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Cohen R, Mukai C, Nelson JL, Zenilman SS, Sosnicki DM, Travis AJ. A genetically targeted sensor reveals spatial and temporal dynamics of acrosomal calcium and sperm acrosome exocytosis. J Biol Chem 2022; 298:101868. [PMID: 35346690 PMCID: PMC9046242 DOI: 10.1016/j.jbc.2022.101868] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 03/19/2022] [Accepted: 03/23/2022] [Indexed: 01/16/2023] Open
Abstract
Secretion of the acrosome, a single vesicle located rostrally in the head of a mammalian sperm, through a process known as "acrosome exocytosis" (AE), is essential for fertilization. However, the mechanisms leading to and regulating this complex process are controversial. In particular, poor understanding of Ca2+ dynamics between sperm subcellular compartments and regulation of membrane fusion mechanisms have led to competing models of AE. Here, we developed a transgenic mouse expressing an Acrosome-targeted Sensor for Exocytosis (AcroSensE) to investigate the spatial and temporal Ca2+ dynamics in AE in live sperm. AcroSensE combines a genetically encoded Ca2+ indicator (GCaMP) fused with an mCherry indicator to spatiotemporally resolve acrosomal Ca2+ rise (ACR) and membrane fusion events, enabling real-time study of AE. We found that ACR is dependent on extracellular Ca2+ and that ACR precedes AE. In addition, we show that there are intermediate steps in ACR and that AE correlates better with the ACR rate rather than absolute Ca2+ amount. Finally, we demonstrate that ACR and membrane fusion progression kinetics and spatial patterns differ with different stimuli and that sites of initiation of ACR and sites of membrane fusion do not always correspond. These findings support a model involving functionally redundant pathways that enable a highly regulated, multistep AE in heterogeneous sperm populations, unlike the previously proposed "acrosome reaction" model.
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Affiliation(s)
- Roy Cohen
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA.
| | - Chinatsu Mukai
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Jacquelyn L Nelson
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Shoshana S Zenilman
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Danielle M Sosnicki
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Alexander J Travis
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA; Department of Public and Ecosystem Health, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
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2
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Bernabò N, Machado-Simoes J, Valbonetti L, Ramal-Sanchez M, Capacchietti G, Fontana A, Zappacosta R, Palestini P, Botto L, Marchisio M, Lanuti P, Ciulla M, Di Stefano A, Fioroni E, Spina M, Barboni B. Graphene Oxide increases mammalian spermatozoa fertilizing ability by extracting cholesterol from their membranes and promoting capacitation. Sci Rep 2019; 9:8155. [PMID: 31148593 PMCID: PMC6544623 DOI: 10.1038/s41598-019-44702-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 05/14/2019] [Indexed: 11/09/2022] Open
Abstract
Graphene Oxide (GO) is a widely used biomaterial with an amazing variety of applications in biology and medicine. Recently, we reported the ability of GO to improve the in vitro fertilization (IVF) outcomes in swine, a validated animal model with a high predictive value for human fertility. For that reason, here we characterized the mechanisms involved in this positive interaction by adopting an experimental approach combining biological methods (confocal microscopy analysis on single cell, flow cytometry on cell populations and co-incubation with epithelial oviductal cells), physical-chemical techniques (Differential Scanning Calorimetry and Thermogravimetric Analysis), and chemical methods (mass spectrometry and lipid measurement). As a result, we propose a model in which GO is able to extract cholesterol from the spermatozoa membrane without causing any detrimental effect. In this way, the cholesterol extraction promotes a change in membrane chemical-physical properties that could positively affect male gamete function, modulating sperm signalling function and increasing in this way the fertilizing potential, without losing the ability to physiologically interact with the female environment. In conclusion, these data seem to suggest new intriguing possibilities in engineering sperm membrane for improving assisted reproduction technologies outcomes, even in human medicine.
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Affiliation(s)
- Nicola Bernabò
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Via Renato Balzarini 1, 64100, Teramo, Italy.
