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Skeletal and cardiac muscle calcium transport regulation in health and disease. Biosci Rep 2022; 42:232141. [PMID: 36413081 DOI: 10.1042/bsr20211997] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 11/04/2022] [Accepted: 11/22/2022] [Indexed: 11/23/2022] Open
Abstract
In healthy muscle, the rapid release of calcium ions (Ca2+) with excitation-contraction (E-C) coupling, results in elevations in Ca2+ concentrations which can exceed 10-fold that of resting values. The sizable transient changes in Ca2+ concentrations are necessary for the activation of signaling pathways, which rely on Ca2+ as a second messenger, including those involved with force generation, fiber type distribution and hypertrophy. However, prolonged elevations in intracellular Ca2+ can result in the unwanted activation of Ca2+ signaling pathways that cause muscle damage, dysfunction, and disease. Muscle employs several calcium handling and calcium transport proteins that function to rapidly return Ca2+ concentrations back to resting levels following contraction. This review will detail our current understanding of calcium handling during the decay phase of intracellular calcium transients in healthy skeletal and cardiac muscle. We will also discuss how impairments in Ca2+ transport can occur and how mishandling of Ca2+ can lead to the pathogenesis and/or progression of skeletal muscle myopathies and cardiomyopathies.
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2
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Heemstra LA, Koch LG, Britton SL, Novak CM. Altered skeletal muscle sarco-endoplasmic reticulum Ca 2+-ATPase calcium transport efficiency after a thermogenic stimulus. Am J Physiol Regul Integr Comp Physiol 2022; 323:R628-R637. [PMID: 36094445 PMCID: PMC9602703 DOI: 10.1152/ajpregu.00173.2022] [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: 06/30/2022] [Revised: 09/01/2022] [Accepted: 09/01/2022] [Indexed: 01/22/2023]
Abstract
Exposure to predator threat induces a rapid and robust increase in skeletal muscle thermogenesis in rats. The central nervous system relays threat information to skeletal muscle through activation of the sympathetic nervous system, but muscle mechanisms mediating this thermogenesis remain unidentified. Given the relevance of sarcolipin-mediated futile calcium cycling through the sarco-endoplasmic reticulum Ca2+-ATPase (SERCA) pump to mammalian muscle nonshivering thermogenesis, we hypothesized that this plays a role in contextually induced muscle thermogenesis as well. This was assessed by measuring enzymatic activity of SERCA and sarcoplasmic reticulum Ca2+ transport, where the apparent coupling ratio (Ca2+ uptake rate divided by ATPase activity rate at a standard Ca2+ concentration) was predicted to decrease in association with muscle thermogenesis. Sprague-Dawley rats exposed to predator (ferret) odor (PO) showed a rapid decrease in the apparent coupling ratio in the soleus muscle, indicating SERCA uncoupling compared with control-odor-exposed rats. A rat model of high aerobic fitness and elevated muscle thermogenesis also demonstrated soleus muscle SERCA uncoupling relative to their obesity-prone, low-fitness counterparts. Both the high- and low-aerobic fitness rats showed soleus SERCA uncoupling with exposure to PO. Finally, no increase in sarcolipin expression in soleus muscle was detected with PO exposure. This dataset implicates muscle uncoupling of SERCA Ca2+ transport and ATP hydrolysis, likely through altered SERCA or sarcolipin function outside of translational regulation, as one contributor to the muscle thermogenesis provoked by exposure to predator threat. These data support the involvement of SERCA uncoupling in both muscle thermogenic induction and enhanced aerobic capacity.
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Affiliation(s)
- Lydia A Heemstra
- Department of Biological Sciences, Kent State University, Kent, Ohio
| | - Lauren G Koch
- Department of Physiology and Pharmacology, The University of Toledo College of Medicine and Life Sciences, Toledo, Ohio
| | - Steven L Britton
- Department of Anesthesiology, University of Michigan, Ann Arbor, Michigan
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan
| | - Colleen M Novak
- Department of Biological Sciences, Kent State University, Kent, Ohio
- School of Biomedical Sciences, Kent State University, Kent, Ohio
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3
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Braun JL, Messner HN, Cleverdon REG, Baranowski RW, Hamstra SI, Geromella MS, Stuart JA, Fajardo VA. Heterozygous SOD2 deletion selectively impairs SERCA function in the soleus of female mice. Physiol Rep 2022; 10:e15285. [PMID: 35581738 PMCID: PMC9114654 DOI: 10.14814/phy2.15285] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 04/05/2022] [Accepted: 04/08/2022] [Indexed: 06/15/2023] Open
Abstract
The sarco(endo)plasmic reticulum Ca2+ ATPase (SERCA) restores intracellular Ca2+ ([Ca2+ ]i ) to resting levels after muscle contraction, ultimately eliciting relaxation. SERCA pumps are highly susceptible to tyrosine (T)-nitration, impairing their ability to take up Ca2+ resulting in reduced muscle function and increased [Ca2+ ]i and cellular damage. The mitochondrial antioxidant enzyme, superoxide dismutase 2 (SOD2), converts superoxide radicals into less reactive H2 O2 . Heterozygous deletion of SOD2 (Sod2+/- ) in mice increases mitochondrial oxidative stress; however, the consequences of reduced SOD2 expression in skeletal and cardiac muscle, specifically the effect on SERCA pumps, has yet to be investigated. We obtained soleus, extensor digitorum longus (EDL), and left ventricle (LV) muscles from 6 to 7 month-old wild-type (WT) and Sod2+/- female C57BL/6J mice. Ca2+ -dependent SERCA activity assays were performed to assess SERCA function. Western blotting was conducted to examine the protein content of SERCA, phospholamban, and sarcolipin; and immunoprecipitation experiments were done to assess SERCA2a- and SERCA1a-specific T-nitration. Heterozygous SOD2 deletion did not alter SERCA1a or SERCA2a expression in the soleus or LV but reduced SERCA2a in the EDL compared with WT, though this was not statistically significant. Soleus muscles from Sod2+/- mice showed a significant reduction in SERCA's apparent affinity for Ca2+ when compared to WT, corresponding with significantly elevated SERCA2a T-nitration in the soleus. No effect was seen in the EDL or the LV. This is the first study to investigate the effects of SOD2 deficiency on muscle SERCA function and shows that it selectively impairs SERCA function in the soleus.
