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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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2
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Lizama BN, North HA, Pandey K, Williams C, Duong D, Cho E, Di Caro V, Ping L, Blennow K, Zetterberg H, Lah J, Levey AI, Grundman M, Caggiano AO, Seyfried NT, Hamby ME. An interim exploratory proteomics biomarker analysis of a phase 2 clinical trial to assess the impact of CT1812 in Alzheimer's disease. Neurobiol Dis 2024; 199:106575. [PMID: 38914170 DOI: 10.1016/j.nbd.2024.106575] [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: 02/01/2024] [Revised: 05/01/2024] [Accepted: 06/21/2024] [Indexed: 06/26/2024] Open
Abstract
CT1812 is a novel, brain penetrant small molecule modulator of the sigma-2 receptor (S2R) that is currently in clinical development for the treatment of Alzheimer's disease (AD). Preclinical and early clinical data show that, through S2R, CT1812 selectively prevents and displaces binding of amyloid beta (Aβ) oligomers from neuronal synapses and improves cognitive function in animal models of AD. SHINE is an ongoing phase 2 randomized, double-blind, placebo-controlled clinical trial (COG0201) in participants with mild to moderate AD, designed to assess the safety and efficacy of 6 months of CT1812 treatment. To elucidate the mechanism of action in AD patients and pharmacodynamic biomarkers of CT1812, the present study reports exploratory cerebrospinal fluid (CSF) biomarker data from 18 participants in an interim analysis of the first set of patients in SHINE (part A). Untargeted mass spectrometry-based discovery proteomics detects >2000 proteins in patient CSF and has documented utility in accelerating the identification of novel AD biomarkers reflective of diverse pathophysiologies beyond amyloid and tau, and enabling identification of pharmacodynamic biomarkers in longitudinal interventional trials. We leveraged this technique to analyze CSF samples taken at baseline and after 6 months of CT1812 treatment. Proteome-wide protein levels were detected using tandem mass tag-mass spectrometry (TMT-MS), change from baseline was calculated for each participant, and differential abundance analysis by treatment group was performed. This analysis revealed a set of proteins significantly impacted by CT1812, including pathway engagement biomarkers (i.e., biomarkers tied to S2R biology) and disease modification biomarkers (i.e., biomarkers with altered levels in AD vs. healthy control CSF but normalized by CT1812, and biomarkers correlated with favorable trends in ADAS-Cog11 scores). Brain network mapping, Gene Ontology, and pathway analyses revealed an impact of CT1812 on synapses, lipoprotein and amyloid beta biology, and neuroinflammation. Collectively, the findings highlight the utility of this method in pharmacodynamic biomarker identification and providing mechanistic insights for CT1812, which may facilitate the clinical development of CT1812 and enable appropriate pre-specification of biomarkers in upcoming clinical trials of CT1812.
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Affiliation(s)
- B N Lizama
- Cognition Therapeutics, Pittsburgh, PA, USA
| | - H A North
- Cognition Therapeutics, Pittsburgh, PA, USA
| | - K Pandey
- Emtherapro Inc, Systems Biology, Atlanta, GA, USA
| | - C Williams
- Cognition Therapeutics, Pittsburgh, PA, USA
| | - D Duong
- Emory University School of Medicine, Biochemistry, Atlanta, GA, USA
| | - E Cho
- Cognition Therapeutics, Pittsburgh, PA, USA
| | - V Di Caro
- Cognition Therapeutics, Pittsburgh, PA, USA
| | - L Ping
- Emory University School of Medicine, Neurology, Atlanta, GA, USA
| | - K Blennow
- Paris Brain Institute, ICM, Pitié-Salpêtrière Hospital, Sorbonne University, Paris, France; Neurodegenerative Disorder Research Center, Division of Life Sciences and Medicine, and Department of Neurology, Institute on Aging and Brain Disorders, University of Science and Technology of China and First Affiliated Hospital of USTC, Hefei, PR China; Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, the Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden; Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
| | - H Zetterberg
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, the Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden; Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden; Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London, UK; UK Dementia Research Institute at UCL, London, UK; Hong Kong Center for Neurodegenerative Diseases, Clear Water Bay, Hong Kong, China; Wisconsin Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA
| | - J Lah
- Emory University School of Medicine, Neurology, Atlanta, GA, USA
| | - A I Levey
- Emory University School of Medicine, Neurology, Atlanta, GA, USA
| | - M Grundman
- Global R&D Partners, LLC, San Diego, California, USA; Dept. of Neurosciences, University of California, San Diego, USA
| | | | - N T Seyfried
- Emory University School of Medicine, Biochemistry, Atlanta, GA, USA
| | - M E Hamby
- Cognition Therapeutics, Pittsburgh, PA, USA.
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3
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Ali Moussa HY, Shin KC, Ponraj J, Park SH, Lee OS, Mansour S, Park Y. PIP 2 Is An Electrostatic Catalyst for Vesicle Fusion by Lowering the Hydration Energy: Arresting Vesicle Fusion by Masking PIP 2. ACS NANO 2024; 18:12737-12748. [PMID: 38717305 DOI: 10.1021/acsnano.3c09614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Lipids are key factors in regulating membrane fusion. Lipids are not only structural components to form membranes but also active catalysts for vesicle fusion and neurotransmitter release, which are driven by soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins. SNARE proteins seem to be partially assembled before fusion, but the mechanisms that arrest vesicle fusion before Ca2+ influx are still not clear. Here, we show that phosphatidylinositol 4,5-bisphosphate (PIP2) electrostatically triggers vesicle fusion as an electrostatic catalyst by lowering the hydration energy and that a myristoylated alanine-rich C-kinase substrate (MARCKS), a PIP2-binding protein, arrests vesicle fusion in a vesicle docking state where the SNARE complex is partially assembled. Vesicle-mimicking liposomes fail to reproduce vesicle fusion arrest by masking PIP2, indicating that native vesicles are essential for the reconstitution of physiological vesicle fusion. PIP2 attracts cations to repel water molecules from membranes, thus lowering the hydration energy barrier.
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Affiliation(s)
- Houda Yasmine Ali Moussa
- Neurological Disorders Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation, Doha, Qatar
| | - Kyung Chul Shin
- Neurological Disorders Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation, Doha, Qatar
| | - Janarthanan Ponraj
- HBKU Core Laboratories, Hamad Bin Khalifa University (HBKU), Doha, Qatar
| | | | - One-Sun Lee
- Center for Interdisciplinary Biosciences, Technology and Innovation Park, P. J. Šafárik University, Košice SK-04001, Slovakia
| | - Said Mansour
- HBKU Core Laboratories, Hamad Bin Khalifa University (HBKU), Doha, Qatar
| | - Yongsoo Park
- Neurological Disorders Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation, Doha, Qatar
- College of Health & Life Sciences (CHLS), Hamad Bin Khalifa University (HBKU), Qatar Foundation, Doha, Qatar
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4
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Gobom J, Brinkmalm A, Brinkmalm G, Blennow K, Zetterberg H. Alzheimer's Disease Biomarker Analysis Using Targeted Mass Spectrometry. Mol Cell Proteomics 2024; 23:100721. [PMID: 38246483 PMCID: PMC10926085 DOI: 10.1016/j.mcpro.2024.100721] [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: 11/14/2023] [Revised: 12/30/2023] [Accepted: 01/04/2024] [Indexed: 01/23/2024] Open
Abstract
Alzheimer's disease (AD) is characterized by several neuropathological changes, mainly extracellular amyloid aggregates (plaques), intraneuronal inclusions of phosphorylated tau (tangles), as well as neuronal and synaptic degeneration, accompanied by tissue reactions to these processes (astrocytosis and microglial activation) that precede neuronal network disturbances in the symptomatic phase of the disease. A number of biomarkers for these brain tissue changes have been developed, mainly using immunoassays. In this review, we discuss how targeted mass spectrometry (TMS) can be used to validate and further characterize classes of biomarkers reflecting different AD pathologies, such as tau- and amyloid-beta pathologies, synaptic dysfunction, lysosomal dysregulation, and axonal damage, and the prospect of using TMS to measure these proteins in clinical research and diagnosis. TMS advantages and disadvantages in relation to immunoassays are discussed, and complementary aspects of the technologies are discussed.
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Affiliation(s)
- Johan Gobom
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden; Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden.
| | - Ann Brinkmalm
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden; Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
| | - Gunnar Brinkmalm
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden
| | - Kaj Blennow
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden; Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
| | - Henrik Zetterberg
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden; Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden; Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK; UK Dementia Research Institute at UCL, London, UK; Hong Kong Center for Neurodegenerative Diseases, Clear Water Bay, Hong Kong, China; Wisconsin Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA.
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5
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Jahn R, Cafiso DC, Tamm LK. Mechanisms of SNARE proteins in membrane fusion. Nat Rev Mol Cell Biol 2024; 25:101-118. [PMID: 37848589 DOI: 10.1038/s41580-023-00668-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/06/2023] [Indexed: 10/19/2023]
Abstract
Soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) are a family of small conserved eukaryotic proteins that mediate membrane fusion between organelles and with the plasma membrane. SNAREs are directly or indirectly anchored to membranes. Prior to fusion, complementary SNAREs assemble between membranes with the aid of accessory proteins that provide a scaffold to initiate SNARE zippering, pulling the membranes together and mediating fusion. Recent advances have enabled the construction of detailed models describing bilayer transitions and energy barriers along the fusion pathway and have elucidated the structures of SNAREs complexed in various states with regulatory proteins. In this Review, we discuss how these advances are yielding an increasingly detailed picture of the SNARE-mediated fusion pathway, leading from first contact between the membranes via metastable non-bilayer intermediates towards the opening and expansion of a fusion pore. We describe how SNARE proteins assemble into complexes, how this assembly is regulated by accessory proteins and how SNARE complexes overcome the free energy barriers that prevent spontaneous membrane fusion.