| | - Juliana Machado-Simoes
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Via Renato Balzarini 1, 64100, Teramo, Italy
| | - Luca Valbonetti
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Via Renato Balzarini 1, 64100, Teramo, Italy
| | - Marina Ramal-Sanchez
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Via Renato Balzarini 1, 64100, Teramo, Italy
| | - Giulia Capacchietti
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Via Renato Balzarini 1, 64100, Teramo, Italy
| | - Antonella Fontana
- Department of Pharmacy, University "G. d'Annunzio", Via dei Vestini, 66100, Chieti, Italy
| | - Romina Zappacosta
- Department of Pharmacy, University "G. d'Annunzio", Via dei Vestini, 66100, Chieti, Italy
| | - Paola Palestini
- School of Medicine and Surgery, University of Milano Bicocca, 20900, Monza, Italy
| | - Laura Botto
- School of Medicine and Surgery, University of Milano Bicocca, 20900, Monza, Italy
| | - Marco Marchisio
- Department of Medicine and Aging Sciences, University "G. d'Annunzio" Chieti-Pescara, 66100, Chieti, Italy.,Center on Aging Sciences and Translational Medicine (CeSI-MeT), University "G. d'Annunzio" Chieti-Pescara, 66100, Chieti, Italy
| | - Paola Lanuti
- Department of Medicine and Aging Sciences, University "G. d'Annunzio" Chieti-Pescara, 66100, Chieti, Italy.,Center on Aging Sciences and Translational Medicine (CeSI-MeT), University "G. d'Annunzio" Chieti-Pescara, 66100, Chieti, Italy
| | - Michele Ciulla
- Department of Pharmacy, University "G. d'Annunzio", Via dei Vestini, 66100, Chieti, Italy
| | - Antonio Di Stefano
- Department of Pharmacy, University "G. d'Annunzio", Via dei Vestini, 66100, Chieti, Italy
| | - Elena Fioroni
- Laboratorio Analisi Dr. Fioroni, Viale A. de Gasperi, 19, 63074, San Benedetto del Tronto, Italy
| | - Michele Spina
- Laboratorio Analisi Dr. Fioroni, Viale A. de Gasperi, 19, 63074, San Benedetto del Tronto, Italy
| | - Barbara Barboni
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Via Renato Balzarini 1, 64100, Teramo, Italy
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Castellanos P, Maroto-Morales A, García-Álvarez O, Garde JJ, Mateo R. AnIn VitroEvaluation of Biochemical Processes Involved in Lead-Induced Changes on Ram Spermatozoa. Reprod Domest Anim 2016; 51:421-7. [DOI: 10.1111/rda.12696] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 03/29/2016] [Indexed: 01/18/2023]
Affiliation(s)
- P Castellanos
- Instituto de Investigación en Recursos Cinegéticos (IREC) UCLM-CSIC-JCCM; Wildlife Toxicology Group; Ciudad Real Spain
| | - A Maroto-Morales
- SaBio; Instituto de Investigación en Recursos Cinegéticos (IREC) UCLM-CSIC-JCCM; Albacete Spain
| | - O García-Álvarez
- SaBio; Instituto de Investigación en Recursos Cinegéticos (IREC) UCLM-CSIC-JCCM; Albacete Spain
| | - JJ Garde
- SaBio; Instituto de Investigación en Recursos Cinegéticos (IREC) UCLM-CSIC-JCCM; Albacete Spain
| | - R Mateo
- Instituto de Investigación en Recursos Cinegéticos (IREC) UCLM-CSIC-JCCM; Wildlife Toxicology Group; Ciudad Real Spain
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Oldenhof H, Heutelbeck A, Blässe AK, Bollwein H, Martinsson G, Wolkers WF, Sieme H. Tolerance of spermatozoa to hypotonic stress: role of membrane fluidity and correlation with cryosurvival. Reprod Fertil Dev 2015; 27:285-93. [DOI: 10.1071/rd13177] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Accepted: 10/03/2013] [Indexed: 01/30/2023] Open
Abstract
The aim of this study was to evaluate inter-individual variability in osmotic properties of stallion spermatozoa and its correlation with cryosurvival. In addition, temperature dependency of hypo-osmotic tolerance and membrane fluidity were studied. Stallion sperm membranes exhibited good resistance towards hypotonic stress in the 15–30°C temperature range, whereas membrane stability was found to be decreased at 4 and 37°C. Bull spermatozoa showed greater hypo-osmotic tolerance compared with stallion spermatozoa, especially at temperatures above 30°C, which coincided with decreased membrane fluidity of bovine spermatozoa in this temperature range. The critical osmolality at 22°C, at which half of the sperm population survived exposure to hypotonic saline solution, was found to vary between 55 and 170 mOsm kg–1 among different stallions. Clear correlations were found for pre- versus post-freeze sperm motility and membrane integrity. Pre-freeze percentages of membrane-intact spermatozoa after exposure to hypotonic stress showed a weak correlation with sperm motility after cryopreservation. This correlation, however, was not found when data were corrected for initial numbers of membrane-intact spermatozoa in the sample. We thus conclude that studies on pre-freeze tolerance towards hypotonic stress cannot be used to predict sperm cryosurvival rates for individual stallions.
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Cohen R, Buttke DE, Asano A, Mukai C, Nelson JL, Ren D, Miller RJ, Cohen-Kutner M, Atlas D, Travis AJ. Lipid modulation of calcium flux through CaV2.3 regulates acrosome exocytosis and fertilization. Dev Cell 2014; 28:310-21. [PMID: 24525187 DOI: 10.1016/j.devcel.2014.01.005] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Revised: 10/23/2013] [Accepted: 01/10/2014] [Indexed: 12/14/2022]
Abstract
Membrane lipid regulation of cell function is poorly understood. In early development, sterol efflux and the ganglioside GM1 regulate sperm acrosome exocytosis (AE) and fertilization competence through unknown mechanisms. Here, we show that sterol efflux and focal enrichment of GM1 trigger Ca(2+) influx necessary for AE through CaV2.3, whose activity has been highly controversial in sperm. Sperm lacking CaV2.3's pore-forming α1E subunit showed altered Ca(2+) responses, reduced AE, and a strong subfertility phenotype. Surprisingly, AE depended on spatiotemporal information encoded by flux through CaV2.3, not merely the presence/amplitude of Ca(2+) waves. Using studies in both sperm and voltage clamp of Xenopus oocytes, we define a molecular mechanism for GM1/CaV2.3 regulatory interaction, requiring GM1's lipid and sugar components and CaV2.3's α1E and α2δ subunits. Our results provide a mechanistic understanding of membrane lipid regulation of Ca(2+) flux and therefore Ca(2+)-dependent cellular and developmental processes such as exocytosis and fertilization.
