51
|
Hillen AEJ, Burbach JPH, Hol EM. Cell adhesion and matricellular support by astrocytes of the tripartite synapse. Prog Neurobiol 2018; 165-167:66-86. [PMID: 29444459 DOI: 10.1016/j.pneurobio.2018.02.002] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 07/25/2017] [Accepted: 02/07/2018] [Indexed: 12/18/2022]
Abstract
Astrocytes contribute to the formation, function, and plasticity of synapses. Their processes enwrap the neuronal components of the tripartite synapse, and due to this close interaction they are perfectly positioned to modulate neuronal communication. The interaction between astrocytes and synapses is facilitated by cell adhesion molecules and matricellular proteins, which have been implicated in the formation and functioning of tripartite synapses. The importance of such neuron-astrocyte integration at the synapse is underscored by the emerging role of astrocyte dysfunction in synaptic pathologies such as autism and schizophrenia. Here we review astrocyte-expressed cell adhesion molecules and matricellular molecules that play a role in integration of neurons and astrocytes within the tripartite synapse.
Collapse
Affiliation(s)
- Anne E J Hillen
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands; Department of Pediatrics/Child Neurology, VU University Medical Center, 1081 HV Amsterdam, The Netherlands
| | - J Peter H Burbach
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands
| | - Elly M Hol
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands; Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, 1098 XH Amsterdam, The Netherlands; Department of Neuroimmunology, Netherlands Institute for Neuroscience, An Institute of the Royal Netherlands Academy of Arts and Sciences, 1105 BA Amsterdam, The Netherlands.
| |
Collapse
|
52
|
Thurm A, Powell EM, Neul JL, Wagner A, Zwaigenbaum L. Loss of skills and onset patterns in neurodevelopmental disorders: Understanding the neurobiological mechanisms. Autism Res 2018; 11:212-222. [PMID: 29226600 PMCID: PMC5825269 DOI: 10.1002/aur.1903] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 11/19/2017] [Accepted: 11/25/2017] [Indexed: 12/15/2022]
Abstract
Patterns of onset in Autism Spectrum Disorder, including a pattern that includes loss of previously acquired skills, have been identified since the first reports of the disorder. However, attempts to study such "regression" have been limited to clinical studies, that until recently mostly involved retrospective reports. The current report reflects discussion that occurred at an NIMH convened meeting in 2016 with the purpose of bridging clinical autism research with basic and translational work in this area. This summary describes the state of the field with respect to clinical studies, describing gaps in knowledge based on limited methods and prospective data collected. Biological mechanisms that have been shown to account for regression early in development in specific conditions are discussed, as well as potential mechanisms that have not yet been explored. Suggestions include use of model systems during the developmental period and cutting-edge methods, including non-invasive imaging that may afford opportunities for a better understanding of the neurobiological pathways that result in loss of previously-attained skills. Autism Res 2018, 11: 212-222. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY Loss of previously acquired skills, or regression, has been reported in Autism Spectrum Disorder since Kanner's reports in the 1950's. The current report reflects discussion from an NIMH convened meeting in 2016 with the purpose of bridging clinical autism research with basic and translational work in this area. This summary describes the state of the field regarding clinical studies and suggests use of model systems during the developmental period and cutting-edge methods, for a better understanding of the neurobiological pathways that result in loss of previously-attained skills.
Collapse
Affiliation(s)
- Audrey Thurm
- Office of the Clinical Director, National Institute of Mental Health, National Institute of Health, Bethesda, Maryland, USA
| | - Elizabeth M. Powell
- Division of Neuroscience and Behavior, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA
| | - Jeffrey L. Neul
- Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Ann Wagner
- Division of Translational Research, National Institute of Mental Health, National Institute of Health, Bethesda, Maryland, USA
| | - Lonnie Zwaigenbaum
- Autism Research Center, Glenrose Rehabilitation Hospital, Edmonton, Alberta, Canada
| |
Collapse
|
53
|
Lee TT, Skafidas E, Dottori M, Zantomio D, Pantelis C, Everall I, Chana G. No preliminary evidence of differences in astrocyte density within the white matter of the dorsolateral prefrontal cortex in autism. Mol Autism 2017; 8:64. [PMID: 29234492 PMCID: PMC5721546 DOI: 10.1186/s13229-017-0181-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 11/28/2017] [Indexed: 12/27/2022] Open
Abstract
Background While evidence for white matter and astrocytic abnormalities exist in autism, a detailed investigation of astrocytes has not been conducted. Such an investigation is further warranted by an increasing role for neuroinflammation in autism pathogenesis, with astrocytes being key players in this process. We present the first study of astrocyte density and morphology within the white matter of the dorsolateral prefrontal cortex (DLPFC) in individuals with autism. Methods DLPFC formalin-fixed sections containing white matter from individuals with autism (n = 8, age = 4-51 years) and age-matched controls (n = 7, age = 4-46 years) were immunostained for glial fibrillary acidic protein (GFAP). Density of astrocytes and other glia were estimated via the optical fractionator, astrocyte somal size estimated via the nucleator, and astrocyte process length via the spaceballs probe. Results We found no evidence for alteration in astrocyte density within DLPFC white matter of individuals with autism versus controls, together with no differences in astrocyte somal size and process length. Conclusion Our results suggest that astrocyte abnormalities within the white matter in the DLPFC in autism may be less pronounced than previously thought. However, astrocytic dysregulation may still exist in autism, even in the absence of gross morphological changes. Our lack of evidence for astrocyte abnormalities could have been confounded to an extent by having a small sample size and wide age range, with pathological features potentially restricted to early stages of autism. Nonetheless, future investigations would benefit from assessing functional markers of astrocytes in light of the underlying pathophysiology of autism.
Collapse
Affiliation(s)
- Ting Ting Lee
- Department of Psychiatry, The University of Melbourne, Parkville, Australia.,Centre for Neural Engineering, The University of Melbourne, Parkville, Australia
| | - Efstratios Skafidas
- Department of Psychiatry, The University of Melbourne, Parkville, Australia.,Centre for Neural Engineering, The University of Melbourne, Parkville, Australia.,Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Australia
| | - Mirella Dottori
- Centre for Neural Engineering, The University of Melbourne, Parkville, Australia.,Department of Biomedical Engineering, The University of Melbourne, Parkville, Australia.,Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, Australia
| | - Daniela Zantomio
- Department of Clinical Haematology, Austin Hospital, Heidelberg, Australia
| | - Christos Pantelis
- Department of Psychiatry, The University of Melbourne, Parkville, Australia.,Centre for Neural Engineering, The University of Melbourne, Parkville, Australia.,Melbourne Neuropsychiatry Centre, The University of Melbourne & Melbourne Health, Parkville, Australia.,Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Australia
| | - Ian Everall
- Department of Psychiatry, The University of Melbourne, Parkville, Australia.,Centre for Neural Engineering, The University of Melbourne, Parkville, Australia.,Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Australia.,The Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Gursharan Chana
- Department of Psychiatry, The University of Melbourne, Parkville, Australia.,Centre for Neural Engineering, The University of Melbourne, Parkville, Australia.,Department of Medicine, The University of Melbourne, Parkville, Australia.,Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Australia
| |
Collapse
|
54
|
Zhao D, Lin M, Pedrosa E, Lachman HM, Zheng D. Characteristics of allelic gene expression in human brain cells from single-cell RNA-seq data analysis. BMC Genomics 2017; 18:860. [PMID: 29126398 PMCID: PMC5681780 DOI: 10.1186/s12864-017-4261-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 11/01/2017] [Indexed: 12/24/2022] Open
Abstract
Background Monoallelic expression of autosomal genes has been implicated in human psychiatric disorders. However, there is a paucity of allelic expression studies in human brain cells at the single cell and genome wide levels. Results In this report, we reanalyzed a previously published single-cell RNA-seq dataset from several postmortem human brains and observed pervasive monoallelic expression in individual cells, largely in a random manner. Examining single nucleotide variants with a predicted functional disruption, we found that the “damaged” alleles were overall expressed in fewer brain cells than their counterparts, and at a lower level in cells where their expression was detected. We also identified many brain cell type-specific monoallelically expressed genes. Interestingly, many of these cell type-specific monoallelically expressed genes were enriched for functions important for those brain cell types. In addition, function analysis showed that genes displaying monoallelic expression and correlated expression across neuronal cells from different individual brains were implicated in the regulation of synaptic function. Conclusions Our findings suggest that monoallelic gene expression is prevalent in human brain cells, which may play a role in generating cellular identity and neuronal diversity and thus increasing the complexity and diversity of brain cell functions. Electronic supplementary material The online version of this article (10.1186/s12864-017-4261-x) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Dejian Zhao
- Department of Neurology, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY, USA.,Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY, USA
| | - Mingyan Lin
- Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY, USA.,Present address: Department of Neuroscience, School of Basic Medical Science, Nanjing Medical University, Nanjing, Jiangsu, 21166, China
| | - Erika Pedrosa
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY, USA
| | - Herbert M Lachman
- Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY, USA.,Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY, USA.,Department of Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY, USA.,Department of Medicine, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY, USA
| | - Deyou Zheng
- Department of Neurology, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY, USA. .,Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY, USA. .,Department of Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY, USA.
| |
Collapse
|
55
|
Sarrouilhe D, Dejean C, Mesnil M. Connexin43- and Pannexin-Based Channels in Neuroinflammation and Cerebral Neuropathies. Front Mol Neurosci 2017; 10:320. [PMID: 29066951 PMCID: PMC5641369 DOI: 10.3389/fnmol.2017.00320] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 09/20/2017] [Indexed: 12/19/2022] Open
Abstract
Connexins (Cx) are largely represented in the central nervous system (CNS) with 11 Cx isoforms forming intercellular channels. Moreover, in the CNS, Cx43 can form hemichannels (HCs) at non-junctional membrane as does the related channel-forming Pannexin1 (Panx1) and Panx2. Opening of Panx1 channels and Cx43 HCs appears to be involved in inflammation and has been documented in various CNS pathologies. Over recent years, evidence has accumulated supporting a link between inflammation and cerebral neuropathies (migraine, Alzheimer’s disease (AD), Parkinson’s disease (PD), major depressive disorder, autism spectrum disorder (ASD), epilepsy, schizophrenia, bipolar disorder). Involvement of Panx channels and Cx43 HCs has been also proposed in pathophysiology of neurological diseases and psychiatric disorders. Other studies showed that following inflammatory injury of the CNS, Panx1 activators are released and prolonged opening of Panx1 channels triggers neuronal death. In neuropsychiatric diseases, comorbidities are frequently present and can aggravate the symptoms and make therapeutic management more complex. The high comorbidity between some neuropathies can be partially understood by the fact that these diseases share a common etiology involving inflammatory pathways and Panx1 channels or Cx43 HCs. Thus, anti-inflammatory therapy opens perspectives of targets for new treatments and could have real potential in controlling a cerebral neuropathy and some of its comorbidities. The purpose of this mini review is to provide information of our knowledge on the link between Cx43- and Panx-based channels, inflammation and cerebral neuropathies.
