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Pingitore V, Pancholi J, Hornsby TW, Warne J, Pryce G, McCormick LJ, Hill J, Bhosale G, Peng J, Newton LS, Towers GJ, Coles SJ, Chan AWE, Duchen MR, Szabadkai G, Baker D, Selwood DL. Delocalized quinolinium-macrocyclic peptides, an atypical chemotype for CNS penetration. SCIENCE ADVANCES 2024; 10:eado3501. [PMID: 38985859 PMCID: PMC11235165 DOI: 10.1126/sciadv.ado3501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Accepted: 06/04/2024] [Indexed: 07/12/2024]
Abstract
Macrocyclic drugs can address an increasing range of molecular targets but enabling central nervous system (CNS) access to these drugs has been viewed as an intractable problem. We designed and synthesized a series of quinolinium-modified cyclosporine derivatives targeted to the mitochondrial cyclophilin D protein. Modification of the cation to enable greater delocalization was confirmed by x-ray crystallography of the cations. Critically, greater delocalization improved brain concentrations. Assessment of the compounds in preclinical assays and for pharmacokinetics identified a molecule JP1-138 with at least 20 times the brain levels of a non-delocalized compound or those reported for cyclosporine. Levels were maintained over 24 hours together with low hERG potential. The paradigm outlined here could have widespread utility in the treatment of CNS diseases.
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Affiliation(s)
- Valeria Pingitore
- Drug Discovery, UCL Wolfson Institute for Biomedical Research, University College London, London WC1E 6BT, UK
- Department of Biological and Health Sciences, Universidad Loyola Andalucía, Dos Hermanas, Seville 41704, Spain
| | - Jessica Pancholi
- Drug Discovery, UCL Wolfson Institute for Biomedical Research, University College London, London WC1E 6BT, UK
| | - Thomas W Hornsby
- Drug Discovery, UCL Wolfson Institute for Biomedical Research, University College London, London WC1E 6BT, UK
| | - Justin Warne
- Drug Discovery, UCL Wolfson Institute for Biomedical Research, University College London, London WC1E 6BT, UK
| | - Gareth Pryce
- Centre for Neuroscience and Trauma, Blizard Institute, Queen Mary University of London, London E1 2AT, UK
| | - Laura J McCormick
- EPSRC National Crystallography Service, School of Chemistry, University of Southampton, Highfield Southampton SO17 1BJ, UK
| | - Julia Hill
- Department of Cell and Developmental Biology, UCL Consortium for Mitochondrial Research, London WC1E 6BT, UK
| | - Gauri Bhosale
- Department of Cell and Developmental Biology, UCL Consortium for Mitochondrial Research, London WC1E 6BT, UK
| | - Jing Peng
- Drug Discovery, UCL Wolfson Institute for Biomedical Research, University College London, London WC1E 6BT, UK
| | - Lydia S Newton
- Division of Infection and Immunity, University College London, London WC1E 6BT, UK
| | - Greg J Towers
- Division of Infection and Immunity, University College London, London WC1E 6BT, UK
| | - Simon J Coles
- EPSRC National Crystallography Service, School of Chemistry, University of Southampton, Highfield Southampton SO17 1BJ, UK
| | - Ah Wing Edith Chan
- Drug Discovery, UCL Wolfson Institute for Biomedical Research, University College London, London WC1E 6BT, UK
| | - Michael R Duchen
- Department of Cell and Developmental Biology, UCL Consortium for Mitochondrial Research, London WC1E 6BT, UK
| | - Gyorgy Szabadkai
- Department of Cell and Developmental Biology, UCL Consortium for Mitochondrial Research, London WC1E 6BT, UK
- Department of Biomedical Sciences, University of Padua, Padua 35131 Italy
| | - David Baker
- Centre for Neuroscience and Trauma, Blizard Institute, Queen Mary University of London, London E1 2AT, UK
| | - David L Selwood
- Drug Discovery, UCL Wolfson Institute for Biomedical Research, University College London, London WC1E 6BT, UK
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O'Brien JT, Jalilvand SP, Suji NA, Jupelly RK, Phensy A, Mwirigi JM, Elahi H, Price TJ, Kroener S. Elevations in the Mitochondrial Matrix Protein Cyclophilin D Correlate With Reduced Parvalbumin Expression in the Prefrontal Cortex of Patients With Schizophrenia. Schizophr Bull 2024:sbae016. [PMID: 38412332 DOI: 10.1093/schbul/sbae016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/29/2024]
Abstract
BACKGROUND AND HYPOTHESIS Cognitive deficits in schizophrenia are linked to dysfunctions of the dorsolateral prefrontal cortex (DLPFC), including alterations in parvalbumin (PV)-expressing interneurons (PVIs). Redox dysregulation and oxidative stress may represent convergence points in the pathology of schizophrenia, causing dysfunction of GABAergic interneurons and loss of PV. Here, we show that the mitochondrial matrix protein cyclophilin D (CypD), a critical initiator of the mitochondrial permeability transition pore (mPTP) and modulator of the intracellular redox state, is altered in PVIs in schizophrenia. STUDY DESIGN Western blotting was used to measure CypD protein levels in postmortem DLPFC specimens of schizophrenic patients (n = 27) and matched comparison subjects with no known history of psychiatric or neurological disorders (n = 26). In a subset of this cohort, multilabel immunofluorescent confocal microscopy with unbiased stereological sampling methods were used to quantify (1) numbers of PVI across the cortical mantle (20 unaffected comparison, 14 schizophrenia) and (2) PV and CypD protein levels from PVIs in the cortical layers 2-4 (23 unaffected comparison, 18 schizophrenia). STUDY RESULTS In schizophrenic patients, the overall number of PVIs in the DLPFC was not significantly altered, but in individual PVIs of layers 2-4 PV protein levels decreased along a superficial-to-deep gradient when compared to unaffected comparison subjects. These laminar-specific PVI alterations were reciprocally linked to significant CypD elevations both in PVIs and total DLPFC gray matter. CONCLUSIONS Our findings support previously reported PVI anomalies in schizophrenia and suggest that CypD-mediated mPTP formation could be a potential contributor to PVI dysfunction in schizophrenia.
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Affiliation(s)
- John T O'Brien
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, USA
| | - Sophia P Jalilvand
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, USA
| | - Neha A Suji
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, USA
| | - Rohan K Jupelly
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, USA
| | - Aarron Phensy
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, USA
| | - Juliet M Mwirigi
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, USA
| | - Hajira Elahi
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, USA
| | - Theodore J Price
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, USA
| | - Sven Kroener
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, USA
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3
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Villa BR, George AG, Shutt TE, Sullivan PG, Rho JM, Teskey GC. Postictal hypoxia involves reactive oxygen species and is ameliorated by chronic mitochondrial uncoupling. Neuropharmacology 2023; 238:109653. [PMID: 37422182 DOI: 10.1016/j.neuropharm.2023.109653] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 07/04/2023] [Accepted: 07/05/2023] [Indexed: 07/10/2023]
Abstract
Prolonged severe hypoxia follows brief seizures and represents a mechanism underlying several negative postictal manifestations without interventions. Approximately 50% of the postictal hypoxia phenomenon can be accounted for by arteriole vasoconstriction. What accounts for the rest of the drop in unbound oxygen is unclear. Here, we determined the effect of pharmacological modulation of mitochondrial function on tissue oxygenation in the hippocampus of rats after repeatedly evoked seizures. Rats were treated with mitochondrial uncoupler 2,4 dinitrophenol (DNP) or antioxidants. Oxygen profiles were recorded using a chronically implanted oxygen-sensing probe, before, during, and after seizure induction. Mitochondrial function and redox tone were measured using in vitro mitochondrial assays and immunohistochemistry. Postictal cognitive impairment was assessed using the novel object recognition task. Mild mitochondrial uncoupling by DNP raised hippocampal oxygen tension and ameliorated postictal hypoxia. Chronic DNP also lowered mitochondrial oxygen-derived reactive species and oxidative stress in the hippocampus during postictal hypoxia. Uncoupling the mitochondria exerts therapeutic benefits on postictal cognitive dysfunction. Finally, antioxidants do not affect postictal hypoxia, but protect the brain from associated cognitive deficits. We provided evidence for a metabolic component of the prolonged oxygen deprivation that follow seizures and its pathological sequelae. Furthermore, we identified a molecular underpinning of this metabolic component, which involves excessive oxygen conversion into reactive species. Mild mitochondrial uncoupling may be a potential therapeutic strategy to treat the postictal state where seizure control is absent or poor.
