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Rahman FA, Baechler BL, Quadrilatero J. Key considerations for investigating and interpreting autophagy in skeletal muscle. Autophagy 2024:1-12. [PMID: 39007805 DOI: 10.1080/15548627.2024.2373676] [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: 03/18/2024] [Accepted: 06/25/2024] [Indexed: 07/16/2024] Open
Abstract
Skeletal muscle plays a crucial role in generating force to facilitate movement. Skeletal muscle is a heterogenous tissue composed of diverse fibers with distinct contractile and metabolic profiles. The intricate classification of skeletal muscle fibers exists on a continuum ranging from type I (slow-twitch, oxidative) to type II (fast-twitch, glycolytic). The heterogenous distribution and characteristics of fibers within and between skeletal muscles profoundly influences cellular signaling; however, this has not been broadly discussed as it relates to macroautophagy/autophagy. The growing interest in skeletal muscle autophagy research underscores the necessity of comprehending the interplay between autophagic responses among skeletal muscles and fibers with different contractile properties, metabolic profiles, and other related signaling processes. We recommend approaching the interpretation of autophagy findings with careful consideration for two key reasons: 1) the distinct behaviors and responses of different skeletal muscles or fibers to various perturbations, and 2) the potential impact of alterations in skeletal muscle fiber type or metabolic profile on observed autophagic outcomes. This review provides an overview of the autophagic profile and response in skeletal muscles/fibers of different types and metabolic profiles. Further, this review discusses autophagic findings in various conditions and diseases that may differentially affect skeletal muscle. Finally, we provide key points of consideration to better enable researchers to fine-tune the design and interpretation of skeletal muscle autophagy experiments.Abbreviation: AKT1: AKT serine/threonine kinase 1; AMPK: AMP-activated protein kinase; ATG: autophagy related; ATG4: autophagy related 4 cysteine peptidase; ATG5: autophagy related 5; ATG7: autophagy related 7; ATG12: autophagy related 12; BECN1: beclin 1; BNIP3: BCL2 interacting protein 3; CKD: chronic kidney disease; COPD: chronic obstructive pulmonary disease; CS: citrate synthase; DIA: diaphragm; EDL: extensor digitorum longus; FOXO3/FOXO3A: forkhead box O3; GAS; gastrocnemius; GP: gastrocnemius-plantaris complex; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MAPK: mitogen-activated protein kinase; MYH: myosin heavy chain; PINK1: PTEN induced kinase 1; PLANT: plantaris; PRKN: parkin RBR E3 ubiquitin protein ligase; QUAD: quadriceps; RA: rectus abdominis; RG: red gastrocnemius; RQ: red quadriceps; SOL: soleus; SQSTM1: sequestosome 1; TA: tibialis anterior; WG: white gastrocnemius; WQ: white quadriceps; WVL: white vastus lateralis; VL: vastus lateralis; ULK1: unc-51 like autophagy activating kinase 1.
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Affiliation(s)
- Fasih A Rahman
- Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, Ontario, Canada
| | - Brittany L Baechler
- Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, Ontario, Canada
| | - Joe Quadrilatero
- Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, Ontario, Canada
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Figueroa-Toledo AM, Gutiérrez-Pino J, Carriel-Nesvara A, Marchese-Bittencourt M, Zbinden-Foncea H, Castro-Sepúlveda M. BMAL1 and CLOCK proteins exhibit differential association with mitochondrial dynamics, protein synthesis pathways and muscle strength in human muscle. J Physiol 2024. [PMID: 38922907 DOI: 10.1113/jp285955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Accepted: 06/11/2024] [Indexed: 06/28/2024] Open
Abstract
Murine models lacking CLOCK/BMAL1 proteins in skeletal muscle (SkM) present muscle deterioration and mitochondria abnormalities. It is unclear whether humans with lower levels of these proteins in the SkM have similar alterations. Here we evaluated the association between BMAL1 and CLOCK protein mass with mitochondrial dynamics parameters and molecular and functional SkM quality markers in males. SkM biopsies were taken from the vastus lateralis of 16 male (non-athletes, non-obese and non-diabetic) subjects (8-9 a.m.). The morphology of mitochondria and their interaction with the sarcoplasmic reticulum (mitochondria-SR) were determined using transmission electron microscopy images. Additionally, protein abundance of the OXPHOS complex, mitochondria fusion/fission regulators, mitophagy and signalling proteins related to muscle protein synthesis were measured. To evaluate the quality of SkM, the cross-sectional area and maximal SkM strength were also measured. The results showed that BMAL1 protein mass was positively associated with mitochondria-SR distance, mitochondria size, mitochondria cristae density and mTOR protein mass. On the other hand, CLOCK protein mass was negatively associated with mitochondria-SR interaction, but positively associated with mitochondria complex III, OPA1 and DRP1 protein mass. Furthermore, CLOCK protein mass was positively associated with the protein synthesis signalling pathway (total mTOR, AKT and P70S6K protein mass) and SkM strength. These findings suggest that the BMAL1 and CLOCK proteins play different roles in regulating mitochondrial dynamics and SkM function in males, and that modulation of these proteins could be a potential therapeutic target for treating muscle diseases. KEY POINTS: In murine models, reductions in BMAL1 and CLOCK proteins lead to changes in mitochondria biology and a decline in muscle function. However, this association has not been explored in humans. We found that in human skeletal muscle, a decrease in BMAL1 protein mass is linked to smaller intermyofibrillar mitochondria, lower mitochondria cristae density, higher interaction between mitochondria and sarcoplasmic reticulum, and reduced mTOR protein mass. Additionally, we found that a decrease in CLOCK protein mass is associated with a higher interaction between mitochondria and sarcoplasmic reticulum, lower protein mass of OPA1 and DRP1, which regulates mitochondria fusion and fission, lower protein synthesis signalling pathway (mTOR, AKT and P70S6K protein mass), and decreased skeletal muscle strength. According to our findings in humans, which are supported by previous studies in animals, the mitochondrial dynamics and skeletal muscle function could be regulated differently by BMAL1 and CLOCK proteins. As a result, targeting the modulation of these proteins could be a potential therapeutic approach for treating muscle diseases and metabolic disorders related to muscle.
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Affiliation(s)
- A M Figueroa-Toledo
- Laboratorio de Fisiología del Ejercicio y Metabolismo (LABFEM), Escuela de Kinesiología, Facultad de Medicina, Universidad Finis Terrae, Santiago, Chile
| | - J Gutiérrez-Pino
- Laboratorio de Fisiología del Ejercicio y Metabolismo (LABFEM), Escuela de Kinesiología, Facultad de Medicina, Universidad Finis Terrae, Santiago, Chile
| | - A Carriel-Nesvara
- Laboratorio de Fisiología del Ejercicio y Metabolismo (LABFEM), Escuela de Kinesiología, Facultad de Medicina, Universidad Finis Terrae, Santiago, Chile
| | - M Marchese-Bittencourt
- Laboratorio de Fisiología del Ejercicio y Metabolismo (LABFEM), Escuela de Kinesiología, Facultad de Medicina, Universidad Finis Terrae, Santiago, Chile
| | - H Zbinden-Foncea
- Laboratorio de Fisiología del Ejercicio y Metabolismo (LABFEM), Escuela de Kinesiología, Facultad de Medicina, Universidad Finis Terrae, Santiago, Chile
| | - M Castro-Sepúlveda
- Laboratorio de Fisiología del Ejercicio y Metabolismo (LABFEM), Escuela de Kinesiología, Facultad de Medicina, Universidad Finis Terrae, Santiago, Chile
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Lukasiewicz CJ, Tranah GJ, Evans DS, Coen PM, Barnes HN, Huo Z, Esser KA, Zhang X, Wolff C, Wu K, Lane NE, Kritchevsky SB, Newman AB, Cummings SR, Cawthon PM, Hepple RT. Higher expression of denervation-responsive genes is negatively associated with muscle volume and performance traits in the study of muscle, mobility, and aging (SOMMA). Aging Cell 2024; 23:e14115. [PMID: 38831622 PMCID: PMC11166368 DOI: 10.1111/acel.14115] [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: 11/04/2023] [Revised: 01/23/2024] [Accepted: 02/02/2024] [Indexed: 06/05/2024] Open
Abstract
With aging skeletal muscle fibers undergo repeating cycles of denervation and reinnervation. In approximately the 8th decade of life reinnervation no longer keeps pace, resulting in the accumulation of persistently denervated muscle fibers that in turn cause an acceleration of muscle dysfunction. The significance of denervation in important clinical outcomes with aging is poorly studied. The Study of Muscle, Mobility, and Aging (SOMMA) is a large cohort study with the primary objective to assess how aging muscle biology impacts clinically important traits. Using transcriptomics data from vastus lateralis muscle biopsies in 575 participants we have selected 49 denervation-responsive genes to provide insights to the burden of denervation in SOMMA, to test the hypothesis that greater expression of denervation-responsive genes negatively associates with SOMMA participant traits that included time to walk 400 meters, fitness (VO2peak), maximal mitochondrial respiration, muscle mass and volume, and leg muscle strength and power. Consistent with our hypothesis, increased transcript levels of: a calciumdependent intercellular adhesion glycoprotein (CDH15), acetylcholine receptor subunits (CHRNA1, CHRND, CHRNE), a glycoprotein promoting reinnervation (NCAM1), a transcription factor regulating aspects of muscle organization (RUNX1), and a sodium channel (SCN5A) were each negatively associated with at least 3 of these traits. VO2peak and maximal respiration had the strongest negative associations with 15 and 19 denervation-responsive genes, respectively. In conclusion, the abundance of denervationresponsive gene transcripts is a significant determinant of muscle and mobility outcomes in aging humans, supporting the imperative to identify new treatment strategies to restore innervation in advanced age.
