1
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Jadiya P, Kolmetzky DW, Tomar D, Thomas M, Cohen HM, Khaledi S, Garbincius JF, Hildebrand AN, Elrod JW. Genetic ablation of neuronal mitochondrial calcium uptake halts Alzheimer's disease progression. bioRxiv 2023:2023.10.11.561889. [PMID: 37904949 PMCID: PMC10614731 DOI: 10.1101/2023.10.11.561889] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/01/2023]
Abstract
Alzheimer's disease (AD) is characterized by the extracellular deposition of amyloid beta, intracellular neurofibrillary tangles, synaptic dysfunction, and neuronal cell death. These phenotypes correlate with and are linked to elevated neuronal intracellular calcium ( i Ca 2+ ) levels. Recently, our group reported that mitochondrial calcium ( m Ca 2+ ) overload, due to loss of m Ca 2+ efflux capacity, contributes to AD development and progression. We also noted proteomic remodeling of the mitochondrial calcium uniporter channel (mtCU) in sporadic AD brain samples, suggestive of altered m Ca 2+ uptake in AD. Since the mtCU is the primary mechanism for Ca 2+ uptake into the mitochondrial matrix, inhibition of the mtCU has the potential to reduce or prevent m Ca 2+ overload in AD. Here, we report that neuronal-specific loss of mtCU-dependent m Ca 2+ uptake in the 3xTg-AD mouse model of AD reduced Aβ and tau-pathology, synaptic dysfunction, and cognitive decline. Knockdown of Mcu in a cellular model of AD significantly decreased matrix Ca 2+ content, oxidative stress, and cell death. These results suggest that inhibition of neuronal m Ca 2+ uptake is a novel therapeutic target to impede AD progression.
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2
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Garbincius JF, Salik O, Cohen HM, Choya-Foces C, Mangold AS, Makhoul AD, Schmidt AE, Khalil DY, Doolittle JJ, Wilkinson AS, Murray EK, Lazaropoulos MP, Hildebrand AN, Tomar D, Elrod JW. TMEM65 regulates NCLX-dependent mitochondrial calcium efflux. bioRxiv 2023:2023.10.06.561062. [PMID: 37873405 PMCID: PMC10592617 DOI: 10.1101/2023.10.06.561062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
The balance between mitochondrial calcium (mCa2+) uptake and efflux regulates ATP production, but if perturbed causes energy starvation or mCa2+ overload and cell death. The mitochondrial sodium-calcium exchanger, NCLX, is a critical route of mCa2+ efflux in excitable tissues, such as the heart and brain, and animal models support NCLX as a promising therapeutic target to limit pathogenic mCa2+ overload. However, the mechanisms that regulate NCLX activity remain largely unknown. We used proximity biotinylation proteomic screening to identify the NCLX interactome and define novel regulators of NCLX function. Here, we discover the mitochondrial inner membrane protein, TMEM65, as an NCLX-proximal protein that potently enhances sodium (Na+)-dependent mCa2+ efflux. Mechanistically, acute pharmacologic NCLX inhibition or genetic deletion of NCLX ablates the TMEM65-dependent increase in mCa2+ efflux. Further, loss-of-function studies show that TMEM65 is required for Na+-dependent mCa2+ efflux. Co-fractionation and in silico structural modeling of TMEM65 and NCLX suggest these two proteins exist in a common macromolecular complex in which TMEM65 directly stimulates NCLX function. In line with these findings, knockdown of Tmem65 in mice promotes mCa2+ overload in the heart and skeletal muscle and impairs both cardiac and neuromuscular function. We further demonstrate that TMEM65 deletion causes excessive mitochondrial permeability transition, whereas TMEM65 overexpression protects against necrotic cell death during cellular Ca2+ stress. Collectively, our results show that loss of TMEM65 function in excitable tissue disrupts NCLX-dependent mCa2+ efflux, causing pathogenic mCa2+ overload, cell death and organ-level dysfunction, and that gain of TMEM65 function mitigates these effects. These findings demonstrate the essential role of TMEM65 in regulating NCLX-dependent mCa2+ efflux and suggest modulation of TMEM65 as a novel strategy for the therapeutic control of mCa2+ homeostasis.
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Affiliation(s)
- Joanne F. Garbincius
- Aging + Cardiovascular Discovery Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Oniel Salik
- Aging + Cardiovascular Discovery Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Henry M. Cohen
- Aging + Cardiovascular Discovery Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Carmen Choya-Foces
- Aging + Cardiovascular Discovery Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
- Unidad de Investigación, Hospital Universitario Santa Cristina, Instituto de Investigación Sanitaria Princesa (IIS-IP), Madrid, Spain
| | - Adam S. Mangold
- Aging + Cardiovascular Discovery Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Angelina D. Makhoul
- Aging + Cardiovascular Discovery Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Anna E. Schmidt
- Aging + Cardiovascular Discovery Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Dima Y. Khalil
- Aging + Cardiovascular Discovery Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Joshua J. Doolittle
- Aging + Cardiovascular Discovery Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Anya S. Wilkinson
- Aging + Cardiovascular Discovery Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Emma K. Murray
- Aging + Cardiovascular Discovery Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Michael P. Lazaropoulos
- Aging + Cardiovascular Discovery Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Alycia N. Hildebrand
- Aging + Cardiovascular Discovery Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Dhanendra Tomar
- Aging + Cardiovascular Discovery Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
- Department of Internal Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - John W. Elrod
- Aging + Cardiovascular Discovery Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
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3
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Tomar D, Thomas M, Garbincius JF, Kolmetzky DW, Salik O, Jadiya P, Joseph SK, Carpenter AC, Hajnóczky G, Elrod JW. MICU1 regulates mitochondrial cristae structure and function independently of the mitochondrial Ca 2+ uniporter channel. Sci Signal 2023; 16:eabi8948. [PMID: 37098122 PMCID: PMC10388395 DOI: 10.1126/scisignal.abi8948] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 03/30/2023] [Indexed: 04/27/2023]
Abstract
MICU1 is a calcium (Ca2+)-binding protein that regulates the mitochondrial Ca2+ uniporter channel complex (mtCU) and mitochondrial Ca2+ uptake. MICU1 knockout mice display disorganized mitochondrial architecture, a phenotype that is distinct from that of mice with deficiencies in other mtCU subunits and, thus, is likely not explained by changes in mitochondrial matrix Ca2+ content. Using proteomic and cellular imaging techniques, we found that MICU1 localized to the mitochondrial contact site and cristae organizing system (MICOS) and directly interacted with the MICOS components MIC60 and CHCHD2 independently of the mtCU. We demonstrated that MICU1 was essential for MICOS complex formation and that MICU1 ablation resulted in altered cristae organization, mitochondrial ultrastructure, mitochondrial membrane dynamics, and cell death signaling. Together, our results suggest that MICU1 is an intermembrane space Ca2+ sensor that modulates mitochondrial membrane dynamics independently of matrix Ca2+ uptake. This system enables distinct Ca2+ signaling in the mitochondrial matrix and at the intermembrane space to modulate cellular energetics and cell death in a concerted manner.
