.A.K., S.H.), Johns Hopkins School of Medicine, Baltimore, MD
| | - Olivia Hanselman
- Department of Biomedical Engineering (V.J., O.H., D.A.K.), Johns Hopkins School of Medicine, Baltimore, MD
| | - Monica Mukherjee
- Division of Cardiology, Department of Medicine (V.J., A.J.F., I.M.C.S., M.M., D.A.K., S.H.), Johns Hopkins School of Medicine, Baltimore, MD
| | - Marc K. Halushka
- Division of Cardiovascular Pathology, Department of Pathology (M.K.H.), Johns Hopkins School of Medicine, Baltimore, MD
| | - Kenneth B. Margulies
- Cardiovascular Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia (K.B.M.)
| | - Kenneth S. Campbell
- Division of Cardiovascular Medicine, Department of Medicine, University of Kentucky, Lexington (G.M., K.S.C.)
| | - Thomas C. Irving
- Biophysics Collaborative Access Team (BioCAT), Department of Biology, Illinois Institute of Technology, Chicago (W.M., H.G., D.N., T.C.I.)
| | - David A. Kass
- Department of Biomedical Engineering (V.J., O.H., D.A.K.), Johns Hopkins School of Medicine, Baltimore, MD
- Division of Cardiology, Department of Medicine (V.J., A.J.F., I.M.C.S., M.M., D.A.K., S.H.), Johns Hopkins School of Medicine, Baltimore, MD
| | - Steven Hsu
- Division of Cardiology, Department of Medicine (V.J., A.J.F., I.M.C.S., M.M., D.A.K., S.H.), Johns Hopkins School of Medicine, Baltimore, MD
| |
Collapse
|
4
|
Tran P, Banerjee P. Myocardial Fatigue at a Glance. Curr Heart Fail Rep 2023; 20:191-193. [PMID: 37133679 DOI: 10.1007/s11897-023-00603-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/21/2023] [Indexed: 05/04/2023]
Abstract
Expanding on the modern lexicon of heart failure (HF), the novel mechano-energetic concept of myocardial fatigue describes a transiently energy-depleted myocardium with impaired contractility and relaxation in the face of adverse haemodynamic load. It encompasses established concepts of ventricular-arterial decoupling, deranged cardiac energetics and impaired myocardial efficiency, offering an alternative explanation for functional causes of HF.
Collapse
Affiliation(s)
- Patrick Tran
- University Hospital Coventry and Warwickshire, Clifford Bridge Road, Coventry, CV2 2DX, UK.
- Centre for Sport, Exercise, Life Sciences, Faculty of Health and Life Sciences, Coventry University, Alison Gingell Building, Coventry, CV1 2DS, UK.
| | - Prithwish Banerjee
- University Hospital Coventry and Warwickshire, Clifford Bridge Road, Coventry, CV2 2DX, UK
- Centre for Sport, Exercise, Life Sciences, Faculty of Health and Life Sciences, Coventry University, Alison Gingell Building, Coventry, CV1 2DS, UK
- Warwick Medical School, University of Warwick, Coventry, CV4 7AL, UK
| |
Collapse
|
5
|
Hanft LM, Robinett JC, Kalogeris TJ, Campbell KS, Biesiadecki BJ, McDonald KS. Thin filament regulation of cardiac muscle power output: Implications for targets to improve human failing hearts. J Gen Physiol 2023; 155:e202213290. [PMID: 37000170 PMCID: PMC10067705 DOI: 10.1085/jgp.202213290] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 02/14/2023] [Accepted: 03/13/2023] [Indexed: 04/01/2023] Open
Abstract
The heart's pumping capacity is determined by myofilament power generation. Power is work done per unit time and measured as the product of force and velocity. At a sarcomere level, these contractile properties are linked to the number of attached cross-bridges and their cycling rate, and many signaling pathways modulate one or both factors. We previously showed that power is increased in rodent permeabilized cardiac myocytes following PKA-mediated phosphorylation of myofibrillar proteins. The current study found that that PKA increased power by ∼30% in permeabilized cardiac myocyte preparations (n = 8) from human failing hearts. To address myofilament molecular specificity of PKA effects, mechanical properties were measured in rat permeabilized slow-twitch skeletal muscle fibers before and after exchange of endogenous slow skeletal troponin with recombinant human Tn complex that contains cardiac (c)TnT, cTnC and either wildtype (WT) cTnI or pseudo-phosphorylated cTnI at sites Ser23/24Asp, Tyr26Glu, or the combinatorial Ser23/24Asp and Tyr26Glu. We found that cTnI Ser23/24Asp, Tyr26Glu, and combinatorial Ser23/24Asp and Tyr26Glu were sufficient to increase power by ∼20%. Next, we determined whether pseudo-phosphorylated cTnI at Ser23/24 was sufficient to increase power in cardiac myocytes from human failing hearts. Following cTn exchange that included cTnI Ser23/24Asp, power output increased ∼20% in permeabilized cardiac myocyte preparations (n = 6) from the left ventricle of human failing hearts. These results implicate cTnI N-terminal phosphorylation as a molecular regulator of myocyte power and could serve as a regional target for small molecule therapy to unmask myocyte power reserve capacity in human failing hearts.
