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Morandini AC, Ramos-Junior ES. Mitochondrial function in oral health and disease. J Immunol Methods 2024; 532:113729. [PMID: 39067635 DOI: 10.1016/j.jim.2024.113729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 07/22/2024] [Accepted: 07/22/2024] [Indexed: 07/30/2024]
Abstract
Monitoring mitochondrial function and mitochondrial quality control in tissues is a crucial aspect of understanding cellular health and dysfunction, which may inform about the pathogenesis of several conditions associated with aging, including chronic inflammatory conditions, neurodegenerative disorders and metabolic diseases. This process involves assessing the functionality, integrity, and abundance of mitochondria within cells. Several lines of evidence have explored techniques and methods for monitoring mitochondrial quality control in tissues. In this review, we summarize and provide our perspective considering the latest evidence in mitochondrial function and mitochondrial quality control in oral health and disease with a particular focus in periodontal inflammation. This research is significant for gaining insights into cellular health and the pathophysiology of periodontal disease, a dysbiosis-related, immune mediated and age-associated chronic condition representing a significant burden to US elderly population. Approaches for assessing mitochondrial health status reviewed here include assessing mitochondrial dynamics, mitophagy, mitochondrial biogenesis, oxidative stress, electron transport chain function and metabolomics. Such assessments help researchers comprehend the role of mitochondrial function in cellular homeostasis and its implications for oral diseases.
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Affiliation(s)
- Ana Carolina Morandini
- Department of Oral Biology and Diagnostic Sciences, Dental College of Georgia at Augusta University, Augusta, GA, USA; Department of Periodontics, Dental College of Georgia at Augusta University, Augusta, GA, USA.
| | - Erivan S Ramos-Junior
- Department of Oral Biology and Diagnostic Sciences, Dental College of Georgia at Augusta University, Augusta, GA, USA
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2
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Cao H, Zhou X, Xu B, Hu H, Guo J, Wang M, Li N, Jun Z. Advances in the study of mitophagy in osteoarthritis. J Zhejiang Univ Sci B 2024; 25:197-211. [PMID: 38453635 PMCID: PMC10918408 DOI: 10.1631/jzus.b2300402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Accepted: 08/21/2023] [Indexed: 03/09/2024]
Abstract
Osteoarthritis (OA), characterized by cartilage degeneration, synovial inflammation, and subchondral bone remodeling, is among the most common musculoskeletal disorders globally in people over 60 years of age. The initiation and progression of OA involves the abnormal metabolism of chondrocytes as an important pathogenic process. Cartilage degeneration features mitochondrial dysfunction as one of the important causative factors of abnormal chondrocyte metabolism. Therefore, maintaining mitochondrial homeostasis is an important strategy to mitigate OA. Mitophagy is a vital process for autophagosomes to target, engulf, and remove damaged and dysfunctional mitochondria, thereby maintaining mitochondrial homeostasis. Cumulative studies have revealed a strong association between mitophagy and OA, suggesting that the regulation of mitophagy may be a novel therapeutic direction for OA. By reviewing the literature on mitophagy and OA published in recent years, this paper elaborates the potential mechanism of mitophagy regulating OA, thus providing a theoretical basis for studies related to mitophagy to develop new treatment options for OA.
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Affiliation(s)
- Hong Cao
- Department of Sport Rehabilitation, Shanghai University of Sport, Shanghai 200438, China
- National Key Laboratory of Immunity and Inflammation, Naval Medical University, Shanghai 200433, China
| | - Xuchang Zhou
- Department of Sport Rehabilitation, Shanghai University of Sport, Shanghai 200438, China
- School of Sport Medicine and Rehabilitation, Beijing Sport University, Beijing 100084, China
| | - Bowen Xu
- National Key Laboratory of Immunity and Inflammation, Naval Medical University, Shanghai 200433, China
| | - Han Hu
- National Key Laboratory of Immunity and Inflammation, Naval Medical University, Shanghai 200433, China
| | - Jianming Guo
- Department of Sport Rehabilitation, Shanghai University of Sport, Shanghai 200438, China
| | - Miao Wang
- Department of Sport Rehabilitation, Shanghai University of Sport, Shanghai 200438, China
| | - Nan Li
- National Key Laboratory of Immunity and Inflammation, Naval Medical University, Shanghai 200433, China.
| | - Zou Jun
- Department of Sport Rehabilitation, Shanghai University of Sport, Shanghai 200438, China.
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3
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Franco A, Li J, Kelly DP, Hershberger RE, Marian AJ, Lewis RM, Song M, Dang X, Schmidt AD, Mathyer ME, Edwards JR, Strong CDG, Dorn GW. A human mitofusin 2 mutation can cause mitophagic cardiomyopathy. eLife 2023; 12:e84235. [PMID: 37910431 PMCID: PMC10619978 DOI: 10.7554/elife.84235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Accepted: 09/26/2023] [Indexed: 11/03/2023] Open
Abstract
Cardiac muscle has the highest mitochondrial density of any human tissue, but mitochondrial dysfunction is not a recognized cause of isolated cardiomyopathy. Here, we determined that the rare mitofusin (MFN) 2 R400Q mutation is 15-20× over-represented in clinical cardiomyopathy, whereas this specific mutation is not reported as a cause of MFN2 mutant-induced peripheral neuropathy, Charcot-Marie-Tooth disease type 2A (CMT2A). Accordingly, we interrogated the enzymatic, biophysical, and functional characteristics of MFN2 Q400 versus wild-type and CMT2A-causing MFN2 mutants. All MFN2 mutants had impaired mitochondrial fusion, the canonical MFN2 function. Compared to MFN2 T105M that lacked catalytic GTPase activity and exhibited normal activation-induced changes in conformation, MFN2 R400Q and M376A had normal GTPase activity with impaired conformational shifting. MFN2 R400Q did not suppress mitochondrial motility, provoke mitochondrial depolarization, or dominantly suppress mitochondrial respiration like MFN2 T105M. By contrast to MFN2 T105M and M376A, MFN2 R400Q was uniquely defective in recruiting Parkin to mitochondria. CRISPR editing of the R400Q mutation into the mouse Mfn2 gene induced perinatal cardiomyopathy with no other organ involvement; knock-in of Mfn2 T105M or M376V did not affect the heart. RNA sequencing and metabolomics of cardiomyopathic Mfn2 Q/Q400 hearts revealed signature abnormalities recapitulating experimental mitophagic cardiomyopathy. Indeed, cultured cardiomyoblasts and in vivo cardiomyocytes expressing MFN2 Q400 had mitophagy defects with increased sensitivity to doxorubicin. MFN2 R400Q is the first known natural mitophagy-defective MFN2 mutant. Its unique profile of dysfunction evokes mitophagic cardiomyopathy, suggesting a mechanism for enrichment in clinical cardiomyopathy.
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Affiliation(s)
- Antonietta Franco
- Department of Internal Medicine, Pharmacogenomics, Washington University School of MedicineSt LouisUnited States
| | - Jiajia Li
- Department of Internal Medicine, Pharmacogenomics, Washington University School of MedicineSt LouisUnited States
| | - Daniel P Kelly
- Department of Medicine, Cardiovascular Institute, Perelman School of Medicine, University of PennsylvaniaPhiladelphiaUnited States
| | - Ray E Hershberger
- Department of Internal Medicine, Divisions of Human Genetics and Cardiovascular Medicine, Ohio State UniversityColumbusUnited States
| | - Ali J Marian
- Center for Cardiovascular Genetic Research, University of Texas Health Science Center at HoustonHoustonUnited States
| | - Renate M Lewis
- Department of Neurology, Washington University School of MedicineSt. LouisUnited States
| | - Moshi Song
- Department of Internal Medicine, Pharmacogenomics, Washington University School of MedicineSt LouisUnited States
| | - Xiawei Dang
- Department of Internal Medicine, Pharmacogenomics, Washington University School of MedicineSt LouisUnited States
| | - Alina D Schmidt
- Department of Internal Medicine (Dermatology), Washington University School of MedicineSt. LouisUnited States
| | - Mary E Mathyer
- Department of Internal Medicine (Dermatology), Washington University School of MedicineSt. LouisUnited States
| | - John R Edwards
- Department of Internal Medicine, Pharmacogenomics, Washington University School of MedicineSt LouisUnited States
| | - Cristina de Guzman Strong
- Department of Internal Medicine (Dermatology), Washington University School of MedicineSt. LouisUnited States
| | - Gerald W Dorn
- Department of Internal Medicine, Pharmacogenomics, Washington University School of MedicineSt LouisUnited States
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Zhang C, Ding WX. Caveats to link in vitro mechanistic mitophagy studies to the pathogenesis of non-alcoholic steatohepatitis. J Hepatol 2023; 79:e162-e163. [PMID: 37156303 DOI: 10.1016/j.jhep.2023.04.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 04/29/2023] [Indexed: 05/10/2023]
Affiliation(s)
- Chen Zhang
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas, 66160, USA; Division of Gastroenterology, Hepatology and Motility, Department of Internal Medicine, University of Kansas Medical Center, Kansas City, Kansas, 66160, USA
| | - Wen-Xing Ding
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas, 66160, USA; Division of Gastroenterology, Hepatology and Motility, Department of Internal Medicine, University of Kansas Medical Center, Kansas City, Kansas, 66160, USA.
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Jiménez-Loygorri JI, Benítez-Fernández R, Viedma-Poyatos Á, Zapata-Muñoz J, Villarejo-Zori B, Gómez-Sintes R, Boya P. Mitophagy in the retina: Viewing mitochondrial homeostasis through a new lens. Prog Retin Eye Res 2023; 96:101205. [PMID: 37454969 DOI: 10.1016/j.preteyeres.2023.101205] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 07/11/2023] [Accepted: 07/13/2023] [Indexed: 07/18/2023]
Abstract
Mitochondrial function is key to support metabolism and homeostasis in the retina, an organ that has one of the highest metabolic rates body-wide and is constantly exposed to photooxidative damage and external stressors. Mitophagy is the selective autophagic degradation of mitochondria within lysosomes, and can be triggered by distinct stimuli such as mitochondrial damage or hypoxia. Here, we review the importance of mitophagy in retinal physiology and pathology. In the developing retina, mitophagy is essential for metabolic reprogramming and differentiation of retina ganglion cells (RGCs). In basal conditions, mitophagy acts as a quality control mechanism, maintaining a healthy mitochondrial pool to meet cellular demands. We summarize the different autophagy- and mitophagy-deficient mouse models described in the literature, and discuss the potential role of mitophagy dysregulation in retinal diseases such as glaucoma, diabetic retinopathy, retinitis pigmentosa, and age-related macular degeneration. Finally, we provide an overview of methods used to monitor mitophagy in vitro, ex vivo, and in vivo. This review highlights the important role of mitophagy in sustaining visual function, and its potential as a putative therapeutic target for retinal and other diseases.