Collapse
Affiliation(s)
- Denis Sarrouilhe
- Laboratoire de Physiologie Humaine, Faculté de Médecine et Pharmacie, Université de Poitiers, Poitiers, France
| | - Catherine Dejean
- Service Pharmacie, Pavillon Janet, Centre Hospitalier Henri Laborit, Poitiers, France
| | - Marc Mesnil
- STIM Laboratory, ERL 7368-CNRS, Université de Poitiers, Pôle Biologie Santé, Poitiers, France
| |
Collapse
|
56
|
Charvériat M, Naus CC, Leybaert L, Sáez JC, Giaume C. Connexin-Dependent Neuroglial Networking as a New Therapeutic Target. Front Cell Neurosci 2017; 11:174. [PMID: 28694772 PMCID: PMC5483454 DOI: 10.3389/fncel.2017.00174] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2017] [Accepted: 06/08/2017] [Indexed: 12/12/2022] Open
Abstract
Astrocytes and neurons dynamically interact during physiological processes, and it is now widely accepted that they are both organized in plastic and tightly regulated networks. Astrocytes are connected through connexin-based gap junction channels, with brain region specificities, and those networks modulate neuronal activities, such as those involved in sleep-wake cycle, cognitive, or sensory functions. Additionally, astrocyte domains have been involved in neurogenesis and neuronal differentiation during development; they participate in the “tripartite synapse” with both pre-synaptic and post-synaptic neurons by tuning down or up neuronal activities through the control of neuronal synaptic strength. Connexin-based hemichannels are also involved in those regulations of neuronal activities, however, this feature will not be considered in the present review. Furthermore, neuronal processes, transmitting electrical signals to chemical synapses, stringently control astroglial connexin expression, and channel functions. Long-range energy trafficking toward neurons through connexin-coupled astrocytes and plasticity of those networks are hence largely dependent on neuronal activity. Such reciprocal interactions between neurons and astrocyte networks involve neurotransmitters, cytokines, endogenous lipids, and peptides released by neurons but also other brain cell types, including microglial and endothelial cells. Over the past 10 years, knowledge about neuroglial interactions has widened and now includes effects of CNS-targeting drugs such as antidepressants, antipsychotics, psychostimulants, or sedatives drugs as potential modulators of connexin function and thus astrocyte networking activity. In physiological situations, neuroglial networking is consequently resulting from a two-way interaction between astrocyte gap junction-mediated networks and those made by neurons. As both cell types are modulated by CNS drugs we postulate that neuroglial networking may emerge as new therapeutic targets in neurological and psychiatric disorders.
Collapse
Affiliation(s)
| | - Christian C Naus
- Department of Cellular and Physiological Science, Life Science Institute, University of British ColumbiaVancouver, BC, Canada
| | - Luc Leybaert
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent UniversityGhent, Belgium
| | - Juan C Sáez
- Departamento de Fisiología, Pontificia Universidad Católica de ChileSantiago, Chile.,Centro Interdisciplinario de Neurociencias de Valparaíso, Instituto MilenioValparaíso, Chile
| | - Christian Giaume
- Center of Interdisciplinary Research in Biology, Collège de FranceParis, France
| |
Collapse
|
57
|
Hattori T, Kaji M, Ishii H, Jureepon R, Takarada-Iemata M, Minh Ta H, Manh Le T, Konno A, Hirai H, Shiraishi Y, Ozaki N, Yamamoto Y, Okamoto H, Yokoyama S, Higashida H, Kitao Y, Hori O. CD38 positively regulates postnatal development of astrocytes cell-autonomously and oligodendrocytes non-cell-autonomously. Glia 2017; 65:974-989. [PMID: 28295574 DOI: 10.1002/glia.23139] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Revised: 02/20/2017] [Accepted: 02/20/2017] [Indexed: 12/11/2022]
Abstract
Glial development is critical for the function of the central nervous system. CD38 is a multifunctional molecule with ADP-ribosyl cyclase activity. While critical roles of CD38 in the adult brain such as oxytocin release and social behavior have been reported, those in the developing brain remain largely unknown. Here we demonstrate that deletion of Cd38 leads to impaired development of astrocytes and oligodendrocytes in mice. CD38 is highly expressed in the developing brains between postnatal day 14 (P14) and day 28 (P28). In situ hybridization and FACS analysis revealed that CD38 is expressed predominantly in astrocytes in these periods. Analyses of the cortex of Cd38 knockout (Cd38-/- ) mice revealed delayed development of astrocytes and subsequently delayed differentiation of oligodendrocytes (OLs) at postnatal stages. In vitro experiments using primary OL cultures, mixed glial cultures, and astrocytic conditioned medium showed that astrocytic CD38 regulates the development of astrocytes in a cell-autonomous manner and the differentiation of OLs in a non-cell-autonomous manner. Further experiments revealed that connexin43 (Cx43) in astrocytes plays a promotive role for CD38-mediated OL differentiation. Finally, increased levels of NAD+ , caused by CD38 deficiency, are likely to be responsible for the suppression of astrocytic Cx43 expression and OL differentiation. Our data indicate that CD38 is a positive regulator of astrocyte and OL development.
Collapse
Affiliation(s)
- Tsuyoshi Hattori
- Department of Neuroanatomy, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Minoru Kaji
- Department of Neuroanatomy, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Hiroshi Ishii
- Department of Neuroanatomy, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Roboon Jureepon
- Department of Neuroanatomy, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Mika Takarada-Iemata
- Department of Neuroanatomy, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Hieu Minh Ta
- Department of Neuroanatomy, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Thuong Manh Le
- Department of Neuroanatomy, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Ayumu Konno
- Department of Neurophysiology and Neural Repair, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Hirokazu Hirai
- Department of Neurophysiology and Neural Repair, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Yoshitake Shiraishi
- Department of Functional Anatomy, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Noriyuki Ozaki
- Department of Functional Anatomy, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Yasuhiko Yamamoto
- Department of Biochemistry and Molecular Vascular Biology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Hiroshi Okamoto
- Department of Biochemistry and Molecular Vascular Biology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan.,Department of Biochemistry, Tohoku University, Graduate School of Medicine, Sendai, Miyagi, Japan
| | - Shigeru Yokoyama
- Department of Basic Research on Social Recognition and Memory, Research Center for Child Mental Development, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Haruhiro Higashida
- Department of Basic Research on Social Recognition and Memory, Research Center for Child Mental Development, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Yasuko Kitao
- Department of Neuroanatomy, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Osamu Hori
- Department of Neuroanatomy, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| |
Collapse
|
58
|
Mony TJ, Lee JW, Dreyfus C, DiCicco-Bloom E, Lee HJ. Valproic Acid Exposure during Early Postnatal Gliogenesis Leads to Autistic-like Behaviors in Rats. CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE 2016; 14:338-344. [PMID: 27776385 PMCID: PMC5083944 DOI: 10.9758/cpn.2016.14.4.338] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 05/11/2016] [Accepted: 05/14/2016] [Indexed: 11/18/2022]
Abstract
Objective We reported that postnatal exposure of rats to valproic acid (VPA) stimulated proliferation of glial precursors during cortical gliogenesis. However, there are no reports whether enhanced postnatal gliogenesis affects behaviors related to neuropsychiatric disorders. Methods After VPA treatment during the postnatal day (PND) 2 to PND 4, four behavioral test, such as open field locomotor test, elevated plus maze test, three-chamber social interaction test, and passive avoidance test, were performed at PND 21 or 22. Results VPA treated rats showed significant hyperactive behavior in the open field locomotor test (p<0.05). Moreover, the velocity of movement in the VPA group was increased by 69.5% (p<0.01). In the elevated plus maze test, VPA exposed rats expressed significantly lower percentage of time spent on and of entries into open arms more than the control group (p<0.05). Also, both sociability and social preference indices with strangers in the three-chamber social interaction test were significantly lower in the VPA exposed rats (p<0.05). Conclusion Our results suggest that altered glial cell development is another locus at which pathogenetic factors can operate to contribute to the neurodevelopmental disorder.
Collapse
Affiliation(s)
- Tamanna Jahan Mony
- Department of Pharmacology, Kangwon National University School of Medicine, Chuncheon, Korea
| | - Jae Won Lee
- Department of Pharmacology, Kangwon National University School of Medicine, Chuncheon, Korea.,Natural Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju, Korea
| | - Cheryl Dreyfus
- Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, Rutgers, the State University of New Jersey, Piscataway, NJ, USA
| | - Emanuel DiCicco-Bloom
- Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, Rutgers, the State University of New Jersey, Piscataway, NJ, USA.,Department of Pediatrics, Rutgers Robert Wood Johnson Medical School, Rutgers, the State University of New Jersey, New Brunswick, NJ, USA
| | - Hee Jae Lee
- Department of Pharmacology, Kangwon National University School of Medicine, Chuncheon, Korea
| |
Collapse
|
59
|
Chandrasekaran A, Avci HX, Leist M, Kobolák J, Dinnyés A. Astrocyte Differentiation of Human Pluripotent Stem Cells: New Tools for Neurological Disorder Research. Front Cell Neurosci 2016; 10:215. [PMID: 27725795 PMCID: PMC5035736 DOI: 10.3389/fncel.2016.00215] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 08/30/2016] [Indexed: 12/22/2022] Open
Abstract
Astrocytes have a central role in brain development and function, and so have gained increasing attention over the past two decades. Consequently, our knowledge about their origin, differentiation and function has increased significantly, with new research showing that astrocytes cultured alone or co-cultured with neurons have the potential to improve our understanding of various central nervous system diseases, such as amyotrophic lateral sclerosis, Alzheimer’s disease, or Alexander disease. The generation of astrocytes derived from pluripotent stem cells (PSCs) opens up a new area for studying neurologic diseases in vitro; these models could be exploited to identify and validate potential drugs by detecting adverse effects in the early stages of drug development. However, as it is now known that a range of astrocyte populations exist in the brain, it will be important in vitro to develop standardized protocols for the in vitro generation of astrocyte subsets with defined maturity status and phenotypic properties. This will then open new possibilities for co-cultures with neurons and the generation of neural organoids for research purposes. The aim of this review article is to compare and summarize the currently available protocols and their strategies to generate human astrocytes from PSCs. Furthermore, we discuss the potential role of human-induced PSCs derived astrocytes in disease modeling.
Collapse
Affiliation(s)
| | - Hasan X Avci
- BioTalentum LtdGödöllő, Hungary; Department of Medical Chemistry, University of SzegedSzeged, Hungary
| | - Marcel Leist
- Dorenkamp-Zbinden Chair, Faculty of Mathematics and Sciences, University of Konstanz Konstanz, Germany
| | | | - Andras Dinnyés
- BioTalentum LtdGödöllő, Hungary; Molecular Animal Biotechnology Laboratory, Szent Istvan UniversityGödöllő, Hungary
| |
Collapse
|
60
|
Kern JK, Geier DA, Sykes LK, Haley BE, Geier MR. The relationship between mercury and autism: A comprehensive review and discussion. J Trace Elem Med Biol 2016; 37:8-24. [PMID: 27473827 DOI: 10.1016/j.jtemb.2016.06.002] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 05/17/2016] [Accepted: 06/01/2016] [Indexed: 12/28/2022]
Abstract
The brain pathology in autism spectrum disorders (ASD) indicates marked and ongoing inflammatory reactivity with concomitant neuronal damage. These findings are suggestive of neuronal insult as a result of external factors, rather than some type of developmental mishap. Various xenobiotics have been suggested as possible causes of this pathology. In a recent review, the top ten environmental compounds suspected of causing autism and learning disabilities were listed and they included: lead, methyl-mercury, polychorinated biphenyls, organophosphate pesticides, organochlorine pesticides, endocrine disruptors, automotive exhaust, polycyclic aromatic hydrocarbons, polybrominated diphenyl ethers, and perfluorinated compounds. This current review, however, will focus specifically on mercury exposure and ASD by conducting a comprehensive literature search of original studies in humans that examine the potential relationship between mercury and ASD, categorizing, summarizing, and discussing the published research that addresses this topic. This review found 91 studies that examine the potential relationship between mercury and ASD from 1999 to February 2016. Of these studies, the vast majority (74%) suggest that mercury is a risk factor for ASD, revealing both direct and indirect effects. The preponderance of the evidence indicates that mercury exposure is causal and/or contributory in ASD.