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Affiliation(s)
- Bianca R Villa
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada; Department of Cell Biology and Anatomy, University of Calgary, Calgary, AB, T2N 4N1, Canada.
| | - Antis G George
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada; Department of Cell Biology and Anatomy, University of Calgary, Calgary, AB, T2N 4N1, Canada.
| | - Timothy E Shutt
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada; Departments of Medical Genetics and Biochemistry & Molecular Biology, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada; Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada.
| | - Patrick G Sullivan
- Department of Anatomy and Neurobiology, and Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY, 40536, USA.
| | - Jong M Rho
- Department of Neurosciences, Pediatrics and Pharmacology, University of California San Diego, Rady Children's Hospital, San Diego, CA, 92037, USA.
| | - G Campbell Teskey
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada; Department of Cell Biology and Anatomy, University of Calgary, Calgary, AB, T2N 4N1, Canada; Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada.
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4
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Scieszka D, Bolt AM, McCormick MA, Brigman JL, Campen MJ. Aging, longevity, and the role of environmental stressors: a focus on wildfire smoke and air quality. FRONTIERS IN TOXICOLOGY 2023; 5:1267667. [PMID: 37900096 PMCID: PMC10600394 DOI: 10.3389/ftox.2023.1267667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 09/25/2023] [Indexed: 10/31/2023] Open
Abstract
Aging is a complex biological process involving multiple interacting mechanisms and is being increasingly linked to environmental exposures such as wildfire smoke. In this review, we detail the hallmarks of aging, emphasizing the role of telomere attrition, cellular senescence, epigenetic alterations, proteostasis, genomic instability, and mitochondrial dysfunction, while also exploring integrative hallmarks - altered intercellular communication and stem cell exhaustion. Within each hallmark of aging, our review explores how environmental disasters like wildfires, and their resultant inhaled toxicants, interact with these aging mechanisms. The intersection between aging and environmental exposures, especially high-concentration insults from wildfires, remains under-studied. Preliminary evidence, from our group and others, suggests that inhaled wildfire smoke can accelerate markers of neurological aging and reduce learning capabilities. This is likely mediated by the augmentation of circulatory factors that compromise vascular and blood-brain barrier integrity, induce chronic neuroinflammation, and promote age-associated proteinopathy-related outcomes. Moreover, wildfire smoke may induce a reduced metabolic, senescent cellular phenotype. Future interventions could potentially leverage combined anti-inflammatory and NAD + boosting compounds to counter these effects. This review underscores the critical need to study the intricate interplay between environmental factors and the biological mechanisms of aging to pave the way for effective interventions.
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Affiliation(s)
- David Scieszka
- Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM, United States
| | - Alicia M. Bolt
- Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM, United States
| | - Mark A. McCormick
- Department of Biochemistry and Molecular Biology, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM, United States
| | - Jonathan L. Brigman
- Department of Neurosciences, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM, United States
| | - Matthew J. Campen
- Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM, United States
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5
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Silaghi CN, Farcaș M, Crăciun AM. Sirtuin 3 (SIRT3) Pathways in Age-Related Cardiovascular and Neurodegenerative Diseases. Biomedicines 2021; 9:biomedicines9111574. [PMID: 34829803 PMCID: PMC8615405 DOI: 10.3390/biomedicines9111574] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 10/22/2021] [Accepted: 10/27/2021] [Indexed: 01/08/2023] Open
Abstract
Age-associated cardiovascular and neurodegenerative diseases lead to high morbidity and mortality around the world. Sirtuins are vital enzymes for metabolic adaptation and provide protective effects against a wide spectrum of pathologies. Among sirtuins, mitochondrial sirtuin 3 (SIRT3) is an essential player in preserving the habitual metabolic profile. SIRT3 activity declines as a result of aging-induced changes in cellular metabolism, leading to increased susceptibility to endothelial dysfunction, hypertension, heart failure and neurodegenerative diseases. Stimulating SIRT3 activity via lifestyle, pharmacological or genetic interventions could protect against a plethora of pathologies and could improve health and lifespan. Thus, understanding how SIRT3 operates and how its protective effects could be amplified, will aid in treating age-associated diseases and ultimately, in enhancing the quality of life in elders.
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6
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Readnower RD, Hubbard WB, Kalimon OJ, Geddes JW, Sullivan PG. Genetic Approach to Elucidate the Role of Cyclophilin D in Traumatic Brain Injury Pathology. Cells 2021; 10:199. [PMID: 33498273 PMCID: PMC7909250 DOI: 10.3390/cells10020199] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/11/2021] [Accepted: 01/15/2021] [Indexed: 12/15/2022] Open
Abstract
Cyclophilin D (CypD) has been shown to play a critical role in mitochondrial permeability transition pore (mPTP) opening and the subsequent cell death cascade. Studies consistently demonstrate that mitochondrial dysfunction, including mitochondrial calcium overload and mPTP opening, is essential to the pathobiology of cell death after a traumatic brain injury (TBI). CypD inhibitors, such as cyclosporin A (CsA) or NIM811, administered following TBI, are neuroprotective and quell neurological deficits. However, some pharmacological inhibitors of CypD have multiple biological targets and, as such, do not directly implicate a role for CypD in arbitrating cell death after TBI. Here, we reviewed the current understanding of the role CypD plays in TBI pathobiology. Further, we directly assessed the role of CypD in mediating cell death following TBI by utilizing mice lacking the CypD encoding gene Ppif. Following controlled cortical impact (CCI), the genetic knockout of CypD protected acute mitochondrial bioenergetics at 6 h post-injury and reduced subacute cortical tissue and hippocampal cell loss at 18 d post-injury. The administration of CsA following experimental TBI in Ppif-/- mice improved cortical tissue sparing, highlighting the multiple cellular targets of CsA in the mitigation of TBI pathology. The loss of CypD appeared to desensitize the mitochondrial response to calcium burden induced by TBI; this maintenance of mitochondrial function underlies the observed neuroprotective effect of the CypD knockout. These studies highlight the importance of maintaining mitochondrial homeostasis after injury and validate CypD as a therapeutic target for TBI. Further, these results solidify the beneficial effects of CsA treatment following TBI.
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Affiliation(s)
- Ryan D. Readnower
- Spinal Cord and Brain Injury Research Center (SCoBIRC), University of Kentucky, Lexington, KY 40536, USA; (R.D.R.); (W.B.H.); (O.J.K.); (J.W.G.)
- Department of Neuroscience, University of Kentucky, Lexington, KY 40508, USA
| | - William Brad Hubbard
- Spinal Cord and Brain Injury Research Center (SCoBIRC), University of Kentucky, Lexington, KY 40536, USA; (R.D.R.); (W.B.H.); (O.J.K.); (J.W.G.)
