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Lin G, Rennie M, Adeeko A, Scarlata S. The role of calcium in neuronal membrane tension and synaptic plasticity. Biochem Soc Trans 2024; 52:937-945. [PMID: 38533899 DOI: 10.1042/bst20231518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 03/13/2024] [Accepted: 03/14/2024] [Indexed: 03/28/2024]
Abstract
Calcium is a primary second messenger that plays a role in cellular functions including growth, movement and responses to drugs. The role that calcium plays in mediating communication between neurons by synaptic vesicle release is well established. This review focuses on the dependence of the physical properties of neuronal plasma membranes on calcium levels. After describing the key features of synaptic plasticity, we summarize the general role of calcium in cell function and the signaling pathways responsible for intracellular increase in calcium levels. We then present findings showing that increases in intracellular calcium levels cause neurites to contract and break synaptic connections by changes in membrane tension.
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Affiliation(s)
- Guanyu Lin
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, 100 Institute Rd., Worcester, MA 01609, U.S.A
| | - Madison Rennie
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, 100 Institute Rd., Worcester, MA 01609, U.S.A
| | - Ayobami Adeeko
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, 100 Institute Rd., Worcester, MA 01609, U.S.A
| | - Suzanne Scarlata
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, 100 Institute Rd., Worcester, MA 01609, U.S.A
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2
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Hendricks EL, Liebl FLW. The CHD family chromatin remodeling enzyme, Kismet, promotes both clathrin-mediated and activity-dependent bulk endocytosis. PLoS One 2024; 19:e0300255. [PMID: 38512854 PMCID: PMC10956772 DOI: 10.1371/journal.pone.0300255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 02/23/2024] [Indexed: 03/23/2024] Open
Abstract
Chromodomain helicase DNA binding domain (CHD) proteins, including CHD7 and CHD8, remodel chromatin to enable transcriptional programs. Both proteins are important for proper neural development as heterozygous mutations in Chd7 and Chd8 are causative for CHARGE syndrome and correlated with autism spectrum disorders, respectively. Their roles in mature neurons are poorly understood despite influencing the expression of genes required for cell adhesion, neurotransmission, and synaptic plasticity. The Drosophila homolog of CHD7 and CHD8, Kismet (Kis), promotes neurotransmission, endocytosis, and larval locomotion. Endocytosis is essential in neurons for replenishing synaptic vesicles, maintaining protein localization, and preserving the size and composition of the presynaptic membrane. Several forms of endocytosis have been identified including clathrin-mediated endocytosis, which is coupled with neural activity and is the most prevalent form of synaptic endocytosis, and activity-dependent bulk endocytosis, which occurs during periods of intense stimulation. Kis modulates the expression of gene products involved in endocytosis including promoting shaggy/GSK3β expression while restricting PI3K92E. kis mutants electrophysiologically phenocopy a liquid facets mutant in response to paradigms that induce clathrin-mediated endocytosis and activity-dependent bulk endocytosis. Further, kis mutants do not show further reductions in endocytosis when activity-dependent bulk endocytosis or clathrin-mediated endocytosis are pharmacologically inhibited. We find that Kis is important in postsynaptic muscle for proper endocytosis but the ATPase domain of Kis is dispensable for endocytosis. Collectively, our data indicate that Kis promotes both clathrin-mediated endocytosis and activity-dependent bulk endocytosis possibly by promoting transcription of several endocytic genes and maintaining the size of the synaptic vesicle pool.
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Affiliation(s)
- Emily L. Hendricks
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, Illinois, United States of America
| | - Faith L. W. Liebl
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, Illinois, United States of America
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3
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Li Q, Wang L, Tang C, Wang X, Yu Z, Ping X, Ding M, Zheng L. Adipose Tissue Exosome circ_sxc Mediates the Modulatory of Adiposomes on Brain Aging by Inhibiting Brain dme-miR-87-3p. Mol Neurobiol 2024; 61:224-238. [PMID: 37597108 DOI: 10.1007/s12035-023-03516-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 07/14/2023] [Indexed: 08/21/2023]
Abstract
Aging of the brain usually leads to the decline of neurological processes and is a major risk factor for various neurodegenerative diseases, including sleep disturbances and cognitive decline. Adipose tissue exosomes, as adipocyte-derived vesicles, may mediate the regulatory processes of adipose tissue on other organs, including the brain; however, the regulatory mechanisms remain unclear. We analyzed the sleep-wake behavior of young (10 days) and old (40 days) Drosophila and found that older Drosophila showed increased sleep fragmentation, which is similar to mammalian aging characteristics. To investigate the cross-tissue regulatory mechanisms of adiposity on brain aging, we extracted 10-day and 40-day Drosophila adipose tissue exosomes and identified circRNAs with age-dependent expression differences by RNA-seq and differential analysis. Furthermore, by combining data from 3 datasets of the GEO database (GSE130158, GSE24992, and GSE184559), circ_sxc that was significantly downregulated with age was finally screened out. Moreover, dme-miR-87-3p, a conserved target of circ_sxc, accumulates in the brain with age and exhibits inhibitory effects in predicted binding relationships with neuroreceptor ligand genes. In summary, the current study showed that the Drosophila brain could obtain circ_sxc by uptake of adipose tissue exosomes which crossed the blood-brain barrier. And circ_sxc suppressed brain miR-87-3p expression through sponge adsorption, which in turn regulated the expression of neurological receptor ligand proteins (5-HT1B, GABA-B-R1, Rdl, Rh7, qvr, NaCP60E) and ensured brain neuronal synaptic signaling normal function of synaptic signaling. However, with aging, this regulatory mechanism is dysregulated by the downregulation of the adipose exosome circ_sxc, which contributes to the brain exhibiting sleep disturbances and other "aging" features.
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Affiliation(s)
- Qiufang Li
- Key Laboratory of Physical Fitness and Exercise Rehabilitation of Hunan Province, Hunan Normal University, Changsha, Hunan, China
| | - Lingxiao Wang
- The Center for Heart Development, State Key Laboratory of Development Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, Hunan, China.
| | - Chao Tang
- Key Laboratory of Physical Fitness and Exercise Rehabilitation of Hunan Province, Hunan Normal University, Changsha, Hunan, China
| | - Xiaoya Wang
- Key Laboratory of Physical Fitness and Exercise Rehabilitation of Hunan Province, Hunan Normal University, Changsha, Hunan, China
| | - Zhengwen Yu
- Key Laboratory of Physical Fitness and Exercise Rehabilitation of Hunan Province, Hunan Normal University, Changsha, Hunan, China
| | - Xu Ping
- Key Laboratory of Physical Fitness and Exercise Rehabilitation of Hunan Province, Hunan Normal University, Changsha, Hunan, China
| | - Meng Ding
- Key Laboratory of Physical Fitness and Exercise Rehabilitation of Hunan Province, Hunan Normal University, Changsha, Hunan, China
| | - Lan Zheng
- Key Laboratory of Physical Fitness and Exercise Rehabilitation of Hunan Province, Hunan Normal University, Changsha, Hunan, China.
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4
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Wang Y, Zhu Y, Li W, Yan S, Li C, Ma K, Hu M, Du C, Fu L, Sun J, Zhang CX. Synaptotagmin-11 Inhibits Synaptic Vesicle Endocytosis via Endophilin A1. J Neurosci 2023; 43:6230-6248. [PMID: 37474308 PMCID: PMC10490507 DOI: 10.1523/jneurosci.1348-21.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 05/12/2023] [Accepted: 06/02/2023] [Indexed: 07/22/2023] Open
Abstract
Synaptic vesicle (SV) endocytosis is a critical and well-regulated process for the maintenance of neurotransmission. We previously reported that synaptotagmin-11 (Syt11), an essential non-Ca2+-binding Syt associated with brain diseases, inhibits neuronal endocytosis (Wang et al., 2016). Here, we found that Syt11 deficiency caused accelerated SV endocytosis and vesicle recycling under sustained stimulation and led to the abnormal membrane partition of synaptic proteins in mouse hippocampal boutons of either sex. Furthermore, our study revealed that Syt11 has direct but Ca2+-independent binding with endophilin A1 (EndoA1), a membrane curvature sensor and endocytic protein recruiter, with high affinity. EndoA1-knockdown significantly reversed Syt11-KO phenotype, identifying EndoA1 as a main inhibitory target of Syt11 during SV endocytosis. The N-terminus of EndoA1 and the C2B domain of Syt11 were responsible for this interaction. A peptide (amino acids 314-336) derived from the Syt11 C2B efficiently blocked Syt11-EndoA1 binding both in vitro and in vivo Application of this peptide inhibited SV endocytosis in WT hippocampal neurons but not in EndoA1-knockdown neurons. Moreover, intracellular application of this peptide in mouse calyx of Held terminals of either sex effectively hampered both fast and slow SV endocytosis at physiological temperature. We thus propose that Syt11 ensures the precision of protein retrieval during SV endocytosis by inhibiting EndoA1 function at neuronal terminals.SIGNIFICANCE STATEMENT Endocytosis is a key stage of synaptic vesicle (SV) recycling. SV endocytosis retrieves vesicular membrane and protein components precisely to support sustained neurotransmission. However, the molecular mechanisms underlying the regulation of SV endocytosis remain elusive. Here, we reported that Syt11-KO accelerated SV endocytosis and impaired membrane partition of synaptic proteins. EndoA1 was identified as a main inhibitory target of Syt11 during SV endocytosis. Our study reveals a novel inhibitory mechanism of SV endocytosis in preventing hyperactivation of endocytosis, potentially safeguarding the recycling of synaptic proteins during sustained neurotransmission.
