1
|
Reis de Assis D, Szabo A, Requena Osete J, Puppo F, O’Connell KS, A. Akkouh I, Hughes T, Frei E, A. Andreassen O, Djurovic S. Using iPSC Models to Understand the Role of Estrogen in Neuron-Glia Interactions in Schizophrenia and Bipolar Disorder. Cells 2021; 10:209. [PMID: 33494281 PMCID: PMC7909800 DOI: 10.3390/cells10020209] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Revised: 12/08/2020] [Accepted: 01/19/2021] [Indexed: 01/04/2023] Open
Abstract
Schizophrenia (SCZ) and bipolar disorder (BIP) are severe mental disorders with a considerable disease burden worldwide due to early age of onset, chronicity, and lack of efficient treatments or prevention strategies. Whilst our current knowledge is that SCZ and BIP are highly heritable and share common pathophysiological mechanisms associated with cellular signaling, neurotransmission, energy metabolism, and neuroinflammation, the development of novel therapies has been hampered by the unavailability of appropriate models to identify novel targetable pathomechanisms. Recent data suggest that neuron-glia interactions are disturbed in SCZ and BIP, and are modulated by estrogen (E2). However, most of the knowledge we have so far on the neuromodulatory effects of E2 came from studies on animal models and human cell lines, and may not accurately reflect many processes occurring exclusively in the human brain. Thus, here we highlight the advantages of using induced pluripotent stem cell (iPSC) models to revisit studies of mechanisms underlying beneficial effects of E2 in human brain cells. A better understanding of these mechanisms opens the opportunity to identify putative targets of novel therapeutic agents for SCZ and BIP. In this review, we first summarize the literature on the molecular mechanisms involved in SCZ and BIP pathology and the beneficial effects of E2 on neuron-glia interactions. Then, we briefly present the most recent developments in the iPSC field, emphasizing the potential of using patient-derived iPSCs as more relevant models to study the effects of E2 on neuron-glia interactions.
Collapse
Affiliation(s)
- Denis Reis de Assis
- NORMENT, Institute of Clinical Medicine, University of Oslo & Division of Mental Health and Addiction, Oslo University Hospital, 0450 Oslo, Norway; (A.S.); (J.R.O.); (F.P.); (K.S.O.); (I.A.A.); (T.H.); (E.F.); (O.A.A.)
- Department of Medical Genetics, Oslo University Hospital, 0450 Oslo, Norway
| | - Attila Szabo
- NORMENT, Institute of Clinical Medicine, University of Oslo & Division of Mental Health and Addiction, Oslo University Hospital, 0450 Oslo, Norway; (A.S.); (J.R.O.); (F.P.); (K.S.O.); (I.A.A.); (T.H.); (E.F.); (O.A.A.)
- Department of Medical Genetics, Oslo University Hospital, 0450 Oslo, Norway
| | - Jordi Requena Osete
- NORMENT, Institute of Clinical Medicine, University of Oslo & Division of Mental Health and Addiction, Oslo University Hospital, 0450 Oslo, Norway; (A.S.); (J.R.O.); (F.P.); (K.S.O.); (I.A.A.); (T.H.); (E.F.); (O.A.A.)
- Department of Medical Genetics, Oslo University Hospital, 0450 Oslo, Norway
| | - Francesca Puppo
- NORMENT, Institute of Clinical Medicine, University of Oslo & Division of Mental Health and Addiction, Oslo University Hospital, 0450 Oslo, Norway; (A.S.); (J.R.O.); (F.P.); (K.S.O.); (I.A.A.); (T.H.); (E.F.); (O.A.A.)
