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Pottorf TS, Rotterman TM, McCallum WM, Haley-Johnson ZA, Alvarez FJ. The Role of Microglia in Neuroinflammation of the Spinal Cord after Peripheral Nerve Injury. Cells 2022; 11:cells11132083. [PMID: 35805167 PMCID: PMC9265514 DOI: 10.3390/cells11132083] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 06/26/2022] [Accepted: 06/27/2022] [Indexed: 12/12/2022] Open
Abstract
Peripheral nerve injuries induce a pronounced immune reaction within the spinal cord, largely governed by microglia activation in both the dorsal and ventral horns. The mechanisms of activation and response of microglia are diverse depending on the location within the spinal cord, type, severity, and proximity of injury, as well as the age and species of the organism. Thanks to recent advancements in neuro-immune research techniques, such as single-cell transcriptomics, novel genetic mouse models, and live imaging, a vast amount of literature has come to light regarding the mechanisms of microglial activation and alluding to the function of microgliosis around injured motoneurons and sensory afferents. Herein, we provide a comparative analysis of the dorsal and ventral horns in relation to mechanisms of microglia activation (CSF1, DAP12, CCR2, Fractalkine signaling, Toll-like receptors, and purinergic signaling), and functionality in neuroprotection, degeneration, regeneration, synaptic plasticity, and spinal circuit reorganization following peripheral nerve injury. This review aims to shed new light on unsettled controversies regarding the diversity of spinal microglial-neuronal interactions following injury.
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Affiliation(s)
- Tana S. Pottorf
- Department of Cell Biology, Emory University, Atlanta, GA 30322, USA; (T.S.P.); (W.M.M.); (Z.A.H.-J.)
| | - Travis M. Rotterman
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30318, USA;
| | - William M. McCallum
- Department of Cell Biology, Emory University, Atlanta, GA 30322, USA; (T.S.P.); (W.M.M.); (Z.A.H.-J.)
| | - Zoë A. Haley-Johnson
- Department of Cell Biology, Emory University, Atlanta, GA 30322, USA; (T.S.P.); (W.M.M.); (Z.A.H.-J.)
| | - Francisco J. Alvarez
- Department of Cell Biology, Emory University, Atlanta, GA 30322, USA; (T.S.P.); (W.M.M.); (Z.A.H.-J.)
- Correspondence:
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Cartarozzi LP, Perez M, Fernandes GG, Chiarotto GB, Luzo ÂCM, Campos AC, Kirchhoff F, de Oliveira ALR. Neuroprotection and gliosis attenuation by intravenous application of human mesenchymal stem cells (hMSC) following ventral root crush in mice. Mol Cell Neurosci 2021; 118:103694. [PMID: 34954382 DOI: 10.1016/j.mcn.2021.103694] [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: 06/09/2021] [Revised: 12/13/2021] [Accepted: 12/17/2021] [Indexed: 11/15/2022] Open
Abstract
Rupture and stretching of spinal roots are common incidents that take place in high-energy accidents. The proximal axotomy of motoneurons by crushing of ventral roots is directly related to the degeneration of half of the lesioned population within the first two weeks. Moreover, only a small percentage of surviving motoneurons can successfully achieve regeneration after such a proximal lesion, and new treatments are necessary to improve this scenario. In this sense, mesenchymal stem cells (MSC) are of great interest once they secrete a broad spectrum of bioactive molecules that are immunomodulatory and can restore the environment after a lesion. The present work aimed at studying the effects of human mesenchymal stem cells (hMSC) therapy after ventral root crush (VRC) in mice. We evaluated motoneuron survival, glial reaction, and synapse preservation at the ventral horn. For this purpose, C57BL/6 J were submitted to a crush procedure of L4 to L6 ventral roots and treated with a single intravenous injection of adipose-derived hMSC. Evaluation of the results was carried out at 7, 14, and 28 days after injury. Analysis of motoneuron survival and astrogliosis showed that hMSC treatment resulted in higher motoneuron preservation (motoneuron survival ipsi/contralateral ratio: VRC group = 53%, VRC + hMSC group = 66%; p < 0.01), combined with reduction of astrogliosis (ipsi/contralateral GFAP immunolabeling: VRC group = 470%, VRC + hMSC group = 250%; p < 0.001). The morphological classification and Sholl analysis of microglial activation revealed that hMSC treatment reduced type V and increased type II profiles, indicating an enhancement of surveying over activated microglial cells. The glial reactivity modulation directly influenced synaptic inputs in apposition to axotomized motoneurons. In the hMSC-treated group, synaptic maintenance was increased (ipsi/contralateral synaptophysin immunolabeling: VRC group = 53%, VRC + hMSC group = 64%; p < 0.05). Overall, the present data show that intravenous injection of hMSC has neuroprotective and anti-inflammatory effects, decreasing reactive astrogliosis, and microglial reaction. Also, such cell therapy results in motoneuron preservation, combined with significant maintenance of spinal cord circuits, in particular those related to the ventral horn.
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Affiliation(s)
- Luciana Politti Cartarozzi
- Laboratory of Nerve Regeneration, University of Campinas - UNICAMP, Cidade Universitaria "Zeferino Vaz", Rua Monteiro Lobato, 255, 13083-970 Campinas, SP, Brazil
| | - Matheus Perez
- School of Physical Education and Sport of Ribeirão Preto, University of São Paulo, Av. Bandeirantes, 3900, 14040-907 Ribeirão Preto, SP, Brazil
| | - Gabriel Gripp Fernandes
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, Av. Bandeirantes, 3900, 14040-907 Ribeirão Preto, SP, Brazil
| | - Gabriela Bortolança Chiarotto
- Laboratory of Nerve Regeneration, University of Campinas - UNICAMP, Cidade Universitaria "Zeferino Vaz", Rua Monteiro Lobato, 255, 13083-970 Campinas, SP, Brazil
| | - Ângela Cristina Malgeiros Luzo
- Hematology and Hemotherapy Center, University of Campinas/Hemocentro-Unicamp, Instituto Nacional de Ciência e Tecnologia do Sangue, Campinas, São Paulo, Brazil
| | - Alline Cristina Campos
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, Av. Bandeirantes, 3900, 14040-907 Ribeirão Preto, SP, Brazil
| | - Frank Kirchhoff
- Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Building 48, 66421 Homburg, Germany
| | - Alexandre Leite Rodrigues de Oliveira
- Laboratory of Nerve Regeneration, University of Campinas - UNICAMP, Cidade Universitaria "Zeferino Vaz", Rua Monteiro Lobato, 255, 13083-970 Campinas, SP, Brazil.
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Zhang J, Jiang H, Wu F, Chi X, Pang Y, Jin H, Sun Y, Zhang S. Neuroprotective Effects of Hesperetin in Regulating Microglia Polarization after Ischemic Stroke by Inhibiting TLR4/NF- κB Pathway. JOURNAL OF HEALTHCARE ENGINEERING 2021; 2021:9938874. [PMID: 34956584 PMCID: PMC8709759 DOI: 10.1155/2021/9938874] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Accepted: 11/16/2021] [Indexed: 12/14/2022]
Abstract
This study aimed to explore the influence of hesperidin on the polarization of microglia to clarify the key mechanism of regulating the polarization of M2 microglia. C57BL/6 mice were randomly divided into middle cerebral artery occlusion model group (MCAO group), MCAO + hesperidin treatment group (MCAO + hesperidin group), and sham group (sham operation group). The mice were assessed with neurological scores for their functional status. 2,3,5-Triphenyltetrazole chloride (TTC) was used to determine the volume of cerebral infarction. Hematoxylin and eosin (H&E) staining was performed to detect brain loss. The system with 1% O2, 5% CO2, and 92% N2 was applied to establish BV2 in vitro model induced by MCAO. TNF-α, IL-1β, TGF-β, and IL-10 levels of cytokines in the supernatant were detected by ELISA. RT-qPCR was used to detect mRNA levels of M1 iNOS, CD11b, CD32, and CD86, and mRNA levels of M2 CD206, Arg-1, and TGF-β. The Iba-1, iNOS, and Arg-1 of microglia and protein levels of TLR4 and p-NF-κB related to the pathway were detected by Western blot. After treatment with hesperidin, BV2 cells induced by MCAO in vitro can reduce the proinflammatory cytokines of TNF-α and IL-1β significantly, further upregulating anti-inflammatory cytokines of TGF-β, IL-10 while inhibiting TLR4 and p-NF-κB expression. The MCAO-induced BV2 cells treated by TLR-4 inhibitor TAK-242 and NF-κB inhibitor BAY 11-7082 had similar polarization effects to those treated with hesperidin. This study found that hesperetin gavage treatment can improve the neurological deficit and regulate the polarization of microglia in MCAO mice. In vitro experiments further verified that hesperidin plays a neuroprotective role by inhibiting the TLR4-NF-κB pathway, thus providing new targets and strategies for neuroprotection and nerve repair after ischemic stroke.
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Affiliation(s)
- Jiawen Zhang
- Department of Neurology Four Ward, The Second Affiliated Hospital of Qiqihar Medical University, Qiqihar 161000, China
| | - Hao Jiang
- The Fifth Affiliated Hospital of Harbin Medical University, Qiqihar 161000, China
| | - Fang Wu
- Division of Liver Disease, Qiqihar Seventh Hospital, Qiqihar 161000, China
| | - Xiaofei Chi
- Department of Neurology Four Ward, The Second Affiliated Hospital of Qiqihar Medical University, Qiqihar 161000, China
| | - Yu Pang
- Department of Neurology Four Ward, The Second Affiliated Hospital of Qiqihar Medical University, Qiqihar 161000, China
| | - Hongwei Jin
- Department of Neurology Four Ward, The Second Affiliated Hospital of Qiqihar Medical University, Qiqihar 161000, China
| | - Yuyang Sun
- Department of Neurology Four Ward, The Second Affiliated Hospital of Qiqihar Medical University, Qiqihar 161000, China
| | - Shicun Zhang
- Department of Neurology Four Ward, The Second Affiliated Hospital of Qiqihar Medical University, Qiqihar 161000, China
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Levi H, Bar E, Cohen-Adiv S, Sweitat S, Kanner S, Galron R, Mitiagin Y, Barzilai A. Dysfunction of cerebellar microglia in Ataxia-telangiectasia. Glia 2021; 70:536-557. [PMID: 34854502 DOI: 10.1002/glia.24122] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 11/09/2021] [Accepted: 11/12/2021] [Indexed: 12/13/2022]
Abstract
Ataxia-telangiectasia (A-T) is a multisystem autosomal recessive disease caused by mutations in the ATM gene and characterized by cerebellar atrophy, progressive ataxia, immunodeficiency, male and female sterility, radiosensitivity, cancer predisposition, growth retardation, insulin-resistant diabetes, and premature aging. ATM phosphorylates more than 1500 target proteins, which are involved in cell cycle control, DNA repair, apoptosis, modulation of chromatin structure, and other cytoplasmic as well as mitochondrial processes. In our quest to better understand the mechanisms by which ATM deficiency causes cerebellar degeneration, we hypothesized that specific vulnerabilities of cerebellar microglia underlie the etiology of A-T. Our hypothesis is based on the recent finding that dysfunction of glial cells affect a variety of process leading to impaired neuronal functionality (Song et al., 2019). Whereas astrocytes and neurons descend from the neural tube, microglia originate from the hematopoietic system, invade the brain at early embryonic stage, and become the innate immune cells of the central nervous system and important participants in development of synaptic plasticity. Here we demonstrate that microglia derived from Atm-/- mouse cerebellum display accelerated cell migration and are severely impaired in phagocytosis, secretion of neurotrophic factors, and mitochondrial activity, suggestive of apoptotic processes. Interestingly, no microglial impairment was detected in Atm-deficient cerebral cortex, and Atm deficiency had less impact on astroglia than microglia. Collectively, our findings validate the roles of glial cells in cerebellar attrition in A-T.
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Affiliation(s)
- Hadar Levi
- Department of Neurobiology, George S. Wise, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Ela Bar
- Department of Neurobiology, George S. Wise, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Stav Cohen-Adiv
- Department of Neurobiology, George S. Wise, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Suzan Sweitat
- Department of Neurobiology, George S. Wise, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Sivan Kanner
- Department of Neurobiology, George S. Wise, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Ronit Galron
- Department of Neurobiology, George S. Wise, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Yulia Mitiagin
- Department of Neurobiology, George S. Wise, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Ari Barzilai
- Department of Neurobiology, George S. Wise, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel.,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
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Perez M, Cartarozzi LP, Chiarotto GB, Guimarães FS, Oliveira ALRD. Short and long-term neuroprotective effects of cannabidiol after neonatal peripheral nerve axotomy. Neuropharmacology 2021; 197:108726. [PMID: 34303725 DOI: 10.1016/j.neuropharm.2021.108726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Revised: 07/05/2021] [Accepted: 07/18/2021] [Indexed: 11/18/2022]
Abstract
Neonatal rat sciatic nerve crush mimics obstetric axonotmesis, leading to extensive loss of motor and sensory neurons. The present study aimed to investigate the neuroprotective potential of cannabidiol (CBD) and the role of cannabinoid receptors after sciatic nerve crush in neonatal rats. For that, two-day-old Wistar rats were used, organized into the following experimental groups: sciatic nerve crush plus CBD treatment (CBD), crush plus vehicle treatment (VE), crush + CBD + AM251 treatment (AM251 - CB1 inverse agonist), crush + CBD + AM630 treatment (AM630 - CB2 antagonist). Spinal motoneuron survival was evaluated by Nissl staining of the lumbar spinal cord, 5- and 56-days following injury. CBD treatment enhanced neuronal survival by ~54 % both 5 days and 8 weeks after injury. However, AM251 and AM630 treatment decreased neuronal rescue by 30 % when compared to the CBD group, suggesting that CBD acts partially through such pathways. However, in the long term, only the CB1 blockade reverted CBD positive results. Synaptic preservation was evaluated by anti-synaptophysin immunolabeling. Five days after the lesion, CBD treatment preserved ~35 % of synapses in the ventral horn, and such effect was partially reversed by CB1 inactivation. Additionally, CBD treatment reduced astroglial reaction both at 5 days (39 %, compared to VE) and 8 weeks (31 %, compared to VE) after lesion. The microglial response was acutely reduced by 62 % after CBD treatment. Overall, the results herein show that CBD is neuroprotective, increasing neuronal survival and reducing glial reaction after neonatal axotomy. Such effects require CB1 and CB2 receptors to be effective, in turn influencing neuroprotection, glial reactivity, and functional recovery.