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Affiliation(s)
| | - Gregory J. Tranah
- California Pacific Medical Center Research InstituteSan FranciscoCaliforniaUSA
- Department of Epidemiology and BiostatisticsUniversity of CaliforniaSan FranciscoCaliforniaUSA
| | - Daniel S. Evans
- California Pacific Medical Center Research InstituteSan FranciscoCaliforniaUSA
- Department of Epidemiology and BiostatisticsUniversity of CaliforniaSan FranciscoCaliforniaUSA
| | - Paul M. Coen
- Translational Research Institute, Advent HealthOrlandoFloridaUSA
| | - Haley N. Barnes
- California Pacific Medical Center Research InstituteSan FranciscoCaliforniaUSA
| | - Zhiguang Huo
- Department of Physiology and AgingUniversity of Florida College of MedicineGainesvilleFloridaUSA
| | - Karyn A. Esser
- Department of Physiology and AgingUniversity of Florida College of MedicineGainesvilleFloridaUSA
| | - Xiping Zhang
- Department of Physiology and AgingUniversity of Florida College of MedicineGainesvilleFloridaUSA
| | - Christopher Wolff
- Department of Physiology and AgingUniversity of Florida College of MedicineGainesvilleFloridaUSA
| | - Kevin Wu
- Department of Physiology and AgingUniversity of Florida College of MedicineGainesvilleFloridaUSA
| | - Nancy E. Lane
- Department of Medicine, Division of RheumatologyUniversity of California Davis HealthSacramentoCaliforniaUSA
| | - Steven B. Kritchevsky
- Department of Internal MedicineWake Forest University School of MedicineWinston‐SalemNorth CarolinaUSA
| | - Anne B. Newman
- School of Public HealthUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Steven R. Cummings
- California Pacific Medical Center Research InstituteSan FranciscoCaliforniaUSA
- Department of Epidemiology and BiostatisticsUniversity of CaliforniaSan FranciscoCaliforniaUSA
| | - Peggy M. Cawthon
- California Pacific Medical Center Research InstituteSan FranciscoCaliforniaUSA
- Department of Epidemiology and BiostatisticsUniversity of CaliforniaSan FranciscoCaliforniaUSA
| | - Russell T. Hepple
- Department of Physical TherapyUniversity of FloridaGainesvilleFloridaUSA
- Department of Physiology and AgingUniversity of Florida College of MedicineGainesvilleFloridaUSA
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Coen PM, Huo Z, Tranah GJ, Barnes HN, Zhang X, Wolff CA, Wu K, Cawthon PM, Hepple RT, Toledo FGS, Evans DS, Santiago‐Fernández O, Cuervo AM, Kritchevsky SB, Newman AB, Cummings SR, Esser KA. Autophagy gene expression in skeletal muscle of older individuals is associated with physical performance, muscle volume and mitochondrial function in the study of muscle, mobility and aging (SOMMA). Aging Cell 2024; 23:e14118. [PMID: 38627910 PMCID: PMC11166359 DOI: 10.1111/acel.14118] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Revised: 01/14/2024] [Accepted: 02/02/2024] [Indexed: 04/30/2024] Open
Abstract
Autophagy is essential for proteostasis, energetic balance, and cell defense and is a key pathway in aging. Identifying associations between autophagy gene expression patterns in skeletal muscle and physical performance outcomes would further our knowledge of mechanisms related with proteostasis and healthy aging. Muscle biopsies were obtained from participants in the Study of Muscle, Mobility, and Aging (SOMMA). For 575 participants, RNA was sequenced and expression of 281 genes related to autophagy regulation, mitophagy, and mTOR/upstream pathways was determined. Associations between gene expression and outcomes including mitochondrial respiration in muscle fiber bundles (MAX OXPHOS), physical performance (VO2 peak, 400 m walking speed, and leg power), and thigh muscle volume, were determined using negative binomial regression models. For autophagy, key transcriptional regulators including TFE3 and NFKB-related genes (RELA, RELB, and NFKB1) were negatively associated with outcomes. On the contrary, regulators of oxidative metabolism that also promote overall autophagy, mitophagy, and pexophagy (PPARGC1A, PPARA, and EPAS1) were positively associated with multiple outcomes. In line with this, several mitophagy, fusion, and fission-related genes (NIPSNAP2, DNM1L, and OPA1) were also positively associated with outcomes. For mTOR pathway and related genes, expression of WDR59 and WDR24, both subunits of GATOR2 complex (an indirect inhibitor of mTORC1), and PRKAG3, which is a regulatory subunit of AMPK, were negatively correlated with multiple outcomes. Our study identifies autophagy and selective autophagy such as mitophagy gene expression patterns in human skeletal muscle related to physical performance, muscle volume, and mitochondrial function in older persons which may lead to target identification to preserve mobility and independence.
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Affiliation(s)
- Paul M. Coen
- Translational Research Institute, AdventHealthOrlandoFloridaUSA
| | - Zhiguang Huo
- Department of Biostatistics, College of Public Health & Health ProfessionsCollege of Medicine University of FloridaGainesvilleFloridaUSA
| | - Gregory J. Tranah
- California Pacific Medical Center Research InstituteSan FranciscoCaliforniaUSA
| | - Haley N. Barnes
- California Pacific Medical Center Research InstituteSan FranciscoCaliforniaUSA
| | - Xiping Zhang
- Department of Physiology and Aging, College of MedicineUniversity of FloridaGainesvilleFloridaUSA
| | - Christopher A. Wolff
- Department of Physiology and Aging, College of MedicineUniversity of FloridaGainesvilleFloridaUSA
| | - Kevin Wu
- Department of Physiology and Aging, College of MedicineUniversity of FloridaGainesvilleFloridaUSA
| | - Peggy M. Cawthon
- California Pacific Medical Center Research InstituteSan FranciscoCaliforniaUSA
- Department of Epidemiology and BiostatisticsUniversity of California San FranciscoSan FranciscoCaliforniaUSA
| | - Russell T. Hepple
- Department of Physical TherapyUniversity of FloridaGainesvilleFloridaUSA
| | - Frederico G. S. Toledo
- Department of Medicine, Division of Endocrinology and MetabolismUniversity of Pittsburgh School of MedicinePittsburghPennsylvaniaUSA
| | - Daniel S. Evans
- California Pacific Medical Center Research InstituteSan FranciscoCaliforniaUSA
- Department of Epidemiology and BiostatisticsUniversity of California San FranciscoSan FranciscoCaliforniaUSA
| | - Olaya Santiago‐Fernández
- Department of Developmental & Molecular BiologyAlbert Einstein College of MedicineNew YorkNew YorkUSA
| | - Ana Maria Cuervo
- Department of Developmental & Molecular BiologyAlbert Einstein College of MedicineNew YorkNew YorkUSA
| | - Stephen B. Kritchevsky
- Department of Internal MedicineWake Forest University School of MedicineWinston‐SalemNorth CarolinaUSA
| | - Anne B. Newman
- Department of Epidemiology, School of Public HealthUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Steven R. Cummings
- California Pacific Medical Center Research InstituteSan FranciscoCaliforniaUSA
- Department of Epidemiology and BiostatisticsUniversity of California San FranciscoSan FranciscoCaliforniaUSA
| | - Karyn A. Esser
- Department of Physiology and Aging, College of MedicineUniversity of FloridaGainesvilleFloridaUSA
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5
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Lei Y, Gan M, Qiu Y, Chen Q, Wang X, Liao T, Zhao M, Chen L, Zhang S, Zhao Y, Niu L, Wang Y, Zhu L, Shen L. The role of mitochondrial dynamics and mitophagy in skeletal muscle atrophy: from molecular mechanisms to therapeutic insights. Cell Mol Biol Lett 2024; 29:59. [PMID: 38654156 PMCID: PMC11036639 DOI: 10.1186/s11658-024-00572-y] [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: 01/09/2024] [Accepted: 04/04/2024] [Indexed: 04/25/2024] Open
Abstract
Skeletal muscle is the largest metabolic organ of the human body. Maintaining the best quality control and functional integrity of mitochondria is essential for the health of skeletal muscle. However, mitochondrial dysfunction characterized by mitochondrial dynamic imbalance and mitophagy disruption can lead to varying degrees of muscle atrophy, but the underlying mechanism of action is still unclear. Although mitochondrial dynamics and mitophagy are two different mitochondrial quality control mechanisms, a large amount of evidence has indicated that they are interrelated and mutually regulated. The former maintains the balance of the mitochondrial network, eliminates damaged or aged mitochondria, and enables cells to survive normally. The latter degrades damaged or aged mitochondria through the lysosomal pathway, ensuring cellular functional health and metabolic homeostasis. Skeletal muscle atrophy is considered an urgent global health issue. Understanding and gaining knowledge about muscle atrophy caused by mitochondrial dysfunction, particularly focusing on mitochondrial dynamics and mitochondrial autophagy, can greatly contribute to the prevention and treatment of muscle atrophy. In this review, we critically summarize the recent research progress on mitochondrial dynamics and mitophagy in skeletal muscle atrophy, and expound on the intrinsic molecular mechanism of skeletal muscle atrophy caused by mitochondrial dynamics and mitophagy. Importantly, we emphasize the potential of targeting mitochondrial dynamics and mitophagy as therapeutic strategies for the prevention and treatment of muscle atrophy, including pharmacological treatment and exercise therapy, and summarize effective methods for the treatment of skeletal muscle atrophy.
