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Guo A, Wu Q, Yan X, Chen K, Liu Y, Liang D, Yang Y, Luo Q, Xiong M, Yu Y, Fei E, Chen F. Differential roles of lysosomal cholesterol transporters in the development of C. elegans NMJs. Life Sci Alliance 2024; 7:e202402584. [PMID: 39084875 PMCID: PMC11291935 DOI: 10.26508/lsa.202402584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 07/21/2024] [Accepted: 07/22/2024] [Indexed: 08/02/2024] Open
Abstract
Cholesterol homeostasis in neurons is critical for synapse formation and maintenance. Neurons with impaired cholesterol uptake undergo progressive synapse loss and eventual degeneration. To investigate the molecular mechanisms of neuronal cholesterol homeostasis and its role during synapse development, we studied motor neurons of Caenorhabditis elegans because these neurons rely on dietary cholesterol. Combining lipidomic analysis, we discovered that NCR-1, a lysosomal cholesterol transporter, promotes cholesterol absorption and synapse development. Loss of ncr-1 causes smaller synapses, and low cholesterol exacerbates the deficits. Moreover, NCR-1 deficiency hinders the increase in synapses under high cholesterol. Unexpectedly, NCR-2, the NCR-1 homolog, increases the use of cholesterol and sphingomyelins and impedes synapse formation. NCR-2 deficiency causes an increase in synapses regardless of cholesterol concentration. Inhibiting the degradation or synthesis of sphingomyelins can induce or suppress the synaptic phenotypes in ncr-2 mutants. Our findings indicate that neuronal cholesterol homeostasis is differentially controlled by two lysosomal cholesterol transporters and highlight the importance of neuronal cholesterol homeostasis in synapse development.
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Affiliation(s)
- Amin Guo
- https://ror.org/042v6xz23 School of Basic Medical Sciences, Jiangxi Medical College, Nanchang University, Nanchang, China
| | - Qi Wu
- https://ror.org/042v6xz23 School of Basic Medical Sciences, Jiangxi Medical College, Nanchang University, Nanchang, China
| | - Xin Yan
- https://ror.org/042v6xz23 School of Life Sciences, Nanchang University, Nanchang, China
| | - Kanghua Chen
- https://ror.org/042v6xz23 School of Basic Medical Sciences, Jiangxi Medical College, Nanchang University, Nanchang, China
| | - Yuxiang Liu
- https://ror.org/042v6xz23 School of Basic Medical Sciences, Jiangxi Medical College, Nanchang University, Nanchang, China
| | - Dingfa Liang
- https://ror.org/042v6xz23 Queen Mary School of Nanchang University, Jiangxi Medical College, Nanchang, China
| | - Yuxiao Yang
- https://ror.org/042v6xz23 School of Basic Medical Sciences, Jiangxi Medical College, Nanchang University, Nanchang, China
| | - Qunfeng Luo
- https://ror.org/042v6xz23 School of Basic Medical Sciences, Jiangxi Medical College, Nanchang University, Nanchang, China
| | - Mingtao Xiong
- https://ror.org/042v6xz23 Institute of Biomedical Innovation, Jiangxi Medical College, Nanchang University, Nanchang, China
| | - Yong Yu
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, China
| | - Erkang Fei
- https://ror.org/042v6xz23 Institute of Biomedical Innovation, Jiangxi Medical College, Nanchang University, Nanchang, China
| | - Fei Chen
- https://ror.org/042v6xz23 School of Basic Medical Sciences, Jiangxi Medical College, Nanchang University, Nanchang, China
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2
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Emperador-Melero J, Andersen JW, Metzbower SR, Levy AD, Dharmasri PA, de Nola G, Blanpied TA, Kaeser PS. Distinct active zone protein machineries mediate Ca 2+ channel clustering and vesicle priming at hippocampal synapses. Nat Neurosci 2024; 27:1680-1694. [PMID: 39160372 DOI: 10.1038/s41593-024-01720-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 06/28/2024] [Indexed: 08/21/2024]
Abstract
Action potentials trigger neurotransmitter release at the presynaptic active zone with spatiotemporal precision. This is supported by protein machinery that mediates synaptic vesicle priming and clustering of CaV2 Ca2+ channels nearby. One model posits that scaffolding proteins directly tether vesicles to CaV2s; however, here we find that at mouse hippocampal synapses, CaV2 clustering and vesicle priming are executed by separate machineries. CaV2 nanoclusters are positioned at variable distances from those of the priming protein Munc13. The active zone organizer RIM anchors both proteins but distinct interaction motifs independently execute these functions. In transfected cells, Liprin-α and RIM form co-assemblies that are separate from CaV2-organizing complexes. At synapses, Liprin-α1-Liprin-α4 knockout impairs vesicle priming but not CaV2 clustering. The cell adhesion protein PTPσ recruits Liprin-α, RIM and Munc13 into priming complexes without co-clustering CaV2s. We conclude that active zones consist of distinct machineries to organize CaV2s and prime vesicles, and Liprin-α and PTPσ specifically support priming site assembly.
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Affiliation(s)
| | | | - Sarah R Metzbower
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Aaron D Levy
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Poorna A Dharmasri
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Giovanni de Nola
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Thomas A Blanpied
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Pascal S Kaeser
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA.
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3
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Sermon JJ, Wiest C, Tan H, Denison T, Duchet B. Evoked resonant neural activity long-term dynamics can be reproduced by a computational model with vesicle depletion. Neurobiol Dis 2024; 199:106565. [PMID: 38880431 PMCID: PMC11300885 DOI: 10.1016/j.nbd.2024.106565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Revised: 06/04/2024] [Accepted: 06/11/2024] [Indexed: 06/18/2024] Open
Abstract
Subthalamic deep brain stimulation (DBS) robustly generates high-frequency oscillations known as evoked resonant neural activity (ERNA). Recently the importance of ERNA has been demonstrated through its ability to predict the optimal DBS contact in the subthalamic nucleus in patients with Parkinson's disease. However, the underlying mechanisms of ERNA are not well understood, and previous modelling efforts have not managed to reproduce the wealth of published data describing the dynamics of ERNA. Here, we aim to present a minimal model capable of reproducing the characteristics of the slow ERNA dynamics published to date. We make biophysically-motivated modifications to the Kuramoto model and fit its parameters to the slow dynamics of ERNA obtained from data. Our results demonstrate that it is possible to reproduce the slow dynamics of ERNA (over hundreds of seconds) with a single neuronal population, and, crucially, with vesicle depletion as one of the key mechanisms behind the ERNA frequency decay in our model. We further validate the proposed model against experimental data from Parkinson's disease patients, where it captures the variations in ERNA frequency and amplitude in response to variable stimulation frequency, amplitude, and to stimulation pulse bursting. We provide a series of predictions from the model that could be the subject of future studies for further validation.
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Affiliation(s)
- James J Sermon
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford, UK; MRC Brain Networks Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Christoph Wiest
- MRC Brain Networks Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Huiling Tan
- MRC Brain Networks Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Timothy Denison
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford, UK; MRC Brain Networks Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Benoit Duchet
- MRC Brain Networks Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.
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4
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Gao C, Xiong R, Zhang ZY, Peng H, Gu YK, Xu W, Yang WT, Liu Y, Gao J, Yin Y. Hybrid nanostructures for neurodegenerative disease theranostics: the art in the combination of biomembrane and non-biomembrane nanostructures. Transl Neurodegener 2024; 13:43. [PMID: 39192378 DOI: 10.1186/s40035-024-00436-7] [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: 04/02/2024] [Accepted: 08/07/2024] [Indexed: 08/29/2024] Open
Abstract
The diagnosis of neurodegenerative diseases (NDDs) remains challenging, and existing therapeutic approaches demonstrate little efficacy. NDD drug delivery can be achieved through the utilization of nanostructures, hence enabling multimodal NDD theranostics. Nevertheless, both biomembrane and non-biomembrane nanostructures possess intrinsic shortcomings that must be addressed by hybridization to create novel nanostructures with versatile applications in NDD theranostics. Hybrid nanostructures display improved biocompatibility, inherent targeting capabilities, intelligent responsiveness, and controlled drug release. This paper provides a concise overview of the latest developments in hybrid nanostructures for NDD theranostics and emphasizes various engineering methodologies for the integration of diverse nanostructures, including liposomes, exosomes, cell membranes, and non-biomembrane nanostructures such as polymers, metals, and hydrogels. The use of a combination technique can significantly augment the precision, intelligence, and efficacy of hybrid nanostructures, therefore functioning as a more robust theranostic approach for NDDs. This paper also addresses the issues that arise in the therapeutic translation of hybrid nanostructures and explores potential future prospects in this field.
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Affiliation(s)
- Chao Gao
- Department of Neurology, Second Affiliated Hospital (Shanghai Changzheng Hospital) of Naval Medical University, Shanghai, 200003, China
| | - Ran Xiong
- Department of Neurology, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, 200120, China
| | - Zhi-Yu Zhang
- Department of Health Management, Second Affliated Hospital (Shanghai Changzheng Hospital) of Naval Medical University, Shanghai, 200003, China
| | - Hua Peng
- Department of Neurology, Second Affiliated Hospital (Shanghai Changzheng Hospital) of Naval Medical University, Shanghai, 200003, China
| | - Yuan-Kai Gu
- Department of Neurology, Second Affiliated Hospital (Shanghai Changzheng Hospital) of Naval Medical University, Shanghai, 200003, China
| | - Wei Xu
- Department of Neurology, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, 200120, China
| | - Wei-Ting Yang
- Department of Neurology, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, 200120, China
| | - Yan Liu
- Department of Clinical Pharmacy, Xinhua Hospital, Clinical Pharmacy Innovation Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, 200000, China.
- Clinical Pharmacy Innovation Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China.
| | - Jie Gao
- Changhai Clinical Research Unit, Shanghai Changhai Hospital, Naval Medical University, Shanghai, 200433, China.
- Shanghai Key Laboratory of Nautical Medicine and Translation of Drugs and Medical Devices, Shanghai, 200433, China.
| | - You Yin
- Department of Neurology, Second Affiliated Hospital (Shanghai Changzheng Hospital) of Naval Medical University, Shanghai, 200003, China.
- Department of Neurology, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, 200120, China.
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5
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Timalsina B, Lee S, Kaang BK. Advances in the labelling and selective manipulation of synapses. Nat Rev Neurosci 2024:10.1038/s41583-024-00851-9. [PMID: 39174832 DOI: 10.1038/s41583-024-00851-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/23/2024] [Indexed: 08/24/2024]
Abstract
Synapses are highly specialized neuronal structures that are essential for neurotransmission, and they are dynamically regulated throughout the lifetime. Although accumulating evidence indicates that these structures are crucial for information processing and storage in the brain, their precise roles beyond neurotransmission are yet to be fully appreciated. Genetically encoded fluorescent tools have deepened our understanding of synaptic structure and function, but developing an ideal methodology to selectively visualize, label and manipulate synapses remains challenging. Here, we provide an overview of currently available synapse labelling techniques and describe their extension to enable synapse manipulation. We categorize these approaches on the basis of their conceptual bases and target molecules, compare their advantages and limitations and propose potential modifications to improve their effectiveness. These methods have broad utility, particularly for investigating mechanisms of synaptic function and synaptopathy.
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Affiliation(s)
- Binod Timalsina
- Center for Cognition and Sociality, Institute for Basic Science (IBS), Daejeon, South Korea
| | - Sangkyu Lee
- Center for Cognition and Sociality, Institute for Basic Science (IBS), Daejeon, South Korea
| | - Bong-Kiun Kaang
- Center for Cognition and Sociality, Institute for Basic Science (IBS), Daejeon, South Korea.
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6
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Fesce R. Old innovations and shifted paradigms in cellular neuroscience. Front Cell Neurosci 2024; 18:1460219. [PMID: 39234031 PMCID: PMC11371623 DOI: 10.3389/fncel.2024.1460219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2024] [Accepted: 08/06/2024] [Indexed: 09/06/2024] Open
Abstract
Once upon a time the statistics of quantal release were fashionable: "n" available vesicles (fusion sites), each with probability "p" of releasing a quantum. The story was not so simple, a nice paradigm to be abandoned. Biophysicists, experimenting with "black films," explained the astonishing rapidity of spike-induced release: calcium can trigger the fusion of lipidic vesicles with a lipid bilayer, by masking the negative charges of the membranes. The idea passed away, buried by the discovery of NSF, SNAPs, SNARE proteins and synaptotagmin, Munc, RIM, complexin. Electrophysiology used to be a field for few adepts. Then came patch clamp, and multielectrode arrays and everybody became electrophysiologists. Now, optogenetics have blossomed, and the whole field has changed again. Nice surprise for me, when Alvarez de Toledo demonstrated that release of transmitters could occur through the transient opening of a pore between the vesicle and the plasma-membrane, no collapse of the vesicle in the membrane needed: my mentor Bruno Ceccarelli had cherished this idea ("kiss and run") and tried to prove it for 20 years. The most impressive developments have probably regarded IT, computers and all their applications; machine learning, AI, and the truly spectacular innovations in brain imaging, especially functional ones, have transformed cognitive neurosciences into a new extraordinarily prolific field, and certainly let us imagine that we may finally understand what is going on in our brains. Cellular neuroscience, on the other hand, though the large public has been much less aware of the incredible amount of information the scientific community has acquired on the cellular aspects of neuronal function, may indeed help us to eventually understand the mechanistic detail of how the brain work. But this is no more in the past, this is the future.
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Affiliation(s)
- Riccardo Fesce
- Department of Biomedical Sciences, Humanitas University Medical School, Pieve Emanuele, Italy
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7
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Hilton BJ, Griffin JM, Fawcett JW, Bradke F. Neuronal maturation and axon regeneration: unfixing circuitry to enable repair. Nat Rev Neurosci 2024:10.1038/s41583-024-00849-3. [PMID: 39164450 DOI: 10.1038/s41583-024-00849-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/19/2024] [Indexed: 08/22/2024]
Abstract
Mammalian neurons lose the ability to regenerate their central nervous system axons as they mature during embryonic or early postnatal development. Neuronal maturation requires a transformation from a situation in which neuronal components grow and assemble to one in which these components are fixed and involved in the machinery for effective information transmission and computation. To regenerate after injury, neurons need to overcome this fixed state to reactivate their growth programme. A variety of intracellular processes involved in initiating or sustaining neuronal maturation, including the regulation of gene expression, cytoskeletal restructuring and shifts in intracellular trafficking, have been shown to prevent axon regeneration. Understanding these processes will contribute to the identification of targets to promote repair after injury or disease.
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Affiliation(s)
- Brett J Hilton
- Department of Cellular and Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada.
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada.
| | - Jarred M Griffin
- Laboratory for Axonal Growth and Regeneration, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - James W Fawcett
- Department of Clinical Neurosciences, John van Geest Centre for Brain Repair, University of Cambridge, Cambridge, UK.
- Centre for Reconstructive Neuroscience, Institute for Experimental Medicine Czech Academy of Science (CAS), Prague, Czechia.
| | - Frank Bradke
- Laboratory for Axonal Growth and Regeneration, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.