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Affiliation(s)
- Juan Ignacio Jiménez-Loygorri
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain.
| | - Rocío Benítez-Fernández
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain; Departament of Neuroscience and Movement Science, Faculty of Science and Medicine, University of Fribourg, 1700, Fribourg, Switzerland
| | - Álvaro Viedma-Poyatos
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Juan Zapata-Muñoz
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Beatriz Villarejo-Zori
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Raquel Gómez-Sintes
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Patricia Boya
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain; Departament of Neuroscience and Movement Science, Faculty of Science and Medicine, University of Fribourg, 1700, Fribourg, Switzerland.
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6
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Fišar Z, Hroudová J, Zvěřová M, Jirák R, Raboch J, Kitzlerová E. Age-Dependent Alterations in Platelet Mitochondrial Respiration. Biomedicines 2023; 11:1564. [PMID: 37371659 DOI: 10.3390/biomedicines11061564] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 05/25/2023] [Accepted: 05/26/2023] [Indexed: 06/29/2023] Open
Abstract
Mitochondrial dysfunction is an important cellular hallmark of aging and neurodegeneration. Platelets are a useful model to study the systemic manifestations of mitochondrial dysfunction. To evaluate the age dependence of mitochondrial parameters, citrate synthase activity, respiratory chain complex activity, and oxygen consumption kinetics were assessed. The effect of cognitive impairment was examined by comparing the age dependence of mitochondrial parameters in healthy individuals and those with neuropsychiatric disease. The study found a significant negative slope of age-dependence for both the activity of individual mitochondrial enzymes (citrate synthase and complex II) and parameters of mitochondrial respiration in intact platelets (routine respiration, maximum capacity of electron transport system, and respiratory rate after complex I inhibition). However, there was no significant difference in the age-related changes of mitochondrial parameters between individuals with and without cognitive impairment. These findings highlight the potential of measuring mitochondrial respiration in intact platelets as a means to assess age-related mitochondrial dysfunction. The results indicate that drugs and interventions targeting mitochondrial respiration may have the potential to slow down or eliminate certain aging and neurodegenerative processes. Mitochondrial respiration in platelets holds promise as a biomarker of aging, irrespective of the degree of cognitive impairment.
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Affiliation(s)
- Zdeněk Fišar
- Department of Psychiatry, First Faculty of Medicine, Charles University and General University Hospital in Prague, Ke Karlovu 11, 120 00 Prague, Czech Republic
| | - Jana Hroudová
- Department of Psychiatry, First Faculty of Medicine, Charles University and General University Hospital in Prague, Ke Karlovu 11, 120 00 Prague, Czech Republic
| | - Martina Zvěřová
- Department of Psychiatry, First Faculty of Medicine, Charles University and General University Hospital in Prague, Ke Karlovu 11, 120 00 Prague, Czech Republic
| | - Roman Jirák
- Department of Psychiatry, First Faculty of Medicine, Charles University and General University Hospital in Prague, Ke Karlovu 11, 120 00 Prague, Czech Republic
| | - Jiří Raboch
- Department of Psychiatry, First Faculty of Medicine, Charles University and General University Hospital in Prague, Ke Karlovu 11, 120 00 Prague, Czech Republic
| | - Eva Kitzlerová
- Department of Psychiatry, First Faculty of Medicine, Charles University and General University Hospital in Prague, Ke Karlovu 11, 120 00 Prague, Czech Republic
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Ma X, Ding WX. Methods for Monitoring Mitochondrial Biogenesis and Turnover in Cultured Hepatocytes and Mouse Liver Using MitoTimer Reporter Assay. Methods Mol Biol 2023; 2675:97-107. [PMID: 37258758 DOI: 10.1007/978-1-0716-3247-5_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Mitochondrial biogenesis and turnover rate are critical to maintain homeostasis of the intracellular mitochondrial pool. Altered mitochondrial biogenesis and mitophagy are closely related to many chronic diseases, highlighting the importance of mitochondrial stasis in various pathological conditions including liver diseases. We describe a detailed protocol for monitoring mitochondrial lifecycle in primary cultured mouse hepatocytes and mouse liver using the dual color fluorescence-based imaging of MitoTimer. Three types of mitochondria were visualized in mouse hepatocytes: green-only mitochondria (newly synthesized mitochondria), red-only mitochondria (old/aging mitochondria), as well as the majority of yellow mitochondria (representing an intermediate stage of mitochondria). The ratio of red/green fluorescence in each cell will be used to track mitochondrial aging. Super-resolution microscopy analysis revealed that majority of mitochondria were spatially heterogeneous with proteins from simultaneous new synthesis, maturation, and turnover in hepatocytes. MitoTimer reporter assay can specifically target to mitochondria and be used to monitor mitochondrial biogenesis and maturation as well as turnover in vitro and in vivo.
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Affiliation(s)
- Xiaowen Ma
- Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center, Kansas City, KS, USA
| | - Wen-Xing Ding
- Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center, Kansas City, KS, USA.
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8
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Mitophagy—A New Target of Bone Disease. Biomolecules 2022; 12:biom12101420. [PMID: 36291629 PMCID: PMC9599755 DOI: 10.3390/biom12101420] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 09/20/2022] [Accepted: 09/28/2022] [Indexed: 01/17/2023] Open
Abstract
Bone diseases are usually caused by abnormal metabolism and death of cells in bones, including osteoblasts, osteoclasts, osteocytes, chondrocytes, and bone marrow mesenchymal stem cells. Mitochondrial dysfunction, as an important cause of abnormal cell metabolism, is widely involved in the occurrence and progression of multiple bone diseases, including osteoarthritis, intervertebral disc degeneration, osteoporosis, and osteosarcoma. As selective mitochondrial autophagy for damaged or dysfunctional mitochondria, mitophagy is closely related to mitochondrial quality control and homeostasis. Accumulating evidence suggests that mitophagy plays an important regulatory role in bone disease, indicating that regulating the level of mitophagy may be a new strategy for bone-related diseases. Therefore, by reviewing the relevant literature in recent years, this paper reviews the potential mechanism of mitophagy in bone-related diseases, including osteoarthritis, intervertebral disc degeneration, osteoporosis, and osteosarcoma, to provide a theoretical basis for the related research of mitophagy in bone diseases.
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9
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Bharti K, den Hollander AI, Lakkaraju A, Sinha D, Williams DS, Finnemann SC, Bowes-Rickman C, Malek G, D'Amore PA. Cell culture models to study retinal pigment epithelium-related pathogenesis in age-related macular degeneration. Exp Eye Res 2022; 222:109170. [PMID: 35835183 PMCID: PMC9444976 DOI: 10.1016/j.exer.2022.109170] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 06/23/2022] [Accepted: 06/29/2022] [Indexed: 11/04/2022]
Abstract
Age-related macular degeneration (AMD) is a disease that affects the macula - the central part of the retina. It is a leading cause of irreversible vision loss in the elderly. AMD onset is marked by the presence of lipid- and protein-rich extracellular deposits beneath the retinal pigment epithelium (RPE), a monolayer of polarized, pigmented epithelial cells located between the photoreceptors and the choroidal blood supply. Progression of AMD to the late nonexudative "dry" stage of AMD, also called geographic atrophy, is linked to progressive loss of areas of the RPE, photoreceptors, and underlying choriocapillaris leading to a severe decline in patients' vision. Differential susceptibility of macular RPE in AMD and the lack of an anatomical macula in most lab animal models has promoted the use of in vitro models of the RPE. In addition, the need for high throughput platforms to test potential therapies has driven the creation and characterization of in vitro model systems that recapitulate morphologic and functional abnormalities associated with human AMD. These models range from spontaneously formed cell line ARPE19, immortalized cell lines such as hTERT-RPE1, RPE-J, and D407, to primary human (fetal or adult) or animal (mouse and pig) RPE cells, and embryonic and induced pluripotent stem cell (iPSC) derived RPE. Hallmark RPE phenotypes, such as cobblestone morphology, pigmentation, and polarization, vary significantly betweendifferent models and culture conditions used in different labs, which would directly impact their usability for investigating different aspects of AMD biology. Here the AMD Disease Models task group of the Ryan Initiative for Macular Research (RIMR) provides a summary of several currently used in vitro RPE models, historical aspects of their development, RPE phenotypes that are attainable in these models, their ability to model different aspects of AMD pathophysiology, and pros/cons for their use in the RPE and AMD fields. In addition, due to the burgeoning use of iPSC derived RPE cells, the critical need for developing standards for differentiating and rigorously characterizing RPE cell appearance, morphology, and function are discussed.
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Affiliation(s)
- Kapil Bharti
- Ocular and Stem Cell Translational Research Section, National Eye Institute, NIH, Bethesda, MD, USA.
| | - Anneke I den Hollander
- Department of Ophthalmology, Radboud University Medical Center, Nijmegen, the Netherlands; AbbVie, Genomics Research Center, Cambridge, MA, USA.
| | - Aparna Lakkaraju
- Department of Ophthalmology, School of Medicine, University of California, San Francisco, USA.
| | - Debasish Sinha
- Department of Ophthalmology, Cell Biology and Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - David S Williams
- Stein Eye Institute, Departments of Ophthalmology and Neurobiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA.
| | - Silvia C Finnemann
- Center of Cancer, Genetic Diseases, and Gene Regulation, Department of Biological Sciences, Fordham University, Bronx, NY, USA.
| | - Catherine Bowes-Rickman
- Duke Eye Center, Department of Ophthalmology, Duke University School of Medicine, Durham, NC, USA; Department of Cell Biology, Duke University School of Medicine, Durham, NC, USA.
| | - Goldis Malek
- Duke Eye Center, Department of Ophthalmology, Duke University School of Medicine, Durham, NC, USA; Department of Pathology, Duke University School of Medicine, Durham, NC, USA.
| | - Patricia A D'Amore
- Mass Eye and Ear, Departments of Ophthalmology and Pathology, Harvard Medical School, Boston, MA, USA.
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Liu Y, Wang M, Hou XO, Hu LF. Roles of microglial mitophagy in neurological disorders. Front Aging Neurosci 2022; 14:979869. [PMID: 36034136 PMCID: PMC9399802 DOI: 10.3389/fnagi.2022.979869] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 07/25/2022] [Indexed: 11/14/2022] Open
Abstract
Microglia are the resident innate immune cells in the central nervous system (CNS) that serve as the first line innate immunity in response to pathogen invasion, ischemia and other pathological stimuli. Once activated, they rapidly release a variety of inflammatory cytokines and phagocytose pathogens or cell debris (termed neuroinflammation), which is beneficial for maintaining brain homeostasis if appropriately activated. However, excessive or uncontrolled neuroinflammation may damage neurons and exacerbate the pathologies in neurological disorders. Microglia are highly dynamic cells, dependent on energy supply from mitochondria. Moreover, dysfunctional mitochondria can serve as a signaling platform to facilitate innate immune responses in microglia. Mitophagy is a means of clearing damaged or redundant mitochondria, playing a critical role in the quality control of mitochondrial homeostasis and turnover. Mounting evidence has shown that mitophagy not only limits the inflammatory response in microglia but also affects their phagocytosis, whereas mitochondria dysfunction and mitophagy defects are associated with aging and neurological disorders. Therefore, targeting microglial mitophagy is a promising therapeutic strategy for neurological disorders. This article reviews and highlights the role and regulation of mitophagy in microglia in neurological conditions, and the research progress in manipulating microglial mitophagy and future directions in this field are also discussed.
