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Suckert C, Zosel C, Schaefer M. Simultaneous TIRF imaging of subplasmalemmal Ca 2+ dynamics and granule fusions in insulin-secreting INS-1 cells reveals coexistent synchronized and asynchronous release. Cell Calcium 2024; 120:102883. [PMID: 38643716 DOI: 10.1016/j.ceca.2024.102883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 03/21/2024] [Accepted: 03/29/2024] [Indexed: 04/23/2024]
Abstract
The basal and glucose-induced insulin secretion from pancreatic beta cells is a tightly regulated process that is triggered in a Ca2+-dependent fashion and further positively modulated by substances that raise intracellular levels of adenosine 3',5'-cyclic monophosphate (cAMP) or by certain antidiabetic drugs. In a previous study, we have temporally resolved the subplasmalemmal [Ca2+]i dynamics in beta cells that are characterized by trains of sharply delimited spikes, reaching peak values up to 5 µM. Applying total internal reflection fluorescence (TIRF) microscopy and synaptopHluorin to visualize fusion events of individual granules, we found that several fusion events can coincide within 50 to 150 ms. To test whether subplasmalemmal [Ca2+]i microdomains around single or clustered Ca2+ channels may cause a synchronized release of insulin-containing vesicles, we applied simultaneous dual-color TIRF microscopy and monitored Ca2+ fluctuations and exocytotic events in INS-1 cells at high frame rates. The results indicate that fusions can be triggered by subplasmalemmal Ca2+ spiking. This, however, does account for a minority of fusion events. About 90 %-95 % of fusion events either happen between Ca2+ spikes or incidentally overlap with subplasmalemmal Ca2+ spikes. We conclude that only a fraction of exocytotic events in glucose-induced and tolbutamide- or forskolin-enhanced insulin release from INS-1 cells is tightly coupled to Ca2+ microdomains around voltage-gated Ca2+ channels.
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Affiliation(s)
- Charlotte Suckert
- Leipzig University, Rudolf-Boehm-Institute of Pharmacology and Toxicology, Härtelstraße 16-18, Leipzig 04107, Germany
| | - Carolin Zosel
- Leipzig University, Rudolf-Boehm-Institute of Pharmacology and Toxicology, Härtelstraße 16-18, Leipzig 04107, Germany
| | - Michael Schaefer
- Leipzig University, Rudolf-Boehm-Institute of Pharmacology and Toxicology, Härtelstraße 16-18, Leipzig 04107, Germany.
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2
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Wang X, Yu D, Wang H, Lei Z, Zhai Y, Sun M, Chen S, Yin P. Rab3 and synaptotagmin proteins in the regulation of vesicle fusion and neurotransmitter release. Life Sci 2022; 309:120995. [PMID: 36167148 DOI: 10.1016/j.lfs.2022.120995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 09/13/2022] [Accepted: 09/21/2022] [Indexed: 10/31/2022]
Abstract
Ca2+-triggered neurotransmitter release involves complex regulatory mechanisms, including a series of protein-protein interactions. Three proteins, synaptobrevin (VAMP), synaptosomal-associated protein of 25kDa (SNAP-25) and syntaxin, constitute the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) core complex that plays key roles in controlling vesicle fusion and exocytosis. Many other proteins participate in the regulation of the processes via direct and/or indirect interaction with the SNARE complex. Although much effort has been made, the regulatory mechanism for exocytosis is still not completely clear. Accumulated evidence indicates that the small GTPase Rab3 and synaptotagmin proteins play important regulatory roles during vesicle fusion and neurotransmitter release. This review outlines our present understanding of the two regulatory proteins, with the focus on the interaction of Rab3 with synaptotagmin in the regulatory process.
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Affiliation(s)
- Xianchun Wang
- State Key Laboratory of Developmental Biology of Freshwater Fish, Protein Chemistry Laboratory, College of Life Sciences, Hunan Normal University, Changsha 410081, China.
| | - Dianmei Yu
- State Key Laboratory of Developmental Biology of Freshwater Fish, Protein Chemistry Laboratory, College of Life Sciences, Hunan Normal University, Changsha 410081, China
| | - Haiyan Wang
- State Key Laboratory of Developmental Biology of Freshwater Fish, Protein Chemistry Laboratory, College of Life Sciences, Hunan Normal University, Changsha 410081, China
| | - Zhixiang Lei
- State Key Laboratory of Developmental Biology of Freshwater Fish, Protein Chemistry Laboratory, College of Life Sciences, Hunan Normal University, Changsha 410081, China
| | - Yiwen Zhai
- State Key Laboratory of Developmental Biology of Freshwater Fish, Protein Chemistry Laboratory, College of Life Sciences, Hunan Normal University, Changsha 410081, China
| | - Minlu Sun
- State Key Laboratory of Developmental Biology of Freshwater Fish, Protein Chemistry Laboratory, College of Life Sciences, Hunan Normal University, Changsha 410081, China
| | - Si Chen
- State Key Laboratory of Developmental Biology of Freshwater Fish, Protein Chemistry Laboratory, College of Life Sciences, Hunan Normal University, Changsha 410081, China
| | - Panfeng Yin
- State Key Laboratory of Developmental Biology of Freshwater Fish, Protein Chemistry Laboratory, College of Life Sciences, Hunan Normal University, Changsha 410081, China
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Lougee MG, Pagar VV, Kim HJ, Pancoe SX, Chia WK, Mach RH, Garcia BA, Petersson EJ. Harnessing the intrinsic photochemistry of isoxazoles for the development of chemoproteomic crosslinking methods. Chem Commun (Camb) 2022; 58:9116-9119. [PMID: 35880535 PMCID: PMC9922157 DOI: 10.1039/d2cc02263j] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The intrinsic photochemistry of the isoxazole, a common heterocycle in medicinal chemistry, can be applied to offer an alternative to existing strategies using more perturbing, extrinsic photo-crosslinkers. The utility of isoxazole photo-crosslinking is demonstrated in a wide range of biologically relevant experiments, including common proteomics workflows.
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Affiliation(s)
- Marshall G. Lougee
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Vinayak Vishnu Pagar
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania, 19104, USA. .,Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, 19104, USA
| | - Hee Jong Kim
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Samantha X. Pancoe
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - W. Kit Chia
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Robert H. Mach
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Benjamin A. Garcia
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - E. James Petersson
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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4
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Zhang Q, Li H, Liu Y, Li J, Wu C, Tang H. Exosomal Non-Coding RNAs: New Insights into the Biology of Hepatocellular Carcinoma. CURRENT ONCOLOGY (TORONTO, ONT.) 2022; 29:5383-5406. [PMID: 36005165 PMCID: PMC9406833 DOI: 10.3390/curroncol29080427] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 07/26/2022] [Accepted: 07/27/2022] [Indexed: 02/07/2023]
Abstract
Exosomes, extracellular vesicles with a diameter of 40 to 160 nm, are among the smallest extracellular vesicles released by cells. They deliver different cargoes, including proteins, DNAs, and RNAs, and facilitate communication between cells to coordinate a variety of physiological and pathological functions. Hepatocellular carcinoma (HCC) is the sixth common malignant tumor and the fourth leading cause of cancer-related death worldwide. Its molecular mechanism remains largely unknown, and there is a lack of reliable and noninvasive biomarkers for early diagnosis and prognosis prediction. Mounting evidence has shown that exosomes carry a variety of ncRNAs, such as long non-coding RNAs (lncRNAs), microRNAs (miRNAs), and circular RNAs (circRNAs), which play critical roles in the occurrence and progression of HCC. In this review, we summarize the recent findings of exosomal miRNAs, lncRNAs, and circRNAs in HCC from their impact on the development of HCC to their potential applications in the diagnosis and treatment of HCC.
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Affiliation(s)
- Qian Zhang
- School of Basic Medical Sciences, Southwest Medical University, Luzhou 646000, China; (Q.Z.); (H.L.); (Y.L.)
| | - Hanlin Li
- School of Basic Medical Sciences, Southwest Medical University, Luzhou 646000, China; (Q.Z.); (H.L.); (Y.L.)
| | - Yang Liu
- School of Basic Medical Sciences, Southwest Medical University, Luzhou 646000, China; (Q.Z.); (H.L.); (Y.L.)
| | - Jian Li
- School of Basic Medical Sciences, Chengdu University, Chengdu 610106, China;
| | - Chunling Wu
- School of Basic Medical Sciences, Southwest Medical University, Luzhou 646000, China; (Q.Z.); (H.L.); (Y.L.)
- Correspondence: (C.W.); (H.T.)
| | - Hua Tang
- School of Basic Medical Sciences, Southwest Medical University, Luzhou 646000, China; (Q.Z.); (H.L.); (Y.L.)
- Central Nervous System Drug Key Laboratory of Sichuan Province, Luzhou 646000, China
- Engineering, Informatics Fusion and Transformation Key Laboratory, Luzhou 646000, China
- Correspondence: (C.W.); (H.T.)
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Hu R, Zhu X, Yuan M, Ho KH, Kaverina I, Gu G. Microtubules and Gαo-signaling modulate the preferential secretion of young insulin secretory granules in islet β cells via independent pathways. PLoS One 2021; 16:e0241939. [PMID: 34292976 PMCID: PMC8297875 DOI: 10.1371/journal.pone.0241939] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 06/15/2021] [Indexed: 12/24/2022] Open
Abstract
For sustainable function, each pancreatic islet β cell maintains thousands of insulin secretory granules (SGs) at all times. Glucose stimulation induces the secretion of a small portion of these SGs and simultaneously boosts SG biosynthesis to sustain this stock. The failure of these processes, often induced by sustained high-insulin output, results in type 2 diabetes. Intriguingly, young insulin SGs are more likely secreted during glucose-stimulated insulin secretion (GSIS) for unknown reasons, while older SGs tend to lose releasability and be degraded. Here, we examine the roles of microtubule (MT) and Gαo-signaling in regulating the preferential secretion of young versus old SGs. We show that both MT-destabilization and Gαo inactivation results in more SGs localization near plasma membrane (PM) despite higher levels of GSIS and reduced SG biosynthesis. Intriguingly, MT-destabilization or Gαo-inactivation results in higher secretion probabilities of older SGs, while combining both having additive effects on boosting GSIS. Lastly, Gαo inactivation does not detectably destabilize the β-cell MT network. These findings suggest that Gαo and MT can modulate the preferential release of younger insulin SGs via largely parallel pathways.
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Affiliation(s)
- Ruiying Hu
- Department of Cell and Developmental Biology, The Program of Developmental Biology and the Center for Stem Cell Biology, Vanderbilt University, Nashville, TN, United States of America
| | - Xiaodong Zhu
- Department of Cell and Developmental Biology, The Program of Developmental Biology and the Center for Stem Cell Biology, Vanderbilt University, Nashville, TN, United States of America
| | - Mingyang Yuan
- Department of Cell and Developmental Biology, The Program of Developmental Biology and the Center for Stem Cell Biology, Vanderbilt University, Nashville, TN, United States of America
| | - Kung-Hsien Ho
- Department of Cell and Developmental Biology, The Program of Developmental Biology and the Center for Stem Cell Biology, Vanderbilt University, Nashville, TN, United States of America
| | - Irina Kaverina
- Department of Cell and Developmental Biology, The Program of Developmental Biology and the Center for Stem Cell Biology, Vanderbilt University, Nashville, TN, United States of America
- * E-mail: (GG); (IK)
| | - Guoqiang Gu
- Department of Cell and Developmental Biology, The Program of Developmental Biology and the Center for Stem Cell Biology, Vanderbilt University, Nashville, TN, United States of America
- * E-mail: (GG); (IK)
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6
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Luo Y, Cui C, Han X, Wang Q, Zhang C. The role of miRNAs in polycystic ovary syndrome with insulin resistance. J Assist Reprod Genet 2021; 38:289-304. [PMID: 33405004 PMCID: PMC7884539 DOI: 10.1007/s10815-020-02019-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 11/22/2020] [Indexed: 02/07/2023] Open
Abstract
PURPOSE This review aims to summarize the key findings of several miRNAs and their roles in polycystic ovary syndrome with insulin resistance, characterize the disease pathogenesis, and establish a new theoretical basis for diagnosing, treating, and preventing polycystic ovary syndrome. METHODS Relevant scientific literature was covered from 1992 to 2020 by searching the PubMed database with search terms: insulin/insulin resistance, polycystic ovary syndrome, microRNAs, and metabolic diseases. References of relevant studies were cross-checked. RESULTS The related miRNAs (including differentially expressed miRNAs) and their roles in pathogenesis, and possible therapeutic targets and pathways, are discussed, highlighting controversies and offering thoughts for future directions. CONCLUSION We found abundant evidence on the role of differentially expressed miRNAs with its related phenotypes in PCOS. Considering the essential role of insulin resistance in the pathogenesis of PCOS, the alterations of associated miRNAs need more research attention. We speculate that race/ethnicity or PCOS phenotype and differences in methodological differences might lead to inconsistencies in research findings; thus, several miRNA profiles need to be investigated further to qualify for the potential therapeutic targets for PCOS-IR.
