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Hirunsai M, Srikuea R. Differential effects of cholecalciferol and calcitriol on muscle proteolysis and oxidative stress in angiotensin II-induced C2C12 myotube atrophy. Physiol Rep 2024; 12:e16011. [PMID: 38627219 PMCID: PMC11021198 DOI: 10.14814/phy2.16011] [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: 12/30/2023] [Revised: 03/13/2024] [Accepted: 03/29/2024] [Indexed: 04/19/2024] Open
Abstract
Renin-angiotensin system activation contributes to skeletal muscle atrophy in aging individuals with chronic diseases. We aimed to explore the effects of cholecalciferol (VD3) and calcitriol (1,25VD3) on signaling of muscle proteolysis and oxidative stress in myotubes challenged with angiotensin II (AII). The mouse C2C12 myotubes were assigned to vehicle, AII, AII + VD3, AII + 1,25VD3, and AII + losartan groups. The expression levels of muscle-specific E3 ubiquitin ligase proteins, autophagy-related proteins, and oxidative stress markers were investigated. We demonstrated the diverse effects of VD3 and 1,25VD3 on AII-induced myotube atrophy. The myotube diameter was preserved by treatment with 100 nM VD3 and losartan, while 1 and 10 nM 1,25VD3 increased levels of FoxO3a, MuRF1, and atrogin-1 protein expression in myotubes exposed to AII. Treatment with AII + 10 nM 1,25VD3 resulted in the upregulation of LC3B-II, LC3B-II/LC3B-I, and mature cathepsin L, which are autophagic marker proteins. The p62/SQSTM1 protein was downregulated and vitamin D receptor was upregulated after treatment with AII + 10 nM 1,25VD3. A cellular redox imbalance was observed as AII + 10 nM 1,25VD3-induced reactive oxygen species and NADPH oxidase-2 overproduction, and these changes were associated with an inadequate response of antioxidant superoxide dismutase-1 and catalase proteins. Collectively, these findings provide a translational perspective on the role of vitamin D3 in alleviating muscle atrophy related to high levels of AII.
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Affiliation(s)
- Muthita Hirunsai
- Department of Biopharmacy, Faculty of PharmacySrinakharinwirot UniversityNakhon NayokThailand
| | - Ratchakrit Srikuea
- Department of Physiology, Faculty of ScienceMahidol UniversityBangkokThailand
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Awata WMC, Alves JV, Costa RM, Bruder-Nascimento A, Singh S, Barbosa GS, Tirapelli CR, Bruder-Nascimento T. Vascular injury associated with ethanol intake is driven by AT1 receptor and mitochondrial dysfunction. Biomed Pharmacother 2023; 169:115845. [PMID: 37951022 DOI: 10.1016/j.biopha.2023.115845] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2023] [Revised: 10/27/2023] [Accepted: 11/05/2023] [Indexed: 11/13/2023] Open
Abstract
BACKGROUND Renin-angiotensin (Ang II)-aldosterone system (RAAS) is crucial for the cardiovascular risk associated with excessive ethanol consumption. Disturbs in mitochondria have been implicated in multiple cardiovascular diseases. However, if mitochondria dysfunction contributes to ethanol-induced vascular dysfunction is still unknown. We investigated whether ethanol leads to vascular dysfunction via RAAS activation, mitochondria dysfunction, and mitochondrial reactive oxygen species (mtROS). METHODS Male C57/BL6J or mt-keima mice (6-8-weeks old) were treated with ethanol (20% vol./vol.) for 12 weeks with or without Losartan (10 mg/kg/day). RESULTS Ethanol induced aortic hypercontractility in an endothelium-dependent manner. PGC1α (a marker of biogenesis), Mfn2, (an essential protein for mitochondria fusion), as well as Pink-1 and Parkin (markers of mitophagy), were reduced in aortas from ethanol-treated mice. Disturb in mitophagy flux was further confirmed in arteries from mt-keima mice. Additionally, ethanol increased mtROS and reduced SOD2 expression. Strikingly, losartan prevented vascular hypercontractility, mitochondrial dysfunction, mtROS, and restored SOD2 expression. Both MnTMPyP (SOD2 mimetic) and CCCP (a mitochondrial uncoupler) reverted ethanol-induced vascular dysfunction. Moreover, L-NAME (NOS inhibitor) and EUK 134 (superoxide dismutase/catalase mimetic) did not affect vascular response in ethanol group, suggesting that ethanol reduces aortic nitric oxide (NO) and H2O2 bioavailability. These responses were prevented by losartan. CONCLUSION AT1 receptor modulates ethanol-induced vascular hypercontractility by promoting mitochondrial dysfunction, mtROS, and reduction of NO and H2O2 bioavailability. Our findings shed a new light in our understanding of ethanol-induced vascular toxicity and open perspectives of new therapeutic approaches for patients with disorder associated with abusive ethanol drinking.
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Affiliation(s)
- Wanessa M C Awata
- Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA, USA; Center for Pediatrics Research in Obesity and Metabolism (CPROM), University of Pittsburgh, Pittsburgh, PA, USA; Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | - Juliano V Alves
- Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA, USA; Center for Pediatrics Research in Obesity and Metabolism (CPROM), University of Pittsburgh, Pittsburgh, PA, USA; Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | - Rafael M Costa
- Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA, USA; Center for Pediatrics Research in Obesity and Metabolism (CPROM), University of Pittsburgh, Pittsburgh, PA, USA; Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | - Ariane Bruder-Nascimento
- Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA, USA; Center for Pediatrics Research in Obesity and Metabolism (CPROM), University of Pittsburgh, Pittsburgh, PA, USA
| | - Shubhnita Singh
- Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA, USA; Center for Pediatrics Research in Obesity and Metabolism (CPROM), University of Pittsburgh, Pittsburgh, PA, USA
| | - Gabriela S Barbosa
- Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA, USA; Center for Pediatrics Research in Obesity and Metabolism (CPROM), University of Pittsburgh, Pittsburgh, PA, USA; UNIPEX, Medical School, Sao Paulo State University (UNESP), Botucatu, Brazil
| | | | - Thiago Bruder-Nascimento
- Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA, USA; Center for Pediatrics Research in Obesity and Metabolism (CPROM), University of Pittsburgh, Pittsburgh, PA, USA; Endocrinology Division at UPMC Children's Hospital of Pittsburgh, University of Pittsburgh, Pittsburgh, PA, USA; Vascular Medicine, Institute (VMI), University of Pittsburgh, Pittsburgh, PA, USA.