Collapse
Affiliation(s)
- Laurin M. Hanft
- Department of Medical Pharmacology and Physiology, School of Medicine, University of Missouri, Columbia, MO, USA
| | - Joel C. Robinett
- Department of Medical Pharmacology and Physiology, School of Medicine, University of Missouri, Columbia, MO, USA
| | - Theodore J. Kalogeris
- Department of Medical Pharmacology and Physiology, School of Medicine, University of Missouri, Columbia, MO, USA
| | - Kenneth S. Campbell
- Department of Physiology and Division of Cardiovascular Medicine, University of Kentucky, Lexington, KY, USA
| | | | - Kerry S. McDonald
- Department of Medical Pharmacology and Physiology, School of Medicine, University of Missouri, Columbia, MO, USA
| |
Collapse
|
6
|
Macrae RGC, Colzani MT, Williams TL, Bayraktar S, Kuc RE, Pullinger AL, Bernard WG, Robinson EL, Davenport EE, Maguire JJ, Sinha S, Davenport AP. Inducible apelin receptor knockdown reduces differentiation efficiency and contractility of hESC-derived cardiomyocytes. Cardiovasc Res 2023; 119:587-598. [PMID: 36239923 PMCID: PMC10064845 DOI: 10.1093/cvr/cvac065] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 04/04/2022] [Accepted: 04/12/2022] [Indexed: 11/14/2022] Open
Abstract
AIMS The apelin receptor, a G protein-coupled receptor, has emerged as a key regulator of cardiovascular development, physiology, and disease. However, there is a lack of suitable human in vitro models to investigate the apelinergic system in cardiovascular cell types. For the first time we have used human embryonic stem cell-derived cardiomyocytes (hESC-CMs) and a novel inducible knockdown system to examine the role of the apelin receptor in both cardiomyocyte development and to determine the consequences of loss of apelin receptor function as a model of disease. METHODS AND RESULTS Expression of the apelin receptor and its ligands in hESCs and hESC-CMs was determined. hESCs carrying a tetracycline-inducible short hairpin RNA targeting the apelin receptor were generated using the sOPTiKD system. Phenotypic assays characterized the consequences of either apelin receptor knockdown before hESC-CM differentiation (early knockdown) or in 3D engineered heart tissues as a disease model (late knockdown). hESC-CMs expressed the apelin signalling system at a similar level to the adult heart. Early apelin receptor knockdown decreased cardiomyocyte differentiation efficiency and prolonged voltage sensing, associated with asynchronous contraction. Late apelin receptor knockdown had detrimental consequences on 3D engineered heart tissue contractile properties, decreasing contractility and increasing stiffness. CONCLUSIONS We have successfully knocked down the apelin receptor, using an inducible system, to demonstrate a key role in hESC-CM differentiation. Knockdown in 3D engineered heart tissues recapitulated the phenotype of apelin receptor down-regulation in a failing heart, providing a potential platform for modelling heart failure and testing novel therapeutic strategies.
