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Shrestha AP, Stiles M, Grambergs RC, Boff JM, Madireddy S, Mondal K, Rajmanna R, Porter H, Sherry DM, Proia RL, Vaithianathan T, Mandal N. The Role of Sphingosine-1-Phosphate Receptor 2 in Mouse Retina Light Responses. Biomolecules 2023; 13:1691. [PMID: 38136563 PMCID: PMC10741782 DOI: 10.3390/biom13121691] [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: 10/10/2023] [Revised: 11/09/2023] [Accepted: 11/19/2023] [Indexed: 12/24/2023] Open
Abstract
The bioactive sphingolipid sphingosine-1-phosphate (S1P) acts as a ligand for a family of G protein-coupled S1P receptors (S1PR1-5) to participate in a variety of signaling pathways. However, their specific roles in the neural retina remain unclear. We previously showed that S1P receptor subtype 2 (S1PR2) is expressed in murine retinas, primarily in photoreceptors and bipolar cells, and its expression is altered by retinal stress. This study aims to elucidate the role of S1PR2 in the mouse retina. We examined light responses by electroretinography (ERG), structural differences by optical coherence tomography (OCT), and protein levels by immunohistochemistry (IHC) in wild-type (WT) and S1PR2 knockout (KO) mice at various ages between 3 and 6 months. We found that a- and b-wave responses significantly increased at flash intensities between 400~2000 and 4~2000 cd.s/m2, respectively, in S1PR2 KO mice relative to those of WT controls at baseline. S1PR2 KO mice also exhibited significantly increased retinal nerve fiber layer (RNFL) and outer plexiform layer (OPL) thickness by OCT relative to the WT. Finally, in S1PR2 KO mice, we observed differential labeling of synaptic markers by immunohistochemistry (IHC) and quantitative reverse transcription polymerase chain reaction (RT-qPCR). These results suggest a specific involvement of S1PR2 in the structure and synaptic organization of the retina and a potential role in light-mediated functioning of the retina.
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Affiliation(s)
- Abhishek P. Shrestha
- Department of Pharmacology, Addiction Science, and Toxicology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Megan Stiles
- Departments of Cell Biology, Neurosurgery, and Pharmacological Sciences, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Richard C. Grambergs
- Department of Ophthalmology, Hamilton Eye Institute, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Johane M. Boff
- Department of Pharmacology, Addiction Science, and Toxicology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Saivikram Madireddy
- College of Medicine, The University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Koushik Mondal
- Department of Ophthalmology, Hamilton Eye Institute, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Rhea Rajmanna
- Department of Pharmacology, Addiction Science, and Toxicology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Hunter Porter
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - David M. Sherry
- Departments of Cell Biology, Neurosurgery, and Pharmacological Sciences, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Richard L. Proia
- Genetics of Development and Disease Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Thirumalini Vaithianathan
- Department of Pharmacology, Addiction Science, and Toxicology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Nawajes Mandal
- Department of Ophthalmology, Hamilton Eye Institute, University of Tennessee Health Science Center, Memphis, TN 38163, USA
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
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Powers BE, Ton ST, Farrer RG, Chaudhary S, Nockels RP, Kartje GL, Tsai SY. Anti-Nogo-A Antibody Therapy Improves Functional Outcome Following Traumatic Brain Injury. Neurorehabil Neural Repair 2023; 37:682-693. [PMID: 37837331 PMCID: PMC10843026 DOI: 10.1177/15459683231203194] [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] [Indexed: 10/16/2023]
Abstract
BACKGROUND Traumatic brain injury (TBI) can cause sensorimotor deficits, and recovery is slow and incomplete. There are no effective pharmacological treatments for recovery from TBI, but research indicates potential for anti-Nogo-A antibody (Ab) therapy. This Ab neutralizes Nogo-A, an endogenous transmembrane protein that inhibits neuronal plasticity and regeneration. OBJECTIVE We hypothesized that anti-Nogo-A Ab treatment following TBI results in disinhibited axonal growth from the contralesional cortex, the establishment of new compensatory neuronal connections, and improved function. METHODS We modeled TBI in rats using the controlled cortical impact method, resulting in focal brain damage and motor deficits like those observed in humans with a moderate cortical TBI. Rats were trained on the skilled forelimb reaching task and the horizontal ladder rung walking task. They were then given a TBI, targeting the caudal forelimb motor cortex, and randomly divided into 3 groups: TBI-only, TBI + Anti-Nogo-A Ab, and TBI + Control Ab. Testing resumed 3 days after TBI and continued for 8 weeks, when rats received an injection of the anterograde neuronal tracer, biotinylated dextran amine (BDA), into the corresponding area contralateral to the TBI. RESULTS We observed significant improvement in rats that received anti-Nogo-A Ab treatment post-TBI compared to controls. Analysis of BDA-positive axons revealed that anti-Nogo-A Ab treatment resulted in cortico-rubral plasticity to the deafferented red nucleus. Conclusions. Anti-Nogo-A Ab treatment may improve functional recovery via neuronal plasticity to brain areas important for skilled movements, and this treatment shows promise to improve outcomes in humans who have suffered a TBI.
