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Bardova K, Janovska P, Vavrova A, Kopecky J, Zouhar P. Adaptive Induction of Nonshivering Thermogenesis in Muscle Rather Than Brown Fat Could Counteract Obesity. Physiol Res 2024; 73:S279-S294. [PMID: 38752772 DOI: 10.33549/physiolres.935361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/04/2024] Open
Abstract
Warm-blooded animals such as birds and mammals are able to protect stable body temperature due to various thermogenic mechanisms. These processes can be facultative (occurring only under specific conditions, such as acute cold) and adaptive (adjusting their capacity according to long-term needs). They can represent a substantial part of overall energy expenditure and, therefore, affect energy balance. Classical mechanisms of facultative thermogenesis include shivering of skeletal muscles and (in mammals) non-shivering thermogenesis (NST) in brown adipose tissue (BAT), which depends on uncoupling protein 1 (UCP1). Existence of several alternative thermogenic mechanisms has been suggested. However, their relative contribution to overall heat production and the extent to which they are adaptive and facultative still needs to be better defined. Here we focus on comparison of NST in BAT with thermogenesis in skeletal muscles, including shivering and NST. We present indications that muscle NST may be adaptive but not facultative, unlike UCP1-dependent NST. Due to its slow regulation and low energy efficiency, reflecting in part the anatomical location, induction of muscle NST may counteract development of obesity more effectively than UCP1-dependent thermogenesis in BAT.
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Affiliation(s)
- K Bardova
- Laboratory of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Prague 4, Czech Republic. or
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2
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Raun SH, Braun JL, Karavaeva I, Henriquez-Olguín C, Ali MS, Møller LLV, Gerhart-Hines Z, Fajardo VA, Richter EA, Sylow L. Mild Cold Stress at Ambient Temperature Elevates Muscle Calcium Cycling and Exercise Adaptations in Obese Female Mice. Endocrinology 2024; 165:bqae102. [PMID: 39136248 DOI: 10.1210/endocr/bqae102] [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: 04/09/2024] [Indexed: 08/28/2024]
Abstract
CONTEXT Housing temperature is a critical regulator of mouse metabolism and thermoneutral housing can improve model translation to humans. However, the impact of housing temperature on the ability of wheel running exercise training to rescue the detrimental effect of diet-induced obese mice is currently not fully understood. OBJECTIVE To investigate how housing temperature affects muscle metabolism in obese mice with regard to calcium handling and exercise training (ET) adaptations in skeletal muscle, and benefits of ET on adiposity and glucometabolic parameters. METHODS Lean or obese female mice were housed at standard ambient temperature (22 °C) or thermoneutrality (30 °C) with/without access to running wheels. The metabolic phenotype was investigated using glucose tolerance tests, indirect calorimetry, and body composition. Molecular muscle adaptations were measured using immunoblotting, qPCR, and spectrophotometric/fluorescent assays. RESULTS Obese female mice housed at 22 °C showed lower adiposity, lower circulating insulin levels, improved glucose tolerance, and elevated basal metabolic rate compared to 30 °C housing. Mice exposed to voluntary wheel running exhibited a larger fat loss and higher metabolic rate at 22 °C housing compared to thermoneutrality. In obese female mice, glucose tolerance improved after ET independent of housing temperature. Independent of diet and training, 22 °C housing increased skeletal muscle sarco(endo)plasmic reticulum Ca2+ ATPase (SERCA) activity. Additionally, housing at 22 °C elevated the induction of training-responsive muscle proteins in obese mice. CONCLUSION Our findings highlight that housing temperature significantly influences adiposity, insulin sensitivity, muscle physiology, and exercise adaptations in diet-induced obese female mice.
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Affiliation(s)
- Steffen H Raun
- Molecular Metabolism in Cancer and Ageing, Department of Biomedical Sciences, Faculty of Health, University of Copenhagen, Copenhagen 2200, Denmark
| | - Jessica L Braun
- Muscle Plasticity in Health and Disease, Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, St. Catharines, L2A 3A1, Canada
| | - Iuliia Karavaeva
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health, University of Copenhagen, Copenhagen 2200, Denmark
| | - Carlos Henriquez-Olguín
- The August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen 2100, Denmark
- Exercise Science Laboratory, Faculty of Medicine, Universidad Finis Terrae, Santiago 7501015, Chile
| | - Mona S Ali
- Molecular Metabolism in Cancer and Ageing, Department of Biomedical Sciences, Faculty of Health, University of Copenhagen, Copenhagen 2200, Denmark
| | - Lisbeth L V Møller
- Molecular Metabolism in Cancer and Ageing, Department of Biomedical Sciences, Faculty of Health, University of Copenhagen, Copenhagen 2200, Denmark
| | - Zachary Gerhart-Hines
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health, University of Copenhagen, Copenhagen 2200, Denmark
| | - Val A Fajardo
- Muscle Plasticity in Health and Disease, Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, St. Catharines, L2A 3A1, Canada
| | - Erik A Richter
- The August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen 2100, Denmark
| | - Lykke Sylow
- Molecular Metabolism in Cancer and Ageing, Department of Biomedical Sciences, Faculty of Health, University of Copenhagen, Copenhagen 2200, Denmark
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Ponce-Balbuena D, Tyrrell DJ, Cruz-Cortés C, Guerrero-Serna G, Da Rocha AM, Herron TJ, Song J, Raza DS, Anumonwo J, Goldstein DR, Espinoza-Fonseca LM. Paradoxical SERCA dysregulation contributes to atrial fibrillation in a model of diet-induced obesity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.02.606385. [PMID: 39149279 PMCID: PMC11326153 DOI: 10.1101/2024.08.02.606385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 08/17/2024]
Abstract
Obesity is a major risk factor for atrial fibrillation (AF) the most common serious cardiac arrhythmia, but the molecular mechanisms underlying diet-induced AF remain unclear. In this study, we subjected mice to a chronic high-fat diet and acute sympathetic activation ('two-hit' model) to study the mechanisms by which diet-induced obesity promotes AF. Surface electrocardiography revealed that diet-induced obesity and sympathetic activation synergize during intracardiac tachypacing to induce AF. At the cellular level, diet-induced obesity and acute adrenergic stimulation facilitate the formation of delayed afterdepolarizations in atrial myocytes, implicating altered Ca2+ dynamics as the underlying cause of AF. We found that diet-induced obesity does not alter the expression of major Ca2+-handling proteins in atria, including the sarcoplasmic reticulum Ca2+-ATPase (SERCA), a major component of beat-to-beat Ca2+ cycling in the heart. Paradoxically, obesity reduces phospholamban phosphorylation, suggesting decreased SERCA activity, yet atrial myocytes from obese mice showed a significantly increased Ca2+ transient amplitude and SERCA-mediated Ca2+ uptake. Adrenergic stimulation further increases the Ca2+ transient amplitude but does not affect Ca2+ reuptake in atrial myocytes from obese mice. Transcriptomics analysis showed that a high-fat diet prompts upregulation of neuronatin, a protein that has been implicated in obesity and is known to stimulate SERCA activity. We propose a mechanism in which obesity primes SERCA for paradoxical activation, and adrenergic stimulation facilitates AF conversion through a Ca2+-induced Ca2+ release gain in atrial myocytes. Overall, this study links obesity, altered Ca2+ signaling, and AF, and targeting this mechanism may prove effective for treating obesity-induced AF.
