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Xi XR, Zhang ZQ, Li YL, Liu Z, Ma DY, Gao Z, Zhang S. Hypothermia promotes tunneling nanotube formation and the transfer of astrocytic mitochondria into oxygen-glucose deprivation/reoxygenation-injured neurons. Brain Res 2024; 1831:148826. [PMID: 38403036 DOI: 10.1016/j.brainres.2024.148826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 02/20/2024] [Accepted: 02/22/2024] [Indexed: 02/27/2024]
Abstract
Mitochondrial transfer occurs between cells, and it is important for damaged cells to receive healthy mitochondria to maintain their normal function and protect against cell death. Accumulating evidence suggests that the functional mitochondria of astrocytes are released and transferred to oxygen-glucose deprivation/reoxygenation (OGD/R)-injured neurons. Mild hypothermia (33 °C) is capable of promoting this process, which partially restores the function of damaged neurons. However, the pathways and mechanisms by which mild hypothermia facilitates mitochondrial transfer remain unclear. We are committed to studying the role of mild hypothermia in neuroprotection to provide reliable evidences and insights for the clinical application of mild hypothermia in brain protection. Tunneling nanotubes (TNTs) are considered to be one of the routes through which mitochondria are transferred between cells. In this study, an OGD/R-injured neuronal model was successfully established, and TNTs, mitochondria, neurons and astrocytes were double labeled using immunofluorescent probes. Our results showed that TNTs were present and involved in the transfer of mitochondria between cells in the mixed-culture system of neurons and astrocytes. When neurons were subjected to OGD/R exposure, TNT formation and mitochondrial transportation from astrocytes to injured neurons were facilitated. Further analysis revealed that mild hypothermia increased the quantity of astrocytic mitochondria transferred into damaged neurons through TNTs, raised the mitochondrial membrane potential (MMP), and decreased the neuronal damage and death during OGD/R. Altogether, our data indicate that TNTs play an important role in the endogenous neuroprotection of astrocytic mitochondrial transfer. Furthermore, mild hypothermia enhances astrocytic mitochondrial transfer into OGD/R-injured neurons via TNTs, thereby promoting neuroprotection and neuronal recovery.
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Affiliation(s)
- Xiao-Rui Xi
- Department of Anesthesiology, Second Hospital of Hebei Medical University, Shijiazhuang, 050000 Hebei, China
| | - Zhi-Qiang Zhang
- Department of Anesthesiology, Second Hospital of Hebei Medical University, Shijiazhuang, 050000 Hebei, China
| | - Yan-Li Li
- Department of Anesthesiology, Second Hospital of Hebei Medical University, Shijiazhuang, 050000 Hebei, China
| | - Zheng Liu
- Department of Anesthesiology, Second Hospital of Hebei Medical University, Shijiazhuang, 050000 Hebei, China
| | - Dong-Yang Ma
- Department of Anesthesiology, Second Hospital of Hebei Medical University, Shijiazhuang, 050000 Hebei, China
| | - Zan Gao
- Department of Anesthesiology, Second Hospital of Hebei Medical University, Shijiazhuang, 050000 Hebei, China
| | - Shan Zhang
- Department of Anesthesiology, Second Hospital of Hebei Medical University, Shijiazhuang, 050000 Hebei, China.
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Purvis EM, Fedorczak N, Prah A, Han D, O’Donnell JC. Porcine Astrocytes and Their Relevance for Translational Neurotrauma Research. Biomedicines 2023; 11:2388. [PMID: 37760829 PMCID: PMC10525191 DOI: 10.3390/biomedicines11092388] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 08/17/2023] [Accepted: 08/22/2023] [Indexed: 09/29/2023] Open
Abstract
Astrocytes are essential to virtually all brain processes, from ion homeostasis to neurovascular coupling to metabolism, and even play an active role in signaling and plasticity. Astrocytic dysfunction can be devastating to neighboring neurons made inherently vulnerable by their polarized, excitable membranes. Therefore, correcting astrocyte dysfunction is an attractive therapeutic target to enhance neuroprotection and recovery following acquired brain injury. However, the translation of such therapeutic strategies is hindered by a knowledge base dependent almost entirely on rodent data. To facilitate additional astrocytic research in the translatable pig model, we present a review of astrocyte findings from pig studies of health and disease. We hope that this review can serve as a road map for intrepid pig researchers interested in studying astrocyte biology.
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Affiliation(s)
- Erin M. Purvis
- Center for Neurotrauma, Neurodegeneration & Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA 19104, USA (D.H.)
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Natalia Fedorczak
- Center for Neurotrauma, Neurodegeneration & Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA 19104, USA (D.H.)
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Annette Prah
- Center for Neurotrauma, Neurodegeneration & Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA 19104, USA (D.H.)
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Daniel Han
- Center for Neurotrauma, Neurodegeneration & Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA 19104, USA (D.H.)
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - John C. O’Donnell
- Center for Neurotrauma, Neurodegeneration & Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA 19104, USA (D.H.)
