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Zhang X, Chen Z, Xiong Y, Zhou Q, Zhu LQ, Liu D. The emerging role of nitric oxide in the synaptic dysfunction of vascular dementia. Neural Regen Res 2025; 20:402-415. [PMID: 38819044 PMCID: PMC11317957 DOI: 10.4103/nrr.nrr-d-23-01353] [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: 08/13/2023] [Revised: 10/23/2023] [Accepted: 11/30/2023] [Indexed: 06/01/2024] Open
Abstract
With an increase in global aging, the number of people affected by cerebrovascular diseases is also increasing, and the incidence of vascular dementia-closely related to cerebrovascular risk-is increasing at an epidemic rate. However, few therapeutic options exist that can markedly improve the cognitive impairment and prognosis of vascular dementia patients. Similarly in Alzheimer's disease and other neurological disorders, synaptic dysfunction is recognized as the main reason for cognitive decline. Nitric oxide is one of the ubiquitous gaseous cellular messengers involved in multiple physiological and pathological processes of the central nervous system. Recently, nitric oxide has been implicated in regulating synaptic plasticity and plays an important role in the pathogenesis of vascular dementia. This review introduces in detail the emerging role of nitric oxide in physiological and pathological states of vascular dementia and summarizes the diverse effects of nitric oxide on different aspects of synaptic dysfunction, neuroinflammation, oxidative stress, and blood-brain barrier dysfunction that underlie the progress of vascular dementia. Additionally, we propose that targeting the nitric oxide-sGC-cGMP pathway using certain specific approaches may provide a novel therapeutic strategy for vascular dementia.
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Affiliation(s)
- Xiaorong Zhang
- Department of Pathology, Affiliated Hospital of Jiujiang University, Jiujiang, Jiangxi Province, China
- Jiujiang Clinical Precision Medicine Research Center, Jiujiang, Jiangxi Province, China
- Center for Cognitive Science and Transdisciplinary Studies, Jiujiang University, Jiangxi Province, China
| | - Zhiying Chen
- Jiujiang Clinical Precision Medicine Research Center, Jiujiang, Jiangxi Province, China
- Department of Neurology, Affiliated Hospital of Jiujiang University, Jiujiang, Jiangxi Province, China
| | - Yinyi Xiong
- Jiujiang Clinical Precision Medicine Research Center, Jiujiang, Jiangxi Province, China
- Department of Rehabilitation, Affiliated Hospital of Jiujiang University, Jiujiang, Jiangxi Province, China
| | - Qin Zhou
- Jiujiang Clinical Precision Medicine Research Center, Jiujiang, Jiangxi Province, China
| | - Ling-Qiang Zhu
- Department of Pathophysiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
| | - Dan Liu
- Department of Pathophysiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
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2
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Trus M, Atlas D. Non-ionotropic voltage-gated calcium channel signaling. Channels (Austin) 2024; 18:2341077. [PMID: 38601983 PMCID: PMC11017947 DOI: 10.1080/19336950.2024.2341077] [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: 02/09/2024] [Accepted: 04/04/2024] [Indexed: 04/12/2024] Open
Abstract
Voltage-gated calcium channels (VGCCs) are the major conduits for calcium ions (Ca2+) within excitable cells. Recent studies have highlighted the non-ionotropic functionality of VGCCs, revealing their capacity to activate intracellular pathways independently of ion flow. This non-ionotropic signaling mode plays a pivotal role in excitation-coupling processes, including gene transcription through excitation-transcription (ET), synaptic transmission via excitation-secretion (ES), and cardiac contraction through excitation-contraction (EC). However, it is noteworthy that these excitation-coupling processes require extracellular calcium (Ca2+) and Ca2+ occupancy of the channel ion pore. Analogous to the "non-canonical" characterization of the non-ionotropic signaling exhibited by the N-methyl-D-aspartate receptor (NMDA), which requires extracellular Ca2+ without the influx of ions, VGCC activation requires depolarization-triggered conformational change(s) concomitant with Ca2+ binding to the open channel. Here, we discuss the contributions of VGCCs to ES, ET, and EC coupling as Ca2+ binding macromolecules that transduces external stimuli to intracellular input prior to elevating intracellular Ca2+. We emphasize the recognition of calcium ion occupancy within the open ion-pore and its contribution to the excitation coupling processes that precede the influx of calcium. The non-ionotropic activation of VGCCs, triggered by the upstroke of an action potential, provides a conceptual framework to elucidate the mechanistic aspects underlying the microseconds nature of synaptic transmission, cardiac contractility, and the rapid induction of first-wave genes.
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Affiliation(s)
- Michael Trus
- Department of Biological Chemistry, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Daphne Atlas
- Department of Biological Chemistry, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
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3
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Wang Y, Pradhan A, Gupta P, Hanrieder J, Zetterberg H, Cans AS. Analyzing Fusion Pore Dynamics and Counting the Number of Acetylcholine Molecules Released by Exocytosis. J Am Chem Soc 2024; 146:25902-25906. [PMID: 39259049 DOI: 10.1021/jacs.4c08450] [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: 09/12/2024]
Abstract
Acetylcholine (ACh) is a critical neurotransmitter influencing various neurophysiological functions. Despite its significance, quantitative methods with adequate spatiotemporal resolution for recording a single exocytotic ACh efflux are lacking. In this study, we introduce an ultrafast amperometric ACh biosensor that enables 50 kHz electrochemical recording of spontaneous single exocytosis events at axon terminals of differentiated cholinergic human SH-SY5Y neuroblastoma cells with sub-millisecond temporal resolution. Characterization of the recorded amperometric traces revealed seven distinct current spike types, each displaying variations in shape, time scale, and ACh quantities released. This finding suggests that exocytotic release is governed by complex fusion pore dynamics in these cells. The absolute number of ACh molecules released during exocytosis was quantified by calibrating the sensor through the electroanalysis of liposomes preloaded with varying ACh concentrations. Notably, the largest quantal release involving approximately 8000 ACh molecules likely represents full exocytosis, while a smaller release of 5000 ACh molecules may indicate partial exocytosis. Following a local administration of bafilomycin A1, a V-ATPase inhibitor, the cholinergic cells exhibited both a larger quantity of ACh released and a higher frequency of exocytosis events. Therefore, this ACh sensor provides a means to monitor minute amounts of ACh and investigate regulatory release mechanisms at the single-cell level, which is vital for understanding healthy brain function and pathologies and optimizing drug treatment for disorders.
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Affiliation(s)
- Yuanmo Wang
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Kemigården 4, SE-412 96 Gothenburg, Sweden
| | - Ajay Pradhan
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience & Physiology, The Sahlgrenska Academy at the University of Gothenburg, SE-43141 Mölndal, Sweden
| | - Pankaj Gupta
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Kemigården 4, SE-412 96 Gothenburg, Sweden
| | - Jörg Hanrieder
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience & Physiology, The Sahlgrenska Academy at the University of Gothenburg, SE-43141 Mölndal, Sweden
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, WC1N 3BG London, U.K
| | - Henrik Zetterberg
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience & Physiology, The Sahlgrenska Academy at the University of Gothenburg, SE-43141 Mölndal, Sweden
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, WC1N 3BG London, U.K
- Clinical Neurochemistry Laboratory, The Sahlgrenska University Hospital, SE-43141 Mölndal, Sweden
- UK Dementia Research Institute at UCL, WC1N 3BG London, U.K
- Hong Kong Center for Neurodegenerative Diseases, Clear Water Bay, 999077 Hong Kong, China
- Wisconsin Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53792, United States
| | - Ann-Sofie Cans
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Kemigården 4, SE-412 96 Gothenburg, Sweden
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4
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Marshall-Phelps KLH, Almeida RG. Axonal neurotransmitter release in the regulation of myelination. Biosci Rep 2024; 44:BSR20231616. [PMID: 39230890 DOI: 10.1042/bsr20231616] [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: 04/24/2024] [Revised: 08/30/2024] [Accepted: 09/04/2024] [Indexed: 09/05/2024] Open
Abstract
Myelination of axons is a key determinant of fast action potential propagation, axonal health and circuit function. Previously considered a static structure, it is now clear that myelin is dynamically regulated in response to neuronal activity in the central nervous system (CNS). However, how activity-dependent signals are conveyed to oligodendrocytes remains unclear. Here, we review the potential mechanisms by which neurons could communicate changing activity levels to myelin, with a focus on the accumulating body of evidence to support activity-dependent vesicular signalling directly onto myelin sheaths. We discuss recent in vivo findings of activity-dependent fusion of neurotransmitter vesicles from non-synaptic axonal sites, and how modulation of this vesicular fusion regulates the stability and growth of myelin sheaths. We also consider the potential mechanisms by which myelin could sense and respond to axon-derived signals to initiate remodelling, and the relevance of these adaptations for circuit function. We propose that axonal vesicular signalling represents an important and underappreciated mode of communication by which neurons can transmit activity-regulated signals to myelinating oligodendrocytes and, potentially, more broadly to other cell types in the CNS.
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Affiliation(s)
- Katy L H Marshall-Phelps
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, U.K
- MS Society Edinburgh Centre for MS Research, University of Edinburgh, Edinburgh, U.K
| | - Rafael G Almeida
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, U.K
- MS Society Edinburgh Centre for MS Research, University of Edinburgh, Edinburgh, U.K
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5
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Dill H, Liewald JF, Becker M, Seidenthal M, Gottschalk A. Neuropeptidergic regulation of neuromuscular signaling in larval zebrafish alters swimming behavior and synaptic transmission. iScience 2024; 27:110687. [PMID: 39252958 PMCID: PMC11381845 DOI: 10.1016/j.isci.2024.110687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 04/13/2024] [Accepted: 08/05/2024] [Indexed: 09/11/2024] Open
Abstract
Chemical synaptic transmission is modulated to accommodate different activity levels, thus enabling homeostatic scaling in pre- and postsynaptic compartments. In nematodes, cholinergic neurons use neuropeptide signaling to modulate synaptic vesicle content. To explore if this mechanism is conserved in vertebrates, we studied the involvement of neuropeptides in cholinergic transmission at the neuromuscular junction of larval zebrafish. Optogenetic stimulation by photoactivated adenylyl cyclase evoked locomotion. We generated mutants lacking the neuropeptide-processing enzyme carboxypeptidase E (cpe), and the most abundant neuropeptide precursor in motor neurons, tachykinin (tac1). Both mutants showed exaggerated locomotion after photostimulation. Recording excitatory postsynaptic currents demonstrated overall larger amplitudes in the wild type. Exaggerated locomotion in the mutants thus reflected upscaling of postsynaptic excitability. Both mutant muscles expressed more nicotinic acetylcholine receptors (nAChRs) on their surface; thus, neuropeptide signaling regulates synaptic transmitter output in zebrafish motor neurons, and muscle cells homeostatically regulate nAChR surface expression, compensating reduced presynaptic input.
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Affiliation(s)
- Holger Dill
- Buchmann Institute, Goethe University, Max-von-Laue-Strasse 15, D-60438 Frankfurt, Germany
- Institute for Biophysical Chemistry, Goethe University, Max-von-Laue-Strasse 9, D-60438 Frankfurt, Germany
| | - Jana F Liewald
- Buchmann Institute, Goethe University, Max-von-Laue-Strasse 15, D-60438 Frankfurt, Germany
- Institute for Biophysical Chemistry, Goethe University, Max-von-Laue-Strasse 9, D-60438 Frankfurt, Germany
| | - Michelle Becker
- Buchmann Institute, Goethe University, Max-von-Laue-Strasse 15, D-60438 Frankfurt, Germany
- Institute for Biophysical Chemistry, Goethe University, Max-von-Laue-Strasse 9, D-60438 Frankfurt, Germany
| | - Marius Seidenthal
- Buchmann Institute, Goethe University, Max-von-Laue-Strasse 15, D-60438 Frankfurt, Germany
- Institute for Biophysical Chemistry, Goethe University, Max-von-Laue-Strasse 9, D-60438 Frankfurt, Germany
| | - Alexander Gottschalk
- Buchmann Institute, Goethe University, Max-von-Laue-Strasse 15, D-60438 Frankfurt, Germany
- Institute for Biophysical Chemistry, Goethe University, Max-von-Laue-Strasse 9, D-60438 Frankfurt, Germany
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6
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Bykhovskaia M. Dynamic formation of the protein-lipid prefusion complex. Biophys J 2024:S0006-3495(24)00601-5. [PMID: 39257001 DOI: 10.1016/j.bpj.2024.09.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2024] [Revised: 08/12/2024] [Accepted: 09/06/2024] [Indexed: 09/12/2024] Open
Abstract
Synaptic vesicles (SVs) fuse with the presynaptic membrane (PM) to release neuronal transmitters. The SV protein synaptotagmin 1 (Syt1) serves as a Ca2+ sensor for evoked fusion. Syt1 is thought to trigger fusion by penetrating the PM upon Ca2+ binding; however, the mechanistic detail of this process is still debated. Syt1 interacts with the SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptors) complex, a coiled-coil four-helical bundle that enables the SV-PM attachment. The SNARE-associated protein complexin (Cpx) promotes Ca2+-dependent fusion, possibly interacting with Syt1. We employed all-atom molecular dynamics to investigate the formation of the Syt1-SNARE-Cpx complex interacting with the lipid bilayers of the PM and SVs. Our simulations demonstrated that the PM-Syt1-SNARE-Cpx complex can transition to a "dead-end" state, wherein Syt1 attaches tightly to the PM but does not immerse into it, as opposed to a prefusion state, which has the tips of the Ca2+-bound C2 domains of Syt1 inserted into the PM. Our simulations unraveled the sequence of Syt1 conformational transitions, including the simultaneous docking of Syt1 to the SNARE-Cpx bundle and the PM, followed by Ca2+ chelation and the penetration of the tips of Syt1 domains into the PM, leading to the prefusion state of the protein-lipid complex. Importantly, we found that direct Syt1-Cpx interactions are required to promote these transitions. Thus, we developed the all-atom dynamic model of the conformational transitions that lead to the formation of the prefusion PM-Syt1-SNARE-Cpx complex. Our simulations also revealed an alternative dead-end state of the protein-lipid complex that can be formed if this pathway is disrupted.