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Affiliation(s)
- Daniela Ponce-Balbuena
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
- Center for Arrhythmia Research, University of Michigan, MI 48109, USA
| | - Daniel J. Tyrrell
- Graduate Program in Immunology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Carlos Cruz-Cortés
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
- Center for Arrhythmia Research, University of Michigan, MI 48109, USA
| | - Guadalupe Guerrero-Serna
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
- Center for Arrhythmia Research, University of Michigan, MI 48109, USA
| | - Andre Monteiro Da Rocha
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
- Center for Arrhythmia Research, University of Michigan, MI 48109, USA
| | - Todd J. Herron
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
- Center for Arrhythmia Research, University of Michigan, MI 48109, USA
| | - Jianrui Song
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Danyal S. Raza
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
- Center for Arrhythmia Research, University of Michigan, MI 48109, USA
| | - Justus Anumonwo
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
- Center for Arrhythmia Research, University of Michigan, MI 48109, USA
| | - Daniel R. Goldstein
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
- Graduate Program in Immunology, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Microbiology and Immunology, University of Michigan, MI 48109, USA
| | - L. Michel Espinoza-Fonseca
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
- Center for Arrhythmia Research, University of Michigan, MI 48109, USA
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Braun JL, Fajardo VA. Spaceflight increases sarcoplasmic reticulum Ca 2+ leak and this cannot be counteracted with BuOE treatment. NPJ Microgravity 2024; 10:78. [PMID: 39030182 PMCID: PMC11271499 DOI: 10.1038/s41526-024-00419-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Accepted: 07/11/2024] [Indexed: 07/21/2024] Open
Abstract
Spending time in a microgravity environment is known to cause significant skeletal muscle atrophy and weakness via muscle unloading, which can be partly attributed to Ca2+ dysregulation. The sarco(endo)plasmic reticulum Ca2+ ATPase (SERCA) pump is responsible for bringing Ca2+ from the cytosol into its storage site, the sarcoplasmic reticulum (SR), at the expense of ATP. We have recently demonstrated that, in the soleus of space-flown mice, the Ca2+ uptake ability of the SERCA pump is severely impaired and this may be attributed to increases in reactive oxygen/nitrogen species (RONS), to which SERCA is highly susceptible. The purpose of this study was therefore to investigate whether treatment with the antioxidant, Manganese(III) meso-tetrakis(N-n-butoxyethylpyridinium-2-yl)porphyrin, MnTnBuOE-2-PyP5+ (BuOE), could attenuate muscle atrophy and SERCA dysfunction. We received soleus muscles from the rodent research 18 mission which had male mice housed on the international space station for 35 days and treated with either saline or BuOE. Spaceflight significantly reduced the soleus:body mass ratio and significantly increased SERCA's ionophore ratio, a measure of SR Ca2+ leak, and 4-HNE content (marker of RONS), none of which could be rescued by BuOE treatment. In conclusion, we find that spaceflight induces significant soleus muscle atrophy and SR Ca2+ leak that cannot be counteracted with BuOE treatment. Future work should investigate alternative therapeutics that are specifically aimed at increasing SERCA activation or reducing Ca2+ leak.
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Affiliation(s)
- Jessica L Braun
- Department of Kinesiology, Brock University, St. Catharines, ON, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - Val A Fajardo
- Department of Kinesiology, Brock University, St. Catharines, ON, Canada.
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada.
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5
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Rahbani JF, Bunk J, Lagarde D, Samborska B, Roesler A, Xiao H, Shaw A, Kaiser Z, Braun JL, Geromella MS, Fajardo VA, Koza RA, Kazak L. Parallel control of cold-triggered adipocyte thermogenesis by UCP1 and CKB. Cell Metab 2024; 36:526-540.e7. [PMID: 38272036 DOI: 10.1016/j.cmet.2024.01.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 11/27/2023] [Accepted: 01/02/2024] [Indexed: 01/27/2024]
Abstract
That uncoupling protein 1 (UCP1) is the sole mediator of adipocyte thermogenesis is a conventional viewpoint that has primarily been inferred from the attenuation of the thermogenic output of mice genetically lacking Ucp1 from birth (germline Ucp1-/-). However, germline Ucp1-/- mice harbor secondary changes within brown adipose tissue. To mitigate these potentially confounding ancillary changes, we constructed mice with inducible adipocyte-selective Ucp1 disruption. We find that, although germline Ucp1-/- mice succumb to cold-induced hypothermia with complete penetrance, most mice with the inducible deletion of Ucp1 maintain homeothermy in the cold. However, inducible adipocyte-selective co-deletion of Ucp1 and creatine kinase b (Ckb, an effector of UCP1-independent thermogenesis) exacerbates cold intolerance. Following UCP1 deletion or UCP1/CKB co-deletion from mature adipocytes, moderate cold exposure triggers the regeneration of mature brown adipocytes that coordinately restore UCP1 and CKB expression. Our findings suggest that thermogenic adipocytes utilize non-paralogous protein redundancy-through UCP1 and CKB-to promote cold-induced energy dissipation.