Collapse
Affiliation(s)
- Robyn G C Macrae
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Addenbrooke’s Hospital, Level 6, Addenbrooke’s Centre for Clinical Investigation, Box 110, Cambridge CB2 0QQ, UK
- Wellcome-MRC Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, University of Cambridge, Cambridge, UK
| | - Maria T Colzani
- Wellcome-MRC Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, University of Cambridge, Cambridge, UK
| | - Thomas L Williams
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Addenbrooke’s Hospital, Level 6, Addenbrooke’s Centre for Clinical Investigation, Box 110, Cambridge CB2 0QQ, UK
| | - Semih Bayraktar
- Wellcome-MRC Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, University of Cambridge, Cambridge, UK
| | - Rhoda E Kuc
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Addenbrooke’s Hospital, Level 6, Addenbrooke’s Centre for Clinical Investigation, Box 110, Cambridge CB2 0QQ, UK
| | - Anna L Pullinger
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Addenbrooke’s Hospital, Level 6, Addenbrooke’s Centre for Clinical Investigation, Box 110, Cambridge CB2 0QQ, UK
- Wellcome-MRC Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, University of Cambridge, Cambridge, UK
| | - William G Bernard
- Wellcome-MRC Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, University of Cambridge, Cambridge, UK
| | - Emma L Robinson
- School of Medicine, Division of Cardiology, University of Colorado Denver, Aurora, CO, USA
| | | | - Janet J Maguire
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Addenbrooke’s Hospital, Level 6, Addenbrooke’s Centre for Clinical Investigation, Box 110, Cambridge CB2 0QQ, UK
| | - Sanjay Sinha
- Wellcome-MRC Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, University of Cambridge, Cambridge, UK
| | - Anthony P Davenport
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Addenbrooke’s Hospital, Level 6, Addenbrooke’s Centre for Clinical Investigation, Box 110, Cambridge CB2 0QQ, UK
| |
Collapse
|
7
|
Velayuthan LP, Moretto L, Tågerud S, Ušaj M, Månsson A. Virus-free transfection, transient expression, and purification of human cardiac myosin in mammalian muscle cells for biochemical and biophysical assays. Sci Rep 2023; 13:4101. [PMID: 36907906 PMCID: PMC10008826 DOI: 10.1038/s41598-023-30576-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 02/27/2023] [Indexed: 03/13/2023] Open
Abstract
Myosin expression and purification is important for mechanistic insights into normal function and mutation induced changes. The latter is particularly important for striated muscle myosin II where mutations cause several debilitating diseases. However, the heavy chain of this myosin is challenging to express and the standard protocol, using C2C12 cells, relies on viral infection. This is time and work intensive and associated with infrastructural demands and biological hazards, limiting widespread use and hampering fast generation of a wide range of mutations. We here develop a virus-free method to overcome these challenges. We use this system to transfect C2C12 cells with the motor domain of the human cardiac myosin heavy chain. After optimizing cell transfection, cultivation and harvesting conditions, we functionally characterized the expressed protein, co-purified with murine essential and regulatory light chains. The gliding velocity (1.5-1.7 µm/s; 25 °C) in the in vitro motility assay as well as maximum actin activated catalytic activity (kcat; 8-9 s-1) and actin concentration for half maximal activity (KATPase; 70-80 µM) were similar to those found previously using virus based infection. The results should allow new types of studies, e.g., screening of a wide range of mutations to be selected for further characterization.
Collapse
Affiliation(s)
- Lok Priya Velayuthan
- Department of Chemistry and Biomedical Sciences, Linnaeus University, 391 82, Kalmar, Sweden
| | - Luisa Moretto
- Department of Chemistry and Biomedical Sciences, Linnaeus University, 391 82, Kalmar, Sweden
| | - Sven Tågerud
- Department of Chemistry and Biomedical Sciences, Linnaeus University, 391 82, Kalmar, Sweden
| | - Marko Ušaj
- Department of Chemistry and Biomedical Sciences, Linnaeus University, 391 82, Kalmar, Sweden.
| | - Alf Månsson
- Department of Chemistry and Biomedical Sciences, Linnaeus University, 391 82, Kalmar, Sweden.