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Khan YA, Ian White K, Pfuetzner RA, Singal B, Esquivies L, Mckenzie G, Liu F, DeLong K, Choi UB, Montabana E, Mclaughlin T, Wickner WT, Brunger AT. Sec18 side-loading is essential for universal SNARE recycling across cellular contexts. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.30.610324. [PMID: 39257774 PMCID: PMC11384006 DOI: 10.1101/2024.08.30.610324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2024]
Abstract
SNARE proteins drive membrane fusion as their core domains zipper into a parallel four-helix bundle1,2. After fusion, these bundles are disassembled by the AAA+ protein Sec18/NSF and its adaptor Sec17/ α-SNAP3,4 to make them available for subsequent rounds of membrane fusion. SNARE domains are often flanked by C-terminal transmembrane or N-terminal domains5. Previous structures of the NSF-α-SNAP-SNARE complex revealed SNARE domain threaded through the D1 ATPase ring6, posing a topological constraint as SNARE transmembrane domains would prevent complete substrate threading as suggested for other AAA+ systems7. Here, in vivo mass-spectrometry reveals N-terminal SNARE domain interactions with Sec18, exacerbating this topological issue. Cryo-EM structures of a yeast SNARE complex, Sec18, and Sec17 in a non-hydrolyzing condition shows SNARE Sso1 threaded through the D1 and D2 ATPase rings of Sec18, with its folded, N-terminal Habc domain interacting with the D2 ring. This domain does not unfold during Sec18/NSF activity. Cryo-EM structures under hydrolyzing conditions revealed substrate-released and substrate-free states of Sec18 with a coordinated opening in the side of the ATPase rings. Thus, Sec18/NSF operates by substrate side-loading and unloading topologically constrained SNARE substrates.
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Affiliation(s)
- Yousuf A Khan
- 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
| | - K Ian White
- 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
| | - Bharti Singal
- Stanford Cryo-EM microscopy center, Stanford University, Palo Alto, 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
| | - Garvey Mckenzie
- Stanford University Mass Spectrometry, Stanford University, Palo Alto, CA, USA
| | - Fang Liu
- Stanford University Mass Spectrometry, Stanford University, Palo Alto, CA, USA
| | - Katherine DeLong
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA
| | - Uchoer B Choi
- 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
| | | | - Theresa Mclaughlin
- Stanford University Mass Spectrometry, Stanford University, Palo Alto, CA, USA
| | - William T Wickner
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Dartmouth College, Hanover, NH 03755
| | - 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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8
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An D, Lindau M. Exploring the structural dynamics of the vesicle priming machinery. Biochem Soc Trans 2024; 52:1715-1725. [PMID: 39082978 DOI: 10.1042/bst20231333] [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: 08/29/2024]
Abstract
Various cell types release neurotransmitters, hormones and many other compounds that are stored in secretory vesicles by exocytosis via the formation of a fusion pore traversing the vesicular membrane and the plasma membrane. This process of membrane fusion is mediated by the Soluble N-ethylmaleimide-Sensitive Factor Attachment Proteins REceptor (SNARE) protein complex, which in neurons and neuroendocrine cells is composed of the vesicular SNARE protein Synaptobrevin and the plasma membrane proteins Syntaxin and SNAP25 (Synaptosomal-Associated Protein of 25 kDa). Before a vesicle can undergo fusion and release of its contents, it must dock at the plasma membrane and undergo a process named 'priming', which makes it ready for release. The primed vesicles form the readily releasable pool, from which they can be rapidly released in response to stimulation. The stimulus is an increase in Ca2+ concentration near the fusion site, which is sensed primarily by the vesicular Ca2+ sensor Synaptotagmin. Vesicle priming involves at least the SNARE proteins as well as Synaptotagmin and the accessory proteins Munc18, Munc13, and Complexin but additional proteins may also participate in this process. This review discusses the current views of the interactions and the structural changes that occur among the proteins of the vesicle priming machinery.
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Affiliation(s)
- Dong An
- Department of Physiology and Biophysics, University of Miami School of Medicine, Miami, FL 33136, U.S.A
| | - Manfred Lindau
- Department of Physiology and Biophysics, University of Miami School of Medicine, Miami, FL 33136, U.S.A
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Bray SR, Wyss LS, Chai C, Lozada ME, Wang B. Adaptive robustness through incoherent signaling mechanisms in a regenerative brain. Cell Rep 2024; 43:114580. [PMID: 39133614 DOI: 10.1016/j.celrep.2024.114580] [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: 06/15/2023] [Revised: 05/08/2024] [Accepted: 07/18/2024] [Indexed: 08/21/2024] Open
Abstract
Animal behavior emerges from collective dynamics of neurons, making it vulnerable to damage. Paradoxically, many organisms exhibit a remarkable ability to maintain significant behavior even after large-scale neural injury. Molecular underpinnings of this extreme robustness remain largely unknown. Here, we develop a quantitative pipeline to measure long-lasting latent states in planarian flatworm behaviors during whole-brain regeneration. By combining >20,000 animal trials with neural network modeling, we show that long-range volumetric peptidergic signals allow the planarian to rapidly restore coarse behavior output after large perturbations to the nervous system, while slow restoration of small-molecule neuromodulator functions refines precision. This relies on the different time and length scales of neuropeptide and small-molecule transmission to generate incoherent patterns of neural activity that competitively regulate behavior. Controlling behavior through opposing communication mechanisms creates a more robust system than either alone and may serve as a generalizable approach for constructing robust neural networks.
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Affiliation(s)
- Samuel R Bray
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Livia S Wyss
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Chew Chai
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Maria E Lozada
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Department of Biomedical Engineering, University of Miami, Coral Gables, FL 33124, USA
| | - Bo Wang
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA.
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10
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Bade A, Yadav P, Zhang L, Naidu Bypaneni R, Xu M, Glass TE. Imaging Neurotransmitters with Small-Molecule Fluorescent Probes. Angew Chem Int Ed Engl 2024; 63:e202406401. [PMID: 38831475 DOI: 10.1002/anie.202406401] [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: 04/03/2024] [Revised: 05/28/2024] [Accepted: 05/29/2024] [Indexed: 06/05/2024]
Abstract
Neurotransmitters play a crucial role in regulating communication between neurons within the brain and central nervous system. Thus, imaging neurotransmitters has become a high priority in neuroscience. This minireview focuses on recent advancements in the development of fluorescent small-molecule fluorescent probes for neurotransmitter imaging and applications of these probes in neuroscience. Innovative approaches for probe design are highlighted as well as attributes which are necessary for practical utility, with a view to inspiring new probe development capable of visualizing neurotransmitters.
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Affiliation(s)
- Anusha Bade
- Department of Chemistry, University of Missouri, Columbia, MO 65211, USA
| | - Peeyush Yadav
- Department of Chemistry, University of Missouri, Columbia, MO 65211, USA
| | - Le Zhang
- Laboratory of Chemical Immunology and Proteomics, The Rockefeller University, New York NY, 10065, USA
| | | | - Ming Xu
- Department of Chemistry, University of Missouri, Columbia, MO 65211, USA
| | - Timothy E Glass
- Department of Chemistry, University of Missouri, Columbia, MO 65211, USA
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11
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Dittman JS. Taking a closer look at the synapse. Proc Natl Acad Sci U S A 2024; 121:e2412457121. [PMID: 39102555 PMCID: PMC11331075 DOI: 10.1073/pnas.2412457121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/07/2024] Open
Affiliation(s)
- Jeremy S. Dittman
- Department of Biochemistry, Weill Cornell Medicine, New York, NY10065
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12
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Jiao H, Li X, Li Y, Guo Y, Hu X, Sho T, Luo Y, Wang J, Cao H, Du W, Li D, Yu L. Localized, highly efficient secretion of signaling proteins by migrasomes. Cell Res 2024; 34:572-585. [PMID: 38918584 PMCID: PMC11291916 DOI: 10.1038/s41422-024-00992-7] [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: 01/19/2024] [Accepted: 06/11/2024] [Indexed: 06/27/2024] Open
Abstract
Migrasomes, enriched with signaling molecules such as chemokines, cytokines and angiogenic factors, play a pivotal role in the spatially defined delivery of these molecules, influencing critical physiological processes including organ morphogenesis and angiogenesis. The mechanism governing the accumulation of signaling molecules in migrasomes has been elusive. In this study, we show that secretory proteins, including signaling proteins, are transported into migrasomes by secretory carriers via both the constitutive and regulated secretion pathways. During cell migration, a substantial portion of these carriers is redirected to the rear of the cell and actively transported into migrasomes, driven by the actin-dependent motor protein Myosin-5a. Once at the migrasomes, these carriers fuse with the migrasome membrane through SNARE-mediated mechanisms. Inhibiting migrasome formation significantly reduces secretion, suggesting migrasomes as a principal secretion route in migrating cells. Our findings reveal a specialized, highly localized secretion paradigm in migrating cells, conceptually paralleling the targeted neurotransmitter release observed in neuronal systems.
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Affiliation(s)
- Haifeng Jiao
- State Key Laboratory of Membrane Biology, Tsinghua University-Peking University Joint Centre for Life Sciences, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing, China.
| | - Xiaopeng Li
- State Key Laboratory of Membrane Biology, Tsinghua University-Peking University Joint Centre for Life Sciences, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing, China
| | - Ying Li
- State Key Laboratory of Membrane Biology, Tsinghua University-Peking University Joint Centre for Life Sciences, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing, China
| | - Yuting Guo
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Xiaoyu Hu
- State Key Laboratory of Membrane Biology, Tsinghua University-Peking University Joint Centre for Life Sciences, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing, China
| | - Takami Sho
- State Key Laboratory of Membrane Biology, Tsinghua University-Peking University Joint Centre for Life Sciences, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing, China
| | - Yiqun Luo
- State Key Laboratory of Membrane Biology, Tsinghua University-Peking University Joint Centre for Life Sciences, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing, China
| | - Jinyu Wang
- SLSTU-Nikon Biological Imaging Center, Center of Biomedical Analysis, Tsinghua University, Beijing, China
| | - Huizhen Cao
- SLSTU-Nikon Biological Imaging Center, Center of Biomedical Analysis, Tsinghua University, Beijing, China
| | - Wanqing Du
- State Key Laboratory of Membrane Biology, Tsinghua University-Peking University Joint Centre for Life Sciences, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing, China
| | - Dong Li
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Li Yu
- State Key Laboratory of Membrane Biology, Tsinghua University-Peking University Joint Centre for Life Sciences, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing, China.
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13
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López-Begines S, Fernández-Chacón R. Handshaking for ultrafast endocytosis: Dynamin1xA and Endophilin A1 sealed the deal. EMBO J 2024; 43:3309-3311. [PMID: 39044099 PMCID: PMC11329764 DOI: 10.1038/s44318-024-00179-1] [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: 06/18/2024] [Revised: 07/08/2024] [Accepted: 07/09/2024] [Indexed: 07/25/2024] Open
Abstract
A new study reveals how preassembled components at the endocytic zone permit ultrafast endocytosis to occur so quickly.
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Affiliation(s)
- Santiago López-Begines
- Instituto de Biomedicina de Sevilla (IBiS, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla), Dpto. de Fisiología Médica y Biofísica, Facultad de Medicina, and CIBERNED ISCIII, Seville, Spain
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Belvaux, Luxembourg
| | - Rafael Fernández-Chacón
- Instituto de Biomedicina de Sevilla (IBiS, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla), Dpto. de Fisiología Médica y Biofísica, Facultad de Medicina, and CIBERNED ISCIII, Seville, Spain.
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14
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Jánosi B, Liewald JF, Seidenthal M, Yu SC, Umbach S, Redzovic J, Rentsch D, Alcantara IC, Bergs ACF, Schneider MW, Shao J, Gottschalk A. RIM and RIM-Binding Protein Localize Synaptic CaV2 Channels to Differentially Regulate Transmission in Neuronal Circuits. J Neurosci 2024; 44:e0535222024. [PMID: 38951038 PMCID: PMC11293454 DOI: 10.1523/jneurosci.0535-22.2024] [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: 03/16/2022] [Revised: 04/16/2024] [Accepted: 05/05/2024] [Indexed: 07/03/2024] Open
Abstract
At chemical synapses, voltage-gated Ca2+ channels (VGCCs) translate electrical signals into a trigger for synaptic vesicle (SV) fusion. VGCCs and the Ca2+ microdomains they elicit must be located precisely to primed SVs to evoke rapid transmitter release. Localization is mediated by Rab3-interacting molecule (RIM) and RIM-binding proteins, which interact and bind to the C terminus of the CaV2 VGCC α-subunit. We studied this machinery at the mixed cholinergic/GABAergic neuromuscular junction of Caenorhabditis elegans hermaphrodites. rimb-1 mutants had mild synaptic defects, through loosening the anchoring of UNC-2/CaV2 and delaying the onset of SV fusion. UNC-10/RIM deletion much more severely affected transmission. Although postsynaptic depolarization was reduced, rimb-1 mutants had increased cholinergic (but reduced GABAergic) transmission, to compensate for the delayed release. This did not occur when the excitation-inhibition (E-I) balance was altered by removing GABA transmission. Further analyses of GABA defective mutants and GABAA or GABAB receptor deletions, as well as cholinergic rescue of RIMB-1, emphasized that GABA neurons may be more affected than cholinergic neurons. Thus, RIMB-1 function differentially affects excitation-inhibition balance in the different motor neurons, and RIMB-1 thus may differentially regulate transmission within circuits. Untethering the UNC-2/CaV2 channel by removing its C-terminal PDZ ligand exacerbated the rimb-1 defects, and similar phenotypes resulted from acute degradation of the CaV2 β-subunit CCB-1. Therefore, untethering of the CaV2 complex is as severe as its elimination, yet it does not abolish transmission, likely due to compensation by CaV1. Thus, robustness and flexibility of synaptic transmission emerge from VGCC regulation.