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Affiliation(s)
- Roy Cohen
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Hungerford Hill Road, Ithaca, NY 14853, USA
| | - Danielle E Buttke
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Hungerford Hill Road, Ithaca, NY 14853, USA
| | - Atsushi Asano
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Hungerford Hill Road, Ithaca, NY 14853, USA
| | - Chinatsu Mukai
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Hungerford Hill Road, Ithaca, NY 14853, USA
| | - Jacquelyn L Nelson
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Hungerford Hill Road, Ithaca, NY 14853, USA
| | - Dongjun Ren
- Department of Biochemistry and Molecular Pharmacology, Northwestern University Medical School, 303 E. Chicago Avenue, Chicago, IL 60611, USA
| | - Richard J Miller
- Department of Biochemistry and Molecular Pharmacology, Northwestern University Medical School, 303 E. Chicago Avenue, Chicago, IL 60611, USA
| | - Moshe Cohen-Kutner
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Daphne Atlas
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Alexander J Travis
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Hungerford Hill Road, Ithaca, NY 14853, USA.
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Truong-Quang BA, Lenne PF. Membrane microdomains: from seeing to understanding. FRONTIERS IN PLANT SCIENCE 2014; 5:18. [PMID: 24600455 PMCID: PMC3927121 DOI: 10.3389/fpls.2014.00018] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 01/15/2014] [Indexed: 05/08/2023]
Abstract
The plasma membrane is a composite material, which forms a semi-permeable barrier and an interface for communication between the intracellular and extracellular environments. While the existence of membrane microdomains with nanoscale organization has been proved by the application of numerous biochemical and physical methods, direct observation of these heterogeneities using optical microscopy has remained challenging for decades, partly due to the optical diffraction limit, which restricts the resolution to ~200 nm. During the past years, new optical methods which circumvent this fundamental limit have emerged. Not only do these techniques allow direct visualization, but also quantitative characterization of nanoscopic structures. We discuss how these emerging optical methods have refined our knowledge of membrane microdomains and how they may shed light on the basic principles of the mesoscopic membrane organization.
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Affiliation(s)
| | - Pierre-François Lenne
- *Correspondence: Pierre-François Lenne, Developmental Biology Institute of Marseilles, UMR 7288 CNRS, Aix-Marseille Université, 13288 Marseille Cedex 9, France e-mail:
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Vecer J, Vesela P, Malinsky J, Herman P. Sphingolipid levels crucially modulate lateral microdomain organization of plasma membrane in living yeast. FEBS Lett 2013; 588:443-9. [DOI: 10.1016/j.febslet.2013.11.038] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Accepted: 11/29/2013] [Indexed: 01/26/2023]
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Jones S, Lukanowska M, Suhorutsenko J, Oxenham S, Barratt C, Publicover S, Copolovici DM, Langel Ü, Howl J. Intracellular translocation and differential accumulation of cell-penetrating peptides in bovine spermatozoa: evaluation of efficient delivery vectors that do not compromise human sperm motility. Hum Reprod 2013; 28:1874-89. [PMID: 23585561 DOI: 10.1093/humrep/det064] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
STUDY QUESTION Do cell penetrating peptides (CPPs) translocate into spermatozoa and, if so, could they be utilized to deliver a much larger protein cargo? SUMMARY ANSWER Chemically diverse polycationic CPPs rapidly and efficiently translocate into spermatozoa. They exhibit differential accumulation within intracellular compartments without detrimental influences upon cellular viability or motility but they are relatively ineffective in transporting larger proteins. WHAT IS ALREADY KNOWN Endocytosis, the prevalent route of protein internalization into eukaryotic cells, is severely compromised in mature spermatozoa. Thus, the translocation of many bioactive agents into sperm is relatively inefficient. However, the delivery of bioactive moieties into mature spermatozoa could be significantly improved by the identification and utility of an efficient and inert vectorial delivery technology. STUDY DESIGN CPP translocation efficacies, their subsequent differential intracellular distribution and the influence of peptides upon viability were determined in bovine spermatozoa. Temporal analyses of sperm motility in the presence of exogenously CPPs utilized normozoospermic human donor samples. MATERIALS AND METHODS CPPs were prepared by manual, automated and microwave-enhanced solid phase synthesis. Confocal fluorescence microscopy determined the intracellular distribution of rhodamine-conjugated CPPs in spermatozoa. Quantitative uptake and kinetic analyses compared the translocation efficacies of chemically diverse CPPs and conjugates of biotinylated CPPs and avidin. 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS) conversion assays were employed to analyse the influence of CPPs upon sperm cell viability and sperm class assays determined the impact of CPPs on motility in capacitated and non-capacitated human samples. MAIN RESULTS Chemically heterogeneous CPPs readily translocated into sperm to accumulate within discrete intracellular compartments. Mitoparan (INLKKLAKL(Aib)KKIL), for example, specifically accumulated within the mitochondria located in the sperm midpiece. The unique plasma membrane composition of sperm is a critical factor that directly influences the uptake efficacy of structurally diverse CPPs. No correlations in efficacies were observed when comparing CPP uptake into sperm with either uptake into fibroblasts or direct translocation across a phosphatidylcholine membrane. These comparative investigations identified C105Y (CSIPPEVKFNKPFVYLI) as a most efficient pharmacokinetic modifier for general applications in sperm biology. Significantly, CPP uptake induced no detrimental influence upon either bovine sperm viability or the motility of human sperm. As a consequence of the lack of endocytotic machinery, the CPP-mediated delivery of much larger protein complexes into sperm is relatively inefficient when compared with the similar process in fibroblasts. LIMITATIONS, REASONS FOR CAUTION It is possible that some CPPs could directly influence aspects of sperm biology and physiology that were not analysed in this study. WIDER IMPLICATIONS OF THE FINDINGS CPP technologies have significant potential to deliver selected bioactive moieties and so could modulate the biology and physiology of human sperm biology both prior- and post-fertilization.
