1
|
Liu YB, Wang Q, Song YL, Song XM, Fan YC, Kong L, Zhang JS, Li S, Lv YJ, Li ZY, Dai JY, Qiu ZK. Abnormal phosphorylation / dephosphorylation and Ca 2+ dysfunction in heart failure. Heart Fail Rev 2024; 29:751-768. [PMID: 38498262 DOI: 10.1007/s10741-024-10395-w] [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] [Accepted: 03/01/2024] [Indexed: 03/20/2024]
Abstract
Heart failure (HF) can be caused by a variety of causes characterized by abnormal myocardial systole and diastole. Ca2+ current through the L-type calcium channel (LTCC) on the membrane is the initial trigger signal for a cardiac cycle. Declined systole and diastole in HF are associated with dysfunction of myocardial Ca2+ function. This disorder can be correlated with unbalanced levels of phosphorylation / dephosphorylation of LTCC, endoplasmic reticulum (ER), and myofilament. Kinase and phosphatase activity changes along with HF progress, resulting in phased changes in the degree of phosphorylation / dephosphorylation. It is important to realize the phosphorylation / dephosphorylation differences between a normal and a failing heart. This review focuses on phosphorylation / dephosphorylation changes in the progression of HF and summarizes the effects of phosphorylation / dephosphorylation of LTCC, ER function, and myofilament function in normal conditions and HF based on previous experiments and clinical research. Also, we summarize current therapeutic methods based on abnormal phosphorylation / dephosphorylation and clarify potential therapeutic directions.
Collapse
Affiliation(s)
- Yan-Bing Liu
- Interventional Medical Center, The Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao, 266003, Shandong Province, China
- Medical College, Qingdao University, Qingdao, China
| | - Qian Wang
- Medical College, Qingdao University, Qingdao, China
| | - Yu-Ling Song
- Department of Pediatrics, Huantai County Hospital of Traditional Chinese Medicine, Zibo, China
| | | | - Yu-Chen Fan
- Medical College, Qingdao University, Qingdao, China
| | - Lin Kong
- Medical College, Qingdao University, Qingdao, China
| | | | - Sheng Li
- Medical College, Qingdao University, Qingdao, China
| | - Yi-Ju Lv
- Medical College, Qingdao University, Qingdao, China
| | - Ze-Yang Li
- Medical College, Qingdao University, Qingdao, China
| | - Jing-Yu Dai
- Department of Oncology, The Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao, 266003, Shandong Province, China.
| | - Zhen-Kang Qiu
- Interventional Medical Center, The Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao, 266003, Shandong Province, China.
| |
Collapse
|
2
|
Zarzycka W, Kobak KA, King CJ, Peelor FF, Miller BF, Chiao YA. Hyperactive mTORC1/4EBP1 Signaling Dysregulates Proteostasis and Accelerates Cardiac Aging. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.13.594044. [PMID: 38798509 PMCID: PMC11118374 DOI: 10.1101/2024.05.13.594044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
The mechanistic target of rapamycin complex 1 (mTORC1) has a major impact on aging by regulation of proteostasis. It is well established that mTORC1 signaling is hyperactivated with aging and age-related diseases. Previous studies have shown that partial inhibition of mTOR signaling by rapamycin reverses the age-related decline in cardiac function and structure in old mice. However, the downstream signaling pathways involved in this protection against cardiac aging have not been established. TORC1 phosphorylates 4E-binding protein 1 (4EBP1) to promote the initiation of cap-dependent translation. The aim of this project is to examine the role of the mTORC1/4EBP1 axis in age-related cardiac dysfunction. We utilized a whole-body 4EBP1 KO mouse model, which mimics a hyperactive 4EBP1/eIF4E axis, to investigate the effects of hyperactive mTORC1/4EBP1 axis in cardiac aging. Echocardiographic measurements revealed that young 4EBP1 KO mice have no difference in cardiac function at baseline compared to WT mice. Interestingly, middle-aged (14-15-month-old) 4EBP1 KO mice show impaired diastolic function and myocardial performance compared to age-matched WT mice and their diastolic function and myocardial performance are at similar levels as 24-month-old WT mice, suggesting that 4EBP1 KO mice experience accelerated cardiac aging. Old 4EBP1 KO mice show further declines in systolic and diastolic function compared to middle-aged 4EBP1 KO mice and have worse systolic and diastolic function than age-matched old WT mice. Gene expression levels of heart failure markers are not different between 4EBP1 KO and WT mice at these advanced ages. However, ribosomal biogenesis and overall protein ubiquitination are significantly increased in 4EBP1 KO mice when compared to WT, which suggests dysregulated proteostasis. Together, these results show that a hyperactive 4EBP1/eIF4E axis accelerates cardiac aging, potentially by dysregulating proteostasis.
Collapse
|
3
|
Tikunova SB, Thuma J, Davis JP. Mouse Models of Cardiomyopathies Caused by Mutations in Troponin C. Int J Mol Sci 2023; 24:12349. [PMID: 37569724 PMCID: PMC10419064 DOI: 10.3390/ijms241512349] [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: 07/01/2023] [Revised: 07/27/2023] [Accepted: 08/01/2023] [Indexed: 08/13/2023] Open
Abstract
Cardiac muscle contraction is regulated via Ca2+ exchange with the hetero-trimeric troponin complex located on the thin filament. Binding of Ca2+ to cardiac troponin C, a Ca2+ sensing subunit within the troponin complex, results in a series of conformational re-arrangements among the thin filament components, leading to an increase in the formation of actomyosin cross-bridges and muscle contraction. Ultimately, a decline in intracellular Ca2+ leads to the dissociation of Ca2+ from troponin C, inhibiting cross-bridge cycling and initiating muscle relaxation. Therefore, troponin C plays a crucial role in the regulation of cardiac muscle contraction and relaxation. Naturally occurring and engineered mutations in troponin C can lead to altered interactions among components of the thin filament and to aberrant Ca2+ binding and exchange with the thin filament. Mutations in troponin C have been associated with various forms of cardiac disease, including hypertrophic, restrictive, dilated, and left ventricular noncompaction cardiomyopathies. Despite progress made to date, more information from human studies, biophysical characterizations, and animal models is required for a clearer understanding of disease drivers that lead to cardiomyopathies. The unique use of engineered cardiac troponin C with the L48Q mutation that had been thoroughly characterized and genetically introduced into mouse myocardium clearly demonstrates that Ca2+ sensitization in and of itself should not necessarily be considered a disease driver. This opens the door for small molecule and protein engineering strategies to help boost impaired systolic function. On the other hand, the engineered troponin C mutants (I61Q and D73N), genetically introduced into mouse myocardium, demonstrate that Ca2+ desensitization under basal conditions may be a driving factor for dilated cardiomyopathy. In addition to enhancing our knowledge of molecular mechanisms that trigger hypertrophy, dilation, morbidity, and mortality, these cardiomyopathy mouse models could be used to test novel treatment strategies for cardiovascular diseases. In this review, we will discuss (1) the various ways mutations in cardiac troponin C might lead to disease; (2) relevant data on mutations in cardiac troponin C linked to human disease, and (3) all currently existing mouse models containing cardiac troponin C mutations (disease-associated and engineered).
Collapse
Affiliation(s)
- Svetlana B. Tikunova
- Department of Physiology and Cell Biology, Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, OH 43210, USA (J.P.D.)
| | | | | |
Collapse
|
4
|
Salhi HE, Shettigar V, Salyer L, Sturgill S, Brundage EA, Robinett J, Xu Z, Abay E, Lowe J, Janssen PML, Rafael-Fortney JA, Weisleder N, Ziolo MT, Biesiadecki BJ. The lack of Troponin I Ser-23/24 phosphorylation is detrimental to in vivo cardiac function and exacerbates cardiac disease. J Mol Cell Cardiol 2023; 176:84-96. [PMID: 36724829 PMCID: PMC10074981 DOI: 10.1016/j.yjmcc.2023.01.010] [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: 09/08/2022] [Revised: 01/11/2023] [Accepted: 01/24/2023] [Indexed: 01/30/2023]
Abstract
Troponin I (TnI) is a key regulator of cardiac contraction and relaxation with TnI Ser-23/24 phosphorylation serving as a myofilament mechanism to modulate cardiac function. Basal cardiac TnI Ser-23/24 phosphorylation is high such that both increased and decreased TnI phosphorylation may modulate cardiac function. While the effects of increasing TnI Ser-23/24 phosphorylation on heart function are well established, the effects of decreasing TnI Ser-23/24 phosphorylation are not clear. To understand the in vivo role of decreased TnI Ser-23/24 phosphorylation, mice expressing TnI with Ser-23/24 mutated to alanine (TnI S23/24A) that lack the ability to be phosphorylated at these residues were subjected to echocardiography and pressure-volume hemodynamic measurements in the absence or presence of physiological (pacing increasing heart rate or adrenergic stimulation) or pathological (transverse aortic constriction (TAC)) stress. In the absence of pathological stress, the lack of TnI Ser-23/24 phosphorylation impaired systolic and diastolic function. TnI S23/24A mice also had an impaired systolic and diastolic response upon stimulation increased heart rate and an impaired adrenergic response upon dobutamine infusion. Following pathological cardiac stress induced by TAC, TnI S23/24A mice had a greater increase in ventricular mass, worse diastolic function, and impaired systolic and diastolic function upon increasing heart rate. These findings demonstrate that mice lacking the ability to phosphorylate TnI at Ser-23/24 have impaired in vivo systolic and diastolic cardiac function, a blunted cardiac reserve and a worse response to pathological stress supporting decreased TnI Ser23/24 phosphorylation is a modulator of these processes in vivo.