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Affiliation(s)
- Barbara Jánosi
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt D-60438, Germany
- Department of Biochemistry, Chemistry and Pharmacy, Institute for Biophysical Chemistry, Goethe University Frankfurt, Frankfurt D-60438, Germany
| | - Jana F Liewald
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt D-60438, Germany
- Department of Biochemistry, Chemistry and Pharmacy, Institute for Biophysical Chemistry, Goethe University Frankfurt, Frankfurt D-60438, Germany
| | - Marius Seidenthal
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt D-60438, Germany
- Department of Biochemistry, Chemistry and Pharmacy, Institute for Biophysical Chemistry, Goethe University Frankfurt, Frankfurt D-60438, Germany
| | - Szi-Chieh Yu
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt D-60438, Germany
- Department of Biochemistry, Chemistry and Pharmacy, Institute for Biophysical Chemistry, Goethe University Frankfurt, Frankfurt D-60438, Germany
| | - Simon Umbach
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt D-60438, Germany
- Department of Biochemistry, Chemistry and Pharmacy, Institute for Biophysical Chemistry, Goethe University Frankfurt, Frankfurt D-60438, Germany
| | - Jasmina Redzovic
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt D-60438, Germany
- Department of Biochemistry, Chemistry and Pharmacy, Institute for Biophysical Chemistry, Goethe University Frankfurt, Frankfurt D-60438, Germany
| | - Dennis Rentsch
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt D-60438, Germany
- Department of Biochemistry, Chemistry and Pharmacy, Institute for Biophysical Chemistry, Goethe University Frankfurt, Frankfurt D-60438, Germany
| | - Ivan C Alcantara
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt D-60438, Germany
- Department of Biochemistry, Chemistry and Pharmacy, Institute for Biophysical Chemistry, Goethe University Frankfurt, Frankfurt D-60438, Germany
| | - Amelie C F Bergs
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt D-60438, Germany
- Department of Biochemistry, Chemistry and Pharmacy, Institute for Biophysical Chemistry, Goethe University Frankfurt, Frankfurt D-60438, Germany
| | - Martin W Schneider
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt D-60438, Germany
- Department of Biochemistry, Chemistry and Pharmacy, Institute for Biophysical Chemistry, Goethe University Frankfurt, Frankfurt D-60438, Germany
| | - Jiajie Shao
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt D-60438, Germany
- Department of Biochemistry, Chemistry and Pharmacy, Institute for Biophysical Chemistry, Goethe University Frankfurt, Frankfurt D-60438, Germany
| | - Alexander Gottschalk
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt D-60438, Germany
- Department of Biochemistry, Chemistry and Pharmacy, Institute for Biophysical Chemistry, Goethe University Frankfurt, Frankfurt D-60438, Germany
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15
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Toulme E, Murach J, Bärfuss S, Kroll J, Malsam J, Trimbuch T, Herman MA, Söllner TH, Rosenmund C. Mutations of Single Residues in the Complexin N-terminus Exhibit Distinct Phenotypes in Synaptic Vesicle Fusion. J Neurosci 2024; 44:e0076242024. [PMID: 38951039 PMCID: PMC11293444 DOI: 10.1523/jneurosci.0076-24.2024] [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: 01/12/2024] [Revised: 04/11/2024] [Accepted: 06/07/2024] [Indexed: 07/03/2024] Open
Abstract
The release of neurotransmitters (NTs) at central synapses is dependent on a cascade of protein interactions, specific to the presynaptic compartment. Among those dedicated molecules, the cytosolic complexins play an incompletely defined role as synaptic transmission regulators. Complexins are multidomain proteins that bind soluble N-ethylmaleimide sensitive factor attachment protein receptor complexes, conferring both inhibitory and stimulatory functions. Using systematic mutagenesis and comparing reconstituted in vitro membrane fusion assays with electrophysiology in cultured neurons from mice of either sex, we deciphered the function of the N-terminus of complexin (Cpx) II. The N-terminus (amino acid 1-27) starts with a region enriched in hydrophobic amino acids (1-12), which binds lipids. Mutants maintaining this hydrophobic character retained the stimulatory function of Cpx, whereas exchanges introducing charged residues perturbed both spontaneous and evoked exocytosis. Mutants in the more distal region of the N-terminal domain (amino acid 11-18) showed a spectrum of effects. On the one hand, mutation of residue A12 increased spontaneous release without affecting evoked release. On the other hand, replacing D15 with amino acids of different shapes or hydrophobic properties (but not charge) not only increased spontaneous release but also impaired evoked release. Most surprising, this substitution reduced the size of the readily releasable pool, a novel function for Cpx at mammalian synapses. Thus, the exact amino acid composition of the Cpx N-terminus fine-tunes the degree of spontaneous and evoked NT release.
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Affiliation(s)
- Estelle Toulme
- Charite - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Neurophysiology, 10117 Berlin, Germany
| | - Jacqueline Murach
- Heidelberg University Biochemistry Center, 69120 Heidelberg, Germany
| | - Simon Bärfuss
- Heidelberg University Biochemistry Center, 69120 Heidelberg, Germany
| | - Jana Kroll
- Charite - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Neurophysiology, 10117 Berlin, Germany
| | - Jörg Malsam
- Heidelberg University Biochemistry Center, 69120 Heidelberg, Germany
| | - Thorsten Trimbuch
- Charite - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Neurophysiology, 10117 Berlin, Germany
| | - Melissa A Herman
- Charite - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Neurophysiology, 10117 Berlin, Germany
| | - Thomas H Söllner
- Heidelberg University Biochemistry Center, 69120 Heidelberg, Germany
| | - Christian Rosenmund
- Charite - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Neurophysiology, 10117 Berlin, Germany
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16
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Wang J, Zhou C, Huang Z, Ji X, Cui R, Kang Y, Zhang G, Wang Y, Zhang T. Repetitive Transcranial Magnetic Stimulation-Mediated Neuroprotection in the 5xFAD Mouse Model of Alzheimer's Disease Through GABRG2 and SNAP25 Modulation. Mol Neurobiol 2024:10.1007/s12035-024-04354-7. [PMID: 39052185 DOI: 10.1007/s12035-024-04354-7] [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: 03/11/2024] [Accepted: 07/06/2024] [Indexed: 07/27/2024]
Abstract
Alzheimer's disease (AD) is a leading neurodegenerative disorder with substantial impacts on cognition and behavior. Repetitive transcranial magnetic stimulation (rTMS), a non-invasive neuromodulation technique, has been used to treat various neuropsychiatric disorders, but its efficacy in AD has not been thoroughly investigated. This study examines the neuroprotective effects of rTMS in the 5xFAD mouse model of AD, with a particular focus on its modulation of GABAergic neuronal activity via the GABRG2 and SNAP25 proteins. Transcriptomic sequencing of rTMS-treated 5xFAD mice revealed 32 genes influenced by the treatment, among which GABRG2 was identified as a critical modulatory target. Electrophysiological assessments, including whole-cell patch clamp recordings from frontal cortex neurons, demonstrated significant alterations in inhibitory synaptic currents following rTMS. Subsequent experiments involved sh-GABRG2 transduction combined with rTMS treatment (20Hz, 14 days), examining behavioral responses, GABAergic neuron functionality, cortical GABA expression, cerebrospinal fluid GABA concentrations, β-amyloid accumulation, and pro-inflammatory cytokine levels. The results indicated notable improvements in behavioral performance, enhanced functionality of GABAergic neurons, and reductions in β-amyloid deposition and neuroinflammation after rTMS treatment. Further analysis revealed that SNAP25 overexpression could counteract the negative effects of GABRG2 silencing, highlighting the crucial role of SNAP25 downstream of GABRG2 in mediating rTMS's therapeutic effects in AD. This research highlights rTMS's potential to modulate synaptic and vesicular transport mechanisms, offering a promising avenue for ameliorating symptoms of AD through neuroprotective pathways.
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Affiliation(s)
- Jinyang Wang
- Department of Neurology, The Third Hospital of Hebei Medical University, Shijiazhuang, 050051, China
| | - Chenming Zhou
- Core Facilities and Centers, Hebei Medical University, Shijiazhuang, 050017, China
| | - Zhimin Huang
- Department of Stomatology, People's Hospital, Shizhu Tujia Autonomous County, Chongqing, 409100, China
| | - Xiaoming Ji
- Laboratory of Neurobiology, Hebei Medical University, Zhongshan Donglu No.361, ShijiazhuangHebei Province, 050017, China
- Neuroscience Research Center, Hebei Medical University, Shijiazhuang, 050017, China
| | - Rui Cui
- Neuroscience Research Center, Hebei Medical University, Shijiazhuang, 050017, China
| | - Yunxiao Kang
- Laboratory of Neurobiology, Hebei Medical University, Zhongshan Donglu No.361, ShijiazhuangHebei Province, 050017, China
- Neuroscience Research Center, Hebei Medical University, Shijiazhuang, 050017, China
| | - Guoliang Zhang
- Neuroscience Research Center, Hebei Medical University, Shijiazhuang, 050017, China
| | - Yu Wang
- Laboratory of Neurobiology, Hebei Medical University, Zhongshan Donglu No.361, ShijiazhuangHebei Province, 050017, China
| | - Tianyun Zhang
- Laboratory of Neurobiology, Hebei Medical University, Zhongshan Donglu No.361, ShijiazhuangHebei Province, 050017, China.
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17
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Tammareddy T, Keyrouz W, Sriram RD, Pant HC, Cardone A, Klauda JB. Investigation of the Effect of Peptide p5 Targeting CDK5-p25 Hyperactivity on Munc18-1 (P67) Regulating Neuronal Exocytosis Using Molecular Simulations. Biochemistry 2024; 63:1837-1857. [PMID: 38953497 DOI: 10.1021/acs.biochem.4c00148] [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: 07/04/2024]
Abstract
Munc18-1 is an SM (sec1/munc-like) family protein involved in vesicle fusion and neuronal exocytosis. Munc18-1 is known to regulate the exocytosis process by binding with closed- and open-state conformations of Syntaxin1, a protein belonging to the SNARE family established to be central to the exocytosis process. Our previous work studied peptide p5 as a promising drug candidate for CDK5-p25 complex, an Alzheimer's disease (AD) pathological target. Experimental in vivo and in vitro studies suggest that Munc18-1 promotes p5 to selectively inhibit the CDK5-p25 complex without affecting the endogenous CDK5 activity, a characteristic of remarkable therapeutic implications. In this paper, we identify several binding modes of p5 with Munc18-1 that could potentially affect the Munc18-1 binding with SNARE proteins and lead to off-target effects on neuronal communication using molecular dynamics simulations. Recent studies indicate that disruption of Munc18-1 function not only disrupts neurotransmitter release but also results in neurodegeneration, exhibiting clinical resemblance to other neurodegenerative conditions such as AD, causing diagnostic and treatment challenges. We characterize such interactions between p5 and Munc18-1, define the corresponding pharmacophores, and provide guidance for the in vitro validation of our findings to improve therapeutic efficacy and safety of p5.
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Affiliation(s)
- Tejaswi Tammareddy
- Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, Maryland 20742, United States
| | | | | | - Harish C Pant
- Neuronal Cytoskeletal Protein Regulation Section, Laboratory of Neurochemistry, NINDS, Bethesda, Maryland 20892, United States
| | | | - Jeffery B Klauda
- Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, Maryland 20742, United States
- Institute for Physical Science & Technology, Biophysics Graduate Program, University of Maryland, College Park, Maryland 20742, United States
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18
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Song SH, Augustine GJ. A role for synapsin tetramerization in synaptic vesicle clustering. J Physiol 2024. [PMID: 38979871 DOI: 10.1113/jp286177] [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: 04/22/2024] [Accepted: 06/06/2024] [Indexed: 07/10/2024] Open
Abstract
Although synapsins have long been proposed to be key regulators of synaptic vesicle (SV) clustering, their mechanism of action has remained mysterious and somewhat controversial. Here, we review synapsins and their associations with each other and with SVs. We highlight the recent hypothesis that synapsin tetramerization is a mechanism for SV clustering. This hypothesis, which aligns with numerous experimental results, suggests that the larger size of synapsin tetramers, in comparison to dimers, allows tetramers to form optimal bridges between SVs that overcome the repulsive force associated with the negatively charged membrane of SVs and allow synapsins to form a reserve pool of SVs within presynaptic terminals.