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Affiliation(s)
- Sarah Jones
- Molecular Pharmacology Research Group, Research Institute in Healthcare Science, University of Wolverhampton, Wolverhampton WV1 1LY, UK
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Selvaraj V, Asano A, Buttke DE, Sengupta P, Weiss RS, Travis AJ. Mechanisms underlying the micron-scale segregation of sterols and GM1 in live mammalian sperm. J Cell Physiol 2009; 218:522-36. [PMID: 19012288 DOI: 10.1002/jcp.21624] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
We demonstrate for the first time that a stable, micron-scale segregation of focal enrichments of sterols exists at physiological temperature in the plasma membrane of live murine and human sperm. These enrichments of sterols represent microheterogeneities within this membrane domain overlying the acrosome. Previously, we showed that cholera toxin subunit B (CTB), which binds the glycosphingolipid, G(M1), localizes to this same domain in live sperm. Interestingly, the G(M1) undergoes an unexplained redistribution upon cell death. We now demonstrate that G(M1) is also enriched in the acrosome, an exocytotic vesicle. Transfer of lipids between this and the plasma membrane occurs at cell death, increasing G(M1) in the plasma membrane without apparent release of acrosomal contents. This finding provides corroborative support for an emerging model of regulated exocytosis in which membrane communications might occur without triggering the "acrosome reaction." Comparison of the dynamics of CTB-bound endogenous G(M1) and exogenous BODIPY-G(M1) in live murine sperm demonstrate that the sub-acrosomal ring (SAR) functions as a specialized diffusion barrier segregating specific lipids within the sperm head plasma membrane. Our data show significant differences between endogenous lipids and exogenous lipid probes in terms of lateral diffusion. Based on these studies, we propose a hierarchical model to explain the segregation of this sterol- and G(M1)-enriched domain in live sperm, which is positioned to regulate sperm fertilization competence and mediate interactions with the oocyte. Moreover, our data suggest potential origins of subtypes of membrane raft microdomains enriched in sterols and/or G(M1) that can be separated biochemically.
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Affiliation(s)
- Vimal Selvaraj
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA
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10
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Companyó M, Iborra A, Villaverde J, Martínez P, Morros A. Membrane fluidity changes in goat sperm induced by cholesterol depletion using beta-cyclodextrin. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2007; 1768:2246-55. [PMID: 17669356 DOI: 10.1016/j.bbamem.2007.06.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2007] [Revised: 06/12/2007] [Accepted: 06/12/2007] [Indexed: 11/24/2022]
Abstract
Cholesterol efflux from membranes promotes acrosome reaction in goat spermatozoa. In 1 h of incubation of sperm in the presence of beta-cyclodextrin (beta CD), all the interchangeable cholesterol is desorbed from sperm membranes, although acrosome reaction is fully accomplished only after 3-4 h of incubation, as previously published. In the present paper we investigate the effect of cholesterol removal from mature goat spermatozoa on the overall membrane "fluidity" of live cell membranes and of liposomes from sperm lipid extracts. Using steady state fluorescence anisotropy of 1,6-diphenyl-1,3,5-hexatriene (DPH), we studied the average thermotropic behaviour of membrane lipids, after incubation of live sperm for 1 h in BSA-free medium with the presence/absence of 8 mM beta-cyclodextrin, as a cholesterol acceptor. Unimodal and bimodal theoretical sigmoids fitted best to the experimental thermotropic profiles of liposomes and whole cells, respectively. In the case of whole sperm, two phase transitions, attributable to different lipid domains, were clearly separated by using the fitting parameters. After cholesterol removal, important changes in the relative anisotropy range of the two transitions were found, indicating an increase in the "fluidity" of some of the lipid microdomains of sperm membranes. These changes in sperm lipid dynamics are produced before the onset of sperm acrosome reaction.
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Affiliation(s)
- Mònica Companyó
- Unitat de Biofísica, Departament de Bioquímica i de Biologia Molecular, Facultat de Medicina, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
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Liu J, Xia J, Cho KH, Clapham DE, Ren D. CatSperbeta, a novel transmembrane protein in the CatSper channel complex. J Biol Chem 2007; 282:18945-52. [PMID: 17478420 DOI: 10.1074/jbc.m701083200] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Four CatSper ion channel subunit genes (CatSpers 1-4) are required for sperm cell hyperactivation and male fertility. The four proteins assemble (presumably as a tetramer) to form a sperm-specific, alkalinization-activated Ca(2+)-selective channel. We set out to identify proteins associating with CatSper that might help explain its unique role in spermatozoa. Using a transgenic approach, a CatSper1 complex was purified from mouse testis that contained heat shock protein 70-2, a testis-specific chaperone, and CatSperbeta, a novel protein with two putative transmembrane-spanning domains. Like the CatSper ion channel subunits, CatSperbeta was restricted to testis and localized to the principal piece of the sperm tail. CatSperbeta protein is absent in CatSper1(-/-) sperm, suggesting that it is required for trafficking or formation of a stable channel complex. CatSperbeta is the first identified auxiliary protein to the CatSper channel.