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Affiliation(s)
- Yang Liu
- Department of Neurology and Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou, China
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou, China
| | - Miao Wang
- Department of Neurology and Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou, China
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou, China
| | - Xiao-Ou Hou
- Department of Neurology and Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou, China
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou, China
- *Correspondence: Xiao-Ou Hou,
| | - Li-Fang Hu
- Department of Neurology and Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou, China
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou, China
- Li-Fang Hu,
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11
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Mendoza A, Karch J. Keeping the beat against time: Mitochondrial fitness in the aging heart. FRONTIERS IN AGING 2022; 3:951417. [PMID: 35958271 PMCID: PMC9360554 DOI: 10.3389/fragi.2022.951417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 06/30/2022] [Indexed: 11/21/2022]
Abstract
The process of aging strongly correlates with maladaptive architectural, mechanical, and biochemical alterations that contribute to the decline in cardiac function. Consequently, aging is a major risk factor for the development of heart disease, the leading cause of death in the developed world. In this review, we will summarize the classic and recently uncovered pathological changes within the aged heart with an emphasis on the mitochondria. Specifically, we describe the metabolic changes that occur in the aging heart as well as the loss of mitochondrial fitness and function and how these factors contribute to the decline in cardiomyocyte number. In addition, we highlight recent pharmacological, genetic, or behavioral therapeutic intervention advancements that may alleviate age-related cardiac decline.
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Affiliation(s)
- Arielys Mendoza
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, United States
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, United States
| | - Jason Karch
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, United States
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, United States
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12
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Role of Mitophagy in the Pathogenesis of Stroke: From Mechanism to Therapy. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:6232902. [PMID: 35265262 PMCID: PMC8898771 DOI: 10.1155/2022/6232902] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 02/02/2022] [Indexed: 12/15/2022]
Abstract
Mitochondria can supply adenosine triphosphate (ATP) to the tissue, which can regulate metabolism during the pathologic process and is also involved in the pathophysiology of neuronal injury after stroke. Recent studies have suggested that selective autophagy could play important roles in the pathophysiological process of stroke, especially mitophagy. It is usually mediated by the PINK1/Parkin-independent pathway or PINK1/Parkin-dependent pathway. Moreover, mitophagy may be a potential target in the therapy of stroke because the control of mitophagy is neuroprotective in stroke in vitro and in vivo. In this review, we briefly summarize recent researches in mitophagy, introduce the role of mitophagy in the pathogenesis of stroke, then highlight the strategies targeting mitophagy in the treatment of stroke, and finally propose several issues in the treatment of stroke by targeting mitophagy.
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Chung KH, Park SB, Streckmann F, Wiskemann J, Mohile N, Kleckner AS, Colloca L, Dorsey SG, Kleckner IR. Mechanisms, Mediators, and Moderators of the Effects of Exercise on Chemotherapy-Induced Peripheral Neuropathy. Cancers (Basel) 2022; 14:1224. [PMID: 35267533 PMCID: PMC8909585 DOI: 10.3390/cancers14051224] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 02/15/2022] [Accepted: 02/22/2022] [Indexed: 12/18/2022] Open
Abstract
Chemotherapy-induced peripheral neuropathy (CIPN) is an adverse effect of neurotoxic antineoplastic agents commonly used to treat cancer. Patients with CIPN experience debilitating signs and symptoms, such as combinations of tingling, numbness, pain, and cramping in the hands and feet that inhibit their daily function. Among the limited prevention and treatment options for CIPN, exercise has emerged as a promising new intervention that has been investigated in approximately two dozen clinical trials to date. As additional studies test and suggest the efficacy of exercise in treating CIPN, it is becoming more critical to develop mechanistic understanding of the effects of exercise in order to tailor it to best treat CIPN symptoms and identify who will benefit most. To address the current lack of clarity around the effect of exercise on CIPN, we reviewed the key potential mechanisms (e.g., neurophysiological and psychosocial factors), mediators (e.g., anti-inflammatory cytokines, self-efficacy, and social support), and moderators (e.g., age, sex, body mass index, physical fitness, exercise dose, exercise adherence, and timing of exercise) that may illuminate the relationship between exercise and CIPN improvement. Our review is based on the studies that tested the use of exercise for patients with CIPN, patients with other types of neuropathies, and healthy adults. The discussion presented herein may be used to (1) guide oncologists in predicting which symptoms are best targeted by specific exercise programs, (2) enable clinicians to tailor exercise prescriptions to patients based on specific characteristics, and (3) inform future research and biomarkers on the relationship between exercise and CIPN.
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Affiliation(s)
- Kaitlin H. Chung
- Department of Surgery, Wilmot Cancer Institute, University of Rochester Medical Center, 265 Crittenden Blvd., Box CU 420658, Rochester, NY 14642, USA; (K.H.C.); (A.S.K.)
| | - Susanna B. Park
- Faculty of Medicine and Health, School of Medical Sciences, Brain and Mind Centre, The University of Sydney, Sydney, NSW 2006, Australia;
| | - Fiona Streckmann
- Department of Sport, Exercise and Health, University of Basel, 4052 Basel, Switzerland;
- Department of Oncology, University Hospital Basel, 4031 Basel, Switzerland
| | - Joachim Wiskemann
- Department of Medical Oncology, National Center for Tumor Diseases and Heidelberg University Hospital, 69120 Heidelberg, Germany;
| | - Nimish Mohile
- Department of Neurology, University of Rochester Medical Center, Rochester, NY 14642, USA;
| | - Amber S. Kleckner
- Department of Surgery, Wilmot Cancer Institute, University of Rochester Medical Center, 265 Crittenden Blvd., Box CU 420658, Rochester, NY 14642, USA; (K.H.C.); (A.S.K.)
- Department of Pain and Translational Symptom Science, University of Maryland School of Nursing, Baltimore, MD 21201, USA; (L.C.); (S.G.D.)
- Center to Advance Chronic Pain Research (CACPR), University of Maryland, Baltimore, MD 21201, USA
| | - Luana Colloca
- Department of Pain and Translational Symptom Science, University of Maryland School of Nursing, Baltimore, MD 21201, USA; (L.C.); (S.G.D.)
- Center to Advance Chronic Pain Research (CACPR), University of Maryland, Baltimore, MD 21201, USA
| | - Susan G. Dorsey
- Department of Pain and Translational Symptom Science, University of Maryland School of Nursing, Baltimore, MD 21201, USA; (L.C.); (S.G.D.)
- Center to Advance Chronic Pain Research (CACPR), University of Maryland, Baltimore, MD 21201, USA
| | - Ian R. Kleckner
- Department of Surgery, Wilmot Cancer Institute, University of Rochester Medical Center, 265 Crittenden Blvd., Box CU 420658, Rochester, NY 14642, USA; (K.H.C.); (A.S.K.)
- Department of Pain and Translational Symptom Science, University of Maryland School of Nursing, Baltimore, MD 21201, USA; (L.C.); (S.G.D.)
- Center to Advance Chronic Pain Research (CACPR), University of Maryland, Baltimore, MD 21201, USA
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14
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Gowda P, Reddy PH, Kumar S. Deregulated mitochondrial microRNAs in Alzheimer's disease: Focus on synapse and mitochondria. Ageing Res Rev 2022; 73:101529. [PMID: 34813976 PMCID: PMC8692431 DOI: 10.1016/j.arr.2021.101529] [Citation(s) in RCA: 61] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Revised: 10/17/2021] [Accepted: 11/16/2021] [Indexed: 01/03/2023]
Abstract
Alzheimer's disease (AD) is the most common cause of dementia and is currently one of the biggest public health concerns in the world. Mitochondrial dysfunction in neurons is one of the major hallmarks of AD. Emerging evidence suggests that mitochondrial miRNAs potentially play important roles in the mitochondrial dysfunctions, focusing on synapse in AD progression. In this meta-analysis paper, a comprehensive literature review was conducted to identify and discuss the (1) role of mitochondrial miRNAs that regulate mitochondrial and synaptic functions; (2) the role of various factors such as mitochondrial dynamics, biogenesis, calcium signaling, biological sex, and aging on synapse and mitochondrial function; (3) how synapse damage and mitochondrial dysfunctions contribute to AD; (4) the structure and function of synapse and mitochondria in the disease process; (5) latest research developments in synapse and mitochondria in healthy and disease states; and (6) therapeutic strategies that improve synaptic and mitochondrial functions in AD. Specifically, we discussed how differences in the expression of mitochondrial miRNAs affect ATP production, oxidative stress, mitophagy, bioenergetics, mitochondrial dynamics, synaptic activity, synaptic plasticity, neurotransmission, and synaptotoxicity in neurons observed during AD. However, more research is needed to confirm the locations and roles of individual mitochondrial miRNAs in the development of AD.
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Affiliation(s)
- Prashanth Gowda
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA; Neuroscience & Pharmacology, Texas Tech University Health Sciences Center, Lubbock, TX, USA; Neurology, Departments of School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA; Public Health Department of Graduate School of Biomedical Sciences, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - P Hemachandra Reddy
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA; Neuroscience & Pharmacology, Texas Tech University Health Sciences Center, Lubbock, TX, USA; Neurology, Departments of School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA; Public Health Department of Graduate School of Biomedical Sciences, Texas Tech University Health Sciences Center, Lubbock, TX, USA; Department of Speech, Language and Hearing Sciences, School Health Professions, Texas Tech University Health Sciences Center, Lubbock, TX, USA.
| | - Subodh Kumar
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA.