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Affiliation(s)
- Reinhard Jahn
- Laboratory of Neurobiology, Max-Planck Institute for Multidisciplinary Sciences, Göttingen, Germany.
| | - David C Cafiso
- Department of Chemistry, University of Virginia, Charlottesville, VA, USA
| | - Lukas K Tamm
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA, USA
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6
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Song B, Zhang Y, Xiong G, Luo H, Zhang B, Li Y, Wang Z, Zhou Z, Chang X. Single-cell transcriptomic analysis reveals the adverse effects of cadmium on the trajectory of neuronal maturation. Cell Biol Toxicol 2023; 39:1697-1713. [PMID: 36114956 DOI: 10.1007/s10565-022-09775-5] [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: 06/27/2022] [Accepted: 09/07/2022] [Indexed: 11/28/2022]
Abstract
Cadmium (Cd) is an extensively existing environmental pollutant that has neurotoxic effects. However, the molecular mechanism of Cd on neuronal maturation is unveiled. Single-cell RNA sequencing (scRNA-seq) has been widely used to uncover cellular heterogeneity and is a powerful tool to reconstruct the developmental trajectory of neurons. In this study, neural stem cells (NSCs) from subventricular zone (SVZ) of newborn mice were treated with CdCl2 for 24 h and differentiated for 7 days to obtain neuronal lineage cells. Then scRNA-seq analysis identified five cell stages with different maturity in neuronal lineage cells. Our findings revealed that Cd altered the trajectory of maturation of neuronal lineage cells by decreasing the number of cells in different stages and hindering their maturation. Cd induced differential transcriptome expression in different cell subpopulations in a stage-specific manner. Specifically, Cd induced oxidative damage and changed the proportion of cell cycle phases in the early stage of neuronal development. Furthermore, the autocrine and paracrine signals of Wnt5a were downregulated in the low mature neurons in response to Cd. Importantly, activation of Wnt5a effectively rescued the number of neurons and promoted their maturation. Taken together, the findings of this study provide new and comprehensive insights into the adverse effect of Cd on neuronal maturation.
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Affiliation(s)
- Bo Song
- School of Public Health and Key Laboratory of Public Health Safety of the Ministry of Education, Fudan University, Shanghai, 200032, China
| | - Yuwei Zhang
- School of Public Health and Key Laboratory of Public Health Safety of the Ministry of Education, Fudan University, Shanghai, 200032, China
| | - Guiya Xiong
- School of Public Health and Key Laboratory of Public Health Safety of the Ministry of Education, Fudan University, Shanghai, 200032, China
| | - Huan Luo
- School of Public Health and Key Laboratory of Public Health Safety of the Ministry of Education, Fudan University, Shanghai, 200032, China
| | - Bing Zhang
- School of Public Health and Key Laboratory of Public Health Safety of the Ministry of Education, Fudan University, Shanghai, 200032, China
| | - Yixi Li
- School of Public Health and Key Laboratory of Public Health Safety of the Ministry of Education, Fudan University, Shanghai, 200032, China
| | - Zhibin Wang
- Faculty of Pharmaceutical Sciences, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, 518055, China
| | - Zhijun Zhou
- School of Public Health and Key Laboratory of Public Health Safety of the Ministry of Education, Fudan University, Shanghai, 200032, China
| | - Xiuli Chang
- School of Public Health and Key Laboratory of Public Health Safety of the Ministry of Education, Fudan University, Shanghai, 200032, China.
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7
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Zhang L, Li D, Yin L, Zhang C, Qu H, Xu J. Neuroglobin protects against cerebral ischemia/reperfusion injury in rats by suppressing mitochondrial dysfunction and endoplasmic reticulum stress-mediated neuronal apoptosis through synaptotagmin-1. ENVIRONMENTAL TOXICOLOGY 2023. [PMID: 37195900 DOI: 10.1002/tox.23815] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Revised: 03/22/2023] [Accepted: 04/16/2023] [Indexed: 05/19/2023]
Abstract
Cerebral ischemia/reperfusion (I/R) injury remains a grievous health threat, and herein effective therapy is urgently needed. This study explored the protection of neuroglobin (Ngb) in rats with cerebral I/R injury. The focal cerebral I/R rat models were established by middle cerebral artery occlusion (MCAO) and neuronal injury models were established by oxygen-glucose deprivation/reoxygenation (OGD/R) treatment. The brain injury of rats was assessed. Levels of Ngb, Bcl-2, Bax, endoplasmic reticulum stress (ERS)-related markers, and Syt1 were measured by immunofluorescence staining and Western blotting. The cytotoxicity in neurons was assessed by lactate dehydrogenase (LDH) release assay. Levels of intracellular Ca2+ and mitochondrial function-related indicators were determined. The binding between Ngb and Syt1 was detected by co-immunoprecipitation. Ngb was upregulated in cerebral I/R rats and its overexpression alleviated brain injury. In OGD/R-induced neurons, Ngb overexpression decreased LDH level and neuronal apoptosis, decreased Ca2+ content, and mitigated mitochondrial dysfunction and ERS-related apoptosis. However, Ngb silencing imposed the opposite effects. Importantly, Ngb could bind to Syt1. Syt1 knockdown partially counteracted the alleviation of Ngb on OGD/R-induced injury in neurons and cerebral I/R injury in rats. Briefly, Ngb extenuated cerebral I/R injury by repressing mitochondrial dysfunction and endoplasmic reticulum stress-mediated neuronal apoptosis through Syt1.
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Affiliation(s)
- Lihong Zhang
- Department of Neurointervention and Neurocritical Care, Dalian Central Hospital Affiliated to Dalian University of Technology, Dalian, China
| | - Di Li
- Department of Neurointervention and Neurocritical Care, Dalian Central Hospital Affiliated to Dalian University of Technology, Dalian, China
| | - Lin Yin
- Department of Neurology, The Second Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Ce Zhang
- Director's Office, The Second Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Hong Qu
- Bidding and Procurement Office, The Second Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Jianping Xu
- Department of Cardiology, The First Affiliated Hospital of Soochow University, Suzhouy, China
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8
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Ali Moussa HY, Shin KC, Ponraj J, Kim SJ, Ryu JK, Mansour S, Park Y. Requirement of Cholesterol for Calcium-Dependent Vesicle Fusion by Strengthening Synaptotagmin-1-Induced Membrane Bending. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2206823. [PMID: 37058136 DOI: 10.1002/advs.202206823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 02/09/2023] [Indexed: 05/27/2023]
Abstract
Cholesterol is essential for neuronal activity and function. Cholesterol depletion in the plasma membrane impairs synaptic transmission. However, the molecular mechanisms by which cholesterol deficiency leads to defects in vesicle fusion remain poorly understood. Here, it is shown that cholesterol is required for Ca2+ -dependent native vesicle fusion using the in vitro reconstitution of fusion and amperometry to monitor exocytosis in chromaffin cells. Purified native vesicles are crucial for the reconstitution of physiological Ca2+ -dependent fusion, because vesicle-mimicking liposomes fail to reproduce the cholesterol effect. Intriguingly, cholesterol has no effect on the membrane binding of synaptotagmin-1, a Ca2+ sensor for ultrafast fusion. Cholesterol strengthens local membrane deformation and bending induced by synaptotagmin-1, thereby lowering the energy barrier for Ca2+ -dependent fusion to occur. The data provide evidence that cholesterol depletion abolishes Ca2+ -dependent vesicle fusion by disrupting synaptotagmin-1-induced membrane bending, and suggests that cholesterol is an essential lipid regulator for Ca2+ -dependent fusion.
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Affiliation(s)
- Houda Yasmine Ali Moussa
- Neurological Disorders Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation, Doha, Qatar
| | - Kyung Chul Shin
- Neurological Disorders Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation, Doha, Qatar
| | | | - Soo Jin Kim
- Division of Molecular and Life Sciences, Pohang University of Science and Technology, Pohang, 790-784, Republic of Korea
| | - Je-Kyung Ryu
- Department of Physics & Astronomy, Seoul National University. 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea
| | - Said Mansour
- HBKU Core Labs, Hamad Bin Khalifa University (HBKU), Doha, Qatar
| | - Yongsoo Park
- Neurological Disorders Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation, Doha, Qatar
- College of Health & Life Sciences (CHLS), Hamad Bin Khalifa University (HBKU), Qatar Foundation, Doha, Qatar
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9
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van Tilburg M, Hilbers PAJ, Markvoort AJ. On the role of membrane embedding, protein rigidity and transmembrane length in lipid membrane fusion. SOFT MATTER 2023; 19:1791-1802. [PMID: 36786821 DOI: 10.1039/d2sm01582j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
The fusion of biological membranes is ubiquitous in natural processes like exo- and endocytosis, intracellular trafficking and viral entry. Membrane fusion is also utilized in artificial biomimetic fusion systems, e.g. for drug delivery. Both the natural and the biomimetic fusion systems rely on a wide range of (artificial) proteins mediating the fusion process. Although the exact mechanisms of these proteins differ, clear analogies in their general behavior can be observed in bringing the membranes in close proximity and mediating the fusion reaction. In our study, we use molecular dynamics simulations with coarse grained models, mimicking the general behavior of fusion proteins (spikes), to systematically examine the effects of specific characteristics of these proteins on the fusion process. The protein characteristics considered are (i) the type of membrane embedding, i.e., either transmembrane or not, (ii) the rigidity, and (iii) the transmembrane domain (TMD) length. The results show essential differences in fusion pathway between monotopic and transmembrane spikes, in which transmembrane spikes seem to inhibit the formation of hemifusion diaphragms, leading to a faster fusion development. Furthermore, we observed that an increased rigidity and a decreased TMD length both proved to contribute to a faster fusion development. Finally, we show that a single spike may suffice to successfully induce a fusion reaction, provided that the spike is sufficiently rigid and attractive. Not only does this shed light on biological fusion of membranes, it also provides clear design rules for artificial membrane fusion systems.
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Affiliation(s)
- Marco van Tilburg
- Department of Biomedical Engineering, Computational Biology Group, Eindhoven University of Technology, The Netherlands.
| | - Peter A J Hilbers
- Department of Biomedical Engineering, Computational Biology Group, Eindhoven University of Technology, The Netherlands.
- Institute of Complex Molecular Systems, Eindhoven University of Technology, The Netherlands
| | - Albert J Markvoort
- Department of Biomedical Engineering, Computational Biology Group, Eindhoven University of Technology, The Netherlands.
- Institute of Complex Molecular Systems, Eindhoven University of Technology, The Netherlands
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10
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Hesselbarth J, Schmidt C. Mass spectrometry uncovers intermediates and off-pathway complexes for SNARE complex assembly. Commun Biol 2023; 6:198. [PMID: 36806321 PMCID: PMC9941103 DOI: 10.1038/s42003-023-04548-0] [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: 07/15/2022] [Accepted: 02/01/2023] [Indexed: 02/22/2023] Open
Abstract
The SNARE complex assembles from vesicular Synaptobrevin-2 as well as Syntaxin-1 and SNAP25 both anchored to the presynaptic membrane. It mediates fusion of synaptic vesicles with the presynaptic plasma membrane resulting in exocytosis of neurotransmitters. While the general sequence of SNARE complex formation is well-established, our knowledge on possible intermediates and stable off-pathway complexes is incomplete. We, therefore, follow the stepwise assembly of the SNARE complex and target individual SNAREs, binary sub-complexes, the ternary SNARE complex as well as interactions with Complexin-1. Using native mass spectrometry, we identify the stoichiometry of sub-complexes and monitor oligomerisation of various assemblies. Importantly, we find that interactions with Complexin-1 reduce multimerisation of the ternary SNARE complex. Chemical cross-linking provides detailed insights into these interactions suggesting a role for membrane fusion. In summary, we unravel the stoichiometry of intermediates and off-pathway complexes and compile a road map of SNARE complex assembly including regulation by Complexin-1.