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Affiliation(s)
- Brian E Powers
- Edward Hines Jr. Veteran Affairs Hospital, Hines, IL, USA
| | - Son T Ton
- Edward Hines Jr. Veteran Affairs Hospital, Hines, IL, USA
| | | | | | - Russ P Nockels
- Department of Neurological Surgery, Loyola University Medical Center, Maywood, IL, USA
| | - Gwendolyn L Kartje
- Edward Hines Jr. Veteran Affairs Hospital, Hines, IL, USA
- Department of Molecular Pharmacology and Neuroscience, Loyola University Health Sciences Division, Maywood, IL, USA
| | - Shih-Yen Tsai
- Edward Hines Jr. Veteran Affairs Hospital, Hines, IL, USA
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3
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Shrestha AP, Stiles M, Grambergs RC, Boff JM, Madireddy S, Mondal K, Rajmanna R, Porter H, Sherry D, Proia RL, Vaithianathan T, Mandal N. The role of sphingosine-1-phosphate receptor 2 in mouse retina light responses. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.01.555709. [PMID: 37732206 PMCID: PMC10508730 DOI: 10.1101/2023.09.01.555709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
The bioactive sphingolipid sphingosine-1-phosphate (S1P) acts as a ligand for a family of G protein-coupled S1P receptors (S1PR1-5) to participate in a variety of signaling pathways. However, their specific roles in the neural retina remain unclear. We previously showed that S1P receptor subtype 2 (S1PR2) is expressed in murine retinas, primarily in photoreceptors and bipolar cells, and its expression is altered by retinal stress. This study aims to elucidate the role of S1PR2 in the mouse retina. We examined light responses by electroretinography (ERG), structural differences by optical coherence tomography (OCT), and protein levels by immunohistochemistry (IHC) in wild-type (WT) and S1PR2 knockout (KO) mice at various ages between 3 and 6 months. We found that a- and b-wave responses significantly increased at flash intensities between 400∼2000 and 4∼2,000 cd.s/m 2 respectively, in S1PR2 KO mice relative to those of WT controls at baseline. S1PR2 KO mice also exhibited significantly increased retinal nerve fiber layer (RNFL) and outer plexiform layer (OPL) thickness by OCT relative to the WT. Finally, in S1PR2 KO mice, we observed differential labeling of synaptic markers by immunohistochemistry (IHC) and quantitative reverse transcription polymerase chain reaction (RT-qPCR). These results suggest a specific involvement of S1PR2 in the structure and synaptic organization of the retina and a potential role in light-mediated functioning of the retina.