- Department of Neuroscience, University of Kentucky, Lexington, KY 40508, USA
- Lexington Veterans’ Affairs Healthcare System, Lexington, KY 40502, USA
| | - Olivia J. Kalimon
- Spinal Cord and Brain Injury Research Center (SCoBIRC), University of Kentucky, Lexington, KY 40536, USA; (R.D.R.); (W.B.H.); (O.J.K.); (J.W.G.)
- Department of Neuroscience, University of Kentucky, Lexington, KY 40508, USA
| | - James W. Geddes
- Spinal Cord and Brain Injury Research Center (SCoBIRC), University of Kentucky, Lexington, KY 40536, USA; (R.D.R.); (W.B.H.); (O.J.K.); (J.W.G.)
- Department of Neuroscience, University of Kentucky, Lexington, KY 40508, USA
| | - Patrick G. Sullivan
- Spinal Cord and Brain Injury Research Center (SCoBIRC), University of Kentucky, Lexington, KY 40536, USA; (R.D.R.); (W.B.H.); (O.J.K.); (J.W.G.)
- Department of Neuroscience, University of Kentucky, Lexington, KY 40508, USA
- Lexington Veterans’ Affairs Healthcare System, Lexington, KY 40502, USA
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7
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SIRT3 Haploinsufficiency Aggravates Loss of GABAergic Interneurons and Neuronal Network Hyperexcitability in an Alzheimer's Disease Model. J Neurosci 2019; 40:694-709. [PMID: 31818974 DOI: 10.1523/jneurosci.1446-19.2019] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 09/26/2019] [Accepted: 11/05/2019] [Indexed: 01/17/2023] Open
Abstract
Impaired mitochondrial function and aberrant neuronal network activity are believed to be early events in the pathogenesis of Alzheimer's disease (AD), but how mitochondrial alterations contribute to aberrant activity in neuronal circuits is unknown. In this study, we examined the function of mitochondrial protein deacetylase sirtuin 3 (SIRT3) in the pathogenesis of AD. Compared with AppPs1 mice, Sirt3-haploinsufficient AppPs1 mice (Sirt3+/-AppPs1) exhibit early epileptiform EEG activity and seizure. Both male and female Sirt3+/-AppPs1 mice were observed to die prematurely before 5 months of age. When comparing male mice among different genotypes, Sirt3 haploinsufficiency renders GABAergic interneurons in the cerebral cortex vulnerable to degeneration and associated neuronal network hyperexcitability. Feeding Sirt3+/-AppPs1 AD mice with a ketone ester-rich diet increases SIRT3 expression and prevents seizure-related death and the degeneration of GABAergic neurons, indicating that the aggravated GABAergic neuron loss and neuronal network hyperexcitability in Sirt3+/-AppPs1 mice are caused by SIRT3 reduction and can be rescued by increase of SIRT3 expression. Consistent with a protective role in AD, SIRT3 levels are reduced in association with cerebral cortical Aβ pathology in AD patients. In summary, SIRT3 preserves GABAergic interneurons and protects cerebral circuits against hyperexcitability, and this neuroprotective mechanism can be bolstered by dietary ketone esters.SIGNIFICANCE STATEMENT GABAergic neurons provide the main inhibitory control of neuronal activity in the brain. By preserving mitochondrial function, SIRT3 protects parvalbumin and calretinin interneurons against Aβ-associated dysfunction and degeneration in AppPs1 Alzheimer's disease mice, thus restraining neuronal network hyperactivity. The neuronal network dysfunction that occurs in Alzheimer's disease can be partially reversed by physiological, dietary, and pharmacological interventions to increase SIRT3 expression and enhance the functionality of GABAergic interneurons.
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8
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Chan F, Lax NZ, Voss CM, Aldana BI, Whyte S, Jenkins A, Nicholson C, Nichols S, Tilley E, Powell Z, Waagepetersen HS, Davies CH, Turnbull DM, Cunningham MO. The role of astrocytes in seizure generation: insights from a novel in vitro seizure model based on mitochondrial dysfunction. Brain 2019; 142:391-411. [PMID: 30689758 DOI: 10.1093/brain/awy320] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 10/29/2018] [Indexed: 12/22/2022] Open
Abstract
Approximately one-quarter of patients with mitochondrial disease experience epilepsy. Their epilepsy is often severe and resistant towards conventional antiepileptic drugs. Despite the severity of this epilepsy, there are currently no animal models available to provide a mechanistic understanding of mitochondrial epilepsy. We conducted neuropathological studies on patients with mitochondrial epilepsy and found the involvement of the astrocytic compartment. As a proof of concept, we developed a novel brain slice model of mitochondrial epilepsy by the application of an astrocytic-specific aconitase inhibitor, fluorocitrate, concomitant with mitochondrial respiratory inhibitors, rotenone and potassium cyanide. The model was robust and exhibited both face and predictive validity. We then used the model to assess the role that astrocytes play in seizure generation and demonstrated the involvement of the GABA-glutamate-glutamine cycle. Notably, glutamine appears to be an important intermediary molecule between the neuronal and astrocytic compartment in the regulation of GABAergic inhibitory tone. Finally, we found that a deficiency in glutamine synthetase is an important pathogenic process for seizure generation in both the brain slice model and the human neuropathological study. Our study describes the first model for mitochondrial epilepsy and provides a mechanistic insight into how astrocytes drive seizure generation in mitochondrial epilepsy.
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Affiliation(s)
- Felix Chan
- Institute of Neuroscience, Newcastle University, The Medical School, Framlington Place, Newcastle upon Tyne, UK.,Wellcome Centre for Mitochondrial Research, Newcastle University, Institute of Neuroscience, The Medical School, Framlington Place, Newcastle upon Tyne, UK
| | - Nichola Z Lax
- Wellcome Centre for Mitochondrial Research, Newcastle University, Institute of Neuroscience, The Medical School, Framlington Place, Newcastle upon Tyne, UK
| | - Caroline Marie Voss
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Blanca Irene Aldana
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Shuna Whyte
- Institute of Neuroscience, Newcastle University, The Medical School, Framlington Place, Newcastle upon Tyne, UK
| | - Alistair Jenkins
- Department of Neurosurgery, Royal Victoria Infirmary, Newcastle upon Tyne, UK
| | - Claire Nicholson
- Department of Neurosurgery, Royal Victoria Infirmary, Newcastle upon Tyne, UK
| | - Sophie Nichols
- Institute of Neuroscience, Newcastle University, The Medical School, Framlington Place, Newcastle upon Tyne, UK
| | - Elizabeth Tilley
- Institute of Neuroscience, Newcastle University, The Medical School, Framlington Place, Newcastle upon Tyne, UK
| | - Zoe Powell
- Institute of Neuroscience, Newcastle University, The Medical School, Framlington Place, Newcastle upon Tyne, UK
| | - Helle S Waagepetersen
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Ceri H Davies
- Neural Pathways DPU, GSK, 11 Biopolis Way, Singapore
| | - Doug M Turnbull
- Wellcome Centre for Mitochondrial Research, Newcastle University, Institute of Neuroscience, The Medical School, Framlington Place, Newcastle upon Tyne, UK
| | - Mark O Cunningham
- Institute of Neuroscience, Newcastle University, The Medical School, Framlington Place, Newcastle upon Tyne, UK.,Discipline of Physiology, School of Medicine, Trinity College Dublin, Dublin 2, Ireland
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9
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Toglia P, Ullah G. Mitochondrial dysfunction and role in spreading depolarization and seizure. J Comput Neurosci 2019; 47:91-108. [PMID: 31506806 DOI: 10.1007/s10827-019-00724-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 03/12/2019] [Accepted: 07/26/2019] [Indexed: 11/24/2022]
Abstract
The effect of pathological phenomena such as epileptic seizures and spreading depolarization (SD) on mitochondria and the potential feedback of mitochondrial dysfunction into the dynamics of those phenomena are complex and difficult to study experimentally due to the simultaneous changes in many variables governing neuronal behavior. By combining a model that accounts for a wide range of neuronal behaviors including seizures, normoxic SD, and hypoxic SD (HSD), together with a detailed model of mitochondrial function and intracellular Ca2+ dynamics, we investigate mitochondrial dysfunction and its potential role in recovery of the neuron from seizures, HSD, and SD. Our results demonstrate that HSD leads to the collapse of mitochondrial membrane potential and cellular ATP levels that recover only when normal oxygen supply is restored. Mitochondrial organic phosphate and pH gradients determine the strength of the depolarization block during HSD and SD, how quickly the cell enters the depolarization block when the oxygen supply is disrupted or potassium in the bath solution is raised beyond the physiological value, and how fast the cell recovers from SD and HSD when normal potassium concentration and oxygen supply are restored. Although not as dramatic as phosphate and pH gradients, mitochondrial Ca2+ uptake has a similar effect on neuronal behavior during these conditions.