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8
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Mueller BD, Merrill SA, Von Diezmann L, Jorgensen EM. Using Localization Microscopy to Quantify Calcium Channels at Presynaptic Boutons. Bio Protoc 2024; 14:e5049. [PMID: 39210951 PMCID: PMC11349493 DOI: 10.21769/bioprotoc.5049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2024] [Revised: 07/07/2024] [Accepted: 07/11/2024] [Indexed: 09/04/2024] Open
Abstract
Calcium channels at synaptic boutons are critical for synaptic function, but their number and distribution are poorly understood. This gap in knowledge is primarily due to the resolution limits of fluorescence microscopy. In the last decade, the diffraction limit of light was surpassed, and fluorescent molecules can now be localized with nanometer precision. Concurrently, new gene editing strategies allowed direct tagging of the endogenous calcium channel genes-expressed in the correct cells and at physiological levels. Further, the repurposing of self-labeling enzymes to attach fluorescent dyes to proteins improved photon yields enabling efficient localization of single molecules. Here, we describe tagging strategies, localization microscopy, and data analysis for calcium channel localization. In this case, we are imaging calcium channels fused with SNAP or HALO tags in live anesthetized C. elegans nematodes, but the analysis is relevant for any super-resolution preparations. We describe how to process images into localizations and protein clusters into confined nanodomains. Finally, we discuss strategies for estimating the number of calcium channels present at synaptic boutons. Key features • Super-resolution imaging of live anesthetized C. elegans. • Three-color super-resolution reconstruction of synapses. • Nanodomains and the distribution of proteins. • Quantification of the number of proteins at synapses from single-molecule localization data.
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Affiliation(s)
- Brian D. Mueller
- School of Biological Sciences, University of Utah, Salt Lake City, UT, USA
- Howard Hughes Medical Institute, Salt Lake City, UT, USA
| | - Sean A. Merrill
- School of Biological Sciences, University of Utah, Salt Lake City, UT, USA
- Howard Hughes Medical Institute, Salt Lake City, UT, USA
| | - Lexy Von Diezmann
- Dept. of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN, USA
| | - Erik M. Jorgensen
- School of Biological Sciences, University of Utah, Salt Lake City, UT, USA
- Howard Hughes Medical Institute, Salt Lake City, UT, USA
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9
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Peng J, Liang D, Zhang Z. Palmitoylation of synaptic proteins: roles in functional regulation and pathogenesis of neurodegenerative diseases. Cell Mol Biol Lett 2024; 29:108. [PMID: 39127627 DOI: 10.1186/s11658-024-00625-2] [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: 05/10/2024] [Accepted: 07/30/2024] [Indexed: 08/12/2024] Open
Abstract
Palmitoylation is a type of lipid modification that plays an important role in various aspects of neuronal function. Over the past few decades, several studies have shown that the palmitoylation of synaptic proteins is involved in neurotransmission and synaptic functions. Palmitoyl acyltransferases (PATs), which belong to the DHHC family, are major players in the regulation of palmitoylation. Dysregulated palmitoylation of synaptic proteins and mutated/dysregulated DHHC proteins are associated with several neurodegenerative diseases, such as Alzheimer's disease (AD), Huntington's disease (HD), and Parkinson's disease (PD). In this review, we summarize the recent discoveries on the subcellular distribution of DHHC proteins and analyze their expression patterns in different brain cells. In particular, this review discusses how palmitoylation of synaptic proteins regulates synaptic vesicle exocytotic fusion and the localization, clustering, and transport of several postsynaptic receptors, as well as the role of palmitoylation of other proteins in regulating synaptic proteins. Additionally, some of the specific known associations of these factors with neurodegenerative disorders are explored, with a few suggestions for the development of therapeutic strategies. Finally, this review provides possible directions for future research to reveal detailed and specific mechanisms underlying the roles of synaptic protein palmitoylation.
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Affiliation(s)
- Jiaying Peng
- Shenzhen Key Laboratory of Marine Bioresources and Ecology, Brain Disease and Big Data Research Institute, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, China
| | - Danchan Liang
- Shenzhen Key Laboratory of Marine Bioresources and Ecology, Brain Disease and Big Data Research Institute, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, China
| | - Zhonghao Zhang
- Shenzhen Key Laboratory of Marine Bioresources and Ecology, Brain Disease and Big Data Research Institute, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, China.
- Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China.
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10
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Kostović I. Development of the basic architecture of neocortical circuitry in the human fetus as revealed by the coupling spatiotemporal pattern of synaptogenesis along with microstructure and macroscale in vivo MR imaging. Brain Struct Funct 2024:10.1007/s00429-024-02838-9. [PMID: 39102068 DOI: 10.1007/s00429-024-02838-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2024] [Accepted: 07/12/2024] [Indexed: 08/06/2024]
Abstract
In humans, a quantifiable number of cortical synapses appears early in fetal life. In this paper, we present a bridge across different scales of resolution and the distribution of synapses across the transient cytoarchitectonic compartments: marginal zone (MZ), cortical plate (CP), subplate (SP), and in vivo MR images. The tissue of somatosensory cortex (7-26 postconceptional weeks (PCW)) was prepared for electron microscopy, and classified synapses with a determined subpial depth were used for creating histograms matched to the histological sections immunoreacted for synaptic markers and aligned to in vivo MR images (1.5 T) of corresponding fetal ages (maternal indication). Two time periods and laminar patterns of synaptogenesis were identified: an early and midfetal two-compartmental distribution (MZ and SP) and a late fetal three-compartmental distribution (CP synaptogenesis). During both periods, a voluminous, synapse-rich SP was visualized on the in vivo MR. Another novel finding concerns the phase of secondary expansion of the SP (13 PCW), where a quantifiable number of synapses appears in the upper SP. This lamina shows a T2 intermediate signal intensity below the low signal CP. In conclusion, the early fetal appearance of synapses shows early differentiation of putative genetic mechanisms underlying the synthesis, transport and assembly of synaptic proteins. "Pioneering" synapses are likely to play a morphogenetic role in constructing of fundamental circuitry architecture due to interaction between neurons. They underlie spontaneous, evoked, and resting state activity prior to ex utero experience. Synapses can also mediate genetic and environmental triggers, adversely altering the development of cortical circuitry and leading to neurodevelopmental disorders.
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Affiliation(s)
- Ivica Kostović
- Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia.
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11
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Jevon D, Cottle L, Hallahan N, Harwood R, Samra JS, Gill AJ, Loudovaris T, Thomas HE, Thorn P. Capillary contact points determine beta cell polarity, control secretion and are disrupted in the db/db mouse model of diabetes. Diabetologia 2024; 67:1683-1697. [PMID: 38814445 PMCID: PMC11343897 DOI: 10.1007/s00125-024-06180-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Accepted: 03/26/2024] [Indexed: 05/31/2024]
Abstract
AIMS/HYPOTHESIS Almost all beta cells contact one capillary and insulin granule fusion is targeted to this region. However, there are reports of beta cells contacting more than one capillary. We therefore set out to determine the proportion of beta cells with multiple contacts and the impact of this on cell structure and function. METHODS We used pancreatic slices in mice and humans to better maintain cell and islet structure than in isolated islets. Cell structure was assayed using immunofluorescence and 3D confocal microscopy. Live-cell two-photon microscopy was used to map granule fusion events in response to glucose stimulation. RESULTS We found that 36% and 22% of beta cells in islets from mice and humans, respectively, have separate contact with two capillaries. These contacts establish a distinct form of cell polarity with multiple basal regions. Both capillary contact points are enriched in presynaptic scaffold proteins, and both are a target for insulin granule fusion. Cells with two capillary contact points have a greater capillary contact area and secrete more, with analysis showing that, independent of the number of contact points, increased contact area is correlated with increased granule fusion. Using db/db mice as a model for type 2 diabetes, we observed changes in islet capillary organisation that significantly reduced total islet capillary surface area, and reduced area of capillary contact in single beta cells. CONCLUSIONS/INTERPRETATION Beta cells that contact two capillaries are a significant subpopulation of beta cells within the islet. They have a distinct form of cell polarity and both contact points are specialised for secretion. The larger capillary contact area of cells with two contact points is correlated with increased secretion. In the db/db mouse, changes in capillary structure impact beta cell capillary contact, implying that this is a new factor contributing to disease progression.
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Affiliation(s)
- Dillon Jevon
- Charles Perkins Centre, School of Medical Sciences, University of Sydney, Camperdown, NSW, Australia
| | - Louise Cottle
- Charles Perkins Centre, School of Medical Sciences, University of Sydney, Camperdown, NSW, Australia
| | - Nicole Hallahan
- Charles Perkins Centre, School of Medical Sciences, University of Sydney, Camperdown, NSW, Australia
| | - Richard Harwood
- Charles Perkins Centre, Sydney Microscopy and Microanalysis, University of Sydney, Camperdown, NSW, Australia
| | - Jaswinder S Samra
- The University of Sydney Northern Clinical School, Sydney, NSW, Australia
- Upper Gastrointestinal Surgical Unit, Royal North Shore Hospital, St Leonards, NSW, Australia
| | - Anthony J Gill
- The University of Sydney Northern Clinical School, Sydney, NSW, Australia
- Department of Anatomical Pathology, Royal North Shore Hospital, St Leonards, NSW, Australia
- Cancer Diagnosis and Pathology Research Group, Kolling Institute of Medical Research, St Leonards, NSW, Australia
| | | | - Helen E Thomas
- St Vincent's Institute, Fitzroy, VIC, Australia
- Department of Medicine, St Vincent's Hospital, University of Melbourne, Fitzroy, VIC, Australia
| | - Peter Thorn
- Charles Perkins Centre, School of Medical Sciences, University of Sydney, Camperdown, NSW, Australia.
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12
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Kim DI, Park S, Park S, Ye M, Chen JY, Kang SJ, Jhang J, Hunker AC, Zweifel LS, Caron KM, Vaughan JM, Saghatelian A, Palmiter RD, Han S. Presynaptic sensor and silencer of peptidergic transmission reveal neuropeptides as primary transmitters in pontine fear circuit. Cell 2024:S0092-8674(24)00709-8. [PMID: 39043179 DOI: 10.1016/j.cell.2024.06.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 11/17/2023] [Accepted: 06/25/2024] [Indexed: 07/25/2024]
Abstract
Neurons produce and release neuropeptides to communicate with one another. Despite their importance in brain function, circuit-based mechanisms of peptidergic transmission are poorly understood, primarily due to the lack of tools for monitoring and manipulating neuropeptide release in vivo. Here, we report the development of two genetically encoded tools for investigating peptidergic transmission in behaving mice: a genetically encoded large dense core vesicle (LDCV) sensor that detects presynaptic neuropeptide release and a genetically encoded silencer that specifically degrades neuropeptides inside LDCVs. Using these tools, we show that neuropeptides, not glutamate, encode the unconditioned stimulus in the parabrachial-to-amygdalar threat pathway during Pavlovian threat learning. We also show that neuropeptides play important roles in encoding positive valence and suppressing conditioned threat response in the amygdala-to-parabrachial endogenous opioidergic circuit. These results show that our sensor and silencer for presynaptic peptidergic transmission are reliable tools to investigate neuropeptidergic systems in awake, behaving animals.
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Affiliation(s)
- Dong-Il Kim
- Peptide Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Sekun Park
- Howard Hughes Medical Institute, Department of Biochemistry, University of Washington, Seattle, WA 98195, USA
| | - Seahyung Park
- Peptide Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Mao Ye
- Peptide Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Jane Y Chen
- Howard Hughes Medical Institute, Department of Biochemistry, University of Washington, Seattle, WA 98195, USA
| | - Sukjae J Kang
- Peptide Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Jinho Jhang
- Peptide Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Avery C Hunker
- Department of Pharmacology, University of Washington, Seattle, WA 98195, USA
| | - Larry S Zweifel
- Department of Pharmacology, University of Washington, Seattle, WA 98195, USA
| | - Kathleen M Caron
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Joan M Vaughan
- Peptide Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Alan Saghatelian
- Peptide Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Richard D Palmiter
- Howard Hughes Medical Institute, Department of Biochemistry, University of Washington, Seattle, WA 98195, USA
| | - Sung Han
- Peptide Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA; Center for Neuroscience Imaging Research, Institute for Basic Science, Suwon 16419, Republic of Korea; Department of Biomedical Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea.
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13
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Held RG, Liang J, Brunger AT. Nanoscale architecture of synaptic vesicles and scaffolding complexes revealed by cryo-electron tomography. Proc Natl Acad Sci U S A 2024; 121:e2403136121. [PMID: 38923992 PMCID: PMC11228483 DOI: 10.1073/pnas.2403136121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2024] [Accepted: 05/16/2024] [Indexed: 06/28/2024] Open
Abstract
The spatial distribution of proteins and their arrangement within the cellular ultrastructure regulates the opening of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors in response to glutamate release at the synapse. Fluorescence microscopy imaging revealed that the postsynaptic density (PSD) and scaffolding proteins in the presynaptic active zone (AZ) align across the synapse to form a trans-synaptic "nanocolumn," but the relation to synaptic vesicle release sites is uncertain. Here, we employ focused-ion beam (FIB) milling and cryoelectron tomography to image synapses under near-native conditions. Improved image contrast, enabled by FIB milling, allows simultaneous visualization of supramolecular nanoclusters within the AZ and PSD and synaptic vesicles. Surprisingly, membrane-proximal synaptic vesicles, which fuse to release glutamate, are not preferentially aligned with AZ or PSD nanoclusters. These synaptic vesicles are linked to the membrane by peripheral protein densities, often consistent in size and shape with Munc13, as well as globular densities bridging the synaptic vesicle and plasma membrane, consistent with prefusion complexes of SNAREs, synaptotagmins, and complexin. Monte Carlo simulations of synaptic transmission events using biorealistic models guided by our tomograms predict that clustering AMPARs within PSD nanoclusters increases the variability of the postsynaptic response but not its average amplitude. Together, our data support a model in which synaptic strength is tuned at the level of single vesicles by the spatial relationship between scaffolding nanoclusters and single synaptic vesicle fusion sites.
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Affiliation(s)
- Richard G. Held
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA94305
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA94305
- Department of Structural Biology, Stanford University, Stanford, CA94305
- Department of Photon Science, Stanford University, Stanford, CA94305
- HHMI, Stanford University, Stanford, CA94305
| | - Jiahao Liang
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA94305
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA94305
- Department of Structural Biology, Stanford University, Stanford, CA94305
- Department of Photon Science, Stanford University, Stanford, CA94305
- HHMI, Stanford University, Stanford, CA94305
| | - Axel T. Brunger
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA94305
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA94305
- Department of Structural Biology, Stanford University, Stanford, CA94305
- Department of Photon Science, Stanford University, Stanford, CA94305
- HHMI, Stanford University, Stanford, CA94305
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14
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Stockwell I, Watson JF, Greger IH. Tuning synaptic strength by regulation of AMPA glutamate receptor localization. Bioessays 2024; 46:e2400006. [PMID: 38693811 PMCID: PMC7616278 DOI: 10.1002/bies.202400006] [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: 01/10/2024] [Revised: 04/19/2024] [Accepted: 04/23/2024] [Indexed: 05/03/2024]
Abstract
Long-term potentiation (LTP) of excitatory synapses is a leading model to explain the concept of information storage in the brain. Multiple mechanisms contribute to LTP, but central amongst them is an increased sensitivity of the postsynaptic membrane to neurotransmitter release. This sensitivity is predominantly determined by the abundance and localization of AMPA-type glutamate receptors (AMPARs). A combination of AMPAR structural data, super-resolution imaging of excitatory synapses, and an abundance of electrophysiological studies are providing an ever-clearer picture of how AMPARs are recruited and organized at synaptic junctions. Here, we review the latest insights into this process, and discuss how both cytoplasmic and extracellular receptor elements cooperate to tune the AMPAR response at the hippocampal CA1 synapse.
