1
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Gonda S, Köhler I, Haase A, Czubay K, Räk A, Riedel C, Wahle P. Optogenetic stimulation shapes dendritic trees of infragranular cortical pyramidal cells. Front Cell Neurosci 2023; 17:1212483. [PMID: 37587917 PMCID: PMC10427221 DOI: 10.3389/fncel.2023.1212483] [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: 04/26/2023] [Accepted: 06/09/2023] [Indexed: 08/18/2023] Open
Abstract
Spontaneous or experimentally evoked activity can lead to changes in length and/or branching of neocortical pyramidal cell dendrites. For instance, an early postnatal overexpression of certain AMPA or kainate glutamate receptor subunits leads to larger amplitudes of depolarizing events driven by spontaneous activity, and this increases apical dendritic complexity. Whether stimulation frequency has a role is less clear. In this study, we report that the expression of channelrhodopsin2-eYFP was followed by a 5-day optogenetic stimulation from DIV 5-10 or 11-15 in organotypic cultures of rat visual cortex-evoked dendritic remodeling. Stimulation at 0.05 Hz, at a frequency range of spontaneous calcium oscillations known to occur in the early postnatal neocortex in vivo until eye opening, had no effect. Stimulation with 0.5 Hz, a frequency at which the cortex in vivo adopts after eye opening, unexpectedly caused shorter and somewhat less branched apical dendrites of infragranular pyramidal neurons. The outcome resembles the remodeling of corticothalamic and callosal projection neurons of layers VI and V, which in the adult have apical dendrites no longer terminating in layer I. Exposure to 2.5 Hz, a frequency not occurring naturally during the time windows, evoked dendritic damage. The results suggested that optogenetic stimulation at a biologically meaningful frequency for the selected developmental stage can influence dendrite growth, but contrary to expectation, the optogenetic stimulation decreased dendritic growth.
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2
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Barros LF, Ruminot I, Sandoval PY, San Martín A. Enlightening brain energy metabolism. Neurobiol Dis 2023:106211. [PMID: 37352985 DOI: 10.1016/j.nbd.2023.106211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 05/06/2023] [Accepted: 06/20/2023] [Indexed: 06/25/2023] Open
Abstract
Brain tissue metabolism is distributed across several cell types and subcellular compartments, which activate at different times and with different temporal patterns. The introduction of genetically-encoded fluorescent indicators that are imaged using time-lapse microscopy has opened the possibility of studying brain metabolism at cellular and sub-cellular levels. There are indicators for sugars, monocarboxylates, Krebs cycle intermediates, amino acids, cofactors, and energy nucleotides, which inform about relative levels, concentrations and fluxes. This review offers a brief survey of the metabolic indicators that have been validated in brain cells, with some illustrative examples from the literature. Whereas only a small fraction of the metabolome is currently accessible to fluorescent probes, there are grounds to be optimistic about coming developments and the application of these tools to the study of brain disease.
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Affiliation(s)
- L F Barros
- Centro de Estudios Científicos (CECs), Valdivia, Chile; Facultad de Medicina y Ciencia, Universidad San Sebastián, Valdivia, Chile.
| | - I Ruminot
- Centro de Estudios Científicos (CECs), Valdivia, Chile; Facultad de Ciencias para el Cuidado de La Salud, Universidad San Sebastián, Valdivia, Chile
| | - P Y Sandoval
- Centro de Estudios Científicos (CECs), Valdivia, Chile; Facultad de Ciencias para el Cuidado de La Salud, Universidad San Sebastián, Valdivia, Chile
| | - A San Martín
- Centro de Estudios Científicos (CECs), Valdivia, Chile; Facultad de Ciencias para el Cuidado de La Salud, Universidad San Sebastián, Valdivia, Chile
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3
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Paciello F, Ripoli C, Fetoni AR, Grassi C. Redox Imbalance as a Common Pathogenic Factor Linking Hearing Loss and Cognitive Decline. Antioxidants (Basel) 2023; 12:antiox12020332. [PMID: 36829891 PMCID: PMC9952092 DOI: 10.3390/antiox12020332] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 01/23/2023] [Accepted: 01/29/2023] [Indexed: 02/04/2023] Open
Abstract
Experimental and clinical data suggest a tight link between hearing and cognitive functions under both physiological and pathological conditions. Indeed, hearing perception requires high-level cognitive processes, and its alterations have been considered a risk factor for cognitive decline. Thus, identifying common pathogenic determinants of hearing loss and neurodegenerative disease is challenging. Here, we focused on redox status imbalance as a possible common pathological mechanism linking hearing and cognitive dysfunctions. Oxidative stress plays a critical role in cochlear damage occurring during aging, as well as in that induced by exogenous factors, including noise. At the same time, increased oxidative stress in medio-temporal brain regions, including the hippocampus, is a hallmark of neurodegenerative disorders like Alzheimer's disease. As such, antioxidant therapy seems to be a promising approach to prevent and/or counteract both sensory and cognitive neurodegeneration. Here, we review experimental evidence suggesting that redox imbalance is a key pathogenetic factor underlying the association between sensorineural hearing loss and neurodegenerative diseases. A greater understanding of the pathophysiological mechanisms shared by these two diseased conditions will hopefully provide relevant information to develop innovative and effective therapeutic strategies.
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Affiliation(s)
- Fabiola Paciello
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| | - Cristian Ripoli
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
- Correspondence: ; Tel.: +39-0630154966
| | - Anna Rita Fetoni
- Unit of Audiology, Department of Neuroscience, Università degli Studi di Napoli Federico II, 80138 Naples, Italy
| | - Claudio Grassi
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
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4
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Abstract
The brain is one of the most energetically demanding tissues in the human body, and mitochondrial pathology is strongly implicated in chronic neurodegenerative diseases. In contrast to acute brain injuries in which bioenergetics and cell death play dominant roles, studies modeling familial neurodegeneration implicate a more complex and nuanced relationship involving the entire mitochondrial life cycle. Recent literature on mitochondrial mechanisms in Parkinson's disease, Alzheimer's disease, frontotemporal dementia, Huntington's disease, and amyotrophic lateral sclerosis is reviewed with an emphasis on mitochondrial quality control, transport and synaptodendritic calcium homeostasis. Potential neuroprotective interventions include targeting the mitochondrial kinase PTEN-induced kinase 1 (PINK1), which plays a role in regulating not only multiple facets of mitochondrial biology, but also neuronal morphogenesis and dendritic arborization.
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Affiliation(s)
- Charleen T Chu
- Departments of Pathology and Ophthalmology, Pittsburgh Institute for Neurodegenerative Diseases, McGowan Institute for Regenerative Medicine, Center for Protein Conformational Diseases, Center for Neuroscience at the University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
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5
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San Martín A, Arce-Molina R, Aburto C, Baeza-Lehnert F, Barros LF, Contreras-Baeza Y, Pinilla A, Ruminot I, Rauseo D, Sandoval PY. Visualizing physiological parameters in cells and tissues using genetically encoded indicators for metabolites. Free Radic Biol Med 2022; 182:34-58. [PMID: 35183660 DOI: 10.1016/j.freeradbiomed.2022.02.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 02/08/2022] [Accepted: 02/10/2022] [Indexed: 02/07/2023]
Abstract
The study of metabolism is undergoing a renaissance. Since the year 2002, over 50 genetically-encoded fluorescent indicators (GEFIs) have been introduced, capable of monitoring metabolites with high spatial/temporal resolution using fluorescence microscopy. Indicators are fusion proteins that change their fluorescence upon binding a specific metabolite. There are indicators for sugars, monocarboxylates, Krebs cycle intermediates, amino acids, cofactors, and energy nucleotides. They permit monitoring relative levels, concentrations, and fluxes in living systems. At a minimum they report relative levels and, in some cases, absolute concentrations may be obtained by performing ad hoc calibration protocols. Proper data collection, processing, and interpretation are critical to take full advantage of these new tools. This review offers a survey of the metabolic indicators that have been validated in mammalian systems. Minimally invasive, these indicators have been instrumental for the purposes of confirmation, rebuttal and discovery. We envision that this powerful technology will foster metabolic physiology.