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3
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Rossios C, Bashir T, Achison M, Adamson S, Akpan A, Aspray T, Avenell A, Band MM, Burton LA, Cvoro V, Donnan PT, Duncan GW, George J, Gordon AL, Gregson CL, Hapca A, Hume C, Jackson TA, Kerr S, Kilgour A, Masud T, McKenzie A, McKenzie E, Patel H, Pilvinyte K, Roberts HC, Sayer AA, Smith KT, Soiza RL, Steves CJ, Struthers AD, Tiwari D, Whitney J, Witham MD, Kemp PR. ACE I/D genotype associates with strength in sarcopenic men but not with response to ACE inhibitor therapy in older adults with sarcopenia: Results from the LACE trial. PLoS One 2023; 18:e0292402. [PMID: 37862321 PMCID: PMC10588903 DOI: 10.1371/journal.pone.0292402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 09/19/2023] [Indexed: 10/22/2023] Open
Abstract
BACKGROUND Angiotensin II (AII), has been suggested to promote muscle loss. Reducing AII synthesis, by inhibiting angiotensin converting enzyme (ACE) activity has been proposed as a method to inhibit muscle loss. The LACE clinical trial was designed to determine whether ACE inhibition would reduce further muscle loss in individuals with sarcopenia but suffered from low recruitment and returned a negative result. Polymorphic variation in the ACE promoter (I/D alleles) has been associated with differences in ACE activity and muscle physiology in a range of clinical conditions. This aim of this analysis was to determine whether I/D polymorphic variation is associated with muscle mass, strength, in sarcopenia or contributed to the lack of response to treatment in the LACE study. METHODS Sarcopenic individuals were recruited into a 2x2 factorial multicentre double-blind study of the effects of perindopril and/or leucine versus placebo on physical performance and muscle mass. DNA extracted from blood samples (n = 130 72 women and 58 men) was genotyped by PCR for the ACE I/D polymorphism. Genotypes were then compared with body composition measured by DXA, hand grip and quadriceps strength before and after 12 months' treatment with leucine and/or perindopril in a cross-sectional analysis of the influence of genotype on these variables. RESULTS Allele frequencies for the normal UK population were extracted from 13 previous studies (I = 0.473, D = 0.527). In the LACE cohort the D allele was over-represented (I = 0.412, D = 0.588, p = 0.046). This over-representation was present in men (I = 0.353, D = 0.647, p = 0.010) but not women (I = 0.458, D = 0.532, p = 0.708). In men but not women, individuals with the I allele had greater leg strength (II/ID = 18.00 kg (14.50, 21.60) vs DD = 13.20 kg (10.50, 15.90), p = 0.028). Over the 12 months individuals with the DD genotype increased in quadriceps strength but those with the II or ID genotype did not. Perindopril did not increase muscle strength or mass in any polymorphism group relative to placebo. CONCLUSION Our results suggest that although ACE genotype was not associated with response to ACE inhibitor therapy in the LACE trial population, sarcopenic men with the ACE DD genotype may be weaker than those with the ACE I/D or II genotype.
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Affiliation(s)
- Christos Rossios
- Cardiovascular and Respiratory Interface Section, National Heart and Lung Institute, Imperial College London, South Kensington Campus, London, United Kingdom
| | - Tufail Bashir
- Cardiovascular and Respiratory Interface Section, National Heart and Lung Institute, Imperial College London, South Kensington Campus, London, United Kingdom
| | - Marcus Achison
- Tayside Clinical Trials Unit (TCTU), Tayside Medical Science Centre (TASC), University of Dundee, Ninewells Hospital & Medical School, Dundee, United Kingdom
| | - Simon Adamson
- Tayside Clinical Trials Unit (TCTU), Tayside Medical Science Centre (TASC), University of Dundee, Ninewells Hospital & Medical School, Dundee, United Kingdom
| | - Asangaedem Akpan
- University of Liverpool, Liverpool University Hospitals NHS FT Trust, Clinical Research Network Northwest Coast, Liverpool, United Kingdom
| | - Terry Aspray
- AGE Research Group, NIHR Newcastle Biomedical Research Centre, Translational Clinical Research Institute, Newcastle University, Cumbria Northumberland Tyne and Wear NHS Foundation Trust and Newcastle upon Tyne Hospitals NHS Trust, Newcastle upon Tyne, United Kingdom
| | - Alison Avenell
- Health Services Research Unit, University of Aberdeen, Aberdeen, United Kingdom
| | - Margaret M. Band
- Tayside Clinical Trials Unit (TCTU), Tayside Medical Science Centre (TASC), University of Dundee, Ninewells Hospital & Medical School, Dundee, United Kingdom
| | - Louise A. Burton
- Medicine for the Elderly, NHS Tayside, Dundee, United Kingdom
- Ageing and Health, University of Dundee, Dundee, United Kingdom
| | - Vera Cvoro
- Victoria Hospital, Kirkcaldy, United Kingdom
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Peter T. Donnan
- Division of Population Health and Genomics, School of Medicine, University of Dundee, Dundee, United Kingdom
| | - Gordon W. Duncan
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
- Medicine for the Elderly, NHS Lothian, Edinburgh, United Kingdom
| | - Jacob George
- Dept Clinical Pharmacology, Division of Molecular & Clinical Medicine, University of Dundee Medical School, Ninewells Hospital, Dundee, United Kingdom
| | - Adam L. Gordon