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Affiliation(s)
- Yingliu Luo
- Zhengzhou University People's Hospital, Henan Provincial People's Hospital, Zhengzhou, 450003, Henan Province, People's Republic of China
| | - Chenchen Cui
- Zhengzhou University People's Hospital, Henan Provincial People's Hospital, Zhengzhou, 450003, Henan Province, People's Republic of China
- Henan Joint International Research Laboratory of Reproductive Bioengineering, Zhengzhou, 450003, Henan Province, People's Republic of China
| | - Xiao Han
- Zhengzhou University People's Hospital, Henan Provincial People's Hospital, Zhengzhou, 450003, Henan Province, People's Republic of China
| | - Qian Wang
- Zhengzhou University People's Hospital, Henan Provincial People's Hospital, Zhengzhou, 450003, Henan Province, People's Republic of China
- Henan Joint International Research Laboratory of Reproductive Bioengineering, Zhengzhou, 450003, Henan Province, People's Republic of China
| | - Cuilian Zhang
- Zhengzhou University People's Hospital, Henan Provincial People's Hospital, Zhengzhou, 450003, Henan Province, People's Republic of China.
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Aravind P, Bulbule SR, Hemalatha N, Babu R, Devaraju K. Elevation of gene expression of calcineurin, calmodulin and calsyntenin in oxidative stress induced PC12 cells. Genes Dis 2021; 8:87-93. [PMID: 33569517 PMCID: PMC7859428 DOI: 10.1016/j.gendis.2019.09.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Revised: 08/01/2019] [Accepted: 09/01/2019] [Indexed: 12/30/2022] Open
Abstract
In normal physiological conditions, reactive oxygen and nitrogen species are used as important signaling molecules in the cell. However, in excess it causes the disruption of cell resulting in their death. Oxidative stress causes influx in intracellular calcium levels leading to higher concentrations of calcium in the cell. This accelerated calcium affects both the mitochondria and nuclei leading to excitotoxicity in neurons. Intracellular calcium levels are controlled by voltage dependent calcium channels located in the plasma membrane, calcium stores like endoplasmic/sarcoplasmic reticulum and majorly by calcium binding proteins. Our study was aimed at analyzing the gene expression of major calcium binding proteins namely calcineurin, calmodulin, calreticulin, synaptotagamin and calsyntenin in stress induced PC 12 cells. Rotenone (1 μM), Peroxynitrite (10 μM), H2O2 (100 μM) and High glucose (33 mM) were used to induce oxidative stress in PC12 cells. Results obtained from the study suggest that calcineurin, calmodulin and calsyntenin gene expression were enhanced compared to the control due to oxidative stress. However, synaptotagmin and calreticulin gene expression were down regulated. Further, Akt protein expression (stress marker) was enhanced in PC12 cells with all other stress inducers except in hyperglycemic condition.
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Affiliation(s)
- P. Aravind
- Department of Biochemistry, Karnatak University, Pavate Nagar, Dharwad, 580 003, India
| | - Sarojini R. Bulbule
- Department of Biochemistry, Karnatak University, Pavate Nagar, Dharwad, 580 003, India
| | - N. Hemalatha
- Department of Biochemistry and Nutrition, CFTRI, V V Moholla, Mysore, 570 020, India
| | - R.L. Babu
- Department of Bioinformatics and Biotechnology, Akkamahadevi Women's University, Vijayapura, Karnataka, 586 108, India
| | - K.S. Devaraju
- Department of Biochemistry, Karnatak University, Pavate Nagar, Dharwad, 580 003, India
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Kajihara R, Numakawa T, Odaka H, Yaginuma Y, Fusaki N, Okumiya T, Furuya H, Inui S, Era T. Novel Drug Candidates Improve Ganglioside Accumulation and Neural Dysfunction in GM1 Gangliosidosis Models with Autophagy Activation. Stem Cell Reports 2020; 14:909-923. [PMID: 32302553 PMCID: PMC7220856 DOI: 10.1016/j.stemcr.2020.03.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 03/13/2020] [Accepted: 03/17/2020] [Indexed: 12/25/2022] Open
Abstract
GM1 gangliosidosis is a lysosomal storage disease caused by loss of lysosomal β-galactosidase activity and characterized by progressive neurodegeneration due to massive accumulation of GM1 ganglioside in the brain. Here, we generated induced pluripotent stem cells (iPSCs) derived from patients with GM1 gangliosidosis, and the resultant neurons showed impaired neurotransmitter release as a presynaptic function and accumulation of GM1 ganglioside. Treatment of normal neurons with GM1 ganglioside also disturbed presynaptic function. A high-content drug-screening system was then established and identified two compounds as drug candidates for GM1 gangliosidosis. Treatment of the patient-derived neurons with the candidate agents activated autophagy pathways, reducing GM1 ganglioside accumulation in vitro and in vivo, and restoring the presynaptic dysfunction. Our findings thus demonstrated the potential value of patient-derived iPSC lines as cellular models of GM1 gangliosidosis and revealed two potential therapeutic agents for future clinical application. GM1 ganglioside accumulation affects presynaptic function in normal neurons Presynaptic function is impaired in neurons from GM1 gangliosidosis iPSCs The drugs candidates are identified using GM1 gangliosidosis iPSCs The drug candidates activate both autophagy and sphingolipid degradation
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Affiliation(s)
- Ryutaro Kajihara
- Department of Cell Modulation, Institute of Molecular Embryology and Genetics, Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto 860-0811, Japan; Department of Biomedical Laboratory Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto 862-0976, Japan
| | - Tadahiro Numakawa
- Department of Cell Modulation, Institute of Molecular Embryology and Genetics, Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto 860-0811, Japan
| | - Haruki Odaka
- Department of Cell Modulation, Institute of Molecular Embryology and Genetics, Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto 860-0811, Japan
| | - Yuji Yaginuma
- Department of Morphological and Physiological Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto 862-0976, Japan
| | - Noemi Fusaki
- University Research Administration Center, Office of Research Promotion, Tohoku University, Tohoku 980-8577, Japan
| | - Toshika Okumiya
- Department of Biomedical Laboratory Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto 862-0976, Japan
| | - Hirokazu Furuya
- Department of Neurology, Kochi Medical School, Kochi University, Kochi 783-8505, Japan
| | - Seiji Inui
- Department of Biomedical Laboratory Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto 862-0976, Japan
| | - Takumi Era
- Department of Cell Modulation, Institute of Molecular Embryology and Genetics, Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto 860-0811, Japan.
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Synaptotagmin 1 Is Involved in Neuropathic Pain and Electroacupuncture-Mediated Analgesic Effect. Int J Mol Sci 2020; 21:ijms21030968. [PMID: 32024024 PMCID: PMC7037106 DOI: 10.3390/ijms21030968] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 01/26/2020] [Accepted: 01/29/2020] [Indexed: 01/09/2023] Open
Abstract
Numerous studies have verified that electroacupuncture (EA) can relieve neuropathic pain through a variety of mechanisms. Synaptotagmin 1 (Syt-1), a synaptic vesicle protein for regulating exocytosis of neurotransmitters, was found to be affected by EA stimulation. However, the roles of Syt-1 in neuropathic pain and EA-induced analgesic effect remain unclear. Here, the effect of Syt-1 on nociception was assessed through an antibody blockade, siRNA silencing, and lentivirus-mediated overexpression of spinal Syt-1 in rats with spared nerve injury (SNI). EA was used for stimulating bilateral "Sanjinjiao" and "Zusanli" acupoints of the SNI rats to evaluate its effect on nociceptive thresholds and spinal Syt-1 expression. The mechanically and thermally nociceptive behaviors were assessed with paw withdrawal threshold (PWT) and paw withdrawal latency (PWL) at different temperatures, respectively, at day 0, 7, 8, 14, and 20. Syt-1 mRNA and protein levels were determined with qRT-PCR and Western blot, respectively, and its distribution was observed with the immunohistochemistry method. The results demonstrated Syt-1 antibody blockade and siRNA silencing increased ipsilateral PWTs and PWLs of SNI rats, while Syt-1 overexpression decreased ipsilateral PWTs and PWLs of rats. EA significantly attenuated nociceptive behaviors and down-regulated spinal Syt-1 protein levels (especially in laminae I-II), which were reversed by Syt-1 overexpression. Our findings firstly indicate that Syt-1 is involved in the development of neuropathic pain and that EA attenuates neuropathic pain, probably through suppressing Syt-1 protein expression in the spinal cord.
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da Silva BS, Cupertino RB, Schuch JB, Kappel DB, Sanvicente-Vieira B, Bandeira CE, von Diemen L, Kessler FHP, Grevet EH, Grassi-Oliveira R, Bau CHD, Rovaris DL. The association between SYT1-rs2251214 and cocaine use disorder further supports its role in psychiatry. Prog Neuropsychopharmacol Biol Psychiatry 2019; 94:109642. [PMID: 31059723 DOI: 10.1016/j.pnpbp.2019.109642] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Revised: 05/02/2019] [Accepted: 05/02/2019] [Indexed: 01/08/2023]
Abstract
Synaptotagmin-1 is an essential regulator of synaptic vesicle exocytosis, and its encoding gene (SYT1) is a genome and transcriptome-wide association hit in cognitive performance, personality and cocaine use disorder (CUD) studies. Additionally, in candidate gene studies the specific variant rs2251214 has been associated with attention-deficit/hyperactivity disorder (ADHD), antisocial personality disorder and other externalizing phenotypes in adults with ADHD, as well as with response to methylphenidate (MPH) treatment. In this context, we sought to evaluate, in an independent sample, the association of this variant with CUD, a phenotype that shares common biological underpinnings with the previously associated traits. We tested the association between SYT1-rs2251214 and CUD susceptibility and severity (addiction severity index) in a sample composed by 315 patients addicted to smoked cocaine and 769 non-addicted volunteers. SYT1-rs2251214 was significantly associated with susceptibility to CUD, where the G allele presented increased risk for the disorder in the genetic models tested (P = 0.0021, OR = 1.44, allelic; P = 0.0012, OR = 1.48, additive; P = 0.0127, OR = 1.41, dominant). This is the same allele that was associated with increased risk for ADHD and other externalizing behaviors, as well as poor response to MPH treatment in previous studies. These findings suggest that the neurotransmitter exocytosis pathway might play a critical role in the liability for psychiatric disorders, especially externalizing behaviors and CUD.