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Affiliation(s)
- Jin Liu
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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Weerachatyanukul W, Probodh I, Kongmanas K, Tanphaichitr N, Johnston LJ. Visualizing the localization of sulfoglycolipids in lipid raft domains in model membranes and sperm membrane extracts. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2007; 1768:299-310. [PMID: 17045957 DOI: 10.1016/j.bbamem.2006.08.022] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2006] [Revised: 08/17/2006] [Accepted: 08/28/2006] [Indexed: 01/18/2023]
Abstract
Sulfogalactosylglycerolipid (SGG) is found in detergent-resistant lipid raft fractions isolated from sperm plasma membranes and has been shown to be important in sperm-egg adhesion. In order to provide more direct evidence for the association of sulfoglycolipids with lipid raft domains, we have examined the distribution of two sulfoglycolipids in supported membranes prepared from artificial lipid mixtures and cellular lipid extracts. Atomic force microscopy has been used to visualize the localization of SGG and sulfogalactosylceramide (SGC) in liquid-ordered domains in supported bilayers of ternary lipid mixtures comprised of dipalmitoylphosphatidylcholine, cholesterol and palmitoyldocosahexaenoylphosphatidylcholine. The localization of SGC/SGG in the liquid-ordered raft domains is demonstrated by changes in bilayer morphology in the presence of sulfoglycolipid, by selective antibody labeling of the domains with anti-SGC/SGG and by the effects of the cholesterol-sequestering agent, methyl-beta-cyclodextrin, on the supported membranes. In addition, we use a combination of atomic force microscopy and immunofluorescence to show that supported bilayers made from lipids extracted from sperm anterior head plasma membranes (APM) and isolated APM vesicles exhibit small SGG-rich domains that are similar to those observed in bilayers of artificial lipid mixtures. The possible implications of these results for the involvement of SGG-rich lipid rafts in modulating sperm-egg interactions in vivo and the utility of model membranes for studying the behavior of lipid rafts are discussed.
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Affiliation(s)
- Wattana Weerachatyanukul
- Steacie Institute for Molecular Sciences, National Research Council Canada,100 Sussex Drive, Ottawa, ON Canada K1A 0R6
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Selvaraj V, Asano A, Buttke DE, McElwee JL, Nelson JL, Wolff CA, Merdiushev T, Fornés MW, Cohen AW, Lisanti MP, Rothblat GH, Kopf GS, Travis AJ. Segregation of micron-scale membrane sub-domains in live murine sperm. J Cell Physiol 2006; 206:636-46. [PMID: 16222699 DOI: 10.1002/jcp.20504] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Lipid rafts, membrane sub-domains enriched in sterols and sphingolipids, are controversial because demonstrations of rafts have often utilized fixed cells. We showed in living sperm that the ganglioside G(M1) localized to a micron-scale membrane sub-domain in the plasma membrane overlying the acrosome. We investigated four models proposed for membrane sub-domain maintenance. G(M1) segregation was maintained in live sperm incubated under non-capacitating conditions, and after sterol efflux, a membrane alteration necessary for capacitation. The complete lack of G(M1) diffusion to the post-acrosomal plasma membrane (PAPM) in live cells argued against the transient confinement zone model. However, within seconds after cessation of sperm motility, G(M1) dramatically redistributed several microns from the acrosomal sub-domain to the post-acrosomal, non-raft sub-domain. This redistribution was not accompanied by movement of sterols, and was induced by the pentameric cholera toxin subunit B (CTB). These data argued against a lipid-lipid interaction model for sub-domain maintenance. Although impossible to rule out a lipid shell model definitively, mice lacking caveolin-1 maintained segregation of both sterols and G(M1), arguing against a role for lipid shells surrounding caveolin-1 in sub-domain maintenance. Scanning electron microscopy of sperm freeze-dried without fixation identified cytoskeletal structures at the sub-domain boundary. Although drugs used to disrupt actin and intermediate filaments had no effect on the segregation of G(M1), we found that disulfide-bonded proteins played a significant role in sub-domain segregation. Together, these data provide an example of membrane sub-domains extreme in terms of size and stability of lipid segregation, and implicate a protein-based membrane compartmentation mechanism.
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Affiliation(s)
- Vimal Selvaraj
- The James A. Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA
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Masserini M, Pitto M, Raimondo F, Cazzaniga E, Sesana S, Bellini T. Methyl-beta-cyclodextrin treatment affects the thermotropic behaviour of membranes and detergent-resistant membrane fractions of cultured A431 cells. Biol Pharm Bull 2005; 28:2185-8. [PMID: 16327146 DOI: 10.1248/bpb.28.2185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Membranes and detergent-resistant membrane fractions isolated from human epidermoid carcinoma A431 cells after treatment with methyl-beta-cyclodextrin, a compound commonly used in pharmaceutical applications and in manipulation of membrane cholesterol content, display thermotropic transitions at about 15 degrees C and above 37 degrees C, respectively, when analyzed by differential scanning calorimetry. The transitions, absent in untreated cells, were reversible upon cycling through heating and cooling scans, and attributable to lipid components of the membranes, possibly sphingolipids. These results suggest that, after treatment with methyl-beta-cyclodextrin, membranes may show thermotropic transitions, an unusual feature for cellular bilayers, which is likely to influence biological functions.
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Affiliation(s)
- Massimo Masserini
- Department of Experimental, Environmental Medicine and Biotechnology, University of Milano-Bicocca, via Cadore 48, 20052 Monza, Italy.
