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Zanfardino P, Amati A, Doccini S, Cox SN, Tullo A, Longo G, D'Erchia A, Picardi E, Nesti C, Santorelli FM, Petruzzella V. OPA1 mutation affects autophagy and triggers senescence in autosomal dominant optic atrophy plus fibroblasts. Hum Mol Genet 2024; 33:768-786. [PMID: 38280232 DOI: 10.1093/hmg/ddae008] [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: 11/02/2023] [Revised: 01/06/2024] [Indexed: 01/29/2024] Open
Abstract
In several cases of mitochondrial diseases, the underlying genetic and bioenergetic causes of reduced oxidative phosphorylation (OxPhos) in mitochondrial dysfunction are well understood. However, there is still limited knowledge about the specific cellular outcomes and factors involved for each gene and mutation, which contributes to the lack of effective treatments for these disorders. This study focused on fibroblasts from a patient with Autosomal Dominant Optic Atrophy (ADOA) plus syndrome harboring a mutation in the Optic Atrophy 1 (OPA1) gene. By combining functional and transcriptomic approaches, we investigated the mitochondrial function and identified cellular phenotypes associated with the disease. Our findings revealed that fibroblasts with the OPA1 mutation exhibited a disrupted mitochondrial network and function, leading to altered mitochondrial dynamics and reduced autophagic response. Additionally, we observed a premature senescence phenotype in these cells, suggesting a previously unexplored role of the OPA1 gene in inducing senescence in ADOA plus patients. This study provides novel insights into the mechanisms underlying mitochondrial dysfunction in ADOA plus and highlights the potential importance of senescence in disease progression.
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Affiliation(s)
- Paola Zanfardino
- Department of Translational Biomedicine and Neuroscience (DiBraiN), University of study of Bari Aldo Moro, Piazza G. Cesare, 11, 70124 Bari, Italy
| | - Alessandro Amati
- Department of Translational Biomedicine and Neuroscience (DiBraiN), University of study of Bari Aldo Moro, Piazza G. Cesare, 11, 70124 Bari, Italy
| | - Stefano Doccini
- Molecular Medicine for Neurodegenerative and Neuromuscular Diseases Unit, IRCCS Stella Maris Foundation, Viale del Tirreno, 56128 Calambrone, Pisa, Italy
| | - Sharon N Cox
- Department of Biosciences, Biotechnology, and Biopharmaceutics, University of study of Bari Aldo Moro, via Orabona 4, 70125, Bari, Italy
| | - Apollonia Tullo
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies (IBIOM), National Research Council, Via G. Amendola 122/O, 70126 Bari, Italy
| | - Giovanna Longo
- Department of Translational Biomedicine and Neuroscience (DiBraiN), University of study of Bari Aldo Moro, Piazza G. Cesare, 11, 70124 Bari, Italy
| | - Annamaria D'Erchia
- Department of Biosciences, Biotechnology, and Biopharmaceutics, University of study of Bari Aldo Moro, via Orabona 4, 70125, Bari, Italy
| | - Ernesto Picardi
- Department of Biosciences, Biotechnology, and Biopharmaceutics, University of study of Bari Aldo Moro, via Orabona 4, 70125, Bari, Italy
| | - Claudia Nesti
- Molecular Medicine for Neurodegenerative and Neuromuscular Diseases Unit, IRCCS Stella Maris Foundation, Viale del Tirreno, 56128 Calambrone, Pisa, Italy
| | - Filippo M Santorelli
- Molecular Medicine for Neurodegenerative and Neuromuscular Diseases Unit, IRCCS Stella Maris Foundation, Viale del Tirreno, 56128 Calambrone, Pisa, Italy
| | - Vittoria Petruzzella
- Department of Translational Biomedicine and Neuroscience (DiBraiN), University of study of Bari Aldo Moro, Piazza G. Cesare, 11, 70124 Bari, Italy
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Koh D, Sonker M, Arriaga EA, Ros A. Numerical modeling reveals improved organelle separation for dielectrophoretic ratchet migration. Electrophoresis 2023; 44:1826-1836. [PMID: 37622551 PMCID: PMC10905386 DOI: 10.1002/elps.202300091] [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: 04/30/2023] [Revised: 08/01/2023] [Accepted: 08/07/2023] [Indexed: 08/26/2023]
Abstract
Organelle size varies with normal and abnormal cell function. Thus, size-based particle separation techniques are key to assessing the properties of organelle subpopulations differing in size. Recently, insulator-based dielectrophoresis (iDEP) has gained significant interest as a technique to manipulate sub-micrometer-sized particles enabling the assessment of organelle subpopulations. Based on iDEP, we recently reported a ratchet device that successfully demonstrated size-based particle fractionation in combination with continuous flow sample injection. Here, we used a numerical model to optimize the performance with flow rates a factor of three higher than previously and increased the channel volume to improve throughput. We evaluated the amplitude and duration of applied low-frequency DC-biased AC potentials improving separation efficiency. A separation efficiency of nearly 0.99 was achieved with the optimization of key parameters-improved from 0.80 in previous studies (Ortiz et al. Electrophoresis, 2022;43;1283-1296)-demonstrating that fine-tuning the periodical driving forces initiating the ratchet migration under continuous flow conditions can significantly improve the fractionation of organelles of different sizes.
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Affiliation(s)
- Domin Koh
- School of Molecular Sciences, Arizona State University, Tempe, Arizona, USA
- Center for Applied Structural Discovery, The Biodesign Institute, Arizona State University, Tempe, Arizona, USA
| | - Mukul Sonker
- School of Molecular Sciences, Arizona State University, Tempe, Arizona, USA
- Center for Applied Structural Discovery, The Biodesign Institute, Arizona State University, Tempe, Arizona, USA
| | - Edgar A Arriaga
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota, USA
| | - Alexandra Ros
- School of Molecular Sciences, Arizona State University, Tempe, Arizona, USA
- Center for Applied Structural Discovery, The Biodesign Institute, Arizona State University, Tempe, Arizona, USA
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3
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Cadile F, Recchia D, Ansaldo M, Rossi P, Rastelli G, Boncompagni S, Brocca L, Pellegrino MA, Canepari M. Diaphragm Fatigue in SMNΔ7 Mice and Its Molecular Determinants: An Underestimated Issue. Int J Mol Sci 2023; 24:14953. [PMID: 37834400 PMCID: PMC10574014 DOI: 10.3390/ijms241914953] [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: 09/11/2023] [Revised: 09/29/2023] [Accepted: 10/03/2023] [Indexed: 10/15/2023] Open
Abstract
Spinal muscular atrophy (SMA) is a genetic disorder characterized by the loss of spinal motor neurons leading to muscle weakness and respiratory failure. Mitochondrial dysfunctions are found in the skeletal muscle of patients with SMA. For obvious ethical reasons, the diaphragm muscle is poorly studied, notwithstanding the very important role that respiratory involvement plays in SMA mortality. The main goal of this study was to investigate diaphragm functionality and the underlying molecular adaptations in SMNΔ7 mice, a mouse model that exhibits symptoms similar to that of patients with intermediate type II SMA. Functional, biochemical, and molecular analyses on isolated diaphragm were performed. The obtained results suggest the presence of an intrinsic energetic imbalance associated with mitochondrial dysfunction and a significant accumulation of reactive oxygen species (ROS). In turn, ROS accumulation can affect muscle fatigue, cause diaphragm wasting, and, in the long run, respiratory failure in SMNΔ7 mice. Exposure to the antioxidant molecule ergothioneine leads to the functional recovery of the diaphragm, confirming the presence of mitochondrial impairment and redox imbalance. These findings suggest the possibility of carrying out a dietary supplementation in SMNΔ7 mice to preserve their diaphragm function and increase their lifespan.
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Affiliation(s)
- Francesca Cadile
- Department of Molecular Medicine, via Forlanini 6, University of Pavia, 27100 Pavia, Italy; (F.C.); (M.A.); (L.B.); (M.A.P.)
| | - Deborah Recchia
- Department of Biology and Biotechnology “L. Spallanzani”, University of Pavia, 27100 Pavia, Italy; (D.R.); (P.R.)
| | - Massimiliano Ansaldo
- Department of Molecular Medicine, via Forlanini 6, University of Pavia, 27100 Pavia, Italy; (F.C.); (M.A.); (L.B.); (M.A.P.)
| | - Paola Rossi
- Department of Biology and Biotechnology “L. Spallanzani”, University of Pavia, 27100 Pavia, Italy; (D.R.); (P.R.)
| | - Giorgia Rastelli
- Center for Advanced Studies and Technology, University G. d’Annunzio of Chieti-Pescara, 66100 Chieti, Italy; (G.R.); (S.B.)
| | - Simona Boncompagni
- Center for Advanced Studies and Technology, University G. d’Annunzio of Chieti-Pescara, 66100 Chieti, Italy; (G.R.); (S.B.)
- Department of Neuroscience, Imaging and Clinical Sciences, University G. d’Annunzio of Chieti-Pescara, 66100 Chieti, Italy
| | - Lorenza Brocca
- Department of Molecular Medicine, via Forlanini 6, University of Pavia, 27100 Pavia, Italy; (F.C.); (M.A.); (L.B.); (M.A.P.)
| | - Maria Antonietta Pellegrino
- Department of Molecular Medicine, via Forlanini 6, University of Pavia, 27100 Pavia, Italy; (F.C.); (M.A.); (L.B.); (M.A.P.)
| | - Monica Canepari
- Department of Molecular Medicine, via Forlanini 6, University of Pavia, 27100 Pavia, Italy; (F.C.); (M.A.); (L.B.); (M.A.P.)
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Li A, Shami GJ, Griffiths L, Lal S, Irving H, Braet F. Giant mitochondria in cardiomyocytes: cellular architecture in health and disease. Basic Res Cardiol 2023; 118:39. [PMID: 37775647 PMCID: PMC10541842 DOI: 10.1007/s00395-023-01011-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 08/29/2023] [Accepted: 09/15/2023] [Indexed: 10/01/2023]
Abstract
Giant mitochondria are frequently observed in different disease models within the brain, kidney, and liver. In cardiac muscle, these enlarged organelles are present across diverse physiological and pathophysiological conditions including in ageing and exercise, and clinically in alcohol-induced heart disease and various cardiomyopathies. This mitochondrial aberration is widely considered an early structural hallmark of disease leading to adverse organ function. In this thematic paper, we discuss the current state-of-knowledge on the presence, structure and functional implications of giant mitochondria in heart muscle. Despite its demonstrated reoccurrence in different heart diseases, the literature on this pathophysiological phenomenon remains relatively sparse since its initial observations in the early 60s. We review historical and contemporary investigations from cultured cardiomyocytes to human tissue samples to address the role of giant mitochondria in cardiac health and disease. Finally, we discuss their significance for the future development of novel mitochondria-targeted therapies to improve cardiac metabolism and functionality.
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Affiliation(s)
- Amy Li
- Department of Rural Clinical Sciences, La Trobe Rural Health School, La Trobe University, Bendigo, VIC, Australia.
- Centre for Healthy Futures, Torrens University Australia, Surry Hills, NSW, Australia.
- School of Medical Sciences, The University of Sydney, Camperdown, NSW, Australia.
| | - Gerald J Shami
- School of Medical Sciences (Molecular and Cellular Biomedicine), The University of Sydney, Camperdown, NSW, Australia
- Australian Centre for Microscopy and Microanalysis, The University of Sydney, Camperdown, NSW, Australia
| | - Lisa Griffiths
- Anatomical Pathology, PathWest, QEII Medical Centre, Nedlands, WA, Australia
| | - Sean Lal
- School of Medical Sciences, The University of Sydney, Camperdown, NSW, Australia
| | - Helen Irving
- Department of Rural Clinical Sciences, La Trobe Rural Health School, La Trobe University, Bendigo, VIC, Australia
| | - Filip Braet
- School of Medical Sciences (Molecular and Cellular Biomedicine), The University of Sydney, Camperdown, NSW, Australia.
- Australian Centre for Microscopy and Microanalysis, The University of Sydney, Camperdown, NSW, Australia.
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Rajasekaran S, Ramaian Santhaseela A, Ragunathan S, Venkataraman S, Jayavelu T. Altered Lysosomal Function Manipulates Cellular Biosynthetic Capacity By Remodeling Intracellular Cholesterol Distribution. Cell Biochem Biophys 2023; 81:29-38. [PMID: 36459362 DOI: 10.1007/s12013-022-01123-y] [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: 09/18/2022] [Accepted: 11/23/2022] [Indexed: 12/03/2022]
Abstract
Lysosomes are known to influence cholesterol trafficking into endoplasmic reticulum (ER) membranes. Though intracellular cholesterol levels are known to influence the lipid biosynthetic responses in ER, the specific effects of lysosomal modulation on these outcomes is not known. To demonstrate this, C2C12 cells were treated with chloroquine, a lysosomotropic agent, and its effects on cellular biosynthetic capacity, structural and functional status of ER was determined. In addition to its known effects on autophagy reduction, chloroquine treatment induced accumulation of total cellular lipid and ER-specific cholesterol content. It was also observed that chloroquine caused an increase in smooth-ER content with defects in overall protein turnover. Further, since ER and mitochondria function in close association through ER membrane contact sites, it is likely that lysosomal modulation also brings about associated changes in mitochondria. In this regard, we found that chloroquine reduces mitochondrial membrane potential and mitochondrial dynamics. Collectively, the differential biosynthetic response of rise in lipid content, but not protein content, cannot be accounted by merely considering that chloroquine induced suppression of autophagy causes defects in organelle function. In this defective autophagy scenario, both biosynthetic responses such as lipid and protein synthesis are expected to be reduced rather than only the latter, as observed with chloroquine. These findings suggest that cholesterol trafficking/distribution within cellular organelles could act as an intracellular mediator of differential biosynthetic remodelling in interconnected organelles.