| |
Collapse
|
8
|
Rasicci DV, Ge J, Milburn GN, Wood NB, Pruznak AM, Lang CH, Previs MJ, Campbell KS, Yengo CM. Cardiac myosin motor deficits are associated with left ventricular dysfunction in human ischemic heart failure. Am J Physiol Heart Circ Physiol 2023; 324:H198-H209. [PMID: 36525480 PMCID: PMC9829461 DOI: 10.1152/ajpheart.00272.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 12/09/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022]
Abstract
During ischemic heart failure (IHF), cardiac muscle contraction is typically impaired, though the molecular changes within the myocardium are not fully understood. Thus, we aimed to characterize the biophysical properties of cardiac myosin in IHF. Cardiac tissue was harvested from 10 age-matched males, either with a history of IHF or nonfailing (NF) controls that had no history of structural or functional cardiac abnormalities. Clinical measures before cardiac biopsy demonstrated significant differences in measures of ejection fraction and left ventricular dimensions. Myofibrils and myosin were extracted from left ventricular free wall cardiac samples. There were no changes in myofibrillar ATPase activity or calcium sensitivity between groups. Using isolated myosin, we found a 15% reduction in the IHF group in actin sliding velocity in the in vitro motility assay, which was observed in the absence of a myosin isoform shift. Oxidative damage (carbonylation) of isolated myosin was compared, in which there were no significant differences between groups. Synthetic thick filaments were formed from purified myosin and the ATPase activity was similar in both basal and actin-activated conditions (20 µM actin). Correlation analysis and Deming linear regression were performed between all studied parameters, in which we found statistically significant correlations between clinical measures of contractility with molecular measures of sliding velocity and ELC carbonylation. Our data indicate that subtle deficits in myosin mechanochemical properties are associated with reduced contractile function and pathological remodeling of the heart, suggesting that the myosin motor may be an effective pharmacological intervention in ischemia.NEW & NOTEWORTHY Ischemic heart failure is associated with impairments in contractile performance of the heart. This study revealed that cardiac myosin isolated from patients with ischemic heart failure had reduced mechanical activity, which correlated with the impaired clinical phenotype of the patients. The results suggest that restoring myosin function with pharmacological intervention may be a viable method for therapeutic intervention.
Collapse
Affiliation(s)
- D. V. Rasicci
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania
- Department of Pathology, Anatomy, and Laboratory Medicine, West Virginia University School of Medicine, Morgantown, West Virginia
| | - J. Ge
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - G. N. Milburn
- Department of Physiology, University of Kentucky, Lexington, Kentucky
| | - N. B. Wood
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, Vermont
| | - A. M. Pruznak
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - C. H. Lang
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - M. J. Previs
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, Vermont
| | - K. S. Campbell
- Department of Physiology, University of Kentucky, Lexington, Kentucky
- Division of Cardiovascular Medicine, University of Kentucky, Lexington, Kentucky
| | - C. M. Yengo
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| |
Collapse
|
9
|
Kumar M, Haghighi K, Koch S, Rubinstein J, Stillitano F, Hajjar RJ, Kranias EG, Sadayappan S. Myofilament Alterations Associated with Human R14del-Phospholamban Cardiomyopathy. Int J Mol Sci 2023; 24:2675. [PMID: 36768995 PMCID: PMC9917359 DOI: 10.3390/ijms24032675] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 01/23/2023] [Accepted: 01/27/2023] [Indexed: 02/01/2023] Open
Abstract
Phospholamban (PLN) is a major regulator of cardiac contractility, and human mutations in this gene give rise to inherited cardiomyopathies. The deletion of Arginine 14 is the most-prevalent cardiomyopathy-related mutation, and it has been linked to arrhythmogenesis and early death. Studies in PLN-humanized mutant mice indicated an increased propensity to arrhythmias, but the underlying cellular mechanisms associated with R14del-PLN cardiac dysfunction in the absence of any apparent structural remodeling remain unclear. The present study addressed the specific role of myofilaments in the setting of R14del-PLN and the long-term effects of R14del-PLN in the heart. Maximal force was depressed in skinned cardiomyocytes from both left and right ventricles, but this effect was more pronounced in the right ventricle of R14del-PLN mice. In addition, the Ca2+ sensitivity of myofilaments was increased in both ventricles of mutant mice. However, the depressive effects of R14del-PLN on contractile parameters could be reversed with the positive inotropic drug omecamtiv mecarbil, a myosin activator. At 12 months of age, corresponding to the mean symptomatic age of R14del-PLN patients, contractile parameters and Ca2+ transients were significantly depressed in the right ventricular R14del-PLN cardiomyocytes. Echocardiography did not reveal any alterations in cardiac function or remodeling, although histological and electron microscopy analyses indicated subtle alterations in mutant hearts. These findings suggest that both aberrant myocyte calcium cycling and aberrant contractility remain specific to the right ventricle in the long term. In addition, altered myofilament activity is an early characteristic of R14del-PLN mutant hearts and the positive inotropic drug omecamtiv mecarbil may be beneficial in treating R14del-PLN cardiomyopathy.