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Affiliation(s)
- Janane F Rahbani
- Rosalind and Morris Goodman Cancer Institute, McGill University, Montreal, QC H3A 1A3, Canada
| | - Jakub Bunk
- Rosalind and Morris Goodman Cancer Institute, McGill University, Montreal, QC H3A 1A3, Canada; Department of Biochemistry, McGill University, Montreal, QC H3G 1Y6, Canada
| | - Damien Lagarde
- Rosalind and Morris Goodman Cancer Institute, McGill University, Montreal, QC H3A 1A3, Canada
| | - Bozena Samborska
- Rosalind and Morris Goodman Cancer Institute, McGill University, Montreal, QC H3A 1A3, Canada
| | - Anna Roesler
- Rosalind and Morris Goodman Cancer Institute, McGill University, Montreal, QC H3A 1A3, Canada; Department of Biochemistry, McGill University, Montreal, QC H3G 1Y6, Canada
| | - Haopeng Xiao
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Abhirup Shaw
- Rosalind and Morris Goodman Cancer Institute, McGill University, Montreal, QC H3A 1A3, Canada
| | - Zafir Kaiser
- Rosalind and Morris Goodman Cancer Institute, McGill University, Montreal, QC H3A 1A3, Canada; Department of Biochemistry, McGill University, Montreal, QC H3G 1Y6, Canada
| | - Jessica L Braun
- Department of Kinesiology, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - Mia S Geromella
- Department of Kinesiology, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - Val A Fajardo
- Department of Kinesiology, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - Robert A Koza
- MaineHealth Institute for Research, Scarborough, ME 04074, USA
| | - Lawrence Kazak
- Rosalind and Morris Goodman Cancer Institute, McGill University, Montreal, QC H3A 1A3, Canada; Department of Biochemistry, McGill University, Montreal, QC H3G 1Y6, Canada.
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Hockey BL, Finch MS, Braun JL, Mohammad A, Maddalena LA, Vandenboom R, Stuart JA, Roy BD, MacPherson REK, Fajardo VA. Characterizing the effects of muscle-specific GSK3α/β reduction on murine muscle contractility and metabolism in female mice. Am J Physiol Cell Physiol 2024; 326:C999-C1009. [PMID: 38344799 DOI: 10.1152/ajpcell.00398.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 02/01/2024] [Accepted: 02/01/2024] [Indexed: 03/06/2024]
Abstract
Dysregulation of skeletal muscle morphology and metabolism is associated with chronic diseases such as obesity and type 2 diabetes. The enzyme glycogen synthase kinase 3 (GSK3) is highly involved in skeletal muscle physiology and metabolism, acting as a negative regulator of muscle size, strength, adaptive thermogenesis, and glucose homeostasis. Correspondingly, we have shown that partial knockdown (∼40%) of GSK3 specifically in skeletal muscle increases lean mass, reduces fat mass, and activates muscle-based adaptive thermogenesis via sarco(endo)plasmic reticulum Ca2+ (SERCA) uncoupling in male mice. However, the effects of GSK3 knockdown in female mice have yet to be investigated. Here, we examined the effects of muscle-specific GSK3 knockdown on body composition, muscle size and strength, and whole body metabolism in female C57BL/6J mice. Our results show that GSK3 content is higher in the female soleus versus the male soleus; however, there were no differences in the extensor digitorum longus (EDL). Furthermore, muscle-specific GSK3 knockdown did not alter body composition in female mice, nor did it alter daily energy expenditure, glucose/insulin tolerance, mitochondrial respiration, or the expression of the SERCA uncouplers sarcolipin and neuronatin. We also did not find any differences in soleus muscle size, strength, or fatigue resistance. In the EDL, we found that an increase in absolute and specific force production, but there were no differences in fatigability. Therefore, our study highlights sex differences in the response to genetic reduction of gsk3, with most of the effects previously observed in male mice being absent in females.NEW & NOTEWORTHY Here we show that partial GSK3 knockdown has minimal effects on whole body metabolism and muscle contractility in female mice. This is partly inconsistent with previous results found in male mice, which reveal a potential influence of biological sex.
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Affiliation(s)
- Briana L Hockey
- Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, Ontario, Canada
| | - Michael S Finch
- Department of Health Sciences, Brock University, St. Catharines, Ontario, Canada
| | - Jessica L Braun
- Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, Ontario, Canada
| | - Ahmad Mohammad
- Department of Health Sciences, Brock University, St. Catharines, Ontario, Canada
| | | | - Rene Vandenboom
- Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, Ontario, Canada
| | - Jeffrey A Stuart
- Department of Biological Sciences, Brock University, St. Catharines, Ontario, Canada
| | - Brian D Roy
- Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, Ontario, Canada
| | | | - V A Fajardo
- Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, Ontario, Canada
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Abstract
Recent advances in pharmacotherapies that promote appetite suppression have shown remarkable weight loss. Therapies targeting energy expenditure lag behind, and as such none have yet been identified to be safe and efficacious for sustaining negative energy balance toward weight loss. Multiple energy dissipating pathways have been identified in adipose tissue and muscle. The molecular effectors of some of these pathways have been identified, but much is still left to be learned about their regulation. Understanding the molecular underpinnings of metabolic inefficiency in adipose tissue and muscle is required if these pathways are to be therapeutically targeted in the context of obesity and obesity-accelerated diseases.