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Affiliation(s)
- Yuhang Lei
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 611130, China
- Key Laboratory of Livestock and Poultry Multi-Omics, Ministry of Agriculture and Rural Affairs, College of Animal and Technology, Sichuan Agricultural University, Chengdu, 611130, China
| | - Mailin Gan
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 611130, China
- Key Laboratory of Livestock and Poultry Multi-Omics, Ministry of Agriculture and Rural Affairs, College of Animal and Technology, Sichuan Agricultural University, Chengdu, 611130, China
| | - Yanhao Qiu
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 611130, China
- Key Laboratory of Livestock and Poultry Multi-Omics, Ministry of Agriculture and Rural Affairs, College of Animal and Technology, Sichuan Agricultural University, Chengdu, 611130, China
| | - Qiuyang Chen
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 611130, China
- Key Laboratory of Livestock and Poultry Multi-Omics, Ministry of Agriculture and Rural Affairs, College of Animal and Technology, Sichuan Agricultural University, Chengdu, 611130, China
| | - Xingyu Wang
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 611130, China
- Key Laboratory of Livestock and Poultry Multi-Omics, Ministry of Agriculture and Rural Affairs, College of Animal and Technology, Sichuan Agricultural University, Chengdu, 611130, China
| | - Tianci Liao
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 611130, China
- Key Laboratory of Livestock and Poultry Multi-Omics, Ministry of Agriculture and Rural Affairs, College of Animal and Technology, Sichuan Agricultural University, Chengdu, 611130, China
| | - Mengying Zhao
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 611130, China
- Key Laboratory of Livestock and Poultry Multi-Omics, Ministry of Agriculture and Rural Affairs, College of Animal and Technology, Sichuan Agricultural University, Chengdu, 611130, China
| | - Lei Chen
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 611130, China
- Key Laboratory of Livestock and Poultry Multi-Omics, Ministry of Agriculture and Rural Affairs, College of Animal and Technology, Sichuan Agricultural University, Chengdu, 611130, China
| | - Shunhua Zhang
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 611130, China
- Key Laboratory of Livestock and Poultry Multi-Omics, Ministry of Agriculture and Rural Affairs, College of Animal and Technology, Sichuan Agricultural University, Chengdu, 611130, China
| | - Ye Zhao
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 611130, China
- Key Laboratory of Livestock and Poultry Multi-Omics, Ministry of Agriculture and Rural Affairs, College of Animal and Technology, Sichuan Agricultural University, Chengdu, 611130, China
| | - Lili Niu
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 611130, China
- Key Laboratory of Livestock and Poultry Multi-Omics, Ministry of Agriculture and Rural Affairs, College of Animal and Technology, Sichuan Agricultural University, Chengdu, 611130, China
| | - Yan Wang
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 611130, China
- Key Laboratory of Livestock and Poultry Multi-Omics, Ministry of Agriculture and Rural Affairs, College of Animal and Technology, Sichuan Agricultural University, Chengdu, 611130, China
| | - Li Zhu
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 611130, China.
- Key Laboratory of Livestock and Poultry Multi-Omics, Ministry of Agriculture and Rural Affairs, College of Animal and Technology, Sichuan Agricultural University, Chengdu, 611130, China.
| | - Linyuan Shen
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 611130, China.
- Key Laboratory of Livestock and Poultry Multi-Omics, Ministry of Agriculture and Rural Affairs, College of Animal and Technology, Sichuan Agricultural University, Chengdu, 611130, China.
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Oliveira AN, Memme JM, Wong J, Hood DA. Dimorphic effect of TFE3 in determining mitochondrial and lysosomal content in muscle following denervation. Skelet Muscle 2024; 14:7. [PMID: 38643162 PMCID: PMC11031958 DOI: 10.1186/s13395-024-00339-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 03/17/2024] [Indexed: 04/22/2024] Open
Abstract
BACKGROUND Muscle atrophy is a common consequence of the loss of innervation and is accompanied by mitochondrial dysfunction. Mitophagy is the adaptive process through which damaged mitochondria are removed via the lysosomes, which are regulated in part by the transcription factor TFE3. The role of lysosomes and TFE3 are poorly understood in muscle atrophy, and the effect of biological sex is widely underreported. METHODS Wild-type (WT) mice, along with mice lacking TFE3 (KO), a transcriptional regulator of lysosomal and autophagy-related genes, were subjected to unilateral sciatic nerve denervation for up to 7 days, while the contralateral limb was sham-operated and served as an internal control. A subset of animals was treated with colchicine to capture mitophagy flux. RESULTS WT females exhibited elevated oxygen consumption rates during active respiratory states compared to males, however this was blunted in the absence of TFE3. Females exhibited higher mitophagy flux rates and greater lysosomal content basally compared to males that was independent of TFE3 expression. Following denervation, female mice exhibited less muscle atrophy compared to male counterparts. Intriguingly, this sex-dependent muscle sparing was lost in the absence of TFE3. Denervation resulted in 45% and 27% losses of mitochondrial content in WT and KO males respectively, however females were completely protected against this decline. Decreases in mitochondrial function were more severe in WT females compared to males following denervation, as ROS emission was 2.4-fold higher. In response to denervation, LC3-II mitophagy flux was reduced by 44% in females, likely contributing to the maintenance of mitochondrial content and elevated ROS emission, however this response was dysregulated in the absence of TFE3. While both males and females exhibited increased lysosomal content following denervation, this response was augmented in females in a TFE3-dependent manner. CONCLUSIONS Females have higher lysosomal content and mitophagy flux basally compared to males, likely contributing to the improved mitochondrial phenotype. Denervation-induced mitochondrial adaptations were sexually dimorphic, as females preferentially preserve content at the expense of function, while males display a tendency to maintain mitochondrial function. Our data illustrate that TFE3 is vital for the sex-dependent differences in mitochondrial function, and in determining the denervation-induced atrophy phenotype.
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Affiliation(s)
- Ashley N Oliveira
- School of Kinesiology and Health Science Muscle Health Research Centre, York University, 4700 Keele St, Toronto, ON, M3J 1P3, Canada
| | - Jonathan M Memme
- School of Kinesiology and Health Science Muscle Health Research Centre, York University, 4700 Keele St, Toronto, ON, M3J 1P3, Canada
| | - Jenna Wong
- School of Kinesiology and Health Science Muscle Health Research Centre, York University, 4700 Keele St, Toronto, ON, M3J 1P3, Canada
| | - David A Hood
- School of Kinesiology and Health Science Muscle Health Research Centre, York University, 4700 Keele St, Toronto, ON, M3J 1P3, Canada.