Collapse
Affiliation(s)
- Mohit Kumar
- Department of Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Kobra Haghighi
- Department of Pharmacology and Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Sheryl Koch
- Department of Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Jack Rubinstein
- Department of Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Francesca Stillitano
- Division Heart and Lung, Department of Cardiology, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands
| | - Roger J. Hajjar
- Phospholamban Heart Foundation, Postbus 66, 1775 ZH Middenmeer, The Netherlands
| | - Evangelia G. Kranias
- Department of Pharmacology and Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Sakthivel Sadayappan
- Department of Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| |
Collapse
|
10
|
Cai L, Wang R, Zhang D. Cardiac Disease Modeling with Engineered Heart Tissue. Handb Exp Pharmacol 2023; 281:235-255. [PMID: 37563250 DOI: 10.1007/164_2023_681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/12/2023]
Abstract
The rhythmically beating heart is the foundation of life-sustaining blood flow. There are four chambers and many different types of cell in the heart, but the twisted myofibrillar structures formed by cardiomyocytes are particularly important for cardiac contraction and electrical impulse transmission properties. The ability to generate cardiomyocytes using human-induced pluripotent stem cells has essentially solved the cell supply shortage for in vitro simulation of cardiac tissue function; however, modeling heart at the tissue level needs mature myocardial structure, electrophysiology, and contractile characteristics. Here, the current research on human functionalized cardiac microtissue in modeling cardiac diseases is reviewed and the design criteria and practical applications of different human engineered heart tissues, including cardiac organoids, cardiac thin films, and cardiac microbundles are analyzed. Table summarizing the ability of several in vitro myocardial models to assess heart structure and function for cardiac disease modeling.
Collapse
Affiliation(s)
- Lin Cai
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Science, Hubei University, Wuhan, Hubei, China
| | - Ruxiang Wang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Science, Hubei University, Wuhan, Hubei, China
| | - Donghui Zhang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Science, Hubei University, Wuhan, Hubei, China.
| |
Collapse
|
11
|
Jani V, Qian W, Yuan S, Irving T, Ma W. EMD-57033 Augments the Contractility in Porcine Myocardium by Promoting the Activation of Myosin in Thick Filaments. Int J Mol Sci 2022; 23:14517. [PMID: 36498844 PMCID: PMC9737153 DOI: 10.3390/ijms232314517] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 11/20/2022] [Accepted: 11/21/2022] [Indexed: 11/23/2022] Open
Abstract
Sufficient cardiac contractility is necessary to ensure the sufficient cardiac output to provide an adequate end-organ perfusion. Inadequate cardiac output and the diminished perfusion of vital organs from depressed myocardium contractility is a hallmark end-stage of heart failure. There are no available therapeutics that directly target contractile proteins to improve the myocardium contractility and reduce mortality. The purpose of this study is to present a proof of concept to aid in the development of muscle activators (myotropes) for augmenting the contractility in clinical heart failure. Here we use a combination of cardiomyocyte mechanics, the biochemical quantification of the ATP turnover, and small angle X-ray diffraction on a permeabilized porcine myocardium to study the mechanisms of EMD-57033 (EMD) for activating myosin. We show that EMD increases the contractility in a porcine myocardium at submaximal and systolic calcium concentrations. Biochemical assays show that EMD decreases the proportion of myosin heads in the energy sparing super-relaxed (SRX) state under relaxing conditions, which are less likely to interact with actin during contraction. Structural assays show that EMD moves the myosin heads in relaxed muscles from a structurally ordered state close to the thick filament backbone, to a disordered state closer to the actin filament, while simultaneously inducing structural changes in the troponin complex on the actin filament. The dual effects of EMD on activating myosin heads and the troponin complex provides a proof of concept for the use of small molecule muscle activators for augmenting the contractility in heart failure.