Collapse
Affiliation(s)
- Janet K Kern
- Institute of Chronic Illnesses, Inc., 14 Redgate Court, Silver Spring, MD, 20905 USA; Council for Nutritional and Environmental Medicine, Mo i Rana, Norway; CoMeD, Inc., 14 Redgate Court, Silver Spring, MD, 20905 USA.
| | - David A Geier
- Institute of Chronic Illnesses, Inc., 14 Redgate Court, Silver Spring, MD, 20905 USA; CoMeD, Inc., 14 Redgate Court, Silver Spring, MD, 20905 USA
| | - Lisa K Sykes
- CoMeD, Inc., 14 Redgate Court, Silver Spring, MD, 20905 USA
| | - Boyd E Haley
- University of Kentucky, 410 Administration Drive, Lexington, KY, 40506 USA
| | - Mark R Geier
- Institute of Chronic Illnesses, Inc., 14 Redgate Court, Silver Spring, MD, 20905 USA; CoMeD, Inc., 14 Redgate Court, Silver Spring, MD, 20905 USA
| |
Collapse
|
61
|
Verkhratsky A, Steardo L, Parpura V, Montana V. Translational potential of astrocytes in brain disorders. Prog Neurobiol 2016; 144:188-205. [PMID: 26386136 PMCID: PMC4794425 DOI: 10.1016/j.pneurobio.2015.09.003] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 09/03/2015] [Accepted: 09/08/2015] [Indexed: 12/11/2022]
Abstract
Fundamentally, all brain disorders can be broadly defined as the homeostatic failure of this organ. As the brain is composed of many different cells types, including but not limited to neurons and glia, it is only logical that all the cell types/constituents could play a role in health and disease. Yet, for a long time the sole conceptualization of brain pathology was focused on the well-being of neurons. Here, we challenge this neuron-centric view and present neuroglia as a key element in neuropathology, a process that has a toll on astrocytes, which undergo complex morpho-functional changes that can in turn affect the course of the disorder. Such changes can be grossly identified as reactivity, atrophy with loss of function and pathological remodeling. We outline the pathogenic potential of astrocytes in variety of disorders, ranging from neurotrauma, infection, toxic damage, stroke, epilepsy, neurodevelopmental, neurodegenerative and psychiatric disorders, Alexander disease to neoplastic changes seen in gliomas. We hope that in near future we would witness glial-based translational medicine with generation of deliverables for the containment and cure of disorders. We point out that such as a task will require a holistic and multi-disciplinary approach that will take in consideration the concerted operation of all the cell types in the brain.
Collapse
Affiliation(s)
- Alexei Verkhratsky
- Faculty of Life Science, The University of Manchester, Manchester, UK
- Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
- University of Nizhny Novgorod, Nizhny Novgorod, Russia
| | - Luca Steardo
- Department of Psychiatry, University of Naples, SUN, Largo Madonna delle Grazie, Naples, Italy
| | - Vladimir Parpura
- Department of Neurobiology, Center for Glial Biology in Medicine and Atomic Force Microscopy & Nanotechnology Laboratories, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Vedrana Montana
- Department of Biotechnology, University of Rijeka, Rijeka, Croatia
| |
Collapse
|
62
|
Yang X, Ransom BR, Ma JF. The role of AQP4 in neuromyelitis optica: More answers, more questions. J Neuroimmunol 2016; 298:63-70. [DOI: 10.1016/j.jneuroim.2016.06.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 05/30/2016] [Accepted: 06/06/2016] [Indexed: 12/14/2022]
|
63
|
Boulay AC, Cisternino S, Cohen-Salmon M. Immunoregulation at the gliovascular unit in the healthy brain: A focus on Connexin 43. Brain Behav Immun 2016; 56:1-9. [PMID: 26674996 DOI: 10.1016/j.bbi.2015.11.017] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 10/26/2015] [Accepted: 11/28/2015] [Indexed: 01/18/2023] Open
Abstract
In the brain, immune cell infiltration is normally kept at a very low level and a unique microenvironment strictly restricts immune reactions and inflammation. Even in such quiescent environment, a constant immune surveillance is at work allowing the brain to rapidly react to threats. To date, knowledge about the factors regulating the brain-immune system interrelationship in healthy conditions remains elusive. Interestingly, astrocytes, the most abundant glial cells in the brain, may participate in many aspects of this unique homeostasis, in particular due to their close interaction with the brain vascular system and expression of a specific molecular repertoire. Indeed, astrocytes maintain the blood-brain barrier (BBB) integrity, interact with immune cells, and participate in the regulation of intracerebral liquid movements. We recently showed that Connexin 43 (Cx43), a gap junction protein highly expressed by astrocytes at the BBB interface, is an immunoregulating factor. The absence of astroglial Cx43 leads to a transient endothelial activation, a continuous immune recruitment as well as the development of a specific humoral autoimmune response against the von Willebrand factor A domain-containing protein 5a, an extracellular matrix protein expressed by astrocytes. In this review, we propose to gather current knowledge on how astrocytes may influence the immune system in the healthy brain, focusing on their roles at the gliovascular interface. We will also consider pathological situations involving astrocyte-specific autoimmunities. Finally, we will discuss the specific role of astroglial Cx43 and the physiological consequences of immune regulations taking place on inflammation, cognition and behavior in the absence of Cx43.
Collapse
Affiliation(s)
- Anne-Cécile Boulay
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB), Centre National de la Recherche Scientifique CNRS, Unité Mixte de Recherche 7241, Institut National de la Santé et de la Recherche Médicale INSERM, U1050, Neuroglial Interactions in Cerebral Physiopathology, 75231 Paris Cedex 05, France; University Pierre et Marie Curie, ED, N°158, 75005 Paris, France; MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, 75005 Paris, France
| | - Salvatore Cisternino
- Variabilité de réponse aux psychotropes, INSERM, U1144, Paris F-75006, France; Université Paris Descartes, Faculté de Pharmacie, UMR-S 1144, 75006 Paris, France; Université Paris Diderot, UMR-S 1144, 75013 Paris, France
| | - Martine Cohen-Salmon
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB), Centre National de la Recherche Scientifique CNRS, Unité Mixte de Recherche 7241, Institut National de la Santé et de la Recherche Médicale INSERM, U1050, Neuroglial Interactions in Cerebral Physiopathology, 75231 Paris Cedex 05, France; University Pierre et Marie Curie, ED, N°158, 75005 Paris, France; MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, 75005 Paris, France.
| |
Collapse
|
64
|
Petrelli F, Pucci L, Bezzi P. Astrocytes and Microglia and Their Potential Link with Autism Spectrum Disorders. Front Cell Neurosci 2016; 10:21. [PMID: 26903806 PMCID: PMC4751265 DOI: 10.3389/fncel.2016.00021] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 01/19/2016] [Indexed: 01/09/2023] Open
Abstract
The cellular mechanism(s) underlying autism spectrum disorders (ASDs) are not fully understood although it has been shown that various genetic and environmental factors contribute to their etiology. As increasing evidence indicates that astrocytes and microglial cells play a major role in synapse maturation and function, and there is evidence of deficits in glial cell functions in ASDs, one current hypothesis is that glial dysfunctions directly contribute to their pathophysiology. The aim of this review is to summarize microglia and astrocyte functions in synapse development and their contributions to ASDs.
Collapse
Affiliation(s)
| | | | - Paola Bezzi
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| |
Collapse
|
65
|
Chrobak AA, Soltys Z. Bergmann Glia, Long-Term Depression, and Autism Spectrum Disorder. Mol Neurobiol 2016; 54:1156-1166. [PMID: 26809583 PMCID: PMC5310553 DOI: 10.1007/s12035-016-9719-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 01/12/2016] [Indexed: 12/22/2022]
Abstract
Bergmann glia (BG), a specific type of radial astrocytes in the cerebellum, play a variety of vital functions in the development of this structure. However, the possible role of BG in the development of abnormalities observed in individuals with autism spectrum disorder (ASD) seems to be underestimated. One of the most consistent findings observed in ASD patients is loss of Purkinje cells (PCs). Such a defect may be caused by dysregulation of glutamate homeostasis, which is maintained mainly by BG. Moreover, these glial cells are involved in long-term depression (LTD), a form of plasticity which can additionally subserve neuroprotective functions. The aim of presented review is to summarize the current knowledge about interactions which occur between PC and BG, with special emphasis on those which are relevant to the survival and proper functioning of cerebellar neurons.
Collapse
Affiliation(s)
- Adrian Andrzej Chrobak
- Department of Neuroanatomy, Institute of Zoology, Jagiellonian University, Gronostajowa St. 9, Cracow, 30-387, Poland. .,Faculty of Medicine, Jagiellonian University Medical College, Kopernika St. 21A, Cracow, 31-501, Poland.
| | - Zbigniew Soltys
- Department of Neuroanatomy, Institute of Zoology, Jagiellonian University, Gronostajowa St. 9, Cracow, 30-387, Poland
| |
Collapse
|
66
|
Kern JK, Geier DA, Sykes LK, Geier MR. Relevance of Neuroinflammation and Encephalitis in Autism. Front Cell Neurosci 2016; 9:519. [PMID: 26834565 PMCID: PMC4717322 DOI: 10.3389/fncel.2015.00519] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2015] [Accepted: 12/24/2015] [Indexed: 12/12/2022] Open
Abstract
In recent years, many studies indicate that children with an autism spectrum disorder (ASD) diagnosis have brain pathology suggestive of ongoing neuroinflammation or encephalitis in different regions of their brains. Evidence of neuroinflammation or encephalitis in ASD includes: microglial and astrocytic activation, a unique and elevated proinflammatory profile of cytokines, and aberrant expression of nuclear factor kappa-light-chain-enhancer of activated B cells. A conservative estimate based on the research suggests that at least 69% of individuals with an ASD diagnosis have microglial activation or neuroinflammation. Encephalitis, which is defined as inflammation of the brain, is medical diagnosis code G04.90 in the International Classification of Disease, 10th revision; however, children with an ASD diagnosis are not generally assessed for a possible medical diagnosis of encephalitis. This is unfortunate because if a child with ASD has neuroinflammation, then treating the underlying brain inflammation could lead to improved outcomes. The purpose of this review of the literature is to examine the evidence of neuroinflammation/encephalitis in those with an ASD diagnosis and to address how a medical diagnosis of encephalitis, when appropriate, could benefit these children by driving more immediate and targeted treatments.