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Affiliation(s)
- Dhanendra Tomar
- Cardiovascular Research Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140
| | - Manfred Thomas
- Cardiovascular Research Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140
| | - Joanne F. Garbincius
- Cardiovascular Research Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140
| | - Devin W. Kolmetzky
- Cardiovascular Research Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140
| | - Oniel Salik
- Cardiovascular Research Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140
- Health and Exercise Physiology, Ursinus College, Collegeville, PA 19426, USA
| | - Pooja Jadiya
- Cardiovascular Research Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140
| | - Suresh K. Joseph
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - April C. Carpenter
- Health and Exercise Physiology, Ursinus College, Collegeville, PA 19426, USA
| | - György Hajnóczky
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - John W. Elrod
- Cardiovascular Research Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140
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4
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Garbincius JF, Luongo TS, Lambert JP, Mangold AS, Murray EK, Hildebrand AN, Jadiya P, Elrod JW. MCU gain- and loss-of-function models define the duality of mitochondrial calcium uptake in heart failure. bioRxiv 2023:2023.04.17.537222. [PMID: 37131819 PMCID: PMC10153142 DOI: 10.1101/2023.04.17.537222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Background Mitochondrial calcium (mCa2+) uptake through the mitochondrial calcium uniporter channel (mtCU) stimulates metabolism to meet acute increases in cardiac energy demand. However, excessive mCa2+ uptake during stress, as in ischemia-reperfusion, initiates permeability transition and cell death. Despite these often-reported acute physiological and pathological effects, a major unresolved controversy is whether mtCU-dependent mCa2+ uptake and long-term elevation of cardiomyocyte mCa2+ contributes to the heart's adaptation during sustained increases in workload. Objective We tested the hypothesis that mtCU-dependent mCa2+ uptake contributes to cardiac adaptation and ventricular remodeling during sustained catecholaminergic stress. Methods Mice with tamoxifen-inducible, cardiomyocyte-specific gain (αMHC-MCM × flox-stop-MCU; MCU-Tg) or loss (αMHC-MCM × Mcufl/fl; Mcu-cKO) of mtCU function received 2-wk catecholamine infusion. Results Cardiac contractility increased after 2d of isoproterenol in control, but not Mcu-cKO mice. Contractility declined and cardiac hypertrophy increased after 1-2-wk of isoproterenol in MCU-Tg mice. MCU-Tg cardiomyocytes displayed increased sensitivity to Ca2+- and isoproterenol-induced necrosis. However, loss of the mitochondrial permeability transition pore (mPTP) regulator cyclophilin D failed to attenuate contractile dysfunction and hypertrophic remodeling, and increased isoproterenol-induced cardiomyocyte death in MCU-Tg mice. Conclusions mtCU mCa2+ uptake is required for early contractile responses to adrenergic signaling, even those occurring over several days. Under sustained adrenergic load excessive MCU-dependent mCa2+ uptake drives cardiomyocyte dropout, perhaps independent of classical mitochondrial permeability transition pore opening, and compromises contractile function. These findings suggest divergent consequences for acute versus sustained mCa2+ loading, and support distinct functional roles for the mPTP in settings of acute mCa2+ overload versus persistent mCa2+ stress.
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Affiliation(s)
- Joanne F. Garbincius
- Cardiovascular Research Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Timothy S. Luongo
- Cardiovascular Research Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Jonathan P. Lambert
- Cardiovascular Research Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Adam S. Mangold
- Cardiovascular Research Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Emma K. Murray
- Cardiovascular Research Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Alycia N. Hildebrand
- Cardiovascular Research Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Pooja Jadiya
- Cardiovascular Research Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
- Department of Internal Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - John W. Elrod
- Cardiovascular Research Center, Department of Cardiovascular Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
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5
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Murashige D, Jung JW, Neinast MD, Levin MG, Chu Q, Lambert JP, Garbincius JF, Kim B, Hoshino A, Marti-Pamies I, McDaid KS, Shewale SV, Flam E, Yang S, Roberts E, Li L, Morley MP, Bedi KC, Hyman MC, Frankel DS, Margulies KB, Assoian RK, Elrod JW, Jang C, Rabinowitz JD, Arany Z. Extra-cardiac BCAA catabolism lowers blood pressure and protects from heart failure. Cell Metab 2022; 34:1749-1764.e7. [PMID: 36223763 PMCID: PMC9633425 DOI: 10.1016/j.cmet.2022.09.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 06/09/2022] [Accepted: 09/12/2022] [Indexed: 01/24/2023]
Abstract
Pharmacologic activation of branched-chain amino acid (BCAA) catabolism is protective in models of heart failure (HF). How protection occurs remains unclear, although a causative block in cardiac BCAA oxidation is widely assumed. Here, we use in vivo isotope infusions to show that cardiac BCAA oxidation in fact increases, rather than decreases, in HF. Moreover, cardiac-specific activation of BCAA oxidation does not protect from HF even though systemic activation does. Lowering plasma and cardiac BCAAs also fails to confer significant protection, suggesting alternative mechanisms of protection. Surprisingly, activation of BCAA catabolism lowers blood pressure (BP), a known cardioprotective mechanism. BP lowering occurred independently of nitric oxide and reflected vascular resistance to adrenergic constriction. Mendelian randomization studies revealed that elevated plasma BCAAs portend higher BP in humans. Together, these data indicate that BCAA oxidation lowers vascular resistance, perhaps in part explaining cardioprotection in HF that is not mediated directly in cardiomyocytes.