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Affiliation(s)
- Julia Hesselbarth
- Interdisciplinary Research Centre HALOmem, Charles Tanford Protein Centre, Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Halle, Germany
- Department of Chemistry - Biochemistry, Biocenter II, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Carla Schmidt
- Interdisciplinary Research Centre HALOmem, Charles Tanford Protein Centre, Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Halle, Germany.
- Department of Chemistry - Biochemistry, Biocenter II, Johannes Gutenberg University Mainz, Mainz, Germany.
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Madaro A, Nilsson J, Whatmore P, Roh H, Grove S, Stien LH, Olsen RE. Acute stress response on Atlantic salmon: a time-course study of the effects on plasma metabolites, mucus cortisol levels, and head kidney transcriptome profile. FISH PHYSIOLOGY AND BIOCHEMISTRY 2023; 49:97-116. [PMID: 36574113 PMCID: PMC9935726 DOI: 10.1007/s10695-022-01163-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 12/08/2022] [Indexed: 06/18/2023]
Abstract
Farmed Atlantic salmon (Salmo salar) welfare and performance can be strongly influenced by stress episodes caused by handling during farming practices. To better understand the changes occurring after an acute stress response, we exposed a group of Atlantic salmon parr to an acute stressor, which involved netting and transferring fish to several new holding tanks. We describe a time-course response to stress by sampling parr in groups before (T0) and 10, 20, 30, 45, 60, 120, 240, 300, and 330 min post-stress. A subgroup of fish was also subjected to the same stressor for a second time to assess their capacity to respond to the same challenge again within a short timeframe (ReStressed). Fish plasma was assessed for adrenocorticotropic hormone (ACTH), cortisol, and ions levels. Mucus cortisol levels were analyzed and compared with the plasma cortisol levels. At 5 selected time points (T0, 60, 90, 120, 240, and ReStressed), we compared the head kidney transcriptome profile of 10 fish per time point. The considerably delayed increase of ACTH in the plasma (60 min post-stress), and the earlier rise of cortisol levels (10 min post-stress), suggests that cortisol release could be triggered by more rapidly responding factors, such as the sympathetic system. This hypothesis may be supported by a high upregulation of several genes involved in synaptic triggering, observed both during the first and the second stress episodes. Furthermore, while the transcriptome profile showed few changes at 60 min post-stress, expression of genes in several immune-related pathways increased markedly with each successive time point, demonstrating the role of the immune system in fish coping capacity. Although many of the genes discussed in this paper are still poorly characterized, this study provides new insights regarding the mechanisms occurring during the stress response of salmon parr and may form the basis for a useful guideline on timing of sampling protocols.
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Affiliation(s)
| | | | - Paul Whatmore
- Department of eResearch, Queensland University of Technology, GPO Box 2434, Brisbane, QLD, 4001, Australia
| | - HyeongJin Roh
- Institute of Marine Research, NO-5984, Matredal, Norway
| | - Søren Grove
- Institute of Marine Research, NO-5984, Matredal, Norway
- Fish Health Group, Norwegian Veterinary Institute, 1433, Ås, Norway
| | - Lars H Stien
- Institute of Marine Research, NO-5984, Matredal, Norway
| | - Rolf Erik Olsen
- Institute of Marine Research, NO-5984, Matredal, Norway
- Department of Biology, Norwegian University of Science and Technology, 7491, Trondheim, Norway
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12
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Xue M, Cao Y, Shen C, Guo W. Computational Advances of Protein/Neurotransmitter-membrane Interactions Involved in Vesicle Fusion and Neurotransmitter Release. J Mol Biol 2023; 435:167818. [PMID: 36089056 DOI: 10.1016/j.jmb.2022.167818] [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: 05/31/2022] [Revised: 08/22/2022] [Accepted: 09/04/2022] [Indexed: 02/04/2023]
Abstract
Vesicle fusion is of crucial importance to neuronal communication at neuron terminals. The exquisite but complex fusion machinery for neurotransmitter release is tightly controlled and regulated by protein/neurotransmitter-membrane interactions. Computational 'microscopies', in particular molecular dynamics simulations and related techniques, have provided notable insight into the physiological process over the past decades, and have made enormous contributions to fields such as neurology, pharmacology and pathophysiology. Here we review the computational advances of protein/neurotransmitter-membrane interactions related to presynaptic vesicle-membrane fusion and neurotransmitter release, and outline the in silico challenges ahead for understanding this important physiological process.
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Affiliation(s)
- Minmin Xue
- Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education, State Key Laboratory of Mechanics and Control of Mechanical Structures, and Institute for Frontier Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
| | - Yuwei Cao
- State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing, China
| | - Chun Shen
- Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education, State Key Laboratory of Mechanics and Control of Mechanical Structures, and Institute for Frontier Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
| | - Wanlin Guo
- Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education, State Key Laboratory of Mechanics and Control of Mechanical Structures, and Institute for Frontier Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China; State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing, China.
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13
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Ali Moussa HY, Park Y. Electrostatic regulation of the cis- and trans-membrane interactions of synaptotagmin-1. Sci Rep 2022; 12:22407. [PMID: 36575295 PMCID: PMC9794720 DOI: 10.1038/s41598-022-26723-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 12/19/2022] [Indexed: 12/28/2022] Open
Abstract
Synaptotagmin-1 is a vesicular protein and Ca2+ sensor for Ca2+-dependent exocytosis. Ca2+ induces synaptotagmin-1 binding to its own vesicle membrane, called the cis-interaction, thus preventing the trans-interaction of synaptotagmin-1 to the plasma membrane. However, the electrostatic regulation of the cis- and trans-membrane interaction of synaptotagmin-1 was poorly understood in different Ca2+-buffering conditions. Here we provide an assay to monitor the cis- and trans-membrane interactions of synaptotagmin-1 by using native purified vesicles and the plasma membrane-mimicking liposomes (PM-liposomes). Both ATP and EGTA similarly reverse the cis-membrane interaction of synaptotagmin-1 in free [Ca2+] of 10-100 μM. High PIP2 concentrations in the PM-liposomes reduce the Hill coefficient of vesicle fusion and synaptotagmin-1 membrane binding; this observation suggests that local PIP2 concentrations control the Ca2+-cooperativity of synaptotagmin-1. Our data provide evidence that Ca2+ chelators, including EGTA and polyphosphate anions such as ATP, ADP, and AMP, electrostatically reverse the cis-interaction of synaptotagmin-1.
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Affiliation(s)
- Houda Yasmine Ali Moussa
- grid.418818.c0000 0001 0516 2170Neurological Disorders Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation, Doha, Qatar
| | - Yongsoo Park
- grid.418818.c0000 0001 0516 2170Neurological Disorders Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation, Doha, Qatar ,grid.418818.c0000 0001 0516 2170College of Health and Life Sciences (CHLS), Hamad Bin Khalifa University (HBKU), Qatar Foundation, Doha, Qatar
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14
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Filipović D, Costina V, Findeisen P, Inta D. Fluoxetine Enhances Synaptic Vesicle Trafficking and Energy Metabolism in the Hippocampus of Socially Isolated Rats. Int J Mol Sci 2022; 23:ijms232315351. [PMID: 36499675 PMCID: PMC9735484 DOI: 10.3390/ijms232315351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 11/27/2022] [Accepted: 12/02/2022] [Indexed: 12/12/2022] Open
Abstract
Chronic social isolation (CSIS)-induced alternation in synaptic and mitochondrial function of specific brain regions is associated with major depressive disorder (MDD). Despite the wide number of available medications, treating MDD remains an important challenge. Although fluoxetine (Flx) is the most frequently prescribed antidepressant, its mode of action is still unknown. To delineate affected molecular pathways of depressive-like behavior and identify potential targets upon Flx treatment, we performed a comparative proteomic analysis of hippocampal purified synaptic terminals (synaptosomes) of rats exposed to six weeks of CSIS, an animal model of depression, and/or followed by Flx treatment (lasting three weeks of six-week CSIS) to explore synaptic protein profile changes. Results showed that Flx in controls mainly induced decreased expression of proteins involved in energy metabolism and the redox system. CSIS led to increased expression of proteins that mainly participate in Ca2+/calmodulin-dependent protein kinase II (Camk2)-related neurotransmission, vesicle transport, and ubiquitination. Flx treatment of CSIS rats predominantly increased expression of proteins involved in synaptic vesicle trafficking (exocytosis and endocytosis), and energy metabolism (glycolytic and mitochondrial respiration). Overall, these Flx-regulated changes in synaptic and mitochondrial proteins of CSIS rats might be critical targets for new therapeutic development for the treatment of MDD.
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Affiliation(s)
- Dragana Filipović
- Department of Molecular Biology and Endocrinology, “VINČA”, Institute of Nuclear Sciences—National Institute of thе Republic of Serbia, University of Belgrade, 11000 Belgrade, Serbia
- Correspondence: ; Tel./Fax: +381-(11)-6455-561
| | - Victor Costina
- Institute for Clinical Chemistry, Medical Faculty Mannheim of the University of Heidelberg, University Hospital Mannheim, 68159 Mannhem, Germany
| | - Peter Findeisen
- Institute for Clinical Chemistry, Medical Faculty Mannheim of the University of Heidelberg, University Hospital Mannheim, 68159 Mannhem, Germany
| | - Dragos Inta
- Department for Community Health Faculty of Natural Sciences, Medicine University of Fribourg, 1700 Fribourg, Switzerland
- Department of Biomedicine, University of Basel, 4052 Basel, Switzerland
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15
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Cheppali SK, Dharan R, Sorkin R. Forces of Change: Optical Tweezers in Membrane Remodeling Studies. J Membr Biol 2022; 255:677-690. [PMID: 35616705 DOI: 10.1007/s00232-022-00241-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 04/22/2022] [Indexed: 12/24/2022]
Abstract
Optical tweezers allow precise measurement of forces and distances with piconewton and nanometer precision, and have thus been instrumental in elucidating the mechanistic details of various biological processes. Some examples include the characterization of motor protein activity, studies of protein-DNA interactions, and characterizing protein folding trajectories. The use of optical tweezers (OT) to study membranes is, however, much less abundant. Here, we review biophysical studies of membranes that utilize optical tweezers, with emphasis on various assays that have been developed and their benefits and limitations. First, we discuss assays that employ membrane-coated beads, and overview protein-membrane interactions studies based on manipulation of such beads. We further overview a body of studies that make use of a very powerful experimental tool, the combination of OT, micropipette aspiration, and fluorescence microscopy, that allow detailed studies of membrane curvature generation and sensitivity. Finally, we describe studies focused on membrane fusion and fission. We then summarize the overall progress in the field and outline future directions.