Collapse
Affiliation(s)
- Hussam E Salhi
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States of America
| | - Vikram Shettigar
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States of America
| | - Lorien Salyer
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States of America
| | - Sarah Sturgill
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States of America
| | - Elizabeth A Brundage
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States of America
| | - Joel Robinett
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States of America
| | - Zhaobin Xu
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States of America
| | - Eaman Abay
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States of America
| | - Jeovanna Lowe
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States of America
| | - Paul M L Janssen
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States of America
| | - Jill A Rafael-Fortney
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States of America
| | - Noah Weisleder
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States of America
| | - Mark T Ziolo
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States of America
| | - Brandon J Biesiadecki
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States of America.
| |
Collapse
|
5
|
Robinett JC, Hanft LM, Biesiadecki B, McDonald KS. Molecular regulation of stretch activation. Am J Physiol Cell Physiol 2022; 323:C1728-C1739. [PMID: 36280392 PMCID: PMC9744651 DOI: 10.1152/ajpcell.00101.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 09/27/2022] [Accepted: 10/17/2022] [Indexed: 12/14/2022]
Abstract
Stretch activation is defined as a delayed increase in force after rapid stretches. Although there is considerable evidence for stretch activation in isolated cardiac myofibrillar preparations, few studies have measured mechanisms of stretch activation in mammalian skeletal muscle fibers. We measured stretch activation following rapid step stretches [∼1%-4% sarcomere length (SL)] during submaximal Ca2+ activations of rat permeabilized slow-twitch skeletal muscle fibers before and after protein kinase A (PKA), which phosphorylates slow myosin binding protein-C. PKA significantly increased stretch activation during low (∼25%) Ca2+ activation and accelerated rates of delayed force development (kef) during both low and half-maximal Ca2+ activation. Following the step stretches and subsequent force development, fibers were rapidly shortened to original sarcomere length, which often elicited a shortening-induced transient force overshoot. After PKA, step shortening-induced transient force overshoot increased ∼10-fold following an ∼4% SL shortening during low Ca2+ activation levels. kdf following step shortening also increased after PKA during low and half-maximal Ca2+ activations. We next investigated thin filament regulation of stretch activation. We tested the interplay between cardiac troponin I (cTnI) phosphorylation at the canonical PKA and novel tyrosine kinase sites on stretch activation. Native slow-skeletal Tn complexes were exchanged with recombinant human cTn complex with different human cTnI N-terminal pseudo-phosphorylation molecules: 1) nonphosphorylated wild type (WT), 2) the canonical S22/23D PKA sites, 3) the tyrosine kinase Y26E site, and 4) the combinatorial S22/23D + Y26E cTnI. All three pseudo-phosphorylated cTnIs elicited greater stretch activation than WT. Following stretch activation, a new, elevated stretch-induced steady-state force was reached with pseudo-phosphorylated cTnI. Combinatorial S22/23D + Y26E pseudo-phosphorylated cTnI increased kdf. These results suggest that slow-skeletal myosin binding protein-C (sMyBP-C) phosphorylation modulates stretch activation by a combination of cross-bridge recruitment and faster cycling kinetics, whereas cTnI phosphorylation regulates stretch activation by both redundant and synergistic mechanisms; and, taken together, these sarcomere phosphoproteins offer precision targets for enhanced contractility.
Collapse
Affiliation(s)
- Joel C Robinett
- Department of Medical Pharmacology and Physiology, School of Medicine, University of Missouri, Columbia, Missouri
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio
| | - Laurin M Hanft
- Department of Medical Pharmacology and Physiology, School of Medicine, University of Missouri, Columbia, Missouri
| | - Brandon Biesiadecki
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio
| | - Kerry S McDonald
- Department of Medical Pharmacology and Physiology, School of Medicine, University of Missouri, Columbia, Missouri
| |
Collapse
|
6
|
Sturgill SL, Salyer LG, Biesiadecki BJ, Ziolo MT. A Simple and Effective Method to Consistently Isolate Mouse Cardiomyocytes. J Vis Exp 2022:10.3791/63056. [PMID: 36440883 PMCID: PMC11000524 DOI: 10.3791/63056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The need for reproducible yet technically simple methods yielding high-quality cardiomyocytes is essential for research in cardiac biology. Cellular and molecular functional experiments (e.g., contraction, electrophysiology, calcium cycling, etc.) on cardiomyocytes are the gold standard for establishing mechanism(s) of disease. The mouse is the species of choice for functional experiments and the described technique is specifically for the isolation of mouse cardiomyocytes. Previous methods requiring a Langendorff apparatus require high levels of training and precision for aortic cannulation, often resulting in ischemia. The field is shifting toward Langendorff-free isolation methods that are simple, are reproducible, and yield viable myocytes for physiological data acquisition and culture. These methods greatly diminish ischemia time compared to aortic cannulation and result in reliably obtained cardiomyocytes. Our adaptation to the Langendorff-free method includes an initial perfusion with ice-cold clearing solution, use of a stabilizing platform that ensures a steady needle during perfusion, and additional digestion steps to ensure reliably obtained cardiomyocytes for use in functional measurements and culture. This method is simple and quick to perform and requires little technical skill.
Collapse
Affiliation(s)
- Sarah L Sturgill
- Department of Physiology and Cell Biology, The Ohio State University
| | - Lorien G Salyer
- Department of Physiology and Cell Biology, The Ohio State University
| | | | - Mark T Ziolo
- Department of Physiology and Cell Biology, The Ohio State University;
| |
Collapse
|
7
|
Sturgill SL, Shettigar V, Ziolo MT. Antiquated ejection fraction: Basic research applications for speckle tracking echocardiography. Front Physiol 2022; 13:969314. [PMID: 36353373 PMCID: PMC9637923 DOI: 10.3389/fphys.2022.969314] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 10/05/2022] [Indexed: 03/24/2024] Open
Abstract
For years, ejection fraction has been an essentially ubiquitous measurement for assessing the cardiovascular function of animal models in research labs. Despite technological advances, it remains the top choice among research labs for reporting heart function to this day, and is often overstated in applications. This unfortunately may lead to misinterpretation of data. Clinical approaches have now surpassed research methods, allowing for deeper analysis of the tiers of cardiovascular performance (cardiovascular performance, heart performance, systolic and diastolic function, and contractility). Analysis of each tier is crucial for understanding heart performance, mechanism of action, and disease diagnosis, classification, and progression. This review will elucidate the differences between the tiers of cardiovascular function and discuss the benefits of measuring each tier via speckle tracking echocardiography for basic scientists.
Collapse
Affiliation(s)
| | | | - Mark T. Ziolo
- Frick Center for Heart Failure and Arrhythmia, Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States
| |
Collapse
|
8
|
Chiao YA, Chakraborty AD, Light CM, Tian R, Sadoshima J, Shi X, Gu H, Lee CF. NAD + Redox Imbalance in the Heart Exacerbates Diabetic Cardiomyopathy. Circ Heart Fail 2021; 14:e008170. [PMID: 34374300 PMCID: PMC8373812 DOI: 10.1161/circheartfailure.120.008170] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Diabetes is a risk factor for heart failure and promotes cardiac dysfunction. Diabetic tissues are associated with nicotinamide adenine dinucleotide (NAD+) redox imbalance; however, the hypothesis that NAD+ redox imbalance causes diabetic cardiomyopathy has not been tested. This investigation used mouse models with altered NAD+ redox balance to test this hypothesis. METHODS Diabetic stress was induced in mice by streptozotocin. Cardiac function was measured by echocardiography. Heart and plasma samples were collected for biochemical, histological, and molecular analyses. Two mouse models with altered NAD+ redox states (1, Ndufs4 [NADH:ubiquinone oxidoreductase subunit S4] knockout, cKO, and 2, NAMPT [nicotinamide phosphoribosyltranferase] transgenic mice, NMAPT) were used. RESULTS Diabetic stress caused cardiac dysfunction and lowered NAD+/NADH ratio (oxidized/reduced ratio of nicotinamide adenine dinucleotide) in wild-type mice. Mice with lowered cardiac NAD+/NADH ratio without baseline dysfunction, cKO mice, were challenged with chronic diabetic stress. NAD+ redox imbalance in cKO hearts exacerbated systolic (fractional shortening: 27.6% versus 36.9% at 4 weeks, male cohort P<0.05), and diastolic dysfunction (early-to-late ratio of peak diastolic velocity: 0.99 versus 1.20, P<0.05) of diabetic mice in both sexes. Collagen levels and transcripts of fibrosis and extracellular matrix-dependent pathways did not show changes in diabetic cKO hearts, suggesting that the exacerbated cardiac dysfunction was due to cardiomyocyte dysfunction. NAD+ redox imbalance promoted superoxide dismutase 2 acetylation, protein oxidation, troponin I S150 phosphorylation, and impaired energetics in diabetic cKO hearts. Importantly, elevation of cardiac NAD+ levels by NAMPT normalized NAD+ redox balance, alleviated cardiac dysfunction (fractional shortening: 40.2% versus 24.8% in cKO:NAMPT versus cKO, P<0.05; early-to-late ratio of peak diastolic velocity: 1.32 versus 1.04, P<0.05), and reversed pathogenic mechanisms in diabetic mice. CONCLUSIONS Our results show that NAD+ redox imbalance to regulate acetylation and phosphorylation is a critical mediator of the progression of diabetic cardiomyopathy and suggest the therapeutic potential for diabetic cardiomyopathy by harnessing NAD+ metabolism.
Collapse
Affiliation(s)
- Ying Ann Chiao
- Aging and Metabolism Research Program (Y.A.C., A.D.C.), Oklahoma Medical Research Foundation, Oklahoma City
| | - Akash Deep Chakraborty
- Aging and Metabolism Research Program (Y.A.C., A.D.C.), Oklahoma Medical Research Foundation, Oklahoma City.,Cardiovascular Biology Research Program (A.D.C., C.M.L., C.F.L.), Oklahoma Medical Research Foundation, Oklahoma City
| | - Christine M Light
- Cardiovascular Biology Research Program (A.D.C., C.M.L., C.F.L.), Oklahoma Medical Research Foundation, Oklahoma City
| | - Rong Tian
- Mitochondria and Metabolism Center, University of Washington, Seattle (R.T.). Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark (J.S.)
| | | | - Xiaojian Shi
- Arizona Metabolomics Laboratory, College of Health Solutions, Arizona State University, Scottsdale (X.S., H.G.)
| | - Haiwei Gu
- Arizona Metabolomics Laboratory, College of Health Solutions, Arizona State University, Scottsdale (X.S., H.G.)
| | - Chi Fung Lee
- Cardiovascular Biology Research Program (A.D.C., C.M.L., C.F.L.), Oklahoma Medical Research Foundation, Oklahoma City.,Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City (C.F.L.)
| |
Collapse
|
9
|
Complex functionality of protein phosphatase 1 isoforms in the heart. Cell Signal 2021; 85:110059. [PMID: 34062239 DOI: 10.1016/j.cellsig.2021.110059] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 05/21/2021] [Accepted: 05/28/2021] [Indexed: 02/04/2023]
Abstract
Protein phosphatase 1(PP1) is a key regulator of cardiac function through dephosphorylating serine/threonine residues within target proteins to oppose the function of protein kinases. Studies from failing hearts of animal models and human patients have demonstrated significant increase of PP1 activity in myocardium, while elevated PP1 activity in transgenic mice leads to cardiac dysfunction, suggesting that PP1 might be a therapeutic target to ameliorate cardiac dysfunction in failing hearts. In fact, cardiac overexpression of inhibitor 1, the endogenous inhibitor of PP1, increases cardiac contractility and suppresses heart failure progression. However, this notion of PP1 inhibition for heart failure treatment has been challenged by recent studies on the isoform-specific roles of PP1 in the heart. PP1 is a holoenzyme composed of catalytic subunits (PP1α, PP1β, or PP1γ) and regulatory proteins that target them to distinct subcellular locations for functional specificity. This review will summarize how PP1 regulates phosphorylation of some of the key cardiac proteins involved in Ca2+ handling and cardiac contraction, and the potential role of PP1 isoforms in controlling cardiac physiology and pathophysiology.