Collapse
Affiliation(s)
- Vivek Jani
- Department of Biomedical Engineering, The Johns Hopkins School of Medicine, The Johns Hopkins University, Baltimore, MD 20205, USA
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Wenjing Qian
- Department of Biology, Illinois Institute of Technology, Chicago, IL 60616, USA
| | - Shengyao Yuan
- BioCAT, Department of Biology, Illinois Institute of Technology, Chicago, IL 60616, USA
| | - Thomas Irving
- BioCAT, Department of Biology, Illinois Institute of Technology, Chicago, IL 60616, USA
| | - Weikang Ma
- BioCAT, Department of Biology, Illinois Institute of Technology, Chicago, IL 60616, USA
| |
Collapse
|
12
|
Milburn GN, Moonschi F, White AM, Thompson M, Thompson K, Birks EJ, Campbell KS. Prior Freezing Has Minimal Impact on the Contractile Properties of Permeabilized Human Myocardium. J Am Heart Assoc 2022; 11:e023010. [PMID: 35535623 PMCID: PMC9238558 DOI: 10.1161/jaha.121.023010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Background Experiments measuring the contractile properties of human myocardium are important for translational research but complicated by the logistical difficulties of acquiring specimens. Accordingly, many groups perform contractile assays using samples that are acquired from patients at one institution and shipped to another institution for experiments. This necessitates freezing the samples and performing subsequent assays using chemically permeabilized preparations. It is unknown how prior freezing affects the contractile function of these preparations. Methods and Results To examine the effects of freezing we measured the contractile function of never‐frozen and previously frozen myocardial samples. Samples of left ventricular tissue were obtained from 7 patients who were having a ventricular assist device implanted. Half of each sample was chemically permeabilized and used immediately for contractile assays. The other half of the sample was snap frozen in liquid nitrogen and maintained at –180 °C for at least 6 months before being thawed and tested in a second series of experiments. Maximum isometric force measured in pCa 4.5 solution, passive force measured in pCa 9.0 solution, and Hill coefficients were not influenced by prior freezing (P=0.07, P=0.14, and P=0.27 respectively). pCa50 in never‐frozen samples (6.11±0.04) was statistically greater (P<0.001) than that measured after prior freezing (5.99±0.04) but the magnitude of the effect was only ≈0.1 pCa units. Conclusions We conclude that prior freezing has minimal impact on the contractile properties that can be measured using chemically permeabilized human myocardium.
Collapse
Affiliation(s)
| | - Faruk Moonschi
- Department of Physiology University of Kentucky Lexington Kentucky
| | - Ashley M White
- Department of Physiology University of Kentucky Lexington Kentucky
| | - Mindy Thompson
- Department of Physiology University of Kentucky Lexington Kentucky
| | | | - Emma J Birks
- Division of Cardiovascular Medicine University of Kentucky Lexington Kentucky
| | - Kenneth S Campbell
- Department of Physiology University of Kentucky Lexington Kentucky.,Division of Cardiovascular Medicine University of Kentucky Lexington Kentucky
| |
Collapse
|
13
|
Sengupta SP, Okwose NC, MacGowan GA, Jakovljevic DG. Peak atrio-ventricular mechanics predicts exercise tolerance in heart failure patients. Int J Cardiol 2022; 359:84-90. [PMID: 35367509 DOI: 10.1016/j.ijcard.2022.03.048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 02/27/2022] [Accepted: 03/23/2022] [Indexed: 12/22/2022]
Abstract