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7
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Noh SG, Ahn A, Davi SM, Lepley LK, Kwon OS. Quadriceps muscle atrophy after non-invasive anterior cruciate ligament injury: evidence linking to autophagy and mitophagy. Front Physiol 2024; 15:1341723. [PMID: 38496299 PMCID: PMC10940348 DOI: 10.3389/fphys.2024.1341723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 02/20/2024] [Indexed: 03/19/2024] Open
Abstract
Introduction: Anterior cruciate ligament (ACL) injury is frequently accompanied by quadriceps muscle atrophy, a process closely linked to mitochondrial health and mitochondria-specific autophagy. However, the temporal progression of key quadricep atrophy-mediating events following ACL injury remains poorly understood. To advance our understanding, we conducted a longitudinal study to elucidate key parameters in quadriceps autophagy and mitophagy. Methods: Long-Evans rats were euthanized at 7, 14, 28, and 56 days after non-invasive ACL injury that was induced via tibial compression overload; controls were not injured. Vastus lateralis muscle was extracted, and subsequent immunoblotting analysis was conducted using primary antibodies targeting key proteins involved in autophagy and mitophagy cellular processes. Results: Our findings demonstrated dynamic changes in autophagy and mitophagy markers in the quadriceps muscle during the recovery period after ACL injury. The early response to the injury was characterized by the induction of autophagy at 14 days (Beclin1), indicating an initial cellular response to the injury. Subsequently, at 14 days we observed increase in the elongation of autophagosomes (Atg4B), suggesting a potential remodeling process. The autophagosome flux was also augmented between 14- and 28 days (LC3-II/LC3-I ratio and p62). Notably, at 56 days, markers associated with the elimination of damaged mitochondria were elevated (PINK1, Parkin, and VDAC1), indicating a possible ongoing cellular repair and restoration process. Conclusion: These data highlight the complexity of muscle recovery after ACL injury and underscore the overlooked but crucial role of autophagy and mitophagy in promoting the recovery process.
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Affiliation(s)
- Sung Gi Noh
- Department of Kinesiology, University of Connecticut, Storrs, CT, United States
| | - Ahram Ahn
- Department of Kinesiology, University of Connecticut, Storrs, CT, United States
| | - Steven M. Davi
- Department of Kinesiology, University of Connecticut, Storrs, CT, United States
- Cooperative Studies Program Coordinating Center (CSPCC), VA Connecticut Healthcare System, West Haven, CT, United States
| | - Lindsey K. Lepley
- School of Kinesiology, University of Michigan, Ann Arbor, MI, United States
| | - Oh Sung Kwon
- Department of Kinesiology, University of Connecticut, Storrs, CT, United States
- Department of Orthopaedic Surgery and Center on Aging, University of Connecticut School of Medicine, Farmington, CT, United States
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8
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Slavin MB, Khemraj P, Hood DA. Exercise, mitochondrial dysfunction and inflammasomes in skeletal muscle. Biomed J 2024; 47:100636. [PMID: 37499756 PMCID: PMC10828562 DOI: 10.1016/j.bj.2023.100636] [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: 05/05/2023] [Revised: 07/18/2023] [Accepted: 07/20/2023] [Indexed: 07/29/2023] Open
Abstract
In the broad field of inflammation, skeletal muscle is a tissue that is understudied. Yet it represents about 40% of body mass in non-obese individuals and is therefore of fundamental importance for whole body metabolism and health. This article provides an overview of the unique features of skeletal muscle tissue, as well as its adaptability to exercise. This ability to adapt, particularly with respect to mitochondrial content and function, confers a level of metabolic "protection" against energy consuming events, and adds a measure of quality control that determines the phenotypic response to stress. Thus, we describe the particular role of mitochondria in promoting inflammasome activation in skeletal muscle, contributing to muscle wasting and dysfunction in aging, disuse and metabolic disease. We will then discuss how exercise training can be anti-inflammatory, mitigating the chronic inflammation that is observed in these conditions, potentially through improvements in mitochondrial quality and function.
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Affiliation(s)
- Mikhaela B Slavin
- School of Kinesiology and Health Science, Muscle Health Research Centre, York University, Toronto, ON, M3J 1P3, Canada
| | - Priyanka Khemraj
- School of Kinesiology and Health Science, Muscle Health Research Centre, York University, Toronto, ON, M3J 1P3, Canada
| | - David A Hood
- School of Kinesiology and Health Science, Muscle Health Research Centre, York University, Toronto, ON, M3J 1P3, Canada.
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9
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Linder BA, Stute NL, Hutchison ZJ, Barnett AM, Tharpe MA, Kavazis AN, Kirkman DL, Gutierrez OM, Robinson AT. Acute high-dose MitoQ does not increase urinary kidney injury markers in healthy adults: a randomized crossover trial. Am J Physiol Renal Physiol 2024; 326:F135-F142. [PMID: 37942539 PMCID: PMC11198989 DOI: 10.1152/ajprenal.00186.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Revised: 10/23/2023] [Accepted: 11/06/2023] [Indexed: 11/10/2023] Open
Abstract
Several human studies have used the mitochondrial antioxidant MitoQ. Recent in vitro data indicating that MitoQ may induce nephrotoxicity caused concern regarding the safety of MitoQ on the kidneys, but the doses were supraphysiological. Therefore, we sought to determine whether acute MitoQ elicits changes in urinary biomarkers associated with tubular injury in healthy adults with our hypothesis being there would be no changes. Using a randomized crossover design, 32 healthy adults (16 females and 16 males, 29 ± 11 yr old) consumed MitoQ (100-160 mg based on body mass) or placebo capsules. We obtained serum samples and a 4- to 6-h postcapsule consumption urine sample. We assessed creatinine clearance and urine kidney injury biomarkers including the chitinase 3-like-1 gene product YKL-40, kidney-injury marker-1, monocyte chemoattractant protein-1, epidermal growth factor, neutrophil gelatinase-associated lipocalin, interleukin-18, and uromodulin using multiplex assays. We used t tests, Wilcoxon tests, and Hotelling's T2 to assess global differences in urinary kidney injury markers between conditions. Acute MitoQ supplementation did not influence urine flow rate (P = 0.086, rrb = 0.39), creatinine clearance (P = 0.085, rrb = 0.42), or urinary kidney injury markers (T22,8 = 30.6, P = 0.121, univariate ps > 0.064). Using exploratory univariate analysis, MitoQ did not alter individual injury markers compared with placebo (e.g., placebo vs. MitoQ: YKL-40, 507 ± 241 vs. 442 ± 236 pg/min, P = 0.241; kidney injury molecule-1, 84.1 ± 43.2 vs. 76.2 ± 51.2 pg/min, P = 0.890; and neutrophil gelatinase-associated lipocalin, 10.8 ± 10.1 vs. 9.83 ± 8.06 ng/min, P = 0.609). In conclusion, although longer-term surveillance and data are needed in clinical populations, our findings suggest that acute high-dose MitoQ had no effect on urinary kidney injury markers in healthy adults.NEW & NOTEWORTHY We found acute high-dose mitochondria-targeted antioxidant (MitoQ) supplementation was not nephrotoxic and had no effect on markers of acute kidney injury in healthy adults. These findings can help bolster further confidence in the safety of MitoQ, particularly for future investigations seeking to examine the role of mitochondrial oxidative stress, via acute MitoQ supplementation, on various physiological outcomes.
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Affiliation(s)
- Braxton A Linder
- School of Kinesiology, Auburn University, Auburn, Alabama, United States
| | - Nina L Stute
- School of Kinesiology, Auburn University, Auburn, Alabama, United States
| | - Zach J Hutchison
- School of Kinesiology, Auburn University, Auburn, Alabama, United States
| | - Alex M Barnett
- School of Kinesiology, Auburn University, Auburn, Alabama, United States
| | - McKenna A Tharpe
- School of Kinesiology, Auburn University, Auburn, Alabama, United States
| | - Andreas N Kavazis
- School of Kinesiology, Auburn University, Auburn, Alabama, United States
| | - Danielle L Kirkman
- Department of Kinesiology and Health Sciences, Virginia Commonwealth University, Richmond, Virginia, United States
| | - Orlando M Gutierrez
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Austin T Robinson
- School of Kinesiology, Auburn University, Auburn, Alabama, United States
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Lukasiewicz CJ, Tranah GJ, Evans DS, Coen PM, Barnes HN, Huo Z, Esser KA, Lane NE, Kritchevsky SB, Newman AB, Cummings SR, Cawthon PM, Hepple RT. Higher Expression of Denervation-responsive Genes is Negatively Associated with Muscle Volume and Performance Traits in the Study of Muscle, Mobility and Aging (SOMMA). MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.11.04.23298090. [PMID: 37961531 PMCID: PMC10635277 DOI: 10.1101/2023.11.04.23298090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
With aging skeletal muscle fibers undergo repeating cycles of denervation and reinnervation. In approximately the 8 th decade of life reinnervation no longer keeps pace, resulting in the accumulation of persistently denervated muscle fibers that in turn cause an acceleration of muscle dysfunction. The significance of denervation in important clinical outcomes with aging is poorly studied. The Study of Muscle, Mobility and Aging (SOMMA) is a large cohort study with the primary objective to assess how aging muscle biology impacts clinically important traits. Using transcriptomics data from vastus lateralis muscle biopsies in 575 participants we have selected 49 denervation-responsive genes to provide insights to the burden of denervation in SOMMA, to test the hypothesis that greater expression of denervation-responsive genes negatively associates with SOMMA participant traits that included time to walk 400 meters, fitness (VO 2peak ), maximal mitochondrial respiration, muscle mass and volume, and leg muscle strength and power. Consistent with our hypothesis, increased transcript levels of: a calcium-dependent intercellular adhesion glycoprotein (CDH15), acetylcholine receptor subunits (Chrna1, Chrnd, Chrne), a glycoprotein promoting reinnervation (NCAM1), a transcription factor regulating aspects of muscle organization (RUNX1), and a sodium channel (SCN5A) were each negatively associated with at least 3 of these traits. VO 2peak and maximal respiration had the strongest negative associations with 15 and 19 denervation-responsive genes, respectively. In conclusion, the abundance of denervation-responsive gene transcripts is a significant determinant of muscle and mobility outcomes in aging humans, supporting the imperative to identify new treatment strategies to restore innervation in advanced age.
