1
|
Bottero M, Pessina G, Bason C, Vigo T, Uccelli A, Ferrara G. Nerve-Glial antigen 2: unmasking the enigmatic cellular identity in the central nervous system. Front Immunol 2024; 15:1393842. [PMID: 39136008 PMCID: PMC11317297 DOI: 10.3389/fimmu.2024.1393842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Accepted: 07/05/2024] [Indexed: 08/15/2024] Open
Abstract
Chondroitin sulfate proteoglycans (CSPGs) are fundamental components of the extracellular matrix in the central nervous system (CNS). Among these, the Nerve-Glial antigen 2 (NG2) stands out as a transmembrane CSPG exclusively expressed in a different population of cells collectively termed NG2-expressing cells. These enigmatic cells, found throughout the developing and adult CNS, have been indicated with various names, including NG2 progenitor cells, polydendrocytes, synantocytes, NG2 cells, and NG2-Glia, but are more commonly referred to as oligodendrocyte progenitor cells. Characterized by high proliferation rates and unique morphology, NG2-expressing cells stand apart from neurons, astrocytes, and oligodendrocytes. Intriguingly, some NG2-expressing cells form functional glutamatergic synapses with neurons, challenging the long-held belief that only neurons possess the intricate machinery required for neurotransmission. In the CNS, the complexity surrounding NG2-expressing cells extends to their classification. Additionally, NG2 expression has been documented in pericytes and immune cells, suggesting a role in regulating brain innate immunity and neuro-immune crosstalk in homeostasis. Ongoing debates revolve around their heterogeneity, potential as progenitors for various cell types, responses to neuroinflammation, and the role of NG2. Therefore, this review aims to shed light on the enigma of NG2-expressing cells by delving into their structure, functions, and signaling pathways. We will critically evaluate the literature on NG2 expression across the CNS, and address the contentious issues surrounding their classification and roles in neuroinflammation and neurodegeneration. By unraveling the intricacies of NG2-expressing cells, we hope to pave the way for a more comprehensive understanding of their contributions to CNS health and during neurological disorders.
Collapse
Affiliation(s)
- Marta Bottero
- IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Giada Pessina
- Department of Experimental Medicine, University of Genoa, Genoa, Italy
| | | | - Tiziana Vigo
- IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Antonio Uccelli
- IRCCS Ospedale Policlinico San Martino, Genoa, Italy
- Department of Neurology, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy
| | | |
Collapse
|
2
|
Tizabi Y, Getachew B, Hauser SR, Tsytsarev V, Manhães AC, da Silva VDA. Role of Glial Cells in Neuronal Function, Mood Disorders, and Drug Addiction. Brain Sci 2024; 14:558. [PMID: 38928557 PMCID: PMC11201416 DOI: 10.3390/brainsci14060558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Revised: 05/19/2024] [Accepted: 05/28/2024] [Indexed: 06/28/2024] Open
Abstract
Mood disorders and substance use disorder (SUD) are of immense medical and social concern. Although significant progress on neuronal involvement in mood and reward circuitries has been achieved, it is only relatively recently that the role of glia in these disorders has attracted attention. Detailed understanding of the glial functions in these devastating diseases could offer novel interventions. Here, following a brief review of circuitries involved in mood regulation and reward perception, the specific contributions of neurotrophic factors, neuroinflammation, and gut microbiota to these diseases are highlighted. In this context, the role of specific glial cells (e.g., microglia, astroglia, oligodendrocytes, and synantocytes) on phenotypic manifestation of mood disorders or SUD are emphasized. In addition, use of this knowledge in the potential development of novel therapeutics is touched upon.
