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Ricobaraza A, Bunuales M, Gonzalez-Aparicio M, Fadila S, Rubinstein M, Vides-Urrestarazu I, Banderas J, Sola-Sevilla N, Sanchez-Carpintero R, Lanciego JL, Roda E, Honrubia A, Arnaiz P, Hernandez-Alcoceba R. Preferential expression of SCN1A in GABAergic neurons improves survival and epileptic phenotype in a mouse model of Dravet syndrome. J Mol Med (Berl) 2023; 101:1587-1601. [PMID: 37819378 PMCID: PMC10697872 DOI: 10.1007/s00109-023-02383-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 09/15/2023] [Accepted: 09/25/2023] [Indexed: 10/13/2023]
Abstract
The SCN1A gene encodes the alpha subunit of a voltage-gated sodium channel (Nav1.1), which is essential for the function of inhibitory neurons in the brain. Mutations in this gene cause severe encephalopathies such as Dravet syndrome (DS). Upregulation of SCN1A expression by different approaches has demonstrated promising therapeutic effects in preclinical models of DS. Limiting the effect to inhibitory neurons may contribute to the restoration of brain homeostasis, increasing the safety and efficacy of the treatment. In this work, we have evaluated different approaches to obtain preferential expression of the full SCN1A cDNA (6 Kb) in GABAergic neurons, using high-capacity adenoviral vectors (HC-AdV). In order to favour infection of these cells, we considered ErbB4 as a surface target. Incorporation of the EGF-like domain from neuregulin 1 alpha (NRG1α) in the fiber of adenovirus capsid allowed preferential infection in cells lines expressing ErbB4. However, it had no impact on the infectivity of the vector in primary cultures or in vivo. For transcriptional control of transgene expression, we developed a regulatory sequence (DP3V) based on the Distal-less homolog enhancer (Dlx), the vesicular GABA transporter (VGAT) promoter, and a portion of the SCN1A gene. The hybrid DP3V promoter allowed preferential expression of transgenes in GABAergic neurons both in vitro and in vivo. A new HC-AdV expressing SCN1A under the control of this promoter showed improved survival and amelioration of the epileptic phenotype in a DS mouse model. These results increase the repertoire of gene therapy vectors for the treatment of DS and indicate a new avenue for the refinement of gene supplementation in this disease. KEY MESSAGES: Adenoviral vectors can deliver the SCN1A cDNA and are amenable for targeting. An adenoviral vector displaying an ErbB4 ligand in the capsid does not target GABAergic neurons. A hybrid promoter allows preferential expression of transgenes in GABAergic neurons. Preferential expression of SCN1A in GABAergic cells is therapeutic in a Dravet syndrome model.
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Affiliation(s)
- Ana Ricobaraza
- Gene Therapy and Regulation of Gene Expression Program, CIMA, University of Navarra, CIMA, Av. Pio XII 55, E-31008, Pamplona, Spain
| | - Maria Bunuales
- Gene Therapy and Regulation of Gene Expression Program, CIMA, University of Navarra, CIMA, Av. Pio XII 55, E-31008, Pamplona, Spain
| | - Manuela Gonzalez-Aparicio
- Gene Therapy and Regulation of Gene Expression Program, CIMA, University of Navarra, CIMA, Av. Pio XII 55, E-31008, Pamplona, Spain
| | - Saja Fadila
- Sackler Faculty of Medicine, Goldschleger Eye Research Institute, Tel Aviv University, Tel Aviv, Israel
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Moran Rubinstein
- Sackler Faculty of Medicine, Goldschleger Eye Research Institute, Tel Aviv University, Tel Aviv, Israel
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Irene Vides-Urrestarazu
- Gene Therapy and Regulation of Gene Expression Program, CIMA, University of Navarra, CIMA, Av. Pio XII 55, E-31008, Pamplona, Spain
| | - Julliana Banderas
- Gene Therapy and Regulation of Gene Expression Program, CIMA, University of Navarra, CIMA, Av. Pio XII 55, E-31008, Pamplona, Spain
| | - Noemi Sola-Sevilla
- Gene Therapy and Regulation of Gene Expression Program, CIMA, University of Navarra, CIMA, Av. Pio XII 55, E-31008, Pamplona, Spain
| | - Rocio Sanchez-Carpintero
- University Clinic of Navarra, Dravet Syndrome Unit, Pediatric Neurology Unit, IdiSNA, Navarra Institute for Health Research, Pamplona, Spain
| | - Jose Luis Lanciego
- Department of Neuroscience, CIMA, University of Navarra, Pamplona, Spain
- Instituto de Investigación Sanitaria de Navarra (IdiSNA), Pamplona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CiberNed), Madrid, Spain
| | - Elvira Roda
- Department of Neuroscience, CIMA, University of Navarra, Pamplona, Spain
| | - Adriana Honrubia
- Department of Neuroscience, CIMA, University of Navarra, Pamplona, Spain
| | - Patricia Arnaiz
- Department of Neuroscience, CIMA, University of Navarra, Pamplona, Spain
| | - Ruben Hernandez-Alcoceba
- Gene Therapy and Regulation of Gene Expression Program, CIMA, University of Navarra, CIMA, Av. Pio XII 55, E-31008, Pamplona, Spain.