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Affiliation(s)
- Patrick Toglia
- Department of Physics, University of South Florida, 4202 E. Fowler Ave., Tampa, FL, 33620, USA
| | - Ghanim Ullah
- Department of Physics, University of South Florida, 4202 E. Fowler Ave., Tampa, FL, 33620, USA.
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Briston T, Selwood DL, Szabadkai G, Duchen MR. Mitochondrial Permeability Transition: A Molecular Lesion with Multiple Drug Targets. Trends Pharmacol Sci 2018; 40:50-70. [PMID: 30527591 DOI: 10.1016/j.tips.2018.11.004] [Citation(s) in RCA: 127] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 11/05/2018] [Accepted: 11/06/2018] [Indexed: 12/13/2022]
Abstract
Mitochondrial permeability transition, as the consequence of opening of a mitochondrial permeability transition pore (mPTP), is a cellular catastrophe. Initiating bioenergetic collapse and cell death, it has been implicated in the pathophysiology of major human diseases, including neuromuscular diseases of childhood, ischaemia-reperfusion injury, and age-related neurodegenerative disease. Opening of the mPTP represents a major therapeutic target, as it can be mitigated by a number of compounds. However, clinical studies have so far been disappointing. We therefore address the prospects and challenges faced in translating in vitro findings to clinical benefit. We review the role of mPTP opening in disease, discuss recent findings defining the putative structure of the mPTP, and explore strategies to identify novel, clinically useful mPTP inhibitors, highlighting key considerations in the drug discovery process.
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Affiliation(s)
- Thomas Briston
- Neurology Innovation Centre, Hatfield Research Laboratories, Eisai Ltd., Hatfield, UK.
| | - David L Selwood
- Wolfson Institute for Biomedical Research, Division of Medicine, University College London, London, UK
| | - Gyorgy Szabadkai
- Department of Cell and Developmental Biology, Consortium for Mitochondrial Research, University College London, London, UK; Department of Biomedical Sciences, University of Padua, Padua, Italy; The Francis Crick Institute, London, UK
| | - Michael R Duchen
- Department of Cell and Developmental Biology, Consortium for Mitochondrial Research, University College London, London, UK
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11
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Rottenberg H, Hoek JB. The path from mitochondrial ROS to aging runs through the mitochondrial permeability transition pore. Aging Cell 2017; 16:943-955. [PMID: 28758328 PMCID: PMC5595682 DOI: 10.1111/acel.12650] [Citation(s) in RCA: 162] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/21/2017] [Indexed: 12/23/2022] Open
Abstract
Excessive production of mitochondrial reactive oxygen species (mROS) is strongly associated with mitochondrial and cellular oxidative damage, aging, and degenerative diseases. However, mROS also induces pathways of protection of mitochondria that slow aging, inhibit cell death, and increase lifespan. Recent studies show that the activation of the mitochondrial permeability transition pore (mPTP), which is triggered by mROS and mitochondrial calcium overloading, is enhanced in aged animals and humans and in aging-related degenerative diseases. mPTP opening initiates further production and release of mROS that damage both mitochondrial and nuclear DNA, proteins, and phospholipids, and also releases matrix NAD that is hydrolyzed in the intermembrane space, thus contributing to the depletion of cellular NAD that accelerates aging. Oxidative damage to calcium transporters leads to calcium overload and more frequent opening of mPTP. Because aging enhances the opening of the mPTP and mPTP opening accelerates aging, we suggest that mPTP opening drives the progression of aging. Activation of the mPTP is regulated, directly and indirectly, not only by the mitochondrial protection pathways that are induced by mROS, but also by pro-apoptotic signals that are induced by DNA damage. We suggest that the integration of these contrasting signals by the mPTP largely determines the rate of cell aging and the initiation of cell death, and thus animal lifespan. The suggestion that the control of mPTP activation is critical for the progression of aging can explain the conflicting and confusing evidence regarding the beneficial and deleterious effects of mROS on health and lifespan.
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Affiliation(s)
- Hagai Rottenberg
- New Hope Biomedical R&D; 23 W. Bridge Street New Hope PA 18038 USA
| | - Jan B. Hoek
- Department of Anatomy, Pathology and Cell Biology; MitoCare Center; Thomas Jefferson University; Philadelphia PA 19107 USA
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12
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Kulbe JR, Hill RL, Singh IN, Wang JA, Hall ED. Synaptic Mitochondria Sustain More Damage than Non-Synaptic Mitochondria after Traumatic Brain Injury and Are Protected by Cyclosporine A. J Neurotrauma 2016; 34:1291-1301. [PMID: 27596283 DOI: 10.1089/neu.2016.4628] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Currently, there are no Food and Drug Administration (FDA)-approved pharmacotherapies for the treatment of those with traumatic brain injury (TBI). As central mediators of the secondary injury cascade, mitochondria are promising therapeutic targets for prevention of cellular death and dysfunction after TBI. One of the most promising and extensively studied mitochondrial targeted TBI therapies is inhibition of the mitochondrial permeability transition pore (mPTP) by the FDA-approved drug, cyclosporine A (CsA). A number of studies have evaluated the effects of CsA on total brain mitochondria after TBI; however, no study has investigated the effects of CsA on isolated synaptic and non-synaptic mitochondria. Synaptic mitochondria are considered essential for proper neurotransmission and synaptic plasticity, and their dysfunction has been implicated in neurodegeneration. Synaptic and non-synaptic mitochondria have heterogeneous characteristics, but their heterogeneity can be masked in total mitochondrial (synaptic and non-synaptic) preparations. Therefore, it is essential that mitochondria targeted pharmacotherapies, such as CsA, be evaluated in both populations. This is the first study to examine the effects of CsA on isolated synaptic and non-synaptic mitochondria after experimental TBI. We conclude that synaptic mitochondria sustain more damage than non-synaptic mitochondria 24 h after severe controlled cortical impact injury (CCI), and that intraperitoneal administration of CsA (20 mg/kg) 15 min after injury improves synaptic and non-synaptic respiration, with a significant improvement being seen in the more severely impaired synaptic population. As such, CsA remains a promising neuroprotective candidate for the treatment of those with TBI.