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Affiliation(s)
- Jessica L. Braun
- Department of KinesiologyBrock UniversitySt. CatharinesOntarioCanada
- Centre for Bone and Muscle HealthBrock UniversitySt. CatharinesOntarioCanada
- Centre for NeuroscienceBrock UniversitySt. CatharinesOntarioCanada
| | - Holt N. Messner
- Department of KinesiologyBrock UniversitySt. CatharinesOntarioCanada
- Centre for Bone and Muscle HealthBrock UniversitySt. CatharinesOntarioCanada
- Department of Biological SciencesBrock UniversitySt. CatharinesOntarioCanada
| | - Riley E. G. Cleverdon
- Department of KinesiologyBrock UniversitySt. CatharinesOntarioCanada
- Centre for Bone and Muscle HealthBrock UniversitySt. CatharinesOntarioCanada
| | - Ryan W. Baranowski
- Department of KinesiologyBrock UniversitySt. CatharinesOntarioCanada
- Centre for Bone and Muscle HealthBrock UniversitySt. CatharinesOntarioCanada
| | - Sophie I. Hamstra
- Department of KinesiologyBrock UniversitySt. CatharinesOntarioCanada
- Centre for Bone and Muscle HealthBrock UniversitySt. CatharinesOntarioCanada
| | - Mia S. Geromella
- Department of KinesiologyBrock UniversitySt. CatharinesOntarioCanada
- Centre for Bone and Muscle HealthBrock UniversitySt. CatharinesOntarioCanada
| | - Jeffrey A. Stuart
- Department of Biological SciencesBrock UniversitySt. CatharinesOntarioCanada
| | - Val A. Fajardo
- Department of KinesiologyBrock UniversitySt. CatharinesOntarioCanada
- Centre for Bone and Muscle HealthBrock UniversitySt. CatharinesOntarioCanada
- Centre for NeuroscienceBrock UniversitySt. CatharinesOntarioCanada
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4
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Chambers PJ, Juracic ES, Fajardo VA, Tupling AR. The role of SERCA and sarcolipin in adaptive muscle remodeling. Am J Physiol Cell Physiol 2022; 322:C382-C394. [PMID: 35044855 DOI: 10.1152/ajpcell.00198.2021] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Sarcolipin (SLN) is a small integral membrane protein that regulates the sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA) pump. When bound to SERCA, SLN reduces the apparent Ca2+ affinity of SERCA and uncouples SERCA Ca2+ transport from its ATP consumption. As such, SLN plays a direct role in altering skeletal muscle relaxation and energy expenditure. Interestingly, the expression of SLN is dynamic during times of muscle adaptation, where large increases in SLN content are found in response to development, atrophy, overload and disease. Several groups have suggested that increases in SLN, especially in dystrophic muscle, are deleterious to muscle function and exacerbate already abhorrent intracellular Ca2+ levels. However, there is also significant evidence to show that increased SLN content is a beneficial adaptive mechanism which protects the SERCA pump and activates Ca2+ signaling and adaptive remodeling during times of cell stress. In this review, we first discuss the role for SLN in healthy muscle during both development and overload, where SLN has been shown to activate Ca2+ signaling to promote mitochondrial biogenesis, fibre type shifts and muscle hypertrophy. Then, with respect to muscle disease, we summarize the discrepancies in the literature as to whether SLN upregulation is adaptive or maladaptive in nature. This review is the first to offer the concept of SLN hormesis in muscle disease, wherein both too much and too little SLN are detrimental to muscle health. Finally, the underlying mechanisms which activate SLN upregulation are discussed, specifically acknowledging a potential positive feedback loop between SLN and Ca2+ signaling molecules.
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Affiliation(s)
- Paige J Chambers
- Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, Ontario, Canada
| | - Emma S Juracic
- Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, Ontario, Canada
| | - Val A Fajardo
- Department Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada.,Centre for Bone and Muscle Health, Brock University, St. Catharines, Ontario, Canada
| | - A Russell Tupling
- Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, Ontario, Canada
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5
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Characterizing SERCA Function in Murine Skeletal Muscles after 35-37 Days of Spaceflight. Int J Mol Sci 2021; 22:ijms222111764. [PMID: 34769190 PMCID: PMC8584217 DOI: 10.3390/ijms222111764] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 10/25/2021] [Accepted: 10/25/2021] [Indexed: 12/17/2022] Open
Abstract
It is well established that microgravity exposure causes significant muscle weakness and atrophy via muscle unloading. On Earth, muscle unloading leads to a disproportionate loss in muscle force and size with the loss in muscle force occurring at a faster rate. Although the exact mechanisms are unknown, a role for Ca2+ dysregulation has been suggested. The sarco(endo)plasmic reticulum Ca2+ ATPase (SERCA) pump actively brings cytosolic Ca2+ into the SR, eliciting muscle relaxation and maintaining low intracellular Ca2+ ([Ca2+]i). SERCA dysfunction contributes to elevations in [Ca2+]i, leading to cellular damage, and may contribute to the muscle weakness and atrophy observed with spaceflight. Here, we investigated SERCA function, SERCA regulatory protein content, and reactive oxygen/nitrogen species (RONS) protein adduction in murine skeletal muscle after 35–37 days of spaceflight. In male and female soleus muscles, spaceflight led to drastic impairments in Ca2+ uptake despite significant increases in SERCA1a protein content. We attribute this impairment to an increase in RONS production and elevated total protein tyrosine (T) nitration and cysteine (S) nitrosylation. Contrarily, in the tibialis anterior (TA), we observed an enhancement in Ca2+ uptake, which we attribute to a shift towards a faster muscle fiber type (i.e., increased myosin heavy chain IIb and SERCA1a) without elevated total protein T-nitration and S-nitrosylation. Thus, spaceflight affects SERCA function differently between the soleus and TA.