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Affiliation(s)
- Sudheer K Cheppali
- Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University, Tel Aviv, Israel.,Center for Physics and Chemistry of Living Systems, Tel Aviv University, Tel Aviv, Israel.,Center for Nanoscience and Nanotechnology, Tel Aviv University, Tel Aviv, Israel.,Center for Light-Matter Interaction, Tel Aviv University, Tel Aviv, Israel
| | - Raviv Dharan
- Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University, Tel Aviv, Israel.,Center for Physics and Chemistry of Living Systems, Tel Aviv University, Tel Aviv, Israel.,Center for Nanoscience and Nanotechnology, Tel Aviv University, Tel Aviv, Israel.,Center for Light-Matter Interaction, Tel Aviv University, Tel Aviv, Israel
| | - Raya Sorkin
- Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University, Tel Aviv, Israel. .,Center for Physics and Chemistry of Living Systems, Tel Aviv University, Tel Aviv, Israel. .,Center for Nanoscience and Nanotechnology, Tel Aviv University, Tel Aviv, Israel. .,Center for Light-Matter Interaction, Tel Aviv University, Tel Aviv, Israel.
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16
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Liu J, Zhang C, Wang J, Huang Y, Shen D, Hu Y, Chu H, Yu X, Zhang L, Ma H. A Class I HDAC Inhibitor BG45 Alleviates Cognitive Impairment through the CaMKII/ITPKA/Ca 2+ Signaling Pathway. Pharmaceuticals (Basel) 2022; 15:ph15121481. [PMID: 36558932 PMCID: PMC9786203 DOI: 10.3390/ph15121481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 11/18/2022] [Accepted: 11/22/2022] [Indexed: 11/30/2022] Open
Abstract
Alzheimer's disease (AD) seriously endangers the health and life of elderly individuals worldwide. However, despite all scientific efforts, at the moment there are no effective clinical treatment options for AD. In this work, the effect of the class I histone deacetylase inhibitor (HDACI) BG45 on synapse-related proteins was investigated in primary neurons from APP/PS1 transgenic mice. The results showed that BG45 can upregulate the expression of synaptotagmin-1 (SYT-1) and neurofilament light chain (NF-L) in primary neurons. In vivo, the APPswe/PS1dE9 (APP/PS1) transgenic mice were treated with BG45 (30 mg/kg) daily for 12 days. Behavioral testing of BG45-treated APP/PS1 mice showed improvements in learning and memory. BG45 can alleviate damage to the dendritic spine and reduce the deposition of Aβ. Similar to the in vitro results, synapse-related proteins in the prefrontal cortex were increased after BG45 treatment. Proteomic analysis results highlighted the differences in the biological processes of energy metabolism and calmodulin regulation in APP/PS1 mice with or without BG45 treatment. Further verification demonstrated that the effect of BG45 on synapses and learning and memory may involve the CaMKII/ITPKA/Ca2+ pathway. These results suggest that class I HDACI BG45 might be a promising drug for the early clinical treatment of AD.
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17
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Özdemir Ç, Şahin N, Edgünlü T. Vesicle trafficking with snares: a perspective for autism. Mol Biol Rep 2022; 49:12193-12202. [PMID: 36198849 DOI: 10.1007/s11033-022-07970-5] [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: 06/08/2022] [Accepted: 09/21/2022] [Indexed: 11/30/2022]
Abstract
Vesicle-mediated membrane traffic is the mechanism fundamental to many biological events, especially the release of neurotransmitters. The main proteins of the mechanism that mediates membrane fusion in vesicle-mediated membrane traffic are N-ethylmaleimide sensitive factor (NSF) supplemental protein (SNAP) receptor (SNAREs) proteins. SNAREs are classified into vesicle-associated SNAREs (vesicle-SNAREs/v-SNAREs) and target membrane-associated SNAREs (target-SNARE/t-SNAREs). Autism spectrum disorders (ASD) are neurodevelopmental disorders characterized by many symptoms, especially complications in social communication and stereotypical behaviours. Defects in synaptogenesis and neurotransmission, oxidative stress, and developmental defects in the early stages of development are defined in the pathogenesis of the disease. SNARE proteins are on the basis of synaptogenesis and neurotransmission. Although the formation mechanisms and underlying causes of the SNARE complex are not fully understood, expression differences, polymorphisms, abnormal expressions or dysfunctions of the proteins that make up the SNARE complex have been associated with many neurodevelopmental diseases, including autism. Further understanding of SNARE mechanisms is crucial both for understanding ASD and for developing new treatments. In this review, the formation mechanisms of the SNARE complex and the roles of various factors involved in this process are explained. In addition, a brief evaluation of clinical and basic studies on the SNARE complex in autism spectrum disorders was made.
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Affiliation(s)
- Çilem Özdemir
- Department of Medical Biology, Health Sciences Institution, Muğla Sıtkı Koçman University, Mugla, Turkey
| | - Nilfer Şahin
- Department of Child and Adolescent Mental Health Diseases School of Medicine, Muğla Sıtkı Koçman University, Mugla, Turkey
| | - Tuba Edgünlü
- Department of Medical Biology, School of Medicine, Muğla Sıtkı Koçman University, 48000, Mugla, Turkey.
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18
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Inhibition of STAT3 signal pathway recovers postsynaptic plasticity to improve cognitive impairment caused by chronic intermittent hypoxia. Sleep Breath 2022; 27:893-902. [DOI: 10.1007/s11325-022-02671-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 06/08/2022] [Accepted: 06/16/2022] [Indexed: 10/16/2022]
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19
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Di Bartolo AL, Tomes CN, Mayorga LS, Masone D. Enhanced Expansion and Reduced Kiss-and-Run Events in Fusion Pores Steered by Synaptotagmin-1 C2B Domains. J Chem Theory Comput 2022; 18:4544-4554. [PMID: 35759758 DOI: 10.1021/acs.jctc.2c00424] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The fusion pore controls the release of exocytotic vesicle contents through a precise orchestration of lipids from the fusing membranes and proteins. There is a major lipid reorganization during the different stages in life of the fusion pore (membrane fusion, nucleation, and expansion) that can be scrutinized thermodynamically. In this work, using umbrella sampling simulations we describe the expansion of the fusion pore. We have calculated free energy profiles to drive a nascent, just nucleated, fusion pore to its expanded configuration. We have quantified the effects on the free energy of one and two Synaptotagmin-1 C2B domains in the cytosolic space. We show that C2B domains cumulatively reduce the cost for expansion, favoring the system to evolve toward full fusion. Finally, by conducting thousands of unbiased molecular dynamics simulations, we show that C2B domains significantly decrease the probability of kiss-and-run events.
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Affiliation(s)
- Ary Lautaro Di Bartolo
- Instituto de Histología y Embriología de Mendoza (IHEM), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Cuyo (UNCuyo), 5500 Mendoza, Argentina.,Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo (UNCuyo), 5500 Mendoza, Argentina
| | - Claudia N Tomes
- Instituto de Histología y Embriología de Mendoza (IHEM), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Cuyo (UNCuyo), 5500 Mendoza, Argentina.,Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo (UNCuyo), 5500 Mendoza, Argentina
| | - Luis S Mayorga
- Instituto de Histología y Embriología de Mendoza (IHEM), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Cuyo (UNCuyo), 5500 Mendoza, Argentina.,Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo (UNCuyo), 5500 Mendoza, Argentina
| | - Diego Masone
- Instituto de Histología y Embriología de Mendoza (IHEM), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Cuyo (UNCuyo), 5500 Mendoza, Argentina.,Facultad de Ingeniería, Universidad Nacional de Cuyo (UNCuyo), 5500 Mendoza, Argentina
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20
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Hong GL, Tang YH, Li WW, Cao KQ, Tan JP, Hu LF, Chen LW, Zhao GJ, Lu ZQ. Vesicle transport related protein Synaptotagmin-1 mediates paraquat transport to antagonize paraquat toxicity. Toxicology 2022; 472:153180. [PMID: 35430322 DOI: 10.1016/j.tox.2022.153180] [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: 12/17/2021] [Revised: 03/30/2022] [Accepted: 04/10/2022] [Indexed: 11/28/2022]
Abstract
In this study, A549/PQ cells with moderate resistance to paraquat (PQ) were obtained by treating A549 cells with PQ, their growth rate was slowed down, the accumulation concentration of PQ and the levels of growth inhibition, injury and early apoptosis induced by PQ were significantly lower than those of parental A549 cells. Microarray screening and RT-qPCR detection found that Synaptotagmin-1 (SYT1) expression in drug-resistant cells was significantly increased, and PQ further enhanced its expression. After inhibiting SYT1 expression in A549/PQ cells, cell viability, intracellular PQ concentration and the expression of Bcl-2, SNAP25 and RAB26 were significantly reduced, while the mortality, early apoptosis rate and Bax expression were significantly increased. In vivo experiments also further showed that PQ promoted the expression of SYT1, SNAP25 and RAB26 in PQ-poisoned mice; when inhibiting SYT1 expression, PQ concentration in lung tissues was significantly increased, and the levels of lung injury and apoptosis were also significantly enhanced, while the expression of SNAP25 and RAB26 was significantly reduced. This indicates that PQ poisoning leads to compensatory up-regulation of vesicle transport related proteins such as SYT1 in vivo, thereby promoting PQ transmembrane transport, and then reducing the pulmonary accumulation of PQ and PQ-caused lung injury.