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Affiliation(s)
| | - George J Augustine
- Temasek Life sciences Laboratory, Singapore
- Department of Physiology, National University of Singapore, Singapore
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19
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Clayton EL, Huggon L, Cousin MA, Mizielinska S. Synaptopathy: presynaptic convergence in frontotemporal dementia and amyotrophic lateral sclerosis. Brain 2024; 147:2289-2307. [PMID: 38451707 PMCID: PMC11224618 DOI: 10.1093/brain/awae074] [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: 02/02/2024] [Accepted: 02/12/2024] [Indexed: 03/09/2024] Open
Abstract
Frontotemporal dementia and amyotrophic lateral sclerosis are common forms of neurodegenerative disease that share overlapping genetics and pathologies. Crucially, no significantly disease-modifying treatments are available for either disease. Identifying the earliest changes that initiate neuronal dysfunction is important for designing effective intervention therapeutics. The genes mutated in genetic forms of frontotemporal dementia and amyotrophic lateral sclerosis have diverse cellular functions, and multiple disease mechanisms have been proposed for both. Identification of a convergent disease mechanism in frontotemporal dementia and amyotrophic lateral sclerosis would focus research for a targetable pathway, which could potentially effectively treat all forms of frontotemporal dementia and amyotrophic lateral sclerosis (both familial and sporadic). Synaptopathies are diseases resulting from physiological dysfunction of synapses, and define the earliest stages in multiple neuronal diseases, with synapse loss a key feature in dementia. At the presynapse, the process of synaptic vesicle recruitment, fusion and recycling is necessary for activity-dependent neurotransmitter release. The unique distal location of the presynaptic terminal means the tight spatio-temporal control of presynaptic homeostasis is dependent on efficient local protein translation and degradation. Recently, numerous publications have shown that mutations associated with frontotemporal dementia and amyotrophic lateral sclerosis present with synaptopathy characterized by presynaptic dysfunction. This review will describe the complex local signalling and membrane trafficking events that occur at the presynapse to facilitate neurotransmission and will summarize recent publications linking frontotemporal dementia/amyotrophic lateral sclerosis genetic mutations to presynaptic function. This evidence indicates that presynaptic synaptopathy is an early and convergent event in frontotemporal dementia and amyotrophic lateral sclerosis and illustrates the need for further research in this area, to identify potential therapeutic targets with the ability to impact this convergent pathomechanism.
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Affiliation(s)
- Emma L Clayton
- UK Dementia Research Institute at King’s College London, London SE5 9RT, UK
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, Maurice Wohl Clinical Neuroscience Institute, London SE5 9RT, UK
| | - Laura Huggon
- UK Dementia Research Institute at King’s College London, London SE5 9RT, UK
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, Maurice Wohl Clinical Neuroscience Institute, London SE5 9RT, UK
| | - Michael A Cousin
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, UK
- Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh EH8 9XD, UK
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Sarah Mizielinska
- UK Dementia Research Institute at King’s College London, London SE5 9RT, UK
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, Maurice Wohl Clinical Neuroscience Institute, London SE5 9RT, UK
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20
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Leitz J, Wang C, Esquivies L, Peters JJ, Gopal N, Pfuetzner RA, Wang AL, Brunger AT. Observing isolated synaptic vesicle association and fusion ex vivo. Nat Protoc 2024:10.1038/s41596-024-01014-x. [PMID: 38956381 DOI: 10.1038/s41596-024-01014-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 05/15/2024] [Indexed: 07/04/2024]
Abstract
Here, we present a protocol for isolating functionally intact glutamatergic synaptic vesicles from whole-mouse brain tissue and using them in a single-vesicle assay to examine their association and fusion with plasma membrane mimic vesicles. This is a Protocol Extension, building on our previous protocol, which used a purely synthetic system comprised of reconstituted proteins in liposomes. We also describe the generation of a peptide based on the vesicular glutamate transporter, which is essential in the isolation process of glutamatergic synaptic vesicles. This method uses easily accessible reagents to generate fusion-competent glutamatergic synaptic vesicles through immunoisolation. The generation of the vGlut peptide can be accomplished in 6 d, while the isolation of the synaptic vesicles by using the peptide can be accomplished in 2 d, with an additional day to fluorescently label the synaptic vesicles for use in a single-vesicle hybrid fusion assay. The single-vesicle fusion assay can be accomplished in 1 d and can unambiguously delineate synaptic vesicle association, dissociation, Ca2+-independent and Ca2+-dependent fusion modalities. This assay grants control of the synaptic vesicle environment while retaining the complexity of the synaptic vesicles themselves. This protocol can be adapted to studies of other types of synaptic vesicles or, more generally, different secretory or transport vesicles. The workflow described here requires expertise in biochemistry techniques, in particular, protein purification and fluorescence imaging. We assume that the laboratory has protein-purification equipment, including chromatography systems.
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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
| | - John J 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
| | - Nisha Gopal
- 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
| | - 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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21
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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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22
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Pizzella A, Penna E, Abate N, Frenna E, Canafoglia L, Ragona F, Russo R, Chambery A, Perrone-Capano C, Cappello S, Crispino M, Di Giaimo R. Pathological Deficit of Cystatin B Impairs Synaptic Plasticity in EPM1 Human Cerebral Organoids. Mol Neurobiol 2024; 61:4318-4334. [PMID: 38087165 PMCID: PMC11236866 DOI: 10.1007/s12035-023-03812-y] [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: 09/19/2023] [Accepted: 11/17/2023] [Indexed: 07/11/2024]
Abstract
Cystatin B (CSTB) is a small protease inhibitor protein being involved in cell proliferation and neuronal differentiation. Loss-of-function mutations in CSTB gene cause progressive myoclonic epilepsy 1 (EPM1). We previously demonstrated that CSTB is locally synthesized in synaptic nerve terminals from rat brain and secreted into the media, indicating its role in synaptic plasticity. In this work, we have further investigated the involvement of CSTB in synaptic plasticity, using synaptosomes from human cerebral organoids (hCOs) as well as from rodents' brain. Our data demonstrate that CSTB is released from synaptosomes in two ways: (i) as a soluble protein and (ii) in extracellular vesicles-mediated pathway. Synaptosomes isolated from hCOs are enriched in pre-synaptic proteins and contain CSTB at all developmental stages analyzed. CSTB presence in the synaptic territories was also confirmed by immunostaining on human neurons in vitro. To investigate if the depletion of CSTB affects synaptic plasticity, we characterized the synaptosomes from EPM1 hCOs. We found that the levels of presynaptic proteins and of an initiation factor linked to local protein synthesis were both reduced in EPM1 hCOs and that the extracellular vesicles trafficking pathway was impaired. Moreover, EPM1 neurons displayed anomalous morphology with longer and more branched neurites bearing higher number of intersections and nodes, suggesting connectivity alterations. In conclusion, our data strengthen the idea that CSTB plays a critical role in the synapse physiology and reveal that pathologically low levels of CSTB may affect synaptic plasticity, leading to synaptopathy and altered neuronal morphology.
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Affiliation(s)
- Amelia Pizzella
- Department of Biology, University of Naples Federico II, Naples, Italy
- Department of Developmental Neurobiology, Max Planck Institute of Psychiatry, Munich, Germany
| | - Eduardo Penna
- Department of Biology, University of Naples Federico II, Naples, Italy
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA, 91766, USA
| | - Natalia Abate
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Elisa Frenna
- Department of Biology, University of Naples Federico II, Naples, Italy
- Department of Developmental Neurobiology, Max Planck Institute of Psychiatry, Munich, Germany
| | - Laura Canafoglia
- Integrated Diagnostics for Epilepsy, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Francesca Ragona
- Department of Pediatric Neuroscience, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Rosita Russo
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, University of Campania "Luigi Vanvitelli, Caserta, Italy
| | - Angela Chambery
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, University of Campania "Luigi Vanvitelli, Caserta, Italy
| | | | - Silvia Cappello
- Department of Developmental Neurobiology, Max Planck Institute of Psychiatry, Munich, Germany
- Biomedical Center, Ludwig Maximilian University of Munich, Munich, Germany
| | - Marianna Crispino
- Department of Biology, University of Naples Federico II, Naples, Italy.
| | - Rossella Di Giaimo
- Department of Biology, University of Naples Federico II, Naples, Italy.
- Department of Developmental Neurobiology, Max Planck Institute of Psychiatry, Munich, Germany.
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23
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Toulmé E, Lázaro AS, Trimbuch T, Rizo J, Rosenmund C. Neurotransmitter release is triggered by a calcium-induced rearrangement in the Synaptotagmin-1/SNARE complex primary interface. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.17.599435. [PMID: 38948868 PMCID: PMC11213007 DOI: 10.1101/2024.06.17.599435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
The Ca2+ sensor synaptotagmin-1 triggers neurotransmitter release together with the neuronal SNARE complex formed by syntaxin-1, SNAP25 and synaptobrevin. Moreover, synaptotagmin-1 increases synaptic vesicle priming and impairs spontaneous vesicle release. The synaptotagmin-1 C2B domain binds to the SNARE complex through a primary interface via two regions (I and II), but how exactly this interface mediates distinct functions of synaptotagmin-1, and the mechanism underlying Ca2+-triggering of release is unknown. Using mutagenesis and electrophysiological experiments, we show that region II is functionally and spatially subdivided: binding of C2B domain arginines to SNAP-25 acidic residues at one face of region II is crucial for Ca2+-evoked release but not for vesicle priming or clamping of spontaneous release, whereas other SNAP-25 and syntaxin-1 acidic residues at the other face mediate priming and clamping of spontaneous release but not evoked release. Mutations that disrupt region I impair the priming and clamping functions of synaptotagmin-1 while, strikingly, mutations that enhance binding through this region increase vesicle priming and clamping of spontaneous release, but strongly inhibit evoked release and vesicle fusogenicity. These results support previous findings that the primary interface mediates the functions of synaptotagmin-1 in vesicle priming and clamping of spontaneous release, and, importantly, show that Ca2+-triggering of release requires a rearrangement of the primary interface involving dissociation of region I, while region II remains bound. Together with modeling and biophysical studies presented in the accompanying paper, our data suggest a model whereby this rearrangement pulls the SNARE complex to facilitate fast synaptic vesicle fusion.
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Affiliation(s)
- Estelle Toulmé
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Neurophysiology, Berlin, Germany
- NeuroCure Cluster of Excellence, Berlin, Germany
| | - Andrea Salazar Lázaro
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Neurophysiology, Berlin, Germany
- NeuroCure Cluster of Excellence, Berlin, Germany
| | - Thorsten Trimbuch
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Neurophysiology, Berlin, Germany
- NeuroCure Cluster of Excellence, Berlin, Germany
| | - 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
| | - Christian Rosenmund
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Neurophysiology, Berlin, Germany
- NeuroCure Cluster of Excellence, Berlin, Germany
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24
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Kim D, Truong PL, Lee CB, Bang H, Choi J, Ham S, Ko JH, Kim K, Lee D, Park HJ. Reconfigurable Resistive Switching Memory for Telegraph Code Sensing and Recognizing Reservoir Computing Systems. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024:e2402961. [PMID: 38895971 DOI: 10.1002/smll.202402961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2024] [Revised: 05/29/2024] [Indexed: 06/21/2024]
Abstract
Reservoir computing (RC) system is based upon the reservoir layer, which non-linearly transforms input signals into high-dimensional states, facilitating simple training in the readout layer-a linear neural network. These layers require different types of devices-the former demonstrated as diffusive memristors and the latter prepared as drift memristors. The integration of these components can increase the structural complexity of RC system. Here, a reconfigurable resistive switching memory (RSM) capable of implementing both diffusive and drift dynamics is demonstrated. This reconfigurability is achieved by preparing a medium with a 3D ion transport channel (ITC), enabling precise control of the metal filament that determines memristor operation. The 3D ITC-RSM operates in a volatile threshold switching (TS) mode under a weak electric field and exhibits short-term dynamics that are confirmed to be applicable as reservoir elements in RC systems. Meanwhile, the 3D ITC-RSM operates in a non-volatile bipolar switching (BS) mode under a strong electric field, and the conductance modulation metrics forming the basis of synaptic weight update are validated, which can be utilized as readout elements in the readout layer. Finally, an RC system is designed for the application of reconfigurable 3D ITC-RSM, and performs real-time recognition on Morse code datasets.