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Kounoupa Z, Tivodar S, Theodorakis K, Kyriakis D, Denaxa M, Karagogeos D. Rac1 and Rac3 GTPases and TPC2 are required for axonal outgrowth and migration of cortical interneurons. J Cell Sci 2023; 136:286920. [PMID: 36744839 DOI: 10.1242/jcs.260373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 01/31/2023] [Indexed: 02/07/2023] Open
Abstract
Rho GTPases, among them Rac1 and Rac3, are major transducers of extracellular signals and are involved in multiple cellular processes. In cortical interneurons, the neurons that control the balance between excitation and inhibition of cortical circuits, Rac1 and Rac3 are essential for their development. Ablation of both leads to a severe reduction in the numbers of mature interneurons found in the murine cortex, which is partially due to abnormal cell cycle progression of interneuron precursors and defective formation of growth cones in young neurons. Here, we present new evidence that upon Rac1 and Rac3 ablation, centrosome, Golgi complex and lysosome positioning is significantly perturbed, thus affecting both interneuron migration and axon growth. Moreover, for the first time, we provide evidence of altered expression and localization of the two-pore channel 2 (TPC2) voltage-gated ion channel that mediates Ca2+ release. Pharmacological inhibition of TPC2 negatively affected axonal growth and migration of interneurons. Our data, taken together, suggest that TPC2 contributes to the severe phenotype in axon growth initiation, extension and interneuron migration in the absence of Rac1 and Rac3.
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Affiliation(s)
- Zouzana Kounoupa
- Institute of Molecular Biology and Biotechnology (IMBB, FORTH), Heraklion 71110, Greece.,Department of Basic Science, Faculty of Medicine, University of Crete, Heraklion 71110, Greece
| | - Simona Tivodar
- Institute of Molecular Biology and Biotechnology (IMBB, FORTH), Heraklion 71110, Greece.,Department of Basic Science, Faculty of Medicine, University of Crete, Heraklion 71110, Greece
| | - Kostas Theodorakis
- Institute of Molecular Biology and Biotechnology (IMBB, FORTH), Heraklion 71110, Greece.,Department of Basic Science, Faculty of Medicine, University of Crete, Heraklion 71110, Greece
| | - Dimitrios Kyriakis
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, L-4365 Esch-sur-Alzette, Luxembourg
| | - Myrto Denaxa
- Institute for Fundamental Biomedical Research, Biomedical Sciences Research Centre 'Al. Fleming', Vari, 16672, Greece
| | - Domna Karagogeos
- Institute of Molecular Biology and Biotechnology (IMBB, FORTH), Heraklion 71110, Greece.,Department of Basic Science, Faculty of Medicine, University of Crete, Heraklion 71110, Greece
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Lépine M, Douceau S, Devienne G, Prunotto P, Lenoir S, Regnauld C, Pouettre E, Piquet J, Lebouvier L, Hommet Y, Maubert E, Agin V, Lambolez B, Cauli B, Ali C, Vivien D. Parvalbumin interneuron-derived tissue-type plasminogen activator shapes perineuronal net structure. BMC Biol 2022; 20:218. [PMID: 36199089 PMCID: PMC9535866 DOI: 10.1186/s12915-022-01419-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 09/27/2022] [Indexed: 11/18/2022] Open