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Kim JS, Chapman WC, Lin Y. Mitochondrial Autophagy in Ischemic Aged Livers. Cells 2022; 11:cells11244083. [PMID: 36552847 PMCID: PMC9816943 DOI: 10.3390/cells11244083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 12/09/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022] Open
Abstract
Mitochondrial autophagy (mitophagy) is a central catabolic event for mitochondrial quality control. Defective or insufficient mitophagy, thus, can result in mitochondrial dysfunction, and ultimately cell death. There is a strong causal relationship between ischemia/reperfusion (I/R) injury and mitochondrial dysfunction following liver resection and transplantation. Compared to young patients, elderly patients poorly tolerate I/R injury. Accumulation of abnormal mitochondria after I/R is more prominent in aged livers than in young counterparts. This review highlights how altered autophagy is mechanistically involved in age-dependent hypersensitivity to reperfusion injury.
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Affiliation(s)
- Jae-Sung Kim
- Department of Surgery, Washington University in St. Louis, St. Louis, MO 63110, USA; (W.C.C.); (Y.L.)
- Department of Cell Biology & Physiology, Washington University in St. Louis, St. Louis, MO 63110, USA
- Correspondence:
| | - William C. Chapman
- Department of Surgery, Washington University in St. Louis, St. Louis, MO 63110, USA; (W.C.C.); (Y.L.)
| | - Yiing Lin
- Department of Surgery, Washington University in St. Louis, St. Louis, MO 63110, USA; (W.C.C.); (Y.L.)
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Li J, Wang Z, Li C, Song Y, Wang Y, Bo H, Zhang Y. Impact of Exercise and Aging on Mitochondrial Homeostasis in Skeletal Muscle: Roles of ROS and Epigenetics. Cells 2022; 11:cells11132086. [PMID: 35805170 PMCID: PMC9266156 DOI: 10.3390/cells11132086] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 06/22/2022] [Accepted: 06/28/2022] [Indexed: 02/01/2023] Open
Abstract
Aging causes degenerative changes such as epigenetic changes and mitochondrial dysfunction in skeletal muscle. Exercise can upregulate muscle mitochondrial homeostasis and enhance antioxidant capacity and represents an effective treatment to prevent muscle aging. Epigenetic changes such as DNA methylation, histone posttranslational modifications, and microRNA expression are involved in the regulation of exercise-induced adaptive changes in muscle mitochondria. Reactive oxygen species (ROS) play an important role in signaling molecules in exercise-induced muscle mitochondrial health benefits, and strong evidence emphasizes that exercise-induced ROS can regulate gene expression via epigenetic mechanisms. The majority of mitochondrial proteins are imported into mitochondria from the cytosol, so mitochondrial homeostasis is regulated by nuclear epigenetic mechanisms. Exercise can reverse aging-induced changes in myokine expression by modulating epigenetic mechanisms. In this review, we provide an overview of the role of exercise-generated ROS in the regulation of mitochondrial homeostasis mediated by epigenetic mechanisms. In addition, the potential epigenetic mechanisms involved in exercise-induced myokine expression are reviewed.
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Affiliation(s)
- Jialin Li
- Tianjin Key Laboratory of Exercise Physiology and Sports Medicine, Institute of Exercise and Health, Tianjin University of Sport, Tianjin 301617, China; (J.L.); (Z.W.); (C.L.); (Y.S.); (Y.W.)
| | - Zhe Wang
- Tianjin Key Laboratory of Exercise Physiology and Sports Medicine, Institute of Exercise and Health, Tianjin University of Sport, Tianjin 301617, China; (J.L.); (Z.W.); (C.L.); (Y.S.); (Y.W.)
| | - Can Li
- Tianjin Key Laboratory of Exercise Physiology and Sports Medicine, Institute of Exercise and Health, Tianjin University of Sport, Tianjin 301617, China; (J.L.); (Z.W.); (C.L.); (Y.S.); (Y.W.)
| | - Yu Song
- Tianjin Key Laboratory of Exercise Physiology and Sports Medicine, Institute of Exercise and Health, Tianjin University of Sport, Tianjin 301617, China; (J.L.); (Z.W.); (C.L.); (Y.S.); (Y.W.)
| | - Yan Wang
- Tianjin Key Laboratory of Exercise Physiology and Sports Medicine, Institute of Exercise and Health, Tianjin University of Sport, Tianjin 301617, China; (J.L.); (Z.W.); (C.L.); (Y.S.); (Y.W.)
| | - Hai Bo
- Tianjin Key Laboratory of Exercise Physiology and Sports Medicine, Institute of Exercise and Health, Tianjin University of Sport, Tianjin 301617, China; (J.L.); (Z.W.); (C.L.); (Y.S.); (Y.W.)
- Department of Military Training Medicines, Logistics University of Chinese People’s Armed Police Force, Tianjin 300162, China
- Correspondence: (H.B.); (Y.Z.)
| | - Yong Zhang
- Tianjin Key Laboratory of Exercise Physiology and Sports Medicine, Institute of Exercise and Health, Tianjin University of Sport, Tianjin 301617, China; (J.L.); (Z.W.); (C.L.); (Y.S.); (Y.W.)
- Correspondence: (H.B.); (Y.Z.)
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Ortiz R, Koh D, Kim DH, Rabbani MT, Anguaya Velasquez C, Sonker M, Arriaga EA, Ros A. Continuous organelle separation in an insulator-based dielectrophoretic device. Electrophoresis 2022; 43:1283-1296. [PMID: 34964147 PMCID: PMC10905415 DOI: 10.1002/elps.202100326] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 11/30/2021] [Accepted: 12/13/2021] [Indexed: 11/06/2022]
Abstract
Heterogeneity in organelle size has been associated with devastating human maladies such as neurodegenerative diseases or cancer. Therefore, assessing the size-based subpopulation of organelles is imperative to understand the biomolecular foundations of these diseases. Here, we demonstrated a ratchet migration mechanism using insulator-based dielectrophoresis in conjunction with a continuous flow component that allows the size-based separation of submicrometer particles. The ratchet mechanism was realized in a microfluidic device exhibiting an array of insulating posts, tailoring electrokinetic and dielectrophoretic transport. A numerical model was developed to elucidate the particle migration and the size-based separation in various conditions. Experimentally, the size-based separation of a mixture of polystyrene beads (0.28 and 0.87 μ $\umu $ m) was accomplished demonstrating good agreement with the numerical model. Furthermore, the size-based separation of mitochondria was investigated using a mitochondria mixture isolated from HepG2 cells and HepG2 cells carrying the gene Mfn-1 knocked out, indicating distinct size-related migration behavior. With the presented continuous flow separation device, larger amounts of fractionated organelles can be collected in the future allowing access to the biomolecular signature of mitochondria subpopulations differing in size.
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Affiliation(s)
- Ricardo Ortiz
- School of Molecular Sciences, Arizona State University, Tempe, AZ, USA
- Center for Applied Structural Discovery, The Biodesign Institute, Arizona State University, Tempe, AZ, USA
| | - Domin Koh
- School of Molecular Sciences, Arizona State University, Tempe, AZ, USA
- Center for Applied Structural Discovery, The Biodesign Institute, Arizona State University, Tempe, AZ, USA
| | - Dai Hyun Kim
- School of Molecular Sciences, Arizona State University, Tempe, AZ, USA
- Center for Applied Structural Discovery, The Biodesign Institute, Arizona State University, Tempe, AZ, USA
| | - Mohammad Towshif Rabbani
- School of Molecular Sciences, Arizona State University, Tempe, AZ, USA
- Center for Applied Structural Discovery, The Biodesign Institute, Arizona State University, Tempe, AZ, USA
| | - Cesar Anguaya Velasquez
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
- Department of Chemistry, University of Minnesota, Minneapolis, MN, USA
| | - Mukul Sonker
- School of Molecular Sciences, Arizona State University, Tempe, AZ, USA
- Center for Applied Structural Discovery, The Biodesign Institute, Arizona State University, Tempe, AZ, USA
| | - Edgar A Arriaga
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
- Department of Chemistry, University of Minnesota, Minneapolis, MN, USA
| | - Alexandra Ros
- School of Molecular Sciences, Arizona State University, Tempe, AZ, USA
- Center for Applied Structural Discovery, The Biodesign Institute, Arizona State University, Tempe, AZ, USA
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Li Q, Wu J, Huang J, Hu R, You H, Liu L, Wang D, Wei L. Paeoniflorin Ameliorates Skeletal Muscle Atrophy in Chronic Kidney Disease via AMPK/SIRT1/PGC-1α-Mediated Oxidative Stress and Mitochondrial Dysfunction. Front Pharmacol 2022; 13:859723. [PMID: 35370668 PMCID: PMC8964350 DOI: 10.3389/fphar.2022.859723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 02/15/2022] [Indexed: 11/13/2022] Open
Abstract
Skeletal muscle atrophy is a common and serious complication of chronic kidney disease (CKD). Oxidative stress and mitochondrial dysfunction are involved in the pathogenesis of muscle atrophy. The aim of this study was to explore the effects and mechanisms of paeoniflorin on CKD skeletal muscle atrophy. We demonstrated that paeoniflorin significantly improved renal function, calcium/phosphorus disorders, nutrition index and skeletal muscle atrophy in the 5/6 nephrectomized model rats. Paeoniflorin ameliorated the expression of proteins associated with muscle atrophy and muscle differentiation, including muscle atrophy F-box (MAFbx/atrogin-1), muscle RING finger 1 (MuRF1), MyoD and myogenin (MyoG). In addition, paeoniflorin modulated redox homeostasis by increasing antioxidant activity and suppressing excessive accumulation of reactive oxygen species (ROS). Paeoniflorin alleviated mitochondrial dysfunction by increasing the activities of electron transport chain complexes and mitochondrial membrane potential. Furthermore, paeoniflorin also regulates mitochondrial dynamics. Importantly, paeoniflorin upregulated the expression of silent information regulator 1 (SIRT1), peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α), and phosphorylation of AMP-activated protein kinase (AMPK). Similar results were observed in C2C12 myoblasts treated with TNF-α and paeoniflorin. Notably, these beneficial effects of paeoniflorin on muscle atrophy were abolished by inhibiting AMPK and SIRT1 and knocking down PGC-1α. Taken together, this study showed for the first time that paeoniflorin has great therapeutic potential for CKD skeletal muscle atrophy through AMPK/SIRT1/PGC-1α-mediated oxidative stress and mitochondrial dysfunction.
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Affiliation(s)
- Qiang Li
- Department of Traditional Chinese Medicine, Shenzhen Hospital, Southern Medical University, Shenzhen, China.,School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, China
| | - Jing Wu
- Department of Rheumatology and Clinical Immunology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Jiawen Huang
- Department of Traditional Chinese Medicine, Shenzhen Hospital, Southern Medical University, Shenzhen, China.,School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, China
| | - Rong Hu
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, China
| | - Haiyan You
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, China
| | - Lingyu Liu
- First Affiliated Hospital of Henan University of Chinese Medicine, Zhengzhou, China
| | - Dongtao Wang
- Department of Traditional Chinese Medicine, Shenzhen Hospital, Southern Medical University, Shenzhen, China
| | - Lianbo Wei
- Department of Traditional Chinese Medicine, Shenzhen Hospital, Southern Medical University, Shenzhen, China
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10
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Mao X, Gu Y, Sui X, Shen L, Han J, Wang H, Xi Q, Zhuang Q, Meng Q, Wu G. Phosphorylation of Dynamin-Related Protein 1 (DRP1) Regulates Mitochondrial Dynamics and Skeletal Muscle Wasting in Cancer Cachexia. Front Cell Dev Biol 2021; 9:673618. [PMID: 34422804 PMCID: PMC8375307 DOI: 10.3389/fcell.2021.673618] [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: 03/01/2021] [Accepted: 07/09/2021] [Indexed: 12/12/2022] Open
Abstract
Background Cancer-associated cachexia (CAC) is a syndrome characterized by skeletal muscle atrophy, and the underlying mechanisms are still unclear. Recent research studies have shed light on a noteworthy link between mitochondrial dynamics and muscle physiology. In the present study, we investigate the role of dynamin-related protein 1 (DRP1), a pivotal factor of mitochondrial dynamics, in myotube atrophy during cancer-associated cachexia. Methods Seventy-six surgical patients, including gastrointestinal tumor and benign disease, were enrolled in the study and divided to three groups: control, non-cachexia, and cancer-associated cachexia. Demographic data were collected. Their rectus abdominis samples were acquired intraoperatively. Muscle fiber size, markers of ubiquitin proteasome system (UPS), mitochondrial ultrastructure, and markers of mitochondrial function and dynamics were assayed. A cachexia model in vitro was established via coculturing a C2C12 myotube with media from C26 colon cancer cells. A specific DRP1 inhibitor, Mdivi-1, and a lentivirus of DRP1 knockdown/overexpression were used to regulate the expression of DRP1. Muscle diameter, mitochondrial morphology, mass, reactive oxygen species (ROS), membrane potential, and markers of UPS, mitochondrial function, and dynamics were determined. Results Patients of cachexia suffered from a conspicuous worsened nutrition status and muscle loss compared to patients of other groups. Severe mitochondrial swelling and enlarged area were observed, and partial alterations in mitochondrial function were found in muscle. Analysis of mitochondrial dynamics indicated an upregulation of phosphorylated DRP1 at the ser616 site. In vitro, cancer media resulted in the atrophy of myotube. This was accompanied with a prominent unbalance of mitochondrial dynamics, as well as enhanced mitochondrial ROS and decreased mitochondrial function and membrane potential. However, certain concentrations of Mdivi-1 and DRP1 knockdown rebalanced the mitochondrial dynamics, mitigating this negative phenotype caused by cachexia. Moreover, overexpression of DRP1 aggravated these phenomena. Conclusion In clinical patients, cachexia induces abnormal mitochondrial changes and possible fission activation for the atrophied muscle. Our cachexia model in vitro further demonstrates that unbalanced mitochondrial dynamics contributes to this atrophy and mitochondrial impairment, and rebuilding the balance by regulating of DRP1 could ameliorate these alterations.
