1
|
Škop V, Liu N, Xiao C, Stinson E, Chen KY, Hall KD, Piaggi P, Gavrilova O, Reitman ML. Beyond day and night: The importance of ultradian rhythms in mouse physiology. Mol Metab 2024; 84:101946. [PMID: 38657735 PMCID: PMC11070603 DOI: 10.1016/j.molmet.2024.101946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 04/11/2024] [Accepted: 04/18/2024] [Indexed: 04/26/2024] Open
Abstract
Our circadian world shapes much of metabolic physiology. In mice ∼40% of the light and ∼80% of the dark phase time is characterized by bouts of increased energy expenditure (EE). These ultradian bouts have a higher body temperature (Tb) and thermal conductance and contain virtually all of the physical activity and awake time. Bout status is a better classifier of mouse physiology than photoperiod, with ultradian bouts superimposed on top of the circadian light/dark cycle. We suggest that the primary driver of ultradian bouts is a brain-initiated transition to a higher defended Tb of the active/awake state. Increased energy expenditure from brown adipose tissue, physical activity, and cardiac work combine to raise Tb from the lower defended Tb of the resting/sleeping state. Thus, unlike humans, much of mouse metabolic physiology is episodic with large ultradian increases in EE and Tb that correlate with the active/awake state and are poorly aligned with circadian cycling.
Collapse
Affiliation(s)
- Vojtěch Škop
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD 20892, USA; Centre for Experimental Medicine, Institute for Clinical and Experimental Medicine, Prague, Czech Republic; Department of Biochemistry and Microbiology, University of Chemistry and Technology, Prague, Czech Republic.
| | - Naili Liu
- Mouse Metabolism Core, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD 20892, USA
| | - Cuiying Xiao
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD 20892, USA
| | - Emma Stinson
- Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Phoenix, AZ 85016, USA
| | - Kong Y Chen
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD 20892, USA
| | - Kevin D Hall
- Laboratory of Biological Modeling, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD 20892, USA
| | - Paolo Piaggi
- Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Phoenix, AZ 85016, USA; Department of Information Engineering, University of Pisa, Pisa 56122, Italy
| | - Oksana Gavrilova
- Mouse Metabolism Core, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD 20892, USA
| | - Marc L Reitman
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD 20892, USA.
| |
Collapse
|
2
|
Mareedu S, Fefelova N, Galindo CL, Prakash G, Mukai R, Sadoshima J, Xie LH, Babu GJ. Improved mitochondrial function in the hearts of sarcolipin-deficient dystrophin and utrophin double-knockout mice. JCI Insight 2024; 9:e170185. [PMID: 38564291 PMCID: PMC11141945 DOI: 10.1172/jci.insight.170185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 03/21/2024] [Indexed: 04/04/2024] Open
Abstract
Duchenne muscular dystrophy (DMD) is a progressive muscle-wasting disease associated with cardiomyopathy. DMD cardiomyopathy is characterized by abnormal intracellular Ca2+ homeostasis and mitochondrial dysfunction. We used dystrophin and utrophin double-knockout (mdx:utrn-/-) mice in a sarcolipin (SLN) heterozygous-knockout (sln+/-) background to examine the effect of SLN reduction on mitochondrial function in the dystrophic myocardium. Germline reduction of SLN expression in mdx:utrn-/- mice improved cardiac sarco/endoplasmic reticulum (SR) Ca2+ cycling, reduced cardiac fibrosis, and improved cardiac function. At the cellular level, reducing SLN expression prevented mitochondrial Ca2+ overload, reduced mitochondrial membrane potential loss, and improved mitochondrial function. Transmission electron microscopy of myocardial tissues and proteomic analysis of mitochondria-associated membranes showed that reducing SLN expression improved mitochondrial structure and SR-mitochondria interactions in dystrophic cardiomyocytes. These findings indicate that SLN upregulation plays a substantial role in the pathogenesis of cardiomyopathy and that reducing SLN expression has clinical implications in the treatment of DMD cardiomyopathy.
Collapse
MESH Headings
- Animals
- Male
- Mice
- Calcium/metabolism
- Cardiomyopathies/metabolism
- Cardiomyopathies/genetics
- Cardiomyopathies/pathology
- Disease Models, Animal
- Dystrophin/genetics
- Dystrophin/metabolism
- Mice, Inbred mdx
- Mice, Knockout
- Mitochondria, Heart/metabolism
- Mitochondria, Heart/ultrastructure
- Mitochondria, Heart/genetics
- Muscle Proteins/metabolism
- Muscle Proteins/genetics
- Muscular Dystrophy, Duchenne/genetics
- Muscular Dystrophy, Duchenne/metabolism
- Muscular Dystrophy, Duchenne/pathology
- Myocardium/metabolism
- Myocardium/pathology
- Myocytes, Cardiac/metabolism
- Myocytes, Cardiac/pathology
- Proteolipids/metabolism
- Proteolipids/genetics
- Utrophin/genetics
- Utrophin/metabolism
Collapse
Affiliation(s)
- Satvik Mareedu
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers University, Newark, New Jersey, USA
| | - Nadezhda Fefelova
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers University, Newark, New Jersey, USA
| | - Cristi L. Galindo
- Vascular Medicine Institute and Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Goutham Prakash
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers University, Newark, New Jersey, USA
| | - Risa Mukai
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers University, Newark, New Jersey, USA
| | - Junichi Sadoshima
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers University, Newark, New Jersey, USA
| | - Lai-Hua Xie
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers University, Newark, New Jersey, USA
| | - Gopal J. Babu
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers University, Newark, New Jersey, USA
| |
Collapse
|
3
|
Burnham HV, Cizauskas HE, Barefield DY. Fine tuning contractility: atrial sarcomere function in health and disease. Am J Physiol Heart Circ Physiol 2024; 326:H568-H583. [PMID: 38156887 DOI: 10.1152/ajpheart.00252.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 12/20/2023] [Accepted: 12/21/2023] [Indexed: 01/03/2024]
Abstract
The molecular mechanisms of sarcomere proteins underlie the contractile function of the heart. Although our understanding of the sarcomere has grown tremendously, the focus has been on ventricular sarcomere isoforms due to the critical role of the ventricle in health and disease. However, atrial-specific or -enriched myofilament protein isoforms, as well as isoforms that become expressed in disease, provide insight into ways this complex molecular machine is fine-tuned. Here, we explore how atrial-enriched sarcomere protein composition modulates contractile function to fulfill the physiological requirements of atrial function. We review how atrial dysfunction negatively affects the ventricle and the many cardiovascular diseases that have atrial dysfunction as a comorbidity. We also cover the pathophysiology of mutations in atrial-enriched contractile proteins and how they can cause primary atrial myopathies. Finally, we explore what is known about contractile function in various forms of atrial fibrillation. The differences in atrial function in health and disease underscore the importance of better studying atrial contractility, especially as therapeutics currently in development to modulate cardiac contractility may have different effects on atrial sarcomere function.
Collapse
Affiliation(s)
- Hope V Burnham
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, Illinois, United States
| | - Hannah E Cizauskas
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, Illinois, United States
| | - David Y Barefield
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, Illinois, United States
| |
Collapse
|
4
|
Queen R, Crosier M, Eley L, Kerwin J, Turner JE, Yu J, Alqahtani A, Dhanaseelan T, Overman L, Soetjoadi H, Baldock R, Coxhead J, Boczonadi V, Laude A, Cockell SJ, Kane MA, Lisgo S, Henderson DJ. Spatial transcriptomics reveals novel genes during the remodelling of the embryonic human arterial valves. PLoS Genet 2023; 19:e1010777. [PMID: 38011284 PMCID: PMC10703419 DOI: 10.1371/journal.pgen.1010777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 12/07/2023] [Accepted: 10/24/2023] [Indexed: 11/29/2023] Open
Abstract
Abnormalities of the arterial valves, including bicuspid aortic valve (BAV) are amongst the most common congenital defects and are a significant cause of morbidity as well as predisposition to disease in later life. Despite this, and compounded by their small size and relative inaccessibility, there is still much to understand about how the arterial valves form and remodel during embryogenesis, both at the morphological and genetic level. Here we set out to address this in human embryos, using Spatial Transcriptomics (ST). We show that ST can be used to investigate the transcriptome of the developing arterial valves, circumventing the problems of accurately dissecting out these tiny structures from the developing embryo. We show that the transcriptome of CS16 and CS19 arterial valves overlap considerably, despite being several days apart in terms of human gestation, and that expression data confirm that the great majority of the most differentially expressed genes are valve-specific. Moreover, we show that the transcriptome of the human arterial valves overlaps with that of mouse atrioventricular valves from a range of gestations, validating our dataset but also highlighting novel genes, including four that are not found in the mouse genome and have not previously been linked to valve development. Importantly, our data suggests that valve transcriptomes are under-represented when using commonly used databases to filter for genes important in cardiac development; this means that causative variants in valve-related genes may be excluded during filtering for genomic data analyses for, for example, BAV. Finally, we highlight "novel" pathways that likely play important roles in arterial valve development, showing that mouse knockouts of RBP1 have arterial valve defects. Thus, this study has confirmed the utility of ST for studies of the developing heart valves and broadens our knowledge of the genes and signalling pathways important in human valve development.
Collapse
Affiliation(s)
- Rachel Queen
- Bioinformatics Support Unit, Faculty of Medical Sciences, Newcastle University, United Kingdom
| | - Moira Crosier
- Human Developmental Biology Resource, Biosciences Institute, Faculty of Medical Sciences, Newcastle University, United Kingdom
| | - Lorraine Eley
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, United Kingdom
| | - Janet Kerwin
- Human Developmental Biology Resource, Biosciences Institute, Faculty of Medical Sciences, Newcastle University, United Kingdom
| | - Jasmin E. Turner
- Human Developmental Biology Resource, Biosciences Institute, Faculty of Medical Sciences, Newcastle University, United Kingdom
| | - Jianshi Yu
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland, United States of America
| | - Ahlam Alqahtani
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, United Kingdom
| | - Tamilvendhan Dhanaseelan
- Human Developmental Biology Resource, Biosciences Institute, Faculty of Medical Sciences, Newcastle University, United Kingdom
| | - Lynne Overman
- Human Developmental Biology Resource, Biosciences Institute, Faculty of Medical Sciences, Newcastle University, United Kingdom
| | - Hannah Soetjoadi
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, United Kingdom
| | - Richard Baldock
- MRC Human Genetics Unit, Institute of Genetics and Cancer, Edinburgh University, United Kingdom
| | - Jonathan Coxhead
- Genomics Core Facility, Biosciences Institute, Faculty of Medical Sciences, Newcastle University, United Kingdom
| | - Veronika Boczonadi
- Bioimaging Unit, Faculty of medical Sciences, Newcastle University, United Kingdom
| | - Alex Laude
- Bioimaging Unit, Faculty of medical Sciences, Newcastle University, United Kingdom
| | - Simon J. Cockell
- School of Biomedical, Nutritional and Sport Sciences, Faculty of Medical Sciences, Newcastle University, United Kingdom
| | - Maureen A. Kane
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland, United States of America
| | - Steven Lisgo
- Human Developmental Biology Resource, Biosciences Institute, Faculty of Medical Sciences, Newcastle University, United Kingdom
| | - Deborah J. Henderson
- Human Developmental Biology Resource, Biosciences Institute, Faculty of Medical Sciences, Newcastle University, United Kingdom
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, United Kingdom
| |
Collapse
|
5
|
Remark J, Tong J, Lin MJ, Concepcion A, Mareedu S, Babu GJ, Feske S, Lu CP. Neurotransmitter signaling specifies sweat gland stem cell fate through SLN-mediated intracellular calcium regulation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.10.557066. [PMID: 37745514 PMCID: PMC10515797 DOI: 10.1101/2023.09.10.557066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
Sympathetic nerves co-develop with their target organs and release neurotransmitters to stimulate their functions after maturation. Here, we provide the molecular mechanism that during sweat gland morphogenesis, neurotransmitters released from sympathetic nerves act first to promote sweat duct elongation via norepinephrine and followed by acetylcholine to specify sweat gland stem cell fate, which matches the sequence of neurotransmitter switch. Without neuronal signals during development, the basal cells switch to exhibit suprabasal (luminal) cell features. Sarcolipin (SLN), a key regulator of sarcoendoplasmic reticulum (SR) Ca 2+ -ATPase (SERCA), expression is significantly down-regulated in the sweat gland myoepithelial cells upon denervation. Loss of SLN in sweat gland myoepithelial cells leads to decreased intracellular Ca 2+ over time in response to ACh stimulation, as well as upregulation of luminal cell features. In cell culture experiments, we showed that contrary to the paradigm that elevation of Ca 2+ promote epidermal differentiation, specification of the glandular myoepithelial (basal) cells requires high Ca 2+ while lowering Ca 2+ level promotes luminal (suprabasal) cell fate. Our work highlights that neuronal signals not only act transiently for mature sweat glands to function, but also exert long-term impact on glandular stem cell specification through regulating intracellular Ca 2+ dynamics.