PURPOSE Exercise intolerance is a cardinal symptom of patients with heart failure (HF). We hypothesized that patients with HF with preserved ejection fraction (HFpEF) in comparison with those with reduced ejection fraction (HFrEF) have disproportionate exercise-induced impairment of left atrial (LA) function that may explain the effort intolerance. METHODS Total 40 HFpEF patients, 40 HFrEF patients, and 20 matched healthy controls underwent resting and exercise stress transthoracic echocardiography using modified Bruce protocol with speckle-tracking derived assessments of peak atrial longitudinal strain (PALS) and left ventricular global longitudinal strain (LVGLS). RESULTS In comparison to controls, PALS and LVGLS were reduced in HFpEF and HFrEF patients (P < 0.01); however, the strain magnitudes were significantly lower in HFrEF than in HFpEF (P < 0.01). Both HFpEF and HFrEF showed a 28% and 30% reduction in exercise time in comparison with controls (HFpEF, 363 ± 152, HFrEF 352 ± 91, controls, 505 ± 42 s, P < 0.01) and exercise-related rise in E/E' in HFpEF patients. However, during exercise PALS reduced from resting values by 26% (resting 23.1 ± 4.7 and peak 18.5 ± 3.5, P < 0.01) in HFpEF but only 8% in HFrEF (resting 11.5 ± 1.4 and peak 10.5 ± 1.5, P < 0.01), and remained unchanged in controls (resting 34 ± 1.9 and peak 34.4 ± 1.2, P = 0.4). Regression analysis of the combined data from the HF patients and controls revealed that PALS was independently associated with exercise time such that a 1% reduction in PALS was associated with a 10 s reduction in exercise duration (p < 0.01). PALS at baseline and peak exercise differentiated normal from HF patients. LVGLS at baseline and peak exercise differentiated HFpEF from HFrEF and patients of HFpEF showed abnormality of both PALS and LVGLS. CONCLUSION Although left ventricle and LA strain are lower in HFrEF than HFpEF at rest and exercise compared to healthy controls, patients with HFpEF show more profound deterioration of LA reservoir function with exercise which appears to contribute to exercise intolerance.
Collapse
Affiliation(s)
- Shantanu P Sengupta
- Sengupta Hospital and Research Institute, Ravinagar, Nagpur, India; Cardiovascular Research Theme, Translational and Clinical, and Biosciences Research Institutes, Faculty of Medical Sciences, Newcastle University, UK.
| | - Nduka C Okwose
- Cardiovascular Research Theme, Translational and Clinical, and Biosciences Research Institutes, Faculty of Medical Sciences, Newcastle University, UK; Cardiovascular and Lifestyle Medicine, Faculty Research Centre (CSELS), Faculty of Health and Life Sciences, Coventry University, UK
| | - Guy A MacGowan
- Cardiovascular Research Theme, Translational and Clinical, and Biosciences Research Institutes, Faculty of Medical Sciences, Newcastle University, UK
| | - Djordje G Jakovljevic
- Cardiovascular Research Theme, Translational and Clinical, and Biosciences Research Institutes, Faculty of Medical Sciences, Newcastle University, UK; Cardiovascular and Lifestyle Medicine, Faculty Research Centre (CSELS), Faculty of Health and Life Sciences, Coventry University, UK
| |
Collapse
|
14
|
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: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [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.
Collapse
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
| |
Collapse
|
15
|
Kirk JA, Cheung JY, Feldman AM. Therapeutic targeting of BAG3: considering its complexity in cancer and heart disease. J Clin Invest 2021; 131:e149415. [PMID: 34396980 DOI: 10.1172/jci149415] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Bcl2-associated athanogene-3 (BAG3) is expressed ubiquitously in humans, but its levels are highest in the heart, the skeletal muscle, and the central nervous system; it is also elevated in many cancers. BAG3's diverse functions are supported by its multiple protein-protein binding domains, which couple with small and large heat shock proteins, members of the Bcl2 family, other antiapoptotic proteins, and various sarcomere proteins. In the heart, BAG3 inhibits apoptosis, promotes autophagy, couples the β-adrenergic receptor with the L-type Ca2+ channel, and maintains the structure of the sarcomere. In cancer cells, BAG3 binds to and supports an identical array of prosurvival proteins, and it may represent a therapeutic target. However, the development of strategies to block BAG3 function in cancer cells may be challenging, as they are likely to interfere with the essential roles of BAG3 in the heart. In this Review, we present the current knowledge regarding the biology of this complex protein in the heart and in cancer and suggest several therapeutic options.