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Pernet V, Joly S, Spiegel S, Meli I, Idriss S, Maigler F, Mdzomba JB, Roenneke AK, Franceschini A, Silvestri L, Pavone FS, Calamai M, Schindowski K, Chan A. Nogo-A antibody delivery through the olfactory mucosa mitigates experimental autoimmune encephalomyelitis in the mouse CNS. Cell Death Discov 2023; 9:290. [PMID: 37558696 PMCID: PMC10412545 DOI: 10.1038/s41420-023-01588-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 07/18/2023] [Accepted: 07/28/2023] [Indexed: 08/11/2023] Open
Abstract
Systemic administration of Nogo-A-neutralizing antibody ameliorates experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. However, the blood-brain barrier (BBB) is a major obstacle limiting the passage of systemically applied antibody to the CNS. To bypass the BBB, in the present study we tested the intranasal route of administration by targeting the olfactory mucosa with the Nogo-A-blocking antibody 11C7 mAb in myelin oligodendrocyte glycoprotein-induced EAE. Antibodies were specifically administered onto the olfactory mucosa using a microcatheter. Antibody distribution was examined in the CNS by ELISA and light-sheet microscopy. The effects of 11C7 mAb on Nogo-A signaling were assessed by Western blotting. EAE-induced deficits were monitored daily. Demyelination was observed on spinal cord histological sections. Gene expression changes were followed by trancriptomic analyses. A sensitive capture ELISA revealed a rapid and widespread distribution of 11C7 mAb in the CNS, including the olfactory bulb, the cerebellum and the lumbar spinal cord, but not in the CSF. Light-sheet microscopy allowed to observe antibody accumulation in the parenchyma, thus demonstrating nose-to-brain transfer of IgG. At the functional level, the widespread penetration of 11C7 mAb in the CNS, including the thoracolumbar spinal cord, resulted in the improvement of motor symptoms and in the preservation of myelin in the spinal cord of EAE mice. This was accompanied by Nogo-A signaling downregulation, as reflected by the decreased level of phosphorylated cofilin observed by Western blotting in the cerebellum. In the brain of EAE score-matched animals, 11C7 modified the expression of genes that can influence neurotransmission and cognitive functions, independently of the demyelination phenotype in the spinal cord. In conclusion, our data show the feasibility of olfactory mucosa-directed administration for the delivery of therapeutic antibodies targeting CNS antigens in EAE mice.
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Affiliation(s)
- Vincent Pernet
- Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.
- Center for experimental neurology (ZEN), Bern University Hospital, University of Bern, Bern, Switzerland.
- Centre de recherche du CHU de Québec-Université Laval and Department of Molecular Medicine, Faculté de médecine, Université Laval, Québec, Québec, Canada.
| | - Sandrine Joly
- Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Center for experimental neurology (ZEN), Bern University Hospital, University of Bern, Bern, Switzerland
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Sebastian Spiegel
- Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Center for experimental neurology (ZEN), Bern University Hospital, University of Bern, Bern, Switzerland
- Institute of Applied Biotechnology, Biberach University of Applied Science, Hubertus-Liebrecht-Strasse 35, Biberach, Germany
- Department of Biomedical Research, University of Bern, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Ivo Meli
- Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Center for experimental neurology (ZEN), Bern University Hospital, University of Bern, Bern, Switzerland
| | - Sherif Idriss
- Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Center for experimental neurology (ZEN), Bern University Hospital, University of Bern, Bern, Switzerland
| | - Frank Maigler
- Institute of Applied Biotechnology, Biberach University of Applied Science, Hubertus-Liebrecht-Strasse 35, Biberach, Germany
| | - Julius Baya Mdzomba
- Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Center for experimental neurology (ZEN), Bern University Hospital, University of Bern, Bern, Switzerland
| | - Anna K Roenneke
- Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Center for experimental neurology (ZEN), Bern University Hospital, University of Bern, Bern, Switzerland
| | - Alessandra Franceschini
- LENS- European Laboratory for Non-Linear Spectroscopy, University of Florence, Sesto-Fiorentino (Firenze), Italy
| | - Ludovico Silvestri
- LENS- European Laboratory for Non-Linear Spectroscopy, University of Florence, Sesto-Fiorentino (Firenze), Italy
| | - Francesco S Pavone
- LENS- European Laboratory for Non-Linear Spectroscopy, University of Florence, Sesto-Fiorentino (Firenze), Italy
| | - Martino Calamai
- LENS- European Laboratory for Non-Linear Spectroscopy, University of Florence, Sesto-Fiorentino (Firenze), Italy
- National Institute of Optics - National Research Council (CNR-INO), Sesto Fiorentino, Italy
| | - Katharina Schindowski
- Institute of Applied Biotechnology, Biberach University of Applied Science, Hubertus-Liebrecht-Strasse 35, Biberach, Germany
| | - Andrew Chan
- Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.