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Affiliation(s)
- Jacqueline R Kulbe
- Spinal Cord & Brain Injury Research Center (SCoBIRC) and Department of Anatomy & Neurobiology, University of Kentucky College of Medicine , Lexington, Kentucky
| | - Rachel L Hill
- Spinal Cord & Brain Injury Research Center (SCoBIRC) and Department of Anatomy & Neurobiology, University of Kentucky College of Medicine , Lexington, Kentucky
| | - Indrapal N Singh
- Spinal Cord & Brain Injury Research Center (SCoBIRC) and Department of Anatomy & Neurobiology, University of Kentucky College of Medicine , Lexington, Kentucky
| | - Juan A Wang
- Spinal Cord & Brain Injury Research Center (SCoBIRC) and Department of Anatomy & Neurobiology, University of Kentucky College of Medicine , Lexington, Kentucky
| | - Edward D Hall
- Spinal Cord & Brain Injury Research Center (SCoBIRC) and Department of Anatomy & Neurobiology, University of Kentucky College of Medicine , Lexington, Kentucky
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Kiss DS, Toth I, Jocsak G, Sterczer A, Bartha T, Frenyo LV, Zsarnovszky A. Preparation of purified perikaryal and synaptosomal mitochondrial fractions from relatively small hypothalamic brain samples. MethodsX 2016; 3:417-29. [PMID: 27284533 PMCID: PMC4887559 DOI: 10.1016/j.mex.2016.05.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 05/11/2016] [Indexed: 10/25/2022] Open
Abstract
In order to measure the activity of neuronal mitochondria, a representative proof of neuronal processes, physiologically relevant mitochondrial samples need to be gained as simply as possible. Existing methods are, however, either for tissue samples of large size and/or homogenous microstructures only, or are not tested for mitochondrial function measurements. In the present article we describe a gradient fractionation method to isolate viable and well-coupled mitochondria from relatively heterogeneous histological microstructures such as the hypothalamus. With this new method, we are able to isolate a sufficient amount of functional mitochondria for determination of respiratory activity, in a short period of time, using affordable equipment. •Verified by electron microscopy, our method separates highly enriched and well-preserved perikaryal and synaptosomal mitochondria. Both fractions contain minimal cell debris and no myelin. Respiratory measurements (carried out by Clark-type electrode) confirmed undisturbed mitochondrial function providing well-evaluable records. The demonstrated protocol yields highly viable mitochondrial subfractions within 3 h from small brain areas for high-precision examinations. Using this procedure, brain regions with relatively heterogeneous histological microstructure (hypothalamus) can also be efficiently sampled.•Up to our present knowledge, our method is the shortest available procedure with the lowest sample size to gain debris-free, fully-viable mitochondria.
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Affiliation(s)
- David S Kiss
- Department of Physiology and Biochemistry, Szent Istvan University Faculty of Veterinary Sciences, Budapest, Hungary
| | - Istvan Toth
- Department of Physiology and Biochemistry, Szent Istvan University Faculty of Veterinary Sciences, Budapest, Hungary
| | - Gergely Jocsak
- Department of Physiology and Biochemistry, Szent Istvan University Faculty of Veterinary Sciences, Budapest, Hungary
| | - Agnes Sterczer
- Department and Clinic of Internal Medicine, Szent Istvan University Faculty of Veterinary Sciences, Budapest, Hungary
| | - Tibor Bartha
- Department of Physiology and Biochemistry, Szent Istvan University Faculty of Veterinary Sciences, Budapest, Hungary
| | - Laszlo V Frenyo
- Department of Physiology and Biochemistry, Szent Istvan University Faculty of Veterinary Sciences, Budapest, Hungary
| | - Attila Zsarnovszky
- Division of Comparative Medicine, Yale University School of Medicine, New Haven, CT, USA; Department of Animal Physiology and Animal Health, Szent Istvan University Faculty of Agricultural and Environmental Sciences, Godollo, Hungary
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14
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Warne J, Pryce G, Hill JM, Shi X, Lennerås F, Puentes F, Kip M, Hilditch L, Walker P, Simone MI, Chan AWE, Towers GJ, Coker AR, Duchen MR, Szabadkai G, Baker D, Selwood DL. Selective Inhibition of the Mitochondrial Permeability Transition Pore Protects against Neurodegeneration in Experimental Multiple Sclerosis. J Biol Chem 2016; 291:4356-73. [PMID: 26679998 PMCID: PMC4813465 DOI: 10.1074/jbc.m115.700385] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 12/09/2015] [Indexed: 12/23/2022] Open
Abstract
The mitochondrial permeability transition pore is a recognized drug target for neurodegenerative conditions such as multiple sclerosis and for ischemia-reperfusion injury in the brain and heart. The peptidylprolyl isomerase, cyclophilin D (CypD, PPIF), is a positive regulator of the pore, and genetic down-regulation or knock-out improves outcomes in disease models. Current inhibitors of peptidylprolyl isomerases show no selectivity between the tightly conserved cyclophilin paralogs and exhibit significant off-target effects, immunosuppression, and toxicity. We therefore designed and synthesized a new mitochondrially targeted CypD inhibitor, JW47, using a quinolinium cation tethered to cyclosporine. X-ray analysis was used to validate the design concept, and biological evaluation revealed selective cellular inhibition of CypD and the permeability transition pore with reduced cellular toxicity compared with cyclosporine. In an experimental autoimmune encephalomyelitis disease model of neurodegeneration in multiple sclerosis, JW47 demonstrated significant protection of axons and improved motor assessments with minimal immunosuppression. These findings suggest that selective CypD inhibition may represent a viable therapeutic strategy for MS and identify quinolinium as a mitochondrial targeting group for in vivo use.
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Affiliation(s)
- Justin Warne
- From the Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Gareth Pryce
- From the Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, United Kingdom, the Neuroimmunology Unit, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London E1 2AT, United Kingdom
| | - Julia M Hill
- the Department of Cell and Developmental Biology, University College London, London WC1E 6BT, United Kingdom
| | - Xiao Shi
- From the Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Felicia Lennerås
- the Neuroimmunology Unit, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London E1 2AT, United Kingdom
| | - Fabiola Puentes
- the Neuroimmunology Unit, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London E1 2AT, United Kingdom
| | - Maarten Kip
- From the Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Laura Hilditch
- the Medical Research Council Centre for Medical Molecular Biology, Division of Infection and Immunity, University College London, London WC1E 6BT, United Kingdom
| | - Paul Walker
- Cyprotex Discovery Ltd., 100 Barbirolli Square, Manchester M2 3AB, United Kingdom, and
| | - Michela I Simone
- From the Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - A W Edith Chan
- From the Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Greg J Towers
- the Medical Research Council Centre for Medical Molecular Biology, Division of Infection and Immunity, University College London, London WC1E 6BT, United Kingdom
| | - Alun R Coker
- From the Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Michael R Duchen
- the Department of Cell and Developmental Biology, University College London, London WC1E 6BT, United Kingdom
| | - Gyorgy Szabadkai
- the Department of Cell and Developmental Biology, University College London, London WC1E 6BT, United Kingdom, the Department of Biomedical Sciences, University of Padua, Padua 35122, Italy
| | - David Baker
- the Neuroimmunology Unit, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London E1 2AT, United Kingdom,
| | - David L Selwood
- From the Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, United Kingdom,
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15
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Ayata C, Lauritzen M. Spreading Depression, Spreading Depolarizations, and the Cerebral Vasculature. Physiol Rev 2015; 95:953-93. [PMID: 26133935 DOI: 10.1152/physrev.00027.2014] [Citation(s) in RCA: 364] [Impact Index Per Article: 40.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Spreading depression (SD) is a transient wave of near-complete neuronal and glial depolarization associated with massive transmembrane ionic and water shifts. It is evolutionarily conserved in the central nervous systems of a wide variety of species from locust to human. The depolarization spreads slowly at a rate of only millimeters per minute by way of grey matter contiguity, irrespective of functional or vascular divisions, and lasts up to a minute in otherwise normal tissue. As such, SD is a radically different breed of electrophysiological activity compared with everyday neural activity, such as action potentials and synaptic transmission. Seventy years after its discovery by Leão, the mechanisms of SD and its profound metabolic and hemodynamic effects are still debated. What we did learn of consequence, however, is that SD plays a central role in the pathophysiology of a number of diseases including migraine, ischemic stroke, intracranial hemorrhage, and traumatic brain injury. An intriguing overlap among them is that they are all neurovascular disorders. Therefore, the interplay between neurons and vascular elements is critical for our understanding of the impact of this homeostatic breakdown in patients. The challenges of translating experimental data into human pathophysiology notwithstanding, this review provides a detailed account of bidirectional interactions between brain parenchyma and the cerebral vasculature during SD and puts this in the context of neurovascular diseases.