- Unit of Injury, Inflammation and Recovery, School of Medicine, University of Nottingham, Nottingham, United Kingdom
- NIHR Nottingham Biomedical Research Centre, Department of Medicine for the Elderly, University Hospitals of Derby and Burton NHS Foundation Trust, Derby, United Kingdom
| | - Celia L. Gregson
- Musculoskeletal Research Unit, Bristol Medical School, University of Bristol, Bristol, United Kingdom
- Older Person’s Unit, Royal United Hospital NHS Foundation Trust Bath, Bath, United Kingdom
| | - Adrian Hapca
- Tayside Clinical Trials Unit (TCTU), Tayside Medical Science Centre (TASC), University of Dundee, Ninewells Hospital & Medical School, Dundee, United Kingdom
| | - Cheryl Hume
- Tayside Clinical Trials Unit (TCTU), Tayside Medical Science Centre (TASC), University of Dundee, Ninewells Hospital & Medical School, Dundee, United Kingdom
| | - Thomas A. Jackson
- Institute of Inflammation and Ageing, University of Birmingham, Birmingham, United Kingdom
| | - Simon Kerr
- Department of Older People’s Medicine, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, United Kingdom
| | - Alixe Kilgour
- Medicine for the Elderly, NHS Lothian, Edinburgh, United Kingdom
- Ageing and Health Research Group, Usher Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Tahir Masud
- Clinical Gerontology Research Unit, Nottingham University Hospitals NHS Trust, City Hospital Campus, Nottingham, United Kingdom
| | - Andrew McKenzie
- Tayside Clinical Trials Unit (TCTU), Tayside Medical Science Centre (TASC), University of Dundee, Ninewells Hospital & Medical School, Dundee, United Kingdom
| | - Emma McKenzie
- Tayside Clinical Trials Unit (TCTU), Tayside Medical Science Centre (TASC), University of Dundee, Ninewells Hospital & Medical School, Dundee, United Kingdom
| | - Harnish Patel
- NIHR Biomedical Research Centre, University of Southampton and University Hospital Southampton NHSFT, Southampton, Hampshire, United Kingdom
| | - Kristina Pilvinyte
- Tayside Clinical Trials Unit (TCTU), Tayside Medical Science Centre (TASC), University of Dundee, Ninewells Hospital & Medical School, Dundee, United Kingdom
| | - Helen C. Roberts
- Academic Geriatric Medicine, University of Southampton, Mailpoint 807 Southampton General Hospital, Southampton, United Kingdom
| | - Avan A. Sayer
- AGE Research Group, NIHR Newcastle Biomedical Research Centre, Translational Clinical Research Institute, Newcastle University, Cumbria Northumberland Tyne and Wear NHS Foundation Trust and Newcastle upon Tyne Hospitals NHS Trust, Newcastle upon Tyne, United Kingdom
| | - Karen T. Smith
- Tayside Clinical Trials Unit (TCTU), Tayside Medical Science Centre (TASC), University of Dundee, Ninewells Hospital & Medical School, Dundee, United Kingdom
| | - Roy L. Soiza
- Ageing & Clinical Experimental Research (ACER) Group, University of Aberdeen, Aberdeen, United Kingdom
| | - Claire J. Steves
- Department of Twin Research and Genetic Epidemiology, King’s College London & Department of Clinical Gerontology, King’s College Hospital, London, United Kingdom
| | - Allan D. Struthers
- Dept Clinical Pharmacology, Division of Molecular & Clinical Medicine, University of Dundee Medical School, Ninewells Hospital, Dundee, United Kingdom
| | - Divya Tiwari
- Bournemouth University and Royal Bournemouth Hospital, Bournemouth, United Kingdom
| | - Julie Whitney
- School of Population Health & Environmental Sciences, King’s College London and King’s College Hospital, London, United Kingdom
| | - Miles D. Witham
- AGE Research Group, NIHR Newcastle Biomedical Research Centre, Translational Clinical Research Institute, Newcastle University, Cumbria Northumberland Tyne and Wear NHS Foundation Trust and Newcastle upon Tyne Hospitals NHS Trust, Newcastle upon Tyne, United Kingdom
| | - Paul R. Kemp
- Cardiovascular and Respiratory Interface Section, National Heart and Lung Institute, Imperial College London, South Kensington Campus, London, United Kingdom
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Rawls A, Diviak BK, Smith CI, Severson GW, Acosta SA, Wilson-Rawls J. Pharmacotherapeutic Approaches to Treatment of Muscular Dystrophies. Biomolecules 2023; 13:1536. [PMID: 37892218 PMCID: PMC10605463 DOI: 10.3390/biom13101536] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 10/10/2023] [Accepted: 10/11/2023] [Indexed: 10/29/2023] Open
Abstract
Muscular dystrophies are a heterogeneous group of genetic muscle-wasting disorders that are subdivided based on the region of the body impacted by muscle weakness as well as the functional activity of the underlying genetic mutations. A common feature of the pathophysiology of muscular dystrophies is chronic inflammation associated with the replacement of muscle mass with fibrotic scarring. With the progression of these disorders, many patients suffer cardiomyopathies with fibrosis of the cardiac tissue. Anti-inflammatory glucocorticoids represent the standard of care for Duchenne muscular dystrophy, the most common muscular dystrophy worldwide; however, long-term exposure to glucocorticoids results in highly adverse side effects, limiting their use. Thus, it is important to develop new pharmacotherapeutic approaches to limit inflammation and fibrosis to reduce muscle damage and promote repair. Here, we examine the pathophysiology, genetic background, and emerging therapeutic strategies for muscular dystrophies.