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Affiliation(s)
- Lawrence Kazak
- Rosalind & Morris Goodman Cancer Institute, McGill University, Montreal, QC H3A 1A3, Canada
- Department of Biochemistry, McGill University, Montreal, QC H3G 1Y6, Canada
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8
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Geromella MS, Braun JL, Fajardo VA. Measuring SERCA-mediated calcium uptake in mouse muscle homogenates. STAR Protoc 2023; 4:101987. [PMID: 36602905 PMCID: PMC9826970 DOI: 10.1016/j.xpro.2022.101987] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 11/09/2022] [Accepted: 12/13/2022] [Indexed: 01/06/2023] Open
Abstract
This protocol employs the indo-1 Ca2+ fluorophore to quantify Ca2+ uptake by the sarco(endo)plasmic reticulum Ca2+ ATPase pump in murine muscle homogenates and allows for real-time kinetic measurement of Ca2+ mobilization within the muscle homogenate. This protocol can be easily adapted for other tissue types and can be modified to single-emission/single-excitation Ca2+ dyes. Fitted to a 96-well plate, this assay can be readily performed in most laboratories with minimal sample requirement and the option of multiple replicates. For complete details on the use and execution of this protocol, please refer to Braun et al. (2022),1 Braun et al. (2021a),2 Braun et al. (2021b),3 Cleverdon et al. (2022),4 and Geromella et al. (2022).5.
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Affiliation(s)
- Mia S Geromella
- Department of Kinesiology, Brock University, St. Catharines, ON L2S 3A1, Canada; Centre for Bone and Muscle Health, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - Jessica L Braun
- Department of Kinesiology, Brock University, St. Catharines, ON L2S 3A1, Canada; Centre for Bone and Muscle Health, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - Val A Fajardo
- Department of Kinesiology, Brock University, St. Catharines, ON L2S 3A1, Canada; Centre for Bone and Muscle Health, Brock University, St. Catharines, ON L2S 3A1, Canada.
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9
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Choi KM, Ko CY, An SM, Cho SH, Rowland DJ, Kim JH, Fasoli A, Chaudhari AJ, Bers DM, Yoon JC. Regulation of beige adipocyte thermogenesis by the cold-repressed ER protein NNAT. Mol Metab 2023; 69:101679. [PMID: 36708951 PMCID: PMC9932177 DOI: 10.1016/j.molmet.2023.101679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 01/17/2023] [Accepted: 01/18/2023] [Indexed: 01/26/2023] Open
Abstract
OBJECTIVE Cold stimuli trigger the conversion of white adipose tissue into beige adipose tissue, which is capable of non-shivering thermogenesis. However, what process drives this activation of thermogenesis in beige fat is not well understood. Here, we examine the ER protein NNAT as a regulator of thermogenesis in adipose tissue. METHODS We investigated the regulation of adipose tissue NNAT expression in response to changes in ambient temperature. We also evaluated the functional role of NNAT in thermogenic regulation using Nnat null mice and primary adipocytes that lack or overexpress NNAT. RESULTS Cold exposure or treatment with a β3-adrenergic agonist reduces the expression of adipose tissue NNAT in mice. Genetic disruption of Nnat in mice enhances inguinal adipose tissue thermogenesis. Nnat null mice exhibit improved cold tolerance both in the presence and absence of UCP1. Gain-of-function studies indicate that ectopic expression of Nnat abolishes adrenergic receptor-mediated respiration in beige adipocytes. NNAT physically interacts with the ER Ca2+-ATPase (SERCA) in adipocytes and inhibits its activity, impairing Ca2+ transport and heat dissipation. We further demonstrate that NHLRC1, an E3 ubiquitin protein ligase implicated in proteasomal degradation of NNAT, is induced by cold exposure or β3-adrenergic stimulation, thus providing regulatory control at the protein level. This serves to link cold stimuli to NNAT degradation in adipose tissue, which in turn leads to enhanced SERCA activity. CONCLUSIONS Our study implicates NNAT in the regulation of adipocyte thermogenesis.
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Affiliation(s)
- Kyung-Mi Choi
- Division of Endocrinology, Department of Internal Medicine, University of California Davis School of Medicine, Davis, CA 95616, USA; Institute of Molecular Biology and Genetics, School of Biological Sciences, Seoul National University, Seoul 08826, South Korea
| | - Christopher Y Ko
- Department of Pharmacology, University of California Davis School of Medicine, Davis, CA 95616, USA
| | - Sung-Min An
- Division of Endocrinology, Department of Internal Medicine, University of California Davis School of Medicine, Davis, CA 95616, USA
| | - Seung-Hee Cho
- Division of Endocrinology, Department of Internal Medicine, University of California Davis School of Medicine, Davis, CA 95616, USA
| | - Douglas J Rowland
- Center for Molecular and Genomic Imaging, Department of Biomedical Engineering, University of California Davis, Davis, CA 95616, USA
| | - Jung Hak Kim
- Division of Endocrinology, Department of Internal Medicine, University of California Davis School of Medicine, Davis, CA 95616, USA
| | - Anna Fasoli
- Department of Pharmacology, University of California Davis School of Medicine, Davis, CA 95616, USA
| | - Abhijit J Chaudhari
- Department of Radiology, University of California Davis School of Medicine, Sacramento, CA 95825, USA
| | - Donald M Bers
- Department of Pharmacology, University of California Davis School of Medicine, Davis, CA 95616, USA
| | - John C Yoon
- Division of Endocrinology, Department of Internal Medicine, University of California Davis School of Medicine, Davis, CA 95616, USA.