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Affiliation(s)
- Cenk Ayata
- Neurovascular Research Laboratory, Department of Radiology, and Stroke Service and Neuroscience Intensive Care Unit, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts; Department of Neuroscience and Pharmacology and Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark; and Department of Clinical Neurophysiology, Glostrup Hospital, Glostrup, Denmark
| | - Martin Lauritzen
- Neurovascular Research Laboratory, Department of Radiology, and Stroke Service and Neuroscience Intensive Care Unit, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts; Department of Neuroscience and Pharmacology and Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark; and Department of Clinical Neurophysiology, Glostrup Hospital, Glostrup, Denmark
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16
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Perrucci GL, Gowran A, Zanobini M, Capogrossi MC, Pompilio G, Nigro P. Peptidyl-prolyl isomerases: a full cast of critical actors in cardiovascular diseases. Cardiovasc Res 2015; 106:353-64. [DOI: 10.1093/cvr/cvv096] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 01/30/2015] [Indexed: 12/28/2022] Open
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17
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Nicholls DG, Brand MD, Gerencser AA. Mitochondrial bioenergetics and neuronal survival modelled in primary neuronal culture and isolated nerve terminals. J Bioenerg Biomembr 2014; 47:63-74. [DOI: 10.1007/s10863-014-9573-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 08/20/2014] [Indexed: 12/20/2022]
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18
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Biology of mitochondria in neurodegenerative diseases. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2012; 107:355-415. [PMID: 22482456 DOI: 10.1016/b978-0-12-385883-2.00005-9] [Citation(s) in RCA: 123] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS) are the most common human adult-onset neurodegenerative diseases. They are characterized by prominent age-related neurodegeneration in selectively vulnerable neural systems. Some forms of AD, PD, and ALS are inherited, and genes causing these diseases have been identified. Nevertheless, the mechanisms of the neuronal degeneration in these familial diseases, and in the more common idiopathic (sporadic) diseases, are unresolved. Genetic, biochemical, and morphological analyses of human AD, PD, and ALS, as well as their cell and animal models, reveal that mitochondria could have roles in this neurodegeneration. The varied functions and properties of mitochondria might render subsets of selectively vulnerable neurons intrinsically susceptible to cellular aging and stress and the overlying genetic variations. In AD, alterations in enzymes involved in oxidative phosphorylation, oxidative damage, and mitochondrial binding of Aβ and amyloid precursor protein have been reported. In PD, mutations in mitochondrial proteins have been identified and mitochondrial DNA mutations have been found in neurons in the substantia nigra. In ALS, changes occur in mitochondrial respiratory chain enzymes and mitochondrial programmed cell death proteins. Transgenic mouse models of human neurodegenerative disease are beginning to reveal possible principles governing the biology of selective neuronal vulnerability that implicate mitochondria and the mitochondrial permeability transition pore. This chapter reviews several aspects of mitochondrial biology and how mitochondrial pathobiology might contribute to the mechanisms of neurodegeneration in AD, PD, and ALS.
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19
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Figueira TR, Castilho RF, Saito A, Oliveira HCF, Vercesi AE. The higher susceptibility of congenital analbuminemic rats to Ca2+-induced mitochondrial permeability transition is associated with the increased expression of cyclophilin D and nitrosothiol depletion. Mol Genet Metab 2011; 104:521-8. [PMID: 21963200 DOI: 10.1016/j.ymgme.2011.08.031] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Revised: 08/30/2011] [Accepted: 08/30/2011] [Indexed: 11/29/2022]
Abstract
Congenital analbuminemia is a rare autosomal recessive disorder characterized by a trace level of albumin in blood plasma and mild clinical symptoms. Analbuminemic patients generally present associated abnormalities, among which dyslipidemia is a hallmark. In this study, we show that mitochondria isolated from different tissues (liver, heart and brain) from 3-month-old analbuminemic rats (NAR) present a higher susceptibility to Ca(2+)-induced mitochondrial permeability transition (MPT), as assessed by either Ca(2+)-induced mitochondrial swelling, dissipation of membrane potential or mitochondrial Ca(2+) release. The Ca(2+) retention capacity of the liver mitochondria isolated from 3-month-old NAR was about 50% that of the control. Interestingly, the assessment of this variable in 21-day-old NAR indicated that the mitochondrial Ca(2+) retention capacity was preserved at this age, as compared to age-matched controls, which indicates that a reduced capacity for mitochondrial Ca(2+) retention is not a constitutive feature. The search for putative mediators of MPT sensitization in NAR revealed a 20% decrease in mitochondrial nitrosothiol content and a 30% increase in cyclophilin D expression. However, the evaluation of other variables related to mitochondrial redox status showed similar results between the controls and NAR, i.e., namely the contents of reduced mitochondrial membrane protein thiol groups and total glutathione, H(2)O(2) release rate, and NAD(P)H reduced state. We conclude that the higher expression of cyclophilin D, a major component of the MPT pore, and decreased nitrosothiol content in NAR mitochondria may underlie MPT sensitization in these animals.
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Affiliation(s)
- Tiago R Figueira
- Departamento de Patologia Clínica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brazil
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20
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Piilgaard H, Witgen BM, Rasmussen P, Lauritzen M. Cyclosporine A, FK506, and NIM811 ameliorate prolonged CBF reduction and impaired neurovascular coupling after cortical spreading depression. J Cereb Blood Flow Metab 2011; 31:1588-98. [PMID: 21427730 PMCID: PMC3137467 DOI: 10.1038/jcbfm.2011.28] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Revised: 02/16/2011] [Accepted: 02/17/2011] [Indexed: 11/08/2022]
Abstract
Cortical spreading depression (CSD) is associated with mitochondrial depolarization, increasing intracellular Ca(2+), and the release of free fatty acids, which favor opening of the mitochondrial permeability transition pore (mPTP) and activation of calcineurin (CaN). Here, we test the hypothesis that cyclosporine A (CsA), which blocks both mPTP and CaN, ameliorates the persistent reduction of cerebral blood flow (CBF), impaired vascular reactivity, and a persistent rise in the cerebral metabolic rate of oxygen (CMRO(2)) following CSD. In addition to CsA, we used the specific mPTP blocker NIM811 and the specific CaN blocker FK506. Cortical spreading depression was induced in rat frontal cortex. Electrocortical activity was recorded by glass microelectrodes, CBF by laser Doppler flowmetry, and tissue oxygen tension with polarographic microelectrodes. Electrocortical activity, basal CBF, CMRO(2), and neurovascular and neurometabolic coupling were unaffected by all three drugs under control conditions. NIM811 augmented the rise in CBF observed during CSD. Cyclosporine A and FK506 ameliorated the persistent decrease in CBF after CSD. All three drugs prevented disruption of neurovascular coupling after CSD; the rise in CMRO(2) was unchanged. Our data suggest that blockade of mPTP formation and CaN activation may prevent persistent CBF reduction and vascular dysfunction after CSD.