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Affiliation(s)
- Danielle Murashige
- Division of Cardiovascular Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jae Woo Jung
- Division of Cardiovascular Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Michael D Neinast
- Division of Cardiovascular Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Ludwig Institute for Cancer Research, Princeton Branch, Princeton, NJ 08544, USA
| | - Michael G Levin
- Division of Cardiovascular Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Qingwei Chu
- Division of Cardiovascular Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jonathan P Lambert
- Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA
| | - Joanne F Garbincius
- Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA
| | - Boa Kim
- Division of Cardiovascular Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Atsushi Hoshino
- Division of Cardiovascular Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Cardiovascular Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Ingrid Marti-Pamies
- Division of Cardiovascular Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Kendra S McDaid
- Division of Cardiovascular Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Swapnil V Shewale
- Division of Cardiovascular Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Emily Flam
- Division of Cardiovascular Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Steven Yang
- Division of Cardiovascular Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Washington University School of Medicine, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Emilia Roberts
- Division of Cardiovascular Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Li Li
- Division of Cardiovascular Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Michael P Morley
- Division of Cardiovascular Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Kenneth C Bedi
- Division of Cardiovascular Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Matthew C Hyman
- Division of Cardiovascular Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - David S Frankel
- Division of Cardiovascular Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Kenneth B Margulies
- Division of Cardiovascular Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Richard K Assoian
- Division of Cardiovascular Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - John W Elrod
- Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA
| | - Cholsoon Jang
- Ludwig Institute for Cancer Research, Princeton Branch, Princeton, NJ 08544, USA; Department of Biological Chemistry, University of California, Irvine, Irvine, CA 92697, USA
| | - Joshua D Rabinowitz
- Ludwig Institute for Cancer Research, Princeton Branch, Princeton, NJ 08544, USA
| | - Zoltan Arany
- Division of Cardiovascular Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.
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6
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Garbincius JF, Luongo T, Lambert JP, Mangold AS, Kolmetzky D, Murray E, Hildebrand A, Jadiya P, Roy R, Nwokedi M, Ibetti J, Koch WJ, Elrod JW. Abstract P3053: Mitochondrial Calcium Accumulation Drives The Progression Of Non-ischemic Heart Failure: Integrated Lessons From Genetic Mouse Models. Circ Res 2022. [DOI: 10.1161/res.131.suppl_1.p3053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Acute mitochondrial calcium (
m
Ca
2+
) uptake stimulates bioenergetics to meet increased ATP demand, but when excessive predisposes to necrotic cell death. A major unresolved controversy is whether chronic alterations in cardiomyocyte
m
Ca
2+
homeostasis contribute to maladaptive remodeling and contractile dysfunction in non-ischemic heart disease. We hypothesized that cardiomyocyte
m
Ca
2+
accumulation drives cardiac maladaptation in response to stressors that chronically increase workload and cytosolic Ca
2+
cycling. We subjected mice with adult, cardiomyocyte-specific manipulation of
m
Ca
2+
uptake through the mitochondrial calcium uniporter (
Mcu
deletion,
Mcu
-cKO; MCU overexpression, MCU-Tg) or
m
Ca
2+
efflux through the mitochondrial sodium-calcium exchanger, NCLX (NCLX overexpression, NCLX-OE), to chronic pressure or neurohormonal overload. Fractional shortening failed to increase in
Mcu
-cKO mice over the first days of isoproterenol (Iso) infusion. Mortality was increased in
Mcu
-cKO mice over this period, and this effect was recapitulated in NCLX-OE mice infused with angiotensin II + phenylephrine (PE), although contractility did not decline in either case. Hypertrophic responses to chronic stress were attenuated in NCLX-OE but not
Mcu
-cKO hearts, and adenoviral NCLX expression limited mitochondrial metabolism, protein synthesis, and cell growth in neonatal rat cardiomyocytes treated with PE. These data indicate that
m
Ca
2+
accumulation is required for cardiac hypertrophy, but MCU is not. MCU-Tg hearts decompensated towards failure with 1-2 weeks of Iso. Although these hearts exhibited increased cardiomyocyte necrosis, deletion of the mPTP regulator cyclophilin D failed to rescue contractility, suggesting that
m
Ca
2+
overload causes cardiac failure, even independent of permeability transition. Fitting with this view, NCLX-OE attenuated the decline in contractile function that occurred with 12-week pressure overload. We conclude that despite initial adaptive effects, sustained
m
Ca
2+
elevation drives the progression of non-ischemic heart disease triggered by a chronic increase in cardiac workload. Our findings raise concern over proposed therapeutic strategies aiming to augment
m
Ca
2+
accumulation in heart failure.
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7
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Abstract
The uptake of calcium into and extrusion of calcium from the mitochondrial matrix is a fundamental biological process that has critical effects on cellular metabolism, signaling, and survival. Disruption of mitochondrial calcium (mCa2+) cycling is implicated in numerous acquired diseases such as heart failure, stroke, neurodegeneration, diabetes, and cancer, and is genetically linked to several inherited neuromuscular disorders. Understanding the mechanisms responsible for mCa2+ exchange therefore holds great promise for the treatment of these diseases. The past decade has seen the genetic identification of many of the key proteins that mediate mitochondrial calcium uptake and efflux. Here, we present an overview of the phenomenon of mCa2+ transport, and a comprehensive examination of the molecular machinery that mediates calcium flux across the inner mitochondrial membrane: the mitochondrial uniporter complex (consisting of MCU, EMRE, MICU1, MICU2, MICU3, MCUB, and MCUR1), NCLX, LETM1, the mitochondrial ryanodine receptor, and the mitochondrial permeability transition pore. We then consider the physiological implications of mCa2+ flux and evaluate how alterations in mCa2+ homeostasis contribute to human disease. This review concludes by highlighting opportunities and challenges for therapeutic intervention in pathologies characterized by aberrant mCa2+ handling and by summarizing critical unanswered questions regarding the biology of mCa2+ flux.