- Department of Neurosciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Kevin S. O’Connell
- NORMENT, Institute of Clinical Medicine, University of Oslo & Division of Mental Health and Addiction, Oslo University Hospital, 0450 Oslo, Norway; (A.S.); (J.R.O.); (F.P.); (K.S.O.); (I.A.A.); (T.H.); (E.F.); (O.A.A.)
| | - Ibrahim A. Akkouh
- NORMENT, Institute of Clinical Medicine, University of Oslo & Division of Mental Health and Addiction, Oslo University Hospital, 0450 Oslo, Norway; (A.S.); (J.R.O.); (F.P.); (K.S.O.); (I.A.A.); (T.H.); (E.F.); (O.A.A.)
- Department of Medical Genetics, Oslo University Hospital, 0450 Oslo, Norway
| | - Timothy Hughes
- NORMENT, Institute of Clinical Medicine, University of Oslo & Division of Mental Health and Addiction, Oslo University Hospital, 0450 Oslo, Norway; (A.S.); (J.R.O.); (F.P.); (K.S.O.); (I.A.A.); (T.H.); (E.F.); (O.A.A.)
- Department of Medical Genetics, Oslo University Hospital, 0450 Oslo, Norway
| | - Evgeniia Frei
- NORMENT, Institute of Clinical Medicine, University of Oslo & Division of Mental Health and Addiction, Oslo University Hospital, 0450 Oslo, Norway; (A.S.); (J.R.O.); (F.P.); (K.S.O.); (I.A.A.); (T.H.); (E.F.); (O.A.A.)
- Department of Medical Genetics, Oslo University Hospital, 0450 Oslo, Norway
| | - Ole A. Andreassen
- NORMENT, Institute of Clinical Medicine, University of Oslo & Division of Mental Health and Addiction, Oslo University Hospital, 0450 Oslo, Norway; (A.S.); (J.R.O.); (F.P.); (K.S.O.); (I.A.A.); (T.H.); (E.F.); (O.A.A.)
- Division of Mental Health and Addiction, Oslo University Hospital, 0372 Oslo, Norway
| | - Srdjan Djurovic
- NORMENT, Institute of Clinical Medicine, University of Oslo & Division of Mental Health and Addiction, Oslo University Hospital, 0450 Oslo, Norway; (A.S.); (J.R.O.); (F.P.); (K.S.O.); (I.A.A.); (T.H.); (E.F.); (O.A.A.)
- NORMENT, Department of Clinical Science, University of Bergen, 5020 Bergen, Norway
| |
Collapse
|
2
|
Papouin T, Dunphy J, Tolman M, Foley JC, Haydon PG. Astrocytic control of synaptic function. Philos Trans R Soc Lond B Biol Sci 2017; 372:rstb.2016.0154. [PMID: 28093548 DOI: 10.1098/rstb.2016.0154] [Citation(s) in RCA: 134] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/27/2016] [Indexed: 12/19/2022] Open
Abstract
Astrocytes intimately interact with synapses, both morphologically and, as evidenced in the past 20 years, at the functional level. Ultrathin astrocytic processes contact and sometimes enwrap the synaptic elements, sense synaptic transmission and shape or alter the synaptic signal by releasing signalling molecules. Yet, the consequences of such interactions in terms of information processing in the brain remain very elusive. This is largely due to two major constraints: (i) the exquisitely complex, dynamic and ultrathin nature of distal astrocytic processes that renders their investigation highly challenging and (ii) our lack of understanding of how information is encoded by local and global fluctuations of intracellular calcium concentrations in astrocytes. Here, we will review the existing anatomical and functional evidence of local interactions between astrocytes and synapses, and how it underlies a role for astrocytes in the computation of synaptic information.This article is part of the themed issue 'Integrating Hebbian and homeostatic plasticity'.