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Affiliation(s)
- A San Martín
- Centro de Estudios Científicos (CECs), Valdivia, Chile.
| | - R Arce-Molina
- Centro de Estudios Científicos (CECs), Valdivia, Chile
| | - C Aburto
- Centro de Estudios Científicos (CECs), Valdivia, Chile; Universidad Austral de Chile, Valdivia, Chile
| | | | - L F Barros
- Centro de Estudios Científicos (CECs), Valdivia, Chile
| | - Y Contreras-Baeza
- Centro de Estudios Científicos (CECs), Valdivia, Chile; Universidad Austral de Chile, Valdivia, Chile
| | - A Pinilla
- Centro de Estudios Científicos (CECs), Valdivia, Chile; Universidad Austral de Chile, Valdivia, Chile
| | - I Ruminot
- Centro de Estudios Científicos (CECs), Valdivia, Chile
| | - D Rauseo
- Centro de Estudios Científicos (CECs), Valdivia, Chile; Universidad Austral de Chile, Valdivia, Chile
| | - P Y Sandoval
- Centro de Estudios Científicos (CECs), Valdivia, Chile
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6
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Huang L, Zhang Y, Wang Y, Lan Y. Relationship Between Chronic Noise Exposure, Cognitive Impairment, and Degenerative Dementia: Update on the Experimental and Epidemiological Evidence and Prospects for Further Research. J Alzheimers Dis 2021; 79:1409-1427. [PMID: 33459723 DOI: 10.3233/jad-201037] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Degenerative dementia, of which Alzheimer's disease is the most common form, is characterized by the gradual deterioration of cognitive function. The events that trigger and promote degenerative dementia are not clear, and treatment options are limited. Experimental and epidemiological studies have revealed chronic noise exposure (CNE) as a potential risk factor for cognitive impairment and degenerative dementia. Experimental studies have indicated that long-term exposure to noise might accelerate cognitive dysfunction, amyloid-β deposition, and tau hyperphosphorylation in different brain regions such as the hippocampus and cortex. Epidemiological studies are increasingly examining the possible association between external noise exposure and dementia. In this review, we sought to construct a comprehensive summary of the relationship between CNE, cognitive dysfunction, and degenerative dementia. We also present the limitations of existing evidence as a guide regarding important prospects for future research.
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Affiliation(s)
- Lei Huang
- Department of Environmental Health and Occupational Medicine, West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, P.R. China.,Department of Occupational Hazard Assessment, West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, P.R. China
| | - Yang Zhang
- Department of Periodical Press and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, P.R. China.,Chinese Evidence-Based Medicine Center, West China Hospital, Sichuan University, Chengdu, Sichuan, P.R. China
| | - Yongwei Wang
- Department of Occupational Hazard Assessment, West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, P.R. China
| | - Yajia Lan
- Department of Environmental Health and Occupational Medicine, West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, P.R. China
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7
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Alves E, Benns HJ, Magnus L, Dominicus C, Dobai T, Blight J, Wincott CJ, Child MA. An Extracellular Redox Signal Triggers Calcium Release and Impacts the Asexual Development of Toxoplasma gondii. Front Cell Infect Microbiol 2021; 11:728425. [PMID: 34447699 PMCID: PMC8382974 DOI: 10.3389/fcimb.2021.728425] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 07/26/2021] [Indexed: 11/13/2022] Open
Abstract
The ability of an organism to sense and respond to environmental redox fluctuations relies on a signaling network that is incompletely understood in apicomplexan parasites such as Toxoplasma gondii. The impact of changes in redox upon the development of this intracellular parasite is not known. Here, we provide a revised collection of 58 genes containing domains related to canonical antioxidant function, with their encoded proteins widely dispersed throughout different cellular compartments. We demonstrate that addition of exogenous H2O2 to human fibroblasts infected with T. gondii triggers a Ca2+ flux in the cytosol of intracellular parasites that can induce egress. In line with existing models, egress triggered by exogenous H2O2 is reliant upon both Calcium-Dependent Protein Kinase 3 and diacylglycerol kinases. Finally, we show that the overexpression a glutaredoxin-roGFP2 redox sensor fusion protein in the parasitophorous vacuole severely impacts parasite replication. These data highlight the rich redox network that exists in T. gondii, evidencing a link between extracellular redox and intracellular Ca2+ signaling that can culminate in parasite egress. Our findings also indicate that the redox potential of the intracellular environment contributes to normal parasite growth. Combined, our findings highlight the important role of redox as an unexplored regulator of parasite biology.
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Affiliation(s)
- Eduardo Alves
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Henry J Benns
- Department of Life Sciences, Imperial College London, London, United Kingdom.,Department of Chemistry, Imperial College London, London, United Kingdom
| | - Lilian Magnus
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Caia Dominicus
- Signaling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Tamás Dobai
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Joshua Blight
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Ceire J Wincott
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Matthew A Child
- Department of Life Sciences, Imperial College London, London, United Kingdom
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8
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Haddad M, Hervé V, Ben Khedher MR, Rabanel JM, Ramassamy C. Glutathione: An Old and Small Molecule with Great Functions and New Applications in the Brain and in Alzheimer's Disease. Antioxid Redox Signal 2021; 35:270-292. [PMID: 33637005 DOI: 10.1089/ars.2020.8129] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Significance: Glutathione (GSH) represents the most abundant and the main antioxidant in the body with important functions in the brain related to Alzheimer's disease (AD). Recent Advances: Oxidative stress is one of the central mechanisms in AD. We and others have demonstrated the alteration of GSH levels in the AD brain, its important role in the detoxification of advanced glycation end-products and of acrolein, a by-product of lipid peroxidation. Recent in vivo studies found a decrease of GSH in several areas of the brain from control, mild cognitive impairment, and AD subjects, which are correlated with cognitive decline. Critical Issues: Several strategies were developed to restore its intracellular level with the l-cysteine prodrugs or the oral administration of γ-glutamylcysteine to prevent alterations observed in AD. To date, no benefit on GSH level or on oxidative biomarkers has been reported in clinical trials. Thus, it remains uncertain if GSH could be considered a potential preventive or therapeutic approach or a biomarker for AD. Future Directions: We address how GSH-coupled nanocarriers represent a promising approach for the functionalization of nanocarriers to overcome the blood/brain barrier (BBB) for the brain delivery of GSH while avoiding cellular toxicity. It is also important to address the presence of GSH in exosomes for its potential intercellular transfer or its shuttle across the BBB under certain conditions. Antioxid. Redox Signal. 35, 270-292.
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Affiliation(s)
- Mohamed Haddad
- INRS-Centre Armand-Frappier Santé Biotechnologie, Laval, Canada.,Institute on Nutrition and Functional Foods, Université Laval, Québec, Canada
| | - Vincent Hervé
- INRS-Centre Armand-Frappier Santé Biotechnologie, Laval, Canada.,Institute on Nutrition and Functional Foods, Université Laval, Québec, Canada
| | - Mohamed Raâfet Ben Khedher
- INRS-Centre Armand-Frappier Santé Biotechnologie, Laval, Canada.,Institute on Nutrition and Functional Foods, Université Laval, Québec, Canada
| | | | - Charles Ramassamy
- INRS-Centre Armand-Frappier Santé Biotechnologie, Laval, Canada.,Institute on Nutrition and Functional Foods, Université Laval, Québec, Canada
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9
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Mott RE, von Reyn CR, Firestein BL, Meaney DF. Regional Neurodegeneration in vitro: The Protective Role of Neural Activity. Front Comput Neurosci 2021; 15:580107. [PMID: 33854425 PMCID: PMC8039287 DOI: 10.3389/fncom.2021.580107] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Accepted: 02/11/2021] [Indexed: 12/20/2022] Open
Abstract
Traumatic brain injury is a devastating public health problem, the eighth leading cause of death across the world. To improve our understanding of how injury at the cellular scale affects neural circuit function, we developed a protocol to precisely injure individual neurons within an in vitro neural network. We used high speed calcium imaging to estimate alterations in neural activity and connectivity that occur followed targeted microtrauma. Our studies show that mechanically injured neurons inactivate following microtrauma and eventually re-integrate into the network. Single neuron re-integration is dependent on its activity prior to injury and initial connections in the network: more active and integrated neurons are more resistant to microtrauma and more likely to re-integrate into the network. Micromechanical injury leads to neuronal death 6 h post-injury in a subset of both injured and uninjured neurons. Interestingly, neural activity and network participation after injury were associated with survival in linear discriminate analysis (77.3% correct prediction, Wilks' Lambda = 0.838). Based on this observation, we modulated neuronal activity to rescue neurons after microtrauma. Inhibition of neuronal activity provided much greater survivability than did activation of neurons (ANOVA, p < 0.01 with post-hoc Tukey HSD, p < 0.01). Rescue of neurons by blocking activity in the post-acute period is partially mediated by mitochondrial energetics, as we observed silencing neurons after micromechanical injury led to a significant reduction in mitochondrial calcium accumulation. Overall, the present study provides deeper insight into the propagation of injury within networks, demonstrating that together the initial activity, network structure, and post-injury activity levels contribute to the progressive changes in a neural circuit after mechanical trauma.