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Affiliation(s)
- Matheus Perez
- Laboratory of Nerve Regeneration, University of Campinas - UNICAMP, Cidade Universitaria "Zeferino Vaz", Rua Monteiro Lobato, 255, 13083-970, Campinas, SP, Brazil; School of Physical Education and Sport of Ribeirão Preto, University of São Paulo, Av. Bandeirantes, 3900, 14040-907, Ribeirão Preto, SP, Brazil
| | - Luciana Politti Cartarozzi
- Laboratory of Nerve Regeneration, University of Campinas - UNICAMP, Cidade Universitaria "Zeferino Vaz", Rua Monteiro Lobato, 255, 13083-970, Campinas, SP, Brazil
| | - Gabriela Bortolança Chiarotto
- Laboratory of Nerve Regeneration, University of Campinas - UNICAMP, Cidade Universitaria "Zeferino Vaz", Rua Monteiro Lobato, 255, 13083-970, Campinas, SP, Brazil
| | - Francisco Silveira Guimarães
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, Av. Bandeirantes, 3900, 14040-907, Ribeirão Preto, SP, Brazil
| | - Alexandre Leite Rodrigues de Oliveira
- Laboratory of Nerve Regeneration, University of Campinas - UNICAMP, Cidade Universitaria "Zeferino Vaz", Rua Monteiro Lobato, 255, 13083-970, Campinas, SP, Brazil.
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Decreasing auditory input induces neurogenesis impairment in the hippocampus. Sci Rep 2021; 11:423. [PMID: 33432038 PMCID: PMC7801596 DOI: 10.1038/s41598-020-80218-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 12/07/2020] [Indexed: 02/06/2023] Open
Abstract
Hearing loss is associated with cognitive decline and dementia risk. Sensorineural hearing loss suppresses hippocampal neurogenesis, resulting in cognitive decline. However, the underlying mechanism of impaired neurogenesis and the role of microglial activation and stress responses related to hearing loss in the hippocampus remains unknown. Using a conductive hearing loss (CHL) model, we investigated whether a decrease in sound level could induce impairment of hippocampal neurogenesis and examined the differences between unilateral CHL (uCHL) and bilateral CHL (bCHL). To establish the CHL mouse model, ears were unilaterally or bilaterally occluded for five weeks by auditory canal ligation. Although hearing thresholds were significantly increased following CHL, CHL mice exhibited no significant loss of spiral ganglion or hippocampal neurons. Hippocampal neurogenesis was significantly and equally decreased in both sides following uCHL. More severe decreases in hippocampal neurogenesis were observed in both sides in bCHL mice compared with that in uCHL mice. Furthermore, microglial invasion significantly increased following CHL. Serum cortisol levels, which indicate stress response, significantly increased following bCHL. Therefore, auditory deprivation could lead to increased microglial invasion and stress responses and might be a risk factor for hippocampal neurogenesis impairment.
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Salvany S, Casanovas A, Piedrafita L, Tarabal O, Hernández S, Calderó J, Esquerda JE. Microglial recruitment and mechanisms involved in the disruption of afferent synaptic terminals on spinal cord motor neurons after acute peripheral nerve injury. Glia 2021; 69:1216-1240. [PMID: 33386754 PMCID: PMC7986680 DOI: 10.1002/glia.23959] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 12/11/2020] [Accepted: 12/14/2020] [Indexed: 12/12/2022]
Abstract
Peripheral nerve section with subsequent disconnection of motor neuron (MN) cell bodies from their skeletal muscle targets leads to a rapid reactive response involving the recruitment and activation of microglia. In addition, the loss of afferent synapses on MNs occurs in concomitance with microglial reaction by a process described as synaptic stripping. However, the way in which postaxotomy‐activated microglia adjacent to MNs are involved in synaptic removal is less defined. Here, we used confocal and electron microscopy to examine interactions between recruited microglial cells and presynaptic terminals in axotomized MNs between 1 and 15 days after sciatic nerve transection in mice. We did not observe any bulk engulfment of synaptic boutons by microglia. Instead, microglial cells internalized small membranous‐vesicular fragments which originated from the acute disruption of synaptic terminals involving the activation of the necroptotic pathway. The presence of abundant extracellular vesicles in the perineuronal space after axotomy, together with the increased expression of phospho‐mixed lineage kinase domain‐like protein and, later, of extracellular vesicle markers, such as CD9, CD63, and flotillin, indicate that the vesicles mainly originated in synapses and were transferred to microglia. The upregulation of Rab7 and Rab10 in microglia interacting with injured MNs, indicated the activation of endocytosis. As activated microglia and synaptic boutons displayed positive C1q immunoreactivity, a complement‐mediated opsonization may also contribute to microglial‐mediated synaptic disruption. In addition to the relevance of our data in the context of neuroinflammation and MN disease, they should also be taken into account for understanding functional recovery after peripheral nerve injury.
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Affiliation(s)
- Sara Salvany
- Patologia Neuromuscular Experimental Departament de Medicina Experimental, Facultat de Medicina, Universitat de Lleida and Institut de Recerca Biomèdica de Lleida (IRBLleida), Lleida, Catalonia, Spain
| | - Anna Casanovas
- Patologia Neuromuscular Experimental Departament de Medicina Experimental, Facultat de Medicina, Universitat de Lleida and Institut de Recerca Biomèdica de Lleida (IRBLleida), Lleida, Catalonia, Spain
| | - Lídia Piedrafita
- Patologia Neuromuscular Experimental Departament de Medicina Experimental, Facultat de Medicina, Universitat de Lleida and Institut de Recerca Biomèdica de Lleida (IRBLleida), Lleida, Catalonia, Spain
| | - Olga Tarabal
- Patologia Neuromuscular Experimental Departament de Medicina Experimental, Facultat de Medicina, Universitat de Lleida and Institut de Recerca Biomèdica de Lleida (IRBLleida), Lleida, Catalonia, Spain
| | - Sara Hernández
- Patologia Neuromuscular Experimental Departament de Medicina Experimental, Facultat de Medicina, Universitat de Lleida and Institut de Recerca Biomèdica de Lleida (IRBLleida), Lleida, Catalonia, Spain
| | - Jordi Calderó
- Patologia Neuromuscular Experimental Departament de Medicina Experimental, Facultat de Medicina, Universitat de Lleida and Institut de Recerca Biomèdica de Lleida (IRBLleida), Lleida, Catalonia, Spain
| | - Josep E Esquerda
- Patologia Neuromuscular Experimental Departament de Medicina Experimental, Facultat de Medicina, Universitat de Lleida and Institut de Recerca Biomèdica de Lleida (IRBLleida), Lleida, Catalonia, Spain
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Zhuang H, Yang J, Huang Z, Liu H, Li X, Zhang H, Wang J, Yu S, Liu K, Liu R, Bi M, Wang J, Salvi RJ, Hu B, Teng G, Liu L. Accelerated age-related decline in hippocampal neurogenesis in mice with noise-induced hearing loss is associated with hippocampal microglial degeneration. Aging (Albany NY) 2020; 12:19493-19519. [PMID: 33041264 PMCID: PMC7732316 DOI: 10.18632/aging.103898] [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: 04/03/2020] [Accepted: 07/23/2020] [Indexed: 01/24/2023]
Abstract
Large-scale epidemiological surveys suggest that hearing loss (HL) is a significant risk factor for dementia. We previously showed that noise-induced HL (NIHL) impairs hippocampal cognitive function and decreases hippocampal neurogenesis and neuronal complexity, suggesting a causal role of HL in dementia. To further investigate the influence of acquired peripheral HL on hippocampal neurogenesis with the aging process as well as the underlying mechanism, we produced NIHL in male CBA/J mice and assessed hippocampal neurogenesis and microglial morphology in the auditory brain and hippocampus at 4 days post-noise exposure (DPN) or 1, 3, 6, or 12 months post-noise exposure (MPN) by immunofluorescence labeling. We found that the age-related decline in hippocampal neurogenesis was accelerated in mice with NIHL. Furthermore, in mice with NIHL, prolonged microglial activation occurred from 1 MPN to 12 MPN across multiple auditory nuclei, while aggravated microglial deterioration occurred in the hippocampus and correlated with the age-related decline in hippocampal neurogenesis. These results suggest that acquired peripheral HL accelerates the age-related decline in hippocampal neurogenesis and that hippocampal microglial degeneration may contribute to the development of neurodegeneration following acquired peripheral HL.
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Affiliation(s)
- Hong Zhuang
- Department of Physiology, Medical College, Southeast University, Nanjing 210009, China
| | - Jing Yang
- Institute of Life Sciences, Southeast University, Nanjing 210096, China
| | - Zhihui Huang
- Institute of Life Sciences, Southeast University, Nanjing 210096, China
| | - Haiqing Liu
- Institute of Life Sciences, Southeast University, Nanjing 210096, China
| | - Xiaobo Li
- Institute of Life Sciences, Southeast University, Nanjing 210096, China
| | - Hongyu Zhang
- Institute of Life Sciences, Southeast University, Nanjing 210096, China
| | - Jiadong Wang
- Medical College, Southeast University, Nanjing 210009, China
| | - Shen Yu
- Medical College, Southeast University, Nanjing 210009, China
| | - Kefei Liu
- Kangda College of Nanjing Medical University, Lianyungang 222000, China
| | - Rui Liu
- Medical College, Southeast University, Nanjing 210009, China
| | - Mingze Bi
- Medical College, Southeast University, Nanjing 210009, China
| | - Jian Wang
- School of Human Communication Disorder, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Richard J. Salvi
- Center for Hearing and Deafness, University at Buffalo, The State University of New York, Buffalo, NY 14214, USA
| | - Bohua Hu
- Center for Hearing and Deafness, University at Buffalo, The State University of New York, Buffalo, NY 14214, USA
| | - Gaojun Teng
- Jiangsu Key Laboratory of Molecular Imaging and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing 210009, China
| | - Lijie Liu
- Department of Physiology, Medical College, Southeast University, Nanjing 210009, China
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Padilla-Zambrano HS, Deora H, Arnout M, Mendoza-Florez R, Cardenas-Chavez WE, Herrera-Martinez MP, Ortega-Sierra MG, Agrawal A, Moscote-Salazar LR. The Role of Microglia in Cerebral Traumatic Injury and its Therapeutic Implications. INDIAN JOURNAL OF NEUROTRAUMA 2020. [DOI: 10.1055/s-0040-1713078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
AbstractMicroglia have a variety of functions in the brain such as synaptic remodeling, damage repair of the central nervous system (CNS), and CNS’ inflammatory response to peripheral infections. The response depends on the type of insult and infection and includes a range of variety of activation states, the duration of which will decide the outcome. In response to traumatic brain injury (TBI), early activation can lead to early restoration of function, while prolonged and continuous activation can cause neurodegeneration states. Current evidence, however, states that this may not be the case. In this article, we discuss this seldom understood topic of microglia response to TBI, and analyze their distribution, function and possible sites of manipulation. Animal studies have allowed genetic and pharmacological manipulations of microglia activation, in order to define their role. Microglia activation can be remote to the site of injury, and thus their manipulation may play a significant role in the response to any trauma.
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Affiliation(s)
- Huber S. Padilla-Zambrano
- Biomedical Research Center (CIB), Cartagena Neurotrauma Research Group Research Line, Faculty of Medicine, University of Cartagena, Cartagena, Colombia
| | - Harsh Deora
- Department of Neurosurgery, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India
| | | | - Romario Mendoza-Florez
- Biomedical Research Center (CIB), Cartagena Neurotrauma Research Group Research Line, Faculty of Medicine, University of Cartagena, Cartagena, Colombia
| | - Wiston Eduardo Cardenas-Chavez
- Biomedical Research Center (CIB), Cartagena Neurotrauma Research Group Research Line, Faculty of Medicine, University of Cartagena, Cartagena, Colombia
| | - Monica Patricia Herrera-Martinez
- Biomedical Research Center (CIB), Cartagena Neurotrauma Research Group Research Line, Faculty of Medicine, University of Cartagena, Cartagena, Colombia
| | | | - Amit Agrawal
- Department of Neurosurgery, All India Institute of Medical Sciences, Bhopal, Madhya Pradesh, India
| | - Luis Rafael Moscote-Salazar
- Biomedical Research Center (CIB), Cartagena Neurotrauma Research Group Research Line, Faculty of Medicine, University of Cartagena, Cartagena, Colombia
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Var SR, Byrd-Jacobs CA. Role of Macrophages and Microglia in Zebrafish Regeneration. Int J Mol Sci 2020; 21:E4768. [PMID: 32635596 PMCID: PMC7369716 DOI: 10.3390/ijms21134768] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 07/02/2020] [Accepted: 07/03/2020] [Indexed: 12/11/2022] Open
Abstract
Currently, there is no treatment for recovery of human nerve function after damage to the central nervous system (CNS), and there are limited regenerative capabilities in the peripheral nervous system. Since fish are known for their regenerative abilities, understanding how these species modulate inflammatory processes following injury has potential translational importance for recovery from damage and disease. Many diseases and injuries involve the activation of innate immune cells to clear damaged cells. The resident immune cells of the CNS are microglia, the primary cells that respond to infection and injury, and their peripheral counterparts, macrophages. These cells serve as key modulators of development and plasticity and have been shown to be important in the repair and regeneration of structure and function after injury. Zebrafish are an emerging model for studying macrophages in regeneration after injury and microglia in neurodegenerative disorders such as Parkinson's disease and Alzheimer's disease. These fish possess a high degree of neuroanatomical, neurochemical, and emotional/social behavioral resemblance with humans, serving as an ideal simulator for many pathologies. This review explores literature on macrophage and microglial involvement in facilitating regeneration. Understanding innate immune cell behavior following damage may help to develop novel methods for treating toxic and chronic inflammatory processes that are seen in trauma and disease.