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Affiliation(s)
- Imogen Stockwell
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Jake F. Watson
- Institute of Science and Technology, Technology (IST) Austria, Klosterneuburg, Austria
| | - Ingo H. Greger
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, UK
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15
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Yang X, Zhou Y, Tan S, Tian X, Meng X, Li Y, Zhou B, Zhao G, Ge X, He C, Cheng W, Zhang Y, Zheng K, Yin K, Yu Y, Pan W. Alterations in gut microbiota contribute to cognitive deficits induced by chronic infection of Toxoplasma gondii. Brain Behav Immun 2024; 119:394-407. [PMID: 38608743 DOI: 10.1016/j.bbi.2024.04.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2023] [Revised: 03/30/2024] [Accepted: 04/09/2024] [Indexed: 04/14/2024] Open
Abstract
Chronic infection with Toxoplasma gondii (T. gondii) emerges as a risk factor for neurodegenerative diseases in animals and humans. However, the underlying mechanisms are largely unknown. We aimed to investigate whether gut microbiota and its metabolites play a role in T. gondii-induced cognitive deficits. We found that T. gondii infection induced cognitive deficits in mice, which was characterized by synaptic ultrastructure impairment and neuroinflammation in the hippocampus. Moreover, the infection led to gut microbiota dysbiosis, barrier integrity impairment, and inflammation in the colon. Interestingly, broad-spectrum antibiotic ablation of gut microbiota attenuated the adverse effects of the parasitic infection on the cognitive function in mice; cognitive deficits and hippocampal pathological changes were transferred from the infected mice to control mice by fecal microbiota transplantation. In addition, the abundance of butyrate-producing bacteria and the production of serum butyrate were decreased in infected mice. Interestingly, dietary supplementation of butyrate ameliorated T. gondii-induced cognitive impairment in mice. Notably, compared to the healthy controls, decreased butyrate production was observed in the serum of human subjects with high levels of anti-T. gondii IgG. Overall, this study demonstrates that gut microbiota is a key regulator of T. gondii-induced cognitive impairment.
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Affiliation(s)
- Xiaoying Yang
- Jiangsu Key Laboratory of Immunity and Metabolism, Jiangsu International Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology, Xuzhou Medical University, Xuzhou, Jiangsu 221004, China
| | - Yuying Zhou
- Jiangsu Key Laboratory of Immunity and Metabolism, Jiangsu International Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology, Xuzhou Medical University, Xuzhou, Jiangsu 221004, China
| | - Shimin Tan
- Jiangsu Key Laboratory of Immunity and Metabolism, Jiangsu International Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology, Xuzhou Medical University, Xuzhou, Jiangsu 221004, China
| | - Xiaokang Tian
- Jiangsu Key Laboratory of Immunity and Metabolism, Jiangsu International Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology, Xuzhou Medical University, Xuzhou, Jiangsu 221004, China
| | - Xianran Meng
- Jiangsu Key Laboratory of Immunity and Metabolism, Jiangsu International Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology, Xuzhou Medical University, Xuzhou, Jiangsu 221004, China
| | - Yiling Li
- Jiangsu Key Laboratory of Immunity and Metabolism, Jiangsu International Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology, Xuzhou Medical University, Xuzhou, Jiangsu 221004, China
| | - Beibei Zhou
- Shandong Institute of Parasitic Diseases, Shandong First Medical University & Shandong Academy of Medical Sciences, Jining, Shandong 272033, China
| | - Guihua Zhao
- Shandong Institute of Parasitic Diseases, Shandong First Medical University & Shandong Academy of Medical Sciences, Jining, Shandong 272033, China
| | - Xing Ge
- Jiangsu Key Laboratory of Immunity and Metabolism, Jiangsu International Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology, Xuzhou Medical University, Xuzhou, Jiangsu 221004, China
| | - Cheng He
- Jiangsu Key Laboratory of Immunity and Metabolism, Jiangsu International Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology, Xuzhou Medical University, Xuzhou, Jiangsu 221004, China
| | - Wanpeng Cheng
- Jiangsu Key Laboratory of Immunity and Metabolism, Jiangsu International Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology, Xuzhou Medical University, Xuzhou, Jiangsu 221004, China
| | - Yumei Zhang
- Department of Pathogenic Biology, Binzhou Medical University, Yantai, Shandong 264003, China
| | - Kuiyang Zheng
- Jiangsu Key Laboratory of Immunity and Metabolism, Jiangsu International Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology, Xuzhou Medical University, Xuzhou, Jiangsu 221004, China
| | - Kun Yin
- Shandong Institute of Parasitic Diseases, Shandong First Medical University & Shandong Academy of Medical Sciences, Jining, Shandong 272033, China.
| | - Yinghua Yu
- Jiangsu Key Laboratory of Immunity and Metabolism, Jiangsu International Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology, Xuzhou Medical University, Xuzhou, Jiangsu 221004, China.
| | - Wei Pan
- Jiangsu Key Laboratory of Immunity and Metabolism, Jiangsu International Key Laboratory of Immunity and Metabolism, Department of Pathogen Biology and Immunology, Xuzhou Medical University, Xuzhou, Jiangsu 221004, China.
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16
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Badal KK, Zhao Y, Raveendra BL, Lozano-Villada S, Miller KE, Puthanveettil SV. PKA Activity-Driven Modulation of Bidirectional Long-Distance transport of Lysosomal vesicles During Synapse Maintenance. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.28.601272. [PMID: 38979384 PMCID: PMC11230415 DOI: 10.1101/2024.06.28.601272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
The bidirectional long-distance transport of organelles is crucial for cell body-synapse communication. However, the mechanisms by which this transport is modulated for synapse formation, maintenance, and plasticity are not fully understood. Here, we demonstrate through quantitative analyses that maintaining sensory neuron-motor neuron synapses in the Aplysia gill-siphon withdrawal reflex is linked to a sustained reduction in the retrograde transport of lysosomal vesicles in sensory neurons. Interestingly, while mitochondrial transport in the anterograde direction increases within 12 hours of synapse formation, the reduction in lysosomal vesicle retrograde transport appears three days after synapse formation. Moreover, we find that formation of new synapses during learning induced by neuromodulatory neurotransmitter serotonin further reduces lysosomal vesicle transport within 24 hours, whereas mitochondrial transport increases in the anterograde direction within one hour of exposure. Pharmacological inhibition of several signaling pathways pinpoints PKA as a key regulator of retrograde transport of lysosomal vesicles during synapse maintenance. These results demonstrate that synapse formation leads to organelle-specific and direction specific enduring changes in long-distance transport, offering insights into the mechanisms underlying synapse maintenance and plasticity.
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Affiliation(s)
- Kerriann. K. Badal
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, 130 Scripps Way, Jupiter, FL 33458, USA
- Integrative Biology PhD Program, Charles E. Schmidt College of Science, Florida Atlantic University, Jupiter, FL 33458, USA
| | - Yibo. Zhao
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Bindu L Raveendra
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Sebastian Lozano-Villada
- Harriet L. Wilkes Honors College, Florida Atlantic University, 5353 Parkside Drive, Jupiter, FL 33458, USA
| | - Kyle. E. Miller
- Harriet L. Wilkes Honors College, Florida Atlantic University, 5353 Parkside Drive, Jupiter, FL 33458, USA
| | - Sathyanarayanan V. Puthanveettil
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, 130 Scripps Way, Jupiter, FL 33458, USA
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17
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Metzbower SR, Levy AD, Dharmasri PA, Anderson MC, Blanpied TA. Distinct SAP102 and PSD-95 Nano-organization Defines Multiple Types of Synaptic Scaffold Protein Domains at Single Synapses. J Neurosci 2024; 44:e1715232024. [PMID: 38777601 PMCID: PMC11211720 DOI: 10.1523/jneurosci.1715-23.2024] [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: 09/10/2023] [Revised: 04/30/2024] [Accepted: 05/05/2024] [Indexed: 05/25/2024] Open
Abstract
MAGUK scaffold proteins play a central role in maintaining and modulating synaptic signaling, providing a framework to retain and position receptors, signaling molecules, and other synaptic components. In particular, the MAGUKs SAP102 and PSD-95 are essential for synaptic function at distinct developmental timepoints and perform both overlapping and unique roles. While their similar structures allow for common binding partners, SAP102 is expressed earlier in synapse development and is required for synaptogenesis, whereas PSD-95 expression peaks later and is associated with synapse maturation. PSD-95 and other key synaptic proteins organize into subsynaptic nanodomains that have a significant impact on synaptic transmission, but the nanoscale organization of SAP102 is unknown. How SAP102 is organized within the synapse, and how it relates spatially to PSD-95 on a nanometer scale, could underlie its unique functions and impact how SAP102 scaffolds synaptic proteins. Here we used DNA-PAINT super-resolution microscopy to measure SAP102 nano-organization and its spatial relationship to PSD-95 at individual synapses in mixed-sex rat cultured neurons. We found that like PSD-95, SAP102 accumulates in high-density subsynaptic nanoclusters (NCs). However, SAP102 NCs were smaller and denser than PSD-95 NCs across development. Additionally, only a subset of SAP102 NCs co-organized with PSD-95, revealing MAGUK nanodomains within individual synapses containing either one or both proteins. These MAGUK nanodomain types had distinct NC properties and were differentially enriched with the presynaptic release protein Munc13-1. This organization into both shared and distinct subsynaptic nanodomains may underlie the ability of SAP102 and PSD-95 to perform both common and unique synaptic functions.
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Affiliation(s)
- Sarah R Metzbower
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Aaron D Levy
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Poorna A Dharmasri
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201
- Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Michael C Anderson
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201
- Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Thomas A Blanpied
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201
- Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland 21201
- University of Maryland Medicine Institute for Neuroscience Discovery, University of Maryland School of Medicine, Baltimore, Maryland 21201
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18
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Hines AD, Kewin AB, Van De Poll MN, Anggono V, Bademosi AT, van Swinderen B. Synapse-Specific Trapping of SNARE Machinery Proteins in the Anesthetized Drosophila Brain. J Neurosci 2024; 44:e0588232024. [PMID: 38749704 PMCID: PMC11170680 DOI: 10.1523/jneurosci.0588-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 05/01/2024] [Accepted: 05/06/2024] [Indexed: 05/18/2024] Open
Abstract
General anesthetics disrupt brain network dynamics through multiple pathways, in part through postsynaptic potentiation of inhibitory ion channels as well as presynaptic inhibition of neuroexocytosis. Common clinical general anesthetic drugs, such as propofol and isoflurane, have been shown to interact and interfere with core components of the exocytic release machinery to cause impaired neurotransmitter release. Recent studies however suggest that these drugs do not affect all synapse subtypes equally. We investigated the role of the presynaptic release machinery in multiple neurotransmitter systems under isoflurane general anesthesia in the adult female Drosophila brain using live-cell super-resolution microscopy and optogenetic readouts of exocytosis and neural excitability. We activated neurotransmitter-specific mushroom body output neurons and imaged presynaptic function under isoflurane anesthesia. We found that isoflurane impaired synaptic release and presynaptic protein dynamics in excitatory cholinergic synapses. In contrast, isoflurane had little to no effect on inhibitory GABAergic or glutamatergic synapses. These results present a distinct inhibitory mechanism for general anesthesia, whereby neuroexocytosis is selectively impaired at excitatory synapses, while inhibitory synapses remain functional. This suggests a presynaptic inhibitory mechanism that complements the other inhibitory effects of these drugs.
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Affiliation(s)
- Adam D Hines
- Queensland Brain Institute, The University of Queensland, St Lucia 4072, Queensland, Australia
| | - Amber B Kewin
- Queensland Brain Institute, The University of Queensland, St Lucia 4072, Queensland, Australia
| | - Matthew N Van De Poll
- Queensland Brain Institute, The University of Queensland, St Lucia 4072, Queensland, Australia
| | - Victor Anggono
- Queensland Brain Institute, The University of Queensland, St Lucia 4072, Queensland, Australia
- Clem Jones Centre for Ageing and Dementia Research, The University of Queensland, St Lucia 4072, Queensland, Australia
| | - Adekunle T Bademosi
- Queensland Brain Institute, The University of Queensland, St Lucia 4072, Queensland, Australia
- Clem Jones Centre for Ageing and Dementia Research, The University of Queensland, St Lucia 4072, Queensland, Australia
| | - Bruno van Swinderen
- Queensland Brain Institute, The University of Queensland, St Lucia 4072, Queensland, Australia
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19
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Bullmann T, Kaas T, Ritzau-Jost A, Wöhner A, Kirmann T, Rizalar FS, Holzer M, Nerlich J, Puchkov D, Geis C, Eilers J, Kittel RJ, Arendt T, Haucke V, Hallermann S. Human iPSC-Derived Neurons with Reliable Synapses and Large Presynaptic Action Potentials. J Neurosci 2024; 44:e0971232024. [PMID: 38724283 PMCID: PMC11170674 DOI: 10.1523/jneurosci.0971-23.2024] [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: 05/23/2023] [Revised: 04/30/2024] [Accepted: 05/01/2024] [Indexed: 06/14/2024] Open
Abstract
Understanding the function of the human brain requires determining basic properties of synaptic transmission in human neurons. One of the most fundamental parameters controlling neurotransmitter release is the presynaptic action potential, but its amplitude and duration remain controversial. Presynaptic action potentials have so far been measured with high temporal resolution only in a limited number of vertebrate but not in human neurons. To uncover properties of human presynaptic action potentials, we exploited recently developed tools to generate human glutamatergic neurons by transient expression of Neurogenin 2 (Ngn2) in pluripotent stem cells. During maturation for 3 to 9 weeks of culturing in different established media, the proportion of cells with multiple axon initial segments decreased, while the amount of axonal tau protein and neuronal excitability increased. Super-resolution microscopy revealed the alignment of the pre- and postsynaptic proteins, Bassoon and Homer. Synaptic transmission was surprisingly reliable at frequencies of 20, 50, and 100 Hz. The synchronicity of synaptic transmission during high-frequency transmission increased during 9 weeks of neuronal maturation. To analyze the mechanisms of synchronous high-frequency glutamate release, we developed direct presynaptic patch-clamp recordings from human neurons. The presynaptic action potentials had large overshoots to ∼25 mV and short durations of ∼0.5 ms. Our findings show that Ngn2-induced neurons represent an elegant model system allowing for functional, structural, and molecular analyses of glutamatergic synaptic transmission with high spatiotemporal resolution in human neurons. Furthermore, our data predict that glutamatergic transmission is mediated by large and rapid presynaptic action potentials in the human brain.