Collapse
|
6
|
Kervadec A, Kezos J, Ni H, Yu M, Marchant J, Spiering S, Kannan S, Kwon C, Andersen P, Bodmer R, Grandi E, Ocorr K, Colas AR. Multiplatform modeling of atrial fibrillation identifies phospholamban as a central regulator of cardiac rhythm. Dis Model Mech 2023; 16:dmm049962. [PMID: 37293707 PMCID: PMC10387351 DOI: 10.1242/dmm.049962] [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: 10/25/2022] [Accepted: 05/26/2023] [Indexed: 06/10/2023] Open
Abstract
Atrial fibrillation (AF) is a common and genetically inheritable form of cardiac arrhythmia; however, it is currently not known how these genetic predispositions contribute to the initiation and/or maintenance of AF-associated phenotypes. One major barrier to progress is the lack of experimental systems to investigate the effects of gene function on rhythm parameters in models with human atrial and whole-organ relevance. Here, we assembled a multi-model platform enabling high-throughput characterization of the effects of gene function on action potential duration and rhythm parameters using human induced pluripotent stem cell-derived atrial-like cardiomyocytes and a Drosophila heart model, and validation of the findings using computational models of human adult atrial myocytes and tissue. As proof of concept, we screened 20 AF-associated genes and identified phospholamban loss of function as a top conserved hit that shortens action potential duration and increases the incidence of arrhythmia phenotypes upon stress. Mechanistically, our study reveals that phospholamban regulates rhythm homeostasis by functionally interacting with L-type Ca2+ channels and NCX. In summary, our study illustrates how a multi-model system approach paves the way for the discovery and molecular delineation of gene regulatory networks controlling atrial rhythm with application to AF.
Collapse
Affiliation(s)
- Anaïs Kervadec
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - James Kezos
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Haibo Ni
- Department of Pharmacology, UC Davis, Davis, CA 95616, USA
| | - Michael Yu
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - James Marchant
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Sean Spiering
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Suraj Kannan
- Johns Hopkins University, Baltimore, MD 21205, USA
| | - Chulan Kwon
- Johns Hopkins University, Baltimore, MD 21205, USA
| | | | - Rolf Bodmer
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | | | - Karen Ocorr
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Alexandre R. Colas
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| |
Collapse
|
7
|
The metabolic cost of physical activity in mice using a physiology-based model of energy expenditure. Mol Metab 2023; 71:101699. [PMID: 36858190 PMCID: PMC10090438 DOI: 10.1016/j.molmet.2023.101699] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 02/14/2023] [Accepted: 02/21/2023] [Indexed: 03/03/2023] Open
Abstract
OBJECTIVE Physical activity is a major component of total energy expenditure (TEE) that exhibits extreme variability in mice. Our objective was to construct a general, physiology-based model of TEE to accurately quantify the energy cost of physical activity. METHODS Spontaneous home cage physical activity, body temperature, TEE, and energy intake were measured with frequent sampling. The energy cost of activity was modeled considering six contributors to TEE (basal metabolic rate, thermic effect of food, body temperature, cold induced thermogenesis, physical activity, and body weight). An ambient temperature of 35 °C was required to remove the contribution from cold induced thermogenesis. Basal metabolic rate was adjusted for body temperature using a Q10 temperature coefficient. RESULTS We developed a TEE model that robustly explains 70-80% of the variance in TEE at 35 °C while fitting only two parameters, the basal metabolic rate and the mass-specific energy cost per unit of physical activity, which averaged 60 cal/km/g body weight. In Ucp1-/- mice the activity cost was elevated by 60%, indicating inefficiency and increased muscle thermogenesis. The diurnal rhythm in TEE was quantitatively explained by the combined diurnal differences in physical activity, body temperature, and energy intake. CONCLUSIONS The physiology-based model of TEE allows quantifying the energy cost of physical activity. While applied here to mice, the model should be generally valid across species. Due to the effect of body temperature, we suggest that basal metabolic rate measurements be corrected to a reference body temperature, including in humans. Having an accurate cost of physical activity allows mechanistic dissection of disorders of energy homeostasis, including obesity.
Collapse
|
8
|
Keefe JA, Moore OM, Ho KS, Wehrens XHT. Role of Ca 2+ in healthy and pathologic cardiac function: from normal excitation-contraction coupling to mutations that cause inherited arrhythmia. Arch Toxicol 2023; 97:73-92. [PMID: 36214829 PMCID: PMC10122835 DOI: 10.1007/s00204-022-03385-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 09/15/2022] [Indexed: 01/19/2023]
Abstract
Calcium (Ca2+) ions are a key second messenger involved in the rhythmic excitation and contraction of cardiomyocytes throughout the heart. Proper function of Ca2+-handling proteins is required for healthy cardiac function, whereas disruption in any of these can cause cardiac arrhythmias. This comprehensive review provides a broad overview of the roles of Ca2+-handling proteins and their regulators in healthy cardiac function and the mechanisms by which mutations in these proteins contribute to inherited arrhythmias. Major Ca2+ channels and Ca2+-sensitive regulatory proteins involved in cardiac excitation-contraction coupling are discussed, with special emphasis on the function of the RyR2 macromolecular complex. Inherited arrhythmia disorders including catecholaminergic polymorphic ventricular tachycardia, long QT syndrome, Brugada syndrome, short QT syndrome, and arrhythmogenic right-ventricular cardiomyopathy are discussed with particular emphasis on subtypes caused by mutations in Ca2+-handling proteins.
Collapse
Affiliation(s)
- Joshua A Keefe
- Cardiovascular Research Institute, Baylor College of Medicine, One Baylor Plaza, BCM335, Houston, TX, 77030, USA.,Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Oliver M Moore
- Cardiovascular Research Institute, Baylor College of Medicine, One Baylor Plaza, BCM335, Houston, TX, 77030, USA.,Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Kevin S Ho
- Cardiovascular Research Institute, Baylor College of Medicine, One Baylor Plaza, BCM335, Houston, TX, 77030, USA.,Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Xander H T Wehrens
- Cardiovascular Research Institute, Baylor College of Medicine, One Baylor Plaza, BCM335, Houston, TX, 77030, USA. .,Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, 77030, USA. .,Department of Medicine, Baylor College of Medicine, Houston, TX, 77030, USA. .,Department of Neuroscience, Baylor College of Medicine, Houston, TX, 77030, USA. .,Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA. .,Center for Space Medicine, Baylor College of Medicine, Houston, TX, 77030, USA.
| |
Collapse
|
9
|
Mengeste AM, Katare P, Dalmao Fernandez A, Lund J, Bakke HG, Baker D, Bartesaghi S, Peng XR, Rustan AC, Thoresen GH, Kase ET. Knockdown of sarcolipin (SLN) impairs substrate utilization in human skeletal muscle cells. Mol Biol Rep 2022; 49:6005-6017. [PMID: 35364719 PMCID: PMC9270280 DOI: 10.1007/s11033-022-07387-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 03/16/2022] [Indexed: 01/04/2023]
Abstract
BACKGROUND Recent studies have highlighted that uncoupling of sarco-/endoplasmic reticulum Ca2+-ATPase (SERCA) by sarcolipin (SLN) increases ATP consumption and contributes to heat liberation. Exploiting this thermogenic mechanism in skeletal muscle may provide an attractive strategy to counteract obesity and associated metabolic disorders. In the present study, we have investigated the role of SLN on substrate metabolism in human skeletal muscle cells. METHODS AND RESULTS After generation of skeletal muscle cells with stable SLN knockdown (SLN-KD), cell viability, glucose and oleic acid (OA) metabolism, mitochondrial function, as well as gene expressions were determined. Depletion of SLN did not influence cell viability. However, glucose and OA oxidation were diminished in SLN-KD cells compared to control myotubes. Basal respiration measured by respirometry was also observed to be reduced in cells with SLN-KD. The metabolic perturbation in SLN-KD cells was reflected by reduced gene expression levels of peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α) and forkhead box O1 (FOXO1). Furthermore, accumulation of OA was increased in cells with SLN-KD compared to control cells. These effects were accompanied by increased lipid formation and incorporation of OA into complex lipids. Additionally, formation of complex lipids and free fatty acid from de novo lipogenesis with acetate as substrate was enhanced in SLN-KD cells. Detection of lipid droplets using Oil red O staining also showed increased lipid accumulation in SLN-KD cells. CONCLUSIONS Overall, our study sheds light on the importance of SLN in maintaining metabolic homeostasis in human skeletal muscle. Findings from the current study suggest that therapeutic strategies involving SLN-mediated futile cycling of SERCA might have significant implications in the treatment of obesity and associated metabolic disorders.
Collapse
Affiliation(s)
- Abel M Mengeste
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, P.O. Box 1068 Blindern, 0316, Oslo, Norway.
| | - Parmeshwar Katare
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, P.O. Box 1068 Blindern, 0316, Oslo, Norway
| | - Andrea Dalmao Fernandez
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, P.O. Box 1068 Blindern, 0316, Oslo, Norway
| | - Jenny Lund
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, P.O. Box 1068 Blindern, 0316, Oslo, Norway
| | - Hege G Bakke
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, P.O. Box 1068 Blindern, 0316, Oslo, Norway
| | - David Baker
- Bioscience Metabolism, Research and Early Development Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Stefano Bartesaghi
- Bioscience Metabolism, Research and Early Development Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Xiao-Rong Peng
- Bioscience Metabolism, Research and Early Development Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Arild C Rustan
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, P.O. Box 1068 Blindern, 0316, Oslo, Norway
| | - G Hege Thoresen
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, P.O. Box 1068 Blindern, 0316, Oslo, Norway
- Department of Pharmacology, Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Eili Tranheim Kase
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, P.O. Box 1068 Blindern, 0316, Oslo, Norway
| |
Collapse
|
10
|
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.
Collapse
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
| |
Collapse
|
11
|
Nusier M, Shah AK, Dhalla NS. Structure-Function Relationships and Modifications of Cardiac Sarcoplasmic Reticulum Ca2+-Transport. Physiol Res 2022; 70:S443-S470. [DOI: 10.33549/physiolres.934805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Sarcoplasmic reticulum (SR) is a specialized tubular network, which not only maintains the intracellular concentration of Ca2+ at a low level but is also known to release and accumulate Ca2+ for the occurrence of cardiac contraction and relaxation, respectively. This subcellular organelle is composed of several phospholipids and different Ca2+-cycling, Ca2+-binding and regulatory proteins, which work in a coordinated manner to determine its function in cardiomyocytes. Some of the major proteins in the cardiac SR membrane include Ca2+-pump ATPase (SERCA2), Ca2+-release protein (ryanodine receptor), calsequestrin (Ca2+-binding protein) and phospholamban (regulatory protein). The phosphorylation of SR Ca2+-cycling proteins by protein kinase A or Ca2+-calmodulin kinase (directly or indirectly) has been demonstrated to augment SR Ca2+-release and Ca2+-uptake activities and promote cardiac contraction and relaxation functions. The activation of phospholipases and proteases as well as changes in different gene expressions under different pathological conditions have been shown to alter the SR composition and produce Ca2+-handling abnormalities in cardiomyocytes for the development of cardiac dysfunction. The post-translational modifications of SR Ca2+ cycling proteins by processes such as oxidation, nitrosylation, glycosylation, lipidation, acetylation, sumoylation, and O GlcNacylation have also been reported to affect the SR Ca2+ release and uptake activities as well as cardiac contractile activity. The SR function in the heart is also influenced in association with changes in cardiac performance by several hormones including thyroid hormones and adiponectin as well as by exercise-training. On the basis of such observations, it is suggested that both Ca2+-cycling and regulatory proteins in the SR membranes are intimately involved in determining the status of cardiac function and are thus excellent targets for drug development for the treatment of heart disease.
Collapse
Affiliation(s)
| | | | - NS Dhalla
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen, Research Centre, 351 Tache Avenue, Winnipeg, MB, R2H 2A6 Canada.
| |
Collapse
|
12
|
Ca 2+ leak through ryanodine receptor 1 regulates thermogenesis in resting skeletal muscle. Proc Natl Acad Sci U S A 2022; 119:2119203119. [PMID: 35046046 PMCID: PMC8794839 DOI: 10.1073/pnas.2119203119] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/13/2021] [Indexed: 11/26/2022] Open
Abstract
The evolution of mammals to use skeletal muscle as a source of heat allowed them to spread to all parts of the globe. The generation of heat requires increased adenosine triphosphate (ATP) hydrolysis in the resting muscle in a regulated manner, but how this mechanism works is unknown. The results suggest that mammals increase their RyR1 Ca2+ leak rate to amplify a basal ATP turnover rate at the sarcoplasmic reticulum Ca2+ pump that is higher than that of lower vertebrates. Muscle-based thermogenesis allows regulation of body temperature that is essential for life in mammals and provides a potential pathway for manipulating body weight or temperature by altering metabolic rate. Mammals rely on nonshivering thermogenesis (NST) from skeletal muscle so that cold temperatures can be tolerated. NST results from activity of the sarcoplasmic reticulum (SR) Ca2+ pump in skeletal muscle, but the mechanisms that regulate this activity are unknown. Here, we develop a single-fiber assay to investigate the role of Ca2+ leak through ryanodine receptor 1 (RyR1) to generate heat at the SR Ca2+ pump in resting muscle. By inhibiting a subpopulation of RyR1s in a single-fiber preparation via targeted delivery of ryanodine through transverse tubules, we achieve in-preparation isolation of RyR1 Ca2+ leak. This maneuver provided a critical increase in signal-to-noise of the SR-temperature-sensitive dye ER thermoyellow fluorescence signal from the fiber to allow detection of SR temperature changes as either RyR1 or SR Ca2+ pump activity was altered. We found that RyR1 Ca2+ leak raises cytosolic [Ca2+] in the local vicinity of the SR Ca2+ pump to amplify thermogenesis. Furthermore, gene-dose-dependent increases in RyR1 leak in RYR1 mutant mice result in progressive rises in leak-dependent heat, consistent with raised local [Ca2+] at the SR Ca2+ pump via RyR1 Ca2+ leak. We also show that basal RyR Ca2+ leak and the heat generated by the SR Ca2+ pump in the absence of RyR Ca2+ leak is greater in fibers from mice than from toads. The distinct function of RyRs and SR Ca2+ pump in endothermic mammals compared to ectothermic amphibians provides insights into the mechanisms by which mammalian skeletal muscle achieves thermogenesis at rest.