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Calvo PM, de la Cruz RR, Pastor AM. A Single Intraventricular Injection of VEGF Leads to Long-Term Neurotrophic Effects in Axotomized Motoneurons. eNeuro 2020; 7:ENEURO.0467-19.2020. [PMID: 32371476 PMCID: PMC7266142 DOI: 10.1523/eneuro.0467-19.2020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 02/21/2020] [Accepted: 03/23/2020] [Indexed: 12/18/2022] Open
Abstract
Vascular endothelial growth factor (VEGF) has been recently demonstrated to induce neuroprotective and synaptotrophic effects on lesioned neurons. Hitherto, the administration of VEGF in different animal models of lesion or disease has been conducted following a chronic protocol of administration. We questioned whether a single dose of VEGF, administered intraventricularly, could induce long-term neurotrophic effects on injured motoneurons. For this purpose, we performed in cats the axotomy of abducens motoneurons and the injection of VEGF into the fourth ventricle in the same surgical session and investigated the discharge characteristics of axotomized and treated motoneurons by single-unit extracellular recordings in the chronic alert preparation. We found that injured motoneurons treated with a single VEGF application discharged with normal characteristics, showing neuronal eye position (EP) and velocity sensitivities similar to control, thereby preventing the axotomy-induced alterations. These effects were present for a prolonged period of time (50 d) after VEGF administration. By confocal immunofluorescence we also showed that the synaptic stripping that ensues lesion was not present, rather motoneurons showed a normal synaptic coverage. Moreover, we demonstrated that VEGF did not lead to any angiogenic response pointing to a direct action of the factor on neurons. In summary, a single dose of VEFG administered just after motoneuron axotomy is able to prevent for a long time the axotomy-induced firing and synaptic alterations without any associated vascular sprouting. We consider that these data are of great relevance due to the potentiality of VEGF as a therapeutic agent in neuronal lesions and diseases.
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Affiliation(s)
- Paula M Calvo
- Departamento de Fisiología, Facultad de Biología, Universidad de Sevilla, Sevilla 41012, Spain
| | - Rosa R de la Cruz
- Departamento de Fisiología, Facultad de Biología, Universidad de Sevilla, Sevilla 41012, Spain
| | - Angel M Pastor
- Departamento de Fisiología, Facultad de Biología, Universidad de Sevilla, Sevilla 41012, Spain
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Rotterman TM, Alvarez FJ. Microglia Dynamics and Interactions with Motoneurons Axotomized After Nerve Injuries Revealed By Two-Photon Imaging. Sci Rep 2020; 10:8648. [PMID: 32457369 PMCID: PMC7250868 DOI: 10.1038/s41598-020-65363-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 05/01/2020] [Indexed: 01/08/2023] Open
Abstract
The significance of activated microglia around motoneurons axotomized after nerve injuries has been intensely debated. In particular, whether microglia become phagocytic is controversial. To resolve these issues we directly observed microglia behaviors with two-photon microscopy in ex vivo spinal cord slices from CX3CR1-GFP mice complemented with confocal analyses of CD68 protein. Axotomized motoneurons were retrogradely-labeled from muscle before nerve injuries. Microglia behaviors close to axotomized motoneurons greatly differ from those within uninjured motor pools. They develop a phagocytic phenotype as early as 3 days after injury, characterized by frequent phagocytic cups, high phagosome content and CD68 upregulation. Interactions between microglia and motoneurons changed with time after axotomy. Microglia first extend processes that end in phagocytic cups at the motoneuron surface, then they closely attach to the motoneuron while extending filopodia over the cell body. Confocal 3D analyses revealed increased microglia coverage of the motoneuron cell body surface with time after injury and the presence of CD68 granules in microglia surfaces opposed to motoneurons. Some microglia formed macroclusters associated with dying motoneurons. Microglia in these clusters display the highest CD68 expression and associate with cytotoxic T-cells. These observations are discussed in relation to current theories on microglia function around axotomized motoneurons.
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Affiliation(s)
- Travis M Rotterman
- Department of Physiology, Emory University, Atlanta, GA, 30322, United States of America.,School of Biological Sciences, Georgia Tech, Atlanta, GA, 30318, United States of America
| | - Francisco J Alvarez
- Department of Physiology, Emory University, Atlanta, GA, 30322, United States of America.
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Kempe PRG, Chiarotto GB, Barraviera B, Ferreira RS, de Oliveira ALR. Neuroprotection and immunomodulation by dimethyl fumarate and a heterologous fibrin biopolymer after ventral root avulsion and reimplantation. J Venom Anim Toxins Incl Trop Dis 2020; 26:e20190093. [PMID: 32518556 PMCID: PMC7250131 DOI: 10.1590/1678-9199-jvatitd-2019-0093] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Background: Ventral root avulsion (VRA) is an experimental approach in which there is an abrupt separation of the motor roots from the surface of the spinal cord. As a result, most of the axotomized motoneurons degenerate by the second week after injury, and the significant loss of synapses and increased glial reaction triggers a chronic inflammatory state. Pharmacological treatment associated with root reimplantation is thought to overcome the degenerative effects of VRA. Therefore, treatment with dimethyl fumarate (DMF), a drug with neuroprotective and immunomodulatory effects, in combination with a heterologous fibrin sealant/biopolymer (FS), a biological glue, may improve the regenerative response. Methods: Adult female Lewis rats were subjected to VRA of L4-L6 roots followed by reimplantation and daily treatment with DMF for four weeks. Survival times were evaluated 1, 4 or 12 weeks after surgery. Neuronal survival assessed by Nissl staining, glial reactivity (anti-GFAP for astrocytes and anti-Iba-1 for microglia) and synapse preservation (anti-VGLUT1 for glutamatergic inputs and anti-GAD65 for GABAergic inputs) evaluated by immunofluorescence, gene expression (pro- and anti-inflammatory molecules) and motor function recovery were measured. Results: Treatment with DMF at a dose of 15 mg/kg was found to be neuroprotective and immunomodulatory because it preserved motoneurons and synapses and decreased astrogliosis and microglial reactions, as well as downregulated the expression of pro-inflammatory gene transcripts. Conclusion: The pharmacological benefit was further enhanced when associated with root reimplantation with FS, in which animals recovered at least 50% of motor function, showing the efficacy of employing multiple regenerative approaches following spinal cord root injury.
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Affiliation(s)
- Paula R G Kempe
- Laboratory of Nerve Regeneration, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | | | - Benedito Barraviera
- Center for the Study of Venoms and Venomous Animals (CEVAP), São Paulo State University (UNESP), Botucatu, SP, Brazil
| | - Rui Seabra Ferreira
- Center for the Study of Venoms and Venomous Animals (CEVAP), São Paulo State University (UNESP), Botucatu, SP, Brazil
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Alvarez FJ, Rotterman TM, Akhter ET, Lane AR, English AW, Cope TC. Synaptic Plasticity on Motoneurons After Axotomy: A Necessary Change in Paradigm. Front Mol Neurosci 2020; 13:68. [PMID: 32425754 PMCID: PMC7203341 DOI: 10.3389/fnmol.2020.00068] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 04/08/2020] [Indexed: 12/12/2022] Open
Abstract
Motoneurons axotomized by peripheral nerve injuries experience profound changes in their synaptic inputs that are associated with a neuroinflammatory response that includes local microglia and astrocytes. This reaction is conserved across different types of motoneurons, injuries, and species, but also displays many unique features in each particular case. These reactions have been amply studied, but there is still a lack of knowledge on their functional significance and mechanisms. In this review article, we compiled data from many different fields to generate a comprehensive conceptual framework to best interpret past data and spawn new hypotheses and research. We propose that synaptic plasticity around axotomized motoneurons should be divided into two distinct processes. First, a rapid cell-autonomous, microglia-independent shedding of synapses from motoneuron cell bodies and proximal dendrites that is reversible after muscle reinnervation. Second, a slower mechanism that is microglia-dependent and permanently alters spinal cord circuitry by fully eliminating from the ventral horn the axon collaterals of peripherally injured and regenerating sensory Ia afferent proprioceptors. This removes this input from cell bodies and throughout the dendritic tree of axotomized motoneurons as well as from many other spinal neurons, thus reconfiguring ventral horn motor circuitries to function after regeneration without direct sensory feedback from muscle. This process is modulated by injury severity, suggesting a correlation with poor regeneration specificity due to sensory and motor axons targeting errors in the periphery that likely render Ia afferent connectivity in the ventral horn nonadaptive. In contrast, reversible synaptic changes on the cell bodies occur only while motoneurons are regenerating. This cell-autonomous process displays unique features according to motoneuron type and modulation by local microglia and astrocytes and generally results in a transient reduction of fast synaptic activity that is probably replaced by embryonic-like slow GABA depolarizations, proposed to relate to regenerative mechanisms.
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Affiliation(s)
- Francisco J Alvarez
- Department of Physiology, Emory University School of Medicine, Atlanta, GA, United States
| | - Travis M Rotterman
- Department of Physiology, Emory University School of Medicine, Atlanta, GA, United States.,Department of Biomedical Engineering, School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, United States
| | - Erica T Akhter
- Department of Physiology, Emory University School of Medicine, Atlanta, GA, United States
| | - Alicia R Lane
- Department of Physiology, Emory University School of Medicine, Atlanta, GA, United States
| | - Arthur W English
- Department of Cellular Biology, Emory University School of Medicine, Atlanta, GA, United States
| | - Timothy C Cope
- Department of Biomedical Engineering, School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, United States
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15
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Cartarozzi LP, Perez M, Kirchhoff F, Oliveira ALRD. Role of MHC-I Expression on Spinal Motoneuron Survival and Glial Reactions Following Ventral Root Crush in Mice. Cells 2019; 8:cells8050483. [PMID: 31117227 PMCID: PMC6563038 DOI: 10.3390/cells8050483] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 05/05/2019] [Accepted: 05/07/2019] [Indexed: 11/28/2022] Open
Abstract
Lesions to the CNS/PNS interface are especially severe, leading to elevated neuronal degeneration. In the present work, we establish the ventral root crush model for mice, and demonstrate the potential of such an approach, by analyzing injury evoked motoneuron loss, changes of synaptic coverage and concomitant glial responses in β2-microglobulin knockout mice (β2m KO). Young adult (8–12 weeks old) C57BL/6J (WT) and β2m KO mice were submitted to a L4–L6 ventral roots crush. Neuronal survival revealed a time-dependent motoneuron-like cell loss, both in WT and β2m KO mice. Along with neuronal loss, astrogliosis increased in WT mice, which was not observed in β2m KO mice. Microglial responses were more pronounced during the acute phase after lesion and decreased over time, in WT and KO mice. At 7 days after lesion β2m KO mice showed stronger Iba-1+ cell reaction. The synaptic inputs were reduced over time, but in β2m KO, the synaptic loss was more prominent between 7 and 28 days after lesion. Taken together, the results herein demonstrate that ventral root crushing in mice provides robust data regarding neuronal loss and glial reaction. The retrograde reactions after injury were altered in the absence of functional MHC-I surface expression.
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Affiliation(s)
- Luciana Politti Cartarozzi
- Laboratory of Nerve Regeneration, University of Campinas-UNICAMP, Cidade Universitaria "Zeferino Vaz, Rua Monteiro Lobato, 255, 13083-970 Campinas, SP, Brazil.
| | - Matheus Perez
- School of Physical Education and Sport of Ribeirao Preto, University of Sao Paulo, Av. Bandeirantes, 3900, 14040-907 Ribeirão Preto, SP, Brazil.
| | - Frank Kirchhoff
- Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Building 48, 66421 Homburg, Germany.
| | - Alexandre Leite Rodrigues de Oliveira
- Laboratory of Nerve Regeneration, University of Campinas-UNICAMP, Cidade Universitaria "Zeferino Vaz, Rua Monteiro Lobato, 255, 13083-970 Campinas, SP, Brazil.