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Affiliation(s)
- Torsten Bullmann
- Carl-Ludwig-Institute of Physiology, Faculty of Medicine, Leipzig University, Leipzig 04103, Germany
| | - Thomas Kaas
- Carl-Ludwig-Institute of Physiology, Faculty of Medicine, Leipzig University, Leipzig 04103, Germany
| | - Andreas Ritzau-Jost
- Carl-Ludwig-Institute of Physiology, Faculty of Medicine, Leipzig University, Leipzig 04103, Germany
| | - Anne Wöhner
- Carl-Ludwig-Institute of Physiology, Faculty of Medicine, Leipzig University, Leipzig 04103, Germany
| | - Toni Kirmann
- Carl-Ludwig-Institute of Physiology, Faculty of Medicine, Leipzig University, Leipzig 04103, Germany
| | - Filiz Sila Rizalar
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin 13125, Germany
| | - Max Holzer
- Paul-Flechsig-Institute for Brain Research, Faculty of Medicine, Leipzig University, Leipzig 04103, Germany
| | - Jana Nerlich
- Carl-Ludwig-Institute of Physiology, Faculty of Medicine, Leipzig University, Leipzig 04103, Germany
| | - Dmytro Puchkov
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin 13125, Germany
| | - Christian Geis
- Section Translational Neuroimmunology, Department of Neurology, Jena University Hospital, Jena 07747, Germany
| | - Jens Eilers
- Carl-Ludwig-Institute of Physiology, Faculty of Medicine, Leipzig University, Leipzig 04103, Germany
| | - Robert J Kittel
- Institute of Biology, Department of Animal Physiology, Leipzig University, Leipzig 04103, Germany
| | - Thomas Arendt
- Paul-Flechsig-Institute for Brain Research, Faculty of Medicine, Leipzig University, Leipzig 04103, Germany
| | - Volker Haucke
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin 13125, Germany
- Faculty of Biology, Chemistry, Pharmacy, Freie Universität Berlin, Berlin 14195, Germany
| | - Stefan Hallermann
- Carl-Ludwig-Institute of Physiology, Faculty of Medicine, Leipzig University, Leipzig 04103, Germany
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20
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Bucher ML, Dicent J, Duarte Hospital C, Miller GW. Neurotoxicology of dopamine: Victim or assailant? Neurotoxicology 2024; 103:175-188. [PMID: 38857676 DOI: 10.1016/j.neuro.2024.06.001] [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: 04/13/2024] [Revised: 06/02/2024] [Accepted: 06/03/2024] [Indexed: 06/12/2024]
Abstract
Since the identification of dopamine as a neurotransmitter in the mid-20th century, investigators have examined the regulation of dopamine homeostasis at a basic biological level and in human disorders. Genetic animal models that manipulate the expression of proteins involved in dopamine homeostasis have provided key insight into the consequences of dysregulated dopamine. As a result, we have come to understand the potential of dopamine to act as an endogenous neurotoxin through the generation of reactive oxygen species and reactive metabolites that can damage cellular macromolecules. Endogenous factors, such as genetic variation and subcellular processes, and exogenous factors, such as environmental exposures, have been identified as contributors to the dysregulation of dopamine homeostasis. Given the variety of dysregulating factors that impact dopamine homeostasis and the potential for dopamine itself to contribute to further cellular dysfunction, dopamine can be viewed as both the victim and an assailant of neurotoxicity. Parkinson's disease has emerged as the exemplar case study of dopamine dysregulation due to the genetic and environmental factors known to contribute to disease risk, and due to the evidence of dysregulated dopamine as a pathologic and pathogenic feature of the disease. This review, inspired by the talk, "Dopamine in Durham: location, location, location" presented by Dr. Miller for the Jacob Hooisma Memorial Lecture at the International Neurotoxicology Association meeting in 2023, offers a primer on dopamine toxicity covering endogenous and exogenous factors that disrupt dopamine homeostasis and the actions of dopamine as an endogenous neurotoxin.
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Affiliation(s)
- Meghan L Bucher
- Department of Environmental Health Sciences, Mailman School of Public Health at Columbia University, New York, NY 10032, USA
| | - Jocelyn Dicent
- Department of Environmental Health Sciences, Mailman School of Public Health at Columbia University, New York, NY 10032, USA
| | - Carolina Duarte Hospital
- Department of Environmental Health Sciences, Mailman School of Public Health at Columbia University, New York, NY 10032, USA
| | - Gary W Miller
- Department of Environmental Health Sciences, Mailman School of Public Health at Columbia University, New York, NY 10032, USA; Department of Molecular Pharmacology and Therapeutics, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
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21
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Xiong GJ, Sheng ZH. Presynaptic perspective: Axonal transport defects in neurodevelopmental disorders. J Cell Biol 2024; 223:e202401145. [PMID: 38568173 PMCID: PMC10988239 DOI: 10.1083/jcb.202401145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2024] [Revised: 03/20/2024] [Accepted: 03/21/2024] [Indexed: 04/05/2024] Open
Abstract
Disruption of synapse assembly and maturation leads to a broad spectrum of neurodevelopmental disorders. Presynaptic proteins are largely synthesized in the soma, where they are packaged into precursor vesicles and transported into distal axons to ensure precise assembly and maintenance of presynapses. Due to their morphological features, neurons face challenges in the delivery of presynaptic cargos to nascent boutons. Thus, targeted axonal transport is vital to build functional synapses. A growing number of mutations in genes encoding the transport machinery have been linked to neurodevelopmental disorders. Emerging lines of evidence have started to uncover presynaptic mechanisms underlying axonal transport defects, thus broadening the view of neurodevelopmental disorders beyond postsynaptic mechanisms. In this review, we discuss presynaptic perspectives of neurodevelopmental disorders by focusing on impaired axonal transport and disturbed assembly and maintenance of presynapses. We also discuss potential strategies for restoring axonal transport as an early therapeutic intervention.
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Affiliation(s)
- Gui-Jing Xiong
- Synaptic Function Section, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Zu-Hang Sheng
- Synaptic Function Section, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
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22
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Trovò L, Kouvaros S, Schwenk J, Fernandez-Fernandez D, Fritzius T, Rem PD, Früh S, Gassmann M, Fakler B, Bischofberger J, Bettler B. Synaptotagmin-11 facilitates assembly of a presynaptic signaling complex in post-Golgi cargo vesicles. EMBO Rep 2024; 25:2610-2634. [PMID: 38698221 PMCID: PMC11169412 DOI: 10.1038/s44319-024-00147-0] [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: 08/18/2023] [Revised: 04/11/2024] [Accepted: 04/12/2024] [Indexed: 05/05/2024] Open
Abstract
GABAB receptors (GBRs), the G protein-coupled receptors for GABA, regulate synaptic transmission throughout the brain. A main synaptic function of GBRs is the gating of Cav2.2-type Ca2+ channels. However, the cellular compartment where stable GBR/Cav2.2 signaling complexes form remains unknown. In this study, we demonstrate that the vesicular protein synaptotagmin-11 (Syt11) binds to both the auxiliary GBR subunit KCTD16 and Cav2.2 channels. Through these dual interactions, Syt11 recruits GBRs and Cav2.2 channels to post-Golgi vesicles, thus facilitating assembly of GBR/Cav2.2 signaling complexes. In addition, Syt11 stabilizes GBRs and Cav2.2 channels at the neuronal plasma membrane by inhibiting constitutive internalization. Neurons of Syt11 knockout mice exhibit deficits in presynaptic GBRs and Cav2.2 channels, reduced neurotransmitter release, and decreased GBR-mediated presynaptic inhibition, highlighting the critical role of Syt11 in the assembly and stable expression of GBR/Cav2.2 complexes. These findings support that Syt11 acts as a vesicular scaffold protein, aiding in the assembly of signaling complexes from low-abundance components within transport vesicles. This mechanism enables insertion of pre-assembled functional signaling units into the synaptic membrane.
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Affiliation(s)
- Luca Trovò
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | | | - Jochen Schwenk
- Institute of Physiology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | | | | | | | - Simon Früh
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Martin Gassmann
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Bernd Fakler
- Institute of Physiology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- CIBSS Center for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
- Center for Basics in NeuroModulation, Freiburg, Germany
| | | | - Bernhard Bettler
- Department of Biomedicine, University of Basel, Basel, Switzerland.
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23
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Leitz J, Wang C, Esquivies L, Pfuetzner RA, Peters JJ, Couoh-Cardel S, Wang AL, Brunger AT. Beyond the MUN domain, Munc13 controls priming and depriming of synaptic vesicles. Cell Rep 2024; 43:114026. [PMID: 38809756 PMCID: PMC11286359 DOI: 10.1016/j.celrep.2024.114026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 02/20/2024] [Accepted: 03/15/2024] [Indexed: 05/31/2024] Open
Abstract
Synaptic vesicle docking and priming are dynamic processes. At the molecular level, SNAREs (soluble NSF attachment protein receptors), synaptotagmins, and other factors are critical for Ca2+-triggered vesicle exocytosis, while disassembly factors, including NSF (N-ethylmaleimide-sensitive factor) and α-SNAP (soluble NSF attachment protein), disassemble and recycle SNAREs and antagonize fusion under some conditions. Here, we introduce a hybrid fusion assay that uses synaptic vesicles isolated from mouse brains and synthetic plasma membrane mimics. We included Munc18, Munc13, complexin, NSF, α-SNAP, and an ATP-regeneration system and maintained them continuously-as in the neuron-to investigate how these opposing processes yield fusogenic synaptic vesicles. In this setting, synaptic vesicle association is reversible, and the ATP-regeneration system produces the most synchronous Ca2+-triggered fusion, suggesting that disassembly factors perform quality control at the early stages of synaptic vesicle association to establish a highly fusogenic state. We uncovered a functional role for Munc13 ancillary to the MUN domain that alleviates an α-SNAP-dependent inhibition of Ca2+-triggered fusion.
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Affiliation(s)
- Jeremy Leitz
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA; Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA, USA; Department of Structural Biology, Stanford University, Stanford, CA, USA; Department of Photon Science, Stanford University, Stanford, CA, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA
| | - Chuchu Wang
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA; Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA, USA; Department of Structural Biology, Stanford University, Stanford, CA, USA; Department of Photon Science, Stanford University, Stanford, CA, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA
| | - Luis Esquivies
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA; Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA, USA; Department of Structural Biology, Stanford University, Stanford, CA, USA; Department of Photon Science, Stanford University, Stanford, CA, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA
| | - Richard A Pfuetzner
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA; Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA, USA; Department of Structural Biology, Stanford University, Stanford, CA, USA; Department of Photon Science, Stanford University, Stanford, CA, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA
| | - John Jacob Peters
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA; Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA, USA; Department of Structural Biology, Stanford University, Stanford, CA, USA; Department of Photon Science, Stanford University, Stanford, CA, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA
| | - Sergio Couoh-Cardel
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA; Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA, USA; Department of Structural Biology, Stanford University, Stanford, CA, USA; Department of Photon Science, Stanford University, Stanford, CA, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA
| | - Austin L Wang
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA; Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA, USA; Department of Structural Biology, Stanford University, Stanford, CA, USA; Department of Photon Science, Stanford University, Stanford, CA, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA
| | - Axel T Brunger
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA; Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA, USA; Department of Structural Biology, Stanford University, Stanford, CA, USA; Department of Photon Science, Stanford University, Stanford, CA, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA.
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24
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Özçete ÖD, Banerjee A, Kaeser PS. Mechanisms of neuromodulatory volume transmission. Mol Psychiatry 2024:10.1038/s41380-024-02608-3. [PMID: 38789677 DOI: 10.1038/s41380-024-02608-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 05/07/2024] [Accepted: 05/10/2024] [Indexed: 05/26/2024]
Abstract
A wealth of neuromodulatory transmitters regulate synaptic circuits in the brain. Their mode of signaling, often called volume transmission, differs from classical synaptic transmission in important ways. In synaptic transmission, vesicles rapidly fuse in response to action potentials and release their transmitter content. The transmitters are then sensed by nearby receptors on select target cells with minimal delay. Signal transmission is restricted to synaptic contacts and typically occurs within ~1 ms. Volume transmission doesn't rely on synaptic contact sites and is the main mode of monoamines and neuropeptides, important neuromodulators in the brain. It is less precise than synaptic transmission, and the underlying molecular mechanisms and spatiotemporal scales are often not well understood. Here, we review literature on mechanisms of volume transmission and raise scientific questions that should be addressed in the years ahead. We define five domains by which volume transmission systems can differ from synaptic transmission and from one another. These domains are (1) innervation patterns and firing properties, (2) transmitter synthesis and loading into different types of vesicles, (3) architecture and distribution of release sites, (4) transmitter diffusion, degradation, and reuptake, and (5) receptor types and their positioning on target cells. We discuss these five domains for dopamine, a well-studied monoamine, and then compare the literature on dopamine with that on norepinephrine and serotonin. We include assessments of neuropeptide signaling and of central acetylcholine transmission. Through this review, we provide a molecular and cellular framework for volume transmission. This mechanistic knowledge is essential to define how neuromodulatory systems control behavior in health and disease and to understand how they are modulated by medical treatments and by drugs of abuse.
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Affiliation(s)
- Özge D Özçete
- Department of Neurobiology, Harvard Medical School, Boston, MA, 02115, USA
| | - Aditi Banerjee
- Department of Neurobiology, Harvard Medical School, Boston, MA, 02115, USA
| | - Pascal S Kaeser
- Department of Neurobiology, Harvard Medical School, Boston, MA, 02115, USA.
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25
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Zhang H, Lei M, Zhang Y, Li H, He Z, Xie S, Zhu L, Wang S, Liu J, Li Y, Lu Y, Ma C. Phosphorylation of Doc2 by EphB2 modulates Munc13-mediated SNARE complex assembly and neurotransmitter release. SCIENCE ADVANCES 2024; 10:eadi7024. [PMID: 38758791 PMCID: PMC11100570 DOI: 10.1126/sciadv.adi7024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 04/12/2024] [Indexed: 05/19/2024]
Abstract
At the synapse, presynaptic neurotransmitter release is tightly controlled by release machinery, involving the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins and Munc13. The Ca2+ sensor Doc2 cooperates with Munc13 to regulate neurotransmitter release, but the underlying mechanisms remain unclear. In our study, we have characterized the binding mode between Doc2 and Munc13 and found that Doc2 originally occludes Munc13 to inhibit SNARE complex assembly. Moreover, our investigation unveiled that EphB2, a presynaptic adhesion molecule (SAM) with inherent tyrosine kinase functionality, exhibits the capacity to phosphorylate Doc2. This phosphorylation attenuates Doc2 block on Munc13 to promote SNARE complex assembly, which functionally induces spontaneous release and synaptic augmentation. Consistently, application of a Doc2 peptide that interrupts Doc2-Munc13 interplay impairs excitatory synaptic transmission and leads to dysfunction in spatial learning and memory. These data provide evidence that SAMs modulate neurotransmitter release by controlling SNARE complex assembly.
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Affiliation(s)
- Hong Zhang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, 430074 Wuhan, China
| | - Mengshi Lei
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, 430074 Wuhan, China
| | - Yu Zhang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, 430074 Wuhan, China
| | - Hao Li
- Institute for Brain Research, Wuhan Center of Brain Science, Huazhong University of Science and Technology, Wuhan 430030, China
- Department of Pathophysiology, School of Basic Medicine and Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Zhen He
- Department of Pathogen Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, 430030 Wuhan, China
| | - Sheng Xie
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, 430074 Wuhan, China
| | - Le Zhu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, 430074 Wuhan, China
| | - Shen Wang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, 430074 Wuhan, China
| | - Jianfeng Liu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, 430074 Wuhan, China
| | - Yan Li
- Department of Pathogen Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, 430030 Wuhan, China
| | - Youming Lu
- Institute for Brain Research, Wuhan Center of Brain Science, Huazhong University of Science and Technology, Wuhan 430030, China
- Department of Pathophysiology, School of Basic Medicine and Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Cong Ma
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, 430074 Wuhan, China
- Institute for Brain Research, Wuhan Center of Brain Science, Huazhong University of Science and Technology, Wuhan 430030, China
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26
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Verpoort B, de Wit J. Cell Adhesion Molecule Signaling at the Synapse: Beyond the Scaffold. Cold Spring Harb Perspect Biol 2024; 16:a041501. [PMID: 38316556 PMCID: PMC11065171 DOI: 10.1101/cshperspect.a041501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
Synapses are specialized intercellular junctions connecting pre- and postsynaptic neurons into functional neural circuits. Synaptic cell adhesion molecules (CAMs) constitute key players in synapse development that engage in homo- or heterophilic interactions across the synaptic cleft. Decades of research have identified numerous synaptic CAMs, mapped their trans-synaptic interactions, and determined their role in orchestrating synaptic connectivity. However, surprisingly little is known about the molecular mechanisms that translate trans-synaptic adhesion into the assembly of pre- and postsynaptic compartments. Here, we provide an overview of the intracellular signaling pathways that are engaged by synaptic CAMs and highlight outstanding issues to be addressed in future work.