Collapse
|
13
|
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.
Collapse
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
| |
Collapse
|
14
|
Liu AY, Aguayo-Ortiz R, Guerrero-Serna G, Wang N, Blin MG, Goldstein DR, Michel Espinoza-Fonseca L. Homologous cardiac calcium pump regulators phospholamban and sarcolipin adopt distinct oligomeric states in the membrane. Comput Struct Biotechnol J 2021; 20:380-384. [PMID: 35035790 PMCID: PMC8748397 DOI: 10.1016/j.csbj.2021.12.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 12/18/2021] [Accepted: 12/21/2021] [Indexed: 11/23/2022] Open
Abstract
Phospholamban (PLN) and Sarcolipin (SLN) are homologous membrane proteins that belong to the family of proteins that regulate the activity of the cardiac calcium pump (sarcoplasmic reticulum Ca2+-ATPase, SERCA). PLN and SLN share highly conserved leucine zipper motifs that control self-association; consequently, it has been proposed that both PLN and SLN assemble into stable pentamers in the membrane. In this study, we used molecular dynamics (MD) simulations and Western blot analysis to investigate the precise molecular architecture of the PLN and SLN oligomers. Analysis showed that the PLN pentamer is the predominant oligomer present in mouse ventricles and ventricle-like human iPSC-derived cardiomyocytes, in agreement with the MD simulations showing stable leucine zipper interactions across all protomer-protomer interfaces and MD replicates. Interestingly, we found that the PLN pentamer populates an asymmetric structure of the transmembrane region, which is likely an intrinsic feature of the oligomer in a lipid bilayer. The SLN pentamer is not favorably formed across MD replicates and species of origin; instead, SLN from human and mouse atria primarily populate coexisting dimeric and trimeric states. In contrast to previous studies, our findings indicate that the SLN pentamer is not the predominant oligomeric state populated in the membrane. We conclude that despite their structural homology, PLN and SLN adopt distinct oligomeric states in the membrane. We propose that the distinct oligomeric states populated by PLN and SLN may contribute to tissue-specific SERCA regulation via differences in protomer-oligomer exchange, oligomer-SERCA dynamics, and noise filtering during β-adrenergic stimulation in the heart.
Collapse
Affiliation(s)
- Andy Y. Liu
- Center for Arrhythmia Research, Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, MI 48109, USA
- McKetta Department of Chemical Engineering, The University of Texas, Austin, TX 78712, USA
| | - Rodrigo Aguayo-Ortiz
- Departamento de Farmacia, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico
| | - Guadalupe Guerrero-Serna
- Center for Arrhythmia Research, Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Nulang Wang
- Center for Arrhythmia Research, Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Muriel G. Blin
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Daniel R. Goldstein
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI 48109, USA
- Institute of Gerontology, University of Michigan, Ann Arbor, MI 48109, USA
| | - L. Michel Espinoza-Fonseca
- Center for Arrhythmia Research, Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| |
Collapse
|
15
|
Function and regulation of phosphatase 1 in healthy and diseased heart. Cell Signal 2021; 90:110203. [PMID: 34822978 DOI: 10.1016/j.cellsig.2021.110203] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 11/12/2021] [Accepted: 11/18/2021] [Indexed: 12/12/2022]
Abstract
Reversible phosphorylation of ion channels and calcium-handling proteins provides precise post-translational regulation of cardiac excitation and contractility. Serine/threonine phosphatases govern dephosphorylation of the majority of cardiac proteins. Accordingly, dysfunction of this regulation contributes to the development and progression of heart failure and atrial fibrillation. On the molecular level, these changes include alterations in the expression level and phosphorylation status of Ca2+ handling and excitation-contraction coupling proteins provoked by dysregulation of phosphatases. The serine/threonine protein phosphatase PP1 is one a major player in the regulation of cardiac excitation-contraction coupling. PP1 essentially impacts on cardiac physiology and pathophysiology via interactions with the cardiac ion channels Cav1.2, NKA, NCX and KCNQ1, sarcoplasmic reticulum-bound Ca2+ handling proteins such as RyR2, SERCA and PLB as well as the contractile proteins MLC2, TnI and MyBP-C. PP1 itself but also PP1-regulatory proteins like inhibitor-1, inhibitor-2 and heat-shock protein 20 are dysregulated in cardiac disease. Therefore, they represent interesting targets to gain more insights in heart pathophysiology and to identify new treatment strategies for patients with heart failure or atrial fibrillation. We describe the genetic and holoenzymatic structure of PP1 and review its role in the heart and cardiac disease. Finally, we highlight the importance of the PP1 regulatory proteins for disease manifestation, provide an overview of genetic models to study the role of PP1 for the development of heart failure and atrial fibrillation and discuss possibilities of pharmacological interventions.
Collapse
|
16
|
Braun JL, Teng ACT, Geromella MS, Ryan CR, Fenech RK, MacPherson REK, Gramolini AO, Fajardo VA. Neuronatin promotes SERCA uncoupling and its expression is altered in skeletal muscles of high-fat diet-fed mice. FEBS Lett 2021; 595:2756-2767. [PMID: 34693525 DOI: 10.1002/1873-3468.14213] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 10/07/2021] [Accepted: 10/15/2021] [Indexed: 11/09/2022]
Abstract
Neuronatin (NNAT) is a transmembrane protein in the endoplasmic reticulum involved in metabolic regulation. It shares sequence homology with sarcolipin (SLN), which negatively regulates the sarco(endo)plasmic reticulum Ca2+ -ATPase (SERCA) that maintains energy homeostasis in muscles. Here, we examined whether NNAT could uncouple the Ca2+ transport activity of SERCA from ATP hydrolysis, similarly to SLN. NNAT significantly reduced Ca2+ uptake without altering SERCA activity, ultimately lowering the apparent coupling ratio of SERCA. This effect of NNAT was reversed by the adenylyl cyclase activator forskolin. Furthermore, soleus muscles from high fat diet (HFD)-fed mice showed a significant downregulation in NNAT content compared with chow-fed mice, whereas an upregulation in NNAT content was observed in fast-twitch muscles from HFD- versus chow- fed mice. Therefore, NNAT is a SERCA uncoupler in cells and may function in adaptive thermogenesis.
Collapse
Affiliation(s)
- Jessica L Braun
- Department of Kinesiology, Brock University, St. Catharines, Canada.,Centre for Bone and Muscle Health, Brock University, St. Catharines, Canada.,Centre for Neuroscience, Brock University, St. Catharines, Canada
| | - Allen C T Teng
- Department of Physiology, University of Toronto, Canada.,Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, Canada
| | - Mia S Geromella
- Department of Kinesiology, Brock University, St. Catharines, Canada.,Centre for Bone and Muscle Health, Brock University, St. Catharines, Canada.,Centre for Neuroscience, Brock University, St. Catharines, Canada
| | - Chantal R Ryan
- Centre for Neuroscience, Brock University, St. Catharines, Canada.,Department of Health Sciences, Brock University, St. Catharines, Canada
| | - Rachel K Fenech
- Centre for Neuroscience, Brock University, St. Catharines, Canada.,Department of Health Sciences, Brock University, St. Catharines, Canada
| | - Rebecca E K MacPherson
- Centre for Neuroscience, Brock University, St. Catharines, Canada.,Department of Health Sciences, Brock University, St. Catharines, Canada
| | - Anthony O Gramolini
- Department of Physiology, University of Toronto, Canada.,Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, Canada
| | - Val A Fajardo
- Department of Kinesiology, Brock University, St. Catharines, Canada.,Centre for Bone and Muscle Health, Brock University, St. Catharines, Canada.,Centre for Neuroscience, Brock University, St. Catharines, Canada
| |
Collapse
|
17
|
Impaired Right Ventricular Calcium Cycling Is an Early Risk Factor in R14del-Phospholamban Arrhythmias. J Pers Med 2021; 11:jpm11060502. [PMID: 34204946 PMCID: PMC8226909 DOI: 10.3390/jpm11060502] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 05/27/2021] [Accepted: 05/30/2021] [Indexed: 12/22/2022] Open
Abstract
The inherited mutation (R14del) in the calcium regulatory protein phospholamban (PLN) is linked to malignant ventricular arrhythmia with poor prognosis starting at adolescence. However, the underlying early mechanisms that may serve as prognostic factors remain elusive. This study generated humanized mice in which the endogenous gene was replaced with either human wild type or R14del-PLN and addressed the early molecular and cellular pathogenic mechanisms. R14del-PLN mice exhibited stress-induced impairment of atrioventricular conduction, and prolongation of both ventricular activation and repolarization times in association with ventricular tachyarrhythmia, originating from the right ventricle (RV). Most of these distinct electrocardiographic features were remarkably similar to those in R14del-PLN patients. Studies in isolated cardiomyocytes revealed RV-specific calcium defects, including prolonged action potential duration, depressed calcium kinetics and contractile parameters, and elevated diastolic Ca-levels. Ca-sparks were also higher although SR Ca-load was reduced. Accordingly, stress conditions induced after contractions, and inclusion of the CaMKII inhibitor KN93 reversed this proarrhythmic parameter. Compensatory responses included altered expression of key genes associated with Ca-cycling. These data suggest that R14del-PLN cardiomyopathy originates with RV-specific impairment of Ca-cycling and point to the urgent need to improve risk stratification in asymptomatic carriers to prevent fatal arrhythmias and delay cardiomyopathy onset.
Collapse
|
18
|
Zhihao L, Jingyu N, Lan L, Michael S, Rui G, Xiyun B, Xiaozhi L, Guanwei F. SERCA2a: a key protein in the Ca 2+ cycle of the heart failure. Heart Fail Rev 2021; 25:523-535. [PMID: 31701344 DOI: 10.1007/s10741-019-09873-3] [Citation(s) in RCA: 67] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Calcium ion (Ca2+) cycle plays a crucial role in the contraction and relaxation of cardiomyocytes. The sarcoplasmic reticulum (SR) acts as an organelle for storing Ca2+, which mediated the release and re-uptake of Ca2+ during contraction and relaxation. Disorders of SR function lead to the dysfunction of Ca2+ cycle and myocardial cell function. The sarcoplasmic/endoplasmic reticulum Ca2+ ATPase 2a (SERCA2a) acts as a subtype of SERCA expressed in the heart, which mediates the contraction of cardiomyocytes and Ca2+ in the cytoplasm to re-enter into the SR. The rate of uptake of Ca2+ by the SR determines the rate of myocardial relaxation. The regulation of SERCA2a activity controls the contractility and relaxation of the heart, affecting cardiac function. The expression and activity of SERCA2a are reduced in failing hearts. Gene therapy by increasing the expression of SERCA2a in the heart has been proven effective. In addition, SERCA2a is regulated by a variety of factors, including transmembrane micropeptides, protein kinases, and post-translational modifications (PTMs). In this review, we discuss the regulatory factors of SERCA2a and provide new insights into future treatments and the direction of heart failure research. In addition, gene therapy for SERCA2a has recently emerged as therapeutic option and hence will be discussed in this review.
Collapse
Affiliation(s)
- Liu Zhihao
- Tianjin Laboratory of Translational Research of TCM Prescription and Syndrome, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Number 314 Anshanxi Road, Nankai District, Tianjin, 300193, People's Republic of China.,State Key Laboratory of Modern Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 301617, People's Republic of China
| | - Ni Jingyu
- Tianjin Laboratory of Translational Research of TCM Prescription and Syndrome, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Number 314 Anshanxi Road, Nankai District, Tianjin, 300193, People's Republic of China.,State Key Laboratory of Modern Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 301617, People's Republic of China
| | - Li Lan
- Tianjin Laboratory of Translational Research of TCM Prescription and Syndrome, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Number 314 Anshanxi Road, Nankai District, Tianjin, 300193, People's Republic of China.,State Key Laboratory of Modern Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 301617, People's Republic of China
| | - Sarhene Michael
- Tianjin Laboratory of Translational Research of TCM Prescription and Syndrome, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Number 314 Anshanxi Road, Nankai District, Tianjin, 300193, People's Republic of China.,State Key Laboratory of Modern Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 301617, People's Republic of China
| | - Guo Rui
- Tianjin Laboratory of Translational Research of TCM Prescription and Syndrome, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Number 314 Anshanxi Road, Nankai District, Tianjin, 300193, People's Republic of China.,State Key Laboratory of Modern Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 301617, People's Republic of China
| | - Bian Xiyun
- Central Laboratory, The Fifth Central Hospital of Tianjin, Tianjin, 300450, People's Republic of China
| | - Liu Xiaozhi
- Central Laboratory, The Fifth Central Hospital of Tianjin, Tianjin, 300450, People's Republic of China
| | - Fan Guanwei
- Tianjin Laboratory of Translational Research of TCM Prescription and Syndrome, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Number 314 Anshanxi Road, Nankai District, Tianjin, 300193, People's Republic of China. .,State Key Laboratory of Modern Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 301617, People's Republic of China.
| |
Collapse
|
19
|
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.