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6
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Bal NC, Gupta SC, Pant M, Sopariwala DH, Gonzalez-Escobedo G, Turner J, Gunn JS, Pierson CR, Harper SQ, Rafael-Fortney JA, Periasamy M. Is Upregulation of Sarcolipin Beneficial or Detrimental to Muscle Function? Front Physiol 2021; 12:633058. [PMID: 33732165 PMCID: PMC7956958 DOI: 10.3389/fphys.2021.633058] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 01/21/2021] [Indexed: 11/25/2022] Open
Abstract
Sarcolipin (SLN) is a regulator of sarco/endo plasmic reticulum Ca2+-ATPase (SERCA) pump and has been shown to be involved in muscle nonshivering thermogenesis (NST) and energy metabolism. Interestingly, SLN expression is significantly upregulated both during muscle development and in several disease states. However, the significance of altered SLN expression in muscle patho-physiology is not completely understood. We have previously shown that transgenic over-expression of SLN in skeletal muscle is not detrimental, and can promote oxidative metabolism and exercise capacity. In contrast, some studies have suggested that SLN upregulation in disease states is deleterious for muscle function and ablation of SLN can be beneficial. In this perspective article, we critically examine both published and some new data to determine the relevance of SLN expression to disease pathology. The new data presented in this paper show that SLN levels are induced in muscle during systemic bacterial (Salmonella) infection or lipopolysaccharides (LPS) treatment. We also present data showing that SLN expression is significantly upregulated in different types of muscular dystrophies including myotubular myopathy. These data taken together reveal that upregulation of SLN expression in muscle disease is progressive and increases with severity. Therefore, we suggest that increased SLN expression should not be viewed as the cause of the disease; rather, it is a compensatory response to meet the higher energy demand of the muscle. We interpret that higher SLN/SERCA ratio positively modulate cytosolic Ca2+ signaling pathways to promote mitochondrial biogenesis and oxidative metabolism to meet higher energy demand in muscle.
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Affiliation(s)
- Naresh C Bal
- School of Biotechnology, KIIT University, Bhubaneswar, India
| | - Subash C Gupta
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH, United States.,Department of Biochemistry, Institute of Science, Banaras Hindu University, Varanasi, India
| | - Meghna Pant
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH, United States
| | - Danesh H Sopariwala
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH, United States
| | - Geoffrey Gonzalez-Escobedo
- Departments of Microbiology and Microbial Infection and Immunity, The Ohio State University, Columbus, OH, United States
| | - Joanne Turner
- Departments of Microbiology and Microbial Infection and Immunity, The Ohio State University, Columbus, OH, United States.,Texas Biomedical Research Institute, San Antonio, TX, United States
| | - John S Gunn
- Departments of Microbiology and Microbial Infection and Immunity, The Ohio State University, Columbus, OH, United States.,Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, United States
| | - Christopher R Pierson
- Department of Pathology and Laboratory Medicine, Nationwide Children's Hospital, Columbus, OH, United States.,Department of Pathology, The Ohio State University, Columbus, OH, United States.,Department of Biomedical Education and Anatomy, The Ohio State University, Columbus, OH, United States
| | - Scott Q Harper
- Department of Laboratory Medicine, Nationwide Children's Hospital, Columbus, OH, United States
| | - Jill A Rafael-Fortney
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH, United States
| | - Muthu Periasamy
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH, United States.,Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, United States
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7
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Phospholamban and sarcolipin prevent thermal inactivation of sarco(endo)plasmic reticulum Ca2+-ATPases. Biochem J 2020; 477:4281-4294. [PMID: 33111944 DOI: 10.1042/bcj20200346] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 10/15/2020] [Accepted: 10/28/2020] [Indexed: 12/31/2022]
Abstract
Na+-K+-ATPase from mice lacking the γ subunit exhibits decreased thermal stability. Phospholamban (PLN) and sarcolipin (SLN) are small homologous proteins that regulate sarco(endo)plasmic reticulum Ca2+-ATPases (SERCAs) with properties similar to the γ subunit, through physical interactions with SERCAs. Here, we tested the hypothesis that PLN and SLN may protect against thermal inactivation of SERCAs. HEK-293 cells were co-transfected with different combinations of cDNAs encoding SERCA2a, PLN, a PLN mutant (N34A) that cannot bind to SERCA2a, and SLN. One-half of the cells were heat stressed at 40°C for 1 h (HS), and one-half were maintained at 37°C (CTL) before harvesting the cells and isolating microsomes. Compared with CTL, maximal SERCA activity was reduced by 25-35% following HS in cells that expressed either SERCA2a alone or SERCA2a and mutant PLN (N34A) whereas no change in maximal SERCA2a activity was observed in cells that co-expressed SERCA2a and either PLN or SLN following HS. Increases in SERCA2a carbonyl group content and nitrotyrosine levels that were detected following HS in cells that expressed SERCA2a alone were prevented in cells co-expressing SERCA2a with PLN or SLN, whereas co-expression of SERCA2a with mutant PLN (N34A) only prevented carbonyl group formation. In other experiments using knock-out mice, we found that thermal inactivation of SERCA was increased in cardiac left ventricle samples from Pln-null mice and in diaphragm samples from Sln-null mice, compared with WT littermates. Our results show that both PLN and SLN form a protective interaction with SERCA pumps during HS, preventing nitrosylation and oxidation of SERCA and thus preserving its maximal activity.
