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Mangini M, Limatola N, Ferrara MA, Coppola G, Chun JT, De Luca AC, Santella L. Application of Raman spectroscopy to the evaluation of F-actin changes in sea urchin eggs at fertilization. ZYGOTE 2024; 32:38-48. [PMID: 38050697 DOI: 10.1017/s0967199423000552] [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] [Indexed: 12/06/2023]
Abstract
The actin filaments on the surface of echinoderm oocytes and eggs readily undergo massive reorganization during meiotic maturation and fertilization. In sea urchin eggs, the actin cytoskeletal response to the fertilizing sperm is fast enough to accompany Ca2+ signals and to guide sperm's entry into the egg. Although recent work using live cell imaging technology confirmed changes in the actin polymerization status in fertilized eggs, as was previously shown using light and electron microscopy, it failed to provide experimental evidence of F-actin depolymerization a few seconds after insemination, which is concurrent with the sperm-induced Ca2+ release. In the present study, we applied Raman microspectroscopy to tackle this issue by examining the spectral profiles of the egg's subplasmalemmal regions before and after treating the eggs with actin drugs or fertilizing sperm. At both early (15 s) and late (15 min) time points after fertilization, specific peak shifts in the Raman spectra revealed change in the actin structure, and Raman imaging detected the cytoskeletal changes corresponding to the F-actin reorganization visualized with LifeAct-GFP in confocal microscopy. Our observation suggests that the application of Raman spectroscopy, which does not require microinjection of fluorescent probes and exogenous gene expression, may serve as an alternative or even advantageous method in disclosing rapid subtle changes in the subplasmalemmal actin cytoskeleton that are difficult to resolve.
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Affiliation(s)
- Maria Mangini
- Institute of Experimental Endocrinology and Oncology 'G. Salvatore', Second Unit, National Research Council, 80131Naples, Italy
| | - Nunzia Limatola
- Department of Research Infrastructures for Marine Biological Resources, Stazione Zoologica Anton Dohrn, 80121Naples, Italy
| | - Maria Antonietta Ferrara
- Institute of Applied Sciences and Intelligent Systems 'E. Caianiello', Unit of Naples, National Research Council, 80131Naples, Italy
| | - Giuseppe Coppola
- Institute of Applied Sciences and Intelligent Systems 'E. Caianiello', Unit of Naples, National Research Council, 80131Naples, Italy
| | - Jong Tai Chun
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, 80121Naples, Italy
| | - Anna Chiara De Luca
- Institute of Experimental Endocrinology and Oncology 'G. Salvatore', Second Unit, National Research Council, 80131Naples, Italy
| | - Luigia Santella
- Department of Research Infrastructures for Marine Biological Resources, Stazione Zoologica Anton Dohrn, 80121Naples, Italy
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2
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Santella L, Chun JT. Structural actin dynamics during oocyte maturation and fertilization. Biochem Biophys Res Commun 2022; 633:13-16. [DOI: 10.1016/j.bbrc.2022.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 09/01/2022] [Indexed: 11/06/2022]
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Limatola N, Chun JT, Cherraben S, Schmitt JL, Lehn JM, Santella L. Effects of Dithiothreitol on Fertilization and Early Development in Sea Urchin. Cells 2021; 10:3573. [PMID: 34944081 PMCID: PMC8700669 DOI: 10.3390/cells10123573] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 12/11/2021] [Accepted: 12/15/2021] [Indexed: 01/20/2023] Open
Abstract
The vitelline layer (VL) of a sea urchin egg is an intricate meshwork of glycoproteins that intimately ensheathes the plasma membrane. During fertilization, the VL plays important roles. Firstly, the receptors for sperm reside on the VL. Secondly, following cortical granule exocytosis, the VL is elevated and transformed into the fertilization envelope (FE), owing to the assembly and crosslinking of the extruded materials. As these two crucial stages involve the VL, its alteration was expected to affect the fertilization process. In the present study, we addressed this question by mildly treating the eggs with a reducing agent, dithiothreitol (DTT). A brief pretreatment with DTT resulted in partial disruption of the VL, as judged by electron microscopy and by a novel fluorescent polyamine probe that selectively labelled the VL. The DTT-pretreated eggs did not elevate the FE but were mostly monospermic at fertilization. These eggs also manifested certain anomalies at fertilization: (i) compromised Ca2+ signaling, (ii) blocked translocation of cortical actin filaments, and (iii) impaired cleavage. Some of these phenotypic changes were reversed by restoring the DTT-exposed eggs in normal seawater prior to fertilization. Our findings suggest that the FE is not the decisive factor preventing polyspermy and that the integrity of the VL is nonetheless crucial to the egg's fertilization response.
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Affiliation(s)
- Nunzia Limatola
- Department of Research Infrastructures for Marine Biological Resources, Stazione Zoologica Anton Dohrn, 80121 Napoli, Italy;
| | - Jong Tai Chun
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, 80121 Napoli, Italy
| | - Sawsen Cherraben
- Laboratory of Supramolecular Chemistry, Institut de Science et d’Ingénierie Supramoléculaires ISIS—Université de Strasbourg, 8 allée Gaspard Monge, 67000 Strasbourg, France; (S.C.); (J.-L.S.); (J.-M.L.)
| | - Jean-Louis Schmitt
- Laboratory of Supramolecular Chemistry, Institut de Science et d’Ingénierie Supramoléculaires ISIS—Université de Strasbourg, 8 allée Gaspard Monge, 67000 Strasbourg, France; (S.C.); (J.-L.S.); (J.-M.L.)
| | - Jean-Marie Lehn
- Laboratory of Supramolecular Chemistry, Institut de Science et d’Ingénierie Supramoléculaires ISIS—Université de Strasbourg, 8 allée Gaspard Monge, 67000 Strasbourg, France; (S.C.); (J.-L.S.); (J.-M.L.)
| | - Luigia Santella
- Department of Research Infrastructures for Marine Biological Resources, Stazione Zoologica Anton Dohrn, 80121 Napoli, Italy;
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Vasilev F, Ezhova Y, Chun JT. Signaling Enzymes and Ion Channels Being Modulated by the Actin Cytoskeleton at the Plasma Membrane. Int J Mol Sci 2021; 22:ijms221910366. [PMID: 34638705 PMCID: PMC8508623 DOI: 10.3390/ijms221910366] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 09/23/2021] [Accepted: 09/23/2021] [Indexed: 02/06/2023] Open
Abstract
A cell should deal with the changing external environment or the neighboring cells. Inevitably, the cell surface receives and transduces a number of signals to produce apt responses. Typically, cell surface receptors are activated, and during this process, the subplasmalemmal actin cytoskeleton is often rearranged. An intriguing point is that some signaling enzymes and ion channels are physically associated with the actin cytoskeleton, raising the possibility that the subtle changes of the local actin cytoskeleton can, in turn, modulate the activities of these proteins. In this study, we reviewed the early and new experimental evidence supporting the notion of actin-regulated enzyme and ion channel activities in various cell types including the cells of immune response, neurons, oocytes, hepatocytes, and epithelial cells, with a special emphasis on the Ca2+ signaling pathway that depends on the synthesis of inositol 1,4,5-trisphosphate. Some of the features that are commonly found in diverse cells from a wide spectrum of the animal species suggest that fine-tuning of the activities of the enzymes and ion channels by the actin cytoskeleton may be an important strategy to inhibit or enhance the function of these signaling proteins.