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Affiliation(s)
- Yalong Wang
- Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences; CAS Key Laboratory of Brain Connectome and Manipulation; Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, Guangdong 518055, China
- Beijing Institute of Brain Disorders, Laboratory of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, 100069, China
| | - Ying Zhu
- State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Wanru Li
- Beijing Institute of Brain Disorders, Laboratory of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, 100069, China
| | - Shuxin Yan
- Beijing Institute of Brain Disorders, Laboratory of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, 100069, China
| | - Chao Li
- State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Kunpeng Ma
- Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences; CAS Key Laboratory of Brain Connectome and Manipulation; Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, Guangdong 518055, China
| | - Meiqin Hu
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan 48109
| | - Cuilian Du
- Beijing Institute of Brain Disorders, Laboratory of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, 100069, China
| | - Lei Fu
- Academy of Pharmacy, Xi'an Jiaotong-Liverpool University, Suzhou, Jiangsu 215123, China
| | - Jianyuan Sun
- Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences; CAS Key Laboratory of Brain Connectome and Manipulation; Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, Guangdong 518055, China
- Beijing Institute of Brain Disorders, Laboratory of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, 100069, China
- State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Claire Xi Zhang
- Beijing Institute of Brain Disorders, Laboratory of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, 100069, China
- Academy of Pharmacy, Xi'an Jiaotong-Liverpool University, Suzhou, Jiangsu 215123, China
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5
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Ogunmowo TH, Jing H, Raychaudhuri S, Kusick GF, Imoto Y, Li S, Itoh K, Ma Y, Jafri H, Dalva MB, Chapman ER, Ha T, Watanabe S, Liu J. Membrane compression by synaptic vesicle exocytosis triggers ultrafast endocytosis. Nat Commun 2023; 14:2888. [PMID: 37210439 PMCID: PMC10199930 DOI: 10.1038/s41467-023-38595-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2022] [Accepted: 05/09/2023] [Indexed: 05/22/2023] Open
Abstract
Compensatory endocytosis keeps the membrane surface area of secretory cells constant following exocytosis. At chemical synapses, clathrin-independent ultrafast endocytosis maintains such homeostasis. This endocytic pathway is temporally and spatially coupled to exocytosis; it initiates within 50 ms at the region immediately next to the active zone where vesicles fuse. However, the coupling mechanism is unknown. Here, we demonstrate that filamentous actin is organized as a ring, surrounding the active zone at mouse hippocampal synapses. Assuming the membrane area conservation is due to this actin ring, our theoretical model suggests that flattening of fused vesicles exerts lateral compression in the plasma membrane, resulting in rapid formation of endocytic pits at the border between the active zone and the surrounding actin-enriched region. Consistent with model predictions, our data show that ultrafast endocytosis requires sufficient compression by exocytosis of multiple vesicles and does not initiate when actin organization is disrupted, either pharmacologically or by ablation of the actin-binding protein Epsin1. Our work suggests that membrane mechanics underlie the rapid coupling of exocytosis to endocytosis at synapses.
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Affiliation(s)
- Tyler H Ogunmowo
- Department of Cell Biology, School of Medicine, Johns Hopkins University, Baltimore, MD, US
- Center for Cell Dynamics, School of Medicine, Johns Hopkins University, Baltimore, MD, US
- Biochemistry, Cellular and Molecular Biology graduate program, Johns Hopkins University, Baltimore, MD, US
| | - Haoyuan Jing
- Department of Cell Biology, School of Medicine, Johns Hopkins University, Baltimore, MD, US
- Center for Cell Dynamics, School of Medicine, Johns Hopkins University, Baltimore, MD, US
| | - Sumana Raychaudhuri
- Department of Cell Biology, School of Medicine, Johns Hopkins University, Baltimore, MD, US
- Center for Cell Dynamics, School of Medicine, Johns Hopkins University, Baltimore, MD, US
| | - Grant F Kusick
- Department of Cell Biology, School of Medicine, Johns Hopkins University, Baltimore, MD, US
- Center for Cell Dynamics, School of Medicine, Johns Hopkins University, Baltimore, MD, US
- Biochemistry, Cellular and Molecular Biology graduate program, Johns Hopkins University, Baltimore, MD, US
| | - Yuuta Imoto
- Department of Cell Biology, School of Medicine, Johns Hopkins University, Baltimore, MD, US
- Center for Cell Dynamics, School of Medicine, Johns Hopkins University, Baltimore, MD, US
| | - Shuo Li
- Department of Cell Biology, School of Medicine, Johns Hopkins University, Baltimore, MD, US
- Center for Cell Dynamics, School of Medicine, Johns Hopkins University, Baltimore, MD, US
- Department of Ophthalmology, School of Medicine, Stanford University, Palo Alto, CA, US
| | - Kie Itoh
- Department of Cell Biology, School of Medicine, Johns Hopkins University, Baltimore, MD, US
- Center for Cell Dynamics, School of Medicine, Johns Hopkins University, Baltimore, MD, US
| | - Ye Ma
- Department of Biomedical Engineering, School of Medicine, Johns Hopkins University, Baltimore, MD, US
| | - Haani Jafri
- Department of Neuroscience and Jefferson Synaptic Biology Center, Thomas Jefferson University, Philadelphia, PA, US
| | - Matthew B Dalva
- Department of Neuroscience and Jefferson Synaptic Biology Center, Thomas Jefferson University, Philadelphia, PA, US
- Department of Cell and Molecular Biology and the Tulane Brain Institute, Tulane University, New Orleans, LA, US
| | - Edwin R Chapman
- Department of Neuroscience, University of Wisconsin-Madison, Madison, WI, US
- Howard Hughes Medical Institute, Madison, WI, US
| | - Taekjip Ha
- Department of Biomedical Engineering, School of Medicine, Johns Hopkins University, Baltimore, MD, US
- Department of Biophysics and Biophysical Chemistry, School of Medicine, Johns Hopkins University, Baltimore, MD, US
- Department of Biophysics, Johns Hopkins University, Baltimore, MD, US
- Howard Hughes Medical Institute, Baltimore, MD, US
| | - Shigeki Watanabe
- Department of Cell Biology, School of Medicine, Johns Hopkins University, Baltimore, MD, US.
- Center for Cell Dynamics, School of Medicine, Johns Hopkins University, Baltimore, MD, US.
- Solomon H. Snyder Department of Neuroscience, School of Medicine, Johns Hopkins University, Baltimore, MD, US.
| | - Jian Liu
- Department of Cell Biology, School of Medicine, Johns Hopkins University, Baltimore, MD, US.
- Center for Cell Dynamics, School of Medicine, Johns Hopkins University, Baltimore, MD, US.
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6
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Song C, Zhou H, Lu H, Luo C, Wang C, Wang Q, Peng Y, Xin Y, Liu T, Yang W. Aberrant expression for microRNA is potential crucial factors of haemorrhoid. Hereditas 2020; 157:25. [PMID: 32620169 PMCID: PMC7334851 DOI: 10.1186/s41065-020-00139-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 06/30/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Haemorrhoids occur commonly and frequently in the human digestive system. There are diverse causes of haemorrhoids and their in-depth pathogenesis is still currently unclear. METHODS In this study, we explored haemorrhoids from an epigenetics perspective by employing RNA-Seq for comprehensive and in-depth analysis of the differences in microRNA (miRNA) transcripts between haemorrhoidal tissue and normal tissue in 48 patients with Grade II and above haemorrhoids. RESULTS The results showed that 9 miRNAs were significantly upregulated (ratio > 3.5 and P-value < 0.01) and 16 miRNAs were significantly downregulated (ratio > 0.6 and P-value < 0.01) in haemorrhoid tissue. Subsequently, target gene prediction results showed that there were 184 potential target genes of significantly upregulated miRNAs (common to both TargetScan7.1 and MirdbV5 databases) and there were 372 potential target genes of significantly downregulated miRNAs. Gene ontology analysis results showed that the target genes of differentially expressed miRNAs in haemorrhoids are involved in regulating "cell composition" and "protein binding". Lastly, KEGG search found that the differentially expressed miRNAs that are associated with the occurrence of haemorrhoids mainly regulate the activity of endocytosis and the synaptic vesicle cycle. CONCLUSIONS In summary, the results of high-throughput RNA-Seq screening suggested that the occurrence of haemorrhoids may be intimately associated with aberrant miRNA transcription, resulting in aberrant target gene expression and an imbalance in certain signal transduction pathways.
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Affiliation(s)
- Chengkun Song
- Department of Anorectal Surgery, Shuguang Hospital, Shanghai University of Traditional Chinese Medicine, 528 Zhangheng Road, Shanghai, 201203, P.R. China
| | - Haikun Zhou
- Department of Anorectal Surgery, Shuguang Hospital, Shanghai University of Traditional Chinese Medicine, 528 Zhangheng Road, Shanghai, 201203, P.R. China
| | - Hong Lu
- Department of Anorectal Surgery, Shuguang Hospital, Shanghai University of Traditional Chinese Medicine, 528 Zhangheng Road, Shanghai, 201203, P.R. China
| | - Chunsheng Luo
- Department of Anorectal Surgery, Shuguang Hospital, Shanghai University of Traditional Chinese Medicine, 528 Zhangheng Road, Shanghai, 201203, P.R. China
| | - Chen Wang
- Department of Anorectal Surgery, Shuguang Hospital, Shanghai University of Traditional Chinese Medicine, 528 Zhangheng Road, Shanghai, 201203, P.R. China
| | - Qingming Wang
- Department of Anorectal Surgery, Shuguang Hospital, Shanghai University of Traditional Chinese Medicine, 528 Zhangheng Road, Shanghai, 201203, P.R. China
| | - Yunhua Peng
- Department of Anorectal Surgery, Shuguang Hospital, Shanghai University of Traditional Chinese Medicine, 528 Zhangheng Road, Shanghai, 201203, P.R. China
| | - Yaojie Xin
- Department of Otolaryngology, Shuguang Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
| | - Te Liu
- Shanghai Geriatric Institute of Chinese Medicine, Shanghai University of Traditional Chinese Medicine, 365 South Xiangyang Road, Shanghai, 200031, P.R. China.