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Affiliation(s)
- Dohyung Kim
- Department of Organic and Nano Engineering, Hanyang University, Seoul, 04763, South Korea
- Human-Tech Convergence Program, Hanyang University, Seoul, 04763, South Korea
| | - Phuoc Loc Truong
- Department of Mechanical Engineering, Gachon University, Gyeonggi, 13120, South Korea
| | - Cheong Beom Lee
- Department of Chemical Engineering, Hanyang University, Seoul, 04763, South Korea
| | - Hyeonsu Bang
- Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon, 16419, South Korea
| | - Jia Choi
- Department of Organic and Nano Engineering, Hanyang University, Seoul, 04763, South Korea
- Human-Tech Convergence Program, Hanyang University, Seoul, 04763, South Korea
| | - Seokhyun Ham
- Department of Organic and Nano Engineering, Hanyang University, Seoul, 04763, South Korea
- Human-Tech Convergence Program, Hanyang University, Seoul, 04763, South Korea
| | - Jong Hwan Ko
- College of Information and Communication Engineering, Sungkyunkwan University, Suwon, 16419, South Korea
| | - Kyeounghak Kim
- Department of Chemical Engineering, Hanyang University, Seoul, 04763, South Korea
| | - Daeho Lee
- Department of Mechanical Engineering, Gachon University, Gyeonggi, 13120, South Korea
| | - Hui Joon Park
- Department of Organic and Nano Engineering, Hanyang University, Seoul, 04763, South Korea
- Human-Tech Convergence Program, Hanyang University, Seoul, 04763, South Korea
- Department of Semiconductor Engineering, Hanyang University, Seoul, 04763, South Korea
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25
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Jaczynska K, Esser V, Xu J, Sari L, Lin MM, Rosenmund C, Rizo J. A lever hypothesis for Synaptotagmin-1 action in neurotransmitter release. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.17.599417. [PMID: 38948826 PMCID: PMC11212951 DOI: 10.1101/2024.06.17.599417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Neurotransmitter release is triggered in microseconds by Ca2+-binding to the Synaptotagmin-1 C2 domains and by SNARE complexes that form four-helix bundles between synaptic vesicles and plasma membranes, but the coupling mechanism between Ca2+-sensing and membrane fusion is unknown. Release requires extension of SNARE helices into juxtamembrane linkers that precede transmembrane regions (linker zippering) and binding of the Synaptotagmin-1 C2B domain to SNARE complexes through a 'primary interface' comprising two regions (I and II). The Synaptotagmin-1 Ca2+-binding loops were believed to accelerate membrane fusion by inducing membrane curvature, perturbing lipid bilayers or helping bridge the membranes, but SNARE complex binding orients the Ca2+-binding loops away from the fusion site, hindering these putative activities. Molecular dynamics simulations now suggest that Synaptotagmin-1 C2 domains near the site of fusion hinder SNARE action, providing an explanation for this paradox and arguing against previous models of Sytnaptotagmin-1 action. NMR experiments reveal that binding of C2B domain arginines to SNARE acidic residues at region II remains after disruption of region I. These results and fluorescence resonance energy transfer assays, together with previous data, suggest that Ca2+ causes reorientation of the C2B domain on the membrane and dissociation from the SNAREs at region I but not region II. Based on these results and molecular modeling, we propose that Synaptotagmin-1 acts as a lever that pulls the SNARE complex when Ca2+ causes reorientation of the C2B domain, facilitating linker zippering and fast membrane fusion. This hypothesis is supported by the electrophysiological data described in the accompanying paper.
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Affiliation(s)
- Klaudia Jaczynska
- 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
| | - 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
| | - Levent Sari
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
- Green Center for Systems Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Milo M. Lin
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
- Green Center for Systems Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Christian Rosenmund
- Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Neurophysiology, Berlin, Germany
- NeuroCure Cluster of Excellence, Berlin, Germany
| | - 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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26
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Jiang L, Zhou Y, Tang S, Yang D, Zhang Y, Zhang J, Yang F, Zhou T, Xia X, Chen Q, Jiang L, Jiang Y, Feng X. Nociceptive adenosine A 2A receptor on trigeminal nerves orchestrates CGRP release to regulate the progression of oral squamous cell carcinoma. Int J Oral Sci 2024; 16:46. [PMID: 38886342 PMCID: PMC11183250 DOI: 10.1038/s41368-024-00308-w] [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: 12/04/2023] [Revised: 04/16/2024] [Accepted: 04/21/2024] [Indexed: 06/20/2024] Open
Abstract
Oral squamous cell carcinoma (OSCC) associated pain commonly predicts adverse events among patients. This clinical feature indicates the engagement of nociceptors on sensory neurons during the development of malignancy. However, it is yet to be determined if targeting oncometabolite-associated nociception processes can hinder OSCC progression. In this study, we reported that nociceptive endings infiltrating both clinical samples and mouse tumor xenografts were associated with poorer clinical outcomes and drove tumor progression in vivo, as evidenced by clinical tissue microarray analysis and murine lingual denervation. We observed that the OSCC microenvironment was characteristic of excessive adenosine due to CD73 upregulation which negatively predicted clinical outcomes in the TCGA-HNSC patient cohort. Notably, such adenosine concentrative OSCC niche was associated with the stimulation of adenosine A2A receptor (A2AR) on trigeminal ganglia. Antagonism of trigeminal A2AR with a selective A2AR inhibitor SCH58261 resulted in impeded OSCC growth in vivo. We showed that trigeminal A2AR overstimulation in OSCC xenograft did not entail any changes in the transcription level of CGRP in trigeminal ganglia but significantly triggered the release of CGRP, an effect counteracted by SCH58261. We further demonstrated the pro-tumor effect of CGRP by feeding mice with the clinically approved CGRP receptor antagonist rimegepant which inhibited the activation of ERK and YAP. Finally, we diminished the impact of CGRP on OSCC with istradefylline, a clinically available drug that targets neuronal A2AR. Therefore, we established trigeminal A2AR-mediated CGRP release as a promising druggable circuit in OSCC treatment.
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Grants
- 82170971, 82373187, 82002888 National Natural Science Foundation of China (National Science Foundation of China)
- 82170971, 82373187, 82002888 National Natural Science Foundation of China (National Science Foundation of China)
- 82170971, 82373187, 82002888 National Natural Science Foundation of China (National Science Foundation of China)
- 82170971, 82373187, 82002888 National Natural Science Foundation of China (National Science Foundation of China)
- 82170971, 82373187, 82002888 National Natural Science Foundation of China (National Science Foundation of China)
- 82170971, 82373187, 82002888 National Natural Science Foundation of China (National Science Foundation of China)
- 82170971, 82373187, 82002888 National Natural Science Foundation of China (National Science Foundation of China)
- 82170971, 82373187, 82002888 National Natural Science Foundation of China (National Science Foundation of China)
- 82170971, 82373187, 82002888 National Natural Science Foundation of China (National Science Foundation of China)
- 82170971, 82373187, 82002888 National Natural Science Foundation of China (National Science Foundation of China)
- Fundamental Research Funds for the Central Universities (YJ201987); Sichuan Science and Technology Program (2021ZYD0090 and 2022YFS0207); Scientific Research Foundation, West China Hospital of Stomatology Sichuan University (QDJF2019-3 and RD-03-202110); CAMS Innovation Fund for Medical Sciences (CIFMS, 2019-I2M-5-004)
- Fundamental Research Funds for the Central Universities (YJ201987), Sichuan Science and Technology Program (2021ZYD0090 and 2022YFS0207), Scientific Research Foundation, West China Hospital of Stomatology Sichuan University (QDJF2019-3 and RD-03-202110), and CAMS Innovation Fund for Medical Sciences (CIFMS, 2019-I2M-5-004)
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Affiliation(s)
- Lanxin Jiang
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Research Unit of Oral Carcinogenesis and Management, Chinese Academy of Medical Sciences, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Ying Zhou
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Research Unit of Oral Carcinogenesis and Management, Chinese Academy of Medical Sciences, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Shijie Tang
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Research Unit of Oral Carcinogenesis and Management, Chinese Academy of Medical Sciences, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Dan Yang
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Research Unit of Oral Carcinogenesis and Management, Chinese Academy of Medical Sciences, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Yixin Zhang
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Research Unit of Oral Carcinogenesis and Management, Chinese Academy of Medical Sciences, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Jiuge Zhang
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Research Unit of Oral Carcinogenesis and Management, Chinese Academy of Medical Sciences, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Fan Yang
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Research Unit of Oral Carcinogenesis and Management, Chinese Academy of Medical Sciences, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Tong Zhou
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Research Unit of Oral Carcinogenesis and Management, Chinese Academy of Medical Sciences, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Xiaoqiang Xia
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Research Unit of Oral Carcinogenesis and Management, Chinese Academy of Medical Sciences, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Qianming Chen
- Key Laboratory of Oral Biomedical Research of Zhejiang Province, Affiliated Stomatology Hospital, Zhejiang University School of Stomatology, Hangzhou, China
| | - Lu Jiang
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Research Unit of Oral Carcinogenesis and Management, Chinese Academy of Medical Sciences, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Yuchen Jiang
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Research Unit of Oral Carcinogenesis and Management, Chinese Academy of Medical Sciences, West China Hospital of Stomatology, Sichuan University, Chengdu, China.
| | - Xiaodong Feng
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Research Unit of Oral Carcinogenesis and Management, Chinese Academy of Medical Sciences, West China Hospital of Stomatology, Sichuan University, Chengdu, China.
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27
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Schwab K, Lauer D, Magbagbeolu M, Theuring F, Gasiorowska A, Zadrozny M, Harrington CR, Wischik CM, Niewiadomska G, Riedel G. Hydromethylthionine rescues synaptic SNARE proteins in a mouse model of tauopathies: Interference by cholinesterase inhibitors. Brain Res Bull 2024; 212:110955. [PMID: 38677558 DOI: 10.1016/j.brainresbull.2024.110955] [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: 02/29/2024] [Revised: 04/14/2024] [Accepted: 04/17/2024] [Indexed: 04/29/2024]
Abstract
In clinical trials for Alzheimer's disease (AD), hydromethylthionine mesylate (HMTM) showed reduced efficacy when administered as an add-on to symptomatic treatments, while it produced a significant improvement of cognitive function when taken as monotherapy. Interference of cholinesterase inhibition with HMTM was observed also in a tau transgenic mouse model, where rivastigmine reduced the pharmacological activity of HMTM at multiple brain levels including hippocampal acetylcholine release, synaptosomal glutamate release and mitochondrial activity. Here, we examined the effect of HMTM, given alone or in combination with the acetylcholinesterase inhibitor, rivastigmine, at the level of expression of selected pre-synaptic proteins (syntaxin-1; SNAP-25, VAMP-2, synaptophysin-1, synapsin-1, α-synuclein) in brain tissue harvested from tau-transgenic Line 1 (L1) and wild-type mice using immunohistochemistry. L1 mice overexpress the tau-core unit that induces tau aggregation and results in an AD-like phenotype. Synaptic proteins were lower in hippocampus and cortex but greater in basal forebrain regions in L1 compared to wild-type mice. HMTM partially normalised the expression pattern of several of these proteins in basal forebrain. This effect was diminished when HMTM was administered in combination with rivastigmine, where mean protein expression seemed supressed. This was further confirmed by group-based correlation network analyses where important levels of co-expression correlations in basal forebrain regions were lost in L1 mice and partially re-established when HMTM was given alone but not in combination with rivastigmine. These data indicate a reduction in pharmacological activity of HMTM when given as an add-on therapy, a result that is consistent with the responses observed in the clinic. Attenuation of the therapeutic effects of HMTM by cholinergic treatments may have important implications for other potential AD therapies.
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Affiliation(s)
- Karima Schwab
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK; Institute of Pharmacology, Charité - Universitätsmedizin Berlin, Hessische Str. 3-4, Berlin 10115, Germany
| | - Dilyara Lauer
- Institute of Pharmacology, Charité - Universitätsmedizin Berlin, Hessische Str. 3-4, Berlin 10115, Germany
| | - Mandy Magbagbeolu
- Institute of Pharmacology, Charité - Universitätsmedizin Berlin, Hessische Str. 3-4, Berlin 10115, Germany
| | - Franz Theuring
- Institute of Pharmacology, Charité - Universitätsmedizin Berlin, Hessische Str. 3-4, Berlin 10115, Germany
| | - Anna Gasiorowska
- Clinical and Research Department of Applied Physiology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Warsaw 02-106, Poland
| | - Maciej Zadrozny
- Clinical and Research Department of Applied Physiology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Warsaw 02-106, Poland
| | - Charles R Harrington
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK; TauRx Therapeutics Ltd., 395 King Street, Aberdeen AB24 5RP, UK
| | - Claude M Wischik
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK; TauRx Therapeutics Ltd., 395 King Street, Aberdeen AB24 5RP, UK
| | - Grażyna Niewiadomska
- Clinical and Research Department of Applied Physiology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Warsaw 02-106, Poland
| | - Gernot Riedel
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK.
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28
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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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29
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Matúš D, Lopez JM, Sando RC, Südhof TC. Essential Role of Latrophilin-1 Adhesion GPCR Nanoclusters in Inhibitory Synapses. J Neurosci 2024; 44:e1978232024. [PMID: 38684366 PMCID: PMC11154861 DOI: 10.1523/jneurosci.1978-23.2024] [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: 10/19/2023] [Revised: 02/03/2024] [Accepted: 02/20/2024] [Indexed: 05/02/2024] Open
Abstract
Latrophilin-1 (Lphn1, aka CIRL1 and CL1; gene symbol Adgrl1) is an adhesion GPCR that has been implicated in excitatory synaptic transmission as a candidate receptor for α-latrotoxin. Here we analyzed conditional knock-in/knock-out mice for Lphn1 that contain an extracellular myc epitope tag. Mice of both sexes were used in all experiments. Surprisingly, we found that Lphn1 is localized in cultured neurons to synaptic nanoclusters that are present in both excitatory and inhibitory synapses. Conditional deletion of Lphn1 in cultured neurons failed to elicit a detectable impairment in excitatory synapses but produced a decrease in inhibitory synapse numbers and synaptic transmission that was most pronounced for synapses close to the neuronal soma. No changes in axonal or dendritic outgrowth or branching were observed. Our data indicate that Lphn1 is among the few postsynaptic adhesion molecules that are present in both excitatory and inhibitory synapses and that Lphn1 by itself is not essential for excitatory synaptic transmission but is required for some inhibitory synaptic connections.