Collapse
|
10
|
Blair CA, Brundage EA, Thompson KL, Stromberg A, Guglin M, Biesiadecki BJ, Campbell KS. Heart Failure in Humans Reduces Contractile Force in Myocardium From Both Ventricles. JACC Basic Transl Sci 2020; 5:786-798. [PMID: 32875169 PMCID: PMC7452203 DOI: 10.1016/j.jacbts.2020.05.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 05/18/2020] [Accepted: 05/18/2020] [Indexed: 01/01/2023]
Abstract
Contractile assays were performed using multicellular preparations isolated from the left and right ventricles of organ donors and patients with heart failure. Heart failure reduced maximum force and power by approximately 30% in the myocardium from both ventricles. Heart failure increased the Ca2+ sensitivity of contraction, but the effect was bigger in right ventricular tissue than in left ventricular samples. The changes in Ca2+ sensitivity may reflect ventricle-specific post-translational modifications to sarcomeric proteins.
This study measured how heart failure affects the contractile properties of the human myocardium from the left and right ventricles. The data showed that maximum force and maximum power were reduced by approximately 30% in multicellular preparations from both ventricles, possibly because of ventricular remodeling (e.g., cellular disarray and/or excess fibrosis). Heart failure increased the calcium (Ca2+) sensitivity of contraction in both ventricles, but the effect was bigger in right ventricular samples. The changes in Ca2+ sensitivity were associated with ventricle-specific changes in the phosphorylation of troponin I, which indicated that adrenergic stimulation might induce different effects in the left and right ventricles.
Collapse
Key Words
- Ca2+ sensitivity
- Ca2+, calcium
- Fact, maximum Ca2+-activated force
- Fpas, passive force
- LV, left ventricle
- MyBP-C, myosin binding protein-C
- PKA, protein kinase A
- Pmax, maximum power output
- RLC, regulatory light chain
- RV, right ventricle
- TnI, troponin I
- Vmax, maximum shortening velocity
- heart failure
- human myocardium
- ktr, rate of force recovery
- myofilament proteins
- nH, Hill coefficient
- ventricular function
Collapse
Affiliation(s)
- Cheavar A Blair
- Department of Physiology, University of Kentucky, Lexington, Kentucky
| | - Elizabeth A Brundage
- Department of Physiology and Cell Biology and The Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio
| | | | - Arnold Stromberg
- Department of Statistics, University of Kentucky, Lexington, Kentucky
| | - Maya Guglin
- Division of Cardiovascular Medicine, University of Kentucky, Lexington, Kentucky
| | - Brandon J Biesiadecki
- Department of Physiology and Cell Biology and The Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio
| | - Kenneth S Campbell
- Department of Physiology, University of Kentucky, Lexington, Kentucky.,Division of Cardiovascular Medicine, University of Kentucky, Lexington, Kentucky
| |
Collapse
|
11
|
Chiao YA, Zhang H, Sweetwyne M, Whitson J, Ting YS, Basisty N, Pino LK, Quarles E, Nguyen NH, Campbell MD, Zhang T, Gaffrey MJ, Merrihew G, Wang L, Yue Y, Duan D, Granzier HL, Szeto HH, Qian WJ, Marcinek D, MacCoss MJ, Rabinovitch P. Late-life restoration of mitochondrial function reverses cardiac dysfunction in old mice. eLife 2020; 9:e55513. [PMID: 32648542 PMCID: PMC7377906 DOI: 10.7554/elife.55513] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 07/07/2020] [Indexed: 12/26/2022] Open
Abstract
Diastolic dysfunction is a prominent feature of cardiac aging in both mice and humans. We show here that 8-week treatment of old mice with the mitochondrial targeted peptide SS-31 (elamipretide) can substantially reverse this deficit. SS-31 normalized the increase in proton leak and reduced mitochondrial ROS in cardiomyocytes from old mice, accompanied by reduced protein oxidation and a shift towards a more reduced protein thiol redox state in old hearts. Improved diastolic function was concordant with increased phosphorylation of cMyBP-C Ser282 but was independent of titin isoform shift. Late-life viral expression of mitochondrial-targeted catalase (mCAT) produced similar functional benefits in old mice and SS-31 did not improve cardiac function of old mCAT mice, implicating normalizing mitochondrial oxidative stress as an overlapping mechanism. These results demonstrate that pre-existing cardiac aging phenotypes can be reversed by targeting mitochondrial dysfunction and implicate mitochondrial energetics and redox signaling as therapeutic targets for cardiac aging.
Collapse
Affiliation(s)
- Ying Ann Chiao
- Department of Pathology, University of WashingtonSeattleUnited States
- Aging and Metabolism Program, Oklahoma Medical Research FoundationOklahoma CityUnited States
| | - Huiliang Zhang
- Department of Pathology, University of WashingtonSeattleUnited States
| | - Mariya Sweetwyne
- Department of Pathology, University of WashingtonSeattleUnited States
| | - Jeremy Whitson
- Department of Pathology, University of WashingtonSeattleUnited States
| | - Ying Sonia Ting
- Department of Genome Science, University of WashingtonSeattleUnited States
| | | | - Lindsay K Pino
- Department of Genome Science, University of WashingtonSeattleUnited States
| | - Ellen Quarles
- Department of Pathology, University of WashingtonSeattleUnited States
| | - Ngoc-Han Nguyen
- Department of Pathology, University of WashingtonSeattleUnited States
| | | | - Tong Zhang
- Biological Sciences Division, Pacific Northwest National LaboratoryRichlandUnited States
| | - Matthew J Gaffrey
- Biological Sciences Division, Pacific Northwest National LaboratoryRichlandUnited States
| | - Gennifer Merrihew
- Department of Genome Science, University of WashingtonSeattleUnited States
| | - Lu Wang
- Department of Environmental and Occupational Health Sciences, University of WashingtonSeattleUnited States
| | - Yongping Yue
- Department of Molecular Microbiology and Immunology, School of Medicine, University of MissouriColumbiaUnited States
| | - Dongsheng Duan
- Department of Molecular Microbiology and Immunology, School of Medicine, University of MissouriColumbiaUnited States
| | - Henk L Granzier
- Department of Cellular and Molecular Medicine, University of ArizonaTucsonUnited States
| | | | - Wei-Jun Qian
- Biological Sciences Division, Pacific Northwest National LaboratoryRichlandUnited States
| | - David Marcinek
- Department of Radiology, University of WashingtonSeattleUnited States
| | - Michael J MacCoss
- Department of Genome Science, University of WashingtonSeattleUnited States
| | - Peter Rabinovitch
- Department of Pathology, University of WashingtonSeattleUnited States
| |
Collapse
|
12
|
Biesiadecki BJ, Brotto MA, Brotto LS, Koch LG, Britton SL, Nosek TM, Jin JP. Rats genetically selected for low and high aerobic capacity exhibit altered soleus muscle myofilament functions. Am J Physiol Cell Physiol 2020; 318:C422-C429. [PMID: 31875694 DOI: 10.1152/ajpcell.00430.2019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Aerobic exercise capacity is critical to bodily health. As a model to investigate the mechanisms that determine health and disease, we employed low (LCR) and high (HCR) capacity running rat models selectively bred to concentrate the genes responsible for divergent aerobic running capacity. To investigate the skeletal muscle contribution to this innate difference in running capacity we employed an approach combining examination of the myofilament protein composition and contractile properties of the fast fiber extensor digitorum longus (EDL) and slow fiber soleus (SOL) muscles from LCR and HCR rats. Intact muscle force experiments demonstrate that SOL, but not EDL, muscles from LCR rats exhibit a three times greater decrease in fatigued force. To investigate the mechanism of this increased fatigability in the LCR SOL muscle, we determined the myofilament protein composition and functional properties. Force-Ca2+ measurements demonstrate decreased Ca2+ sensitivity of single skinned SOL muscle fibers from LCR compared with that of HCR rats. Segregating SOL fibers into fast and slow types demonstrates that the decreased Ca2+ sensitivity in LCR SOL results from a specific decrease in slow-type SOL fiber Ca2+ sensitivity such that it was similar to that of fast-type fibers. These results identify that the altered myofilament contractile properties of LCR SOL slow-type fibers result in a fast muscle type Ca2+ sensitivity and the LCR muscle phenotype. Overall our findings demonstrate alterations of the myofilament proteins could contribute to fatigability of the SOL muscle and the decreased innate aerobic running performance of LCR compared with HCR rats.
Collapse
Affiliation(s)
- B J Biesiadecki
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, Ohio.,Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio
| | - M A Brotto
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, Ohio.,Bone-Muscle Research Center, University of Texas, Arlington, Texas
| | - L S Brotto
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, Ohio.,Bone-Muscle Research Center, University of Texas, Arlington, Texas
| | - L G Koch
- Department of Physiology and Pharmacology, The University of Toledo College of Medicine and Life Sciences, Toledo, Ohio
| | - S L Britton
- Department of Anesthesiology, University of Michigan, Ann Arbor, Michigan.,Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan
| | - T M Nosek
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - J-P Jin
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, Ohio.,Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan
| |
Collapse
|
13
|
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] [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.