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15
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Tran R, Ho S, Dea P. Effects of ethanol on lipid bilayers with and without cholesterol: the distearoylphosphatidylcholine system. Biophys Chem 2004; 110:39-47. [PMID: 15223142 DOI: 10.1016/j.bpc.2004.01.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2003] [Revised: 01/06/2004] [Accepted: 01/06/2004] [Indexed: 11/25/2022]
Abstract
Differential scanning calorimetry (DSC) and fluorescence spectroscopy are useful techniques for investigating the phase transitions of phospholipid bilayers. In this study, these methods have been extended to determine the effects of ethanol on DSPC and DSPC/2 mol.% cholesterol bilayers. The biphasic effect of the main transition was observed on the DSC heating scans above 0.60 M ethanol. In addition, the concentration at which the biphasic effect occurs is not significantly changed in the presence of 2 mol.% cholesterol. For the fluorescence studies, 1,6-diphenyl-1,3,5-hexatriene (DPH) has been incorporated into the bilayer to monitor the phase transitions through the displacement of DPH. This fluorescent probe is used to directly determine the onset of interdigitation in the bilayer systems as indicated by a large decrease in the DPH fluorescence intensity. The addition of cholesterol lowered and broadened the transition temperatures of the phosphatidylcholine (PC) system. However, 2 mol.% cholesterol did not have a significant effect on the induction of the interdigitated phase in DSPC as observed from the small difference in ethanol threshold concentration for the two systems. This suggests that DSPC forms a more stable interdigitated gel phase than other PCs with shorter acyl chains.
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Affiliation(s)
- Rosalie Tran
- Department of Chemistry, Occidental College, 1600 Campus Road, Los Angeles, CA 90041, USA
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16
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Cowan AE, Koppel DE, Vargas LA, Hunnicutt GR. Guinea pig fertilin exhibits restricted lateral mobility in epididymal sperm and becomes freely diffusing during capacitation. Dev Biol 2001; 236:502-9. [PMID: 11476588 DOI: 10.1006/dbio.2001.0343] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The guinea pig sperm protein fertilin functions in sperm-egg plasma membrane binding. Fertilin is initially present in the plasma membrane of the whole head in testicular sperm, then becomes concentrated into the posterior head domain during epididymal passage. Fertilin remains localized to the posterior head plasma membrane following the acrosome reaction, when it functions in sperm-egg interaction. Fluorescence redistribution after photobleaching was used to examine the lateral mobility of fertilin in both acrosome-intact and acrosome-reacted sperm. Fertilin exhibited highly restricted lateral mobility in both testicular and epididymal sperm (D < 10(-10) cm(2)/s). However, fertilin in acrosome-reacted sperm was highly mobile within the membrane bilayer (D = 1.8 x 10(-9) cm(2)/s and %R = 84). Measurement of the lateral mobility of fertilin in capacitated, acrosome-intact sperm revealed two populations of cells. In approximately one-half of the cells, lateral mobility of fertilin was similar to sperm freshly isolated from the cauda epididymis; while in the other half fertilin was highly mobile. The release of fertilin from interactions that restrict its lateral mobility may regulate its function in sperm-egg interaction.
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Affiliation(s)
- A E Cowan
- Department of Biochemistry, University of Connecticut Health Center, Farmington, Connecticut 06030, USA.
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17
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Attar M, Kates M, Bou Khalil M, Carrier D, Wong PT, Tanphaichitr N. A Fourier-transform infrared study of the interaction between germ-cell specific sulfogalactosylglycerolipid and dimyristoylglycerophosphocholine. Chem Phys Lipids 2000; 106:101-14. [PMID: 10930563 DOI: 10.1016/s0009-3084(00)00147-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In this study, we investigated structural and dynamic changes of sulfogalactosylglycerolipid (SGG) and dimyristoylglycerophosphocholine (DMPC) in a liposomal system (SGG+DMPC, molar ratio 2:3) by Fourier-transform infrared (FTIR) spectroscopy. Cooling of the preheated SGG liposomes (5-65 degrees C) revealed that the liquid crystalline-to-gel phase transition was centered at 45 degrees C. SGG+DMPC liposomes showed a single phase transition at 28 degrees C. Spectral changes of the ester C&z. dbnd6;O groups of SGG and DMPC in the mixed liposomes indicated a decrease in their interfacial hydrogen bonding intermolecularly and with water. Analysis of SGG's symmetric and antisymmetric CH(2) stretching bands revealed that the insertion of DMPC into SGG bilayers increased the number of gauche conformers in SGG's hydrocarbon chains. Overall, the SGG+DMPC liposomes were homogeneous, with reduced interfacial hydrogen bonding and increased orientational and conformational disorder of SGG's hydrocarbon chains.