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Affiliation(s)
| | - Catherine R von Reyn
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA, United States.,Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Bonnie L Firestein
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, NJ, United States
| | - David F Meaney
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, United States.,Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA, United States
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10
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Savalia NK, Shao LX, Kwan AC. A Dendrite-Focused Framework for Understanding the Actions of Ketamine and Psychedelics. Trends Neurosci 2020; 44:260-275. [PMID: 33358035 DOI: 10.1016/j.tins.2020.11.008] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 11/07/2020] [Accepted: 11/24/2020] [Indexed: 02/09/2023]
Abstract
Pilot studies have hinted that serotonergic psychedelics such as psilocybin may relieve depression, and could possibly do so by promoting neural plasticity. Intriguingly, another psychotomimetic compound, ketamine, is a fast-acting antidepressant and induces synapse formation. The similarities in behavioral and neural effects have been puzzling because the compounds target distinct molecular receptors in the brain. In this opinion article, we develop a conceptual framework that suggests the actions of ketamine and serotonergic psychedelics may converge at the dendrites, to both enhance and suppress membrane excitability. We speculate that mismatches in the opposing actions on dendritic excitability may relate to these compounds' cell-type and region selectivity, their moderate range of effects and toxicity, and their plasticity-promoting capacities.
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Affiliation(s)
- Neil K Savalia
- Medical Scientist Training Program, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Ling-Xiao Shao
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Alex C Kwan
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06511, USA; Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06511, USA.
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11
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Chung CG, Park SS, Park JH, Lee SB. Dysregulated Plasma Membrane Turnover Underlying Dendritic Pathology in Neurodegenerative Diseases. Front Cell Neurosci 2020; 14:556461. [PMID: 33192307 PMCID: PMC7580253 DOI: 10.3389/fncel.2020.556461] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 09/03/2020] [Indexed: 12/29/2022] Open
Abstract
Due to their enormous surface area compared to other cell types, neurons face unique challenges in properly handling supply and retrieval of the plasma membrane (PM)-a process termed PM turnover-in their distal areas. Because of the length and extensiveness of dendritic branches in neurons, the transport of materials needed for PM turnover from soma to distal dendrites will be inefficient and quite burdensome for somatic organelles. To meet local demands, PM turnover in dendrites most likely requires local cellular machinery, such as dendritic endocytic and secretory systems, dysregulation of which may result in dendritic pathology observed in various neurodegenerative diseases (NDs). Supporting this notion, a growing body of literature provides evidence to suggest the pathogenic contribution of dysregulated PM turnover to dendritic pathology in certain NDs. In this article, we present our perspective view that impaired dendritic endocytic and secretory systems may contribute to dendritic pathology by encumbering PM turnover in NDs.
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Affiliation(s)
- Chang Geon Chung
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, South Korea
| | - Sung Soon Park
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, South Korea
| | - Jeong Hyang Park
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, South Korea
| | - Sung Bae Lee
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, South Korea
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12
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Ugbode C, Garnham N, Fort-Aznar L, Evans GJO, Chawla S, Sweeney ST. JNK signalling regulates antioxidant responses in neurons. Redox Biol 2020; 37:101712. [PMID: 32949970 PMCID: PMC7502373 DOI: 10.1016/j.redox.2020.101712] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/14/2020] [Accepted: 08/31/2020] [Indexed: 02/06/2023] Open
Abstract
Reactive oxygen species (ROS) are generated during physiological bouts of synaptic activity and as a consequence of pathological conditions in the central nervous system. How neurons respond to and distinguish between ROS in these different contexts is currently unknown. In Drosophila mutants with enhanced JNK activity, lower levels of ROS are observed and these animals are resistant to both changes in ROS and changes in synapse morphology induced by oxidative stress. In wild type flies, disrupting JNK-AP-1 signalling perturbs redox homeostasis suggesting JNK activity positively regulates neuronal antioxidant defense. We validated this hypothesis in mammalian neurons, finding that JNK activity regulates the expression of the antioxidant gene Srxn-1, in a c-Jun dependent manner. We describe a conserved ‘adaptive’ role for neuronal JNK in the maintenance of redox homeostasis that is relevant to several neurodegenerative diseases.
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Affiliation(s)
- Chris Ugbode
- Department of Biology, University of York, York, YO10 5DD, UK; York Biomedical Research Institute, University of York, York, YO10 5DD, UK
| | - Nathan Garnham
- Department of Biology, University of York, York, YO10 5DD, UK; York Biomedical Research Institute, University of York, York, YO10 5DD, UK
| | - Laura Fort-Aznar
- Department of Biology, University of York, York, YO10 5DD, UK; York Biomedical Research Institute, University of York, York, YO10 5DD, UK
| | - Gareth J O Evans
- Department of Biology, University of York, York, YO10 5DD, UK; York Biomedical Research Institute, University of York, York, YO10 5DD, UK
| | - Sangeeta Chawla
- Department of Biology, University of York, York, YO10 5DD, UK; York Biomedical Research Institute, University of York, York, YO10 5DD, UK.
| | - Sean T Sweeney
- Department of Biology, University of York, York, YO10 5DD, UK; York Biomedical Research Institute, University of York, York, YO10 5DD, UK.
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13
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Radhakrishnan S, Norley J, Wendt S, LeRoy N, Hall H, Norcross S, Doan S, Snaider J, MacVicar BA, Weake VM, Huang L, Tantama M. Neuron Activity Dependent Redox Compartmentation Revealed with a Second Generation Red-Shifted Ratiometric Sensor. ACS Chem Neurosci 2020; 11:2666-2678. [PMID: 32786310 PMCID: PMC7526680 DOI: 10.1021/acschemneuro.0c00342] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Oxidative stress is a hallmark of several aging and trauma related neurological disorders, but the precise details of how altered neuronal activity elicits subcellular redox changes have remained difficult to resolve. Current redox sensitive dyes and fluorescent proteins can quantify spatially distinct changes in reactive oxygen species levels, but multicolor probes are needed to accurately analyze compartment-specific redox dynamics in single cells that can be masked by population averaging. We previously engineered genetically encoded red-shifted redox-sensitive fluorescent protein sensors using a Förster resonance energy transfer relay strategy. Here, we developed a second-generation excitation ratiometric sensor called rogRFP2 with improved red emission for quantitative live-cell imaging. Using this sensor to measure activity-dependent redox changes in individual cultured neurons, we observed an anticorrelation in which mitochondrial oxidation was accompanied by a concurrent reduction in the cytosol. This behavior was dependent on the activity of Complex I of the mitochondrial electron transport chain and could be modulated by the presence of cocultured astrocytes. We also demonstrated that the red fluorescent rogRFP2 facilitates ratiometric one- and two-photon redox imaging in rat brain slices and Drosophila retinas. Overall, the proof-of-concept studies reported here demonstrate that this new rogRFP2 redox sensor can be a powerful tool for understanding redox biology both in vitro and in vivo across model organisms.
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Affiliation(s)
- Saranya Radhakrishnan
- Department of Chemistry, 560 Oval Drive, West Lafayette, IN 47907, United States
- Purdue Institute for Integrative Neuroscience, 560 Oval Drive, West Lafayette, IN 47907, United States
- Purdue Interdisciplinary Life Sciences Graduate Program, 560 Oval Drive, West Lafayette, IN 47907, United States
| | - Jacob Norley
- Department of Chemistry, 560 Oval Drive, West Lafayette, IN 47907, United States
| | - Stefan Wendt
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Vancouver, 2215 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada
| | - Nathan LeRoy
- Department of Chemistry, 560 Oval Drive, West Lafayette, IN 47907, United States
| | - Hana Hall
- Department of Biochemistry, 175 South University Street, West Lafayette, IN 47907, United States
| | - Stevie Norcross
- Department of Chemistry, 560 Oval Drive, West Lafayette, IN 47907, United States
- Purdue Interdisciplinary Life Sciences Graduate Program, 560 Oval Drive, West Lafayette, IN 47907, United States
| | - Sara Doan
- Department of Chemistry, 560 Oval Drive, West Lafayette, IN 47907, United States
| | - Jordan Snaider
- Department of Chemistry, 560 Oval Drive, West Lafayette, IN 47907, United States
| | - Brian A. MacVicar
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Vancouver, 2215 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada
| | - Vikki M. Weake
- Department of Biochemistry, 175 South University Street, West Lafayette, IN 47907, United States
- Purdue Center for Cancer Research, 175 South University Street, West Lafayette, IN 47907, United States
| | - Libai Huang
- Department of Chemistry, 560 Oval Drive, West Lafayette, IN 47907, United States
| | - Mathew Tantama
- Department of Chemistry, 560 Oval Drive, West Lafayette, IN 47907, United States
- Purdue Institute for Integrative Neuroscience, 560 Oval Drive, West Lafayette, IN 47907, United States
- Purdue Interdisciplinary Life Sciences Graduate Program, 560 Oval Drive, West Lafayette, IN 47907, United States
- Department of Chemistry, Wellesley College, 106 Central Street, Wellesley, MA 02481, United States
- Biochemistry Program, Wellesley College, 106 Central Street, Wellesley, MA 02481, United States
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14
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Nadhimi Y, Llano DA. Does hearing loss lead to dementia? A review of the literature. Hear Res 2020; 402:108038. [PMID: 32814645 DOI: 10.1016/j.heares.2020.108038] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 06/04/2020] [Accepted: 07/02/2020] [Indexed: 12/31/2022]
Abstract
Recent studies have revealed a correlation between aging-related hearing loss and the likelihood of developing Alzheimer Disease. However, it is not yet known if the correlation simply reflects the fact that these two disorders share common risk factors or whether there is a causal link between them. The answer to this question carries therapeutic implications. Unfortunately, it is not possible to study the question of causality between aging-related hearing loss and dementia in human subjects. Here, we evaluate the research surrounding induced-hearing loss in animal models on non-auditory cognition to help infer if there is any causal evidence linking hearing loss and a more general dementia. We find ample evidence that induction of hearing loss in animals produces cognitive decline, particularly hippocampal dysfunction. The data suggest that noise-exposure produces a toxic milieu in the hippocampus consisting of a spike in glucocorticoid levels, elevations of mediators of oxidative stress and excitotoxicity, which as a consequence induce cessation of neurogenesis, synaptic loss and tau hyperphosphorylation. These data suggest that hearing loss can lead to pathological hallmarks similar to those seen in Alzheimer's Disease and other dementias. However, the rodent data do not establish that hearing loss on its own can induce a progressive degenerative dementing illness. Therefore, we conclude that an additional "hit", such as aging, APOE genotype, microvascular disease or others, may be necessary to trigger an ongoing degenerative process such as Alzheimer Disease.