- Center for experimental neurology (ZEN), Bern University Hospital, University of Bern, Bern, Switzerland.
- Department of Biomedical Research, University of Bern, Bern, Switzerland.
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Pavon MV, Navakkode S, Wong LW, Sajikumar S. Inhibition of Nogo-A rescues synaptic plasticity and associativity in APP/PS1 animal model of Alzheimer's disease. Semin Cell Dev Biol 2023; 139:111-120. [PMID: 35431138 DOI: 10.1016/j.semcdb.2022.04.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 03/30/2022] [Accepted: 04/06/2022] [Indexed: 12/31/2022]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by memory loss and cognitive decline. Synaptic impairment is one of the first events to occur in the progression of this disease. Synaptic plasticity and cellular association of various plastic events have been shown to be affected in AD models. Nogo-A, a well-known axonal growth inhibitor with a recently discovered role as a plasticity suppressor, and its main receptor Nogo-66 receptor 1 (NGR1) have been found to be overexpressed in the hippocampus of Alzheimer's patients. However, the role of Nogo-A and its receptor in the pathology of AD is still widely unknown. In this work we set out to investigate whether Nogo-A is working as a plasticity suppressor in AD. Our results show that inhibition of the Nogo-A pathway via the Nogo-R antibody in an Alzheimer's mouse model, APP/PS1, leads to the restoration of both synaptic plasticity and associativity in a protein synthesis and NMDR-dependent manner. We also show that inhibition of the p75NTR pathway, which is strongly associated with NGR1, restores synaptic plasticity as well. Mechanistically, we propose that the restoration of synaptic plasticity in APP/PS1 via inhibition of the Nogo-A pathway is due to the modulation of the RhoA-ROCK2 pathway and increase in plasticity related proteins. Our study identifies Nogo-A as a plasticity suppressor in AD models hence targeting Nogo-A could be a promising strategy to understanding AD pathology.
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Affiliation(s)
- Maria Vazquez Pavon
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore; Life Sciences Institute, Neurobiology Programme, National University of Singapore, Singapore 117456, Singapore
| | - Sheeja Navakkode
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 308232, Singapore
| | - Lik-Wei Wong
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore; Life Sciences Institute, Neurobiology Programme, National University of Singapore, Singapore 117456, Singapore
| | - Sreedharan Sajikumar
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore; Life Sciences Institute, Neurobiology Programme, National University of Singapore, Singapore 117456, Singapore; Healthy Longevity Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117456, Singapore.
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6
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Kragness S, Clark Z, Mullin A, Guidry J, Earls LR. An Rtn4/Nogo-A-interacting micropeptide modulates synaptic plasticity with age. PLoS One 2022; 17:e0269404. [PMID: 35771867 PMCID: PMC9246188 DOI: 10.1371/journal.pone.0269404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 05/18/2022] [Indexed: 11/18/2022] Open
Abstract
Micropeptides, encoded from small open reading frames of 300 nucleotides or less, are hidden throughout mammalian genomes, though few functional studies of micropeptides in the brain are published. Here, we describe a micropeptide known as the Plasticity–Associated Neural Transcript Short (Pants), located in the 22q11.2 region of the human genome, the microdeletion of which conveys a high risk for schizophrenia. Our data show that Pants is upregulated in early adulthood in the mossy fiber circuit of the hippocampus, where it exerts a powerful negative effect on long-term potentiation (LTP). Further, we find that Pants is secreted from neurons, where it associates with synapses but is rapidly degraded with stimulation. Pants dynamically interacts with Rtn4/Nogo-A, a well-studied regulator of adult plasticity. Pants interaction with Nogo-A augments its influence over postsynaptic AMPA receptor clustering, thus gating plasticity at adult synapses. This work shows that neural micropeptides can act as architectural modules that increase the functional diversity of the known proteome.