Collapse
Affiliation(s)
- Yousef Tizabi
- Department of Pharmacology, Howard University College of Medicine, 520 W Street NW, Washington, DC 20059, USA;
| | - Bruk Getachew
- Department of Pharmacology, Howard University College of Medicine, 520 W Street NW, Washington, DC 20059, USA;
| | - Sheketha R. Hauser
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Vassiliy Tsytsarev
- Department of Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA;
| | - Alex C. Manhães
- Laboratório de Neurofisiologia, Departamento de Ciências Fisiológicas, IBRAG, Universidade do Estado do Rio de Janeiro, Rio de Janeiro 20550-170, RJ, Brazil
| | - Victor Diogenes Amaral da Silva
- Laboratory of Neurochemistry and Cell Biology, Department of Biochemistry and Biophysics, Institute of Health Sciences, Federal University of Bahia, Salvador 40110-100, BA, Brazil;
| |
Collapse
|
3
|
Yu Y, Chen R, Mao K, Deng M, Li Z. The Role of Glial Cells in Synaptic Dysfunction: Insights into Alzheimer's Disease Mechanisms. Aging Dis 2024; 15:459-479. [PMID: 37548934 PMCID: PMC10917533 DOI: 10.14336/ad.2023.0718] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 07/18/2023] [Indexed: 08/08/2023] Open
Abstract
Alzheimer's disease (AD) is a devastating neurodegenerative disorder that impacts a substantial number of individuals globally. Despite its widespread prevalence, there is currently no cure for AD. It is widely acknowledged that normal synaptic function holds a key role in memory, cognitive abilities, and the interneuronal transfer of information. As AD advances, symptoms including synaptic impairment, decreased synaptic density, and cognitive decline become increasingly noticeable. The importance of glial cells in the formation of synapses, the growth of neurons, brain maturation, and safeguarding the microenvironment of the central nervous system is well recognized. However, during AD progression, overactive glial cells can cause synaptic dysfunction, neuronal death, and abnormal neuroinflammation. Both neuroinflammation and synaptic dysfunction are present in the early stages of AD. Therefore, focusing on the changes in glia-synapse communication could provide insights into the mechanisms behind AD. In this review, we aim to provide a summary of the role of various glial cells, including microglia, astrocytes, oligodendrocytes, and oligodendrocyte precursor cells, in regulating synaptic dysfunction. This may offer a new perspective on investigating the underlying mechanisms of AD.
Collapse
Affiliation(s)
- Yang Yu
- Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China.
| | - Ran Chen
- Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China.
- School of Medicine, Sun Yat-sen University, Shenzhen, China.
| | - Kaiyue Mao
- Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China.
- School of Medicine, Sun Yat-sen University, Shenzhen, China.
| | - Maoyan Deng
- Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China.
- School of Medicine, Sun Yat-sen University, Shenzhen, China.
| | - Zhigang Li
- Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China.
- Shenzhen Key Laboratory of Chinese Medicine Active Substance Screening and Translational Research, Shenzhen, China.
| |
Collapse
|
4
|
Janeckova L, Knotek T, Kriska J, Hermanova Z, Kirdajova D, Kubovciak J, Berkova L, Tureckova J, Camacho Garcia S, Galuskova K, Kolar M, Anderova M, Korinek V. Astrocyte-like subpopulation of NG2 glia in the adult mouse cortex exhibits characteristics of neural progenitor cells. Glia 2024; 72:245-273. [PMID: 37772368 DOI: 10.1002/glia.24471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 09/05/2023] [Accepted: 09/05/2023] [Indexed: 09/30/2023]
Abstract
Glial cells expressing neuron-glial antigen 2 (NG2), also known as oligodendrocyte progenitor cells (OPCs), play a critical role in maintaining brain health. However, their ability to differentiate after ischemic injury is poorly understood. The aim of this study was to investigate the properties and functions of NG2 glia in the ischemic brain. Using transgenic mice, we selectively labeled NG2-expressing cells and their progeny in both healthy brain and after focal cerebral ischemia (FCI). Using single-cell RNA sequencing, we classified the labeled glial cells into five distinct subpopulations based on their gene expression patterns. Additionally, we examined the membrane properties of these cells using the patch-clamp technique. Of the identified subpopulations, three were identified as OPCs, whereas the fourth subpopulation had characteristics indicative of cells likely to develop into oligodendrocytes. The fifth subpopulation of NG2 glia showed astrocytic markers and had similarities to neural progenitor cells. Interestingly, this subpopulation was present in both healthy and post-ischemic tissue; however, its gene expression profile changed after ischemia, with increased numbers of genes related to neurogenesis. Immunohistochemical analysis confirmed the temporal expression of neurogenic genes and showed an increased presence of NG2 cells positive for Purkinje cell protein-4 at the periphery of the ischemic lesion 12 days after FCI, as well as NeuN-positive NG2 cells 28 and 60 days after injury. These results suggest the potential development of neuron-like cells arising from NG2 glia in the ischemic tissue. Our study provides insights into the plasticity of NG2 glia and their capacity for neurogenesis after stroke.