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15
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The zinc transporter ZIP7 (Slc39a7) controls myocardial reperfusion injury by regulating mitophagy. Basic Res Cardiol 2021; 116:54. [PMID: 34581906 DOI: 10.1007/s00395-021-00894-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 09/16/2021] [Accepted: 09/16/2021] [Indexed: 10/20/2022]
Abstract
Whereas elimination of damaged mitochondria by mitophagy is proposed to be cardioprotective, the regulation of mitophagy at reperfusion and the underlying mechanism remain elusive. Since mitochondrial Zn2+ may control mitophagy by regulating mitochondrial membrane potential (MMP), we hypothesized that the zinc transporter ZIP7 that controls Zn2+ levels within mitochondria would contribute to reperfusion injury by regulating mitophagy. Mouse hearts were subjected to ischemia/reperfusion in vivo. Mitophagy was evaluated by detecting mitoLC3II, mito-Keima, and mitoQC. ROS were measured with DHE and mitoB. Infarct size was measured with TTC staining. The cardiac-specific ZIP7 conditional knockout mice (ZIP7 cKO) were generated by adopting the CRISPR/Cas9 system. Human heart samples were obtained from donors and recipients of heart transplant surgeries. KO or cKO of ZIP7 increased mitophagy under physiological conditions. Mitophagy was not activated at the early stage of reperfusion in mouse hearts. ZIP7 is upregulated at reperfusion and ZIP7 cKO enhanced mitophagy upon reperfusion. cKO of ZIP7 led to mitochondrial depolarization by increasing mitochondrial Zn2+ and, accumulation of PINK1 and Parkin in mitochondria, suggesting that the decrease in mitochondrial Zn2+ in response to ZIP7 upregulation resulting in mitochondrial hyperpolarization may impede PINK1 and Parkin accumulation in mitochondria. Notably, ZIP7 is markedly upregulated in cardiac mitochondria from patients with heart failure (HF), whereas mitochondrial PINK1 accumulation and mitophagy were suppressed. Furthermore, ZIP7 cKO reduced mitochondrial ROS generation and myocardial infarction via a PINK1-dependet manner, whereas overexpression of ZIP7 exacerbated myocardial infarction. Our findings identify upregulation of ZIP7 leading to suppression of mitophagy as a critical feature of myocardial reperfusion injury. A timely suppression of cardiac ZIP7 upregulation or inactivation of ZIP7 is essential for the treatment of reperfusion injury.
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16
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Wang H, Zheng Y, Huang J, Li J. Mitophagy in Antiviral Immunity. Front Cell Dev Biol 2021; 9:723108. [PMID: 34540840 PMCID: PMC8446632 DOI: 10.3389/fcell.2021.723108] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 08/06/2021] [Indexed: 12/22/2022] Open
Abstract
Mitochondria are important organelles whose primary function is energy production; in addition, they serve as signaling platforms for apoptosis and antiviral immunity. The central role of mitochondria in oxidative phosphorylation and apoptosis requires their quality to be tightly regulated. Mitophagy is the main cellular process responsible for mitochondrial quality control. It selectively sends damaged or excess mitochondria to the lysosomes for degradation and plays a critical role in maintaining cellular homeostasis. However, increasing evidence shows that viruses utilize mitophagy to promote their survival. Viruses use various strategies to manipulate mitophagy to eliminate critical, mitochondria-localized immune molecules in order to escape host immune attacks. In this article, we will review the scientific advances in mitophagy in viral infections and summarize how the host immune system responds to viral infection and how viruses manipulate host mitophagy to evade the host immune system.
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Affiliation(s)
- Hongna Wang
- Affiliated Cancer Hospital and Institute of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Cell Homeostasis and Cancer Research of Guangdong Higher Education Institutes, Guangzhou, China.,GMU-GIBH Joint School of Life Sciences, Guangzhou Medical University, Guangzhou, China
| | - Yongfeng Zheng
- Affiliated Cancer Hospital and Institute of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Cell Homeostasis and Cancer Research of Guangdong Higher Education Institutes, Guangzhou, China
| | - Jieru Huang
- Affiliated Cancer Hospital and Institute of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Cell Homeostasis and Cancer Research of Guangdong Higher Education Institutes, Guangzhou, China
| | - Jin Li
- Affiliated Cancer Hospital and Institute of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Cell Homeostasis and Cancer Research of Guangdong Higher Education Institutes, Guangzhou, China
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17
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Rodriguez YA, Kaur S, Nolte E, Zheng Z, Blagg BSJ, Dobrowsky RT. Novologue Therapy Requires Heat Shock Protein 70 and Thioredoxin-Interacting Protein to Improve Mitochondrial Bioenergetics and Decrease Mitophagy in Diabetic Sensory Neurons. ACS Chem Neurosci 2021; 12:3049-3059. [PMID: 34340312 PMCID: PMC8456717 DOI: 10.1021/acschemneuro.1c00340] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Diabetic peripheral neuropathy (DPN) is a complication of diabetes whose pathophysiology is linked to altered mitochondrial bioenergetics (mtBE). KU-596 is a small molecule neurotherapeutic that reverses symptoms of DPN, improves sensory neuron mtBE, and decreases the pro-oxidant protein, thioredoxin-interacting protein (Txnip) in a heat shock protein 70 (Hsp70)-dependent manner. However, the mechanism by which KU-596 improves mtBE and the role of Txnip in drug efficacy remains unknown. Mitophagy is a quality-control mechanism that selectively targets damaged mitochondria for degradation. The goal of this study was to determine if KU-596 therapy improved DPN, mtBE, and mitophagy in an Hsp70- and Txnip-dependent manner. Mito-QC (MQC) mice express a mitochondrially targeted mCherry-GFP fusion protein that enables visualizing mitophagy. Diabetic MQC, MQC × Hsp70 knockout (KO), and MQC × Txnip KO mice developed sensory and nerve conduction dysfunctions consistent with the onset of DPN. KU-596 therapy improved these measures, and this was dependent on Hsp70 but not Txnip. In MQC mice, diabetes decreased mtBE and increased mitophagy and KU-596 treatment reversed these effects. In contrast, KU-596 was unable to improve mtBE and decrease mitophagy in MQC × Hsp70 and MQC × Txnip KO mice. These data suggest that Txnip is not necessary for the development of the sensory symptoms and mitochondrial dysfunction induced by diabetes. KU-596 therapy may improve mitochondrial tolerance to diabetic stress to decrease mitophagic clearance in an Hsp70- and Txnip-dependent manner.
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Affiliation(s)
- Yssa A Rodriguez
- Department of Pharmacology and Toxicology, University of Kansas, 5064 Malott Hall/1251 Wescoe Hall Drive, Lawrence, Kansas 66045, United States
| | - Sukmanjit Kaur
- Department of Pharmacology and Toxicology, University of Kansas, 5064 Malott Hall/1251 Wescoe Hall Drive, Lawrence, Kansas 66045, United States
| | - Erika Nolte
- Department of Pharmacology and Toxicology, University of Kansas, 5064 Malott Hall/1251 Wescoe Hall Drive, Lawrence, Kansas 66045, United States
| | - Zhang Zheng
- Department of Chemistry and Biochemistry University of Notre Dame, 305 McCourtney Hall, Notre Dame, Indiana 46556, United States
| | - Brian S J Blagg
- Department of Chemistry and Biochemistry University of Notre Dame, 305 McCourtney Hall, Notre Dame, Indiana 46556, United States
| | - Rick T Dobrowsky
- Department of Pharmacology and Toxicology, University of Kansas, 5064 Malott Hall/1251 Wescoe Hall Drive, Lawrence, Kansas 66045, United States
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18
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Zhuang W, Dong X, Wang B, Liu N, Guo H, Zhang C, Gan W. NRF-1 directly regulates TFE3 and promotes the proliferation of renal cancer cells. Oncol Lett 2021; 22:679. [PMID: 34345304 PMCID: PMC8323008 DOI: 10.3892/ol.2021.12940] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 06/07/2021] [Indexed: 11/06/2022] Open
Abstract
The role of transcription factor binding to IGHM enhancer 3 (TFE3) in renal cell carcinoma (RCC) is not well understood. Nuclear respiratory factor 1 (NRF-1) may be the positive upstream regulatory gene of TFE3. The aim of the present study was to determine whether NRF-1 could directly regulate the expression of TFE3 and regulate tumorigenesis and progression of RCC through TFE3. Short hairpin RNA (shRNA) was used to silence the expression of NRF-1 in the 786-O human kidney adenocarcinoma cell line and the 293T human embryonic kidney cell line. Luciferase reporter assays were used to determine the relationship between NRF-1 and TFE3. The CHIP experiment was used to verify the actual binding of NRF-1 and TFE3 promoter regions. MitoTimer staining was used to measure mitochondrial biosynthesis. Flow cytometry was used to detect cell cycle and apoptosis. The 786-O and 293T cells were used to examine the underlying mechanism of action. The results demonstrated that NRF-1 could bind to the promoter region of the TFE3 gene and directly regulate the expression of TFE3. Following NRF-1 knockdown, the protein levels of phosphorylated (p)-AKT and p-S6 of mTOR pathway was inhibited, cell cycle progression was blocked, the levels of apoptosis increased, and mitochondrial generation was reduced. Following overexpression of TFE3, the levels of mTOR-associated markers were restored in NRF-1 knockdown cells. These findings suggest that NRF-1 may regulate the mTOR pathway through TFE3 and regulate the energy metabolism, proliferation and growth of cancer cells by directly regulating the expression of TFE3.
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Affiliation(s)
- Wenyuan Zhuang
- Department of Urology, Nanjing Drum Tower Hospital, Medical School of Nanjing University, Nanjing University, Nanjing, Jiangsu 210008, P.R. China
| | - Xiang Dong
- Department of Urology, Drum Tower Clinical Medical School of Nanjing Medical University, Nanjing University, Nanjing, Jiangsu 210008, P.R. China
| | - Bo Wang
- Department of Urology, Nanjing Drum Tower Hospital, Medical School of Nanjing University, Nanjing University, Nanjing, Jiangsu 210008, P.R. China
| | - Ning Liu
- Department of Urology, Nanjing Drum Tower Hospital, Medical School of Nanjing University, Nanjing University, Nanjing, Jiangsu 210008, P.R. China
| | - Hongqian Guo
- Department of Urology, Nanjing Drum Tower Hospital, Medical School of Nanjing University, Nanjing University, Nanjing, Jiangsu 210008, P.R. China
| | - Chunni Zhang
- Department of Clinical Laboratory, Jinling Hospital, Nanjing University School of Medicine, Nanjing University, Nanjing, Jiangsu 210008, P.R. China
| | - Weidong Gan
- Department of Urology, Nanjing Drum Tower Hospital, Medical School of Nanjing University, Nanjing University, Nanjing, Jiangsu 210008, P.R. China
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19
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Ma X, Ding WX. A fluorescence imaging based-assay to monitor mitophagy in cultured hepatocytes and mouse liver. LIVER RESEARCH 2021; 5:16-20. [PMID: 34350054 PMCID: PMC8330398 DOI: 10.1016/j.livres.2020.12.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND AND AIM Mitophagy is a lysosomal degradation pathway that selectively removes damaged, aged and dysfunctional mitochondria. Recent advances in understanding mitophagy highlight its importance in various physiological and pathological conditions including liver diseases. However, reliable quantitative assays to monitor mitophagy in cultured cells and in tissues are still scarce. METHODS We describe a detailed protocol for monitoring mitophagy in primary cultured hepatocytes and mouse livers using cytochrome C oxidase subunit 8 (Cox8)-enhanced green fluorescent protein (EGFP)-mCherry, a dual color fluorescence based-imaging method. RESULTS Mitochondria are visualized in yellow fluorescence due to the merged EGFP and mCherry signal. In contrast, autolysosome enclosed mitochondria are shown as red puncta due to quenching of EGFP green fluorescence in acidic compartments. Quantifying the number of red-only puncta in each cell can obtain a quantitative measure for mitophagy. CONCLUSIONS Cox8-EGFP-mCherry assay can specifically target to mitochondria and be used to monitor mitophagy in vitro and in vivo.