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Bar E, Barak B. Microglia roles in synaptic plasticity and myelination in homeostatic conditions and neurodevelopmental disorders. Glia 2019; 67:2125-2141. [DOI: 10.1002/glia.23637] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Revised: 04/15/2019] [Accepted: 04/16/2019] [Indexed: 12/28/2022]
Affiliation(s)
- Ela Bar
- The School of Psychological Sciences, Faculty of Social Sciences, and The Sagol School of NeuroscienceTel Aviv University Tel Aviv Israel
- The School of Neurobiology, Biochemistry & Biophysics, Faculty of Life SciencesTel Aviv University Tel Aviv Israel
| | - Boaz Barak
- The School of Psychological Sciences, Faculty of Social Sciences, and The Sagol School of NeuroscienceTel Aviv University Tel Aviv Israel
- The Sagol School of NeuroscienceTel Aviv University Tel Aviv Israel
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Thangaraj A, Periyasamy P, Guo ML, Chivero ET, Callen S, Buch S. Mitigation of cocaine-mediated mitochondrial damage, defective mitophagy and microglial activation by superoxide dismutase mimetics. Autophagy 2019; 16:289-312. [PMID: 30990365 DOI: 10.1080/15548627.2019.1607686] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Although cocaine exposure has been shown to potentiate neuroinflammation by upregulating glial activation in the brain, the role of mitophagy in this process remains an enigma. In the present study, we sought to examine the role of impaired mitophagy in cocaine-mediated activation of microglia and to determine the ameliorative potential of superoxide dismutase mimetics in this context. Our findings demonstrated that exposure of mouse primary microglial cells (mPMs) to cocaine resulted in decreased mitochondrial membrane potential, that was accompanied by increased expression of mitophagy markers, PINK1 and PRKN. Exposure of microglia to cocaine also resulted in increased expression of DNM1L and OPTN with a concomitant decrease in the rate of mitochondrial oxygen consumption as well as impaired mitochondrial functioning. Additionally, in the presence of cocaine, microglia also exhibited upregulated expression of autophagosome markers, BECN1, MAP1LC3B-II, and SQSTM1. Taken together, these findings suggested diminished mitophagy flux and accumulation of mitophagosomes in the presence of cocaine. These findings were further confirmed by imaging techniques such as transmission electron microscopy and confocal microscopy. Cocaine-mediated activation of microglia was further monitored by assessing the expression of the microglial marker (ITGAM) and the inflammatory cytokine (Tnf, Il1b, and Il6) mRNAs. Pharmacological, as well as gene-silencing approaches aimed at blocking both the autophagy/mitophagy and SIGMAR1 expression, underscored the role of impaired mitophagy in cocaine-mediated activation of microglia. Furthermore, superoxide dismutase mimetics such as TEMPOL and MitoTEMPO were shown to alleviate cocaine-mediated impaired mitophagy as well as microglial activation.Abbreviations: 3-MA: 3-methyladenine; Δψm: mitochondrial membrane potential; ACTB: actin, beta; AIF1: allograft inflammatory factor 1; ATP: adenosine triphosphate; BAF: bafilomycin A1; BECN1: beclin 1, autophagy related; CNS: central nervous system; DNM1L: dynamin 1 like; DMEM: Dulbecco modified Eagle medium; DAPI: 4,6-Diamidino-2-phenylindole; DRD2: dopamine receptor D2; ECAR: extracellular acidification rate; FBS: fetal bovine serum; FCCP: Trifluoromethoxy carbonylcyanide phenylhydrazone; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; IL1B: interleukin 1, beta; IL6: interleukin 6; ITGAM: integrin subunit alpha M; MAP1LC3B: microtubule-associated protein 1 light chain 3 beta; mPMs: mouse primary microglial cells; MRC: maximal respiratory capacity; NFKB: nuclear factor kappa B; NLRP3: NLR family pyrin domain containing 3; NTRK2: neurotrophic receptor tyrosine kinase 2; OCR: oxygen consumption rate; OPTN: optineurin; PBS: phosphate buffered saline; PINK1: PTEN induced putative kinase 1; PRKN: parkin RBR E3 ubiquitin protein ligase; ROS: reactive oxygen species; siRNA: small interfering RNA; SQSTM1: sequestosome 1; TNF: tumor necrosis factor.
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Affiliation(s)
- Annadurai Thangaraj
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, USA
| | - Palsamy Periyasamy
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, USA
| | - Ming-Lei Guo
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, USA
| | - Ernest T Chivero
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, USA
| | - Shannon Callen
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, USA
| | - Shilpa Buch
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, USA
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Spinal Motor Circuit Synaptic Plasticity after Peripheral Nerve Injury Depends on Microglia Activation and a CCR2 Mechanism. J Neurosci 2019; 39:3412-3433. [PMID: 30833511 DOI: 10.1523/jneurosci.2945-17.2019] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 02/03/2019] [Accepted: 02/27/2019] [Indexed: 12/24/2022] Open
Abstract
Peripheral nerve injury results in persistent motor deficits, even after the nerve regenerates and muscles are reinnervated. This lack of functional recovery is partly explained by brain and spinal cord circuit alterations triggered by the injury, but the mechanisms are generally unknown. One example of this plasticity is the die-back in the spinal cord ventral horn of the projections of proprioceptive axons mediating the stretch reflex (Ia afferents). Consequently, Ia information about muscle length and dynamics is lost from ventral spinal circuits, degrading motor performance after nerve regeneration. Simultaneously, there is activation of microglia around the central projections of peripherally injured Ia afferents, suggesting a possible causal relationship between neuroinflammation and Ia axon removal. Therefore, we used mice (both sexes) that allow visualization of microglia (CX3CR1-GFP) and infiltrating peripheral myeloid cells (CCR2-RFP) and related changes in these cells to Ia synaptic losses (identified by VGLUT1 content) on retrogradely labeled motoneurons. Microgliosis around axotomized motoneurons starts and peaks within 2 weeks after nerve transection. Thereafter, this region becomes infiltrated by CCR2 cells, and VGLUT1 synapses are lost in parallel. Immunohistochemistry, flow cytometry, and genetic lineage tracing showed that infiltrating CCR2 cells include T cells, dendritic cells, and monocytes, the latter differentiating into tissue macrophages. VGLUT1 synapses were rescued after attenuating the ventral microglial reaction by removal of colony stimulating factor 1 from motoneurons or in CCR2 global KOs. Thus, both activation of ventral microglia and a CCR2-dependent mechanism are necessary for removal of VGLUT1 synapses and alterations in Ia-circuit function following nerve injuries.SIGNIFICANCE STATEMENT Synaptic plasticity and reorganization of essential motor circuits after a peripheral nerve injury can result in permanent motor deficits due to the removal of sensory Ia afferent synapses from the spinal cord ventral horn. Our data link this major circuit change with the neuroinflammatory reaction that occurs inside the spinal cord following injury to peripheral nerves. We describe that both activation of microglia and recruitment into the spinal cord of blood-derived myeloid cells are necessary for motor circuit synaptic plasticity. This study sheds new light into mechanisms that trigger major network plasticity in CNS regions removed from injury sites and that might prevent full recovery of function, even after successful regeneration.
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Ma CW, Kwan PY, Wu KLK, Shum DKY, Chan YS. Regulatory roles of perineuronal nets and semaphorin 3A in the postnatal maturation of the central vestibular circuitry for graviceptive reflex. Brain Struct Funct 2018; 224:613-626. [PMID: 30460552 DOI: 10.1007/s00429-018-1795-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 11/12/2018] [Indexed: 10/27/2022]
Abstract
Perineuronal nets (PN) restrict neuronal plasticity in the adult brain. We hypothesize that activity-dependent consolidation of PN is required for functional maturation of behavioral circuits. Using the postnatal maturation of brainstem vestibular nucleus (VN) circuits as a model system, we report a neonatal period in which consolidation of central vestibular circuitry for graviception is accompanied by activity-dependent consolidation of chondroitin sulfate (CS)-rich PN around GABAergic neurons in the VN. Postnatal onset of negative geotaxis was used as an indicator for functional maturation of vestibular circuits. Rats display negative geotaxis from postnatal day (P) 9, coinciding with the condensation of CS-rich PN around GABAergic interneurons in the VN. Delaying PN formation, by removal of primordial CS moieties on VN with chondroitinase ABC (ChABC) treatment at P6, postponed emergence of negative geotaxis to P13. Similar postponement was observed following inhibition of GABAergic transmission with bicuculline, in line with the reported role of PN in increasing excitability of parvalbumin neurons. We further reasoned that PN-CS restricts bioavailability of plasticity-inducing factors such as semaphorin 3A (Sema3A) to bring about circuit maturation. Treatment of VN explants with ChABC to liberate PN-bound Sema3A resulted in dendritic growth and arborization, implicating structural plasticity that delays synapse formation. Evidence is thus provided for the role of PN-CS-Sema3A in regulating structural and circuit plasticity at VN interneurons with impacts on the development of graviceptive postural control.
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Affiliation(s)
- Chun-Wai Ma
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Hong Kong SAR, People's Republic of China
| | - Pui-Yi Kwan
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Hong Kong SAR, People's Republic of China
| | - Kenneth Lap-Kei Wu
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Hong Kong SAR, People's Republic of China
| | - Daisy Kwok-Yan Shum
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Hong Kong SAR, People's Republic of China. .,State Key Laboratory of Brain and Cognitive Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Hong Kong SAR, People's Republic of China.
| | - Ying-Shing Chan
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Hong Kong SAR, People's Republic of China. .,State Key Laboratory of Brain and Cognitive Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Hong Kong SAR, People's Republic of China.
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Ramadan WS, Abdel-Hamid GA, Al-Karim S, Zakar NAMB, Elassouli MZ. Neuroectodermal stem cells: A remyelinating potential in acute compressed spinal cord injury in rat model. J Biosci 2018. [DOI: 10.1007/s12038-018-9812-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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21
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Akil O, Blits B, Lustig LR, Leake PA. Virally Mediated Overexpression of Glial-Derived Neurotrophic Factor Elicits Age- and Dose-Dependent Neuronal Toxicity and Hearing Loss. Hum Gene Ther 2018; 30:88-105. [PMID: 30183384 DOI: 10.1089/hum.2018.028] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Contemporary cochlear implants (CI) are generally very effective for remediation of severe to profound sensorineural hearing loss, but outcomes are still highly variable. Auditory nerve survival is likely one of the major factors underlying this variability. Neurotrophin therapy therefore has been proposed for CI recipients, with the goal of improving outcomes by promoting improved survival of cochlear spiral ganglion neurons (SGN) and/or residual hair cells. Previous studies have shown that glial-derived neurotrophic factor (GDNF), brain-derived neurotrophic factor, and neurotrophin-3 can rescue SGNs following insult. The current study was designed to determine whether adeno-associated virus vector serotype 5 (AAV-5) encoding either green fluorescent protein or GDNF can transduce cells in the mouse cochlea to express useful levels of neurotrophin and to approximate the optimum therapeutic dose(s) for transducing hair cells and SGN. The findings demonstrate that AAV-5 is a potentially useful gene therapy vector for the cochlea, resulting in extremely high levels of transgene expression in the cochlear inner hair cells and SGN. However, overexpression of human GDNF in newborn mice caused severe neurological symptoms and hearing loss, likely due to Purkinje cell loss and cochlear nucleus pathology. Thus, extremely high levels of transgene protein expression should be avoided, particularly for proteins that have neurological function in neonatal subjects.
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Affiliation(s)
- Omar Akil
- 1 Department of Otolaryngology-Head and Neck Surgery, University of California, San Francisco, San Francisco, California
| | - Bas Blits
- 2 Department of Research and Development, UniQure Biopharma B.V., Amsterdam, The Netherlands
| | - Lawrence R Lustig
- 3 Department of Otolaryngology-Head and Neck Surgery, Columbia University Medical Center, New York, New York
| | - Patricia A Leake
- 1 Department of Otolaryngology-Head and Neck Surgery, University of California, San Francisco, San Francisco, California
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Botulinum Neurotoxin Application to the Severed Femoral Nerve Modulates Spinal Synaptic Responses to Axotomy and Enhances Motor Recovery in Rats. Neural Plast 2018; 2018:7975013. [PMID: 30254669 PMCID: PMC6145158 DOI: 10.1155/2018/7975013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 07/15/2018] [Accepted: 08/05/2018] [Indexed: 12/22/2022] Open
Abstract
Botulinum neurotoxin A (BoNT) and brain-derived neurotrophic factor (BDNF) are known for their ability to influence synaptic inputs to neurons. Here, we tested if these drugs can modulate the deafferentation of motoneurons following nerve section/suture and, as a consequence, modify the outcome of peripheral nerve regeneration. We applied drug solutions to the proximal stump of the freshly cut femoral nerve of adult rats to achieve drug uptake and transport to the neuronal perikarya. The most marked effect of this application was a significant reduction of the axotomy-induced loss of perisomatic cholinergic terminals by BoNT at one week and two months post injury. The attenuation of the synaptic deficit was associated with enhanced motor recovery of the rats 2–20 weeks after injury. Although BDNF also reduced cholinergic terminal loss at 1 week, it had no effect on this parameter at two months and no effect on functional recovery. These findings strengthen the idea that persistent partial deafferentation of axotomized motoneurons may have a significant negative impact on functional outcome after nerve injury. Intraneural application of drugs may be a promising way to modify deafferentation and, thus, elucidate relationships between synaptic plasticity and restoration of function.
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Chen M, Vial ML, Tello Velasquez J, Ekberg JAK, Davis RA, St John JA. The serrulatane diterpenoid natural products RAD288 and RAD289 stimulate properties of olfactory ensheathing cells useful for neural repair therapies. Sci Rep 2018; 8:10240. [PMID: 29980748 PMCID: PMC6035228 DOI: 10.1038/s41598-018-28551-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 06/20/2018] [Indexed: 01/16/2023] Open
Abstract
Olfactory ensheathing cells (OECs) are being trialled for cell transplantation therapies for neural repair as they have unique properties which can enhance neuron regeneration. However, improvements in cell viability, proliferation and migration are needed to enhance therapeutic outcomes. Growth factors can enhance cell activity, but they can also induce side effects as they can act on numerous cell types. An alternative approach is to identify natural products (NPs) that more selectively activate specific cell functions. We have examined two pure NPs, 3-acetoxy-7,8-dihydroxyserrulat-14-en-19-oic acid (RAD288) and 3,7,8-trihydroxyserrulat-14-en-19-oic acid (RAD289) isolated from the Australian plant Eremophila microtheca. We determined that RAD288 and RAD289 stimulated the viability and proliferation of OECs in two-dimensional cultures and increased cell viability in three-dimensional spheroids. Both compounds also enhanced OEC-mediated phagocytosis of neural debris. However, only RAD288 stimulated migration of OECs, demonstrating that key structural changes to the compound can dramatically affect the resultant cellular action. In addition, cell-type specific action is highlighted by the result that neither compound stimulated the viability of Schwann cells which are a closely-related glial cell type. Therefore, these small molecules may have high potential for selective activation of specific therapeutically-useful activities of OECs for transplantation therapies to repair the nervous system.