Collapse
Affiliation(s)
- Lucie Janeckova
- Laboratory of Cell and Developmental Biology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Tomas Knotek
- Department of Cellular Neurophysiology, Institute of Experimental Medicine of the Czech Academy of Sciences, Prague, Czech Republic
- Second Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Jan Kriska
- Department of Cellular Neurophysiology, Institute of Experimental Medicine of the Czech Academy of Sciences, Prague, Czech Republic
| | - Zuzana Hermanova
- Department of Cellular Neurophysiology, Institute of Experimental Medicine of the Czech Academy of Sciences, Prague, Czech Republic
- Second Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Denisa Kirdajova
- Department of Cellular Neurophysiology, Institute of Experimental Medicine of the Czech Academy of Sciences, Prague, Czech Republic
| | - Jan Kubovciak
- Laboratory of Genomics and Bioinformatics, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Linda Berkova
- Laboratory of Cell and Developmental Biology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Jana Tureckova
- Department of Cellular Neurophysiology, Institute of Experimental Medicine of the Czech Academy of Sciences, Prague, Czech Republic
| | - Sara Camacho Garcia
- Department of Cellular Neurophysiology, Institute of Experimental Medicine of the Czech Academy of Sciences, Prague, Czech Republic
| | - Katerina Galuskova
- Laboratory of Cell and Developmental Biology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Michal Kolar
- Laboratory of Genomics and Bioinformatics, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Miroslava Anderova
- Department of Cellular Neurophysiology, Institute of Experimental Medicine of the Czech Academy of Sciences, Prague, Czech Republic
| | - Vladimir Korinek
- Laboratory of Cell and Developmental Biology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| |
Collapse
|
5
|
Wu Z, Yu W, Song Y, Zhao P. General anaesthesia, the developing brain, and cerebral white matter alterations: a narrative review. Br J Anaesth 2023; 131:1022-1029. [PMID: 37833128 DOI: 10.1016/j.bja.2023.09.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 09/03/2023] [Accepted: 09/06/2023] [Indexed: 10/15/2023] Open
Abstract
The potential neurotoxic impact of anaesthetic agents has been the subject of sustained debate and continuing research. White matter, which comprises more than half of the brain volume and largely consists of myelinated axonal bundles, is critical for communication between diverse brain regions and for supporting neurobehavioural function. Evidence points to a correlation between exposure to anaesthesia and white matter alterations, which might underpin the ensuing cognitive and behavioural abnormalities. This review summarises the neuropathological and neuroimaging findings related to anaesthesia-induced white matter alterations in the developing brain. Future research is required to understand the effects of anaesthesia exposure on white matter development.
Collapse
Affiliation(s)
- Ziyi Wu
- Department of Anaesthesiology, Shengjing Hospital of China Medical University, Shenyang, China
| | - Weiwei Yu
- Department of Anaesthesiology, Shengjing Hospital of China Medical University, Shenyang, China
| | - Yanhong Song
- Department of Anaesthesiology, Shengjing Hospital of China Medical University, Shenyang, China
| | - Ping Zhao
- Department of Anaesthesiology, Shengjing Hospital of China Medical University, Shenyang, China.