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8
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Effect of sarcolipin-mediated cell transdifferentiation in sarcopenia-associated skeletal muscle fibrosis. Exp Cell Res 2020; 389:111890. [PMID: 32035132 DOI: 10.1016/j.yexcr.2020.111890] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 02/02/2020] [Accepted: 02/04/2020] [Indexed: 02/06/2023]
Abstract
Fibrosis is a key pathological event during muscle aging that accelerates the development of sarcopenia. We show that sarcolipin (SLN) is highly expressed during aging, promotes intracellular calcium overload and participates in impaired myogenic differentiation. d-Galactose (D-gal) was used to induce senescence in C2C12 myoblasts. Conventional AAV-mediated SLN knockdown cells were used to study the role of SLN in muscle physiology and pathophysiology. C2C12 cells were treated with D-gal, which promoted fibrosis and SLN upregulation. The expression of TGF-β1 and α-SMA, which participate in myogenic transdifferentiation, were also elevated. C2C12 cells with reduced sarcolipin expression produced decreased amounts of collagen. Our study identified an unrecognized role of SLN in regulating myogenic transdifferentiation during aging-associated skeletal muscle cell fibrosis. Targeting SLN may be a novel therapeutic strategy to relieve sarcopenia-associated muscle fibrosis.
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9
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Moradi F, Copeland EN, Baranowski RW, Scholey AE, Stuart JA, Fajardo VA. Calmodulin-Binding Proteins in Muscle: A Minireview on Nuclear Receptor Interacting Protein, Neurogranin, and Growth-Associated Protein 43. Int J Mol Sci 2020; 21:E1016. [PMID: 32033037 PMCID: PMC7038096 DOI: 10.3390/ijms21031016] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 01/27/2020] [Accepted: 01/31/2020] [Indexed: 01/26/2023] Open
Abstract
Calmodulin (CaM) is an important Ca2+-sensing protein with numerous downstream targets that are either CaM-dependant or CaM-regulated. In muscle, CaM-dependent proteins, which are critical regulators of dynamic Ca2+ handling and contractility, include calcineurin (CaN), CaM-dependant kinase II (CaMKII), ryanodine receptor (RyR), and dihydropyridine receptor (DHPR). CaM-regulated targets include genes associated with oxidative metabolism, muscle plasticity, and repair. Despite its importance in muscle, the regulation of CaM-particularly its availability to bind to and activate downstream targets-is an emerging area of research. In this minireview, we discuss recent studies revealing the importance of small IQ motif proteins that bind to CaM to either facilitate (nuclear receptor interacting protein; NRIP) its activation of downstream targets, or sequester (neurogranin, Ng; and growth-associated protein 43, GAP43) CaM away from their downstream targets. Specifically, we discuss recent studies that have begun uncovering the physiological roles of NRIP, Ng, and GAP43 in skeletal and cardiac muscle, thereby highlighting the importance of endogenously expressed CaM-binding proteins and their regulation of CaM in muscle.
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Affiliation(s)
- Fereshteh Moradi
- Department of Biological Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada; (F.M.); (J.A.S.)
| | - Emily N. Copeland
- Centre for Neuroscience, Brock University, St. Catharines, ON L2S 3A1, Canada;
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON L2S 3A1, Canada;
| | - Ryan W. Baranowski
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON L2S 3A1, Canada;
- Department of Kinesiology, Brock University, St. Catharines, ON L2S 3A1, Canada;
| | - Aiden E. Scholey
- Department of Kinesiology, Brock University, St. Catharines, ON L2S 3A1, Canada;
| | - Jeffrey A. Stuart
- Department of Biological Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada; (F.M.); (J.A.S.)
| | - Val A. Fajardo
- Centre for Neuroscience, Brock University, St. Catharines, ON L2S 3A1, Canada;
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON L2S 3A1, Canada;
- Department of Kinesiology, Brock University, St. Catharines, ON L2S 3A1, Canada;
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10
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Wang W, Wang J, Lin W, Kao C, Hung M, Teng Y, Tsai T, Chi Y. Progerin in muscle leads to thermogenic and metabolic defects via impaired calcium homeostasis. Aging Cell 2020; 19:e13090. [PMID: 31833196 PMCID: PMC6996945 DOI: 10.1111/acel.13090] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 10/26/2019] [Accepted: 11/21/2019] [Indexed: 12/19/2022] Open
Abstract
Mutations in lamin A (LMNA) are responsible for a variety of human dystrophic and metabolic diseases. Here, we created a mouse model in which progerin, the lamin A mutant protein that causes Hutchinson–Gilford progeria syndrome (HGPS), can be inducibly overexpressed. Muscle‐specific overexpression of progerin was sufficient to induce muscular dystrophy and alter whole‐body energy expenditure, leading to premature death. Intriguingly, sarcolipin (Sln), an endoplasmic reticulum (ER)‐associated protein involved in heat production, is upregulated in progerin‐expressing and Lmna knockout (Lmna−/−) skeletal muscle. The depletion of Sln accelerated the early death of Lmna−/− mice. An examination at the molecular level revealed that progerin recruits Sln and Calnexin to the nuclear periphery. Furthermore, progerin‐expressing myoblasts presented enhanced store‐operated Ca2+ entry, as well as increased co‐localization of STIM1 and ORAI1. These findings suggest that progerin dysregulates calcium homeostasis through an interaction with a subset of ER‐associated proteins, resulting in thermogenic and metabolic abnormalities.
