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Cai L, Shi L, Peng Z, Sun Y, Chen J. Ageing of skeletal muscle extracellular matrix and mitochondria: finding a potential link. Ann Med 2023; 55:2240707. [PMID: 37643318 PMCID: PMC10732198 DOI: 10.1080/07853890.2023.2240707] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 06/13/2023] [Accepted: 07/21/2023] [Indexed: 08/31/2023] Open
Abstract
Aim: To discuss the progress of extracellular matrix (ECM) characteristics, mitochondrial homeostasis, and their potential crosstalk in the pathogenesis of sarcopenia, a geriatric syndrome characterized by a generalized and progressive reduction in muscle mass, strength, and physical performance.Methods: This review focuses on the anatomy and physiology of skeletal muscle, alterations of ECM and mitochondria during ageing, and the role of the interplay between ECM and mitochondria in the pathogenesis of sarcopenia.Results: Emerging evidence points to a clear interplay between mitochondria and ECM in various tissues and organs. Under the ageing process, the ECM undergoes changes in composition and physical properties that may mediate mitochondrial changes via the systematic metabolism, ROS, SPARC pathway, and AMPK/PGC-1α signalling, which in turn exacerbate muscle degeneration. However, the precise effects of such crosstalk on the pathobiology of ageing, particularly in skeletal muscle, have not yet been fully understood.Conclusion: The changes in skeletal muscle ECM and mitochondria are partially responsible for the worsened muscle function during the ageing process. A deeper understanding of their alterations and interactions in sarcopenic patients can help prevent sarcopenia and improve its prognoses.
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Affiliation(s)
- Lubing Cai
- Department of Sports Medicine, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Luze Shi
- Department of Sports Medicine, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhen Peng
- Department of Sports Medicine, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yaying Sun
- Department of Sports Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Jiwu Chen
- Department of Sports Medicine, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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2
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Zamboni M, Mazzali G, Brunelli A, Saatchi T, Urbani S, Giani A, Rossi AP, Zoico E, Fantin F. The Role of Crosstalk between Adipose Cells and Myocytes in the Pathogenesis of Sarcopenic Obesity in the Elderly. Cells 2022; 11:3361. [PMID: 36359757 PMCID: PMC9655977 DOI: 10.3390/cells11213361] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 10/08/2022] [Accepted: 10/14/2022] [Indexed: 11/15/2023] Open
Abstract
As a result of aging, body composition changes, with a decline in muscle mass and an increase in adipose tissue (AT), which reallocates from subcutaneous to visceral depots and stores ectopically in the liver, heart and muscles. Furthermore, with aging, muscle and AT, both of which have recognized endocrine activity, become dysfunctional and contribute, in the case of positive energy balance, to the development of sarcopenic obesity (SO). SO is defined as the co-existence of excess adiposity and low muscle mass and function, and its prevalence increases with age. SO is strongly associated with greater morbidity and mortality. The pathogenesis of SO is complex and multifactorial. This review focuses mainly on the role of crosstalk between age-related dysfunctional adipose and muscle cells as one of the mechanisms leading to SO. A better understanding of this mechanisms may be useful for development of prevention strategies and treatments aimed at reducing the occurrence of SO.
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Affiliation(s)
- Mauro Zamboni
- Geriatrics Division, Department of Surgery, Dentistry, Pediatric and Gynecology, Healthy Aging Center, University of Verona, 37126 Verona, Italy
| | - Gloria Mazzali
- Geriatrics Division, Department of Medicine, University of Verona, 37126 Verona, Italy
| | - Anna Brunelli
- Geriatrics Division, Department of Surgery, Dentistry, Pediatric and Gynecology, Healthy Aging Center, University of Verona, 37126 Verona, Italy
| | - Tanaz Saatchi
- Geriatrics Division, Department of Surgery, Dentistry, Pediatric and Gynecology, Healthy Aging Center, University of Verona, 37126 Verona, Italy
| | - Silvia Urbani
- Geriatrics Division, Department of Surgery, Dentistry, Pediatric and Gynecology, Healthy Aging Center, University of Verona, 37126 Verona, Italy
| | - Anna Giani
- Geriatrics Division, Department of Surgery, Dentistry, Pediatric and Gynecology, Healthy Aging Center, University of Verona, 37126 Verona, Italy
| | - Andrea P. Rossi
- Geriatrics Division, Department of Medicine, AULSS2, Ospedale Ca’Foncello, 31100 Treviso, Italy
| | - Elena Zoico
- Geriatrics Division, Department of Medicine, University of Verona, 37126 Verona, Italy
| | - Francesco Fantin
- Geriatrics Division, Department of Medicine, University of Verona, 37126 Verona, Italy