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Affiliation(s)
- Xiangyu Mao
- Department of General Surgery/Shanghai Clinical Nutrition Research Center, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yihua Gu
- Shanghai Institute of Planned Parenthood Research, Shanghai, China
| | - Xiangyu Sui
- Department of General Surgery/Shanghai Clinical Nutrition Research Center, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Lei Shen
- Department of General Surgery/Shanghai Clinical Nutrition Research Center, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Jun Han
- Department of General Surgery/Shanghai Clinical Nutrition Research Center, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Haiyu Wang
- Department of General Surgery/Shanghai Clinical Nutrition Research Center, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Qiulei Xi
- Department of General Surgery/Shanghai Clinical Nutrition Research Center, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Qiulin Zhuang
- Department of General Surgery/Shanghai Clinical Nutrition Research Center, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Qingyang Meng
- Department of General Surgery/Shanghai Clinical Nutrition Research Center, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Guohao Wu
- Department of General Surgery/Shanghai Clinical Nutrition Research Center, Zhongshan Hospital, Fudan University, Shanghai, China
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11
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Fealy CE, Grevendonk L, Hoeks J, Hesselink MKC. Skeletal muscle mitochondrial network dynamics in metabolic disorders and aging. Trends Mol Med 2021; 27:1033-1044. [PMID: 34417125 DOI: 10.1016/j.molmed.2021.07.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 07/13/2021] [Accepted: 07/26/2021] [Indexed: 01/05/2023]
Abstract
With global demographics trending towards an aging population, the numbers of individuals with an age-associated loss of independence is increasing. A key contributing factor is loss of skeletal muscle mitochondrial, metabolic, and contractile function. Recent advances in imaging technologies have demonstrated the importance of mitochondrial morphology and dynamics in the pathogenesis of disease. In this review, we examine the evidence for altered mitochondrial dynamics as a mechanism in age and obesity-associated loss of skeletal muscle function, with a particular focus on the available human data. We highlight some of the areas where more data are needed to identify the specific mechanisms connecting mitochondrial morphology and skeletal muscle dysfunction.
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Affiliation(s)
- Ciarán E Fealy
- Department of Nutrition and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, The Netherlands; Department of Physical Education and Sport Sciences, University of Limerick, Castletroy, Limerick, Ireland
| | - Lotte Grevendonk
- Department of Nutrition and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, The Netherlands
| | - Joris Hoeks
- Department of Nutrition and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, The Netherlands
| | - Matthijs K C Hesselink
- Department of Nutrition and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, The Netherlands.
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12
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Dulac M, Leduc-Gaudet JP, Cefis M, Ayoub MB, Reynaud O, Shams A, Moamer A, Nery Ferreira MF, Hussain SN, Gouspillou G. Regulation of muscle and mitochondrial health by the mitochondrial fission protein Drp1 in aged mice. J Physiol 2021; 599:4045-4063. [PMID: 34269418 DOI: 10.1113/jp281752] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 07/06/2021] [Indexed: 12/12/2022] Open
Abstract
KEY POINTS The maintenance of mitochondrial integrity is critical for skeletal muscle health. Mitochondrial dynamics play key roles in mitochondrial quality control; however, the exact role that mitochondrial fission plays in the muscle ageing process remains unclear. Here we report that both Drp1 knockdown and Drp1 overexpression late in life in mice is detrimental to skeletal muscle function and mitochondrial health. Drp1 knockdown in 18-month-old mice resulted in severe skeletal muscle atrophy, mitochondrial dysfunction, muscle degeneration/regeneration, oxidative stress and impaired autophagy. Overexpressing Drp1 in 18-month-old mice resulted in mild skeletal muscle atrophy and decreased mitochondrial quality. Our data indicate that silencing or overexpressing Drp1 late in life is detrimental to skeletal muscle integrity. We conclude that modulating Drp1 expression is unlikely to be a viable approach to counter the muscle ageing process. ABSTRACT Sarcopenia, the ageing-related loss of skeletal muscle mass and function, is a debilitating process negatively impacting the quality of life of afflicted individuals. Although the mechanisms underlying sarcopenia are still only partly understood, impairments in mitochondrial dynamics, and specifically mitochondrial fission, have been proposed as an underlying mechanism. Importantly, conflicting data exist in the field and both excessive and insufficient mitochondrial fission were proposed to contribute to sarcopenia. In Drosophila melanogaster, enhancing mitochondrial fission in midlife through overexpression of dynamin-1-like protein (Drp1) extended lifespan and attenuated several key hallmarks of muscle ageing. Whether a similar outcome of Drp1 overexpression is observed in mammalian muscles remains unknown. In this study, we investigated the impact of knocking down and overexpressing Drp1 protein for 4 months in skeletal muscles of late middle-aged (18 months) mice using intra-muscular injections of adeno-associated viruses expressing shRNA targeting Drp1 or full Drp1 cDNA. We report that knocking down Drp1 expression late in life triggers severe muscle atrophy, mitochondrial dysfunctions, degeneration/regeneration, oxidative stress and impaired autophagy. Drp1 overexpression late in life triggered mild muscle atrophy and decreased mitochondrial quality. Taken altogether, our results indicate that both overexpression and silencing of Drp1 in late middle-aged mice negatively impact skeletal muscle mass and mitochondrial health. These data suggest that Drp1 content must remain within a narrow physiological range to preserve muscle and mitochondrial integrity during ageing. Altering Drp1 expression is therefore unlikely to be a viable target to counter sarcopenia.
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Affiliation(s)
- Maude Dulac
- Département des sciences biologiques, Faculté des Sciences, UQAM, Québec, Canada.,Département des sciences de l'activité physique, Faculté des Sciences, UQAM, Québec, Canada.,Groupe de recherche en Activité Physique Adaptée, Québec, Canada
| | - Jean-Philippe Leduc-Gaudet
- Département des sciences de l'activité physique, Faculté des Sciences, UQAM, Québec, Canada.,Groupe de recherche en Activité Physique Adaptée, Québec, Canada.,Meakins-Christie Laboratories and Translational Research in Respiratory Diseases Program, Department of Critical Care, Research Institute of the McGill University Health Centre, Montréal, Québec, Canada.,Division of Experimental Medicine, Department of Medicine, McGill University, Montréal, Québec, Canada
| | - Marina Cefis
- Département des sciences de l'activité physique, Faculté des Sciences, UQAM, Québec, Canada
| | - Marie-Belle Ayoub
- Département des sciences de l'activité physique, Faculté des Sciences, UQAM, Québec, Canada.,Groupe de recherche en Activité Physique Adaptée, Québec, Canada
| | - Olivier Reynaud
- Département des sciences biologiques, Faculté des Sciences, UQAM, Québec, Canada.,Département des sciences de l'activité physique, Faculté des Sciences, UQAM, Québec, Canada.,Groupe de recherche en Activité Physique Adaptée, Québec, Canada
| | - Anwar Shams
- Meakins-Christie Laboratories and Translational Research in Respiratory Diseases Program, Department of Critical Care, Research Institute of the McGill University Health Centre, Montréal, Québec, Canada.,Department of Pharmacology, Faculty of Medicine, Taif University, Taif, Saudi Arabia
| | - Alaa Moamer
- Meakins-Christie Laboratories and Translational Research in Respiratory Diseases Program, Department of Critical Care, Research Institute of the McGill University Health Centre, Montréal, Québec, Canada
| | | | - Sabah Na Hussain
- Meakins-Christie Laboratories and Translational Research in Respiratory Diseases Program, Department of Critical Care, Research Institute of the McGill University Health Centre, Montréal, Québec, Canada.,Division of Experimental Medicine, Department of Medicine, McGill University, Montréal, Québec, Canada
| | - Gilles Gouspillou
- Département des sciences de l'activité physique, Faculté des Sciences, UQAM, Québec, Canada.,Groupe de recherche en Activité Physique Adaptée, Québec, Canada.,Division of Experimental Medicine, Department of Medicine, McGill University, Montréal, Québec, Canada.,Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, Québec, Canada
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13
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Anzell AR, Fogo GM, Gurm Z, Raghunayakula S, Wider JM, Maheras KJ, Emaus KJ, Bryson TD, Wang M, Neumar RW, Przyklenk K, Sanderson TH. Mitochondrial fission and mitophagy are independent mechanisms regulating ischemia/reperfusion injury in primary neurons. Cell Death Dis 2021; 12:475. [PMID: 33980811 PMCID: PMC8115279 DOI: 10.1038/s41419-021-03752-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 04/21/2021] [Accepted: 04/22/2021] [Indexed: 02/03/2023]
Abstract
Mitochondrial dynamics and mitophagy are constitutive and complex systems that ensure a healthy mitochondrial network through the segregation and subsequent degradation of damaged mitochondria. Disruption of these systems can lead to mitochondrial dysfunction and has been established as a central mechanism of ischemia/reperfusion (I/R) injury. Emerging evidence suggests that mitochondrial dynamics and mitophagy are integrated systems; however, the role of this relationship in the context of I/R injury remains unclear. To investigate this concept, we utilized primary cortical neurons isolated from the novel dual-reporter mitochondrial quality control knockin mice (C57BL/6-Gt(ROSA)26Sortm1(CAG-mCherry/GFP)Ganl/J) with conditional knockout (KO) of Drp1 to investigate changes in mitochondrial dynamics and mitophagic flux during in vitro I/R injury. Mitochondrial dynamics was quantitatively measured in an unbiased manner using a machine learning mitochondrial morphology classification system, which consisted of four different classifications: network, unbranched, swollen, and punctate. Evaluation of mitochondrial morphology and mitophagic flux in primary neurons exposed to oxygen-glucose deprivation (OGD) and reoxygenation (OGD/R) revealed extensive mitochondrial fragmentation and swelling, together with a significant upregulation in mitophagic flux. Furthermore, the primary morphology of mitochondria undergoing mitophagy was classified as punctate. Colocalization using immunofluorescence as well as western blot analysis revealed that the PINK1/Parkin pathway of mitophagy was activated following OGD/R. Conditional KO of Drp1 prevented mitochondrial fragmentation and swelling following OGD/R but did not alter mitophagic flux. These data provide novel evidence that Drp1 plays a causal role in the progression of I/R injury, but mitophagy does not require Drp1-mediated mitochondrial fission.
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Affiliation(s)
- Anthony R. Anzell
- grid.214458.e0000000086837370Department of Emergency Medicine, University of Michigan Medical School, Ann Arbor, MI 48109 USA ,grid.254444.70000 0001 1456 7807Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201 USA ,grid.21925.3d0000 0004 1936 9000Department of Human Genetics, University of Pittsburgh, Pittsburgh, PA 15269 USA
| | - Garrett M. Fogo
- grid.214458.e0000000086837370Department of Emergency Medicine, University of Michigan Medical School, Ann Arbor, MI 48109 USA ,grid.214458.e0000000086837370Neuroscience Graduate Program, University of Michigan Medical School, Ann Arbor, MI 48109 USA
| | - Zoya Gurm
- grid.214458.e0000000086837370Department of Emergency Medicine, University of Michigan Medical School, Ann Arbor, MI 48109 USA ,grid.214458.e0000000086837370Frankel Cardiovascular Center, University of Michigan Medical School, Ann Arbor, MI 48109 USA
| | - Sarita Raghunayakula
- grid.214458.e0000000086837370Department of Emergency Medicine, University of Michigan Medical School, Ann Arbor, MI 48109 USA
| | - Joseph M. Wider
- grid.214458.e0000000086837370Department of Emergency Medicine, University of Michigan Medical School, Ann Arbor, MI 48109 USA
| | - Kathleen J. Maheras
- grid.214458.e0000000086837370Department of Emergency Medicine, University of Michigan Medical School, Ann Arbor, MI 48109 USA
| | - Katlynn J. Emaus
- grid.214458.e0000000086837370Department of Emergency Medicine, University of Michigan Medical School, Ann Arbor, MI 48109 USA ,grid.214458.e0000000086837370Neuroscience Graduate Program, University of Michigan Medical School, Ann Arbor, MI 48109 USA
| | - Timothy D. Bryson
- grid.214458.e0000000086837370Department of Emergency Medicine, University of Michigan Medical School, Ann Arbor, MI 48109 USA ,grid.214458.e0000000086837370Frankel Cardiovascular Center, University of Michigan Medical School, Ann Arbor, MI 48109 USA
| | - Madison Wang
- grid.254444.70000 0001 1456 7807Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201 USA
| | - Robert W. Neumar
- grid.214458.e0000000086837370Department of Emergency Medicine, University of Michigan Medical School, Ann Arbor, MI 48109 USA
| | - Karin Przyklenk
- grid.254444.70000 0001 1456 7807Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201 USA
| | - Thomas H. Sanderson
- grid.214458.e0000000086837370Department of Emergency Medicine, University of Michigan Medical School, Ann Arbor, MI 48109 USA ,grid.214458.e0000000086837370Neuroscience Graduate Program, University of Michigan Medical School, Ann Arbor, MI 48109 USA ,grid.214458.e0000000086837370Frankel Cardiovascular Center, University of Michigan Medical School, Ann Arbor, MI 48109 USA ,grid.214458.e0000000086837370Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI 48109 USA
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14
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The Interplay between Mitochondrial Morphology and Myomitokines in Aging Sarcopenia. Int J Mol Sci 2020; 22:ijms22010091. [PMID: 33374852 PMCID: PMC7796142 DOI: 10.3390/ijms22010091] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 12/22/2020] [Accepted: 12/23/2020] [Indexed: 12/13/2022] Open
Abstract
Sarcopenia is a chronic disease characterized by the progressive loss of skeletal muscle mass, force, and function during aging. It is an emerging public problem associated with poor quality of life, disability, frailty, and high mortality. A decline in mitochondria quality control pathways constitutes a major mechanism driving aging sarcopenia, causing abnormal organelle accumulation over a lifetime. The resulting mitochondrial dysfunction in sarcopenic muscles feedbacks systemically by releasing the myomitokines fibroblast growth factor 21 (FGF21) and growth and differentiation factor 15 (GDF15), influencing the whole-body homeostasis and dictating healthy or unhealthy aging. This review describes the principal pathways controlling mitochondrial quality, many of which are potential therapeutic targets against muscle aging, and the connection between mitochondrial dysfunction and the myomitokines FGF21 and GDF15 in the pathogenesis of aging sarcopenia.