Collapse
Affiliation(s)
- Thomas Papouin
- Neuroscience Department, Tufts University, Boston, MA 02111, USA
| | - Jaclyn Dunphy
- Neuroscience Department, Tufts University, Boston, MA 02111, USA
| | - Michaela Tolman
- Neuroscience Department, Tufts University, Boston, MA 02111, USA
| | - Jeannine C Foley
- Neurobiology Department, Harvard Medical School, Boston, MA 02115, USA
| | - Philip G Haydon
- Neuroscience Department, Tufts University, Boston, MA 02111, USA
| |
Collapse
|
3
|
Affiliation(s)
- Ihssane Zouikr
- Laboratory for Molecular Mechanisms of Thalamus Development, RIKEN BSI, Wako, Japan
| | - Sanae Hasegawa-Ishii
- Department of Pharmacology, Pennsylvania State University College of Medicine, Hershey, PA, United States
| | | |
Collapse
|
4
|
Wan G, Gómez-Casati ME, Gigliello AR, Liberman MC, Corfas G. Neurotrophin-3 regulates ribbon synapse density in the cochlea and induces synapse regeneration after acoustic trauma. eLife 2014; 3. [PMID: 25329343 PMCID: PMC4227045 DOI: 10.7554/elife.03564] [Citation(s) in RCA: 169] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 10/09/2014] [Indexed: 12/23/2022] Open
Abstract
Neurotrophin-3 (Ntf3) and brain derived neurotrophic factor (Bdnf) are critical for sensory neuron survival and establishment of neuronal projections to sensory epithelia in the embryonic inner ear, but their postnatal functions remain poorly understood. Using cell-specific inducible gene recombination in mice we found that, in the postnatal inner ear, Bbnf and Ntf3 are required for the formation and maintenance of hair cell ribbon synapses in the vestibular and cochlear epithelia, respectively. We also show that supporting cells in these epithelia are the key endogenous source of the neurotrophins. Using a new hair cell CreER(T) line with mosaic expression, we also found that Ntf3's effect on cochlear synaptogenesis is highly localized. Moreover, supporting cell-derived Ntf3, but not Bbnf, promoted recovery of cochlear function and ribbon synapse regeneration after acoustic trauma. These results indicate that glial-derived neurotrophins play critical roles in inner ear synapse density and synaptic regeneration after injury.
Collapse
Affiliation(s)
- Guoqiang Wan
- F M Kirby Neurobiology Center, Boston Children's Hospital, Boston, United States
| | - Maria E Gómez-Casati
- F M Kirby Neurobiology Center, Boston Children's Hospital, Boston, United States
| | - Angelica R Gigliello
- F M Kirby Neurobiology Center, Boston Children's Hospital, Boston, United States
| | - M Charles Liberman
- Department of Otology and Laryngology, Harvard Medical School, Boston, United States
| | - Gabriel Corfas
- F M Kirby Neurobiology Center, Boston Children's Hospital, Boston, United States
| |
Collapse
|
5
|
Zhao J, Ha Y, Liou GI, Gonsalvez GB, Smith SB, Bollinger KE. Sigma receptor ligand, (+)-pentazocine, suppresses inflammatory responses of retinal microglia. Invest Ophthalmol Vis Sci 2014; 55:3375-84. [PMID: 24812552 PMCID: PMC4042630 DOI: 10.1167/iovs.13-12823] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2013] [Accepted: 04/29/2014] [Indexed: 02/05/2023] Open
Abstract
PURPOSE To evaluate the effects of the σ 1 receptor (σR1) agonist, (+)-pentazocine, on lipopolysaccharide (LPS)-induced inflammatory changes in retinal microglia cells. METHODS Retinal microglia cells were isolated from Sprague-Dawley rat pups. Cells were treated with LPS with or without (+)-pentazocine and with or without the σR1 antagonist BD1063. Morphologic changes were assayed. Cell viability was assessed by using MTT assay. Supernatant levels of tumor necrosis factor α (TNF-α), interleukin 10, (IL-10), monocyte chemoattractant protein-1 (MCP-1), and nitric oxide (NO) were determined. Reactive oxygen species (ROS) formation was assayed, and levels of mitogen-activated protein kinases (MAPKs) were analyzed by using Western blot. RESULTS The σR1 protein was expressed in retinal microglia. Incubation with LPS and/or (+)-pentazocine did not alter cell viability or σR1 protein levels. Incubation with LPS for 24 hours induced a marked change in microglial morphology and a significant increase in secreted levels of TNF-α, IL-10, MCP-1, and NO. Pretreatment with (+)-pentazocine inhibited the LPS-induced morphologic changes. Release of TNF-α, IL-10, MCP-1, and NO was reduced with (+)-pentazocine. Intracellular ROS formation was suppressed with (+)-pentazocine. Phosphorylation of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) was reduced in the presence of (+)-pentazocine. The σR1 antagonist BD1063 blocked the (+)-pentazocine-mediated inhibition of LPS-induced morphologic changes. In addition, BD1063 treatment blocked (+)-pentazocine-mediated suppression of LPS-induced TNF-α, IL-10, MCP-1, NO, and intracellular ROS release. CONCLUSIONS Treatment with (+)-pentazocine suppressed inflammatory responses of retinal microglia and inhibited LPS-induced activation of ERK/JNK MAPK. In neurodegenerative disease, (+)-pentazocine may exert neuroprotective effects through manipulation of microglia.