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Affiliation(s)
- Joanne F Garbincius
- Center for Translational Medicine, Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States
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8
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Gibb AA, Murray EK, Eaton DM, Huynh AT, Tomar D, Garbincius JF, Kolmetzky DW, Berretta RM, Wallner M, Houser SR, Elrod JW. Molecular Signature of HFpEF: Systems Biology in a Cardiac-Centric Large Animal Model. JACC Basic Transl Sci 2021; 6:650-672. [PMID: 34466752 PMCID: PMC8385567 DOI: 10.1016/j.jacbts.2021.07.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 07/11/2021] [Accepted: 07/11/2021] [Indexed: 12/30/2022]
Abstract
In this study the authors used systems biology to define progressive changes in metabolism and transcription in a large animal model of heart failure with preserved ejection fraction (HFpEF). Transcriptomic analysis of cardiac tissue, 1-month post-banding, revealed loss of electron transport chain components, and this was supported by changes in metabolism and mitochondrial function, altogether signifying alterations in oxidative metabolism. Established HFpEF, 4 months post-banding, resulted in changes in intermediary metabolism with normalized mitochondrial function. Mitochondrial dysfunction and energetic deficiencies were noted in skeletal muscle at early and late phases of disease, suggesting cardiac-derived signaling contributes to peripheral tissue maladaptation in HFpEF. Collectively, these results provide insights into the cellular biology underlying HFpEF progression.
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Key Words
- BCAA, branched chain amino acids
- DAG, diacylglycerol
- ECM, extracellular matrix
- EF, ejection fraction
- ESI, electrospray ionization
- ETC, electron transport chain
- FC, fold change
- FDR, false discovery rate
- GO, gene ontology
- HF, heart failure
- HFpEF, heart failure with preserved ejection fraction
- HFrEF, heart failure with reduced ejection fraction
- LA, left atrial
- LAV, left atrial volume
- LV, left ventricle/ventricular
- MS/MS, tandem mass spectrometry
- RCR, respiratory control ratio
- RI, retention index
- UPLC, ultraperformance liquid chromatography
- heart failure
- m/z, mass to charge ratio
- metabolomics
- mitochondria
- preserved ejection fraction
- systems biology
- transcriptomics
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Affiliation(s)
- Andrew A. Gibb
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania, USA
| | - Emma K. Murray
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania, USA
| | - Deborah M. Eaton
- Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania, USA
| | - Anh T. Huynh
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania, USA
| | - Dhanendra Tomar
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania, USA
| | - Joanne F. Garbincius
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania, USA
| | - Devin W. Kolmetzky
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania, USA
| | - Remus M. Berretta
- Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania, USA
| | - Markus Wallner
- Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania, USA
- Division of Cardiology, Medical University of Graz, Graz, Austria
- Center for Biomarker Research in Medicine, CBmed GmbH, Graz, Austria
| | - Steven R. Houser
- Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania, USA
| | - John W. Elrod
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania, USA
- Address for correspondence: Dr John W. Elrod, Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, 3500 N Broad Street, MERB 949, Philadelphia, Pennsylvania 19140, USA.
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9
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Jadiya P, Garbincius JF, Elrod JW. Reappraisal of metabolic dysfunction in neurodegeneration: Focus on mitochondrial function and calcium signaling. Acta Neuropathol Commun 2021; 9:124. [PMID: 34233766 PMCID: PMC8262011 DOI: 10.1186/s40478-021-01224-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 06/27/2021] [Indexed: 02/06/2023] Open
Abstract
The cellular and molecular mechanisms that drive neurodegeneration remain poorly defined. Recent clinical trial failures, difficult diagnosis, uncertain etiology, and lack of curative therapies prompted us to re-examine other hypotheses of neurodegenerative pathogenesis. Recent reports establish that mitochondrial and calcium dysregulation occur early in many neurodegenerative diseases (NDDs), including Alzheimer's disease, Parkinson's disease, Huntington's disease, and others. However, causal molecular evidence of mitochondrial and metabolic contributions to pathogenesis remains insufficient. Here we summarize the data supporting the hypothesis that mitochondrial and metabolic dysfunction result from diverse etiologies of neuropathology. We provide a current and comprehensive review of the literature and interpret that defective mitochondrial metabolism is upstream and primary to protein aggregation and other dogmatic hypotheses of NDDs. Finally, we identify gaps in knowledge and propose therapeutic modulation of mCa2+ exchange and mitochondrial function to alleviate metabolic impairments and treat NDDs.
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Affiliation(s)
- Pooja Jadiya
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, 3500 N Broad St, MERB 949, Philadelphia, PA, 19140, USA
| | - Joanne F Garbincius
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, 3500 N Broad St, MERB 949, Philadelphia, PA, 19140, USA
| | - John W Elrod
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, 3500 N Broad St, MERB 949, Philadelphia, PA, 19140, USA.
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10
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Affiliation(s)
- Joanne F. Garbincius
- Center for Translational Medicine, Lewis Katz School of
Medicine at Temple University, Philadelphia, PA 19140
| | - John W. Elrod
- Center for Translational Medicine, Lewis Katz School of
Medicine at Temple University, Philadelphia, PA 19140
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11
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Gross P, Johnson J, Romero CM, Eaton DM, Poulet C, Sanchez-Alonso J, Lucarelli C, Ross J, Gibb AA, Garbincius JF, Lambert J, Varol E, Yang Y, Wallner M, Feldsott EA, Kubo H, Berretta RM, Yu D, Rizzo V, Elrod J, Sabri A, Gorelik J, Chen X, Houser SR. Interaction of the Joining Region in Junctophilin-2 With the L-Type Ca 2+ Channel Is Pivotal for Cardiac Dyad Assembly and Intracellular Ca 2+ Dynamics. Circ Res 2021; 128:92-114. [PMID: 33092464 PMCID: PMC7790862 DOI: 10.1161/circresaha.119.315715] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
RATIONALE Ca2+-induced Ca2+ release (CICR) in normal hearts requires close approximation of L-type calcium channels (LTCCs) within the transverse tubules (T-tubules) and RyR (ryanodine receptors) within the junctional sarcoplasmic reticulum. CICR is disrupted in cardiac hypertrophy and heart failure, which is associated with loss of T-tubules and disruption of cardiac dyads. In these conditions, LTCCs are redistributed from the T-tubules to disrupt CICR. The molecular mechanism responsible for LTCCs recruitment to and from the T-tubules is not well known. JPH (junctophilin) 2 enables close association between T-tubules and the junctional sarcoplasmic reticulum to ensure efficient CICR. JPH2 has a so-called joining region that is located near domains that interact with T-tubular plasma membrane, where LTCCs are housed. The idea that this joining region directly interacts with LTCCs and contributes to LTCC recruitment to T-tubules is unknown. OBJECTIVE To determine if the joining region in JPH2 recruits LTCCs to T-tubules through direct molecular interaction in cardiomyocytes to enable efficient CICR. METHODS AND RESULTS Modified abundance of JPH2 and redistribution of LTCC were studied in left ventricular hypertrophy in vivo and in cultured adult feline and rat ventricular myocytes. Protein-protein interaction studies showed that the joining region in JPH2 interacts with LTCC-α1C subunit and causes LTCCs distribution to the dyads, where they colocalize with RyRs. A JPH2 with induced mutations in the joining region (mutPG1JPH2) caused T-tubule remodeling and dyad loss, showing that an interaction between LTCC and JPH2 is crucial for T-tubule stabilization. mutPG1JPH2 caused asynchronous Ca2+-release with impaired excitation-contraction coupling after β-adrenergic stimulation. The disturbed Ca2+ regulation in mutPG1JPH2 overexpressing myocytes caused calcium/calmodulin-dependent kinase II activation and altered myocyte bioenergetics. CONCLUSIONS The interaction between LTCC and the joining region in JPH2 facilitates dyad assembly and maintains normal CICR in cardiomyocytes.