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Affiliation(s)
- Yosra Nadhimi
- Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, USA
| | - Daniel A Llano
- Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, USA; Neuroscience Program, University of Illinois at Urbana-Champaign, USA; Carle Neuroscience Institute, Urbana, IL, USA; Beckman Institute for Advanced Science and Technology, Urbana, IL, USA.
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15
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Kostyuk AI, Kokova AD, Podgorny OV, Kelmanson IV, Fetisova ES, Belousov VV, Bilan DS. Genetically Encoded Tools for Research of Cell Signaling and Metabolism under Brain Hypoxia. Antioxidants (Basel) 2020; 9:E516. [PMID: 32545356 PMCID: PMC7346190 DOI: 10.3390/antiox9060516] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 06/04/2020] [Accepted: 06/06/2020] [Indexed: 02/08/2023] Open
Abstract
Hypoxia is characterized by low oxygen content in the tissues. The central nervous system (CNS) is highly vulnerable to a lack of oxygen. Prolonged hypoxia leads to the death of brain cells, which underlies the development of many pathological conditions. Despite the relevance of the topic, different approaches used to study the molecular mechanisms of hypoxia have many limitations. One promising lead is the use of various genetically encoded tools that allow for the observation of intracellular parameters in living systems. In the first part of this review, we provide the classification of oxygen/hypoxia reporters as well as describe other genetically encoded reporters for various metabolic and redox parameters that could be implemented in hypoxia studies. In the second part, we discuss the advantages and disadvantages of the primary hypoxia model systems and highlight inspiring examples of research in which these experimental settings were combined with genetically encoded reporters.
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Affiliation(s)
- Alexander I. Kostyuk
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.D.K.); (O.V.P.); (I.V.K.); (E.S.F.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| | - Aleksandra D. Kokova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.D.K.); (O.V.P.); (I.V.K.); (E.S.F.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| | - Oleg V. Podgorny
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.D.K.); (O.V.P.); (I.V.K.); (E.S.F.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
- Koltzov Institute of Developmental Biology, 119334 Moscow, Russia
| | - Ilya V. Kelmanson
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.D.K.); (O.V.P.); (I.V.K.); (E.S.F.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| | - Elena S. Fetisova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.D.K.); (O.V.P.); (I.V.K.); (E.S.F.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
- Faculty of Biology, Lomonosov Moscow State University, 119992 Moscow, Russia
| | - Vsevolod V. Belousov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.D.K.); (O.V.P.); (I.V.K.); (E.S.F.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
- Institute for Cardiovascular Physiology, Georg August University Göttingen, D-37073 Göttingen, Germany
- Federal Center for Cerebrovascular Pathology and Stroke, 117997 Moscow, Russia
| | - Dmitry S. Bilan
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.D.K.); (O.V.P.); (I.V.K.); (E.S.F.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
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16
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The cyanobacterial neurotoxin β-N-methylamino-L-alanine (BMAA) targets the olfactory bulb region. Arch Toxicol 2020; 94:2799-2808. [PMID: 32435914 PMCID: PMC7395073 DOI: 10.1007/s00204-020-02775-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 05/04/2020] [Indexed: 12/20/2022]
Abstract
Olfactory dysfunction is implicated in neurodegenerative disorders and typically manifests years before other symptoms. The cyanobacterial neurotoxin β-N-methylamino-l-alanine (BMAA) is suggested as a risk factor for neurodegenerative disease. Detection of BMAA in air filters has increased the concern that aerosolization may lead to human BMAA exposure through the air. The aim of this study was to determine if BMAA targets the olfactory system. Autoradiographic imaging showed a distinct localization of radioactivity in the right olfactory mucosa and bulb following a unilateral intranasal instillation of 3H-BMAA (0.018 µg) in mice, demonstrating a direct transfer of BMAA via the olfactory pathways to the brain circumventing the blood–brain barrier, which was confirmed by liquid scintillation. Treatment of mouse primary olfactory bulb cells with 100 µM BMAA for 24 h caused a disruption of the neurite network, formation of dendritic varicosities and reduced cell viability. The NMDA receptor antagonist MK-801 and the metabotropic glutamate receptor antagonist MCPG protected against the BMAA-induced alterations, demonstrating the importance of glutamatergic mechanisms. The ionotropic non-NMDA receptor antagonist CNQX prevented the BMAA-induced decrease of cell viability in mixed cultures containing both neuronal and glial cells, but not in cultures with neurons only, suggesting a role of neuron–glial interactions and glial AMPA receptors in the BMAA-induced toxicity. The results show that the olfactory region may be a target for BMAA following inhalation exposure. Further studies on the relations between environmental olfactory toxicants and neurodegenerative disorders are warranted.
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17
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Qiu J, Dando O, Febery JA, Fowler JH, Chandran S, Hardingham GE. Neuronal Activity and Its Role in Controlling Antioxidant Genes. Int J Mol Sci 2020; 21:ijms21061933. [PMID: 32178355 PMCID: PMC7139385 DOI: 10.3390/ijms21061933] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 03/02/2020] [Accepted: 03/07/2020] [Indexed: 12/14/2022] Open
Abstract
Forebrain neurons have relatively weak intrinsic antioxidant defenses compared to astrocytes, in part due to hypo-expression of Nrf2, an oxidative stress-induced master regulator of antioxidant and detoxification genes. Nevertheless, neurons do possess the capacity to auto-regulate their antioxidant defenses in response to electrical activity. Activity-dependent Ca2+ signals control the expression of several antioxidant genes, boosting redox buffering capacity, thus meeting the elevated antioxidant requirements associated with metabolically expensive electrical activity. These genes include examples which are reported Nrf2 target genes and yet are induced in a Nrf2-independent manner. Here we discuss the implications for Nrf2 hypofunction in neurons and the mechanisms underlying the Nrf2-independent induction of antioxidant genes by electrical activity. A significant proportion of Nrf2 target genes, defined as those genes controlled by Nrf2 in astrocytes, are regulated by activity-dependent Ca2+ signals in human stem cell-derived neurons. We propose that neurons interpret Ca2+ signals in a similar way to other cell types sense redox imbalance, to broadly induce antioxidant and detoxification genes.
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Affiliation(s)
- Jing Qiu
- UK Dementia Research Institute, The Medical School, University of Edinburgh, Chancellor’s Building, Edinburgh EH16 4SB, UK; (J.Q.); (O.D.); (S.C.)
- Centre for Discovery Brain Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK; (J.A.F.); (J.H.F.)
| | - Owen Dando
- UK Dementia Research Institute, The Medical School, University of Edinburgh, Chancellor’s Building, Edinburgh EH16 4SB, UK; (J.Q.); (O.D.); (S.C.)
- Centre for Discovery Brain Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK; (J.A.F.); (J.H.F.)
| | - James A. Febery
- Centre for Discovery Brain Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK; (J.A.F.); (J.H.F.)
| | - Jill H. Fowler
- Centre for Discovery Brain Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK; (J.A.F.); (J.H.F.)
| | - Siddharthan Chandran
- UK Dementia Research Institute, The Medical School, University of Edinburgh, Chancellor’s Building, Edinburgh EH16 4SB, UK; (J.Q.); (O.D.); (S.C.)