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Affiliation(s)
- Mo Chen
- Griffith Institute for Drug Discovery, Griffith University, Brisbane, 4111, QLD, Australia.,Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Brisbane, 4111, QLD, Australia
| | - Marie-Laure Vial
- Griffith Institute for Drug Discovery, Griffith University, Brisbane, 4111, QLD, Australia.,Menzies Health Institute Queensland, Griffith University, Southport, 4222, QLD, Australia.,Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Brisbane, 4111, QLD, Australia
| | - Johana Tello Velasquez
- Griffith Institute for Drug Discovery, Griffith University, Brisbane, 4111, QLD, Australia.,Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Brisbane, 4111, QLD, Australia
| | - Jenny A K Ekberg
- Menzies Health Institute Queensland, Griffith University, Southport, 4222, QLD, Australia
| | - Rohan A Davis
- Griffith Institute for Drug Discovery, Griffith University, Brisbane, 4111, QLD, Australia
| | - James A St John
- Griffith Institute for Drug Discovery, Griffith University, Brisbane, 4111, QLD, Australia. .,Menzies Health Institute Queensland, Griffith University, Southport, 4222, QLD, Australia. .,Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Brisbane, 4111, QLD, Australia.
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24
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Fuentes-Santamaría V, Alvarado JC, Melgar-Rojas P, Gabaldón-Ull MC, Miller JM, Juiz JM. The Role of Glia in the Peripheral and Central Auditory System Following Noise Overexposure: Contribution of TNF-α and IL-1β to the Pathogenesis of Hearing Loss. Front Neuroanat 2017; 11:9. [PMID: 28280462 PMCID: PMC5322242 DOI: 10.3389/fnana.2017.00009] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 02/09/2017] [Indexed: 12/12/2022] Open
Abstract
Repeated noise exposure induces inflammation and cellular adaptations in the peripheral and central auditory system resulting in pathophysiology of hearing loss. In this study, we analyzed the mechanisms by which noise-induced inflammatory-related events in the cochlea activate glial-mediated cellular responses in the cochlear nucleus (CN), the first relay station of the auditory pathway. The auditory function, glial activation, modifications in gene expression and protein levels of inflammatory mediators and ultrastructural changes in glial-neuronal interactions were assessed in rats exposed to broadband noise (0.5-32 kHz, 118 dB SPL) for 4 h/day during 4 consecutive days to induce long-lasting hearing damage. Noise-exposed rats developed a permanent threshold shift which was associated with hair cell loss and reactive glia. Noise-induced microglial activation peaked in the cochlea between 1 and 10D post-lesion; their activation in the CN was more prolonged reaching maximum levels at 30D post-exposure. RT-PCR analyses of inflammatory-related genes expression in the cochlea demonstrated significant increases in the mRNA expression levels of pro- and anti-inflammatory cytokines, inducible nitric oxide synthase, intercellular adhesion molecule and tissue inhibitor of metalloproteinase-1 at 1 and 10D post-exposure. In noise-exposed cochleae, interleukin-1β (IL-1β), and tumor necrosis factor α (TNF-α) were upregulated by reactive microglia, fibrocytes, and neurons at all time points examined. In the CN, however, neurons were the sole source of these cytokines. These observations suggest that noise exposure causes peripheral and central inflammatory reactions in which TNF-α and IL-1β are implicated in regulating the initiation and progression of noise-induced hearing loss.
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Affiliation(s)
- Verónica Fuentes-Santamaría
- Instituto de Investigación en Discapacidades NeurológicasAlbacete, Spain; Facultad de Medicina, Universidad de Castilla-La ManchaAlbacete, Spain
| | - Juan Carlos Alvarado
- Instituto de Investigación en Discapacidades NeurológicasAlbacete, Spain; Facultad de Medicina, Universidad de Castilla-La ManchaAlbacete, Spain
| | - Pedro Melgar-Rojas
- Instituto de Investigación en Discapacidades NeurológicasAlbacete, Spain; Facultad de Medicina, Universidad de Castilla-La ManchaAlbacete, Spain
| | - María C Gabaldón-Ull
- Instituto de Investigación en Discapacidades NeurológicasAlbacete, Spain; Facultad de Medicina, Universidad de Castilla-La ManchaAlbacete, Spain
| | - Josef M Miller
- Center for Hearing and Communication Research and Department of Clinical Neuroscience, Karolinska InstitutetStockholm, Sweden; Kresge Hearing Research Institute, University of MichiganAnn Arbor, MI, USA
| | - José M Juiz
- Instituto de Investigación en Discapacidades NeurológicasAlbacete, Spain; Facultad de Medicina, Universidad de Castilla-La ManchaAlbacete, Spain
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25
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Vickers J, Kirkcaldie M, Phipps A, King A. Alterations in neurofilaments and the transformation of the cytoskeleton in axons may provide insight into the aberrant neuronal changes of Alzheimer’s disease. Brain Res Bull 2016; 126:324-333. [DOI: 10.1016/j.brainresbull.2016.07.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 07/25/2016] [Accepted: 07/26/2016] [Indexed: 01/09/2023]
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26
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Bombeiro AL, Thomé R, Oliveira Nunes SL, Monteiro Moreira B, Verinaud L, de Oliveira ALR. MHC-I and PirB Upregulation in the Central and Peripheral Nervous System following Sciatic Nerve Injury. PLoS One 2016; 11:e0161463. [PMID: 27551751 PMCID: PMC4995013 DOI: 10.1371/journal.pone.0161463] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Accepted: 08/05/2016] [Indexed: 12/12/2022] Open
Abstract
Major histocompatibility complex class one (MHC-I) antigen-presenting molecules participate in central nervous system (CNS) synaptic plasticity, as does the paired immunoglobulin-like receptor B (PirB), an MHC-I ligand that can inhibit immune-cells and bind to myelin axon growth inhibitors. Based on the dual roles of both molecules in the immune and nervous systems, we evaluated their expression in the central and peripheral nervous system (PNS) following sciatic nerve injury in mice. Increased PirB and MHC-I protein and gene expression is present in the spinal cord one week after nerve transection, PirB being mostly expressed in the neuropile region. In the crushed nerve, MHC-I protein levels increased 2 weeks after lesion (wal) and progressively decreased over the next eight weeks. The same kinetics were observed for infiltrating cytotoxic T lymphocytes (CTLs) but not for PirB expression, which continuously increased. Both MHC-I and PirB were found in macrophages and Schwann cells but rarely in axons. Interestingly, at 8 wal, PirB was mainly restricted to the myelin sheath. Our findings reinforce the participation of MHC-I and PirB in CNS plasticity events. In contrast, opposing expression levels of these molecules were found in the PNS, so that MHC-I and PirB seem to be mostly implicated in antigen presentation to CTLs and axon myelination, respectively.
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Affiliation(s)
- André Luis Bombeiro
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas – UNICAMP, Rua Monteiro Lobato, 255, CEP: 13083–865, Campinas, SP, Brazil
| | - Rodolfo Thomé
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas – UNICAMP, Rua Monteiro Lobato, 255, CEP: 13083–865, Campinas, SP, Brazil
| | - Sérgio Luiz Oliveira Nunes
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas – UNICAMP, Rua Monteiro Lobato, 255, CEP: 13083–865, Campinas, SP, Brazil
| | - Bárbara Monteiro Moreira
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas – UNICAMP, Rua Monteiro Lobato, 255, CEP: 13083–865, Campinas, SP, Brazil
| | - Liana Verinaud
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas – UNICAMP, Rua Monteiro Lobato, 255, CEP: 13083–865, Campinas, SP, Brazil
| | - Alexandre Leite Rodrigues de Oliveira
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas – UNICAMP, Rua Monteiro Lobato, 255, CEP: 13083–865, Campinas, SP, Brazil
- * E-mail:
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27
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Rangarajan P, Karthikeyan A, Dheen ST. Role of dietary phenols in mitigating microglia-mediated neuroinflammation. Neuromolecular Med 2016; 18:453-64. [DOI: 10.1007/s12017-016-8430-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 07/21/2016] [Indexed: 12/30/2022]
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28
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Shiina T, Blancher A, Inoko H, Kulski JK. Comparative genomics of the human, macaque and mouse major histocompatibility complex. Immunology 2016; 150:127-138. [PMID: 27395034 DOI: 10.1111/imm.12624] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2016] [Revised: 04/22/2016] [Accepted: 04/27/2016] [Indexed: 12/20/2022] Open
Abstract
The MHC is a highly polymorphic genomic region that encodes the transplantation and immune regulatory molecules. It receives special attention for genetic investigation because of its important role in the regulation of innate and adaptive immune responses and its strong association with numerous infectious and/or autoimmune diseases. The MHC locus was first discovered in the mouse and for the past 50 years it has been studied most intensively in both mice and humans. However, in recent years the macaque species have emerged as some of the more important and advanced experimental animal models for biomedical research into MHC with important human immunodeficiency virus/simian immunodeficiency virus and transplantation studies undertaken in association with precise MHC genotyping and haplotyping methods using Sanger sequencing and next-generation sequencing. Here, in this special issue on 'Macaque Immunology' we provide a short review of the genomic similarities and differences among the human, macaque and mouse MHC class I and class II regions, with an emphasis on the association of the macaque class I region with MHC polymorphism, haplotype structure and function.
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Affiliation(s)
- Takashi Shiina
- Department of Molecular Life Science, Division of Basic Medical Science and Molecular Medicine, Tokai University School of Medicine, Isehara, Kanagawa, Japan
| | - Antoine Blancher
- Laboratoire d'Immunogénétique moléculaire (LIMT, EA 3034), Laboratoire d'immunologie, Faculté de Médecine Purpan, Université Toulouse 3, CHU de Toulouse, Toulouse, France
| | - Hidetoshi Inoko
- Department of Molecular Life Science, Division of Basic Medical Science and Molecular Medicine, Tokai University School of Medicine, Isehara, Kanagawa, Japan
| | - Jerzy K Kulski
- Department of Molecular Life Science, Division of Basic Medical Science and Molecular Medicine, Tokai University School of Medicine, Isehara, Kanagawa, Japan.,School of Psychiatry and Clinical Neurosciences, The University of Western Australia, Crawley, WA, Australia
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29
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Casas C, Manzano R, Vaz R, Osta R, Brites D. Synaptic Failure: Focus in an Integrative View of ALS. Brain Plast 2016; 1:159-175. [PMID: 29765840 PMCID: PMC5928542 DOI: 10.3233/bpl-140001] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
From early description by Charcot, the classification of the Amyotrophic Lateral Sclerosis (ALS) is evolving from a subtype of Motor Neuron (MN) Disease to be considered rather a multi-systemic, non-cell autonomous and complex neurodegenerative disease. In the last decade, the huge amount of knowledge acquired has shed new insights on the pathological mechanisms underlying ALS from different perspectives. However, a whole vision on the multiple dysfunctional pathways is needed with the inclusion of information often excluded in other published revisions. We propose an integrative view of ALS pathology, although centered on the synaptic failure as a converging and crucial player to the etiology of the disease. Homeostasis of input and output synaptic activity of MNs has been proved to be severely and early disrupted and to definitively contribute to microcircuitry alterations at the spinal cord. Several cells play roles in synaptic communication across the MNs network system such as interneurons, astrocytes, microglia, Schwann and skeletal muscle cells. Microglia are described as highly dynamic surveying cells of the nervous system but also as determinant contributors to the synaptic plasticity linked to neuronal activity. Several signaling axis such as TNFα/TNFR1 and CX3CR1/CX3CL1 that characterize MN-microglia cross talk contribute to synaptic scaling and maintenance, have been found altered in ALS. The presence of dystrophic and atypical microglia in late stages of ALS, with a decline in their dynamic motility and phagocytic ability, together with less synaptic and neuronal contacts disrupts the MN-microglia dialogue, decreases homeostatic regulation of neuronal activity, perturbs “on/off” signals and accelerates disease progression associated to impaired synaptic function and regeneration. Other hotspot in the ALS affected network system is the unstable neuromuscular junction (NMJ) leading to distal axonal degeneration. Reduced neuromuscular spontaneous synaptic activity in ALS mice models was also suggested to account for the selective vulnerability of MNs and decreased regenerative capability. Synaptic destabilization may as well derive from increased release of molecules by muscle cells (e.g. NogoA) and by terminal Schwann cells (e.g. semaphorin 3A) conceivably causing nerve terminal retraction and denervation, as well as inhibition of re-connection to muscle fibers. Indeed, we have overviewed the alterations on the metabolic pathways and self-regenerative capacity presented in skeletal muscle cells that contribute to muscle wasting in ALS. Finally, a detailed footpath of pathologic changes on MNs and associated dysfunctional and synaptic alterations is provided. The oriented motivation in future ALS studies as outlined in the present article will help in fruitful novel achievements on the mechanisms involved and in developing more target-driven therapies that will bring new hope in halting or delaying disease progression in ALS patients.