Collapse
Affiliation(s)
- Jonathan A Kirk
- Department of Cell and Molecular Physiology, Loyola University Chicago, Chicago, Illinois, USA
| | - Joseph Y Cheung
- Division of Renal Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Arthur M Feldman
- Department of Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania, USA
| |
Collapse
|
16
|
Martin TG, Myers VD, Dubey P, Dubey S, Perez E, Moravec CS, Willis MS, Feldman AM, Kirk JA. Cardiomyocyte contractile impairment in heart failure results from reduced BAG3-mediated sarcomeric protein turnover. Nat Commun 2021; 12:2942. [PMID: 34011988 PMCID: PMC8134551 DOI: 10.1038/s41467-021-23272-z] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Accepted: 04/22/2021] [Indexed: 12/22/2022] Open
Abstract
The association between reduced myofilament force-generating capacity (Fmax) and heart failure (HF) is clear, however the underlying molecular mechanisms are poorly understood. Here, we show impaired Fmax arises from reduced BAG3-mediated sarcomere turnover. Myofilament BAG3 expression decreases in human HF and positively correlates with Fmax. We confirm this relationship using BAG3 haploinsufficient mice, which display reduced Fmax and increased myofilament ubiquitination, suggesting impaired protein turnover. We show cardiac BAG3 operates via chaperone-assisted selective autophagy (CASA), conserved from skeletal muscle, and confirm sarcomeric CASA complex localization is BAG3/proteotoxic stress-dependent. Using mass spectrometry, we characterize the myofilament CASA interactome in the human heart and identify eight clients of BAG3-mediated turnover. To determine if increasing BAG3 expression in HF can restore sarcomere proteostasis/Fmax, HF mice were treated with rAAV9-BAG3. Gene therapy fully rescued Fmax and CASA protein turnover after four weeks. Our findings indicate BAG3-mediated sarcomere turnover is fundamental for myofilament functional maintenance. Decreased expression of BAG3 in the heart is associated with contractile dysfunction and heart failure. Here the authors show that this is due to decreased BAG3-dependent sarcomere protein turnover, which impairs mechanical function, and that sarcomere force-generating capacity is restored with BAG3 gene therapy.
Collapse
Affiliation(s)
- Thomas G Martin
- Department of Cell and Molecular Physiology, Loyola University Stritch School of Medicine, Maywood, IL, USA
| | - Valerie D Myers
- Department of Medicine, Temple University Lewis Katz School of Medicine, Philadelphia, PA, USA
| | - Praveen Dubey
- Department of Medicine, Temple University Lewis Katz School of Medicine, Philadelphia, PA, USA
| | - Shubham Dubey
- Department of Medicine, Temple University Lewis Katz School of Medicine, Philadelphia, PA, USA
| | - Edith Perez
- Department of Cell and Molecular Physiology, Loyola University Stritch School of Medicine, Maywood, IL, USA
| | - Christine S Moravec
- Department of Medicine, Cleveland Clinic Lerner College of Medicine, Cleveland, OH, USA
| | - Monte S Willis
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Arthur M Feldman
- Department of Medicine, Temple University Lewis Katz School of Medicine, Philadelphia, PA, USA
| | - Jonathan A Kirk
- Department of Cell and Molecular Physiology, Loyola University Stritch School of Medicine, Maywood, IL, USA.
| |
Collapse
|
17
|
Aslam MI, Jani V, Lin BL, Dunkerly-Eyring B, Livingston CE, Ramachandran A, Ranek MJ, Bedi KC, Margulies KB, Kass DA, Hsu S. Pulmonary artery pulsatility index predicts right ventricular myofilament dysfunction in advanced human heart failure. Eur J Heart Fail 2021; 23:339-341. [PMID: 33347674 DOI: 10.1002/ejhf.2084] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 12/18/2020] [Indexed: 11/11/2022] Open
Affiliation(s)
- M Imran Aslam
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Vivek Jani
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Brian L Lin
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Brittany Dunkerly-Eyring
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Department of Pharmacology & Molecular Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - Carissa E Livingston
- Cardiovascular Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Abhinay Ramachandran
- Cardiovascular Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Mark J Ranek
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Kenneth C Bedi
- Cardiovascular Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Kenneth B Margulies
- Cardiovascular Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - David A Kass
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Steven Hsu
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| |
Collapse
|