Abstract
Background Perineuronal nets (PNNs) are specialized extracellular matrix structures mainly found around fast-spiking parvalbumin (FS-PV) interneurons. In the adult, their degradation alters FS-PV-driven functions, such as brain plasticity and memory, and altered PNN structures have been found in neurodevelopmental and central nervous system disorders such as Alzheimer’s disease, leading to interest in identifying targets able to modify or participate in PNN metabolism. The serine protease tissue-type plasminogen activator (tPA) plays multifaceted roles in brain pathophysiology. However, its cellular expression profile in the brain remains unclear and a possible role in matrix plasticity through PNN remodeling has never been investigated. Result By combining a GFP reporter approach, immunohistology, electrophysiology, and single-cell RT-PCR, we discovered that cortical FS-PV interneurons are a source of tPA in vivo. We found that mice specifically lacking tPA in FS-PV interneurons display denser PNNs in the somatosensory cortex, suggesting a role for tPA from FS-PV interneurons in PNN remodeling. In vitro analyses in primary cultures of mouse interneurons also showed that tPA converts plasminogen into active plasmin, which in turn, directly degrades aggrecan, a major structural chondroitin sulfate proteoglycan (CSPG) in PNNs. Conclusions We demonstrate that tPA released from FS-PV interneurons in the central nervous system reduces PNN density through CSPG degradation. The discovery of this tPA-dependent PNN remodeling opens interesting insights into the control of brain plasticity. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-022-01419-8.
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Affiliation(s)
- Matthieu Lépine
- Normandie Univ, UNICAEN, INSERM, INSERM UMR-S U1237, Physiopathology and Imaging of Neurological Disorders, Institut Blood and Brain @ Caen Normandie, Cyceron, Bd Becquerel, BP 5229-14074, 14000, Caen, France
| | - Sara Douceau
- Normandie Univ, UNICAEN, INSERM, INSERM UMR-S U1237, Physiopathology and Imaging of Neurological Disorders, Institut Blood and Brain @ Caen Normandie, Cyceron, Bd Becquerel, BP 5229-14074, 14000, Caen, France
| | - Gabrielle Devienne
- Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), Sorbonne Université UM119, CNRS UMR8246, INSERM U1130, 75005, Paris, France
| | - Paul Prunotto
- Normandie Univ, UNICAEN, INSERM, INSERM UMR-S U1237, Physiopathology and Imaging of Neurological Disorders, Institut Blood and Brain @ Caen Normandie, Cyceron, Bd Becquerel, BP 5229-14074, 14000, Caen, France
| | - Sophie Lenoir
- Normandie Univ, UNICAEN, INSERM, INSERM UMR-S U1237, Physiopathology and Imaging of Neurological Disorders, Institut Blood and Brain @ Caen Normandie, Cyceron, Bd Becquerel, BP 5229-14074, 14000, Caen, France
| | - Caroline Regnauld
- Normandie Univ, UNICAEN, INSERM, INSERM UMR-S U1237, Physiopathology and Imaging of Neurological Disorders, Institut Blood and Brain @ Caen Normandie, Cyceron, Bd Becquerel, BP 5229-14074, 14000, Caen, France
| | - Elsa Pouettre
- Normandie Univ, UNICAEN, INSERM, INSERM UMR-S U1237, Physiopathology and Imaging of Neurological Disorders, Institut Blood and Brain @ Caen Normandie, Cyceron, Bd Becquerel, BP 5229-14074, 14000, Caen, France