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Affiliation(s)
- Caty Casas
- Group of Neuroplasticity and Regeneration, Institut de Neurociències and Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Bellaterra, Barcelona, Spain
| | - Raquel Manzano
- Laboratory of Genetic Biochemistry (LAGENBIO-I3A), Aragón Institute of Health Sciences, Universidad de Zaragoza, Zaragoza, Spain
| | - Rita Vaz
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa Lisbon, Portugal; Department of Biochemistry and Human Biology, Faculdade de Farmácia, Universidade de Lisboa Lisbon, Portugal
| | - Rosario Osta
- Laboratory of Genetic Biochemistry (LAGENBIO-I3A), Aragón Institute of Health Sciences, Universidad de Zaragoza, Zaragoza, Spain
| | - Dora Brites
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa Lisbon, Portugal; Department of Biochemistry and Human Biology, Faculdade de Farmácia, Universidade de Lisboa Lisbon, Portugal
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30
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Perussi Biscola N, Politti Cartarozzi L, Ferreira Junior RS, Barraviera B, Leite Rodrigues de Oliveira A. Long-Standing Motor and Sensory Recovery following Acute Fibrin Sealant Based Neonatal Sciatic Nerve Repair. Neural Plast 2016; 2016:9028126. [PMID: 27446617 PMCID: PMC4942656 DOI: 10.1155/2016/9028126] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 05/03/2016] [Accepted: 05/17/2016] [Indexed: 11/17/2022] Open
Abstract
Brachial plexus lesion results in loss of motor and sensory function, being more harmful in the neonate. Therefore, this study evaluated neuroprotection and regeneration after neonatal peripheral nerve coaptation with fibrin sealant. Thus, P2 neonatal Lewis rats were divided into three groups: AX: sciatic nerve axotomy (SNA) without treatment; AX+FS: SNA followed by end-to-end coaptation with fibrin sealant derived from snake venom; AX+CFS: SNA followed by end-to-end coaptation with commercial fibrin sealant. Results were analyzed 4, 8, and 12 weeks after lesion. Astrogliosis, microglial reaction, and synapse preservation were evaluated by immunohistochemistry. Neuronal survival, axonal regeneration, and ultrastructural changes at ventral spinal cord were also investigated. Sensory-motor recovery was behaviorally studied. Coaptation preserved synaptic covering on lesioned motoneurons and led to neuronal survival. Reactive gliosis and microglial reaction decreased in the same groups (AX+FS, AX+CFS) at 4 weeks. Regarding axonal regeneration, coaptation allowed recovery of greater number of myelinated fibers, with improved morphometric parameters. Preservation of inhibitory synaptic terminals was accompanied by significant improvement in the motor as well as in the nociceptive recovery. Overall, the present data suggest that acute repair of neonatal peripheral nerves with fibrin sealant results in neuroprotection and regeneration of motor and sensory axons.
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Affiliation(s)
- Natalia Perussi Biscola
- Department of Tropical Diseases, Botucatu Medical School, São Paulo State University (UNESP), 18618-000 Botucatu, SP, Brazil
- Center for the Study of Venoms and Venomous Animals (CEVAP), São Paulo State University (UNESP), 18610-307 Botucatu, SP, Brazil
| | - Luciana Politti Cartarozzi
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas, 13083-970 Campinas, SP, Brazil
| | - Rui Seabra Ferreira Junior
- Department of Tropical Diseases, Botucatu Medical School, São Paulo State University (UNESP), 18618-000 Botucatu, SP, Brazil
- Center for the Study of Venoms and Venomous Animals (CEVAP), São Paulo State University (UNESP), 18610-307 Botucatu, SP, Brazil
| | - Benedito Barraviera
- Department of Tropical Diseases, Botucatu Medical School, São Paulo State University (UNESP), 18618-000 Botucatu, SP, Brazil
- Center for the Study of Venoms and Venomous Animals (CEVAP), São Paulo State University (UNESP), 18610-307 Botucatu, SP, Brazil
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Modulation of Matrix Metalloproteinases Activity in the Ventral Horn of the Spinal Cord Re-stores Neuroglial Synaptic Homeostasis and Neurotrophic Support following Peripheral Nerve Injury. PLoS One 2016; 11:e0152750. [PMID: 27028103 PMCID: PMC4814041 DOI: 10.1371/journal.pone.0152750] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 03/18/2016] [Indexed: 12/20/2022] Open
Abstract
Modulation of extracellular matrix (ECM) remodeling after peripheral nerve injury (PNI) could represent a valid therapeutic strategy to prevent maladaptive synaptic plasticity in central nervous system (CNS). Inhibition of matrix metalloproteinases (MMPs) and maintaining a neurotrophic support could represent two approaches to prevent or reduce the maladaptive plastic changes in the ventral horn of spinal cord following PNI. The purpose of our study was to analyze changes in the ventral horn produced by gliopathy determined by the suffering of motor neurons following spared nerve injury (SNI) of the sciatic nerve and how the intrathecal (i.t.) administration of GM6001 (a MMPs inhibitor) or the NGF mimetic peptide BB14 modulate these events. Immunohistochemical analysis of spinal cord sections revealed that motor neuron disease following SNI was associated with increased microglial (Iba1) and astrocytic (GFAP) response in the ventral horn of the spinal cord, indicative of reactive gliosis. These changes were paralleled by decreased glial aminoacid transporters (glutamate GLT1 and glycine GlyT1), increased levels of the neuronal glutamate transporter EAAC1, and a net increase of the Glutamate/GABA ratio, as measured by HPLC analysis. These molecular changes correlated to a significant reduction of mature NGF levels in the ventral horn. Continuous i.t. infusion of both GM6001 and BB14 reduced reactive astrogliosis, recovered the expression of neuronal and glial transporters, lowering the Glutamate/GABA ratio. Inhibition of MMPs by GM6001 significantly increased mature NGF levels, but it was absolutely ineffective in modifying the reactivity of microglia cells. Therefore, MMPs inhibition, although supplies neurotrophic support to ECM components and restores neuro-glial transporters expression, differently modulates astrocytic and microglial response after PNI.
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von Bernhardi R, Heredia F, Salgado N, Muñoz P. Microglia Function in the Normal Brain. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 949:67-92. [PMID: 27714685 DOI: 10.1007/978-3-319-40764-7_4] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The activation of microglia has been recognized for over a century by their morphological changes. Long slender microglia acquire a short sturdy ramified shape when activated. During the past 20 years, microglia have been accepted as an essential cellular component for understanding the pathogenic mechanism of many brain diseases, including neurodegenerative diseases. More recently, functional studies and imaging in mouse models indicate that microglia are active in the healthy central nervous system. It has become evident that microglia release several signal molecules that play key roles in the crosstalk among brain cells, i.e., astrocytes and oligodendrocytes with neurons, as well as with regulatory immune cells. Recent studies also reveal the heterogeneous nature of microglia diverse functions depending on development, previous exposure to stimulation events, brain region of residence, or pathological state. Subjects to approach by future research are still the unresolved questions regarding the conditions and mechanisms that render microglia protective, capable of preventing or reducing damage, or deleterious, capable of inducing or facilitating the progression of neuropathological diseases. This novel knowledge will certainly change our view on microglia as therapeutic target, shifting our goal from their general silencing to the generation of treatments able to change their activation pattern.
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Affiliation(s)
- Rommy von Bernhardi
- Escuela de Medicina. Departamento de Neurología, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago, Chile.
| | - Florencia Heredia
- Escuela de Medicina. Departamento de Neurología, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago, Chile
| | - Nicole Salgado
- Escuela de Medicina. Departamento de Neurología, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago, Chile
| | - Paola Muñoz
- Escuela de Medicina. Departamento de Neurología, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago, Chile
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Petrenko V, Mihhailova J, Salmon P, Kiss JZ. Apoptotic neurons induce proliferative responses of progenitor cells in the postnatal neocortex. Exp Neurol 2015; 273:126-37. [PMID: 26291762 DOI: 10.1016/j.expneurol.2015.08.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Revised: 07/13/2015] [Accepted: 08/11/2015] [Indexed: 12/29/2022]
Abstract
Apoptotic cell death is the leading cause of neuronal loss after neonatal brain injury. Little is known about the intrinsic capacity of the immature cerebral cortex for replacing dead cells. Here we test the hypothesis that neuronal apoptosis is able to trigger compensatory proliferation in surrounding cells. In order to establish a "pure" apoptotic cell death model and to avoid the confounding effects of broken blood-brain barrier and inflammatory reactions, we used a diphtheria toxin (DT) and diphtheria toxin receptor (DTR) system to induce ablation of layer IV neurons in the rodent somatosensory cortex during the early postnatal period. We found that DT-triggered apoptosis is a slowly progressing event lasting about for 7 days. While dying cells expressed the morphological features of apoptosis, we could not detect immunoreactivity for activated caspase-3 in these cells. Microglia activation and proliferation represented the earliest cellular responses to apoptotic cell death. In addition, we found that induced apoptosis triggered a massive proliferation of undifferentiated progenitor cell pool including Sox2 as well as NG2 cells. The default differentiation pattern of proliferating progenitors appears to be the glial phenotype; we could not find evidence for newly generated neurons in response to apoptotic neuronal death. These results suggest that mitotically active progenitor populations are intrinsically capable to contribute to the repair process of injured cortical tissue and may represent a potential target for neuronal replacement strategies.
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Affiliation(s)
- Volodymyr Petrenko
- Department of Neurosciences, University of Geneva Medical School, CH-1211 Geneva 4, Switzerland
| | - Jevgenia Mihhailova
- Department of Neurosciences, University of Geneva Medical School, CH-1211 Geneva 4, Switzerland
| | - Patrick Salmon
- Department of Neurosciences, University of Geneva Medical School, CH-1211 Geneva 4, Switzerland
| | - Jozsef Z Kiss
- Department of Neurosciences, University of Geneva Medical School, CH-1211 Geneva 4, Switzerland.
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34
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Xu Y, Hu W, Liu Y, Xu P, Li Z, Wu R, Shi X, Tang Y. P2Y6 Receptor-Mediated Microglial Phagocytosis in Radiation-Induced Brain Injury. Mol Neurobiol 2015; 53:3552-3564. [PMID: 26099306 PMCID: PMC4937101 DOI: 10.1007/s12035-015-9282-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 06/02/2015] [Indexed: 11/06/2022]
Abstract
Microglia are the resident immune cells and the professional phagocytic cells of the CNS, showing a multitude of cellular responses after activation. However, how microglial phagocytosis changes and whether it is involved in radiation-induced brain injury remain unknown. In the current study, we found that microglia were activated and microglial phagocytosis was increased by radiation exposure both in cultured microglia in vitro and in mice in vivo. Radiation increased the protein expression of the purinergic receptor P2Y6 receptor (P2Y6R) located on microglia. The selective P2Y6 receptor antagonist MRS2578 suppressed microglial phagocytosis after radiation exposure. Inhibition of microglial phagocytosis increased inhibitory factor Nogo-A and exacerbated radiation-induced neuronal apoptosis and demyelination. We also found that the levels of protein expression for phosphorylated Ras-related C3 botulinum toxin substrate 1 (Rac1) and myosin light chain kinase (MLCK) were elevated, indicating that radiation exposure activated Rac1 and MLCK. The Rac1 inhibitor NSC23766 suppressed expression of MLCK, indicating that the Rac1-MLCK pathway was involved in microglial phagocytosis. Taken together, these findings suggest that the P2Y6 receptor plays a critical role in mediating microglial phagocytosis in radiation-induced brain injury, which might be a potential strategy for therapeutic intervention to alleviate radiation-induced brain injury.
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Affiliation(s)
- Yongteng Xu
- Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Number 107, Yan Jiang Xi Road, Guangzhou, Guangdong Province, 510120, China.,Key Laboratory of Malignant Tumor Gene Regulation and Target Therapy of Guangdong Higher Education Institutes, Sun Yat-Sen University, Guangzhou, 510120, China
| | - Weihan Hu
- Department of Radiation Oncology, Cancer Center of Sun Yat-Sen University, Guangzhou, 510120, China
| | - Yimin Liu
- Department of Radiation Oncology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510120, China
| | - Pengfei Xu
- Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Number 107, Yan Jiang Xi Road, Guangzhou, Guangdong Province, 510120, China
| | - Zichen Li
- Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Number 107, Yan Jiang Xi Road, Guangzhou, Guangdong Province, 510120, China
| | - Rong Wu
- Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Number 107, Yan Jiang Xi Road, Guangzhou, Guangdong Province, 510120, China
| | - Xiaolei Shi
- Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Number 107, Yan Jiang Xi Road, Guangzhou, Guangdong Province, 510120, China
| | - Yamei Tang
- Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Number 107, Yan Jiang Xi Road, Guangzhou, Guangdong Province, 510120, China. .,Key Laboratory of Malignant Tumor Gene Regulation and Target Therapy of Guangdong Higher Education Institutes, Sun Yat-Sen University, Guangzhou, 510120, China.