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15
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Heine KB, Justyn NM, Hill GE, Hood WR. Ultraviolet irradiation alters the density of inner mitochondrial membrane and proportion of inter-mitochondrial junctions in copepod myocytes. Mitochondrion 2020; 56:82-90. [PMID: 33220503 DOI: 10.1016/j.mito.2020.11.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 10/18/2020] [Accepted: 11/02/2020] [Indexed: 01/11/2023]
Abstract
The efficient production of energy via oxidative phosphorylation is essential to the growth, survival, and reproduction of eukaryotes. The behavior (position of, and communication between, mitochondria) and morphology of mitochondria play key roles in efficient energy production and are influenced by oxidative stressors such as ultraviolet (UV) radiation. We tested the hypothesis that mitochondria change their behavior and morphology to meet energetic demands of responding to changes in oxidative stress. Specifically, we predicted that UV irradiation would increase the density of inner mitochondrial membrane and proportion of inter-mitochondrial junctions to influence whole-animal metabolic rate. Using transmission electron microscopy, we found that both three and six hours of UV-A/B irradiation (0.5 W/m2) increased the proportion of inter-mitochondrial junctions (with increasing mitochondrial aspect ratio) and the density of inner mitochondrial membrane in myocytes of Tigriopus californicus copepods. Mitochondrial density increased following both irradiation treatments, but mitochondrial size decreased under the six hour treatment. Metabolic rate was maintained under three hours of irradiation but decreased following six hours of exposure. These observations demonstrate that the density of inner mitochondrial membrane and proportion of inter-mitochondrial junctions can play formative roles in maintaining whole-animal metabolic rate, and ultimately organismal performance, under exposure to an oxidative stressor.
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Affiliation(s)
- Kyle B Heine
- Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA.
| | - Nicholas M Justyn
- Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA
| | - Geoffrey E Hill
- Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA
| | - Wendy R Hood
- Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA
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16
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Webb M, Sideris DP. Intimate Relations-Mitochondria and Ageing. Int J Mol Sci 2020; 21:ijms21207580. [PMID: 33066461 PMCID: PMC7589147 DOI: 10.3390/ijms21207580] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 10/05/2020] [Accepted: 10/06/2020] [Indexed: 12/14/2022] Open
Abstract
Mitochondrial dysfunction is associated with ageing, but the detailed causal relationship between the two is still unclear. We review the major phenomenological manifestations of mitochondrial age-related dysfunction including biochemical, regulatory and energetic features. We conclude that the complexity of these processes and their inter-relationships are still not fully understood and at this point it seems unlikely that a single linear cause and effect relationship between any specific aspect of mitochondrial biology and ageing can be established in either direction.
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Affiliation(s)
- Michael Webb
- Mitobridge Inc., an Astellas Company, 1030 Massachusetts Ave, Cambridge, MA 02138, USA
| | - Dionisia P Sideris
- Mitobridge Inc., an Astellas Company, 1030 Massachusetts Ave, Cambridge, MA 02138, USA
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17
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Dave DT, Patel BM. Mitochondrial Metabolism in Cancer Cachexia: Novel Drug Target. Curr Drug Metab 2020; 20:1141-1153. [PMID: 31418657 DOI: 10.2174/1389200220666190816162658] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 07/23/2019] [Accepted: 07/25/2019] [Indexed: 12/15/2022]
Abstract
BACKGROUND Cancer cachexia is a metabolic syndrome prevalent in the majority of the advanced cancers and is associated with complications such as anorexia, early satiety, weakness, anaemia, and edema, thereby reducing performance and impairing quality of life. Skeletal muscle wasting is a characteristic feature of cancer-cachexia and mitochondria is responsible for regulating total protein turnover in skeletal muscle tissue. METHODS We carried out exhaustive search for cancer cachexia and role of mitochondria in the same in various databases. All the relevant articles were gathered and the pertinent information was extracted out and compiled which was further structured into different sub-sections. RESULTS Various findings on the mitochondrial alterations in connection to its disturbed normal physiology in various models of cancer-cachexia have been recently reported, suggesting a significant role of the organelle in the pathogenesis of the complications involved in the disorder. It has also been reported that reduced mitochondrial oxidative capacity is due to reduced mitochondrial biogenesis as well as altered balance between fusion and fission protein activities. Moreover, autophagy in mitochondria (termed as mitophagy) is reported to play an important role in cancer cachexia. CONCLUSION The present review aims to put forth the changes occurring in mitochondria and hence explore possible targets which can be exploited in cancer-induced cachexia for treatment of such a debilitating condition.
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Affiliation(s)
- Dhwani T Dave
- Department of Pharmacology, Institute of Pharmacy, Nirma University, Sarkhej-Gandhinagar Highway, Ahmedabad 382481, Gujarat, India
| | - Bhoomika M Patel
- Department of Pharmacology, Institute of Pharmacy, Nirma University, Sarkhej-Gandhinagar Highway, Ahmedabad 382481, Gujarat, India
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18
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Heine KB, Hood WR. Mitochondrial behaviour, morphology, and animal performance. Biol Rev Camb Philos Soc 2020; 95:730-737. [PMID: 32022456 DOI: 10.1111/brv.12584] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Revised: 01/10/2020] [Accepted: 01/14/2020] [Indexed: 12/14/2022]
Abstract
We have a limited understanding of the proximate mechanisms that are responsible for the development of variation in animal performance and life-history strategies. Provided that components of an organism's successful life history - for example, mate competition, gestation, lactation, etc. - are energetically demanding, increased energy production within mitochondria is likely the foundation from which organisms are able to perform these tasks. Mitochondrial behaviour (positioning within the cell and communication between mitochondria) and morphology affect variation in energy production at the molecular, cellular, and organismal levels. Therefore, adaptations in mitochondrial behaviour and morphology that favour efficient energy production likely influence variation in animal performance. Previous work has linked greater proportions of inter-mitochondrial junctions and density of the inner mitochondrial membrane, among other traits, with increased energetic demand. Future research should focus on how inter-mitochondrial junctions and morphology of the inner mitochondrial membrane, in particular, influence animal performance in accordance with mitochondrial density, fission, and fusion.
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Affiliation(s)
- Kyle B Heine
- Department of Biological Sciences, Auburn University, 101 Rouse Life Sciences Building, Auburn, AL, 36849, U.S.A
| | - Wendy R Hood
- Department of Biological Sciences, Auburn University, 101 Rouse Life Sciences Building, Auburn, AL, 36849, U.S.A
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19
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Steinberg GR, Carling D. AMP-activated protein kinase: the current landscape for drug development. Nat Rev Drug Discov 2020; 18:527-551. [PMID: 30867601 DOI: 10.1038/s41573-019-0019-2] [Citation(s) in RCA: 390] [Impact Index Per Article: 97.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Since the discovery of AMP-activated protein kinase (AMPK) as a central regulator of energy homeostasis, many exciting insights into its structure, regulation and physiological roles have been revealed. While exercise, caloric restriction, metformin and many natural products increase AMPK activity and exert a multitude of health benefits, developing direct activators of AMPK to elicit beneficial effects has been challenging. However, in recent years, direct AMPK activators have been identified and tested in preclinical models, and a small number have entered clinical trials. Despite these advances, which disease(s) represent the best indications for therapeutic AMPK activation and the long-term safety of such approaches remain to be established.
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Affiliation(s)
- Gregory R Steinberg
- Centre for Metabolism, Obesity and Diabetes Research, Department of Medicine and Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada.
| | - David Carling
- Cellular Stress Group, Medical Research Council London Institute of Medical Sciences, Hammersmith Hospital, Imperial College, London, UK
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20
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Zhang T, Hong ZY, Tang SY, Li W, Inglis DW, Hosokawa Y, Yalikun Y, Li M. Focusing of sub-micrometer particles in microfluidic devices. LAB ON A CHIP 2020; 20:35-53. [PMID: 31720655 DOI: 10.1039/c9lc00785g] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Sub-micrometer particles (0.10-1.0 μm) are of great significance to study, e.g., microvesicles and protein aggregates are targets for therapeutic intervention, and sub-micrometer fluorescent polystyrene (PS) particles are used as probes for diagnostic imaging. Focusing of sub-micrometer particles - precisely control over the position of sub-micrometer particles in a tightly focused stream - has a wide range of applications in the field of biology, chemistry and environment, by acting as a prerequisite step for downstream detection, manipulation and quantification. Microfluidic devices have been attracting great attention as desirable tools for sub-micrometer particle focusing, due to their small size, low reagent consumption, fast analysis and low cost. Recent advancements in fundamental knowledge and fabrication technologies have enabled microfluidic focusing of particles at sub-micrometer scale in a continuous, label-free and high-throughput manner. Microfluidic methods for the focusing of sub-micrometer particles can be classified into two main groups depending on whether an external field is applied: 1) passive methods, which utilize intrinsic fluidic properties without the need of external actuation, such as inertial, deterministic lateral displacement (DLD), viscoelastic and hydrophoretic focusing; and 2) active methods, where external fields are used, such as dielectrophoretic, thermophoretic, acoustophoretic and optical focusing. This article mainly reviews the studies on the focusing of sub-micrometer particles in microfluidic devices over the past 10 years. It aims to bridge the gap between the focusing of micrometer and nanometer scale (1.0-100 nm) particles and to improve the understanding of development progress, current advances and future prospects in microfluidic focusing techniques.
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Affiliation(s)
- Tianlong Zhang
- Division of Materials Science, Nara Institute of Science and Technology, Nara 630-0192, Japan. and School of Engineering, Macquarie University, Sydney 2122, Australia.
| | - Zhen-Yi Hong
- Division of Materials Science, Nara Institute of Science and Technology, Nara 630-0192, Japan.
| | - Shi-Yang Tang
- School of Mechanical, Materials, Mechatronic and Biomedical Engineering, University of Wollongong, Wollongong 2522, Australia
| | - Weihua Li
- School of Mechanical, Materials, Mechatronic and Biomedical Engineering, University of Wollongong, Wollongong 2522, Australia
| | - David W Inglis
- School of Engineering, Macquarie University, Sydney 2122, Australia.
| | - Yoichiroh Hosokawa
- Division of Materials Science, Nara Institute of Science and Technology, Nara 630-0192, Japan.
| | - Yaxiaer Yalikun
- Division of Materials Science, Nara Institute of Science and Technology, Nara 630-0192, Japan.
| | - Ming Li
- School of Engineering, Macquarie University, Sydney 2122, Australia.
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21
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Panier S, Maric M, Hewitt G, Mason-Osann E, Gali H, Dai A, Labadorf A, Guervilly JH, Ruis P, Segura-Bayona S, Belan O, Marzec P, Gaillard PHL, Flynn RL, Boulton SJ. SLX4IP Antagonizes Promiscuous BLM Activity during ALT Maintenance. Mol Cell 2019; 76:27-43.e11. [PMID: 31447390 PMCID: PMC6863466 DOI: 10.1016/j.molcel.2019.07.010] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 06/03/2019] [Accepted: 07/08/2019] [Indexed: 12/18/2022]
Abstract
Cancer cells acquire unlimited proliferative capacity by either re-expressing telomerase or inducing alternative lengthening of telomeres (ALT), which relies on telomere recombination. Here, we show that ALT recombination requires coordinate regulation of the SMX and BTR complexes to ensure the appropriate balance of resolution and dissolution activities at recombining telomeres. Critical to this control is SLX4IP, which accumulates at ALT telomeres and interacts with SLX4, XPF, and BLM. Loss of SLX4IP increases ALT-related phenotypes, which is incompatible with cell growth following concomitant loss of SLX4. Inactivation of BLM is sufficient to rescue telomere aggregation and the synthetic growth defect in this context, suggesting that SLX4IP favors SMX-dependent resolution by antagonizing promiscuous BLM activity during ALT recombination. Finally, we show that SLX4IP is inactivated in a subset of ALT-positive osteosarcomas. Collectively, our findings uncover an SLX4IP-dependent regulatory mechanism critical for telomere maintenance in ALT cancer cells.