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3
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Pang BPS, Chan WS, Chan CB. Mitochondria Homeostasis and Oxidant/Antioxidant Balance in Skeletal Muscle-Do Myokines Play a Role? Antioxidants (Basel) 2021; 10:antiox10020179. [PMID: 33513795 PMCID: PMC7911667 DOI: 10.3390/antiox10020179] [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: 12/29/2020] [Revised: 01/19/2021] [Accepted: 01/21/2021] [Indexed: 12/19/2022] Open
Abstract
Mitochondria are the cellular powerhouses that generate adenosine triphosphate (ATP) to substantiate various biochemical activities. Instead of being a static intracellular structure, they are dynamic organelles that perform constant structural and functional remodeling in response to different metabolic stresses. In situations that require a high ATP supply, new mitochondria are assembled (mitochondrial biogenesis) or formed by fusing the existing mitochondria (mitochondrial fusion) to maximize the oxidative capacity. On the other hand, nutrient overload may produce detrimental metabolites such as reactive oxidative species (ROS) that wreck the organelle, leading to the split of damaged mitochondria (mitofission) for clearance (mitophagy). These vital processes are tightly regulated by a sophisticated quality control system involving energy sensing, intracellular membrane interaction, autophagy, and proteasomal degradation to optimize the number of healthy mitochondria. The effective mitochondrial surveillance is particularly important to skeletal muscle fitness because of its large tissue mass as well as its high metabolic activities for supporting the intensive myofiber contractility. Indeed, the failure of the mitochondrial quality control system in skeletal muscle is associated with diseases such as insulin resistance, aging, and muscle wasting. While the mitochondrial dynamics in cells are believed to be intrinsically controlled by the energy content and nutrient availability, other upstream regulators such as hormonal signals from distal organs or factors generated by the muscle itself may also play a critical role. It is now clear that skeletal muscle actively participates in systemic energy homeostasis via producing hundreds of myokines. Acting either as autocrine/paracrine or circulating hormones to crosstalk with other organs, these secretory myokines regulate a large number of physiological activities including insulin sensitivity, fuel utilization, cell differentiation, and appetite behavior. In this article, we will review the mechanism of myokines in mitochondrial quality control and ROS balance, and discuss their translational potential.
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Warner SC, Nair A, Marpadga R, Chubinskaya S, Doherty M, Valdes AM, Scanzello CR. IL-15 and IL15RA in Osteoarthritis: Association With Symptoms and Protease Production, but Not Structural Severity. Front Immunol 2020; 11:1385. [PMID: 32793194 PMCID: PMC7390829 DOI: 10.3389/fimmu.2020.01385] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 05/29/2020] [Indexed: 01/30/2023] Open
Abstract
Objective: Interleukin-15 (IL-15) is a pro-inflammatory cytokine that is increased in joint fluids of early-stage osteoarthritis (OA) patients, and has been associated with expression of proteases that can damage cartilage, and the development of neuropathic pain-like symptoms (NP) after nerve injury. The objective of this study was to further explore the role of IL-15 in the pathogenesis of OA cartilage degeneration and test genetic variation in the IL-15 receptor α gene (IL15RA) for an association with OA with radiographic severity and symptoms. Methods: Cartilage samples from donors (n = 10) were analyzed for expression of the IL15 receptor α-chain using immunohistochemistry, and for responses to IL-15 in vitro using explant cultures. Data from two independent Nottinghamshire-based studies (n = 795 and n = 613) were used to test genetic variants in the IL15RA gene (rs2228059 and rs7097780) for an association with radiographic severity, symptomatic vs. asymptomatic OA and NP. Results: IL-15Rα was expressed in chondrocytes from cartilage obtained from normal and degenerative knees. IL-15 significantly increased the release of matrix metalloproteinase-1 and -3 (MMP-1 and -3), but did not affect loss of proteoglycan from the articular matrix. Genetic variants in the IL15RA gene are associated with risk of symptomatic vs. asymptomatic OA (rs7097780 OR = 1.48 95% 1.10-1.98 p < 0.01) and with the risk of NP post-total joint replacement (rs2228059 OR = 0.76 95% 0.63-0.92 p < 0.01) but not with radiographic severity. Conclusions: In two different cohorts of patients, we show an association between genetic variation at the IL15 receptor and pain. Although ex vivo cartilage explants could respond to IL-15 with increased protease production, we found no effect of IL-15 on cartilage matrix loss and no association between IL15RA variants and radiographic severity. Together, these results suggest that IL-15 signaling may be a target for pain, but may not impact structural progression, in OA.