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Affiliation(s)
- Filip Vasilev
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), 900 Rue St Denis, Montreal, QC H2X 0A9, Canada
- Correspondence: (F.V.); (J.T.C.); Tel.: +1-514-249-5862 (F.V.); +39-081-583-3407 (J.T.C.)
| | - Yulia Ezhova
- Maisonneuve-Rosemont Hospital Research Centre, University of Montreal, Montreal, QC H1T 2M4, Canada;
| | - Jong Tai Chun
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, 80121 Napoli, Italy
- Correspondence: (F.V.); (J.T.C.); Tel.: +1-514-249-5862 (F.V.); +39-081-583-3407 (J.T.C.)
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Limatola N, Chun JT, Santella L. Effects of Salinity and pH of Seawater on the Reproduction of the Sea Urchin Paracentrotus lividus. THE BIOLOGICAL BULLETIN 2020; 239:13-23. [PMID: 32812816 DOI: 10.1086/710126] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
AbstractFertilization and early development are usually the most vulnerable stages in the life of marine animals, and the biological processes during this period are highly sensitive to the environment. In nature, sea urchin gametes are shed in seawater, where they undergo external fertilization and embryonic development. In a laboratory, it is possible to follow the exact morphological and biochemical changes taking place in the fertilized eggs and the developing embryos. Thus, observation of successful fertilization and the subsequent embryonic development of sea urchin eggs can be used as a convenient biosensor to assess the quality of the marine environment. In this paper, we have examined how salinity and pH changes affect the normal fertilization process and the following development of Paracentrotus lividus. The results of our studies using confocal microscopy, scanning and transmission electron microscopy, and time-lapse Ca2+ image recording indicated that both dilution and acidification of seawater have subtle but detrimental effects on many aspects of the fertilization process. They include Ca2+ signaling and coordinated actin cytoskeletal changes, leading to a significantly reduced rate of successful fertilization and, eventually, to abnormal or delayed embryonic development.
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Santella L, Limatola N, Chun JT. Cellular and molecular aspects of oocyte maturation and fertilization: a perspective from the actin cytoskeleton. ZOOLOGICAL LETTERS 2020; 6:5. [PMID: 32313685 PMCID: PMC7158055 DOI: 10.1186/s40851-020-00157-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 03/26/2020] [Indexed: 05/06/2023]
Abstract
ABSTRACT Much of the scientific knowledge on oocyte maturation, fertilization, and embryonic development has come from the experiments using gametes of marine organisms that reproduce by external fertilization. In particular, echinoderm eggs have enabled the study of structural and biochemical changes related to meiotic maturation and fertilization owing to the abundant availability of large and transparent oocytes and eggs. Thus, in vitro studies of oocyte maturation and sperm-induced egg activation in starfish are carried out under experimental conditions that resemble those occurring in nature. During the maturation process, immature oocytes of starfish are released from the prophase of the first meiotic division, and acquire the competence to be fertilized through a highly programmed sequence of morphological and physiological changes at the oocyte surface. In addition, the changes in the cortical and nuclear regions are essential for normal and monospermic fertilization. This review summarizes the current state of research on the cortical actin cytoskeleton in mediating structural and physiological changes during oocyte maturation and sperm and egg activation in starfish and sea urchin. The common denominator in these studies with echinoderms is that exquisite rearrangements of the egg cortical actin filaments play pivotal roles in gamete interactions, Ca2+ signaling, exocytosis of cortical granules, and control of monospermic fertilization. In this review, we also compare findings from studies using invertebrate eggs with what is known about the contributions made by the actin cytoskeleton in mammalian eggs. Since the cortical actin cytoskeleton affects microvillar morphology, movement, and positioning of organelles and vesicles, and the topography of the egg surface, these changes have impacts on the fertilization process, as has been suggested by recent morphological studies on starfish oocytes and eggs using scanning electron microscopy. Drawing the parallelism between vitelline layer of echinoderm eggs and the zona pellucida of mammalian eggs, we also discuss the importance of the egg surface in mediating monospermic fertilization. GRAPHICAL ABSTRACT
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Affiliation(s)
- Luigia Santella
- Department of Research Infrastructures for Marine Biological Resources, Stazione Zoologica Anton Dohrn, Villa Comunale, Napoli 80121, Italy
| | - Nunzia Limatola
- Department of Research Infrastructures for Marine Biological Resources, Stazione Zoologica Anton Dohrn, Villa Comunale, Napoli 80121, Italy
| | - Jong Tai Chun
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Villa Comunale, Napoli 80121, Italy
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Calcium in Cell-Extracellular Matrix Interactions. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1131:1079-1102. [PMID: 31646546 DOI: 10.1007/978-3-030-12457-1_43] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In multicellular organisms, the cells are surrounded by persistent, dynamic extracellular matrix (ECM), the largest calcium reservoir in animals. ECM regulates several aspects of cell behavior including cell migration and adhesion, survival, gene expression and differentiation, thus playing a significant role in health and disease. Calcium is reported to be important in the assembly of ECM, where it binds to many ECM proteins. While serving as a calcium reservoir, ECM macromolecules can directly interact with cell surface receptors resulting in calcium transport across the membrane. This chapter mainly focusses on the role of cell-ECM interactions in cellular calcium regulation and how calcium itself mediates these interactions.
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Nicotine Induces Polyspermy in Sea Urchin Eggs through a Non-Cholinergic Pathway Modulating Actin Dynamics. Cells 2019; 9:cells9010063. [PMID: 31881774 PMCID: PMC7016604 DOI: 10.3390/cells9010063] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 12/02/2019] [Accepted: 12/21/2019] [Indexed: 01/02/2023] Open
Abstract
While alkaloids often exert unique pharmacological effects on animal cells, exposure of sea urchin eggs to nicotine causes polyspermy at fertilization in a dose-dependent manner. Here, we studied molecular mechanisms underlying the phenomenon. Although nicotine is an agonist of ionotropic acetylcholine receptors, we found that nicotine-induced polyspermy was neither mimicked by acetylcholine and carbachol nor inhibited by specific antagonists of nicotinic acetylcholine receptors. Unlike acetylcholine and carbachol, nicotine uniquely induced drastic rearrangement of egg cortical microfilaments in a dose-dependent way. Such cytoskeletal changes appeared to render the eggs more receptive to sperm, as judged by the significant alleviation of polyspermy by latrunculin-A and mycalolide-B. In addition, our fluorimetric assay provided the first evidence that nicotine directly accelerates polymerization kinetics of G-actin and attenuates depolymerization of preassembled F-actin. Furthermore, nicotine inhibited cofilin-induced disassembly of F-actin. Unexpectedly, our results suggest that effects of nicotine can also be mediated in some non-cholinergic pathways.