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Affiliation(s)
| | - Marija Maric
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Graeme Hewitt
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Emily Mason-Osann
- Boston University School of Medicine, 72 East Concord Street, Boston, MA 02118, USA
| | - Himabindu Gali
- Boston University School of Medicine, 72 East Concord Street, Boston, MA 02118, USA
| | - Anqi Dai
- Boston University School of Medicine, 72 East Concord Street, Boston, MA 02118, USA
| | - Adam Labadorf
- Boston University School of Medicine, 72 East Concord Street, Boston, MA 02118, USA
| | - Jean-Hugues Guervilly
- Centre de Recherche en Cancérologie de Marseille, CRCM, CNRS, Aix Marseille Université, INSERM, Institut Paoli-Calmettes, 27 Boulevard Leï Roure, 13009 Marseille, France
| | - Philip Ruis
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | | | - Ondrej Belan
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Paulina Marzec
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Pierre-Henri L Gaillard
- Centre de Recherche en Cancérologie de Marseille, CRCM, CNRS, Aix Marseille Université, INSERM, Institut Paoli-Calmettes, 27 Boulevard Leï Roure, 13009 Marseille, France
| | - Rachel L Flynn
- Boston University School of Medicine, 72 East Concord Street, Boston, MA 02118, USA
| | - Simon J Boulton
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK.
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22
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Mitochondrial fission protein 1 up-regulation ameliorates senescence-related endothelial dysfunction of human endothelial progenitor cells. Angiogenesis 2019; 22:569-582. [DOI: 10.1007/s10456-019-09680-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 08/26/2019] [Indexed: 12/15/2022]
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Toms M, Burgoyne T, Tracey-White D, Richardson R, Dubis AM, Webster AR, Futter C, Moosajee M. Phagosomal and mitochondrial alterations in RPE may contribute to KCNJ13 retinopathy. Sci Rep 2019; 9:3793. [PMID: 30846767 PMCID: PMC6405871 DOI: 10.1038/s41598-019-40507-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 02/18/2019] [Indexed: 12/29/2022] Open
Abstract
Mutations in KCNJ13 are associated with two retinal disorders; Leber congenital amaurosis (LCA) and snowflake vitreoretinal degeneration (SVD). We examined the retina of kcnj13 mutant zebrafish (obelixtd15, c.502T > C p.[Phe168Leu]) to provide new insights into the pathophysiology underlying these conditions. Detailed phenotyping of obelixtd15 fish revealed a late onset retinal degeneration at 12 months. Electron microscopy of the obelixtd15 retinal pigment epithelium (RPE) uncovered reduced phagosome clearance and increased mitochondrial number and size prior any signs of retinal degeneration. Melanosome distribution was also affected in dark-adapted 12-month obelixtd15 fish. At 6 and 12 months, ATP levels were found to be reduced along with increased expression of glial fibrillary acidic protein and heat shock protein 60. Quantitative RT-PCR of polg2, fis1, opa1, sod1/2 and bcl2a from isolated retina showed expression changes consistent with altered mitochondrial activity and retinal stress. We propose that the retinal disease in this model is primarily a failure of phagosome physiology with a secondary mitochondrial dysfunction. Our findings suggest that alterations in the RPE and photoreceptor cellular organelles may contribute to KCNJ13-related retinal degeneration and provide a therapeutic target.
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Affiliation(s)
- Maria Toms
- UCL Institute of Ophthalmology, London, UK
| | | | | | | | - Adam M Dubis
- UCL Institute of Ophthalmology, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Andrew R Webster
- UCL Institute of Ophthalmology, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | | | - Mariya Moosajee
- UCL Institute of Ophthalmology, London, UK. .,Moorfields Eye Hospital NHS Foundation Trust, London, UK. .,Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK.
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24
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Swimming Exercise and Transient Food Deprivation in Caenorhabditis elegans Promote Mitochondrial Maintenance and Protect Against Chemical-Induced Mitotoxicity. Sci Rep 2018; 8:8359. [PMID: 29844465 PMCID: PMC5974391 DOI: 10.1038/s41598-018-26552-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2017] [Accepted: 05/14/2018] [Indexed: 12/11/2022] Open
Abstract
Exercise and caloric restriction improve health, including reducing risk of cardiovascular disease, neurological disease, and cancer. However, molecular mechanisms underlying these protections are poorly understood, partly due to the cost and time investment of mammalian long-term diet and exercise intervention studies. We subjected Caenorhabditis elegans nematodes to a 6-day, twice daily swimming exercise regimen, during which time the animals also experienced brief, transient food deprivation. Accordingly, we included a non-exercise group with the same transient food deprivation, a non-exercise control with ad libitum access to food, and a group that exercised in food-containing medium. Following these regimens, we assessed mitochondrial health and sensitivity to mitochondrial toxicants. Exercise protected against age-related decline in mitochondrial morphology in body-wall muscle. Food deprivation increased organismal basal respiration; however, exercise was the sole intervention that increased spare respiratory capacity and proton leak. We observed increased lifespan in exercised animals compared to both control and transiently food-deprived nematodes. Finally, exercised animals (and to a lesser extent, transiently food-deprived animals) were markedly protected against lethality from acute exposures to the mitotoxicants rotenone and arsenic. Thus, swimming exercise and brief food deprivation provide effective intervention in C. elegans, protecting from age-associated mitochondrial decline and providing resistance to mitotoxicant exposures.
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25
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Kim D, Luo J, Arriaga EA, Ros A. Deterministic Ratchet for Sub-micrometer (Bio)particle Separation. Anal Chem 2018; 90:4370-4379. [PMID: 29506379 DOI: 10.1021/acs.analchem.7b03774] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Resolving the heterogeneity of particle populations by size is important when the particle size is a signature of abnormal biological properties leading to disease. Accessing size heterogeneity in the sub-micrometer regime is particularly important to resolve populations of subcellular species or diagnostically relevant bioparticles. Here, we demonstrate a ratchet migration mechanism capable of separating sub-micrometer sized species by size and apply it to biological particles. The phenomenon is based on a deterministic ratchet effect, is realized in a microfluidic device, and exhibits fast migration allowing separation in tens of seconds. We characterize this phenomenon extensively with the aid of a numerical model allowing one to predict the speed and resolution of this method. We further demonstrate the deterministic ratchet migration with two sub-micrometer sized beads as model system experimentally as well as size-heterogeneous mouse liver mitochondria and liposomes as model system for other organelles. We demonstrate excellent agreement between experimentally observed migration and the numerical model.
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Affiliation(s)
- Daihyun Kim
- School of Molecular Sciences , Arizona State University , Tempe , Arizona 85287 , United States.,Center for Applied Structural Discovery, The Biodesign Institute , Arizona State University , Tempe , Arizona 85281 , United States
| | - Jinghui Luo
- School of Molecular Sciences , Arizona State University , Tempe , Arizona 85287 , United States.,Center for Applied Structural Discovery, The Biodesign Institute , Arizona State University , Tempe , Arizona 85281 , United States
| | - Edgar A Arriaga
- Department of Biochemistry, Molecular Biology and Biophysics , University of Minnesota , Minneapolis , Minnesota 55455 , United States.,Department of Chemistry , University of Minnesota , Minneapolis , Minnesota 55455 , United States
| | - Alexandra Ros
- School of Molecular Sciences , Arizona State University , Tempe , Arizona 85287 , United States.,Center for Applied Structural Discovery, The Biodesign Institute , Arizona State University , Tempe , Arizona 85281 , United States
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26
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Kozlov S, Afonin A, Evsyukov I, Bondarenko A. Alzheimer's disease: as it was in the beginning. Rev Neurosci 2018; 28:825-843. [PMID: 28704198 DOI: 10.1515/revneuro-2017-0006] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 05/19/2017] [Indexed: 01/09/2023]
Abstract
Since Alzheimer's disease was first described in 1907, many attempts have been made to reveal its main cause. Nowadays, two forms of the disease are known, and while the hereditary form of the disease is clearly caused by mutations in one of several genes, the etiology of the sporadic form remains a mystery. Both forms share similar sets of neuropathological and molecular manifestations, including extracellular deposition of amyloid-beta, intracellular accumulation of hyperphosphorylated tau protein, disturbances in both the structure and functions of mitochondria, oxidative stress, metal ion metabolism disorders, impairment of N-methyl-D-aspartate receptor-related signaling pathways, abnormalities of lipid metabolism, and aberrant cell cycle reentry in some neurons. Such a diversity of symptoms led to proposition of various hypotheses for explaining the development of Alzheimer's disease, the amyloid hypothesis, which postulates the key role of amyloid-beta in Alzheimer's disease development, being the most prominent. However, this hypothesis does not fully explain all of the molecular abnormalities and is therefore heavily criticized. In this review, we propose a hypothetical model of Alzheimer's disease progression, assuming a key role of age-related mitochondrial dysfunction, as was postulated in the mitochondrial cascade hypothesis. Our model explains the connections between all the symptoms of Alzheimer's disease, with particular attention to autophagy, metal metabolism disorders, and aberrant cell cycle re-entry in neurons. Progression of the Alzheimer's disease appears to be a complex process involving aging and too many protective mechanisms affecting one another, thereby leading to even greater deleterious effects.
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27
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Cardinale DA, Lilja M, Mandić M, Gustafsson T, Larsen FJ, Lundberg TR. Resistance Training with Co-ingestion of Anti-inflammatory Drugs Attenuates Mitochondrial Function. Front Physiol 2017; 8:1074. [PMID: 29311990 PMCID: PMC5742251 DOI: 10.3389/fphys.2017.01074] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 12/06/2017] [Indexed: 01/09/2023] Open
Abstract
Aim: The current study aimed to examine the effects of resistance exercise with concomitant consumption of high vs. low daily doses of non-steroidal anti-inflammatory drugs (NSAIDs) on mitochondrial oxidative phosphorylation in skeletal muscle. As a secondary aim, we compared the effects of eccentric overload with conventional training. Methods: Twenty participants were randomized to either a group taking high doses (3 × 400 mg/day) of ibuprofen (IBU; 27 ± 5 year; n = 11) or a group ingesting a low dose (1 × 75 mg/day) of acetylsalicylic acid (ASA; 26 ± 4 year; n = 9) during 8 weeks of supervised knee extensor resistance training. Each of the subject's legs were randomized to complete the training program using either a flywheel (FW) device emphasizing eccentric overload, or a traditional weight stack machine (WS). Maximal mitochondrial oxidative phosphorylation (CI+IIP) from permeabilized skeletal muscle bundles was assessed using high-resolution respirometry. Citrate synthase (CS) activity was assessed using spectrophotometric techniques and mitochondrial protein content using western blotting. Results: After training, CI+IIP decreased (P < 0.05) in both IBU (23%) and ASA (29%) with no difference across medical treatments. Although CI+IIP decreased in both legs, the decrease was greater (interaction p = 0.015) in WS (33%, p = 0.001) compared with FW (19%, p = 0.078). CS activity increased (p = 0.027) with resistance training, with no interactions with medical treatment or training modality. Protein expression of ULK1 increased with training in both groups (p < 0.001). The increase in quadriceps muscle volume was not correlated with changes in CI+IIP (R = 0.16). Conclusion: These results suggest that 8 weeks of resistance training with co-ingestion of anti-inflammatory drugs reduces mitochondrial function but increases mitochondrial content. The observed changes were not affected by higher doses of NSAIDs consumption, suggesting that the resistance training intervention was the prime mediator of the decreased mitochondrial phosphorylation. Finally, we noted that flywheel resistance training, emphasizing eccentric overload, rescued some of the reduction in mitochondrial function seen with conventional resistance training.
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Affiliation(s)
- Daniele A Cardinale
- Åstrand Laboratory, The Swedish School of Sport and Health Sciences, Stockholm, Sweden.,Elite Performance Centre, Bosön-Swedish Sports Confederation, Lidingö, Sweden
| | - Mats Lilja
- Division of Clinical Physiology, Department of Laboratory Medicine, Karolinska Institutet, and Unit of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
| | - Mirko Mandić
- Division of Clinical Physiology, Department of Laboratory Medicine, Karolinska Institutet, and Unit of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
| | - Thomas Gustafsson
- Division of Clinical Physiology, Department of Laboratory Medicine, Karolinska Institutet, and Unit of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
| | - Filip J Larsen
- Åstrand Laboratory, The Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - Tommy R Lundberg
- Division of Clinical Physiology, Department of Laboratory Medicine, Karolinska Institutet, and Unit of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
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Nicassio L, Fracasso F, Sirago G, Musicco C, Picca A, Marzetti E, Calvani R, Cantatore P, Gadaleta MN, Pesce V. Dietary supplementation with acetyl-l-carnitine counteracts age-related alterations of mitochondrial biogenesis, dynamics and antioxidant defenses in brain of old rats. Exp Gerontol 2017; 98:99-109. [PMID: 28807823 DOI: 10.1016/j.exger.2017.08.017] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 07/31/2017] [Accepted: 08/11/2017] [Indexed: 12/21/2022]
Abstract
We previously reported the ability of dietary supplementation with acetyl-l-carnitine (ALCAR) to prevent age-related decreases of mitochondrial biogenesis in skeletal muscle and liver of old rats. Here, we investigate the effects of ALCAR supplementation in cerebral hemispheres and cerebellum of old rats by analyzing several parameters linked to mitochondrial biogenesis, mitochondrial dynamics and antioxidant defenses. We measured the level of the coactivators PGC-1α and PGC-1β and of the factors regulating mitochondrial biogenesis, finding an age-related decrease of PGC-1β, whereas PGC-1α level was unvaried. Twenty eight-month old rats supplemented with ALCAR for one and two months showed increased levels of both factors. Accordingly, the expression of the two transcription factors NRF-1 and TFAM followed the same trend of PGC-1β. The level of mtDNA, ND1 and the activity of citrate synthase, were decreased with aging and increased following ALCAR treatment. Furthermore, ALCAR counteracted the age-related increase of deleted mtDNA. We also analyzed the content of proteins involved in mitochondrial dynamics (Drp1, Fis1, OPA1 and MNF2) and found an age-dependent increase of MFN2 and of the long form of OPA1. ALCAR treatment restored the content of the two proteins to the level of the young rats. No changes with aging and ALCAR were observed for Drp1 and Fis1. ALCAR reduced total cellular levels of oxidized PRXs and counteracted the age-related decrease of PRX3 and SOD2. Overall, our findings indicate a systemic positive effect of ALCAR dietary treatment and a tissue specific regulation of mitochondrial homeostasis in brain of old rats. Moreover, it appears that ALCAR acts as a nutrient since in most cases its effects were almost completely abolished one month after treatment suspension. Dietary supplementation of old rats with this compound seems a valuable approach to prevent age-related mitochondrial dysfunction and might ultimately represent a strategy to delay age-associated negative consequences in mitochondrial homeostasis.