| |
Collapse
|
6
|
Zhou Y, Zhang J. Neuronal activity and remyelination: new insights into the molecular mechanisms and therapeutic advancements. Front Cell Dev Biol 2023; 11:1221890. [PMID: 37564376 PMCID: PMC10410458 DOI: 10.3389/fcell.2023.1221890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Accepted: 07/18/2023] [Indexed: 08/12/2023] Open
Abstract
This article reviews the role of neuronal activity in myelin regeneration and the related neural signaling pathways. The article points out that neuronal activity can stimulate the formation and regeneration of myelin, significantly improve its conduction speed and neural signal processing ability, maintain axonal integrity, and support axonal nutrition. However, myelin damage is common in various clinical diseases such as multiple sclerosis, stroke, dementia, and schizophrenia. Although myelin regeneration exists in these diseases, it is often incomplete and cannot promote functional recovery. Therefore, seeking other ways to improve myelin regeneration in clinical trials in recent years is of great significance. Research has shown that controlling neuronal excitability may become a new intervention method for the clinical treatment of demyelinating diseases. The article discusses the latest research progress of neuronal activity on myelin regeneration, including direct or indirect stimulation methods, and the related neural signaling pathways, including glutamatergic, GABAergic, cholinergic, histaminergic, purinergic and voltage-gated ion channel signaling pathways, revealing that seeking treatment strategies to promote myelin regeneration through precise regulation of neuronal activity has broad prospects.
Collapse
Affiliation(s)
| | - Jing Zhang
- Department of Pharmacy, School of Medicine, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou, China
| |
Collapse
|
7
|
Yi C, Verkhratsky A, Niu J. Pathological potential of oligodendrocyte precursor cells: terra incognita. Trends Neurosci 2023:S0166-2236(23)00103-0. [PMID: 37183154 DOI: 10.1016/j.tins.2023.04.003] [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: 01/08/2023] [Revised: 03/12/2023] [Accepted: 04/13/2023] [Indexed: 05/16/2023]
Abstract
Adult oligodendrocyte precursor cells (aOPCs), transformed from fetal OPCs, are idiosyncratic neuroglia of the central nervous system (CNS) that are distinct in many ways from other glial cells. OPCs have been classically studied in the context of their remyelinating capacity. Recent studies, however, revealed that aOPCs not only contribute to post-lesional remyelination but also play diverse crucial roles in multiple neurological diseases. In this review we briefly present the physiology of aOPCs and summarize current knowledge of the beneficial and detrimental roles of aOPCs in different CNS diseases. We discuss unique features of aOPC death, reactivity, and changes during senescence, as well as aOPC interactions with other glial cells and pathological remodeling during disease. Finally, we outline future perspectives for the study of aOPCs in brain pathologies which may instigate the development of aOPC-targeting therapeutic strategies.
Collapse
Affiliation(s)
- Chenju Yi
- Research Centre, Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen 518107, China; Department of Pathology, First Affiliated Hospital of Gannan Medical University, Ganzhou, 341000, China; Shenzhen Key Laboratory of Chinese Medicine Active Substance Screening and Translational Research, Shenzhen 518107, China; Guangdong Provincial Key Laboratory of Brain Function and Disease, Guangzhou, China.
| | - Alexei Verkhratsky
- Faculty of Biology, Medicine, and Health, University of Manchester, Manchester M13 9PL, UK; Achucarro Centre for Neuroscience, Basque Foundation for Science (IKERBASQUE), Bilbao 48011, Spain; Department of Stem Cell Biology, State Research Institute Centre for Innovative Medicine, LT-01102 Vilnius, Lithuania; Department of Forensic Analytical Toxicology, School of Forensic Medicine, China Medical University, Shenyang, China.
| | - Jianqin Niu
- Department of Histology and Embryology, Chongqing Key Laboratory of Neurobiology, Brain and Intelligence Research Key Laboratory of Chongqing Education Commission, Third Military Medical University, Chongqing 400038, China.