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MESH Headings
- Animals
- Calcium/metabolism
- Calcium Channels, L-Type/genetics
- Calcium Channels, L-Type/metabolism
- Calcium Signaling
- Calcium-Calmodulin-Dependent Protein Kinase Type 2/metabolism
- Cats
- Cells, Cultured
- Disease Models, Animal
- Excitation Contraction Coupling
- Humans
- Hypertrophy, Left Ventricular/metabolism
- Hypertrophy, Left Ventricular/pathology
- Hypertrophy, Left Ventricular/physiopathology
- Kinetics
- Male
- Membrane Proteins/genetics
- Membrane Proteins/metabolism
- Mitochondria, Heart/metabolism
- Mitochondria, Heart/pathology
- Muscle Proteins/genetics
- Muscle Proteins/metabolism
- Mutation
- Myocytes, Cardiac/metabolism
- Myocytes, Cardiac/pathology
- Organelle Biogenesis
- Protein Binding
- Protein Interaction Domains and Motifs
- Rats, Sprague-Dawley
- Ryanodine Receptor Calcium Release Channel
- Rats
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Affiliation(s)
- Polina Gross
- Lewis Katz Temple University School of Medicine, Cardiovascular Research Center, Department of Physiology, Philadelphia
| | - Jaslyn Johnson
- Lewis Katz Temple University School of Medicine, Cardiovascular Research Center, Department of Physiology, Philadelphia
| | - Carlos M. Romero
- Lewis Katz Temple University School of Medicine, Cardiovascular Research Center, Department of Physiology, Philadelphia
| | - Deborah M. Eaton
- Lewis Katz Temple University School of Medicine, Cardiovascular Research Center, Department of Physiology, Philadelphia
| | - Claire Poulet
- Imperial College London, Department of Cardiovascular Sciences, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, London
| | - Jose Sanchez-Alonso
- Imperial College London, Department of Cardiovascular Sciences, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, London
| | - Carla Lucarelli
- Imperial College London, Department of Cardiovascular Sciences, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, London
| | - Jean Ross
- Bioimaging Center Research, Delaware Biotechnology Institute, Newark
| | - Andrew A. Gibb
- Lewis Katz Temple University School of Medicine, Center for Translational Medicine, Department of Pharmacology, Philadelphia
| | - Joanne F. Garbincius
- Lewis Katz Temple University School of Medicine, Center for Translational Medicine, Department of Pharmacology, Philadelphia
| | - Jonathan Lambert
- Lewis Katz Temple University School of Medicine, Center for Translational Medicine, Department of Pharmacology, Philadelphia
| | - Erdem Varol
- Columbia University, Center for Theoretical Neuroscience, Department of Statistics, New York, NY
| | - Yijun Yang
- Lewis Katz Temple University School of Medicine, Cardiovascular Research Center, Department of Physiology, Philadelphia
| | - Markus Wallner
- Lewis Katz Temple University School of Medicine, Cardiovascular Research Center, Department of Physiology, Philadelphia
- Medical University of Graz, Division of Cardiology, Graz, Austria
- Center for Biomarker Research in Medicine, CBmed GmbH, Graz, Austria
| | - Eric A. Feldsott
- Lewis Katz Temple University School of Medicine, Cardiovascular Research Center, Department of Physiology, Philadelphia
| | - Hajime Kubo
- Lewis Katz Temple University School of Medicine, Cardiovascular Research Center, Department of Physiology, Philadelphia
| | - Remus M. Berretta
- Lewis Katz Temple University School of Medicine, Cardiovascular Research Center, Department of Physiology, Philadelphia
| | - Daohai Yu
- Clinical Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia
| | - Victor Rizzo
- Lewis Katz Temple University School of Medicine, Cardiovascular Research Center, Department of Physiology, Philadelphia
| | - John Elrod
- Lewis Katz Temple University School of Medicine, Center for Translational Medicine, Department of Pharmacology, Philadelphia
| | - Abdelkarim Sabri
- Lewis Katz Temple University School of Medicine, Cardiovascular Research Center, Department of Physiology, Philadelphia
| | - Julia Gorelik
- Imperial College London, Department of Cardiovascular Sciences, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, London
| | - Xiongwen Chen
- Lewis Katz Temple University School of Medicine, Cardiovascular Research Center, Department of Physiology, Philadelphia
| | - Steven R. Houser
- Lewis Katz Temple University School of Medicine, Cardiovascular Research Center, Department of Physiology, Philadelphia
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12
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Garbincius JF, Merz LE, Cuttitta AJ, Bayne KV, Schrade S, Armstead EA, Converso-Baran KL, Whitesall SE, D'Alecy LG, Michele DE. Enhanced dimethylarginine degradation improves coronary flow reserve and exercise tolerance in Duchenne muscular dystrophy carrier mice. Am J Physiol Heart Circ Physiol 2020; 319:H582-H603. [PMID: 32762558 DOI: 10.1152/ajpheart.00333.2019] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Duchenne muscular dystrophy (DMD) is an X-linked disease caused by null mutations in dystrophin and characterized by muscle degeneration. Cardiomyopathy is common and often prevalent at similar frequency in female DMD carriers irrespective of whether they manifest skeletal muscle disease. Impaired muscle nitric oxide (NO) production in DMD disrupts muscle blood flow regulation and exaggerates postexercise fatigue. We show that circulating levels of endogenous methylated arginines including asymmetric dimethylarginine (ADMA), which act as NO synthase inhibitors, are elevated by acute necrotic muscle damage and in chronically necrotic dystrophin-deficient mice. We therefore hypothesized that excessive ADMA impairs muscle NO production and diminishes exercise tolerance in DMD. We used transgenic expression of dimethylarginine dimethylaminohydrolase 1 (DDAH), which degrades methylated arginines, to investigate their contribution to exercise-induced fatigue in DMD. Although infusion of exogenous ADMA was sufficient to impair exercise performance in wild-type mice, transgenic DDAH expression did not rescue exercise-induced fatigue in dystrophin-deficient male mdx mice. Surprisingly, DDAH transgene expression did attenuate exercise-induced fatigue in dystrophin-heterozygous female mdx carrier mice. Improved exercise tolerance was associated with reduced heart weight and improved cardiac β-adrenergic responsiveness in DDAH-transgenic mdx carriers. We conclude that DDAH overexpression increases exercise