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Affiliation(s)
- Alan Rawls
- School of Life Sciences, Arizona State University, Tempe, AZ 85287-4501, USA; (B.K.D.); (C.I.S.); (G.W.S.); (S.A.A.)
| | - Bridget K. Diviak
- School of Life Sciences, Arizona State University, Tempe, AZ 85287-4501, USA; (B.K.D.); (C.I.S.); (G.W.S.); (S.A.A.)
- Molecular and Cellular Biology Graduate Program, School of Life Sciences, Tempe, AZ 85287 4501, USA
| | - Cameron I. Smith
- School of Life Sciences, Arizona State University, Tempe, AZ 85287-4501, USA; (B.K.D.); (C.I.S.); (G.W.S.); (S.A.A.)
- Molecular and Cellular Biology Graduate Program, School of Life Sciences, Tempe, AZ 85287 4501, USA
| | - Grant W. Severson
- School of Life Sciences, Arizona State University, Tempe, AZ 85287-4501, USA; (B.K.D.); (C.I.S.); (G.W.S.); (S.A.A.)
- Molecular and Cellular Biology Graduate Program, School of Life Sciences, Tempe, AZ 85287 4501, USA
| | - Sofia A. Acosta
- School of Life Sciences, Arizona State University, Tempe, AZ 85287-4501, USA; (B.K.D.); (C.I.S.); (G.W.S.); (S.A.A.)
- Molecular and Cellular Biology Graduate Program, School of Life Sciences, Tempe, AZ 85287 4501, USA
| | - Jeanne Wilson-Rawls
- School of Life Sciences, Arizona State University, Tempe, AZ 85287-4501, USA; (B.K.D.); (C.I.S.); (G.W.S.); (S.A.A.)
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Song Y, Gu J, You J, Tao Y, Zhang Y, Wang L, Gao J. The functions of SID1 transmembrane family, member 2 (Sidt2). FEBS J 2023; 290:4626-4637. [PMID: 36176242 DOI: 10.1111/febs.16641] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 09/02/2022] [Accepted: 09/28/2022] [Indexed: 11/30/2022]
Abstract
The SID1 transmembrane family, member 2, namely, Sidt2, is a highly glycosylated multichannel lysosomal transmembrane protein, but its specific physiological function remains unknown. Lysosomal membrane proteins are very important for the executive functioning of lysosomes. As an important part of the lysosomal membrane, Sidt2 can maintain the normal morphology of lysosomes and help stabilize them from the acidic pH environment within. As a receptor/transporter, it binds and transports nucleic acids and mediates the uptake and degradation of RNA and DNA by the lysosome. During glucose metabolism, deletion of Sidt2 can cause an increase in fasting blood glucose and the impairment of grape tolerance, which is closely related to the secretion of insulin. During lipid metabolism, the loss of Sidt2 can cause hepatic steatosis and lipid metabolism disorders and can also play a role in signal regulation and transport. Here, we review the function of the lysosomal membrane protein Sidt2, and focus on its role in glucose and lipid metabolism, autophagy and nucleotide (DNA/RNA) transport.
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Affiliation(s)
- Yingying Song
- Department of Endocrinology and Genetic Metabolism, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, China
- Department of Endocrinology and Genetic Metabolism, Institute of Endocrine and Metabolic Diseases, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, China
- Anhui Province Key Laboratory of Biological Macro-Molecules Research, Wannan Medical College, Wuhu, China
| | - Jing Gu
- Department of Endocrinology and Genetic Metabolism, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, China
- Department of Endocrinology and Genetic Metabolism, Institute of Endocrine and Metabolic Diseases, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, China
- Anhui Province Key Laboratory of Biological Macro-Molecules Research, Wannan Medical College, Wuhu, China
| | - Jingya You
- Anhui Province Key Laboratory of Biological Macro-Molecules Research, Wannan Medical College, Wuhu, China
- School of Clinical Medicine, Wannan Medical College, Wuhu, China
| | - Yiyang Tao
- Anhui Province Key Laboratory of Biological Macro-Molecules Research, Wannan Medical College, Wuhu, China
- School of Clinical Medicine, Wannan Medical College, Wuhu, China
| | - Yao Zhang
- Anhui Province Key Laboratory of Biological Macro-Molecules Research, Wannan Medical College, Wuhu, China
- Department of Biochemistry and Molecular Biology, Wannan Medical College, Wuhu, China
| | - Lizhuo Wang
- Anhui Province Key Laboratory of Biological Macro-Molecules Research, Wannan Medical College, Wuhu, China
- Department of Biochemistry and Molecular Biology, Wannan Medical College, Wuhu, China
| | - Jialin Gao
- Department of Endocrinology and Genetic Metabolism, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, China
- Department of Endocrinology and Genetic Metabolism, Institute of Endocrine and Metabolic Diseases, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, China
- Anhui Province Key Laboratory of Biological Macro-Molecules Research, Wannan Medical College, Wuhu, China
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Holder ER, Alibhai FJ, Caudle SL, McDermott JC, Tobin SW. The importance of biological sex in cardiac cachexia. Am J Physiol Heart Circ Physiol 2022; 323:H609-H627. [PMID: 35960634 DOI: 10.1152/ajpheart.00187.2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cardiac cachexia is a catabolic muscle wasting syndrome observed in approximately 1 in 10 heart failure patients. Increased skeletal muscle atrophy leads to frailty and limits mobility which impacts quality of life, exacerbates clinical care, and is associated with higher rates of mortality. Heart failure is known to exhibit a wide range of prevalence and severity when examined across individuals of different ages and with co-morbidities related to diabetes, renal failure and pulmonary dysfunction. It is also recognized that men and women exhibit striking differences in the pathophysiology of heart failure as well as skeletal muscle homeostasis. Given that both skeletal muscle and heart failure physiology are in-part sex dependent, the diagnosis and treatment of cachexia in heart failure patients may depend on a comprehensive examination of how these organs interact. In this review we explore the potential for sex-specific differences in cardiac cachexia. We summarize advantages and disadvantages of clinical methods used to measure muscle mass and function and provide alternative measurements that should be considered in preclinical studies. Additionally, we summarize sex-dependent effects on muscle wasting in preclinical models of heart failure, disuse, and cancer. Lastly, we discuss the endocrine function of the heart and outline unanswered questions that could directly impact patient care.