Collapse
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
| |
Collapse
|
20
|
Wang X, Chen X, Dobrev D, Li N. The crosstalk between cardiomyocyte calcium and inflammasome signaling pathways in atrial fibrillation. Pflugers Arch 2021; 473:389-405. [PMID: 33511453 DOI: 10.1007/s00424-021-02515-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 12/14/2020] [Accepted: 01/04/2021] [Indexed: 02/07/2023]
Abstract
Atrial fibrillation (AF) is the most frequent arrhythmia in adults. The prevalence and incidence of AF is going to increase substantially over the next few decades. Because AF increases the risk of stroke, heart failure, dementia, and others, it severely impacts the quality of life, morbidity, and mortality. Although the pathogenesis of AF is multifaceted and complex, focal ectopic activity and reentry are considered as the fundamental proarrhythmic mechanisms underlying AF development. Over the past 2 decades, large amount of evidence points to the key role of intracellular Ca2+ dysregulation in both initiation and maintenance of AF. More recently, emerging evidence reveal that NLRP3 (NACHT, LRR, PYD domain-containing 3) inflammasome pathway contributes to the substrate of both triggered activity and reentry, ultimately promoting AF. In this article, we review the current state of knowledge on Ca2+ signaling and NLRP3 inflammasome activity in AF. We also discuss the potential crosstalk between these two quintessential contributors to AF promotion.
Collapse
Affiliation(s)
- Xiaolei Wang
- Department of Medicine (Section of Cardiovascular Research), Baylor College of Medicine, Houston, TX, USA
| | - Xiaohui Chen
- Department of Medicine (Section of Cardiovascular Research), Baylor College of Medicine, Houston, TX, USA
| | - Dobromir Dobrev
- Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany
| | - Na Li
- Department of Medicine (Section of Cardiovascular Research), Baylor College of Medicine, Houston, TX, USA. .,Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA. .,Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA.
| |
Collapse
|
21
|
Mareedu S, Pachon R, Thilagavathi J, Fefelova N, Balakrishnan R, Niranjan N, Xie LH, Babu GJ. Sarcolipin haploinsufficiency prevents dystrophic cardiomyopathy in mdx mice. Am J Physiol Heart Circ Physiol 2021; 320:H200-H210. [PMID: 33216625 PMCID: PMC7847070 DOI: 10.1152/ajpheart.00601.2020] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 10/21/2020] [Accepted: 11/17/2020] [Indexed: 02/07/2023]
Abstract
Sarcolipin (SLN) is an inhibitor of sarco/endoplasmic reticulum (SR) Ca2+-ATPase (SERCA) and expressed at high levels in the ventricles of animal models for and patients with Duchenne muscular dystrophy (DMD). The goal of this study was to determine whether the germline ablation of SLN expression improves cardiac SERCA function and intracellular Ca2+ (Ca2+i) handling and prevents cardiomyopathy in the mdx mouse model of DMD. Wild-type, mdx, SLN-haploinsufficient mdx (mdx:sln+/-), and SLN-deficient mdx (mdx:sln-/-) mice were used for this study. SERCA function and Ca2+i handling were determined by Ca2+ uptake assays and by measuring single-cell Ca2+ transients, respectively. Age-dependent disease progression was determined by histopathological examinations and by echocardiography in 6-, 12-, and 20-mo-old mice. Gene expression changes in the ventricles of mdx:sln+/- mice were determined by RNA-Seq analysis. SERCA function and Ca2+i cycling were improved in the ventricles of mdx:sln+/- mice. Fibrosis and necrosis were significantly decreased, and cardiac function was enhanced in the mdx:sln+/- mice until the study endpoint. The mdx:sln-/- mice also exhibited similar beneficial effects. RNA-Seq analysis identified distinct gene expression changes including the activation of the apelin pathway in the ventricles of mdx:sln+/- mice. Our findings suggest that reducing SLN expression is sufficient to improve cardiac SERCA function and Ca2+i cycling and prevent cardiomyopathy in mdx mice.NEW & NOTEWORTHY First, reducing sarcopolin (SLN) expression improves sarco/endoplasmic reticulum Ca2+ uptake and intracellular Ca2+ handling and prevents cardiomyopathy in mdx mice. Second, reducing SLN expression prevents diastolic dysfunction and improves cardiac contractility in mdx mice Third, reducing SLN expression activates apelin-mediated cardioprotective signaling pathways in mdx heart.
Collapse
Affiliation(s)
- Satvik Mareedu
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers University, Newark, New Jersey
| | - Ronald Pachon
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers University, Newark, New Jersey
| | - Jayapalraj Thilagavathi
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers University, Newark, New Jersey
| | - Nadezhda Fefelova
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers University, Newark, New Jersey
| | - Rekha Balakrishnan
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers University, Newark, New Jersey
| | - Nandita Niranjan
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers University, Newark, New Jersey
| | - Lai-Hua Xie
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers University, Newark, New Jersey
| | - Gopal J Babu
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers University, Newark, New Jersey
| |
Collapse
|
22
|
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.
Collapse
|
23
|
UCP1-independent thermogenesis. Biochem J 2020; 477:709-725. [PMID: 32059055 DOI: 10.1042/bcj20190463] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 01/20/2020] [Accepted: 01/21/2020] [Indexed: 12/24/2022]
Abstract
Obesity results from energy imbalance, when energy intake exceeds energy expenditure. Brown adipose tissue (BAT) drives non-shivering thermogenesis which represents a powerful mechanism of enhancing the energy expenditure side of the energy balance equation. The best understood thermogenic system in BAT that evolved to protect the body from hypothermia is based on the uncoupling of protonmotive force from oxidative phosphorylation through the actions of uncoupling protein 1 (UCP1), a key regulator of cold-mediated thermogenesis. Similarly, energy expenditure is triggered in response to caloric excess, and animals with reduced thermogenic fat function can succumb to diet-induced obesity. Thus, it was surprising when inactivation of Ucp1 did not potentiate diet-induced obesity. In recent years, it has become clear that multiple thermogenic mechanisms exist, based on ATP sinks centered on creatine, lipid, or calcium cycling, along with Fatty acid-mediated UCP1-independent leak pathways driven by the ADP/ATP carrier (AAC). With a key difference between cold- and diet-induced thermogenesis being the dynamic changes in purine nucleotide (primarily ATP) levels, ATP-dependent thermogenic pathways may play a key role in diet-induced thermogenesis. Additionally, the ubiquitous expression of AAC may facilitate increased energy expenditure in many cell types, in the face of over feeding. Interest in UCP1-independent energy expenditure has begun to showcase the therapeutic potential that lies in refining our understanding of the diversity of biochemical pathways controlling thermogenic respiration.
Collapse
|
24
|
Campbell HM, Quick AP, Abu-Taha I, Chiang DY, Kramm CF, Word TA, Brandenburg S, Hulsurkar M, Alsina KM, Liu HB, Martin B, Uhlenkamp D, Moore OM, Lahiri SK, Corradini E, Kamler M, Heck AJR, Lehnart SE, Dobrev D, Wehrens XHT. Loss of SPEG Inhibitory Phosphorylation of Ryanodine Receptor Type-2 Promotes Atrial Fibrillation. Circulation 2020; 142:1159-1172. [PMID: 32683896 DOI: 10.1161/circulationaha.120.045791] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Enhanced diastolic calcium (Ca2+) release through ryanodine receptor type-2 (RyR2) has been implicated in atrial fibrillation (AF) promotion. Diastolic sarcoplasmic reticulum Ca2+ leak is caused by increased RyR2 phosphorylation by PKA (protein kinase A) or CaMKII (Ca2+/calmodulin-dependent kinase-II) phosphorylation, or less dephosphorylation by protein phosphatases. However, considerable controversy remains regarding the molecular mechanisms underlying altered RyR2 function in AF. We thus aimed to determine the role of SPEG (striated muscle preferentially expressed protein kinase), a novel regulator of RyR2 phosphorylation, in AF pathogenesis. METHODS Western blotting was performed with right atrial biopsies from patients with paroxysmal AF. SPEG atrial knockout mice were generated using adeno-associated virus 9. In mice, AF inducibility was determined using intracardiac programmed electric stimulation, and diastolic Ca2+ leak in atrial cardiomyocytes was assessed using confocal Ca2+ imaging. Phosphoproteomics studies and Western blotting were used to measure RyR2 phosphorylation. To test the effects of RyR2-S2367 phosphorylation, knockin mice with an inactivated S2367 phosphorylation site (S2367A) and a constitutively activated S2367 residue (S2367D) were generated by using CRISPR-Cas9. RESULTS Western blotting revealed decreased SPEG protein levels in atrial biopsies from patients with paroxysmal AF in comparison with patients in sinus rhythm. SPEG atrial-specific knockout mice exhibited increased susceptibility to pacing-induced AF by programmed electric stimulation and enhanced Ca2+ spark frequency in atrial cardiomyocytes with Ca2+ imaging, establishing a causal role for decreased SPEG in AF pathogenesis. Phosphoproteomics in hearts from SPEG cardiomyocyte knockout mice identified RyR2-S2367 as a novel kinase substrate of SPEG. Western blotting demonstrated that RyR2-S2367 phosphorylation was also decreased in patients with paroxysmal AF. RyR2-S2367A mice exhibited an increased susceptibility to pacing-induced AF, and aberrant atrial sarcoplasmic reticulum Ca2+ leak, as well. In contrast, RyR2-S2367D mice were resistant to pacing-induced AF. CONCLUSIONS Unlike other kinases (PKA, CaMKII) that increase RyR2 activity, SPEG phosphorylation reduces RyR2-mediated sarcoplasmic reticulum Ca2+ release. Reduced SPEG levels and RyR2-S2367 phosphorylation typified patients with paroxysmal AF. Studies in S2367 knockin mouse models showed a causal relationship between reduced S2367 phosphorylation and AF susceptibility. Thus, modulating SPEG activity and phosphorylation levels of the novel S2367 site on RyR2 may represent a novel target for AF treatment.
Collapse
Affiliation(s)
- Hannah M Campbell
- Cardiovascular Research Institute (H.M.C., A.P.Q., D.Y.C., C.F.K., T.A.W., M.H., K.MA., H.-B.L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX.,Department of Molecular Physiology & Biophysics (H.M.C., A.P.Q., D.Y.C., F.K., T.A.W., M.H., K.M.A., H.-L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX
| | - Ann P Quick
- Cardiovascular Research Institute (H.M.C., A.P.Q., D.Y.C., C.F.K., T.A.W., M.H., K.MA., H.-B.L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX.,Department of Molecular Physiology & Biophysics (H.M.C., A.P.Q., D.Y.C., F.K., T.A.W., M.H., K.M.A., H.-L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX
| | - Issam Abu-Taha
- Institute of Pharmacology (I.A.-T., D.D.), University Duisburg-Essen, Germany
| | - David Y Chiang
- Cardiovascular Research Institute (H.M.C., A.P.Q., D.Y.C., C.F.K., T.A.W., M.H., K.MA., H.-B.L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX.,Department of Molecular Physiology & Biophysics (H.M.C., A.P.Q., D.Y.C., F.K., T.A.W., M.H., K.M.A., H.-L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX.,Department of Medicine (Cardiovascular Division), Brigham and Women's Hospital, Harvard Medical School, Boston, MA (D.Y.C.)
| | - Carlos F Kramm
- Cardiovascular Research Institute (H.M.C., A.P.Q., D.Y.C., C.F.K., T.A.W., M.H., K.MA., H.-B.L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX
| | - Tarah A Word
- Cardiovascular Research Institute (H.M.C., A.P.Q., D.Y.C., C.F.K., T.A.W., M.H., K.MA., H.-B.L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX.,Department of Molecular Physiology & Biophysics (H.M.C., A.P.Q., D.Y.C., F.K., T.A.W., M.H., K.M.A., H.-L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX
| | - Sören Brandenburg
- Heart Research Center Göttingen, Department of Cardiology & Pneumology, University Medical Center Göttingen, Germany (S.B., D.U., S.E.L.)