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Affiliation(s)
- Guang-Liang Hong
- Emergency Department, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, China; Wenzhou Key Laboratory of emergency and disaster medicine, Wenzhou 325000, China
| | - Ya-Hui Tang
- Emergency Department, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, China; Wenzhou Key Laboratory of emergency and disaster medicine, Wenzhou 325000, China
| | - Wen-Wen Li
- Emergency Department, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, China; Wenzhou Key Laboratory of emergency and disaster medicine, Wenzhou 325000, China
| | - Kai-Qiang Cao
- Emergency Department, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, China; Wenzhou Key Laboratory of emergency and disaster medicine, Wenzhou 325000, China
| | - Jia-Ping Tan
- Emergency Department, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, China; Wenzhou Key Laboratory of emergency and disaster medicine, Wenzhou 325000, China
| | - Lu-Feng Hu
- Emergency Department, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, China; Wenzhou Key Laboratory of emergency and disaster medicine, Wenzhou 325000, China
| | - Long-Wang Chen
- Emergency Department, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, China; Wenzhou Key Laboratory of emergency and disaster medicine, Wenzhou 325000, China
| | - Guang-Ju Zhao
- Emergency Department, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, China; Wenzhou Key Laboratory of emergency and disaster medicine, Wenzhou 325000, China
| | - Zhong-Qiu Lu
- Emergency Department, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, China; Wenzhou Key Laboratory of emergency and disaster medicine, Wenzhou 325000, China.
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21
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Tian R, Zhang Y, Pan Q, Wang Y, Wen Q, Fan X, Qin G, Zhang D, Chen L, Zhang Y, Zhou J. Calcitonin gene-related peptide receptor antagonist BIBN4096BS regulates synaptic transmission in the vestibular nucleus and improves vestibular function via PKC/ERK/CREB pathway in an experimental chronic migraine rat model. J Headache Pain 2022; 23:35. [PMID: 35260079 PMCID: PMC8903578 DOI: 10.1186/s10194-022-01403-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Accepted: 02/15/2022] [Indexed: 02/07/2023] Open
Abstract
Background Vestibular symptoms are frequently reported in patients with chronic migraine (CM). However, whether vestibular symptoms arise through overlapping neurobiology of migraine remains to be elucidated. The neuropeptide calcitonin gene-related peptide (CGRP) and CGRP1 receptor play important pathological roles in facilitating central sensitization in CM. Therefore, we aimed to investigate whether CGRP1 receptor contributes to vestibular dysfunction after CM by improving synaptic transmission in the vestibular nucleus (VN). Methods A CM rat model was established by recurrent intermittent administration of nitroglycerin (NTG). Migraine- and vestibular-related behaviors were assessed. CGRP1 receptor specific antagonist, BIBN4096BS, and protein kinase C (PKC) inhibitor chelerythrine chloride (CHE) were administered intracerebroventricularly. The expressions of CGRP and CGRP1 receptor components, calcitonin receptor-like receptor (CLR) and receptor activity modifying protein 1 (RAMP1) were evaluated by western blot, immunofluorescent staining and quantitative real-time polymerase chain reaction in the vestibular nucleus (VN). Synaptic associated proteins and synaptic morphological characteristics were explored by western blot, transmission electron microscope, and Golgi-cox staining. The expressions of PKC, phosphorylated extracellular signal regulated kinase (p-ERK), phosphorylated cAMP response element-binding protein at serine 133 site (p-CREB-S133) and c-Fos were detected using western blot or immunofluorescent staining. Results The expressions of CGRP, CLR and RAMP1 were significantly upregulated in CM rats. CLR and RAMP1 were expressed mainly in neurons. BIBN4096BS treatment and PKC inhibition alleviated mechanical allodynia, thermal hyperalgesia and vestibular dysfunction in CM rats. Additionally, BIBN4096BS treatment and PKC inhibition markedly inhibited the overexpression of synaptic associated proteins and restored the abnormal synaptic structure in VN after CM. Furthermore, BIBN4096BS treatment dysregulated the expression levels of PKC, p-ERK and p-CREB-S133, and attenuated neuronal activation in VN after CM. Conclusions The present study demonstrated that CGRP1 receptor inhibition improved vestibular function after CM by reversing the aberrant synaptic transmission via downregulating PKC/ERK/CREB signaling pathway. Therapeutic interventions by inhibiting CGRP/CGRP1 signaling may be a new target for the treatment of vestibular symptoms in CM.
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22
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Dietz J, Oelkers M, Hubrich R, Pérez-Lara A, Jahn R, Steinem C, Janshoff A. Forces, Kinetics, and Fusion Efficiency Altered by the Full-Length Synaptotagmin-1 -PI(4,5)P 2 Interaction in Constrained Geometries. NANO LETTERS 2022; 22:1449-1455. [PMID: 34855407 DOI: 10.1021/acs.nanolett.1c02491] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
A mechanism for full-length synaptotagmin-1 (syt-1) to interact with anionic bilayers and to promote fusion in the presence of SNAREs is proposed. Colloidal probe force spectroscopy in conjunction with tethered particle motion monitoring showed that in the absence of Ca2+ the binding of syt-1 to membranes depends on the presence and content of PI(4,5)P2. Addition of Ca2+ switches the interaction forces from weak to strong, eventually exceeding the cohesion of the C2A domain of syt-1 leading to partial unfolding of the protein. Fusion of single unilamellar vesicles equipped with syt-1 and synaptobrevin 2 with planar pore-spanning target membranes containing PS and PI(4,5)P2 shows an almost complete suppression of stalled intermediate fusion states and an accelerated fusion kinetics in the presence of Ca2+, which is further enhanced upon addition of ATP.
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Affiliation(s)
- Joern Dietz
- Institute for Physical Chemistry, Georg-August Universität, Tammannstr. 6, 37077 Göttingen, Germany
| | - Marieelen Oelkers
- Institute for Physical Chemistry, Georg-August Universität, Tammannstr. 6, 37077 Göttingen, Germany
| | - Raphael Hubrich
- Institute for Organic and Biomolecular Chemistry, Georg-August Universität, Tammannstr. 2, 37077 Göttingen, Germany
| | - Angel Pérez-Lara
- Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, Am Faβberg 11, 37077 Göttingen, Germany
| | - Reinhard Jahn
- Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, Am Faβberg 11, 37077 Göttingen, Germany
| | - Claudia Steinem
- Institute for Organic and Biomolecular Chemistry, Georg-August Universität, Tammannstr. 2, 37077 Göttingen, Germany
| | - Andreas Janshoff
- Institute for Physical Chemistry, Georg-August Universität, Tammannstr. 6, 37077 Göttingen, Germany
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23
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Di Bartolo AL, Masone D. Synaptotagmin-1 C2B domains cooperatively stabilize the fusion stalk via a master-servant mechanism. Chem Sci 2022; 13:3437-3446. [PMID: 35432859 PMCID: PMC8943895 DOI: 10.1039/d1sc06711g] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 02/22/2022] [Indexed: 11/21/2022] Open
Abstract
Synaptotagmin-1 is a low-affinity Ca2+ sensor that triggers synchronous vesicle fusion. It contains two similar C2 domains (C2A and C2B) that cooperate in membrane binding, being the C2B domain the...
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Affiliation(s)
- Ary Lautaro Di Bartolo
- Instituto de Histología y Embriología de Mendoza (IHEM) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Cuyo (UNCuyo) 5500 Mendoza Argentina
- Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo (UNCuyo) 5500 Mendoza Argentina
| | - Diego Masone
- Instituto de Histología y Embriología de Mendoza (IHEM) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Cuyo (UNCuyo) 5500 Mendoza Argentina
- Facultad de Ingeniería, Universidad Nacional de Cuyo (UNCuyo) 5500 Mendoza Argentina
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24
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Perić I, Costina V, Djordjević S, Gass P, Findeisen P, Inta D, Borgwardt S, Filipović D. Tianeptine modulates synaptic vesicle dynamics and favors synaptic mitochondria processes in socially isolated rats. Sci Rep 2021; 11:17747. [PMID: 34493757 PMCID: PMC8423821 DOI: 10.1038/s41598-021-97186-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 08/09/2021] [Indexed: 11/09/2022] Open
Abstract
Deregulation of synaptic function and neurotransmission has been linked with the development of major depression disorder (MDD). Tianeptine (Tian) has been used as antidepressant with anxiolytic properties and recently as a nootropic to improve cognitive performance, but its mechanism of action is unknown. We conducted a proteomic study on the hippocampal synaptosomal fractions of adult male Wistar rats exposed to chronic social isolation (CSIS, 6 weeks), an animal model of depression and after chronic Tian treatment in controls (nootropic effect) and CSIS-exposed rats (lasting 3 weeks of 6-week CSIS) (therapeutic effect). Increased expression of Syn1 and Camk2-related neurotransmission, vesicle transport and energy processes in Tian-treated controls were found. CSIS led to upregulation of proteins associated with actin cytoskeleton, signaling transduction and glucose metabolism. In CSIS rats, Tian up-regulated proteins involved in mitochondrial energy production, mitochondrial transport and dynamics, antioxidative defense and glutamate clearance, while attenuating the CSIS-increased glycolytic pathway and cytoskeleton organization proteins expression and decreased the expression of proteins involved in V-ATPase and vesicle endocytosis. Our overall findings revealed that synaptic vesicle dynamics, specifically exocytosis, and mitochondria-related energy processes might be key biological pathways modulated by the effective nootropic and antidepressant treatment with Tian and be a potential target for therapeutic efficacy of the stress-related mood disorders.
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Affiliation(s)
- Ivana Perić
- Department of Molecular Biology and Endocrinology, "VINČA", Institute of Nuclear Sciences - National Institute of the Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Victor Costina
- Institute for Clinical Chemistry, Medical Faculty Mannheim of the University of Heidelberg, University Hospital Mannheim, 68159, Mannheim, Germany
| | | | - Peter Gass
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, 68159, Mannheim, Germany
| | - Peter Findeisen
- Institute for Clinical Chemistry, Medical Faculty Mannheim of the University of Heidelberg, University Hospital Mannheim, 68159, Mannheim, Germany
| | - Dragoš Inta
- Department of Psychiatry (UPK), University of Basel, Basel, Switzerland
| | - Stefan Borgwardt
- Department of Psychiatry and Psychotherapy, University of Lübeck, Lübeck, Germany
| | - Dragana Filipović
- Department of Molecular Biology and Endocrinology, "VINČA", Institute of Nuclear Sciences - National Institute of the Republic of Serbia, University of Belgrade, Belgrade, Serbia.