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Affiliation(s)
- Daniel Matúš
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California 94305
| | - Jaybree M Lopez
- Department of Pharmacology, Vanderbilt Brain Institute, Vanderbilt University, Nashville, Tennessee 37240
| | - Richard C Sando
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California 94305
- Department of Pharmacology, Vanderbilt Brain Institute, Vanderbilt University, Nashville, Tennessee 37240
| | - Thomas C Südhof
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California 94305
- Hughes Medical Institute, Stanford University School of Medicine, Stanford, California 94305
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30
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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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31
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van Boven MA, Mestroni M, Zwijnenburg PJG, Verhage M, Cornelisse LN. A de novo missense mutation in synaptotagmin-1 associated with neurodevelopmental disorder desynchronizes neurotransmitter release. Mol Psychiatry 2024; 29:1798-1809. [PMID: 38321119 PMCID: PMC11371641 DOI: 10.1038/s41380-024-02444-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 01/12/2024] [Accepted: 01/22/2024] [Indexed: 02/08/2024]
Abstract
Synaptotagmin-1 (Syt1) is a presynaptic calcium sensor with two calcium binding domains, C2A and C2B, that triggers action potential-induced synchronous neurotransmitter release, while suppressing asynchronous and spontaneous release. We identified a de novo missense mutation (P401L) in the C2B domain in a patient with developmental delay and autistic symptoms. Expressing the orthologous mouse mutant (P400L) in cultured Syt1 null mutant neurons revealed a reduction in dendrite outgrowth with a proportional reduction in synapses. This was not observed in single Syt1PL-rescued neurons that received normal synaptic input when cultured in a control network. Patch-clamp recordings showed that spontaneous miniature release events per synapse were increased more than 500% in Syt1PL-rescued neurons, even beyond the increased rates in Syt1 KO neurons. Furthermore, action potential-induced asynchronous release was increased more than 100%, while synchronous release was unaffected. A similar shift to more asynchronous release was observed during train stimulations. These cellular phenotypes were also observed when Syt1PL was overexpressed in wild type neurons. Our findings show that Syt1PL desynchronizes neurotransmission by increasing the readily releasable pool for asynchronous release and reducing the suppression of spontaneous and asynchronous release. Neurons respond to this by shortening their dendrites, possibly to counteract the increased synaptic input. Syt1PL acts in a dominant-negative manner supporting a causative role for the mutation in the heterozygous patient. We propose that the substitution of a rigid proline to a more flexible leucine at the bottom of the C2B domain impairs clamping of release by interfering with Syt1's primary interface with the SNARE complex. This is a novel cellular phenotype, distinct from what was previously found for other SYT1 disease variants, and points to a role for spontaneous and asynchronous release in SYT1-associated neurodevelopmental disorder.
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Affiliation(s)
- Maaike A van Boven
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research (CNCR), Vrije Universiteit (VU) Amsterdam, 1081 HV, Amsterdam, The Netherlands
| | - Marta Mestroni
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research (CNCR), Vrije Universiteit (VU) Amsterdam, 1081 HV, Amsterdam, The Netherlands
| | | | - Matthijs Verhage
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research (CNCR), Vrije Universiteit (VU) Amsterdam, 1081 HV, Amsterdam, The Netherlands
- Department of Functional Genomics and Department of Human Genetics, Center for Neurogenomics and Cognitive Research (CNCR), Amsterdam UMC-Location VUmc, 1081 HV, Amsterdam, The Netherlands
| | - L Niels Cornelisse
- Department of Functional Genomics and Department of Human Genetics, Center for Neurogenomics and Cognitive Research (CNCR), Amsterdam UMC-Location VUmc, 1081 HV, Amsterdam, The Netherlands.
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32
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Tsotsokou G, Trompoukis G, Papatheodoropoulos C. Muscarinic Modulation of Synaptic Transmission and Short-Term Plasticity in the Dorsal and Ventral Hippocampus. Mol Cell Neurosci 2024; 129:103935. [PMID: 38703973 DOI: 10.1016/j.mcn.2024.103935] [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: 09/29/2023] [Revised: 04/29/2024] [Accepted: 04/30/2024] [Indexed: 05/06/2024] Open
Abstract
Muscarinic neurotransmission is fundamentally involved in supporting several brain functions by modulating flow of information in brain neural circuits including the hippocampus which displays a remarkable functional segregation along its longitudinal axis. However, how muscarinic neuromodulation contributes to the functional segregation along the hippocampus remains unclear. In this study we show that the nonselective muscarinic receptor agonist carbachol similarly suppresses basal synaptic transmission in the dorsal and ventral CA1 hippocampal field, in a concentration-depended manner. Furthermore, using a ten-pulse stimulation train of varying frequency we found that carbachol changes the frequency filtering properties more in ventral than dorsal hippocampus by facilitating synaptic inputs at a wide range of input frequencies in the ventral compared with dorsal hippocampus. Using the M2 receptor antagonist gallamine and the M4 receptor antagonist tropicamide, we found that M2 receptors are involved in controlling basal synaptic transmission and short-term synaptic plasticity (STSP) in the ventral but not the dorsal hippocampus, while M4 receptors participate in modulating basal synaptic transmission and STSP in both segments of the hippocampus. These results were corroborated by the higher protein expression levels of M2 receptors in the ventral compared with dorsal hippocampus. We conclude that muscarinic transmission modulates excitatory synaptic transmission and short-term synaptic plasticity along the entire rat hippocampus by acting through M4 receptors and recruiting M2 receptors only in the ventral hippocampus. Furthermore, M4 receptors appear to exert a permissive role on the actions of M2 receptors on STSP in the ventral hippocampus. This dorsoventral differentiation of muscarinic modulation is expected to have important implications in information processing along the endogenous hippocampal circuitry.
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Affiliation(s)
- Giota Tsotsokou
- Laboratory of Physiology, University of Patras, Department of Medicine, Rion, Greece
| | - George Trompoukis
- Laboratory of Physiology, University of Patras, Department of Medicine, Rion, Greece
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33
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Trinchese G, Feola A, Cavaliere G, Cimmino F, Catapano A, Penna E, Scala G, Greco L, Bernardo L, Porcellini A, Crispino M, Pezone A, Mollica MP. Mitochondrial metabolism and neuroinflammation in the cerebral cortex and cortical synapses of rats: effect of milk intake through DNA methylation. J Nutr Biochem 2024; 128:109624. [PMID: 38518858 DOI: 10.1016/j.jnutbio.2024.109624] [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: 12/13/2023] [Revised: 02/24/2024] [Accepted: 03/15/2024] [Indexed: 03/24/2024]
Abstract
Brain plasticity and cognitive functions are tightly influenced by foods or nutrients, which determine a metabolic modulation having a long-term effect on health, involving also epigenetic mechanisms. Breast milk or formula based on cow milk is the first food for human beings, who, throughout their lives, are then exposed to different types of milk. We previously demonstrated that rats fed with milk derived from distinct species, with different compositions and nutritional properties, display selective modulation of systemic metabolic and inflammatory profiles through changes of mitochondrial functions and redox state in liver, skeletal and cardiac muscle. Here, in a rat model, we demonstrated that isoenergetic supplementation of milk from cow (CM), donkey (DM) or human (HM) impacts mitochondrial functions and redox state in the brain cortex and cortical synapses, affecting neuroinflammation and synaptic plasticity. Interestingly, we found that the administration of different milk modulates DNA methylation in rat brain cortex and consequently affects gene expression. Our results emphasize the importance of nutrition in brain and synapse physiology, and highlight the key role played in this context by mitochondria, nutrient-sensitive organelles able to orchestrate metabolic and inflammatory responses.
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Affiliation(s)
| | - Antonia Feola
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Gina Cavaliere
- Department of Pharmaceutical Sciences, University of Perugia, Perugia, Italy
| | - Fabiano Cimmino
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Angela Catapano
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Eduardo Penna
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Giovanni Scala
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Luigi Greco
- Department of Translational Medical Sciences, Section of Pediatrics, University of Naples Federico II, Naples, Italy
| | - Luca Bernardo
- Department of Childhood and Developmental Medicine, Fatebenefratelli Hospital, Milan, Italy
| | | | - Marianna Crispino
- Department of Biology, University of Naples Federico II, Naples, Italy.
| | - Antonio Pezone
- Department of Biology, University of Naples Federico II, Naples, Italy.
| | - Maria Pina Mollica
- Department of Biology, University of Naples Federico II, Naples, Italy; Task Force on Microbiome Studies, University of Naples Federico II, Naples, Italy
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34
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Jiang HH, Xu R, Nie X, Su Z, Xu X, Pang R, Zhou Y, Luo F. Neurexins control the strength and precise timing of glycinergic inhibition in the auditory brainstem. eLife 2024; 13:RP94315. [PMID: 38814174 PMCID: PMC11139475 DOI: 10.7554/elife.94315] [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: 05/31/2024] Open
Abstract
Neurexins play diverse functions as presynaptic organizers in various glutamatergic and GABAergic synapses. However, it remains unknown whether and how neurexins are involved in shaping functional properties of the glycinergic synapses, which mediate prominent inhibition in the brainstem and spinal cord. To address these issues, we examined the role of neurexins in a model glycinergic synapse between the principal neuron in the medial nucleus of the trapezoid body (MNTB) and the principal neuron in the lateral superior olive (LSO) in the auditory brainstem. Combining RNAscope with stereotactic injection of AAV-Cre in the MNTB of neurexin1/2/3 conditional triple knockout mice, we showed that MNTB neurons highly express all isoforms of neurexins although their expression levels vary remarkably. Selective ablation of all neurexins in MNTB neurons not only reduced the amplitude but also altered the kinetics of the glycinergic synaptic transmission at LSO neurons. The synaptic dysfunctions primarily resulted from an impaired Ca2+ sensitivity of release and a loosened coupling between voltage-gated Ca2+ channels and synaptic vesicles. Together, our current findings demonstrate that neurexins are essential in controlling the strength and temporal precision of the glycinergic synapse, which therefore corroborates the role of neurexins as key presynaptic organizers in all major types of fast chemical synapses.
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Affiliation(s)
- He-Hai Jiang
- Guangzhou National LaboratoryGuangzhouChina
- Bioland LaboratoryGuangzhouChina
- School of Basic Medical Sciences, Guangzhou Medical UniversityGuangzhouChina
| | - Ruoxuan Xu
- Guangzhou National LaboratoryGuangzhouChina
| | | | | | | | - Ruiqi Pang
- Department of Neurobiology, School of Basic Medicine, Army Medical UniversityChongqingChina
- Advanced Institute for Brain and Intelligence, School of Medicine, Guangxi UniversityNanningChina
| | - Yi Zhou
- Department of Neurobiology, School of Basic Medicine, Army Medical UniversityChongqingChina
| | - Fujun Luo
- Guangzhou National LaboratoryGuangzhouChina
- School of Basic Medical Sciences, Guangzhou Medical UniversityGuangzhouChina
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35
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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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36
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Saha Roy D, Gupta A, Vishvakarma V, Krupa P, Li MS, Maiti S. Serotonin Promotes Vesicular Association and Fusion by Modifying Lipid Bilayers. J Phys Chem B 2024; 128:4975-4985. [PMID: 38743687 DOI: 10.1021/acs.jpcb.4c00115] [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: 05/16/2024]
Abstract
The primary event in chemical neurotransmission involves the fusion of a membrane-limited vesicle at the plasma membrane and the subsequent release of its chemical neurotransmitter cargo. The cargo itself is not known to have any effect on the fusion event. However, amphiphilic monoamine neurotransmitters (e.g., serotonin and dopamine) are known to strongly interact with lipid bilayers and to affect their mechanical properties, which can in principle impact membrane-mediated processes. Here, we probe whether serotonin can enhance the association and fusion of artificial lipid vesicles in vitro. We employ fluorescence correlation spectroscopy and total internal reflection fluorescence microscopy to measure the attachment and fusion of vesicles whose lipid compositions mimic the major lipid components of synaptic vesicles. We find that the association between vesicles and supported lipid bilayers is strongly enhanced in a serotonin dose-dependent manner, and this drives an increase in the rate of spontaneous fusion. Molecular dynamics simulations and fluorescence spectroscopy data show that serotonin insertion increases the water content of the hydrophobic part of the bilayer. This suggests that the enhanced membrane association is likely driven by an energetically favorable drying transition. Other monoamines, such as dopamine and norepinephrine, but not other related species, such as tryptophan, show similar effects on membrane association. Our results reveal a lipid bilayer-mediated mechanism by which monoamines can themselves modulate vesicle fusion, potentially adding to the control toolbox for the tightly regulated process of neurotransmission in vivo.
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Affiliation(s)
- Debsankar Saha Roy
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005, India
| | - Ankur Gupta
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005, India
| | - Vicky Vishvakarma
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005, India
| | - Pawel Krupa
- Institute of Physics, Polish Academy of Sciences, Warsaw 02-668, Poland
| | - Mai Suan Li
- Institute of Physics, Polish Academy of Sciences, Warsaw 02-668, Poland
- Institute for Computational Science and Technology, Quang Trung Software City, Tan Chanh Hiep Ward, District 12, 729110 Ho Chi Minh City, Vietnam
| | - Sudipta Maiti
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005, India
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37
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Xia X, Li Y. A new GRAB sensor reveals differences in the dynamics and molecular regulation between neuropeptide and neurotransmitter release. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.22.595424. [PMID: 38826473 PMCID: PMC11142204 DOI: 10.1101/2024.05.22.595424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
The co-existence and co-transmission of neuropeptides and small molecule neurotransmitters in the same neuron is a fundamental aspect of almost all neurons across various species. However, the differences regarding their in vivo spatiotemporal dynamics and underlying molecular regulation remain poorly understood. Here, we developed a GPCR-activation-based (GRAB) sensor for detecting short neuropeptide F (sNPF) with high sensitivity and spatiotemporal resolution. Furthermore, we explore the differences of in vivo dynamics and molecular regulation between sNPF and acetylcholine (ACh) from the same neurons. Interestingly, the release of sNPF and ACh shows different spatiotemporal dynamics. Notably, we found that distinct synaptotagmins (Syt) are involved in these two processes, as Syt7 and Sytα for sNPF release, while Syt1 for ACh release. Thus, this new GRAB sensor provides a powerful tool for studying neuropeptide release and providing new insights into the distinct release dynamics and molecular regulation between neuropeptides and small molecule neurotransmitters.