- Centre for Clinical Brain Sciences, University of Edinburgh Chancellor’s Building, Edinburgh, EH16 4SB, UK
| | - Giles E. Hardingham
- UK Dementia Research Institute, The Medical School, University of Edinburgh, Chancellor’s Building, Edinburgh EH16 4SB, UK; (J.Q.); (O.D.); (S.C.)
- Centre for Discovery Brain Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK; (J.A.F.); (J.H.F.)
- Correspondence:
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18
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Alabdullah AA, Al-Abdulaziz B, Alsalem H, Magrashi A, Pulicat SM, Almzroua AA, Almohanna F, Assiri AM, Al Tassan NA, Al-Mubarak BR. Estimating transfection efficiency in differentiated and undifferentiated neural cells. BMC Res Notes 2019; 12:225. [PMID: 30987672 PMCID: PMC6466792 DOI: 10.1186/s13104-019-4249-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Accepted: 04/03/2019] [Indexed: 11/21/2022] Open
Abstract
Objective Delivery of constructs for silencing or over-expressing genes or their modified versions is a crucial step for studying neuronal cell biology. Therefore, efficient transfection is important for the success of these experimental techniques especially in post-mitotic cells like neurons. In this study, we have assessed the transfection rate, using a previously established protocol, in both primary cortical cultures and neuroblastoma cell lines. Transfection efficiencies in these preparations have not been systematically determined before. Results Transfection efficiencies obtained herein were (10–12%) for neuroblastoma, (5–12%) for primary astrocytes and (1.3–6%) for primary neurons. We also report on cell-type specific transfection efficiency of neurons and astrocytes within primary cortical cultures when applying cell-type selective transfection protocols. Previous estimations described in primary cortical or hippocampal cultures were either based on general observations or on data derived from unspecified number of biological and/or technical replicates. Also to the best of our knowledge, transfection efficiency of pure primary neuronal cultures or astrocytes cultured in the context of pure or mixed (neurons/astrocytes) population cultures have not been previously determined. The transfection strategy used herein represents a convenient, and a straightforward tool for targeted cell transfection that can be utilized in a variety of in vitro applications. Electronic supplementary material The online version of this article (10.1186/s13104-019-4249-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Abeer A Alabdullah
- Behavioral Genetics Unit, Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, 11211, Saudi Arabia.,National Center for Genomics Technology, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Basma Al-Abdulaziz
- Behavioral Genetics Unit, Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, 11211, Saudi Arabia.,National Center for Genomics Technology, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Hanan Alsalem
- Behavioral Genetics Unit, Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, 11211, Saudi Arabia
| | - Amna Magrashi
- Behavioral Genetics Unit, Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, 11211, Saudi Arabia
| | - Subramanian M Pulicat
- Stem Cell & Tissue Re-Engineering Program, King Faisal Specialist Hospital and Research Center, Riyadh, 11211, Saudi Arabia
| | - Amer A Almzroua
- Stem Cell & Tissue Re-Engineering Program, King Faisal Specialist Hospital and Research Center, Riyadh, 11211, Saudi Arabia
| | - Falah Almohanna
- Department of Comparative Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, 11211, Saudi Arabia
| | - Abdullah Mohamed Assiri
- Department of Comparative Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, 11211, Saudi Arabia.,College of Medicine, Alfaisal University, Riyadh, Saudi Arabia.,Institute of Research and Medical Consultations, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Nada A Al Tassan
- Behavioral Genetics Unit, Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, 11211, Saudi Arabia.,Clinical Laboratory Department, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Bashayer R Al-Mubarak
- Behavioral Genetics Unit, Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, 11211, Saudi Arabia.
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19
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Depp C, Bas-Orth C, Schroeder L, Hellwig A, Bading H. Synaptic Activity Protects Neurons Against Calcium-Mediated Oxidation and Contraction of Mitochondria During Excitotoxicity. Antioxid Redox Signal 2018; 29:1109-1124. [PMID: 28990420 DOI: 10.1089/ars.2017.7092] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AIMS Excitotoxicity triggered by extrasynaptic N-methyl-d-aspartate-type glutamate receptors has been implicated in many neurodegenerative conditions, including Alzheimer's disease, Huntington's disease, amyotrophic lateral sclerosis, and stroke. Mitochondrial calcium overload leading to mitochondrial dysfunction represents an early event in excitotoxicity. Neurons are rendered resistant to excitotoxicity by previous periods of synaptic activity that activates a nuclear calcium-driven neuroprotective gene program. This process, termed acquired neuroprotection, involves transcriptional repression of the mitochondrial calcium uniporter leading to a reduction in excitotoxcity-associated mitochondrial calcium load. As mitochondrial calcium and the production of reactive oxygen species may be linked, we monitored excitotoxicity-associated changes in the mitochondrial redox status using the ratiometric glutathione redox potential indicator, glutaredoxin 1 (GRX1)-redox-sensitive green fluorescent protein (roGFP)2, targeted to the mitochondrial matrix. Aim of this study was to investigate if suppression of oxidative stress underlies mitoprotection afforded by synaptic activity. RESULTS We found that synaptic activity protects primary rat hippocampal neurons against acute excitotoxicity-induced mitochondrial oxidative stress and mitochondrial contraction associated with it. Downregulation of the mitochondrial uniporter by genetic means mimics the protective effect of synaptic activity on mitochondrial redox status. These findings indicate that oxidative stress acts downstream of mitochondrial calcium overload in excitotoxicity. Innovation and Conclusion: We established mito-GRX1-roGFP2 as a reliable and sensitive tool to monitor rapid redox changes in mitochondria during excitotoxicity. Our results highlight the importance of developing means of blocking mitochondrial calcium overload for therapeutic targeting of oxidative stress and mitochondrial dysfunction in neurodegenerative diseases. Antioxid. Redox. Signal. 29, 1109-1124.
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Affiliation(s)
- Constanze Depp
- Department of Neurobiology, Interdisciplinary Center for Neurosciences, Heidelberg University , Heidelberg, Germany
| | - Carlos Bas-Orth
- Department of Neurobiology, Interdisciplinary Center for Neurosciences, Heidelberg University , Heidelberg, Germany
| | - Lisa Schroeder
- Department of Neurobiology, Interdisciplinary Center for Neurosciences, Heidelberg University , Heidelberg, Germany
| | - Andrea Hellwig
- Department of Neurobiology, Interdisciplinary Center for Neurosciences, Heidelberg University , Heidelberg, Germany
| | - Hilmar Bading
- Department of Neurobiology, Interdisciplinary Center for Neurosciences, Heidelberg University , Heidelberg, Germany
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20
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Chung CG, Kwon MJ, Jeon KH, Hyeon DY, Han MH, Park JH, Cha IJ, Cho JH, Kim K, Rho S, Kim GR, Jeong H, Lee JW, Kim T, Kim K, Kim KP, Ehlers MD, Hwang D, Lee SB. Golgi Outpost Synthesis Impaired by Toxic Polyglutamine Proteins Contributes to Dendritic Pathology in Neurons. Cell Rep 2018; 20:356-369. [PMID: 28700938 DOI: 10.1016/j.celrep.2017.06.059] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 04/28/2017] [Accepted: 06/21/2017] [Indexed: 11/29/2022] Open
Abstract
Dendrite aberration is a common feature of neurodegenerative diseases caused by protein toxicity, but the underlying mechanisms remain largely elusive. Here, we show that nuclear polyglutamine (polyQ) toxicity resulted in defective terminal dendrite elongation accompanied by a loss of Golgi outposts (GOPs) and a decreased supply of plasma membrane (PM) in Drosophila class IV dendritic arborization (da) (C4 da) neurons. mRNA sequencing revealed that genes downregulated by polyQ proteins included many secretory pathway-related genes, including COPII genes regulating GOP synthesis. Transcription factor enrichment analysis identified CREB3L1/CrebA, which regulates COPII gene expression. CrebA overexpression in C4 da neurons restores the dysregulation of COPII genes, GOP synthesis, and PM supply. Chromatin immunoprecipitation (ChIP)-PCR revealed that CrebA expression is regulated by CREB-binding protein (CBP), which is sequestered by polyQ proteins. Furthermore, co-overexpression of CrebA and Rac1 synergistically restores the polyQ-induced dendrite pathology. Collectively, our results suggest that GOPs impaired by polyQ proteins contribute to dendrite pathology through the CBP-CrebA-COPII pathway.