| |
Collapse
|
8
|
Dean T, Ghaemmaghami J, Corso J, Gallo V. The cortical NG2-glia response to traumatic brain injury. Glia 2023; 71:1164-1175. [PMID: 36692058 PMCID: PMC10404390 DOI: 10.1002/glia.24342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 12/21/2022] [Accepted: 01/03/2023] [Indexed: 01/25/2023]
Abstract
Traumatic brain injury (TBI) is a significant worldwide cause of morbidity and mortality. A chronic neurologic disease bearing the moniker of "the silent epidemic," TBI currently has no targeted therapies to ameliorate cellular loss or enhance functional recovery. Compared with those of astrocytes, microglia, and peripheral immune cells, the functions and mechanisms of NG2-glia following TBI are far less understood, despite NG2-glia comprising the largest population of regenerative cells in the mature cortex. Here, we synthesize the results from multiple rodent models of TBI, with a focus on cortical NG2-glia proliferation and lineage potential, and propose future avenues for glia researchers to address this unique cell type in TBI. As the molecular mechanisms that regulate NG2-glia regenerative potential are uncovered, we posit that future therapeutic strategies may exploit cortical NG2-glia to augment local cellular recovery following TBI.
Collapse
Affiliation(s)
- Terry Dean
- Center for Neuroscience Research, Children's National Hospital, Washington, District of Columbia, USA
- Division of Critical Care Medicine, Children's National Hospital, Washington, District of Columbia, USA
| | - Javid Ghaemmaghami
- Center for Neuroscience Research, Children's National Hospital, Washington, District of Columbia, USA
| | - John Corso
- Center for Neuroscience Research, Children's National Hospital, Washington, District of Columbia, USA
| | - Vittorio Gallo
- Center for Neuroscience Research, Children's National Hospital, Washington, District of Columbia, USA
| |
Collapse
|
9
|
Gao Y, Xie D, Wang Y, Niu L, Jiang H. Short-Chain Fatty Acids Reduce Oligodendrocyte Precursor Cells Loss by Inhibiting the Activation of Astrocytes via the SGK1/IL-6 Signalling Pathway. Neurochem Res 2022; 47:3476-3489. [PMID: 36098889 PMCID: PMC9546972 DOI: 10.1007/s11064-022-03710-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 07/21/2022] [Accepted: 07/22/2022] [Indexed: 12/09/2022]
Abstract
Short-chain fatty acids (SCFAs) are known to be actively involved in neurological diseases, but their roles in hypoxic-ischaemic brain injury (HIBI) are unclear. In this study, a rat model of HIBI was established, and this study measured the changes in IL-6 and NOD-like receptor thermal protein domain associated protein 3 (NLRP3), in addition to proliferation and apoptosis indicators of oligodendrocyte precursor cells (OPCs). The mechanism of action of SCFA on astrocytes was also investigated. Astrocytes were subjected to hypoxia in vitro, and OPCs were treated with IL-6. The results showed that SCFAs significantly alleviated HIBI-induced activation of astrocytes and loss of OPCs. SCFA pretreatment (1) downregulated the expression of NLRP3, IL-6, CCL2, and IP-10; (2) had no effect on the proliferation of OPCs; (3) ameliorated the abnormal expression of Bax and Bcl-2; and (4) regulated IL-6 expression via the SGK1-related pathway in astrocytes. Our findings revealed that SCFAs alleviated the loss of OPCs by regulating astrocyte activation through the SGK1/IL-6 signalling pathway.
Collapse
Affiliation(s)
- Yanmin Gao
- Department of General Practice, Shanghai East Hospital, School of Medicine, Tongji University, No.150, Jimo Road, Pudong New District, Shanghai, 200120, China.,Department of General Practice, Kongjiang Community Health Service Center, No. 100, Yanji West Road, Yangpu District, Shanghai, 200093, China
| | - Di Xie
- Emergency Department, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, No.1665, Kongjiang Road, Yangpu District, Shanghai, 200092, China
| | - Yang Wang
- Department of General Practice, Shanghai East Hospital, School of Medicine, Tongji University, No.150, Jimo Road, Pudong New District, Shanghai, 200120, China.,Emergency Department, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, No.1665, Kongjiang Road, Yangpu District, Shanghai, 200092, China
| | - Lei Niu
- Department of General Practice, Shanghai East Hospital, School of Medicine, Tongji University, No.150, Jimo Road, Pudong New District, Shanghai, 200120, China.,Emergency Department, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, No.1665, Kongjiang Road, Yangpu District, Shanghai, 200092, China
| | - Hua Jiang
- Department of General Practice, Shanghai East Hospital, School of Medicine, Tongji University, No.150, Jimo Road, Pudong New District, Shanghai, 200120, China. .,Emergency Department, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, No.1665, Kongjiang Road, Yangpu District, Shanghai, 200092, China.