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ATR regulates neuronal activity by modulating presynaptic firing. Nat Commun 2021; 12:4067. [PMID: 34210973 PMCID: PMC8249387 DOI: 10.1038/s41467-021-24217-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 06/01/2021] [Indexed: 02/06/2023] Open
Abstract
Ataxia Telangiectasia and Rad3-related (ATR) protein, as a key DNA damage response (DDR) regulator, plays an essential function in response to replication stress and controls cell viability. Hypomorphic mutations of ATR cause the human ATR-Seckel syndrome, characterized by microcephaly and intellectual disability, which however suggests a yet unknown role for ATR in non-dividing cells. Here we show that ATR deletion in postmitotic neurons does not compromise brain development and formation; rather it enhances intrinsic neuronal activity resulting in aberrant firing and an increased epileptiform activity, which increases the susceptibility of ataxia and epilepsy in mice. ATR deleted neurons exhibit hyper-excitability, associated with changes in action potential conformation and presynaptic vesicle accumulation, independent of DDR signaling. Mechanistically, ATR interacts with synaptotagmin 2 (SYT2) and, without ATR, SYT2 is highly upregulated and aberrantly translocated to excitatory neurons in the hippocampus, thereby conferring a hyper-excitability. This study identifies a physiological function of ATR, beyond its DDR role, in regulating neuronal activity.
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Binotti B, Jahn R, Pérez-Lara Á. An overview of the synaptic vesicle lipid composition. Arch Biochem Biophys 2021; 709:108966. [PMID: 34139199 DOI: 10.1016/j.abb.2021.108966] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 06/10/2021] [Accepted: 06/10/2021] [Indexed: 11/29/2022]
Abstract
Chemical neurotransmission is the major mechanism of neuronal communication. Neurotransmitters are released from secretory organelles, the synaptic vesicles (SVs) via exocytosis into the synaptic cleft. Fusion of SVs with the presynaptic plasma membrane is balanced by endocytosis, thus maintaining the presynaptic membrane at steady-state levels. The protein machineries responsible for exo- and endocytosis have been extensively investigated. In contrast, less is known about the role of lipids in synaptic transmission and how the lipid composition of SVs is affected by dynamic exo-endocytotic cycling. Here we summarize the current knowledge about the composition, organization, and function of SV membrane lipids. We also cover lipid biogenesis and maintenance during the synaptic vesicle cycle.
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Affiliation(s)
- Beyenech Binotti
- Department of Biochemistry, University of Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Reinhard Jahn
- Department of Neurobiology, Max-Planck-Institute for Biophysical Chemistry, Am Faßberg 11, 37077, Göttingen, Germany.
| | - Ángel Pérez-Lara
- Department of Physical Chemistry, University of Granada, Campus Universitario de Cartuja, 18071, Granada, Spain.
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27
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Function of Drosophila Synaptotagmins in membrane trafficking at synapses. Cell Mol Life Sci 2021; 78:4335-4364. [PMID: 33619613 PMCID: PMC8164606 DOI: 10.1007/s00018-021-03788-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 01/29/2021] [Accepted: 02/09/2021] [Indexed: 12/13/2022]
Abstract
The Synaptotagmin (SYT) family of proteins play key roles in regulating membrane trafficking at neuronal synapses. Using both Ca2+-dependent and Ca2+-independent interactions, several SYT isoforms participate in synchronous and asynchronous fusion of synaptic vesicles (SVs) while preventing spontaneous release that occurs in the absence of stimulation. Changes in the function or abundance of the SYT1 and SYT7 isoforms alter the number and route by which SVs fuse at nerve terminals. Several SYT family members also regulate trafficking of other subcellular organelles at synapses, including dense core vesicles (DCV), exosomes, and postsynaptic vesicles. Although SYTs are linked to trafficking of multiple classes of synaptic membrane compartments, how and when they interact with lipids, the SNARE machinery and other release effectors are still being elucidated. Given mutations in the SYT family cause disorders in both the central and peripheral nervous system in humans, ongoing efforts are defining how these proteins regulate vesicle trafficking within distinct neuronal compartments. Here, we review the Drosophila SYT family and examine their role in synaptic communication. Studies in this invertebrate model have revealed key similarities and several differences with the predicted activity of their mammalian counterparts. In addition, we highlight the remaining areas of uncertainty in the field and describe outstanding questions on how the SYT family regulates membrane trafficking at nerve terminals.
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28
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Wittig S, Ganzella M, Barth M, Kostmann S, Riedel D, Pérez-Lara Á, Jahn R, Schmidt C. Cross-linking mass spectrometry uncovers protein interactions and functional assemblies in synaptic vesicle membranes. Nat Commun 2021; 12:858. [PMID: 33558502 PMCID: PMC7870876 DOI: 10.1038/s41467-021-21102-w] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Accepted: 12/18/2020] [Indexed: 02/08/2023] Open
Abstract
Synaptic vesicles are storage organelles for neurotransmitters. They pass through a trafficking cycle and fuse with the pre-synaptic membrane when an action potential arrives at the nerve terminal. While molecular components and biophysical parameters of synaptic vesicles have been determined, our knowledge on the protein interactions in their membranes is limited. Here, we apply cross-linking mass spectrometry to study interactions of synaptic vesicle proteins in an unbiased approach without the need for specific antibodies or detergent-solubilisation. Our large-scale analysis delivers a protein network of vesicle sub-populations and functional assemblies including an active and an inactive conformation of the vesicular ATPase complex as well as non-conventional arrangements of the luminal loops of SV2A, Synaptophysin and structurally related proteins. Based on this network, we specifically target Synaptobrevin-2, which connects with many proteins, in different approaches. Our results allow distinction of interactions caused by 'crowding' in the vesicle membrane from stable interaction modules.
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Affiliation(s)
- Sabine Wittig
- Interdisciplinary Research Centre HALOmem, Charles Tanford Protein Centre, Institute for Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Marcelo Ganzella
- Department for Neurobiology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Marie Barth
- Interdisciplinary Research Centre HALOmem, Charles Tanford Protein Centre, Institute for Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Susann Kostmann
- Interdisciplinary Research Centre HALOmem, Charles Tanford Protein Centre, Institute for Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Dietmar Riedel
- Department for Neurobiology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Ángel Pérez-Lara
- Department for Neurobiology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
- Department of Physical Chemistry, Faculty of Pharmacy, University of Granada, Granada, Spain
| | - Reinhard Jahn
- Department for Neurobiology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Carla Schmidt
- Interdisciplinary Research Centre HALOmem, Charles Tanford Protein Centre, Institute for Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Halle, Germany.
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Saric A, Freeman SA. Endomembrane Tension and Trafficking. Front Cell Dev Biol 2021; 8:611326. [PMID: 33490077 PMCID: PMC7820182 DOI: 10.3389/fcell.2020.611326] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 12/09/2020] [Indexed: 12/11/2022] Open
Abstract
Eukaryotic cells employ diverse uptake mechanisms depending on their specialized functions. While such mechanisms vary widely in their defining criteria: scale, molecular machinery utilized, cargo selection, and cargo destination, to name a few, they all result in the internalization of extracellular solutes and fluid into membrane-bound endosomes. Upon scission from the plasma membrane, this compartment is immediately subjected to extensive remodeling which involves tubulation and vesiculation/budding of the limiting endomembrane. This is followed by a maturation process involving concomitant retrograde transport by microtubule-based motors and graded fusion with late endosomes and lysosomes, organelles that support the degradation of the internalized content. Here we review an important determinant for sorting and trafficking in early endosomes and in lysosomes; the control of tension on the endomembrane. Remodeling of endomembranes is opposed by high tension (caused by high hydrostatic pressure) and supported by the relief of tension. We describe how the timely and coordinated efflux of major solutes along the endocytic pathway affords the cell control over such tension. The channels and transporters that expel the smallest components of the ingested medium from the early endocytic fluid are described in detail as these systems are thought to enable endomembrane deformation by curvature-sensing/generating coat proteins. We also review similar considerations for the lysosome where resident hydrolases liberate building blocks from luminal macromolecules and transporters flux these organic solutes to orchestrate trafficking events. How the cell directs organellar trafficking based on the luminal contents of organelles of the endocytic pathway is not well-understood, however, we propose that the control over membrane tension by solute transport constitutes one means for this to ensue.
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Affiliation(s)
- Amra Saric
- Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | - Spencer A Freeman
- Program in Cell Biology, Peter Gilgan Center for Research and Learning, Hospital for Sick Children, Toronto, ON, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON, Canada
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Xiang W, Long Z, Zeng J, Zhu X, Yuan M, Wu J, Wu Y, Liu L. Mechanism of Radix Rhei Et Rhizome Intervention in Cerebral Infarction: A Research Based on Chemoinformatics and Systematic Pharmacology. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE : ECAM 2021; 2021:6789835. [PMID: 34531920 PMCID: PMC8440083 DOI: 10.1155/2021/6789835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 08/13/2021] [Indexed: 02/05/2023]
Abstract
OBJECTIVE To explore the therapeutic targets, network modules, and coexpressed genes of Radix Rhei Et Rhizome intervention in cerebral infarction (CI), and to predict significant biological processes and pathways through network pharmacology. To explore the differential proteins of Radix Rhei Et Rhizome intervention in CI, conduct bioinformatics verification, and initially explain the possible therapeutic mechanism of Radix Rhei Et Rhizome intervention in CI through proteomics. METHODS The TCM database was used to predict the potential compounds of Radix Rhei Et Rhizome, and the PharmMapper was used to predict its potential targets. GeneCards and OMIM were used to search for CI-related genes. Cytoscape was used to construct a protein-protein interaction (PPI) network and to screen out core genes and detection network modules. Then, DAVID and Metascape were used for enrichment analysis. After that, in-depth analysis of the proteomics data was carried out to further explore the mechanism of Radix Rhei Et Rhizome intervention in CI. RESULTS (1) A total of 14 Radix Rhei Et Rhizome potential components and 425 potential targets were obtained. The core components include sennoside A, palmidin A, emodin, toralactone, and so on. The potential targets were combined with 297 CI genes to construct a PPI network. The targets shared by Radix Rhei Et Rhizome and CI include ALB, AKT1, MMP9, IGF1, CASP3, etc. The biological processes that Radix Rhei Et Rhizome may treat CI include platelet degranulation, cell migration, fibrinolysis, platelet activation, hypoxia, angiogenesis, endothelial cell apoptosis, coagulation, and neuronal apoptosis. The signaling pathways include Ras, PI3K-Akt, TNF, FoxO, HIF-1, and Rap1 signaling pathways. (2) Proteomics shows that the top 20 proteins in the differential protein PPI network were Syp, Syn1, Mbp, Gap43, Aif1, Camk2a, Syt1, Calm1, Calb1, Nsf, Nefl, Hspa5, Nefh, Ncam1, Dcx, Unc13a, Mapk1, Syt2, Dnm1, and Cltc. Differential protein enrichment results show that these proteins may be related to synaptic vesicle cycle, vesicle-mediated transport in synapse, presynaptic endocytosis, synaptic vesicle endocytosis, axon guidance, calcium signaling pathway, and so on. CONCLUSION This study combined network pharmacology and proteomics to explore the main material basis of Radix Rhei Et Rhizome for the treatment of CI such as sennoside A, palmidin A, emodin, and toralactone. The mechanism may be related to the regulation of biological processes (such as synaptic vesicle cycle, vesicle-mediated transport in synapse, presynaptic endocytosis, and synaptic vesicle endocytosis) and signaling pathways (such as Ras, PI3K-Akt, TNF, FoxO, HIF-1, Rap1, and axon guidance).