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Hunter KD, Crozier RWE, Braun JL, Fajardo VA, MacNeil AJ. Acute activation of SERCA with CDN1163 attenuates IgE-mediated mast cell activation through selective impairment of ROS and p38 signaling. FASEB J 2023; 37:e22748. [PMID: 36624659 DOI: 10.1096/fj.202201272r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 11/13/2022] [Accepted: 12/19/2022] [Indexed: 01/11/2023]
Abstract
Mast cells are granulocytic immune sentinels present in vascularized tissues that drive chronic inflammatory mechanisms characteristic of allergic pathologies. IgE-mediated mast cell activation leads to a rapid mobilization of Ca2+ from intracellular stores, which is essential for the release of preformed mediators via degranulation and de novo synthesized proinflammatory cytokines and chemokines. Given its potent signaling capacity, the dynamics of Ca2+ localization are highly regulated by various pumps and channels controlling cytosolic Ca2+ concentrations. Among these is sarco/endoplasmic reticulum Ca2+ -ATPase (SERCA), which functions to maintain low cytosolic Ca2+ concentrations by actively transporting cytosolic Ca2+ ions into the endoplasmic reticulum. In this study, we characterized the role of SERCA in allergen-activated mast cells using IgE-sensitized bone marrow-derived mast cells (BMMCs) treated with the SERCA activating compound, CDN1163, and simultaneously stimulated with allergen through FcεRI under stem cell factor (SCF) potentiation. Acute treatment with CDN1163 was found to attenuate early phase mast cell degranulation along with reactive oxygen species (ROS) production. Additionally, treatment with CDN1163 significantly reduced secretion of IL-6, IL-13, and CCL3, suggesting a role for SERCA in the late phase mast cell response. The protective effects of SERCA activation via CDN1163 treatment on the early and late phase mast cell response may be driven by the selective suppression of p38 MAPK signaling. Together, these findings implicate SERCA as an important regulator of the mast cell response to allergen and suggest SERCA activity may offer therapeutic potential targeting allergic pathologies, warranting further investigation.
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Affiliation(s)
- Katie D Hunter
- Department of Health Sciences, Faculty of Applied Health Sciences, Cairns Family Health and Bioscience Research Complex, Brock University, Niagara Region, Ontario, Canada
| | - Robert W E Crozier
- Department of Health Sciences, Faculty of Applied Health Sciences, Cairns Family Health and Bioscience Research Complex, Brock University, Niagara Region, Ontario, Canada
| | - Jessica L Braun
- Department of Kinesiology, Faculty of Applied Health Sciences, Cairns Family Health and Bioscience Research Complex, Brock University, Niagara Region, Ontario, Canada
| | - Val A Fajardo
- Department of Kinesiology, Faculty of Applied Health Sciences, Cairns Family Health and Bioscience Research Complex, Brock University, Niagara Region, Ontario, Canada
| | - Adam J MacNeil
- Department of Health Sciences, Faculty of Applied Health Sciences, Cairns Family Health and Bioscience Research Complex, Brock University, Niagara Region, Ontario, Canada
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Hamstra SI, Roy BD, Tiidus P, MacNeil AJ, Klentrou P, MacPherson RE, Fajardo VA. Beyond its Psychiatric Use: The Benefits of Low-dose Lithium Supplementation. Curr Neuropharmacol 2023; 21:891-910. [PMID: 35236261 PMCID: PMC10227915 DOI: 10.2174/1570159x20666220302151224] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/16/2022] [Accepted: 02/10/2022] [Indexed: 11/22/2022] Open
Abstract
Lithium is most well-known for its mood-stabilizing effects in the treatment of bipolar disorder. Due to its narrow therapeutic window (0.5-1.2 mM serum concentration), there is a stigma associated with lithium treatment and the adverse effects that can occur at therapeutic doses. However, several studies have indicated that doses of lithium under the predetermined therapeutic dose used in bipolar disorder treatment may have beneficial effects not only in the brain but across the body. Currently, literature shows that low-dose lithium (≤0.5 mM) may be beneficial for cardiovascular, musculoskeletal, metabolic, and cognitive function, as well as inflammatory and antioxidant processes of the aging body. There is also some evidence of low-dose lithium exerting a similar and sometimes synergistic effect on these systems. This review summarizes these findings with a focus on low-dose lithium's potential benefits on the aging process and age-related diseases of these systems, such as cardiovascular disease, osteoporosis, sarcopenia, obesity and type 2 diabetes, Alzheimer's disease, and the chronic low-grade inflammatory state known as inflammaging. Although lithium's actions have been widely studied in the brain, the study of the potential benefits of lithium, particularly at a low dose, is still relatively novel. Therefore, this review aims to provide possible mechanistic insights for future research in this field.
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Affiliation(s)
- Sophie I. Hamstra
- Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, Ontario, Canada
| | - Brian D. Roy
- Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, Ontario, Canada
| | - Peter Tiidus
- Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada
| | - Adam J. MacNeil
- Department of Health Sciences, Brock University, St. Catharines, ON, Canada
| | - Panagiota Klentrou
- Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, Ontario, Canada
| | - Rebecca E.K. MacPherson
- Department of Health Sciences, Brock University, St. Catharines, ON, Canada
- Centre for Neurosciences, Brock University, St. Catharines, Ontario, Canada
| | - Val A. Fajardo
- Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, Ontario, Canada
- Centre for Neurosciences, Brock University, St. Catharines, Ontario, Canada
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12
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Mukherjee S, Choi M, Yun JW. Trans-anethole Induces Thermogenesis via Activating SERCA/SLN Axis in C2C12 Muscle Cells. BIOTECHNOL BIOPROC E 2022. [DOI: 10.1007/s12257-022-0242-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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13
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Geromella MS, Ryan CR, Braun JL, Finch MS, Maddalena LA, Bagshaw O, Hockey BL, Moradi F, Fenech RK, Ryoo J, Marko DM, Dhaliwal R, Sweezey-Munroe J, Hamstra SI, Gardner G, Silvera S, Vandenboom R, Roy BD, Stuart JA, MacPherson RE, Fajardo VA. Low-dose lithium supplementation promotes adipose tissue browning and sarco(endo)plasmic reticulum Ca2+ ATPase uncoupling in muscle. J Biol Chem 2022; 298:102568. [DOI: 10.1016/j.jbc.2022.102568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 09/20/2022] [Accepted: 09/23/2022] [Indexed: 11/11/2022] Open
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14
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Teng ACT, Gu L, Di Paola M, Lakin R, Williams ZJ, Au A, Chen W, Callaghan NI, Zadeh FH, Zhou YQ, Fatah M, Chatterjee D, Jourdan LJ, Liu J, Simmons CA, Kislinger T, Yip CM, Backx PH, Gourdie RG, Hamilton RM, Gramolini AO. Tmem65 is critical for the structure and function of the intercalated discs in mouse hearts. Nat Commun 2022; 13:6166. [PMID: 36257954 PMCID: PMC9579145 DOI: 10.1038/s41467-022-33303-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 09/07/2022] [Indexed: 12/24/2022] Open
Abstract
The intercalated disc (ICD) is a unique membrane structure that is indispensable to normal heart function, yet its structural organization is not completely understood. Previously, we showed that the ICD-bound transmembrane protein 65 (Tmem65) was required for connexin43 (Cx43) localization and function in cultured mouse neonatal cardiomyocytes. Here, we investigate the functional and cellular effects of Tmem65 reductions on the myocardium in a mouse model by injecting CD1 mouse pups (3-7 days after birth) with recombinant adeno-associated virus 9 (rAAV9) harboring Tmem65 shRNA, which reduces Tmem65 expression by 90% in mouse ventricles compared to scrambled shRNA injection. Tmem65 knockdown (KD) results in increased mortality which is accompanied by eccentric hypertrophic cardiomyopathy within 3 weeks of injection and progression to dilated cardiomyopathy with severe cardiac fibrosis by 7 weeks post-injection. Tmem65 KD hearts display depressed hemodynamics as measured echocardiographically as well as slowed conduction in optical recording accompanied by prolonged PR intervals and QRS duration in electrocardiograms. Immunoprecipitation and super-resolution microscopy demonstrate a physical interaction between Tmem65 and sodium channel β subunit (β1) in mouse hearts and this interaction appears to be required for both the establishment of perinexal nanodomain structure and the localization of both voltage-gated sodium channel 1.5 (NaV1.5) and Cx43 to ICDs. Despite the loss of NaV1.5 at ICDs, whole-cell patch clamp electrophysiology did not reveal reductions in Na+ currents but did show reduced Ca2+ and K+ currents in Tmem65 KD cardiomyocytes in comparison to control cells. We conclude that disrupting Tmem65 function results in impaired ICD structure, abnormal cardiac electrophysiology, and ultimately cardiomyopathy.