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Affiliation(s)
- Bruna S da Silva
- Department of Genetics, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; ADHD Outpatient Program, Adult Division, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | - Renata B Cupertino
- Department of Genetics, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; ADHD Outpatient Program, Adult Division, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | - Jaqueline B Schuch
- Laboratory of Immunosenescence, Graduate Program in Biomedical Gerontology, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil; Center for Drug and Alcohol Research, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Djenifer B Kappel
- Department of Genetics, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; ADHD Outpatient Program, Adult Division, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | - Breno Sanvicente-Vieira
- Developmental Cognitive Neuroscience Lab, Biomedical Research Institute, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil
| | - Cibele E Bandeira
- Department of Genetics, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; ADHD Outpatient Program, Adult Division, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | - Lisia von Diemen
- Center for Drug and Alcohol Research, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Felix H P Kessler
- Center for Drug and Alcohol Research, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Eugenio H Grevet
- ADHD Outpatient Program, Adult Division, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil; Department of Psychiatry, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Rodrigo Grassi-Oliveira
- Developmental Cognitive Neuroscience Lab, Biomedical Research Institute, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil
| | - Claiton H D Bau
- Department of Genetics, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; ADHD Outpatient Program, Adult Division, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | - Diego L Rovaris
- ADHD Outpatient Program, Adult Division, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil; Department of Psychiatry, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
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11
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Zhou J, Liao Z, Jia J, Chen JL, Xiao Q. The effects of resveratrol feeding and exercise training on the skeletal muscle function and transcriptome of aged rats. PeerJ 2019; 7:e7199. [PMID: 31304063 PMCID: PMC6610545 DOI: 10.7717/peerj.7199] [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: 02/28/2019] [Accepted: 05/27/2019] [Indexed: 02/05/2023] Open
Abstract
This study investigated the effects of resveratrol feeding and exercise training on the skeletal muscle function and transcriptome of aged rats. Male SD rats (25 months old) were divided into the control group (Old), the daily exercise training group (Trained), and the resveratrol feeding group (Resveratrol). After 6 weeks of intervention, the body mass, grip strength, and gastrocnemius muscle mass were determined, and the muscle samples were analyzed by transcriptome sequencing. The differentially expressed genes were analyzed followed by GO enrichment analysis and KEGG analysis. The Old group showed positive increases in body mass, while both the Trained and Resveratrol groups showed negative growth. No significant differences in the gastrocnemius muscle index and absolute grip strength were found among the three groups. However, the relative grip strength was higher in the Trained group than in the Old group. Only 21 differentially expressed genes were identified in the Trained group vs. the Old group, and 12 differentially expressed genes were identified in the Resveratrol group vs. the Old group. The most enriched GO terms in the Trained group vs. the Old group were mainly associated with RNA metabolic processes and transmembrane transporters, and the significantly upregulated KEGG pathways included mucin-type O-glycan biosynthesis, drug metabolism, and pyrimidine metabolism. The most enriched GO terms in the Resveratrol group vs. the Old group were primarily associated with neurotransmitter transport and synaptic vesicle, and the upregulated KEGG pathways included synaptic vesicle cycle, nicotine addiction, retinol metabolism, insulin secretion, retrograde endocannabinoid signaling, and glutamatergic synapse. Neither exercise training nor resveratrol feeding has a notable effect on skeletal muscle function and related gene expression in aged rats. However, both exercise training and resveratrol feeding have strong effects on weight loss, which is beneficial for reducing the exercise loads of the elderly.
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Affiliation(s)
- Jing Zhou
- Chongqing Medical and Pharmaceutical College, Chongqing, China.,Department of Geriatrics, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Zhiyin Liao
- Department of Geriatrics, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Jia Jia
- Chongqing Medical and Pharmaceutical College, Chongqing, China
| | - Jin-Liang Chen
- Department of Geriatrics, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Qian Xiao
- Department of Geriatrics, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
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12
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Chakrabarti R, Wichmann C. Nanomachinery Organizing Release at Neuronal and Ribbon Synapses. Int J Mol Sci 2019; 20:E2147. [PMID: 31052288 PMCID: PMC6539712 DOI: 10.3390/ijms20092147] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 04/26/2019] [Accepted: 04/26/2019] [Indexed: 11/17/2022] Open
Abstract
A critical aim in neuroscience is to obtain a comprehensive view of how regulated neurotransmission is achieved. Our current understanding of synapses relies mainly on data from electrophysiological recordings, imaging, and molecular biology. Based on these methodologies, proteins involved in a synaptic vesicle (SV) formation, mobility, and fusion at the active zone (AZ) membrane have been identified. In the last decade, electron tomography (ET) combined with a rapid freezing immobilization of neuronal samples opened a window for understanding the structural machinery with the highest spatial resolution in situ. ET provides significant insights into the molecular architecture of the AZ and the organelles within the presynaptic nerve terminal. The specialized sensory ribbon synapses exhibit a distinct architecture from neuronal synapses due to the presence of the electron-dense synaptic ribbon. However, both synapse types share the filamentous structures, also commonly termed as tethers that are proposed to contribute to different steps of SV recruitment and exocytosis. In this review, we discuss the emerging views on the role of filamentous structures in SV exocytosis gained from ultrastructural studies of excitatory, mainly central neuronal compared to ribbon-type synapses with a focus on inner hair cell (IHC) ribbon synapses. Moreover, we will speculate on the molecular entities that may be involved in filament formation and hence play a crucial role in the SV cycle.
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Affiliation(s)
- Rituparna Chakrabarti
- Molecular Architecture of Synapses Group, Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, 37075 Göttingen, Germany.
- Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, 37075 Göttingen, Germany.
- Collaborative Research Center 889 "Cellular Mechanisms of Sensory Processing", 37099 Göttingen, Germany.
| | - Carolin Wichmann
- Molecular Architecture of Synapses Group, Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, 37075 Göttingen, Germany.
- Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, 37075 Göttingen, Germany.
- Collaborative Research Center 889 "Cellular Mechanisms of Sensory Processing", 37099 Göttingen, Germany.
- Collaborative Research Center 1286 "Quantitative Synaptology", 37099 Göttingen, Germany.
- Auditory Neuroscience Group, Max Planck Institute for Experimental Medicine, 37075 Göttingen, Germany.
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Veras PST, Ramos PIP, de Menezes JPB. In Search of Biomarkers for Pathogenesis and Control of Leishmaniasis by Global Analyses of Leishmania-Infected Macrophages. Front Cell Infect Microbiol 2018; 8:326. [PMID: 30283744 PMCID: PMC6157484 DOI: 10.3389/fcimb.2018.00326] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 08/27/2018] [Indexed: 12/12/2022] Open
Abstract
Leishmaniasis is a vector-borne, neglected tropical disease with a worldwide distribution that can present in a variety of clinical forms, depending on the parasite species and host genetic background. The pathogenesis of this disease remains far from being elucidated because the involvement of a complex immune response orchestrated by host cells significantly affects the clinical outcome. Among these cells, macrophages are the main host cells, produce cytokines and chemokines, thereby triggering events that contribute to the mediation of the host immune response and, subsequently, to the establishment of infection or, alternatively, disease control. There has been relatively limited commercial interest in developing new pharmaceutical compounds to treat leishmaniasis. Moreover, advances in the understanding of the underlying biology of Leishmania spp. have not translated into the development of effective new chemotherapeutic compounds. As a result, biomarkers as surrogate disease endpoints present several potential advantages to be used in the identification of targets capable of facilitating therapeutic interventions considered to ameliorate disease outcome. More recently, large-scale genomic and proteomic analyses have allowed the identification and characterization of the pathways involved in the infection process in both parasites and the host, and these analyses have been shown to be more effective than studying individual molecules to elucidate disease pathogenesis. RNA-seq and proteomics are large-scale approaches that characterize genes or proteins in a given cell line, tissue, or organism to provide a global and more integrated view of the myriad biological processes that occur within a cell than focusing on an individual gene or protein. Bioinformatics provides us with the means to computationally analyze and integrate the large volumes of data generated by high-throughput sequencing approaches. The integration of genomic expression and proteomic data offers a rich multi-dimensional analysis, despite the inherent technical and statistical challenges. We propose that these types of global analyses facilitate the identification, among a large number of genes and proteins, those that hold potential as biomarkers. The present review focuses on large-scale studies that have identified and evaluated relevant biomarkers in macrophages in response to Leishmania infection.
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Affiliation(s)
- Patricia Sampaio Tavares Veras
- Laboratory of Host-Parasite Interaction and Epidemiology, Gonçalo Moniz Institute, Fiocruz-Bahia, Salvador, Brazil.,National Institute of Tropical Disease, Brasilia, Brazil
| | - Pablo Ivan Pereira Ramos
- Center for Data and Knowledge Integration for Health, Gonçalo Moniz Institute, Fiocruz-Bahia, Salvador, Brazil
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Aureli M, Samarani M, Loberto N, Chiricozzi E, Mauri L, Grassi S, Schiumarini D, Prinetti A, Sonnino S. Neuronal membrane dynamics as fine regulator of sphingolipid composition. Glycoconj J 2018; 35:397-402. [PMID: 30145639 DOI: 10.1007/s10719-018-9841-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 08/13/2018] [Indexed: 02/01/2023]
Abstract
Sphingolipid metabolism is an intricate network of several interdependent and co-regulated pathways. In addition to the mainstream biosynthetic and catabolic pathways, several processes, even if less important in contributing to the final tissue sphingolipid composition from the quantitative point of view, might become relevant when sphingolipid metabolism is for any reason dysregulated and concur to the onset of neuronal pathologies. The main subcellular sites involved in the mainstream metabolic pathway are represented by the Golgi apparatus (for the biosynthesis) and by the lysosomes (for catabolism). On the other hand, the minor collateral pathways are associated with the plasma membrane and membranes of other organelles, and likely play important roles in the local regulation of membrane dynamics and contribute to maintain a perfect membrane organization functional to the physiology of the cell. In this review, we will consider few aspects of the sphingolipid metabolic pathway depending by the dynamic of the membranes that seems to become relevant in neurodegenerative diseases.
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Affiliation(s)
- Massimo Aureli
- Department of Medical Biotechnology and Translational Medicine, University of Milano, Via Fratelli Cervi 93, 20090, Segrate, Milan, Italy.
| | - Maura Samarani
- Department of Medical Biotechnology and Translational Medicine, University of Milano, Via Fratelli Cervi 93, 20090, Segrate, Milan, Italy
| | - Nicoletta Loberto
- Department of Medical Biotechnology and Translational Medicine, University of Milano, Via Fratelli Cervi 93, 20090, Segrate, Milan, Italy.
| | - Elena Chiricozzi
- Department of Medical Biotechnology and Translational Medicine, University of Milano, Via Fratelli Cervi 93, 20090, Segrate, Milan, Italy
| | - Laura Mauri
- Department of Medical Biotechnology and Translational Medicine, University of Milano, Via Fratelli Cervi 93, 20090, Segrate, Milan, Italy
| | - Sara Grassi
- Department of Medical Biotechnology and Translational Medicine, University of Milano, Via Fratelli Cervi 93, 20090, Segrate, Milan, Italy
| | - Domitilla Schiumarini
- Department of Medical Biotechnology and Translational Medicine, University of Milano, Via Fratelli Cervi 93, 20090, Segrate, Milan, Italy
| | - Alessandro Prinetti
- Department of Medical Biotechnology and Translational Medicine, University of Milano, Via Fratelli Cervi 93, 20090, Segrate, Milan, Italy
| | - Sandro Sonnino
- Department of Medical Biotechnology and Translational Medicine, University of Milano, Via Fratelli Cervi 93, 20090, Segrate, Milan, Italy
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Hessvik NP, Llorente A. Current knowledge on exosome biogenesis and release. Cell Mol Life Sci 2018; 75:193-208. [PMID: 28733901 PMCID: PMC5756260 DOI: 10.1007/s00018-017-2595-9] [Citation(s) in RCA: 1550] [Impact Index Per Article: 258.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 06/22/2017] [Accepted: 07/13/2017] [Indexed: 12/12/2022]
Abstract
Exosomes are nanosized membrane vesicles released by fusion of an organelle of the endocytic pathway, the multivesicular body, with the plasma membrane. This process was discovered more than 30 years ago, and during these years, exosomes have gone from being considered as cellular waste disposal to mediate a novel mechanism of cell-to-cell communication. The exponential interest in exosomes experienced during recent years is due to their important roles in health and disease and to their potential clinical application in therapy and diagnosis. However, important aspects of the biology of exosomes remain unknown. To explore the use of exosomes in the clinic, it is essential that the basic molecular mechanisms behind the transport and function of these vesicles are better understood. We have here summarized what is presently known about how exosomes are formed and released by cells. Moreover, other cellular processes related to exosome biogenesis and release, such as autophagy and lysosomal exocytosis are presented. Finally, methodological aspects related to exosome release studies are discussed.
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Affiliation(s)
- Nina Pettersen Hessvik
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, The Norwegian Radium Hospital, 0379, Oslo, Norway
- Centre for Cancer Biomedicine, University of Oslo, 0379, Oslo, Norway
| | - Alicia Llorente
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, The Norwegian Radium Hospital, 0379, Oslo, Norway.
- Centre for Cancer Biomedicine, University of Oslo, 0379, Oslo, Norway.