| | - Juliette Piquet
- Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), Sorbonne Université UM119, CNRS UMR8246, INSERM U1130, 75005, Paris, France
| | - Laurent Lebouvier
- Normandie Univ, UNICAEN, INSERM, INSERM UMR-S U1237, Physiopathology and Imaging of Neurological Disorders, Institut Blood and Brain @ Caen Normandie, Cyceron, Bd Becquerel, BP 5229-14074, 14000, Caen, France
| | - Yannick Hommet
- Normandie Univ, UNICAEN, INSERM, INSERM UMR-S U1237, Physiopathology and Imaging of Neurological Disorders, Institut Blood and Brain @ Caen Normandie, Cyceron, Bd Becquerel, BP 5229-14074, 14000, Caen, France
| | - Eric Maubert
- Normandie Univ, UNICAEN, INSERM, INSERM UMR-S U1237, Physiopathology and Imaging of Neurological Disorders, Institut Blood and Brain @ Caen Normandie, Cyceron, Bd Becquerel, BP 5229-14074, 14000, Caen, France
| | - Véronique Agin
- Normandie Univ, UNICAEN, INSERM, INSERM UMR-S U1237, Physiopathology and Imaging of Neurological Disorders, Institut Blood and Brain @ Caen Normandie, Cyceron, Bd Becquerel, BP 5229-14074, 14000, Caen, France
| | - Bertrand Lambolez
- Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), Sorbonne Université UM119, CNRS UMR8246, INSERM U1130, 75005, Paris, France
| | - Bruno Cauli
- Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), Sorbonne Université UM119, CNRS UMR8246, INSERM U1130, 75005, Paris, France
| | - Carine Ali
- Normandie Univ, UNICAEN, INSERM, INSERM UMR-S U1237, Physiopathology and Imaging of Neurological Disorders, Institut Blood and Brain @ Caen Normandie, Cyceron, Bd Becquerel, BP 5229-14074, 14000, Caen, France.
| | - Denis Vivien
- Department of clinical research, CHU de Caen Normandie, Caen, France
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FXR1 regulation of parvalbumin interneurons in the prefrontal cortex is critical for schizophrenia-like behaviors. Mol Psychiatry 2021; 26:6845-6867. [PMID: 33863995 PMCID: PMC8521570 DOI: 10.1038/s41380-021-01096-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Revised: 03/18/2021] [Accepted: 03/31/2021] [Indexed: 12/13/2022]
Abstract
Parvalbumin interneurons (PVIs) are affected in many psychiatric disorders including schizophrenia (SCZ), however the mechanism remains unclear. FXR1, a high confident risk gene for SCZ, is indispensable but its role in the brain is largely unknown. We show that deleting FXR1 from PVIs of medial prefrontal cortex (mPFC) leads to reduced PVI excitability, impaired mPFC gamma oscillation, and SCZ-like behaviors. PVI-specific translational profiling reveals that FXR1 regulates the expression of Cacna1h/Cav3.2 a T-type calcium channel implicated in autism and epilepsy. Inhibition of Cav3.2 in PVIs of mPFC phenocopies whereas elevation of Cav3.2 in PVIs of mPFC rescues behavioral deficits resulted from FXR1 deficiency. Stimulation of PVIs using a gamma oscillation-enhancing light flicker rescues behavioral abnormalities caused by FXR1 deficiency in PVIs. This work unveils the function of a newly identified SCZ risk gene in SCZ-relevant neurons and identifies a therapeutic target and a potential noninvasive treatment for psychiatric disorders.