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7
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Function and regulation of ULK1: From physiology to pathology. Gene 2022; 840:146772. [PMID: 35905845 DOI: 10.1016/j.gene.2022.146772] [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: 05/30/2022] [Revised: 07/03/2022] [Accepted: 07/24/2022] [Indexed: 11/21/2022]
Abstract
The expression of ULK1, a core protein of autophagy, is closely related to autophagic activity. Numerous studies have shown that pathological abnormal expression of ULK1 is associated with various human diseases such as neurological disorders, infections, cardiovascular diseases, liver diseases and cancers. In addition, new advances in the regulation of ULK1 have been identified. Furthermore, targeting ULK1 as a therapeutic strategy for diseases is gaining attention as new corresponding activators or inhibitors are being developed. In this review, we describe the structure and regulation of ULK1 as well as the current targeted activators and inhibitors. Moreover, we highlight the pathological disorders of ULK1 expression and its critical role in human diseases.
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Videla LA, Marimán A, Ramos B, José Silva M, Del Campo A. Standpoints in mitochondrial dysfunction: Underlying mechanisms in search of therapeutic strategies. Mitochondrion 2022; 63:9-22. [PMID: 34990812 DOI: 10.1016/j.mito.2021.12.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 12/27/2021] [Accepted: 12/29/2021] [Indexed: 02/07/2023]
Abstract
Mitochondrial dysfunction has been defined as a reduced efficiency of mitochondria to produce ATP given by a loss of mitochondrial membrane potential, alterations in the electron transport chain (ETC) function, with increase in reactive oxygen species (ROS) generation and decrease in oxygen consumption. During the last decades, mitochondrial dysfunction has been the focus of many researchers as a convergent point for the pathophysiology of several diseases. Numerous investigations have demonstrated that mitochondrial dysfunction is detrimental to cells, tissues and organisms, nevertheless, dysfunctional mitochondria can signal in a particular way in response to stress, a characteristic that may be useful to search for new therapeutic strategies with a common feature. The aim of this review addresses mitochondrial dysfunction and stress signaling as a promising target for future drug development.
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Affiliation(s)
- Luis A Videla
- Molecular and Clinical Pharmacology Program, Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago 8380453, Chile.
| | - Andrea Marimán
- Laboratorio de Fisiología y Bioenergética Celular, Departamento de Farmacia, Facultad de Química y de Farmacia, Pontificia Universidad Católica de Chile, Santiago 7810000, Chile
| | - Bastián Ramos
- Laboratorio de Fisiología y Bioenergética Celular, Departamento de Farmacia, Facultad de Química y de Farmacia, Pontificia Universidad Católica de Chile, Santiago 7810000, Chile
| | - María José Silva
- Laboratorio de Fisiología y Bioenergética Celular, Departamento de Farmacia, Facultad de Química y de Farmacia, Pontificia Universidad Católica de Chile, Santiago 7810000, Chile
| | - Andrea Del Campo
- Laboratorio de Fisiología y Bioenergética Celular, Departamento de Farmacia, Facultad de Química y de Farmacia, Pontificia Universidad Católica de Chile, Santiago 7810000, Chile.
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Angiotensin II inhibition: a potential treatment to slow the progression of sarcopenia. Clin Sci (Lond) 2021; 135:2503-2520. [PMID: 34751393 DOI: 10.1042/cs20210719] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 10/21/2021] [Accepted: 10/29/2021] [Indexed: 02/07/2023]
Abstract
Sarcopenia is defined as the progressive and generalized loss of skeletal muscle mass and strength, which is associated with increased likelihood of adverse outcomes including falls, fractures, physical disability, and mortality. The etiology of sarcopenia has been postulated to be multifactorial with genetics, aging, immobility, nutritional deficiencies, inflammation, stress, and endocrine factors all contributing to the imbalance of muscle anabolism and catabolism. The prevalence of sarcopenia is estimated to range from 13 to 24% in adults over 60 years of age and up to 50% in persons aged 80 and older. As the population continues to age, the prevalence of sarcopenia continues to increase and is expected to affect 500 million people by the year 2050. Sarcopenia impacts the overall health of patients through limitations in functional status, increase in hospital readmissions, poorer hospital outcomes, and increase in overall mortality. Thus, there exists a need to prevent or reduce the occurrence of sarcopenia. Here, we explore the potential mechanisms and current studies regarding angiotensin receptor blockers (ARBs) and angiotensin-converting enzyme (ACE) inhibitors on reducing the development of sarcopenia through the associated changes in cardiovascular function, renal function, muscle fiber composition, inflammation, endothelial dysfunction, metabolic efficiency, and mitochondrial function.