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Affiliation(s)
- Xiaowen Ma
- Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center, Kansas City, KS, USA
| | - Wen-Xing Ding
- Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center, Kansas City, KS, USA
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20
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Bennett JP, Onyango IG. Energy, Entropy and Quantum Tunneling of Protons and Electrons in Brain Mitochondria: Relation to Mitochondrial Impairment in Aging-Related Human Brain Diseases and Therapeutic Measures. Biomedicines 2021; 9:225. [PMID: 33671585 PMCID: PMC7927033 DOI: 10.3390/biomedicines9020225] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 02/18/2021] [Accepted: 02/18/2021] [Indexed: 11/16/2022] Open
Abstract
Adult human brains consume a disproportionate amount of energy substrates (2-3% of body weight; 20-25% of total glucose and oxygen). Adenosine triphosphate (ATP) is a universal energy currency in brains and is produced by oxidative phosphorylation (OXPHOS) using ATP synthase, a nano-rotor powered by the proton gradient generated from proton-coupled electron transfer (PCET) in the multi-complex electron transport chain (ETC). ETC catalysis rates are reduced in brains from humans with neurodegenerative diseases (NDDs). Declines of ETC function in NDDs may result from combinations of nitrative stress (NS)-oxidative stress (OS) damage; mitochondrial and/or nuclear genomic mutations of ETC/OXPHOS genes; epigenetic modifications of ETC/OXPHOS genes; or defects in importation or assembly of ETC/OXPHOS proteins or complexes, respectively; or alterations in mitochondrial dynamics (fusion, fission, mitophagy). Substantial free energy is gained by direct O2-mediated oxidation of NADH. Traditional ETC mechanisms require separation between O2 and electrons flowing from NADH/FADH2 through the ETC. Quantum tunneling of electrons and much larger protons may facilitate this separation. Neuronal death may be viewed as a local increase in entropy requiring constant energy input to avoid. The ATP requirement of the brain may partially be used for avoidance of local entropy increase. Mitochondrial therapeutics seeks to correct deficiencies in ETC and OXPHOS.
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Affiliation(s)
| | - Isaac G. Onyango
- International Clinical Research Center, St. Anne’s University Hospital, CZ-65691 Brno, Czech Republic;
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21
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Vangrieken P, Al-Nasiry S, Bast A, Leermakers PA, Tulen CBM, Schiffers PMH, van Schooten FJ, Remels AHV. Placental Mitochondrial Abnormalities in Preeclampsia. Reprod Sci 2021; 28:2186-2199. [PMID: 33523425 PMCID: PMC8289780 DOI: 10.1007/s43032-021-00464-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 01/11/2021] [Indexed: 02/06/2023]
Abstract
Preeclampsia complicates 5–8% of all pregnancies worldwide, and although its pathophysiology remains obscure, placental oxidative stress and mitochondrial abnormalities are considered to play a key role. Mitochondrial abnormalities in preeclamptic placentae have been described, but the extent to which mitochondrial content and the molecular pathways controlling this (mitochondrial biogenesis and mitophagy) are affected in preeclamptic placentae is unknown. Therefore, in preeclamptic (n = 12) and control (n = 11) placentae, we comprehensively assessed multiple indices of placental antioxidant status, mitochondrial content, mitochondrial biogenesis, mitophagy, and mitochondrial fusion and fission. In addition, we also explored gene expression profiles related to inflammation and apoptosis. Preeclamptic placentae were characterized by higher levels of oxidized glutathione, a higher total antioxidant capacity, and higher mRNA levels of the mitochondrial-located antioxidant enzyme manganese-dependent superoxide dismutase 2 compared to controls. Furthermore, mitochondrial content was significantly lower in preeclamptic placentae, which was accompanied by an increased abundance of key constituents of glycolysis. Moreover, mRNA and protein levels of key molecules involved in the regulation of mitochondrial biogenesis were lower in preeclamptic placentae, while the abundance of constituents of the mitophagy, autophagy, and mitochondrial fission machinery was higher compared to controls. In addition, we found evidence for activation of apoptosis and inflammation in preeclamptic placentae. This study is the first to comprehensively demonstrate abnormalities at the level of the mitochondrion and the molecular pathways controlling mitochondrial content/function in preeclamptic placentae. These aberrations may well contribute to the pathophysiology of preeclampsia by upregulating placental inflammation, oxidative stress, and apoptosis. Graphical Abstract ![]()
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Affiliation(s)
- Philippe Vangrieken
- School of Nutrition and Translational Research in Metabolism (NUTRIM), Department of Pharmacology and Toxicology, Maastricht University Medical Center+, Maastricht, The Netherlands. .,School for Cardiovascular Diseases (CARIM), Department of Internal Medicine, Maastricht University Medical Center+, Maastricht, The Netherlands.
| | - Salwan Al-Nasiry
- School for Oncology and Developmental Biology (GROW), Department of Obstetrics and Gynaecology, Maastricht University Medical Center+, Maastricht, The Netherlands
| | - Aalt Bast
- School of Nutrition and Translational Research in Metabolism (NUTRIM), Department of Pharmacology and Toxicology, Maastricht University Medical Center+, Maastricht, The Netherlands
| | - Pieter A Leermakers
- School of Nutrition and Translational Research in Metabolism (NUTRIM), Department of Pharmacology and Toxicology, Maastricht University Medical Center+, Maastricht, The Netherlands
| | - Christy B M Tulen
- School of Nutrition and Translational Research in Metabolism (NUTRIM), Department of Pharmacology and Toxicology, Maastricht University Medical Center+, Maastricht, The Netherlands
| | - Paul M H Schiffers
- School for Cardiovascular Diseases (CARIM), Department of Pharmacology and Toxicology, Maastricht University Medical Center+, Maastricht, The Netherlands
| | - Frederik J van Schooten
- School of Nutrition and Translational Research in Metabolism (NUTRIM), Department of Pharmacology and Toxicology, Maastricht University Medical Center+, Maastricht, The Netherlands
| | - Alex H V Remels
- School of Nutrition and Translational Research in Metabolism (NUTRIM), Department of Pharmacology and Toxicology, Maastricht University Medical Center+, Maastricht, The Netherlands
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22
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Jayatunga DPW, Hone E, Bharadwaj P, Garg M, Verdile G, Guillemin GJ, Martins RN. Targeting Mitophagy in Alzheimer's Disease. J Alzheimers Dis 2020; 78:1273-1297. [PMID: 33285629 DOI: 10.3233/jad-191258] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Mitochondria perform many essential cellular functions including energy production, calcium homeostasis, transduction of metabolic and stress signals, and mediating cell survival and death. Maintaining viable populations of mitochondria is therefore critical for normal cell function. The selective disposal of damaged mitochondria, by a pathway known as mitophagy, plays a key role in preserving mitochondrial integrity and quality. Mitophagy reduces the formation of reactive oxygen species and is considered as a protective cellular process. Mitochondrial dysfunction and deficits of mitophagy have important roles in aging and especially in neurodegenerative disorders such as Alzheimer's disease (AD). Targeting mitophagy pathways has been suggested to have potential therapeutic effects against AD. In this review, we aim to briefly discuss the emerging concepts on mitophagy, molecular regulation of the mitophagy process, current mitophagy detection methods, and mitophagy dysfunction in AD. Finally, we will also briefly examine the stimulation of mitophagy as an approach for attenuating neurodegeneration in AD.
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Affiliation(s)
- Dona P W Jayatunga
- Centre of Excellence for Alzheimer's Disease Research & Care, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
| | - Eugene Hone
- Centre of Excellence for Alzheimer's Disease Research & Care, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia.,Cooperative Research Centre for Mental Health, Carlton, VIC, Australia
| | - Prashant Bharadwaj
- Centre of Excellence for Alzheimer's Disease Research & Care, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia.,Cooperative Research Centre for Mental Health, Carlton, VIC, Australia
| | - Manohar Garg
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW, Australia.,Riddet Institute, Massey University, Palmerston North, New Zealand
| | - Giuseppe Verdile
- Centre of Excellence for Alzheimer's Disease Research & Care, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia.,School of Pharmacy and Biomedical Sciences, Faculty of Health Sciences, Curtin Health Innovation Research Institute, Curtin University, Perth, WA, Australia
| | - Gilles J Guillemin
- Department of Pharmacology, School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia.,St. Vincent's Centre for Applied Medical Research, Sydney, NSW, Australia
| | - Ralph N Martins
- Centre of Excellence for Alzheimer's Disease Research & Care, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia.,Australian Alzheimer's Research Foundation, Ralph and Patricia Sarich Neuroscience Research Institute, Nedlands, WA, Australia.,Department of Biomedical Sciences, Macquarie University, Sydney, NSW, Australia.,School of Psychiatry and Clinical Neurosciences, University of Western Australia, Perth, WA, Australia.,KaRa Institute of Neurological Diseases, Sydney, NSW, Australia
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23
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Defective mitophagy in Alzheimer's disease. Ageing Res Rev 2020; 64:101191. [PMID: 33022416 DOI: 10.1016/j.arr.2020.101191] [Citation(s) in RCA: 162] [Impact Index Per Article: 40.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 08/25/2020] [Accepted: 09/28/2020] [Indexed: 02/06/2023]
Abstract
Alzheimer's disease (AD) is a progressive, mental illness without cure. Several years of intense research on postmortem AD brains, cell and mouse models of AD have revealed that multiple cellular changes are involved in the disease process, including mitochondrial abnormalities, synaptic damage, and glial/astrocytic activation, in addition to age-dependent accumulation of amyloid beta (Aβ) and hyperphosphorylated tau (p-tau). Synaptic damage and mitochondrial dysfunction are early cellular changes in the disease process. Healthy and functionally active mitochondria are essential for cellular functioning. Dysfunctional mitochondria play a central role in aging and AD. Mitophagy is a cellular process whereby damaged mitochondria are selectively removed from cell and mitochondrial quality and biogenesis. Mitophagy impairments cause the progressive accumulation of defective organelle and damaged mitochondria in cells. In AD, increased levels of Aβ and p-tau can induce reactive oxygen species (ROS) production, causing excessive fragmentation of mitochondria and promoting defective mitophagy. The current article discusses the latest developments of mitochondrial research and also highlights multiple types of mitophagy, including Aβ and p-tau-induced mitophagy, stress-induced mitophagy, receptor-mediated mitophagy, ubiquitin mediated mitophagy and basal mitophagy. This article also discusses the physiological states of mitochondria, including fission-fusion balance, Ca2+ transport, and mitochondrial transport in normal and diseased conditions. Our article summarizes current therapeutic interventions, like chemical or natural mitophagy enhancers, that influence mitophagy in AD. Our article discusses whether a partial reduction of Drp1 can be a mitophagy enhancer and a therapeutic target for mitophagy in AD and other neurological diseases.