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Affiliation(s)
- Luigi Nicassio
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari "A. Moro", Bari, Italy
| | - Flavio Fracasso
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari "A. Moro", Bari, Italy
| | - Giuseppe Sirago
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari "A. Moro", Bari, Italy
| | - Clara Musicco
- Institute of Biomembranes and Bioenergetics (IBBE), National Research Council of Italy (CNR), Bari, Italy
| | - Anna Picca
- Department of Geriatrics, Neuroscience and Orthopedics, Catholic University of the Sacred Heart School of Medicine, Rome, Italy
| | - Emanuele Marzetti
- Department of Geriatrics, Neuroscience and Orthopedics, Catholic University of the Sacred Heart School of Medicine, Rome, Italy
| | - Riccardo Calvani
- Department of Geriatrics, Neuroscience and Orthopedics, Catholic University of the Sacred Heart School of Medicine, Rome, Italy
| | - Palmiro Cantatore
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari "A. Moro", Bari, Italy
| | - Maria Nicola Gadaleta
- Institute of Biomembranes and Bioenergetics (IBBE), National Research Council of Italy (CNR), Bari, Italy
| | - Vito Pesce
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari "A. Moro", Bari, Italy.
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29
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Impact of Aging and Exercise on Mitochondrial Quality Control in Skeletal Muscle. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:3165396. [PMID: 28656072 PMCID: PMC5471566 DOI: 10.1155/2017/3165396] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 05/03/2017] [Indexed: 12/17/2022]
Abstract
Mitochondria are characterized by its pivotal roles in managing energy production, reactive oxygen species, and calcium, whose aging-related structural and functional deteriorations are observed in aging muscle. Although it is still unclear how aging alters mitochondrial quality and quantity in skeletal muscle, dysregulation of mitochondrial biogenesis and dynamic controls has been suggested as key players for that. In this paper, we summarize current understandings on how aging regulates muscle mitochondrial biogenesis, while focusing on transcriptional regulations including PGC-1α, AMPK, p53, mtDNA, and Tfam. Further, we review current findings on the muscle mitochondrial dynamic systems in aging muscle: fusion/fission, autophagy/mitophagy, and protein import. Next, we also discuss how endurance and resistance exercises impact on the mitochondrial quality controls in aging muscle, suggesting possible effective exercise strategies to improve/maintain mitochondrial health.
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30
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Hepple RT. Impact of aging on mitochondrial function in cardiac and skeletal muscle. Free Radic Biol Med 2016; 98:177-186. [PMID: 27033952 DOI: 10.1016/j.freeradbiomed.2016.03.017] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 03/12/2016] [Indexed: 12/13/2022]
Abstract
Both skeletal muscle and cardiac muscle are subject to marked structural and functional impairment with aging and these changes contribute to the reduced capacity for exercise as we age. Since mitochondria are involved in multiple aspects of cellular homeostasis including energetics, reactive oxygen species signaling, and regulation of intrinsic apoptotic pathways, defects in this organelle are frequently implicated in the deterioration of skeletal and cardiac muscle with aging. On this basis, the purpose of this review is to evaluate the evidence that aging causes dysfunction in mitochondria in striated muscle with a view towards drawing conclusions about the potential of these changes to contribute to the deterioration seen in striated muscle with aging. As will be shown, impairment in respiration and reactive oxygen species emission with aging are highly variable between studies and seem to be largely a consequence of physical inactivity. On the other hand, both skeletal and cardiac muscle mitochondria are more susceptible to permeability transition and this seems a likely cause of the increased recruitment of mitochondrial-mediated pathways of apoptosis seen in striated muscle. The review concludes by examining the role of degeneration of mitochondrial DNA versus impaired mitochondrial quality control mechanisms in the accumulation of mitochondria that are sensitized to permeability transition, whereby the latter mechanism is favored as the most likely cause.
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Affiliation(s)
- R T Hepple
- Department of Kinesiology, Centre for Translational Biology, McGill University Health Center, Canada; Meakins Christie Laboratories, Canada; Department of Medicine, McGill University, Canada
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31
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El-Sikhry HE, Alsaleh N, Dakarapu R, Falck JR, Seubert JM. Novel Roles of Epoxyeicosanoids in Regulating Cardiac Mitochondria. PLoS One 2016; 11:e0160380. [PMID: 27494529 PMCID: PMC4975494 DOI: 10.1371/journal.pone.0160380] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 07/18/2016] [Indexed: 11/18/2022] Open
Abstract
Maintenance of a healthy pool of mitochondria is important for the function and survival of terminally differentiated cells such as cardiomyocytes. Epoxyeicosatrienoic acids (EETs) are epoxy lipids derived from metabolism of arachidonic acid by cytochrome P450 epoxygenases. We have previously shown that EETs trigger a protective response limiting mitochondrial dysfunction and reducing cellular death. The aim of this study was to investigate whether EET-mediated effects influence mitochondrial quality in HL-1 cardiac cells during starvation. HL-1 cells were subjected to serum- and amino acid free conditions for 24h. We employed a dual-acting synthetic analog UA-8 (13-(3-propylureido)tridec-8-enoic acid), possessing both EET-mimetic and soluble epoxide hydrolase (sEH) inhibitory properties, or 14,15-EET as model EET molecules. We demonstrated that EET-mediated events significantly improved mitochondrial function as assessed by preservation of the ADP/ATP ratio and oxidative respiratory capacity. Starvation induced mitochondrial hyperfusion observed in control cells was attenuated by UA-8. However, EET-mediated events did not affect the expression of mitochondrial dynamic proteins Fis1, DRP-1 or Mfn2. Rather we observed increased levels of OPA-1 oligomers and increased mitochondrial cristae density, which correlated with the preserved mitochondrial function. Increased DNA binding activity of pCREB and Nrf1/2 and increased SIRT1 activity together with elevated mitochondrial proteins suggest EET-mediated events led to preserved mitobiogenesis. Thus, we provide new evidence for EET-mediated events that preserve a healthier pool of mitochondria in cardiac cells following starvation-induced stress.
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Affiliation(s)
- Haitham E. El-Sikhry
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada
| | - Nasser Alsaleh
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada
| | - Rambabu Dakarapu
- Departments of Biochemistry and Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - John R. Falck
- Departments of Biochemistry and Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - John M. Seubert
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada
- Department of Pharmacology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
- * E-mail:
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32
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Yao X, Sha S, Wang Y, Sun X, Cao J, Kang J, Jiang L, Chen M, Ma Y. Perfluorooctane Sulfonate Induces Autophagy-Dependent Apoptosis through Spinster 1-Mediated lysosomal-Mitochondrial Axis and Impaired Mitophagy. Toxicol Sci 2016; 153:198-211. [DOI: 10.1093/toxsci/kfw118] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
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33
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Exercise Promotes Healthy Aging of Skeletal Muscle. Cell Metab 2016; 23:1034-1047. [PMID: 27304505 PMCID: PMC5045036 DOI: 10.1016/j.cmet.2016.05.007] [Citation(s) in RCA: 292] [Impact Index Per Article: 36.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 05/18/2016] [Accepted: 05/24/2016] [Indexed: 02/08/2023]
Abstract
Primary aging is the progressive and inevitable process of bodily deterioration during adulthood. In skeletal muscle, primary aging causes defective mitochondrial energetics and reduced muscle mass. Secondary aging refers to additional deleterious structural and functional age-related changes caused by diseases and lifestyle factors. Secondary aging can exacerbate deficits in mitochondrial function and muscle mass, concomitant with the development of skeletal muscle insulin resistance. Exercise opposes deleterious effects of secondary aging by preventing the decline in mitochondrial respiration, mitigating aging-related loss of muscle mass and enhancing insulin sensitivity. This review focuses on mechanisms by which exercise promotes "healthy aging" by inducing modifications in skeletal muscle.
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34
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Luo J, Muratore KA, Arriaga EA, Ros A. Deterministic Absolute Negative Mobility for Micro- and Submicrometer Particles Induced in a Microfluidic Device. Anal Chem 2016; 88:5920-7. [PMID: 27149097 PMCID: PMC5316477 DOI: 10.1021/acs.analchem.6b00837] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Efficient separations of particles with micron and submicron dimensions are extremely useful in preparation and analysis of materials for nanotechnological and biological applications. Here, we demonstrate a nonintuitive, yet efficient, separation mechanism for μm and subμm colloidal particles and organelles, taking advantage of particle transport in a nonlinear post array in a microfluidic device under the periodic action of electrokinetic and dielectrophoretic forces. We reveal regimes in which deterministic particle migration opposite to the average applied force occurs for a larger particle, a typical signature of deterministic absolute negative mobility (dANM), whereas normal response is obtained for smaller particles. The coexistence of dANM and normal migration was characterized and optimized in numerical modeling and subsequently implemented in a microfluidic device demonstrating at least 2 orders of magnitude higher migration speeds as compared to previous ANM systems. We also induce dANM for mouse liver mitochondria and envision that the separation mechanisms described here provide size selectivity required in future separations of organelles, nanoparticles, and protein nanocrystals.
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Affiliation(s)
- Jinghui Luo
- School of Molecular Sciences, The Biodesign Institute, Arizona State University, Tempe, Arizona 85287, United States
- Center for Applied Structural Discovery, The Biodesign Institute, Arizona State University, Tempe, Arizona 85287, United States
| | - Katherine A. Muratore
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Edgar A. Arriaga
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, United States
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Alexandra Ros
- School of Molecular Sciences, The Biodesign Institute, Arizona State University, Tempe, Arizona 85287, United States
- Center for Applied Structural Discovery, The Biodesign Institute, Arizona State University, Tempe, Arizona 85287, United States
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35
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Leduc-Gaudet JP, Picard M, St-Jean Pelletier F, Sgarioto N, Auger MJ, Vallée J, Robitaille R, St-Pierre DH, Gouspillou G. Mitochondrial morphology is altered in atrophied skeletal muscle of aged mice. Oncotarget 2016; 6:17923-37. [PMID: 26053100 PMCID: PMC4627226 DOI: 10.18632/oncotarget.4235] [Citation(s) in RCA: 181] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 05/12/2015] [Indexed: 02/05/2023] Open
Abstract
Skeletal muscle aging is associated with a progressive decline in muscle mass and strength, a process termed sarcopenia. Evidence suggests that accumulation of mitochondrial dysfunction plays a causal role in sarcopenia, which could be triggered by impaired mitophagy. Mitochondrial function, mitophagy and mitochondrial morphology are interconnected aspects of mitochondrial biology, and may coordinately be altered with aging. However, mitochondrial morphology has remained challenging to characterize in muscle, and whether sarcopenia is associated with abnormal mitochondrial morphology remains unknown. Therefore, we assessed the morphology of SubSarcolemmal (SS) and InterMyoFibrillar (IMF) mitochondria in skeletal muscle of young (8-12wk-old) and old (88-96wk-old) mice using a quantitative 2-dimensional transmission electron microscopy approach. We show that sarcopenia is associated with larger and less circular SS mitochondria. Likewise, aged IMF mitochondria were longer and more branched, suggesting increased fusion and/or decreased fission. Accordingly, although no difference in the content of proteins regulating mitochondrial dynamics (Mfn1, Mfn2, Opa1 and Drp1) was observed, a mitochondrial fusion index (Mfn2-to-Drp1 ratio) was significantly increased in aged muscles. Our results reveal that sarcopenia is associated with complex changes in mitochondrial morphology that could interfere with mitochondrial function and mitophagy, and thus contribute to aging-related accumulation of mitochondrial dysfunction and sarcopenia.