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Sfera A, Osorio C, Zapata Martín del Campo CM, Pereida S, Maurer S, Maldonado JC, Kozlakidis Z. Endothelial Senescence and Chronic Fatigue Syndrome, a COVID-19 Based Hypothesis. Front Cell Neurosci 2021; 15:673217. [PMID: 34248502 PMCID: PMC8267916 DOI: 10.3389/fncel.2021.673217] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Accepted: 05/25/2021] [Indexed: 12/14/2022] Open
Abstract
Myalgic encephalomyelitis/chronic fatigue syndrome is a serious illness of unknown etiology, characterized by debilitating exhaustion, memory impairment, pain and sleep abnormalities. Viral infections are believed to initiate the pathogenesis of this syndrome although the definite proof remains elusive. With the unfolding of COVID-19 pandemic, the interest in this condition has resurfaced as excessive tiredness, a major complaint of patients infected with the SARS-CoV-2 virus, often lingers for a long time, resulting in disability, and poor life quality. In a previous article, we hypothesized that COVID-19-upregulated angiotensin II triggered premature endothelial cell senescence, disrupting the intestinal and blood brain barriers. Here, we hypothesize further that post-viral sequelae, including myalgic encephalomyelitis/chronic fatigue syndrome, are promoted by the gut microbes or toxin translocation from the gastrointestinal tract into other tissues, including the brain. This model is supported by the SARS-CoV-2 interaction with host proteins and bacterial lipopolysaccharide. Conversely, targeting microbial translocation and cellular senescence may ameliorate the symptoms of this disabling illness.
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Affiliation(s)
- Adonis Sfera
- Patton State Hospital, San Bernardino, CA, United States
| | | | | | | | - Steve Maurer
- Patton State Hospital, San Bernardino, CA, United States
| | - Jose Campo Maldonado
- Department of Internal Medicine, The University of Texas Rio Grande Valley, Edinburg, TX, United States
| | - Zisis Kozlakidis
- International Agency for Research on Cancer (IARC), Lyon, France
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11
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Zhuang ZQ, Zhang ZZ, Zhang YM, Ge HH, Sun SY, Zhang P, Chen GH. A Long-Term Enriched Environment Ameliorates the Accelerated Age-Related Memory Impairment Induced by Gestational Administration of Lipopolysaccharide: Role of Plastic Mitochondrial Quality Control. Front Cell Neurosci 2021; 14:559182. [PMID: 33613195 PMCID: PMC7886998 DOI: 10.3389/fncel.2020.559182] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 10/27/2020] [Indexed: 11/13/2022] Open
Abstract
Studies have shown that gestational inflammation accelerates age-related memory impairment in mother mice. An enriched environment (EE) can improve age-related memory impairment, whereas mitochondrial dysfunction has been implicated in the pathogenesis of brain aging. However, it is unclear whether an EE can counteract the accelerated age-related memory impairment induced by gestational inflammation and whether this process is associated with the disruption of mitochondrial quality control (MQC) processes. In this study, CD-1 mice received daily intraperitoneal injections of lipopolysaccharide (LPS, 50 μg/kg) or normal saline (CON group) during gestational days 15–17 and were separated from their offspring at the end of normal lactation. The mothers that received LPS were divided into LPS group and LPS plus EE (LPS-E) treatment groups based on whether the mice were exposed to an EE until the end of the experiment. At 6 and 18 months of age, the Morris water maze test was used to evaluate spatial learning and memory abilities. Quantitative reverse transcription polymerase chain reaction and Western blot were used to measure the messenber RNA (mRNA) and protein levels of MQC-related genes in the hippocampus, respectively. The results showed that all the aged (18 months old) mice underwent a striking decline in spatial learning and memory performances and decreased mRNA/protein levels related to mitochondrial dynamics (Mfn1/Mfn2, OPA1, and Drp1), biogenesis (PGC-1α), and mitophagy (PINK1/parkin) in the hippocampi compared with the young (6 months old) mice. LPS treatment exacerbated the decline in age-related spatial learning and memory and enhanced the reduction in the mRNA and protein levels of MQC-related genes but increased the levels of PGC-1α in young mice. Exposure to an EE could alleviate the accelerated decline in age-related spatial learning and memory abilities and the accelerated changes in MQC-related mRNA or protein levels resulting from LPS treatment, especially in aged mice. In conclusion, long-term exposure to an EE can counteract the accelerated age-related spatial cognition impairment modulated by MQC in CD-1 mother mice that experience inflammation during pregnancy.