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Affiliation(s)
- Sophie C Warner
- Academic Rheumatology, Nottingham City Hospital, Nottingham, United Kingdom
| | - Anjali Nair
- Section of Rheumatology, Rush University Medical Center, Chicago, IL, United States
| | - Rahul Marpadga
- Section of Rheumatology, Rush University Medical Center, Chicago, IL, United States
| | - Susan Chubinskaya
- Division of Pediatrics, Rush University Medical Center, Chicago, IL, United States
| | - Michael Doherty
- Academic Rheumatology, Nottingham City Hospital, Nottingham, United Kingdom.,Arthritis Research UK Pain Centre and National Institutes for Health Research Nottingham Biomedical Research Centre, Nottingham, United Kingdom
| | - Ana M Valdes
- Academic Rheumatology, Nottingham City Hospital, Nottingham, United Kingdom.,Arthritis Research UK Pain Centre and National Institutes for Health Research Nottingham Biomedical Research Centre, Nottingham, United Kingdom
| | - Carla R Scanzello
- Translational Musculoskeletal Research Center & Section of Rheumatology, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA, United States.,Division of Rheumatology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
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5
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Nadeau L, Aguer C. Interleukin-15 as a myokine: mechanistic insight into its effect on skeletal muscle metabolism. Appl Physiol Nutr Metab 2019; 44:229-238. [DOI: 10.1139/apnm-2018-0022] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Interleukin (IL)-15 is a cytokine with important immunological functions. It is highly expressed in skeletal muscle and is believed to be a myokine, a hypothesis supported by the rapid increase in circulating levels of IL-15 in response to exercise. Treatment with high doses of IL-15 results in metabolic adaptations such as improved insulin sensitivity and whole-body fatty acid oxidation and protection from high-fat-diet-induced obesity and insulin resistance. IL-15 secreted by contracting muscle may therefore act as an endocrine factor to improve adiposity and energy metabolism in different tissues. Most studies have used supraphysiological doses of IL-15 that do not represent circulating IL-15 in response to exercise. However, evidence shows that IL-15 levels are higher in muscle interstitium and that IL-15 might improve muscle glucose homeostasis and oxidative metabolism in an autocrine/paracrine manner. Nevertheless, how IL-15 signals in skeletal muscle to improve muscle energy metabolism is not understood completely, especially because the absence of the α subunit of the IL-15 receptor (IL-15Rα) results in a phenotype similar to that of overexpressing/oversecreting IL-15 in mice. In this article, we review the literature to propose a model for the regulation of IL-15 by the soluble form of IL-15Rα to explain why some findings in the literature seem, at first glance, to be contradictory.
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Affiliation(s)
- Lucien Nadeau
- Institut du Savoir Montfort – Recherche, 713 Montreal Road, Ottawa, ON K1K 0T2, Canada
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Céline Aguer
- Institut du Savoir Montfort – Recherche, 713 Montreal Road, Ottawa, ON K1K 0T2, Canada
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
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Nadeau L, Patten DA, Caron A, Garneau L, Pinault-Masson E, Foretz M, Haddad P, Anderson BG, Quinn LS, Jardine K, McBurney MW, Pistilli EE, Harper ME, Aguer C. IL-15 improves skeletal muscle oxidative metabolism and glucose uptake in association with increased respiratory chain supercomplex formation and AMPK pathway activation. Biochim Biophys Acta Gen Subj 2018; 1863:395-407. [PMID: 30448294 DOI: 10.1016/j.bbagen.2018.10.021] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 10/05/2018] [Accepted: 10/16/2018] [Indexed: 12/21/2022]
Abstract
BACKGROUND IL-15 is believed to play a role in the beneficial impact of exercise on muscle energy metabolism. However, previous studies have generally used supraphysiological levels of IL-15 that do not represent contraction-induced IL-15 secretion. METHODS L6 myotubes were treated acutely (3 h) and chronically (48 h) with concentrations of IL-15 mimicking circulating (1-10 pg/ml) and muscle interstitial (100 pg/ml -20 ng/ml) IL-15 levels with the aim to better understand its autocrine/paracrine role on muscle glucose uptake and mitochondrial function. RESULTS Acute exposure to IL-15 levels representing muscle interstitial IL-15 increased basal glucose uptake without affecting insulin sensitivity. This was accompanied by increased mitochondrial oxidative functions in association with increased AMPK pathway and formation of complex III-containing supercomplexes. Conversely, chronic IL-15 exposure resulted in a biphasic effect on mitochondrial oxidative functions and ETC supercomplex formation was increased with low IL-15 levels but decreased with higher IL-15 concentrations. The AMPK pathway was activated only by high levels of chronic IL-15 treatment. Similar results were obtained in skeletal muscle from muscle-specific IL-15 overexpressing mice that show very high circulating IL-15 levels. CONCLUSIONS Acute IL-15 treatment that mimics local IL-15 concentrations enhances muscle glucose uptake and mitochondrial oxidative functions. That mitochondria respond differently to different levels of IL-15 during chronic treatments indicates that IL-15 might activate two different pathways in muscle depending on IL-15 concentrations. GENERAL SIGNIFICANCE Our results suggest that IL-15 may act in an autocrine/paracrine fashion and be, at least in part, involved in the positive effect of exercise on muscle energy metabolism.