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Jean A, Bonnet P, Liere P, Mhaouty-Kodja S, Hardin-Pouzet H. Revisiting medial preoptic area plasticity induced in male mice by sexual experience. Sci Rep 2017; 7:17846. [PMID: 29259324 PMCID: PMC5736590 DOI: 10.1038/s41598-017-18248-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 12/07/2017] [Indexed: 01/25/2023] Open
Abstract
Sexual experience in male rodents, induced by a first exposure to a receptive female, improves efficiency of following copulations. In mice, the mechanisms supporting this improvement are poorly understood. We characterized molecular modifications of the mouse hypothalamic medial preoptic area (mPOA), the main integrative structure for male sexual behaviour, after a single mating event. This paradigm induced long-lasting behavioural improvements and mPOA morphological changes, evidenced by dendritic spine maturation and an increase in the acetylated and tri-methylated forms of histone H3. Ejaculation affected testosterone, progesterone and corticosterone levels in both naive and experienced mice, but sexual experience did not modify basal plasma or hypothalamic levels of steroids. In contrast to studies carried out in rats, no changes were observed, either in the nitrergic system, or in sex steroid receptor levels. However, levels of glutamate- and calcium-associated proteins, including PSD-95, calbindin and the GluN1 subunit of the NMDA receptor, were increased in sexually experienced male mice. The Iba-1 microglial marker was up-regulated in these animals suggesting multicellular interactions induced within the mPOA by sexual experience. In conclusion, plasticity mechanisms induced by sexual experience differ between rat and mouse, even if in both cases they converge to potentiation of the mPOA network.
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Affiliation(s)
- Arnaud Jean
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Neuroscience Paris - Seine; Institut de Biologie Paris Seine, 75005, Paris, France
| | - Pauline Bonnet
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Neuroscience Paris - Seine; Institut de Biologie Paris Seine, 75005, Paris, France
| | - Philippe Liere
- U1195 INSERM and Université Paris Sud and Université Paris-Saclay, 80 rue du Général Leclerc, 94276, Le Kremlin-Bicêtre, France
| | - Sakina Mhaouty-Kodja
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Neuroscience Paris - Seine; Institut de Biologie Paris Seine, 75005, Paris, France
| | - Helene Hardin-Pouzet
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Neuroscience Paris - Seine; Institut de Biologie Paris Seine, 75005, Paris, France.
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17
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Cupertino RB, Schuch JB, Bandeira CE, da Silva BS, Rovaris DL, Kappel DB, Contini V, Salatino-Oliveira A, Vitola ES, Karam RG, Hutz MH, Rohde LA, Grevet EH, Bau CHD, Mota NR. Replicated association of Synaptotagmin (SYT1) with ADHD and its broader influence in externalizing behaviors. Eur Neuropsychopharmacol 2017; 27:239-247. [PMID: 28130000 DOI: 10.1016/j.euroneuro.2017.01.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 10/30/2016] [Accepted: 01/05/2017] [Indexed: 12/20/2022]
Abstract
Attention-Deficit/Hyperactivity Disorder (ADHD) is a common psychiatric disorder, affecting both children and adults. The Soluble N-ethylmaleimide sensitive factor Attachment REceptors (SNARE) complex has been implicated in ADHD pathophysiology since it is a key component of neurotransmitter release events and neurodevelopment processes, and SNPs in this complex have been associated with ADHD. Here we aim to analyze the effects of SNARE complex variants on ADHD susceptibility and its clinical heterogeneity in affected adults. We tested the association between ADHD and polymorphisms on the SNARE genes STX1A (rs2228607), SYT1 (rs1880867 and rs2251214), VAMP2 (26bp Ins/Del) and SNAP25 (rs6108461 and rs8636) on a sample comprised of 548 adults with ADHD and 644 non-affected controls. Regarding clinical heterogeneity, we further investigated the effects of associated SNPs on age at onset of impairment due to ADHD and on relevant externalizing behaviors (i.e. school suspensions/expulsions and problems with law/authority) and comorbidities (i.e. Substance Use Disorder, Oppositional Defiant Disorder, Conduct Disorder and Antisocial Personality Disorder). We replicated a previously reported association between SYT1-rs2251214 and ADHD in adulthood. This SNP was also associated with age at onset of impairment due to ADHD symptoms and with a range of externalizing phenotypes. These findings involving SYT1 suggest that variation in neurotransmitter exocytosis mechanisms may represent an underlying genetic factor shared by a spectrum of externalizing behaviors and disorders, including - but not restricted to - ADHD.
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Affiliation(s)
- Renata Basso Cupertino
- Department of Genetics, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Jaqueline Bohrer Schuch
- Department of Genetics, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Cibele Edom Bandeira
- Department of Genetics, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Bruna Santos da Silva
- Department of Genetics, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Diego Luiz Rovaris
- Department of Genetics, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Djenifer B Kappel
- Department of Genetics, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Verônica Contini
- PPGBIOTEC - Postgraduate Program in Biotechnology, Centro Universitário Univates, Lajeado, Brazil
| | - Angélica Salatino-Oliveira
- Department of Genetics, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Eduardo Schneider Vitola
- Department of Psychiatry, Faculdade de Medicina, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Rafael Gomes Karam
- ADHD Outpatient Program, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil
| | - Mara Helena Hutz
- Department of Genetics, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; ADHD Outpatient Program, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil
| | - Luis Augusto Rohde
- Department of Psychiatry, Faculdade de Medicina, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; ADHD Outpatient Program, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil; National Institute of Developmental Psychiatry for Children and Adolescents, Brazil
| | - Eugenio Horacio Grevet
- Department of Psychiatry, Faculdade de Medicina, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; ADHD Outpatient Program, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil
| | - Claiton Henrique Dotto Bau
- Department of Genetics, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; ADHD Outpatient Program, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil.
| | - Nina Roth Mota
- Department of Genetics, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
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Zoltowska KM, Maesako M, Lushnikova I, Takeda S, Keller LJ, Skibo G, Hyman BT, Berezovska O. Dynamic presenilin 1 and synaptotagmin 1 interaction modulates exocytosis and amyloid β production. Mol Neurodegener 2017; 12:15. [PMID: 28193235 PMCID: PMC5307796 DOI: 10.1186/s13024-017-0159-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 02/09/2017] [Indexed: 01/09/2023] Open
Abstract
Background Alzheimer’s disease (AD)-linked protein, presenilin 1 (PS1), is present at the synapse, and the knock-out of presenilin in mice leads to synaptic dysfunction. On the other hand, synaptic activity was shown to influence PS1-dependent generation of distinct amyloid β (Aβ) species. However, the precise nature of these regulations remains unclear. The current study reveals novel role of PS1 at the synapse, and deciphers how PS1 and synaptic vesicle-associated protein, synaptotagmin 1 (Syt1) modulate each other functions in neurons via direct activity-triggered interaction. Additionally, the therapeutic potential of fostering PS1-Syt1 binding is investigated as a synapse-specific strategy for AD prevention. Methods PS1-based cell-permeable peptide targeting PS1-Syt1 binding site was designed to inhibit PS1-Syt1 interaction in neurons. PS1 conformation, synaptic vesicle exocytosis and trafficking were assayed by fluorescence lifetime imaging microscopy (FLIM), glutamate release/synaptopHluorin assay, and fluorescence recovery after photobleaching, respectively. Syt1 level and interaction with PS1 in control and sporadic AD brains were determined by immunohistochemistry and FLIM. AAV-mediated delivery of Syt1 into mouse hippocampi was used to investigate the therapeutic potential of strengthening PS1-Syt1 binding in vivo. Statistical significance was determined using two-tailed unpaired Student’s t-test, Mann-Whitney’s U-test or two-way ANOVA followed by a Bonferroni’s post-test. Results We demonstrate that targeted inhibition of the PS1-Syt1 binding in neurons, without changing the proteins’ expression level, triggers “pathogenic” conformational shift of PS1, and consequent increase in the Aβ42/40 ratio. Moreover, our data indicate that PS1, by binding directly to Syt1, regulates synaptic vesicle trafficking and facilitates exocytosis and neurotransmitter release. Analysis of human brain tissue revealed that not only Syt1 levels but also interactions between remaining Syt1 and PS1 are diminished in sporadic AD. On the other hand, overexpression of Syt1 in mouse hippocampi was found to potentiate PS1-Syt1 binding and promote “protective” PS1 conformation. Conclusions The study reports novel functions of PS1 and Syt1 at the synapse, and demonstrates the importance of PS1-Syt1 binding for exocytosis and safeguarding PS1 conformation. It suggests that reduction in the Syt1 level and PS1-Syt1 interactions in AD brain may present molecular underpinning of the pathogenic PS1 conformation, increased Aβ42/40 ratio, and impaired exocytosis. Electronic supplementary material The online version of this article (doi:10.1186/s13024-017-0159-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Katarzyna Marta Zoltowska
- Department of Neurology, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, 114 16th Street, Rm. 2006, 02129, Charlestown, MA, USA
| | - Masato Maesako
- Department of Neurology, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, 114 16th Street, Rm. 2006, 02129, Charlestown, MA, USA
| | - Iryna Lushnikova
- Department of Cytology, Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, 4 Bogomoletz Street, 01024, Kyiv, Ukraine
| | - Shuko Takeda
- Department of Neurology, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, 114 16th Street, Rm. 2006, 02129, Charlestown, MA, USA
| | - Laura J Keller
- Department of Neurology, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, 114 16th Street, Rm. 2006, 02129, Charlestown, MA, USA
| | - Galina Skibo
- Department of Cytology, Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, 4 Bogomoletz Street, 01024, Kyiv, Ukraine
| | - Bradley T Hyman
- Department of Neurology, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, 114 16th Street, Rm. 2006, 02129, Charlestown, MA, USA
| | - Oksana Berezovska
- Department of Neurology, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, 114 16th Street, Rm. 2006, 02129, Charlestown, MA, USA.
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Guo T, Duan Z, Chen J, Xie C, Wang Y, Chen P, Wang X. Pull-down combined with proteomic strategy reveals functional diversity of synaptotagmin I. PeerJ 2017; 5:e2973. [PMID: 28194317 PMCID: PMC5301975 DOI: 10.7717/peerj.2973] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 01/10/2017] [Indexed: 12/05/2022] Open
Abstract
Synaptotagmin I (Syt I) is most abundant in the brain and is involved in multiple cellular processes. Its two C2 domains, C2A and C2B, are the main functional regions. Our present study employed a pull-down combined with proteomic strategy to identify the C2 domain-interacting proteins to comprehensively understand the biological roles of the C2 domains and thus the functional diversity of Syt I. A total of 135 non-redundant proteins interacting with the C2 domains of Syt I were identified. Out of them, 32 and 64 proteins only bound to C2A or C2B domains, respectively, and 39 proteins bound to both of them. Compared with C2A, C2B could bind to many more proteins particularly those involved in synaptic transmission and metabolic regulation. Functional analysis indicated that Syt I may exert impacts by interacting with other proteins on multiple cellular processes, including vesicular membrane trafficking, synaptic transmission, metabolic regulation, catalysis, transmembrane transport and structure formation, etc. These results demonstrate that the functional diversity of Syt I is higher than previously expected, that its two domains may mediate the same and different cellular processes cooperatively or independently, and that C2B domain may play even more important roles than C2A in the functioning of Syt I. This work not only further deepened our understanding of the functional diversity of Syt I and the functional differences between its two C2 domains, but also provided important clues for the further related researches.
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Affiliation(s)
- Tianyao Guo
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University , Changsha , Hunan , P. R. of China
| | - Zhigui Duan
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University , Changsha , Hunan , P. R. of China
| | - Jia Chen
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University , Changsha , Hunan , P. R. of China
| | - Chunliang Xie
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University , Changsha , Hunan , P. R. of China
| | - Ying Wang
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University , Changsha , Hunan , P. R. of China
| | - Ping Chen
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University , Changsha , Hunan , P. R. of China
| | - Xianchun Wang
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University , Changsha , Hunan , P. R. of China
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Abstract
The synaptotagmin family of vesicle proteins is believed to mediate calcium-dependent regulation of membrane trafficking. Detailed biochemical and in vivo studies of the most characterized isoform, synaptotagmin 1 (syt 1), have provided compelling evidence that it functions as a calcium sensor for fast neurotransmitter release at synapses. However, the function of the remaining isoforms is unclear, and multiple roles have been hypothesized for several of these. Recent evidence in Drosophila has given insight into the function of some of the remaining synaptotagmin family members. Of the five evolutionarily conserved isoforms in Drosophila, only two, syt 1 and syt 4, localize to most, if not all, synapses. The former is localized to presynaptic terminals, whereas the latter is predominantly postsynaptic. This suggests an intriguing possibility that syt 4 may mediate a postsynaptic vesicle trafficking pathway, providing a molecular basis for an evolutionarily conserved bidirectional vesicular trafficking communication system at synapses.