tolerance in female DMD carriers, possibly by limiting cardiac pathology and preserving the heart's responses to changes in physiological demand. Methylated arginine metabolism may be a new target to improve exercise tolerance and cardiac function in DMD carriers or act as an adjuvant to promote NO signaling alongside therapies that partially restore dystrophin expression in patients with DMD.NEW & NOTEWORTHY Duchenne muscular dystrophy (DMD) carriers are at risk for cardiomyopathy. The nitric oxide synthase inhibitor asymmetric dimethylarginine (ADMA) is released from damaged muscle in DMD and impairs exercise performance. Transgenic expression of dimethylarginine dimethylaminohydrolase to degrade ADMA prevents cardiac hypertrophy, improves cardiac function, and improves exercise tolerance in DMD carrier mice. These findings highlight the relevance of ADMA to muscular dystrophy and have important implications for therapies targeting nitric oxide in patients with DMD and DMD carriers.
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Affiliation(s)
- Joanne F Garbincius
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan
| | - Lauren E Merz
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan
| | - Ashley J Cuttitta
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan
| | - Kaitlynn V Bayne
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan
| | - Sara Schrade
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan
| | - Emily A Armstead
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan
| | | | - Steven E Whitesall
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan.,Physiology Phenotyping Core, University of Michigan, Ann Arbor, Michigan
| | - Louis G D'Alecy
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan.,Physiology Phenotyping Core, University of Michigan, Ann Arbor, Michigan
| | - Daniel E Michele
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan.,Physiology Phenotyping Core, University of Michigan, Ann Arbor, Michigan.,Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
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13
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Garbincius JF, Luongo TS, Lambert JP, Mangold AS, Murray EK, Hildebrand AN, Jadiya P, Elrod JW. Abstract 506: Enhanced Mitochondrial Calcium Uptake During Chronic β-adrenergic Stimulation Causes Maladaptive Remodeling and Impaired Left Ventricular Function Independent of Cyclophilin D-mediated Mitochondrial Permeability Transition. Circ Res 2020. [DOI: 10.1161/res.127.suppl_1.506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The mitochondrial calcium uniporter (MCU) forms the pore of the mitochondrial calcium uniporter channel (mtCU) and is required for rapid mitochondrial Ca
2+
(
m
Ca
2+
) uptake. MCU is necessary to increase cardiac energetics to fuel an increase in cardiac contractility during acute sympathetic stimulation. However, little is known about how MCU-dependent Ca
2+
flux may contribute to the heart’s adaptations to chronic stress. We therefore compared mice with adult cardiomyocyte (ACM)-specific loss (
Mcu
fl/fl
; Mcu-cKO) or gain (CAG-CAT-MCU; MCU-Tg) of MCU function to examine the role of MCU-dependent
m
Ca
2+
uptake in a model of chronic catecholamine overload.
In vitro
characterization of ACMs confirmed that MCU overexpression enhanced and
Mcu
deletion inhibited acute
m
Ca
2+
uptake. Neither loss nor gain of MCU function altered baseline contractile function
in vivo
. In αMHC-MCM control mice, fractional shortening was transiently increased after 2 days of isoproterenol infusion. This initial increase in contractility was attenuated in MCU-cKO mice. In contrast, MCU-Tg mice exhibited decreased fractional shortening at 7 and 14 days of isoproterenol infusion. This detrimental effect on contractile function was associated with increased LV dilation, HW/BW ratio, and lung edema. MCU-Tg cardiomyocytes
in vitro
exhibited increased ROS production and a trend towards increased cell death upon elevation of cytosolic Ca
2+
with ionomycin. These data prompted us to test the hypothesis that isoproterenol-induced contractile dysfunction in MCU-Tg hearts is caused by cardiomyocyte dropout due to
m
Ca
2+
overload and mitochondrial permeability transition. However, genetic deletion of the mPTP component cyclophilin D did not prevent the decline in contractile function, diminish cardiomyocyte death, or attenuate LV remodeling in MCU-Tg animals during chronic isoproterenol infusion. We conclude that although mtCU-dependent
m
Ca
2+
uptake is essential for early energetic adaptations to high adrenergic load, under conditions of chronic adrenergic stress it is maladaptive and predisposes to heart failure. Our data suggest that this maladaptive response occurs via mechanisms independent of cyclophilin D-mediated permeability transition.
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Affiliation(s)
| | | | | | - Adam S Mangold
- Lewis Katz Sch of Medicine at Temple Univ, Philadelphia, PA
| | - Emma K Murray
- Lewis Katz Sch of Medicine at Temple Univ, Philadelphia, PA
| | | | - Pooja Jadiya
- Lewis Katz Sch of Medicine at Temple Univ, Philadelphia, PA
| | - John W Elrod
- Lewis Katz Sch of Medicine at Temple Univ, Philadelphia, PA
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14
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Garbincius JF, Luongo TS, Elrod JW. The debate continues - What is the role of MCU and mitochondrial calcium uptake in the heart? J Mol Cell Cardiol 2020; 143:163-174. [PMID: 32353353 DOI: 10.1016/j.yjmcc.2020.04.029] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 04/15/2020] [Accepted: 04/24/2020] [Indexed: 12/12/2022]
Abstract
Since the identification of the mitochondrial calcium uniporter (MCU) in 2011, several studies utilizing genetic models have attempted to decipher the role of mitochondrial calcium uptake in cardiac physiology. Confounding results in various mutant mouse models have led to an ongoing debate regarding the function of MCU in the heart. In this review, we evaluate and discuss the totality of evidence for mitochondrial calcium uptake in the cardiac stress response and highlight recent reports that implicate MCU in the control of homeostatic cardiac metabolism and function. This review concludes with a discussion of current gaps in knowledge and remaining experiments to define how MCU contributes to contractile function, cell death, metabolic regulation, and heart failure progression.