Collapse
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.
| |
Collapse
|
14
|
van der Velden J, Stienen GJM. Cardiac Disorders and Pathophysiology of Sarcomeric Proteins. Physiol Rev 2019; 99:381-426. [PMID: 30379622 DOI: 10.1152/physrev.00040.2017] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The sarcomeric proteins represent the structural building blocks of heart muscle, which are essential for contraction and relaxation. During recent years, it has become evident that posttranslational modifications of sarcomeric proteins, in particular phosphorylation, tune cardiac pump function at rest and during exercise. This delicate, orchestrated interaction is also influenced by mutations, predominantly in sarcomeric proteins, which cause hypertrophic or dilated cardiomyopathy. In this review, we follow a bottom-up approach starting from a description of the basic components of cardiac muscle at the molecular level up to the various forms of cardiac disorders at the organ level. An overview is given of sarcomere changes in acquired and inherited forms of cardiac disease and the underlying disease mechanisms with particular reference to human tissue. A distinction will be made between the primary defect and maladaptive/adaptive secondary changes. Techniques used to unravel functional consequences of disease-induced protein changes are described, and an overview of current and future treatments targeted at sarcomeric proteins is given. The current evidence presented suggests that sarcomeres not only form the basis of cardiac muscle function but also represent a therapeutic target to combat cardiac disease.
Collapse
Affiliation(s)
- Jolanda van der Velden
- Amsterdam UMC, Vrije Universiteit Amsterdam, Physiology, Amsterdam Cardiovascular Sciences, Amsterdam , The Netherlands ; and Department of Physiology, Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | - Ger J M Stienen
- Amsterdam UMC, Vrije Universiteit Amsterdam, Physiology, Amsterdam Cardiovascular Sciences, Amsterdam , The Netherlands ; and Department of Physiology, Kilimanjaro Christian Medical University College, Moshi, Tanzania
| |
Collapse
|
15
|
Biesiadecki BJ, Westfall MV. Troponin I modulation of cardiac performance: Plasticity in the survival switch. Arch Biochem Biophys 2019; 664:9-14. [PMID: 30684464 DOI: 10.1016/j.abb.2019.01.025] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 12/11/2018] [Accepted: 01/22/2019] [Indexed: 01/21/2023]
Abstract
Signaling complexes targeting the myofilament are essential in modulating cardiac performance. A central target of this signaling is cardiac troponin I (cTnI) phosphorylation. This review focuses on cTnI phosphorylation as a model for myofilament signaling, discussing key gaps and future directions towards understanding complex myofilament modulation of cardiac performance. Human heart cTnI is phosphorylated at 14 sites, giving rise to a complex modulatory network of varied functional responses. For example, while classical Ser23/24 phosphorylation mediates accelerated relaxation, protein kinase C phosphorylation of cTnI serves as a brake on contractile function. Additionally, the functional response of cTnI multi-site phosphorylation cannot necessarily be predicted from the response of individual sites alone. These complexities underscore the need for systematically evaluating single and multi-site phosphorylation on myofilament cellular and in vivo contractile function. Ultimately, a complete understanding of these multi-site responses requires work to establish site occupancy and dominance, kinase/phosphatase signaling balance, and the function of adaptive secondary phosphorylation. As cTnI phosphorylation is essential for modulating cardiac performance, future insight into the complex role of cTnI phosphorylation is important to establish sarcomere signaling in the healthy heart as well as identification of novel myofilament targets in the treatment of disease.
Collapse
Affiliation(s)
- Brandon J Biesiadecki
- Department of Physiology and Cell Biology, The Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, 43210, USA.
| | - Margaret V Westfall
- Department of Cardiac Surgery, University of Michigan, Ann Arbor, MI, 48109, USA.
| |
Collapse
|
16
|
Assessment of PKA and PKC inhibitors on force and kinetics of non-failing and failing human myocardium. Life Sci 2018; 215:119-127. [PMID: 30399377 DOI: 10.1016/j.lfs.2018.10.065] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 10/22/2018] [Accepted: 10/29/2018] [Indexed: 01/08/2023]
Abstract
AIMS Heart failure (HF) is a prevalent disease that is considered the foremost reason for hospitalization in the United States. Most protein kinases (PK) are activated in heart disease and their inhibition has been shown to improve cardiac function in both animal and human studies. However, little is known about the direct impact of PKA and PKC inhibitors on human cardiac contractile function. MATERIAL AND METHODS We investigated the ex vivo effect of such inhibitors on force as well as on kinetics of left ventricular (LV) trabeculae dissected from non-failing and failing human hearts. In these experiments, we applied 0.5 μM of H-89 and GF109203X, which are PKA and PKC inhibitors, respectively, in comparison to their vehicle DMSO (0.05%). KEY FINDINGS AND CONCLUSION Statistical analyses revealed no significant effect for H-89 and GF109203X on either contractile force or kinetics parameters of both non-failing and failing muscles even though they were used at a concentration higher than the reported IC50s and Kis. Therefore, several factors such as selectivity, concentration, and treatment time, which are related to these PK inhibitors according to previous studies require further exploration.
Collapse
|
17
|
Wilder CDE, Pavlaki N, Dursun T, Gyimah P, Caldwell‐Dunn E, Ranieri A, Lewis HR, Curtis MJ. Facilitation of ischaemia-induced ventricular fibrillation by catecholamines is mediated by β 1 and β 2 agonism in the rat heart in vitro. Br J Pharmacol 2018; 175:1669-1690. [PMID: 29473948 PMCID: PMC5913407 DOI: 10.1111/bph.14176] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 01/26/2018] [Accepted: 02/08/2018] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND AND PURPOSE Antiarrhythmic β-blockers are used in patients at risk of myocardial ischaemia, but the survival benefit and mechanisms are unclear. We hypothesized that β-blockers do not prevent ventricular fibrillation (VF) but instead inhibit the ability of catecholamines to facilitate ischaemia-induced VF, limiting the scope of their usefulness. EXPERIMENTAL APPROACH ECGs were analysed from ischaemic Langendorff-perfused rat hearts perfused with adrenoceptor antagonists and/or exogenous catecholamines (CATs: 313 nM noradrenaline + 75 nM adrenaline) in a blinded and randomized study. Ischaemic zone (IZ) size was deliberately made small or large. KEY RESULTS In rat hearts with large IZs, ischaemia-induced VF incidence was high in controls. Atenolol, butoxamine and trimazosin did not affect VF at concentrations with β1 -, β2 - or α1 - adrenoceptor specificity and selectivity (confirmed in separate rat aortae myography experiments). In hearts with small IZs and low baseline incidence of ischaemia-induced VF, CATs, delivered to the uninvolved zone (UZ), increased ischaemia-induced VF incidence. This effect was not mimicked by atrial pacing, hence, not due to sinus tachycardia. However, the CATs-facilitated increase in ischaemia-induced VF was inhibited by atenolol and butoxamine (but not trimazosin), indicative of β1 - and β2 - but not α1 -adrenoceptor involvement (confirmed by immunoblot analysis of downstream phosphoproteins). CATs did not facilitate VF in low-flow globally ischaemic hearts, which have no UZ. CONCLUSIONS AND IMPLICATIONS Catecholamines facilitated ischaemia-induced VF when risk was low, acting via β1 - and β2 - adrenoceptors located in the UZ. There was no scope for facilitation when VF risk was high (large IZ), which may explain why β-blockers have equivocal effectiveness in humans.
Collapse
Affiliation(s)
- Catherine D E Wilder
- Cardiovascular Division, Faculty of Life Sciences and Medicine, The Rayne InstituteSt Thomas' HospitalLondonSE1 7EHUK
| | - Nikoleta Pavlaki
- Cardiovascular Division, Faculty of Life Sciences and Medicine, The Rayne InstituteSt Thomas' HospitalLondonSE1 7EHUK
| | - Tutku Dursun
- Cardiovascular Division, Faculty of Life Sciences and Medicine, The Rayne InstituteSt Thomas' HospitalLondonSE1 7EHUK
| | - Paul Gyimah
- Cardiovascular Division, Faculty of Life Sciences and Medicine, The Rayne InstituteSt Thomas' HospitalLondonSE1 7EHUK
| | - Ellice Caldwell‐Dunn
- Cardiovascular Division, Faculty of Life Sciences and Medicine, The Rayne InstituteSt Thomas' HospitalLondonSE1 7EHUK
| | - Antonella Ranieri
- Cardiovascular Division, Faculty of Life Sciences and Medicine, The Rayne InstituteSt Thomas' HospitalLondonSE1 7EHUK
| | - Hannah R Lewis
- Cardiovascular Division, Faculty of Life Sciences and Medicine, The Rayne InstituteSt Thomas' HospitalLondonSE1 7EHUK
| | - Michael J Curtis
- Cardiovascular Division, Faculty of Life Sciences and Medicine, The Rayne InstituteSt Thomas' HospitalLondonSE1 7EHUK
| |
Collapse
|
18
|
Ngkelo A, Richart A, Kirk JA, Bonnin P, Vilar J, Lemitre M, Marck P, Branchereau M, Le Gall S, Renault N, Guerin C, Ranek MJ, Kervadec A, Danelli L, Gautier G, Blank U, Launay P, Camerer E, Bruneval P, Menasche P, Heymes C, Luche E, Casteilla L, Cousin B, Rodewald HR, Kass DA, Silvestre JS. Mast cells regulate myofilament calcium sensitization and heart function after myocardial infarction. J Exp Med 2017; 213:1353-74. [PMID: 27353089 PMCID: PMC4925026 DOI: 10.1084/jem.20160081] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2016] [Accepted: 05/12/2016] [Indexed: 11/24/2022] Open
Abstract
Ngkelo et al. use a mast cell–deficient mouse model to reveal a protective role of mast cells in myocardial infarction, through regulation of the cardiac contractile machinery. Acute myocardial infarction (MI) is a severe ischemic disease responsible for heart failure and sudden death. Inflammatory cells orchestrate postischemic cardiac remodeling after MI. Studies using mice with defective mast/stem cell growth factor receptor c-Kit have suggested key roles for mast cells (MCs) in postischemic cardiac remodeling. Because c-Kit mutations affect multiple cell types of both immune and nonimmune origin, we addressed the impact of MCs on cardiac function after MI, using the c-Kit–independent MC-deficient (Cpa3Cre/+) mice. In response to MI, MC progenitors originated primarily from white adipose tissue, infiltrated the heart, and differentiated into mature MCs. MC deficiency led to reduced postischemic cardiac function and depressed cardiomyocyte contractility caused by myofilament Ca2+ desensitization. This effect correlated with increased protein kinase A (PKA) activity and hyperphosphorylation of its targets, troponin I and myosin-binding protein C. MC-specific tryptase was identified to regulate PKA activity in cardiomyocytes via protease-activated receptor 2 proteolysis. This work reveals a novel function for cardiac MCs modulating cardiomyocyte contractility via alteration of PKA-regulated force–Ca2+ interactions in response to MI. Identification of this MC-cardiomyocyte cross-talk provides new insights on the cellular and molecular mechanisms regulating the cardiac contractile machinery and a novel platform for therapeutically addressable regulators.