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Affiliation(s)
- S. Kragness
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA, United States of America
| | - Z. Clark
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA, United States of America
| | - A. Mullin
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA, United States of America
- Tulane University Transgenic Core Facility, New Orleans, LA, United States of America
| | - J. Guidry
- Department of Biochemistry and Molecular Biology, LSU School of Medicine and Health Sciences Center, New Orleans, LA, United States of America
- The Proteomics Core Facility, LSUHSC, New Orleans, LA, United States of America
| | - L. R. Earls
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA, United States of America
- * E-mail:
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7
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Tipton AE, Russek SJ. Regulation of Inhibitory Signaling at the Receptor and Cellular Level; Advances in Our Understanding of GABAergic Neurotransmission and the Mechanisms by Which It Is Disrupted in Epilepsy. Front Synaptic Neurosci 2022; 14:914374. [PMID: 35874848 PMCID: PMC9302637 DOI: 10.3389/fnsyn.2022.914374] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 05/17/2022] [Indexed: 11/13/2022] Open
Abstract
Inhibitory signaling in the brain organizes the neural circuits that orchestrate how living creatures interact with the world around them and how they build representations of objects and ideas. Without tight control at multiple points of cellular engagement, the brain’s inhibitory systems would run down and the ability to extract meaningful information from excitatory events would be lost leaving behind a system vulnerable to seizures and to cognitive decline. In this review, we will cover many of the salient features that have emerged regarding the dynamic regulation of inhibitory signaling seen through the lens of cell biology with an emphasis on the major building blocks, the ligand-gated ion channel receptors that are the first transduction point when the neurotransmitter GABA is released into the synapse. Epilepsy association will be used to indicate importance of key proteins and their pathways to brain function and to introduce novel areas for therapeutic intervention.
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Affiliation(s)
- Allison E. Tipton
- Graduate Program for Neuroscience, Boston University, Boston, MA, United States
- Biomolecular Pharmacology Program, Boston University School of Medicine, Boston, MA, United States
- Boston University MD/PhD Training Program, Boston, MA, United States
| | - Shelley J. Russek
- Biomolecular Pharmacology Program, Boston University School of Medicine, Boston, MA, United States
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA, United States
- Center for Systems Neuroscience, Boston University, Boston, MA, United States
- Boston University MD/PhD Training Program, Boston, MA, United States
- *Correspondence: Shelley J. Russek,
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Janach GMS, Böhm M, Döhne N, Kim HR, Rosário M, Strauss U. Interferon-γ enhances neocortical synaptic inhibition by promoting membrane association and phosphorylation of GABA A receptors in a protein kinase C-dependent manner. Brain Behav Immun 2022; 101:153-164. [PMID: 34998939 DOI: 10.1016/j.bbi.2022.01.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 12/11/2021] [Accepted: 01/03/2022] [Indexed: 12/16/2022] Open
Abstract
Interferon-γ (IFN-γ), an important mediator of the antiviral immune response, can also act as a neuromodulator. CNS IFN-γ levels rise acutely in response to infection and therapeutically applied IFN-γ provokes CNS related side effects. Moreover, IFN-γ plays a key role in neurophysiological processes and a variety of chronic neurological and neuropsychiatric conditions. To close the gap between basic research, behavioral implications and clinical applicability, knowledge of the mechanism behind IFN-γ related changes in brain function is crucial. Here, we studied the underlying mechanism of acutely augmented neocortical inhibition by IFN-γ (1.000 IU ml-1) in layer 5 pyramidal neurons of male Wistar rats. We demonstrate postsynaptic mediation of IFN-γ augmented inhibition by pressure application of GABA and analysis of paired pulse ratios. IFN-γ increases membrane presence of GABAAR γ2, as quantified by cell surface biotinylation and functional synaptic GABAAR number, as determined by peak-scaled non-stationary noise analysis. The increase in functional receptor number was comparable to the increase in underlying miniature inhibitory postsynaptic current (mIPSC) amplitudes. Blockage of putative intracellular mediators, namely phosphoinositide 3-kinase and protein kinase C (PKC) by Wortmannin and Calphostin C, respectively, revealed PKC-dependency of the pro-inhibitory IFN-γ effect. This was corroborated by increased serine phosphorylation of P-serine PKC motifs on GABAAR γ2 upon IFN-γ application. GABAAR single channel conductance, intracellular chloride levels and GABAAR driving force are unlikely to contribute to the effect, as shown by single channel recordings and chloride imaging. The effect of IFN-γ on mIPSC amplitudes was similar in female and male rats, suggesting a gender-independent mechanism of action. Collectively, these results indicate a novel mechanism for the regulation of inhibition by IFN-γ, which could impact on neocortical function and therewith behavior.