Collapse
Affiliation(s)
- Janet K. Kern
- Institute of Chronic Illnesses, Inc., Silver SpringMD, USA
| | - David A. Geier
- Institute of Chronic Illnesses, Inc., Silver SpringMD, USA
| | | | - Mark R. Geier
- Institute of Chronic Illnesses, Inc., Silver SpringMD, USA
| |
Collapse
|
67
|
Jeanson T, Pondaven A, Ezan P, Mouthon F, Charvériat M, Giaume C. Antidepressants Impact Connexin 43 Channel Functions in Astrocytes. Front Cell Neurosci 2016; 9:495. [PMID: 26778961 PMCID: PMC4703821 DOI: 10.3389/fncel.2015.00495] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 12/09/2015] [Indexed: 12/20/2022] Open
Abstract
Glial cells, and in particular astrocytes, are crucial to maintain neuronal microenvironment by regulating energy metabolism, neurotransmitter uptake, gliotransmission, and synaptic development. Moreover, a typical feature of astrocytes is their high expression level of connexins, a family of membrane proteins that form gap junction channels allowing intercellular exchanges and hemichannels that provide release and uptake pathways for neuroactive molecules. Interestingly, several studies have revealed unexpected changes in astrocytes from depressive patients and rodent models of depressive-like behavior. Moreover, changes in the expression level of the astroglial connexin 43 (Cx43) have been reported in a depressive context. On the other hand, antidepressive drugs have also been shown to impact the expression of this connexin in astrocytes. However, so far there is little information concerning the functional consequence of these changes, i.e., the status of gap junctional communication and hemichannel activity in astrocytes exposed to antidepressants. In the present work we focused our attention on the action of seven antidepressants from four different therapeutic classes and tested their effects on Cx43 expression and on the two connexin-based channels functions studied in cultured astrocytes. We here report that when used at non-toxic and clinically relevant concentrations they have no effects on Cx43 expression but differential effects on Cx43 gap junction channels. Moreover, all tested antidepressants inhibit Cx43 hemichannel with different efficiency depending on their therapeutic classe. By studying the impact of antidepressants on the functional status of astroglial connexin channels, contributing to dynamic neuroglial interactions, our observations should help to better understand the mechanism by which these drugs provide their effect in the brain.
Collapse
Affiliation(s)
- Tiffany Jeanson
- Collège de France, Center for Interdisciplinary Research in Biology/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050Paris, France; University Pierre et Marie CurieParis, France; MemoLife Laboratory of Excellence and Paris Science Lettre Research UniversityParis, France; TheranexusLyon, France
| | - Audrey Pondaven
- Collège de France, Center for Interdisciplinary Research in Biology/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050Paris, France; University Pierre et Marie CurieParis, France; MemoLife Laboratory of Excellence and Paris Science Lettre Research UniversityParis, France
| | - Pascal Ezan
- Collège de France, Center for Interdisciplinary Research in Biology/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050Paris, France; University Pierre et Marie CurieParis, France; MemoLife Laboratory of Excellence and Paris Science Lettre Research UniversityParis, France
| | | | | | - Christian Giaume
- Collège de France, Center for Interdisciplinary Research in Biology/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050Paris, France; University Pierre et Marie CurieParis, France; MemoLife Laboratory of Excellence and Paris Science Lettre Research UniversityParis, France
| |
Collapse
|
68
|
Verkhratsky A, Parpura V. Astrogliopathology in neurological, neurodevelopmental and psychiatric disorders. Neurobiol Dis 2016; 85:254-261. [PMID: 25843667 PMCID: PMC4592688 DOI: 10.1016/j.nbd.2015.03.025] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 03/20/2015] [Accepted: 03/26/2015] [Indexed: 12/17/2022] Open
Abstract
Astroglial cells represent a main element in the maintenance of homeostasis and providing defense to the brain. Consequently, their dysfunction underlies many, if not all, neurological, neurodevelopmental and neuropsychiatric disorders. General astrogliopathy is evident in diametrically opposing morpho-functional changes in astrocytes, i.e. their hypertrophy along with reactivity or atrophy with asthenia. Neurological disorders with astroglial participation can be genetic, of which Alexander disease is a primary sporadic astrogliopathy, environmentally caused, such as heavy metal encephalopathies, or neurodevelopmental in origin. Astroglia contribute to neurodegenerative processes seen in amyotrophic lateral sclerosis, Alzheimer's and Huntington's diseases. Furthermore, astroglia also play a role in major neuropsychiatric disorders, ranging from schizophrenia to depression, as well as in addictive disorders.
Collapse
Affiliation(s)
- Alexei Verkhratsky
- Faculty of Life Sciences, The University of Manchester, Manchester M13 9PT, UK; Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain; Department of Neurosciences, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain.
| | - Vladimir Parpura
- Department of Neurobiology, Civitan International Research Center and Center for Glial Biology in Medicine, Evelyn F. McKnight Brain Institute, Atomic Force Microscopy & Nanotechnology Laboratories, University of Alabama at Birmingham, 1719 6th Avenue South, CIRC 429, Birmingham, AL 35294-0021, USA; Department of Biotechnology, University of Rijeka, Radmile Matejčić 2, 51000 Rijeka, Croatia.
| |
Collapse
|
69
|
Durieux AMS, Fernandes C, Murphy D, Labouesse MA, Giovanoli S, Meyer U, Li Q, So PW, McAlonan G. Targeting Glia with N-Acetylcysteine Modulates Brain Glutamate and Behaviors Relevant to Neurodevelopmental Disorders in C57BL/6J Mice. Front Behav Neurosci 2015; 9:343. [PMID: 26696857 PMCID: PMC4677305 DOI: 10.3389/fnbeh.2015.00343] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 11/23/2015] [Indexed: 01/25/2023] Open
Abstract
An imbalance between excitatory (E) glutamate and inhibitory (I) GABA transmission may underlie neurodevelopmental conditions such as autism spectrum disorder (ASD) and schizophrenia. This may be direct, through alterations in synaptic genes, but there is increasing evidence for the importance of indirect modulation of E/I balance through glial mechanisms. Here, we used C57BL/6J mice to test the hypothesis that striatal glutamate levels can be shifted by N-acetylcysteine (NAC), which acts at the cystine-glutamate antiporter of glial cells. Striatal glutamate was quantified in vivo using proton magnetic resonance spectroscopy. The effect of NAC on behaviors relevant to ASD was examined in a separate cohort. NAC induced a time-dependent decrease in striatal glutamate, which recapitulated findings of lower striatal glutamate reported in ASD. NAC-treated animals were significantly less active and more anxious in the open field test; and NAC-treated females had significantly impaired prepulse inhibition of startle response. This at least partly mimics greater anxiety and impaired sensorimotor gating reported in neurodevelopmental disorders. Thus glial mechanisms regulate glutamate acutely and have functional consequences even in adulthood. Glial cells may be a potential drug target for the development of new therapies for neurodevelopmental disorders across the life-span.
Collapse
Affiliation(s)
- Alice M S Durieux
- Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology and Neuroscience, King's College London London, UK
| | - Cathy Fernandes
- Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London London, UK
| | - Declan Murphy
- Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology and Neuroscience, King's College London London, UK
| | - Marie Anais Labouesse
- Physiology and Behaviour Laboratory, Swiss Federal Institute of Technology Schwerzenbach, Switzerland
| | - Sandra Giovanoli
- Physiology and Behaviour Laboratory, Swiss Federal Institute of Technology Schwerzenbach, Switzerland ; Institute of Pharmacology and Toxicology, University of Zurich-Vetsuisse Zurich, Switzerland
| | - Urs Meyer
- Physiology and Behaviour Laboratory, Swiss Federal Institute of Technology Schwerzenbach, Switzerland ; Institute of Pharmacology and Toxicology, University of Zurich-Vetsuisse Zurich, Switzerland
| | - Qi Li
- Department of Psychiatry, Li Ka Shing Faculty of Medicine, The University of Hong Kong Hong Kong, China
| | - Po-Wah So
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London London, UK
| | - Grainne McAlonan
- Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology and Neuroscience, King's College London London, UK
| |
Collapse
|
70
|
Chever O, Pannasch U, Ezan P, Rouach N. Astroglial connexin 43 sustains glutamatergic synaptic efficacy. Philos Trans R Soc Lond B Biol Sci 2015; 369:20130596. [PMID: 25225090 DOI: 10.1098/rstb.2013.0596] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Astrocytes dynamic interactions with neurons play an active role in neurotransmission. The gap junction (GJ) subunits connexins 43 and 30 are strongly expressed in astrocytes and have recently been shown to regulate synaptic activity and plasticity. However, the specific role of connexin 43 in the morphological and electrophysiological properties of astrocytes in situ as well as in synaptic transmission remains unknown. Here, we show that connexin 43, a major determinant of astroglial GJ coupling, regulates astrocyte cell volume, but has no impact on astroglial passive membrane properties. Furthermore, we demonstrate that connexin 43 modulates glutamatergic synaptic activity of hippocampal CA1 pyramidal cells. This regulation involves changes in synaptically released glutamate, with no alteration in neuronal excitability or postsynaptic function. These results reveal connexin 43 as a critical player in neuroglial interactions by supporting synaptic efficacy.
Collapse
Affiliation(s)
- Oana Chever
- Neuroglial Interactions in Cerebral Physiopathology, Center for Interdisciplinary Research in Biology, Collège de France, Centre National de la Recherche Scientifique UMR 7241, Institut National de la Santé et de la Recherche Médicale U1050, Labex Memolife, PSL Research University, 75005 Paris, France
| | - Ulrike Pannasch
- Neuroglial Interactions in Cerebral Physiopathology, Center for Interdisciplinary Research in Biology, Collège de France, Centre National de la Recherche Scientifique UMR 7241, Institut National de la Santé et de la Recherche Médicale U1050, Labex Memolife, PSL Research University, 75005 Paris, France
| | - Pascal Ezan
- Neuroglial Interactions in Cerebral Physiopathology, Center for Interdisciplinary Research in Biology, Collège de France, Centre National de la Recherche Scientifique UMR 7241, Institut National de la Santé et de la Recherche Médicale U1050, Labex Memolife, PSL Research University, 75005 Paris, France
| | - Nathalie Rouach
- Neuroglial Interactions in Cerebral Physiopathology, Center for Interdisciplinary Research in Biology, Collège de France, Centre National de la Recherche Scientifique UMR 7241, Institut National de la Santé et de la Recherche Médicale U1050, Labex Memolife, PSL Research University, 75005 Paris, France
| |
Collapse
|
71
|
Targeted Gene Resequencing (Astrochip) to Explore the Tripartite Synapse in Autism-Epilepsy Phenotype with Macrocephaly. Neuromolecular Med 2015; 18:69-80. [PMID: 26537360 DOI: 10.1007/s12017-015-8378-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 10/27/2015] [Indexed: 12/26/2022]
Abstract
The frequent co-occurrence of autism spectrum disorders (ASD) and epilepsy, or paroxysmal EEG abnormalities, defines a condition termed autism-epilepsy phenotype (AEP). This condition results, in some cases , from dysfunctions of glial inwardly rectifying potassium channels (Kir), which are mainly expressed in astrocytes where they mediate neuron-glia communication. Macrocephaly is also often comorbid with autism-epilepsy (autism-epilepsy phenotype with macrocephaly, MAEP), and it is tempting to hypothesize that shared pathogenic mechanisms might explain concurrence of these conditions. In the present study, we assessed whether protein pathways involved, along with Kir channels, in astrocyte-neuron interaction at the tripartite synapse play a role in the etiopathogenesis of MAEP. Using a targeted resequencing methodology, we investigated the coding regions of 35 genes in 61 patients and correlated genetic results with clinical features. Variants were subdivided into 12 classes and clustered into four groups. We detected rare or previously unknown predicted deleterious missense changes in GJA1, SLC12A2, SNTA1, EFNA3, CNTNAP2, EPHA4, and STXBP1 in seven patients and two high-frequency variants in DLG1 in six individuals. We also found that a group of variants (predicted deleterious and non-coding), segregating with the comorbid MAEP/AEP subgroups, belong to proteins specifically involved in glutamate transport and metabolism (namely, SLC17A6, GRM8, and GLUL), as well as in potassium conductance (KCNN3). This "endophenotype-oriented" study, performed using a targeted strategy, helped to further delineate part of the complex genetic background of ASD, particularly in the presence of coexisting macrocephaly and/or epilepsy/paroxysmal EEG, and suggests that use of stringent clinical clustering might be an approach worth adopting in order to unravel the complex genomic data in neurodevelopmental disorders.