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Affiliation(s)
- Chang Geon Chung
- Department of Brain and Cognitive Sciences, DGIST, Daegu 42988, Republic of Korea
| | - Min Jee Kwon
- Department of Brain and Cognitive Sciences, DGIST, Daegu 42988, Republic of Korea
| | - Keun Hye Jeon
- Department of Brain and Cognitive Sciences, DGIST, Daegu 42988, Republic of Korea; Department of Family Medicine, Samsung Medical Center, Seoul 06351, Republic of Korea
| | - Do Young Hyeon
- School of Interdisciplinary Bioscience and Bioengineering, POSTECH, Pohang 37673, Republic of Korea
| | - Myeong Hoon Han
- Department of Brain and Cognitive Sciences, DGIST, Daegu 42988, Republic of Korea
| | - Jeong Hyang Park
- Department of Brain and Cognitive Sciences, DGIST, Daegu 42988, Republic of Korea
| | - In Jun Cha
- Department of Brain and Cognitive Sciences, DGIST, Daegu 42988, Republic of Korea
| | - Jae Ho Cho
- Department of Brain and Cognitive Sciences, DGIST, Daegu 42988, Republic of Korea
| | - Kunhyung Kim
- Department of New Biology, DGIST, Daegu 42988, Republic of Korea
| | - Sangchul Rho
- Center for Plant Aging Research, Institute for Basic Science, DGIST, Daegu 42988, Republic of Korea
| | - Gyu Ree Kim
- Department of Brain and Cognitive Sciences, DGIST, Daegu 42988, Republic of Korea
| | - Hyobin Jeong
- Center for Plant Aging Research, Institute for Basic Science, DGIST, Daegu 42988, Republic of Korea
| | - Jae Won Lee
- Department of Applied Chemistry, Institute of Natural Science, College of Applied Science, Kyung Hee University, Yongin 17104, Republic of Korea
| | - TaeSoo Kim
- Department of Life Science and the Research Center for Cellular Homeostasis, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Keetae Kim
- Department of New Biology, DGIST, Daegu 42988, Republic of Korea
| | - Kwang Pyo Kim
- Department of Applied Chemistry, Institute of Natural Science, College of Applied Science, Kyung Hee University, Yongin 17104, Republic of Korea
| | | | - Daehee Hwang
- School of Interdisciplinary Bioscience and Bioengineering, POSTECH, Pohang 37673, Republic of Korea; Department of New Biology, DGIST, Daegu 42988, Republic of Korea; Center for Plant Aging Research, Institute for Basic Science, DGIST, Daegu 42988, Republic of Korea.
| | - Sung Bae Lee
- Department of Brain and Cognitive Sciences, DGIST, Daegu 42988, Republic of Korea.
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21
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Jackson EK, Kotermanski SE, Menshikova EV, Dubey RK, Jackson TC, Kochanek PM. Adenosine production by brain cells. J Neurochem 2017; 141:676-693. [PMID: 28294336 DOI: 10.1111/jnc.14018] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Revised: 03/06/2017] [Accepted: 03/07/2017] [Indexed: 02/06/2023]
Abstract
The early release of adenosine following traumatic brain injury (TBI) suppresses seizures and brain inflammation; thus, it is important to elucidate the cellular sources of adenosine following injurious stimuli triggered by TBI so that therapeutics for enhancing the early adenosine-release response can be optimized. Using mass spectrometry with 13 C-labeled standards, we investigated in cultured rat neurons, astrocytes, and microglia the effects of oxygen-glucose deprivation (OGD; models energy failure), H2 O2 (produces oxidative stress), and glutamate (induces excitotoxicity) on intracellular and extracellular levels of 5'-AMP (adenosine precursor), adenosine, and inosine and hypoxanthine (adenosine metabolites). In neurons, OGD triggered increases in intracellular 5'-AMP (2.8-fold), adenosine (2.6-fold), inosine (2.2-fold), and hypoxanthine (5.3-fold) and extracellular 5'-AMP (2.2-fold), adenosine (2.4-fold), and hypoxanthine (2.5-fold). In neurons, H2 O2 did not affect intracellular or extracellular purines; yet, glutamate increased intracellular adenosine, inosine, and hypoxanthine (1.7-fold, 1.7-fold, and 1.6-fold, respectively) and extracellular adenosine, inosine, and hypoxanthine (2.9-fold, 2.1-fold, and 1.6-fold, respectively). In astrocytes, neither H2 O2 nor glutamate affected intracellular or extracellular purines, and OGD only slightly increased intracellular and extracellular hypoxanthine. Microglia were unresponsive to OGD and glutamate, but were remarkably responsive to H2 O2 , which increased intracellular 5'-AMP (1.6-fold), adenosine (1.6-fold), inosine (2.1-fold), and hypoxanthine (1.6-fold) and extracellular 5'-AMP (5.9-fold), adenosine (4.0-fold), inosine (4.3-fold), and hypoxanthine (1.9-fold). CONCLUSION Under these particular experimental conditions, cultured neurons are the main contributors to adenosine production/release in response to OGD and glutamate, whereas cultured microglia are the main contributors upon oxidative stress. Developing therapeutics that recruit astrocytes to produce/release adenosine could have beneficial effects in TBI.
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Affiliation(s)
- Edwin K Jackson
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Shawn E Kotermanski
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Elizabeth V Menshikova
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Raghvendra K Dubey
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.,Department of Reproductive Endocrinology, University Hospital Zurich and Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland
| | - Travis C Jackson
- Department of Critical Care Medicine and the Safar Center for Resuscitation Research, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Patrick M Kochanek
- Department of Critical Care Medicine and the Safar Center for Resuscitation Research, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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22
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Riew TR, Kim HL, Jin X, Choi JH, Shin YJ, Kim JS, Lee MY. Spatiotemporal expression of osteopontin in the striatum of rats subjected to the mitochondrial toxin 3-nitropropionic acid correlates with microcalcification. Sci Rep 2017; 7:45173. [PMID: 28345671 PMCID: PMC5366947 DOI: 10.1038/srep45173] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Accepted: 02/20/2017] [Indexed: 11/18/2022] Open
Abstract
Our aim was to elucidate whether osteopontin (OPN) is involved in the onset of mineralisation and progression of extracellular calcification in striatal lesions due to mitochondrial toxin 3-nitropropionic acid exposure. OPN expression had two different patterns when observed using light microscopy. It was either localised to the Golgi complex in brain macrophages or had a small granular pattern scattered in the affected striatum. OPN labelling tended to increase in number and size over a 2-week period following the lesion. Ultrastructural investigations revealed that OPN is initially localised to degenerating mitochondria within distal dendrites, which were then progressively surrounded by profuse OPN on days 7–14. Electron probe microanalysis of OPN-positive and calcium-fixated neurites indicated that OPN accumulates selectively on the surfaces of degenerating calcifying dendrites, possibly via interactions between OPN and calcium. In addition, 3-dimensional reconstruction of OPN-positive neurites revealed that they are in direct contact with larger OPN-negative degenerating dendrites rather than with fragmented cell debris. Our overall results indicate that OPN expression is likely to correlate with the spatiotemporal progression of calcification in the affected striatum, and raise the possibility that OPN may play an important role in the initiation and progression of microcalcification in response to brain insults.
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Affiliation(s)
- Tae-Ryong Riew
- Department of Anatomy, Catholic Neuroscience Institute, Cell Death Disease Research Center, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Hong Lim Kim
- Integrative Research Support Center, Laboratory of Electron Microscope, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Xuyan Jin
- Department of Anatomy, Catholic Neuroscience Institute, Cell Death Disease Research Center, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Jeong-Heon Choi
- Department of Anatomy, Catholic Neuroscience Institute, Cell Death Disease Research Center, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Yoo-Jin Shin
- Department of Anatomy, Catholic Neuroscience Institute, Cell Death Disease Research Center, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Ji Soo Kim
- Gumi Electronics &Information Technology Research Institute, Gumi, Korea
| | - Mun-Yong Lee
- Department of Anatomy, Catholic Neuroscience Institute, Cell Death Disease Research Center, College of Medicine, The Catholic University of Korea, Seoul, Korea
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23
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Tsuyama T, Tsubouchi A, Usui T, Imamura H, Uemura T. Mitochondrial dysfunction induces dendritic loss via eIF2α phosphorylation. J Cell Biol 2017; 216:815-834. [PMID: 28209644 PMCID: PMC5346966 DOI: 10.1083/jcb.201604065] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 11/30/2016] [Accepted: 01/19/2017] [Indexed: 12/25/2022] Open
Abstract
Mitochondrial dysfunction is associated with neuropathological events, but how it mediates loss of specific neuronal subtypes is unclear. Tsuyama et al. show that mitochondrial dysfunction triggers selective dendritic loss in class IV arborization neurons in a manner dependent on eIF2α phosphorylation and translation inhibition. Mitochondria are key contributors to the etiology of diseases associated with neuromuscular defects or neurodegeneration. How changes in cellular metabolism specifically impact neuronal intracellular processes and cause neuropathological events is still unclear. We here dissect the molecular mechanism by which mitochondrial dysfunction induced by Prel aberrant function mediates selective dendritic loss in Drosophila melanogaster class IV dendritic arborization neurons. Using in vivo ATP imaging, we found that neuronal cellular ATP levels during development are not correlated with the progression of dendritic loss. We searched for mitochondrial stress signaling pathways that induce dendritic loss and found that mitochondrial dysfunction is associated with increased eIF2α phosphorylation, which is sufficient to induce dendritic pathology in class IV arborization neurons. We also observed that eIF2α phosphorylation mediates dendritic loss when mitochondrial dysfunction results from other genetic perturbations. Furthermore, mitochondrial dysfunction induces translation repression in class IV neurons in an eIF2α phosphorylation-dependent manner, suggesting that differential translation attenuation among neuron subtypes is a determinant of preferential vulnerability.