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Affiliation(s)
- L Nadeau
- Institut du Savoir Montfort - Recherche, Ottawa, ON, Canada; University of Ottawa, Faculty of Medicine, Department of Biochemistry, Microbiology, and Immunology, Ottawa, ON, Canada
| | - D A Patten
- University of Ottawa, Faculty of Medicine, Department of Biochemistry, Microbiology, and Immunology, Ottawa, ON, Canada
| | - A Caron
- Institut du Savoir Montfort - Recherche, Ottawa, ON, Canada; University of Ottawa, Faculty of Medicine, Department of Biochemistry, Microbiology, and Immunology, Ottawa, ON, Canada
| | - L Garneau
- Institut du Savoir Montfort - Recherche, Ottawa, ON, Canada; University of Ottawa, Faculty of Medicine, Department of Biochemistry, Microbiology, and Immunology, Ottawa, ON, Canada
| | - E Pinault-Masson
- Institut du Savoir Montfort - Recherche, Ottawa, ON, Canada; University of Ottawa, Faculty of Science, Ottawa, ON, Canada
| | - M Foretz
- INSERM, U1016, Institut Cochin, Paris 75014, France; CNRS, UMR8104, Paris 75014, France; Université Paris Descartes, Sorbonne Paris Cité, Paris 75014, France
| | - P Haddad
- Institut du Savoir Montfort - Recherche, Ottawa, ON, Canada; University of Ottawa, Faculty of Science, Ottawa, ON, Canada
| | - B G Anderson
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, WA, United States
| | - L S Quinn
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, WA, United States
| | - K Jardine
- Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - M W McBurney
- Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - E E Pistilli
- West Virginia University School of Medicine, Morgantown, WV, United States
| | - M E Harper
- University of Ottawa, Faculty of Medicine, Department of Biochemistry, Microbiology, and Immunology, Ottawa, ON, Canada
| | - C Aguer
- Institut du Savoir Montfort - Recherche, Ottawa, ON, Canada; University of Ottawa, Faculty of Medicine, Department of Biochemistry, Microbiology, and Immunology, Ottawa, ON, Canada.
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7
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Bohlen J, McLaughlin SL, Hazard‐Jenkins H, Infante AM, Montgomery C, Davis M, Pistilli EE. Dysregulation of metabolic-associated pathways in muscle of breast cancer patients: preclinical evaluation of interleukin-15 targeting fatigue. J Cachexia Sarcopenia Muscle 2018; 9:701-714. [PMID: 29582584 PMCID: PMC6104109 DOI: 10.1002/jcsm.12294] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 11/27/2017] [Accepted: 01/31/2018] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Breast cancer patients report a perception of increased muscle fatigue, which can persist following surgery and standardized therapies. In a clinical experiment, we tested the hypothesis that pathways regulating skeletal muscle fatigue are down-regulated in skeletal muscle of breast cancer patients and that different muscle gene expression patterns exist between breast tumour subtypes. In a preclinical study, we tested the hypothesis that mammary tumour growth in mice induces skeletal muscle fatigue and that overexpression of the cytokine interleukin-15 (IL-15) can attenuate mammary tumour-induced muscle fatigue. METHODS Early stage non-metastatic female breast cancer patients (n = 14) and female non-cancer patients (n = 6) provided a muscle biopsy of the pectoralis major muscle during mastectomy, lumpectomy, or breast reconstruction surgeries. The breast cancer patients were diagnosed with either luminal (ER+ /PR+ , n = 6), triple positive (ER+ /PR+ /Her2/neu+ , n = 5), or triple negative (ER- /PR- /Her2/neu- , n = 3) breast tumours and were being treated with curative intent either with neoadjuvant chemotherapy followed by surgery or surgery followed by standard post-operative therapy. Biopsies were used for RNA-sequencing to compare the skeletal muscle gene expression patterns between breast cancer patients and non-cancer patients. The C57BL/6 mouse syngeneic mammary tumour cell line, E0771, was used to induce mammary tumours in immunocompetent mice, and isometric muscle contractile properties and fatigue properties were analysed following 4 weeks of tumour growth. RESULTS RNA-sequencing and subsequent bioinformatics analyses revealed a dysregulation of canonical pathways involved in oxidative phosphorylation, mitochondrial dysfunction, peroxisome proliferator-activated receptor signalling and activation, and IL-15 signalling and production. In a preclinical mouse model of breast cancer, the rate of muscle fatigue was greater in mice exposed to mammary tumour growth for 4 weeks, and this greater muscle fatigue was attenuated in transgenic mice that overexpressed the cytokine IL-15. CONCLUSIONS Our data identify novel genes and pathways dysregulated in the muscles of breast cancer patients with early stage non-metastatic disease, with particularly aberrant expression among genes that would predispose these patients to greater muscle fatigue. Furthermore, we demonstrate that IL-15 overexpression can attenuate muscle fatigue associated with mammary tumour growth in a preclinical mouse model of breast cancer. Therefore, we propose that skeletal muscle fatigue is an inherent consequence of breast tumour growth, and this greater fatigue can be targeted therapeutically.