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Affiliation(s)
- Jean-Philippe Leduc-Gaudet
- Département des Sciences de l'Activité Physique, Faculté des Sciences, UQAM, Montréal, Canada.,Groupe de Recherche en Activité Physique Adaptée, Montréal, Canada.,Centre de Recherche du CHU Sainte-Justine, Montréal, Canada
| | - Martin Picard
- The Center for Mitochondrial and Epigenomic Medicine, Children's Hospital of Philadelphia and University of Pennsylvania, Philadelphia, PA, USA
| | - Félix St-Jean Pelletier
- Département des Sciences de l'Activité Physique, Faculté des Sciences, UQAM, Montréal, Canada
| | - Nicolas Sgarioto
- Département des Sciences de l'Activité Physique, Faculté des Sciences, UQAM, Montréal, Canada
| | - Marie-Joëlle Auger
- Département des Sciences de l'Activité Physique, Faculté des Sciences, UQAM, Montréal, Canada
| | - Joanne Vallée
- Département de Neurosciences, Université de Montréal, Montréal, Canada
| | - Richard Robitaille
- Département de Neurosciences, Université de Montréal, Montréal, Canada.,Groupe de Recherche sur le Système Nerveux Central, Montréal, Canada
| | - David H St-Pierre
- Département des Sciences de l'Activité Physique, Faculté des Sciences, UQAM, Montréal, Canada.,Groupe de Recherche en Activité Physique Adaptée, Montréal, Canada.,Centre de Recherche du CHU Sainte-Justine, Montréal, Canada
| | - Gilles Gouspillou
- Département des Sciences de l'Activité Physique, Faculté des Sciences, UQAM, Montréal, Canada.,Groupe de Recherche en Activité Physique Adaptée, Montréal, Canada.,Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, Montréal, Canada
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36
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Gouras P, Ivert L, Neuringer M, Nagasaki T. Mitochondrial elongation in the macular RPE of aging monkeys, evidence of metabolic stress. Graefes Arch Clin Exp Ophthalmol 2016; 254:1221-7. [PMID: 27106622 DOI: 10.1007/s00417-016-3342-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2015] [Revised: 03/29/2016] [Accepted: 04/04/2016] [Indexed: 12/11/2022] Open
Abstract
PURPOSE This study was conducted to determine whether mitochondria of the macular retinal pigment epithelium (RPE) change with age in rhesus monkeys (Macaca mulatta). Mitochondria are the main instigators of oxidative stress, which has often been considered to play a role in the pathogenesis of age-related macular degeneration (AMD). Any pathological changes in the mitochondria of aging macular RPE, the main target of AMD, would be a clue to the pathogenesis of this common retinal degeneration afflicting both monkey and man. METHODS Transmission electron microscopy was used to identify mitochondria and to determine their appearance, their density per unit area of RPE cytoplasm and their length. The eyes of seven monkeys, 1, 2, 6.5, 23, 26, 27 and 35 years of age, were studied. Measurements were kept separate for the basal, middle and apical third of each cell. The basal third of the macular RPE had many more mitochondria than the middle third, and the apical third was almost devoid of mitochondria. RESULTS Mitochondrial number decreased and length increased with age. The increase in length was associated with an unusual clustering of mitochondria into parallel arrays of elongated mitochondria, with their long axis orthogonal to the basal membrane of the cell, structures not described before in RPE. CONCLUSIONS Mitochondrial elongation is associated with metabolic and/or oxidative stress, which implies that age produces stress in macular RPE. The increased clustering of very elongated mitochondria suggests that pathological changes occur in mitochondrial organization with age. These changes support the hypothesis that age-related mitochondrial dysfunction plays a role in the pathogenesis of AMD.
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Affiliation(s)
- Peter Gouras
- Department of Ophthalmology, Columbia University, New York City, NY, USA. .,Edward S. Harkness Eye Institute, Research Annex, 635 West 165th Street, Box #76, New York, NY, 10032, USA.
| | - L Ivert
- St. Erik's Eye Hospital, Karolinska Institute, Stockholm, Sweden
| | - M Neuringer
- Oregon Health & Science University, Portland, OR, USA
| | - T Nagasaki
- Department of Ophthalmology, Columbia University, New York City, NY, USA
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Carter HN, Chen CCW, Hood DA. Mitochondria, muscle health, and exercise with advancing age. Physiology (Bethesda) 2016; 30:208-23. [PMID: 25933821 DOI: 10.1152/physiol.00039.2014] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Skeletal muscle health is dependent on the optimal function of its mitochondria. With advancing age, decrements in numerous mitochondrial variables are evident in muscle. Part of this decline is due to reduced physical activity, whereas the remainder appears to be attributed to age-related alterations in mitochondrial synthesis and degradation. Exercise is an important strategy to stimulate mitochondrial adaptations in older individuals to foster improvements in muscle function and quality of life.
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Affiliation(s)
- Heather N Carter
- Muscle Health Research Centre, School of Kinesiology and Health Science, York University, Toronto, Ontario, Canada
| | - Chris C W Chen
- 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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38
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Romanello V, Sandri M. Mitochondrial Quality Control and Muscle Mass Maintenance. Front Physiol 2016; 6:422. [PMID: 26793123 PMCID: PMC4709858 DOI: 10.3389/fphys.2015.00422] [Citation(s) in RCA: 225] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 12/22/2015] [Indexed: 12/24/2022] Open
Abstract
Loss of muscle mass and force occurs in many diseases such as disuse/inactivity, diabetes, cancer, renal, and cardiac failure and in aging-sarcopenia. In these catabolic conditions the mitochondrial content, morphology and function are greatly affected. The changes of mitochondrial network influence the production of reactive oxygen species (ROS) that play an important role in muscle function. Moreover, dysfunctional mitochondria trigger catabolic signaling pathways which feed-forward to the nucleus to promote the activation of muscle atrophy. Exercise, on the other hand, improves mitochondrial function by activating mitochondrial biogenesis and mitophagy, possibly playing an important part in the beneficial effects of physical activity in several diseases. Optimized mitochondrial function is strictly maintained by the coordinated activation of different mitochondrial quality control pathways. In this review we outline the current knowledge linking mitochondria-dependent signaling pathways to muscle homeostasis in aging and disease and the resulting implications for the development of novel therapeutic approaches to prevent muscle loss.
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Affiliation(s)
| | - Marco Sandri
- Venetian Institute of Molecular MedicinePadova, Italy; Department of Biomedical Science, University of PadovaPadova, Italy; Institute of Neuroscience, Consiglio Nazionale delle RicerchePadova, Italy; Department of Medicine, McGill UniversityMontreal, QC, Canada
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39
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Fan J, Kou X, Jia S, Yang X, Yang Y, Chen N. Autophagy as a Potential Target for Sarcopenia. J Cell Physiol 2015; 231:1450-9. [DOI: 10.1002/jcp.25260] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 11/17/2015] [Indexed: 12/17/2022]
Affiliation(s)
- Jingjing Fan
- College of Health Science; Hubei Provincial Collaborative Innovation Center for Exercise and Health Promotion; Wuhan Sports University; Wuhan China
- Hubei Exercise Training and Monitoring Key Laboratory; Wuhan Sports University; Wuhan China
| | - Xianjuan Kou
- College of Health Science; Hubei Provincial Collaborative Innovation Center for Exercise and Health Promotion; Wuhan Sports University; Wuhan China
- Hubei Exercise Training and Monitoring Key Laboratory; Wuhan Sports University; Wuhan China
| | - Shaohui Jia
- College of Health Science; Hubei Provincial Collaborative Innovation Center for Exercise and Health Promotion; Wuhan Sports University; Wuhan China
- Hubei Exercise Training and Monitoring Key Laboratory; Wuhan Sports University; Wuhan China
| | - Xiaoqi Yang
- Graduate School; Wuhan Sports University; Wuhan China
| | - Yi Yang
- Hubei Exercise Training and Monitoring Key Laboratory; Wuhan Sports University; Wuhan China
| | - Ning Chen
- College of Health Science; Hubei Provincial Collaborative Innovation Center for Exercise and Health Promotion; Wuhan Sports University; Wuhan China
- Hubei Exercise Training and Monitoring Key Laboratory; Wuhan Sports University; Wuhan China
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40
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Joseph AM, Adhihetty PJ, Leeuwenburgh C. Beneficial effects of exercise on age-related mitochondrial dysfunction and oxidative stress in skeletal muscle. J Physiol 2015; 594:5105-23. [PMID: 26503074 DOI: 10.1113/jp270659] [Citation(s) in RCA: 110] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 10/05/2015] [Indexed: 12/12/2022] Open
Abstract
Mitochondria are negatively affected by ageing leading to their inability to adapt to higher levels of oxidative stress and this ultimately contributes to the systemic loss of muscle mass and function termed sarcopenia. Since mitochondria are central mediators of muscle health, they have become highly sought-after targets of physiological and pharmacological interventions. Exercise is the only known strategy to combat sarcopenia and this is largely mediated through improvements in mitochondrial plasticity. More recently a critical role for mitochondrial turnover in preserving muscle has been postulated. Specifically, cellular pathways responsible for the regulation of mitochondrial turnover including biogenesis, dynamics and autophagy may become dysregulated during ageing resulting in the reduced clearance and accumulation of damaged organelles within the cell. When mitochondrial quality is compromised and homeostasis is not re-established, myonuclear cell death is activated and muscle atrophy ensues. In contrast, acute and chronic exercise attenuates these deficits, restoring mitochondrial turnover and promoting a healthier mitochondrial pool that leads to the preservation of muscle. Additionally, the magnitude of these exercise-induced mitochondrial adaptations is currently debated with several studies reporting a lower adaptability of old muscle relative to young, but the processes responsible for this diminished training response are unclear. Based on these observations, understanding the molecular details of how advancing age and exercise influence mitochondria in older muscle will provide invaluable insight into the development of exercise protocols that will maximize beneficial adaptations in the elderly. This information will also be imperative for future research exploring pharmacological targets of mitochondrial plasticity.
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Affiliation(s)
- Anna-Maria Joseph
- Department of Aging and Geriatric Research, Division of Biology of Aging, University of Florida, Gainesville, FL, 32611, USA.
| | - Peter J Adhihetty
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, 32611, USA
| | - Christiaan Leeuwenburgh
- Department of Aging and Geriatric Research, Division of Biology of Aging, University of Florida, Gainesville, FL, 32611, USA
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41
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Khan M, Syed GH, Kim SJ, Siddiqui A. Mitochondrial dynamics and viral infections: A close nexus. BIOCHIMICA ET BIOPHYSICA ACTA 2015; 1853:2822-33. [PMID: 25595529 PMCID: PMC4500740 DOI: 10.1016/j.bbamcr.2014.12.040] [Citation(s) in RCA: 119] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Revised: 12/09/2014] [Accepted: 12/25/2014] [Indexed: 12/17/2022]
Abstract
Viruses manipulate cellular machinery and functions to subvert intracellular environment conducive for viral proliferation. They strategically alter functions of the multitasking mitochondria to influence energy production, metabolism, survival, and immune signaling. Mitochondria either occur as heterogeneous population of individual organelles or large interconnected tubular network. The mitochondrial network is highly susceptible to physiological and environmental insults, including viral infections, and is dynamically maintained by mitochondrial fission and fusion. Mitochondrial dynamics in tandem with mitochondria-selective autophagy 'mitophagy' coordinates mitochondrial quality control and homeostasis. Mitochondrial dynamics impacts cellular homeostasis, metabolism, and innate-immune signaling, and thus can be major determinant of the outcome of viral infections. Herein, we review how mitochondrial dynamics is affected during viral infections and how this complex interplay benefits the viral infectious process and associated diseases.
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Affiliation(s)
- Mohsin Khan
- Division of Infectious Diseases, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Gulam Hussain Syed
- Division of Infectious Diseases, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Seong-Jun Kim
- Division of Infectious Diseases, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Aleem Siddiqui
- Division of Infectious Diseases, Department of Medicine, University of California, San Diego, La Jolla, CA, USA.
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42
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Wolken GG, Arriaga EA. Simultaneous measurement of individual mitochondrial membrane potential and electrophoretic mobility by capillary electrophoresis. Anal Chem 2014; 86:4217-26. [PMID: 24673334 PMCID: PMC4018156 DOI: 10.1021/ac403849x] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
![]()
Mitochondrial membrane
potential varies, depending on energy demand,
subcellular location, and morphology and is commonly used as an indicator
of mitochondrial functional status. Electrophoretic mobility is a
heterogeneous surface property reflective of mitochondrial surface
composition and morphology, which could be used as a basis for separation
of mitochondrial subpopulations. Since these properties are heterogeneous,
methods for their characterization in individual mitochondria are
needed to better design and understand electrophoretic separations
of subpopulations of mitochondria. Here we report on the first method
for simultaneous determination of individual mitochondrial membrane
potential and electrophoretic mobility by capillary electrophoresis
with laser-induced fluorescence detection (CE-LIF). Mitochondria were
isolated from cultured cells, mouse muscle, or liver, and then polarized,
labeled with JC-1 (a ratiometric fluorescent probe, which indicates
changes in membrane potential), and separated with CE-LIF. Red/green
fluorescence intensity ratios from individual mitochondria were used
as an indicator of mitochondrial membrane potential. Reproducible
distributions of individual mitochondrial membrane potential and electrophoretic
mobility were observed. Analysis of polarized and depolarized regions
of interest defined using red/green ratios and runs of depolarized
controls allowed for the determination of membrane potential and comparison
of electrophoretic mobility distributions in preparations containing
depolarized mitochondria. Through comparison of these regions of interest,
we observed dependence of electrophoretic mobility on membrane potential,
with polarized regions of interest displaying decreased electrophoretic
mobility. This method could be applied to investigate mitochondrial
heterogeneity in aging or disease models where membrane potential
is an important factor.