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11
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Zhang QB, Liu AY, Fang QZ, Wang F, Wang H, Zhou Y. Effect of Electrical Stimulation on Disuse Muscular Atrophy Induced by Immobilization: Correlation With Upregulation of PERK Signal and Parkin-Mediated Mitophagy. Am J Phys Med Rehabil 2023; 102:692-700. [PMID: 36630294 DOI: 10.1097/phm.0000000000002182] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
OBJECTIVES The aims of the study are to investigate the effect of electrical stimulation on disuse muscular atrophy induced by immobilization (IM) and to explore the role of PERK signal and Parkin-dependent mitophagy in this process. DESIGN In the first subexperiment, 24 rabbits were divided into four groups, which underwent different periods of IM. In the second subexperiment, 24 rabbits were divided into four groups on average in accordance with different kinds of interventions. To test the time-dependent changes of rectus femoris after IM, and to evaluate the effect of electrical stimulation, the wet weights, cross-sectional area and fat deposition of rectus femoris were assessed in this study, along with the protein levels of atrogin-1, p-PERK, Parkin, and COXIV. RESULTS The wet weights and cross-sectional area decreased, and the fat deposition increased in rectus femoris after IM, along with the elevated protein levels of atrogin-1, p-PERK, Parkin, and decreased protein levels of COXIV. The above histomorphological and molecular changes can be partially ameliorated by electrical stimulation. CONCLUSIONS Immobilization of unilateral lower limb could induce rectus femoris atrophy, which can be partially rectified by electrical stimulation. PERK signal and Parkin-mediated mitophagy may be the mechanisms by which electrical stimulation can play a significant role.
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Affiliation(s)
- Quan-Bing Zhang
- From the Department of Rehabilitation Medicine, The Second Affiliated Hospital of Anhui Medical University, Hefei, China (Q-BZ, FW, YZ); The Center for Scientific Research of the First Affiliated Hospital of Anhui Medical University, Hefei, China (A-YL); The Second Clinical Medicine College of Anhui Medical University, Hefei, China (Q-ZF); Key Laboratory of Environmental Toxicology of Anhui Higher Education Institutes, Hefei, China (HW); and Department of Toxicology, School of Public Health, Anhui Medical University, Hefei, China (HW)
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12
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Chen X, Ji Y, Liu R, Zhu X, Wang K, Yang X, Liu B, Gao Z, Huang Y, Shen Y, Liu H, Sun H. Mitochondrial dysfunction: roles in skeletal muscle atrophy. J Transl Med 2023; 21:503. [PMID: 37495991 PMCID: PMC10373380 DOI: 10.1186/s12967-023-04369-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 07/18/2023] [Indexed: 07/28/2023] Open
Abstract
Mitochondria play important roles in maintaining cellular homeostasis and skeletal muscle health, and damage to mitochondria can lead to a series of pathophysiological changes. Mitochondrial dysfunction can lead to skeletal muscle atrophy, and its molecular mechanism leading to skeletal muscle atrophy is complex. Understanding the pathogenesis of mitochondrial dysfunction is useful for the prevention and treatment of skeletal muscle atrophy, and finding drugs and methods to target and modulate mitochondrial function are urgent tasks in the prevention and treatment of skeletal muscle atrophy. In this review, we first discussed the roles of normal mitochondria in skeletal muscle. Importantly, we described the effect of mitochondrial dysfunction on skeletal muscle atrophy and the molecular mechanisms involved. Furthermore, the regulatory roles of different signaling pathways (AMPK-SIRT1-PGC-1α, IGF-1-PI3K-Akt-mTOR, FoxOs, JAK-STAT3, TGF-β-Smad2/3 and NF-κB pathways, etc.) and the roles of mitochondrial factors were investigated in mitochondrial dysfunction. Next, we analyzed the manifestations of mitochondrial dysfunction in muscle atrophy caused by different diseases. Finally, we summarized the preventive and therapeutic effects of targeted regulation of mitochondrial function on skeletal muscle atrophy, including drug therapy, exercise and diet, gene therapy, stem cell therapy and physical therapy. This review is of great significance for the holistic understanding of the important role of mitochondria in skeletal muscle, which is helpful for researchers to further understanding the molecular regulatory mechanism of skeletal muscle atrophy, and has an important inspiring role for the development of therapeutic strategies for muscle atrophy targeting mitochondria in the future.
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Affiliation(s)
- Xin Chen
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, 226001, Jiangsu, People's Republic of China
| | - Yanan Ji
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, 226001, Jiangsu, People's Republic of China
| | - Ruiqi Liu
- Department of Clinical Medicine, Medical College, Nantong University, Nantong, Jiangsu, 226001, People's Republic of China
| | - Xucheng Zhu
- Department of Clinical Medicine, Medical College, Nantong University, Nantong, Jiangsu, 226001, People's Republic of China
| | - Kexin Wang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, 226001, Jiangsu, People's Republic of China
| | - Xiaoming Yang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, 226001, Jiangsu, People's Republic of China
| | - Boya Liu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, 226001, Jiangsu, People's Republic of China
| | - Zihui Gao
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, 226001, Jiangsu, People's Republic of China
| | - Yan Huang
- Department of Clinical Medicine, Medical College, Nantong University, Nantong, Jiangsu, 226001, People's Republic of China
| | - Yuntian Shen
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, 226001, Jiangsu, People's Republic of China.
| | - Hua Liu
- Department of Orthopedics, Haian Hospital of Traditional Chinese Medicine, 55 Ninghai Middle Road, Nantong, Jiangsu, 226600, People's Republic of China.
| | - Hualin Sun
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, 226001, Jiangsu, People's Republic of China.
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13
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Picca A, Lozanoska-Ochser B, Calvani R, Coelho-Júnior HJ, Leewenburgh C, Marzetti E. Inflammatory, mitochondrial, and senescence-related markers: Underlying biological pathways of muscle aging and new therapeutic targets. Exp Gerontol 2023; 178:112204. [PMID: 37169101 DOI: 10.1016/j.exger.2023.112204] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 05/04/2023] [Accepted: 05/09/2023] [Indexed: 05/13/2023]
Abstract
The maintenance of functional health is pivotal for achieving independent life in older age. The aged muscle is characterized by ultrastructural changes, including loss of type I and type II myofibers and a greater proportion of cytochrome c oxidase deficient and succinate dehydrogenase positive fibers. Both intrinsic (e.g., altered proteostasis, DNA damage, and mitochondrial dysfunction) and extrinsic factors (e.g., denervation, altered metabolic regulation, declines in satellite cells, and inflammation) contribute to muscle aging. Being a hub for several cellular activities, mitochondria are key to myocyte viability and mitochondrial dysfunction has been implicated in age-associated physical decline. The maintenance of functional organelles via mitochondrial quality control (MQC) processes is, therefore, crucial to skeletal myofiber viability and organismal health. The autophagy-lysosome pathway has emerged as a critical step of MQC in muscle by disposing organelles and proteins via their tagging for autophagosome incorporation and delivery to the lysosome for clearance. This pathway was found to be altered in muscle of physically inactive older adults. A relationship between this pathway and muscle tissue composition of the lower extremities as well as physical performance was also identified. Therefore, integrating muscle structure and myocyte quality control measures in the evaluation of muscle health may be a promising strategy for devising interventions fostering muscle health.