- Department of Pathology, Yale University School of Medicine, New Haven, CT, 06520, USA.
| | - Wei Yang
- Department of Anorectal Surgery, Shuguang Hospital, Shanghai University of Traditional Chinese Medicine, 528 Zhangheng Road, Shanghai, 201203, P.R. China.
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Kadri S, El Ayed M, Cosette P, Jouenne T, Elkhaoui S, Zekri S, Limam F, Aouani E, Mokni M. Neuroprotective effect of grape seed extract on brain ischemia: a proteomic approach. Metab Brain Dis 2019; 34:889-907. [PMID: 30796716 DOI: 10.1007/s11011-019-00396-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 02/04/2019] [Indexed: 01/01/2023]
Abstract
Stroke is one of the leading causes of long-lasting disability in human and oxidative stress an important underlying cause. Molecular insights into pathophysiology of ischemic stroke are still obscure, and the present study investigated the protective effect of high dosage Grape Seed Extract (GSE 2.5 g/kg) on brain ischemia-reperfusion (I/R) injury using a proteomic approach. Ischemia was realized by occlusion of the common carotid arteries for 30 min followed by 1 h reperfusion on control or GSE pre-treated rats, and a label-free quantification followed by mass spectrometry analysis used to evaluate I/R induced alterations in protein abundance and metabolic pathways as well as the protection afforded by GSE. I/R-induced whole brain ionogram dyshomeostasis, ultrastructural alterations, as well as inflammation into hippocampal dentate gyrus area, which were evaluated using ICP-OES, transmission electron microscopy and immuno-histochemistry respectively. I/R altered the whole brain proteome abundance among which 108 proteins were significantly modified (35 up and 73 down-regulated proteins). Eighty-four proteins were protected upon GSE treatment among which 27 were up and 57 down-regulated proteins, suggesting a potent protective effect of GSE close to 78%of the disturbed proteome. Furthermore, GSE efficiently prevented the brain from I/R-induced ion dyshomeostasis, ultrastructural alterations, inflammatory biomarkers as CD56 or CD68 and calcium burst within the hippocampus. To conclude, a potent protective effect of GSE on brain ischemia is evidenced and clinical trials using high dosage GSE should be envisaged on people at high risk for stroke.
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Affiliation(s)
- Safwen Kadri
- Bioactive Substances Laboratory, Biotechnology Centre, TechnopolisBorj-Cedria, BP-901, 2050, Hammam-Lif, Tunis, Tunisia.
| | - Mohamed El Ayed
- Bioactive Substances Laboratory, Biotechnology Centre, TechnopolisBorj-Cedria, BP-901, 2050, Hammam-Lif, Tunis, Tunisia
| | - Pascal Cosette
- Plateforme Protéomique PISSARO, Institut de Recherche et d'Innovation Biomédicale, Normandie Université, Mont Saint Aignan, France
| | - Thierry Jouenne
- Plateforme Protéomique PISSARO, Institut de Recherche et d'Innovation Biomédicale, Normandie Université, Mont Saint Aignan, France
| | - Salem Elkhaoui
- Bioactive Substances Laboratory, Biotechnology Centre, TechnopolisBorj-Cedria, BP-901, 2050, Hammam-Lif, Tunis, Tunisia
| | - Sami Zekri
- Common Services Unit on Transmission Electron Microscopy, Faculty of Medicineof Tunis, University of Tunis El Manar, Bab Saâdoun, Tunis, Tunisia
| | - Ferid Limam
- Bioactive Substances Laboratory, Biotechnology Centre, TechnopolisBorj-Cedria, BP-901, 2050, Hammam-Lif, Tunis, Tunisia
| | - Ezzedine Aouani
- Bioactive Substances Laboratory, Biotechnology Centre, TechnopolisBorj-Cedria, BP-901, 2050, Hammam-Lif, Tunis, Tunisia
| | - Meherzia Mokni
- Bioactive Substances Laboratory, Biotechnology Centre, TechnopolisBorj-Cedria, BP-901, 2050, Hammam-Lif, Tunis, Tunisia
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8
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Guzman GA, Guzman RE, Jordan N, Hidalgo P. A Tripartite Interaction Among the Calcium Channel α 1- and β-Subunits and F-Actin Increases the Readily Releasable Pool of Vesicles and Its Recovery After Depletion. Front Cell Neurosci 2019; 13:125. [PMID: 31130843 PMCID: PMC6509170 DOI: 10.3389/fncel.2019.00125] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 03/13/2019] [Indexed: 11/13/2022] Open
Abstract
Neurotransmitter release is initiated by the influx of Ca2+via voltage-gated calcium channels. The accessory β-subunit (CaVβ) of these channels shapes synaptic transmission by associating with the pore-forming subunit (CaVα1) and up-regulating presynaptic calcium currents. Besides CaVα1, CaVβ interacts with several partners including actin filaments (F-actin). These filaments are known to associate with synaptic vesicles (SVs) at the presynaptic terminals and support their translocation within different pools, but the role of CaVβ/F-actin association on synaptic transmission has not yet been explored. We here study how CaVβ4, the major calcium channel β isoform in mamalian brain, modifies synaptic transmission in concert with F-actin in cultured hippocampal neurons. We analyzed the effect of exogenous CaVβ4 before and after pharmacological disruption of the actin cytoskeleton and dissected calcium channel-dependent and -independent functions by comparing the effects of the wild-type subunit with the one bearing a double mutation that impairs binding to CaVα1. We found that exogenously expressed wild-type CaVβ4 enhances spontaneous and depolarization-evoked excitatory postsynaptic currents (EPSCs) without altering synaptogenesis. CaVβ4 increases the size of the readily releasable pool (RRP) of SVs at resting conditions and accelerates their recovery after depletion. The enhanced neurotransmitter release induced by CaVβ4 is abolished upon disruption of the actin cytoskeleton. The CaVα1 association-deficient CaVβ4 mutant associates with actin filaments, but neither alters postsynaptic responses nor the time course of the RRP recovery. Furthermore, this mutant protein preserves the ability to increase the RRP size. These results indicate that the interplay between CaVβ4 and F-actin also support the recruitment of SVs to the RRP in a CaVα1-independent manner. Our studies show an emerging role of CaVβ in determining SV maturation toward the priming state and its replenishment after release. We envision that this subunit plays a role in coupling exocytosis to endocytosis during the vesicle cycle.
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Affiliation(s)
- Gustavo A Guzman
- Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, Jülich, Germany
| | - Raul E Guzman
- Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, Jülich, Germany
| | - Nadine Jordan
- Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, Jülich, Germany
| | - Patricia Hidalgo
- Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, Jülich, Germany.,Institute of Biochemistry, Heinrich-Heine University, Düsseldorf, Germany
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9
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Tarasova EO, Gaydukov AE, Balezina OP. Calcineurin and Its Role in Synaptic Transmission. BIOCHEMISTRY (MOSCOW) 2018; 83:674-689. [PMID: 30195324 DOI: 10.1134/s0006297918060056] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Calcineurin (CaN) is a serine/threonine phosphatase widely expressed in different cell types and structures including neurons and synapses. The most studied role of CaN is its involvement in the functioning of postsynaptic structures of central synapses. The role of CaN in the presynaptic structures of central and peripheral synapses is less understood, although it has generated a considerable interest and is a subject of a growing number of studies. The regulatory role of CaN in synaptic vesicle endocytosis in the synapse terminals is actively studied. In recent years, new targets of CaN have been identified and its role in the regulation of enzymes and neurotransmitter secretion in peripheral neuromuscular junctions has been revealed. CaN is the only phosphatase that requires calcium and calmodulin for activation. In this review, we present details of CaN molecular structure and give a detailed description of possible mechanisms of CaN activation involving calcium, enzymes, and endogenous and exogenous inhibitors. Known and newly discovered CaN targets at pre- and postsynaptic levels are described. CaN activity in synaptic structures is discussed in terms of functional involvement of this phosphatase in synaptic transmission and neurotransmitter release.