Collapse
Affiliation(s)
- Jing Zhao
- James and Jean Culver Vision Discovery Institute, Georgia Regents University, Augusta, Georgia, United States
| | - Yonju Ha
- James and Jean Culver Vision Discovery Institute, Georgia Regents University, Augusta, Georgia, United States
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Georgia Regents University, Augusta, Georgia, United States
| | - Gregory I. Liou
- James and Jean Culver Vision Discovery Institute, Georgia Regents University, Augusta, Georgia, United States
- Department of Ophthalmology, Medical College of Georgia, Georgia Regents University, Augusta, Georgia, United States
| | - Graydon B. Gonsalvez
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Georgia Regents University, Augusta, Georgia, United States
| | - Sylvia B. Smith
- James and Jean Culver Vision Discovery Institute, Georgia Regents University, Augusta, Georgia, United States
| | - Kathryn E. Bollinger
- James and Jean Culver Vision Discovery Institute, Georgia Regents University, Augusta, Georgia, United States
| |
Collapse
|
6
|
Davila D, Thibault K, Fiacco TA, Agulhon C. Recent molecular approaches to understanding astrocyte function in vivo. Front Cell Neurosci 2013; 7:272. [PMID: 24399932 PMCID: PMC3871966 DOI: 10.3389/fncel.2013.00272] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Accepted: 12/06/2013] [Indexed: 12/11/2022] Open
Abstract
Astrocytes are a predominant glial cell type in the nervous systems, and are becoming recognized as important mediators of normal brain function as well as neurodevelopmental, neurological, and neurodegenerative brain diseases. Although numerous potential mechanisms have been proposed to explain the role of astrocytes in the normal and diseased brain, research into the physiological relevance of these mechanisms in vivo is just beginning. In this review, we will summarize recent developments in innovative and powerful molecular approaches, including knockout mouse models, transgenic mouse models, and astrocyte-targeted gene transfer/expression, which have led to advances in understanding astrocyte biology in vivo that were heretofore inaccessible to experimentation. We will examine the recently improved understanding of the roles of astrocytes – with an emphasis on astrocyte signaling – in the context of both the healthy and diseased brain, discuss areas where the role of astrocytes remains debated, and suggest new research directions.