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Affiliation(s)
- Allen C T Teng
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada.
- Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON, M5G 1M1, Canada.
| | - Liyang Gu
- Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON, M5G 1M1, Canada
| | - Michelle Di Paola
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
- Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON, M5G 1M1, Canada
| | - Robert Lakin
- Department of Biology, York University, Toronto, ON, M3J 1P3, Canada
| | - Zachary J Williams
- The Center for Heart and Reparative Medicine, Fralin Biomedical Research Institute at Virginia Tech. Carilion, Roanoke, VA, 24016, USA
- Translational Biology Medicine and Health Graduate Program, Virginia Tech, Roanoke, VA, 24016, USA
| | - Aaron Au
- Institute of Biomedical Engineering, Faculty of Applied Science and Engineering, University of Toronto, Toronto, ON, M5S 3G9, Canada
- Donnelly Centre, University of Toronto, Toronto, ON, M5S 3E1, Canada
| | - Wenliang Chen
- Department of Biology, York University, Toronto, ON, M3J 1P3, Canada
| | - Neal I Callaghan
- Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON, M5G 1M1, Canada
- Institute of Biomedical Engineering, Faculty of Applied Science and Engineering, University of Toronto, Toronto, ON, M5S 3G9, Canada
| | - Farigol Hakem Zadeh
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
- Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON, M5G 1M1, Canada
| | - Yu-Qing Zhou
- Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON, M5G 1M1, Canada
- Institute of Biomedical Engineering, Faculty of Applied Science and Engineering, University of Toronto, Toronto, ON, M5S 3G9, Canada
| | - Meena Fatah
- The Labatt Family Heart Centre (Dept. of Pediatrics) and Translational Medicine, The Hospital for Sick Children & Research Institute, University of Toronto, Toronto, ON., M5G 1X8, Canada
| | - Diptendu Chatterjee
- The Labatt Family Heart Centre (Dept. of Pediatrics) and Translational Medicine, The Hospital for Sick Children & Research Institute, University of Toronto, Toronto, ON., M5G 1X8, Canada
| | - L Jane Jourdan
- The Center for Heart and Reparative Medicine, Fralin Biomedical Research Institute at Virginia Tech. Carilion, Roanoke, VA, 24016, USA
- Virginia Tech Carilion School of Medicine, Roanoke, VA, 24016, USA
- Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24060, USA
| | - Jack Liu
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Craig A Simmons
- Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON, M5G 1M1, Canada
- Institute of Biomedical Engineering, Faculty of Applied Science and Engineering, University of Toronto, Toronto, ON, M5S 3G9, Canada
| | - Thomas Kislinger
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON, M5G 1L7, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, ON, M5G 1L7, Canada
| | - Christopher M Yip
- Institute of Biomedical Engineering, Faculty of Applied Science and Engineering, University of Toronto, Toronto, ON, M5S 3G9, Canada
- Donnelly Centre, University of Toronto, Toronto, ON, M5S 3E1, Canada
| | - Peter H Backx
- Department of Biology, York University, Toronto, ON, M3J 1P3, Canada
| | - Robert G Gourdie
- The Center for Heart and Reparative Medicine, Fralin Biomedical Research Institute at Virginia Tech. Carilion, Roanoke, VA, 24016, USA
- Virginia Tech Carilion School of Medicine, Roanoke, VA, 24016, USA
- Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24060, USA
| | - Robert M Hamilton
- The Labatt Family Heart Centre (Dept. of Pediatrics) and Translational Medicine, The Hospital for Sick Children & Research Institute, University of Toronto, Toronto, ON., M5G 1X8, Canada
| | - Anthony O Gramolini
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada.
- Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON, M5G 1M1, Canada.
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15
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Hamstra SI, Braun JL, Chelko SP, Fajardo VA. GSK3-inhibition improves maximal SERCA activity in a murine model of Arrhythmogenic cardiomyopathy. Biochim Biophys Acta Mol Basis Dis 2022; 1868:166536. [PMID: 36057371 DOI: 10.1016/j.bbadis.2022.166536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 08/09/2022] [Accepted: 08/29/2022] [Indexed: 12/01/2022]
Affiliation(s)
- Sophie I Hamstra
- Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, St. Catharines, ON, Canada; Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - Jessica L Braun
- Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, St. Catharines, ON, Canada; Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - Stephen P Chelko
- Department of Medicine/Cardiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, FL, USA
| | - Val A Fajardo
- Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, St. Catharines, ON, Canada; Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada.