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Astrocytes and Microglia-Mediated Immune Response in Maladaptive Plasticity is Differently Modulated by NGF in the Ventral Horn of the Spinal Cord Following Peripheral Nerve Injury. Cell Mol Neurobiol 2015; 36:37-46. [PMID: 26084599 DOI: 10.1007/s10571-015-0218-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 05/29/2015] [Indexed: 01/12/2023]
Abstract
Reactive astrocytes and activated microglia are the key players in several pathophysiologic modifications of the central nervous system. We used the spared nerve injury (SNI) of the sciatic nerve to induce glial maladaptive response in the ventral horn of lumbar spinal cord and examine its role in the remodeling of the tripartite synapse plasticity. Imaging the ventral horn revealed that SNI was associated with both an early microglial and astrocytic activation, assessed, respectively, by analysis of Iba1 and GFAP expression. Microglia, in particular, localized peculiarly surrounding the motor neurons somata. Perineuronal astrocytes, which play a key role in maintaining the homeostasis of neuronal circuitry, underwent a substantial phenotypic change following peripheral axotomy, producing reactive gliosis. The gliosis was associated with the reduction of glial aminoacid transporters (GLT1 and GlyT1) and increase of neuronal glutamate transporter EAAC1. Although the expression of GABAergic neuronal marker GAD65/67 showed no change, glutamate increase, as demonstrated by HPLC analysis, shifted the excitatory/inhibitory balance as showed by the net increase of the glutamate/GABA ratio. Moreover, endogenous NGF levels were altered in SNI animals and not restored by the intrathecal NGF administration. This treatment reverted phenotypic changes associated with reactive astrocytosis, but failed to modify microglia activation. These findings on one hand confirm the correlation between gliopathy and maladaptive plasticity of the spinal synaptic circuitry, on the other hand add new data concerning the complex peculiar behavior of different glial cells in neuronal degenerative processes, defining a special role of microglia in sustaining the inflammatory response.
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Ling ZM, Tang Y, Li YQ, Luo HX, Liu LL, Tu QQ, Zhou LH. Evaluation of Avulsion-Induced Neuropathology in Rat Spinal Cords with 18F-FDG Micro-PET/CT. PLoS One 2015; 10:e0127685. [PMID: 26010770 PMCID: PMC4444271 DOI: 10.1371/journal.pone.0127685] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2014] [Accepted: 04/17/2015] [Indexed: 01/10/2023] Open
Abstract
Brachial plexus root avulsion (BPRA) leads to dramatic motoneuron death and glial reactions in the corresponding spinal segments at the late stage of injury. To protect spinal motoneurons, assessment of the affected spinal segments should be done at an earlier stage of the injury. In this study, we employed 18F-FDG small-animal PET/CT to assess the severity of BPRA-induced cervical spinal cord injuries. Adult Sprague-Dawley rats were randomly treated and divided into three groups: Av+NS (brachial plexus root avulsion (Av) treated with normal saline), Av+GM1 (treated with monosialoganglioside), and control. At time points of 3 day (d), 1 week (w), 2 w, 4 w and 8 w post-injury, 18F-FDG micro-PET/CT scans and neuropathology assessments of the injured spinal roots, as well as the spinal cord, were performed. The outcomes of the different treatments were compared. The results showed that BPRA induced local bleeding and typical Wallerian degeneration of the avulsed roots accompanied by 18F-FDG accumulations at the ipsilateral cervical intervertebral foramen. BPRA-induced astrocyte reactions and overexpression of neuronal nitric oxide synthase in the motoneurons correlated with higher 18F-FDG uptake in the ipsilateral cervical spinal cord during the first 2 w post-injury. The GM1 treatment reduced BPRA-induced astrocyte reactions and inhibited the de novo nNOS expressions in spinal motoneurons. The GM1 treatment also protected spinal motoneurons from avulsion within the first 4 w post-injury. The data from this study suggest that 18F-FDG PET/CT could be used to assess the severity of BPRA-induced primary and secondary injuries in the spinal cord. Furthermore, GM1 is an effective drug for reducing primary and secondary spinal cord injuries following BPRA.
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Affiliation(s)
- Ze-Min Ling
- Department of Anatomy, Zhongshan School of Medicine, Sun Yat-sen University, No. 74 Zhongshan Road 2, Guangzhou, 510080, P.R. China
| | - Ying Tang
- Department of Anatomy, Zhongshan School of Medicine, Sun Yat-sen University, No. 74 Zhongshan Road 2, Guangzhou, 510080, P.R. China
| | - Ying-Qin Li
- Department of Anatomy, Zhongshan School of Medicine, Sun Yat-sen University, No. 74 Zhongshan Road 2, Guangzhou, 510080, P.R. China
| | - Hao-Xuan Luo
- Department of Anatomy, Zhongshan School of Medicine, Sun Yat-sen University, No. 74 Zhongshan Road 2, Guangzhou, 510080, P.R. China
| | - Lin-Lin Liu
- Department of Anatomy, Zhongshan School of Medicine, Sun Yat-sen University, No. 74 Zhongshan Road 2, Guangzhou, 510080, P.R. China
| | - Qing-Qiang Tu
- Small Animal Molecular Imaging Center, Laboratories of Translational Medicine and Clinical Research, Sun Yat-sen University, No. 74 Zhongshan Road 2, Guangzhou, 510080, P.R. China
| | - Li-Hua Zhou
- Department of Anatomy, Zhongshan School of Medicine, Sun Yat-sen University, No. 74 Zhongshan Road 2, Guangzhou, 510080, P.R. China
- * E-mail:
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Takatsuru Y, Koibuchi N. Alteration of somatosensory response in adulthood by early life stress. Front Mol Neurosci 2015; 8:15. [PMID: 26041988 PMCID: PMC4436820 DOI: 10.3389/fnmol.2015.00015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 05/05/2015] [Indexed: 01/01/2023] Open
Abstract
Early life stress is well-known as a critical risk factor for mental and cognitive disorders in adulthood. Such disorders are accompanied by altered neuro- (synapto-) genesis and gene expression. Because psychosomatic disorders induced by early life stress (e.g., physical and/or sexual abuse, and neglect) have become a socio-economic problem, it is very important to clarify the mechanisms underlying these changes. However, despite of intensive clinical and animal studies, such mechanisms have not yet been clarified. Although the disturbance of glucocorticoid and glutamate homeostasis by stress has been well-documented, it has not yet been clarified whether such disturbance by early life stress persists for life. Furthermore, since previous studies have focused on the detection of changes in specific brain regions, such as the hippocampus and prefrontal cortex, it has not been clarified whether early life stress induced changes in the sensory/motor system. Thus, in this review, we introduce recent studies on functional/structural changes in the somatosensory cortex induced by early life stress. We believe that this review provides new insights into the functional alteration of the somatosensory system induced by early life stress. Such information may have clinical relevance in terms of providing effective therapeutic interventions to early life stressed individuals.
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Affiliation(s)
- Yusuke Takatsuru
- Department of Integrative Physiology, Graduate School of Medicine, Gunma University, Maebashi Japan
| | - Noriyuki Koibuchi
- Department of Integrative Physiology, Graduate School of Medicine, Gunma University, Maebashi Japan
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Xia CY, Zhang S, Gao Y, Wang ZZ, Chen NH. Selective modulation of microglia polarization to M2 phenotype for stroke treatment. Int Immunopharmacol 2015; 25:377-82. [DOI: 10.1016/j.intimp.2015.02.019] [Citation(s) in RCA: 122] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 01/28/2015] [Accepted: 02/11/2015] [Indexed: 11/27/2022]
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Michell-Robinson MA, Touil H, Healy LM, Owen DR, Durafourt BA, Bar-Or A, Antel JP, Moore CS. Roles of microglia in brain development, tissue maintenance and repair. Brain 2015; 138:1138-59. [PMID: 25823474 DOI: 10.1093/brain/awv066] [Citation(s) in RCA: 282] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 02/01/2015] [Indexed: 12/23/2022] Open
Abstract
The emerging roles of microglia are currently being investigated in the healthy and diseased brain with a growing interest in their diverse functions. In recent years, it has been demonstrated that microglia are not only immunocentric, but also neurobiological and can impact neural development and the maintenance of neuronal cell function in both healthy and pathological contexts. In the disease context, there is widespread consensus that microglia are dynamic cells with a potential to contribute to both central nervous system damage and repair. Indeed, a number of studies have found that microenvironmental conditions can selectively modify unique microglia phenotypes and functions. One novel mechanism that has garnered interest involves the regulation of microglial function by microRNAs, which has therapeutic implications such as enhancing microglia-mediated suppression of brain injury and promoting repair following inflammatory injury. Furthermore, recently published articles have identified molecular signatures of myeloid cells, suggesting that microglia are a distinct cell population compared to other cells of myeloid lineage that access the central nervous system under pathological conditions. Thus, new opportunities exist to help distinguish microglia in the brain and permit the study of their unique functions in health and disease.
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Affiliation(s)
- Mackenzie A Michell-Robinson
- 1 Neuroimmunology Unit, Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
| | - Hanane Touil
- 1 Neuroimmunology Unit, Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
| | - Luke M Healy
- 1 Neuroimmunology Unit, Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
| | - David R Owen
- 2 Division of Brain Sciences, Department of Medicine, Imperial College London, London, UK
| | - Bryce A Durafourt
- 1 Neuroimmunology Unit, Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
| | - Amit Bar-Or
- 1 Neuroimmunology Unit, Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
| | - Jack P Antel
- 1 Neuroimmunology Unit, Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
| | - Craig S Moore
- 3 Division of BioMedical Sciences, Faculty of Medicine, Memorial University, St. John's, Newfoundland, Canada
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Spejo AB, Oliveira ALR. Synaptic rearrangement following axonal injury: Old and new players. Neuropharmacology 2014; 96:113-23. [PMID: 25445484 DOI: 10.1016/j.neuropharm.2014.11.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 11/03/2014] [Accepted: 11/04/2014] [Indexed: 10/24/2022]
Abstract
Following axotomy, the contact between motoneurons and muscle fibers is disrupted, triggering a retrograde reaction at the neuron cell body within the spinal cord. Together with chromatolysis, a hallmark of such response to injury is the elimination of presynaptic terminals apposing to the soma and proximal dendrites of the injured neuron. Excitatory inputs are preferentially eliminated, leaving the cells under an inhibitory influence during the repair process. This is particularly important to avoid glutamate excitotoxicity. Such shift from transmission to a regeneration state is also reflected by deep metabolic changes, seen by the regulation of several genes related to cell survival and axonal growth. It is unclear, however, how exactly synaptic stripping occurs, but there is substantial evidence that glial cells play an active role in this process. In one hand, immune molecules, such as the major histocompatibility complex (MHC) class I, members of the complement family and Toll-like receptors are actively involved in the elimination/reapposition of presynaptic boutons. On the other hand, plastic changes that involve sprouting might be negatively regulated by extracellular matrix proteins such as Nogo-A, MAG and scar-related chondroitin sulfate proteoglycans. Also, neurotrophins, stem cells, physical exercise and several drugs seem to improve synaptic stability, leading to functional recovery after lesion. This article is part of a Special Issue entitled 'Neuroimmunology and Synaptic Function'.
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Affiliation(s)
- Aline Barroso Spejo
- Laboratory of Nerve Regeneration, Department of Structural and Functional Biology, University of Campinas - UNICAMP, Campinas, SP, Brazil
| | - Alexandre L R Oliveira
- Laboratory of Nerve Regeneration, Department of Structural and Functional Biology, University of Campinas - UNICAMP, Campinas, SP, Brazil.
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Arbat-Plana A, Torres-Espín A, Navarro X, Udina E. Activity dependent therapies modulate the spinal changes that motoneurons suffer after a peripheral nerve injury. Exp Neurol 2014; 263:293-305. [PMID: 25448160 DOI: 10.1016/j.expneurol.2014.10.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 10/10/2014] [Accepted: 10/14/2014] [Indexed: 12/11/2022]
Abstract
Injury of a peripheral nerve not only leads to target denervation, but also induces massive stripping of spinal synapses on axotomized motoneurons, with disruption of spinal circuits. Even when regeneration is successful, unspecific reinnervation and the limited reconnection of the spinal circuits impair functional recovery. The aim of this study was to describe the changes that axotomized motoneurons suffer after peripheral nerve injury and how activity-dependent therapies and neurotrophic factors can modulate these events. We observed a marked decrease in glutamatergic synapses, with a maximum peak at two weeks post-axotomy, which was only partially reversed with time. This decrease was accompanied by an increase in gephyrin immunoreactivity and a disintegration of perineuronal nets (PNNs) surrounding the motoneurons. Direct application of neurotrophins at the proximal stump was not able to reverse these effects. In contrast, activity-dependent treatment, in the form of treadmill running, reduced the observed destructuring of perineuronal nets and the loss of glutamatergic synapses two weeks after injury. These changes were proportional to the intensity of the exercise protocol. Blockade of sensory inputs from the homolateral hindlimb also reduced PNN immunoreactivity around intact motoneurons, and in that case treadmill running did not reverse that loss, suggesting that the effects of exercise on motoneuron PNN depend on increased sensory activity. Preservation of motoneuron PNN and reduction of synaptic stripping by exercise could facilitate the maintenance of the spinal circuitry and benefit functional recovery after peripheral nerve injury.
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Affiliation(s)
- Ariadna Arbat-Plana
- Institute of Neurosciences, Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Bellaterra, Spain
| | - Abel Torres-Espín
- Institute of Neurosciences, Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Bellaterra, Spain
| | - Xavier Navarro
- Institute of Neurosciences, Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Bellaterra, Spain
| | - Esther Udina
- Institute of Neurosciences, Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Bellaterra, Spain.
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Cernak I, Wing ID, Davidsson J, Plantman S. A novel mouse model of penetrating brain injury. Front Neurol 2014; 5:209. [PMID: 25374559 PMCID: PMC4205813 DOI: 10.3389/fneur.2014.00209] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Accepted: 09/30/2014] [Indexed: 02/06/2023] Open
Abstract
Penetrating traumatic brain injury (pTBI) has been difficult to model in small laboratory animals, such as rats or mice. Previously, we have established a non-fatal, rat model for pTBI using a modified air-rifle that accelerates a pellet, which hits a small probe that then penetrates the experimental animal’s brain. Knockout and transgenic strains of mice offer attractive tools to study biological reactions induced by TBI. Hence, in the present study, we adapted and modified our model to be used with mice. The technical characterization of the impact device included depth and speed of impact, as well as dimensions of the temporary cavity formed in a brain surrogate material after impact. Biologically, we have focused on three distinct levels of severity (mild, moderate, and severe), and characterized the acute phase response to injury in terms of tissue destruction, neural degeneration, and gliosis. Functional outcome was assessed by measuring bodyweight and motor performance on rotarod. The results showed that this model is capable of reproducing major morphological and neurological changes of pTBI; as such, we recommend its utilization in research studies aiming to unravel the biological events underlying injury and regeneration after pTBI.