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Tauopathy-associated tau modifications selectively impact neurodegeneration and mitophagy in a novel C. elegans single-copy transgenic model. Mol Neurodegener 2020; 15:65. [PMID: 33168053 PMCID: PMC7654055 DOI: 10.1186/s13024-020-00410-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 10/07/2020] [Indexed: 12/29/2022] Open
Abstract
Background A defining pathological hallmark of the progressive neurodegenerative disorder Alzheimer’s disease (AD) is the accumulation of misfolded tau with abnormal post-translational modifications (PTMs). These include phosphorylation at Threonine 231 (T231) and acetylation at Lysine 274 (K274) and at Lysine 281 (K281). Although tau is recognized to play a central role in pathogenesis of AD, the precise mechanisms by which these abnormal PTMs contribute to the neural toxicity of tau is unclear. Methods Human 0N4R tau (wild type) was expressed in touch receptor neurons of the genetic model organism C. elegans through single-copy gene insertion. Defined mutations were then introduced into the single-copy tau transgene through CRISPR-Cas9 genome editing. These mutations included T231E, to mimic phosphorylation of a commonly observed pathological epitope, and K274/281Q, to mimic disease-associated lysine acetylation – collectively referred as “PTM-mimetics” – as well as a T231A phosphoablation mutant. Stereotypical touch response assays were used to assess behavioral defects in the transgenic strains as a function of age. Genetically-encoded fluorescent biosensors were expressed in touch neurons and used to measure neuronal morphology, mitochondrial morphology, mitophagy, and macro autophagy. Results Unlike existing tau overexpression models, C. elegans single-copy expression of tau did not elicit overt pathological phenotypes at baseline. However, strains expressing disease associated PTM-mimetics (T231E and K274/281Q) exhibited reduced touch sensation and neuronal morphological abnormalities that increased with age. In addition, the PTM-mimetic mutants lacked the ability to engage neuronal mitophagy in response to mitochondrial stress. Conclusions Limiting the expression of tau results in a genetic model where modifications that mimic pathologic tauopathy-associated PTMs contribute to cryptic, stress-inducible phenotypes that evolve with age. These findings and their relationship to mitochondrial stress provides a new perspective into the pathogenic mechanisms underlying AD. Supplementary information The online version contains supplementary material available at 10.1186/s13024-020-00410-7.
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An optimized procedure for quantitative analysis of mitophagy with the mtKeima system using flow cytometry. Biotechniques 2020; 69:249-256. [PMID: 32806949 DOI: 10.2144/btn-2020-0071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/09/2022] Open
Abstract
Mitophagy is the process by which mitochondria are selectively targeted and removed via autophagic machinery to maintain mitochondrial homeostasis in the cell. Recently, flow cytometry-based assays that utilize the fluorescent mtKeima reporter system have allowed for quantitative assessment of mitophagy at a single-cell level. However, clear guidelines for appropriate flow cytometry workflow and downstream analysis are lacking and studies using flow cytometry in mtKeima-expressing cells often display incorrect and arbitrary binary mitophagic or nonmitophagic cutoffs that prevent proper quantitative analyses. In this paper we propose a novel method of mtKeima data analysis that preserves subtle differences present within flow cytometry data in a manner that ensures reproducibility.
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The mito-QC Reporter for Quantitative Mitophagy Assessment in Primary Retinal Ganglion Cells and Experimental Glaucoma Models. Int J Mol Sci 2020; 21:ijms21051882. [PMID: 32164182 PMCID: PMC7084520 DOI: 10.3390/ijms21051882] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 03/05/2020] [Accepted: 03/06/2020] [Indexed: 12/15/2022] Open
Abstract
Mitochondrial damage plays a prominent role in glaucoma. The only way cells can degrade whole mitochondria is via autophagy, in a process called mitophagy. Thus, studying mitophagy in the context of glaucoma is essential to understand the disease. Up to date limited tools are available for analyzing mitophagy in vivo. We have taken advantage of the mito-QC reporter, a recently generated mouse model that allows an accurate mitophagy assessment to fill this gap. We used primary RGCs and retinal explants derived from mito-QC mice to quantify mitophagy activation in vitro and ex vivo. We also analyzed mitophagy in retinal ganglion cells (RGCs), in vivo, using different mitophagy inducers, as well as after optic nerve crush (ONC) in mice, a commonly used surgical procedure to model glaucoma. Using mito-QC reporter we quantified mitophagy induced by several known inducers in primary RGCs in vitro, ex vivo and in vivo. We also found that RGCs were rescued from some glaucoma relevant stress factors by incubation with the iron chelator deferiprone (DFP). Thus, the mito-QC reporter-based model is a valuable tool for accurately analyzing mitophagy in the context of glaucoma.
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Yang Y, Li T, Li Z, Liu N, Yan Y, Liu B. Role of Mitophagy in Cardiovascular Disease. Aging Dis 2020; 11:419-437. [PMID: 32257551 PMCID: PMC7069452 DOI: 10.14336/ad.2019.0518] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 05/18/2019] [Indexed: 12/17/2022] Open
Abstract
Cardiovascular disease is the leading cause of mortality worldwide, and mitochondrial dysfunction is the primary contributor to these disorders. Recent studies have elaborated on selective autophagy-mitophagy, which eliminates damaged and dysfunctional mitochondria, stabilizes mitochondrial structure and function, and maintains cell survival and growth. Numerous recent studies have reported that mitophagy plays an important role in the pathogenesis of various cardiovascular diseases. This review summarizes the mechanisms underlying mitophagy and advancements in studies on the role of mitophagy in cardiovascular disease.
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Affiliation(s)
- Yibo Yang
- Department of Cardiology, The Second Hospital of Jilin University, Changchun 130041, China
| | - Tianyi Li
- Department of Cardiology, The Second Hospital of Jilin University, Changchun 130041, China
| | - Zhibo Li
- Department of Cardiology, The Second Hospital of Jilin University, Changchun 130041, China
| | - Ning Liu
- Department of Cardiology, The Second Hospital of Jilin University, Changchun 130041, China
| | - Youyou Yan
- Department of Cardiology, The Second Hospital of Jilin University, Changchun 130041, China
| | - Bin Liu
- Department of Cardiology, The Second Hospital of Jilin University, Changchun 130041, China
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Gökerküçük EB, Tramier M, Bertolin G. Imaging Mitochondrial Functions: from Fluorescent Dyes to Genetically-Encoded Sensors. Genes (Basel) 2020; 11:E125. [PMID: 31979408 PMCID: PMC7073610 DOI: 10.3390/genes11020125] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Revised: 01/20/2020] [Accepted: 01/21/2020] [Indexed: 12/18/2022] Open
Abstract
Mitochondria are multifunctional organelles that are crucial to cell homeostasis. They constitute the major site of energy production for the cell, they are key players in signalling pathways using secondary messengers such as calcium, and they are involved in cell death and redox balance paradigms. Mitochondria quickly adapt their dynamics and biogenesis rates to meet the varying energy demands of the cells, both in normal and in pathological conditions. Therefore, understanding simultaneous changes in mitochondrial functions is crucial in developing mitochondria-based therapy options for complex pathological conditions such as cancer, neurological disorders, and metabolic syndromes. To this end, fluorescence microscopy coupled to live imaging represents a promising strategy to track these changes in real time. In this review, we will first describe the commonly available tools to follow three key mitochondrial functions using fluorescence microscopy: Calcium signalling, mitochondrial dynamics, and mitophagy. Then, we will focus on how the development of genetically-encoded fluorescent sensors became a milestone for the understanding of these mitochondrial functions. In particular, we will show how these tools allowed researchers to address several biochemical activities in living cells, and with high spatiotemporal resolution. With the ultimate goal of tracking multiple mitochondrial functions simultaneously, we will conclude by presenting future perspectives for the development of novel genetically-encoded fluorescent biosensors.
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Affiliation(s)
| | | | - Giulia Bertolin
- Univ Rennes, CNRS, IGDR [Institut de génétique et développement de Rennes] UMR 6290, F-35000 Rennes, France
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Sheremet NL, Andreeva NA, Shmel'kova MS, Tsigankova PG. [Mitochondrial biogenesis in hereditary optic neuropathies]. Vestn Oftalmol 2019; 135:85-91. [PMID: 31714518 DOI: 10.17116/oftalma201913505185] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The article offers a review of mitochondrial biogenesis in hereditary optic neuropathies. It covers the mechanisms of mitochondrial biogenesis, factors affecting it and tools for mitochondrial turnover assessment.
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Affiliation(s)
- N L Sheremet
- Research Institute of Eye Diseases, 11A Rossolimo St., Moscow, Russian Federation, 119021
| | - N A Andreeva
- Research Institute of Eye Diseases, 11A Rossolimo St., Moscow, Russian Federation, 119021
| | - M S Shmel'kova
- Research Institute of Eye Diseases, 11A Rossolimo St., Moscow, Russian Federation, 119021
| | - P G Tsigankova
- Research Centre for Medical Genetics, 1 Moskvorech'e St., Moscow, Russian Federation, 115522
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30
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Live cell imaging of signaling and metabolic activities. Pharmacol Ther 2019; 202:98-119. [DOI: 10.1016/j.pharmthera.2019.06.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 05/31/2019] [Indexed: 12/15/2022]
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31
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Zhao C, He R, Shen M, Zhu F, Wang M, Liu Y, Chen H, Li X, Qin R. PINK1/Parkin-Mediated Mitophagy Regulation by Reactive Oxygen Species Alleviates Rocaglamide A-Induced Apoptosis in Pancreatic Cancer Cells. Front Pharmacol 2019; 10:968. [PMID: 31551778 PMCID: PMC6735223 DOI: 10.3389/fphar.2019.00968] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2019] [Accepted: 07/29/2019] [Indexed: 01/07/2023] Open
Abstract
Pancreatic cancer (PC) is one of the most lethal diseases, and effective treatment of PC patients remains an enormous challenge. Rocaglamide A (Roc-A), a bioactive molecule extracted from the plant Aglaia elliptifolia, has aroused considerable attention as a therapeutic choice for numerous cancer treatments. Nevertheless, the effects and underlying mechanism of Roc-A in PC are still poorly understood. Here, we found that Roc-A inhibited growth and stimulated apoptosis by induction of mitochondria dysfunction in PC. Moreover, Roc-A accelerated autophagosome synthesis and triggered mitophagy involving the PTEN-induced putative kinase 1 (PINK1)/Parkin signal pathway. We also demonstrated that inhibition of autophagy/mitophagy can sensitize PC cells to Roc-A. Finally, Roc-A treatment results in an obvious accumulation of reactive oxygen species (ROS), and pretreatment of cells with the reactive oxygen species scavenger N-acetylcysteine reversed the apoptosis and autophagy/mitophagy induced by Roc-A. Together, our results elucidate the potential mechanisms of action of Roc-A. Our findings indicate Roc-A as a potential therapeutic agent against PC and suggest that combination inhibition of autophagy/mitophagy may be a promising therapeutic strategy in PC.