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Affiliation(s)
- Ben Verpoort
- VIB-KU Leuven Center for Brain and Disease Research, 3000 Leuven, Belgium
- KU Leuven, Department of Neurosciences, Leuven Brain Institute, 3000 Leuven, Belgium
| | - Joris de Wit
- VIB-KU Leuven Center for Brain and Disease Research, 3000 Leuven, Belgium
- KU Leuven, Department of Neurosciences, Leuven Brain Institute, 3000 Leuven, Belgium
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27
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Turrel O, Gao L, Sigrist SJ. Presynaptic regulators in memory formation. Learn Mem 2024; 31:a054013. [PMID: 38862173 PMCID: PMC11199941 DOI: 10.1101/lm.054013.124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2024] [Accepted: 04/17/2024] [Indexed: 06/13/2024]
Abstract
The intricate molecular and structural sequences guiding the formation and consolidation of memories within neuronal circuits remain largely elusive. In this study, we investigate the roles of two pivotal presynaptic regulators, the small GTPase Rab3, enriched at synaptic vesicles, and the cell adhesion protein Neurexin-1, in the formation of distinct memory phases within the Drosophila mushroom body Kenyon cells. Our findings suggest that both proteins play crucial roles in memory-supporting processes within the presynaptic terminal, operating within distinct plasticity modules. These modules likely encompass remodeling and maturation of existing active zones (AZs), as well as the formation of new AZs.
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Affiliation(s)
- Oriane Turrel
- Institute for Biology, Genetics, Freie Universität Berlin, 14195 Berlin, Germany
| | - Lili Gao
- Institute for Biology, Genetics, Freie Universität Berlin, 14195 Berlin, Germany
| | - Stephan J Sigrist
- Institute for Biology, Genetics, Freie Universität Berlin, 14195 Berlin, Germany
- Cluster of Excellence NeuroCure, Charité Universitätsmedizin Berlin, 10117 Berlin, Germany
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28
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Chen XQ, Zuo X. New insights into the effects of APP gene dose on synapse in Down syndrome. Neural Regen Res 2024; 19:961-962. [PMID: 37862189 PMCID: PMC10749626 DOI: 10.4103/1673-5374.382245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 06/27/2023] [Accepted: 07/13/2023] [Indexed: 10/22/2023] Open
Affiliation(s)
- Xu-Qiao Chen
- Department of Neurosciences, University of California San Diego, La Jolla, CA, USA
| | - Xinxin Zuo
- Department of Neurosciences, University of California San Diego, La Jolla, CA, USA
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29
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Pribbenow C, Owald D. Skewing information flow through pre- and postsynaptic plasticity in the mushroom bodies of Drosophila. Learn Mem 2024; 31:a053919. [PMID: 38876487 PMCID: PMC11199954 DOI: 10.1101/lm.053919.124] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 04/26/2024] [Indexed: 06/16/2024]
Abstract
Animal brains need to store information to construct a representation of their environment. Knowledge of what happened in the past allows both vertebrates and invertebrates to predict future outcomes by recalling previous experience. Although invertebrate and vertebrate brains share common principles at the molecular, cellular, and circuit-architectural levels, there are also obvious differences as exemplified by the use of acetylcholine versus glutamate as the considered main excitatory neurotransmitters in the respective central nervous systems. Nonetheless, across central nervous systems, synaptic plasticity is thought to be a main substrate for memory storage. Therefore, how brain circuits and synaptic contacts change following learning is of fundamental interest for understanding brain computations tied to behavior in any animal. Recent progress has been made in understanding such plastic changes following olfactory associative learning in the mushroom bodies (MBs) of Drosophila A current framework of memory-guided behavioral selection is based on the MB skew model, in which antagonistic synaptic pathways are selectively changed in strength. Here, we review insights into plasticity at dedicated Drosophila MB output pathways and update what is known about the plasticity of both pre- and postsynaptic compartments of Drosophila MB neurons.
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Affiliation(s)
- Carlotta Pribbenow
- Institute of Neurophysiology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10117 Berlin, Germany
| | - David Owald
- Institute of Neurophysiology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10117 Berlin, Germany
- Einstein Center for Neurosciences Berlin, 10117 Berlin, Germany
- NeuroCure, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10117 Berlin, Germany
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30
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Qiu H, Wu X, Ma X, Li S, Cai Q, Ganzella M, Ge L, Zhang H, Zhang M. Short-distance vesicle transport via phase separation. Cell 2024; 187:2175-2193.e21. [PMID: 38552623 DOI: 10.1016/j.cell.2024.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 01/17/2024] [Accepted: 03/02/2024] [Indexed: 04/28/2024]
Abstract
In addition to long-distance molecular motor-mediated transport, cellular vesicles also need to be moved at short distances with defined directions to meet functional needs in subcellular compartments but with unknown mechanisms. Such short-distance vesicle transport does not involve molecular motors. Here, we demonstrate, using synaptic vesicle (SV) transport as a paradigm, that phase separation of synaptic proteins with vesicles can facilitate regulated, directional vesicle transport between different presynaptic bouton sub-compartments. Specifically, a large coiled-coil scaffold protein Piccolo, in response to Ca2+ and via its C2A domain-mediated Ca2+ sensing, can extract SVs from the synapsin-clustered reserve pool condensate and deposit the extracted SVs onto the surface of the active zone protein condensate. We further show that the Trk-fused gene, TFG, also participates in COPII vesicle trafficking from ER to the ER-Golgi intermediate compartment via phase separation. Thus, phase separation may play a general role in short-distance, directional vesicle transport in cells.
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Affiliation(s)
- Hua Qiu
- Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Xiandeng Wu
- Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Xiaoli Ma
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shulin Li
- State Key Laboratory of Membrane Biology, Beijing, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China; School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Qixu Cai
- Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China; State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, Department of Laboratory Medicine, School of Public Health, Xiamen University, Xiamen 361102, China
| | - Marcelo Ganzella
- Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, Göttingen 37077, Germany
| | - Liang Ge
- State Key Laboratory of Membrane Biology, Beijing, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China; School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Hong Zhang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Mingjie Zhang
- Greater Bay Biomedical Innocenter, Shenzhen Bay Laboratory, Shenzhen 518036, China; School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China.
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31
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Zhou H, Bi GQ, Liu G. Intracellular magnesium optimizes transmission efficiency and plasticity of hippocampal synapses by reconfiguring their connectivity. Nat Commun 2024; 15:3406. [PMID: 38649706 PMCID: PMC11035601 DOI: 10.1038/s41467-024-47571-3] [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: 07/24/2023] [Accepted: 04/02/2024] [Indexed: 04/25/2024] Open
Abstract
Synapses at dendritic branches exhibit specific properties for information processing. However, how the synapses are orchestrated to dynamically modify their properties, thus optimizing information processing, remains elusive. Here, we observed at hippocampal dendritic branches diverse configurations of synaptic connectivity, two extremes of which are characterized by low transmission efficiency, high plasticity and coding capacity, or inversely. The former favors information encoding, pertinent to learning, while the latter prefers information storage, relevant to memory. Presynaptic intracellular Mg2+ crucially mediates the dynamic transition continuously between the two extreme configurations. Consequently, varying intracellular Mg2+ levels endow individual branches with diverse synaptic computations, thus modulating their ability to process information. Notably, elevating brain Mg2+ levels in aging animals restores synaptic configuration resembling that of young animals, coincident with improved learning and memory. These findings establish intracellular Mg2+ as a crucial factor reconfiguring synaptic connectivity at dendrites, thus optimizing their branch-specific properties in information processing.
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Affiliation(s)
- Hang Zhou
- Faculty of Life and Health Sciences, Shenzhen University of Advanced Technology, Shenzhen, 518107, China.
- Interdisciplinary Center for Brain Information, Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China.
| | - Guo-Qiang Bi
- Faculty of Life and Health Sciences, Shenzhen University of Advanced Technology, Shenzhen, 518107, China
- Interdisciplinary Center for Brain Information, Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
- Shenzhen-Hong Kong Institute of Brain Science, Shenzhen, 518055, China
- Hefei National Laboratory for Physical Sciences at the Microscale, and School of Life Sciences, University of Science and Technology of China, Hefei, 230031, China
| | - Guosong Liu
- School of Medicine, Tsinghua University, Beijing, 100084, China.
- NeuroCentria Inc., Walnut Creek, CA, 94596, USA.
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32
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Xu J, Esser V, Gołębiowska-Mendroch K, Bolembach AA, Rizo J. Control of Munc13-1 Activity by Autoinhibitory Interactions Involving the Variable N-terminal Region. J Mol Biol 2024; 436:168502. [PMID: 38417672 DOI: 10.1016/j.jmb.2024.168502] [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: 12/29/2023] [Revised: 02/17/2024] [Accepted: 02/20/2024] [Indexed: 03/01/2024]
Abstract
Regulation of neurotransmitter release during presynaptic plasticity underlies varied forms of information processing in the brain. Munc13s play essential roles in release via their conserved C-terminal region, which contains a MUN domain involved in SNARE complex assembly, and controls multiple presynaptic plasticity processes. Munc13s also have a variable N-terminal region, which in Munc13-1 includes a calmodulin binding (CaMb) domain involved in short-term plasticity and a C2A domain that forms an inhibitory homodimer. The C2A domain is activated by forming a heterodimer with the zinc-finger domain of αRIMs, providing a link to αRIM-dependent short- and long-term plasticity. However, it is unknown how the functions of the N- and C-terminal regions are integrated, in part because of the difficulty of purifying Munc13-1 fragments containing both regions. We describe for the first time the purification of a Munc13-1 fragment spanning its entire sequence except for a flexible region between the C2A and CaMb domains. We show that this fragment is much less active than the Munc13-1 C-terminal region in liposome fusion assays and that its activity is strongly enhanced by the RIM2α zinc-finger domain together with calmodulin. NMR experiments show that the C2A and CaMb domains bind to the MUN domain and that these interactions are relieved by the RIM2α ZF domain and calmodulin, respectively. These results suggest a model whereby Munc13-1 activity in promoting SNARE complex assembly and neurotransmitter release are inhibited by interactions of the C2A and CaMb domains with the MUN domain that are relieved by αRIMs and calmodulin.
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Affiliation(s)
- Junjie Xu
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Victoria Esser
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Katarzyna Gołębiowska-Mendroch
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Agnieszka A Bolembach
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Josep Rizo
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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33
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Paulussen I, Beckert H, Musial TF, Gschossmann LJ, Wolf J, Schmitt M, Clasadonte J, Mairet-Coello G, Wolff C, Schoch S, Dietrich D. SV2B defines a subpopulation of synaptic vesicles. J Mol Cell Biol 2024; 15:mjad054. [PMID: 37682518 PMCID: PMC11184983 DOI: 10.1093/jmcb/mjad054] [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: 08/25/2022] [Revised: 04/03/2023] [Accepted: 09/07/2023] [Indexed: 09/09/2023] Open
Abstract
Synaptic vesicles can undergo several modes of exocytosis, endocytosis, and trafficking within individual synapses, and their fates may be linked to different vesicular protein compositions. Here, we mapped the intrasynaptic distribution of the synaptic vesicle proteins SV2B and SV2A in glutamatergic synapses of the hippocampus using three-dimensional electron microscopy. SV2B was almost completely absent from docked vesicles and a distinct cluster of vesicles found near the active zone. In contrast, SV2A was found in all domains of the synapse and was slightly enriched near the active zone. SV2B and SV2A were found on the membrane in the peri-active zone, suggesting the recycling from both clusters of vesicles. SV2B knockout mice displayed an increased seizure induction threshold only in a model employing high-frequency stimulation. Our data show that glutamatergic synapses generate molecularly distinct populations of synaptic vesicles and are able to maintain them at steep spatial gradients. The almost complete absence of SV2B from vesicles at the active zone of wildtype mice may explain why SV2A has been found more important for vesicle release.
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Affiliation(s)
- Isabelle Paulussen
- Synaptic Neuroscience Team, Department of Neurosurgery, University Hospital Bonn, Bonn 53127, Germany
- Synaptic Neuroscience Team, Department of Neuropathology, University Hospital Bonn, Bonn 53127, Germany
| | - Hannes Beckert
- Microscopy Core Facility, Medical Faculty, University of Bonn, Bonn 53127, Germany
| | - Timothy F Musial
- Microscopy Core Facility, Medical Faculty, University of Bonn, Bonn 53127, Germany
| | - Lena J Gschossmann
- Synaptic Neuroscience Team, Department of Neurosurgery, University Hospital Bonn, Bonn 53127, Germany
- Synaptic Neuroscience Team, Department of Neuropathology, University Hospital Bonn, Bonn 53127, Germany
| | - Julia Wolf
- Synaptic Neuroscience Team, Department of Neurosurgery, University Hospital Bonn, Bonn 53127, Germany
- Synaptic Neuroscience Team, Department of Neuropathology, University Hospital Bonn, Bonn 53127, Germany
| | | | | | | | | | - Susanne Schoch
- Synaptic Neuroscience Team, Department of Neuropathology, University Hospital Bonn, Bonn 53127, Germany
| | - Dirk Dietrich
- Synaptic Neuroscience Team, Department of Neurosurgery, University Hospital Bonn, Bonn 53127, Germany
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Iwanaga R, Yahagi N, Hakeda-Suzuki S, Suzuki T. Cell adhesion and actin dynamics factors promote axonal extension and synapse formation in transplanted Drosophila photoreceptor cells. Dev Growth Differ 2024; 66:205-218. [PMID: 38403285 DOI: 10.1111/dgd.12916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 01/22/2024] [Accepted: 01/23/2024] [Indexed: 02/27/2024]
Abstract
Vision is formed by the transmission of light stimuli to the brain through axons extending from photoreceptor cells. Damage to these axons leads to loss of vision. Despite research on neural circuit regeneration through transplantation, achieving precise axon projection remains challenging. To achieve optic nerve regeneration by transplantation, we employed the Drosophila visual system. We previously established a transplantation method for Drosophila utilizing photoreceptor precursor cells extracted from the eye disc. However, little axonal elongation of transplanted cells into the brain, the lamina, was observed. We verified axonal elongation to the lamina by modifying the selection process for transplanted cells. Moreover, we focused on N-cadherin (Ncad), a cell adhesion factor, and Twinstar (Tsr), which has been shown to promote actin reorganization and induce axon elongation in damaged nerves. Overexpression of Ncad and tsr promoted axon elongation to the lamina, along with presynaptic structure formation in the elongating axons. Furthermore, overexpression of Neurexin-1 (Nrx-1), encoding a protein identified as a synaptic organizer, was found to not only promote presynapse formation but also enhance axon elongation. By introducing Ncad, tsr, and Nrx-1, we not only successfully achieved axonal projection of transplanted cells to the brain beyond the retina, but also confirmed the projection of transplanted cells into a deeper ganglion, the medulla. The present study offers valuable insights to realize regeneration through transplantation in a more complex nervous system.