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Affiliation(s)
- Joseph Bohlen
- Division of Exercise Physiology, Department of Human PerformanceWest Virginia University School of MedicineMorgantownWV26506USA
| | - Sarah L. McLaughlin
- Cancer InstituteWest Virginia University School of MedicineMorgantownWV26506USA
| | - Hannah Hazard‐Jenkins
- Department of SurgeryWest Virginia University School of MedicineMorgantownWV26506USA
| | | | - Cortney Montgomery
- Cancer InstituteWest Virginia University School of MedicineMorgantownWV26506USA
| | - Mary Davis
- Department of Physiology and PharmacologyWest Virginia University School of MedicineMorgantownWV26506USA
| | - Emidio E. Pistilli
- Division of Exercise Physiology, Department of Human PerformanceWest Virginia University School of MedicineMorgantownWV26506USA
- Cancer InstituteWest Virginia University School of MedicineMorgantownWV26506USA
- Department of Microbiology, Immunology and Cell BiologyWest Virginia University School of MedicineMorgantownWV26506USA
- West Virginia Clinical and Translational Sciences InstituteWest Virginia University School of MedicineMorgantownWV26506USA
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IL-15 promotes human myogenesis and mitigates the detrimental effects of TNFα on myotube development. Sci Rep 2017; 7:12997. [PMID: 29021612 PMCID: PMC5636823 DOI: 10.1038/s41598-017-13479-w] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 09/26/2017] [Indexed: 12/12/2022] Open
Abstract
Studies in murine cell lines and in mouse models suggest that IL-15 promotes myogenesis and may protect against the inflammation-mediated skeletal muscle atrophy which occurs in sarcopenia and cachexia. The effects of IL-15 on human skeletal muscle growth and development remain largely uncharacterised. Myogenic cultures were isolated from the skeletal muscle of young and elderly subjects. Myoblasts were differentiated for 8 d, with or without the addition of recombinant cytokines (rIL-15, rTNFα) and an IL-15 receptor neutralising antibody. Although myotubes were 19% thinner in cultures derived from elderly subjects, rIL-15 increased the thickness of myotubes (MTT) from both age groups to a similar extent. Neutralisation of the high-affinity IL-15 receptor binding subunit, IL-15rα in elderly myotubes confirmed that autocrine concentrations of IL-15 also support myogenesis. Co-incubation of differentiating myoblasts with rIL-15 and rTNFα, limited the reduction in MTT and nuclear fusion index (NFI) associated with rTNFα stimulation alone. IL-15rα neutralisation and rTNFα decreased MTT and NFI further. This, coupled with our observation that myotubes secrete IL-15 in response to TNFα stimulation supports the notion that IL-15 serves to mitigate inflammatory skeletal muscle loss. IL-15 may be an effective therapeutic target for the attenuation of inflammation-mediated skeletal muscle atrophy.
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9
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Duan Y, Li F, Wang W, Guo Q, Wen C, Li Y, Yin Y. Interleukin-15 in obesity and metabolic dysfunction: current understanding and future perspectives. Obes Rev 2017; 18:1147-1158. [PMID: 28752527 DOI: 10.1111/obr.12567] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 04/16/2017] [Accepted: 04/28/2017] [Indexed: 12/13/2022]
Abstract
Obesity rises rapidly and is a major health concern for modern people. Importantly, it is a major risk factor in the development of numerous chronic diseases such as type 2 diabetes mellitus (T2DM). Recently, interleukin (IL)-15 has attracted considerable attention as a potential regulator for the prevention and/or treatment of obesity and T2DM. The beneficial effects include increased loss of fat mass and body weight, improved lipid and glucose metabolism, reduced white adipose tissue inflammation, enhanced mitochondrial function, alterations in the composition of muscle fibres and gut bacterial and attenuated endoplasmic reticulum stress. Although these beneficial effects are somewhat controversial, IL-15, exogenously delivered or endogenously produced, may be a promising target in the prevention and treatment of obesity and T2DM.