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Affiliation(s)
- Motojiro Yoshihara
- The Picower Center for Learning and Memory, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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Dual Transcriptome Profiling of Leishmania-Infected Human Macrophages Reveals Distinct Reprogramming Signatures. mBio 2016; 7:mBio.00027-16. [PMID: 27165796 PMCID: PMC4959658 DOI: 10.1128/mbio.00027-16] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Macrophages are mononuclear phagocytes that constitute a first line of defense against pathogens. While lethal to many microbes, they are the primary host cells of Leishmania spp. parasites, the obligate intracellular pathogens that cause leishmaniasis. We conducted transcriptomic profiling of two Leishmania species and the human macrophage over the course of intracellular infection by using high-throughput RNA sequencing to characterize the global gene expression changes and reprogramming events that underlie the interactions between the pathogen and its host. A systematic exclusion of the generic effects of large-particle phagocytosis revealed a vigorous, parasite-specific response of the human macrophage early in the infection that was greatly tempered at later time points. An analogous temporal expression pattern was observed with the parasite, suggesting that much of the reprogramming that occurs as parasites transform into intracellular forms generally stabilizes shortly after entry. Following that, the parasite establishes an intracellular niche within macrophages, with minimal communication between the parasite and the host cell later during the infection. No significant difference was observed between parasite species transcriptomes or in the transcriptional response of macrophages infected with each species. Our comparative analysis of gene expression changes that occur as mouse and human macrophages are infected by Leishmania spp. points toward a general signature of the Leishmania-macrophage infectome. Little is known about the transcriptional changes that occur within mammalian cells harboring intracellular pathogens. This study characterizes the gene expression signatures of Leishmania spp. parasites and the coordinated response of infected human macrophages as the pathogen enters and persists within them. After accounting for the generic effects of large-particle phagocytosis, we observed a parasite-specific response of the human macrophages early in infection that was reduced at later time points. A similar expression pattern was observed in the parasites. Our analyses provide specific insights into the interplay between human macrophages and Leishmania parasites and constitute an important general resource for the study of how pathogens evade host defenses and modulate the functions of the cell to survive intracellularly.
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Evans CS, He Z, Bai H, Lou X, Jeggle P, Sutton RB, Edwardson JM, Chapman ER. Functional analysis of the interface between the tandem C2 domains of synaptotagmin-1. Mol Biol Cell 2016; 27:979-89. [PMID: 26792839 PMCID: PMC4791141 DOI: 10.1091/mbc.e15-07-0503] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 01/12/2016] [Indexed: 11/20/2022] Open
Abstract
Synaptotagmin (syt)-1 is a Ca2+ sensor that triggers rapid synaptic vesicle exocytosis. Mutations that disrupt physical interactions between the tandem Ca2+-sensing modules (C2 domains) of syt-1 disrupt regulated membrane fusion in reconstituted fusion reactions and in neurons. Hence contacts between these domains are important for function. C2 domains are widespread motifs that often serve as Ca2+-binding modules; some proteins have more than one copy. An open issue is whether these domains, when duplicated within the same parent protein, interact with one another to regulate function. In the present study, we address the functional significance of interfacial residues between the tandem C2 domains of synaptotagmin (syt)-1, a Ca2+ sensor for neuronal exocytosis. Substitution of four residues, YHRD, at the domain interface, disrupted the interaction between the tandem C2 domains, altered the intrinsic affinity of syt-1 for Ca2+, and shifted the Ca2+ dependency for binding to membranes and driving membrane fusion in vitro. When expressed in syt-1 knockout neurons, the YHRD mutant yielded reductions in synaptic transmission, as compared with the wild-type protein. These results indicate that physical interactions between the tandem C2 domains of syt-1 contribute to excitation–secretion coupling.
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Affiliation(s)
- Chantell S Evans
- Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, WI 53705-2275 Department of Neuroscience, University of Wisconsin-Madison, Madison, WI 53705-2275 Molecular and Cellular Pharmacology Program, University of Wisconsin-Madison, Madison, WI 53705-2275
| | - Zixuan He
- Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, WI 53705-2275 Department of Neuroscience, University of Wisconsin-Madison, Madison, WI 53705-2275
| | - Hua Bai
- Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, WI 53705-2275 Department of Neuroscience, University of Wisconsin-Madison, Madison, WI 53705-2275
| | - Xiaochu Lou
- Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, WI 53705-2275 Department of Neuroscience, University of Wisconsin-Madison, Madison, WI 53705-2275
| | - Pia Jeggle
- Department of Pharmacology, University of Cambridge, Cambridge CB2 1PD, UK
| | - R Bryan Sutton
- Department of Cell Physiology and Molecular Biophysics, Texas Tech University Health Sciences Center, Lubbock, TX 79430
| | | | - Edwin R Chapman
- Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, WI 53705-2275 Department of Neuroscience, University of Wisconsin-Madison, Madison, WI 53705-2275 Molecular and Cellular Pharmacology Program, University of Wisconsin-Madison, Madison, WI 53705-2275
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Wang H, Han S, Siao W, Song C, Xiang Y, Wu X, Cheng P, Li H, Jásik J, Mičieta K, Turňa J, Voigt B, Baluška F, Liu J, Wang Y, Zhao H. Arabidopsis Synaptotagmin 2 Participates in Pollen Germination and Tube Growth and Is Delivered to Plasma Membrane via Conventional Secretion. MOLECULAR PLANT 2015; 8:1737-50. [PMID: 26384245 DOI: 10.1016/j.molp.2015.09.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Revised: 08/18/2015] [Accepted: 09/05/2015] [Indexed: 05/15/2023]
Abstract
Arabidopsis synaptotagmin 2 (SYT2) has been reported to participate in an unconventional secretory pathway in somatic cells. Our results showed that SYT2 was expressed mainly in the pollen of Arabidopsis thaliana. The pollen of syt2 T-DNA and RNA interference mutant lines exhibited reduced total germination and impeded pollen tube growth. Analysis of the expression of SYT2-GFP fusion protein in the pollen tube indicates that SYT2 was localized to distinct, patchy compartments but could co-localize with the Golgi markers, BODIPY TR C5 ceramide and GmMan1-mCherry. However, SYT2-DsRed-E5 was localized to the plasma membrane in Arabidopsis suspension cells, in addition to the Golgi apparatus. The localization of SYT2 at the plasma membrane was further supported by immunofluorescence staining in pollen tubes. Moreover, brefeldin A treatment inhibited the transport of SYT2 to the plasma membrane and caused SYT2 to aggregate and form enlarged compartments. Truncation of the SYT2-C2AB domains also resulted in retention of SYT2 in the Golgi apparatus. An in vitro phospholipid-binding assay showed that SYT2-C2AB domains bind to the phospholipid membrane in a calcium-dependent manner. Take together, our results indicated that SYT2 was required for pollen germination and pollen tube growth, and was involved in conventional exocytosis.
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Affiliation(s)
- Hui Wang
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Science, Beijing Normal University, Beijing 100875, China
| | - Shengcheng Han
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Science, Beijing Normal University, Beijing 100875, China
| | - Wei Siao
- Department of Plant Cell Biology, IZMB, University of Bonn, Kirschallee 1, 53115 Bonn, Germany
| | - Chunqing Song
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Science, Beijing Normal University, Beijing 100875, China
| | - Yun Xiang
- School of Life Science, Lanzhou University, Lanzhou 730000, China
| | - Xiaorong Wu
- School of Life Science, Lanzhou University, Lanzhou 730000, China
| | - Pengyu Cheng
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Science, Beijing Normal University, Beijing 100875, China
| | - Hongjuan Li
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Science, Beijing Normal University, Beijing 100875, China
| | - Ján Jásik
- Comenius University Science Park, Comenius University, Bratislava, Mlynská dolina, 842 15 Bratislava 4, Slovakia
| | - Karol Mičieta
- Department of Botany, Faculty of Natural Sciences, Comenius University, Révová 39, 811 02 Bratislava 1, Slovakia
| | - Ján Turňa
- Department of Molecular Biology, Comenius University, Faculty of Natural Sciences, Mlynská dolina, pavilion B-2, 842 15 Bratislava 4, Slovakia
| | - Boris Voigt
- Department of Plant Cell Biology, IZMB, University of Bonn, Kirschallee 1, 53115 Bonn, Germany
| | - František Baluška
- Department of Plant Cell Biology, IZMB, University of Bonn, Kirschallee 1, 53115 Bonn, Germany; Institute of Botany, Slovak Academy of Sciences, Dubravska cesta 9, SK-84523 Bratislava, Slovak Republic.
| | - Jin Liu
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Science, Beijing Normal University, Beijing 100875, China
| | - Yingdian Wang
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Science, Beijing Normal University, Beijing 100875, China
| | - Heping Zhao
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Science, Beijing Normal University, Beijing 100875, China.
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Wnt signalling tunes neurotransmitter release by directly targeting Synaptotagmin-1. Nat Commun 2015; 6:8302. [PMID: 26400647 PMCID: PMC4667432 DOI: 10.1038/ncomms9302] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 08/07/2015] [Indexed: 01/22/2023] Open
Abstract
The functional assembly of the synaptic release machinery is well understood; however, how signalling factors modulate this process remains unknown. Recent studies suggest that Wnts play a role in presynaptic function. To examine the mechanisms involved, we investigated the interaction of release machinery proteins with Dishevelled-1 (Dvl1), a scaffold protein that determines the cellular locale of Wnt action. Here we show that Dvl1 directly interacts with Synaptotagmin-1 (Syt-1) and indirectly with the SNARE proteins SNAP25 and Syntaxin (Stx-1). Importantly, the interaction of Dvl1 with Syt-1, which is regulated by Wnts, modulates neurotransmitter release. Moreover, presynaptic terminals from Wnt signalling-deficient mice exhibit reduced release probability and are unable to sustain high-frequency release. Consistently, the readily releasable pool size and formation of SNARE complexes are reduced. Our studies demonstrate that Wnt signalling tunes neurotransmitter release and identify Syt-1 as a target for modulation by secreted signalling proteins.
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Fahmy K, Gonzalez A, Arafa M, Peixoto P, Bellahcène A, Turtoi A, Delvenne P, Thiry M, Castronovo V, Peulen O. Myoferlin plays a key role in VEGFA secretion and impacts tumor-associated angiogenesis in human pancreas cancer. Int J Cancer 2015; 138:652-63. [PMID: 26311411 DOI: 10.1002/ijc.29820] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 07/31/2015] [Accepted: 08/17/2015] [Indexed: 01/14/2023]
Abstract
Pancreatic ductal adenocarcinoma is one of the most deadly forms of cancers with no satisfactory treatment to date. Recent studies have identified myoferlin, a ferlin family member, in human pancreas adenocarcinoma where its expression was associated to a bad prognosis. However, the function of myoferlin in pancreas adenocarcinoma has not been reported. In other cell types, myoferlin is involved in several key plasma membrane processes such as fusion, repair, endocytosis and tyrosine kinase receptor activity. In this study, we showed that myoferlin silencing in BxPC-3 human pancreatic cancer cells resulted in the inhibition of cell proliferation in vitro and in a significant reduction of the tumor volume in chick chorioallantoic membrane assay. In addition to be smaller, the tumors formed by the myoferlin-silenced cells showed a marked absence of functional blood vessels. We further demonstrated that this effect was due, at least in part, to an inhibition of VEGFA secretion by BxPC-3 myoferlin-silenced cells. Using immunofluorescence and electron microscopy, we linked the decreased VEGFA secretion to an impairment of VEGFA exocytosis. The clinical relevance of our results was further strengthened by a significant correlation between myoferlin expression in a series of human pancreatic malignant lesions and their angiogenic status evaluated by the determination of the blood vessel density.