| | - Mohit Hulsurkar
- Cardiovascular Research Institute (H.M.C., A.P.Q., D.Y.C., C.F.K., T.A.W., M.H., K.MA., H.-B.L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX.,Department of Molecular Physiology & Biophysics (H.M.C., A.P.Q., D.Y.C., F.K., T.A.W., M.H., K.M.A., H.-L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX
| | - Katherina M Alsina
- Cardiovascular Research Institute (H.M.C., A.P.Q., D.Y.C., C.F.K., T.A.W., M.H., K.MA., H.-B.L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX.,Department of Molecular Physiology & Biophysics (H.M.C., A.P.Q., D.Y.C., F.K., T.A.W., M.H., K.M.A., H.-L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX
| | - Hui-Bin Liu
- Cardiovascular Research Institute (H.M.C., A.P.Q., D.Y.C., C.F.K., T.A.W., M.H., K.MA., H.-B.L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX.,Department of Molecular Physiology & Biophysics (H.M.C., A.P.Q., D.Y.C., F.K., T.A.W., M.H., K.M.A., H.-L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX.,Institute of Clinical Pharmacy, the Second Affiliated Hospital of Harbin Medical University, China (H.-B.L.)
| | - Brian Martin
- Cardiovascular Research Institute (H.M.C., A.P.Q., D.Y.C., C.F.K., T.A.W., M.H., K.MA., H.-B.L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX.,Department of Molecular Physiology & Biophysics (H.M.C., A.P.Q., D.Y.C., F.K., T.A.W., M.H., K.M.A., H.-L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX
| | - Dennis Uhlenkamp
- Institute of Pharmacology (I.A.-T., D.D.), University Duisburg-Essen, Germany.,Heart Research Center Göttingen, Department of Cardiology & Pneumology, University Medical Center Göttingen, Germany (S.B., D.U., S.E.L.)
| | - Oliver M Moore
- Cardiovascular Research Institute (H.M.C., A.P.Q., D.Y.C., C.F.K., T.A.W., M.H., K.MA., H.-B.L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX.,Department of Neuroscience (O.M.M., X.H.T.W.), Baylor College of Medicine, Houston, TX
| | - Satadru K Lahiri
- Cardiovascular Research Institute (H.M.C., A.P.Q., D.Y.C., C.F.K., T.A.W., M.H., K.MA., H.-B.L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX
| | - Eleonora Corradini
- Biomolecular Mass Spectrometry & Proteomics, Utrecht Institute for Pharmaceutical Sciences and Bijvoet Center for Biomolecular Research, Utrecht University, The Netherlands (E.C., A.J.R.H.)
| | - Markus Kamler
- Department of Thoracic and Cardiovascular Surgery Huttrop (M.K.), University Duisburg-Essen, Germany
| | - Albert J R Heck
- Biomolecular Mass Spectrometry & Proteomics, Utrecht Institute for Pharmaceutical Sciences and Bijvoet Center for Biomolecular Research, Utrecht University, The Netherlands (E.C., A.J.R.H.)
| | - Stephan E Lehnart
- Heart Research Center Göttingen, Department of Cardiology & Pneumology, University Medical Center Göttingen, Germany (S.B., D.U., S.E.L.)
| | | | - Xander H T Wehrens
- Cardiovascular Research Institute (H.M.C., A.P.Q., D.Y.C., C.F.K., T.A.W., M.H., K.MA., H.-B.L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX.,Department of Molecular Physiology & Biophysics (H.M.C., A.P.Q., D.Y.C., F.K., T.A.W., M.H., K.M.A., H.-L., B.M., O.M.M., S.K.L., X.H.T.W.), Baylor College of Medicine, Houston, TX.,Department of Neuroscience (O.M.M., X.H.T.W.), Baylor College of Medicine, Houston, TX.,Department of Medicine (Cardiology) (X.H.T.W.), Baylor College of Medicine, Houston, TX.,Department of Pediatrics (X.H.T.W.), Baylor College of Medicine, Houston, TX.,Center for Space Medicine (X.H.T.W.), Baylor College of Medicine, Houston, TX
| |
Collapse
|
25
|
Chen J, Sitsel A, Benoy V, Sepúlveda MR, Vangheluwe P. Primary Active Ca 2+ Transport Systems in Health and Disease. Cold Spring Harb Perspect Biol 2020; 12:cshperspect.a035113. [PMID: 31501194 DOI: 10.1101/cshperspect.a035113] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Calcium ions (Ca2+) are prominent cell signaling effectors that regulate a wide variety of cellular processes. Among the different players in Ca2+ homeostasis, primary active Ca2+ transporters are responsible for keeping low basal Ca2+ levels in the cytosol while establishing steep Ca2+ gradients across intracellular membranes or the plasma membrane. This review summarizes our current knowledge on the three types of primary active Ca2+-ATPases: the sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA) pumps, the secretory pathway Ca2+- ATPase (SPCA) isoforms, and the plasma membrane Ca2+-ATPase (PMCA) Ca2+-transporters. We first discuss the Ca2+ transport mechanism of SERCA1a, which serves as a reference to describe the Ca2+ transport of other Ca2+ pumps. We further highlight the common and unique features of each isoform and review their structure-function relationship, expression pattern, regulatory mechanisms, and specific physiological roles. Finally, we discuss the increasing genetic and in vivo evidence that links the dysfunction of specific Ca2+-ATPase isoforms to a broad range of human pathologies, and highlight emerging therapeutic strategies that target Ca2+ pumps.
Collapse
Affiliation(s)
- Jialin Chen
- Laboratory of Cellular Transport Systems, Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium
| | - Aljona Sitsel
- Laboratory of Cellular Transport Systems, Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium
| | - Veronick Benoy
- Laboratory of Cellular Transport Systems, Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium
| | - M Rosario Sepúlveda
- Department of Cell Biology, Faculty of Sciences, University of Granada, 18071 Granada, Spain
| | - Peter Vangheluwe
- Laboratory of Cellular Transport Systems, Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium
| |
Collapse
|
26
|
Asfaw TN, Tyan L, Glukhov AV, Bondarenko VE. A compartmentalized mathematical model of mouse atrial myocytes. Am J Physiol Heart Circ Physiol 2020; 318:H485-H507. [PMID: 31951471 DOI: 10.1152/ajpheart.00460.2019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Various experimental mouse models are extensively used to research human diseases, including atrial fibrillation, the most common cardiac rhythm disorder. Despite this, there are no comprehensive mathematical models that describe the complex behavior of the action potential and [Ca2+]i transients in mouse atrial myocytes. Here, we develop a novel compartmentalized mathematical model of mouse atrial myocytes that combines the action potential, [Ca2+]i dynamics, and β-adrenergic signaling cascade for a subpopulation of right atrial myocytes with developed transverse-axial tubule system. The model consists of three compartments related to β-adrenergic signaling (caveolae, extracaveolae, and cytosol) and employs local control of Ca2+ release. It also simulates ionic mechanisms of action potential generation and describes atrial-specific Ca2+ handling as well as frequency dependences of the action potential and [Ca2+]i transients. The model showed that the T-type Ca2+ current significantly affects the later stage of the action potential, with little effect on [Ca2+]i transients. The block of the small-conductance Ca2+-activated K+ current leads to a prolongation of the action potential at high intracellular Ca2+. Simulation results obtained from the atrial model cells were compared with those from ventricular myocytes. The developed model represents a useful tool to study complex electrical properties in the mouse atria and could be applied to enhance the understanding of atrial physiology and arrhythmogenesis.NEW & NOTEWORTHY A new compartmentalized mathematical model of mouse right atrial myocytes was developed. The model simulated action potential and Ca2+ dynamics at baseline and after stimulation of the β-adrenergic signaling system. Simulations showed that the T-type Ca2+ current markedly prolonged the later stage of atrial action potential repolarization, with a minor effect on [Ca2+]i transients. The small-conductance Ca2+-activated K+ current block resulted in prolongation of the action potential only at the relatively high intracellular Ca2+.
Collapse
Affiliation(s)
- Tesfaye Negash Asfaw
- Department of Mathematics and Statistics, Georgia State University, Atlanta, Georgia
| | - Leonid Tyan
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin
| | - Alexey V Glukhov
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin
| | - Vladimir E Bondarenko
- Department of Mathematics and Statistics, Georgia State University, Atlanta, Georgia.,Neuroscience Institute, Georgia State University, Atlanta, Georgia
| |
Collapse
|
27
|
Bal NC, Periasamy M. Uncoupling of sarcoendoplasmic reticulum calcium ATPase pump activity by sarcolipin as the basis for muscle non-shivering thermogenesis. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190135. [PMID: 31928193 DOI: 10.1098/rstb.2019.0135] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Thermogenesis in endotherms relies on both shivering and non-shivering thermogenesis (NST). The role of brown adipose tissue (BAT) in NST is well recognized, but the role of muscle-based NST has been contested. However, recent studies have provided substantial evidence for the importance of muscle-based NST in mammals. This review focuses primarily on the role of sarcoplasmic reticulum (SR) Ca2+-cycling in muscle NST; specifically, it will discuss recent data showing how uncoupling of sarcoendoplasmic reticulum calcium ATPase (SERCA) (inhibition of Ca2+ transport but not ATP hydrolysis) by sarcolipin (SLN) results in futile SERCA pump activity, increased ATP hydrolysis and heat production contributing to muscle NST. It will also critically examine how activation of muscle NST can be an important factor in regulating metabolic rate and whole-body energy homeostasis. In this regard, SLN has emerged as a powerful signalling molecule to promote mitochondrial biogenesis and oxidative metabolism in muscle. Furthermore, we will discuss the functional interplay between BAT and muscle, especially with respect to how reduced BAT function in mammals could be compensated by muscle-based NST. Based on the existing data, we argue that SLN-mediated thermogenesis is an integral part of muscle NST and that muscle NST potentially contributed to the evolution of endothermy within the vertebrate clade. This article is part of the theme issue 'Vertebrate palaeophysiology'.
Collapse
Affiliation(s)
- Naresh C Bal
- KIIT School of Biotechnology, KIIT University, Bhubaneswar, Odisha 751021, India
| | - Muthu Periasamy
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32827, USA
| |
Collapse
|
28
|
Bao T, Han H, Li B, Zhao Y, Bou G, Zhang X, Du M, Zhao R, Mongke T, Laxima, Ding W, Jia Z, Dugarjaviin M, Bai D. The distinct transcriptomes of fast-twitch and slow-twitch muscles in Mongolian horses. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2019; 33:100649. [PMID: 31869634 DOI: 10.1016/j.cbd.2019.100649] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 11/27/2019] [Accepted: 11/27/2019] [Indexed: 01/19/2023]
Abstract
Skeletal muscle is the largest organ system in the mammalian body and plays a key role in locomotion of horses. Fast and slow muscle fibers have different abilities and functions to adapt to exercises. To investigate the RNA and miRNA expression profiles in the muscles with different muscle fiber compositions on Mongolian horses. We examined the muscle fiber type population and produced deep RNA sequencing for different parts of skeletal muscles. And chose two of them with the highest difference in fast and slow muscle fiber population (splenius and gluteus medius) for comparing the gene expression profile of slow and fast muscle fiber types. We identified a total of 275 differentially expressed genes (DEGs), and 11 differentially expressed miRNAs (DEmiRs). In addition, target gene prediction and alternative splicing analysis were also performed. Significant correlations were found between the differentially expressed gene, miRNAs, and alternative splicing events. The result indicated that differentially expressed muscle-specific genes and target genes of miRNAs might co-regulating the performance of slow and fast muscle fiber types in Mongolian horses.