Collapse
|
72
|
Les jonctions gap : une nouvelle cible thérapeutique pour le traitement des troubles dépressifs majeurs ? Rev Neurol (Paris) 2015; 171:762-7. [DOI: 10.1016/j.neurol.2015.07.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Revised: 07/08/2015] [Accepted: 07/16/2015] [Indexed: 01/04/2023]
|
73
|
Stout RF, Snapp EL, Spray DC. Connexin Type and Fluorescent Protein Fusion Tag Determine Structural Stability of Gap Junction Plaques. J Biol Chem 2015; 290:23497-514. [PMID: 26265468 DOI: 10.1074/jbc.m115.659979] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2015] [Indexed: 12/22/2022] Open
Abstract
Gap junctions (GJs) are made up of plaques of laterally clustered intercellular channels and the membranes in which the channels are embedded. Arrangement of channels within a plaque determines subcellular distribution of connexin binding partners and sites of intercellular signaling. Here, we report the discovery that some connexin types form plaque structures with strikingly different degrees of fluidity in the arrangement of the GJ channel subcomponents of the GJ plaque. We uncovered this property of GJs by applying fluorescence recovery after photobleaching to GJs formed from connexins fused with fluorescent protein tags. We found that connexin 26 (Cx26) and Cx30 GJs readily diffuse within the plaque structures, whereas Cx43 GJs remain persistently immobile for more than 2 min after bleaching. The cytoplasmic C terminus of Cx43 was required for stability of Cx43 plaque arrangement. We provide evidence that these qualitative differences in GJ arrangement stability reflect endogenous characteristics, with the caveat that the sizes of the GJs examined were necessarily large for these measurements. We also uncovered an unrecognized effect of non-monomerized fluorescent protein on the dynamically arranged GJs and the organization of plaques composed of multiple connexin types. Together, these findings redefine our understanding of the GJ plaque structure and should be considered in future studies using fluorescent protein tags to probe dynamics of highly ordered protein complexes.
Collapse
Affiliation(s)
- Randy F Stout
- From the Dominick P. Purpura Department of Neuroscience and
| | - Erik Lee Snapp
- the Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York 10461
| | - David C Spray
- From the Dominick P. Purpura Department of Neuroscience and
| |
Collapse
|
74
|
Grubišić V, Parpura V. The second brain in autism spectrum disorder: could connexin 43 expressed in enteric glial cells play a role? Front Cell Neurosci 2015; 9:242. [PMID: 26190971 PMCID: PMC4490256 DOI: 10.3389/fncel.2015.00242] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 06/15/2015] [Indexed: 12/28/2022] Open
Affiliation(s)
- Vladimir Grubišić
- Department of Neurobiology, University of Alabama at Birmingham Birmingham, AL, USA ; Neuroscience Program, Department of Physiology, Michigan State University East Lansing, MI, USA
| | - Vladimir Parpura
- Department of Neurobiology, University of Alabama at Birmingham Birmingham, AL, USA
| |
Collapse
|
75
|
Edgar JC, Heiken K, Chen YH, Herrington JD, Chow V, Liu S, Bloy L, Huang M, Pandey J, Cannon KM, Qasmieh S, Levy SE, Schultz RT, Roberts TPL. Resting-state alpha in autism spectrum disorder and alpha associations with thalamic volume. J Autism Dev Disord 2015; 45:795-804. [PMID: 25231288 PMCID: PMC6102716 DOI: 10.1007/s10803-014-2236-1] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Alpha circuits (8-12 Hz), necessary for basic and complex brain processes, are abnormal in autism spectrum disorder (ASD). The present study obtained estimates of resting-state (RS) alpha activity in children with ASD and examined associations between alpha activity, age, and clinical symptoms. Given that the thalamus modulates cortical RS alpha rhythms, associations between thalamic structure and alpha activity were examined. RS magnetoencephalography was obtained from 47 typically-developing children (TDC) and 41 children with ASD. RS alpha activity was measured using distributed source localization. Left and right thalamic volume measurements were also obtained. In both groups, the strongest alpha activity was observed in Calcarine Sulcus regions. In Calcarine regions, only TDC showed the expected association between age and alpha peak frequency. ASD had more alpha activity than TDC in regions bordering the Central Sulcus as well as parietal association cortices. In ASD, whereas greater left Central Sulcus relative alpha activity was associated with higher Social Responsiveness Scale (SRS) scores, greater Calcarine region relative alpha activity was associated with lower SRS scores. Although thalamic volume group differences were not observed, relationships between thalamic volume and Calcarine alpha power were unique to TDC. The present study also identified a failure to shift peak alpha frequency as a function of age in primary alpha-generating areas in children with ASD. Findings suggested that increased RS alpha activity in primary motor and somatosensory as well as parietal multimodal areas-with increased alpha thought to reflect greater inhibition-might impair the ability to identify or interpret social cues. Finally, to our knowledge, this is the first study to report associations between thalamic volume and alpha power, an association observed only in TDC. The lack of thalamic and alpha associations in ASD suggests thalamic contributions to RS alpha abnormalities in ASD.
Collapse
Affiliation(s)
- J Christopher Edgar
- Lurie Family Foundations MEG Imaging Center, Department of Radiology, The Children's Hospital of Philadelphia, 34th and Civic Center Blvd, Wood Building, Suite 2115, Philadelphia, PA, 10104, USA,
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
76
|
Morgan JT, Barger N, Amaral DG, Schumann CM. Stereological study of amygdala glial populations in adolescents and adults with autism spectrum disorder. PLoS One 2014; 9:e110356. [PMID: 25330013 PMCID: PMC4201518 DOI: 10.1371/journal.pone.0110356] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 09/06/2014] [Indexed: 11/23/2022] Open
Abstract
The amygdala undergoes aberrant development in autism spectrum disorder (ASD). We previously found that there are reduced neuron numbers in the adult postmortem amygdala from individuals with ASD compared to typically developing controls. The current study is a comprehensive stereological examination of four non-neuronal cell populations: microglia, oligodendrocytes, astrocytes, and endothelial cells, in the same brains studied previously. We provide a detailed neuroanatomical protocol for defining each cell type that may be applied to other studies of the amygdala in neurodevelopmental and psychiatric disorders. We then assess whether cell numbers and average volumes differ between ASD and typically developing brains. We hypothesized that a reduction in neuron numbers in ASD might relate to altered immune function and/or aberrant microglial activation, as indicated by increased microglial number and cell body volume. Overall, average non-neuronal cell numbers and volumes did not differ between ASD and typically developing brains. However, there was evident heterogeneity within the ASD cohort. Two of the eight ASD brains displayed strong microglial activation. Contrary to our original hypothesis, there was a trend toward a positive correlation between neuronal and microglial numbers in both ASD and control cases. There were fewer oligodendrocytes in the amygdala of adult individuals with ASD ages 20 and older compared to typically developing controls. This finding may provide a possible sign of altered connectivity or impaired neuronal communication that may change across the lifespan in ASD.
Collapse
Affiliation(s)
- John T. Morgan
- Department of Psychiatry and Behavioral Sciences and the M. I. N. D. Institute, University of California Davis, Sacramento, California, United States of America
| | - Nicole Barger
- Department of Psychiatry and Behavioral Sciences and the M. I. N. D. Institute, University of California Davis, Sacramento, California, United States of America
| | - David G. Amaral
- Department of Psychiatry and Behavioral Sciences and the M. I. N. D. Institute, University of California Davis, Sacramento, California, United States of America
| | - Cynthia M. Schumann
- Department of Psychiatry and Behavioral Sciences and the M. I. N. D. Institute, University of California Davis, Sacramento, California, United States of America
- * E-mail:
| |
Collapse
|
77
|
The need for a comprehensive molecular characterization of autism spectrum disorders. Int J Neuropsychopharmacol 2014; 17:651-73. [PMID: 24229490 DOI: 10.1017/s146114571300117x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Autism spectrum disorders (ASD) are a heterogeneous group of disorders which have complex behavioural phenotypes. Although ASD is a highly heritable neuropsychiatric disorder, genetic research alone has not provided a profound understanding of the underlying causes. Recent developments using biochemical tools such as transcriptomics, proteomics and cellular models, will pave the way to gain new insights into the underlying pathological pathways. This review addresses the state-of-the-art in the search for molecular biomarkers for ASD. In particular, the most important findings in the biochemical field are highlighted and the need for establishing streamlined interaction between behavioural studies, genetics and proteomics is stressed. Eventually, these approaches will lead to suitable translational ASD models and, therefore, a better disease understanding which may facilitate novel drug discovery efforts in this challenging field.
Collapse
|
78
|
Sloan SA, Barres BA. Mechanisms of astrocyte development and their contributions to neurodevelopmental disorders. Curr Opin Neurobiol 2014; 27:75-81. [PMID: 24694749 DOI: 10.1016/j.conb.2014.03.005] [Citation(s) in RCA: 181] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2013] [Revised: 03/06/2014] [Accepted: 03/10/2014] [Indexed: 10/25/2022]
Abstract
The development of functional neural circuits relies upon the coordination of various cell types. In particular, astrocytes play a crucial role in orchestrating neural development by powerfully coordinating synapse formation and function, neuronal survival, and axon guidance. While astrocytes help to shape neural circuits in the developing brain, the mechanisms underlying their own development may play an equally crucial role in nervous system function. The onset of astrogenesis is a temporally regulated phenomenon that relies upon exogenously secreted cues and intrinsic chromatin changes. Defects in the mechanisms underlying astrogenesis or in astrocyte function during early development may contribute to the progression of a variety of neurodevelopmental disorders.
Collapse
Affiliation(s)
- Steven A Sloan
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA 94305-5125, United States.
| | - Ben A Barres
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA 94305-5125, United States
| |
Collapse
|
79
|
de Theije CGM, Koelink PJ, Korte-Bouws GAH, Lopes da Silva S, Korte SM, Olivier B, Garssen J, Kraneveld AD. Intestinal inflammation in a murine model of autism spectrum disorders. Brain Behav Immun 2014; 37:240-7. [PMID: 24321212 DOI: 10.1016/j.bbi.2013.12.004] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 11/25/2013] [Accepted: 12/02/2013] [Indexed: 11/26/2022] Open
Abstract
Autism spectrum disorder (ASD) is a cluster of neurodevelopmental disorders characterized by impairments in communication, social interest and stereotypical behaviour. Dysfunction of the intestinal tract is reported in patients with ASD and implicated in the development and severity of ASD symptoms. However, more research is required to investigate the association of intestinal problems with ASD and the potential underlying mechanisms. The purpose of this study was to investigate comorbid symptoms of intestinal inflammation in a murine model of ASD induced by prenatal exposure to valproic acid (VPA). Pregnant BALB/c females were treated subcutaneously with 600 mg/kg VPA or phosphate buffered saline on gestational day 11. Offspring were housed with their mother until weaning on postnatal day 21 (P21). All pups were exposed to a social behaviour test on P28. Inflammatory correlates and activity of the serotonergic system were measured in brain and intestinal tissue. Here we demonstrate, in addition to reduced social behaviour and increased expression of neuroinflammatory markers in the brain, that VPA in utero- exposed male offspring showed epithelial cell loss and neutrophil infiltration in the intestinal tract. Furthermore, reduced levels of serotonin were not only observed the prefrontal cortex and amygdala of VPA in utero- exposed males, but also in the small intestine. Overall, we demonstrate that gender-specific inflammatory conditions are present in the small intestines of VPA in utero- exposed mice and are accompanied by a disturbed serotonergic system in the brain as well as in the intestinal tract.