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Helassa N, Nugues C, Rajamanoharan D, Burgoyne RD, Haynes LP. A centrosome-localized calcium signal is essential for mammalian cell mitosis. FASEB J 2019; 33:14602-14610. [PMID: 31682764 PMCID: PMC6910830 DOI: 10.1096/fj.201901662r] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 09/23/2019] [Indexed: 02/02/2023]
Abstract
Mitosis defects can lead to premature ageing and cancer. Understanding mitosis regulation therefore has important implications for human disease. Early data suggested that calcium (Ca2+) signals could influence mitosis, but these have hitherto not been observed in mammalian cells. Here, we reveal a prolonged yet spatially restricted Ca2+ signal at the centrosomes of actively dividing cells. Local buffering of the centrosomal Ca2+ signals, by flash photolysis of the caged Ca2+ chelator diazo-2-acetoxymethyl ester, arrests mitosis. We also provide evidence that this Ca2+ signal emanates from the endoplasmic reticulum. In summary, we characterize a unique centrosomal Ca2+ signal as a functionally essential input into mitosis.-Helassa, N., Nugues, C., Rajamanoharan, D., Burgoyne, R. D., Haynes, L. P. A centrosome-localized calcium signal is essential for mammalian cell mitosis.
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Affiliation(s)
- Nordine Helassa
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Charlotte Nugues
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Dayani Rajamanoharan
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Robert D. Burgoyne
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Lee P. Haynes
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
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Sodium-mediated fast electrical depolarization does not prevent polyspermic fertilization in Paracentrotus lividus eggs. ZYGOTE 2019; 27:241-249. [PMID: 31397235 DOI: 10.1017/s0967199419000364] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
During sea urchins fertilization, the activating spermatozoon triggers a series of physiological changes that transforms the quiescent egg into a dynamic zygote. It has been suggested that several of these egg activation events, e.g. sperm-induced plasma membrane depolarization and the Ca2+-linked cortical reaction, play additional roles to prevent the entry of supernumerary spermatozoa. In particular, the abrupt shift in egg membrane potential at fertilization, which is sustained by a Na+ influx, has been considered as a fast mechanism to block polyspermy. To test the relevance of the Na+-mediated fast electrical block to polyspermy, we fertilized sea urchin eggs in artificial seawater with a low concentration of Na+; nearly all the eggs were still monospermic, as judged by the number of Hoechst 33422-stained sperm. When fertilized in normal seawater, eggs that were pre-incubated in the low Na+ medium exhibited impaired elevation of the fertilization envelope. Nevertheless, these eggs manifested entry of a single spermatozoon, suggesting that the fertilization envelope was not the primary determinant of the block to polyspermy. Furthermore, we showed that the abnormal cleavage patterns displayed by eggs pre-incubated in low Na+, which were often considered a hallmark of polyspermy, were due to the alterations in the cortical actin filaments dynamics following fertilization, and not to the formation of multipolar spindles associated with supernumerary sperm centrosomes. Hence, our results suggested that Paracentrotus lividus eggs do not utilize Na+ to rapidly prevent additional spermatozoa from entering the egg, at variance with the hypothesis of an electrical fast block to polyspermy.
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11
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Altered actin cytoskeleton in ageing eggs of starfish affects fertilization process. Exp Cell Res 2019; 381:179-190. [PMID: 31082375 DOI: 10.1016/j.yexcr.2019.05.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 05/03/2019] [Accepted: 05/04/2019] [Indexed: 11/21/2022]
Abstract
Integrity of oocytes is of pivotal interest in the medical and zootechnical practice of in vitro fertilization. With time, oocytes undergo deterioration in quality, and ageing oocytes often exhibit compromised competence in fertilization and the subsequent embryonic development. With ageing oocytes and eggs of starfish (Astropecten aranciacus), we addressed the issue by examining changes of the subcellular structure and their performance at fertilization. Ageing eggs were simulated in two different experimental paradigms: i) oocytes were overmatured by 6 hours stimulation with 1-methyladenine (1-MA); ii) oocytes were removed from the gonad and maintained in seawater for 24 or 48 h before applying the hormonal stimulation (1-MA, 70 min). These eggs were compared with normally matured eggs (stimulated after isolation from the gonad with 1-MA for 70 min) with respect to the sperm-induced intracellular Ca2+ signaling and the structural changes of the egg surface. The cytoskeletal and ultrastructural differences in these eggs were assessed by confocal and transmission electron microscopy, respectively. In the two categories of ageing eggs, we have found remarkable structural modifications of the actin cytoskeleton and the cortical vesicles beneath the plasma membrane. At fertilization, these ageing eggs manifested an altered pattern of intracellular Ca2+ release, aberrant actin dynamics, and increased rate of polyspermy often despite full elevation of the fertilization envelope. Taken together, our results highlight the importance of spatio-temporal regulation of the actin cytoskeleton in the cortex of the eggs, and we postulate that the status of the actin cytoskeleton is one of the major determinants of the oocyte quality that ensures successful monospermic fertilization.
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12
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Maturation and fertilization of echinoderm eggs: Role of actin cytoskeleton dynamics. Biochem Biophys Res Commun 2018; 506:361-371. [DOI: 10.1016/j.bbrc.2018.09.084] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 09/13/2018] [Indexed: 01/31/2023]
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Chun JT, Vasilev F, Limatola N, Santella L. Fertilization in Starfish and Sea Urchin: Roles of Actin. Results Probl Cell Differ 2018; 65:33-47. [PMID: 30083914 DOI: 10.1007/978-3-319-92486-1_3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Marine animals relying on "external fertilization" provide advantageous opportunities to study the mechanisms of gamete activation and fusion, as well as the subsequent embryonic development. Owing to the large number of eggs that are easily available and handled, starfish and sea urchins have been chosen as favorable animal models in this line of research for over 150 years. Indeed, much of our knowledge on fertilization came from studies in the echinoderms. Fertilization involves mutual stimulation between eggs and sperm, which leads to morphological, biochemical, and physiological changes on both sides to ensure successful gamete fusion. In this chapter, we review the roles of actin in the fertilization of starfish and sea urchin eggs. As fertilization is essentially an event that takes place on the egg surface, it has been predicted that suboolemmal actin filaments would make significant contributions to sperm entry. A growing body of evidence from starfish and sea urchin eggs suggests that the prompt reorganization of the actin pools around the time of fertilization plays crucial regulatory roles not only in guiding sperm entry but also in modulating intracellular Ca2+ signaling and egg activation.
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Affiliation(s)
- Jong Tai Chun
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Napoli, Italy.
| | - Filip Vasilev
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Napoli, Italy
| | - Nunzia Limatola
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Napoli, Italy
| | - Luigia Santella
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Napoli, Italy.