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Affiliation(s)
- Xiju Xia
- State Key Laboratory of Membrane Biology, School of Life Sciences, Peking University, Beijing 100871, China
- PKU-IDG/McGovern Institute for Brain Research, Beijing 100871, China
- Academy for Advanced Interdisciplinary Studies (AAIS), and Peking University–Tsinghua University–National Institute of Biological Sciences Joint Graduate Program (PTN), Peking University, Beijing, 100871, China
| | - Yulong Li
- State Key Laboratory of Membrane Biology, School of Life Sciences, Peking University, Beijing 100871, China
- PKU-IDG/McGovern Institute for Brain Research, Beijing 100871, China
- Academy for Advanced Interdisciplinary Studies (AAIS), and Peking University–Tsinghua University–National Institute of Biological Sciences Joint Graduate Program (PTN), Peking University, Beijing, 100871, China
- Chinese Institute for Brain Research, Beijing 102206, China
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38
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Zhang FL, Yang XK, Qi YT, Tian SY, Huang WH. Nanoelectrochemistry reveals how presynaptic neurons regulate vesicle release to sustain synaptic plasticity under repetitive stimuli. Chem Sci 2024; 15:7651-7658. [PMID: 38784745 PMCID: PMC11110134 DOI: 10.1039/d4sc01664e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Accepted: 04/12/2024] [Indexed: 05/25/2024] Open
Abstract
Synaptic plasticity is the ability of synapses to modulate synaptic strength in response to dynamic changes within, as well as environmental changes. Although there is a considerable body of knowledge on protein expression and receptor migration in different categories of synaptic plasticity, the contribution and impact of presynaptic vesicle release and neurotransmitter levels towards plasticity remain largely unclear. Herein, nanoelectrochemistry using carbon fiber nanoelectrodes with excellent spatio-temporal resolution was applied for real-time monitoring of presynaptic vesicle release of dopamine inside single synapses of dopaminergic neurons, and exocytotic variations in quantity and kinetics under repetitive electrical stimuli. We found that the presynaptic terminal tends to maintain synaptic strength by rapidly recruiting vesicles, changing the dynamics of exocytosis, and maintaining sufficient neurotransmitter release in following stimuli. Except for small clear synaptic vesicles, dense core vesicles are involved in exocytosis to sustain the neurotransmitter level in later periods of repetitive stimuli. These data indicate that vesicles use a potential regulatory mechanism to establish short-term plasticity, and provide new directions for exploring the synaptic mechanisms in connection and plasticity.
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Affiliation(s)
- Fu-Li Zhang
- College of Chemistry and Molecular Sciences, Wuhan University Wuhan 430072 P. R. China
| | - Xiao-Ke Yang
- College of Chemistry and Molecular Sciences, Wuhan University Wuhan 430072 P. R. China
| | - Yu-Ting Qi
- College of Chemistry and Molecular Sciences, Wuhan University Wuhan 430072 P. R. China
| | - Si-Yu Tian
- College of Chemistry and Molecular Sciences, Wuhan University Wuhan 430072 P. R. China
| | - Wei-Hua Huang
- College of Chemistry and Molecular Sciences, Wuhan University Wuhan 430072 P. R. China
- Department of Hepatobiliary and Pancreatic Surgery, Zhongnan Hospital of Wuhan University Wuhan 430071 P. R. China
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39
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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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40
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Bhaskar BR, Yadav L, Sriram M, Sanghrajka K, Gupta M, V BK, Nellikka RK, Das D. Differential SNARE chaperoning by Munc13-1 and Munc18-1 dictates fusion pore fate at the release site. Nat Commun 2024; 15:4132. [PMID: 38755165 PMCID: PMC11099066 DOI: 10.1038/s41467-024-46965-7] [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: 04/21/2023] [Accepted: 03/14/2024] [Indexed: 05/18/2024] Open
Abstract
The regulated release of chemical messengers is crucial for cell-to-cell communication; abnormalities in which impact coordinated human body function. During vesicular secretion, multiple SNARE complexes assemble at the release site, leading to fusion pore opening. How membrane fusion regulators act on heterogeneous SNARE populations to assemble fusion pores in a timely and synchronized manner, is unknown. Here, we demonstrate the role of SNARE chaperones Munc13-1 and Munc18-1 in rescuing individual nascent fusion pores from their diacylglycerol lipid-mediated inhibitory states. At the onset of membrane fusion, Munc13-1 clusters multiple SNARE complexes at the release site and synchronizes release events, while Munc18-1 stoichiometrically interacts with trans-SNARE complexes to enhance N- to C-terminal zippering. When both Munc proteins are present simultaneously, they differentially access dynamic trans-SNARE complexes to regulate pore properties. Overall, Munc proteins' direct action on fusion pore assembly indicates their role in controlling quantal size during vesicular secretion.
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Affiliation(s)
- Bhavya R Bhaskar
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, 400005, India
| | - Laxmi Yadav
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, 400005, India
| | - Malavika Sriram
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, 400005, India
| | - Kinjal Sanghrajka
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, 400005, India
| | - Mayank Gupta
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, 400005, India
| | - Boby K V
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, 400005, India
| | - Rohith K Nellikka
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, 400005, India
| | - Debasis Das
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, 400005, India.
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41
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Hepburn I, Lallouette J, Chen W, Gallimore AR, Nagasawa-Soeda SY, De Schutter E. Vesicle and reaction-diffusion hybrid modeling with STEPS. Commun Biol 2024; 7:573. [PMID: 38750123 PMCID: PMC11096338 DOI: 10.1038/s42003-024-06276-5] [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: 09/11/2023] [Accepted: 05/01/2024] [Indexed: 05/18/2024] Open
Abstract
Vesicles carry out many essential functions within cells through the processes of endocytosis, exocytosis, and passive and active transport. This includes transporting and delivering molecules between different parts of the cell, and storing and releasing neurotransmitters in neurons. To date, computational simulation of these key biological players has been rather limited and has not advanced at the same pace as other aspects of cell modeling, restricting the realism of computational models. We describe a general vesicle modeling tool that has been designed for wide application to a variety of cell models, implemented within our software STochastic Engine for Pathway Simulation (STEPS), a stochastic reaction-diffusion simulator that supports realistic reconstructions of cell tissue in tetrahedral meshes. The implementation is validated in an extensive test suite, parallel performance is demonstrated in a realistic synaptic bouton model, and example models are visualized in a Blender extension module.
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Affiliation(s)
- Iain Hepburn
- Computational Neuroscience Unit, Okinawa Institute of Science and Technology, 1919-1 Tancha, Onna-son, Okinawa, Japan
| | - Jules Lallouette
- Computational Neuroscience Unit, Okinawa Institute of Science and Technology, 1919-1 Tancha, Onna-son, Okinawa, Japan
| | - Weiliang Chen
- Computational Neuroscience Unit, Okinawa Institute of Science and Technology, 1919-1 Tancha, Onna-son, Okinawa, Japan
| | - Andrew R Gallimore
- Computational Neuroscience Unit, Okinawa Institute of Science and Technology, 1919-1 Tancha, Onna-son, Okinawa, Japan
| | - Sarah Y Nagasawa-Soeda
- Computational Neuroscience Unit, Okinawa Institute of Science and Technology, 1919-1 Tancha, Onna-son, Okinawa, Japan
| | - Erik De Schutter
- Computational Neuroscience Unit, Okinawa Institute of Science and Technology, 1919-1 Tancha, Onna-son, Okinawa, Japan.
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42
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Bykhovskaia M. Dynamic Formation of the Protein-Lipid Pre-fusion Complex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.17.589983. [PMID: 38659925 PMCID: PMC11042276 DOI: 10.1101/2024.04.17.589983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Synaptic vesicles (SVs) fuse with the presynaptic membrane (PM) to release neuronal transmitters. The SV protein Synaptotagmin 1 (Syt1) serves as a Ca2+ sensor for evoked fusion. Syt1 is thought to trigger fusion by penetrating into PM upon Ca2+ binding, however the mechanistic detail of this process is still debated. Syt1 interacts with the SNARE complex, a coiled-coil four-helical bundle that enables the SV-PM attachment. The SNARE-associated protein Complexin (Cpx) promotes the Ca2+-dependent fusion, possibly interacting with Syt1. We employed all-atom molecular dynamics (MD) to investigate the formation of the Syt1-SNARE-Cpx complex interacting with the lipid bilayers of PM and SV. Our simulations demonstrated that the PM-Syt1-SNARE-Cpx complex can transition to a "dead-end" state, wherein Syt1 attaches tightly to PM but does not immerse into it, as opposed to a pre-fusion state, which has the tips of the Ca2+-bound C2 domains of Syt1 inserted into PM. Our simulations unraveled the sequence of Syt1 conformational transitions, including the simultaneous Syt1 docking to the SNARE-Cpx bundle and PM, followed by the Ca2+ chelation and the penetration of the tips of Syt1 domains into PM, leading to the pre-fusion state of the protein-lipid complex. Importantly, we found that the direct Syt1-Cpx interactions are required to promote these transitions. Thus, we developed the all-atom dynamic model of the conformational transitions that lead to the formation of the pre-fusion PM-Syt1-SNARE-Cpx complex. Our simulations also revealed an alternative "dead-end" state of the protein-lipid complex that can be formed if this pathway is disrupted.
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43
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Vaknin A, Grossman A, Durham ND, Lupovitz I, Goren S, Golani G, Roichman Y, Munro JB, Sorkin R. Ebola Virus Glycoprotein Strongly Binds to Membranes in the Absence of Receptor Engagement. ACS Infect Dis 2024; 10:1590-1601. [PMID: 38684073 PMCID: PMC11091876 DOI: 10.1021/acsinfecdis.3c00622] [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: 11/15/2023] [Revised: 04/07/2024] [Accepted: 04/09/2024] [Indexed: 05/02/2024]
Abstract
Ebola virus (EBOV) is an enveloped virus that must fuse with the host cell membrane in order to release its genome and initiate infection. This process requires the action of the EBOV envelope glycoprotein (GP), encoded by the virus, which resides in the viral envelope and consists of a receptor binding subunit, GP1, and a membrane fusion subunit, GP2. Despite extensive research, a mechanistic understanding of the viral fusion process is incomplete. To investigate GP-membrane association, a key step in the fusion process, we used two approaches: high-throughput measurements of single-particle diffusion and single-molecule measurements with optical tweezers. Using these methods, we show that the presence of the endosomal Niemann-Pick C1 (NPC1) receptor is not required for primed GP-membrane binding. In addition, we demonstrate this binding is very strong, likely attributed to the interaction between the GP fusion loop and the membrane's hydrophobic core. Our results also align with previously reported findings, emphasizing the significance of acidic pH in the protein-membrane interaction. Beyond Ebola virus research, our approach provides a powerful toolkit for studying other protein-membrane interactions, opening new avenues for a better understanding of protein-mediated membrane fusion events.
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Affiliation(s)
- Alisa Vaknin
- School
of Chemistry, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
- Center
for Physics and Chemistry of Living Systems, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Alon Grossman
- School
of Chemistry, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
- Center
for Physics and Chemistry of Living Systems, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Natasha D. Durham
- Department
of Microbiology and Physiological Systems, University of Massachusetts Chan Medical School, Worcester, Massachusetts 01605, United States
| | - Inbal Lupovitz
- School
of Chemistry, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
- Center
for Physics and Chemistry of Living Systems, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Shahar Goren
- School
of Chemistry, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
- Center
for Physics and Chemistry of Living Systems, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Gonen Golani
- Department
of Physics and Haifa Research Center for Theoretical Physics and Astrophysics, University of Haifa, Haifa 3498838, Israel
| | - Yael Roichman
- School
of Chemistry, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
- Center
for Physics and Chemistry of Living Systems, Tel Aviv University, Tel Aviv 6997801, Israel
- Raymond
and Beverly Sackler School of Physics & Astronomy, Tel Aviv University, Tel Aviv 6997801, Israel
| | - James B. Munro
- Department
of Microbiology and Physiological Systems, University of Massachusetts Chan Medical School, Worcester, Massachusetts 01605, United States
- Department
of Biochemistry and Molecular Biotechnology, University of Massachusetts Chan Medical School, Worcester, Massachusetts 01605, United States
| | - Raya Sorkin
- School
of Chemistry, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
- Center
for Physics and Chemistry of Living Systems, Tel Aviv University, Tel Aviv 6997801, Israel
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44
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Tebbe L, Kakakhel M, Al-Ubaidi MR, Naash MI. The role of syntaxins in retinal function and health. Front Cell Neurosci 2024; 18:1380064. [PMID: 38799985 PMCID: PMC11119284 DOI: 10.3389/fncel.2024.1380064] [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: 01/31/2024] [Accepted: 04/16/2024] [Indexed: 05/29/2024] Open
Abstract
The soluble N-ethylmaleimide-sensitive factor (NSF) attachment protein (SNAP) receptor (SNARE) superfamily plays a pivotal role in cellular trafficking by facilitating membrane fusion events. These SNARE proteins, including syntaxins, assemble into complexes that actively facilitate specific membrane fusion events. Syntaxins, as integral components of the SNARE complex, play a crucial role in initiating and regulating these fusion activities. While specific syntaxins have been extensively studied in various cellular processes, including neurotransmitter release, autophagy and endoplasmic reticulum (ER)-to-Golgi protein transport, their roles in the retina remain less explored. This review aims to enhance our understanding of syntaxins' functions in the retina by shedding light on how syntaxins mediate membrane fusion events unique to the retina. Additionally, we seek to establish a connection between syntaxin mutations and retinal diseases. By exploring the intricate interplay of syntaxins in retinal function and health, we aim to contribute to the broader comprehension of cellular trafficking in the context of retinal physiology and pathology.