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Affiliation(s)
- Zhan-Qiang Zhuang
- Department of Neurology (Sleep Disorders), The Affiliated Chaohu Hospital of Anhui Medical University, Hefei, China.,Division of Life Sciences and Medicine, Department of Neurology, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei, China
| | - Zhe-Zhe Zhang
- Department of Neurology (Sleep Disorders), The Affiliated Chaohu Hospital of Anhui Medical University, Hefei, China
| | - Yue-Ming Zhang
- Department of Neurology (Sleep Disorders), The Affiliated Chaohu Hospital of Anhui Medical University, Hefei, China
| | - He-Hua Ge
- Department of Neurology (Sleep Disorders), The Affiliated Chaohu Hospital of Anhui Medical University, Hefei, China
| | - Shi-Yu Sun
- Department of Neurology (Sleep Disorders), The Affiliated Chaohu Hospital of Anhui Medical University, Hefei, China
| | - Ping Zhang
- Department of Neurology (Sleep Disorders), The Affiliated Chaohu Hospital of Anhui Medical University, Hefei, China
| | - Gui-Hai Chen
- Department of Neurology (Sleep Disorders), The Affiliated Chaohu Hospital of Anhui Medical University, Hefei, China.,Institute of Sleep Medicine of Anhui Medical University, Hefei, China
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12
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Angiotensin-(1-7) Prevents Lipopolysaccharide-Induced Autophagy via the Mas Receptor in Skeletal Muscle. Int J Mol Sci 2020; 21:ijms21249344. [PMID: 33302427 PMCID: PMC7762589 DOI: 10.3390/ijms21249344] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 11/27/2020] [Accepted: 12/04/2020] [Indexed: 12/18/2022] Open
Abstract
Skeletal muscle atrophy, which occurs in lipopolysaccharide (LPS)-induced sepsis, causes a severe muscle function reduction. The increased autophagy contributes to sepsis-induced skeletal muscle atrophy in a model of LPS injection, increasing LC3II/LC3I ratio, autophagy flux, and autophagosomes. Angiotensin-(1-7) (Ang-(1-7)) has anti-atrophic effects via the Mas receptor in skeletal muscle. However, the impact of Ang-(1-7) on LPS-induced autophagy is unknown. In this study, we determined the effect of Ang-(1-7) on sepsis-induced muscle autophagy. C57BL6 wild-type (WT) mice and mice lacking the Mas receptor (KO Mas) were injected with LPS together with the systemic administration of Ang-(1-7) to determine autophagy in skeletal muscle. We also evaluated autophagy and p38 and c-Jun N-terminal kinase (JNK)activation. Our results show that Ang-(1-7) prevents LPS-induced autophagy in the diaphragm, tibialis anterior, and gastrocnemius of WT mice, which is demonstrated by a decrease in the LC3II/LC3I ratio and mRNA levels of lc3b and ctsl. This effect was lost in KO Mas mice, suggesting the role of the Mas receptor. The results in C2C12 cells show that Ang-(1-7) reduces several LPS-dependent effects, such as autophagy (LC3II/LC3I ratio, autophagic flux, and autophagosomes), activation of p38 and JNK, B-cell lymphoma-2 (BCL2) phosphorylation, and disassembly of the Beclin1/BCL2 complex. In conclusion, Ang-(1-7)/Mas receptor reduces LPS-induced autophagy in skeletal muscle. In vitro assays indicate that Ang-(1-7) prevents LPS-induced autophagy and modifies the MAPK signaling and the disassembly of a complex involved at the beginning of autophagy.
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13
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Yoshida T, Delafontaine P. Mechanisms of IGF-1-Mediated Regulation of Skeletal Muscle Hypertrophy and Atrophy. Cells 2020; 9:cells9091970. [PMID: 32858949 PMCID: PMC7564605 DOI: 10.3390/cells9091970] [Citation(s) in RCA: 261] [Impact Index Per Article: 65.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 08/18/2020] [Accepted: 08/19/2020] [Indexed: 12/18/2022] Open
Abstract
Insulin-like growth factor-1 (IGF-1) is a key growth factor that regulates both anabolic and catabolic pathways in skeletal muscle. IGF-1 increases skeletal muscle protein synthesis via PI3K/Akt/mTOR and PI3K/Akt/GSK3β pathways. PI3K/Akt can also inhibit FoxOs and suppress transcription of E3 ubiquitin ligases that regulate ubiquitin proteasome system (UPS)-mediated protein degradation. Autophagy is likely inhibited by IGF-1 via mTOR and FoxO signaling, although the contribution of autophagy regulation in IGF-1-mediated inhibition of skeletal muscle atrophy remains to be determined. Evidence has suggested that IGF-1/Akt can inhibit muscle atrophy-inducing cytokine and myostatin signaling via inhibition of the NF-κΒ and Smad pathways, respectively. Several miRNAs have been found to regulate IGF-1 signaling in skeletal muscle, and these miRs are likely regulated in different pathological conditions and contribute to the development of muscle atrophy. IGF-1 also potentiates skeletal muscle regeneration via activation of skeletal muscle stem (satellite) cells, which may contribute to muscle hypertrophy and/or inhibit atrophy. Importantly, IGF-1 levels and IGF-1R downstream signaling are suppressed in many chronic disease conditions and likely result in muscle atrophy via the combined effects of altered protein synthesis, UPS activity, autophagy, and muscle regeneration.
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Affiliation(s)
- Tadashi Yoshida
- Heart and Vascular Institute, John W. Deming Department of Medicine, Tulane University School of Medicine, 1430 Tulane Ave SL-48, New Orleans, LA 70112, USA
- Department of Physiology, Tulane University School of Medicine, 1430 Tulane Ave, New Orleans, LA 70112, USA
- Correspondence: (T.Y.); (P.D.)
| | - Patrice Delafontaine
- Heart and Vascular Institute, John W. Deming Department of Medicine, Tulane University School of Medicine, 1430 Tulane Ave SL-48, New Orleans, LA 70112, USA
- Department of Physiology, Tulane University School of Medicine, 1430 Tulane Ave, New Orleans, LA 70112, USA
- Correspondence: (T.Y.); (P.D.)