Collapse
Affiliation(s)
- David Davila
- Glia-Glia and Glia-Neuron Interactions Group, National Center for Scientific Research, UFR Biomedicale, Paris Descartes University Paris, France
| | - Karine Thibault
- Glia-Glia and Glia-Neuron Interactions Group, National Center for Scientific Research, UFR Biomedicale, Paris Descartes University Paris, France
| | - Todd A Fiacco
- Department of Cell Biology and Neuroscience, and Center for Glial-Neuronal Interactions and Program in Cellular, Molecular and Developmental Biology, University of California at Riverside Riverside, CA, USA
| | - Cendra Agulhon
- Glia-Glia and Glia-Neuron Interactions Group, National Center for Scientific Research, UFR Biomedicale, Paris Descartes University Paris, France
| |
Collapse
|
7
|
Del Puerto A, Wandosell F, Garrido JJ. Neuronal and glial purinergic receptors functions in neuron development and brain disease. Front Cell Neurosci 2013; 7:197. [PMID: 24191147 PMCID: PMC3808753 DOI: 10.3389/fncel.2013.00197] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2013] [Accepted: 10/10/2013] [Indexed: 11/23/2022] Open
Abstract
Brain development requires the interaction of complex signaling pathways, involving different cell types and molecules. For a long time, most attention has focused on neurons in a neuronocentric conceptualization of central nervous system development, these cells fulfilling an intrinsic program that establishes the brain’s morphology and function. By contrast, glia have mainly been studied as support cells, offering guidance or as the cells that react to brain injury. However, new evidence is appearing that demonstrates a more fundamental role of glial cells in the control of different aspects of neuronal development and function, events in which the influence of neurons is at best weak. Moreover, it is becoming clear that the function and organization of the nervous system depends heavily on reciprocal neuron–glia interactions. During development, neurons are often generated far from their final destination and while intrinsic mechanisms are responsible for neuronal migration and growth, they need support and regulatory influences from glial cells in order to migrate correctly. Similarly, the axons emitted by neurons often have to reach faraway targets and in this sense, glia help define the way that axons grow. Moreover, oligodendrocytes and Schwann cells ultimately envelop axons, contributing to the generation of nodes of Ranvier. Finally, recent publications show that astrocytes contribute to the modulation of synaptic transmission. In this sense, purinergic receptors are expressed widely by glial cells and neurons, and recent evidence points to multiple roles of purines and purinergic receptors in neuronal development and function, from neurogenesis to axon growth and functional axonal maturation, as well as in pathological conditions in the brain. This review will focus on the role of glial and neuronal secreted purines, and on the purinergic receptors, fundamentally in the control of neuronal development and function, as well as in diseases of the nervous system.
Collapse
Affiliation(s)
- Ana Del Puerto
- Department of Molecular, Cellular and Developmental Neurobiology, Instituto Cajal, Consejo Superior de Investigaciones Científicas Madrid, Spain ; Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas Madrid, Spain
| | | | | |
Collapse
|
8
|
Abstract
Neurons are exquisitely specialized for rapid electrical transmission of signals, but some properties of glial cells, which do not communicate with electrical impulses, are well suited for participating in complex cognitive functions requiring broad spatial integration and long-term temporal regulation. Astrocytes, microglia, and oligodendrocytes all have biological properties that could influence learning and cognition. Myelination by oligodendrocytes increases conduction velocity, affecting spike timing and oscillations in neuronal activity. Astrocytes can modulate synaptic transmission and may couple multiple neurons and synapses into functional assemblies. Microglia can remove synapses in an activity-dependent manner altering neural networks. Incorporating glia into a bicellular mechanism of nervous system function may help answer long-standing questions concerning the cellular mechanisms of learning and cognition.
Collapse
Affiliation(s)
| | | | | | | | - Gary Lynch
- University of California, Irvine, CA, USA
| | - Klaus-Armin Nave
- Max-Planck Institute for Experimental Medicine, Gottingen, Germany
| | | | - Ray Perez
- Office of Naval Research, Arlington, VA, USA
| | | | - Hiroaki Wake
- National Institute for Basic Biology, Okazaki, Japan
| |
Collapse
|
9
|
Fields RD. Imaging single photons and intrinsic optical signals for studies of vesicular and non-vesicular ATP release from axons. Front Neuroanat 2011; 5:32. [PMID: 21852965 PMCID: PMC3151621 DOI: 10.3389/fnana.2011.00032] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2011] [Accepted: 05/26/2011] [Indexed: 12/12/2022] Open
Abstract
The temporal and spatial dynamics of neurotransmitter release are fundamental to understanding activity-dependent signaling between axons and other cells, including neurons, glia, and vascular cells. A microscopic imaging technique is described that enables studying release of the neurotransmitter ATP from axons in response to action potentials. The method combines imaging single-photons, intrinsic optical signal imaging, and high magnification time-lapse microcopy to enable investigations of action potential-induced ATP release together with cell morphology and activity-dependent axon swelling. ATP released from axons catalyzes a chemiluminescent reaction between luciferin and luciferase that generates single photons that can be imaged individually. In addition to vesicular release, ATP release through membrane channels activated by axon swelling was monitored simultaneously with intrinsic optical signals. Repeated emissions of photons were observed from localized 15 μm regions of axons, with a frequency distribution that differed from a normal distribution and from the frequency of emissions outside these localized regions.