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Affiliation(s)
- M Attar
- Hormones/Growth/Development Research Group, Loeb Health Research Institute, 725 Parkdale Avenue, K1Y 4E9, Ottawa, Ont., Canada
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18
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Loura LMS, Fedorov A, Prieto M. Membrane Probe Distribution Heterogeneity: A Resonance Energy Transfer Study. J Phys Chem B 2000. [DOI: 10.1021/jp000246q] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Luís M. S. Loura
- Centro de Química-Física Molecular, Instituto Superior Técnico, P-1049-001 Lisboa, Portugal, and Departamento de Química, Universidade de Évora, Rua Romão Ramalho, 59, P-7000−671 Évora, Portugal
| | - Aleksandre Fedorov
- Centro de Química-Física Molecular, Instituto Superior Técnico, P-1049-001 Lisboa, Portugal, and Departamento de Química, Universidade de Évora, Rua Romão Ramalho, 59, P-7000−671 Évora, Portugal
| | - Manuel Prieto
- Centro de Química-Física Molecular, Instituto Superior Técnico, P-1049-001 Lisboa, Portugal, and Departamento de Química, Universidade de Évora, Rua Romão Ramalho, 59, P-7000−671 Évora, Portugal
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19
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Dumaual AC, Jenski LJ, Stillwell W. Liquid crystalline/gel state phase separation in docosahexaenoic acid-containing bilayers and monolayers. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1463:395-406. [PMID: 10675516 DOI: 10.1016/s0005-2736(99)00235-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The phase behavior of lipid mixtures containing 1-stearoyl-2-docosahexaenoyl-sn-glycero-3-phosphocholine (18:0, 22:6 PC) with 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) was studied with bilayers using differential scanning calorimetry (DSC), and with monolayers monitoring pressure/area isotherms and surface elasticity, and lipid domain formation followed by epifluorescence microscopy. From DSC studies it is concluded that DPPC/18:0, 22:6 PC phase separates into DPPC-rich and 18:0, 22:6 PC-rich phases. In monolayers, phase separation is indicated by changes in pressure-area isotherms implying phase separation where 18:0, 22:6 PC is 'squeezed out' of the remaining DPPC monolayer. Phase separation into lipid domains in the mixed PC monolayer is quantified by epifluorescence microscopy using the fluorescently labeled phospholipid membrane probe, 1, 2-dioleoyl-sn-glycero-3-phosphoethanolamine-N-(lissamine rhodamine B sulfonyl). These results further describe the ability of docosahexaenoic acid to participate in lipid phase separations in membranes.
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Affiliation(s)
- A C Dumaual
- Department of Biology, Indiana University-Purdue University at Indianapolis, 723 W. Michigan Street, Indianapolis, IN 46202-5132, USA
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20
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Stillwell W, Jenski LJ, Zerouga M, Dumaual AC. Detection of lipid domains in docasahexaenoic acid-rich bilayers by acyl chain-specific FRET probes. Chem Phys Lipids 2000; 104:113-32. [PMID: 10669305 DOI: 10.1016/s0009-3084(99)00122-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
A major problem in defining biological membrane structure is deducing the nature and even existence of lipid microdomains. Lipid microdomains have been defined operationally as heterogeneities in the behavior of fluorescent membrane probes, particularly the fluorescence resonance energy transfer (FRET) probes 7-nitrobenz-2-oxa-1,3-diazol-4-yl-diacyl-sn-glycero-3-phosphoethan olamine (N-NBD-PE) and (N-lissamine rhodamine B sulfonyl)-diacyl-snglycero-3-phosphoethanolamine (N-Rh-PE). Here we test a variety of N-NBD-PEs and N-Rh-PEs containing: (a) undefined acyl chains, (b) liquid crystalline- and gel-state acyl chains, and (c) defined acyl chains matching those of phase separated membrane lipids. The phospholipid bilayer systems employed represent a liquid crystalline/gel phase separation and a cholesterol-driven fluid/fluid phase separation; phase separation is confirmed by differential scanning calorimetry. We tested the hypothesis that acyl chain affinities may dictate the phase into which N-NBD-PE and N-Rh-PE FRET probes partition. While these FRET probes were largely successful at tracking liquid crystalline/gel phase separations, they were less useful in following fluid/fluid separations and appeared to preferentially partition into the liquid-disordered phase. Additionally, partition measurements indicate that the rhodamine-containing probes are substantially less hydrophobic than the analogous NBD probes. These experiments indicate that acyl chain affinities may not be sufficient to employ acyl chain-specific N-NBD-PE/N-Rh-PE FRET probes to investigate phase separations into biologically relevant fluid/fluid lipid microdomains.
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Affiliation(s)
- W Stillwell
- Department of Biology, Indiana University-Purdue University at Indianapolis, 46202-5132, USA.
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21
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James PS, Wolfe CA, Mackie A, Ladha S, Prentice A, Jones R. Lipid dynamics in the plasma membrane of fresh and cryopreserved human spermatozoa. Hum Reprod 1999; 14:1827-32. [PMID: 10402398 DOI: 10.1093/humrep/14.7.1827] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Preserving the integrity of the plasma membrane of spermatozoa is crucial for retention of their fertilizing capacity, especially after stressful procedures such as freezing and storage. In this investigation we have measured lipid diffusion in different regions of the plasma membrane of fresh and cryopreserved human spermatozoa using a sensitive, high resolution fluorescence photobleaching technique (FRAP) with 5-(N-octadecanyl)aminofluorescein as reporter probe. Results show that diffusion was significantly faster on the plasma membrane overlying the acrosome and decreased progressively in the postacrosome, midpiece and principal piece. The midpiece plasma contains a higher proportion of immobile lipids than other regions. In cryopreserved spermatozoa, lipid diffusion in the plasma membrane was significantly reduced on the acrosome, postacrosome and midpiece relative to fresh spermatozoa. Diffusion, however, could be restored to normal levels by washing spermatozoa in a medium containing 0.4% polyvinylpyrrolidine but not in medium alone or in medium containing 0.4% albumin. These results suggest that (i) lipid dynamics in the plasma membrane of human spermatozoa varies significantly between surface regions; (ii) in-plane diffusion is adversely affected by cryopreservation; and (iii) washing frozen spermatozoa in 0.4% polyvinylpyrrolidine restores membrane lipid fluidity to normal levels. The latter finding has important implications for improving the fertility of human spermatozoa following cryopreservation.