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Affiliation(s)
- Gregory G Wolken
- Department of Chemistry, University of Minnesota , 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
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43
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Luo J, Abdallah BG, Wolken GG, Arriaga EA, Ros A. Insulator-based dielectrophoresis of mitochondria. BIOMICROFLUIDICS 2014; 8:021801. [PMID: 24959306 PMCID: PMC4056684 DOI: 10.1063/1.4866852] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Accepted: 01/28/2014] [Indexed: 05/03/2023]
Abstract
Isolated mitochondria display a wide range of sizes plausibly resulting from the coexistence of subpopulations, some of which may be associated with disease or aging. Strategies to separate subpopulations are needed to study the importance of these organelles in cellular functions. Here, insulator-based dielectrophoresis (iDEP) was exploited to provide a new dimension of organelle separation. The dielectrophoretic properties of isolated Fischer 344 (F344) rat semimembranosus muscle mitochondria and C57BL/6 mouse hepatic mitochondria in low conductivity buffer (0.025-0.030 S/m) at physiological pH (7.2-7.4) were studied using polydimethylsiloxane (PDMS) microfluidic devices. First, direct current (DC) and alternating current (AC) of 0-50 kHz with potentials of 0-3000 V applied over a channel length of 1 cm were separately employed to generate inhomogeneous electric fields and establish that mitochondria exhibit negative DEP (nDEP). DEP trapping potential thresholds at 0-50 kHz were also determined to be weakly dependent on applied frequency and were generally above 200 V. Second, we demonstrated a separation scheme using DC potentials <100 V to perform the first size-based iDEP sorting of mitochondria. Samples of isolated mitochondria with heterogeneous sizes (150 nm-2 μm diameters) were successfully separated into sub-micron fractions, indicating the ability to isolate mitochondria into populations based on their size.
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Affiliation(s)
- Jinghui Luo
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287, USA
| | - Bahige G Abdallah
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287, USA
| | - Gregory G Wolken
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Edgar A Arriaga
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Alexandra Ros
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287, USA
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44
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Bereiter-Hahn J. Do we age because we have mitochondria? PROTOPLASMA 2014; 251:3-23. [PMID: 23794102 DOI: 10.1007/s00709-013-0515-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Accepted: 05/21/2013] [Indexed: 06/02/2023]
Abstract
The process of aging remains a great riddle. Production of reactive oxygen species (ROS) by mitochondria is an inevitable by-product of respiration, which has led to a hypothesis proposing the oxidative impairment of mitochondrial components (e.g., mtDNA, proteins, lipids) that initiates a vicious cycle of dysfunctional respiratory complexes producing more ROS, which again impairs function. This does not exclude other processes acting in parallel or targets for ROS action in other organelles than mitochondria. Given that aging is defined as the process leading to death, the role of mitochondria-based impairments in those organ systems responsible for human death (e.g., the cardiovascular system, cerebral dysfunction, and cancer) is described within the context of "garbage" accumulation and increasing insulin resistance, type 2 diabetes, and glycation of proteins. Mitochondrial mass, fusion, and fission are important factors in coping with impaired function. Both biogenesis of mitochondria and their degradation are important regulatory mechanisms stimulated by physical exercise and contribute to healthy aging. The hypothesis of mitochondria-related aging should be revised to account for the limitations of the degradative capacity of the lysosomal system. The processes involved in mitochondria-based impairments are very similar across a large range of organisms. Therefore, studies on model organisms from yeast, fungi, nematodes, flies to vertebrates, and from cells to organisms also add considerably to the understanding of human aging.
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Affiliation(s)
- Jürgen Bereiter-Hahn
- Institut für Zellbiologie und Neurowissenschaften, Goethe Universität Frankfurt am Main, Max-von-Lauestrasse 13, 60438, Frankfurt am Main, Germany,
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45
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Gouspillou G, Sgarioto N, Kapchinsky S, Purves-Smith F, Norris B, Pion CH, Barbat-Artigas S, Lemieux F, Taivassalo T, Morais JA, Aubertin-Leheudre M, Hepple RT. Increased sensitivity to mitochondrial permeability transition and myonuclear translocation of endonuclease G in atrophied muscle of physically active older humans. FASEB J 2013; 28:1621-33. [PMID: 24371120 DOI: 10.1096/fj.13-242750] [Citation(s) in RCA: 149] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Mitochondrial dysfunction is implicated in skeletal muscle atrophy and dysfunction with aging, with strong support for an increased mitochondrial-mediated apoptosis in sedentary rodent models. Whether this applies to aged human muscle is unknown, nor is it clear whether these changes are caused by sedentary behavior. Thus, we examined mitochondrial function [respiration, reactive oxygen species (ROS) emission, and calcium retention capacity (CRC)] in permeabilized myofibers obtained from vastus lateralis muscle biopsies of healthy physically active young (23.7±2.7 yr; mean±SD) and older (71.2±4.9 yr) men. Although mitochondrial ROS and maximal respiratory capacity were unaffected, the acceptor control ratio was reduced by 18% with aging, suggesting mild uncoupling of oxidative phosphorylation. CRC was reduced by 50% with aging, indicating sensitization of the mitochondrial permeability transition pore (mPTP) to apoptosis. Consistent with the mPTP sensitization, older muscles showed a 3-fold greater fraction of endonuclease G (a mitochondrial proapoptotic factor)-positive myonuclei. Aged muscles also had lower mitophagic potential, based on a 43% reduction in Parkin to the voltage-dependent anion channel (VDAC) protein ratio. Collectively, these results show that mitochondrial-mediated apoptotic signaling is increased in older human muscle and suggest that accumulation of dysfunctional mitochondria with exaggerated apoptotic sensitivity is due to impaired mitophagy.
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Affiliation(s)
- Gilles Gouspillou
- 1Department of Critical Care Medicine, Royal Victoria Hospital, 687 Pine Ave. W., Montreal, QC, Canada H3A 1A.
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46
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Tzika AA, Fontes-Oliveira CC, Shestov AA, Constantinou C, Psychogios N, Righi V, Mintzopoulos D, Busquets S, Lopez-Soriano FJ, Milot S, Lepine F, Mindrinos MN, Rahme LG, Argiles JM. Skeletal muscle mitochondrial uncoupling in a murine cancer cachexia model. Int J Oncol 2013; 43:886-94. [PMID: 23817738 PMCID: PMC6903904 DOI: 10.3892/ijo.2013.1998] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 01/14/2013] [Indexed: 12/20/2022] Open
Abstract
Approximately half of all cancer patients present with cachexia, a condition in which disease-associated metabolic changes lead to a severe loss of skeletal muscle mass. Working toward an integrated and mechanistic view of cancer cachexia, we investigated the hypothesis that cancer promotes mitochondrial uncoupling in skeletal muscle. We subjected mice to in vivo phosphorous-31 nuclear magnetic resonance (31P NMR) spectroscopy and subjected murine skeletal muscle samples to gas chromatography/mass spectrometry (GC/MS). The mice used in both experiments were Lewis lung carcinoma models of cancer cachexia. A novel ‘fragmented mass isotopomer’ approach was used in our dynamic analysis of 13C mass isotopomer data. Our 31P NMR and GC/MS results indicated that the adenosine triphosphate (ATP) synthesis rate and tricarboxylic acid (TCA) cycle flux were reduced by 49% and 22%, respectively, in the cancer-bearing mice (p<0.008; t-test vs. controls). The ratio of ATP synthesis rate to the TCA cycle flux (an index of mitochondrial coupling) was reduced by 32% in the cancer-bearing mice (p=0.036; t-test vs. controls). Genomic analysis revealed aberrant expression levels for key regulatory genes and transmission electron microscopy (TEM) revealed ultrastructural abnormalities in the muscle fiber, consistent with the presence of abnormal, giant mitochondria. Taken together, these data suggest that mitochondrial uncoupling occurs in cancer cachexia and thus point to the mitochondria as a potential pharmaceutical target for the treatment of cachexia. These findings may prove relevant to elucidating the mechanisms underlying skeletal muscle wasting observed in other chronic diseases, as well as in aging.
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Affiliation(s)
- A Aria Tzika
- NMR Surgical Laboratory, Department of Surgery, Massachusetts General Hospital and Shriners Burn Institute, Harvard Medical School, Boston, MA 02114, USA
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47
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Satori CP, Henderson MM, Krautkramer EA, Kostal V, Distefano MM, Arriaga EA. Bioanalysis of eukaryotic organelles. Chem Rev 2013; 113:2733-811. [PMID: 23570618 PMCID: PMC3676536 DOI: 10.1021/cr300354g] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Chad P. Satori
- Department of Chemistry, University of Minnesota, Twin Cities, Minneapolis, MN, USA, 55455
| | - Michelle M. Henderson
- Department of Chemistry, University of Minnesota, Twin Cities, Minneapolis, MN, USA, 55455
| | - Elyse A. Krautkramer
- Department of Chemistry, University of Minnesota, Twin Cities, Minneapolis, MN, USA, 55455
| | - Vratislav Kostal
- Tescan, Libusina trida 21, Brno, 623 00, Czech Republic
- Institute of Analytical Chemistry ASCR, Veveri 97, Brno, 602 00, Czech Republic
| | - Mark M. Distefano
- Department of Chemistry, University of Minnesota, Twin Cities, Minneapolis, MN, USA, 55455
| | - Edgar A. Arriaga
- Department of Chemistry, University of Minnesota, Twin Cities, Minneapolis, MN, USA, 55455
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48
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Gouspillou G, Hepple RT. Facts and controversies in our understanding of how caloric restriction impacts the mitochondrion. Exp Gerontol 2013; 48:1075-84. [PMID: 23523973 DOI: 10.1016/j.exger.2013.03.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 02/26/2013] [Accepted: 03/11/2013] [Indexed: 12/11/2022]
Abstract
Caloric restriction (CR) has pronounced benefits in promoting healthy aging. Amongst the most frequently implicated physiological mechanisms implicated in this benefit is altered mitochondrial function. Whereas a reduction in mitochondrial reactive oxygen species (ROS) production is a widely consistent effect of CR, an increase in mitochondrial biogenesis, which is accepted by many as fact, is contradicted on several levels, most critically by a lack of increase in mitochondrial protein synthesis rate in vivo. Furthermore, an increase in PGC-1α protein and markers of mitochondrial content with CR is a highly variable observation between studies. On the other hand, deacetylation of several mitochondrial proteins by the sirtuin, Sirt3, is an increasingly reported observation and at least so far, this observation is consistent between studies. Notwithstanding this point, the controversies evident in the published literature underscore the significant questions that remain in our understanding of how CR impacts the mitochondrion and suggest we have yet to fully understand the complexities herein.
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Affiliation(s)
- Gilles Gouspillou
- McGill University Health Center, Department of Kinesiology, McGill University, Montreal, QC, Canada
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49
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Joseph AM, Adhihetty PJ, Buford TW, Wohlgemuth SE, Lees HA, Nguyen LMD, Aranda JM, Sandesara BD, Pahor M, Manini TM, Marzetti E, Leeuwenburgh C. The impact of aging on mitochondrial function and biogenesis pathways in skeletal muscle of sedentary high- and low-functioning elderly individuals. Aging Cell 2012; 11:801-9. [PMID: 22681576 DOI: 10.1111/j.1474-9726.2012.00844.x] [Citation(s) in RCA: 260] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
Age-related loss of muscle mass and strength (sarcopenia) leads to a decline in physical function and frailty in the elderly. Among the many proposed underlying causes of sarcopenia, mitochondrial dysfunction is inherent in a variety of aged tissues. The intent of this study was to examine the effect of aging on key groups of regulatory proteins involved in mitochondrial biogenesis and how this relates to physical performance in two groups of sedentary elderly participants, classified as high- and low-functioning based on the Short Physical Performance Battery test. Muscle mass was decreased by 38% and 30% in low-functioning elderly (LFE) participants when compared to young and high-functioning elderly participants, respectively, and positively correlated to physical performance. Mitochondrial respiration in permeabilized muscle fibers was reduced (41%) in the LFE group when compared to the young, and this was associated with a 30% decline in cytochrome c oxidase activity. Levels of key metabolic regulators, SIRT3 and PGC-1α, were significantly reduced (50%) in both groups of elderly participants when compared to young. Similarly, the fusion protein OPA1 was lower in muscle from elderly subjects; however, no changes were detected in Mfn2, Drp1 or Fis1 among the groups. In contrast, protein import machinery components Tom22 and cHsp70 were increased in the LFE group when compared to the young. This study suggests that aging in skeletal muscle is associated with impaired mitochondrial function and altered biogenesis pathways and that this may contribute to muscle atrophy and the decline in muscle performance observed in the elderly population.
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Affiliation(s)
- Anna-Maria Joseph
- Department of Aging and Geriatric Research, University of Florida, Gainesville, FL 32610, USA
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50
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Anand RK, Chiu DT. Analytical tools for characterizing heterogeneity in organelle content. Curr Opin Chem Biol 2012; 16:391-9. [PMID: 22694875 DOI: 10.1016/j.cbpa.2012.05.187] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Accepted: 05/10/2012] [Indexed: 11/16/2022]
Abstract
Heterogeneity in the content and function of subcellular organelles on the intercellular and intracellular level plays an important role in determining cell fate. These variations extend to normal-state and disease-state cellular functions and responses to environmental stimuli, such as oxidative stress and therapeutic drugs. Analytical tools to characterize variation in all types of organelles are essential to provide insights that can lead to advances in medicine, such as therapies targeted to specific subcellular regions. In this review, we discuss analytical techniques for interrogating individual intact organelles (e.g. mitochondria and synaptic vesicles) and lysates in a high-throughput manner, including a recently developed nanoscale fluorescence-activated subcellular sorter and techniques based on capillary electrophoresis with laser-induced fluorescence detection. We then highlight the advantages that droplet microfluidics offers for probing subcellular heterogeneity.
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Affiliation(s)
- Robbyn K Anand
- Department of Chemistry, University of Washington, Seattle, WA 98195-1700, USA
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