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Affiliation(s)
- Wan‐Ping Wang
- Institute of Biotechnology and Pharmaceutical Research National Health Research Institutes Zhunan Taiwan
| | - Jing‐Ya Wang
- Institute of Biotechnology and Pharmaceutical Research National Health Research Institutes Zhunan Taiwan
| | - Wen‐Hsin Lin
- Institute of Biotechnology and Pharmaceutical Research National Health Research Institutes Zhunan Taiwan
| | - Cheng‐Heng Kao
- Center of General Education Chang Gung University Taoyuan Taiwan
| | - Ming‐Chun Hung
- Institute of Biotechnology and Pharmaceutical Research National Health Research Institutes Zhunan Taiwan
| | - Yuan‐Chi Teng
- Department of Life Sciences and Institute of Genome Sciences National Yang‐Ming University Taipei Taiwan
| | - Ting‐Fen Tsai
- Institute of Biotechnology and Pharmaceutical Research National Health Research Institutes Zhunan Taiwan
- Department of Life Sciences and Institute of Genome Sciences National Yang‐Ming University Taipei Taiwan
| | - Ya‐Hui Chi
- Institute of Biotechnology and Pharmaceutical Research National Health Research Institutes Zhunan Taiwan
- Graduate Institute of Biomedical Sciences China Medical University Taichung Taiwan
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11
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Kurgan N, Whitley KC, Maddalena LA, Moradi F, Stoikos J, Hamstra SI, Rubie EA, Kumar M, Roy BD, Woodgett JR, Stuart JA, Fajardo VA. A Low-Therapeutic Dose of Lithium Inhibits GSK3 and Enhances Myoblast Fusion in C2C12 Cells. Cells 2019; 8:cells8111340. [PMID: 31671858 PMCID: PMC6912290 DOI: 10.3390/cells8111340] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 10/23/2019] [Accepted: 10/26/2019] [Indexed: 12/14/2022] Open
Abstract
Glycogen synthase kinase 3 (GSK3) slows myogenic differentiation and myoblast fusion partly by inhibiting the Wnt/β-catenin signaling pathway. Lithium, a common medication for bipolar disorder, inhibits GSK3 via Mg+ competition and increased Ser21 (GSK3α) or Ser9 (GSK3β) phosphorylation, leading to enhanced myoblast fusion and myogenic differentiation. However, previous studies demonstrating the effect of lithium on GSK3 have used concentrations up to 10 mM, which greatly exceeds concentrations measured in the serum of patients being treated for bipolar disorder (0.5–1.2 mM). Here, we determined whether a low-therapeutic (0.5 mM) dose of lithium could promote myoblast fusion and myogenic differentiation in C2C12 cells. C2C12 myotubes differentiated for three days in media containing 0.5 mM lithium chloride (LiCl) had significantly higher GSK3β (ser9) and GSK3α (ser21) phosphorylation compared with control myotubes differentiated in the same media without LiCl (+2–2.5 fold, p < 0.05), a result associated with an increase in total β-catenin. To further demonstrate that 0.5 mM LiCl inhibited GSK3 activity, we also developed a novel GSK3-specific activity assay. Using this enzyme-linked spectrophotometric assay, we showed that 0.5 mM LiCl-treated myotubes had significantly reduced GSK3 activity (−86%, p < 0.001). Correspondingly, 0.5 mM LiCl treated myotubes had a higher myoblast fusion index compared with control (p < 0.001) and significantly higher levels of markers of myogenesis (myogenin, +3-fold, p < 0.001) and myogenic differentiation (myosin heavy chain, +10-fold, p < 0.001). These results indicate that a low-therapeutic dose of LiCl is sufficient to promote myoblast fusion and myogenic differentiation in muscle cells, which has implications for the treatment of several myopathic conditions.
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Affiliation(s)
- Nigel Kurgan
- Department of Kinesiology, Brock University 1812 Sir Isaac Brock Way, St. Catharines, ON L2S 3A1, Canada; (N.K.); (K.C.W.); (J.S.); (S.I.H.); (B.D.R.)
- Centre for Bone and Muscle Health, Brock University 1812 Sir Isaac Brock Way, St. Catharines, ON L2S 3A1, Canada
| | - Kennedy C. Whitley
- Department of Kinesiology, Brock University 1812 Sir Isaac Brock Way, St. Catharines, ON L2S 3A1, Canada; (N.K.); (K.C.W.); (J.S.); (S.I.H.); (B.D.R.)
- Centre for Bone and Muscle Health, Brock University 1812 Sir Isaac Brock Way, St. Catharines, ON L2S 3A1, Canada
| | - Lucas A. Maddalena
- Department of Biological Sciences, Brock University 1812 Sir Isaac Brock Way, St. Catharines, ON L2S 3A1, Canada; (L.A.M.); (F.M.); (J.A.S.)
| | - Fereshteh Moradi
- Department of Biological Sciences, Brock University 1812 Sir Isaac Brock Way, St. Catharines, ON L2S 3A1, Canada; (L.A.M.); (F.M.); (J.A.S.)
| | - Joshua Stoikos
- Department of Kinesiology, Brock University 1812 Sir Isaac Brock Way, St. Catharines, ON L2S 3A1, Canada; (N.K.); (K.C.W.); (J.S.); (S.I.H.); (B.D.R.)
| | - Sophie I. Hamstra
- Department of Kinesiology, Brock University 1812 Sir Isaac Brock Way, St. Catharines, ON L2S 3A1, Canada; (N.K.); (K.C.W.); (J.S.); (S.I.H.); (B.D.R.)
- Centre for Bone and Muscle Health, Brock University 1812 Sir Isaac Brock Way, St. Catharines, ON L2S 3A1, Canada
| | - Elizabeth A. Rubie
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, 600 University Avenue, Toronto, ON M5G 1X5, Canada; (E.A.R.); (M.K.); (J.R.W.)
| | - Megha Kumar
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, 600 University Avenue, Toronto, ON M5G 1X5, Canada; (E.A.R.); (M.K.); (J.R.W.)
| | - Brian D. Roy
- Department of Kinesiology, Brock University 1812 Sir Isaac Brock Way, St. Catharines, ON L2S 3A1, Canada; (N.K.); (K.C.W.); (J.S.); (S.I.H.); (B.D.R.)
- Centre for Bone and Muscle Health, Brock University 1812 Sir Isaac Brock Way, St. Catharines, ON L2S 3A1, Canada
| | - James R. Woodgett
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, 600 University Avenue, Toronto, ON M5G 1X5, Canada; (E.A.R.); (M.K.); (J.R.W.)
| | - Jeffrey A. Stuart
- Department of Biological Sciences, Brock University 1812 Sir Isaac Brock Way, St. Catharines, ON L2S 3A1, Canada; (L.A.M.); (F.M.); (J.A.S.)
| | - Val A. Fajardo
- Department of Kinesiology, Brock University 1812 Sir Isaac Brock Way, St. Catharines, ON L2S 3A1, Canada; (N.K.); (K.C.W.); (J.S.); (S.I.H.); (B.D.R.)