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Affiliation(s)
- Karim Fahmy
- Metastasis Research Laboratory, GIGA-Cancer, University of Liege, Liege, Belgium
| | - Arnaud Gonzalez
- Metastasis Research Laboratory, GIGA-Cancer, University of Liege, Liege, Belgium
| | - Mohammad Arafa
- Department of Pathology, Faculty of Medicine, University of Mansoura, Mansoura, Egypt
| | - Paul Peixoto
- Metastasis Research Laboratory, GIGA-Cancer, University of Liege, Liege, Belgium
| | - Akeila Bellahcène
- Metastasis Research Laboratory, GIGA-Cancer, University of Liege, Liege, Belgium
| | - Andrei Turtoi
- Metastasis Research Laboratory, GIGA-Cancer, University of Liege, Liege, Belgium
| | - Philippe Delvenne
- Laboratory of Experimental Pathology, GIGA-Cancer, University of Liege, Liege, Belgium
| | - Marc Thiry
- Laboratory of Cell Biology, GIGA-R, University of Liege, Liege, Belgium
| | - Vincent Castronovo
- Metastasis Research Laboratory, GIGA-Cancer, University of Liege, Liege, Belgium
| | - Olivier Peulen
- Metastasis Research Laboratory, GIGA-Cancer, University of Liege, Liege, Belgium
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26
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Gogoi P, Chandravanshi M, Mandal SK, Srivastava A, Kanaujia SP. Heterogeneous behavior of metalloproteins toward metal ion binding and selectivity: insights from molecular dynamics studies. J Biomol Struct Dyn 2015; 34:1470-85. [PMID: 26248730 DOI: 10.1080/07391102.2015.1080629] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
About one-third of the existing proteins require metal ions as cofactors for their catalytic activities and structural complexities. While many of them bind only to a specific metal, others bind to multiple (different) metal ions. However, the exact mechanism of their metal preference has not been deduced to clarity. In this study, we used molecular dynamics (MD) simulations to investigate whether a cognate metal (bound to the structure) can be replaced with other similar metal ions. We have chosen seven different proteins (phospholipase A2, sucrose phosphatase, pyrazinamidase, cysteine dioxygenase (CDO), plastocyanin, monoclonal anti-CD4 antibody Q425, and synaptotagmin 1 C2B domain) bound to seven different divalent metal ions (Ca(2+), Mg(2+), Zn(2+), Fe(2+), Cu(2+), Ba(2+), and Sr(2+), respectively). In total, 49 MD simulations each of 50 ns were performed and each trajectory was analyzed independently. Results demonstrate that in some cases, cognate metal ions can be exchanged with similar metal ions. On the contrary, some proteins show binding affinity specifically to their cognate metal ions. Surprisingly, two proteins CDO and plastocyanin which are known to bind Fe(2+) and Cu(2+), respectively, do not exhibit binding affinity to any metal ion. Furthermore, the study reveals that in some cases, the active site topology remains rigid even without cognate metals, whereas, some require them for their active site stability. Thus, it will be interesting to experimentally verify the accuracy of these observations obtained computationally. Moreover, the study can help in designing novel active sites for proteins to sequester metal ions particularly of toxic nature.
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Affiliation(s)
- Prerana Gogoi
- a Department of Biosciences and Bioengineering , Indian Institute of Technology Guwahati , Guwahati , Assam 781039 , India
| | - Monika Chandravanshi
- a Department of Biosciences and Bioengineering , Indian Institute of Technology Guwahati , Guwahati , Assam 781039 , India
| | - Suraj Kumar Mandal
- a Department of Biosciences and Bioengineering , Indian Institute of Technology Guwahati , Guwahati , Assam 781039 , India
| | - Ambuj Srivastava
- a Department of Biosciences and Bioengineering , Indian Institute of Technology Guwahati , Guwahati , Assam 781039 , India
| | - Shankar Prasad Kanaujia
- a Department of Biosciences and Bioengineering , Indian Institute of Technology Guwahati , Guwahati , Assam 781039 , India
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27
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Sancho-Knapik S, Guillén N, Osada J. Cloning and expression of hepatic synaptotagmin 1 in mouse. Gene 2015; 562:236-43. [PMID: 25735570 DOI: 10.1016/j.gene.2015.02.074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 02/17/2015] [Accepted: 02/27/2015] [Indexed: 11/29/2022]
Abstract
Mouse hepatic synaptotagmin 1 (SYT1) cDNA was cloned, characterized and compared to the brain one. The hepatic transcript was 1807 bp in length, smaller than the brain, and only encoded by 9 of 11 gene exons. In this regard, 5'-and 3'-untranslated regions were 66 and 476 bp, respectively; the open reading frame of 1266 bp codified for a protein of 421 amino acids, identical to the brain, with a predicted molecular mass of 47.4 kDa and highly conserved across different species. Immunoblotting of protein showed two isoforms of higher molecular masses than the theoretical prediction based on amino acid sequence suggesting posttranslational modifications. Subcellular distribution of protein isoforms corresponded to plasma membrane, lysosomes and microsomes and was identical between the brain and liver. Nonetheless, the highest molecular weight isoform was smaller in the liver, irrespective of subcellular location. Quantitative mRNA tissue distribution showed that it was widely expressed and that the highest values corresponded to the brain, followed by the liver, spleen, abdominal fat, intestine and skeletal muscle. These findings indicate tissue-specific splicing of the gene and posttranslational modification and the variation in expression in the different tissues might suggest a different requirement of SYT1 for the specific function in each organ.
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Affiliation(s)
- Sara Sancho-Knapik
- Departamento Bioquímica y Biología Molecular y Celular, Facultad de Veterinaria, Instituto de Investigación Sanitaria de Aragón (IIS), Universidad de Zaragoza, Spain
| | - Natalia Guillén
- Departamento de Toxicología, Facultad de Veterinaria, Universidad de Zaragoza, Spain
| | - Jesús Osada
- Departamento Bioquímica y Biología Molecular y Celular, Facultad de Veterinaria, Instituto de Investigación Sanitaria de Aragón (IIS), Universidad de Zaragoza, Spain; CIBER de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Spain.
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28
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Kiessling V, Liang B, Tamm LK. Reconstituting SNARE-mediated membrane fusion at the single liposome level. Methods Cell Biol 2015; 128:339-63. [PMID: 25997356 DOI: 10.1016/bs.mcb.2015.02.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Successful reconstitutions of SNARE-mediated intracellular membrane fusion have been achieved in bulk fusion assays since 1998 and in single liposome fusion assays since 2004. Especially in neuronal presynaptic SNARE-mediated exocytosis, fusion is controlled by numerous accessory proteins, of which some functions have also been reconstituted in vitro. The development of and results obtained with two fundamentally different single liposome fusion assays, namely liposome-to-supported membrane and liposome-to-liposome, are reviewed. Both assays distinguish between liposome docking and fusion steps of the overall fusion reaction and both assays are capable of resolving hemi-and full-fusion intermediates and end states. They have opened new windows for elucidating the mechanisms of these fundamentally important cellular reactions with unprecedented time and molecular resolution. Although many of the molecular actors in this process have been discovered, we have only scratched the surface of looking at their fascinating plays, interactions, and choreographies that lead to vesicle traffic as well as neurotransmitter and hormone release in the cell.
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Affiliation(s)
- Volker Kiessling
- Center for Membrane Biology and Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA, USA
| | - Binyong Liang
- Center for Membrane Biology and Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA, USA
| | - Lukas K Tamm
- Center for Membrane Biology and Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA, USA
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29
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Bozzolan F, Duportets L, Limousin D, Wycke MA, Demondion E, François A, Abrieux A, Debernard S. Synaptotagmin I, a molecular target for steroid hormone signaling controlling the maturation of sexual behavior in an insect. FEBS J 2015; 282:1432-44. [DOI: 10.1111/febs.13231] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 12/19/2014] [Accepted: 02/10/2015] [Indexed: 11/29/2022]
Affiliation(s)
- Françoise Bozzolan
- Département d'Ecologie Sensorielle; UMR 1392; Institut d'Ecologie et des Sciences de l'Environnement de Paris; Université Paris VI; France
| | - Line Duportets
- Département d'Ecologie Sensorielle; UMR 1392; Institut d'Ecologie et des Sciences de l'Environnement de Paris; Université Paris VI; France
- Service d'Enseignement de Biologie Animale; Université Paris-Sud; Orsay France
| | - Denis Limousin
- Département d'Ecologie Sensorielle; UMR 1392; Institut d'Ecologie et des Sciences de l'Environnement de Paris; INRA; Versailles France
| | - Marie-Anne Wycke
- Département d'Ecologie Sensorielle; UMR 1392; Institut d'Ecologie et des Sciences de l'Environnement de Paris; INRA; Versailles France
| | - Elodie Demondion
- Département d'Ecologie Sensorielle; UMR 1392; Institut d'Ecologie et des Sciences de l'Environnement de Paris; INRA; Versailles France
| | - Adrien François
- INRA; UR1197; Jouy-en-Josas France
- Université de Versailles; France
| | - Antoine Abrieux
- Laboratoire Récepteurs et Canaux Ioniques Membranaires (RCIM); Université d'Angers; UPRES-EA 2647 USC INRA 1330; France
| | - Stéphane Debernard
- Département d'Ecologie Sensorielle; UMR 1392; Institut d'Ecologie et des Sciences de l'Environnement de Paris; Université Paris VI; France
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30
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Liu H, Bai H, Xue R, Takahashi H, Edwardson JM, Chapman ER. Linker mutations reveal the complexity of synaptotagmin 1 action during synaptic transmission. Nat Neurosci 2014; 17:670-7. [PMID: 24657966 PMCID: PMC4139111 DOI: 10.1038/nn.3681] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Accepted: 02/21/2014] [Indexed: 12/13/2022]
Abstract
The Ca(2+) sensor for rapid synaptic vesicle exocytosis, synaptotagmin 1 (syt), is largely composed of two Ca(2+)-sensing C2 domains, C2A and C2B. We investigated the apparent synergy between the tandem C2 domains by altering the length and rigidity of the linker that connects them. The behavior of the linker mutants revealed a correlation between the ability of the C2 domains to penetrate membranes in response to Ca(2+) and to drive evoked neurotransmitter release in cultured mouse neurons, uncovering a step in excitation-secretion coupling. Using atomic force microscopy, we found that the synergy between these C2 domains involved intra-molecular interactions between them. Thus, syt function is markedly affected by changes in the physical nature of the linker that connects its tandem C2 domains. Moreover, the linker mutations uncoupled syt-mediated regulation of evoked and spontaneous release, revealing that syt also acts as a fusion clamp before the Ca(2+) trigger.
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Affiliation(s)
- Huisheng Liu
- 1] Howard Hughes Medical Institute and Department of Neuroscience, University of Wisconsin, Madison, Wisconsin, USA. [2] [3]
| | - Hua Bai
- 1] Howard Hughes Medical Institute and Department of Neuroscience, University of Wisconsin, Madison, Wisconsin, USA. [2]
| | - Renhao Xue
- Howard Hughes Medical Institute and Department of Neuroscience, University of Wisconsin, Madison, Wisconsin, USA
| | | | | | - Edwin R Chapman
- Howard Hughes Medical Institute and Department of Neuroscience, University of Wisconsin, Madison, Wisconsin, USA
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31
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Altered microRNA and gene expression in the follicular fluid of women with polycystic ovary syndrome. J Assist Reprod Genet 2014; 31:355-62. [PMID: 24390626 DOI: 10.1007/s10815-013-0161-4] [Citation(s) in RCA: 128] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Accepted: 12/17/2013] [Indexed: 01/14/2023] Open
Abstract
PURPOSE To determine if microRNAs are differentially expressed in the follicular fluid of women with PCOS compared to fertile oocyte donors and identify associated altered gene expression. METHODS Women undergoing IVF who met Rotterdam criteria for PCOS or who were fertile oocyte donors were recruited from a private IVF center. Individual follicle fluid was collected at the time of oocyte retrieval. MicroRNA analysis was performed using microarray and validated using real-time PCR on additional samples. Potential gene targets were identified and their expression analyzed by real time PCR. RESULTS Microarray profiling of human follicular fluid revealed expression of 235 miRNAs, 29 were differentially expressed between the groups. Using PCR validation, 5 miRNAs (32, 34c, 135a, 18b, and 9) showed significantly increased expression in the PCOS group. Pathway analysis revealed genes involved in insulin regulation and inflammation. Three potential target genes were found to have significantly decreased expression in the PCOS group (interleukin 8, synaptogamin 1, and insulin receptor substrate 2). CONCLUSIONS MicroRNAs are differentially expressed in the follicular fluid of women with PCOS when compared to fertile oocyte donors. There is also altered expression of potential target genes associated with the PCOS phenotype.
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32
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Abstract
Phosphoinositides (PIs) make up only a small fraction of cellular phospholipids, yet they control almost all aspects of a cell's life and death. These lipids gained tremendous research interest as plasma membrane signaling molecules when discovered in the 1970s and 1980s. Research in the last 15 years has added a wide range of biological processes regulated by PIs, turning these lipids into one of the most universal signaling entities in eukaryotic cells. PIs control organelle biology by regulating vesicular trafficking, but they also modulate lipid distribution and metabolism via their close relationship with lipid transfer proteins. PIs regulate ion channels, pumps, and transporters and control both endocytic and exocytic processes. The nuclear phosphoinositides have grown from being an epiphenomenon to a research area of its own. As expected from such pleiotropic regulators, derangements of phosphoinositide metabolism are responsible for a number of human diseases ranging from rare genetic disorders to the most common ones such as cancer, obesity, and diabetes. Moreover, it is increasingly evident that a number of infectious agents hijack the PI regulatory systems of host cells for their intracellular movements, replication, and assembly. As a result, PI converting enzymes began to be noticed by pharmaceutical companies as potential therapeutic targets. This review is an attempt to give an overview of this enormous research field focusing on major developments in diverse areas of basic science linked to cellular physiology and disease.