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Affiliation(s)
- Y Duan
- Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences; National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production; Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production; Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Changsha, Hunan, China.,University of Chinese Academy of Sciences, Beijing, China
| | - F Li
- Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences; National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production; Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production; Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Changsha, Hunan, China.,Hunan Co-Innovation Center of Safety Animal Production, CICSAP, Changsha, China
| | - W Wang
- Laboratory of Animal Nutrition and Human Health, School of Biology, Hunan Normal University, Changsha, China
| | - Q Guo
- Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences; National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production; Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production; Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Changsha, Hunan, China.,University of Chinese Academy of Sciences, Beijing, China
| | - C Wen
- Laboratory of Animal Nutrition and Human Health, School of Biology, Hunan Normal University, Changsha, China
| | - Y Li
- Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences; National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production; Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production; Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Changsha, Hunan, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Y Yin
- Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences; National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production; Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production; Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Changsha, Hunan, China.,Laboratory of Animal Nutrition and Human Health, School of Biology, Hunan Normal University, Changsha, China
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Sarcopenic obesity or obese sarcopenia: A cross talk between age-associated adipose tissue and skeletal muscle inflammation as a main mechanism of the pathogenesis. Ageing Res Rev 2017; 35:200-221. [PMID: 27702700 DOI: 10.1016/j.arr.2016.09.008] [Citation(s) in RCA: 434] [Impact Index Per Article: 62.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 08/23/2016] [Accepted: 09/26/2016] [Indexed: 02/08/2023]
Abstract
Sarcopenia, an age-associated decline in skeletal muscle mass coupled with functional deterioration, may be exacerbated by obesity leading to higher disability, frailty, morbidity and mortality rates. In the combination of sarcopenia and obesity, the state called sarcopenic obesity (SOB), some key age- and obesity-mediated factors and pathways may aggravate sarcopenia. This review will analyze the mechanisms underlying the pathogenesis of SOB. In obese adipose tissue (AT), adipocytes undergo hypertrophy, hyperplasia and activation resulted in accumulation of pro-inflammatory macrophages and other immune cells as well as dysregulated production of various adipokines that together with senescent cells and the immune cell-released cytokines and chemokines create a local pro-inflammatory status. In addition, obese AT is characterized by excessive production and disturbed capacity to store lipids, which accumulate ectopically in skeletal muscle. These intramuscular lipids and their derivatives induce mitochondrial dysfunction characterized by impaired β-oxidation capacity and increased reactive oxygen species formation providing lipotoxic environment and insulin resistance as well as enhanced secretion of some pro-inflammatory myokines capable of inducing muscle dysfunction by auto/paracrine manner. In turn, by endocrine manner, these myokines may exacerbate AT inflammation and also support chronic low grade systemic inflammation (inflammaging), overall establishing a detrimental vicious circle maintaining AT and skeletal muscle inflammation, thus triggering and supporting SOB development. Under these circumstances, we believe that AT inflammation dominates over skeletal muscle inflammation. Thus, in essence, it redirects the vector of processes from "sarcopenia→obesity" to "obesity→sarcopenia". We therefore propose that this condition be defined as "obese sarcopenia", to reflect the direction of the pathological pathway.
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11
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Nguyen L, Bohlen J, Stricker J, Chahal I, Zhang H, Pistilli EE. Hippocampus-specific deficiency of IL-15Rα contributes to greater anxiety-like behaviors in mice. Metab Brain Dis 2017; 32:297-302. [PMID: 27837366 DOI: 10.1007/s11011-016-9930-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 11/08/2016] [Indexed: 02/06/2023]
Abstract
A hippocampus-specific IL15RαKO mouse (hipIl15ra fl/fl /Cre+) was generated to test the hypothesis that the targeted deletion of interleukin-15 receptor alpha (IL-15Rα) in the hippocampus contributes to altered behavior, including greater levels of anxiety and ambulatory activity. Using Cre-loxP, exons 2 and 3 of the IL-15Rα gene were excised within the hippocampus, while normal expression was maintained within the rest of the brain. In the open field test (OFT), hipIl15ra fl/fl /Cre+ spent a greater amount of time in the periphery and less time in the central portions of the chamber, and there was also a noticeable trend for decreased rearing activity; these behaviors are consistent with greater levels of anxiety-like behavior in these mice. However, there were no differences in the overall locomotor counts in the OFT when comparing hipIl15ra fl/fl /Cre+ mice to their littermate controls. These data implicate IL-15-related signaling within the hippocampus has a role in anxiety-like behavior.
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Affiliation(s)
- Linda Nguyen
- Departments of Behavioral Medicine & Psychiatry and Physiology & Pharmacology, West Virginia University School of Medicine, Morgantown, WV, 26506, USA
| | - Joseph Bohlen
- Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, WV, 26506, USA
| | - Janelle Stricker
- Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, WV, 26506, USA
| | - Ikttesh Chahal
- Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, WV, 26506, USA
| | - Hanting Zhang
- Departments of Behavioral Medicine & Psychiatry and Physiology & Pharmacology, West Virginia University School of Medicine, Morgantown, WV, 26506, USA
| | - Emidio E Pistilli
- Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, WV, 26506, USA.
- West Virginia University Cancer Institute, West Virginia University, Morgantown, WV, 26506, USA.
- West Virginia Clinical and Translational Sciences Institute, West Virginia University School of Medicine, Morgantown, WV, 26506, USA.
- Division of Exercise Physiology, Department of Human Performance and Applied Exercise Physiology, West Virginia University School of Medicine, Morgantown, WV, 26506-9227, USA.