- Centre for Bone and Muscle Health, Brock University 1812 Sir Isaac Brock Way, St. Catharines, ON L2S 3A1, Canada
- Correspondence:
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12
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Fajardo VA, Watson CJF, Bott KN, Moradi F, Maddalena LA, Bellissimo CA, Turner KD, Peters SJ, LeBlanc PJ, MacNeil AJ, Stuart JA, Tupling AR. Neurogranin is expressed in mammalian skeletal muscle and inhibits calcineurin signaling and myoblast fusion. Am J Physiol Cell Physiol 2019; 317:C1025-C1033. [PMID: 31433693 DOI: 10.1152/ajpcell.00345.2018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Calcineurin is a Ca2+/calmodulin (CaM)-dependent phosphatase that plays a critical role in promoting the slow fiber phenotype and myoblast fusion in skeletal muscle, thereby making calcineurin an attractive cellular target for enhancing fatigue resistance, muscle metabolism, and muscle repair. Neurogranin (Ng) is a CaM-binding protein thought to be expressed solely in brain and neurons, where it inhibits calcineurin signaling by sequestering CaM, thus lowering its cellular availability. Here, we demonstrate for the first time the expression of Ng protein and mRNA in mammalian skeletal muscle. Both protein and mRNA levels are greater in slow-oxidative compared with fast-glycolytic muscles. Coimmunoprecipitation of CaM with Ng in homogenates of C2C12 myotubes, mouse soleus, and human vastus lateralis suggests that these proteins physically interact. To determine whether Ng inhibits calcineurin signaling in muscle, we used Ng siRNA with C2C12 myotubes to reduce Ng protein levels by 60%. As a result of reduced Ng expression, C2C12 myotubes had enhanced CaM-calcineurin binding and calcineurin signaling as indicated by reduced phosphorylation of nuclear factor of activated T cells and increased utrophin mRNA. In addition, calcineurin signaling affects the expression of myogenin and stabilin-2, which are involved in myogenic differentiation and myoblast fusion, respectively. Here, we found that both myogenin and stabilin-2 were significantly elevated by Ng siRNA in C2C12 cells, concomitantly with an increased fusion index. Taken together, these results demonstrate the expression of Ng in mammalian skeletal muscle where it appears to be a novel regulator of calcineurin signaling.
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Affiliation(s)
- Val A Fajardo
- Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada.,Centre for Bone and Muscle Health, Brock University, St. Catharines, Ontario, Canada
| | - Colton J F Watson
- Department of Health Sciences, Brock University, St. Catharines, Ontario, Canada
| | - Kirsten N Bott
- Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada
| | - Fereshteh Moradi
- Department of Biological Sciences, Brock University, St. Catharines, Ontario, Canada
| | - Lucas A Maddalena
- Department of Biological Sciences, Brock University, St. Catharines, Ontario, Canada
| | | | - Kelli D Turner
- Department of Health Sciences, Brock University, St. Catharines, Ontario, Canada
| | - Sandra J Peters
- Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada.,Centre for Bone and Muscle Health, Brock University, St. Catharines, Ontario, Canada
| | - Paul J LeBlanc
- Department of Health Sciences, Brock University, St. Catharines, Ontario, Canada.,Centre for Bone and Muscle Health, Brock University, St. Catharines, Ontario, Canada
| | - Adam J MacNeil
- Department of Health Sciences, Brock University, St. Catharines, Ontario, Canada
| | - Jeffrey A Stuart
- Department of Biological Sciences, Brock University, St. Catharines, Ontario, Canada
| | - A Russell Tupling
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
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13
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Fajardo VA, Chambers PJ, Juracic ES, Rietze BA, Gamu D, Bellissimo C, Kwon F, Quadrilatero J, Russell Tupling A. Sarcolipin deletion in mdx mice impairs calcineurin signalling and worsens dystrophic pathology. Hum Mol Genet 2019; 27:4094-4102. [PMID: 30137316 DOI: 10.1093/hmg/ddy302] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 08/15/2018] [Indexed: 12/11/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is the most severe form of muscular dystrophy affecting 1 in 3500 live male births. Although there is no cure for DMD, therapeutic strategies aimed at enhancing calcineurin signalling and promoting the slow fibre phenotype have shown promise in mdx mice, which is the classical mouse model for DMD. Sarcolipin (SLN) is a small protein that regulates the sarco(endo)plasmic reticulum Ca2+-ATPase pump and its expression is highly upregulated in dystrophic skeletal muscle. We have recently shown that SLN in skeletal muscle amplifies calcineurin signalling thereby increasing myofibre size and the slow fibre phenotype. Therefore, in the present study we sought to determine the physiological impact of genetic Sln deletion in mdx mice, particularly on calcineurin signalling, fibre-type distribution and size and dystrophic pathology. We generated an mdx/Sln-null (mdx/SlnKO) mouse colony and hypothesized that the soleus and diaphragm muscles from these mice would display blunted calcineurin signalling, smaller myofibre sizes, an increased proportion of fast fibres and worsened dystrophic pathology compared with mdx mice. Our results show that calcineurin signalling was impaired in mdx/SlnKO mice as indicated by reductions in utrophin, stabilin-2 and calcineurin expression. In addition, mdx/SlnKO muscles contained smaller myofibres, exhibited a slow-to-fast fibre-type switch that corresponded with reduced expression of mitochondrial proteins and displayed a worsened dystrophic pathology compared with mdx muscles. Altogether, our findings demonstrate a critical role for SLN upregulation in dystrophic muscles and suggest that SLN can be viewed as a potential therapeutic target.