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Affiliation(s)
- Riku Iwanaga
- School of Life Science and Technology, Tokyo Institute of Technology, Yokahama, Japan
| | - Nagisa Yahagi
- School of Life Science and Technology, Tokyo Institute of Technology, Yokahama, Japan
| | - Satoko Hakeda-Suzuki
- School of Life Science and Technology, Tokyo Institute of Technology, Yokahama, Japan
- Research Initiatives and Promotion Organization, Yokohama National University, Yokohama, Japan
| | - Takashi Suzuki
- School of Life Science and Technology, Tokyo Institute of Technology, Yokahama, Japan
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Marcó de la Cruz B, Campos J, Molinaro A, Xie X, Jin G, Wei Z, Acuna C, Sterky FH. Liprin-α proteins are master regulators of human presynapse assembly. Nat Neurosci 2024; 27:629-642. [PMID: 38472649 PMCID: PMC11001580 DOI: 10.1038/s41593-024-01592-9] [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: 07/16/2023] [Accepted: 01/30/2024] [Indexed: 03/14/2024]
Abstract
The formation of mammalian synapses entails the precise alignment of presynaptic release sites with postsynaptic receptors but how nascent cell-cell contacts translate into assembly of presynaptic specializations remains unclear. Guided by pioneering work in invertebrates, we hypothesized that in mammalian synapses, liprin-α proteins directly link trans-synaptic initial contacts to downstream steps. Here we show that, in human neurons lacking all four liprin-α isoforms, nascent synaptic contacts are formed but recruitment of active zone components and accumulation of synaptic vesicles is blocked, resulting in 'empty' boutons and loss of synaptic transmission. Interactions with presynaptic cell adhesion molecules of either the LAR-RPTP family or neurexins via CASK are required to localize liprin-α to nascent synaptic sites. Liprin-α subsequently recruits presynaptic components via a direct interaction with ELKS proteins. Thus, assembly of human presynaptic terminals is governed by a hierarchical sequence of events in which the recruitment of liprin-α proteins by presynaptic cell adhesion molecules is a critical initial step.
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Affiliation(s)
- Berta Marcó de la Cruz
- Department of Laboratory Medicine, Institute for Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Joaquín Campos
- Chica and Heinz Schaller Foundation, Institute of Anatomy and Cell Biology, Heidelberg University, Heidelberg, Germany
| | - Angela Molinaro
- Department of Laboratory Medicine, Institute for Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Xingqiao Xie
- School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
- Brain Research Center, Southern University of Science and Technology, Shenzhen, China
- Shenzhen Key Laboratory of Biomolecular Assembling and Regulation, Shenzhen, China
| | - Gaowei Jin
- School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
- Brain Research Center, Southern University of Science and Technology, Shenzhen, China
| | - Zhiyi Wei
- School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
- Brain Research Center, Southern University of Science and Technology, Shenzhen, China
- Shenzhen Key Laboratory of Biomolecular Assembling and Regulation, Shenzhen, China
| | - Claudio Acuna
- Chica and Heinz Schaller Foundation, Institute of Anatomy and Cell Biology, Heidelberg University, Heidelberg, Germany.
| | - Fredrik H Sterky
- Department of Laboratory Medicine, Institute for Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
- Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Gothenburg, Sweden.
- Department of Clinical Chemistry, Sahlgrenska University Hospital, Gothenburg, Sweden.
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36
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Vandael D, Jonas P. Structure, biophysics, and circuit function of a "giant" cortical presynaptic terminal. Science 2024; 383:eadg6757. [PMID: 38452088 DOI: 10.1126/science.adg6757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 01/19/2024] [Indexed: 03/09/2024]
Abstract
The hippocampal mossy fiber synapse, formed between axons of dentate gyrus granule cells and dendrites of CA3 pyramidal neurons, is a key synapse in the trisynaptic circuitry of the hippocampus. Because of its comparatively large size, this synapse is accessible to direct presynaptic recording, allowing a rigorous investigation of the biophysical mechanisms of synaptic transmission and plasticity. Furthermore, because of its placement in the very center of the hippocampal memory circuit, this synapse seems to be critically involved in several higher network functions, such as learning, memory, pattern separation, and pattern completion. Recent work based on new technologies in both nanoanatomy and nanophysiology, including presynaptic patch-clamp recording, paired recording, super-resolution light microscopy, and freeze-fracture and "flash-and-freeze" electron microscopy, has provided new insights into the structure, biophysics, and network function of this intriguing synapse. This brings us one step closer to answering a fundamental question in neuroscience: how basic synaptic properties shape higher network computations.
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Affiliation(s)
- David Vandael
- Institute of Science and Technology Austria (ISTA), A-3400 Klosterneuburg, Austria
| | - Peter Jonas
- Institute of Science and Technology Austria (ISTA), A-3400 Klosterneuburg, Austria
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37
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Chen JJ, Kaufmann WA, Chen C, Arai I, Kim O, Shigemoto R, Jonas P. Developmental transformation of Ca 2+ channel-vesicle nanotopography at a central GABAergic synapse. Neuron 2024; 112:755-771.e9. [PMID: 38215739 DOI: 10.1016/j.neuron.2023.12.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 07/12/2023] [Accepted: 12/05/2023] [Indexed: 01/14/2024]
Abstract
The coupling between Ca2+ channels and release sensors is a key factor defining the signaling properties of a synapse. However, the coupling nanotopography at many synapses remains unknown, and it is unclear how it changes during development. To address these questions, we examined coupling at the cerebellar inhibitory basket cell (BC)-Purkinje cell (PC) synapse. Biophysical analysis of transmission by paired recording and intracellular pipette perfusion revealed that the effects of exogenous Ca2+ chelators decreased during development, despite constant reliance of release on P/Q-type Ca2+ channels. Structural analysis by freeze-fracture replica labeling (FRL) and transmission electron microscopy (EM) indicated that presynaptic P/Q-type Ca2+ channels formed nanoclusters throughout development, whereas docked vesicles were only clustered at later developmental stages. Modeling suggested a developmental transformation from a more random to a more clustered coupling nanotopography. Thus, presynaptic signaling developmentally approaches a point-to-point configuration, optimizing speed, reliability, and energy efficiency of synaptic transmission.
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Affiliation(s)
- Jing-Jing Chen
- Institute of Science and Technology Austria (ISTA), Am Campus 1, 3400 Klosterneuburg, Austria
| | - Walter A Kaufmann
- Institute of Science and Technology Austria (ISTA), Am Campus 1, 3400 Klosterneuburg, Austria
| | - Chong Chen
- Institute of Science and Technology Austria (ISTA), Am Campus 1, 3400 Klosterneuburg, Austria
| | - Itaru Arai
- Institute of Science and Technology Austria (ISTA), Am Campus 1, 3400 Klosterneuburg, Austria
| | - Olena Kim
- Institute of Science and Technology Austria (ISTA), Am Campus 1, 3400 Klosterneuburg, Austria
| | - Ryuichi Shigemoto
- Institute of Science and Technology Austria (ISTA), Am Campus 1, 3400 Klosterneuburg, Austria
| | - Peter Jonas
- Institute of Science and Technology Austria (ISTA), Am Campus 1, 3400 Klosterneuburg, Austria.
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Montefusco A, Helfmann L, Okunola T, Winkelmann S, Schütte C. Partial mean-field model for neurotransmission dynamics. Math Biosci 2024; 369:109143. [PMID: 38220067 DOI: 10.1016/j.mbs.2024.109143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 12/07/2023] [Accepted: 01/09/2024] [Indexed: 01/16/2024]
Abstract
This article addresses reaction networks in which spatial and stochastic effects are of crucial importance. For such systems, particle-based models allow us to describe all microscopic details with high accuracy. However, they suffer from computational inefficiency if particle numbers and density get too large. Alternative coarse-grained-resolution models reduce computational effort tremendously, e.g., by replacing the particle distribution by a continuous concentration field governed by reaction-diffusion PDEs. We demonstrate how models on the different resolution levels can be combined into hybrid models that seamlessly combine the best of both worlds, describing molecular species with large copy numbers by macroscopic equations with spatial resolution while keeping the spatial-stochastic particle-based resolution level for the species with low copy numbers. To this end, we introduce a simple particle-based model for the binding dynamics of ions and vesicles at the heart of the neurotransmission process. Within this framework, we derive a novel hybrid model and present results from numerical experiments which demonstrate that the hybrid model allows for an accurate approximation of the full particle-based model in realistic scenarios.
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Affiliation(s)
- Alberto Montefusco
- Mathematics of Complex Systems, Zuse-Institut Berlin, Takustraße 7, Berlin, 14195, Germany
| | - Luzie Helfmann
- Mathematics of Complex Systems, Zuse-Institut Berlin, Takustraße 7, Berlin, 14195, Germany
| | - Toluwani Okunola
- Mathematics of Complex Systems, Zuse-Institut Berlin, Takustraße 7, Berlin, 14195, Germany; Institute Of Mathematics, Technische Universität Berlin, Straße des 17. Juni 136, Berlin, 10623, Germany
| | - Stefanie Winkelmann
- Mathematics of Complex Systems, Zuse-Institut Berlin, Takustraße 7, Berlin, 14195, Germany.
| | - Christof Schütte
- Mathematics of Complex Systems, Zuse-Institut Berlin, Takustraße 7, Berlin, 14195, Germany; Institute of Mathematics, Freie Universität Berlin, Arnimallee 6, Berlin, 14195, Germany
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39
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Masilamoni GJ, Kelly H, Swain AJ, Pare JF, Villalba RM, Smith Y. Structural Plasticity of GABAergic Pallidothalamic Terminals in MPTP-Treated Parkinsonian Monkeys: A 3D Electron Microscopic Analysis. eNeuro 2024; 11:ENEURO.0241-23.2024. [PMID: 38514185 PMCID: PMC10957232 DOI: 10.1523/eneuro.0241-23.2024] [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: 07/09/2023] [Revised: 02/22/2024] [Accepted: 02/26/2024] [Indexed: 03/23/2024] Open
Abstract
The internal globus pallidus (GPi) is a major source of tonic GABAergic inhibition to the motor thalamus. In parkinsonism, the firing rate of GPi neurons is increased, and their pattern switches from a tonic to a burst mode, two pathophysiological changes associated with increased GABAergic pallidothalamic activity. In this study, we used high-resolution 3D electron microscopy to demonstrate that GPi terminals in the parvocellular ventral anterior nucleus (VApc) and the centromedian nucleus (CM), the two main GPi-recipient motor thalamic nuclei in monkeys, undergo significant morphometric changes in parkinsonian monkeys including (1) increased terminal volume in both nuclei; (2) increased surface area of synapses in both nuclei; (3) increased number of synapses/GPi terminals in the CM, but not VApc; and (4) increased total volume, but not number, of mitochondria/terminals in both nuclei. In contrast to GPi terminals, the ultrastructure of putative GABAergic nonpallidal terminals was not affected. Our results also revealed striking morphological differences in terminal volume, number/area of synapses, and volume/number of mitochondria between GPi terminals in VApc and CM of control monkeys. In conclusion, GABAergic pallidothalamic terminals are endowed with a high level of structural plasticity that may contribute to the development and maintenance of the abnormal increase in pallidal GABAergic outflow to the thalamus in the parkinsonian state. Furthermore, the evidence for ultrastructural differences between GPi terminals in VApc and CM suggests that morphologically distinct pallidothalamic terminals from single pallidal neurons may underlie specific physiological properties of pallidal inputs to VApc and CM in normal and diseased states.
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Affiliation(s)
- G J Masilamoni
- Emory National Primate Research Center, Atlanta, Georgia 30322
- Udall Center of Excellence for Parkinson's Disease, Emory University, Atlanta, Georgia 30322
| | - H Kelly
- Emory National Primate Research Center, Atlanta, Georgia 30322
- Udall Center of Excellence for Parkinson's Disease, Emory University, Atlanta, Georgia 30322
| | - A J Swain
- Emory National Primate Research Center, Atlanta, Georgia 30322
- Udall Center of Excellence for Parkinson's Disease, Emory University, Atlanta, Georgia 30322
| | - J F Pare
- Emory National Primate Research Center, Atlanta, Georgia 30322
- Udall Center of Excellence for Parkinson's Disease, Emory University, Atlanta, Georgia 30322
| | - R M Villalba
- Emory National Primate Research Center, Atlanta, Georgia 30322
- Udall Center of Excellence for Parkinson's Disease, Emory University, Atlanta, Georgia 30322
| | - Y Smith
- Emory National Primate Research Center, Atlanta, Georgia 30322
- Udall Center of Excellence for Parkinson's Disease, Emory University, Atlanta, Georgia 30322
- Department of Neurology, Emory University, Atlanta, Georgia 30322
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40
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Rai S, Singh MP, Sinha A, Srivastava A, Datta D, Srivastava S. Unravelling a novel CTNND1-RAB6A fusion transcript: Implications in colon cancer cell migration. Int J Biol Macromol 2024; 262:129981. [PMID: 38336316 DOI: 10.1016/j.ijbiomac.2024.129981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 01/22/2024] [Accepted: 01/31/2024] [Indexed: 02/12/2024]
Abstract
The interchange of DNA sequences between genes may occur because of chromosomal rearrangements leading to the formation of chimeric genes. These chimeric genes have been linked to various cancers, accumulated significant interest in recent times. We used paired-end RNA-seq. data of four CRC and one normal sample generated from our previous study. The STAR-Fusion pipeline was utilized to identify the fusion genes unique to CRC. The in-silico identified fusion gene(s) were explored for their diagnostic, prognostic and therapeutic biomarker potential using TCGA-datasets, then validated through PCR and DNA sequencing. Further, cell line-based studies were performed to gain functional insights of the novel fusion transcript CTNND1-RAB6A, which was amplified in one sample. Sequencing revealed that there was a total loss of the CTNND1 gene, whereas RAB6A retained its coding sequence. Further, RAB6A was functionally characterized for its oncogenic potential in HCT116 cell line. RAB6A under-expression was found to be significantly associated with increased cell migration and is proposed to be regulated via the RAB6A-ECR1-Liprin-α axis. We conclude that RAB6A gene may play significant role in CRC oncogenesis, and could be used as a potential biomarker and therapeutic target in future for better management of a subset of CRCs harbouring this fusion.
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Affiliation(s)
- Sandhya Rai
- Department of Biotechnology, Motilal Nehru National Institute of Technology, Teliyarganj-Prayagraj, U.P. 211004, India
| | - Manish Pratap Singh
- Department of Zoology, Deen Dayal Upadhyay Gorakhpur University, Gorakhpur, (U.P.) 273009, India
| | - Abhipsa Sinha
- Division of cancer biology, CSIR-Central Drug Research Institute, Jankipuram Extension, Sitapur Road, Lucknow, Uttar Pradesh 226031, India
| | - Ankit Srivastava
- Department of Biotechnology, Motilal Nehru National Institute of Technology, Teliyarganj-Prayagraj, U.P. 211004, India
| | - Dipak Datta
- Division of cancer biology, CSIR-Central Drug Research Institute, Jankipuram Extension, Sitapur Road, Lucknow, Uttar Pradesh 226031, India
| | - Sameer Srivastava
- Department of Biotechnology, Motilal Nehru National Institute of Technology, Teliyarganj-Prayagraj, U.P. 211004, India.