Collapse
Affiliation(s)
- Tugeqin Bao
- Inner Mongolia Key Laboratory of Equine Genetics, Breeding and Reproduction, Hohhot 010018, China; Scientific Observing and Experimental Station of Equine Genetics, Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Hohhot 010018, China; Equine Research Center, College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Haige Han
- Inner Mongolia Key Laboratory of Equine Genetics, Breeding and Reproduction, Hohhot 010018, China; Scientific Observing and Experimental Station of Equine Genetics, Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Hohhot 010018, China; Equine Research Center, College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Bei Li
- Inner Mongolia Key Laboratory of Equine Genetics, Breeding and Reproduction, Hohhot 010018, China; Scientific Observing and Experimental Station of Equine Genetics, Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Hohhot 010018, China; Equine Research Center, College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Yiping Zhao
- Inner Mongolia Key Laboratory of Equine Genetics, Breeding and Reproduction, Hohhot 010018, China; Scientific Observing and Experimental Station of Equine Genetics, Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Hohhot 010018, China; Equine Research Center, College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Gerelchimeg Bou
- Inner Mongolia Key Laboratory of Equine Genetics, Breeding and Reproduction, Hohhot 010018, China; Scientific Observing and Experimental Station of Equine Genetics, Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Hohhot 010018, China; Equine Research Center, College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Xinzhuang Zhang
- Inner Mongolia Key Laboratory of Equine Genetics, Breeding and Reproduction, Hohhot 010018, China; Scientific Observing and Experimental Station of Equine Genetics, Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Hohhot 010018, China; Equine Research Center, College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Ming Du
- Inner Mongolia Key Laboratory of Equine Genetics, Breeding and Reproduction, Hohhot 010018, China; Scientific Observing and Experimental Station of Equine Genetics, Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Hohhot 010018, China; Equine Research Center, College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Ruoyang Zhao
- Inner Mongolia Key Laboratory of Equine Genetics, Breeding and Reproduction, Hohhot 010018, China; Scientific Observing and Experimental Station of Equine Genetics, Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Hohhot 010018, China; Equine Research Center, College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Togtokh Mongke
- Inner Mongolia Key Laboratory of Equine Genetics, Breeding and Reproduction, Hohhot 010018, China; Scientific Observing and Experimental Station of Equine Genetics, Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Hohhot 010018, China; Equine Research Center, College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Laxima
- Inner Mongolia Key Laboratory of Equine Genetics, Breeding and Reproduction, Hohhot 010018, China; Scientific Observing and Experimental Station of Equine Genetics, Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Hohhot 010018, China; Equine Research Center, College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Wenqi Ding
- Inner Mongolia Key Laboratory of Equine Genetics, Breeding and Reproduction, Hohhot 010018, China; Scientific Observing and Experimental Station of Equine Genetics, Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Hohhot 010018, China; Equine Research Center, College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Zijie Jia
- Inner Mongolia Key Laboratory of Equine Genetics, Breeding and Reproduction, Hohhot 010018, China; Scientific Observing and Experimental Station of Equine Genetics, Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Hohhot 010018, China; Equine Research Center, College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Manglai Dugarjaviin
- Inner Mongolia Key Laboratory of Equine Genetics, Breeding and Reproduction, Hohhot 010018, China; Scientific Observing and Experimental Station of Equine Genetics, Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Hohhot 010018, China; Equine Research Center, College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Dongyi Bai
- Inner Mongolia Key Laboratory of Equine Genetics, Breeding and Reproduction, Hohhot 010018, China; Scientific Observing and Experimental Station of Equine Genetics, Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Hohhot 010018, China; Equine Research Center, College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010018, China.
| |
Collapse
|
29
|
Sarcolipin Signaling Promotes Mitochondrial Biogenesis and Oxidative Metabolism in Skeletal Muscle. Cell Rep 2019; 24:2919-2931. [PMID: 30208317 PMCID: PMC6481681 DOI: 10.1016/j.celrep.2018.08.036] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 04/30/2018] [Accepted: 08/13/2018] [Indexed: 12/19/2022] Open
Abstract
The major objective of this study was to understand the molecular basis of how sarcolipin uncoupling of SERCA regulates muscle oxidative metabolism. Using genetically engineered sarcolipin (SLN) mouse models and primary muscle cells, we demonstrate that SLN plays a crucial role in mitochondrial biogenesis and oxidative metabolism in muscle. Loss of SLN severely compromised muscle oxidative capacity without affecting fiber-type composition. Mice overexpressing SLN in fast-twitch glycolytic muscle reprogrammed mitochondrial phenotype, increasing fat utilization and protecting against high-fat dietinduced lipotoxicity. We show that SLN affects cytosolic Ca2+ transients and activates the Ca2+/ calmodulin-dependent protein kinase II (CamKII) and PGC1α axis to increase mitochondrial biogenesis and oxidative metabolism. These studies provide a fundamental framework for understanding the role of sarcoplasmic reticulum (SR)-Ca2+ cycling as an important factor in mitochondrial health and muscle metabolism. We propose that SLN can be targeted to enhance energy expenditure in muscle and prevent metabolic disease. Maurya et al. report that sarcolipin, a regulator of the SERCA pump, promotes mitochondrial biogenesis and oxidative phenotype in muscle. Loss of SLN decreases fat oxidation, whereas overexpression of SLN in muscle provides resistance against diet-induced lipotoxicity. By increasing cytosolic Ca2+ transients, SLN activates the CamKII-PGC1α signaling pathway to promote mitochondrial biogenesis.
Collapse
|
30
|
Niranjan N, Mareedu S, Tian Y, Kodippili K, Fefelova N, Voit A, Xie LH, Duan D, Babu GJ. Sarcolipin overexpression impairs myogenic differentiation in Duchenne muscular dystrophy. Am J Physiol Cell Physiol 2019; 317:C813-C824. [PMID: 31365291 DOI: 10.1152/ajpcell.00146.2019] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Reduction in the expression of sarcolipin (SLN), an inhibitor of sarco(endo)plasmic reticulum (SR) Ca2+-ATPase (SERCA), ameliorates severe muscular dystrophy in mice. However, the mechanism by which SLN inhibition improves muscle structure remains unclear. Here, we describe the previously unknown function of SLN in muscle differentiation in Duchenne muscular dystrophy (DMD). Overexpression of SLN in C2C12 resulted in decreased SERCA pump activity, reduced SR Ca2+ load, and increased intracellular Ca2+ (Cai2+) concentration. In addition, SLN overexpression resulted in altered expression of myogenic markers and poor myogenic differentiation. In dystrophin-deficient dog myoblasts and myotubes, SLN expression was significantly high and associated with defective Cai2+ cycling. The dystrophic dog myotubes were less branched and associated with decreased autophagy and increased expression of mitochondrial fusion and fission proteins. Reduction in SLN expression restored these changes and enhanced dystrophic dog myoblast fusion during differentiation. In summary, our data suggest that SLN upregulation is an intrinsic secondary change in dystrophin-deficient myoblasts and could account for the Cai2+ mishandling, which subsequently contributes to poor myogenic differentiation. Accordingly, reducing SLN expression can improve the Cai2+ cycling and differentiation of dystrophic myoblasts. These findings provide cellular-level supports for targeting SLN expression as a therapeutic strategy for DMD.
Collapse
Affiliation(s)
- Nandita Niranjan
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers University, Newark, New Jersey
| | - Satvik Mareedu
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers University, Newark, New Jersey
| | - Yimin Tian
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers University, Newark, New Jersey
| | - Kasun Kodippili
- Department of Molecular Microbiology and Immunology, University of Missouri, Columbia, Missouri
| | - Nadezhda Fefelova
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers University, Newark, New Jersey
| | - Antanina Voit
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers University, Newark, New Jersey
| | - Lai-Hua Xie
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers University, Newark, New Jersey
| | - Dongsheng Duan
- Department of Molecular Microbiology and Immunology, University of Missouri, Columbia, Missouri.,Department of Neurology, University of Missouri, Columbia, Missouri.,Department of Biomedical, Biological & Chemical Engineering, University of Missouri, Columbia, Missouri.,Department of Biomedical Sciences, University of Missouri, Columbia, Missouri
| | - Gopal J Babu
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers University, Newark, New Jersey
| |
Collapse
|
31
|
Gamu D, Juracic ES, Hall KJ, Tupling AR. The sarcoplasmic reticulum and SERCA: a nexus for muscular adaptive thermogenesis. Appl Physiol Nutr Metab 2019; 45:1-10. [PMID: 31116956 DOI: 10.1139/apnm-2019-0067] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
We are currently facing an "obesity epidemic" worldwide. Promoting inefficient metabolism in muscle represents a potential treatment for obesity and its complications. Sarco(endo)plasmic reticulum (SR) Ca2+-ATPase (SERCA) pumps in muscle are responsible for maintaining low cytosolic Ca2+ concentration through the ATP-dependent pumping of Ca2+ from the cytosol into the SR lumen. SERCA activity has the potential to be a critical regulator of body mass and adiposity given that it is estimated to contribute upwards of 20% of daily energy expenditure. More interestingly, this fraction can be modified physiologically in the face of stressors, such as ambient temperature and diet, through its physical interaction with several regulators known to inhibit Ca2+ uptake and muscle function. In this review, we discuss advances in our understanding of Ca2+-cycling thermogenesis within skeletal muscle, focusing on SERCA and its protein regulators, which were thought previously to only modulate muscular contractility. Novelty ATP consumption by SERCA pumps comprises a large proportion of resting energy expenditure in muscle and is dynamically regulated through interactions with small SERCA regulatory proteins. SERCA efficiency correlates significantly with resting metabolism, such that individuals with a higher resting metabolic rate have less energetically efficient SERCA Ca2+ pumping in muscle (i.e., lower coupling ratio). Futile Ca2+ cycling is a versatile heat generating mechanism utilized by both skeletal muscle and beige fat.
Collapse
Affiliation(s)
- Daniel Gamu
- Department of Kinesiology, University of Waterloo, Waterloo, ON N2L 3G1, Canada.,Department of Kinesiology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Emma Sara Juracic
- Department of Kinesiology, University of Waterloo, Waterloo, ON N2L 3G1, Canada.,Department of Kinesiology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Karlee J Hall
- Department of Kinesiology, University of Waterloo, Waterloo, ON N2L 3G1, Canada.,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.,Department of Kinesiology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| |
Collapse
|
32
|
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.
Collapse
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
| |
Collapse
|
33
|
Denham NC, Pearman CM, Caldwell JL, Madders GWP, Eisner DA, Trafford AW, Dibb KM. Calcium in the Pathophysiology of Atrial Fibrillation and Heart Failure. Front Physiol 2018; 9:1380. [PMID: 30337881 PMCID: PMC6180171 DOI: 10.3389/fphys.2018.01380] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 09/11/2018] [Indexed: 12/20/2022] Open
Abstract
Atrial fibrillation (AF) is commonly associated with heart failure. A bidirectional relationship exists between the two-AF exacerbates heart failure causing a significant increase in heart failure symptoms, admissions to hospital and cardiovascular death, while pathological remodeling of the atria as a result of heart failure increases the risk of AF. A comprehensive understanding of the pathophysiology of AF is essential if we are to break this vicious circle. In this review, the latest evidence will be presented showing a fundamental role for calcium in both the induction and maintenance of AF. After outlining atrial electrophysiology and calcium handling, the role of calcium-dependent afterdepolarizations and atrial repolarization alternans in triggering AF will be considered. The atrial response to rapid stimulation will be discussed, including the short-term protection from calcium overload in the form of calcium signaling silencing and the eventual progression to diastolic calcium leak causing afterdepolarizations and the development of an electrical substrate that perpetuates AF. The role of calcium in the bidirectional relationship between heart failure and AF will then be covered. The effects of heart failure on atrial calcium handling that promote AF will be reviewed, including effects on both atrial myocytes and the pulmonary veins, before the aspects of AF which exacerbate heart failure are discussed. Finally, the limitations of human and animal studies will be explored allowing contextualization of what are sometimes discordant results.
Collapse
Affiliation(s)
- Nathan C. Denham
- Unit of Cardiac Physiology, Division of Cardiovascular Sciences, Manchester Academic Health Science Centre, University of Manchester, Manchester, United Kingdom
| | | | | | | | | | | | - Katharine M. Dibb
- Unit of Cardiac Physiology, Division of Cardiovascular Sciences, Manchester Academic Health Science Centre, University of Manchester, Manchester, United Kingdom
| |
Collapse
|
34
|
Marfan Syndrome Variability: Investigation of the Roles of Sarcolipin and Calcium as Potential Transregulator of FBN1 Expression. Genes (Basel) 2018; 9:genes9090421. [PMID: 30134586 PMCID: PMC6162465 DOI: 10.3390/genes9090421] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 08/08/2018] [Accepted: 08/14/2018] [Indexed: 02/05/2023] Open
Abstract
Marfan syndrome (MFS) is an autosomal dominant connective tissue disorder that displays a great clinical variability. Previous work in our laboratory showed that fibrillin-1 (FBN1) messenger RNA (mRNA) expression is a surrogate endpoint for MFS severity. Therefore, an expression quantitative trait loci (eQTL) analysis was performed to identify trans-acting regulators of FBN1 expression, and a significant signal reached genome-wide significant threshold on chromosome 11. This signal delineated a region comprising one expressed gene, SLN (encoding sarcolipin), and a single pseudogene, SNX7-ps1 (CTD-2651C21.3). We first investigated the region and then looked for association between the genes in the region and FBN1 expression. For the first time, we showed that the SLN gene is weakly expressed in skin fibroblasts. There is no direct correlation between SLN and FBN1 gene expression. We showed that calcium influx modulates FBN1 gene expression. Finally, SLN gene expression is highly correlated to that of the neighboring SNX7-ps1. We were able to confirm the impact of calcium influx on FBN1 gene expression but we could not conclude regarding the role of sarcolipin and/or the eQTL locus in this regulation.
Collapse
|
35
|
Singh S, Sahoo SK, Periasamy M. Sarcolipin. ENCYCLOPEDIA OF SIGNALING MOLECULES 2018:4832-4836. [DOI: 10.1007/978-3-319-67199-4_101787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
|
36
|
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: 64] [Impact Index Per Article: 9.1] [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.
Collapse
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.
| |
Collapse
|
37
|
Periasamy M, Herrera JL, Reis FCG. Skeletal Muscle Thermogenesis and Its Role in Whole Body Energy Metabolism. Diabetes Metab J 2017; 41:327-336. [PMID: 29086530 PMCID: PMC5663671 DOI: 10.4093/dmj.2017.41.5.327] [Citation(s) in RCA: 120] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 09/08/2017] [Indexed: 12/25/2022] Open
Abstract
Obesity and diabetes has become a major epidemic across the globe. Controlling obesity has been a challenge since this would require either increased physical activity or reduced caloric intake; both are difficult to enforce. There has been renewed interest in exploiting pathways such as uncoupling protein 1 (UCP1)-mediated uncoupling in brown adipose tissue (BAT) and white adipose tissue to increase energy expenditure to control weight gain. However, relying on UCP1-based thermogenesis alone may not be sufficient to control obesity in humans. On the other hand, skeletal muscle is the largest organ and a major contributor to basal metabolic rate and increasing energy expenditure in muscle through nonshivering thermogenic mechanisms, which can substantially affect whole body metabolism and weight gain. In this review we will describe the role of Sarcolipin-mediated uncoupling of Sarcoplasmic Reticulum Calcium ATPase (SERCA) as a potential mechanism for increased energy expenditure both during cold and diet-induced thermogenesis.