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Affiliation(s)
- Val A Fajardo
- Department of Kinesiology, University of Waterloo, Waterloo, ON N2L 3G1 Canada
| | - Paige J Chambers
- Department of Kinesiology, University of Waterloo, Waterloo, ON N2L 3G1 Canada
| | - Emma S Juracic
- Department of Kinesiology, University of Waterloo, Waterloo, ON N2L 3G1 Canada
| | - Bradley A Rietze
- Department of Kinesiology, University of Waterloo, Waterloo, ON N2L 3G1 Canada
| | - Daniel Gamu
- Department of Kinesiology, University of Waterloo, Waterloo, ON N2L 3G1 Canada
| | | | - Frenk Kwon
- Department of Kinesiology, University of Waterloo, Waterloo, ON N2L 3G1 Canada
| | - Joe Quadrilatero
- Department of Kinesiology, University of Waterloo, Waterloo, ON N2L 3G1 Canada
| | - A Russell Tupling
- Department of Kinesiology, University of Waterloo, Waterloo, ON N2L 3G1 Canada
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14
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Gamu D, Juracic ES, Fajardo VA, Rietze BA, Tran K, Bombardier E, Tupling AR. Phospholamban deficiency does not alter skeletal muscle SERCA pumping efficiency or predispose mice to diet-induced obesity. Am J Physiol Endocrinol Metab 2019; 316:E432-E442. [PMID: 30601702 DOI: 10.1152/ajpendo.00288.2018] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA) pump is a major contributor to skeletal muscle Ca2+ homeostasis and metabolic rate. SERCA activity can become adaptively uncoupled by its regulator sarcolipin (SLN) to increase the energy demand of Ca2+ pumping, preventing excessive obesity and glucose intolerance in mice. Several other SERCA regulators bear structural and functional resemblance to SLN, including phospholamban (PLN). Here, we sought to examine whether endogenous levels of skeletal muscle PLN control SERCA Ca2+ pumping efficiency and whole body metabolism. Using PLN-null mice ( Pln-/-), we found that soleus (SOL) muscle's SERCA pumping efficiency (measured as an apparent coupling ratio: Ca2+ uptake/ATP hydrolysis) was unaffected by PLN. Expression of Ca2+-handling proteins within the SOL, including SLN, were comparable between Pln-/- and wild-type (WT) littermates, as were fiber-type characteristics. Not surprisingly then, Pln-/- mice developed a similar degree of diet-induced obesity and glucose intolerance as WT controls when given a "Western" high-fat diet. Lack of an excessively obesogenic phenotype of Pln-/- could not be explained by compensation from skeletal muscle SLN or brown adipose tissue uncoupling protein-1 content. In agreement with several other reports, our study lends support to the notion that PLN serves a functionally distinct role from that of SLN in skeletal muscle physiology.
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Affiliation(s)
- Daniel Gamu
- Department of Kinesiology, University of Waterloo , Waterloo, Ontario , Canada
| | - Emma Sara Juracic
- Department of Kinesiology, University of Waterloo , Waterloo, Ontario , Canada
| | - Val A Fajardo
- Department of Kinesiology, University of Waterloo , Waterloo, Ontario , Canada
| | | | - Khanh Tran
- Department of Kinesiology, University of Waterloo , Waterloo, Ontario , Canada
| | - Eric Bombardier
- Department of Kinesiology, University of Waterloo , Waterloo, Ontario , Canada
| | - A Russell Tupling
- Department of Kinesiology, University of Waterloo , Waterloo, Ontario , Canada
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15
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Fajardo VA, Mikhaeil JS, Leveille CF, Tupling AR, LeBlanc PJ. Elevated whole muscle phosphatidylcholine: phosphatidylethanolamine ratio coincides with reduced SERCA activity in murine overloaded plantaris muscles. Lipids Health Dis 2018. [PMID: 29534725 PMCID: PMC5851149 DOI: 10.1186/s12944-018-0687-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND An increase in phosphatidylcholine:phosphatidylethanolamine (PC:PE) and a decrease in fatty acyl chain length, monounsaturated:polyunsaturated (MUFA:PUFA) fatty acyl ratio reduces SERCA activity in liposomes and in mouse models of obesity and muscular dystrophy. We have previously shown that maximal SERCA activity is significantly reduced in mechanically overloaded (OVL) plantaris, however, whether changes in PC:PE ratio or fatty acyl composition may contribute to the alterations in maximal SERCA activity remain unknown. Here, we tested the hypotheses that in OVL plantaris 1) PC:PE ratio would negatively correlate with maximal SERCA activity and 2) PC fatty acyl chain length (ACL) and/or MUFA:PUFA ratio would positively correlate with maximal SERCA activity. METHODS To overload plantaris in mice, we transected the soleus and gastrocnemius tendons from one leg, while the contralateral leg underwent a sham surgery. After two weeks, plantaris muscles were extracted, homogenized and processed for SERCA activity and lipid analyses. Specifically, we performed HPTLC densitometry to examine changes in PC, PE, and the ratio of PC:PE. We also performed gas chromatography to assess any potential changes to fatty acyl composition. RESULTS SERCA activity was significantly reduced in OVL plantaris compared with sham. Coinciding with this, we found a significant increase in PC but not PE in OVL plantaris. In turn, there was an increase in PC:PE but did not reach significance (p = 0.09). However, we found a significant negative correlation between PC:PE and maximal SERCA activity. Fatty acyl composition of PE remained similar between OLV and sham and PC demonstrated higher percent mole fraction of 17:1, 18:1, and ACL compared to sham. In addition, PC ACL, % MUFA, % PUFA, or MUFA:PUFA did not significantly correlate with maximal SERCA activity. CONCLUSIONS Our results indicate that the phospholipid headgroup PC:PE negatively correlated and could potentially contribute to reductions in SERCA activity seen in functionally overloaded plantaris. In contrast, fatty acyl chain (ACL, % MUFA, % PUFA, MUFA:PUFA) did not correlate with maximal SERCA activity. Future studies will determine whether altering PC:PE with genetic and dietary interventions can influence SERCA activity and ultimately change the physiological outcome in response to muscle overloading.