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14
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Shi J, Wang D, Zhou Y, Gu Y, Wu D, Wang J, Hong Y. Comparative proteomics analysis of spermary and ovary in Hyriopsis schlegelii. Biosci Biotechnol Biochem 2017; 81:491-499. [DOI: 10.1080/09168451.2016.1259553] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Abstract
We provide the first large-scale quantitative proteomics analysis in Hyriopsis schlegelii. To investigate the proteins expressed in the gonads, a quantitative proteomics approach has been utilized to analyze differentially expressed proteins between the spermary and ovary. In this study, we identified and quantified 2416 proteins in the gonads of Hyriopsis schlegelii. Of these, 559 proteins showed significantly different expression between the spermary and ovary. Some specific proteins expressed in either the spermary or ovary were identified in Hyriopsis schlegelii. In addition, a series of proteins related to gametogenesis were also identified. Compared with previous reports, many proteins in Hyriopsis schlegelii identified here have different expression patterns between the spermary and ovary. The special hermaphroditism in Hyriopsis schlegelii may contribute to these inconsistent results. The provided proteomics data could be considered as a starting point for subsequent studies focusing on the proteins involved in sexual gland development and maturity.
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Affiliation(s)
- Jianwu Shi
- School of Life Sciences, Nanchang University, Nanchang, China
| | - Dexia Wang
- School of Life Sciences, Nanchang University, Nanchang, China
| | - Yan Zhou
- School of Life Sciences, Nanchang University, Nanchang, China
| | - Yiran Gu
- School of Life Sciences, Nanchang University, Nanchang, China
| | - Di Wu
- School of Life Sciences, Nanchang University, Nanchang, China
| | - Junhua Wang
- School of Life Sciences, Nanchang University, Nanchang, China
| | - Yijiang Hong
- School of Life Sciences, Nanchang University, Nanchang, China
- Key Laboratory of Molecular Biology and Genetic Engineering of Jiangxi, Nanchang University, Nanchang, China
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Ca 2+ Signalling and Membrane Dynamics During Cytokinesis in Animal Cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 981:389-412. [PMID: 29594869 DOI: 10.1007/978-3-319-55858-5_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2023]
Abstract
Interest in the role of Ca2+ signalling as a possible regulator of the combinatorial processes that result in the separation of the daughter cells during cytokinesis, extend back almost a 100 years. One of the key processes required for the successful completion of cytokinesis in animal cells (especially in the large holoblastically and meroblastically dividing embryonic cells of a number of amphibian and fish species), is the dynamic remodelling of the plasma membrane. Ca2+ signalling was subsequently demonstrated to regulate various different aspects of cytokinesis in animal cells, and so here we focus specifically on the role of Ca2+ signalling in the remodelling of the plasma membrane. We begin by providing a brief history of the animal models used and the research accomplished by the early twentieth century investigators, with regards to this aspect of animal cell cytokinesis. We then review the most recent progress made (i.e., in the last 10 years), which has significantly advanced our current understanding on the role of cytokinetic Ca2+ signalling in membrane remodelling. To this end, we initially summarize what is currently known about the Ca2+ transients generated during animal cell cytokinesis, and then we describe the latest findings regarding the source of Ca2+ generating these transients. Finally, we review the current evidence about the possible targets of the different cytokinetic Ca2+ transients with a particular emphasis on those that either directly or indirectly affect plasma membrane dynamics. With regards to the latter, we discuss the possible role of the early Ca2+ signalling events in the deformation of the plasma membrane at the start of cytokinesis (i.e., during furrow positioning), as well as the role of the subsequent Ca2+ signals in the trafficking and fusion of vesicles, which help to remodel the plasma membrane during the final stages of cell division. As it is becoming clear that each of the cytokinetic Ca2+ transients might have multiple, integrated targets, deciphering the precise role of each transient represents a significant (and ongoing) challenge.
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Zhou Q, Hu H, Li Z. An EF-hand-containing Protein in Trypanosoma brucei Regulates Cytokinesis Initiation by Maintaining the Stability of the Cytokinesis Initiation Factor CIF1. J Biol Chem 2016; 291:14395-409. [PMID: 27226595 DOI: 10.1074/jbc.m116.726133] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Indexed: 11/06/2022] Open
Abstract
Trypanosoma brucei undergoes cytokinesis uni-directionally from the anterior tip of the new flagellum attachment zone (FAZ) toward the posterior end of the cell. We recently delineated a novel signaling pathway composed of polo-like kinase, cytokinesis initiation factor 1 (CIF1), and aurora B kinase that acts in concert at the new FAZ tip to regulate cytokinesis initiation. To identify new cytokinesis regulators, we carried out proximity-dependent biotin identification and identified many CIF1 binding partners and near neighbors. Here we report a novel CIF1-binding protein, named CIF2, and its mechanistic role in cytokinesis initiation. CIF2 interacts with CIF1 in vivo and co-localizes with CIF1 at the new FAZ tip during early cell cycle stages. RNAi of CIF2 inhibited the normal, anterior-to-posterior cytokinesis but activated an alternative, posterior-to-anterior cytokinesis. CIF2 depletion destabilized CIF1 and disrupted the localization of polo-like kinase and aurora B kinase to the new FAZ tip, thus revealing the mechanistic role of CIF2 in cytokinesis initiation. Surprisingly, overexpression of CIF2 also inhibited the normal, anterior-to-posterior cytokinesis and triggered the alternative, posterior-to-anterior cytokinesis, suggesting a tight control of CIF2 protein abundance. These results identified a new regulator in the cytokinesis regulatory pathway and reiterated that a backup cytokinesis pathway is activated by inhibiting the normal cytokinesis pathway.
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Affiliation(s)
- Qing Zhou
- From the Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas 77030
| | - Huiqing Hu
- From the Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas 77030
| | - Ziyin Li
- From the Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas 77030
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Cofilin as a Promising Therapeutic Target for Ischemic and Hemorrhagic Stroke. Transl Stroke Res 2015; 7:33-41. [PMID: 26670926 DOI: 10.1007/s12975-015-0438-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 12/01/2015] [Accepted: 12/03/2015] [Indexed: 01/22/2023]
Abstract
Neurovascular unit (NVU) is considered as a conceptual framework for investigating the mechanisms as well as developing therapeutic targets for ischemic and hemorrhagic stroke. From a molecular perspective, oxidative stress, excitotoxicity, inflammation, and disruption of the blood brain barrier are broad pathophysiological frameworks on the basis on which potential therapeutic candidates for ischemic and hemorrhagic stroke could be discussed. Cofilin is a potent actin-binding protein that severs and depolymerizes actin filaments in order to generate the dynamics of the actin cytoskeleton. Although studies of the molecular mechanisms of cofilin-induced reorganization of the actin cytoskeleton have been ongoing for decades, the multicellular functions of cofilin and its regulation in different molecular pathways are expanding beyond its primary role in actin cytoskeleton. This review focuses on the role of cofilin in oxidative stress, excitotoxicity, inflammation, and disruption of the blood brain barrier in the context of NVU as well as how and why cofilin could be studied further as a potential target for ischemic and hemorrhagic stroke.