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Affiliation(s)
- Joanne F Garbincius
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA.
| | - Timothy S Luongo
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA.
| | - John W Elrod
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA.
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15
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Tomar D, Garbincius JF, Kolmetzky D, Thomas M, Jadiya P, Elrod JW. Abstract 101: Identification of Novel MICU1 Interactors Independent of the mtCU Complex. Circ Res 2019. [DOI: 10.1161/res.125.suppl_1.101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
MICU1 is an EF-hand containing mitochondrial protein that gates the mitochondrial Ca
2+
uniporter complex (mtCU) and directly interacts with the pore-forming subunit MCU. Previous studies have shown perinatal lethality and altered mitochondrial architecture in MICU1 knockout (
Micu1
-/-
) mice, phenotypes that are distinct from other knockout models of mtCU components, such as MCU, and thus are likely not explained solely by changes in matrix [Ca
2+
] uptake. Further, our proteomic studies suggest that MICU1 exists in mitochondrial complexes void of MCU. This suggests that MICU1 may have cellular functions independent of mtCU regulation. To discern novel MICU1 molecular interactors we employed a biotinylation-based proteomic approach in
Mcu
-/-
and
Micu1
-/-
cells to detect proteins interacting with MICU1 using fusion protein containing BioID2, a small biotin ligase for proximity-dependent labeling. Expression of MICU1-BioID2 in
Mcu
-/-
cells allowed the identification of mtCU-independent interactors. Fast protein liquid chromatography (FPLC), blue native-PAGE, co-immunoprecipitation, live-cell Ca
2+
imaging, confocal and super-resolution imaging methods were used to confirm novel roles for MICU1 in mitochondrial biology. LC-MS analysis of biotinylated proteins after avidin-based purification identified the Mitochondrial Contact Site and Cristae Organizing System (MICOS) components IMMT, CHCHD2, and CHCHD3 as interacting with MICU1 (MICU1-BioD2 expressed in Micu1
-/-
cells to avoid aberrant expression). These same MICOS components were identified in MCU
-/-
cells, suggesting that MICU1 could be involved in the regulation of MICOS independent of the mtCU. Further, the deletion of CHCHD2 resulted in the loss of MICOS and cristae disorganization without any observable effect on
m
Ca
2+
uptake. RNA sequencing revealed correlative expression changes in MICU1 and MICOS components in response to heart failure progression during transverse aortic constriction and myocardial infarction. These results suggest MICU1 likely serves cellular functions independent of the mtCU and may serve as a key regulator of Ca
2+
-dependent signaling (EF-hands) in other cellular processes that are dysregulated during heart failure.
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16
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Garbincius JF, Luongo TS, Kolmetzky DW, Hildebrand AN, Elrod JW. Abstract 851: NCLX Expression Attenuates Pathological Remodeling in Experimental Cardiac Hypertrophy and Non-ischemic Heart Failure. Circ Res 2019. [DOI: 10.1161/res.125.suppl_1.851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Mitochondrial calcium (
m
Ca
2+
) uptake couples acute changes in cardiomyocyte bioenergetic demand to ATP production, but in excess triggers mitochondrial permeability transition and cardiomyocyte necrosis, as occurs during cardiac injury. Despite established roles for
m
Ca
2+
flux in response to acute stress, the role of
m
Ca
2+
signaling in chronic stress is poorly defined. As
m
Ca
2+
regulates the TCA cycle with the potential to affect mitochondrial signaling and/or metabolite pools required for biosynthesis, we reasoned that altered
m
Ca
2+
homeostasis may be an essential mechanism underlying hypertrophic growth and remodeling of the myocardium. Here, we used mice with cardiac-specific overexpression (OE) of the mitochondrial Na
+
/Ca
2+
exchanger (NCLX), the primary mediator of
m
Ca
2+
efflux in the heart, to test the hypothesis that
m
Ca
2+
signaling contributes to cardiac remodeling during sustained hemodynamic stress. We subjected NCLX OE (TRE-NCLX x α-MHC-tTA) and control (αMHC-tTA) mice to 12-wk transverse aortic constriction (TAC) or 4-wk infusion with angiotensin II + phenylephrine (AngII/PE) as experimental models of cardiac hypertrophy and non-ischemic heart failure. Cardiac function of NCLX OE and control mice was monitored throughout these studies via echocardiography and remodeling was assessed via tissue gravimetrics, histology, and qPCR gene expression analysis. Cardiac NCLX OE preserved ejection fraction, prevented afterload-induced hypertrophy and fibrosis, and attenuated the induction of both hypertrophic (
Nppa
,
Nppb
,
Acta1
) and fibrotic (
Postn1
,
Spp1
) gene programs in mice subjected to 12-wk TAC. Examination at 2-wk post-TAC revealed attenuated hypertrophy and blunted hypertrophic and fibrotic gene expression in NCLX OE mice. These data indicate that increased capacity for
m
Ca
2+
efflux mitigates TAC-induced remodeling, prior to the development of contractile dysfunction. NCLX OE similarly attenuated atrial hypertrophy and the induction of hypertrophic and fibrotic gene programs in mice infused with AngII/PE. Together, these findings support a critical role for
m
Ca
2+
in driving pathological remodeling in non-ischemic heart disease and point to NCLX as a potent therapeutic target for cardiovascular disease.