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Affiliation(s)
- Chunle Zhao
- Laboratory of Biliary-Pancreatic Surgery, Department of Biliary-Pancreatic Surgery, Affiliated Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ruizhi He
- Laboratory of Biliary-Pancreatic Surgery, Department of Biliary-Pancreatic Surgery, Affiliated Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ming Shen
- Laboratory of Biliary-Pancreatic Surgery, Department of Biliary-Pancreatic Surgery, Affiliated Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Feng Zhu
- Laboratory of Biliary-Pancreatic Surgery, Department of Biliary-Pancreatic Surgery, Affiliated Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Min Wang
- Laboratory of Biliary-Pancreatic Surgery, Department of Biliary-Pancreatic Surgery, Affiliated Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yuhui Liu
- Laboratory of Biliary-Pancreatic Surgery, Department of Biliary-Pancreatic Surgery, Affiliated Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hua Chen
- Laboratory of Biliary-Pancreatic Surgery, Department of Biliary-Pancreatic Surgery, Affiliated Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xu Li
- Laboratory of Biliary-Pancreatic Surgery, Department of Biliary-Pancreatic Surgery, Affiliated Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Renyi Qin
- Laboratory of Biliary-Pancreatic Surgery, Department of Biliary-Pancreatic Surgery, Affiliated Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Evans CS, Holzbaur ELF. Quality Control in Neurons: Mitophagy and Other Selective Autophagy Mechanisms. J Mol Biol 2019; 432:240-260. [PMID: 31295455 DOI: 10.1016/j.jmb.2019.06.031] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 06/28/2019] [Accepted: 06/29/2019] [Indexed: 12/19/2022]
Abstract
The cargo-specific removal of organelles via selective autophagy is important to maintain neuronal homeostasis. Genetic studies indicate that deficits in these pathways are implicated in neurodegenerative diseases, including Parkinson's and amyotrophic lateral sclerosis. Here, we review our current understanding of the pathways that regulate mitochondrial quality control, and compare these mechanisms to those regulating turnover of the endoplasmic reticulum and the clearance of protein aggregates. Research suggests that there are multiple mechanisms regulating the degradation of specific cargos, such as dysfunctional organelles and protein aggregates. These mechanisms are critical for neuronal health, as neurons are uniquely vulnerable to impairment in organelle quality control pathways due to their morphology, size, polarity, and postmitotic nature. We highlight the consequences of dysregulation of selective autophagy in neurons and discuss current challenges in correlating noncongruent findings from in vitro and in vivo systems.
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Affiliation(s)
- Chantell S Evans
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104-6085, USA.
| | - Erika L F Holzbaur
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104-6085, USA.
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33
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Mitochondrial antigen presentation: a mechanism linking Parkinson’s disease to autoimmunity. Curr Opin Immunol 2019; 58:31-37. [DOI: 10.1016/j.coi.2019.02.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 02/15/2019] [Accepted: 02/19/2019] [Indexed: 12/12/2022]
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Karise I, Bargut TC, Del Sol M, Aguila MB, Mandarim-de-Lacerda CA. Metformin enhances mitochondrial biogenesis and thermogenesis in brown adipocytes of mice. Biomed Pharmacother 2019; 111:1156-1165. [PMID: 30841429 DOI: 10.1016/j.biopha.2019.01.021] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 01/04/2019] [Accepted: 01/06/2019] [Indexed: 11/18/2022] Open
Abstract
AIMS We studied the effect of metformin on the brown adipose tissue (BAT) in a fructose-rich-fed model, focusing on BAT proliferation, differentiation, and thermogenic markers. MAIN METHODS C57Bl/6 mice received isoenergetic diets for ten weeks: control (C) or high-fructose (F). For additional eight weeks, animals received metformin hydrochloride (M, 250 mg/kg/day) or saline. After sacrifice, BAT and white fat pads were prepared for light microscopy and molecular analyses. KEY FINDINGS Body mass gain, white fat pads, and adiposity index were not different among the groups. There was a reduction in energy intake in the F group and energy expenditure in the F and FM groups. Metformin led to a more massive BAT in both groups CM and FM, associated with a higher adipocyte proliferation (β1-adrenergic receptor, proliferating cell nuclear antigen, and vascular endothelial growth factor), and differentiation (PR domain containing 16, bone morphogenetic protein 7), in part by activating 5' adenosine monophosphate-activated protein kinase. Metformin also enhanced thermogenic markers in the BAT (uncoupling protein type 1, peroxisome proliferator-activated receptor gamma coactivator-1 alpha) through adrenergic stimuli and fibroblast growth factor 21. Metformin might improve mitochondrial biogenesis in the BAT (nuclear respiratory factor 1, mitochondrial transcription factor A), lipolysis (perilipin, adipose triglyceride lipase, hormone-sensitive lipase), and fatty acid uptake (lipoprotein lipase, cluster of differentiation 36, adipocyte protein 2). SIGNIFICANCE Metformin effects are not linked to body mass changes, but affect BAT thermogenesis, mitochondrial biogenesis, and fatty acid uptake. Therefore, BAT may be a metformin adjuvant target for the treatment of metabolic disorders.
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Affiliation(s)
- Iara Karise
- Laboratory of Morphometry, Metabolism and Cardiovascular Disease, Biomedical Center, Institute of Biology, The University of the State of Rio de Janeiro, Rio de Janeiro, Brazil.
| | - Thereza Cristina Bargut
- Laboratory of Morphometry, Metabolism and Cardiovascular Disease, Biomedical Center, Institute of Biology, The University of the State of Rio de Janeiro, Rio de Janeiro, Brazil.
| | - Mariano Del Sol
- Doctoral Program in Morphological Sciences, Universidad de La Frontera, Temuco, Chile.
| | - Marcia Barbosa Aguila
- Laboratory of Morphometry, Metabolism and Cardiovascular Disease, Biomedical Center, Institute of Biology, The University of the State of Rio de Janeiro, Rio de Janeiro, Brazil.
| | - Carlos A Mandarim-de-Lacerda
- Laboratory of Morphometry, Metabolism and Cardiovascular Disease, Biomedical Center, Institute of Biology, The University of the State of Rio de Janeiro, Rio de Janeiro, Brazil.
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35
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Dehydroepiandrosterone Ameliorates Abnormal Mitochondrial Dynamics and Mitophagy of Cumulus Cells in Poor Ovarian Responders. J Clin Med 2018; 7:jcm7100293. [PMID: 30241351 PMCID: PMC6210273 DOI: 10.3390/jcm7100293] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Revised: 09/19/2018] [Accepted: 09/19/2018] [Indexed: 12/30/2022] Open
Abstract
Mitochondrial dysfunction is related to reproductive decline in humans, with consequences for in vitro fertilization (IVF). We assessed whether dehydroepiandrosterone (DHEA) could regulate mitochondrial homeostasis and mitophagy of cumulus cells (CCs) in poor ovarian responders (PORs). A total of 66 women who underwent IVF treatment at the Reproductive Medicine Center of Kaohsiung Veterans General Hospital were included in this study. Twenty-eight normal ovarian responders (NOR) and 38 PORs were enrolled. PORs were assigned to receive DHEA supplementation (n = 19) or not (n = 19) before IVF cycles. DHEA prevents mitochondrial dysfunction by decreasing the activation of DNM1L and MFF, and increasing MFN1 expression. Downregulation of PINK1 and PRKN occurred after DHEA treatment, along with increased lysosome formation. DHEA not only promoted mitochondrial mass but also improved mitochondrial homeostasis and dynamics in the CCs of POR. We also observed effects of alterations in mRNAs known to regulate mitochondrial dynamics and mitophagy in the CCs of POR. DHEA may prevent mitochondrial dysfunction through regulating mitochondrial homeostasis and mitophagy.
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Harwig MC, Viana MP, Egner JM, Harwig JJ, Widlansky ME, Rafelski SM, Hill RB. Methods for imaging mammalian mitochondrial morphology: A prospective on MitoGraph. Anal Biochem 2018; 552:81-99. [PMID: 29505779 DOI: 10.1016/j.ab.2018.02.022] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 02/06/2018] [Accepted: 02/22/2018] [Indexed: 12/22/2022]
Abstract
Mitochondria are found in a variety of shapes, from small round punctate structures to a highly interconnected web. This morphological diversity is important for function, but complicates quantification. Consequently, early quantification efforts relied on various qualitative descriptors that understandably reduce the complexity of the network leading to challenges in consistency across the field. Recent application of state-of-the-art computational tools have resulted in more quantitative approaches. This prospective highlights the implementation of MitoGraph, an open-source image analysis platform for measuring mitochondrial morphology initially optimized for use with Saccharomyces cerevisiae. Here Mitograph was assessed on five different mammalian cells types, all of which were accurately segmented by MitoGraph analysis. MitoGraph also successfully differentiated between distinct mitochondrial morphologies that ranged from entirely fragmented to hyper-elongated. General recommendations are also provided for confocal imaging of labeled mitochondria (using mito-YFP, MitoTracker dyes and immunostaining parameters). Widespread adoption of MitoGraph will help achieve a long-sought goal of consistent and reproducible quantification of mitochondrial morphology.
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Affiliation(s)
- Megan C Harwig
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, 53226, United States
| | - Matheus P Viana
- Visual Analytics and Comprehension Group, IBM Research, Brazil; Department of Developmental and Cell Biology and Center for Complex Biological Systems, University of California Irvine, Irvine, CA, 92697, United States
| | - John M Egner
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, 53226, United States
| | | | - Michael E Widlansky
- Division of Cardiovascular Medicine, Department of Medicine, Medical College of Wisconsin, Milwaukee, WI, 53226, United States
| | - Susanne M Rafelski
- Department of Developmental and Cell Biology and Center for Complex Biological Systems, University of California Irvine, Irvine, CA, 92697, United States; Assay Development, Allen Institute for Cell Science, Seattle, WA, 98109, United States
| | - R Blake Hill
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, 53226, United States.