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Affiliation(s)
- Gabriel M S Janach
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Cell Biology and Neurobiology, Charitéplatz 1, 10117 Berlin, Germany
| | - Maximilian Böhm
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Cell Biology and Neurobiology, Charitéplatz 1, 10117 Berlin, Germany
| | - Noah Döhne
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Cell Biology and Neurobiology, Charitéplatz 1, 10117 Berlin, Germany
| | - Ha-Rang Kim
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Cell Biology and Neurobiology, Charitéplatz 1, 10117 Berlin, Germany; CNRS, Interdisciplinary Institute for Neuroscience, UMR 5297, University of Bordeaux, Bordeaux, France
| | - Marta Rosário
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Cell Biology and Neurobiology, Charitéplatz 1, 10117 Berlin, Germany
| | - Ulf Strauss
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Cell Biology and Neurobiology, Charitéplatz 1, 10117 Berlin, Germany.
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Metzdorf K, Fricke S, Balia MT, Korte M, Zagrebelsky M. Nogo-A Modulates the Synaptic Excitation of Hippocampal Neurons in a Ca 2+-Dependent Manner. Cells 2021; 10:cells10092299. [PMID: 34571950 PMCID: PMC8467072 DOI: 10.3390/cells10092299] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 08/27/2021] [Accepted: 08/30/2021] [Indexed: 11/16/2022] Open
Abstract
A tight regulation of the balance between inhibitory and excitatory synaptic transmission is a prerequisite for synaptic plasticity in neuronal networks. In this context, the neurite growth inhibitor membrane protein Nogo-A modulates synaptic plasticity, strength, and neurotransmitter receptor dynamics. However, the molecular mechanisms underlying these actions are unknown. We show that Nogo-A loss-of-function in primary mouse hippocampal cultures by application of a function-blocking antibody leads to higher excitation following a decrease in GABAARs at inhibitory and an increase in the GluA1, but not GluA2 AMPAR subunit at excitatory synapses. This unbalanced regulation of AMPAR subunits results in the incorporation of Ca2+-permeable GluA2-lacking AMPARs and increased intracellular Ca2+ levels due to a higher Ca2+ influx without affecting its release from the internal stores. Increased neuronal activation upon Nogo-A loss-of-function prompts the phosphorylation of the transcription factor CREB and the expression of c-Fos. These results contribute to the understanding of the molecular mechanisms underlying the regulation of the excitation/inhibition balance and thereby of plasticity in the brain.
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Affiliation(s)
- Kristin Metzdorf
- Division of Cellular Neurobiology, Zoological Institute, TU Braunschweig, D-38106 Braunschweig, Germany; (K.M.); (M.T.B.); (M.K.)