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Affiliation(s)
- Wang Xiang
- The Affiliated Hospital of Guilin Medical University, Guilin, Guangxi Province, China
| | - Zhiyong Long
- Shantou University Medical College, Shantou University, Shantou, Guangdong, China
| | - Jinsong Zeng
- The First Affiliated Hospital of Hunan University of Chinese Medicine, Changsha, Hunan Province, China
- Hunan University of Chinese Medicine, Changsha, Hunan Province, China
| | - Xiaofei Zhu
- Hunan University of Chinese Medicine, Changsha, Hunan Province, China
| | - Mengxia Yuan
- Shantou University Medical College, Shantou University, Shantou, Guangdong, China
| | - Jiamin Wu
- Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Yonghe Wu
- Hunan University of Chinese Medicine, Changsha, Hunan Province, China
| | - Liang Liu
- Hunan University of Chinese Medicine, Changsha, Hunan Province, China
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31
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Gao Y, Raj JU. Extracellular Vesicles as Unique Signaling Messengers: Role in Lung Diseases. Compr Physiol 2020; 11:1351-1369. [PMID: 33294981 DOI: 10.1002/cphy.c200006] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Extracellular vesicles (EVs) are lipid bilayer-enclosed extracellular particles carrying rich cargo such as proteins, lipids, and microRNAs with distinct characteristics of their parental cells. EVs are emerging as an important form of cellular communication with the ability to selectively deliver a kit of directional instructions to nearby or distant cells to modulate their functions and phenotypes. According to their biogenesis, EVs can be divided into two groups: those of endocytic origin are called exosomes and those derived from outward budding of the plasma membrane are called microvesicles (also known as ectosomes or microparticles). Under physiological conditions, EVs are actively involved in maintenance of pulmonary hemostasis. However, EVs can contribute to the pathogenesis of diseases such as chronic obstructive pulmonary disease, asthma, acute lung injury/acute respiratory distress syndrome, interstitial lung disease, and pulmonary arterial hypertension. EVs, especially those derived from mesenchymal/stromal stem cells, can also be beneficial and can curb the development of lung diseases. Novel technologies are continuously being developed to minimize the undesirable effects of EVs and also to engineer EVs so that they may have beneficial effects and can be used as therapeutic agents in lung diseases. © 2021 American Physiological Society. Compr Physiol 11:1351-1369, 2021.
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Affiliation(s)
- Yuansheng Gao
- Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, China
| | - J Usha Raj
- Department of Pediatrics, College of Medicine at Chicago, University of Illinois, Chicago, Illinois, USA
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32
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Caparotta M, Tomes CN, Mayorga LS, Masone D. The Synaptotagmin-1 C2B Domain Is a Key Regulator in the Stabilization of the Fusion Pore. J Chem Theory Comput 2020; 16:7840-7851. [DOI: 10.1021/acs.jctc.0c00734] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Marcelo Caparotta
- Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo (UNCuyo), Mendoza 5500, Argentina
| | - Claudia N. Tomes
- Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo (UNCuyo), Mendoza 5500, Argentina
- Instituto de Histología y Embriología de Mendoza (IHEM) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Cuyo (UNCuyo), Mendoza 5500, Argentina
| | - Luis S. Mayorga
- Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo (UNCuyo), Mendoza 5500, Argentina
- Instituto de Histología y Embriología de Mendoza (IHEM) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Cuyo (UNCuyo), Mendoza 5500, Argentina
| | - Diego Masone
- Instituto de Histología y Embriología de Mendoza (IHEM) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Cuyo (UNCuyo), Mendoza 5500, Argentina
- Facultad de Ingeniería, Universidad Nacional de Cuyo (UNCuyo), Mendoza 5500, Argentina
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33
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Huson V, Meijer M, Dekker R, Ter Veer M, Ruiter M, van Weering JR, Verhage M, Cornelisse LN. Post-tetanic potentiation lowers the energy barrier for synaptic vesicle fusion independently of Synaptotagmin-1. eLife 2020; 9:55713. [PMID: 32831174 PMCID: PMC7500951 DOI: 10.7554/elife.55713] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 08/23/2020] [Indexed: 11/13/2022] Open
Abstract
Previously, we showed that modulation of the energy barrier for synaptic vesicle fusion boosts release rates supralinearly (Schotten, 2015). Here we show that mouse hippocampal synapses employ this principle to trigger Ca2+-dependent vesicle release and post-tetanic potentiation (PTP). We assess energy barrier changes by fitting release kinetics in response to hypertonic sucrose. Mimicking activation of the C2A domain of the Ca2+-sensor Synaptotagmin-1 (Syt1), by adding a positive charge (Syt1D232N) or increasing its hydrophobicity (Syt14W), lowers the energy barrier. Removing Syt1 or impairing its release inhibitory function (Syt19Pro) increases spontaneous release without affecting the fusion barrier. Both phorbol esters and tetanic stimulation potentiate synaptic strength, and lower the energy barrier equally well in the presence and absence of Syt1. We propose a model where tetanic stimulation activates Syt1-independent mechanisms that lower the energy barrier and act additively with Syt1-dependent mechanisms to produce PTP by exerting multiplicative effects on release rates.
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Affiliation(s)
- Vincent Huson
- Department of Functional Genomics, Clinical Genetics, Center for Neurogenomics and Cognitive Research, Amsterdam University Medical Center- Location VUmc, Amsterdam, Netherlands
| | - Marieke Meijer
- Department of Functional Genomics, Clinical Genetics, Center for Neurogenomics and Cognitive Research, Amsterdam University Medical Center- Location VUmc, Amsterdam, Netherlands
| | - Rien Dekker
- Department of Functional Genomics, Clinical Genetics, Center for Neurogenomics and Cognitive Research, Amsterdam University Medical Center- Location VUmc, Amsterdam, Netherlands
| | - Mirelle Ter Veer
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam, Amsterdam, Netherlands
| | - Marvin Ruiter
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam, Amsterdam, Netherlands
| | - Jan Rt van Weering
- Department of Functional Genomics, Clinical Genetics, Center for Neurogenomics and Cognitive Research, Amsterdam University Medical Center- Location VUmc, Amsterdam, Netherlands
| | - Matthijs Verhage
- Department of Functional Genomics, Clinical Genetics, Center for Neurogenomics and Cognitive Research, Amsterdam University Medical Center- Location VUmc, Amsterdam, Netherlands.,Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam, Amsterdam, Netherlands
| | - Lennart Niels Cornelisse
- Department of Functional Genomics, Clinical Genetics, Center for Neurogenomics and Cognitive Research, Amsterdam University Medical Center- Location VUmc, Amsterdam, Netherlands
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Camporesi E, Nilsson J, Brinkmalm A, Becker B, Ashton NJ, Blennow K, Zetterberg H. Fluid Biomarkers for Synaptic Dysfunction and Loss. Biomark Insights 2020; 15:1177271920950319. [PMID: 32913390 PMCID: PMC7444114 DOI: 10.1177/1177271920950319] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 07/13/2020] [Indexed: 12/11/2022] Open
Abstract
Synapses are the site for brain communication where information is transmitted between neurons and stored for memory formation. Synaptic degeneration is a global and early pathogenic event in neurodegenerative disorders with reduced levels of pre- and postsynaptic proteins being recognized as a core feature of Alzheimer's disease (AD) pathophysiology. Together with AD, other neurodegenerative and neurodevelopmental disorders show altered synaptic homeostasis as an important pathogenic event, and due to that, they are commonly referred to as synaptopathies. The exact mechanisms of synapse dysfunction in the different diseases are not well understood and their study would help understanding the pathogenic role of synaptic degeneration, as well as differences and commonalities among them and highlight candidate synaptic biomarkers for specific disorders. The assessment of synaptic proteins in cerebrospinal fluid (CSF), which can reflect synaptic dysfunction in patients with cognitive disorders, is a keen area of interest. Substantial research efforts are now directed toward the investigation of CSF synaptic pathology to improve the diagnosis of neurodegenerative disorders at an early stage as well as to monitor clinical progression. In this review, we will first summarize the pathological events that lead to synapse loss and then discuss the available data on established (eg, neurogranin, SNAP-25, synaptotagmin-1, GAP-43, and α-syn) and emerging (eg, synaptic vesicle glycoprotein 2A and neuronal pentraxins) CSF biomarkers for synapse dysfunction, while highlighting possible utilities, disease specificity, and technical challenges for their detection.
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Affiliation(s)
- Elena Camporesi
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Johanna Nilsson
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Ann Brinkmalm
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Bruno Becker
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
| | - Nicholas J Ashton
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- King’s College London, Institute of Psychiatry, Psychology & Neuroscience, The Maurice Wohl Clinical Neuroscience Institute, London, UK
- NIHR Biomedical Research Centre for Mental Health & Biomedical Research Unit for Dementia at South London & Maudsley NHS Foundation, London, UK
- Wallenberg Centre for Molecular and Translational Medicine, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Kaj Blennow
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
| | - Henrik Zetterberg
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK
- UK Dementia Research Institute at UCL, London, UK
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Prasad R, Zhou HX. Membrane Association and Functional Mechanism of Synaptotagmin-1 in Triggering Vesicle Fusion. Biophys J 2020; 119:1255-1265. [PMID: 32882186 DOI: 10.1016/j.bpj.2020.08.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 07/23/2020] [Accepted: 08/10/2020] [Indexed: 12/23/2022] Open
Abstract
Upon Ca2+ influx, synaptic vesicles fuse with the presynaptic plasma membrane (PM) to release neurotransmitters. Membrane fusion is triggered by synaptotagmin-1, a transmembrane protein in the vesicle membrane (VM), but the mechanism is under debate. Synaptotagmin-1 contains a single transmembrane helix (TM) and two tandem C2 domains (C2A and C2B). This study aimed to use molecular dynamics simulations to elucidate how Ca2+-bound synaptotagmin-1, by simultaneously associating with VM and PM, brings them together for fusion. Although C2A stably associates with VM via two Ca2+-binding loops, C2B has a propensity to partially dissociate. Importantly, an acidic motif in the TM-C2A linker competes with VM for interacting with C2B, thereby flipping its orientation to face PM. Subsequently, C2B readily associates with PM via a polybasic cluster and a Ca2+-binding loop. The resulting mechanistic model for the triggering of membrane fusion by synaptotagmin-1 reconciles many experimental observations.