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Affiliation(s)
- Tamas Balla
- Section on Molecular Signal Transduction, Program for Developmental Neuroscience, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA.
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33
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Becherer U, Medart MR, Schirra C, Krause E, Stevens D, Rettig J. Regulated exocytosis in chromaffin cells and cytotoxic T lymphocytes: How similar are they? Cell Calcium 2012; 52:303-12. [DOI: 10.1016/j.ceca.2012.04.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Revised: 03/27/2012] [Accepted: 04/09/2012] [Indexed: 10/28/2022]
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34
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Wakana Y, van Galen J, Meissner F, Scarpa M, Polishchuk RS, Mann M, Malhotra V. A new class of carriers that transport selective cargo from the trans Golgi network to the cell surface. EMBO J 2012; 31:3976-90. [PMID: 22909819 DOI: 10.1038/emboj.2012.235] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Accepted: 07/24/2012] [Indexed: 11/09/2022] Open
Abstract
We have isolated a membrane fraction enriched in a class of transport carriers that form at the trans Golgi network (TGN) and are destined for the cell surface in HeLa cells. Protein kinase D (PKD) is required for the biogenesis of these carriers that contain myosin II, Rab6a, Rab8a, and synaptotagmin II, as well as a number of secretory and plasma membrane-specific cargoes. Our findings reveal a requirement for myosin II in the migration of these transport carriers but not in their biogenesis per se. Based on the cargo secreted by these carriers we have named them CARTS for CARriers of the TGN to the cell Surface. Surprisingly, CARTS are distinct from the carriers that transport vesicular stomatitis virus (VSV)-G protein and collagen I from the TGN to the cell surface. Altogether, the identification of CARTS provides a valuable means to understand TGN to cell surface traffic.
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Affiliation(s)
- Yuichi Wakana
- Cell and Developmental Biology Programme, Centre for Genomic Regulation (CRG) and UPF, Barcelona, Spain
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35
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Verkhratsky A, Rodríguez JJ, Parpura V. Neurotransmitters and integration in neuronal-astroglial networks. Neurochem Res 2012; 37:2326-38. [PMID: 22476701 DOI: 10.1007/s11064-012-0765-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Revised: 03/18/2012] [Accepted: 03/22/2012] [Indexed: 10/28/2022]
Abstract
Two major neural cell types, glia, astrocytes in particular, and neurones can release chemical transmitters that act as soluble signalling compounds for intercellular communication. Exocytosis, a process which depends on an increase in cytosolic Ca(2+) levels, represents a common denominator for release of neurotransmitters, stored in secretory vesicles, from these neural cells. While neurones rely predominately on the immediate entry of Ca(2+) from the extracellular space to the cytosol in this process, astrocytes support their cytosolic Ca(2+) increases by appropriating this ion from the intracellular endoplasmic reticulum store and extracellular space. Additionally, astrocytes can release neurotransmitters using a variety of non-vesicular pathways which are mediated by an assortment of plasmalemmal channels and transporters. Once a neuronal and/or astrocytic neurotransmitter is released into the extracellular space, it can activate plasma membrane neurotransmitter receptors on neural cells, causing autocrine and/or paracrine signalling. Moreover, chemical transmission is essential not only for homocellular, but also for heterocellular bi-directional communication in the brain. Further detailed understanding of chemical transmission will aid our comprehension of the brain (dys)function in heath and disease.
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Affiliation(s)
- Alexei Verkhratsky
- Faculty of Life Sciences, The University of Manchester, Manchester, M13 9PT, UK.
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Regulation of voltage-gated calcium channels by synaptic proteins. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 740:759-75. [PMID: 22453968 DOI: 10.1007/978-94-007-2888-2_33] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Calcium entry through neuronal voltage-gated calcium channels into presynaptic nerve terminal is a key step in synaptic exocytosis. In order to receive the calcium signal and trigger fast, efficient and spatially delimited neurotransmitter release, the vesicle-docking/release machinery must be located near the calcium source. In many cases, this close localization is achieved by a direct interaction of several members of the vesicle release machinery with the calcium channels. In turn, the binding of synaptic proteins to presynaptic calcium channels modulates channel activity to provide fine control over calcium entry, and thus modulates synaptic strength. In this chapter we summarize our present knowledge of the molecular mechanisms by which synaptic proteins regulate presynaptic calcium channel activity.
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Falkowski MA, Thomas DDH, Messenger SW, Martin TF, Groblewski GE. Expression, localization, and functional role for synaptotagmins in pancreatic acinar cells. Am J Physiol Gastrointest Liver Physiol 2011; 301:G306-16. [PMID: 21636530 PMCID: PMC3154608 DOI: 10.1152/ajpgi.00108.2011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Accepted: 06/01/2011] [Indexed: 01/31/2023]
Abstract
Secretagogue-induced changes in intracellular Ca(2+) play a pivotal role in secretion in pancreatic acini yet the molecules that respond to Ca(2+) are uncertain. Zymogen granule (ZG) exocytosis is regulated by soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complexes. In nerve and endocrine cells, Ca(2+)-stimulated exocytosis is regulated by the SNARE-associated family of proteins termed synaptotagmins. This study examined a potential role for synaptotagmins in acinar secretion. RT-PCR revealed that synaptotagmin isoforms 1, 3, 6, and 7 are present in isolated acini. Immunoblotting and immunofluorescence using three different antibodies demonstrated synaptotagmin 1 immunoreactivity in apical cytoplasm and ZG fractions of acini, where it colocalized with vesicle-associated membrane protein 2. Synaptotagmin 3 immunoreactivity was detected in membrane fractions and colocalized with an endolysosomal marker. A potential functional role for synaptotagmin 1 in secretion was indicated by results that introduction of synaptotagmin 1 C2AB domain into permeabilized acini inhibited Ca(2+)-dependent exocytosis by 35%. In contrast, constructs of synaptotagmin 3 had no effect. Confirmation of these findings was achieved by incubating intact acini with an antibody specific to the intraluminal domain of synaptotagmin 1, which is externalized following exocytosis. Externalized synaptotagmin 1 was detected exclusively along the apical membrane. Treatment with CCK-8 (100 pM, 5 min) enhanced immunoreactivity by fourfold, demonstrating that synaptotagmin is inserted into the apical membrane during ZG fusion. Collectively, these data indicate that acini express synaptotagmin 1 and support that it plays a functional role in secretion whereas synaptotagmin 3 has an alternative role in endolysosomal membrane trafficking.
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Selga E, Pérez-Cano FJ, Franch A, Ramírez-Santana C, Rivero M, Ciudad CJ, Castellote C, Noé V. Gene expression profiles in rat mesenteric lymph nodes upon supplementation with conjugated linoleic acid during gestation and suckling. BMC Genomics 2011; 12:182. [PMID: 21481241 PMCID: PMC3094308 DOI: 10.1186/1471-2164-12-182] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Accepted: 04/11/2011] [Indexed: 12/25/2022] Open
Abstract
Background Diet plays a role on the development of the immune system, and polyunsaturated fatty acids can modulate the expression of a variety of genes. Human milk contains conjugated linoleic acid (CLA), a fatty acid that seems to contribute to immune development. Indeed, recent studies carried out in our group in suckling animals have shown that the immune function is enhanced after feeding them with an 80:20 isomer mix composed of c9,t11 and t10,c12 CLA. However, little work has been done on the effects of CLA on gene expression, and even less regarding immune system development in early life. Results The expression profile of mesenteric lymph nodes from animals supplemented with CLA during gestation and suckling through dam's milk (Group A) or by oral gavage (Group B), supplemented just during suckling (Group C) and control animals (Group D) was determined with the aid of the specific GeneChip® Rat Genome 230 2.0 (Affymettrix). Bioinformatics analyses were performed using the GeneSpring GX software package v10.0.2 and lead to the identification of 89 genes differentially expressed in all three dietary approaches. Generation of a biological association network evidenced several genes, such as connective tissue growth factor (Ctgf), tissue inhibitor of metalloproteinase 1 (Timp1), galanin (Gal), synaptotagmin 1 (Syt1), growth factor receptor bound protein 2 (Grb2), actin gamma 2 (Actg2) and smooth muscle alpha actin (Acta2), as highly interconnected nodes of the resulting network. Gene underexpression was confirmed by Real-Time RT-PCR. Conclusions Ctgf, Timp1, Gal and Syt1, among others, are genes modulated by CLA supplementation that may have a role on mucosal immune responses in early life.
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Affiliation(s)
- Elisabet Selga
- Department of Biochemistry and Molecular Biology, School of Pharmacy, University of Barcelona, Spain
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Sasakawa N, Ohara-Imaizumi M, Fukuda M, Kabayama H, Mikoshiba K, Kumakura K. Dissociation of inositol polyphosphates from the C2B domain of synaptotagmin facilitates spontaneous release of catecholamines in adrenal chromaffin cells. A suggestive evidence of a fusion clamp by synaptotagmin. Neuropharmacology 2011; 60:1364-70. [PMID: 21402086 DOI: 10.1016/j.neuropharm.2011.03.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2010] [Revised: 10/21/2010] [Accepted: 03/02/2011] [Indexed: 11/19/2022]
Abstract
Synaptotagmins (Syts) serve as a Ca²+ sensor in the release of neurotransmitters and hormones. Inositol polyphosphates (InsPPs) such as Inositol 1,3,4,5,6-pentakisphosphate (InsP₅) and inositol hexakisphosphate (InsP₆) bind to Ca²+-binding C2B domain of Syt I and II, and inhibit transmitter release. We have shown that the inhibition by InsPPs is reversed by Ca²+ in adrenal chromaffin cells, while a rapid accumulation of endogenous InsP₅ and InsP₆ upon depolarizing stimuli have been reported in these and some other cells. Such a rapid accumulation of InsPPs, if not all, might reflect their dissociation from C2B domain of Syt. To elucidate the functional relevance, we studied the effects of antibodies against C2A and C2B domains (anti-C2A Ab, anti-C2B Ab) on the accumulation of InsPPs induced by Ca²+ in digitonin-permeabilized adrenal chromaffin cells. Anti-C2B Ab by itself caused an accumulation of InsPPs in the permeabilizing medium, and increased spontaneous release of catecholamines (CA). Anti-C2A Ab abolished Ca²+-induced increase of InsPPs in cytosolic component, and inhibited Ca²+-evoked release of CA with little effect on the spontaneous release. Microinjection of InsP₆ but not inositol hexakissulfate into intact chromaffin cells inhibited both spontaneous and nicotine-evoked exocytotic events. These results suggest that endogenous InsPPs bound to the C2B domain clamp spontaneous fusion of the docked or primed vesicles at resting level of intracellular Ca²+, and binding of Ca²+ to the C2A or/and C2B domain facilitate fusion dissociating InsPPs from Syt in adrenal chromaffin cells. This article is part of a Special Issue entitled 'Trends in neuropharmacology: in memory of Erminio Costa'.
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Affiliation(s)
- Nobuyuki Sasakawa
- Life Science Institute, Sophia University, 7-1 Kioi-cho, Chiyoda-ku, Tokyo 102-8554, Japan
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40
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McCormick JA, Ellison DH. The WNKs: atypical protein kinases with pleiotropic actions. Physiol Rev 2011; 91:177-219. [PMID: 21248166 DOI: 10.1152/physrev.00017.2010] [Citation(s) in RCA: 201] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
WNKs are serine/threonine kinases that comprise a unique branch of the kinome. They are so-named owing to the unusual placement of an essential catalytic lysine. WNKs have now been identified in diverse organisms. In humans and other mammals, four genes encode WNKs. WNKs are widely expressed at the message level, although data on protein expression is more limited. Soon after the WNKs were identified, mutations in genes encoding WNK1 and -4 were determined to cause the human disease familial hyperkalemic hypertension (also known as pseudohypoaldosteronism II, or Gordon's Syndrome). For this reason, a major focus of investigation has been to dissect the role of WNK kinases in renal regulation of ion transport. More recently, a different mutation in WNK1 was identified as the cause of hereditary sensory and autonomic neuropathy type II, an early-onset autosomal disease of peripheral sensory nerves. Thus the WNKs represent an important family of potential targets for the treatment of human disease, and further elucidation of their physiological actions outside of the kidney and brain is necessary. In this review, we describe the gene structure and mechanisms regulating expression and activity of the WNKs. Subsequently, we outline substrates and targets of WNKs as well as effects of WNKs on cellular physiology, both in the kidney and elsewhere. Next, consequences of these effects on integrated physiological function are outlined. Finally, we discuss the known and putative pathophysiological relevance of the WNKs.