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Affiliation(s)
- E O Tarasova
- Lomonosov Moscow State University, Faculty of Biology, Moscow, 119991, Russia
| | - A E Gaydukov
- Lomonosov Moscow State University, Faculty of Biology, Moscow, 119991, Russia. .,Pirogov Russian National Research Medical University, Moscow, 117997, Russia
| | - O P Balezina
- Lomonosov Moscow State University, Faculty of Biology, Moscow, 119991, Russia
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10
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The remembrance of the things past: Conserved signalling pathways link protozoa to mammalian nervous system. Cell Calcium 2018; 73:25-39. [DOI: 10.1016/j.ceca.2018.04.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 04/01/2018] [Accepted: 04/01/2018] [Indexed: 12/13/2022]
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11
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Plattner H. Evolutionary Cell Biology of Proteins from Protists to Humans and Plants. J Eukaryot Microbiol 2017; 65:255-289. [PMID: 28719054 DOI: 10.1111/jeu.12449] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 07/04/2017] [Accepted: 07/07/2017] [Indexed: 01/10/2023]
Abstract
During evolution, the cell as a fine-tuned machine had to undergo permanent adjustments to match changes in its environment, while "closed for repair work" was not possible. Evolution from protists (protozoa and unicellular algae) to multicellular organisms may have occurred in basically two lineages, Unikonta and Bikonta, culminating in mammals and angiosperms (flowering plants), respectively. Unicellular models for unikont evolution are myxamoebae (Dictyostelium) and increasingly also choanoflagellates, whereas for bikonts, ciliates are preferred models. Information accumulating from combined molecular database search and experimental verification allows new insights into evolutionary diversification and maintenance of genes/proteins from protozoa on, eventually with orthologs in bacteria. However, proteins have rarely been followed up systematically for maintenance or change of function or intracellular localization, acquirement of new domains, partial deletion (e.g. of subunits), and refunctionalization, etc. These aspects are discussed in this review, envisaging "evolutionary cell biology." Protozoan heritage is found for most important cellular structures and functions up to humans and flowering plants. Examples discussed include refunctionalization of voltage-dependent Ca2+ channels in cilia and replacement by other types during evolution. Altogether components serving Ca2+ signaling are very flexible throughout evolution, calmodulin being a most conservative example, in contrast to calcineurin whose catalytic subunit is lost in plants, whereas both subunits are maintained up to mammals for complex functions (immune defense and learning). Domain structure of R-type SNAREs differs in mono- and bikonta, as do Ca2+ -dependent protein kinases. Unprecedented selective expansion of the subunit a which connects multimeric base piece and head parts (V0, V1) of H+ -ATPase/pump may well reflect the intriguing vesicle trafficking system in ciliates, specifically in Paramecium. One of the most flexible proteins is centrin when its intracellular localization and function throughout evolution is traced. There are many more examples documenting evolutionary flexibility of translation products depending on requirements and potential for implantation within the actual cellular context at different levels of evolution. From estimates of gene and protein numbers per organism, it appears that much of the basic inventory of protozoan precursors could be transmitted to highest eukaryotic levels, with some losses and also with important additional "inventions."
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Affiliation(s)
- Helmut Plattner
- Department of Biology, University of Konstanz, P. O. Box M625, Konstanz, 78457, Germany
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12
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Eich ML, Dembla E, Wahl S, Dembla M, Schwarz K, Schmitz F. The Calcineurin-Binding, Activity-Dependent Splice Variant Dynamin1xb Is Highly Enriched in Synapses in Various Regions of the Central Nervous System. Front Mol Neurosci 2017; 10:230. [PMID: 28790889 PMCID: PMC5524891 DOI: 10.3389/fnmol.2017.00230] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2017] [Accepted: 07/06/2017] [Indexed: 12/22/2022] Open
Abstract
In the present study, we generated and characterized a splice site-specific monoclonal antibody that selectively detects the calcineurin-binding dynamin1 splice variant dynamin1xb. Calcineurin is a Ca2+-regulated phosphatase that enhances dynamin1 activity and is an important Ca2+-sensing mediator of homeostatic synaptic plasticity in neurons. Using this dynamin1xb-specific antibody, we found dynamin1xb highly enriched in synapses of all analyzed brain regions. In photoreceptor ribbon synapses, dynamin1xb was enriched in close vicinity to the synaptic ribbon in a manner indicative of a peri-active zone immunolabeling. Interestingly, in dark-adapted mice we observed an enhanced and selective enrichment of dynamin1xb in both synaptic layers of the retina in comparison to light-adapted mice. This could be due to an illumination-dependent recruitment of dynamin1xb to retinal synapses and/or due to a darkness-induced increase of dynamin1xb biosynthesis. These latter findings indicate that dynamin1xb is part of a versatile and highly adjustable, activity-regulated endocytic synaptic machinery.
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Affiliation(s)
- Marie-Lisa Eich
- Department of Neuroanatomy, Medical School Homburg/Saar, Institute for Anatomy and Cell Biology, Saarland UniversityHomburg/Saar, Germany
| | - Ekta Dembla
- Department of Neuroanatomy, Medical School Homburg/Saar, Institute for Anatomy and Cell Biology, Saarland UniversityHomburg/Saar, Germany
| | - Silke Wahl
- Department of Neuroanatomy, Medical School Homburg/Saar, Institute for Anatomy and Cell Biology, Saarland UniversityHomburg/Saar, Germany
| | - Mayur Dembla
- Department of Neuroanatomy, Medical School Homburg/Saar, Institute for Anatomy and Cell Biology, Saarland UniversityHomburg/Saar, Germany
| | - Karin Schwarz
- Department of Neuroanatomy, Medical School Homburg/Saar, Institute for Anatomy and Cell Biology, Saarland UniversityHomburg/Saar, Germany
| | - Frank Schmitz
- Department of Neuroanatomy, Medical School Homburg/Saar, Institute for Anatomy and Cell Biology, Saarland UniversityHomburg/Saar, Germany
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13
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Wang YL, Zhang CX. Putting a brake on synaptic vesicle endocytosis. Cell Mol Life Sci 2017; 74:2917-2927. [PMID: 28361181 PMCID: PMC11107501 DOI: 10.1007/s00018-017-2506-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 02/14/2017] [Accepted: 03/14/2017] [Indexed: 01/16/2023]
Abstract
In chemical synapses, action potentials evoke synaptic vesicle fusion with the presynaptic membrane at the active zone to release neurotransmitter. Synaptic vesicle endocytosis (SVE) then follows exocytosis to recapture vesicle proteins and lipid components for recycling and the maintenance of membrane homeostasis. Therefore, SVE plays an essential role during neurotransmission and is one of the most precisely regulated biological processes. Four modes of SVE have been characterized and both positive and negative regulators have been identified. However, our understanding of SVE regulation remains unclear, especially the identity of negative regulators and their mechanisms of action. Here, we review the current knowledge of proteins that function as inhibitors of SVE and their modes of action in different forms of endocytosis. We also propose possible physiological roles of such negative regulation. We believe that a better understanding of SVE regulation, especially the inhibitory mechanisms, will shed light on neurotransmission in health and disease.
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Affiliation(s)
- Ya-Long Wang
- Center of Parkinson's Disease, Beijing Institute for Brain Disorders, Capital Medical University, Key Laboratory for the Neurodegenerative Disorders of the Chinese Ministry of Education, Beijing, China
| | - Claire Xi Zhang
- Center of Parkinson's Disease, Beijing Institute for Brain Disorders, Capital Medical University, Key Laboratory for the Neurodegenerative Disorders of the Chinese Ministry of Education, Beijing, China.
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14
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Plasma membrane and cytoskeleton dynamics during single-cell wound healing. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015. [DOI: 10.1016/j.bbamcr.2015.07.012] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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15
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High-Throughput All-Optical Analysis of Synaptic Transmission and Synaptic Vesicle Recycling in Caenorhabditis elegans. PLoS One 2015; 10:e0135584. [PMID: 26312752 PMCID: PMC4552474 DOI: 10.1371/journal.pone.0135584] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 07/24/2015] [Indexed: 12/13/2022] Open
Abstract
Synaptic vesicles (SVs) undergo a cycle of biogenesis and membrane fusion to release transmitter, followed by recycling. How exocytosis and endocytosis are coupled is intensively investigated. We describe an all-optical method for identification of neurotransmission genes that can directly distinguish SV recycling factors in C. elegans, by motoneuron photostimulation and muscular RCaMP Ca2+ imaging. We verified our approach on mutants affecting synaptic transmission. Mutation of genes affecting SV recycling (unc-26 synaptojanin, unc-41 stonin, unc-57 endophilin, itsn-1 intersectin, snt-1 synaptotagmin) showed a distinct ‘signature’ of muscle Ca2+ dynamics, induced by cholinergic motoneuron photostimulation, i.e. faster rise, and earlier decrease of the signal, reflecting increased synaptic fatigue during ongoing photostimulation. To facilitate high throughput, we measured (3–5 times) ~1000 nematodes for each gene. We explored if this method enables RNAi screening for SV recycling genes. Previous screens for synaptic function genes, based on behavioral or pharmacological assays, allowed no distinction of the stage of the SV cycle in which a protein might act. We generated a strain enabling RNAi specifically only in cholinergic neurons, thus resulting in healthier animals and avoiding lethal phenotypes resulting from knockdown elsewhere. RNAi of control genes resulted in Ca2+ measurements that were consistent with results obtained in the respective genomic mutants, albeit to a weaker extent in most cases, and could further be confirmed by opto-electrophysiological measurements for mutants of some of the genes, including synaptojanin. We screened 95 genes that were previously implicated in cholinergic transmission, and several controls. We identified genes that clustered together with known SV recycling genes, exhibiting a similar signature of their Ca2+ dynamics. Five of these genes (C27B7.7, erp-1, inx-8, inx-10, spp-10) were further assessed in respective genomic mutants; however, while all showed electrophysiological phenotypes indicative of reduced cholinergic transmission, no obvious SV recycling phenotypes could be uncovered for these genes.