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5
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Marty S, Beekhuijzen M, Charlton A, Hallmark N, Hannas BR, Jacobi S, Melching-Kollmuss S, Sauer UG, Sheets LP, Strauss V, Urbisch D, Botham PA, van Ravenzwaay B. Towards a science-based testing strategy to identify maternal thyroid hormone imbalance and neurodevelopmental effects in the progeny - part II: how can key events of relevant adverse outcome pathways be addressed in toxicological assessments? Crit Rev Toxicol 2021; 51:328-358. [PMID: 34074207 DOI: 10.1080/10408444.2021.1910625] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The current understanding of thyroid-related adverse outcome pathways (AOPs) with adverse neurodevelopmental outcomes in mammals has been reviewed. This served to establish if standard rodent toxicity test methods and in vitro assays allow identifying thyroid-related modes-of-action potentially leading to adverse neurodevelopmental outcomes, and the human relevance of effects - in line with the European Commission's Endocrine Disruptor Criteria. The underlying hypothesis is that an understanding of the key events of relevant AOPs provides insight into differences in incidence, magnitude, or species sensitivity of adverse outcomes. The rodent studies include measurements of serum thyroid hormones, thyroid gland pathology and neurodevelopmental assessments, but do not directly inform on specific modes-of-action. Opportunities to address additional non-routine parameters reflecting critical events of AOPs in toxicological assessments are presented. These parameters appear relevant to support the identification of specific thyroid-related modes-of-action, provided that prevailing technical limitations are overcome. Current understanding of quantitative key event relationships is often weak, but would be needed to determine if the triggering of a molecular initiating event will ultimately result in an adverse outcome. Also, significant species differences in all processes related to thyroid hormone signalling are evident, but the biological implications thereof (including human relevance) are often unknown. In conclusion, careful consideration of the measurement (e.g. timing, method) and interpretation of additional non-routine parameters is warranted. These findings will be used in a subsequent paper to propose a testing strategy to identify if a substance may elicit maternal thyroid hormone imbalance and potentially also neurodevelopmental effects in the progeny.
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Affiliation(s)
- Sue Marty
- The Dow Chemical Company, Midland, MI, USA
| | | | | | | | | | | | | | - Ursula G Sauer
- Scientific Consultancy - Animal Welfare, Neubiberg, Germany
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Interneuron Origins in the Embryonic Porcine Medial Ganglionic Eminence. J Neurosci 2021; 41:3105-3119. [PMID: 33637558 DOI: 10.1523/jneurosci.2738-20.2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 12/18/2020] [Accepted: 01/08/2021] [Indexed: 02/06/2023] Open
Abstract
Interneurons contribute to the complexity of neural circuits and maintenance of normal brain function. Rodent interneurons originate in embryonic ganglionic eminences, but developmental origins in other species are less understood. Here, we show that transcription factor expression patterns in porcine embryonic subpallium are similar to rodents, delineating a distinct medial ganglionic eminence (MGE) progenitor domain. On the basis of Nkx2.1, Lhx6, and Dlx2 expression, in vitro differentiation into neurons expressing GABA, and robust migratory capacity in explant assays, we propose that cortical and hippocampal interneurons originate from a porcine MGE region. Following xenotransplantation into adult male and female rat hippocampus, we further demonstrate that porcine MGE progenitors, like those from rodents, migrate and differentiate into morphologically distinct interneurons expressing GABA. Our findings reveal that basic rules for interneuron development are conserved across species, and that porcine embryonic MGE progenitors could serve as a valuable source for interneuron-based xenotransplantation therapies.SIGNIFICANCE STATEMENT Here we demonstrate that porcine medial ganglionic eminence, like rodents, exhibit a distinct transcriptional and interneuron-specific antibody profile, in vitro migratory capacity and are amenable to xenotransplantation. This is the first comprehensive examination of embryonic interneuron origins in the pig; and because a rich neurodevelopmental literature on embryonic mouse medial ganglionic eminence exists (with some additional characterizations in other species, e.g., monkey and human), our work allows direct neurodevelopmental comparisons with this literature.
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Chantranupong L, Saulnier JL, Wang W, Jones DR, Pacold ME, Sabatini BL. Rapid purification and metabolomic profiling of synaptic vesicles from mammalian brain. eLife 2020; 9:59699. [PMID: 33043885 PMCID: PMC7575323 DOI: 10.7554/elife.59699] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 10/11/2020] [Indexed: 12/14/2022] Open
Abstract
Neurons communicate by the activity-dependent release of small-molecule neurotransmitters packaged into synaptic vesicles (SVs). Although many molecules have been identified as neurotransmitters, technical limitations have precluded a full metabolomic analysis of SV content. Here, we present a workflow to rapidly isolate SVs and to interrogate their metabolic contents at high-resolution using mass spectrometry. We validated the enrichment of glutamate in SVs of primary cortical neurons using targeted polar metabolomics. Unbiased and extensive global profiling of SVs isolated from these neurons revealed that the only detectable polar metabolites they contain are the established neurotransmitters glutamate and GABA. In addition, we adapted the approach to enable quick capture of SVs directly from brain tissue and determined the neurotransmitter profiles of diverse brain regions in a cell-type-specific manner. The speed, robustness, and precision of this method to interrogate SV contents will facilitate novel insights into the chemical basis of neurotransmission.