Collapse
Affiliation(s)
- Muthu Periasamy
- Sanford Burnham Prebys Medical Discovery Institute at Lake Nona, Orlando, FL, USA.
| | - Jose Luis Herrera
- Sanford Burnham Prebys Medical Discovery Institute at Lake Nona, Orlando, FL, USA
| | - Felipe C G Reis
- Sanford Burnham Prebys Medical Discovery Institute at Lake Nona, Orlando, FL, USA
| |
Collapse
|
38
|
Periasamy M, Maurya SK, Sahoo SK, Singh S, Reis FCG, Bal NC. Role of SERCA Pump in Muscle Thermogenesis and Metabolism. Compr Physiol 2017. [DOI: 10.1002/cphy.c160030] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
39
|
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.
Collapse
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
| |
Collapse
|
40
|
Gamu D, Trinh A, Fajardo VA, Bombardier E, Tupling AR. Sarcolipin expression is not required for the mitochondrial enzymatic response to physical activity or diet. J Appl Physiol (1985) 2017; 122:1276-1283. [PMID: 28183820 DOI: 10.1152/japplphysiol.00833.2016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 02/06/2017] [Accepted: 02/06/2017] [Indexed: 11/22/2022] Open
Abstract
In mice, transgenic manipulation of Ca2+-handling proteins is sufficient to alter the metabolic phenotype of muscle. We have previously shown that ablation of sarcolipin (SLN), a regulatory protein and uncoupler of sarco(endo)plasmic reticulum Ca2+-ATPases, leads to excessive diet-induced obesity and glucose intolerance in mice. However, it is unclear how loss of SLN per se affects muscle oxidative capacity and the ability of mitochondria to adapt to physiological stimuli, such as exercise training or calorie overload. To address this question, Sln-/- and wild-type (WT) littermates were given access to voluntary running wheels or underwent a treadmill training protocol for 8 wk. Furthermore, a separate group of mice were given a high-fat diet (42% kcal from fat for 8 wk) to determine whether the excessively obese phenotype of Sln-/- mice is associated with altered oxidative capacity. While voluntary running was insufficient to elicit mitochondrial adaptations, treadmill-trained mice showed significant increases (P < 0.05) in the maximal activities of succinate dehydrogenase (+11%), citrate synthase (+12%), cytochrome oxidase (COX: +17%), along with increased protein expression of cytochrome c (+34%) and COX IV (+28%), which were irrespective of SLN expression. Lastly, no changes in the activities of mitochondrial marker enzymes existed with high-fat feeding, regardless of genotype. Together, these findings indicate that SLN is not required for the regulation of oxidative capacity in response to physiological stress, namely exercise or caloric surfeit.NEW & NOTEWORTHY Sarcolipin (SLN) has gained considerable attention for its uncoupling role of sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA). Because of SLN's ability to alter both cellular energy use and cytosolic [Ca2+], the potential exists for a regulatory role of mitochondrial biogenesis. Herein, we show skeletal muscle oxidative capacity to be unaltered in mice lacking SLN following exercise training or high-fat feeding. Our results contrast with published studies of SLN-overexpressing mice, possibly owing to supraphysiological uncoupling of SERCA.
Collapse
Affiliation(s)
- Daniel Gamu
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
| | - Anton Trinh
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
| | - Val A Fajardo
- 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
| |
Collapse
|
41
|
Cao Y, Wu X, Yang R, Wang X, Sun H, Lee I. Self-assembling study of sarcolipin and its mutants in multiple molecular dynamic simulations. Proteins 2017; 85:1065-1077. [PMID: 28241400 DOI: 10.1002/prot.25273] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 01/16/2017] [Accepted: 02/12/2017] [Indexed: 01/12/2023]
Abstract
The Sarcolipin (SLN) is a single trans-membrane protein that can self-assembly to dimer and oligomer for playing importantphysiological function. In this work, we addressed the dimerization of wild type SLN (wSLN) and its mutants (mSLNs) - I17A and I20A, using both coarse-grained (CG) and atomistic (AT) molecular dynamics (MD) simulations. Our results demonstrated that wSLN homodimer assembled as a left-handed helical complex, while mSLNs heterodimers assembled as right-handed complexes. Analysis of residue-residue contacts map indicated that isoleucine (Ile)-leucione (Leu) zipper domain played an important role in dimerization. The potential of mean force (PMF) demonstrated that wSLN homodimer was more stable than mSLNs heterodimers. Meanwhile, the mSLNs heterodimers preferred right-handed rather than left-handed helix. AT-MD simulations for wSLN and mSLNs were also in line with CG-MD simulations. These results provided the insights for understanding the mechanisms of SLNs self-assembling. Proteins 2017; 85:1065-1077. © 2017 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Yipeng Cao
- School of Physics, Nankai University, 94 Weijin Road, Tianjin, 300071, P.R.China
| | - Xue Wu
- School of Physics, Nankai University, 94 Weijin Road, Tianjin, 300071, P.R.China
| | - Rui Yang
- School of Medicine, Nankai University, 94 Weijin Road, Tianjin, 300071, P.R.China
| | - Xinyu Wang
- School of Physics, Nankai University, 94 Weijin Road, Tianjin, 300071, P.R.China
| | - Haiying Sun
- School of Physics, Nankai University, 94 Weijin Road, Tianjin, 300071, P.R.China
| | - Imshik Lee
- School of Physics, Nankai University, 94 Weijin Road, Tianjin, 300071, P.R.China
| |
Collapse
|
42
|
Fajardo VA, Gamu D, Mitchell A, Bloemberg D, Bombardier E, Chambers PJ, Bellissimo C, Quadrilatero J, Tupling AR. Sarcolipin deletion exacerbates soleus muscle atrophy and weakness in phospholamban overexpressing mice. PLoS One 2017; 12:e0173708. [PMID: 28278204 PMCID: PMC5344511 DOI: 10.1371/journal.pone.0173708] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 02/24/2017] [Indexed: 11/18/2022] Open
Abstract
Sarcolipin (SLN) and phospholamban (PLN) are two small proteins that regulate the sarco(endo)plasmic reticulum Ca2+-ATPase pumps. In a recent study, we discovered that Pln overexpression (PlnOE) in slow-twitch type I skeletal muscle fibers drastically impaired SERCA function and caused a centronuclear myopathy-like phenotype, severe muscle atrophy and weakness, and an 8 to 9-fold upregulation of SLN protein in the soleus muscles. Here, we sought to determine the physiological role of SLN upregulation, and based on its role as a SERCA inhibitor, we hypothesized that it would represent a maladaptive response that contributes to the SERCA dysfunction and the overall myopathy observed in the PlnOE mice. To this end, we crossed Sln-null (SlnKO) mice with PlnOE mice to generate a PlnOE/SlnKO mouse colony and assessed SERCA function, CNM pathology, in vitro contractility, muscle mass, calcineurin signaling, daily activity and food intake, and proteolytic enzyme activity. Our results indicate that genetic deletion of Sln did not improve SERCA function nor rescue the CNM phenotype, but did result in exacerbated muscle atrophy and weakness, due to a failure to induce type II fiber compensatory hypertrophy and a reduction in total myofiber count. Mechanistically, our findings suggest that impaired calcineurin activation and resultant decreased expression of stabilin-2, and/or impaired autophagic signaling could be involved. Future studies should examine these possibilities. In conclusion, our study demonstrates the importance of SLN upregulation in combating muscle myopathy in the PlnOE mice, and since SLN is upregulated across several myopathies, our findings may reveal SLN as a novel and universal therapeutic target.
Collapse
Affiliation(s)
- Val A. Fajardo
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada, N2L 3G1
| | - Daniel Gamu
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada, N2L 3G1
| | - Andrew Mitchell
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada, N2L 3G1
| | - Darin Bloemberg
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada, N2L 3G1
| | - Eric Bombardier
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada, N2L 3G1
| | - Paige J. Chambers
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada, N2L 3G1
| | - Catherine Bellissimo
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada, N2L 3G1
| | - Joe Quadrilatero
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada, N2L 3G1
| | - A. Russell Tupling
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada, N2L 3G1
- * E-mail:
| |
Collapse
|
43
|
Abstract
Cardiac arrhythmias can follow disruption of the normal cellular electrophysiological processes underlying excitable activity and their tissue propagation as coherent wavefronts from the primary sinoatrial node pacemaker, through the atria, conducting structures and ventricular myocardium. These physiological events are driven by interacting, voltage-dependent, processes of activation, inactivation, and recovery in the ion channels present in cardiomyocyte membranes. Generation and conduction of these events are further modulated by intracellular Ca2+ homeostasis, and metabolic and structural change. This review describes experimental studies on murine models for known clinical arrhythmic conditions in which these mechanisms were modified by genetic, physiological, or pharmacological manipulation. These exemplars yielded molecular, physiological, and structural phenotypes often directly translatable to their corresponding clinical conditions, which could be investigated at the molecular, cellular, tissue, organ, and whole animal levels. Arrhythmogenesis could be explored during normal pacing activity, regular stimulation, following imposed extra-stimuli, or during progressively incremented steady pacing frequencies. Arrhythmic substrate was identified with temporal and spatial functional heterogeneities predisposing to reentrant excitation phenomena. These could arise from abnormalities in cardiac pacing function, tissue electrical connectivity, and cellular excitation and recovery. Triggering events during or following recovery from action potential excitation could thereby lead to sustained arrhythmia. These surface membrane processes were modified by alterations in cellular Ca2+ homeostasis and energetics, as well as cellular and tissue structural change. Study of murine systems thus offers major insights into both our understanding of normal cardiac activity and its propagation, and their relationship to mechanisms generating clinical arrhythmias.
Collapse
Affiliation(s)
- Christopher L-H Huang
- Physiological Laboratory and the Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| |
Collapse
|
44
|
Pant M, Bal NC, Periasamy M. Sarcolipin: A Key Thermogenic and Metabolic Regulator in Skeletal Muscle. Trends Endocrinol Metab 2016; 27:881-892. [PMID: 27637585 PMCID: PMC5424604 DOI: 10.1016/j.tem.2016.08.006] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 08/19/2016] [Accepted: 08/22/2016] [Indexed: 12/14/2022]
Abstract
Skeletal muscle constitutes ∼40% of body mass and has the capacity to play a major role as thermogenic, metabolic, and endocrine organ. In addition to shivering, muscle also contributes to nonshivering thermogenesis via futile sarcoplasmic/endoplasmic reticulum Ca2+ ATPase (SERCA) activity. Sarcolipin (SLN), a regulator of SERCA activity in muscle, plays an important role in regulating muscle thermogenesis and metabolism. Uncoupling of SERCA by SLN increases ATP hydrolysis and heat production, and contributes to temperature homeostasis. SLN also affects whole-body metabolism and weight gain in mice, and is upregulated in various muscle diseases including muscular dystrophy, suggesting a role for SLN during increased metabolic demand. In this review we also highlight the physiological roles of skeletal muscle beyond contraction.
Collapse
Affiliation(s)
- Meghna Pant
- Department of Physiology and Cell Biology, Ohio State University, Columbus, OH, USA
| | - Naresh C Bal
- Sanford Burnham Medical Research Institute at Lake Nona, Orlando, FL, USA; School of Biotechnology, KIIT University, Bhubaneswar, Odisha, India
| | - Muthu Periasamy
- Department of Physiology and Cell Biology, Ohio State University, Columbus, OH, USA; Sanford Burnham Medical Research Institute at Lake Nona, Orlando, FL, USA.
| |
Collapse
|
45
|
Abstract
Hibernation is characterized by prolonged periods of inactivity with concomitantly low nutrient intake, conditions that would typically result in muscle atrophy combined with a loss of oxidative fibers. Yet, hibernators consistently emerge from winter with very little atrophy, frequently accompanied by a slight shift in fiber ratios to more oxidative fiber types. Preservation of muscle morphology is combined with down-regulation of glycolytic pathways and increased reliance on lipid metabolism instead. Furthermore, while rates of protein synthesis are reduced during hibernation, balance is maintained by correspondingly low rates of protein degradation. Proposed mechanisms include a number of signaling pathways and transcription factors that lead to increased oxidative fiber expression, enhanced protein synthesis and reduced protein degradation, ultimately resulting in minimal loss of skeletal muscle protein and oxidative capacity. The functional significance of these outcomes is maintenance of skeletal muscle strength and fatigue resistance, which enables hibernating animals to resume active behaviors such as predator avoidance, foraging and mating immediately following terminal arousal in the spring.