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Affiliation(s)
- Ramesh Prasad
- Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois
| | - Huan-Xiang Zhou
- Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois; Department of Physics, University of Illinois at Chicago, Chicago, Illinois.
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Hepatic Synaptotagmin 1 is involved in the remodelling of liver plasma- membrane lipid composition and gene expression in male Apoe-deficient mice consuming a Western diet. Biochim Biophys Acta Mol Cell Biol Lipids 2020; 1865:158790. [PMID: 32771460 DOI: 10.1016/j.bbalip.2020.158790] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 07/28/2020] [Accepted: 08/02/2020] [Indexed: 11/20/2022]
Abstract
BACKGROUND AND AIMS The molecular mechanisms by which the liver develops steatotic disease still remain unclear. Previous studies using nutritional and genetic models of hepatic steatosis in mice showed that liver synaptotagmin 1 (Syt1) expression was associated with lipid droplet area. Hepatic Syt1 overexpression was used as a tool to explore its effect on hepatic and plasma lipids. METHODS AND RESULTS To find out a cause-effect, hepatic mouse Syt1 mRNA was cloned into a vector driving hepatocyte-specific expression and administered by hydrodynamic injection to male Apoe-deficient mice fed on a Western diet, the latter as a model of rapid spontaneous steatosis development. Hepatic microsomal, large vesicle, lysosomal and plasma membrane fractions were enriched in SYT1 protein following gene overexpression. In these conditions, very low density lipoprotein esterified cholesterol increased. Likewise, the transgene caused an alteration in lipid droplet surface and a positive correlation between Syt1 expression and hepatic total cholesterol content. A lipidomic approach evidenced a decrease in lysophosphatidylcholine, phosphatidylcholine and triglycerides in isolated plasma membrane fraction. Expressions of genes involved in biosynthesis of bile acids, fatty acid metabolism, lipoprotein dynamics and vesicular transport were modified by the increased SYT1 expression. CONCLUSIONS These results indicate that this protein is involved in hepatic management of lipids and in the regulation of genes involved in lipid metabolism.
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37
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Expression of ArfGAP3 in Vaginal Anterior Wall of Patients With Pelvic Floor Organ Prolapse in Pelvic Organ Prolapse and Non-Pelvic Organ Prolapse Patients. Female Pelvic Med Reconstr Surg 2020; 27:e64-e69. [PMID: 31868832 PMCID: PMC7774809 DOI: 10.1097/spv.0000000000000808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The purpose of this study was to study the expression of adenosine diphosphate ribosylation factor GTPase-activating protein 3 (ArfGAP3) in the anterior vaginal wall of patients with pelvic organ prolapse (POP).
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Synaptotagmin-1 and Doc2b Exhibit Distinct Membrane-Remodeling Mechanisms. Biophys J 2019; 118:643-656. [PMID: 31952804 DOI: 10.1016/j.bpj.2019.12.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 12/13/2019] [Accepted: 12/16/2019] [Indexed: 11/24/2022] Open
Abstract
Synaptotagmin-1 (Syt1) is a calcium sensor protein that is critical for neurotransmission and is therefore extensively studied. Here, we use pairs of optically trapped beads coated with SNARE-free synthetic membranes to investigate Syt1-induced membrane remodeling. This activity is compared with that of Doc2b, which contains a conserved C2AB domain and induces membrane tethering and hemifusion in this cell-free model. We find that the soluble C2AB domain of Syt1 strongly affects the probability and strength of membrane-membrane interactions in a strictly Ca2+- and protein-dependent manner. Single-membrane loading of Syt1 yielded the highest probability and force of membrane interactions, whereas in contrast, Doc2b was more effective after loading both membranes. A lipid-mixing assay with confocal imaging reveals that both Syt1 and Doc2b are able to induce hemifusion; however, significantly higher Syt1 concentrations are required. Consistently, both C2AB fragments cause a reduction in the membrane-bending modulus, as measured by a method based on atomic force microscopy. This lowering of the energy required for membrane deformation may contribute to Ca2+-induced fusion.
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Karatekin E, Rothman JE. FEBS Letters Special Issue on Exocytosis and Endocytosis. FEBS Lett 2019; 592:3477-3479. [PMID: 30417372 DOI: 10.1002/1873-3468.13274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Erdem Karatekin
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT, USA.,Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA.,Nanobiology Institute, Yale University, West Haven, CT, USA.,Centre National de la Recherche Scientifique (CNRS), Paris, France
| | - James E Rothman
- Nanobiology Institute, Yale University, West Haven, CT, USA.,Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA.,Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London, UK
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Gundersen CB. Fast, synchronous neurotransmitter release: Past, present and future. Neuroscience 2019; 439:22-27. [PMID: 31047980 DOI: 10.1016/j.neuroscience.2019.04.030] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 04/11/2019] [Accepted: 04/12/2019] [Indexed: 01/23/2023]
Abstract
This mini-review starts with a summary of the crucial contributions Ricardo Miledi made to our understanding of how the action potential triggers fast, synchronous transmitter release. It then transitions to the discovery of synaptotagmin and its role as the exocytotic Ca2+ sensor at nerve terminals. The final section confronts the array of unique models that have been proposed to explain the membrane fusion step of exocytosis. More than a dozen different hypotheses seek to explain the terminal steps of the exocytotic cascade. It will be an interesting challenge for the field to distinguish among these possibilities. Nevertheless, with ongoing technological advances, perhaps we will have a better picture of this process by the end of the coming decade. This article is part of a Special Issue entitled: Honoring Ricardo Miledi - outstanding neuroscientist of XX-XXI centuries.
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Affiliation(s)
- Cameron B Gundersen
- Department of Molecular and Medical Pharmacology, David Geffen UCLA School of Medicine, Los Angeles, CA 90095.
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Melrose J. Functional Consequences of Keratan Sulfate Sulfation in Electrosensory Tissues and in Neuronal Regulation. ACTA ACUST UNITED AC 2019; 3:e1800327. [PMID: 32627425 DOI: 10.1002/adbi.201800327] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 01/16/2019] [Indexed: 12/20/2022]
Abstract
Keratan sulfate (KS) is a functional electrosensory and neuro-instructive molecule. Recent studies have identified novel low sulfation KS in auditory and sensory tissues such as the tectorial membrane of the organ of Corti and the Ampullae of Lorenzini in elasmobranch fish. These are extremely sensitive proton gradient detection systems that send signals to neural interfaces to facilitate audition and electrolocation. High and low sulfation KS have differential functional roles in song learning in the immature male zebra song-finch with high charge density KS in song nuclei promoting brain development and cognitive learning. The conductive properties of KS are relevant to the excitable neural phenotype. High sulfation KS interacts with a large number of guidance and neuroregulatory proteins. The KS proteoglycan microtubule associated protein-1B (MAP1B) stabilizes actin and tubulin cytoskeletal development during neuritogenesis. A second 12 span transmembrane synaptic vesicle associated KS proteoglycan (SV2) provides a smart gel storage matrix for the storage of neurotransmitters. MAP1B and SV2 have prominent roles to play in neuroregulation. Aggrecan and phosphacan have roles in perineuronal net formation and in neuroregulation. A greater understanding of the biology of KS may be insightful as to how neural repair might be improved.
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Affiliation(s)
- James Melrose
- Raymond Purves Bone and Joint Research Laboratories, Kolling Institute of Medical Research, Royal North Shore Hospital and University of Sydney, St. Leonards, NSW, 2065, Australia.,Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW, 2052, Australia.,Sydney Medical School, Northern, Sydney University, Royal North Shore Hospital, St. Leonards, NSW, 2065, Australia.,Faculty of Medicine and Health, University of Sydney, Royal North Shore Hospital, St. Leonards, NSW, 2065, Australia
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Bornschein G, Schmidt H. Synaptotagmin Ca 2+ Sensors and Their Spatial Coupling to Presynaptic Ca v Channels in Central Cortical Synapses. Front Mol Neurosci 2019; 11:494. [PMID: 30697148 PMCID: PMC6341215 DOI: 10.3389/fnmol.2018.00494] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 12/21/2018] [Indexed: 11/21/2022] Open
Abstract
Ca2+ concentrations drop rapidly over a distance of a few tens of nanometers from an open voltage-gated Ca2+ channel (Cav), thereby, generating a spatially steep and temporally short-lived Ca2+ gradient that triggers exocytosis of a neurotransmitter filled synaptic vesicle. These non-steady state conditions make the Ca2+-binding kinetics of the Ca2+ sensors for release and their spatial coupling to the Cavs important parameters of synaptic efficacy. In the mammalian central nervous system, the main release sensors linking action potential mediated Ca2+ influx to synchronous release are Synaptotagmin (Syt) 1 and 2. We review here quantitative work focusing on the Ca2+ kinetics of Syt2-mediated release. At present similar quantitative detail is lacking for Syt1-mediated release. In addition to triggering release, Ca2+ remaining bound to Syt after the first of two successive high-frequency activations was found to be capable of facilitating release during the second activation. More recently, the Ca2+ sensor Syt7 was identified as additional facilitation sensor. We further review how several recent functional studies provided quantitative insights into the spatial topographical relationships between Syts and Cavs and identified mechanisms regulating the sensor-to-channel coupling distances at presynaptic active zones. Most synapses analyzed in matured cortical structures were found to operate at tight, nanodomain coupling. For fast signaling synapses a developmental switch from loose, microdomain to tight, nanodomain coupling was found. The protein Septin5 has been known for some time as a developmentally down-regulated “inhibitor” of tight coupling, while Munc13-3 was found only recently to function as a developmentally up-regulated mediator of tight coupling. On the other hand, a highly plastic synapse was found to operate at loose coupling in the matured hippocampus. Together these findings suggest that the coupling topography and its regulation is a specificity of the type of synapse. However, to definitely draw such conclusion our knowledge of functional active zone topographies of different types of synapses in different areas of the mammalian brain is too incomplete.
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Affiliation(s)
- Grit Bornschein
- Carl-Ludwig Institute for Physiology, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Hartmut Schmidt
- Carl-Ludwig Institute for Physiology, Medical Faculty, University of Leipzig, Leipzig, Germany
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