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14
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Song JJ, Yang M, Liu Y, Song JW, Wang J, Chi HJ, Liu XY, Zuo K, Yang XC, Zhong JC. MicroRNA-122 aggravates angiotensin II-mediated apoptosis and autophagy imbalance in rat aortic adventitial fibroblasts via the modulation of SIRT6-elabela-ACE2 signaling. Eur J Pharmacol 2020; 883:173374. [PMID: 32682786 PMCID: PMC7364171 DOI: 10.1016/j.ejphar.2020.173374] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 07/11/2020] [Accepted: 07/13/2020] [Indexed: 12/14/2022]
Abstract
Abnormal aortic adventitial fibroblasts (AFs) play essential roles in the development of vascular remodeling and disorders. Previous studies revealed that microRNA-122 (miR-122) levels were elevated in the aortic adventitia of hypertensive rats with vascular injury. Here, we aim to evaluate the biological effects and underlying mechanisms of miR-122 in rat AFs. Exposure to angiotensin II (ATII) in rat AFs resulted in decreased levels of sirtuin 6 (SIRT6), elabela (ELA), and angiotensin-converting enzyme 2 (ACE2). Additionally, stimulation with ATII contributed to a decline in autophagic flux and obvious increases in cellular migration, oxidative stress, and apoptosis, which were exacerbated by the transfection of miR-122-5p mimic but were rescued by miR-122-5p inhibitor, exogenous replenishment of ELA, and recombinant adeno-associated virus expressing SIRT6 (rAAV-SIRT6), respectively. Moreover, stimulation with miR-122-5p mimic led to a marked reduction in the levels of SIRT6 and ELA in rat AFs, which were elevated by stimulation with rAAV-SIRT6. Furthermore, miR-122-5p inhibitor-mediated pro-autophagic, anti-oxidant and anti-apoptotic effects in rat AFs were partially suppressed by 3-methyladenine, SIRT6 small interfering RNA (siRNA) and ELA siRNA, which were linked with the downregulation in the protein levels of LC3-II, beclin-1, and ACE2 and the upregulation of p62 expression and bax/bcl-2 ratio. Our findings indicated that miR-122-5p inhibition prevented ATII-mediated loss of autophagy, and the promotion of apoptosis and oxidative stress via activating the SIRT6-ELA-ACE2 signaling. MiR-122-5p may be a novel predictive biomarker of adventitial injury, and targeting the SIRT6-ELA-ACE2 signaling may have the potential therapeutic importance of controlling vascular remodeling and disorders.
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Affiliation(s)
- Juan-Juan Song
- Heart Center and Beijing Key Laboratory of Hypertension, Beijing Chaoyang Hospital, Capital Medical University, Beijing, 100020, China
| | - Mei Yang
- Heart Center and Beijing Key Laboratory of Hypertension, Beijing Chaoyang Hospital, Capital Medical University, Beijing, 100020, China
| | - Ying Liu
- Heart Center and Beijing Key Laboratory of Hypertension, Beijing Chaoyang Hospital, Capital Medical University, Beijing, 100020, China
| | - Jia-Wei Song
- Heart Center and Beijing Key Laboratory of Hypertension, Beijing Chaoyang Hospital, Capital Medical University, Beijing, 100020, China
| | - Juan Wang
- Heart Center and Beijing Key Laboratory of Hypertension, Beijing Chaoyang Hospital, Capital Medical University, Beijing, 100020, China
| | - Hong-Jie Chi
- Heart Center and Beijing Key Laboratory of Hypertension, Beijing Chaoyang Hospital, Capital Medical University, Beijing, 100020, China
| | - Xiao-Yan Liu
- Heart Center and Beijing Key Laboratory of Hypertension, Beijing Chaoyang Hospital, Capital Medical University, Beijing, 100020, China; Medical Research Center, Beijing Chaoyang Hospital, Capital Medical University, Beijing, 100020, China
| | - Kun Zuo
- Heart Center and Beijing Key Laboratory of Hypertension, Beijing Chaoyang Hospital, Capital Medical University, Beijing, 100020, China
| | - Xin-Chun Yang
- Heart Center and Beijing Key Laboratory of Hypertension, Beijing Chaoyang Hospital, Capital Medical University, Beijing, 100020, China
| | - Jiu-Chang Zhong
- Heart Center and Beijing Key Laboratory of Hypertension, Beijing Chaoyang Hospital, Capital Medical University, Beijing, 100020, China; Medical Research Center, Beijing Chaoyang Hospital, Capital Medical University, Beijing, 100020, China.
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15
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The effect of NAMPT deletion in projection neurons on the function and structure of neuromuscular junction (NMJ) in mice. Sci Rep 2020; 10:99. [PMID: 31919382 PMCID: PMC6952356 DOI: 10.1038/s41598-019-57085-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 12/20/2019] [Indexed: 12/14/2022] Open
Abstract
Nicotinamide adenine dinucleotide (NAD+) plays a critical role in energy metabolism and bioenergetic homeostasis. Most NAD+ in mammalian cells is synthesized via the NAD+ salvage pathway, where nicotinamide phosphoribosyltransferase (NAMPT) is the rate-limiting enzyme, converting nicotinamide into nicotinamide mononucleotide (NMN). Using a Thy1-Nampt−/− projection neuron conditional knockout (cKO) mouse, we studied the impact of NAMPT on synaptic vesicle cycling in the neuromuscular junction (NMJ), end-plate structure of NMJs and muscle contractility of semitendinosus muscles. Loss of NAMPT impaired synaptic vesicle endocytosis/exocytosis in the NMJs. The cKO mice also had motor endplates with significantly reduced area and thickness. When the cKO mice were treated with NMN, vesicle endocytosis/exocytosis was improved and endplate morphology was restored. Electrical stimulation induced muscle contraction was significantly impacted in the cKO mice in a frequency dependent manner. The cKO mice were unresponsive to high frequency stimulation (100 Hz), while the NMN-treated cKO mice responded similarly to the control mice. Transmission electron microscopy (TEM) revealed sarcomere misalignment and changes to mitochondrial morphology in the cKO mice, with NMN treatment restoring sarcomere alignment but not mitochondrial morphology. This study demonstrates that neuronal NAMPT is important for pre-/post-synaptic NMJ function, and maintaining skeletal muscular function and structure.
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