Collapse
Affiliation(s)
- Caroline G M de Theije
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands.
| | - Pim J Koelink
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| | - Gerdien A H Korte-Bouws
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| | - Sofia Lopes da Silva
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands; Nutricia Research, Uppsalalaan 12, 3584 CT Utrecht, The Netherlands
| | - S Mechiel Korte
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| | - Berend Olivier
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| | - Johan Garssen
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands; Nutricia Research, Uppsalalaan 12, 3584 CT Utrecht, The Netherlands
| | - Aletta D Kraneveld
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| |
Collapse
|
80
|
Kurtenbach S, Kurtenbach S, Zoidl G. Gap junction modulation and its implications for heart function. Front Physiol 2014; 5:82. [PMID: 24578694 PMCID: PMC3936571 DOI: 10.3389/fphys.2014.00082] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 02/10/2014] [Indexed: 01/04/2023] Open
Abstract
Gap junction communication (GJC) mediated by connexins is critical for heart function. To gain insight into the causal relationship of molecular mechanisms of disease pathology, it is important to understand which mechanisms contribute to impairment of gap junctional communication. Here, we present an update on the known modulators of connexins, including various interaction partners, kinases, and signaling cascades. This gap junction network (GJN) can serve as a blueprint for data mining approaches exploring the growing number of publicly available data sets from experimental and clinical studies.
Collapse
Affiliation(s)
- Stefan Kurtenbach
- Department of Psychology, Faculty of Health, York University Toronto, ON, Canada
| | - Sarah Kurtenbach
- Department of Psychology, Faculty of Health, York University Toronto, ON, Canada
| | - Georg Zoidl
- Department of Psychology, Faculty of Health, York University Toronto, ON, Canada ; Department of Biology, Faculty of Science, York University Toronto, ON, Canada ; Center for Vision Research, York University Toronto, ON, Canada
| |
Collapse
|
81
|
Edmonson C, Ziats MN, Rennert OM. Altered glial marker expression in autistic post-mortem prefrontal cortex and cerebellum. Mol Autism 2014; 5:3. [PMID: 24410870 PMCID: PMC3914711 DOI: 10.1186/2040-2392-5-3] [Citation(s) in RCA: 114] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2013] [Accepted: 12/23/2013] [Indexed: 01/29/2023] Open
Abstract
Background The cellular mechanism(s) underlying autism spectrum disorders (ASDs) are not completely understood, but ASDs are thought to ultimately result from disrupted synaptogenesis. However, studies have also shown that glial cell numbers and function are abnormal in post-mortem brain tissue from autistic patients. Direct assessment of glial cells in post-mortem human brain tissue is technically challenging, limiting glial research in human ASD studies. Therefore, we attempted to determine if glial cell-type specific markers may be altered in autistic brain tissue in a manner that is consistent with known cellular findings, such that they could serve as a proxy for glial cell numbers and/or activation patterns. Methods We assessed the relative expression of five glial-specific markers and two neuron-specific markers via qRT-PCR. We studied tissue samples from the prefrontal cortex (PFC) and cerebellum of nine post-mortem autistic brain samples and nine neurologically-normal controls. Relative fold-change in gene expression was determined using the ΔΔCt method normalized to housekeeping gene β-actin, with a two-tailed Student’s t-test P <0.05 between groups considered as significant. Results Both astrocyte- and microglial-specific markers were significantly more highly expressed in autistic PFC as compared to matched controls, while in the cerebellum only astrocyte markers were elevated in autistic samples. In contrast, neuron-specific markers showed significantly lower expression in both the PFC and cerebellum of autistic patients as compared to controls. Conclusions These results are in line with previous findings showing increased glial cell numbers and up-regulation of glial cell gene expression in autistic post-mortem brain tissue, particularly in the PFC, as well as decreased number of neurons in both the PFC and cerebellum of autistic patients. The concordance of these results with cell-level studies in post-mortem autistic brain tissue suggests that expression of glial cell-type specific markers may serve as a useful alternative to traditional cellular characterization methods, especially when appropriately-preserved post-mortem tissue is lacking. Additionally, these results demonstrate abnormal glial-specific gene expression in autistic brains, supporting previous studies that have observed altered glial cell numbers or activation patterns in ASDs. Future work should directly assess the correlation between cell-type specific marker levels and cell number and activation patterns.
Collapse
Affiliation(s)
- Catherine Edmonson
- Laboratory of Clinical and Developmental Genomics, National Institute of Child Health and Human Development, National Institutes of Health, 49 Convent Drive, Building 49, Room 2C078, Bethesda, MD 20814, USA.,University of Florida College of Medicine, 1600 SW Archer Rd, Gainesville, FL 32603, USA
| | - Mark N Ziats
- Laboratory of Clinical and Developmental Genomics, National Institute of Child Health and Human Development, National Institutes of Health, 49 Convent Drive, Building 49, Room 2C078, Bethesda, MD 20814, USA.,University of Cambridge, Robinson College, Grange Rd, Cambridgeshire CB3 9AN, UK.,Baylor College of Medicine MSTP, One Baylor Plaza, Houston, TX 77030, USA
| | - Owen M Rennert
- Laboratory of Clinical and Developmental Genomics, National Institute of Child Health and Human Development, National Institutes of Health, 49 Convent Drive, Building 49, Room 2C078, Bethesda, MD 20814, USA
| |
Collapse
|
82
|
Alabdali A, Al-Ayadhi L, El-Ansary A. Association of social and cognitive impairment and biomarkers in autism spectrum disorders. J Neuroinflammation 2014; 11:4. [PMID: 24400970 PMCID: PMC3896747 DOI: 10.1186/1742-2094-11-4] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Accepted: 12/17/2013] [Indexed: 11/21/2022] Open
Abstract
Objectives The neurological basis for autism is still not fully understood, and the role of the interaction between neuro-inflammation and neurotransmission impairment needs to be clearer. This study aims to test the possible association between impaired levels of gamma aminobutyric acid (GABA), serotonin, dopamine, oxytocin, and interferon-γ-induced protein-16 (IFI16) and the severity of social and cognitive dysfunctions in individuals with autism spectrum disorders. Materials and methods GABA, serotonin, dopamine, oxytocin, and IFI16 as biochemical parameters related to neurochemistry and inflammation were determined in the plasma of 52 Saudi autistic male patients, categorized as mild-moderate and severe as indicated by their Childhood Autism Rating Scale (CARS) or social responsiveness scale (SRS), and compared to 30 age- and gender-matched control samples. Results The data indicated that Saudi patients with autism have remarkably impaired plasma levels of the measured parameters compared to age and gender-matched controls. While serotonin in platelet-free plasma and dopamine did not correlated with the severity in social and cognitive dysfunction, GABA, oxytocin, and IFI16 were remarkably associated with the severity of both tested scores (SRS and CARS). Conclusions The relationship between the selected parameters confirms the role of impaired neurochemistry and neuro-inflammation in the etiology of autism spectrum disorders and the possibility of using GABA, oxytocin, and IFI16 as markers of autism severity. Receiver operating characteristic analysis together with predictiveness diagrams proved that the measured parameters could be used as predictive biomarkers of clinical symptoms and provide significant guidance for future therapeutic strategy to re-establish physiological homeostasis.
Collapse
Affiliation(s)
| | | | - Afaf El-Ansary
- Biochemistry Department, Science College, King Saud University, P,O box 22452, Zip code 11495 Riyadh, Saudi Arabia.
| |
Collapse
|
83
|
Zeidán-Chuliá F, Salmina AB, Malinovskaya NA, Noda M, Verkhratsky A, Moreira JCF. The glial perspective of autism spectrum disorders. Neurosci Biobehav Rev 2014; 38:160-72. [DOI: 10.1016/j.neubiorev.2013.11.008] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Revised: 11/03/2013] [Accepted: 11/21/2013] [Indexed: 01/01/2023]
|
84
|
Verkhratsky A, Rodríguez JJ, Steardo L. Astrogliopathology: a central element of neuropsychiatric diseases? Neuroscientist 2013; 20:576-88. [PMID: 24301046 DOI: 10.1177/1073858413510208] [Citation(s) in RCA: 106] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Astroglia are the homoeostatic cells of the central nervous system that control a normal function of synaptically connected neuronal networks and contribute to brain defense. Recent advances in comprehension of pathological potential of astroglia indicate that astrocytes are fundamental for most (if not all) neurological diseases. Neuropathological and neuroimaging studies demonstrate prominent astroglial atrophy and astroglial asthenia occurring in most of neuropsychiatric illnesses. In chronic diseases such as schizophrenia and major depression, decrease in astroglial numbers and functional capabilities are, arguably, fundamental for pathological developments being responsible for neurotransmitter disbalance and failures in connectivity within neural networks. In neurodegenerative diseases atrophic changes in astrocytes are complemented by astrogliosis triggered by specific lesions such as senile plaques or dying neurons, these two processes contributing to cognitive decline and ultimately neuronal death. It is therefore possible to hypothesize that neuropsychiatric diseases represent a chronic astrogliopathology, which compromises glial homeostatic and defensive capabilities, and the degree and the alacrity of gliodegenerative changes define the progression and outcome of these disorders.
Collapse
Affiliation(s)
- Alexei Verkhratsky
- Faculty of Life Sciences, The University of Manchester, Manchester, UK IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
| | - José J Rodríguez
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain Department of Neurosciences, University of the Basque Country UPV/EHU, Leioa, Spain
| | - Luca Steardo
- Department of Physiology and Pharmacology "Vittorio Erspamer" Sapienza University of Rome, Italy
| |
Collapse
|
85
|
Abstract
Autism spectrum conditions (ASCs) are defined behaviorally, but they also involve multileveled disturbances of underlying biology that find striking parallels in the physiological impacts of electromagnetic frequency and radiofrequency radiation exposures (EMF/RFR). Part I (Vol 776) of this paper reviewed the critical contributions pathophysiology may make to the etiology, pathogenesis and ongoing generation of behaviors currently defined as being core features of ASCs. We reviewed pathophysiological damage to core cellular processes that are associated both with ASCs and with biological effects of EMF/RFR exposures that contribute to chronically disrupted homeostasis. Many studies of people with ASCs have identified oxidative stress and evidence of free radical damage, cellular stress proteins, and deficiencies of antioxidants such as glutathione. Elevated intracellular calcium in ASCs may be due to genetics or may be downstream of inflammation or environmental exposures. Cell membrane lipids may be peroxidized, mitochondria may be dysfunctional, and various kinds of immune system disturbances are common. Brain oxidative stress and inflammation as well as measures consistent with blood-brain barrier and brain perfusion compromise have been documented. Part II of this paper documents how behaviors in ASCs may emerge from alterations of electrophysiological oscillatory synchronization, how EMF/RFR could contribute to these by de-tuning the organism, and policy implications of these vulnerabilities. It details evidence for mitochondrial dysfunction, immune system dysregulation, neuroinflammation and brain blood flow alterations, altered electrophysiology, disruption of electromagnetic signaling, synchrony, and sensory processing, de-tuning of the brain and organism, with autistic behaviors as emergent properties emanating from this pathophysiology. Changes in brain and autonomic nervous system electrophysiological function and sensory processing predominate, seizures are common, and sleep disruption is close to universal. All of these phenomena also occur with EMF/RFR exposure that can add to system overload ('allostatic load') in ASCs by increasing risk, and can worsen challenging biological problems and symptoms; conversely, reducing exposure might ameliorate symptoms of ASCs by reducing obstruction of physiological repair. Various vital but vulnerable mechanisms such as calcium channels may be disrupted by environmental agents, various genes associated with autism or the interaction of both. With dramatic increases in reported ASCs that are coincident in time with the deployment of wireless technologies, we need aggressive investigation of potential ASC-EMF/RFR links. The evidence is sufficient to warrant new public exposure standards benchmarked to low-intensity (non-thermal) exposure levels now known to be biologically disruptive, and strong, interim precautionary practices are advocated.