Collapse
Affiliation(s)
- Clark J Cotton
- Department of Biology, College of St Benedict/St John's University, Collegeville, MN 56321, USA
| |
Collapse
|
46
|
Sakakibara I, Wurmser M, Dos Santos M, Santolini M, Ducommun S, Davaze R, Guernec A, Sakamoto K, Maire P. Six1 homeoprotein drives myofiber type IIA specialization in soleus muscle. Skelet Muscle 2016; 6:30. [PMID: 27597886 PMCID: PMC5011358 DOI: 10.1186/s13395-016-0102-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 08/16/2016] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Adult skeletal muscles are composed of slow and fast myofiber subtypes which each express selective genes required for their specific contractile and metabolic activity. Six homeoproteins are transcription factors regulating muscle cell fate through activation of myogenic regulatory factors and driving fast-type gene expression during embryogenesis. RESULTS We show here that Six1 protein accumulates more robustly in the nuclei of adult fast-type muscles than in adult slow-type muscles, this specific enrichment takes place during perinatal growth. Deletion of Six1 in soleus impaired fast-type myofiber specialization during perinatal development, resulting in a slow phenotype and a complete lack of Myosin heavy chain 2A (MyHCIIA) expression. Global transcriptomic analysis of wild-type and Six1 mutant myofibers identified the gene networks controlled by Six1 in adult soleus muscle. This analysis showed that Six1 is required for the expression of numerous genes encoding fast-type sarcomeric proteins, glycolytic enzymes and controlling intracellular calcium homeostasis. Parvalbumin, a key player of calcium buffering, in particular, is a direct target of Six1 in the adult myofiber. CONCLUSIONS This analysis revealed that Six1 controls distinct aspects of adult muscle physiology in vivo, and acts as a main determinant of fast-fiber type acquisition and maintenance.
Collapse
Affiliation(s)
- Iori Sakakibara
- INSERM U1016, Institut Cochin, Paris, 75014 France
- CNRS UMR 8104, Paris, 75014 France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, 75014 France
- Division of Integrative Pathophysiology, Proteo-Science Center, Graduate School of Medicine, Ehime University, Ehime, Japan
| | - Maud Wurmser
- INSERM U1016, Institut Cochin, Paris, 75014 France
- CNRS UMR 8104, Paris, 75014 France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, 75014 France
| | - Matthieu Dos Santos
- INSERM U1016, Institut Cochin, Paris, 75014 France
- CNRS UMR 8104, Paris, 75014 France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, 75014 France
| | - Marc Santolini
- Laboratoire de Physique Statistique, CNRS, Université P. et M. Curie, Université D. Diderot, École Normale Supérieure, Paris, 75005 France
| | - Serge Ducommun
- Nestlé Institute of Health Sciences SA, EPFL Innovation Park, Lausanne, Switzerland
| | - Romain Davaze
- INSERM U1016, Institut Cochin, Paris, 75014 France
- CNRS UMR 8104, Paris, 75014 France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, 75014 France
| | - Anthony Guernec
- INSERM U1016, Institut Cochin, Paris, 75014 France
- CNRS UMR 8104, Paris, 75014 France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, 75014 France
| | - Kei Sakamoto
- Nestlé Institute of Health Sciences SA, EPFL Innovation Park, Lausanne, Switzerland
| | - Pascal Maire
- INSERM U1016, Institut Cochin, Paris, 75014 France
- CNRS UMR 8104, Paris, 75014 France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, 75014 France
| |
Collapse
|
47
|
Goette A, Kalman JM, Aguinaga L, Akar J, Cabrera JA, Chen SA, Chugh SS, Corradi D, D'Avila A, Dobrev D, Fenelon G, Gonzalez M, Hatem SN, Helm R, Hindricks G, Ho SY, Hoit B, Jalife J, Kim YH, Lip GYH, Ma CS, Marcus GM, Murray K, Nogami A, Sanders P, Uribe W, Van Wagoner DR, Nattel S. EHRA/HRS/APHRS/SOLAECE expert consensus on Atrial cardiomyopathies: Definition, characterisation, and clinical implication. J Arrhythm 2016; 32:247-78. [PMID: 27588148 PMCID: PMC4996910 DOI: 10.1016/j.joa.2016.05.002] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Affiliation(s)
- Andreas Goette
- Departement of Cardiology and Intensive Care Medicine, St. Vincenz-Hospital Paderborn, Working Group: Molecular Electrophysiology, University Hospital Magdeburg, Germany
| | - Jonathan M Kalman
- University of Melbourne, Royal Melbourne Hospital, Melbourne, VIC, Australia
| | | | | | | | | | - Sumeet S Chugh
- The Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | | | | | - Dobromir Dobrev
- Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany
| | | | - Mario Gonzalez
- Penn State Heart and Vascular Institute, Penn State University, Hershey, PA, USA
| | - Stephane N Hatem
- Department of Cardiology, Assistance Publique - Hô pitaux de Paris, Pitié-Salpêtrière Hospital, Sorbonne University, INSERM UMR_S1166, Institute of Cardiometabolism and Nutrition-ICAN, Paris, France
| | - Robert Helm
- Boston University School of Medicine, Boston Medical Center, Boston, MA, USA
| | | | - Siew Yen Ho
- Royal Brompton Hospital and Imperial College London, London, UK
| | - Brian Hoit
- UH Case Medical Center, Cleveland, OH, USA
| | | | | | | | | | | | | | | | - Prashanthan Sanders
- Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute, University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia
| | - William Uribe
- Electrophysiology Deparment at Centros Especializados de San Vicente Fundació n and Clínica CES. Universidad CES, Universidad Pontificia Bolivariana (UPB), Medellin, Colombia
| | | | - Stanley Nattel
- Université de Montréal, Montreal Heart Institute Research Center and McGill University, Montreal, Quebec, Canada; Institute of Pharmacology, West German Heart and Vascular Center, Faculty of Medicine, University Duisburg-Essen, Essen, Germany
| | | | | |
Collapse
|
48
|
Goette A, Kalman JM, Aguinaga L, Akar J, Cabrera JA, Chen SA, Chugh SS, Corradi D, D'Avila A, Dobrev D, Fenelon G, Gonzalez M, Hatem SN, Helm R, Hindricks G, Ho SY, Hoit B, Jalife J, Kim YH, Lip GYH, Ma CS, Marcus GM, Murray K, Nogami A, Sanders P, Uribe W, Van Wagoner DR, Nattel S. EHRA/HRS/APHRS/SOLAECE expert consensus on atrial cardiomyopathies: definition, characterization, and clinical implication. Europace 2016; 18:1455-1490. [PMID: 27402624 DOI: 10.1093/europace/euw161] [Citation(s) in RCA: 426] [Impact Index Per Article: 53.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- Andreas Goette
- Departement of Cardiology and Intensive Care Medicine, St. Vincenz-Hospital Paderborn, Working Group: Molecular Electrophysiology, University Hospital Magdeburg, Germany
| | - Jonathan M Kalman
- University of Melbourne, Royal Melbourne Hospital, Melbourne, VIC, Australia
| | | | | | | | | | - Sumeet S Chugh
- The Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | | | | | - Dobromir Dobrev
- Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany
| | | | - Mario Gonzalez
- Penn State Heart and Vascular Institute, Penn State University, Hershey, PA, USA
| | - Stephane N Hatem
- Department of Cardiology, Assistance Publique - Hôpitaux de Paris, Pitié-Salpêtrière Hospital; Sorbonne University; INSERM UMR_S1166; Institute of Cardiometabolism and Nutrition-ICAN, Paris, France
| | - Robert Helm
- Boston University School of Medicine, Boston Medical Center, Boston, MA, USA
| | | | - Siew Yen Ho
- Royal Brompton Hospital and Imperial College London, London, UK
| | - Brian Hoit
- UH Case Medical Center, Cleveland, OH, USA
| | | | | | | | | | | | | | | | - Prashanthan Sanders
- Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute, University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia
| | - William Uribe
- Electrophysiology Deparment at Centros Especializados de San Vicente Fundación and Clínica CES. Universidad CES, Universidad Pontificia Bolivariana (UPB), Medellin, Colombia
| | | | - Stanley Nattel
- Université de Montréal, Montreal Heart Institute Research Center and McGill University, Montreal, Quebec, Canada .,Institute of Pharmacology, West German Heart and Vascular Center, Faculty of Medicine, University Duisburg-Essen, Essen, Germany
| | | |
Collapse
|
49
|
Rowland LA, Maurya SK, Bal NC, Kozak L, Periasamy M. Sarcolipin and uncoupling protein 1 play distinct roles in diet-induced thermogenesis and do not compensate for one another. Obesity (Silver Spring) 2016; 24:1430-3. [PMID: 27238087 PMCID: PMC4925282 DOI: 10.1002/oby.21542] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 03/24/2016] [Accepted: 04/01/2016] [Indexed: 02/03/2023]
Abstract
OBJECTIVE It is well known that uncoupling protein 1 (UCP1) in brown adipose tissue plays an important role in diet-induced thermogenesis. In this study, whether sarcolipin (SLN), a regulator of sarco/endoplasmic reticulum Ca(2+) -ATPase pump in muscle, is also an important player of diet-induced thermogenesis was investigated, as well as whether loss of SLN could be compensated by increased UCP1 expression and vice versa. METHODS Age- and sex-matched UCP1(-/-) , SLN(-/-) , and double knockout for both UCP1 and SLN mice maintained in C57Bl/6J background were challenged to high-fat diet for 12 weeks and then analyzed for weight gain, alterations in serum metabolites, and changes in thermogenic protein expression. RESULTS Loss of either SLN or UCP1 alone was sufficient to cause diet-induced obesity. No compensatory upregulation of UCP1 in SLN(-/-) mice or vice versa was found. Paradoxically, loss of both mechanisms failed to exacerbate the obesity phenotype. CONCLUSIONS Data suggest that both SLN- and UCP1-based adaptive thermogenic mechanisms were essential for achieving maximal diet-induced thermogenesis. When both mechanisms were absent, less efficient thermogenic mechanisms were activated to counter energy imbalance.
Collapse
Affiliation(s)
- Leslie A Rowland
- Department of Physiology and Cell Biology, The Ohio State University, College of Medicine, Columbus, Ohio, USA
| | - Santosh K Maurya
- Sanford Burnham Prebys Medical Discovery Institute, Lake Nona, Orlando, Florida, USA
| | - Naresh C Bal
- Department of Physiology and Cell Biology, The Ohio State University, College of Medicine, Columbus, Ohio, USA
- Sanford Burnham Prebys Medical Discovery Institute, Lake Nona, Orlando, Florida, USA
| | - Leslie Kozak
- Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, Olsztyn, Poland
| | - Muthu Periasamy
- Department of Physiology and Cell Biology, The Ohio State University, College of Medicine, Columbus, Ohio, USA
- Sanford Burnham Prebys Medical Discovery Institute, Lake Nona, Orlando, Florida, USA
| |
Collapse
|
50
|
Cao Y, Wu X, Wang X, Sun H, Lee I. Transmembrane dynamics of the Thr-5 phosphorylated sarcolipin pentameric channel. Arch Biochem Biophys 2016; 604:143-51. [PMID: 27378083 DOI: 10.1016/j.abb.2016.06.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2016] [Revised: 06/23/2016] [Accepted: 06/24/2016] [Indexed: 12/16/2022]
Abstract
Sarcolipin (SLN), an important membrane protein expressed in the sarcoplasmic reticulum (SR), regulates muscle contractions in cardiac and skeletal muscle. The phosphorylation at amino acid Thr5 of the SLN protein modulates the amount of Ca(2+) that passes through the SR. Using molecular dynamics simulation, we evaluated the phosphorylation at Thr5 of pentameric SLN (phospho-SLN) channel's energy barrier and pore characteristics by calculating the potential of mean force (PMF) along the channel pore and determining the diffusion coefficient. The results indicate that pentameric phospho-SLN promotes penetration of monovalent and divalent ions through the channel. The analysis of PMF, pore radius and diffusion coefficient indicates that Leu21 is the hydrophobic gate of the pentameric SLN channel. In the channel, water molecules near the Leu21 pore demonstrated a clear hydrated-dehydrated transition; however, the mutation of Leu21 to an Alanine (L21A) destroyed the hydrated-dehydrated transitions. These water-dynamic behaviors and PMF confirm that Leu21 is the key residue that regulates the ion permeability of the pentameric SLN channel. These results provide the structural-basis insights and molecular-dynamic information that are needed to understand the regulatory mechanisms of ion permeability in the pentameric SLN channel.
Collapse
Affiliation(s)
- Yipeng Cao
- Institute of Physics, Nankai University, No.94 Weijin Road, Tianjin, 300071, PR China
| | - Xue Wu
- Institute of Physics, Nankai University, No.94 Weijin Road, Tianjin, 300071, PR China
| | - Xinyu Wang
- Institute of Physics, Nankai University, No.94 Weijin Road, Tianjin, 300071, PR China
| | - Haiying Sun
- Institute of Physics, Nankai University, No.94 Weijin Road, Tianjin, 300071, PR China
| | - Imshik Lee
- Institute of Physics, Nankai University, No.94 Weijin Road, Tianjin, 300071, PR China.
| |
Collapse
|