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12
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Boa BCS, Yudkin JS, van Hinsbergh VWM, Bouskela E, Eringa EC. Exercise effects on perivascular adipose tissue: endocrine and paracrine determinants of vascular function. Br J Pharmacol 2017; 174:3466-3481. [PMID: 28147449 DOI: 10.1111/bph.13732] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 01/20/2017] [Accepted: 01/23/2017] [Indexed: 12/11/2022] Open
Abstract
Obesity is a global epidemic, accompanied by increased risk of type 2 diabetes and cardiovascular disease. Adipose tissue hypertrophy is associated with adipose tissue inflammation, which alters the secretion of adipose tissue-derived bioactive products, known as adipokines. Adipokines determine vessel wall properties such as smooth muscle tone and vessel wall inflammation. Exercise is a mainstay of prevention of chronic, non-communicable diseases, type 2 diabetes and cardiovascular disease in particular. Aside from reducing adipose tissue mass, exercise has been shown to reduce inflammatory activity in this tissue. Mechanistically, contracting muscles release bioactive molecules known as myokines, which alter the metabolic phenotype of adipose tissue. In adipose tissue, myokines induce browning, enhance fatty acid oxidation and improve insulin sensitivity. In the past years, the perivascular adipose tissue (PVAT) which surrounds the vasculature, has been shown to control vascular tone and inflammation through local release of adipokines. In obesity, an increase in mass and inflammation of PVAT culminate in dysregulation of adipokine secretion, which contributes to vascular dysfunction. This review describes our current understanding of the mechanisms by which active muscles interact with adipose tissue and improve vascular function. Aside from the exercise-dependent regulation of canonical adipose tissue function, we will focus on the interactions between skeletal muscle and PVAT and the role of novel myokines, such as IL-15, FGF21 and irisin, in these interactions. LINKED ARTICLES This article is part of a themed section on Molecular Mechanisms Regulating Perivascular Adipose Tissue - Potential Pharmacological Targets? To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.20/issuetoc.
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Affiliation(s)
- B C S Boa
- Department of Physiology, VU University Medical Centre, Amsterdam, The Netherlands.,Laboratory for Clinical and Experimental Research on Vascular Biology (BioVasc), Biomedical Center, State University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - J S Yudkin
- Department of Medicine, University College London, London, UK
| | - V W M van Hinsbergh
- Department of Physiology, VU University Medical Centre, Amsterdam, The Netherlands
| | - E Bouskela
- Laboratory for Clinical and Experimental Research on Vascular Biology (BioVasc), Biomedical Center, State University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - E C Eringa
- Department of Physiology, VU University Medical Centre, Amsterdam, The Netherlands
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13
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Krolopp JE, Thornton SM, Abbott MJ. IL-15 Activates the Jak3/STAT3 Signaling Pathway to Mediate Glucose Uptake in Skeletal Muscle Cells. Front Physiol 2016; 7:626. [PMID: 28066259 PMCID: PMC5167732 DOI: 10.3389/fphys.2016.00626] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 11/30/2016] [Indexed: 12/19/2022] Open
Abstract
Myokines are specialized cytokines that are secreted from skeletal muscle (SKM) in response to metabolic stimuli, such as exercise. Interleukin-15 (IL-15) is a myokine with potential to reduce obesity and increase lean mass through induction of metabolic processes. It has been previously shown that IL-15 acts to increase glucose uptake in SKM cells. However, the downstream signals orchestrating the link between IL-15 signaling and glucose uptake have not been fully explored. Here we employed the mouse SKM C2C12 cell line to examine potential downstream targets of IL-15-induced alterations in glucose uptake. Following differentiation, C2C12 cells were treated overnight with 100 ng/ml of IL-15. Activation of factors associated with glucose metabolism (Akt and AMPK) and known downstream targets of IL-15 (Jak1, Jak3, STAT3, and STAT5) were assessed with IL-15 stimulation. IL-15 stimulated glucose uptake and GLUT4 translocation to the plasma membrane. IL-15 treatment had no effect on phospho-Akt, phospho-Akt substrates, phospho-AMPK, phospho-Jak1, or phospho-STAT5. However, with IL-15, phospho-Jak3 and phospho-STAT3 levels were increased along with increased interaction of Jak3 and STAT3. Additionally, IL-15 induced a translocation of phospho-STAT3 from the cytoplasm to the nucleus. We have evidence that a mediator of glucose uptake, HIF1α, expression was dependent on IL-15 induced STAT3 activation. Finally, upon inhibition of STAT3 the positive effects of IL-15 on glucose uptake and GLUT4 translocation were abolished. Taken together, we provide evidence for a novel signaling pathway for IL-15 acting through Jak3/STAT3 to regulate glucose metabolism.