Collapse
|
86
|
Herbert MR, Sage C. Autism and EMF? Plausibility of a pathophysiological link - Part I. ACTA ACUST UNITED AC 2013; 20:191-209. [PMID: 24095003 DOI: 10.1016/j.pathophys.2013.08.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2013] [Revised: 05/06/2013] [Accepted: 07/15/2013] [Indexed: 01/02/2023]
Abstract
Although autism spectrum conditions (ASCs) are defined behaviorally, they also involve multileveled disturbances of underlying biology that find striking parallels in the physiological impacts of electromagnetic frequency and radiofrequency exposures (EMF/RFR). Part I of this paper will review the critical contributions pathophysiology may make to the etiology, pathogenesis and ongoing generation of core features of ASCs. We will review pathophysiological damage to core cellular processes that are associated both with ASCs and with biological effects of EMF/RFR exposures that contribute to chronically disrupted homeostasis. Many studies of people with ASCs have identified oxidative stress and evidence of free radical damage, cellular stress proteins, and deficiencies of antioxidants such as glutathione. Elevated intracellular calcium in ASCs may be due to genetics or may be downstream of inflammation or environmental exposures. Cell membrane lipids may be peroxidized, mitochondria may be dysfunctional, and various kinds of immune system disturbances are common. Brain oxidative stress and inflammation as well as measures consistent with blood-brain barrier and brain perfusion compromise have been documented. Part II of this paper will review how behaviors in ASCs may emerge from alterations of electrophysiological oscillatory synchronization, how EMF/RFR could contribute to these by de-tuning the organism, and policy implications of these vulnerabilities. Changes in brain and autonomic nervous system electrophysiological function and sensory processing predominate, seizures are common, and sleep disruption is close to universal. All of these phenomena also occur with EMF/RFR exposure that can add to system overload ('allostatic load') in ASCs by increasing risk, and worsening challenging biological problems and symptoms; conversely, reducing exposure might ameliorate symptoms of ASCs by reducing obstruction of physiological repair. Various vital but vulnerable mechanisms such as calcium channels may be disrupted by environmental agents, various genes associated with autism or the interaction of both. With dramatic increases in reported ASCs that are coincident in time with the deployment of wireless technologies, we need aggressive investigation of potential ASC - EMF/RFR links. The evidence is sufficient to warrant new public exposure standards benchmarked to low-intensity (non-thermal) exposure levels now known to be biologically disruptive, and strong, interim precautionary practices are advocated.
Collapse
Affiliation(s)
- Martha R Herbert
- TRANSCEND Research Program Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02129, USA.
| | | |
Collapse
|
87
|
Abstract
The effects of the aquaporin-4 (AQP-4) inhibitor TGN-020 on regional cerebral blood flow (rCBF) was examined in wild-type (WT) and AQP-4 knockout (KO) mice in vivo. Although baseline absolute rCBF of WT and KO mice were equivalent (158.9 ± 17.7 and 155.5 ± 10.4 ml/100 g/min, respectively), TGN-020 produced a significant increase in rCBF compared with saline-treated WT mice (control), reaching a plateau 20 min after administration (118.45 ± 8.13%, P<0.01). TGN-020 showed no effect on KO mice, supporting the concept that the observed increase in rCBF in WT mice was AQP-4 dependent. Administration of acetazolamide (positive control) produced an even greater increase in rCBF in WT compared with TGN-020 and a similar response in KO mice as well, reaching a sustained plateau 5 min after administration (138.50 ± 9.75 and 138.52 ± 9.76%, respectively, P<0.01 compared with baseline or saline-treated control mice). The study demonstrated that AQP-4 plays a role in regulation of rCBF.
Collapse
|
88
|
Yang Y, Higashimori H, Morel L. Developmental maturation of astrocytes and pathogenesis of neurodevelopmental disorders. J Neurodev Disord 2013; 5:22. [PMID: 23988237 PMCID: PMC3765765 DOI: 10.1186/1866-1955-5-22] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Accepted: 08/20/2013] [Indexed: 11/10/2022] Open
Abstract
Recent studies have implicated potentially significant roles for astrocytes in the pathogenesis of neurodevelopmental disorders. Astrocytes undergo a dramatic maturation process following early differentiation from which typical morphology and important functions are acquired. Despite significant progress in understanding their early differentiation, very little is known about how astrocytes become functionally mature. In addition, whether functional maturation of astrocytes is disrupted in neurodevelopmental disorders and the consequences of this disruption remains essentially unknown. In this review, we discuss our perspectives about how astrocyte developmental maturation is regulated, and how disruption of the astrocyte functional maturation process, especially alterations in their ability to regulate glutamate homeostasis, may alter synaptic physiology and contribute to the pathogenesis of neurodevelopmental disorders.
Collapse
Affiliation(s)
- Yongjie Yang
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Ave, Boston, MA 02111, USA
| | | | | |
Collapse
|
89
|
Pannasch U, Rouach N. Emerging role for astroglial networks in information processing: from synapse to behavior. Trends Neurosci 2013; 36:405-17. [PMID: 23659852 DOI: 10.1016/j.tins.2013.04.004] [Citation(s) in RCA: 179] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Revised: 04/01/2013] [Accepted: 04/01/2013] [Indexed: 01/05/2023]
Abstract
Astrocytes contribute to neurotransmission through a variety of mechanisms ranging from synapse isolation to active signaling. Astroglial involvement in neurophysiology has been mostly investigated at the single-cell level. However, a unique feature of astrocytes is their high level of intercellular connectivity mediated by connexins, the proteins forming gap junction (GJ) channels. These astroglial GJ circuits enable the rapid intercellular exchange of ions, metabolites, and neuroactive substances. Recent findings have suggested that, despite their extensity, astroglial networks are also selective, preferential as well as plastic, and can regulate synapses, neuronal circuits, and behavior. The present review critically discusses the impact of astroglial networks on normal and pathological neuronal information processing as well as the underlying mechanisms.
Collapse
Affiliation(s)
- Ulrike Pannasch
- Neuroglial Interactions in Cerebral Physiopathology, Center for Interdisciplinary Research in Biology, Centre Nationale de la Recherche Scientifique (CNRS) Unité Mixte de Recherche 7241, Institut National de la Santé et de la Recherche Médicale (INSERM) Unité 1050, Collège de France, 75005 Paris, France
| | | |
Collapse
|
90
|
Majumder A, Dhara SK, Swetenburg R, Mithani M, Cao K, Medrzycki M, Fan Y, Stice SL. Inhibition of DNA methyltransferases and histone deacetylases induces astrocytic differentiation of neural progenitors. Stem Cell Res 2013; 11:574-86. [PMID: 23644509 DOI: 10.1016/j.scr.2013.03.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Revised: 03/06/2013] [Accepted: 03/25/2013] [Indexed: 11/25/2022] Open
Abstract
Understanding how to specify rapid differentiation of human neural progenitor towards enriched non-transformed human astrocyte progenitors will provide a critical cell source to further our understanding of how astrocytes play a pivotal role in neural function and development. Human neural progenitors derived from pluripotent embryonic stem cells and propagated in adherent serum-free cultures provide a fate restricted renewable source for quick production of neural cells; however, such cells are highly refractive to astrocytogenesis and show a strong neurogenic bias, similar to neural progenitors from the early embryonic central nervous system (CNS). We found that several astrocytic genes are hypermethylated in such progenitors potentially preventing generation of astrocytes and leading to the proneuronal fate of these progenitors. However, epigenetic modification by Azacytidine (Aza-C) and Trichostatin A (TSA), with concomitant signaling from BMP2 and LIF in neural progenitor cultures shifts this bias, leading to expression of astrocytic markers as early as 5days of differentiation, with near complete suppression of neuronal differentiation. The resultant cells express major astrocytic markers, are amenable to co-culture with neurons, can be propagated as astrocyte progenitors and are cryopreservable. Although previous reports have generated astrocytes from pluripotent cells, the differentiation required extensive culture or selection based on cell surface antigens. The development of a label free and rapid differentiation process will expedite future derivation of astrocytes from various sources pluripotent cells including, but not limited to, human astrocytes associated with various neurological diseases.
Collapse
Affiliation(s)
- Anirban Majumder
- Regenerative Bioscience Center, University of Georgia, 425 River Rd, Athens, GA 30602, USA
| | | | | | | | | | | | | | | |
Collapse
|
91
|
Zeng L, Zhang P, Shi L, Yamamoto V, Lu W, Wang K. Functional impacts of NRXN1 knockdown on neurodevelopment in stem cell models. PLoS One 2013; 8:e59685. [PMID: 23536886 PMCID: PMC3607566 DOI: 10.1371/journal.pone.0059685] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Accepted: 02/16/2013] [Indexed: 12/28/2022] Open
Abstract
Exonic deletions in NRXN1 have been associated with several neurodevelopmental disorders, including autism, schizophrenia and developmental delay. However, the molecular mechanism by which NRXN1 deletions impact neurodevelopment remains unclear. Here we used human induced pluripotent stem cells (hiPSCs) and human embryonic stem cells (hESCs) as models to investigate the functional impacts of NRXN1 knockdown. We first generated hiPSCs from skin fibroblasts and differentiated them into neural stem cells (NSCs). We reduced NRXN1 expression in NSCs via a controlled shRNAmir-based knockdown system during differentiation, and monitored the transcriptome alteration by RNA-Seq and quantitative PCR at several time points. Interestingly, half reduction of NRXN1 expression resulted in changes of expression levels for the cell adhesion pathway (20 genes, P = 2.8×10−6) and neuron differentiation pathway (13 genes, P = 2.1×10−4), implicating that single-gene perturbation can impact biological networks important for neurodevelopment. Furthermore, astrocyte marker GFAP was significantly reduced in a time dependent manner that correlated with NRXN1 reduction. This observation was reproduced in both hiPSCs and hESCs. In summary, based on in vitro models, NRXN1 deletions impact several biological processes during neurodevelopment, including synaptic adhesion and neuron differentiation. Our study highlights the utility of stem cell models in understanding the functional roles of copy number variations (CNVs) in conferring susceptibility to neurodevelopmental diseases.