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Affiliation(s)
- Taiichi Tsuyama
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan
| | - Asako Tsubouchi
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan
| | - Tadao Usui
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan
| | - Hiromi Imamura
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan
| | - Tadashi Uemura
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan
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24
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Baxter PS, Hardingham GE. Adaptive regulation of the brain's antioxidant defences by neurons and astrocytes. Free Radic Biol Med 2016; 100:147-152. [PMID: 27365123 PMCID: PMC5145800 DOI: 10.1016/j.freeradbiomed.2016.06.027] [Citation(s) in RCA: 163] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 06/20/2016] [Accepted: 06/21/2016] [Indexed: 12/30/2022]
Abstract
The human brain generally remains structurally and functionally sound for many decades, despite the post-mitotic and non-regenerative nature of neurons. This is testament to the brain's profound capacity for homeostasis: both neurons and glia have in-built mechanisms that enable them to mount adaptive or protective responses to potentially challenging situations, ensuring that cellular viability and functionality is maintained. The high and variable metabolic and mitochondrial activity of neurons places several demands on the brain, including the task of neutralizing the associated reactive oxygen species (ROS) produced, to limit the accumulation of oxidative damage. Astrocytes play a key role in providing antioxidant support to nearby neurons, and redox regulation of the astrocytic Nrf2 pathway represents a powerful homeostatic regulator of the large cohort of Nrf2-regulated antioxidant genes that they express. In contrast, the Nrf2 pathway is weak in neurons, robbing them of this particular homeostatic device. However, many neuronal antioxidant genes are controlled by synaptic activity, enabling activity-dependent increases in ROS production to be offset by enhanced antioxidant capacity of both glutathione and thioredoxin-peroxiredoxin systems. These distinct homeostatic mechanisms in neurons and astrocytes together combine to promote neuronal resistance to oxidative insults. Future investigations into signaling between distinct cell types within the neuro-glial unit are likely to uncover further mechanisms underlying redox homeostasis in the brain.
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Affiliation(s)
- Paul S Baxter
- School of Biomedical Sciences, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Giles E Hardingham
- School of Biomedical Sciences, University of Edinburgh, Edinburgh EH8 9XD, UK.
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25
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Riew TR, Shin YJ, Kim HL, Cho JM, Pak HJ, Lee MY. Spatiotemporal Progression of Microcalcification in the Hippocampal CA1 Region following Transient Forebrain Ischemia in Rats: An Ultrastructural Study. PLoS One 2016; 11:e0159229. [PMID: 27414398 PMCID: PMC4945069 DOI: 10.1371/journal.pone.0159229] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 06/29/2016] [Indexed: 11/19/2022] Open
Abstract
Calcification in areas of neuronal degeneration is a common finding in several neuropathological disorders including ischemic insults. Here, we performed a detailed examination of the onset and spatiotemporal profile of calcification in the CA1 region of the hippocampus, where neuronal death has been observed after transient forebrain ischemia. Histopathological examinations showed very little alizarin red staining in the CA1 pyramidal cell layer until day 28 after reperfusion, while prominent alizarin red staining was detected in CA1 dendritic subfields, particularly in the stratum radiatum, by 14 days after reperfusion. Electron microscopy using the osmium/potassium dichromate method and electron probe microanalysis revealed selective calcium deposits within the mitochondria of degenerating dendrites at as early as 7 days after reperfusion, with subsequent complete mineralization occurring throughout the dendrites, which then coalesced to form larger mineral conglomerates with the adjacent calcifying neurites by 14 days after reperfusion. Large calcifying deposits were frequently observed at 28 days after reperfusion, when they were closely associated with or completely engulfed by astrocytes. In contrast, no prominent calcification was observed in the somata of CA1 pyramidal neurons showing the characteristic features of necrotic cell death after ischemia, although what appeared to be calcified mitochondria were noted in some degenerated neurons that became dark and condensed. Thus, our data indicate that intrahippocampal calcification after ischemic insults initially occurs within the mitochondria of degenerating dendrites, which leads to the extensive calcification that is associated with ischemic injuries. These findings suggest that in degenerating neurons, the calcified mitochondria in the dendrites, rather than in the somata, may serve as the nidus for further calcium precipitation in the ischemic hippocampus.
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Affiliation(s)
- Tae-Ryong Riew
- Department of Anatomy, Catholic Neuroscience Institute, Cell Death Disease Research Center, College of Medicine, The Catholic University of Korea, 137-701, Seoul, Korea
| | - Yoo-Jin Shin
- Department of Anatomy, Catholic Neuroscience Institute, Cell Death Disease Research Center, College of Medicine, The Catholic University of Korea, 137-701, Seoul, Korea
| | - Hong Lim Kim
- Integrative Research Support Center, Laboratory of Electron Microscope, College of Medicine, The Catholic University of Korea, Seoul, Korea, 137-701, Seoul, Korea
| | - Jeong Min Cho
- Department of Anatomy, Catholic Neuroscience Institute, Cell Death Disease Research Center, College of Medicine, The Catholic University of Korea, 137-701, Seoul, Korea
| | - Ha-Jin Pak
- Department of Anatomy, Catholic Neuroscience Institute, Cell Death Disease Research Center, College of Medicine, The Catholic University of Korea, 137-701, Seoul, Korea
| | - Mun-Yong Lee
- Department of Anatomy, Catholic Neuroscience Institute, Cell Death Disease Research Center, College of Medicine, The Catholic University of Korea, 137-701, Seoul, Korea
- * E-mail:
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26
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Schwarzländer M, Dick TP, Meyer AJ, Morgan B. Dissecting Redox Biology Using Fluorescent Protein Sensors. Antioxid Redox Signal 2016; 24:680-712. [PMID: 25867539 DOI: 10.1089/ars.2015.6266] [Citation(s) in RCA: 191] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
SIGNIFICANCE Fluorescent protein sensors have revitalized the field of redox biology by revolutionizing the study of redox processes in living cells and organisms. RECENT ADVANCES Within one decade, a set of fundamental new insights has been gained, driven by the rapid technical development of in vivo redox sensing. Redox-sensitive yellow and green fluorescent protein variants (rxYFP and roGFPs) have been the central players. CRITICAL ISSUES Although widely used as an established standard tool, important questions remain surrounding their meaningful use in vivo. We review the growing range of thiol redox sensor variants and their application in different cells, tissues, and organisms. We highlight five key findings where in vivo sensing has been instrumental in changing our understanding of redox biology, critically assess the interpretation of in vivo redox data, and discuss technical and biological limitations of current redox sensors and sensing approaches. FUTURE DIRECTIONS We explore how novel sensor variants may further add to the current momentum toward a novel mechanistic and integrated understanding of redox biology in vivo. Antioxid. Redox Signal. 24, 680-712.
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Affiliation(s)
- Markus Schwarzländer
- 1 Plant Energy Biology Lab, Department Chemical Signalling, Institute of Crop Science and Resource Conservation (INRES), University of Bonn , Bonn, Germany
| | - Tobias P Dick
- 2 Division of Redox Regulation, German Cancer Research Center (DKFZ) , DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Andreas J Meyer
- 3 Department Chemical Signalling, Institute of Crop Science and Resource Conservation (INRES), University of Bonn , Bonn, Germany
| | - Bruce Morgan
- 2 Division of Redox Regulation, German Cancer Research Center (DKFZ) , DKFZ-ZMBH Alliance, Heidelberg, Germany .,4 Cellular Biochemistry, Department of Biology, University of Kaiserslautern , Kaiserslautern, Germany
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27
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Márkus NM, Hasel P, Qiu J, Bell KFS, Heron S, Kind PC, Dando O, Simpson TI, Hardingham GE. Expression of mRNA Encoding Mcu and Other Mitochondrial Calcium Regulatory Genes Depends on Cell Type, Neuronal Subtype, and Ca2+ Signaling. PLoS One 2016; 11:e0148164. [PMID: 26828201 PMCID: PMC4734683 DOI: 10.1371/journal.pone.0148164] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2015] [Accepted: 01/13/2016] [Indexed: 02/02/2023] Open
Abstract
Uptake of Ca2+ into the mitochondrial matrix controls cellular metabolism and survival-death pathways. Several genes are implicated in controlling mitochondrial Ca2+ uptake (mitochondrial calcium regulatory genes, MCRGs), however, less is known about the factors which influence their expression level. Here we have compared MCRG mRNA expression, in neural cells of differing type (cortical neurons vs. astrocytes), differing neuronal subtype (CA3 vs. CA1 hippocampus) and in response to Ca2+ influx, using a combination of qPCR and RNA-seq analysis. Of note, we find that the Mcu-regulating Micu gene family profile differs substantially between neurons and astrocytes, while expression of Mcu itself is markedly different between CA3 and CA1 regions in the adult hippocampus. Moreover, dynamic control of MCRG mRNA expression in response to membrane depolarization-induced Ca2+ influx is also apparent, resulting in repression of Letm1, as well as Mcu. Thus, the mRNA expression profile of MCRGs is not fixed, which may cause differences in the coupling between cytoplasmic and mitochondrial Ca2+, as well as diversity of mitochondrial Ca2+ uptake mechanisms.