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Affiliation(s)
| | | | | | | | - John W Elrod
- Lewis Katz Sch of Medicine at Temple Univ, Philadelphia, PA
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17
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Affiliation(s)
- David Y Barefield
- 1 Center for Genetic Medicine Feinberg School of Medicine Northwestern University Chicago IL
| | - Joanne F Garbincius
- 2 Center for Translational Medicine Department of Pharmacology Lewis Katz School of Medicine Temple University Philadelphia PA
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18
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Garbincius JF, Luongo TS, Lambert JP, Elrod JW. Abstract 277: Enhanced Mitochondrial Calcium Uptake Promotes Deleterious Remodeling and Impaired Left Ventricular Function During Chronic Adrenergic Stimulation. Circ Res 2018. [DOI: 10.1161/res.123.suppl_1.277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The mitochondrial calcium uniporter (MCU) constitutes the pore-forming unit of the mitochondrial calcium uniporter channel (mtCU) and is necessary for mitochondrial Ca
2+
(
m
Ca
2+
) uptake. We previously reported that MCU is required to increase cardiac energetics and contractility in response to acute β-adrenergic stimulation. However, deletion of MCU has no detrimental effect on basal cardiac function or metabolism. While these findings support a role for MCU-dependent Ca
2+
flux in functional adaptations to acute stress, little is known about the involvement of MCU in cardiac responses to sustained stress. We compared mice with adult, cardiomyocyte (ACM)-specific loss (
Mcu
fl/fl
;
Mcu
-cKO) or gain (CAG-CAG-MCU; MCU-Tg) of MCU function to explore the role of
m
Ca
2+
uptake in a model of chronic catecholamine overload. Biophysical characterization confirmed that MCU overexpression enhanced and MCU deletion inhibited ACM
m
Ca
2+
uptake. Neither loss nor gain of MCU had a significant impact on baseline contractile function. In αMHC-MCM control mice, fractional shortening was transiently increased after 2 days of isoproterenol infusion (Fig 1). This early increase in contractility was attenuated in
Mcu
-cKO mice. MCU-Tg mice exhibited decreased fractional shortening at 7 and 14 days of isoproterenol infusion. This detrimental effect on LV function was associated with increased LV dilation, HW/BW ratio, and lung edema as compared to αMHC-MCM controls. These data suggest that although mtCU-dependent
m
Ca
2+
uptake is essential for early energetic adaptations to high adrenergic load, under conditions of chronic adrenergic stress it is maladaptive and predisposes to heart failure.
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Affiliation(s)
| | | | | | - John W Elrod
- Lewis Katz Sch of Medicine at Temple Univ, Philadelphia, PA
| |
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19
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Garbincius JF, Merz LE, Cuttita AJ, Bayne KV, Schrade S, Armstead EA, Converso-Baran KL, Whitesall SE, D’Alecy LG, Michele DE. Abstract 415: Transgenic Expression of Dimethylarginine Dimethylaminohydrolase Attenuates Exercise-induced Fatigue in Duchenne Muscular Dystrophy Carrier Mice. Circ Res 2017. [DOI: 10.1161/res.121.suppl_1.415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Duchenne muscular dystrophy (DMD) is an X-linked disease caused by mutations in dystrophin and characterized by muscle degeneration, cardiomyopathy, and impaired muscle nitric oxide (NO) production that disrupts muscle blood flow regulation and leads to excessive post-exercise fatigue. Interestingly, circulating levels of the endogenous NO synthase inhibitor asymmetric dimethylarginine (ADMA) are elevated in dystrophin-deficient subjects. Therefore, we hypothesized that excessive circulating ADMA impairs muscle NO production and thus negatively impacts exercise tolerance in DMD. The objectives of this study were to determine whether increased circulating ADMA is itself sufficient to affect exercise performance, and whether transgenic modulation of ADMA metabolism could improve exercise-induced fatigue in the
mdx
mouse model of DMD. Although infusion of exogenous ADMA did impair exercise performance in healthy, wild-type mice, transgenic expression of dimethylarginine dimethylaminohydrolase 1 (DDAH), the enzyme that degrades ADMA, did not affect exercise-induced fatigue in dystrophin-deficient male
mdx
mice. Surprisingly, DDAH transgene expression did attenuate exercise-induced fatigue in dystrophin-heterozygous female
mdx
carrier mice. This improvement in exercise tolerance was associated with reduced heart weight, improved cardiac contractile function, and improved chronotropic responsiveness to beta-adrenergic stimulation in DDAH-transgenic female
mdx
carriers. In contrast, DDAH transgene expression did not significantly affect skeletal muscle pathology in female
mdx
carriers. We conclude that DDAH transgene expression improves exercise tolerance in dystrophin-heterozygous females, possibly by limiting pathological cardiac remodeling and helping to maintain heart performance. These findings emphasize the importance of methylated arginines to the development of cardiomyopathy in female DMD carriers, and have interesting implications for current genetic therapies that may only partially restore dystrophin expression in the hearts of male DMD patients.
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20
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Garbincius JF, Michele DE. Dystrophin-glycoprotein complex regulates muscle nitric oxide production through mechanoregulation of AMPK signaling. Proc Natl Acad Sci U S A 2015. [PMID: 26483453 DOI: 10.1073./pnas.1512991112] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Patients deficient in dystrophin, a protein that links the cytoskeleton to the extracellular matrix via the dystrophin-glycoprotein complex (DGC), exhibit muscular dystrophy, cardiomyopathy, and impaired muscle nitric oxide (NO) production. We used live-cell NO imaging and in vitro cyclic stretch of isolated adult mouse cardiomyocytes as a model system to investigate if and how the DGC directly regulates the mechanical activation of muscle NO signaling. Acute activation of NO synthesis by mechanical stretch was impaired in dystrophin-deficient mdx cardiomyocytes, accompanied by loss of stretch-induced neuronal NO synthase (nNOS) S1412 phosphorylation. Intriguingly, stretch induced the acute activation of AMP-activated protein kinase (AMPK) in normal cardiomyocytes but not in mdx cardiomyocytes, and specific inhibition of AMPK was sufficient to attenuate mechanoactivation of NO production. Therefore, we tested whether direct pharmacologic activation of AMPK could bypass defective mechanical signaling to restore nNOS activity in dystrophin-deficient cardiomyocytes. Indeed, activation of AMPK with 5-aminoimidazole-4-carboxamide riboside or salicylate increased nNOS S1412 phosphorylation and was sufficient to enhance NO production in mdx cardiomyocytes. We conclude that the DGC promotes the mechanical activation of cardiac nNOS by acting as a mechanosensor to regulate AMPK activity, and that pharmacologic AMPK activation may be a suitable therapeutic strategy for restoring nNOS activity in dystrophin-deficient hearts and muscle.
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Affiliation(s)
- Joanne F Garbincius
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109
| | - Daniel E Michele
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109; Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109
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