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16
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Yu M, Wang D, Zhong D, Xie W, Luo J. Adropin Carried by Reactive Oxygen Species-Responsive Nanocapsules Ameliorates Renal Lipid Toxicity in Diabetic Mice. ACS APPLIED MATERIALS & INTERFACES 2022; 14:37330-37344. [PMID: 35951354 DOI: 10.1021/acsami.2c06957] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Diabetic kidney disease (DKD) is a common diabetes complication mainly caused by lipid toxicity characterized by oxidative stress. Studies have shown that adropin (Ad) regulates energy metabolism and may be an effective target to improve DKD. This study investigated the effect of exogenous Ad encapsulated in reactive oxygen species (ROS)-responsive nanocapsules (Ad@Gel) on DKD. HK2 cells were induced with high glucose (HG) and intervened with Ad@Gel. A diabetes mouse model was established using HG and high-fat diet combined with streptozotocin and treated with Ad@Gel to observe its effects on renal function, pathological damage, lipid metabolism, and oxidative stress. Results showed that Ad@Gel could protect HK2 from HG stimulation in vitro. It also effectively controls blood glucose and lipid levels, improves renal function, inhibits excessive production of ROS, protects mitochondria from damage, improves lipid deposition in renal tissues, and downregulates the expression of lipogenic proteins SEBP-1 and ADRP in DKD mice. In HG-induced HK2 cells or the kidney of DKD patients, the low expression of neuronatin (Nnat) and high expression of translocator protein (TSPO) were observed. Knockdown Nnat or overexpression of TSPO significantly reversed the effect of Ad@Gel on improving mitochondrial damage. In addition, knockdown Nnat also significantly reversed the effect of Ad@Gel on lipid metabolism. The results suggest that the effect of Ad on DKD may be achieved by activating Nnat to improve lipid metabolism and inhibit TSPO activity, thereby enhancing mitochondrial function.
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Affiliation(s)
- Mingchuan Yu
- Department of Rehabilitation Medicine, The Second Affiliated Hospital of Nanchang University, 1 Minde Road, Nanchang 330006, Jiangxi, P. R. China
| | - Di Wang
- Department of Rehabilitation Medicine, The Second Affiliated Hospital of Nanchang University, 1 Minde Road, Nanchang 330006, Jiangxi, P. R. China
| | - Da Zhong
- Nanchang University, Nanchang 330006, Jiangxi, P. R. China
| | - Weichang Xie
- Nanchang University, Nanchang 330006, Jiangxi, P. R. China
| | - Jun Luo
- Department of Rehabilitation Medicine, The Second Affiliated Hospital of Nanchang University, 1 Minde Road, Nanchang 330006, Jiangxi, P. R. China
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17
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Braun JL, Messner HN, Cleverdon REG, Baranowski RW, Hamstra SI, Geromella MS, Stuart JA, Fajardo VA. Heterozygous SOD2 deletion selectively impairs SERCA function in the soleus of female mice. Physiol Rep 2022; 10:e15285. [PMID: 35581738 PMCID: PMC9114654 DOI: 10.14814/phy2.15285] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 04/05/2022] [Accepted: 04/08/2022] [Indexed: 06/15/2023] Open
Abstract
The sarco(endo)plasmic reticulum Ca2+ ATPase (SERCA) restores intracellular Ca2+ ([Ca2+ ]i ) to resting levels after muscle contraction, ultimately eliciting relaxation. SERCA pumps are highly susceptible to tyrosine (T)-nitration, impairing their ability to take up Ca2+ resulting in reduced muscle function and increased [Ca2+ ]i and cellular damage. The mitochondrial antioxidant enzyme, superoxide dismutase 2 (SOD2), converts superoxide radicals into less reactive H2 O2 . Heterozygous deletion of SOD2 (Sod2+/- ) in mice increases mitochondrial oxidative stress; however, the consequences of reduced SOD2 expression in skeletal and cardiac muscle, specifically the effect on SERCA pumps, has yet to be investigated. We obtained soleus, extensor digitorum longus (EDL), and left ventricle (LV) muscles from 6 to 7 month-old wild-type (WT) and Sod2+/- female C57BL/6J mice. Ca2+ -dependent SERCA activity assays were performed to assess SERCA function. Western blotting was conducted to examine the protein content of SERCA, phospholamban, and sarcolipin; and immunoprecipitation experiments were done to assess SERCA2a- and SERCA1a-specific T-nitration. Heterozygous SOD2 deletion did not alter SERCA1a or SERCA2a expression in the soleus or LV but reduced SERCA2a in the EDL compared with WT, though this was not statistically significant. Soleus muscles from Sod2+/- mice showed a significant reduction in SERCA's apparent affinity for Ca2+ when compared to WT, corresponding with significantly elevated SERCA2a T-nitration in the soleus. No effect was seen in the EDL or the LV. This is the first study to investigate the effects of SOD2 deficiency on muscle SERCA function and shows that it selectively impairs SERCA function in the soleus.