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Affiliation(s)
- James E Krolopp
- Department of Health Sciences and Kinesiology, Crean College of Health and Behavioral Sciences, Chapman University Orange, CA, USA
| | - Shantaé M Thornton
- Department of Health Sciences and Kinesiology, Crean College of Health and Behavioral Sciences, Chapman University Orange, CA, USA
| | - Marcia J Abbott
- Department of Health Sciences and Kinesiology, Crean College of Health and Behavioral Sciences, Chapman UniversityOrange, CA, USA; Department of Biological Sciences, Human and Evolutionary Biology Section, Dana and David Dornsife College of Letters, Arts and Sciences, University of Southern CaliforniaLos Angeles, CA, USA
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14
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IL-15 Mediates Mitochondrial Activity through a PPAR δ-Dependent-PPAR α-Independent Mechanism in Skeletal Muscle Cells. PPAR Res 2016; 2016:5465804. [PMID: 27738421 PMCID: PMC5050360 DOI: 10.1155/2016/5465804] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 08/01/2016] [Accepted: 08/21/2016] [Indexed: 11/17/2022] Open
Abstract
Molecular mediators of metabolic processes, to increase energy expenditure, have become a focus for therapies of obesity. The discovery of cytokines secreted from the skeletal muscle (SKM), termed "myokines," has garnered attention due to their positive effects on metabolic processes. Interleukin-15 (IL-15) is a myokine that has numerous positive metabolic effects and is linked to the PPAR family of mitochondrial regulators. Here, we aimed to determine the importance of PPARα and/or PPARδ as targets of IL-15 signaling. C2C12 SKM cells were differentiated for 6 days and treated every other day with IL-15 (100 ng/mL), a PPARα inhibitor (GW-6471), a PPARδ inhibitor (GSK-3787), or both IL-15 and the inhibitors. IL-15 increased mitochondrial activity and induced PPARα, PPARδ, PGC1α, PGC1β, UCP2, and Nrf1 expression. There was no effect of inhibiting PPARα, in combination with IL-15, on the aforementioned mRNA levels except for PGC1β and Nrf1. However, with PPARδ inhibition, IL-15 failed to induce the expression levels of PGC1α, PGC1β, UCP2, and Nrf1. Further, inhibition of PPARδ abolished IL-15 induced increases in citrate synthase activity, ATP production, and overall mitochondrial activity. IL-15 had no effects on mitochondrial biogenesis. Our data indicates that PPARδ activity is required for the beneficial metabolic effects of IL-15 signaling in SKM.
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15
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Ahima RS, Park HK. Connecting Myokines and Metabolism. Endocrinol Metab (Seoul) 2015; 30:235-45. [PMID: 26248861 PMCID: PMC4595346 DOI: 10.3803/enm.2015.30.3.235] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 06/22/2015] [Accepted: 06/29/2015] [Indexed: 12/20/2022] Open
Abstract
Skeletal muscle is the largest organ of the body in non-obese individuals and is now considered to be an endocrine organ. Hormones (myokines) secreted by skeletal muscle mediate communications between muscle and liver, adipose tissue, brain, and other organs. Myokines affect muscle mass and myofiber switching, and have profound effects on glucose and lipid metabolism and inflammation, thus contributing to energy homeostasis and the pathogenesis of obesity, diabetes, and other diseases. In this review, we summarize recent findings on the biology of myokines and provide an assessment of their potential as therapeutic targets.
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Affiliation(s)
- Rexford S Ahima
- Division of Endocrinology, Diabetes and Metabolism, and the Institute for Diabetes, Obesity and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA.
| | - Hyeong Kyu Park
- Department of Internal Medicine, Soonchunhyang University College of Medicine, Seoul, Korea
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16
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Loro E, Seifert EL, Moffat C, Romero F, Mishra MK, Sun Z, Krajacic P, Anokye-Danso F, Summer RS, Ahima RS, Khurana TS. IL-15Rα is a determinant of muscle fuel utilization, and its loss protects against obesity. Am J Physiol Regul Integr Comp Physiol 2015; 309:R835-44. [PMID: 26269523 DOI: 10.1152/ajpregu.00505.2014] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 08/12/2015] [Indexed: 12/19/2022]
Abstract
IL-15Rα is the widely expressed primary binding partner for IL-15. Because of the wide distribution in nonlymphoid tissues like skeletal muscle, adipose, or liver, IL-15/IL-15Rα take part in physiological and metabolic processes not directly related to immunity. In fast muscle, lack of IL-15Rα promotes an oxidative switch, with increased mitochondrial biogenesis and fatigue resistance. These effects are predicted to reproduce some of the benefits of exercise and, therefore, improve energy homeostasis. However, the direct effects of IL-15Rα on metabolism and obesity are currently unknown. We report that mice lacking IL-15Rα (IL-15Rα(-/-)) are resistant to diet-induced obesity (DIO). High-fat diet-fed IL-15Rα(-/-) mice have less body and liver fat accumulation than controls. The leaner phenotype is associated with increased energy expenditure and enhanced fatty acid oxidation by muscle mitochondria. Despite being protected against DIO, IL-15Rα(-/-) are hyperglycemic and insulin-resistant. These findings identify novel roles for IL-15Rα in metabolism and obesity.
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Affiliation(s)
- Emanuele Loro
- Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania; Department of Physiology and Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Erin L Seifert
- Department of Pathology, Anatomy, and Cell Biology and MitoCare Center, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Cynthia Moffat
- Department of Pathology, Anatomy, and Cell Biology and MitoCare Center, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Freddy Romero
- Department of Translational Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania; and
| | - Manoj K Mishra
- Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania; Department of Physiology and Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Zheng Sun
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, Philadelphia, Pennsylvania
| | - Predrag Krajacic
- Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania; Department of Physiology and Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, Pennsylvania; West Virginia School of Osteopathic Medicine, Lewisburg, West Virginia; and
| | - Frederick Anokye-Danso
- Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania; Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, Philadelphia, Pennsylvania
| | - Ross S Summer
- Department of Translational Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania; and
| | - Rexford S Ahima
- Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania; Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, Philadelphia, Pennsylvania
| | - Tejvir S Khurana
- Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania; Department of Physiology and Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, Pennsylvania;
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