Collapse
Affiliation(s)
- R. Douglas Fields
- Nervous Systems Development and Plasticity Section, National Institute of Child Health and Human Development, National Institutes of HealthBethesda, MD, USA
| |
Collapse
|
10
|
Fields RD. Nonsynaptic and nonvesicular ATP release from neurons and relevance to neuron-glia signaling. Semin Cell Dev Biol 2011; 22:214-9. [PMID: 21320624 PMCID: PMC3163842 DOI: 10.1016/j.semcdb.2011.02.009] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2010] [Revised: 01/11/2011] [Accepted: 02/07/2011] [Indexed: 12/22/2022]
Abstract
Studies on the release of ATP from neurons began with the earliest investigations of quantal neurotransmitter release in the 1950s, but in contrast to ATP release from other cells, studies of ATP release from neurons have been narrowly constrained to one mechanism, vesicular release. This is a consequence of the prominence of synaptic transmission in neuronal communication, but nonvesicular mechanisms for ATP release from neurons are likely to have a broader range of functions than synaptic release. Investigations of activity-dependent communication between axons and myelinating glia have stimulated a search for mechanisms that could release ATP from axons and other nonsynaptic regions in response to action potential firing. This has identified volume-activated anion channels as an important mechanism in activity-dependent ATP release from axons, and renewed interest in micromechanical changes in axons that accompany action potential firing.
Collapse
Affiliation(s)
- R Douglas Fields
- Nervous Systems Development and Plasticity Section, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, United States.
| |
Collapse
|
11
|
Lein PJ, Beck HN, Chandrasekaran V, Gallagher PJ, Chen HL, Lin Y, Guo X, Kaplan PL, Tiedge H, Higgins D. Glia induce dendritic growth in cultured sympathetic neurons by modulating the balance between bone morphogenetic proteins (BMPs) and BMP antagonists. J Neurosci 2002; 22:10377-87. [PMID: 12451137 PMCID: PMC6758753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/27/2023] Open
Abstract
Dendritic growth in cultured sympathetic neurons requires specific trophic interactions. Previous studies have demonstrated that either coculture with glia or exposure to recombinant bone morphogenetic proteins (BMPs) is both necessary and sufficient to induce dendrite formation. These observations led us to test the hypothesis that BMPs mediate glial-induced dendritic growth. In situ hybridization and immunocytochemical studies indicate that the spatiotemporal expression of BMP5, -6, and -7 in rat superior cervical ganglia (SCG) is consistent with their proposed role in dendritogenesis. In vitro, both SCG glia and neurons were found to express BMP mRNA and protein when grown in the presence or absence of the other cell type. However, addition of ganglionic glia to cultured sympathetic neurons causes a marked increase in BMP proteins coincident with a significant decrease in follistatin and noggin. Functional assays indicate that glial-induced dendritic growth is significantly reduced by BMP7 antibodies and completely inhibited by exogenous noggin and follistatin. These data suggest that glia influence the rapid perinatal expansion of the dendritic arbor in sympathetic neurons by increasing BMP activity via modulation of the balance between BMPs and their antagonists.
Collapse
Affiliation(s)
- Pamela J Lein
- Department of Environmental Health Sciences, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland 21205-2179, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|