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Zhang J, Culp ML, Craver JG, Darley-Usmar V. Mitochondrial function and autophagy: integrating proteotoxic, redox, and metabolic stress in Parkinson's disease. J Neurochem 2018; 144:691-709. [PMID: 29341130 PMCID: PMC5897151 DOI: 10.1111/jnc.14308] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 01/04/2018] [Accepted: 01/09/2018] [Indexed: 12/14/2022]
Abstract
Parkinson's disease (PD) is a movement disorder with widespread neurodegeneration in the brain. Significant oxidative, reductive, metabolic, and proteotoxic alterations have been observed in PD postmortem brains. The alterations of mitochondrial function resulting in decreased bioenergetic health is important and needs to be further examined to help develop biomarkers for PD severity and prognosis. It is now becoming clear that multiple hits on metabolic and signaling pathways are likely to exacerbate PD pathogenesis. Indeed, data obtained from genetic and genome association studies have implicated interactive contributions of genes controlling protein quality control and metabolism. For example, loss of key proteins that are responsible for clearance of dysfunctional mitochondria through a process called mitophagy has been found to cause PD, and a significant proportion of genes associated with PD encode proteins involved in the autophagy-lysosomal pathway. In this review, we highlight the evidence for the targeting of mitochondria by proteotoxic, redox and metabolic stress, and the role autophagic surveillance in maintenance of mitochondrial quality. Furthermore, we summarize the role of α-synuclein, leucine-rich repeat kinase 2, and tau in modulating mitochondrial function and autophagy. Among the stressors that can overwhelm the mitochondrial quality control mechanisms, we will discuss 4-hydroxynonenal and nitric oxide. The impact of autophagy is context depend and as such can have both beneficial and detrimental effects. Furthermore, we highlight the potential of targeting mitochondria and autophagic function as an integrated therapeutic strategy and the emerging contribution of the microbiome to PD susceptibility.
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Affiliation(s)
- Jianhua Zhang
- Center for Free Radical Biology, University of Alabama at Birmingham
- Department of Pathology, University of Alabama at Birmingham
- Department of Veterans Affairs, Birmingham VA Medical Center
| | - M Lillian Culp
- Center for Free Radical Biology, University of Alabama at Birmingham
- Department of Pathology, University of Alabama at Birmingham
| | - Jason G Craver
- Center for Free Radical Biology, University of Alabama at Birmingham
- Department of Pathology, University of Alabama at Birmingham
| | - Victor Darley-Usmar
- Center for Free Radical Biology, University of Alabama at Birmingham
- Department of Pathology, University of Alabama at Birmingham
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Williams JA, Ding WX. Mechanisms, pathophysiological roles and methods for analyzing mitophagy - recent insights. Biol Chem 2018; 399:147-178. [PMID: 28976892 DOI: 10.1515/hsz-2017-0228] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 09/13/2017] [Indexed: 12/17/2022]
Abstract
In 2012, we briefly summarized the mechanisms, pathophysiological roles and methods for analyzing mitophagy. As then, the mitophagy field has continued to grow rapidly, and many new molecular mechanisms regulating mitophagy and molecular tools for monitoring mitophagy have been discovered and developed. Therefore, the purpose of this review is to update information regarding these advances in mitophagy while focusing on basic molecular mechanisms of mitophagy in different organisms and its pathophysiological roles. We also discuss the advantage and limitations of current methods to monitor and quantify mitophagy in cultured cells and in vivo mouse tissues.
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Affiliation(s)
- Jessica A Williams
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS 66160, USA
| | - Wen-Xing Ding
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160, USA
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Indira D, Varadarajan SN, Subhasingh Lupitha S, Lekshmi A, Mathew KA, Chandrasekharan A, Rajappan Pillai P, Pulikkal Kadamberi I, Ramachandran I, Sekar H, Kochucherukkan Gopalakrishnan A, Tr S. Strategies for imaging mitophagy in high-resolution and high-throughput. Eur J Cell Biol 2017; 97:1-14. [PMID: 29092745 DOI: 10.1016/j.ejcb.2017.10.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 10/26/2017] [Accepted: 10/26/2017] [Indexed: 12/20/2022] Open
Abstract
The selective autophagic removal of mitochondria called mitophagy is an essential physiological signaling for clearing damaged mitochondria and thus maintains the functional integrity of mitochondria and cells. Defective mitophagy is implicated in several diseases, placing mitophagy as a target for drug development. The identification of key regulators of mitophagy as well as chemical modulators of mitophagy requires sensitive and reliable quantitative approaches. Since mitophagy is a rapidly progressing event and sub-microscopic in nature, live cell image-based detection tools with high spatial and temporal resolution is preferred over end-stage assays. We describe two approaches for measuring mitophagy in mammalian cells using stable cells expressing EGFP-LC3 - Mito-DsRed to mark early phase of mitophagy and Mitochondria-EGFP - LAMP1-RFP stable cells for late events of mitophagy. Both the assays showed good spatial and temporal resolution in wide-field, confocal and super-resolution microscopy with high-throughput adaptable capability. A limited compound screening allowed us to identify a few new mitophagy inducers. Compared to the current mitophagy tools, mito-Keima or mito-QC, the assay described here determines the direct delivery of mitochondrial components to the lysosome in real time mode with accurate quantification if monoclonal cells expressing a homogenous level of both probes are established. Since the assay described here employs real-time imaging approach in a high-throughput mode, the platform can be used both for siRNA screening or compound screening to identify key regulators of mitophagy at decisive stages.
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Affiliation(s)
- Deepa Indira
- Cancer Research Program-1, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India.
| | | | | | - Asha Lekshmi
- Cancer Research Program-1, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India.
| | - Krupa Ann Mathew
- Cancer Research Program-1, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India.
| | - Aneesh Chandrasekharan
- Cancer Research Program-1, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India.
| | - Prakash Rajappan Pillai
- Cancer Research Program-1, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India.
| | | | - Indu Ramachandran
- Cancer Research Program-1, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India.
| | - Hari Sekar
- Cancer Research Program-1, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India.
| | | | - Santhoshkumar Tr
- Cancer Research Program-1, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India.
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Slower Dynamics and Aged Mitochondria in Sporadic Alzheimer's Disease. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:9302761. [PMID: 29201274 PMCID: PMC5672147 DOI: 10.1155/2017/9302761] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 07/25/2017] [Accepted: 08/17/2017] [Indexed: 12/30/2022]
Abstract
Sporadic Alzheimer's disease corresponds to 95% of cases whose origin is multifactorial and elusive. Mitochondrial dysfunction is a major feature of Alzheimer's pathology, which might be one of the early events that trigger downstream principal events. Here, we show that multiple genes that control mitochondrial homeostasis, including fission and fusion, are downregulated in Alzheimer's patients. Additionally, we demonstrate that some of these dysregulations, such as diminished DLP1 levels and its mitochondrial localization, as well as reduced STOML2 and MFN2 fusion protein levels, take place in fibroblasts from sporadic Alzheimer's disease patients. The analysis of mitochondrial network disruption using CCCP indicates that the patients' fibroblasts exhibit slower dynamics and mitochondrial membrane potential recovery. These defects lead to strong accumulation of aged mitochondria in Alzheimer's fibroblasts. Accordingly, the analysis of autophagy and mitophagy involved genes in the patients demonstrates a downregulation indicating that the recycling mechanism of these aged mitochondria might be impaired. Our data reinforce the idea that mitochondrial dysfunction is one of the key early events of the disease intimately related with aging.
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Huenchuguala S, Muñoz P, Segura-Aguilar J. The Importance of Mitophagy in Maintaining Mitochondrial Function in U373MG Cells. Bafilomycin A1 Restores Aminochrome-Induced Mitochondrial Damage. ACS Chem Neurosci 2017; 8:2247-2253. [PMID: 28763613 DOI: 10.1021/acschemneuro.7b00152] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Aminochrome, an orthoquinone formed during the dopamine oxidation of neuromelanin, is neurotoxic because it induces mitochondria dysfunction, protein degradation dysfunction (both autophagy and proteasomal systems), α-synuclein aggregation to neurotoxic oligomers, neuroinflammation, and oxidative and endoplasmic reticulum stress. In this study, we investigated the relationship between aminochrome-induced autophagy/lysosome dysfunction and mitochondrial dysfunction in U373MGsiGST6 cells. Aminochrome (75 μM) induces mitochondrial dysfunction as determined by (i) a significant decrease in ATP levels (70%; P < 0.001) and (ii) a significant decrease in mitochondrial membrane potential (P < 0.001). Interestingly, the pretreatment of U373MGsiGST6 cells with 100 nM bafilomycin-A1, an inhibitor of lysosomal vacuolar-type H+-ATPase, restores ATP levels, mitochondrial membrane potential, and mitophagy, and decreases cell death. These results reveal (i) the importance of macroautophagy/the lysosomal degradation system for the normal functioning of mitochondria and for cell survival, and (ii) aminochrome-induced lysosomal dysfunction depends on the aminochrome-dependent inactivation of the vacuolar-type H+-ATPase, which pumps protons into the lysosomes. This study also supports the proposed protective role of glutathione transferase mu2-2 (GSTM2) in astrocytes against aminochrome toxicity, mediated by mitochondrial and lysosomal dysfunction.
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Affiliation(s)
- Sandro Huenchuguala
- Molecular & Clinical Pharmacology, ICBM, Faculty of Medicine, University of Chile, Santiago, Chile
| | - Patricia Muñoz
- Molecular & Clinical Pharmacology, ICBM, Faculty of Medicine, University of Chile, Santiago, Chile
| | - Juan Segura-Aguilar
- Molecular & Clinical Pharmacology, ICBM, Faculty of Medicine, University of Chile, Santiago, Chile
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T-Cell Intracellular Antigens and Hu Antigen R Antagonistically Modulate Mitochondrial Activity and Dynamics by Regulating Optic Atrophy 1 Gene Expression. Mol Cell Biol 2017. [PMID: 28630277 DOI: 10.1128/mcb.00174-17] [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] [Indexed: 11/20/2022] Open
Abstract
Mitochondria undergo frequent morphological changes to control their function. We show here that T-cell intracellular antigens (TIA1b/TIARb) and Hu antigen R (HuR) have antagonistic roles in mitochondrial function by modulating the expression of mitochondrial shaping proteins. Expression of TIA1b/TIARb alters the mitochondrial dynamic network by enhancing fission and clustering, which is accompanied by a decrease in respiration. In contrast, HuR expression promotes fusion and cristae remodeling and increases respiratory activity. Mechanistically, TIA proteins downregulate the expression of optic atrophy 1 (OPA1) protein via switching of the splicing patterns of OPA1 to facilitate the production of OPA1 variant 5 (OPA1v5). Conversely, HuR enhances the expression of OPA1 mRNA isoforms through increasing steady-state levels and targeting translational efficiency at the 3' untranslated region. Knockdown of TIA1/TIAR or HuR partially reversed the expression profile of OPA1, whereas knockdown of OPA1 or overexpression of OPA1v5 provoked mitochondrial clustering. Middle-term expression of TIA1b/TIARb triggers reactive oxygen species production and mitochondrial DNA damage, which is accompanied by mitophagy, autophagy, and apoptosis. In contrast, HuR expression promotes mitochondrion-dependent cell proliferation. Collectively, these results provide molecular insights into the antagonistic functions of TIA1b/TIARb and HuR in mitochondrial activity dynamics and suggest that their balance might contribute to mitochondrial physiopathology.
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