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Novel Ca2+ increases in the maturing oocytes of starfish during the germinal vesicle breakdown. Cell Calcium 2015; 58:500-10. [DOI: 10.1016/j.ceca.2015.08.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 08/04/2015] [Accepted: 08/04/2015] [Indexed: 11/20/2022]
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Santella L, Limatola N, Chun JT. Calcium and actin in the saga of awakening oocytes. Biochem Biophys Res Commun 2015; 460:104-13. [PMID: 25998739 DOI: 10.1016/j.bbrc.2015.03.028] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 03/06/2015] [Indexed: 12/12/2022]
Abstract
The interaction of the spermatozoon with the egg at fertilization remains one of the most fascinating mysteries of life. Much of our scientific knowledge on fertilization comes from studies on sea urchin and starfish, which provide plenty of gametes. Large and transparent, these eggs have served as excellent model systems for studying egg activation and embryo development in seawater, a plain natural medium. Starfish oocytes allow the study of the cortical, cytoplasmic and nuclear changes during the meiotic maturation process, which can also be triggered in vitro by hormonal stimulation. These morphological and biochemical changes ensure successful fertilization of the eggs at the first metaphase. On the other hand, sea urchin eggs are fertilized after the completion of meiosis, and are particularly suitable for the study of sperm-egg interaction, early events of egg activation, and embryonic development, as a large number of mature eggs can be fertilized synchronously. Starfish and sea urchin eggs undergo abrupt changes in the cytoskeleton and ion fluxes in response to the fertilizing spermatozoon. The plasma membrane and cortex of an egg thus represent "excitable media" that quickly respond to the stimulus with the Ca(2+) swings and structural changes. In this article, we review some of the key findings on the rapid dynamic rearrangements of the actin cytoskeleton in the oocyte/egg cortex upon hormonal or sperm stimulation and their roles in the modulation of the Ca(2+) signals and in the control of monospermic fertilization.
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Affiliation(s)
- Luigia Santella
- Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Villa Comunale 1, Napoli, I-80121, Italy.
| | - Nunzia Limatola
- Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Villa Comunale 1, Napoli, I-80121, Italy
| | - Jong T Chun
- Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Villa Comunale 1, Napoli, I-80121, Italy
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Chun JT, Limatola N, Vasilev F, Santella L. Early events of fertilization in sea urchin eggs are sensitive to actin-binding organic molecules. Biochem Biophys Res Commun 2014; 450:1166-74. [DOI: 10.1016/j.bbrc.2014.06.057] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Accepted: 06/11/2014] [Indexed: 10/25/2022]
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Nakano T, Deguchi R, Kyozuka K. Intracellular calcium signaling in the fertilized eggs of Annelida. Biochem Biophys Res Commun 2014; 450:1188-94. [PMID: 24953697 DOI: 10.1016/j.bbrc.2014.06.056] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 06/11/2014] [Indexed: 11/19/2022]
Abstract
Fertilization is such a universal and indispensable step in sexual reproduction, but a high degree of variability exists in the way it takes place in the animal kingdom. As discussed in other reviews in this issue, recent works on this subject clarified many points. However, important results on the mechanisms of fertilization are obtained mainly from a few restricted model organisms. In this sense, it is utterly important to collect more information from various phyla. In this review, we have re-introduced Annelida as one of the most suitable models for the analysis of fertilization process. We have briefly reviewed the historical works on the fertilization of Annelida. Then, we have described recent findings on the two independent Ca(2+) increases in the fertilized eggs of Annelida, which arise from two different mechanisms and may have distinct physiological roles toward sperm entry and egg activation. We propose that the Ca(2+) increase in the fertilized eggs reflect the specific needs of the zygote in a given species.
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Affiliation(s)
- Takeshi Nakano
- Research Center for Marine Biology, Asamushi, Graduate School of Life Science, Tohoku University Asamushi, Aomori 039-3501, Japan.
| | - Ryusaku Deguchi
- Department of Biology, Miyagi University of Education, Sendai, Miyagi 980-0845, Japan.
| | - Keiichiro Kyozuka
- Research Center for Marine Biology, Asamushi, Graduate School of Life Science, Tohoku University Asamushi, Aomori 039-3501, Japan.
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Chun JT, Vasilev F, Santella L. Antibody against the actin-binding protein depactin attenuates Ca2+ signaling in starfish eggs. Biochem Biophys Res Commun 2013; 441:301-7. [DOI: 10.1016/j.bbrc.2013.09.103] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 09/20/2013] [Indexed: 10/26/2022]
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Santella L, Vasilev F, Chun JT. Fertilization in echinoderms. Biochem Biophys Res Commun 2012; 425:588-94. [PMID: 22925679 DOI: 10.1016/j.bbrc.2012.07.159] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Accepted: 07/28/2012] [Indexed: 11/27/2022]
Abstract
For more than 150 years, echinoderm eggs have served as overly favored experimental model systems in which to study fertilization. Sea urchin and starfish belong to the same phylum and thus share many similarities in their fertilization patterns. However, several subtle but fundamental differences do exist in the fertilization of sea urchin and starfish, reflecting their phylogenetic bifurcation approximately 500 million years ago. In this article we review some of the seminal and recent findings that feature similarities and differences in sea urchin and starfish at fertilization.
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Affiliation(s)
- Luigia Santella
- Laboratory of Cellular and Developmental Biology Stazione Zoologica Anton Dohrn, Villa Comunale 1, Napoli 80121, Italy.
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Corporeau C, Vanderplancke G, Boulais M, Suquet M, Quéré C, Boudry P, Huvet A, Madec S. Proteomic identification of quality factors for oocytes in the Pacific oyster Crassostrea gigas. J Proteomics 2012; 75:5554-63. [DOI: 10.1016/j.jprot.2012.07.040] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Revised: 07/02/2012] [Accepted: 07/21/2012] [Indexed: 12/26/2022]
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Vasilev F, Chun JT, Gragnaniello G, Garante E, Santella L. Effects of ionomycin on egg activation and early development in starfish. PLoS One 2012; 7:e39231. [PMID: 22723970 PMCID: PMC3377674 DOI: 10.1371/journal.pone.0039231] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Accepted: 05/21/2012] [Indexed: 11/21/2022] Open
Abstract
Ionomycin is a Ca2+-selective ionophore that is widely used to increase intracellular Ca2+ levels in cell biology laboratories. It is also occasionally used to activate eggs in the clinics practicing in vitro fertilization. However, neither the precise molecular action of ionomycin nor its secondary effects on the eggs' structure and function is well known. In this communication we have studied the effects of ionomycin on starfish oocytes and zygotes. By use of confocal microscopy, calcium imaging, as well as light and transmission electron microscopy, we have demonstrated that immature oocytes exposed to ionomycin instantly increase intracellular Ca2+ levels and undergo structural changes in the cortex. Surprisingly, when microinjected into the cells, ionomycin produced no Ca2+ increase. The ionomycin-induced Ca2+ rise was followed by fast alteration of the actin cytoskeleton displaying conspicuous depolymerization at the oocyte surface and in microvilli with concomitant polymerization in the cytoplasm. In addition, cortical granules were disrupted or fused with white vesicles few minutes after the addition of ionomycin. These structural changes prevented cortical maturation of the eggs despite the normal progression of nuclear envelope breakdown. At fertilization, the ionomycin-pretreated eggs displayed reduced Ca2+ response, no elevation of the fertilization envelope, and the lack of orderly centripetal translocation of actin fibers. These alterations led to difficulties in cell cleavage in the monospermic zygotes and eventually to a higher rate of abnormal development. In conclusion, ionomycin has various deleterious impacts on egg activation and the subsequent embryonic development in starfish. Although direct comparison is difficult to make between our findings and the use of the ionophore in the in vitro fertilization clinics, our results call for more defining investigations on the issue of a potential risk in artificial egg activation.