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16
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Ackermann F, Waites CL, Garner CC. Presynaptic active zones in invertebrates and vertebrates. EMBO Rep 2015; 16:923-38. [PMID: 26160654 DOI: 10.15252/embr.201540434] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 06/19/2015] [Indexed: 11/09/2022] Open
Abstract
The regulated release of neurotransmitter occurs via the fusion of synaptic vesicles (SVs) at specialized regions of the presynaptic membrane called active zones (AZs). These regions are defined by a cytoskeletal matrix assembled at AZs (CAZ), which functions to direct SVs toward docking and fusion sites and supports their maturation into the readily releasable pool. In addition, CAZ proteins localize voltage-gated Ca(2+) channels at SV release sites, bringing the fusion machinery in close proximity to the calcium source. Proteins of the CAZ therefore ensure that vesicle fusion is temporally and spatially organized, allowing for the precise and reliable release of neurotransmitter. Importantly, AZs are highly dynamic structures, supporting presynaptic remodeling, changes in neurotransmitter release efficacy, and thus presynaptic forms of plasticity. In this review, we discuss recent advances in the study of active zones, highlighting how the CAZ molecularly defines sites of neurotransmitter release, endocytic zones, and the integrity of synapses.
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Affiliation(s)
- Frauke Ackermann
- German Center for Neurodegenerative Disease, Charité Medical University, Berlin, Germany
| | - Clarissa L Waites
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - Craig C Garner
- German Center for Neurodegenerative Disease, Charité Medical University, Berlin, Germany
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17
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Abstract
Ca(2+)-dependent synaptic vesicle recycling is essential for structural homeostasis of synapses and maintenance of neurotransmission. Although, the executive role of intrasynaptic Ca(2+) transients in synaptic vesicle exocytosis is well established, identifying the exact role of Ca(2+) in endocytosis has been difficult. In some studies, Ca(2+) has been suggested as an essential trigger required to initiate synaptic vesicle retrieval, whereas others manipulating synaptic Ca(2+) concentrations reported a modulatory role for Ca(2+) leading to inhibition or acceleration of endocytosis. Molecular studies of synaptic vesicle endocytosis, on the other hand, have consistently focused on the roles of Ca(2+)-calmodulin dependent phosphatase calcineurin and synaptic vesicle protein synaptotagmin as potential Ca(2+) sensors for endocytosis. Most studies probing the role of Ca(2+) in endocytosis have relied on measurements of synaptic vesicle retrieval after strong stimulation. Strong stimulation paradigms elicit fusion and retrieval of multiple synaptic vesicles and therefore can be affected by several factors besides the kinetics and duration of Ca(2+) signals that include the number of exocytosed vesicles and accumulation of released neurotransmitters thus altering fusion and retrieval processes indirectly via retrograde signaling. Studies monitoring single synaptic vesicle endocytosis may help resolve this conundrum as in these settings the impact of Ca(2+) on synaptic fusion probability can be uncoupled from its putative role on synaptic vesicle retrieval. Future experiments using these single vesicle approaches will help dissect the specific role(s) of Ca(2+) and its sensors in synaptic vesicle endocytosis.
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Affiliation(s)
- Jeremy Leitz
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX, USA
| | - Ege T Kavalali
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX, USA Department of Physiology, UT Southwestern Medical Center, Dallas, TX, USA
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18
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Tremblay MG, Herdman C, Guillou F, Mishra PK, Baril J, Bellenfant S, Moss T. Extended Synaptotagmin Interaction with the Fibroblast Growth Factor Receptor Depends on Receptor Conformation, Not Catalytic Activity. J Biol Chem 2015; 290:16142-56. [PMID: 25922075 DOI: 10.1074/jbc.m115.656918] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2015] [Indexed: 11/06/2022] Open
Abstract
We previously demonstrated that ESyt2 interacts specifically with the activated FGF receptor and is required for a rapid phase of receptor internalization and for functional signaling via the ERK pathway in early Xenopus embryos. ESyt2 is one of the three-member family of Extended Synaptotagmins that were recently shown to be implicated in the formation of endoplasmic reticulum (ER)-plasma membrane (PM) junctions and in the Ca(2+) dependent regulation of these junctions. Here we show that ESyt2 is directed to the ER by its putative transmembrane domain, that the ESyts hetero- and homodimerize, and that ESyt2 homodimerization in vivo requires a TM adjacent sequence but not the SMP domain. ESyt2 and ESyt3, but not ESyt1, selectively interact in vivo with activated FGFR1. In the case of ESyt2, this interaction requires a short TM adjacent sequence and is independent of receptor autophosphorylation, but dependent on receptor conformation. The data show that ESyt2 recognizes a site in the upper kinase lobe of FGFR1 that is revealed by displacement of the kinase domain activation loop during receptor activation.
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Affiliation(s)
- Michel G Tremblay
- From the Laboratory of Growth and Development, St-Patrick Research Group in Basic Oncology, Cancer Division of the Québec University Hospital Research Centre, and Department of Molecular Biology, Medical Biochemistry and Pathology, Faculty of Medicine, Laval University, Edifice St Patrick, 9 rue McMahon, Québec, Québec G1R 3S3, Canada
| | - Chelsea Herdman
- From the Laboratory of Growth and Development, St-Patrick Research Group in Basic Oncology, Cancer Division of the Québec University Hospital Research Centre, and Department of Molecular Biology, Medical Biochemistry and Pathology, Faculty of Medicine, Laval University, Edifice St Patrick, 9 rue McMahon, Québec, Québec G1R 3S3, Canada
| | - François Guillou
- From the Laboratory of Growth and Development, St-Patrick Research Group in Basic Oncology, Cancer Division of the Québec University Hospital Research Centre, and Department of Molecular Biology, Medical Biochemistry and Pathology, Faculty of Medicine, Laval University, Edifice St Patrick, 9 rue McMahon, Québec, Québec G1R 3S3, Canada
| | - Prakash K Mishra
- From the Laboratory of Growth and Development, St-Patrick Research Group in Basic Oncology, Cancer Division of the Québec University Hospital Research Centre, and Department of Molecular Biology, Medical Biochemistry and Pathology, Faculty of Medicine, Laval University, Edifice St Patrick, 9 rue McMahon, Québec, Québec G1R 3S3, Canada
| | - Joëlle Baril
- From the Laboratory of Growth and Development, St-Patrick Research Group in Basic Oncology, Cancer Division of the Québec University Hospital Research Centre, and Department of Molecular Biology, Medical Biochemistry and Pathology, Faculty of Medicine, Laval University, Edifice St Patrick, 9 rue McMahon, Québec, Québec G1R 3S3, Canada
| | - Sabrina Bellenfant
- From the Laboratory of Growth and Development, St-Patrick Research Group in Basic Oncology, Cancer Division of the Québec University Hospital Research Centre, and Department of Molecular Biology, Medical Biochemistry and Pathology, Faculty of Medicine, Laval University, Edifice St Patrick, 9 rue McMahon, Québec, Québec G1R 3S3, Canada
| | - Tom Moss
- From the Laboratory of Growth and Development, St-Patrick Research Group in Basic Oncology, Cancer Division of the Québec University Hospital Research Centre, and Department of Molecular Biology, Medical Biochemistry and Pathology, Faculty of Medicine, Laval University, Edifice St Patrick, 9 rue McMahon, Québec, Québec G1R 3S3, Canada
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19
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Rapid kinetics of endocytosis at rod photoreceptor synapses depends upon endocytic load and calcium. Vis Neurosci 2014; 31:227-35. [PMID: 24735554 DOI: 10.1017/s095252381400011x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Release from rods is triggered by the opening of L-type Ca2+ channels that lie beneath synaptic ribbons. After exocytosis, vesicles are retrieved by compensatory endocytosis. Previous work showed that endocytosis is dynamin-dependent in rods but dynamin-independent in cones. We hypothesized that fast endocytosis in rods may also differ from cones in its dependence upon the amount of Ca2+ influx and/or endocytic load. We measured exocytosis and endocytosis from membrane capacitance (C m) changes evoked by depolarizing steps in voltage clamped rods from tiger salamander retinal slices. Similar to cones, the time constant for endocytosis in rods was quite fast, averaging <200 ms. We manipulated Ca2+ influx and the amount of vesicle release by altering the duration and voltage of depolarizing steps. Unlike cones, endocytosis kinetics in rods slowed after increasing Ca2+ channel activation with longer step durations or more strongly depolarized voltage steps. Endocytosis kinetics also slowed as Ca2+ buffering was decreased by replacing BAPTA (10 or 1 mM) with the slower Ca2+ buffer EGTA (5 or 0.5 mM) in the pipette solution. These data provide further evidence that endocytosis mechanisms differ in rods and cones and suggest that endocytosis in rods is regulated by both endocytic load and local Ca2+ levels.