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Affiliation(s)
- Jessica L. Braun
- Department of KinesiologyBrock UniversitySt. CatharinesOntarioCanada
- Centre for Bone and Muscle HealthBrock UniversitySt. CatharinesOntarioCanada
- Centre for NeuroscienceBrock UniversitySt. CatharinesOntarioCanada
| | - Holt N. Messner
- Department of KinesiologyBrock UniversitySt. CatharinesOntarioCanada
- Centre for Bone and Muscle HealthBrock UniversitySt. CatharinesOntarioCanada
- Department of Biological SciencesBrock UniversitySt. CatharinesOntarioCanada
| | - Riley E. G. Cleverdon
- Department of KinesiologyBrock UniversitySt. CatharinesOntarioCanada
- Centre for Bone and Muscle HealthBrock UniversitySt. CatharinesOntarioCanada
| | - Ryan W. Baranowski
- Department of KinesiologyBrock UniversitySt. CatharinesOntarioCanada
- Centre for Bone and Muscle HealthBrock UniversitySt. CatharinesOntarioCanada
| | - Sophie I. Hamstra
- Department of KinesiologyBrock UniversitySt. CatharinesOntarioCanada
- Centre for Bone and Muscle HealthBrock UniversitySt. CatharinesOntarioCanada
| | - Mia S. Geromella
- Department of KinesiologyBrock UniversitySt. CatharinesOntarioCanada
- Centre for Bone and Muscle HealthBrock UniversitySt. CatharinesOntarioCanada
| | - Jeffrey A. Stuart
- Department of Biological SciencesBrock UniversitySt. CatharinesOntarioCanada
| | - Val A. Fajardo
- Department of KinesiologyBrock UniversitySt. CatharinesOntarioCanada
- Centre for Bone and Muscle HealthBrock UniversitySt. CatharinesOntarioCanada
- Centre for NeuroscienceBrock UniversitySt. CatharinesOntarioCanada
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18
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Braun JL, Ryoo J, Goodwin K, Copeland EN, Geromella MS, Baranowski RW, MacPherson REK, Fajardo VA. The effects of neurogranin knockdown on SERCA pump efficiency in soleus muscles of female mice fed a high fat diet. Front Endocrinol (Lausanne) 2022; 13:957182. [PMID: 36072929 PMCID: PMC9441848 DOI: 10.3389/fendo.2022.957182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 08/05/2022] [Indexed: 11/26/2022] Open
Abstract
The sarco(endo)plasmic reticulum Ca2+ ATPase (SERCA) pump is responsible for the transport of Ca2+ from the cytosol into the sarcoplasmic reticulum at the expense of ATP, making it a regulator of both muscle relaxation and muscle-based energy expenditure. Neurogranin (Ng) is a small protein that negatively regulates calcineurin signaling. Calcineurin is Ca2+/calmodulin dependent phosphatase that promotes the oxidative fibre type in skeletal muscle and regulates muscle-based energy expenditure. A recent study has shown that calcineurin activation reduces SERCA Ca2+ transport efficiency, ultimately raising energy expenditure. Since the biomedical view of obesity states that it arises as an imbalance between energy intake and expenditure which favors the former, we questioned whether heterozygous Ng deletion (Ng+/- ) would reduce SERCA efficiency and increase energy expenditure in female mice fed a high-fat diet (HFD). Young (3-4-month-old) female wild type (WT) and Ng+/- mice were fed a HFD for 12 weeks with their metabolic profile being analyzed using metabolic cages and DXA scanning, while soleus SERCA efficiency was measured using SERCA specific Ca2+ uptake and ATPase activity assays. Ng+/- mice showed significantly less cage ambulation compared to WT mice but this did not lead to any added weight gain nor changes in daily energy expenditure, glucose or insulin tolerance despite a similar level of food intake. Furthermore, we observed significant reductions in SERCA's apparent coupling ratio which were associated with significant reductions in SERCA1 and phospholamban content. Thus, our results show that Ng regulates SERCA pump efficiency, and future studies should further investigate the potential cellular mechanisms.
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Affiliation(s)
- Jessica L. Braun
- Department of Kinesiology, Brock University, St. Catharines, ON, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
- Centre for Neuroscience, Brock University, St. Catharines, ON, Canada
| | - Jisook Ryoo
- Department of Kinesiology, Brock University, St. Catharines, ON, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - Kyle Goodwin
- Department of Kinesiology, Brock University, St. Catharines, ON, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - Emily N. Copeland
- Department of Kinesiology, Brock University, St. Catharines, ON, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
- Centre for Neuroscience, Brock University, St. Catharines, ON, Canada
| | - Mia S. Geromella
- Department of Kinesiology, Brock University, St. Catharines, ON, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - Ryan W. Baranowski
- Department of Kinesiology, Brock University, St. Catharines, ON, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - Rebecca E. K. MacPherson
- Centre for Neuroscience, Brock University, St. Catharines, ON, Canada
- Department of Health Sciences, Brock University, St. Catharines, ON, Canada
| | - Val A. Fajardo
- Department of Kinesiology, Brock University, St. Catharines, ON, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
- Centre for Neuroscience, Brock University, St. Catharines, ON, Canada
- *Correspondence: Val A. Fajardo,
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Characterizing SERCA Function in Murine Skeletal Muscles after 35-37 Days of Spaceflight. Int J Mol Sci 2021; 22:ijms222111764. [PMID: 34769190 PMCID: PMC8584217 DOI: 10.3390/ijms222111764] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 10/25/2021] [Accepted: 10/25/2021] [Indexed: 12/17/2022] Open
Abstract
It is well established that microgravity exposure causes significant muscle weakness and atrophy via muscle unloading. On Earth, muscle unloading leads to a disproportionate loss in muscle force and size with the loss in muscle force occurring at a faster rate. Although the exact mechanisms are unknown, a role for Ca2+ dysregulation has been suggested. The sarco(endo)plasmic reticulum Ca2+ ATPase (SERCA) pump actively brings cytosolic Ca2+ into the SR, eliciting muscle relaxation and maintaining low intracellular Ca2+ ([Ca2+]i). SERCA dysfunction contributes to elevations in [Ca2+]i, leading to cellular damage, and may contribute to the muscle weakness and atrophy observed with spaceflight. Here, we investigated SERCA function, SERCA regulatory protein content, and reactive oxygen/nitrogen species (RONS) protein adduction in murine skeletal muscle after 35–37 days of spaceflight. In male and female soleus muscles, spaceflight led to drastic impairments in Ca2+ uptake despite significant increases in SERCA1a protein content. We attribute this impairment to an increase in RONS production and elevated total protein tyrosine (T) nitration and cysteine (S) nitrosylation. Contrarily, in the tibialis anterior (TA), we observed an enhancement in Ca2+ uptake, which we attribute to a shift towards a faster muscle fiber type (i.e., increased myosin heavy chain IIb and SERCA1a) without elevated total protein T-nitration and S-nitrosylation. Thus, spaceflight affects SERCA function differently between the soleus and TA.
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