| |
Collapse
|
10
|
Pantazopoulos H, Hossain NM, Chelini G, Durning P, Barbas H, Zikopoulos B, Berretta S. Chondroitin Sulphate Proteoglycan Axonal Coats in the Human Mediodorsal Thalamic Nucleus. Front Integr Neurosci 2022; 16:934764. [PMID: 35875507 PMCID: PMC9298528 DOI: 10.3389/fnint.2022.934764] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 06/21/2022] [Indexed: 12/21/2022] Open
Abstract
Mounting evidence supports a key involvement of the chondroitin sulfate proteoglycans (CSPGs) NG2 and brevican (BCAN) in the regulation of axonal functions, including axon guidance, fasciculation, conductance, and myelination. Prior work suggested the possibility that these functions may, at least in part, be carried out by specialized CSPG structures surrounding axons, termed axonal coats. However, their existence remains controversial. We tested the hypothesis that NG2 and BCAN, known to be associated with oligodendrocyte precursor cells, form axonal coats enveloping myelinated axons in the human brain. In tissue blocks containing the mediodorsal thalamic nucleus (MD) from healthy donors (n = 5), we used dual immunofluorescence, confocal microscopy, and unbiased stereology to characterize BCAN and NG2 immunoreactive (IR) axonal coats and measure the percentage of myelinated axons associated with them. In a subset of donors (n = 3), we used electron microscopy to analyze the spatial relationship between axons and NG2- and BCAN-IR axonal coats within the human MD. Our results show that a substantial percentage (∼64%) of large and medium myelinated axons in the human MD are surrounded by NG2- and BCAN-IR axonal coats. Electron microscopy studies show NG2- and BCAN-IR axonal coats are interleaved with myelin sheets, with larger axons displaying greater association with axonal coats. These findings represent the first characterization of NG2 and BCAN axonal coats in the human brain. The large percentage of axons surrounded by CSPG coats, and the role of CSPGs in axonal guidance, fasciculation, conductance, and myelination suggest that these structures may contribute to several key axonal properties.
Collapse
Affiliation(s)
- Harry Pantazopoulos
- Department of Psychiatry and Program in Neuroscience, University of Mississippi Medical Center, Jackson, MS, United States
| | | | - Gabriele Chelini
- Translational Neuroscience Laboratory, Mclean Hospital, Belmont, MA, United States
- Department of Psychiatry, Harvard Medical School, Boston, MA, United States
| | - Peter Durning
- Translational Neuroscience Laboratory, Mclean Hospital, Belmont, MA, United States
| | - Helen Barbas
- Department of Health Sciences, Boston University, Boston, MA, United States
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA, United States
- Neural Systems Laboratory, Boston University, Boston, MA, United States
| | - Basilis Zikopoulos
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA, United States
- Neural Systems Laboratory, Boston University, Boston, MA, United States
| | - Sabina Berretta
- Translational Neuroscience Laboratory, Mclean Hospital, Belmont, MA, United States
- Department of Psychiatry, Harvard Medical School, Boston, MA, United States
- Program in Neuroscience, Harvard Medical School, Boston, MA, United States
- *Correspondence: Sabina Berretta,
| |
Collapse
|
11
|
Mira RG, Lira M, Cerpa W. Traumatic Brain Injury: Mechanisms of Glial Response. Front Physiol 2021; 12:740939. [PMID: 34744783 PMCID: PMC8569708 DOI: 10.3389/fphys.2021.740939] [Citation(s) in RCA: 76] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 09/20/2021] [Indexed: 11/17/2022] Open
Abstract