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Affiliation(s)
- Henning Piilgaard
- Department of Neuroscience and Pharmacology, Center for Healthy Aging, The Panum Institute, University of Copenhagen, Copenhagen N, Denmark
| | - Brent M Witgen
- Department of Neuroscience and Pharmacology, Center for Healthy Aging, The Panum Institute, University of Copenhagen, Copenhagen N, Denmark
| | - Peter Rasmussen
- Department of Neuroscience and Pharmacology, Center for Healthy Aging, The Panum Institute, University of Copenhagen, Copenhagen N, Denmark
| | - Martin Lauritzen
- Department of Neuroscience and Pharmacology, Center for Healthy Aging, The Panum Institute, University of Copenhagen, Copenhagen N, Denmark
- Department of Clinical Neurophysiology, Glostrup Hospital, Glostrup, Denmark
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21
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Kristian T, Balan I, Schuh R, Onken M. Mitochondrial dysfunction and nicotinamide dinucleotide catabolism as mechanisms of cell death and promising targets for neuroprotection. J Neurosci Res 2011; 89:1946-55. [PMID: 21488086 DOI: 10.1002/jnr.22626] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2010] [Revised: 01/07/2011] [Accepted: 01/17/2011] [Indexed: 11/12/2022]
Abstract
Both acute and chronic neurodegenerative diseases are frequently associated with mitochondrial dysfunction as an essential component of mechanisms leading to brain damage. Although loss of mitochondrial functions resulting from prolonged activation of the mitochondrial permeability transition (MPT) pore has been shown to play a significant role in perturbation of cellular bioenergetics and in cell death, the detailed mechanisms are still elusive. Enzymatic reactions linked to glycolysis, the tricarboxylic acid cycle, and mitochondrial respiration are dependent on the reduced or oxidized form of nicotinamide dinucleotide [NAD(H)] as a cofactor. Loss of mitochondrial NAD(+) resulting from MPT pore opening, although transient, allows detrimental depletion of mitochondrial and cellular NAD(+) pools by activated NAD(+) glycohydrolases. Poly(ADP-ribose) polymerase (PARP) is considered to be a major NAD(+) degrading enzyme, particularly under conditions of extensive DNA damage. We propose that CD38, a main cellular NAD(+) level regulator, can significantly contribute to NAD(+) catabolism. We discuss NAD(+) catabolic and NAD(+) synthesis pathways and their role in different strategies to prevent cellular NAD(+) degradation in brain, particularly following an ischemic insult. These therapeutic approaches are based on utilizing endogenous intermediates of NAD(+) metabolism that feed into the NAD(+) salvage pathway and also inhibit CD38 activity.
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Affiliation(s)
- Tibor Kristian
- Department of Anesthesiology, Center for Shock, Trauma and Anesthesiology Research, School of Medicine, University of Maryland Baltimore, Baltimore, Maryland 21201, USA.
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22
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Reyes RC, Perry G, Lesort M, Parpura V. Immunophilin deficiency augments Ca2+-dependent glutamate release from mouse cortical astrocytes. Cell Calcium 2011; 49:23-34. [PMID: 21163525 PMCID: PMC3073643 DOI: 10.1016/j.ceca.2010.11.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2010] [Accepted: 11/08/2010] [Indexed: 11/23/2022]
Abstract
Immunophilins are receptors for immunosuppressive drugs such as the macrolides cyclosporin A (CsA) and FK506; correspondingly these immunophilins are referred to as cyclophilins and FK506-binding proteins (FKBPs). In particular, CsA targets cyclophilin D (CypD), which can modulate mitochondrial Ca(2+) dynamics. Since mitochondria have been implicated in the regulation of astrocytic cytosolic Ca(2+) (Ca(cyt)(2+)) dynamics and consequential Ca(2+)-dependent exocytotic release of glutamate, we investigated the role of CypD in this process. Cortical astrocytes isolated from CypD deficient mice Ppif(-/-) displayed reduced mechanically induced Ca(cyt)(2+) increases, even though these cells showed augmented exocytotic release of glutamate, when compared to responses obtained from astrocytes isolated from wild-type mice. Furthermore, acute treatment with CsA to inhibit CypD modulation of mitochondrial Ca(2+) buffering, or with FK506 to inhibit FKBP12 interaction with inositol-trisphosphate receptor of the endoplasmic reticulum, led to similar reductive effects on astrocytic Ca(cyt)(2+) dynamics, but also to an enhanced Ca(2+)-dependent exocytotic release of glutamate in wild-type astrocytes. These findings point to a possible role of immunophilin signal transduction pathways in astrocytic modulation of neuronal activity at the tripartite synapse.
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Affiliation(s)
- Reno C. Reyes
- Department of Neurobiology, Center for Glial Biology in Medicine, Atomic Force Microscopy & Nanotechnology Laboratories, Civitan International Research Center, Evelyn F. McKnight Brain Institute, University of Alabama, Birmingham, AL 35294
- Department of Neurology, University of California, San Francisco and Veterans Affairs Medical Center, San Francisco, CA 94121
| | - Giselle Perry
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama, Birmingham, Birmingham, AL 35294
| | - Mathieu Lesort
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama, Birmingham, Birmingham, AL 35294
| | - Vladimir Parpura
- Department of Neurobiology, Center for Glial Biology in Medicine, Atomic Force Microscopy & Nanotechnology Laboratories, Civitan International Research Center, Evelyn F. McKnight Brain Institute, University of Alabama, Birmingham, AL 35294
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Neuronal-immune interactions in mediating stress effects in the etiology and course of schizophrenia: role of the amygdala in developmental co-ordination. Med Hypotheses 2010; 76:54-60. [PMID: 20843610 DOI: 10.1016/j.mehy.2010.08.029] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2010] [Accepted: 08/10/2010] [Indexed: 11/24/2022]
Abstract
Stress, in its many forms, is long associated with the etiology and course of schizophrenia. The mechanisms mediating the impacts of stress are not fully elucidated. Here it is proposed that stress induced cortisol alters kynurenic acid (KA) and quinolinic acid (QA) in the cortex and amygdala/striatum, respectively. These effects are significantly modulated by BAG-1 (bcl-2 associated anthanogene) and involve ROS, IL-18, and the induction of IDO (indoleamine 2,3-dioxygenase). The kynurenine pathway (KP) products response to stress seems to mediate both prenatal etiology and symptom course in adulthood. It is suggested that the effects of cortisol and quinolinic acid in the amygdala, coupled to an increase in dopamine efflux, mediate amygdala driven developmental changes in the cortex and VTA/N.Accumbens junction. This change in patterned brain activity co-ordinates alterations in motivated behaviour and thought outputs. Such developmental alterations determine changes in sensory-amygdala interactions, readily allowing developmental links to changes in lateral inhibition and pre-pulse inhibition. Decreases in vitamin D3 and melatonin further potentiate such stress induced changes. The likely involvement of glia in mediating increases in the KP products suggests that adaptation to stress is driven by neuronal activity as a form of glia to glia communication.
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Abstract
This unit contains a protocol describing the isolation of brain mitochondria by using discontinuous Percoll gradient centrifugation. The Percoll density gradient centrifugation separates synaptosomes, myelin, and free nonsynaptic mitochondria released from cells during tissue homogenization into individual fractions. Mitochondria entrapped in synaptosomes (synaptic mitochondria) can be liberated using nitrogen cavitation and then further purified by Percoll gradient centrifugation. These methods yield mitochondria that exhibit good respiratory coupling and high respiratory rates.