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Glausier JR, Bouchet-Marquis C, Maier M, Banks-Tibbs T, Wu K, Ning J, Melchitzky D, Lewis DA, Freyberg Z. Characterization of the three-dimensional synaptic and mitochondrial nanoarchitecture within glutamatergic synaptic complexes in postmortem human brain via focused ion beam-scanning electron microscopy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.26.582174. [PMID: 38463986 PMCID: PMC10925168 DOI: 10.1101/2024.02.26.582174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Glutamatergic synapses are the primary site of excitatory synaptic signaling and neural communication in the cerebral cortex. Electron microscopy (EM) studies in non-human model organisms have demonstrated that glutamate synaptic activity and functioning are directly reflected in quantifiable ultrastructural features. Thus, quantitative EM analysis of glutamate synapses in ex vivo preserved human brain tissue has the potential to provide novel insight into in vivo synaptic functioning. However, factors associated with the acquisition and preservation of human brain tissue have resulted in persistent concerns regarding the potential confounding effects of antemortem and postmortem biological processes on synaptic and sub-synaptic ultrastructural features. Thus, we sought to determine how well glutamate synaptic relationships and nanoarchitecture are preserved in postmortem human dorsolateral prefrontal cortex (DLPFC), a region that substantially differs in size and architecture from model systems. Focused ion beam-scanning electron microscopy (FIB-SEM), a powerful volume EM (VEM) approach, was employed to generate high-fidelity, fine-resolution, three-dimensional (3D) micrographic datasets appropriate for quantitative analyses. Using postmortem human DLPFC with a 6-hour postmortem interval, we optimized a tissue preservation and staining workflow that generated samples of excellent ultrastructural preservation and the high-contrast staining intensity required for FIB-SEM imaging. Quantitative analysis of sub-cellular, sub-synaptic and organelle components within glutamate axo-spinous synapses revealed that ultrastructural features of synaptic function and activity were well-preserved within and across individual synapses in postmortem human brain tissue. The synaptic, sub-synaptic and organelle measures were highly consistent with findings from experimental models that are free from antemortem or postmortem effects. Further, dense reconstruction of neuropil revealed a unique, ultrastructurally-complex, spiny dendritic shaft that exhibited features characteristic of neuronal processes with heightened synaptic communication, integration and plasticity. Altogether, our findings provide a critical proof-of-concept that ex vivo VEM analysis provides a valuable and informative means to infer in vivo functioning of human brain.
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Affiliation(s)
| | | | | | - Tabitha Banks-Tibbs
- Department of Psychiatry, University of Pittsburgh
- Department of Human Genetics, University of Pittsburgh
- College of Medicine, The Ohio State University
| | - Ken Wu
- Materials and Structural Analysis, Thermo Fisher Scientific
| | - Jiying Ning
- Department of Psychiatry, University of Pittsburgh
| | | | | | - Zachary Freyberg
- Department of Psychiatry, University of Pittsburgh
- Department of Cell Biology, University of Pittsburgh
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Han KA, Yoon TH, Kim J, Lee J, Lee JY, Jang G, Um JW, Kim JK, Ko J. Specification of neural circuit architecture shaped by context-dependent patterned LAR-RPTP microexons. Nat Commun 2024; 15:1624. [PMID: 38388459 PMCID: PMC10883964 DOI: 10.1038/s41467-024-45695-0] [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: 07/13/2023] [Accepted: 01/30/2024] [Indexed: 02/24/2024] Open
Abstract
LAR-RPTPs are evolutionarily conserved presynaptic cell-adhesion molecules that orchestrate multifarious synaptic adhesion pathways. Extensive alternative splicing of LAR-RPTP mRNAs may produce innumerable LAR-RPTP isoforms that act as regulatory "codes" for determining the identity and strength of specific synapse signaling. However, no direct evidence for this hypothesis exists. Here, using targeted RNA sequencing, we detected LAR-RPTP mRNAs in diverse cell types across adult male mouse brain areas. We found pronounced cell-type-specific patterns of two microexons, meA and meB, in Ptprd mRNAs. Moreover, diverse neural circuits targeting the same neuronal populations were dictated by the expression of different Ptprd variants with distinct inclusion patterns of microexons. Furthermore, conditional ablation of Ptprd meA+ variants at presynaptic loci of distinct hippocampal circuits impaired distinct modes of synaptic transmission and objection-location memory. Activity-triggered alterations of the presynaptic Ptprd meA code in subicular neurons mediates NMDA receptor-mediated postsynaptic responses in CA1 neurons and objection-location memory. Our data provide the evidence of cell-type- and/or circuit-specific expression patterns in vivo and physiological functions of LAR-RPTP microexons that are dynamically regulated.
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Affiliation(s)
- Kyung Ah Han
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, Korea
- Center for Synapse Diversity and Specificity, DGIST, Daegu, 42988, Korea
| | - Taek-Han Yoon
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, Korea
| | - Jinhu Kim
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, Korea
| | - Jusung Lee
- Department of New Biology, DGIST, Daegu, 42988, Korea
| | - Ju Yeon Lee
- Korea Basic Science Institute, Research Center for Bioconvergence Analysis, Cheongju, 28119, Korea
| | - Gyubin Jang
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, Korea
- Center for Synapse Diversity and Specificity, DGIST, Daegu, 42988, Korea
| | - Ji Won Um
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, Korea
- Center for Synapse Diversity and Specificity, DGIST, Daegu, 42988, Korea
| | - Jong Kyoung Kim
- Department of New Biology, DGIST, Daegu, 42988, Korea
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Korea
| | - Jaewon Ko
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, Korea.
- Center for Synapse Diversity and Specificity, DGIST, Daegu, 42988, Korea.
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Miyano R, Sakamoto H, Hirose K, Sakaba T. RIM-BP2 regulates Ca 2+ channel abundance and neurotransmitter release at hippocampal mossy fiber terminals. eLife 2024; 12:RP90799. [PMID: 38329474 PMCID: PMC10945523 DOI: 10.7554/elife.90799] [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: 02/09/2024] Open
Abstract
Synaptic vesicles dock and fuse at the presynaptic active zone (AZ), the specialized site for transmitter release. AZ proteins play multiple roles such as recruitment of Ca2+ channels as well as synaptic vesicle docking, priming, and fusion. However, the precise role of each AZ protein type remains unknown. In order to dissect the role of RIM-BP2 at mammalian cortical synapses having low release probability, we applied direct electrophysiological recording and super-resolution imaging to hippocampal mossy fiber terminals of RIM-BP2 knockout (KO) mice. By using direct presynaptic recording, we found the reduced Ca2+ currents. The measurements of excitatory postsynaptic currents (EPSCs) and presynaptic capacitance suggested that the initial release probability was lowered because of the reduced Ca2+ influx and impaired fusion competence in RIM-BP2 KO. Nevertheless, larger Ca2+ influx restored release partially. Consistent with presynaptic recording, STED microscopy suggested less abundance of P/Q-type Ca2+ channels at AZs deficient in RIM-BP2. Our results suggest that the RIM-BP2 regulates both Ca2+ channel abundance and transmitter release at mossy fiber synapses.
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Affiliation(s)
- Rinako Miyano
- Graduate School of Brain Science, Doshisha UniversityKyotoJapan
| | - Hirokazu Sakamoto
- Department of Pharmacology, Graduate School of Medicine, The University of TokyoBunkyo-kuJapan
| | - Kenzo Hirose
- Department of Pharmacology, Graduate School of Medicine, The University of TokyoBunkyo-kuJapan
- International Research Center for Neurointelligence (WPI-IRCN), The University of TokyoBunkyo-kuJapan
| | - Takeshi Sakaba
- Graduate School of Brain Science, Doshisha UniversityKyotoJapan
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Xu J, Esser V, Gołębiowska-Mendroch K, Bolembach AA, Rizo J. Control of Munc13-1 Activity by Autoinhibitory Interactions Involving the Variable N-terminal Region. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.24.577102. [PMID: 38328168 PMCID: PMC10849727 DOI: 10.1101/2024.01.24.577102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Regulation of neurotransmitter release during presynaptic plasticity underlies varied forms of information processing in the brain. Munc13s play essential roles in release via their conserved C-terminal region, which contains a MUN domain involved SNARE complex assembly, and control multiple presynaptic plasticity processes. Munc13s also have a variable N-terminal region, which in Munc13-1 includes a calmodulin binding (CaMb) domain involved in short-term plasticity and a C2A domain that forms an inhibitory homodimer. The C2A domain is activated by forming a heterodimer with the zinc-finger domain of αRIMs, providing a link to αRIM-dependent short- and long-term plasticity. However, it is unknown how the functions of the N- and C-terminal regions are integrated, in part because of the difficulty of purifying Munc13-1 fragments containing both regions. We describe for the first time the purification of a Munc13-1 fragment spanning its entire sequence except for a flexible region between the C2A and CaMb domains. We show that this fragment is much less active than the Munc13-1 C-terminal region in liposome fusion assays and that its activity is strongly enhanced by the RIM2α zinc-finger domain together with calmodulin. NMR experiments show that the C2A and CaMb domains bind to the MUN domain and that these interactions are relieved by the RIM2α ZF domain and calmodulin, respectively. These results suggest a model whereby Munc13-1 activity in promoting SNARE complex assembly and neurotransmitter release are inhibited by interactions of the C2A and CaMb domains with the MUN domain that are relieved by αRIMs and calmodulin.
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Affiliation(s)
- Junjie Xu
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Victoria Esser
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Katarzyna Gołębiowska-Mendroch
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
- Current address: Jagiellonian University, Faculty of Chemistry, Department of Organic Chemistry, Gronostajowa 2, 30-387, Krakow, Poland
| | - Agnieszka A Bolembach
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
- Current address: Dioscuri Centre for RNA-Protein Interactions in Human Health and Disease, International Institute of Molecular and Cell Biology in Warsaw, 4 Ks. Trojdena Street, 02-109 Warsaw, Poland
| | - Josep Rizo
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
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Silva M, Tran V, Marty A. A maximum of two readily releasable vesicles per docking site at a cerebellar single active zone synapse. eLife 2024; 12:RP91087. [PMID: 38180320 PMCID: PMC10963025 DOI: 10.7554/elife.91087] [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: 01/06/2024] Open
Abstract
Recent research suggests that in central mammalian synapses, active zones contain several docking sites acting in parallel. Before release, one or several synaptic vesicles (SVs) are thought to bind to each docking site, forming the readily releasable pool (RRP). Determining the RRP size per docking site has important implications for short-term synaptic plasticity. Here, using mouse cerebellar slices, we take advantage of recently developed methods to count the number of released SVs at single glutamatergic synapses in response to trains of action potentials (APs). In each recording, the number of docking sites was determined by fitting with a binomial model the number of released SVs in response to individual APs. After normalization with respect to the number of docking sites, the summed number of released SVs following a train of APs was used to estimate of the RRP size per docking site. To improve this estimate, various steps were taken to maximize the release probability of docked SVs, the occupancy of docking sites, as well as the extent of synaptic depression. Under these conditions, the RRP size reached a maximum value close to two SVs per docking site. The results indicate that each docking site contains two distinct SV-binding sites that can simultaneously accommodate up to one SV each. They further suggest that under special experimental conditions, as both sites are close to full occupancy, a maximal RRP size of two SVs per docking site can be reached. More generally, the results validate a sequential two-step docking model previously proposed at this preparation.
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Affiliation(s)
- Melissa Silva
- Université Paris Cité, SPPIN-Saints Pères Paris Institute for the Neurosciences, CNRSParisFrance
| | - Van Tran
- Université Paris Cité, SPPIN-Saints Pères Paris Institute for the Neurosciences, CNRSParisFrance
| | - Alain Marty
- Université Paris Cité, SPPIN-Saints Pères Paris Institute for the Neurosciences, CNRSParisFrance
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Shen XY, Zhang J, Huang HZ, Li SD, Zhou L, Wu SP, Tang C, Huang X, Liu ZQ, Guo ZY, Li X, Man HY, Lu YM, Zhu LQ, Liu D. The interaction of Synapsin 2a and Synaptogyrin-3 regulates fear extinction in mice. J Clin Invest 2024; 134:e172802. [PMID: 38175724 PMCID: PMC10866652 DOI: 10.1172/jci172802] [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: 06/05/2023] [Accepted: 12/20/2023] [Indexed: 01/05/2024] Open
Abstract
The mechanisms behind a lack of efficient fear extinction in some individuals are unclear. Here, by employing a principal components analysis-based approach, we differentiated the mice into extinction-resistant and susceptible groups. We determined that elevated synapsin 2a (Syn2a) in the infralimbic cortex (IL) to basolateral amygdala (BLA) circuit disrupted presynaptic orchestration, leading to an excitatory/inhibitory imbalance in the BLA region and causing extinction resistance. Overexpression or silencing of Syn2a levels in IL neurons replicated or alleviated behavioral, electrophysiological, and biochemical phenotypes in resistant mice. We further identified that the proline-rich domain H in the C-terminus of Syn2a was indispensable for the interaction with synaptogyrin-3 (Syngr3) and demonstrated that disrupting this interaction restored extinction impairments. Molecular docking revealed that ritonavir, an FDA-approved HIV drug, could disrupt Syn2a-Syngr3 binding and rescue fear extinction behavior in Syn2a-elevated mice. In summary, the aberrant elevation of Syn2a expression and its interaction with Syngr3 at the presynaptic site were crucial in fear extinction resistance, suggesting a potential therapeutic avenue for related disorders.
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Affiliation(s)
- Xi-Ya Shen
- Department of Pathophysiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Juan Zhang
- Department of Pathophysiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - He-Zhou Huang
- Department of Pathophysiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Shao-Dan Li
- Department of Pathophysiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Ling Zhou
- Department of Pathophysiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Shi-Ping Wu
- Department of Pathophysiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Cheng Tang
- Department of Pathophysiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Xian Huang
- Department of Pathophysiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Zhi-Qiang Liu
- Department of Pathophysiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Zi-Yuan Guo
- Center for Stem Cell and Organoid Medicine (CuSTOM), Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
| | - Xiang Li
- Department of Neurosurgery and
- Brain Research Center, Zhongnan Hospital of Wuhan University, Wuhan, China
- Medical Research Institute, Wuhan University, Wuhan, Hubei, China
| | - Heng-Ye Man
- Department of Biology, Boston University, Boston, Massachusetts, USA
| | - You-Ming Lu
- Department of Pathophysiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Ling-Qiang Zhu
- Department of Pathophysiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Dan Liu
- Department of Medical Genetics, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
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Paul MS, Michener SL, Pan H, Chan H, Pfliger JM, Rosenfeld JA, Lerma VC, Tran A, Longley MA, Lewis RA, Weisz-Hubshman M, Bekheirnia MR, Bekheirnia N, Massingham L, Zech M, Wagner M, Engels H, Cremer K, Mangold E, Peters S, Trautmann J, Mester JL, Guillen Sacoto MJ, Person R, McDonnell PP, Cohen SR, Lusk L, Cohen ASA, Le Pichon JB, Pastinen T, Zhou D, Engleman K, Racine C, Faivre L, Moutton S, Denommé-Pichon AS, Koh HY, Poduri A, Bolton J, Knopp C, Julia Suh DS, Maier A, Toosi MB, Karimiani EG, Maroofian R, Schaefer GB, Ramakumaran V, Vasudevan P, Prasad C, Osmond M, Schuhmann S, Vasileiou G, Russ-Hall S, Scheffer IE, Carvill GL, Mefford H, Bacino CA, Lee BH, Chao HT. A syndromic neurodevelopmental disorder caused by rare variants in PPFIA3. Am J Hum Genet 2024; 111:96-118. [PMID: 38181735 PMCID: PMC10806447 DOI: 10.1016/j.ajhg.2023.12.004] [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: 04/06/2023] [Revised: 12/01/2023] [Accepted: 12/04/2023] [Indexed: 01/07/2024] Open
Abstract
PPFIA3 encodes the protein-tyrosine phosphatase, receptor-type, F-polypeptide-interacting-protein-alpha-3 (PPFIA3), which is a member of the LAR-protein-tyrosine phosphatase-interacting-protein (liprin) family involved in synapse formation and function, synaptic vesicle transport, and presynaptic active zone assembly. The protein structure and function are evolutionarily well conserved, but human diseases related to PPFIA3 dysfunction are not yet reported in OMIM. Here, we report 20 individuals with rare PPFIA3 variants (19 heterozygous and 1 compound heterozygous) presenting with developmental delay, intellectual disability, hypotonia, dysmorphisms, microcephaly or macrocephaly, autistic features, and epilepsy with reduced penetrance. Seventeen unique PPFIA3 variants were detected in 18 families. To determine the pathogenicity of PPFIA3 variants in vivo, we generated transgenic fruit flies producing either human wild-type (WT) PPFIA3 or five missense variants using GAL4-UAS targeted gene expression systems. In the fly overexpression assays, we found that the PPFIA3 variants in the region encoding the N-terminal coiled-coil domain exhibited stronger phenotypes compared to those affecting the C-terminal region. In the loss-of-function fly assay, we show that the homozygous loss of fly Liprin-α leads to embryonic lethality. This lethality is partially rescued by the expression of human PPFIA3 WT, suggesting human PPFIA3 function is partially conserved in the fly. However, two of the tested variants failed to rescue the lethality at the larval stage and one variant failed to rescue lethality at the adult stage. Altogether, the human and fruit fly data reveal that the rare PPFIA3 variants are dominant-negative loss-of-function alleles that perturb multiple developmental processes and synapse formation.