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Affiliation(s)
- Val A Fajardo
- Department of Health Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada.,Centre for Bone and Muscle Health, Faculty of Applied Health Sciences, Brock University, St. Catharines, ON, Canada
| | - John S Mikhaeil
- Department of Health Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada.,Centre for Bone and Muscle Health, Faculty of Applied Health Sciences, Brock University, St. Catharines, ON, Canada
| | - Cameron F Leveille
- Department of Health Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada.,Centre for Bone and Muscle Health, Faculty of Applied Health Sciences, Brock University, St. Catharines, ON, Canada
| | - A Russell Tupling
- Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada
| | - Paul J LeBlanc
- Department of Health Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada. .,Centre for Bone and Muscle Health, Faculty of Applied Health Sciences, Brock University, St. Catharines, ON, Canada.
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16
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Voit A, Patel V, Pachon R, Shah V, Bakhutma M, Kohlbrenner E, McArdle JJ, Dell'Italia LJ, Mendell JR, Xie LH, Hajjar RJ, Duan D, Fraidenraich D, Babu GJ. Reducing sarcolipin expression mitigates Duchenne muscular dystrophy and associated cardiomyopathy in mice. Nat Commun 2017; 8:1068. [PMID: 29051551 PMCID: PMC5648780 DOI: 10.1038/s41467-017-01146-7] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 08/22/2017] [Indexed: 01/16/2023] Open
Abstract
Sarcolipin (SLN) is an inhibitor of the sarco/endoplasmic reticulum (SR) Ca2+ ATPase (SERCA) and is abnormally elevated in the muscle of Duchenne muscular dystrophy (DMD) patients and animal models. Here we show that reducing SLN levels ameliorates dystrophic pathology in the severe dystrophin/utrophin double mutant (mdx:utr -/-) mouse model of DMD. Germline inactivation of one allele of the SLN gene normalizes SLN expression, restores SERCA function, mitigates skeletal muscle and cardiac pathology, improves muscle regeneration, and extends the lifespan. To translate our findings into a therapeutic strategy, we knock down SLN expression in 1-month old mdx:utr -/- mice via adeno-associated virus (AAV) 9-mediated RNA interference. The AAV treatment markedly reduces SLN expression, attenuates muscle pathology and improves diaphragm, skeletal muscle and cardiac function. Taken together, our findings suggest that SLN reduction is a promising therapeutic approach for DMD.
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Affiliation(s)
- Antanina Voit
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA
| | - Vishwendra Patel
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA
| | - Ronald Pachon
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA
| | - Vikas Shah
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA
| | - Mohammad Bakhutma
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA
| | - Erik Kohlbrenner
- Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Joseph J McArdle
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA
| | - Louis J Dell'Italia
- Department of Medicine, University of Alabama at Birmingham, and Birmingham VA Medical Center, Birmingham, AL, 35294, USA
| | - Jerry R Mendell
- Department of Pediatrics and Department of Neurology, Ohio State University Research Institute at Nationwide Children's Hospital, Columbus, OH, 43205, USA
| | - Lai-Hua Xie
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA
| | - Roger J Hajjar
- Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Dongsheng Duan
- Department of Molecular Microbiology and Immunology, Neurology, Bioengineering, Biomedical Sciences, The University of Missouri, Columbia, MO, 65212, USA
| | - Diego Fraidenraich
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA
| | - Gopal J Babu
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA.
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17
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Fajardo VA, Rietze BA, Chambers PJ, Bellissimo C, Bombardier E, Quadrilatero J, Tupling AR. Effects of sarcolipin deletion on skeletal muscle adaptive responses to functional overload and unload. Am J Physiol Cell Physiol 2017; 313:C154-C161. [PMID: 28592414 DOI: 10.1152/ajpcell.00291.2016] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 05/30/2017] [Accepted: 05/30/2017] [Indexed: 12/22/2022]
Abstract
Overexpression of sarcolipin (SLN), a regulator of sarco(endo)plasmic reticulum Ca2+-ATPases (SERCAs), stimulates calcineurin signaling to enhance skeletal muscle oxidative capacity. Some studies have shown that calcineurin may also control skeletal muscle mass and remodeling in response to functional overload and unload stimuli by increasing myofiber size and the proportion of slow fibers. To examine whether SLN might mediate these adaptive responses, we performed soleus and gastrocnemius tenotomy in wild-type (WT) and Sln-null (Sln-/-) mice and examined the overloaded plantaris and unloaded/tenotomized soleus muscles. In the WT overloaded plantaris, we observed ectopic expression of SLN, myofiber hypertrophy, increased fiber number, and a fast-to-slow fiber type shift, which were associated with increased calcineurin signaling (NFAT dephosphorylation and increased stabilin-2 protein content) and reduced SERCA activity. In the WT tenotomized soleus, we observed a 14-fold increase in SLN protein, myofiber atrophy, decreased fiber number, and a slow-to-fast fiber type shift, which were also associated with increased calcineurin signaling and reduced SERCA activity. Genetic deletion of Sln altered these physiological outcomes, with the overloaded plantaris myofibers failing to grow in size and number, and transition towards the slow fiber type, while the unloaded soleus muscles exhibited greater reductions in fiber size and number, and an accelerated slow-to-fast fiber type shift. In both the Sln-/- overloaded and unloaded muscles, these findings were associated with elevated SERCA activity and blunted calcineurin signaling. Thus, SLN plays an important role in adaptive muscle remodeling potentially through calcineurin stimulation, which could have important implications for other muscle diseases and conditions.
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Affiliation(s)
- Val A Fajardo
- Department of Kinesiology, University of Waterloo, Waterloo Ontario, Canada
| | - Bradley A Rietze
- Department of Kinesiology, University of Waterloo, Waterloo Ontario, Canada
| | - Paige J Chambers
- Department of Kinesiology, University of Waterloo, Waterloo Ontario, Canada
| | | | - Eric Bombardier
- Department of Kinesiology, University of Waterloo, Waterloo Ontario, Canada
| | - Joe Quadrilatero
- Department of Kinesiology, University of Waterloo, Waterloo Ontario, Canada
| | - A Russell Tupling
- Department of Kinesiology, University of Waterloo, Waterloo Ontario, Canada
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