Collapse
Affiliation(s)
- Anta Ngkelo
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMRS-970, Centre de Recherche Cardiovasculaire, Université Paris Descartes, Sorbonne Paris Cité, F-75015 Paris, France
| | - Adèle Richart
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMRS-970, Centre de Recherche Cardiovasculaire, Université Paris Descartes, Sorbonne Paris Cité, F-75015 Paris, France
| | - Jonathan A Kirk
- Division of Cardiology, Johns Hopkins Medical Institutions, Baltimore, MD 212015
| | - Philippe Bonnin
- INSERM, U965, Hôpital Lariboisière-Fernand-Widal, Assistance Publique Hôpitaux de Paris, F-75010 Paris, France
| | - Jose Vilar
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMRS-970, Centre de Recherche Cardiovasculaire, Université Paris Descartes, Sorbonne Paris Cité, F-75015 Paris, France
| | - Mathilde Lemitre
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMRS-970, Centre de Recherche Cardiovasculaire, Université Paris Descartes, Sorbonne Paris Cité, F-75015 Paris, France
| | - Pauline Marck
- INSERM, UMR-1048, Institut des Maladies Métaboliques et Cardiovasculaires, F-31004 Toulouse, France
| | - Maxime Branchereau
- INSERM, UMR-1048, Institut des Maladies Métaboliques et Cardiovasculaires, F-31004 Toulouse, France
| | - Sylvain Le Gall
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMRS-970, Centre de Recherche Cardiovasculaire, Université Paris Descartes, Sorbonne Paris Cité, F-75015 Paris, France
| | - Nisa Renault
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMRS-970, Centre de Recherche Cardiovasculaire, Université Paris Descartes, Sorbonne Paris Cité, F-75015 Paris, France
| | - Coralie Guerin
- National Cytometry Platform, Department of Infection and Immunity, Luxembourg Institute of Health, L-4354 Esch-sur-Alzette, Luxembourg
| | - Mark J Ranek
- Division of Cardiology, Johns Hopkins Medical Institutions, Baltimore, MD 212015
| | - Anaïs Kervadec
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMRS-970, Centre de Recherche Cardiovasculaire, Université Paris Descartes, Sorbonne Paris Cité, F-75015 Paris, France
| | - Luca Danelli
- Laboratoire d'Excellence INFLAMEX, Université Paris Diderot, Sorbonne Paris Cité, F-75018 Paris, France INSERM, U1149, F-75018 Paris, France Centre National de la Recherche Scientifique (CNRS) ERL 8252, F-75018 Paris, France
| | - Gregory Gautier
- Laboratoire d'Excellence INFLAMEX, Université Paris Diderot, Sorbonne Paris Cité, F-75018 Paris, France INSERM, U1149, F-75018 Paris, France
| | - Ulrich Blank
- Laboratoire d'Excellence INFLAMEX, Université Paris Diderot, Sorbonne Paris Cité, F-75018 Paris, France INSERM, U1149, F-75018 Paris, France Centre National de la Recherche Scientifique (CNRS) ERL 8252, F-75018 Paris, France
| | - Pierre Launay
- Laboratoire d'Excellence INFLAMEX, Université Paris Diderot, Sorbonne Paris Cité, F-75018 Paris, France INSERM, U1149, F-75018 Paris, France
| | - Eric Camerer
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMRS-970, Centre de Recherche Cardiovasculaire, Université Paris Descartes, Sorbonne Paris Cité, F-75015 Paris, France
| | - Patrick Bruneval
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMRS-970, Centre de Recherche Cardiovasculaire, Université Paris Descartes, Sorbonne Paris Cité, F-75015 Paris, France Hôpital European George Pompidou, Assistance Publique Hôpitaux de Paris, F-75015 Paris, France
| | - Philippe Menasche
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMRS-970, Centre de Recherche Cardiovasculaire, Université Paris Descartes, Sorbonne Paris Cité, F-75015 Paris, France Hôpital European George Pompidou, Assistance Publique Hôpitaux de Paris, F-75015 Paris, France
| | - Christophe Heymes
- INSERM, UMR-1048, Institut des Maladies Métaboliques et Cardiovasculaires, F-31004 Toulouse, France
| | - Elodie Luche
- STROMALab, Etablissement Français du Sang, INSERM U1031, CNRS ERL 5311, Université de Toulouse, F-31004 Toulouse, France
| | - Louis Casteilla
- STROMALab, Etablissement Français du Sang, INSERM U1031, CNRS ERL 5311, Université de Toulouse, F-31004 Toulouse, France
| | - Béatrice Cousin
- STROMALab, Etablissement Français du Sang, INSERM U1031, CNRS ERL 5311, Université de Toulouse, F-31004 Toulouse, France
| | - Hans-Reimer Rodewald
- Division of Cellular Immunology, German Cancer Research Center, D-69120 Heidelberg, Germany
| | - David A Kass
- Division of Cardiology, Johns Hopkins Medical Institutions, Baltimore, MD 212015
| | - Jean-Sébastien Silvestre
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMRS-970, Centre de Recherche Cardiovasculaire, Université Paris Descartes, Sorbonne Paris Cité, F-75015 Paris, France
| |
Collapse
|
19
|
Lang SE, Stevenson TK, Schatz TM, Biesiadecki BJ, Westfall MV. Functional communication between PKC-targeted cardiac troponin I phosphorylation sites. Arch Biochem Biophys 2017; 627:1-9. [PMID: 28587770 DOI: 10.1016/j.abb.2017.05.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 05/16/2017] [Accepted: 05/31/2017] [Indexed: 11/18/2022]
Abstract
Increased protein kinase C (PKC) activity is associated with heart failure, and can target multiple cardiac troponin I (cTnI) residues in myocytes, including S23/24, S43/45 and T144. In earlier studies, cTnI-S43D and/or -S45D augmented S23/24 and T144 phosphorylation, which suggested there is communication between clusters. This communication is now explored by evaluating the impact of phospho-mimetic cTnI S43/45D combined with S23/24D (cTnIS4D) or T144D (cTnISDTD). Gene transfer of epitope-tagged cTnIS4D and cTnISDTD into adult cardiac myocytes progressively replaced endogenous cTnI. Partial replacement with cTnISDTD or cTnIS4D accelerated the time to peak (TTP) shortening and time to 50% re-lengthening (TTR50%) on day 2, but peak shortening was only diminished by cTnIS4D. Extensive cTnIS4D replacement continued to accelerate TTP, and decrease shortening amplitude, while TTR50% returned to baseline levels on day 4. In contrast, cTnISDTD modestly reduced shortening amplitude and continued to accelerate myocyte TTP and TTR50%. These results indicate cTnIS43/45 communicates with S23/24 and T144, with S23/24 exacerbating and T144 attenuating the S43/45D-dependent functional deficit. In addition, more severe functional alterations in cTnIS4D myocytes were accompanied by higher levels of secondary phosphorylation compared to cTnISDTD. These results suggest that secondary phosphorylation helps to maintain steady-state contractile function during chronic cTnI phosphorylation at PKC sites.
Collapse
Affiliation(s)
- Sarah E Lang
- Department of Cardiac Surgery, University of Michigan, Ann Arbor, MI 48109, United States; Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, MI 48109, United States
| | - Tamara K Stevenson
- Department of Cardiac Surgery, University of Michigan, Ann Arbor, MI 48109, United States
| | - Tabea M Schatz
- Department of Cardiac Surgery, University of Michigan, Ann Arbor, MI 48109, United States
| | - Brandon J Biesiadecki
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, United States
| | - Margaret V Westfall
- Department of Cardiac Surgery, University of Michigan, Ann Arbor, MI 48109, United States; Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, MI 48109, United States.
| |
Collapse
|
20
|
Ryba DM, Li J, Cowan CL, Russell B, Wolska BM, Solaro RJ. Long-Term Biased β-Arrestin Signaling Improves Cardiac Structure and Function in Dilated Cardiomyopathy. Circulation 2017; 135:1056-1070. [PMID: 28104714 DOI: 10.1161/circulationaha.116.024482] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 01/12/2017] [Indexed: 12/20/2022]
Abstract
BACKGROUND Biased agonism of the angiotensin II receptor is known to promote cardiac contractility. Our laboratory indicated that these effects may be attributable to changes at the level of the myofilaments. However, these signaling mechanisms remain unknown. Because a common finding in dilated cardiomyopathy is a reduction in the myofilament-Ca2+ response, we hypothesized that β-arrestin signaling would increase myofilament-Ca2+ responsiveness in a model of familial dilated cardiomyopathy and improve cardiac function and morphology. METHODS We treated a dilated cardiomyopathy-linked mouse model expressing a mutant tropomyosin (Tm-E54K) for 3 months with either TRV120067, a β-arrestin 2-biased ligand of the angiotensin II receptor, or losartan, an angiotensin II receptor blocker. At the end of the treatment protocol, we assessed cardiac function using echocardiography, the myofilament-Ca2+ response of detergent-extracted fiber bundles, and used proteomic approaches to understand changes in posttranslational modifications of proteins that may explain functional changes. We also assessed signaling pathways altered in vivo and by using isolated myocytes. RESULTS TRV120067- treated Tm-E54K mice showed improved cardiac structure and function, whereas losartan-treated mice had no improvement. Myofilaments of TRV120067-treated Tm-E54K mice had significantly improved myofilament-Ca2+ responsiveness, which was depressed in untreated Tm-E54K mice. We attributed these changes to increased MLC2v and MYPT1/2 phosphorylation seen only in TRV120067-treated mice. We found that the functional changes were attributable to an activation of ERK1/2-RSK3 signaling, mediated through β-arrestin, which may have a novel role in increasing MLC2v phosphorylation through a previously unrecognized interaction of β-arrestin localized to the sarcomere. CONCLUSIONS Long-term β-arrestin 2-biased agonism of the angiotensin II receptor may be a viable approach to the treatment of dilated cardiomyopathy by not only preventing maladaptive signaling, but also improving cardiac function by altering the myofilament-Ca2+ response via β-arrestin signaling pathways.