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Affiliation(s)
- Filip Vasilev
- Laboratory of Cellular and Developmental Biology, Stazione Zoologica Anton Dohrn, Villa Comunale, Napoli, Italy
| | - Jong T. Chun
- Laboratory of Cellular and Developmental Biology, Stazione Zoologica Anton Dohrn, Villa Comunale, Napoli, Italy
| | - Giovanni Gragnaniello
- Laboratory of Cellular and Developmental Biology, Stazione Zoologica Anton Dohrn, Villa Comunale, Napoli, Italy
| | - Ezio Garante
- Laboratory of Cellular and Developmental Biology, Stazione Zoologica Anton Dohrn, Villa Comunale, Napoli, Italy
| | - Luigia Santella
- Laboratory of Cellular and Developmental Biology, Stazione Zoologica Anton Dohrn, Villa Comunale, Napoli, Italy
- * E-mail:
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Actin, more than just a housekeeping protein at the scene of fertilization. SCIENCE CHINA-LIFE SCIENCES 2011; 54:733-43. [DOI: 10.1007/s11427-011-4202-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Accepted: 06/20/2011] [Indexed: 10/18/2022]
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Louzao MC, Ares IR, Cagide E, Espiña B, Vilariño N, Alfonso A, Vieytes MR, Botana LM. Palytoxins and cytoskeleton: An overview. Toxicon 2011; 57:460-9. [DOI: 10.1016/j.toxicon.2010.09.017] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Revised: 09/23/2010] [Accepted: 09/28/2010] [Indexed: 11/30/2022]
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The biphasic increase of PIP2 in the fertilized eggs of starfish: new roles in actin polymerization and Ca2+ signaling. PLoS One 2010; 5:e14100. [PMID: 21124897 PMCID: PMC2990714 DOI: 10.1371/journal.pone.0014100] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Accepted: 11/01/2010] [Indexed: 12/17/2022] Open
Abstract
Background Fertilization of echinoderm eggs is accompanied by dynamic changes of the actin cytoskeleton and by a drastic increase of cytosolic Ca2+. Since the plasma membrane-enriched phospholipid phosphatidylinositol 4,5-bisphosphate (PIP2) serves as the precursor of inositol 1,4,5 trisphosphate (InsP3) and also regulates actin-binding proteins, PIP2 might be involved in these two processes. Methodology/Principal Findings In this report, we have studied the roles of PIP2 at fertilization of starfish eggs by using fluorescently tagged pleckstrin homology (PH) domain of PLC-δ1, which has specific binding affinity to PIP2, in combination with Ca2+ and F-actin imaging techniques and transmission electron microscopy. During fertilization, PIP2 increased at the plasma membrane in two phases rather than continually decreasing. The first increase was quickly followed by a decrease about 40 seconds after sperm-egg contact. However, these changes took place only after the Ca2+ wave had already initiated and propagated. The fertilized eggs then displayed a prolonged increase of PIP2 that was accompanied by the appearance of numerous spikes in the perivitelline space during the elevation of the fertilization envelope (FE). These spikes, protruding from the plasma membrane, were filled with microfilaments. Sequestration of PIP2 by RFP-PH at higher doses resulted in changes of subplasmalemmal actin networks which significantly delayed the intracellular Ca2+ signaling, impaired elevation of FE, and increased occurrences of polyspermic fertilization. Conclusions/Significance Our results suggest that PIP2 plays comprehensive roles in shaping Ca2+ waves and guiding structural and functional changes required for successful fertilization. We propose that the PIP2 increase and the subsequent formation of actin spikes not only provide the mechanical supports for the elevating FE, but also accommodate increased membrane surfaces during cortical granule exocytosis.
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Impact of marine drugs on cytoskeleton-mediated reproductive events. Mar Drugs 2010; 8:881-915. [PMID: 20479959 PMCID: PMC2866467 DOI: 10.3390/md8040881] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2010] [Revised: 03/02/2010] [Accepted: 03/23/2010] [Indexed: 12/30/2022] Open
Abstract
Marine organisms represent an important source of novel bioactive compounds, often showing unique modes of action. Such drugs may be useful tools to study complex processes such as reproduction; which is characterized by many crucial steps that start at gamete maturation and activation and virtually end at the first developmental stages. During these processes cytoskeletal elements such as microfilaments and microtubules play a key-role. In this review we describe: (i) the involvement of such structures in both cellular and in vitro processes; (ii) the toxins that target the cytoskeletal elements and dynamics; (iii) the main steps of reproduction and the marine drugs that interfere with these cytoskeleton-mediated processes. We show that marine drugs, acting on microfilaments and microtubules, exert a wide range of impacts on reproductive events including sperm maturation and motility, oocyte maturation, fertilization, and early embryo development.
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Atilla-Gokcumen GE, Castoreno AB, Sasse S, Eggert US. Making the cut: the chemical biology of cytokinesis. ACS Chem Biol 2010; 5:79-90. [PMID: 20014865 DOI: 10.1021/cb900256m] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Cytokinesis is the last step in the cell cycle, where daughter cells finally separate. It is precisely regulated in both time and space to ensure that each daughter cell receives an equal share of DNA and other cellular materials. Chemical biology approaches have been used very successfully to study the mechanism of cytokinesis. In this review, we discuss the use of small molecule probes to perturb cytokinesis, as well as the role naturally occurring small molecule metabolites such as lipids play during cytokinesis.
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Affiliation(s)
- G. Ekin Atilla-Gokcumen
- Dana-Farber Cancer Institute and Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115
| | - Adam B. Castoreno
- Dana-Farber Cancer Institute and Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115
| | - Sofia Sasse
- Dana-Farber Cancer Institute and Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115
- Westfälische Wilhelms-Universität Münster, Germany
| | - Ulrike S. Eggert
- Dana-Farber Cancer Institute and Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115
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Guanine nucleotides in the meiotic maturation of starfish oocytes: regulation of the actin cytoskeleton and of Ca(2+) signaling. PLoS One 2009; 4:e6296. [PMID: 19617909 PMCID: PMC2706993 DOI: 10.1371/journal.pone.0006296] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2009] [Accepted: 06/15/2009] [Indexed: 11/19/2022] Open
Abstract
Background Starfish oocytes are arrested at the first prophase of meiosis until they are stimulated by 1-methyladenine (1-MA). The two most immediate responses to the maturation-inducing hormone are the quick release of intracellular Ca2+ and the accelerated changes of the actin cytoskeleton in the cortex. Compared with the later events of oocyte maturation such as germinal vesicle breakdown, the molecular mechanisms underlying the early events involving Ca2+ signaling and actin changes are poorly understood. Herein, we have studied the roles of G-proteins in the early stage of meiotic maturation. Methodology/Principal Findings By microinjecting starfish oocytes with nonhydrolyzable nucleotides that stabilize either active (GTPγS) or inactive (GDPβS) forms of G-proteins, we have demonstrated that: i) GTPγS induces Ca2+ release that mimics the effect of 1-MA; ii) GDPβS completely blocks 1-MA-induced Ca2+; iii) GDPβS has little effect on the amplitude of the Ca2+ peak, but significantly expedites the initial Ca2+ waves induced by InsP3 photoactivation, iv) GDPβS induces unexpectedly striking modification of the cortical actin networks, suggesting a link between the cytoskeletal change and the modulation of the Ca2+ release kinetics; v) alteration of cortical actin networks with jasplakinolide, GDPβS, or actinase E, all led to significant changes of 1-MA-induced Ca2+ signaling. Conclusions/Significance Taken together, these results indicate that G-proteins are implicated in the early events of meiotic maturation and support our previous proposal that the dynamic change of the actin cytoskeleton may play a regulatory role in modulating intracellular Ca2+ release.