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Affiliation(s)
- Nóra M. Márkus
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, EH8 9XD, United Kingdom
| | - Philip Hasel
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, EH8 9XD, United Kingdom
| | - Jing Qiu
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, EH8 9XD, United Kingdom
| | - Karen F. S. Bell
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, EH8 9XD, United Kingdom
| | - Samuel Heron
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, EH8 9XD, United Kingdom
- School of Informatics, University of Edinburgh, Edinburgh, EH8 9AB, United Kingdom
| | - Peter C. Kind
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, EH8 9XD, United Kingdom
- Centre for Brain Development and Repair, Institute for Stem Cell Biology and Regenerative Medicine, National Centre for Biological Sciences, Bangalore, 560065, India
| | - Owen Dando
- Centre for Brain Development and Repair, Institute for Stem Cell Biology and Regenerative Medicine, National Centre for Biological Sciences, Bangalore, 560065, India
| | - T. Ian Simpson
- School of Informatics, University of Edinburgh, Edinburgh, EH8 9AB, United Kingdom
| | - Giles E. Hardingham
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, EH8 9XD, United Kingdom
- * E-mail:
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28
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Yin B, Barrionuevo G, Weber SG. Optimized real-time monitoring of glutathione redox status in single pyramidal neurons in organotypic hippocampal slices during oxygen-glucose deprivation and reperfusion. ACS Chem Neurosci 2015; 6:1838-48. [PMID: 26291433 DOI: 10.1021/acschemneuro.5b00186] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
A redox-sensitive Grx1-roGFP2 fusion protein was introduced by transfection into single pyramidal neurons in the CA1 subfield of organotypic hippocampal slice cultures (OHSCs). We assessed changes in the GSH system in neuronal cytoplasm and mitochondria during oxygen-glucose deprivation and reperfusion (OGD/RP), an in vitro model of stroke. Pyramidal cells in a narrow range of depths below the surface of the OHSC were transfected by gene gun or single-cell electroporation with cyto- or mito-Grx1-roGFP2. To mimic the conditions of acute stroke, we developed an optimized superfusion system with the capability of rapid and reproducible exchange of the solution bathing the OHSCs. Measurements of pO2 as a function of tissue depth show that in the region containing the transfected cells, the pO2 is well-controlled. We also found that the pO2 changes on the same time scale as changes in intracranial pressure, cerebral blood flow, and pO2 during acute stroke. Determining the reduction potential, EGSH, from the ratiometric fluorescence signal requires an absolute intensity measurement during calibration of the Grx1-roGFP2. Using the signal from cotransfected tdTomato as an internal standard during calibration improves quantitative measurements of Grx1-roGFP2 redox status and allows EGSH to be determined. EGSH becomes more reducing during OGD and more oxidizing during RP in mitochondria while changes in cytoplasm are not significant compared with controls.
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Affiliation(s)
- Bocheng Yin
- Department
of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Germán Barrionuevo
- Department
of Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Stephen G. Weber
- Department
of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
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29
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Görlach A, Bertram K, Hudecova S, Krizanova O. Calcium and ROS: A mutual interplay. Redox Biol 2015; 6:260-271. [PMID: 26296072 PMCID: PMC4556774 DOI: 10.1016/j.redox.2015.08.010] [Citation(s) in RCA: 935] [Impact Index Per Article: 103.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 08/08/2015] [Accepted: 08/10/2015] [Indexed: 02/07/2023] Open
Abstract
Calcium is an important second messenger involved in intra- and extracellular signaling cascades and plays an essential role in cell life and death decisions. The Ca2+ signaling network works in many different ways to regulate cellular processes that function over a wide dynamic range due to the action of buffers, pumps and exchangers on the plasma membrane as well as in internal stores. Calcium signaling pathways interact with other cellular signaling systems such as reactive oxygen species (ROS). Although initially considered to be potentially detrimental byproducts of aerobic metabolism, it is now clear that ROS generated in sub-toxic levels by different intracellular systems act as signaling molecules involved in various cellular processes including growth and cell death. Increasing evidence suggests a mutual interplay between calcium and ROS signaling systems which seems to have important implications for fine tuning cellular signaling networks. However, dysfunction in either of the systems might affect the other system thus potentiating harmful effects which might contribute to the pathogenesis of various disorders. Calcium and ROS act as signaling molecules inside the cell and their pathways can interact. The mutual interplay of calcium and ROS is required for the fine tuning of signaling. Failure in the interplay results in dysfunction and pathologies.
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Affiliation(s)
- Agnes Görlach
- Experimental and Molecular Pediatric Cardiology, German Heart Center Munich at the Technical University Munich, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, Munich, Germany.
| | - Katharina Bertram
- Experimental and Molecular Pediatric Cardiology, German Heart Center Munich at the Technical University Munich, Germany
| | - Sona Hudecova
- Center for Molecular Medicine, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Olga Krizanova
- Center for Molecular Medicine, Slovak Academy of Sciences, Bratislava, Slovakia; Institute of Virology, Slovak Academy of Sciences, Bratislava, Slovakia.
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30
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Bell KFS, Al-Mubarak B, Martel MA, McKay S, Wheelan N, Hasel P, Márkus NM, Baxter P, Deighton RF, Serio A, Bilican B, Chowdhry S, Meakin PJ, Ashford MLJ, Wyllie DJA, Scannevin RH, Chandran S, Hayes JD, Hardingham GE. Neuronal development is promoted by weakened intrinsic antioxidant defences due to epigenetic repression of Nrf2. Nat Commun 2015; 6:7066. [PMID: 25967870 PMCID: PMC4441249 DOI: 10.1038/ncomms8066] [Citation(s) in RCA: 130] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 03/30/2015] [Indexed: 12/13/2022] Open
Abstract
Forebrain neurons have weak intrinsic antioxidant defences compared with astrocytes, but the molecular basis and purpose of this is poorly understood. We show that early in mouse cortical neuronal development in vitro and in vivo, expression of the master-regulator of antioxidant genes, transcription factor NF-E2-related-factor-2 (Nrf2), is repressed by epigenetic inactivation of its promoter. Consequently, in contrast to astrocytes or young neurons, maturing neurons possess negligible Nrf2-dependent antioxidant defences, and exhibit no transcriptional responses to Nrf2 activators, or to ablation of Nrf2's inhibitor Keap1. Neuronal Nrf2 inactivation seems to be required for proper development: in maturing neurons, ectopic Nrf2 expression inhibits neurite outgrowth and aborization, and electrophysiological maturation, including synaptogenesis. These defects arise because Nrf2 activity buffers neuronal redox status, inhibiting maturation processes dependent on redox-sensitive JNK and Wnt pathways. Thus, developmental epigenetic Nrf2 repression weakens neuronal antioxidant defences but is necessary to create an environment that supports neuronal development.
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Affiliation(s)
- Karen F S Bell
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Bashayer Al-Mubarak
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Marc-André Martel
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Sean McKay
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Nicola Wheelan
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Philip Hasel
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Nóra M Márkus
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Paul Baxter
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Ruth F Deighton
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Andrea Serio
- MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Bilada Bilican
- MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Sudhir Chowdhry
- Medical Research Institute, University of Dundee, Ninewells Hospital and Medical School, Dundee DD1 9SY, UK
| | - Paul J Meakin
- Medical Research Institute, University of Dundee, Ninewells Hospital and Medical School, Dundee DD1 9SY, UK
| | - Michael L J Ashford
- Medical Research Institute, University of Dundee, Ninewells Hospital and Medical School, Dundee DD1 9SY, UK
| | - David J A Wyllie
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh EH8 9XD, UK
| | | | - Siddharthan Chandran
- MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - John D Hayes
- Medical Research Institute, University of Dundee, Ninewells Hospital and Medical School, Dundee DD1 9SY, UK
| | - Giles E Hardingham
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh EH8 9XD, UK
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