Collapse
Affiliation(s)
- David M Ryba
- From Department of Physiology and Biophysics and Center for Cardiovascular Research, University of Illinois at Chicago (D.M.R., J.L., B.R., B.M.W., R.J.S.); Department of Medicine, Division of Cardiology, University of Illinois at Chicago (B.M.W.); and Trevena, Inc. King of Prussia, PA (B.M.W.)
| | - Jieli Li
- From Department of Physiology and Biophysics and Center for Cardiovascular Research, University of Illinois at Chicago (D.M.R., J.L., B.R., B.M.W., R.J.S.); Department of Medicine, Division of Cardiology, University of Illinois at Chicago (B.M.W.); and Trevena, Inc. King of Prussia, PA (B.M.W.)
| | - Conrad L Cowan
- From Department of Physiology and Biophysics and Center for Cardiovascular Research, University of Illinois at Chicago (D.M.R., J.L., B.R., B.M.W., R.J.S.); Department of Medicine, Division of Cardiology, University of Illinois at Chicago (B.M.W.); and Trevena, Inc. King of Prussia, PA (B.M.W.)
| | - Brenda Russell
- From Department of Physiology and Biophysics and Center for Cardiovascular Research, University of Illinois at Chicago (D.M.R., J.L., B.R., B.M.W., R.J.S.); Department of Medicine, Division of Cardiology, University of Illinois at Chicago (B.M.W.); and Trevena, Inc. King of Prussia, PA (B.M.W.)
| | - Beata M Wolska
- From Department of Physiology and Biophysics and Center for Cardiovascular Research, University of Illinois at Chicago (D.M.R., J.L., B.R., B.M.W., R.J.S.); Department of Medicine, Division of Cardiology, University of Illinois at Chicago (B.M.W.); and Trevena, Inc. King of Prussia, PA (B.M.W.)
| | - R John Solaro
- From Department of Physiology and Biophysics and Center for Cardiovascular Research, University of Illinois at Chicago (D.M.R., J.L., B.R., B.M.W., R.J.S.); Department of Medicine, Division of Cardiology, University of Illinois at Chicago (B.M.W.); and Trevena, Inc. King of Prussia, PA (B.M.W.).
| |
Collapse
|
21
|
Siddiqui JK, Tikunova SB, Walton SD, Liu B, Meyer M, de Tombe PP, Neilson N, Kekenes-Huskey PM, Salhi HE, Janssen PML, Biesiadecki BJ, Davis JP. Myofilament Calcium Sensitivity: Consequences of the Effective Concentration of Troponin I. Front Physiol 2016; 7:632. [PMID: 28066265 PMCID: PMC5175494 DOI: 10.3389/fphys.2016.00632] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 12/05/2016] [Indexed: 12/04/2022] Open
Abstract
Control of calcium binding to and dissociation from cardiac troponin C (TnC) is essential to healthy cardiac muscle contraction/relaxation. There are numerous aberrant post-translational modifications and mutations within a plethora of contractile, and even non-contractile, proteins that appear to imbalance this delicate relationship. The direction and extent of the resulting change in calcium sensitivity is thought to drive the heart toward one type of disease or another. There are a number of molecular mechanisms that may be responsible for the altered calcium binding properties of TnC, potentially the most significant being the ability of the regulatory domain of TnC to bind the switch peptide region of TnI. Considering TnI is essentially tethered to TnC and cannot diffuse away in the absence of calcium, we suggest that the apparent calcium binding properties of TnC are highly dependent upon an “effective concentration” of TnI available to bind TnC. Based on our previous work, TnI peptide binding studies and the calcium binding properties of chimeric TnC-TnI fusion constructs, and building upon the concept of effective concentration, we have developed a mathematical model that can simulate the steady-state and kinetic calcium binding properties of a wide assortment of disease-related and post-translational protein modifications in the isolated troponin complex and reconstituted thin filament. We predict that several TnI and TnT modifications do not alter any of the intrinsic calcium or TnI binding constants of TnC, but rather alter the ability of TnC to “find” TnI in the presence of calcium. These studies demonstrate the apparent consequences of the effective TnI concentration in modulating the calcium binding properties of TnC.
Collapse
Affiliation(s)
- Jalal K Siddiqui
- Department of Physiology and Cell Biology and the Davis Heart and Lung Research Institute, The Ohio State University Columbus, OH, USA
| | - Svetlana B Tikunova
- Department of Physiology and Cell Biology and the Davis Heart and Lung Research Institute, The Ohio State University Columbus, OH, USA
| | - Shane D Walton
- Department of Physiology and Cell Biology and the Davis Heart and Lung Research Institute, The Ohio State University Columbus, OH, USA
| | - Bin Liu
- Department of Physiology and Cell Biology and the Davis Heart and Lung Research Institute, The Ohio State University Columbus, OH, USA
| | - Meredith Meyer
- Department of Physiology and Cell Biology and the Davis Heart and Lung Research Institute, The Ohio State University Columbus, OH, USA
| | - Pieter P de Tombe
- Cell and Molecular Physiology, Loyola University Chicago Maywood, IL, USA
| | - Nathan Neilson
- Department of Physiology and Cell Biology and the Davis Heart and Lung Research Institute, The Ohio State University Columbus, OH, USA
| | | | - Hussam E Salhi
- Department of Physiology and Cell Biology and the Davis Heart and Lung Research Institute, The Ohio State University Columbus, OH, USA
| | - Paul M L Janssen
- Department of Physiology and Cell Biology and the Davis Heart and Lung Research Institute, The Ohio State University Columbus, OH, USA
| | - Brandon J Biesiadecki
- Department of Physiology and Cell Biology and the Davis Heart and Lung Research Institute, The Ohio State University Columbus, OH, USA
| | - Jonathan P Davis
- Department of Physiology and Cell Biology and the Davis Heart and Lung Research Institute, The Ohio State University Columbus, OH, USA
| |
Collapse
|
22
|
Salhi HE, Hassel NC, Siddiqui JK, Brundage EA, Ziolo MT, Janssen PML, Davis JP, Biesiadecki BJ. Myofilament Calcium Sensitivity: Mechanistic Insight into TnI Ser-23/24 and Ser-150 Phosphorylation Integration. Front Physiol 2016; 7:567. [PMID: 28018230 PMCID: PMC5156683 DOI: 10.3389/fphys.2016.00567] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 11/08/2016] [Indexed: 11/14/2022] Open
Abstract
Troponin I (TnI) is a major regulator of cardiac muscle contraction and relaxation. During physiological and pathological stress, TnI is differentially phosphorylated at multiple residues through different signaling pathways to match cardiac function to demand. The combination of these TnI phosphorylations can exhibit an expected or unexpected functional integration, whereby the function of two phosphorylations are different than that predicted from the combined function of each individual phosphorylation alone. We have shown that TnI Ser-23/24 and Ser-150 phosphorylation exhibit functional integration and are simultaneously increased in response to cardiac stress. In the current study, we investigated the functional integration of TnI Ser-23/24 and Ser-150 to alter cardiac contraction. We hypothesized that Ser-23/24 and Ser-150 phosphorylation each utilize distinct molecular mechanisms to alter the TnI binding affinity within the thin filament. Mathematical modeling predicts that Ser-23/24 and Ser-150 phosphorylation affect different TnI affinities within the thin filament to distinctly alter the Ca2+-binding properties of troponin. Protein binding experiments validate this assertion by demonstrating pseudo-phosphorylated Ser-150 decreases the affinity of isolated TnI for actin, whereas Ser-23/24 pseudo-phosphorylation is not different from unphosphorylated. Thus, our data supports that TnI Ser-23/24 affects TnI-TnC binding, while Ser-150 phosphorylation alters TnI-actin binding. By measuring force development in troponin-exchanged skinned myocytes, we demonstrate that the Ca2+ sensitivity of force is directly related to the amount of phosphate present on TnI. Furthermore, we demonstrate that Ser-150 pseudo-phosphorylation blunts Ser-23/24-mediated decreased Ca2+-sensitive force development whether on the same or different TnI molecule. Therefore, TnI phosphorylations can integrate across troponins along the myofilament. These data demonstrate that TnI Ser-23/24 and Ser-150 phosphorylation regulates muscle contraction in part by modulating different TnI interactions in the thin filament and it is the combination of these differential mechanisms that provides understanding of their functional integration.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | - Brandon J. Biesiadecki
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, Ohio State UniversityColumbus, OH, USA
| |
Collapse
|
23
|
Westfall MV. Contribution of Post-translational Phosphorylation to Sarcomere-Linked Cardiomyopathy Phenotypes. Front Physiol 2016; 7:407. [PMID: 27683560 PMCID: PMC5021686 DOI: 10.3389/fphys.2016.00407] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 08/30/2016] [Indexed: 01/24/2023] Open
Abstract
Secondary shifts develop in post-translational phosphorylation of sarcomeric proteins in multiple animal models of inherited cardiomyopathy. These signaling alterations together with the primary mutation are predicted to contribute to the overall cardiac phenotype. As a result, identification and integration of post-translational myofilament signaling responses are identified as priorities for gaining insights into sarcomeric cardiomyopathies. However, significant questions remain about the nature and contribution of post-translational phosphorylation to structural remodeling and cardiac dysfunction in animal models and human patients. This perspective essay discusses specific goals for filling critical gaps about post-translational signaling in response to these inherited mutations, especially within sarcomeric proteins. The discussion focuses primarily on pre-clinical analysis of animal models and defines challenges and future directions in this field.