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Chun JT, Santella L. The actin cytoskeleton in meiotic maturation and fertilization of starfish eggs. Biochem Biophys Res Commun 2009; 384:141-3. [DOI: 10.1016/j.bbrc.2009.04.087] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2009] [Accepted: 04/19/2009] [Indexed: 10/20/2022]
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Abstract
Starfish oocytes undergo massive intracellular Ca2+ signalling during meiotic maturation and fertilization. Although the igniting stimulus of Ca2+ mobilization may differ in different cell contexts, its final leverage is usually the Ca2+-releasing second messengers such as InsP3, cADPr and NAADP. The general scheme of intracellular Ca2+ release is that the corresponding receptors for these molecules serve as ion channels to release free Ca2+ from its internal stores such as the lumen of the endoplasmic reticulum. However, a growing body of evidence has suggested that intracellular Ca2+ release can be strongly modulated by the actin cytoskeleton. Although it is known that Ca2+ contributes to remodelling of the actin cytoskeleton, whether the actin cytoskeleton modulates Ca2+ signalling in return has not been much explored. An emerging candidate to answer to this reciprocal causality of Ca2+ and the actin cytoskeleton may be actin-binding proteins. In this review, we discuss how the actin cytoskeleton may fit into the known mechanisms of intracellular Ca2+ release, and propose two models to explain the experimental data.
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Affiliation(s)
- J T Chun
- Stazione Zoologica Anton Dohrn, Napoli, Italy
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Turzanski J, Daniels I, Haynes AP. Internalisation of uncross-linked rituximab is not essential for the induction of caspase-independent killing in Burkitt lymphoma cell lines. Leuk Lymphoma 2008; 49:1578-91. [PMID: 18766972 DOI: 10.1080/10428190802163313] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Characterising the mechanisms underpinning caspase-independent programmed cell death (CI-PCD) induction by uncross-linked rituximab in B-cells may positively impact upon the treatment of disease states in which the classical apoptotic pathway is disabled. The necessity of rituximab internalisation for CI-PCD induction was investigated by flow cytometry and confocal microscopy in human BL cell lines with (e.g. Mutu I) and without (Mutu III) susceptibility to rituximab-induced killing. Flow cytometry demonstrated small, significant and similar amounts of rituximab internalisation by Mutu I cells after 1, 2, 4 and 24 h (p < 0.03, n = 5) and Mutu III cells after 0.5, 2, 4 and 24 h (p < 0.05, n = 4). Confocal microscopy confirmed this. Cytochalasin B and latrunculin A significantly inhibited rituximab-induced CI-PCD (p < or = 0.04, n = 6 and p = 0.01, n = 6, respectively) and internalisation (p = 0.02, n = 5 and p = 0.0002, n = 6, respectively) in Mutu I cells, but confocal microscopy showed no correlation between internalised rituximab and phosphatidylserine exposure. We conclude that rituximab internalisation is not essential for CI-PCD induction in BL cell lines.
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Affiliation(s)
- Julie Turzanski
- The David Evans Medical Research Centre, Nottingham University Hospitals NHS Trust, City Hospital Campus, Nottingham, UK.
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Puppo A, Chun JT, Gragnaniello G, Garante E, Santella L. Alteration of the cortical actin cytoskeleton deregulates Ca2+ signaling, monospermic fertilization, and sperm entry. PLoS One 2008; 3:e3588. [PMID: 18974786 PMCID: PMC2570615 DOI: 10.1371/journal.pone.0003588] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2008] [Accepted: 10/10/2008] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND When preparing for fertilization, oocytes undergo meiotic maturation during which structural changes occur in the endoplasmic reticulum (ER) that lead to a more efficient calcium response. During meiotic maturation and subsequent fertilization, the actin cytoskeleton also undergoes dramatic restructuring. We have recently observed that rearrangements of the actin cytoskeleton induced by actin-depolymerizing agents, or by actin-binding proteins, strongly modulate intracellular calcium (Ca2+) signals during the maturation process. However, the significance of the dynamic changes in F-actin within the fertilized egg has been largely unclear. METHODOLOGY/PRINCIPAL FINDINGS We have measured changes in intracellular Ca2+ signals and F-actin structures during fertilization. We also report the unexpected observation that the conventional antagonist of the InsP(3) receptor, heparin, hyperpolymerizes the cortical actin cytoskeleton in postmeiotic eggs. Using heparin and other pharmacological agents that either hypo- or hyperpolymerize the cortical actin, we demonstrate that nearly all aspects of the fertilization process are profoundly affected by the dynamic restructuring of the egg cortical actin cytoskeleton. CONCLUSIONS/SIGNIFICANCE Our findings identify important roles for subplasmalemmal actin fibers in the process of sperm-egg interaction and in the subsequent events related to fertilization: the generation of Ca2+ signals, sperm penetration, cortical granule exocytosis, and the block to polyspermy.
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Affiliation(s)
- A. Puppo
- Stazione Zoologica Anton Dohrn, Villa Comunale, Napoli, Italy
| | - Jong T. Chun
- Stazione Zoologica Anton Dohrn, Villa Comunale, Napoli, Italy
| | | | - Ezio Garante
- Stazione Zoologica Anton Dohrn, Villa Comunale, Napoli, Italy
| | - Luigia Santella
- Stazione Zoologica Anton Dohrn, Villa Comunale, Napoli, Italy
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Kyozuka K, Chun JT, Puppo A, Gragnaniello G, Garante E, Santella L. Actin cytoskeleton modulates calcium signaling during maturation of starfish oocytes. Dev Biol 2008; 320:426-35. [DOI: 10.1016/j.ydbio.2008.05.549] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2007] [Revised: 05/23/2008] [Accepted: 05/27/2008] [Indexed: 10/22/2022]
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Abstract
Ferritin is an iron storage protein expressed in varying concentrations in mammalian cells. The deposition of ferric iron in the core of ferritin makes it a magnetic resonance imaging contrast agent, and ferritin has recently been proposed as a gene expression reporter protein for magnetic resonance imaging. To date, ferritin has been overexpressed in vivo and has been coexpressed with transferrin receptor to increase iron loading in cells. However, ferritin has a relatively low T(2) relaxivity (R(2) approximately 1 mM(-1)s(-1)) at typical magnetic field strengths and so requires high levels of expression to be detected. One way to modulate the transverse relaxivity of a superparamagnetic agent is to cause it to aggregate, thereby manipulating the magnetic field gradients through which water diffuses. In this work, it is demonstrated by computer simulation and in vitro that aggregation of ferritin can alter relaxivity. The effects of aggregate size and intraaggregate perturber spacing on R(2) are studied. Computer modeling indicates that the optimal spacing of the ferritin molecules in aggregate for increasing R(2) is 100-200 nm for a typical range of water diffusion rates. Chemical cross-linking of ferritin at 12 A spacing led to a 70% increase in R(2) compared to uncross-linked ferritin controls. To modulate ferritin aggregation in a potentially biologically relevant manner, ferritin was attached to actin and polymerized in vitro. The polymerization of ferritin-F-actin caused a 20% increase in R(2) compared to unpolymerized ferritin-G-actin. The R(2)-value was increased by another 10% by spacing the ferritin farther apart on the actin filaments. The modulation of ferritin aggregation by binding to cytoskeletal elements may be a useful strategy to make a functional reporter gene for magnetic resonance imaging.