Traumatic brain injury (TBI) is a heterogeneous disorder that involves brain damage due to external forces. TBI is the main factor of death and morbidity in young males with a high incidence worldwide. TBI causes central nervous system (CNS) damage under a variety of mechanisms, including synaptic dysfunction, protein aggregation, mitochondrial dysfunction, oxidative stress, and neuroinflammation. Glial cells comprise most cells in CNS, which are mediators in the brain’s response to TBI. In the CNS are present astrocytes, microglia, oligodendrocytes, and polydendrocytes (NG2 cells). Astrocytes play critical roles in brain’s ion and water homeostasis, energy metabolism, blood-brain barrier, and immune response. In response to TBI, astrocytes change their morphology and protein expression. Microglia are the primary immune cells in the CNS with phagocytic activity. After TBI, microglia also change their morphology and release both pro and anti-inflammatory mediators. Oligodendrocytes are the myelin producers of the CNS, promoting axonal support. TBI causes oligodendrocyte apoptosis, demyelination, and axonal transport disruption. There are also various interactions between these glial cells and neurons in response to TBI that contribute to the pathophysiology of TBI. In this review, we summarize several glial hallmarks relevant for understanding the brain injury and neuronal damage under TBI conditions.
Collapse
Affiliation(s)
- Rodrigo G Mira
- Laboratorio de Función y Patología Neuronal, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Matías Lira
- Laboratorio de Función y Patología Neuronal, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Waldo Cerpa
- Laboratorio de Función y Patología Neuronal, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Excelencia en Biomedicina de Magallanes (CEBIMA), Universidad de Magallanes, Punta Arenas, Chile
| |
Collapse
|
12
|
Li C, Xie Z, Xing Z, Zhu H, Zhou W, Xie S, Zhang Z, Li MH. The Notch Signaling Pathway Regulates Differentiation of NG2 Cells into Oligodendrocytes in Demyelinating Diseases. Cell Mol Neurobiol 2021; 42:1-11. [PMID: 33826017 DOI: 10.1007/s10571-021-01089-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 03/29/2021] [Indexed: 12/13/2022]
Abstract
NG2 cells are highly proliferative glial cells that can self-renew or differentiate into oligodendrocytes, promoting remyelination. Following demyelination, the proliferative and differentiation potentials of NG2 cells increase rapidly, enhancing their differentiation into functional myelinating cells. Levels of the transcription factors Olig1 and Olig2 increase during the differentiation of NG2 cells and play important roles in the development and repair of oligodendrocytes. However, the ability to generate new oligodendrocytes is hampered by injury-related factors (e.g., myelin fragments, Wnt and Notch signaling components), leading to failed differentiation and maturation of NG2 cells into oligodendrocytes. Here, we review Notch signaling as a negative regulator of oligodendrocyte differentiation and discuss the extracellular ligands, intracellular pathways, and key transcription factors involved.
Collapse
Affiliation(s)
- Chengcai Li
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, No. 17 Yongwai Zheng Street, Nanchang, 330006, Jiangxi, People's Republic of China
| | - Zhiping Xie
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, No. 17 Yongwai Zheng Street, Nanchang, 330006, Jiangxi, People's Republic of China
| | - Zelong Xing
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, No. 17 Yongwai Zheng Street, Nanchang, 330006, Jiangxi, People's Republic of China
| | - Huaxin Zhu
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, No. 17 Yongwai Zheng Street, Nanchang, 330006, Jiangxi, People's Republic of China
| | - Wu Zhou
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, No. 17 Yongwai Zheng Street, Nanchang, 330006, Jiangxi, People's Republic of China
| | - Shenke Xie
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, No. 17 Yongwai Zheng Street, Nanchang, 330006, Jiangxi, People's Republic of China
| | - Zhixiong Zhang
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, No. 17 Yongwai Zheng Street, Nanchang, 330006, Jiangxi, People's Republic of China
| | - Mei-Hua Li
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, No. 17 Yongwai Zheng Street, Nanchang, 330006, Jiangxi, People's Republic of China.
| |
Collapse
|