Collapse
|
24
|
Cheng Y, Regnier M. Cardiac troponin structure-function and the influence of hypertrophic cardiomyopathy associated mutations on modulation of contractility. Arch Biochem Biophys 2016; 601:11-21. [PMID: 26851561 PMCID: PMC4899195 DOI: 10.1016/j.abb.2016.02.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Revised: 01/30/2016] [Accepted: 02/02/2016] [Indexed: 11/29/2022]
Abstract
Cardiac troponin (cTn) acts as a pivotal regulator of muscle contraction and relaxation and is composed of three distinct subunits (cTnC: a highly conserved Ca(2+) binding subunit, cTnI: an actomyosin ATPase inhibitory subunit, and cTnT: a tropomyosin binding subunit). In this mini-review, we briefly summarize the structure-function relationship of cTn and its subunits, its modulation by PKA-mediated phosphorylation of cTnI, and what is known about how these properties are altered by hypertrophic cardiomyopathy (HCM) associated mutations of cTnI. This includes recent work using computational modeling approaches to understand the atomic-based structural level basis of disease-associated mutations. We propose a viewpoint that it is alteration of cTnC-cTnI interaction (rather than the Ca(2+) binding properties of cTn) per se that disrupt the ability of PKA-mediated phosphorylation at cTnI Ser-23/24 to alter contraction and relaxation in at least some HCM-associated mutations. The combination of state of the art biophysical approaches can provide new insight on the structure-function mechanisms of contractile dysfunction resulting cTnI mutations and exciting new avenues for the diagnosis, prevention, and even treatment of heart diseases.
Collapse
Affiliation(s)
- Yuanhua Cheng
- University of Washington, Department of Bioengineering, Seattle, WA, USA
| | - Michael Regnier
- University of Washington, Department of Bioengineering, Seattle, WA, USA.
| |
Collapse
|
25
|
Shettigar V, Zhang B, Little SC, Salhi HE, Hansen BJ, Li N, Zhang J, Roof SR, Ho HT, Brunello L, Lerch JK, Weisleder N, Fedorov VV, Accornero F, Rafael-Fortney JA, Gyorke S, Janssen PML, Biesiadecki BJ, Ziolo MT, Davis JP. Rationally engineered Troponin C modulates in vivo cardiac function and performance in health and disease. Nat Commun 2016; 7:10794. [PMID: 26908229 PMCID: PMC4770086 DOI: 10.1038/ncomms10794] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 01/21/2016] [Indexed: 12/26/2022] Open
Abstract
Treatment for heart disease, the leading cause of death in the world, has progressed little for several decades. Here we develop a protein engineering approach to directly tune in vivo cardiac contractility by tailoring the ability of the heart to respond to the Ca(2+) signal. Promisingly, our smartly formulated Ca(2+)-sensitizing TnC (L48Q) enhances heart function without any adverse effects that are commonly observed with positive inotropes. In a myocardial infarction (MI) model of heart failure, expression of TnC L48Q before the MI preserves cardiac function and performance. Moreover, expression of TnC L48Q after the MI therapeutically enhances cardiac function and performance, without compromising survival. We demonstrate engineering TnC can specifically and precisely modulate cardiac contractility that when combined with gene therapy can be employed as a therapeutic strategy for heart disease.
Collapse
Affiliation(s)
- Vikram Shettigar
- Davis Heart and Lung Research Institute and Department of Physiology and Cell Biology, Columbus, Ohio 43210, USA
| | - Bo Zhang
- Davis Heart and Lung Research Institute and Department of Physiology and Cell Biology, Columbus, Ohio 43210, USA
| | - Sean C Little
- Bristol-Myers Squibb, Department of Discovery Biology, Wallingford, Connecticut 06492, USA
| | - Hussam E Salhi
- Davis Heart and Lung Research Institute and Department of Physiology and Cell Biology, Columbus, Ohio 43210, USA
| | - Brian J Hansen
- Davis Heart and Lung Research Institute and Department of Physiology and Cell Biology, Columbus, Ohio 43210, USA
| | - Ning Li
- Davis Heart and Lung Research Institute and Department of Physiology and Cell Biology, Columbus, Ohio 43210, USA
| | - Jianchao Zhang
- Davis Heart and Lung Research Institute and Department of Physiology and Cell Biology, Columbus, Ohio 43210, USA
| | | | - Hsiang-Ting Ho
- Davis Heart and Lung Research Institute and Department of Physiology and Cell Biology, Columbus, Ohio 43210, USA
| | - Lucia Brunello
- Davis Heart and Lung Research Institute and Department of Physiology and Cell Biology, Columbus, Ohio 43210, USA
| | - Jessica K Lerch
- Center for Brain and Spinal Cord Repair, Department of Neuroscience, The Ohio State University College of Medicine, Columbus, Ohio 43210, USA
| | - Noah Weisleder
- Davis Heart and Lung Research Institute and Department of Physiology and Cell Biology, Columbus, Ohio 43210, USA
| | - Vadim V Fedorov
- Davis Heart and Lung Research Institute and Department of Physiology and Cell Biology, Columbus, Ohio 43210, USA
| | - Federica Accornero
- Davis Heart and Lung Research Institute and Department of Physiology and Cell Biology, Columbus, Ohio 43210, USA
| | - Jill A Rafael-Fortney
- Davis Heart and Lung Research Institute and Department of Physiology and Cell Biology, Columbus, Ohio 43210, USA
| | - Sandor Gyorke
- Davis Heart and Lung Research Institute and Department of Physiology and Cell Biology, Columbus, Ohio 43210, USA
| | - Paul M L Janssen
- Davis Heart and Lung Research Institute and Department of Physiology and Cell Biology, Columbus, Ohio 43210, USA
| | - Brandon J Biesiadecki
- Davis Heart and Lung Research Institute and Department of Physiology and Cell Biology, Columbus, Ohio 43210, USA
| | - Mark T Ziolo
- Davis Heart and Lung Research Institute and Department of Physiology and Cell Biology, Columbus, Ohio 43210, USA
| | - Jonathan P Davis
- Davis Heart and Lung Research Institute and Department of Physiology and Cell Biology, Columbus, Ohio 43210, USA
| |
Collapse
|
26
|
Designing proteins to combat disease: Cardiac troponin C as an example. Arch Biochem Biophys 2016; 601:4-10. [PMID: 26901433 DOI: 10.1016/j.abb.2016.02.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 02/04/2016] [Indexed: 01/18/2023]
Abstract
Throughout history, muscle research has led to numerous scientific breakthroughs that have brought insight to a more general understanding of all biological processes. Potentially one of the most influential discoveries was the role of the second messenger calcium and its myriad of handling and sensing systems that mechanistically control muscle contraction. In this review we will briefly discuss the significance of calcium as a universal second messenger along with some of the most common calcium binding motifs in proteins, focusing on the EF-hand. We will also describe some of our approaches to rationally design calcium binding proteins to palliate, or potentially even cure cardiovascular disease. Considering not all failing hearts have the same etiology, genetic background and co-morbidities, personalized therapies will need to be developed. We predict designer proteins will open doors for unprecedented personalized, and potentially, even generalized medicines as gene therapy or protein delivery techniques come to fruition.
Collapse
|
27
|
Zhang M, Martin JL, Kumar M, Khairallah RJ, de Tombe PP. Rapid large-scale purification of myofilament proteins using a cleavable His6-tag. Am J Physiol Heart Circ Physiol 2015; 309:H1509-15. [PMID: 26386113 PMCID: PMC4666967 DOI: 10.1152/ajpheart.00598.2015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 09/15/2015] [Indexed: 11/22/2022]
Abstract
With the advent of high-throughput DNA sequencing, the number of identified cardiomyopathy-causing mutations has increased tremendously. As the majority of these mutations affect myofilament proteins, there is a need to understand their functional consequence on contraction. Permeabilized myofilament preparations coupled with protein exchange protocols are a common method for examining into contractile mechanics. However, producing large quantities of myofilament proteins can be time consuming and requires different approaches for each protein of interest. In the present study, we describe a unified automated method to produce troponin C, troponin T, and troponin I as well as myosin light chain 2 fused to a His6-tag followed by a tobacco etch virus (TEV) protease site. TEV protease has the advantage of a relaxed P1' cleavage site specificity, allowing for no residues left after proteolysis and preservation of the native sequence of the protein of interest. After expression in Esherichia coli, cells were lysed by sonication in imidazole-containing buffer. The His6-tagged protein was then purified using a HisTrap nickel metal affinity column, and the His6-tag was removed by His6-TEV protease digestion for 4 h at 30°C. The protease was then removed using a HisTrap column, and complex assembly was performed via column-assisted sequential desalting. This mostly automated method allows for the purification of protein in 1 day and can be adapted to most soluble proteins. It has the advantage of greatly increasing yield while reducing the time and cost of purification. Therefore, production and purification of mutant proteins can be accelerated and functional data collected in a faster, less expensive manner.
Collapse
Affiliation(s)
- Mengjie Zhang
- Department of Cell and Molecular Physiology, Loyola University, Chicago, Illinois
| | - Jody L Martin
- Department of Cell and Molecular Physiology, Loyola University, Chicago, Illinois
| | - Mohit Kumar
- Department of Cell and Molecular Physiology, Loyola University, Chicago, Illinois
| | - Ramzi J Khairallah
- Department of Cell and Molecular Physiology, Loyola University, Chicago, Illinois
| | - Pieter P de Tombe
- Department of Cell and Molecular Physiology, Loyola University, Chicago, Illinois
| |
Collapse
|
28
|
Sheng JJ, Jin JP. TNNI1, TNNI2 and TNNI3: Evolution, regulation, and protein structure-function relationships. Gene 2015; 576:385-94. [PMID: 26526134 DOI: 10.1016/j.gene.2015.10.052] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 09/21/2015] [Accepted: 10/20/2015] [Indexed: 12/11/2022]
Abstract
Troponin I (TnI) is the inhibitory subunit of the troponin complex in the sarcomeric thin filament of striated muscle and plays a central role in the calcium regulation of contraction and relaxation. Vertebrate TnI has evolved into three isoforms encoded by three homologous genes: TNNI1 for slow skeletal muscle TnI, TNNI2 for fast skeletal muscle TnI and TNNI3 for cardiac TnI, which are expressed under muscle type-specific and developmental regulations. To summarize the current knowledge on the TnI isoform genes and products, this review focuses on the evolution, gene regulation, posttranslational modifications, and structure-function relationship of TnI isoform proteins. Their physiological and medical significances are also discussed.