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20
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Tomàs J, Santafé MM, Garcia N, Lanuza MA, Tomàs M, Besalduch N, Obis T, Priego M, Hurtado E. Presynaptic membrane receptors in acetylcholine release modulation in the neuromuscular synapse. J Neurosci Res 2014; 92:543-54. [PMID: 24464361 DOI: 10.1002/jnr.23346] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Revised: 11/11/2013] [Accepted: 11/19/2013] [Indexed: 01/06/2023]
Abstract
Over the past few years, we have studied, in the mammalian neuromuscular junction (NMJ), the local involvement in transmitter release of the presynaptic muscarinic ACh autoreceptors (mAChRs), purinergic adenosine autoreceptors (P1Rs), and trophic factor receptors (TFRs; for neurotrophins and trophic cytokines) during development and in the adult. At any given moment, the way in which a synapse works is largely the logical outcome of the confluence of these (and other) metabotropic signalling pathways on intracellular kinases, which phosphorylate protein targets and materialize adaptive changes. We propose an integrated interpretation of the complementary function of these receptors in the adult NMJ. The activity of a given receptor group can modulate a given combination of spontaneous, evoked, and activity-dependent release characteristics. For instance, P1Rs can conserve resources by limiting spontaneous quantal leak of ACh (an A1 R action) and protect synapse function, because stimulation with adenosine reduces the magnitude of depression during repetitive activity. The overall outcome of the mAChRs seems to contribute to upkeep of spontaneous quantal output of ACh, save synapse function by decreasing the extent of evoked release (mainly an M2 action), and reduce depression. We have also identified several links among P1Rs, mAChRs, and TFRs. We found a close dependence between mAChR and some TFRs and observed that the muscarinic group has to operate correctly if the tropomyosin-related kinase B receptor (trkB) is also to operate correctly, and vice versa. Likewise, the functional integrity of mAChRs depends on P1Rs operating normally.
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Affiliation(s)
- Josep Tomàs
- Unitat d'Histologia i Neurobiologia (UHN), Facultat de Medicina i Ciències de la Salut, Universitat Rovira i Virgili, Reus, Spain
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21
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Zhang Y, Tang W, Zhang H, Niu X, Xu Y, Zhang J, Gao K, Pan W, Boggon TJ, Toomre D, Min W, Wu D. A network of interactions enables CCM3 and STK24 to coordinate UNC13D-driven vesicle exocytosis in neutrophils. Dev Cell 2014; 27:215-226. [PMID: 24176643 DOI: 10.1016/j.devcel.2013.09.021] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Revised: 09/14/2013] [Accepted: 09/22/2013] [Indexed: 12/15/2022]
Abstract
Neutrophil degranulation plays an important role in acute innate immune responses and is tightly regulated because the granule contents can cause tissue damage. However, this regulation remains poorly understood. Here, we identify the complex of STK24 and CCM3 as being an important regulator of neutrophil degranulation. Lack of either STK24 or CCM3 increases the release of a specific granule pool without affecting other neutrophil functions. STK24 appears to suppress exocytosis by interacting and competing with UNC13D C2B domain for lipid binding, whereas CCM3 has dual roles in exocytosis regulation. Although CCM3 stabilizes STK24, it counteracts STK24-mediated inhibition of exocytosis by recruiting STK24 away from the C2B domain through its Ca(2+)-sensitive interaction with UNC13D C2A domain. This STK24/CCM3-regulated exocytosis plays an important role in the protection of kidneys from ischemia-reperfusion injury. Together, these findings reveal a function of the STK24 and CCM3 complex in the regulation of ligand-stimulated exocytosis.
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Affiliation(s)
- Yong Zhang
- Department of Pharmacology, Yale School of Medicine, New Haven, CT 06520, USA; Department of Vascular Biology and Therapeutic Program, Yale School of Medicine, New Haven, CT 06520, USA
| | - Wenwen Tang
- Department of Pharmacology, Yale School of Medicine, New Haven, CT 06520, USA; Department of Vascular Biology and Therapeutic Program, Yale School of Medicine, New Haven, CT 06520, USA
| | - Haifeng Zhang
- Department of Vascular Biology and Therapeutic Program, Yale School of Medicine, New Haven, CT 06520, USA; Department of Pathology, Yale School of Medicine, New Haven, CT 06520, USA
| | - Xiaofeng Niu
- Department of Pharmacology, Yale School of Medicine, New Haven, CT 06520, USA; Department of Vascular Biology and Therapeutic Program, Yale School of Medicine, New Haven, CT 06520, USA
| | - Yingke Xu
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06520, USA
| | - Jiasheng Zhang
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06520, USA
| | - Kun Gao
- Department of Pharmacology, Yale School of Medicine, New Haven, CT 06520, USA; Department of Vascular Biology and Therapeutic Program, Yale School of Medicine, New Haven, CT 06520, USA
| | - Weijun Pan
- Key Laboratory of Stem Cell Biology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences and Shanghai Jiao Tong University School of Medicine, 200025 Shanghai, China
| | - Titus J Boggon
- Department of Pharmacology, Yale School of Medicine, New Haven, CT 06520, USA
| | - Derek Toomre
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06520, USA
| | - Wang Min
- Department of Vascular Biology and Therapeutic Program, Yale School of Medicine, New Haven, CT 06520, USA; Department of Pathology, Yale School of Medicine, New Haven, CT 06520, USA.
| | - Dianqing Wu
- Department of Pharmacology, Yale School of Medicine, New Haven, CT 06520, USA; Department of Vascular Biology and Therapeutic Program, Yale School of Medicine, New Haven, CT 06520, USA.
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22
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Martins-de-Souza D, Carvalho PC, Schmitt A, Junqueira M, Nogueira FCS, Turck CW, Domont GB. Deciphering the human brain proteome: characterization of the anterior temporal lobe and corpus callosum as part of the Chromosome 15-centric Human Proteome Project. J Proteome Res 2013; 13:147-57. [PMID: 24274931 DOI: 10.1021/pr4009157] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Defining the proteomes encoded by each chromosome and characterizing proteins related to human illnesses are among the goals of the Chromosome-centric Human Proteome Project (C-HPP) and the Biology and Disease-driven HPP. Following these objectives, we investigated the proteomes of the human anterior temporal lobe (ATL) and corpus callosum (CC) collected post-mortem from eight subjects. Using a label-free GeLC-MS/MS approach, we identified 2454 proteins in the ATL and 1887 in the CC through roughly 7500 and 5500 peptides, respectively. Considering that the ATL is a gray-matter region while the CC is a white-matter region, they presented proteomes specific to their functions. Besides, 38 proteins were found to be differentially expressed between the two regions. Furthermore, the proteome data sets were classified according to their chromosomal origin, and five proteins were evidenced at the MS level for the first time. We identified 70 proteins of the chromosome 15 - one of them for the first time by MS - which were submitted to an in silico pathway analysis. These revealed branch point proteins associated with Prader-Willi and Angelman syndromes and dyskeratosis congenita, which are chromosome-15-associated diseases. Data presented here can be a useful for brain disorder studies as well as for contributing to the C-HPP initiative. Our data are publicly available as resource data to C-HPP participant groups at http://yoda.iq.ufrj.br/Daniel/chpp2013. Additionally, the mass spectrometry proteomics data have been deposited to the ProteomeXchange with identifier PXD000547 for the corpus callosum and PXD000548 for the anterior temporal lobe.
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Affiliation(s)
- Daniel Martins-de-Souza
- Research Group of Proteomics, Department of Psychiatry and Psychotherapy, Ludwig Maximilians University of Munich (LMU) , Nußbaumstraße 7, Munich D-80336, Germany
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23
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Morgan JR, Comstra HS, Cohen M, Faundez V. Presynaptic membrane retrieval and endosome biology: defining molecularly heterogeneous synaptic vesicles. Cold Spring Harb Perspect Biol 2013; 5:a016915. [PMID: 24086045 DOI: 10.1101/cshperspect.a016915] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The release and uptake of neurotransmitters by synaptic vesicles is a tightly controlled process that occurs in response to diverse stimuli at morphologically disparate synapses. To meet these architectural and functional synaptic demands, it follows that there should be diversity in the mechanisms that control their secretion and retrieval and possibly in the composition of synaptic vesicles within the same terminal. Here we pay particular attention to areas where such diversity is generated, such as the variance in exocytosis/endocytosis coupling, SNAREs defining functionally diverse synaptic vesicle populations and the adaptor-dependent sorting machineries capable of generating vesicle diversity. We argue that there are various synaptic vesicle recycling pathways at any given synapse and discuss several lines of evidence that support the role of the endosome in synaptic vesicle recycling.
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Affiliation(s)
- Jennifer R Morgan
- Eugene Bell Center for Regenerative Biology and Tissue Engineering, Marine Biological Laboratory, Woods Hole, Massachusetts 02543
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24
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Nimmervoll B, Flucher BE, Obermair GJ. Dominance of P/Q-type calcium channels in depolarization-induced presynaptic FM dye release in cultured hippocampal neurons. Neuroscience 2013; 253:330-40. [PMID: 24012836 PMCID: PMC3824072 DOI: 10.1016/j.neuroscience.2013.08.052] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 08/09/2013] [Accepted: 08/27/2013] [Indexed: 11/26/2022]
Abstract
We analyzed depolarization-induced synaptic FM dye release in hippocampal neurons. We pharmacologically isolated the contribution of voltage-gated Ca2+ channels. 85% of synapses utilize N- and P/Q-type channels, 15% only P/Q-type channels. In both groups of synapses release kinetics are determined by P/Q-type channels. We propose a more direct coupling of P/Q-type channels to synaptic release.