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Affiliation(s)
- Maimuna S Paul
- Department of Pediatrics, Section of Neurology and Developmental Neuroscience, Baylor College of Medicine, Houston, TX, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA; Cain Pediatric Neurology Research Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute, Houston, TX, USA
| | - Sydney L Michener
- Department of Pediatrics, Section of Neurology and Developmental Neuroscience, Baylor College of Medicine, Houston, TX, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA; Cain Pediatric Neurology Research Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute, Houston, TX, USA
| | - Hongling Pan
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Hiuling Chan
- Cain Pediatric Neurology Research Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute, Houston, TX, USA; Augustana College, Rock Island, IL, USA; Summer Undergraduate Research Training (SMART) Program, Baylor College of Medicine, Houston, TX, USA
| | - Jessica M Pfliger
- Department of Pediatrics, Section of Neurology and Developmental Neuroscience, Baylor College of Medicine, Houston, TX, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA; Graduate Program in Electrical and Computer Engineering, Rice University, Houston, TX, USA
| | - Jill A Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Vanesa C Lerma
- Department of Pediatrics, Section of Neurology and Developmental Neuroscience, Baylor College of Medicine, Houston, TX, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA; Department of Psychology, University of Houston, Houston, TX, USA
| | - Alyssa Tran
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Megan A Longley
- Department of Pediatrics, Section of Neurology and Developmental Neuroscience, Baylor College of Medicine, Houston, TX, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Richard A Lewis
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA
| | - Monika Weisz-Hubshman
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Mir Reza Bekheirnia
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Renal Genetics Clinic, Baylor College of Medicine, Houston, TX, USA
| | - Nasim Bekheirnia
- Renal Genetics Clinic, Baylor College of Medicine, Houston, TX, USA
| | - Lauren Massingham
- Rhode Island Hospital and Hasbro Children's Hospital, Providence, RI, USA
| | - Michael Zech
- Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany; Institute of Human Genetics, School of Medicine, Technical University, Munich, Germany; Institute for Advanced Study, Technical University of Munich, Garching, Germany
| | - Matias Wagner
- Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany; Institute of Human Genetics, School of Medicine, Technical University, Munich, Germany; Division of Pediatric Neurology, Developmental Neurology and Social Pediatrics, Dr. von Hauner Children's Hospital, Munich, Germany
| | - Hartmut Engels
- Institute of Human Genetics, School of Medicine, University Hospital Bonn, University of Bonn, Bonn, Germany
| | - Kirsten Cremer
- Division of Pediatric Neurology, Developmental Neurology and Social Pediatrics, Dr. von Hauner Children's Hospital, Munich, Germany
| | - Elisabeth Mangold
- Division of Pediatric Neurology, Developmental Neurology and Social Pediatrics, Dr. von Hauner Children's Hospital, Munich, Germany
| | - Sophia Peters
- Division of Pediatric Neurology, Developmental Neurology and Social Pediatrics, Dr. von Hauner Children's Hospital, Munich, Germany
| | - Jessica Trautmann
- Division of Pediatric Neurology, Developmental Neurology and Social Pediatrics, Dr. von Hauner Children's Hospital, Munich, Germany
| | | | | | | | - Pamela P McDonnell
- Epilepsy NeuroGenetics Initiative (ENGIN), Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, PA, USA; Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Stacey R Cohen
- Epilepsy NeuroGenetics Initiative (ENGIN), Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Laina Lusk
- Epilepsy NeuroGenetics Initiative (ENGIN), Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Ana S A Cohen
- Children's Mercy Kansas City, Genomic Medicine Center, The University of Missouri-Kansas City (UMKC), School of Medicine, Kansas City, MO, USA
| | | | - Tomi Pastinen
- Children's Mercy Kansas City, Genomic Medicine Center, The University of Missouri-Kansas City (UMKC), School of Medicine, Kansas City, MO, USA; Children's Mercy Research Institute, Kansas City, MO, USA
| | - Dihong Zhou
- Children's Mercy Hospital, Kansas City, MO, USA
| | | | - Caroline Racine
- University Hospital, Dijon, France; INSERM UMR1231 GAD "Génétique des Anomalies Du Développement," FHU-TRANSLAD, University of Burgundy, Dijon, France; Functional Unit for Diagnostic Innovation in Rare Diseases, FHU-TRANSLAD, Dijon Bourgogne, France
| | - Laurence Faivre
- Functional Unit for Diagnostic Innovation in Rare Diseases, FHU-TRANSLAD, Dijon Bourgogne, France; Department of Genetics and Reference Center for Development Disorders and Intellectual Disabilities, FHU-TRANSLAD and GIMI Institute, Dijon Bourgogne University Hospital, Dijon, France
| | - Sébastien Moutton
- Functional Unit for Diagnostic Innovation in Rare Diseases, FHU-TRANSLAD, Dijon Bourgogne, France; Department of Genetics and Reference Center for Development Disorders and Intellectual Disabilities, FHU-TRANSLAD and GIMI Institute, Dijon Bourgogne University Hospital, Dijon, France
| | - Anne-Sophie Denommé-Pichon
- University Hospital, Dijon, France; INSERM UMR1231 GAD "Génétique des Anomalies Du Développement," FHU-TRANSLAD, University of Burgundy, Dijon, France; Functional Unit for Diagnostic Innovation in Rare Diseases, FHU-TRANSLAD, Dijon Bourgogne, France
| | - Hyun Yong Koh
- Department of Pediatrics, Section of Neurology and Developmental Neuroscience, Baylor College of Medicine, Houston, TX, USA; Department of Neurology, Boston Children's Hospital, Boston, MA, USA
| | - Annapurna Poduri
- Department of Neurology, Boston Children's Hospital, Boston, MA, USA
| | - Jeffrey Bolton
- Department of Neurology, Boston Children's Hospital, Boston, MA, USA
| | - Cordula Knopp
- Institute for Human Genetics and Genomic Medicine, Medical Faculty, RWTH, Aachen University, Aachen, Germany
| | - Dong Sun Julia Suh
- Institute for Human Genetics and Genomic Medicine, Medical Faculty, RWTH, Aachen University, Aachen, Germany
| | - Andrea Maier
- Medical Treatment Center for Adults with Intellectual Disabilities and/or Severe Multiple Disabilities (MZEB), RWTH Aachen University Hospital, Aachen, Germany
| | - Mehran Beiraghi Toosi
- Department of Pediatrics, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran; Neuroscience Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Ehsan Ghayoor Karimiani
- Department of Medical Genetics, Next Generation Genetic Polyclinic, Mashhad, Iran; Molecular and Clinical Sciences Institute, St. George's, University of London, Cranmer Terrace, London, UK
| | - Reza Maroofian
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, UK
| | | | | | - Pradeep Vasudevan
- LNR Genomics Medicine, University Hospitals of Leicester, Leicester, UK
| | - Chitra Prasad
- London Health Sciences Centre, and Division of Medical Genetics, Department of Pediatrics, Western University, London, ON, Canada
| | - Matthew Osmond
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, ON, Canada
| | - Sarah Schuhmann
- Institute of Human Genetics, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Georgia Vasileiou
- Institute of Human Genetics, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Sophie Russ-Hall
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, VIC, Australia
| | - Ingrid E Scheffer
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, VIC, Australia; Department of Pediatrics, University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, VIC, Melbourne, Australia
| | - Gemma L Carvill
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Heather Mefford
- Center for Pediatric Neurological Disease Research, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Carlos A Bacino
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Texas Children's Hospital, Houston, TX, USA
| | - Brendan H Lee
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Texas Children's Hospital, Houston, TX, USA
| | - Hsiao-Tuan Chao
- Department of Pediatrics, Section of Neurology and Developmental Neuroscience, Baylor College of Medicine, Houston, TX, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA; Cain Pediatric Neurology Research Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute, Houston, TX, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Texas Children's Hospital, Houston, TX, USA; Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA; McNair Medical Institute, The Robert and Janice McNair Foundation, Houston, TX, USA.
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Imrie G, Gray MB, Raghuraman V, Farhy-Tselnicker I. Gene Expression at the Tripartite Synapse: Bridging the Gap Between Neurons and Astrocytes. ADVANCES IN NEUROBIOLOGY 2024; 39:95-136. [PMID: 39190073 DOI: 10.1007/978-3-031-64839-7_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/28/2024]
Abstract
Astrocytes, a major class of glial cells, are an important element at the synapse where they engage in bidirectional crosstalk with neurons to regulate numerous aspects of neurotransmission, circuit function, and behavior. Mutations in synapse-related genes expressed in both neurons and astrocytes are central factors in a vast number of neurological disorders, making the proteins that they encode prominent targets for therapeutic intervention. Yet, while the roles of many of these synaptic proteins in neurons are well established, the functions of the same proteins in astrocytes are largely unknown. This gap in knowledge must be addressed to refine therapeutic approaches. In this chapter, we integrate multiomic meta-analysis and a comprehensive overview of current literature to show that astrocytes express an astounding number of genes that overlap with the neuronal and synaptic transcriptomes. Further, we highlight recent reports that characterize the expression patterns and potential novel roles of these genes in astrocytes in both physiological and pathological conditions, underscoring the importance of considering both cell types when investigating the function and regulation of synaptic proteins.
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Affiliation(s)
- Gillian Imrie
- Department of Biology, Texas A&M University, College Station, TX, USA
| | - Madison B Gray
- Department of Biology, Texas A&M University, College Station, TX, USA
| | - Vishnuvasan Raghuraman
- Department of Biology, Texas A&M University, College Station, TX, USA
- Department of Computer Science and Engineering, Texas A&M University, College Station, TX, USA
| | - Isabella Farhy-Tselnicker
- Department of Biology, Texas A&M University, College Station, TX, USA.
- Texas A&M Institute for Neuroscience (TAMIN), Texas A&M University, College Station, TX, USA.
- Center for Biological Clocks Research, Texas A&M University, College Station, TX, USA.
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49
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Hoffmann C, Milovanovic D. Dipping contacts - a novel type of contact site at the interface between membraneless organelles and membranes. J Cell Sci 2023; 136:jcs261413. [PMID: 38149872 PMCID: PMC10785658 DOI: 10.1242/jcs.261413] [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: 12/28/2023] Open
Abstract
Liquid-liquid phase separation is a major mechanism for organizing macromolecules, particularly proteins with intrinsically disordered regions, in compartments not limited by a membrane or a scaffold. The cell can therefore be perceived as a complex emulsion containing many of these membraneless organelles, also referred to as biomolecular condensates, together with numerous membrane-bound organelles. It is currently unclear how such a complex concoction operates to allow for intracellular trafficking, signaling and metabolic processes to occur with high spatiotemporal precision. Based on experimental observations of synaptic vesicle condensates - a membraneless organelle that is in fact packed with membranes - we present here the framework of dipping contacts: a novel type of contact site between membraneless organelles and membranes. In this Hypothesis, we propose that our framework of dipping contacts can serve as a foundation to investigate the interface that couples the diffusion and material properties of condensates to biochemical processes occurring in membranes. The identity and regulation of this interface is especially critical in the case of neurodegenerative diseases, where aberrant inclusions of misfolded proteins and damaged organelles underlie cellular pathology.
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Affiliation(s)
- Christian Hoffmann
- Laboratory of Molecular Neuroscience, German Center for Neurodegenerative Diseases (DZNE), 10117 Berlin, Germany
- Whitman Center, Marine Biological Laboratory, Woods Hole, MA 02543, USA
| | - Dragomir Milovanovic
- Laboratory of Molecular Neuroscience, German Center for Neurodegenerative Diseases (DZNE), 10117 Berlin, Germany
- Whitman Center, Marine Biological Laboratory, Woods Hole, MA 02543, USA
- National Center for X-ray Tomography, Advanced Light Source, Berkeley, CA 94720, USA
- Einstein Center for Neuroscience, Charité-Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität Berlin and Berlin Institute of Health, 10117 Berlin, Germany
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50
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Mrestani A, Dannhäuser S, Pauli M, Kollmannsberger P, Hübsch M, Morris L, Langenhan T, Heckmann M, Paul MM. Nanoscaled RIM clustering at presynaptic active zones revealed by endogenous tagging. Life Sci Alliance 2023; 6:e202302021. [PMID: 37696575 PMCID: PMC10494931 DOI: 10.26508/lsa.202302021] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 08/27/2023] [Accepted: 08/28/2023] [Indexed: 09/13/2023] Open
Abstract
Chemical synaptic transmission involves neurotransmitter release from presynaptic active zones (AZs). The AZ protein Rab-3-interacting molecule (RIM) is important for normal Ca2+-triggered release. However, its precise localization within AZs of the glutamatergic neuromuscular junctions of Drosophila melanogaster remains elusive. We used CRISPR/Cas9-assisted genome engineering of the rim locus to incorporate small epitope tags for targeted super-resolution imaging. A V5-tag, derived from simian virus 5, and an HA-tag, derived from human influenza virus, were N-terminally fused to the RIM Zinc finger. Whereas both variants are expressed in co-localization with the core AZ scaffold Bruchpilot, electrophysiological characterization reveals that AP-evoked synaptic release is disturbed in rimV5-Znf but not in rimHA-Znf In addition, rimHA-Znf synapses show intact presynaptic homeostatic potentiation. Combining super-resolution localization microscopy and hierarchical clustering, we detect ∼10 RIMHA-Znf subclusters with ∼13 nm diameter per AZ that are compacted and increased in numbers in presynaptic homeostatic potentiation.
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Affiliation(s)
- Achmed Mrestani
- https://ror.org/00fbnyb24 Department of Neurophysiology, Institute of Physiology, University of Würzburg, Würzburg, Germany
- Department of Neurology, Leipzig University Medical Center, Leipzig, Germany
- Division of General Biochemistry, Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany
| | - Sven Dannhäuser
- https://ror.org/00fbnyb24 Department of Neurophysiology, Institute of Physiology, University of Würzburg, Würzburg, Germany
| | - Martin Pauli
- https://ror.org/00fbnyb24 Department of Neurophysiology, Institute of Physiology, University of Würzburg, Würzburg, Germany
| | | | - Martha Hübsch
- https://ror.org/00fbnyb24 Department of Neurophysiology, Institute of Physiology, University of Würzburg, Würzburg, Germany
| | - Lydia Morris
- Division of General Biochemistry, Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany
| | - Tobias Langenhan
- Division of General Biochemistry, Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany
| | - Manfred Heckmann
- https://ror.org/00fbnyb24 Department of Neurophysiology, Institute of Physiology, University of Würzburg, Würzburg, Germany
| | - Mila M Paul
- https://ror.org/00fbnyb24 Department of Neurophysiology, Institute of Physiology, University of Würzburg, Würzburg, Germany
- https://ror.org/03pvr2g57 Department of Orthopedic Trauma, Hand, Plastic and Reconstructive Surgery, University Hospital of Würzburg, Würzburg, Germany
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