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Affiliation(s)
- Tibor Kristian
- Department of Anesthesiology, Organized Research Center, School of Medicine, University of Maryland, Baltimore, Maryland, USA
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25
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Abstract
Alzheimer’s disease (AD), Parkinson’s disease (PD) and amyotrophic lateral sclerosis (ALS) are the most common human adult-onset neurodegenerative diseases. They are characterized by prominent age-related neurodegeneration in selectively vulnerable neural systems. Some forms of AD, PD, and ALS are inherited, and genes causing these diseases have been identified. Nevertheless, the mechanisms of the neuronal cell death are unresolved. Morphological, biochemical, genetic, as well as cell and animal model studies reveal that mitochondria could have roles in this neurodegeneration. The functions and properties of mitochondria might render subsets of selectively vulnerable neurons intrinsically susceptible to cellular aging and stress and overlying genetic variations, triggering neurodegeneration according to a cell death matrix theory. In AD, alterations in enzymes involved in oxidative phosphorylation, oxidative damage, and mitochondrial binding of Aβ and amyloid precursor protein have been reported. In PD, mutations in putative mitochondrial proteins have been identified and mitochondrial DNA mutations have been found in neurons in the substantia nigra. In ALS, changes occur in mitochondrial respiratory chain enzymes and mitochondrial cell death proteins. Transgenic mouse models of human neurodegenerative disease are beginning to reveal possible principles governing the biology of selective neuronal vulnerability that implicate mitochondria and the mitochondrial permeability transition pore. This review summarizes how mitochondrial pathobiology might contribute to neuronal death in AD, PD, and ALS and could serve as a target for drug therapy.
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26
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Martin LJ. The mitochondrial permeability transition pore: a molecular target for amyotrophic lateral sclerosis therapy. Biochim Biophys Acta Mol Basis Dis 2009; 1802:186-97. [PMID: 19651206 DOI: 10.1016/j.bbadis.2009.07.009] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2009] [Revised: 07/22/2009] [Accepted: 07/23/2009] [Indexed: 01/23/2023]
Abstract
Effective therapies are needed for the treatment of amyotrophic lateral sclerosis (ALS), a fatal type of motor neuron disease. Morphological, biochemical, molecular genetic, and cell/animal model studies suggest that mitochondria have potentially diverse roles in neurodegenerative disease mechanisms and neuronal cell death. In human ALS, abnormalities have been found in mitochondrial structure, mitochondrial respiratory chain enzymes, and mitochondrial cell death proteins indicative of some non-classical form of programmed cell death. Mouse models of ALS are beginning to reveal possible principles governing the biology of selective neuronal vulnerability that implicate mitochondria. This minireview summarizes work on the how malfunctioning mitochondria might contribute to neuronal death in ALS through the biophysical entity called the mitochondrial permeability pore (mPTP). The major protein components of the mPTP are enriched in mouse motor neurons. Early in the course of disease in ALS mice expressing human mutant superoxide dismutase-1, mitochondria in motor neurons undergo trafficking abnormalities and dramatic remodeling resulting in the formation of mega-mitochondria and coinciding with increased protein carbonyl formation and nitration of mPTP components. The genetic deletion of a major mPTP component, cyclophilin D, has robust effects in ALS mice by delaying disease onset and extending survival. Thus, attention should be directed to the mPTP as a rational target for the development of drugs designed to treat ALS.
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Affiliation(s)
- Lee J Martin
- Department of Pathology, Division of Neuropathology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205-2196, USA.
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Heterogeneity of nervous system mitochondria: Location, location, location! Exp Neurol 2009; 218:293-307. [DOI: 10.1016/j.expneurol.2009.05.020] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2009] [Revised: 04/30/2009] [Accepted: 05/08/2009] [Indexed: 01/03/2023]
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Martin LJ, Gertz B, Pan Y, Price AC, Molkentin JD, Chang Q. The mitochondrial permeability transition pore in motor neurons: involvement in the pathobiology of ALS mice. Exp Neurol 2009; 218:333-46. [PMID: 19272377 PMCID: PMC2710399 DOI: 10.1016/j.expneurol.2009.02.015] [Citation(s) in RCA: 144] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2008] [Revised: 02/17/2009] [Accepted: 02/19/2009] [Indexed: 12/19/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease of motor neurons (MNs) that causes paralysis. Some forms of ALS are inherited, caused by mutations in the superoxide dismutase-1 (SOD1) gene. The mechanisms of human mutant SOD1 (mSOD1) toxicity to MNs are unresolved. Mitochondria in MNs might be key sites for ALS pathogenesis, but cause-effect relationships between mSOD1 and mitochondriopathy need further study. We used transgenic mSOD1 mice to test the hypothesis that the mitochondrial permeability transition pore (mPTP) is involved in the MN degeneration of ALS. Components of the multi-protein mPTP are expressed highly in mouse MNs, including the voltage-dependent anion channel, adenine nucleotide translocator (ANT), and cyclophilin D (CyPD), and are present in mitochondria marked by manganese SOD. MNs in pre-symptomatic mSOD1-G93A mice form swollen megamitochondria with CyPD immunoreactivity. Early disease is associated with mitochondrial cristae remodeling and matrix vesiculation in ventral horn neuron dendrites. MN cell bodies accumulate mitochondria derived from the distal axons projecting to skeletal muscle. Incipient disease in spinal cord is associated with increased oxidative and nitrative stress, indicated by protein carbonyls and nitration of CyPD and ANT. Reducing the levels of CyPD by genetic ablation significantly delays disease onset and extends the lifespan of G93A-mSOD1 mice expressing high and low levels of mutant protein in a gender-dependent pattern. These results demonstrate that mitochondria have causal roles in the disease mechanisms in MNs in ALS mice. This work defines a new mitochondrial mechanism for MN degeneration in ALS.
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Affiliation(s)
- Lee J Martin
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205-2196, USA.
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Choi SW, Gerencser AA, Nicholls DG. Bioenergetic analysis of isolated cerebrocortical nerve terminals on a microgram scale: spare respiratory capacity and stochastic mitochondrial failure. J Neurochem 2009; 109:1179-91. [PMID: 19519782 DOI: 10.1111/j.1471-4159.2009.06055.x] [Citation(s) in RCA: 172] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Pre-synaptic nerve terminals (synaptosomes) require ATP for neurotransmitter exocytosis and recovery and for ionic homeostasis, and are consequently abundantly furnished with mitochondria. Pre-synaptic mitochondrial dysfunction is implicated in a variety of neurodegenerative disorders, although there is no precise definition of the term 'dysfunction'. In this study, we test the hypothesis that partial restriction of electron transport through Complexes I and II in synaptosomes to mimic possible defects associated with Parkinson's and Huntington's diseases respectively, sensitizes individual terminals to mitochondrial depolarization under conditions of enhanced proton current utilization, even though these stresses are within the respiratory capacity of the synaptosomes when averaged over the entire population. We combine two novel techniques, firstly using a modification of a plate-based respiration and glycolysis assay that requires only microgram quantities of synaptosomal protein, and secondly developing an improved method for fluorescent imaging and statistical analysis of single synaptosomes. Conditions are defined for optimal substrate supply to the in situ mitochondria within mouse cerebrocortical synaptosomes, and the energetic demands of ion cycling and action-potential firing at the plasma membrane are additionally determined.
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Affiliation(s)
- Sung W Choi
- Buck Institute for Age Research, Novato, California 94945, USA
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