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Affiliation(s)
- Lynne Chantranupong
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, United States
| | - Jessica L Saulnier
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, United States
| | - Wengang Wang
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, United States
| | - Drew R Jones
- New York University School of Medicine, Metabolomics Core Resource Laboratory at NYU Langone Health, New York, United States
| | - Michael E Pacold
- Department of Radiation Oncology, New York University Langone Medical Center, New York, United States
| | - Bernardo L Sabatini
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, United States
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Neuregulins 1, 2, and 3 Promote Early Neurite Outgrowth in ErbB4-Expressing Cortical GABAergic Interneurons. Mol Neurobiol 2020; 57:3568-3588. [PMID: 32542595 DOI: 10.1007/s12035-020-01966-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 05/29/2020] [Indexed: 12/27/2022]
Abstract
The neuregulins (Nrgs 1-4) are a family of signaling molecules that play diverse roles in the nervous system. Nrg1 has been implicated in the formation of synapses and in synaptic plasticity. Previous studies have shown Nrg1 can affect neurite outgrowth in several neuronal populations, while the role of Nrg2 and Nrg3 in this process has remained understudied. The Nrgs can bind and activate the ErbB4 receptor tyrosine kinase which is preferentially expressed in GABAergic interneurons in the rodent hippocampus and cerebral cortex. In the present study, we evaluated the effects of Nrgs 1, 2, and 3 on neurite outgrowth of dissociated rat cortical ErbB4-positive (+)/GABA+ interneurons in vitro. All three Nrgs were able to promote neurite outgrowth during the first 2 days in vitro, with increases detected for both the axon (116-120%) and other neurites (100-120%). Increases in the average number of primary and secondary neurites were also observed. Treatment with the Nrgs for an additional 3 days promoted an increase in axonal length (86-96%), with only minimal effects on the remaining neurites (8-13%). ErbB4 expression persisted throughout the dendritic arbor and cell soma at all stages examined, while its expression in the axon was transient and declined with cell maturation. ErbB4 overexpression in GABAergic neurons promoted neurite outgrowth, an effect that was potentiated by Nrg treatment. These results show that Nrgs 1, 2, and 3 are each capable of influencing dendritic and axonal growth at early developmental stages in GABAergic neurons grown in vitro.
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Mechanistic insights into autocrine and paracrine roles of endothelial GABA signaling in the embryonic forebrain. Sci Rep 2019; 9:16256. [PMID: 31700116 PMCID: PMC6838150 DOI: 10.1038/s41598-019-52729-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 10/18/2019] [Indexed: 12/24/2022] Open
Abstract
The developing cerebral cortex uses a complex developmental plan involving angiogenesis, neurogenesis and neuronal migration. Our recent studies have highlighted the importance of endothelial cell secreted GABA signaling in the embryonic forebrain and established novel autonomous links between blood vessels and the origin of neuropsychiatric diseases. A GABA pathway operates in both endothelial cells and GABAergic neurons of the embryonic telencephalon; however, while the neuronal GABA pathway has been extensively studied, little is known about the endothelial GABA pathway. Our recently generated Vgat endothelial cell knockout mouse model that blocks GABA release from endothelial cells, serves as a new tool to study how endothelial GABA signaling shapes angiogenesis and neurovascular interactions during prenatal development. Quantitative gene expression profiling reveals that the endothelial GABA signaling pathway influences genes connected to specific processes like endothelial cell proliferation, differentiation, migration, tight junction formation, vascular sprouting and integrity. It also shows how components of the neuronal GABA pathway, for instance receptor mediated signaling, cell cycle related components and transcription factors are affected in the absence of endothelial GABA release. Taken together, our findings delineate the close relationship between vascular and nervous systems that begin early in embryogenesis establishing their future interactions and interdependence.
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