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Affiliation(s)
- James A McCormick
- Division of Nephrology and Hypertension, Oregon Health and Science University and Veterans Affairs Medical Center, Portland, Oregon 97239, USA.
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41
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Lai AL, Huang H, Herrick DZ, Epp N, Cafiso DS. Synaptotagmin 1 and SNAREs form a complex that is structurally heterogeneous. J Mol Biol 2010; 405:696-706. [PMID: 21087613 DOI: 10.1016/j.jmb.2010.11.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Revised: 10/14/2010] [Accepted: 11/05/2010] [Indexed: 01/08/2023]
Abstract
Synaptotagmin 1 (syt1) functions as a Ca(2+)-sensor for neuronal exocytosis. Here, site-directed spin labeling was used to examine the complex formed between a soluble fragment of syt1, which contains its two C2 domains, and the neuronal core soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complex. Changes in electron paramagnetic resonance lineshape and accessibility for spin-labeled syt1 mutants indicate that in solution, the assembled core SNARE complex contacts syt1 in several regions. For the C2B domain, contact occurs in the polybasic face and sites opposite the Ca(2+)-binding loops. For the C2A domain, contact is seen with the SNARE complex in a region near loop 2. Double electron-electron resonance was used to estimate distances between the two C2 domains of syt1. These distances have broad distributions in solution, which do not significantly change when syt1 is fully associated with the core SNARE complex. The broad distance distributions indicate that syt1 is structurally heterogeneous when bound to the SNAREs and does not assume a well-defined structure. Simulated annealing using electron paramagnetic resonance-derived distance restraints produces a family of syt1 structures where the Ca(2+)-binding regions of each domain face in roughly opposite directions. The results suggest that when associated with the SNAREs, syt1 is configured to bind opposing bilayers, but that the syt1/SNARE complex samples multiple conformational states.
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Affiliation(s)
- Alex L Lai
- Department of Chemistry, Biophysics Program and Center for Membrane Biology at the University of Virginia, Charlottesville, VA 22904-4319, USA
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Therrien C, Di Fulvio S, Pickles S, Sinnreich M. Characterization of lipid binding specificities of dysferlin C2 domains reveals novel interactions with phosphoinositides. Biochemistry 2010; 48:2377-84. [PMID: 19253956 DOI: 10.1021/bi802242r] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Dysferlin is a type II transmembrane protein implicated in Ca(2+)-dependent sarcolemmal membrane repair. Dysferlin has seven C2 domains, which are lipid and protein binding modules. In this study, we sought to characterize the lipid binding specificity of dysferlin's seven C2 domains. Dysferlin's C2A domain was able to bind to phosphatidylserine (PS), phosphatidylinositol 4-phosphate [PtdIns(4)P], and phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P(2)] in a Ca(2+)-dependent fashion. The remainder of the C2 domains exhibited weaker and Ca(2+)-independent binding to PS and no significant binding to phosphoinositides.
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Affiliation(s)
- Christian Therrien
- Neuromuscular Research Group, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada
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Maritzen T, Podufall J, Haucke V. Stonins-Specialized Adaptors for Synaptic Vesicle Recycling and Beyond? Traffic 2009; 11:8-15. [DOI: 10.1111/j.1600-0854.2009.00971.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Mittelsteadt T, Seifert G, Alvárez-Barón E, Steinhäuser C, Becker AJ, Schoch S. Differential mRNA expression patterns of the synaptotagmin gene family in the rodent brain. J Comp Neurol 2009; 512:514-28. [DOI: 10.1002/cne.21908] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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45
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Zhang Z, Bhalla A, Dean C, Chapman ER, Jackson MB. Synaptotagmin IV: a multifunctional regulator of peptidergic nerve terminals. Nat Neurosci 2009; 12:163-71. [PMID: 19136969 PMCID: PMC2710815 DOI: 10.1038/nn.2252] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2008] [Accepted: 12/02/2008] [Indexed: 12/31/2022]
Abstract
Many members of the synaptotagmin (Syt) protein family bind Ca(2+) and trigger exocytosis, but some Syt proteins appear to have no Ca(2+)-dependent actions and their biological functions remain obscure. Syt IV is an activity-induced brain protein with no known Ca(2+)-dependent interactions and its subcellular localization and biological functions have sparked considerable controversy. We found Syt IV on both micro- and dense-core vesicles in posterior pituitary nerve terminals in mice. In terminals from Syt IV knockout mice compared with those from wild types, low Ca(2+) entry triggered more exocytosis, high Ca(2+) entry triggered less exocytosis and endocytosis was accelerated. In Syt IV knockouts, dense-core and microvesicle fusion was enhanced in cell-attached patches and dense-core vesicle fusion pores had conductances that were half as large as those in wild types. Given the neuroendocrine functions of the posterior pituitary, changes in Syt IV levels could be involved in endocrine transitions involving alterations in the release of the neuropeptides oxytocin and vasopressin.
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Affiliation(s)
- Zhenjie Zhang
- Department of Physiology, University of Wisconsin School of Medicine and Public Health, 1300 University Avenue, Madison, Wisconsin 53706, USA
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Abstract
Neurotransmitter release at synapses involves a highly specialized form of membrane fusion that is triggered by Ca(2+) ions and is optimized for speed. These observations were established decades ago, but only recently have the molecular mechanisms that underlie this process begun to come into view. Here, we summarize findings obtained from genetically modified neurons and neuroendocrine cells, as well as from reconstituted systems, which are beginning to reveal the molecular mechanism by which Ca(2+)-acting on the synaptic vesicle (SV) protein synaptotagmin I (syt)-triggers rapid exocytosis. This work sheds light not only on presynaptic aspects of synaptic transmission, but also on the fundamental problem of membrane fusion, which has remained a puzzle that has yet to be solved in any biological system.
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Affiliation(s)
- Edwin R Chapman
- Howard Hughes Medical Institute and Department of Physiology, University of Wisconsin, Madison, WI 53706, USA.
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47
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Albertson R, Cao J, Hsieh TS, Sullivan W. Vesicles and actin are targeted to the cleavage furrow via furrow microtubules and the central spindle. ACTA ACUST UNITED AC 2008; 181:777-90. [PMID: 18504302 PMCID: PMC2396810 DOI: 10.1083/jcb.200803096] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
During cytokinesis, cleavage furrow invagination requires an actomyosin-based contractile ring and addition of new membrane. Little is known about how this actin and membrane traffic to the cleavage furrow. We address this through live analysis of fluorescently tagged vesicles in postcellularized Drosophila melanogaster embryos. We find that during cytokinesis, F-actin and membrane are targeted as a unit to invaginating furrows through formation of F-actin–associated vesicles. F-actin puncta strongly colocalize with endosomal, but not Golgi-derived, vesicles. These vesicles are recruited to the cleavage furrow along the central spindle and a distinct population of microtubules (MTs) in contact with the leading furrow edge (furrow MTs). We find that Rho-specific guanine nucleotide exchange factor mutants, pebble (pbl), severely disrupt this F-actin–associated vesicle transport. These transport defects are a consequence of the pbl mutants' inability to properly form furrow MTs and the central spindle. Transport of F-actin–associated vesicles on furrow MTs and the central spindle is thus an important mechanism by which actin and membrane are delivered to the cleavage furrow.
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Affiliation(s)
- Roger Albertson
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
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48
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C2 domain of synaptotagmin I associates with lipid rafts of plasma membrane. Sci Bull (Beijing) 2008. [DOI: 10.1007/s11434-008-0201-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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49
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Mohrmann R, Matthies HJ, Woodruff E, Broadie K. Stoned B mediates sorting of integral synaptic vesicle proteins. Neuroscience 2008; 153:1048-63. [PMID: 18436388 DOI: 10.1016/j.neuroscience.2008.02.060] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2007] [Revised: 02/01/2008] [Accepted: 02/01/2008] [Indexed: 10/22/2022]
Abstract
A continuous supply of fusion-competent synaptic vesicles is essential for sustainable neurotransmission. Drosophila mutations of the dicistronic stoned locus disrupt normal vesicle cycling and cause functional deficits in synaptic transmission. Although both Stoned A and B proteins putatively participate in reconstituting synaptic vesicles, their precise function is still unclear. Here we investigate the effects of progressive depletion of Stoned B protein (STNB) on the release properties of neuromuscular synapses using a novel set of synthetic stnB hypomorphic alleles. Decreasing neuronal STNB expression to < or =35% of wild-type level causes a strong reduction in excitatory junctional current amplitude at low stimulation frequencies and a marked slowing in synaptic depression during high-frequency stimulation, suggesting vesicle depletion is attenuated by decreased release probability. Recovery from synaptic depression after prolonged stimulation is also decelerated in mutants, indicating a delayed recovery of fusion-ready vesicles. These phenotypes appear not to be due to a diminished vesicle population, since the docked vesicle pool is ultrastructurally unaffected, and the total number of vesicles is only slightly reduced in these hypomorphs, unlike lethal stoned mutants. Therefore, we conclude that STNB not only functions as an essential component of the endocytic complex for vesicle reconstitution, as previously proposed, but also regulates the competence of recycled vesicles to undergo fusion. In support of such role of STNB, synaptic levels of the vesicular glutamate transporter (vGLUT) and synaptotagmin-1 are strongly reduced with diminishing STNB function, while other synaptic proteins are largely unaffected. We conclude that STNB organizes the endocytic sorting of a subset of integral synaptic vesicle proteins thereby regulating the fusion-competence of the recycled vesicle.
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Affiliation(s)
- R Mohrmann
- Department of Biological Sciences, Vanderbilt University, 1210 Medical Research Building III, , Nashville, TN 37235-1634, USA
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50
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Genetic analysis of synaptotagmin-7 function in synaptic vesicle exocytosis. Proc Natl Acad Sci U S A 2008; 105:3986-91. [PMID: 18308933 DOI: 10.1073/pnas.0712372105] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Synaptotagmin-7 is a candidate Ca(2+) sensor for exocytosis that is at least partly localized to synapses. Similar to synaptotagmin-1, which functions as a Ca(2+) sensor for fast synaptic vesicle (SV) exocytosis, synaptotagmin-7 contains C(2)A and C(2)B domains that exhibit Ca(2+)-dependent phospholipid binding. However, synaptotagmin-7 cannot replace synaptotagmin-1 as a Ca(2+) sensor for fast SV exocytosis, raising questions about the physiological significance of its Ca(2+)-binding properties. Here, we examine how synaptotagmin-7 binds Ca(2+) and test whether this Ca(2+) binding regulates Ca(2+)-triggered SV exocytosis. We show that the synaptotagmin-7 C(2)A domain exhibits a Ca(2+)-binding mode similar to that of the synaptotagmin-1 C(2)A domain, suggesting that the synaptotagmin-1 and -7 C(2) domains generally employ comparable Ca(2+)-binding mechanisms. We then generated mutant mice that lack synaptotagmin-7 or contain point mutations inactivating Ca(2+) binding either to both C(2) domains of synaptotagmin-7 or only to its C(2)B domain. Synaptotagmin-7-mutant mice were viable and fertile. Inactivation of Ca(2+) binding to both C(2) domains caused an approximately 70% reduction in synaptotagmin-7 levels, whereas inactivation of Ca(2+) binding to only the C(2)B domain did not alter synaptotagmin-7 levels. The synaptotagmin-7 deletion did not change fast synchronous release, slow asynchronous release, or short-term synaptic plasticity of release of neurotransmitters. Thus, our results show that Ca(2+) binding to the synaptotagmin-7 C(2) domains is physiologically important for stabilizing synaptotagmin-7, but that Ca(2+) binding by synaptotagmin-7 likely does not regulate SV exocytosis, consistent with a role for synaptotagmin-7 in other forms of Ca(2+)-dependent synaptic exocytosis.
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