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Affiliation(s)
| | | | | | - Muna I. Naash
- *Correspondence: Muna I. Naash, ; Muayyad R. Al-Ubaidi,
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45
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Jia J, Chen T, Chen C, Si T, Gao C, Fang Y, Sun J, Wang J, Zhang Z. Astrocytes in preoptic area regulate acute nociception-induced hypothermia through adenosine receptors. CNS Neurosci Ther 2024; 30:e14726. [PMID: 38715251 PMCID: PMC11076694 DOI: 10.1111/cns.14726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 02/27/2024] [Accepted: 04/01/2024] [Indexed: 05/12/2024] Open
Abstract
AIMS The preoptic area (POA) of the hypothalamus, crucial in thermoregulation, has long been implicated in the pain process. However, whether nociceptive stimulation affects body temperature and its mechanism remains poorly studied. METHODS We used capsaicin, formalin, and surgery to induce acute nociceptive stimulation and monitored rectal temperature. Optical fiber recording, chemical genetics, confocal imaging, and pharmacology assays were employed to confirm the role and interaction of POA astrocytes and extracellular adenosine. Immunofluorescence was utilized for further validation. RESULTS Acute nociception could activate POA astrocytes and induce a decrease in body temperature. Manipulation of astrocytes allowed bidirectional control of body temperature. Furthermore, acute nociception and astrocyte activation led to increased extracellular adenosine concentration within the POA. Activation of adenosine A1 or A2A receptors contributed to decreased body temperature, while inhibition of these receptors mitigated the thermo-lowering effect of astrocytes. CONCLUSION Our results elucidate the interplay between acute nociception and thermoregulation, specifically highlighting POA astrocyte activation. This enriches our understanding of physiological responses to painful stimuli and contributes to the analysis of the anatomical basis involved in the process.
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Affiliation(s)
- Junke Jia
- Department of Anesthesiology, Zhongnan HospitalWuhan UniversityWuhanChina
| | - Ting Chen
- Department of Anesthesiology, Zhongnan HospitalWuhan UniversityWuhanChina
| | - Chang Chen
- Department of Anesthesiology, Zhongnan HospitalWuhan UniversityWuhanChina
| | - Tengxiao Si
- Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and TechnologyChinese Academy of SciencesWuhanChina
| | - Chenyi Gao
- Department of Anesthesiology, Zhongnan HospitalWuhan UniversityWuhanChina
| | - Yuanyuan Fang
- Department of Anesthesiology, Zhongnan HospitalWuhan UniversityWuhanChina
| | - Jiahui Sun
- Department of Anesthesiology, Zhongnan HospitalWuhan UniversityWuhanChina
| | - Jie Wang
- Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and TechnologyChinese Academy of SciencesWuhanChina
- Institute of Neuroscience and Brain Diseases, Xiangyang Central HospitalAffiliated Hospital of Hubei University of Arts and ScienceXiangyangChina
- Shanghai Key Laboratory of Emotions and Affective Disorders, Shanghai Jiao Tong University School of MedicineSongjiang Hospital and Songjiang Research InstituteShanghaiChina
| | - Zongze Zhang
- Department of Anesthesiology, Zhongnan HospitalWuhan UniversityWuhanChina
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46
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Ralowicz AJ, Hokeness S, Hoppa MB. Frequency of Spontaneous Neurotransmission at Individual Boutons Corresponds to the Size of the Readily Releasable Pool of Vesicles. J Neurosci 2024; 44:e1253232024. [PMID: 38383495 PMCID: PMC11063817 DOI: 10.1523/jneurosci.1253-23.2024] [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: 07/06/2023] [Revised: 02/09/2024] [Accepted: 02/13/2024] [Indexed: 02/23/2024] Open
Abstract
Synapses maintain two forms of neurotransmitter release to support communication in the brain. First, evoked neurotransmitter release is triggered by the invasion of an action potential (AP) across en passant boutons that form along axons. The probability of evoked release (Pr) varies substantially across boutons, even within a single axon. Such heterogeneity is the result of differences in the probability of a single synaptic vesicle (SV) fusing (Pv) and in the number of vesicles available for immediate release, known as the readily releasable pool (RRP). Spontaneous release (also known as a mini) is an important form of neurotransmission that occurs in the absence of APs. Because it cannot be triggered with electrical stimulation, much less is known about potential heterogeneity in the frequency of spontaneous release between boutons. We utilized a photostable and bright fluorescent indicator of glutamate release (iGluSnFR3) to quantify both spontaneous and evoked release at individual glutamatergic boutons. We found that the rate of spontaneous release is quite heterogenous at the level of individual boutons. Interestingly, when measuring both evoked and spontaneous release at single synapses, we found that boutons with the highest rates of spontaneous release also displayed the largest evoked responses. Using a new optical method to measure RRP at individual boutons, we found that this heterogeneity in spontaneous release was strongly correlated with the size of the RRP, but not related to Pv. We conclude that the RRP is a critical and dynamic aspect of synaptic strength that contributes to both evoked and spontaneous vesicle release.
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Affiliation(s)
- Amelia J Ralowicz
- Department of Biology, Dartmouth College, Hanover, New Hampshire 03755
| | - Sasipha Hokeness
- Department of Biology, Dartmouth College, Hanover, New Hampshire 03755
| | - Michael B Hoppa
- Department of Biology, Dartmouth College, Hanover, New Hampshire 03755
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47
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Wang CS, McCarthy CI, Guzikowski NJ, Kavalali ET, Monteggia LM. Brain-derived neurotrophic factor scales presynaptic calcium transients to modulate excitatory neurotransmission. Proc Natl Acad Sci U S A 2024; 121:e2303664121. [PMID: 38621124 PMCID: PMC11047077 DOI: 10.1073/pnas.2303664121] [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: 03/06/2023] [Accepted: 02/28/2024] [Indexed: 04/17/2024] Open
Abstract
Brain-derived neurotrophic factor (BDNF) plays a critical role in synaptic physiology, as well as mechanisms underlying various neuropsychiatric diseases and their treatment. Despite its clear physiological role and disease relevance, BDNF's function at the presynaptic terminal, a fundamental unit of neurotransmission, remains poorly understood. In this study, we evaluated single synapse dynamics using optical imaging techniques in hippocampal cell cultures. We find that exogenous BDNF selectively increases evoked excitatory neurotransmission without affecting spontaneous neurotransmission. However, acutely blocking endogenous BDNF has no effect on evoked or spontaneous release, demonstrating that different approaches to studying BDNF may yield different results. When we suppressed BDNF-Tropomyosin receptor kinase B (TrkB) activity chronically over a period of days to weeks using a mouse line enabling conditional knockout of TrkB, we found that evoked glutamate release was significantly decreased while spontaneous release remained unchanged. Moreover, chronic blockade of BDNF-TrkB activity selectively downscales evoked calcium transients without affecting spontaneous calcium events. Via pharmacological blockade by voltage-gated calcium channel (VGCC) selective blockers, we found that the changes in evoked calcium transients are mediated by the P/Q subtype of VGCCs. These results suggest that BDNF-TrkB activity increases presynaptic VGCC activity to selectively increase evoked glutamate release.
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Affiliation(s)
- Camille S. Wang
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN3729-7933
- Department of Pharmacology, Vanderbilt University, Nashville, TN37240-7933
| | - Clara I. McCarthy
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN3729-7933
- Department of Pharmacology, Vanderbilt University, Nashville, TN37240-7933
| | - Natalie J. Guzikowski
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN3729-7933
- Department of Pharmacology, Vanderbilt University, Nashville, TN37240-7933
| | - Ege T. Kavalali
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN3729-7933
- Department of Pharmacology, Vanderbilt University, Nashville, TN37240-7933
| | - Lisa M. Monteggia
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN3729-7933
- Department of Pharmacology, Vanderbilt University, Nashville, TN37240-7933
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48
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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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49
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Bose D, Bera M, Norman CA, Timofeeva Y, Volynski KE, Krishnakumar SS. A minimal presynaptic protein machinery mediating synchronous and asynchronous exocytosis and short-term plasticity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.15.589559. [PMID: 38659918 PMCID: PMC11042279 DOI: 10.1101/2024.04.15.589559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Neurotransmitters are released from synaptic vesicles with remarkable precision in response to presynaptic Ca2+ influx but exhibit significant heterogeneity in exocytosis timing and efficacy based on the recent history of activity. This heterogeneity is critical for information transfer in the brain, yet its molecular basis remains poorly understood. Here, we employ a biochemically-defined fusion assay under physiologically-relevant conditions to delineate the minimal protein machinery sufficient to account for different modes of Ca2+-triggered vesicle fusion and short-term facilitation. We find that Synaptotagmin-1, Synaptotagmin-7, and Complexin, synergistically restrain SNARE complex assembly, thus preserving vesicles in a stably docked state at rest. Upon Ca2+ activation, Synaptotagmin-1 induces rapid vesicle fusion, while Synaptotagmin-7 mediates delayed fusion. Competitive binding of Synaptotagmin-1 and Synaptotagmin-7 to the same SNAREs, coupled with differential rates of Ca2+-triggered fusion clamp reversal, govern the kinetics of vesicular fusion. Under conditions mimicking sustained neuronal activity, the Synaptotagmin-7 fusion clamp is destabilized by the elevated basal Ca2+ concentration, thereby enhancing the synchronous component of fusion. These findings provide a direct demonstration that a small set of proteins is sufficient to account for how nerve terminals adapt and regulate the Ca2+-evoked neurotransmitter exocytosis process to support their specialized functions in the nervous system.
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Affiliation(s)
- Dipayan Bose
- Yale Nanobiology Institute, Yale University School of Medicine, New Haven, USA
- Department of Neurology, Yale University School of Medicine, New Haven, USA
| | - Manindra Bera
- Yale Nanobiology Institute, Yale University School of Medicine, New Haven, USA
- Cell Biology, Yale University School of Medicine, New Haven, USA
| | - Chris A Norman
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, University College London, UK
- Department of Computer Science, University of Warwick, Coventry, UK
| | - Yulia Timofeeva
- Department of Computer Science, University of Warwick, Coventry, UK
| | - Kirill E Volynski
- Cell Biology, Yale University School of Medicine, New Haven, USA
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, University College London, UK
| | - Shyam S Krishnakumar
- Yale Nanobiology Institute, Yale University School of Medicine, New Haven, USA
- Department of Neurology, Yale University School of Medicine, New Haven, USA
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, University College London, UK
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50
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Rizo J, Sari L, Jaczynska K, Rosenmund C, Lin MM. Molecular mechanism underlying SNARE-mediated membrane fusion enlightened by all-atom molecular dynamics simulations. Proc Natl Acad Sci U S A 2024; 121:e2321447121. [PMID: 38593076 PMCID: PMC11032479 DOI: 10.1073/pnas.2321447121] [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: 12/05/2023] [Accepted: 03/18/2024] [Indexed: 04/11/2024] Open
Abstract
The SNAP receptor (SNARE) proteins syntaxin-1, SNAP-25, and synaptobrevin mediate neurotransmitter release by forming tight SNARE complexes that fuse synaptic vesicles with the plasma membranes in microseconds. Membrane fusion is generally explained by the action of proteins on macroscopic membrane properties such as curvature, elastic modulus, and tension, and a widespread model envisions that the SNARE motifs, juxtamembrane linkers, and C-terminal transmembrane regions of synaptobrevin and syntaxin-1 form continuous helices that act mechanically as semirigid rods, squeezing the membranes together as they assemble ("zipper") from the N to the C termini. However, the mechanism underlying fast SNARE-induced membrane fusion remains unknown. We have used all-atom molecular dynamics simulations to investigate this mechanism. Our results need to be interpreted with caution because of the limited number and length of the simulations, but they suggest a model of membrane fusion that has a natural physicochemical basis, emphasizes local molecular events over general membrane properties, and explains extensive experimental data. In this model, the central event that initiates fast (microsecond scale) membrane fusion occurs when the SNARE helices zipper into the juxtamembrane linkers which, together with the adjacent transmembrane regions, promote encounters of acyl chains from both bilayers at the polar interface. The resulting hydrophobic nucleus rapidly expands into stalk-like structures that gradually progress to form a fusion pore, aided by the SNARE transmembrane regions and without clearly discernible intermediates. The propensity of polyunsaturated lipids to participate in encounters that initiate fusion suggests that these lipids may be important for the high speed of neurotransmitter release.
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Affiliation(s)
- Josep Rizo
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX75390
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX75390
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX75390
| | - Levent Sari
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX75390
- Green Center for Systems Biology, University of Texas Southwestern Medical Center, Dallas, TX75390
| | - Klaudia Jaczynska
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX75390
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX75390
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX75390
| | - Christian Rosenmund
- Institute of Neurophysiology, Charité—Universitätsmedizin Berlin, Berlin10117, Germany
- NeuroCure Cluster of Excellence, Berlin10117, Germany
| | - Milo M. Lin
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX75390
- Green Center for Systems Biology, University of Texas Southwestern Medical Center, Dallas, TX75390
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