Neurotransmitter release probability is related by high power to the local concentration of calcium in presynaptic terminals, which in turn is controlled by voltage-gated calcium channels. P/Q- and N-type channels trigger synaptic transmission in the majority of neurons of the central nervous system. However, whether and under which conditions both channel types act cooperatively or independently is still insufficiently understood. Previous studies suggested either a dominance of N- or P/Q-type channels, or a synergistic action of both channels, depending on the experimental paradigms. Thus, to provide insight into the properties of neurotransmitter release in cultured mouse hippocampal neurons, we used quantitative analysis of FM dye release from presynaptic boutons induced by high potassium membrane depolarization. Increasing extracellular potassium concentrations revealed a sigmoid dependence of FM dye release to the stimulation strength. Individual and combined application of the P/Q- and N-type channel-specific blockers ω-agatoxin-IVA and ω-conotoxin-GVIA, respectively, allowed us to specifically isolate the contribution of both channel types to release triggered with 40 mM KCl. Analysis of the release kinetics and the fractional release amplitude demonstrate that, whereas in only 15% of the synapses release depended exclusively on P/Q-type channels, the majority of synapses (85%) contained both N- and P/Q-type channels. Nevertheless, the kinetics of FM dye release in synapses containing both channel types was determined by the P/Q-type channels. Together, our data suggest a more direct coupling of P/Q-type channels to synaptic release compared to N-type channels, which may explain the high prevalence of neurological P/Q-type channelopathies.
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Affiliation(s)
- B Nimmervoll
- Division of Physiology, Medical University Innsbruck, Fritz-Pregl-Str. 3, 6020 Innsbruck, Austria
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A local, periactive zone endocytic machinery at photoreceptor synapses in close vicinity to synaptic ribbons. J Neurosci 2013; 33:10278-300. [PMID: 23785143 DOI: 10.1523/jneurosci.5048-12.2013] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Photoreceptor ribbon synapses are continuously active synapses with large active zones that contain synaptic ribbons. Synaptic ribbons are anchored to the active zones and are associated with large numbers of synaptic vesicles. The base of the ribbon that is located close to L-type voltage-gated Ca(2+) channels is a hotspot of exocytosis. The continuous exocytosis at the ribbon synapse needs to be balanced by compensatory endocytosis. Recent analyses indicated that vesicle recycling at the synaptic ribbon is also an important determinant of synaptic signaling at the photoreceptor synapse. To get insights into mechanisms of vesicle recycling at the photoreceptor ribbon synapse, we performed super-resolution structured illumination microscopy and immunogold electron microscopy to localize major components of the endocytotic membrane retrieval machinery in the photoreceptor synapse of the mouse retina. We found dynamin, syndapin, amphiphysin, and calcineurin, a regulator of activity-dependent endocytosis, to be highly enriched around the active zone and the synaptic ribbon. We present evidence for two clathrin heavy chain variants in the photoreceptor terminal; one is enriched around the synaptic ribbon, whereas the other is localized in the entry region of the terminal. The focal enrichment of endocytic proteins around the synaptic ribbon is consistent with a focal uptake of endocytic markers at that site. This endocytic activity functionally depends on dynamin. These data propose that the presynaptic periactive zone surrounding the synaptic ribbon complex is a hotspot of endocytosis in photoreceptor ribbon synapses.
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26
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Abstract
Neurons use a calcium-dependent mechanism to optimize the rate at which synaptic vesicles are recycled.
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Affiliation(s)
- Melissa A Herman
- is at Neurocure NWFZ , Charité Universitätsmedizin Berlin , Berlin , Germany
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27
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Yan H, Pablo JL, Pitt GS. FGF14 regulates presynaptic Ca2+ channels and synaptic transmission. Cell Rep 2013; 4:66-75. [PMID: 23831029 DOI: 10.1016/j.celrep.2013.06.012] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Revised: 05/13/2013] [Accepted: 06/07/2013] [Indexed: 10/26/2022] Open
Abstract
Fibroblast growth factor homologous factors (FHFs) are not growth factors, but instead bind to voltage-gated Na+ channels (NaV) and regulate their function. Mutations in FGF14, an FHF that is the locus for spinocerebellar ataxia 27 (SCA27), are believed to be pathogenic because of a dominant-negative reduction of NaV currents in cerebellar granule cells. Here, we demonstrate that FGF14 also regulates members of the presynaptic CaV2 Ca2+ channel family. Knockdown of FGF14 in granule cells reduced Ca2+ currents and diminished vesicular recycling, a marker for presynaptic Ca2+ influx. As a consequence, excitatory postsynaptic currents (EPSCs) at the granule cell to Purkinje cell synapse were markedly diminished. Expression of the SCA27-causing FGF14 mutant in granule cells exerted a dominant-negative reduction in Ca2+ currents, vesicular recycling, and the resultant EPSCs in Purkinje cells. Thus, FHFs are multimodal, regulating several discrete neuronal signaling events. SCA27 most likely results at least in part from dysregulation of Ca2+ channel function.
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Affiliation(s)
- Haidun Yan
- Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
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Takamori M. Structure of the neuromuscular junction: function and cooperative mechanisms in the synapse. Ann N Y Acad Sci 2013; 1274:14-23. [PMID: 23252893 DOI: 10.1111/j.1749-6632.2012.06784.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
As an overview of the structure of the neuromuscular junction, three items are described focusing on cooperative mechanisms involving the synapse and leading to muscle contraction: (1) presynaptic acetylcholine release regulated by vesicle cycling (exocytosis and endocytosis); the fast-mode of endocytosis requires a large influx of external Ca(2+) and is promoted by the activation of G protein-coupled receptors and receptor tyrosine kinases; (2) postsynaptic acetylcholine receptor clustering mediated by the muscle-specific, Dok7-stimulated tyrosine kinase (MuSK) through two signaling mechanisms: one via agrin-Lrp4-MuSK (Ig1/2 domains) and the second via Wnt-MuSK (Frizzled-like cysteine-rich domain)-adaptor Dishevelled; Wnts/MuSK and Lrp4 direct a retrograde signal to presynaptic differentiation; (3) muscle contractile machinery regulated by Ca(2+) -release and Ca(2+) -influx channels, including the depolarization-activated ryanodine receptor-1 and the receptor- and/or store-operated transient receptor potential canonical. The first mechanism is dysfunctional in Lambert-Eaton myasthenic syndrome, the second in anti-acetylcholine receptor-negative myasthenia gravis (MG), and the third in thymoma-associated MG.
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Wu WH, Cooper R. Physiological separation of vesicle pools in low- and high-output nerve terminals. Neurosci Res 2013; 75:275-82. [DOI: 10.1016/j.neures.2013.01.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Revised: 01/18/2013] [Accepted: 01/18/2013] [Indexed: 10/27/2022]
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Egawa R, Hososhima S, Hou X, Katow H, Ishizuka T, Nakamura H, Yawo H. Optogenetic probing and manipulation of the calyx-type presynaptic terminal in the embryonic chick ciliary ganglion. PLoS One 2013; 8:e59179. [PMID: 23555628 PMCID: PMC3605445 DOI: 10.1371/journal.pone.0059179] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Accepted: 02/12/2013] [Indexed: 11/23/2022] Open
Abstract
The calyx-type synapse of chick ciliary ganglion (CG) has been intensively studied for decades as a model system for the synaptic development, morphology and physiology. Despite recent advances in optogenetics probing and/or manipulation of the elementary steps of the transmitter release such as membrane depolarization and Ca2+ elevation, the current gene-manipulating methods are not suitable for targeting specifically the calyx-type presynaptic terminals. Here, we evaluated a method for manipulating the molecular and functional organization of the presynaptic terminals of this model synapse. We transfected progenitors of the Edinger-Westphal (EW) nucleus neurons with an EGFP expression vector by in ovo electroporation at embryonic day 2 (E2) and examined the CG at E8–14. We found that dozens of the calyx-type presynaptic terminals and axons were selectively labeled with EGFP fluorescence. When a Brainbow construct containing the membrane-tethered fluorescent proteins m-CFP, m-YFP and m-RFP, was introduced together with a Cre expression construct, the color coding of each presynaptic axon facilitated discrimination among inter-tangled projections, particularly during the developmental re-organization period of synaptic connections. With the simultaneous expression of one of the chimeric variants of channelrhodopsins, channelrhodopsin-fast receiver (ChRFR), and R-GECO1, a red-shifted fluorescent Ca2+-sensor, the Ca2+ elevation was optically measured under direct photostimulation of the presynaptic terminal. Although this optically evoked Ca2+ elevation was mostly dependent on the action potential, a significant component remained even in the absence of extracellular Ca2+. It is suggested that the photo-activation of ChRFR facilitated the release of Ca2+ from intracellular Ca2+ stores directly or indirectly. The above system, by facilitating the molecular study of the calyx-type presynaptic terminal, would provide an experimental platform for unveiling the molecular mechanisms underlying the morphology, physiology and development of synapses.