Collapse
Affiliation(s)
- Liyun Zeng
- Zilhka Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Peilin Zhang
- Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Lingling Shi
- Zilhka Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Vicky Yamamoto
- Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- Department of Biochemistry and Molecular Biology, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Wange Lu
- Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- Department of Biochemistry and Molecular Biology, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- * E-mail: (WL); (KW)
| | - Kai Wang
- Zilhka Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- Department of Psychiatry and Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- * E-mail: (WL); (KW)
| |
Collapse
|
92
|
Zeidán-Chuliá F, Rybarczyk-Filho JL, Salmina AB, de Oliveira BHN, Noda M, Moreira JCF. Exploring the Multifactorial Nature of Autism Through Computational Systems Biology: Calcium and the Rho GTPase RAC1 Under the Spotlight. Neuromolecular Med 2013; 15:364-83. [DOI: 10.1007/s12017-013-8224-3] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 02/16/2013] [Indexed: 01/08/2023]
|
93
|
Bristot Silvestrin R, Bambini-Junior V, Galland F, Daniele Bobermim L, Quincozes-Santos A, Torres Abib R, Zanotto C, Batassini C, Brolese G, Gonçalves CA, Riesgo R, Gottfried C. Animal model of autism induced by prenatal exposure to valproate: altered glutamate metabolism in the hippocampus. Brain Res 2012; 1495:52-60. [PMID: 23219577 DOI: 10.1016/j.brainres.2012.11.048] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2012] [Revised: 11/05/2012] [Accepted: 11/28/2012] [Indexed: 10/27/2022]
Abstract
Autism spectrum disorders (ASD) are characterized by deficits in social interaction, language and communication impairments and repetitive and stereotyped behaviors, with involvement of several areas of the central nervous system (CNS), including hippocampus. Although neurons have been the target of most studies reported in the literature, recently, considerable attention has been centered upon the functionality and plasticity of glial cells, particularly astrocytes. These cells participate in normal brain development and also in neuropathological processes. The present work investigated hippocampi from 15 (P15) and 120 (P120) days old male rats prenatally exposed to valproic acid (VPA) as an animal model of autism. Herein, we analyzed astrocytic parameters such as glutamate transporters and glutamate uptake, glutamine synthetase (GS) activity and glutathione (GSH) content. In the VPA group glutamate uptake was unchanged at P15 and increased 160% at P120; the protein expression of GLAST did not change neither in P15 nor in P120, while GLT1 decreased 40% at P15 and increased 92% at P120; GS activity increased 43% at P15 and decreased 28% at P120; GSH content was unaltered at P15 and had a 27% increase at P120. These data highlight that the astrocytic clearance and destination of glutamate in the synaptic cleft might be altered in autism, pointing out important aspects to be considered from both pathophysiologic and pharmacological approaches in ASD.
Collapse
Affiliation(s)
- Roberta Bristot Silvestrin
- Research Group in Neuroglial Plasticity at the Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
94
|
Mitterauer BJ. Astrocyte mega-domain hypothesis of the autistic savantism. Med Hypotheses 2012; 80:17-22. [PMID: 23098371 DOI: 10.1016/j.mehy.2012.09.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Revised: 09/07/2012] [Accepted: 09/23/2012] [Indexed: 11/16/2022]
Abstract
Individuals with autism who show high abilities are called savants. Whereas in their brains a disconnection in and between neural networks has been identified, savantism is yet poorly understood. Focusing on astrocyte domain organization, it is hypothesized that local astrocyte mega-organizations may be responsible for exerting high capabilities in brains of autistic savants. Astrocytes, the dominant glial cell type, modulate synaptic information transmission. Each astrocyte is organized in non-overlapping domains. Formally, each astrocyte contacting n-neurons with m-synapses via its processes generates dynamic domains of synaptic interactions based on qualitative computation criteria, and hereby it structures neuronal information processing. If the number of processes is genetically significantly increased, these astrocytes operate in a mega-domain with a higher complexitiy of computation. From this model savant abilities are deduced.
Collapse
Affiliation(s)
- Bernhard J Mitterauer
- University of Salzburg, Volitronics-Institute for Basic Research, Psychopathology and Brain Philosophy, Autobahnweg 7, A-5071 Wals, Austria.
| |
Collapse
|
95
|
Barker AJ, Ullian EM. New roles for astrocytes in developing synaptic circuits. Commun Integr Biol 2012; 1:207-11. [PMID: 19513261 DOI: 10.4161/cib.1.2.7284] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2008] [Accepted: 10/27/2008] [Indexed: 01/21/2023] Open
Affiliation(s)
- Alison J Barker
- Departments of Ophthalmology and Physiology; University of California, San Francisco; San Francisco, California USA
| | | |
Collapse
|
96
|
Pannasch U, Derangeon M, Chever O, Rouach N. Astroglial gap junctions shape neuronal network activity. Commun Integr Biol 2012; 5:248-54. [PMID: 22896785 PMCID: PMC3419107 DOI: 10.4161/cib.19410] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Astrocytes, the third element of the tripartite synapse, are active players in neurotransmission. Up to now, their involvement in neuronal functions has primarily been investigated at the single cell level. However, a key property of astrocytes is that they communicate via extensive networks formed by gap junction channels. Recently, we have shown that this networking modulates the moment to moment basal synaptic transmission and plasticity via the regulation of extracellular potassium and glutamate levels. Here we show that astroglial gap junctional communication also regulates neuronal network activity. We discuss these findings and their implications for brain information processing.
Collapse
Affiliation(s)
- Ulrike Pannasch
- Neuroglial Interactions in Cerebral Physiopathology; Center for Interdisciplinary Research in Biology; Collège de France; CNRS UMR7241; INSERM U1050; Paris, France
| | | | | | | |
Collapse
|
97
|
Brain water channel proteins in health and disease. Mol Aspects Med 2012; 33:562-78. [DOI: 10.1016/j.mam.2012.03.008] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Revised: 03/28/2012] [Accepted: 03/31/2012] [Indexed: 02/07/2023]
|
98
|
Cao F, Yin A, Wen G, Sheikh AM, Tauqeer Z, Malik M, Nagori A, Schirripa M, Schirripa F, Merz G, Brown WT, Li X. Alteration of astrocytes and Wnt/β-catenin signaling in the frontal cortex of autistic subjects. J Neuroinflammation 2012; 9:223. [PMID: 22999633 PMCID: PMC3544729 DOI: 10.1186/1742-2094-9-223] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Accepted: 08/27/2012] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Autism is a neurodevelopmental disorder characterized by impairments in social interaction, verbal communication and repetitive behaviors. To date the etiology of this disorder is poorly understood. Studies suggest that astrocytes play critical roles in neural plasticity by detecting neuronal activity and modulating neuronal networks. Recently, a number of studies suggested that an abnormal function of glia/astrocytes may be involved in the development of autism. However, there is yet no direct evidence showing how astrocytes develop in the brain of autistic individuals. METHODS Study subjects include brain tissue from autistic subjects, BTBR T + tfJ (BTBR) and Neuroligin (NL)-3 knock-down mice. Western blot analysis, Immunohistochemistry and confocal microscopy studies have be used to examine the density and morphology of astrocytes, as well as Wnt and β-catenin protein expression. RESULTS In this study, we demonstrate that the astrocytes in autisitcsubjects exhibit significantly reduced branching processes, total branching length and cell body sizes. We also detected an astrocytosis in the frontal cortex of autistic subjects. In addition, we found that the astrocytes in the brain of an NL3 knockdown mouse exhibited similar alterations to what we found in the autistic brain. Furthermore, we detected that both Wnt and β-catenin proteins are decreased in the frontal cortex of autistic subjects. Wnt/β-catenin pathway has been suggested to be involved in the regulation of astrocyte development. CONCLUSIONS Our findings imply that defects in astrocytes could impair neuronal plasticity and partially contribute to the development of autistic-like behaviors in both humans and mice. The alteration of Wnt/β-catenin pathway in the brain of autistic subjects may contribute to the changes of astrocytes.
Collapse
Affiliation(s)
- Fujiang Cao
- Department of Neurochemistry, NY State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island New York, NY 10314, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
99
|
Evidence of microglial activation in autism and its possible role in brain underconnectivity. ACTA ACUST UNITED AC 2012; 7:205-13. [PMID: 22874006 PMCID: PMC3523548 DOI: 10.1017/s1740925x12000142] [Citation(s) in RCA: 126] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Evidence indicates that children with autism spectrum disorder (ASD) suffer from an
ongoing neuroinflammatory process in different regions of the brain involving microglial
activation. When microglia remain activated for an extended period, the production of
mediators is sustained longer than usual and this increase in mediators contributes to
loss of synaptic connections and neuronal cell death. Microglial activation can then
result in a loss of connections or underconnectivity. Underconnectivity is reported in
many studies in autism. One way to control neuroinflammation is to reduce or inhibit
microglial activation. It is plausible that by reducing brain inflammation and microglial
activation, the neurodestructive effects of chronic inflammation could be reduced and
allow for improved developmental outcomes. Future studies that examine treatments that may
reduce microglial activation and neuroinflammation, and ultimately help to mitigate
symptoms in ASD, are warranted.
Collapse
|
100
|
Das A, Wallace GC, Holmes C, McDowell ML, Smith JA, Marshall JD, Bonilha L, Edwards JC, Glazier SS, Ray SK, Banik NL. Hippocampal tissue of patients with refractory temporal lobe epilepsy is associated with astrocyte activation, inflammation, and altered expression of channels and receptors. Neuroscience 2012; 220:237-46. [PMID: 22698689 DOI: 10.1016/j.neuroscience.2012.06.002] [Citation(s) in RCA: 150] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2012] [Revised: 05/17/2012] [Accepted: 06/03/2012] [Indexed: 11/24/2022]
Abstract
Temporal lobe epilepsy (TLE) is the most common form of focal epilepsy. Previous research has demonstrated several trends in human tissue that, undoubtedly, contribute to the development and progression of TLE. In this study we examined resected human hippocampus tissue for a variety of changes including gliosis that might contribute to the development and presentation of TLE. The study subjects consisted of six TLE patients and three sudden-death controls. Clinicopathological characteristics were evaluated by H&E staining. Immunohistological staining and Western blotting methods were used to analyze the samples. Neuronal hypertrophy was observed in resected epileptic tissue. Immunohistological staining demonstrated that activation of astrocytes was significantly increased in epileptic tissue as compared to corresponding regions of the control group. The Western blot data also showed increased CX43 and AQP4 in the hippocampus and downregulation of Kir4.1, α-syntrophin, and dystrophin, the key constituents of AQP4 multi-molecular complex. These tissues also demonstrated changes in inflammatory factors (COX-2, TGF-β, NF-κB) suggesting that these molecules may play an important role in TLE pathogenesis. In addition we detected increases in metabotropic glutamate receptor (mGluR) 2/3, mGluR5 and kainic acid receptor subunits KA1 (Grik4) and KA2 (Grik5) in patients' hippocampi. We noted increased expression of the α1c subunit comprising class C L-type Ca(2+) channels and calpain expression in these tissues, suggesting that these subunits might have an integral role in TLE pathogenesis. These changes found in the resected tissue suggest that they may contribute to TLE and that the kainic acid receptor (KAR) and deregulation of GluR2 receptor may play an important role in TLE development and disease course. This study identifies alterations in number of commonly studied molecular targets associated with astrogliosis, cellular hypertrophy, water homeostasis, inflammation, and modulation of excitatory neurotransmission in hippocampal tissues from TLE patients.
Collapse
Affiliation(s)
- A Das
- Department of Neurosciences (Divisions of Neurology and Neurosurgery), Medical University of South Carolina, Charleston, SC 29425, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|