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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Hamner MA, McDonough A, Gong DC, Todd LJ, Rojas G, Hodecker S, Ransom CB, Reh TA, Ransom BR, Weinstein JR. Microglial depletion abolishes ischemic preconditioning in white matter. Glia 2021; 70:661-674. [PMID: 34939240 DOI: 10.1002/glia.24132] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 12/10/2021] [Accepted: 12/10/2021] [Indexed: 01/17/2023]
Abstract
Ischemic preconditioning (IPC) is a phenomenon whereby a brief, non-injurious ischemic exposure enhances tolerance to a subsequent ischemic challenge. The mechanism of IPC has mainly been studied in rodent stroke models where gray matter (GM) constitutes about 85% of the cerebrum. In humans, white matter (WM) is 50% of cerebral volume and is a critical component of stroke damage. We developed a novel CNS WM IPC model using the mouse optic nerve (MON) and identified the involved immune signaling pathways. Here we tested the hypothesis that microglia are necessary for WM IPC. Microglia were depleted by treatment with the colony stimulating factor 1 receptor (CSF1R) inhibitor PLX5622. MONs were exposed to transient ischemia in vivo, acutely isolated 72 h later, and subjected to oxygen-glucose deprivation (OGD) to simulate a severe ischemic injury (i.e., stroke). Functional and structural axonal recovery was assessed by recording compound action potentials (CAPs) and by microscopy using quantitative stereology. Microglia depletion eliminated IPC-mediated protection. In control mice, CAP recovery was improved in preconditioned MONs compared with non-preconditioned MONs, however, in PLX5622-treated mice, we observed no difference in CAP recovery between preconditioned and non-preconditioned MONs. Microgliadepletion also abolished IPC protective effects on axonal integrity and survival of mature (APC+ ) oligodendrocytes after OGD. IPC-mediated protection was independent of retinal injury suggesting it results from mechanistic processes intrinsic to ischemia-exposed WM. We conclude that preconditioned microglia are critical for IPC in WM. The "preconditioned microglia" phenotype might protect against other CNS pathologies and is a neurotherapeutic horizon worth exploring.
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Affiliation(s)
- Margaret A Hamner
- Department of Neurology, School of Medicine, University of Washington, Seattle, Washington, USA
| | - Ashley McDonough
- Department of Neurology, School of Medicine, University of Washington, Seattle, Washington, USA
| | - Davin C Gong
- Department of Neurology, School of Medicine, University of Washington, Seattle, Washington, USA
| | - Levi J Todd
- Department of Biological Structure, School of Medicine, University of Washington, Seattle, Washington, USA
| | - German Rojas
- Department of Neurology, School of Medicine, University of Washington, Seattle, Washington, USA
| | - Sibylle Hodecker
- Department of Neurology, School of Medicine, University of Washington, Seattle, Washington, USA
| | - Christopher B Ransom
- Department of Neurology, School of Medicine, University of Washington, Seattle, Washington, USA
| | - Thomas A Reh
- Department of Biological Structure, School of Medicine, University of Washington, Seattle, Washington, USA
| | - Bruce R Ransom
- Department of Neurology, School of Medicine, University of Washington, Seattle, Washington, USA.,Neuroscience Department, City University of Hong Kong, Kowloon, Hong Kong
| | - Jonathan R Weinstein
- Department of Neurology, School of Medicine, University of Washington, Seattle, Washington, USA.,Department of Neurological Surgery, School of Medicine, University of Washington, Seattle, Washington, USA
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Stifani S. Taking Cellular Heterogeneity Into Consideration When Modeling Astrocyte Involvement in Amyotrophic Lateral Sclerosis Using Human Induced Pluripotent Stem Cells. Front Cell Neurosci 2021; 15:707861. [PMID: 34602979 PMCID: PMC8485040 DOI: 10.3389/fncel.2021.707861] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 08/24/2021] [Indexed: 12/25/2022] Open
Abstract
Astrocytes are a large group of glial cells that perform a variety of physiological functions in the nervous system. They provide trophic, as well as structural, support to neuronal cells. Astrocytes are also involved in neuroinflammatory processes contributing to neuronal dysfunction and death. Growing evidence suggests important roles for astrocytes in non-cell autonomous mechanisms of motor neuron degeneration in amyotrophic lateral sclerosis (ALS). Understanding these mechanisms necessitates the combined use of animal and human cell-based experimental model systems, at least in part because human astrocytes display a number of unique features that cannot be recapitulated in animal models. Human induced pluripotent stem cell (hiPSC)-based approaches provide the opportunity to generate disease-relevant human astrocytes to investigate the roles of these cells in ALS. These approaches are facing the growing recognition that there are heterogenous populations of astrocytes in the nervous system which are not functionally equivalent. This review will discuss the importance of taking astrocyte heterogeneity into consideration when designing hiPSC-based strategies aimed at generating the most informative preparations to study the contribution of astrocytes to ALS pathophysiology.
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Affiliation(s)
- Stefano Stifani
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montreal, QC, Canada
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