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Affiliation(s)
- Anna Picca
- Department of Medicine and Surgery, LUM University, Casamassima, 70100 Bari, Italy; Fondazione Policlinico Universitario "Agostino Gemelli" IRCSS, 00168 Rome, Italy
| | - Biliana Lozanoska-Ochser
- Department of Medicine and Surgery, LUM University, Casamassima, 70100 Bari, Italy; DAHFMO Unit of Histology and Medical Embryology, Sapienza University of Rome, 00161 Rome, Italy
| | - Riccardo Calvani
- Fondazione Policlinico Universitario "Agostino Gemelli" IRCSS, 00168 Rome, Italy; Department of Geriatrics and Orthopedics, Università Cattolica del Sacro Cuore, 00168 Rome, Italy.
| | - Hélio José Coelho-Júnior
- Department of Geriatrics and Orthopedics, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
| | | | - Emanuele Marzetti
- Fondazione Policlinico Universitario "Agostino Gemelli" IRCSS, 00168 Rome, Italy; Department of Geriatrics and Orthopedics, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
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14
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Wang J, Tierney L, Wilson C, Phillips V, Goldman L, Mumaw C, Muang E, Walker CL. Carboxyl-terminal modulator protein (CTMP) deficiency mitigates denervation-induced skeletal muscle atrophy. Biochem Biophys Res Commun 2023; 644:155-161. [PMID: 36652767 DOI: 10.1016/j.bbrc.2023.01.023] [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: 12/09/2022] [Accepted: 01/10/2023] [Indexed: 01/13/2023]
Abstract
Denervated skeletal muscles show decreased Akt activity and phosphorylation, resulting in atrophy. Akt inhibits downstream transcription of atrophy-associated ubiquitin ligases like muscle ring-finger protein 1 (MuRF-1). In addition, reduced Akt signaling contributes to aberrant protein synthesis in muscles. In ALS mice, we recently found that carboxyl-terminator modulator protein (CTMP) expression is increased and correlated with reduced Akt signaling in atrophic skeletal muscle. CTMP has also been implicated in promoting muscle degeneration and catabolism in an in vitro muscle atrophy model. The present study examined whether sciatic nerve injury (SNI) stimulated CTMP expression in denervated skeletal muscle during muscle atrophy. We hypothesized that CTMP deficiency would reduce neurogenic atrophy and reverse Akt signaling downregulation. Compared to the unaffected contralateral muscle, wild-type (WT) gastrocnemius muscle had a significant increase in CTMP (p < 0.05). Furthermore, denervated CTMP knockout (CTMP-KO) gastrocnemius weighed more than WT muscle (p < 0.05). Denervated CTMP-KO gastrocnemius also showed higher Akt and downstream glycogen synthase kinase 3β (GSK3β) phosphorylation compared to WT muscle (p < 0.05) as well as ribosomal proteins S6 and 4E-BP1 phosphorylation (p < 0.001 and p < 0.05, respectively). Moreover, CTMP-KO mice showed significantly lower levels of E3 ubiquitin ligase MuRF-1 and myostatin than WT muscle (p < 0.05). Our findings suggest that CTMP is essential to muscle atrophy after denervation and it may act by reducing Akt signaling, protein synthesis, and increasing myocellular catabolism.
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Affiliation(s)
- Junmei Wang
- Department of Biomedical Sciences and Comprehensive Care, Indiana University School of Dentistry, Indianapolis, IN, 46202, USA
| | - Lydia Tierney
- Department of Biomedical Sciences and Comprehensive Care, Indiana University School of Dentistry, Indianapolis, IN, 46202, USA
| | - Christopher Wilson
- Department of Biomedical Sciences and Comprehensive Care, Indiana University School of Dentistry, Indianapolis, IN, 46202, USA
| | - Victoria Phillips
- Department of Biomedical Sciences and Comprehensive Care, Indiana University School of Dentistry, Indianapolis, IN, 46202, USA
| | - Lillian Goldman
- Department of Biomedical Sciences and Comprehensive Care, Indiana University School of Dentistry, Indianapolis, IN, 46202, USA
| | - Christen Mumaw
- Department of Biomedical Sciences and Comprehensive Care, Indiana University School of Dentistry, Indianapolis, IN, 46202, USA; Neuromusculoskeletal Research Group, Richard L. Roudebush Veterans Affairs Medical Center, Indianapolis, IN, 46202, USA
| | - En Muang
- Department of Biomedical Sciences and Comprehensive Care, Indiana University School of Dentistry, Indianapolis, IN, 46202, USA
| | - Chandler L Walker
- Department of Biomedical Sciences and Comprehensive Care, Indiana University School of Dentistry, Indianapolis, IN, 46202, USA; Neuromusculoskeletal Research Group, Richard L. Roudebush Veterans Affairs Medical Center, Indianapolis, IN, 46202, USA.
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15
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Picca A, Triolo M, Wohlgemuth SE, Martenson MS, Mankowski RT, Anton SD, Marzetti E, Leeuwenburgh C, Hood DA. Relationship between Mitochondrial Quality Control Markers, Lower Extremity Tissue Composition, and Physical Performance in Physically Inactive Older Adults. Cells 2023; 12:183. [PMID: 36611976 PMCID: PMC9818256 DOI: 10.3390/cells12010183] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 12/29/2022] [Accepted: 12/30/2022] [Indexed: 01/03/2023] Open
Abstract
Altered mitochondrial quality and function in muscle may be involved in age-related physical function decline. The role played by the autophagy-lysosome system, a major component of mitochondrial quality control (MQC), is incompletely understood. This study was undertaken to obtain initial indications on the relationship between autophagy, mitophagy, and lysosomal markers in muscle and measures of physical performance and lower extremity tissue composition in young and older adults. Twenty-three participants were enrolled, nine young (mean age: 24.3 ± 4.3 years) and 14 older adults (mean age: 77.9 ± 6.3 years). Lower extremity tissue composition was quantified volumetrically by magnetic resonance imaging and a tissue composition index was calculated as the ratio between muscle and intermuscular adipose tissue volume. Physical performance in older participants was assessed via the Short Physical Performance Battery (SPPB). Protein levels of the autophagy marker p62, the mitophagy mediator BCL2/adenovirus E1B 19 kDa protein-interacting protein 3 (BNIP3), the lysosomal markers transcription factor EB, vacuolar-type ATPase, and lysosomal-associated membrane protein 1 were measured by Western immunoblotting in vastus lateralis muscle biopsies. Older adults had smaller muscle volume and lower tissue composition index than young participants. The protein content of p62 and BNIP3 was higher in older adults. A negative correlation was detected between p62 and BNIP3 and the tissue composition index. p62 and BNIP3 were also related to the performance on the 5-time sit-to-stand test of the SPPB. Our results suggest that an altered expression of markers of the autophagy/mitophagy-lysosomal system is related to deterioration of lower extremity tissue composition and muscle dysfunction. Additional studies are needed to clarify the role of defective MQC in human muscle aging and identify novel biological targets for drug development.
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Affiliation(s)
- Anna Picca
- Fondazione Policlinico Universitario “A. Gemelli”, IRCCS, 00168 Rome, Italy
- Department of Medicine and Surgery, LUM University, 70100 Casamassima, Italy
| | - Matthew Triolo
- Muscle Health Research Centre, York University, Toronto, ON M3J 1P3, Canada
- School of Kinesiology and Health Science, York University, Toronto, ON M3J 1P3, Canada
| | | | - Matthew S. Martenson
- Department of Physiology and Aging, University of Florida, Gainesville, FL 32610, USA
| | - Robert T. Mankowski
- Department of Physiology and Aging, University of Florida, Gainesville, FL 32610, USA
| | - Stephen D. Anton
- Department of Physiology and Aging, University of Florida, Gainesville, FL 32610, USA
| | - Emanuele Marzetti
- Fondazione Policlinico Universitario “A. Gemelli”, IRCCS, 00168 Rome, Italy
- Department of Geriatrics and Orthopedics, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
| | | | - David A. Hood
- Muscle Health Research Centre, York University, Toronto, ON M3J 1P3, Canada
- School of Kinesiology and Health Science, York University, Toronto, ON M3J 1P3, Canada
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16
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Handy RM, Holloway GP. Insights into the development of insulin resistance: Unraveling the interaction of physical inactivity, lipid metabolism and mitochondrial biology. Front Physiol 2023; 14:1151389. [PMID: 37153211 PMCID: PMC10157178 DOI: 10.3389/fphys.2023.1151389] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 04/07/2023] [Indexed: 05/09/2023] Open
Abstract
While impairments in peripheral tissue insulin signalling have a well-characterized role in the development of insulin resistance and type 2 diabetes (T2D), the specific mechanisms that contribute to these impairments remain debatable. Nonetheless, a prominent hypothesis implicates the presence of a high-lipid environment, resulting in both reactive lipid accumulation and increased mitochondrial reactive oxygen species (ROS) production in the induction of peripheral tissue insulin resistance. While the etiology of insulin resistance in a high lipid environment is rapid and well documented, physical inactivity promotes insulin resistance in the absence of redox stress/lipid-mediated mechanisms, suggesting alternative mechanisms-of-action. One possible mechanism is a reduction in protein synthesis and the resultant decrease in key metabolic proteins, including canonical insulin signaling and mitochondrial proteins. While reductions in mitochondrial content associated with physical inactivity are not required for the induction of insulin resistance, this could predispose individuals to the detrimental effects of a high-lipid environment. Conversely, exercise-training induced mitochondrial biogenesis has been implicated in the protective effects of exercise. Given mitochondrial biology may represent a point of convergence linking impaired insulin sensitivity in both scenarios of chronic overfeeding and physical inactivity, this review aims to describe the interaction between mitochondrial biology, physical (in)activity and lipid metabolism within the context of insulin signalling.