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Roux MM, Radeke MJ, Goel M, Mushegian A, Foltz KR. 2DE identification of proteins exhibiting turnover and phosphorylation dynamics during sea urchin egg activation. Dev Biol 2008; 313:630-47. [DOI: 10.1016/j.ydbio.2007.10.053] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2007] [Revised: 10/29/2007] [Accepted: 10/31/2007] [Indexed: 10/22/2022]
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Kitamura C, Takahashi M, Kondoh Y, Tashiro H, Tashiro T. Identification of synaptic activity-dependent genes by exposure of cultured cortical neurons to tetrodotoxin followed by its withdrawal. J Neurosci Res 2007; 85:2385-99. [PMID: 17551986 DOI: 10.1002/jnr.21391] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Activity-dependent gene expression is one of the key mechanisms of synaptic plasticity that form the basis of higher order functions such as learning and memory. In the present study, we surveyed for activity-dependent genes by analyzing gene expression changes accompanying reversible inhibition of synaptic activity by tetrodotoxin (TTX) using two types of DNA microarrays; our focused oligo DNA microarray "Synaptoarray" and the commercially available high-density array. Cerebral cortical cells from E18 rat embryos were cultured for 14 days to ensure synaptogenesis, then treated with 1 muM TTX for 48 hr without detectable effect on cell viability. Synaptic density estimated by the amount of Synapsin I and Synaptotagmin I was decreased 21-24% by TTX treatment, but recovered to the control level 48 hr after TTX withdrawal. Comparison of gene expression profiles by competitive hybridization of fluorescently labeled cRNA from TTX-treated and control cells showed an overall downregulation of the genes on the Synaptoarray by TTX-treatment with different recovery rates after TTX withdrawal. With 16 representative genes, microarray data were validated by real-time PCR analysis. Genes most severely downregulated by TTX and upregulated above the control level at 5 hr after TTX withdrawal were munc13-1 (involved in docking and priming of synaptic vesicles) and Shank2 (involved in the postsynaptic scaffold). In addition, comprehensive screening at 5 hr after TTX withdrawal using high density arrays resulted in additional identification of Rgs2, a regulator of trimeric G-protein signaling, as an activity-dependent gene. These three genes are thus likely to be key factors in the regulation of synaptic plasticity. (c) 2007 Wiley-Liss, Inc.
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Affiliation(s)
- Chikara Kitamura
- Department of Chemistry and Biological Science, School of Science and Engineering, Aoyama-Gakuin University, Sagamihara, Kanagawa, Japan
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40
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Boni R, Gualtieri R, Talevi R, Tosti E. Calcium and other ion dynamics during gamete maturation and fertilization. Theriogenology 2007; 68 Suppl 1:S156-64. [PMID: 17572483 DOI: 10.1016/j.theriogenology.2007.05.048] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Ion currents and cytosolic free calcium ([Ca(2+)](i)) elevations are crucial events in triggering the complex machinery involved in both gamete maturation and fertilization. Oocyte maturation is triggered by hormone signaling which causes ion currents and [Ca(2+)](i) increase. Extracellular calcium seems to be required for meiosis progression since: (i) calcium depletion in the maturation medium severely affects oocyte developmental competence; (ii) the activity of plasma membrane L-type Ca(2+) currents decreases during maturation; (iii) the exposure to verapamil, a specific Ca(2+) channel blocker, decreases in vitro maturation efficiency. In spermatozoa, maturation initiates inside the epididymis and ends in the female genital tract. During their journey through the female reproductive tract, sperm undergo a dramatic selection and capacitation achieving fertilization competence. Adhesion to the tubal epithelium extends sperm life through depression of [Ca(2+)](i) until capacitation signals trigger an [Ca(2+)](i) elevation followed by sperm release. At fertilization, egg-sperm interaction evokes well-described transient and almost simultaneous events: i.e., fertilization current, a change in resting potential, and an increase in free [Ca(2+)](i) concentration. These events, termed oocyte activation, are the direct consequence of sperm interaction via either activation of a receptor or entry of a sperm factor. The latter hypothesis has been recently supported by the discovery of PCLzeta, a sperm-specific isozyme triggering a dramatic [Ca(2+)](i) increase via inositol 1,4,5-trisphosphate (IP(3)) production. The course of ion currents and [Ca(2+)](i) transients during maturation and fertilization plays a pivotal role in correct embryo development.
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Affiliation(s)
- Raffaele Boni
- Dip Scienze delle Produzioni Animali, Università della, Basilicata, 85100 Potenza, Italy.
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Campbell JJ, Blain EJ, Chowdhury TT, Knight MM. Loading alters actin dynamics and up-regulates cofilin gene expression in chondrocytes. Biochem Biophys Res Commun 2007; 361:329-34. [PMID: 17662250 DOI: 10.1016/j.bbrc.2007.06.185] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2007] [Accepted: 06/28/2007] [Indexed: 11/25/2022]
Abstract
Chondrocyte mechanotransduction in response to mechanical loading is essential for the health and homeostasis of articular cartilage. The actin cytoskeleton has been implicated in cell mechanics and mechanotransduction. This study tests the hypothesis that loading modulates actin dynamics and organisation with subsequent changes in gene expression for actin associated proteins. Chondrocytes were transfected with eGFP-actin, seeded in agarose and subjected to cyclic compression (10 cycles, 1 Hz, 0-15% strain) on the stage of a confocal microscope. Compression resulted in a subsequent reduction in cortical eGFP-actin intensity and a reduction in fluorescence recovery after photobleaching (FRAP), suggesting net cortical actin de-polymerisation, compared to unloaded controls. Cyclic compression for 10 min up-regulated gene expression for the actin depolymerising proteins, cofilin and destrin. Thus mechanical loading alters cortical actin dynamics, providing a potential mechanism through which chondrocytes can adapt their mechanical properties and mechanosensitivity to the local mechanical environment.
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Affiliation(s)
- J J Campbell
- Medical Engineering Division, School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London E1 4NS, UK
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Calcium and fertilization. ACTA ACUST UNITED AC 2007. [DOI: 10.1016/s0167-7306(06)41016-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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