- Helmholtz Centre for Infection Research, AG NIND, Inhoffenstr. 7, D-38124 Braunschweig, Germany
| | - Steffen Fricke
- Division of Cell Physiology, Zoological Institute, TU Braunschweig, D-38106 Braunschweig, Germany;
| | - Maria Teresa Balia
- Division of Cellular Neurobiology, Zoological Institute, TU Braunschweig, D-38106 Braunschweig, Germany; (K.M.); (M.T.B.); (M.K.)
| | - Martin Korte
- Division of Cellular Neurobiology, Zoological Institute, TU Braunschweig, D-38106 Braunschweig, Germany; (K.M.); (M.T.B.); (M.K.)
- Helmholtz Centre for Infection Research, AG NIND, Inhoffenstr. 7, D-38124 Braunschweig, Germany
| | - Marta Zagrebelsky
- Division of Cellular Neurobiology, Zoological Institute, TU Braunschweig, D-38106 Braunschweig, Germany; (K.M.); (M.T.B.); (M.K.)
- Correspondence: ; Tel.: +49-(0)-531-3913225
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Bannai H, Niwa F, Sakuragi S, Mikoshiba K. Inhibitory synaptic transmission tuned by Ca 2+ and glutamate through the control of GABA A R lateral diffusion dynamics. Dev Growth Differ 2020; 62:398-406. [PMID: 32329058 PMCID: PMC7496684 DOI: 10.1111/dgd.12667] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 04/08/2020] [Accepted: 04/18/2020] [Indexed: 11/30/2022]
Abstract
The GABAergic synapses, a primary inhibitory synapse in the mammalian brain, is important for the normal development of brain circuits, and for the regulation of the excitation‐inhibition balance critical for brain function from the developmental stage throughout life. However, the molecular mechanism underlying the formation, maintenance, and modulation of GABAergic synapses is less understood compared to that of excitatory synapses. Quantum dot‐single particle tracking (QD‐SPT), a super‐resolution imaging technique that enables the analysis of membrane molecule dynamics at single‐molecule resolution, is a powerful tool to analyze the behavior of proteins and lipids on the plasma membrane. In this review, we summarize the recent application of QD‐SPT in understanding of GABAergic synaptic transmission. Here we introduce QD‐SPT experiments that provide further insights into the molecular mechanism supporting GABAergic synapses. QD‐SPT studies revealed that glutamate and Ca2+ signaling is involved in (a) the maintenance of GABAergic synapses, (b) GABAergic long‐term depression, and GABAergic long‐term potentiation, by specifically activating signaling pathways unique to each phenomenon. We also introduce a novel Ca2+ imaging technique to describe the diversity of Ca2+ signals that may activate the downstream signaling pathways that induce specific biological output.
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Affiliation(s)
- Hiroko Bannai
- School of Advanced Science and Engineering, Department of Electrical Engineering and Biosciences, Waseda University, Tokyo, Japan.,Department of Neurophysiology, Keio University School of Medicine, Tokyo, Japan.,Japan Science and Technology Agency, PRESTO, Kawaguchi, Saitama, Japan.,Laboratory for Developmental Neurobiology, RIKEN Center for Brain Science, Wako, Japan
| | - Fumihiro Niwa
- Laboratory for Developmental Neurobiology, RIKEN Center for Brain Science, Wako, Japan.,Institut de Biologie de l'ENS (IBENS), École Normale Supérieure, PSL Research University, INSERM, CNRS, Paris, France
| | - Shigeo Sakuragi
- School of Advanced Science and Engineering, Department of Electrical Engineering and Biosciences, Waseda University, Tokyo, Japan.,Department of Pharmacology, Faculty of Medicine, Yamagata University, Yamagata, Japan
| | - Katsuhiko Mikoshiba
- Laboratory for Developmental Neurobiology, RIKEN Center for Brain Science, Wako, Japan.,Shanghai Institute for Advanced Immunochemical Studies (SIAIS), ShanghaiTech University, Shanghai, China.,Department of Biomolecular Science, Faculty of Science, Toho University, Funabashi, Japan
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Affiliation(s)
- Bor Luen Tang
- Department of Biochemistry, Yong Loo Lin School of Medicine; National University of Singapore Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore
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