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17
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Triolo M, Bhattacharya D, Hood DA. Denervation induces mitochondrial decline and exacerbates lysosome dysfunction in middle-aged mice. Aging (Albany NY) 2022; 14:8900-8913. [PMID: 36342767 PMCID: PMC9740366 DOI: 10.18632/aging.204365] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 10/24/2022] [Indexed: 11/06/2022]
Abstract
With age, skeletal muscle undergoes a progressive decline in size and quality. Imbalanced mitochondrial turnover and the resultant dysfunction contribute to these phenotypic alterations. Motor neuron denervation (Den) is a contributor to the etiology of muscle atrophy associated with age. Further, aged muscle exhibits reduced plasticity to both enhanced and suppressed contractile activity. It remains unclear when the onset of this blunted response occurs, and how middle-aged muscle adapts to denervation. The purpose of this study was to compare mitochondrial turnover pathways in young (Y, ~5months) and middle-aged (MA, ~15months) mice, and determine the influence of Den. Transgenic mt-Keima mice were subjected to 1,3 or 7 days of Den. Muscle mass, mitochondrial content, and PGC-1α protein were not different between Y and MA mice. However, indications of enhanced mitochondrial fission and mitophagy were evident in MA muscle which were supported by a greater abundance of lysosome proteins. Den resulted in muscle atrophy and reductions in mitochondrial protein content by 7-days. These changes occurred concomitant with modest decreases in PGC-1α protein, but without further elevations in mitophagy. Although both autophagosomal and lysosomal proteins were elevated, evidence of lysosome dysfunction was present following Den in MA mice. These data suggest that increases in fission drive an acceleration of mitophagy in muscle of MA mice to preserve mitochondrial quality. Den exacerbates the aging phenotype by reducing biogenesis in the absence of a change in mitophagy, perhaps limited by lysosomal capacity, leading to an accumulation of dysfunctional mitochondria with an age-related loss of neuromuscular innervation.
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Affiliation(s)
- Matthew Triolo
- Muscle Health Research Centre, York University, Toronto, Ontario M3J 1P3, Canada,School of Kinesiology and Health Science, York University, Toronto, Ontario M3J 1P3, Canada
| | - Debasmita Bhattacharya
- Muscle Health Research Centre, York University, Toronto, Ontario M3J 1P3, Canada,School of Kinesiology and Health Science, York University, Toronto, Ontario M3J 1P3, Canada
| | - David A. Hood
- Muscle Health Research Centre, York University, Toronto, Ontario M3J 1P3, Canada,School of Kinesiology and Health Science, York University, Toronto, Ontario M3J 1P3, Canada
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18
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Tinline-Goodfellow CT, Fung HJW, Estafanos S, Bailleul C, Lees MJ. Is denervation-induced TFEB translocation hitting an mTOR nerve? J Physiol 2022; 600:3403-3404. [PMID: 35781286 DOI: 10.1113/jp283409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
| | - Hugo J W Fung
- Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, ON, Canada
| | - Stephanie Estafanos
- Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, ON, Canada
| | - Celine Bailleul
- Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, ON, Canada
| | - Matthew J Lees
- Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, ON, Canada
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19
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Triolo M, Oliveira AN, Kumari R, Hood DA. The influence of age, sex, and exercise on autophagy, mitophagy, and lysosome biogenesis in skeletal muscle. Skelet Muscle 2022; 12:13. [PMID: 35690879 PMCID: PMC9188089 DOI: 10.1186/s13395-022-00296-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 05/15/2022] [Indexed: 12/25/2022] Open
Abstract
Background Aging decreases skeletal muscle mass and quality. Maintenance of healthy muscle is regulated by a balance between protein and organellar synthesis and their degradation. The autophagy-lysosome system is responsible for the selective degradation of protein aggregates and organelles, such as mitochondria (i.e., mitophagy). Little data exist on the independent and combined influence of age, biological sex, and exercise on the autophagy system and lysosome biogenesis. The purpose of this study was to characterize sex differences in autophagy and lysosome biogenesis in young and aged muscle and to determine if acute exercise influences these processes. Methods Young (4–6 months) and aged (22–24 months) male and female mice were assigned to a sedentary or an acute exercise group. Mitochondrial content, the autophagy-lysosome system, and mitophagy were measured via protein analysis. A TFEB-promoter-construct was utilized to examine Tfeb transcription, and nuclear-cytosolic fractions allowed us to examine TFEB localization in sedentary and exercised muscle with age and sex. Results Our results indicate that female mice, both young and old, had more mitochondrial protein than age-matched males. However, mitochondria in the muscle of females had a reduced respiratory capacity. Mitochondrial content was only reduced with age in the male cohort. Young female mice had a greater abundance of autophagy, mitophagy, and lysosome proteins than young males; however, increases were evident with age irrespective of sex. Young sedentary female mice had indices of greater autophagosomal turnover than male counterparts. Exhaustive exercise was able to stimulate autophagic clearance solely in young male mice. Similarly, nuclear TFEB protein was enhanced to a greater extent in young male, compared to young female mice following exercise, but no changes were observed in aged mice. Finally, TFEB-promoter activity was upregulated following exercise in both young and aged muscle. Conclusions The present study demonstrates that biological sex influences mitochondrial homeostasis, the autophagy-lysosome system, and mitophagy in skeletal muscle with age. Furthermore, our data suggest that young male mice have a more profound ability to activate these processes with exercise than in the other groups. Ultimately, this may contribute to a greater remodeling of muscle in response to exercise training in males.
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Affiliation(s)
- Matthew Triolo
- School of Kinesiology and Health Science, Muscle Health Research Centre, York University, Toronto, Ontario, M3J 1P3, Canada.,Muscle Health Research Centre, York University, Toronto, Ontario, M3J 1P3, Canada
| | - Ashley N Oliveira
- School of Kinesiology and Health Science, Muscle Health Research Centre, York University, Toronto, Ontario, M3J 1P3, Canada.,Muscle Health Research Centre, York University, Toronto, Ontario, M3J 1P3, Canada
| | - Rita Kumari
- School of Kinesiology and Health Science, Muscle Health Research Centre, York University, Toronto, Ontario, M3J 1P3, Canada.,Muscle Health Research Centre, York University, Toronto, Ontario, M3J 1P3, Canada
| | - David A Hood
- School of Kinesiology and Health Science, Muscle Health Research Centre, York University, Toronto, Ontario, M3J 1P3, Canada. .,Muscle Health Research Centre, York University, Toronto, Ontario, M3J 1P3, Canada.