Collapse
Affiliation(s)
- Juan-Juan Sheng
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Jian-Ping Jin
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, USA.
| |
Collapse
|
29
|
Biesiadecki BJ, Ziolo MT. Should we treat heart failure with phosphatase inhibitors? Better to start at the end. J Mol Cell Cardiol 2015; 89:116-8. [PMID: 26497613 DOI: 10.1016/j.yjmcc.2015.10.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 10/16/2015] [Accepted: 10/19/2015] [Indexed: 01/21/2023]
Affiliation(s)
- Brandon J Biesiadecki
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA.
| | - Mark T Ziolo
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
| |
Collapse
|
30
|
Wilder T, Ryba DM, Wieczorek DF, Wolska BM, Solaro RJ. N-acetylcysteine reverses diastolic dysfunction and hypertrophy in familial hypertrophic cardiomyopathy. Am J Physiol Heart Circ Physiol 2015; 309:H1720-30. [PMID: 26432840 DOI: 10.1152/ajpheart.00339.2015] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 09/25/2015] [Indexed: 12/15/2022]
Abstract
S-glutathionylation of cardiac myosin-binding protein C (cMyBP-C) induces Ca(2+) sensitization and a slowing of cross-bridge kinetics as a result of increased oxidative signaling. Although there is evidence for a role of oxidative stress in disorders associated with hypertrophic cardiomyopathy (HCM), this mechanism is not well understood. We investigated whether oxidative myofilament modifications may be in part responsible for diastolic dysfunction in HCM. We administered N-acetylcysteine (NAC) for 30 days to 1-mo-old wild-type mice and to transgenic mice expressing a mutant tropomyosin (Tm-E180G) and nontransgenic littermates. Tm-E180G hearts demonstrate a phenotype similar to human HCM. After NAC administration, the morphology and diastolic function of Tm-E180G mice was not significantly different from controls, indicating that NAC had reversed baseline diastolic dysfunction and hypertrophy in our model. NAC administration also increased sarco(endo)plasmic reticulum Ca(2+) ATPase protein expression, reduced extracellular signal-related kinase 1/2 phosphorylation, and normalized phosphorylation of phospholamban, as assessed by Western blot. Detergent-extracted fiber bundles from NAC-administered Tm-E180G mice showed nearly nontransgenic (NTG) myofilament Ca(2+) sensitivity. Additionally, we found that NAC increased tension cost and rate of cross-bridge reattachment. Tm-E180G myofilaments were found to have a significant increase in S-glutathionylation of cMyBP-C, which was returned to NTG levels upon NAC administration. Taken together, our results indicate that oxidative myofilament modifications are an important mediator in diastolic function, and by relieving this modification we were able to reverse established diastolic dysfunction and hypertrophy in HCM.
Collapse
Affiliation(s)
- Tanganyika Wilder
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, Chicago, Illinois; Department of Biology, College of Science and Technology, Florida A & M University, Tallahassee, Florida
| | - David M Ryba
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - David F Wieczorek
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Beata M Wolska
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, Chicago, Illinois; Department of Medicine, Section of Cardiology, University of Illinois at Chicago, Chicago, Illinois; and
| | - R John Solaro
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, Chicago, Illinois;
| |
Collapse
|
31
|
Dissociation of Calcium Transients and Force Development following a Change in Stimulation Frequency in Isolated Rabbit Myocardium. BIOMED RESEARCH INTERNATIONAL 2015; 2015:468548. [PMID: 25961020 PMCID: PMC4413957 DOI: 10.1155/2015/468548] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 08/01/2014] [Accepted: 08/19/2014] [Indexed: 01/02/2023]
Abstract
As the heart transitions from one exercise intensity to another, changes in cardiac output occur, which are modulated by alterations in force development and calcium handling. Although the steady-state force-calcium relationship at various heart rates is well investigated, regulation of these processes during transitions in heart rate is poorly understood. In isolated right ventricular muscle preparations from the rabbit, we investigated the beat-to-beat alterations in force and calcium during the transition from one stimulation frequency to another, using contractile assessments and confocal microscopy. We show that a change in steady-state conditions occurs in multiple phases: a rapid phase, which is characterized by a fast change in force production mirrored by a change in calcium transient amplitude, and a slow phase, which follows the rapid phase and occurs as the muscle proceeds to stabilize at the new frequency. This second/late phase is characterized by a quantitative dissociation between the calcium transient amplitude and developed force. Twitch timing kinetics, such as time to peak tension and 50% relaxation rate, reached steady-state well before force development and calcium transient amplitude. The dynamic relationship between force and calcium upon a switch in stimulation frequency unveils the dynamic involvement of myofilament-based properties in frequency-dependent activation.
Collapse
|
32
|
Biesiadecki BJ, Davis JP, Ziolo MT, Janssen PML. Tri-modal regulation of cardiac muscle relaxation; intracellular calcium decline, thin filament deactivation, and cross-bridge cycling kinetics. Biophys Rev 2014; 6:273-289. [PMID: 28510030 PMCID: PMC4255972 DOI: 10.1007/s12551-014-0143-5] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Accepted: 06/27/2014] [Indexed: 01/09/2023] Open
Abstract
Cardiac muscle relaxation is an essential step in the cardiac cycle. Even when the contraction of the heart is normal and forceful, a relaxation phase that is too slow will limit proper filling of the ventricles. Relaxation is too often thought of as a mere passive process that follows contraction. However, many decades of advancements in our understanding of cardiac muscle relaxation have shown it is a highly complex and well-regulated process. In this review, we will discuss three distinct events that can limit the rate of cardiac muscle relaxation: the rate of intracellular calcium decline, the rate of thin-filament de-activation, and the rate of cross-bridge cycling. Each of these processes are directly impacted by a plethora of molecular events. In addition, these three processes interact with each other, further complicating our understanding of relaxation. Each of these processes is continuously modulated by the need to couple bodily oxygen demand to cardiac output by the major cardiac physiological regulators. Length-dependent activation, frequency-dependent activation, and beta-adrenergic regulation all directly and indirectly modulate calcium decline, thin-filament deactivation, and cross-bridge kinetics. We hope to convey our conclusion that cardiac muscle relaxation is a process of intricate checks and balances, and should not be thought of as a single rate-limiting step that is regulated at a single protein level. Cardiac muscle relaxation is a system level property that requires fundamental integration of three governing systems: intracellular calcium decline, thin filament deactivation, and cross-bridge cycling kinetics.
Collapse
Affiliation(s)
- Brandon J Biesiadecki
- Department of Physiology and Cell Biology and Dorothy M. Davis Heart Lung Institute, College of Medicine, The Ohio State University, 304 Hamilton Hall, 1645 Neil Avenue, Columbus, OH, 43210-1218, USA
| | - Jonathan P Davis
- Department of Physiology and Cell Biology and Dorothy M. Davis Heart Lung Institute, College of Medicine, The Ohio State University, 304 Hamilton Hall, 1645 Neil Avenue, Columbus, OH, 43210-1218, USA
| | - Mark T Ziolo
- Department of Physiology and Cell Biology and Dorothy M. Davis Heart Lung Institute, College of Medicine, The Ohio State University, 304 Hamilton Hall, 1645 Neil Avenue, Columbus, OH, 43210-1218, USA
| | - Paul M L Janssen
- Department of Physiology and Cell Biology and Dorothy M. Davis Heart Lung Institute, College of Medicine, The Ohio State University, 304 Hamilton Hall, 1645 Neil Avenue, Columbus, OH, 43210-1218, USA.
| |
Collapse
|
33
|
Salhi HE, Walton SD, Hassel NC, Brundage EA, de Tombe PP, Janssen PML, Davis JP, Biesiadecki BJ. Cardiac troponin I tyrosine 26 phosphorylation decreases myofilament Ca2+ sensitivity and accelerates deactivation. J Mol Cell Cardiol 2014; 76:257-64. [PMID: 25252176 DOI: 10.1016/j.yjmcc.2014.09.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Revised: 09/09/2014] [Accepted: 09/12/2014] [Indexed: 10/24/2022]
Abstract
Troponin I (TnI), the inhibitory subunit of the troponin complex, can be phosphorylated as a key regulatory mechanism to alter the calcium regulation of contraction. Recent work has identified phosphorylation of TnI Tyr-26 in the human heart with unknown functional effects. We hypothesized that TnI Tyr-26N-terminal phosphorylation decreases calcium sensitivity of the thin filament, similar to the desensitizing effects of TnI Ser-23/24 phosphorylation. Our results demonstrate that Tyr-26 phosphorylation and pseudo-phosphorylation decrease calcium binding to troponin C (TnC) on the thin filament and calcium sensitivity of force development to a similar magnitude as TnI Ser-23/24 pseudo-phosphorylation. To investigate the effects of TnI Tyr-26 phosphorylation on myofilament deactivation, we measured the rate of calcium dissociation from TnC. Results demonstrate that filaments containing Tyr-26 pseudo-phosphorylated TnI accelerate the rate of calcium dissociation from TnC similar to that of TnI Ser-23/24. Finally, to assess functional integration of TnI Tyr-26 with Ser-23/24 phosphorylation, we generated recombinant TnI phospho-mimetic substitutions at all three residues. Our biochemical analyses demonstrated no additive effect on calcium sensitivity or calcium-sensitive force development imposed by Tyr-26 and Ser-23/24 phosphorylation integration. However, integration of Tyr-26 phosphorylation with pseudo-phosphorylated Ser-23/24 further accelerated thin filament deactivation. Our findings suggest that TnI Tyr-26 phosphorylation functions similarly to Ser-23/24N-terminal phosphorylation to decrease myofilament calcium sensitivity and accelerate myofilament relaxation. Furthermore, Tyr-26 phosphorylation can buffer the desensitization of Ser-23/24 phosphorylation while further accelerating thin filament deactivation. Therefore, the functional integration of TnI phosphorylation may be a common mechanism to modulate Ser-23/24 phosphorylation function.
Collapse
Affiliation(s)
- Hussam E Salhi
- The Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH 43210, USA; The Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
| | - Shane D Walton
- The Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH 43210, USA; The Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
| | - Nathan C Hassel
- The Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH 43210, USA; The Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
| | - Elizabeth A Brundage
- The Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH 43210, USA; The Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
| | - Pieter P de Tombe
- The Department of Cell and Molecular Physiology, Health Sciences Division, Loyola University Chicago, Maywood, IL 60153, USA
| | - Paul M L Janssen
- The Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH 43210, USA; The Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
| | - Jonathan P Davis
- The Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH 43210, USA; The Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
| | - Brandon J Biesiadecki
- The Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH 43210, USA; The Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA.
| |
Collapse
|
34
|
The art of the deal in myofilament modulation of function. J Mol Cell Cardiol 2014; 72:238-40. [PMID: 24732213 DOI: 10.1016/j.yjmcc.2014.04.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Revised: 04/02/2014] [Accepted: 04/03/2014] [Indexed: 10/25/2022]
|