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Affiliation(s)
- Ryo Egawa
- Department of Developmental Biology and Neuroscience, Tohoku University Graduate School of Life Sciences, Sendai, Japan
- Japan Science and Technology Agency (JST), Core Research of Evolutional Science & Technology (CREST), Tokyo, Japan
- Tohoku University Institute for International Advanced Research and Education, Sendai, Japan
| | - Shoko Hososhima
- Department of Developmental Biology and Neuroscience, Tohoku University Graduate School of Life Sciences, Sendai, Japan
- Japan Science and Technology Agency (JST), Core Research of Evolutional Science & Technology (CREST), Tokyo, Japan
| | - Xubin Hou
- Department of Developmental Biology and Neuroscience, Tohoku University Graduate School of Life Sciences, Sendai, Japan
- Department of Molecular Neurobiology, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Hidetaka Katow
- Department of Developmental Biology and Neuroscience, Tohoku University Graduate School of Life Sciences, Sendai, Japan
- Japan Science and Technology Agency (JST), Core Research of Evolutional Science & Technology (CREST), Tokyo, Japan
| | - Toru Ishizuka
- Department of Developmental Biology and Neuroscience, Tohoku University Graduate School of Life Sciences, Sendai, Japan
- Japan Science and Technology Agency (JST), Core Research of Evolutional Science & Technology (CREST), Tokyo, Japan
| | - Harukazu Nakamura
- Department of Developmental Biology and Neuroscience, Tohoku University Graduate School of Life Sciences, Sendai, Japan
- Department of Molecular Neurobiology, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Hiromu Yawo
- Department of Developmental Biology and Neuroscience, Tohoku University Graduate School of Life Sciences, Sendai, Japan
- Japan Science and Technology Agency (JST), Core Research of Evolutional Science & Technology (CREST), Tokyo, Japan
- Center for Neuroscience, Tohoku University Graduate School of Medicine, Sendai, Japan
- * E-mail:
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31
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Gaydukov AE, Tarasova EO, Balezina OP. Calcium-dependent phosphatase calcineurin downregulates evoked neurotransmitter release in neuromuscular junctions of mice. NEUROCHEM J+ 2013. [DOI: 10.1134/s1819712413010030] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Zhang T, Wang Z, Wang L, Luo N, Jiang L, Liu Z, Wu CF, Dong K. Role of the DSC1 channel in regulating neuronal excitability in Drosophila melanogaster: extending nervous system stability under stress. PLoS Genet 2013; 9:e1003327. [PMID: 23505382 PMCID: PMC3591268 DOI: 10.1371/journal.pgen.1003327] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2012] [Accepted: 01/01/2013] [Indexed: 11/18/2022] Open
Abstract
Voltage-gated ion channels are essential for electrical signaling in neurons and other excitable cells. Among them, voltage-gated sodium and calcium channels are four-domain proteins, and ion selectivity is strongly influenced by a ring of amino acids in the pore regions of these channels. Sodium channels contain a DEKA motif (i.e., amino acids D, E, K, and A at the pore positions of domains I, II, III, and IV, respectively), whereas voltage-gated calcium channels contain an EEEE motif (i.e., acidic residues, E, at all four positions). Recently, a novel family of ion channel proteins that contain an intermediate DEEA motif has been found in a variety of invertebrate species. However, the physiological role of this new family of ion channels in animal biology remains elusive. DSC1 in Drosophila melanogaster is a prototype of this new family of ion channels. In this study, we generated two DSC1 knockout lines using ends-out gene targeting via homologous recombination. DSC1 mutant flies exhibited impaired olfaction and a distinct jumpy phenotype that is intensified by heat shock and starvation. Electrophysiological analysis of the giant fiber system (GFS), a well-defined central neural circuit, revealed that DSC1 mutants are altered in the activities of the GFS, including the ability of the GFS to follow repetitive stimulation (i.e., following ability) and response to heat shock, starvation, and pyrethroid insecticides. These results reveal an important role of the DSC1 channel in modulating the stability of neural circuits, particularly under environmental stresses, likely by maintaining the sustainability of synaptic transmission. Voltage-gated sodium and calcium channels are four-domain proteins that are essential for electrical signaling in neurons and other excitable cells. Recent genomic and functional analyses reveal a novel family of four-domain, Ca2+-selective cation channels in a variety of invertebrates, from sea anemones to insects. The amino acid sequences and gating properties of these channels appear to be intermediate between sodium and calcium channels; as such, these channels could potentially be an important evolutionary link between sodium and calcium channels. Despite the intriguing nature of this family of cation channels, their role in animal physiology remains mysterious. In this study, taking advantage of the genetic tractability of the fruit fly, Drosophila melanogaster, we examined the physiological role of such a channel, called DSC1, in this model insect. We generated two DSC1 knockout lines and conducted behavioral and electrophysiological analyses. Our results show that the DSC1 channel contributes to neuronal excitability regulation and plays a unique role in retaining stability of the nervous system function in response to environmental stresses, including heat shock and starvation. Interestingly, the DSC1 knockout flies were also more susceptible to pyrethroid insecticides, which are used globally as a major weapon against the malaria-carrying mosquitoes.
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Affiliation(s)
- Tianxiang Zhang
- Department of Entomology, Michigan State University, East Lansing, Michigan, United States of America
- Department of Microbiology and Molecular Genetdics, Michigan State University, East Lansing, Michigan, United States of America
| | - Zhe Wang
- Department of Biology, University of Iowa, Iowa City, Iowa, United States of America
| | - Lingxin Wang
- Department of Entomology, Michigan State University, East Lansing, Michigan, United States of America
| | - Ningguang Luo
- Department of Entomology, Michigan State University, East Lansing, Michigan, United States of America
| | - Lan Jiang
- Department of Biological Sciences, Oakland University, Rochester, Michigan, United States of America
| | - Zhiqi Liu
- Department of Entomology, Michigan State University, East Lansing, Michigan, United States of America
| | - Chun-Fang Wu
- Department of Biology, University of Iowa, Iowa City, Iowa, United States of America
- * E-mail: (C-FW); (KD)
| | - Ke Dong
- Department of Entomology, Michigan State University, East Lansing, Michigan, United States of America
- * E-mail: (C-FW); (KD)
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33
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Abstract
Following synaptic vesicle exocytosis, neurons retrieve the fused membrane by a process of endocytosis to provide a supply of vesicles for subsequent release and maintain the presynaptic active zone. Rod and cone photoreceptors use a specialized structure called the synaptic ribbon that enables them to sustain high rates of neurotransmitter release. They must also employ mechanisms of synaptic vesicle endocytosis capable of keeping up with release. While much is known about endocytosis at another retinal ribbon synapse, that of the goldfish Mb1 bipolar cell, less is known about endocytosis in photoreceptors. We used capacitance recording techniques to measure vesicle membrane fusion and retrieval in photoreceptors from salamander retinal slices. We found that application of brief depolarizing steps (<100 ms) to cones evoked exocytosis followed by rapid endocytosis with a time constant ∼250 ms. In some cases, the capacitance trace overshot the baseline, indicating excess endocytosis. Calcium had no effect on the time constant, but enhanced excess endocytosis resulting in a faster rate of membrane retrieval. Surprisingly, endocytosis was unaffected by blockers of dynamin, suggesting that cone endocytosis is dynamin independent. This contrasts with synaptic vesicle endocytosis in rods, which was inhibited by the dynamin inhibitor dynasore and GTPγS introduced through the patch pipette, suggesting that the two photoreceptor types employ distinct pathways for vesicle retrieval. The fast kinetics of synaptic vesicle endocytosis in photoreceptors likely enables these cells to maintain a high rate of transmitter release, allowing them to faithfully signal changes in illumination to second-order neurons.
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34
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The regulation and packaging of synaptic vesicles as related to recruitment within glutamatergic synapses. Neuroscience 2012; 225:185-98. [DOI: 10.1016/j.neuroscience.2012.08.037] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Revised: 08/15/2012] [Accepted: 08/16/2012] [Indexed: 11/18/2022]
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35
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Song W, Wu CF, Liu P, Xiang RW, Wang F, Dong YX, Yang JY. Characterization of Basal and Morphine-Induced Uridine Release in the Striatum: An In Vivo Microdialysis Study in Mice. Neurochem Res 2012; 38:153-61. [DOI: 10.1007/s11064-012-0903-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Revised: 08/15/2012] [Accepted: 10/04/2012] [Indexed: 10/27/2022]
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36
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Stenbeck G, Lawrence KM, Albert AP. Hormone-stimulated modulation of endocytic trafficking in osteoclasts. Front Endocrinol (Lausanne) 2012; 3:103. [PMID: 22936925 PMCID: PMC3424527 DOI: 10.3389/fendo.2012.00103] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Accepted: 08/05/2012] [Indexed: 11/30/2022] Open
Abstract
A precise control of vesicular trafficking is crucial not only for osteoclastic bone resorption, but also for the crosstalk between osteoclasts and osteoblasts, which regulates bone homeostasis. In addition to the release of growth factors and modulators, such as glutamate, flux through the intracellular trafficking routes could also provide the osteoclast with a monitoring function of its resorption activity. To establish the signaling pathways regulating trafficking events in resorbing osteoclasts, we used the bone conserving hormone calcitonin, which has the unique property of inducing osteoclast quiescence. Calcitonin acts through the calcitonin receptor and activates multiple signaling pathways. By monitoring trafficking of a fluorescent low molecular weight probe in mature, bone resorbing osteoclasts we show for the first time that calcitonin blocks endocytosis from the ruffled border by phospholipase C (PLC) activation. Furthermore, we identify a requirement for polyunsaturated fatty acids in endocytic trafficking in osteoclasts. Inhibition of PLC prior to calcitonin treatment restores endocytosis to 75% of untreated rates. This effect is independent of protein kinase C activation and can be mimicked by an increase in intracellular calcium. We thus define an essential role for intracellular calcium levels in the maintenance of endocytosis in osteoclasts.
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Affiliation(s)
- Gudrun Stenbeck
- Centre for Cell and Chromosome Biology, School of Health Science and Social Care, Brunel UniversityUxbridge, UK
- *Correspondence: Gudrun Stenbeck, Centre for Cell and Chromosome Biology, School of Health Science and Social Care, Heinz Wolff Building, Brunel University, Uxbridge UB8 3PH, UK. e-mail:
| | - Kevin M. Lawrence
- Pharmacology and Cell Physiology, Biomedical Sciences Research Centre, Division of Biomedical Sciences, St George’s, University of LondonLondon, UK
| | - Anthony P. Albert
- Pharmacology and Cell Physiology, Biomedical Sciences Research Centre, Division of Biomedical Sciences, St George’s, University of LondonLondon, UK
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