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Affiliation(s)
- Ibolja Cernak
- Military and Veterans' Clinical Rehabilitation Research, University of Alberta , Edmonton, AB , Canada
| | - Ian D Wing
- Johns Hopkins University Applied Physics Laboratory , Laurel, MD , USA
| | - Johan Davidsson
- Division of Vehicle Safety, Chalmers University of Technology , Göteborg , Sweden
| | - Stefan Plantman
- Department of Neuroscience, Karolinska Institutet , Stockholm , Sweden
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43
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Fuentes-Santamaría V, Alvarado JC, López-Muñoz DF, Melgar-Rojas P, Gabaldón-Ull MC, Juiz JM. Glia-related mechanisms in the anteroventral cochlear nucleus of the adult rat in response to unilateral conductive hearing loss. Front Neurosci 2014; 8:319. [PMID: 25352772 PMCID: PMC4195288 DOI: 10.3389/fnins.2014.00319] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 09/19/2014] [Indexed: 11/13/2022] Open
Abstract
Conductive hearing loss causes a progressive decline in cochlear activity that may result in functional and structural modifications in auditory neurons. However, whether these activity-dependent changes are accompanied by a glial response involving microglia, astrocytes, or both has not yet been fully elucidated. Accordingly, the present study was designed to determine the involvement of glial related mechanisms in the anteroventral cochlear nucleus (AVCN) of adult rats at 1, 4, 7, and 15 d after removing middle ear ossicles. Quantitative immunohistochemistry analyses at light microscopy with specific markers of microglia or astroglia along with immunocytochemistry at the electron microscopy level were used. Also, in order to test whether trophic support by neurotrophins is modulated in glial cells by auditory activity, the expression and distribution of neurotrophin-3 (NT-3) and its colocalization with microglial or astroglial markers was investigated. Diminished cochlear activity after middle ear ossicle removal leads to a significant ipsilateral increase in the mean gray levels and stained area of microglial cells but not astrocytes in the AVCN at 1 and 4 d post-lesion as compared to the contralateral side and control animals. These results suggest that microglial cells but not astrocytes may act as dynamic modulators of synaptic transmission in the cochlear nucleus immediately following unilateral hearing loss. On the other hand, NT-3 immunostaining was localized mainly in neuronal cell bodies and axons and was upregulated at 1, 4 and 7 d post-lesion. Very few glial cells expressed this neurotrophin in both control and experimental rats, suggesting that NT-3 is primarily activated in neurons and not as much in glia after limiting auditory activity in the AVCN by conductive hearing loss.
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Affiliation(s)
- Verónica Fuentes-Santamaría
- Facultad de Medicina, Instituto de Investigación en Discapacidades, Neurológicas (IDINE), Universidad de Castilla-La Mancha Albacete, Spain
| | - Juan C Alvarado
- Facultad de Medicina, Instituto de Investigación en Discapacidades, Neurológicas (IDINE), Universidad de Castilla-La Mancha Albacete, Spain
| | - Diego F López-Muñoz
- Facultad de Medicina, Instituto de Investigación en Discapacidades, Neurológicas (IDINE), Universidad de Castilla-La Mancha Albacete, Spain
| | - Pedro Melgar-Rojas
- Facultad de Medicina, Instituto de Investigación en Discapacidades, Neurológicas (IDINE), Universidad de Castilla-La Mancha Albacete, Spain
| | - María C Gabaldón-Ull
- Facultad de Medicina, Instituto de Investigación en Discapacidades, Neurológicas (IDINE), Universidad de Castilla-La Mancha Albacete, Spain
| | - José M Juiz
- Facultad de Medicina, Instituto de Investigación en Discapacidades, Neurológicas (IDINE), Universidad de Castilla-La Mancha Albacete, Spain
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Cuenca N, Fernández-Sánchez L, Campello L, Maneu V, De la Villa P, Lax P, Pinilla I. Cellular responses following retinal injuries and therapeutic approaches for neurodegenerative diseases. Prog Retin Eye Res 2014; 43:17-75. [PMID: 25038518 DOI: 10.1016/j.preteyeres.2014.07.001] [Citation(s) in RCA: 296] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 07/03/2014] [Accepted: 07/07/2014] [Indexed: 01/17/2023]
Abstract
Retinal neurodegenerative diseases like age-related macular degeneration, glaucoma, diabetic retinopathy and retinitis pigmentosa each have a different etiology and pathogenesis. However, at the cellular and molecular level, the response to retinal injury is similar in all of them, and results in morphological and functional impairment of retinal cells. This retinal degeneration may be triggered by gene defects, increased intraocular pressure, high levels of blood glucose, other types of stress or aging, but they all frequently induce a set of cell signals that lead to well-established and similar morphological and functional changes, including controlled cell death and retinal remodeling. Interestingly, an inflammatory response, oxidative stress and activation of apoptotic pathways are common features in all these diseases. Furthermore, it is important to note the relevant role of glial cells, including astrocytes, Müller cells and microglia, because their response to injury is decisive for maintaining the health of the retina or its degeneration. Several therapeutic approaches have been developed to preserve retinal function or restore eyesight in pathological conditions. In this context, neuroprotective compounds, gene therapy, cell transplantation or artificial devices should be applied at the appropriate stage of retinal degeneration to obtain successful results. This review provides an overview of the common and distinctive features of retinal neurodegenerative diseases, including the molecular, anatomical and functional changes caused by the cellular response to damage, in order to establish appropriate treatments for these pathologies.
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Affiliation(s)
- Nicolás Cuenca
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain; Multidisciplinary Institute for Environmental Studies "Ramon Margalef", University of Alicante, Alicante, Spain.
| | - Laura Fernández-Sánchez
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Laura Campello
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Victoria Maneu
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain
| | - Pedro De la Villa
- Department of Systems Biology, University of Alcalá, Alcalá de Henares, Spain
| | - Pedro Lax
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Isabel Pinilla
- Department of Ophthalmology, Lozano Blesa University Hospital, Aragon Institute of Health Sciences, Zaragoza, Spain
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Fu R, Shen Q, Xu P, Luo JJ, Tang Y. Phagocytosis of microglia in the central nervous system diseases. Mol Neurobiol 2014; 49:1422-34. [PMID: 24395130 PMCID: PMC4012154 DOI: 10.1007/s12035-013-8620-6] [Citation(s) in RCA: 401] [Impact Index Per Article: 40.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 12/15/2013] [Indexed: 12/20/2022]
Abstract
Microglia, the resident macrophages of the central nervous system, rapidly activate in nearly all kinds of neurological diseases. These activated microglia become highly motile, secreting inflammatory cytokines, migrating to the lesion area, and phagocytosing cell debris or damaged neurons. During the past decades, the secretory property and chemotaxis of microglia have been well-studied, while relatively less attention has been paid to microglial phagocytosis. So far there is no obvious concordance with whether it is beneficial or detrimental in tissue repair. This review focuses on phagocytic phenotype of microglia in neurological diseases such as Alzheimer's disease, multiple sclerosis, Parkinson's disease, traumatic brain injury, ischemic and other brain diseases. Microglial morphological characteristics, involved receptors and signaling pathways, distribution variation along with time and space changes, and environmental factors that affecting phagocytic function in each disease are reviewed. Moreover, a comparison of contributions between macrophages from peripheral circulation and the resident microglia to these pathogenic processes will also be discussed.
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Affiliation(s)
- Ruying Fu
- Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Number 107, Yan Jiang Xi Road, Guangzhou, 510120 Guangdong Province China
| | - Qingyu Shen
- Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Number 107, Yan Jiang Xi Road, Guangzhou, 510120 Guangdong Province China
- Department of Neurology, Zengcheng People’s Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Pengfei Xu
- Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Number 107, Yan Jiang Xi Road, Guangzhou, 510120 Guangdong Province China
| | - Jin Jun Luo
- Department of Neurology, School of Medicine, Temple University, Philadelphia, PA USA
| | - Yamei Tang
- Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Number 107, Yan Jiang Xi Road, Guangzhou, 510120 Guangdong Province China
- Key Laboratory of Malignant Tumor Gene Regulation and Target Therapy of Guangdong Higher Education Institutes, Sun Yat-Sen University, Guangzhou, China
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Normal distribution of VGLUT1 synapses on spinal motoneuron dendrites and their reorganization after nerve injury. J Neurosci 2014; 34:3475-92. [PMID: 24599449 DOI: 10.1523/jneurosci.4768-13.2014] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Peripheral nerve injury induces permanent alterations in spinal cord circuitries that are not reversed by regeneration. Nerve injury provokes the loss of many proprioceptive IA afferent synapses (VGLUT1-IR boutons) from motoneurons, the reduction of IA EPSPs in motoneurons, and the disappearance of stretch reflexes. After motor and sensory axons successfully reinnervate muscle, lost IA VGLUT1 synapses are not re-established and the stretch reflex does not recover; however, electrically evoked EPSPs do recover. The reasons why remaining IA synapses can evoke EPSPs on motoneurons, but fail to transmit useful stretch signals are unknown. To better understand changes in the organization of VGLUT1 IA synapses that might influence their input strength, we analyzed their distribution over the entire dendritic arbor of motoneurons before and after nerve injury. Adult rats underwent complete tibial nerve transection followed by microsurgical reattachment and 1 year later motoneurons were intracellularly recorded and filled with neurobiotin to map the distribution of VGLUT1 synapses along their dendrites. We found in control motoneurons an average of 911 VGLUT1 synapses; ~62% of them were lost after injury. In controls, VGLUT1 synapses were focused to proximal dendrites where they were grouped in tight clusters. After injury, most synaptic loses occurred in the proximal dendrites and remaining synapses were declustered, smaller, and uniformly distributed throughout the dendritic arbor. We conclude that this loss and reorganization renders IA afferent synapses incompetent for efficient motoneuron synaptic depolarization in response to natural stretch, while still capable of eliciting EPSPs when synchronously fired by electrical volleys.
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47
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Fuentes-Santamaría V, Alvarado JC, Gabaldón-Ull MC, Manuel Juiz J. Upregulation of insulin-like growth factor and interleukin 1β occurs in neurons but not in glial cells in the cochlear nucleus following cochlear ablation. J Comp Neurol 2014; 521:3478-99. [PMID: 23681983 DOI: 10.1002/cne.23362] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2013] [Revised: 04/30/2013] [Accepted: 05/03/2013] [Indexed: 12/30/2022]
Abstract
One of the main mechanisms used by neurons and glial cells to promote repair following brain injury is to upregulate activity-dependent molecules such as insulin-like growth factor 1 (IGF-1) and interleukin-1β (IL-1β). In the auditory system, IGF-1 is crucial for restoring synaptic transmission following hearing loss; however, whether IL-1β is also involved in this process is unknown. In this study, we evaluated the expression of IGF-1 and IL-1β within neurons and glial cells of the ventral cochlear nucleus in adult rats at 1, 7, 15, and 30 days following bilateral cochlear ablation. After the lesion, significant increases in both the overall mean gray levels of IGF-1 immunostaining and the mean gray levels within cells of the cochlear nucleus were observed at 1, 7, and 15 days compared with control animals. The expression and distribution of IL-1β in the ventral cochlear nucleus of ablated animals was temporally and spatially correlated with IGF-1. We also observed a lack of colocalization between IGF-1 and IL-1β with either astrocytes or microglia at any of the time points following ablation. These results suggest that the upregulation of IGF-1 and IL-1β levels within neurons-but not within glial cells-may reflect a plastic mechanism involved in repairing synaptic homeostasis of the overall cellular environment of the cochlear nucleus following bilateral cochlear ablation.
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Affiliation(s)
- Verónica Fuentes-Santamaría
- Institute for Research on Neurological Disorders (IDINE), Faculty of Medicine, University of Castilla-La Mancha, 02006, Albacete, Spain
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Savastano LE, Laurito SR, Fitt MR, Rasmussen JA, Gonzalez Polo V, Patterson SI. Sciatic nerve injury: A simple and subtle model for investigating many aspects of nervous system damage and recovery. J Neurosci Methods 2014; 227:166-80. [DOI: 10.1016/j.jneumeth.2014.01.020] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 01/16/2014] [Accepted: 01/20/2014] [Indexed: 02/04/2023]
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Janz P, Illing RB. A role for microglial cells in reshaping neuronal circuitry of the adult rat auditory brainstem after its sensory deafferentation. J Neurosci Res 2014; 92:432-45. [DOI: 10.1002/jnr.23334] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 10/24/2013] [Accepted: 11/06/2013] [Indexed: 11/07/2022]
Affiliation(s)
- Philipp Janz
- Neurobiological Research Laboratory; Department of Otorhinolaryngology; University of Freiburg; Freiburg Germany
| | - Robert-Benjamin Illing
- Neurobiological Research Laboratory; Department of Otorhinolaryngology; University of Freiburg; Freiburg Germany
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Fuxe K, Borroto-Escuela DO, Tarakanov A, Fernandez WR, Manger P, Rivera A, van Craenenbroeck K, Skieterska K, Diaz-Cabiale Z, Filip M, Ferraro L, Tanganelli S, Guidolin D, Cullheim S, de la Mora MP, Agnati LF. Understanding the balance and integration of volume and synaptic transmission. Relevance for psychiatry. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.npbr.2013.10.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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