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20
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Frank E. Denervation-induced muscle atrophy - saved by the lysosomes. J Physiol 2022; 600:3217-3218. [PMID: 35653586 DOI: 10.1113/jp283207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 05/31/2022] [Indexed: 11/08/2022] Open
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21
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Liu AY, Zhang QB, Zhu HL, Xiong YW, Wang F, Huang PP, Xu QY, Zhong HZ, Wang H, Zhou Y. Low-frequency electrical stimulation alleviates immobilization-evoked disuse muscle atrophy by repressing autophagy in skeletal muscle of rabbits. BMC Musculoskelet Disord 2022; 23:398. [PMID: 35484550 PMCID: PMC9047266 DOI: 10.1186/s12891-022-05350-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 04/18/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The study aimed to investigate the effect of low-frequency electrical stimulation (LFES) on disuse muscle atrophy and its mechanism in a rabbit model of knee extension contracture. METHODS This study involved two experiments. In the time-point experiment, 24 rabbits were randomly divided into 4 groups: Control 1 (Ctrl1 group), immobilization for 2 weeks (I-2 group), immobilization for 4 weeks (I-4 group), and immobilization for 6 weeks (I-6 group). In the intervention experiment, 24 rabbits were randomly divided into 4 groups: Control 2 (Ctrl2 group), electrical stimulation (ESG group), natural recovery (NRG group), and electrical stimulation treatment (ESTG group). All intervention effects were assessed by evaluating the knee joint range of motion (ROM), cross-sectional area (CSA) of the rectus femoris muscle, and expression of autophagy-related proteins. RESULTS The time-point experiment showed that immobilization reduced the knee ROM, reduced the rectus femoris muscle CSA, and activated autophagy in skeletal muscle. The levels of five autophagy-related proteins [mammalian target of rapamycin (mTOR), phosphorylated mTOR (p-mTOR), autophagy-related protein 7 (Atg7), p62, and microtubule-associated protein light chain 3B-II (LC3B-II)] were significantly elevated in the skeletal muscle of the I-4 group. The intervention experiment further showed that LFES significantly improved the immobilization-induced reductions in ROM and CSA. Additionally, LFES resulted in a significant decrease in the protein expression of mTOR, p-mTOR, Atg7, p62, and LC3B-II in the rectus femoris muscle. CONCLUSIONS LFES alleviates immobilization-evoked disuse muscle atrophy possibly by inhibiting autophagy in the skeletal muscle of rabbits.
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Affiliation(s)
- A-Ying Liu
- Department of Rehabilitation Medicine, The Second Hospital of Anhui Medical University, No.678 Furong Road, Economic and Technological Development Zone, Hefei, 230601, China
| | - Quan-Bing Zhang
- Department of Rehabilitation Medicine, The Second Hospital of Anhui Medical University, No.678 Furong Road, Economic and Technological Development Zone, Hefei, 230601, China
| | - Hua-Long Zhu
- Key Laboratory of Environmental Toxicology of Anhui Higher Education Institutes, Hefei, China.,Department of Toxicology, School of Public Health, Anhui Medical University, Hefei, 230032, China
| | - Yong-Wei Xiong
- Key Laboratory of Environmental Toxicology of Anhui Higher Education Institutes, Hefei, China.,Department of Toxicology, School of Public Health, Anhui Medical University, Hefei, 230032, China
| | - Feng Wang
- Department of Rehabilitation Medicine, The Second Hospital of Anhui Medical University, No.678 Furong Road, Economic and Technological Development Zone, Hefei, 230601, China
| | - Peng-Peng Huang
- Department of Rehabilitation Medicine, The Second Hospital of Anhui Medical University, No.678 Furong Road, Economic and Technological Development Zone, Hefei, 230601, China
| | - Qi-Yu Xu
- Department of Rehabilitation Medicine, The Second Hospital of Anhui Medical University, No.678 Furong Road, Economic and Technological Development Zone, Hefei, 230601, China
| | - Hua-Zhang Zhong
- Department of Orthopedics, The Second Hospital of Anhui Medical University, Hefei, China
| | - Hua Wang
- Key Laboratory of Environmental Toxicology of Anhui Higher Education Institutes, Hefei, China. .,Department of Toxicology, School of Public Health, Anhui Medical University, Hefei, 230032, China.
| | - Yun Zhou
- Department of Rehabilitation Medicine, The Second Hospital of Anhui Medical University, No.678 Furong Road, Economic and Technological Development Zone, Hefei, 230601, China.
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22
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Slavin MB, Memme JM, Oliveira AN, Moradi N, Hood DA. Regulatory networks controlling mitochondrial quality control in skeletal muscle. Am J Physiol Cell Physiol 2022; 322:C913-C926. [PMID: 35353634 DOI: 10.1152/ajpcell.00065.2022] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The adaptive plasticity of mitochondria within skeletal muscle is regulated by signals converging on a myriad of regulatory networks that operate during conditions of increased (i.e. exercise) and decreased (inactivity, disuse) energy requirements. Notably, some of the initial signals that induce adaptive responses are common to both conditions, differing in their magnitude and temporal pattern, to produce vastly opposing mitochondrial phenotypes. In response to exercise, signaling to PGC-1α and other regulators ultimately produces an abundance of high quality mitochondria, leading to reduced mitophagy and a higher mitochondrial content. This is accompanied by the presence of an enhanced protein quality control system that consists of the protein import machinery as well chaperones and proteases termed the UPRmt. The UPRmt monitors intra-organelle proteostasis, and strives to maintain a mito-nuclear balance between nuclear- and mtDNA-derived gene products via retrograde signaling from the organelle to the nucleus. In addition, antioxidant capacity is improved, affording greater protection against oxidative stress. In contrast, chronic disuse conditions produce similar signaling but result in decrements in mitochondrial quality and content. Thus, the interactive cross-talk of the regulatory networks that control organelle turnover during wide variations in muscle use and disuse remain incompletely understood, despite our improving knowledge of the traditional regulators of organelle content and function. This brief review acknowledges existing regulatory networks and summarizes recent discoveries of novel biological pathways involved in determining organelle biogenesis, dynamics, mitophagy, protein quality control and antioxidant capacity, identifying ample protein targets for therapeutic intervention that determine muscle and mitochondrial health.
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Affiliation(s)
- Mikhaela B Slavin
- Muscle Health Research Centre, School of Kinesiology and Health Science, York University, Toronto, Ontario, Canada.,School of Kinesiology and Health Science, York University, Toronto, ON, Canada
| | - Jonathan M Memme
- Muscle Health Research Centre, School of Kinesiology and Health Science, York University, Toronto, Ontario, Canada.,School of Kinesiology and Health Science, York University, Toronto, ON, Canada
| | - Ashley N Oliveira
- Muscle Health Research Centre, School of Kinesiology and Health Science, York University, Toronto, Ontario, Canada.,School of Kinesiology and Health Science, York University, Toronto, ON, Canada
| | - Neushaw Moradi
- Muscle Health Research Centre, School of Kinesiology and Health Science, York University, Toronto, Ontario, Canada.,School of Kinesiology and Health Science, York University, Toronto, ON, Canada
| | - David A Hood
- Muscle Health Research Centre, School of Kinesiology and Health Science, York University, Toronto, Ontario, Canada.,School of Kinesiology and Health Science, York University, Toronto, ON, Canada
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23
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Memme JM, Oliveira AN, Hood DA. p53 regulates skeletal muscle mitophagy and mitochondrial quality control following denervation-induced muscle disuse. J Biol Chem 2022; 298:101540. [PMID: 34958797 PMCID: PMC8790503 DOI: 10.1016/j.jbc.2021.101540] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 12/10/2021] [Accepted: 12/13/2021] [Indexed: 02/06/2023] Open
Abstract
Persistent inactivity promotes skeletal muscle atrophy, marked by mitochondrial aberrations that affect strength, mobility, and metabolic health leading to the advancement of disease. Mitochondrial quality control (MQC) pathways include biogenesis (synthesis), mitophagy/lysosomal turnover, and the mitochondrial unfolded protein response, which serve to maintain an optimal organelle network. Tumor suppressor p53 has been implicated in regulating muscle mitochondria in response to cellular stress; however, its role in the context of muscle disuse has yet to be explored, and whether p53 is necessary for MQC remains unclear. To address this, we subjected p53 muscle-specific KO (mKO) and WT mice to unilateral denervation. Transcriptomic and pathway analyses revealed dysregulation of pathways pertaining to mitochondrial function, and especially turnover, in mKO muscle following denervation. Protein and mRNA data of the MQC pathways indicated activation of the mitochondrial unfolded protein response and mitophagy-lysosome systems along with reductions in mitochondrial biogenesis and content in WT and mKO tissue following chronic denervation. However, p53 ablation also attenuated the expression of autophagy-mitophagy machinery, reduced autophagic flux, and enhanced lysosomal dysfunction. While similar reductions in mitochondrial biogenesis and content were observed between genotypes, MQC dysregulation exacerbated mitochondrial dysfunction in mKO fibers, evidenced by elevated reactive oxygen species. Moreover, acute experiments indicate that p53 mediates the expression of transcriptional regulators of MQC pathways as early as 1 day following denervation. Together, our data illustrate exacerbated mitochondrial dysregulation with denervation stress in p53 mKO tissue, thus indicating that p53 contributes to organellar maintenance via regulation of MQC pathways during muscle atrophy.
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Affiliation(s)
- Jonathan M Memme
- Muscle Health Research Centre, School of Kinesiology and Health Science, York University, Toronto, Ontario, Canada
| | - Ashley N Oliveira
- Muscle Health Research Centre, School of Kinesiology and Health Science, York University, Toronto, Ontario, Canada
| | - David A Hood
- Muscle Health Research Centre, School of Kinesiology and Health Science, York University, Toronto, Ontario, Canada.
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