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Affiliation(s)
- P S James
- Department of Signalling, The Babraham Institute, Cambridge CB2 4AT, Department of Food Biophysics, Institute of Food Research, Norwich NR4 7UA, UK
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22
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James PS, Wolfe CA, Ladha S, Jones R. Lipid diffusion in the plasma membrane of ram and boar spermatozoa during maturation in the epididymis measured by fluorescence recovery after photobleaching. Mol Reprod Dev 1999; 52:207-15. [PMID: 9890752 DOI: 10.1002/(sici)1098-2795(199902)52:2<207::aid-mrd12>3.0.co;2-w] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Maturation of spermatozoa in the epididymis involves remodelling of many protein and lipid components of the plasma membrane. In this investigation we have examined whether (a) diffusion of lipid molecules in the surface membrane changes during epididymal maturation; (b) diffusion is spatially restricted; and (c) differences in lipid diffusion can be related to known changes in membrane composition. For this purpose we have used the technique of fluorescence recovery after photobleaching (FRAP) to measure diffusion of the lipid reporter probe ODAF (5-(octa-decanoyl)aminofluorescein) in spermatozoa from two species: ram, where substantial changes in membrane lipids occur during passage through the epididymis, and boar, where there are relatively few changes. Results on ram spermatozoa show that between the testis and cauda epididymidis, diffusion coefficients values (D) for ODAF increase significantly in all the surface domains. Percentage recovery values (%R) remain constant irrespective of maturational status. In boar spermatozoa, however, D and %R values do not change significantly between epididymal regions. Cholesterol, which has widespread effects on the behaviour of lipid molecules in cell membranes, was visualized by binding of filipin. In both species filipin was concentrated over the acrosomal domain and cytoplasmic droplet of testicular spermatozoa, but in the epididymis it had a heterogenous distribution over the whole head and tail. These results are discussed in relation to the establishment and maintenance of lipid domains in spermatozoa and their influence on development of fertilizing capacity.
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Affiliation(s)
- P S James
- Department of Signalling, The Babraham Institute, Cambridge, United Kingdom
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23
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Wolfe CA, James PS, Mackie AR, Ladha S, Jones R. Regionalized lipid diffusion in the plasma membrane of mammalian spermatozoa. Biol Reprod 1998; 59:1506-14. [PMID: 9828199 DOI: 10.1095/biolreprod59.6.1506] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
The plasma membrane of mammalian spermatozoa shows pronounced lateral asymmetry with many glycoproteins restricted to specific domains. Some of these antigens are freely diffusing throughout the membrane whereas others appear static in position. It is not clear whether these concepts also apply to membrane lipids. In this investigation we have used fluorescence recovery after photobleaching (FRAP) techniques to spatially resolve lipid dynamics in various surface domains of 5 species of mammalian spermatozoa (bull, boar, ram, mouse, and guinea pig). Sperm plasma membranes were loaded with 5-(N-octadecanoyl)aminofluorescein (ODAF) reporter probe, and its diffusion was measured in various domains by FRAP analysis. Results showed that in live bull, boar, ram, and mouse spermatozoa, diffusion coefficients (D) were significantly higher over the acrosome and postacrosome than on the midpiece and principal piece of the tail. In dead or permeabilized cells, on the other hand, large immobile phases developed, particularly on the sperm tail, that severely reduced D values. ODAF diffusion was also sensitive to temperature and cross-linking of protein components within the membrane with paraformaldehyde. Guinea pig spermatozoa were different in almost all respects from those of the other species tested. It is concluded that lipid diffusion in the plasma membrane of live spermatozoa varies significantly between surface domains, because of either compositional heterogeneity, or differences in bilayer disposition, or the presence of intramembranous barriers that impede free exchange between domains. This study emphasizes the important role of membrane lipids in regulating polarized migration of sperm surface antigens during developmental processes such as maturation and capacitation.
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Affiliation(s)
- C A Wolfe
- Department of Food Biophysics, Institute of Food Research, Colney, Norwich NR4 7UA, United Kingdom
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24
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Hazel JR, McKinley SJ, Gerrits MF. Thermal acclimation of phase behavior in plasma membrane lipids of rainbow trout hepatocytes. THE AMERICAN JOURNAL OF PHYSIOLOGY 1998; 275:R861-9. [PMID: 9728085 DOI: 10.1152/ajpregu.1998.275.3.r861] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The fluorescent probes laurdan (6-dodecanoyl-2-dimethylaminonapthalene) and N-[7-nitrobenz-2-oxa-1, 3-diazol-4-yl] dipalmitoyl-L-alpha-phosphatidylethanolamine (NBD-PE) in addition to Fourier transform infrared spectroscopy (FTIR) were employed to measure the phase behavior and physical properties of hepatocyte plasma membranes isolated from the livers of thermally acclimated (5 and 20 degreesC) rainbow trout (Oncorhynchus mykiss). The primary objective was to determine the extent to which the phase behavior of membrane lipids is conserved at different growth temperatures. Arrhenius plots of laurdan-generalized polarization revealed a single discontinuity believed to reflect either the onset of the gel-fluid phase transition or the formation of gel phase microdomains, and this discontinuity occurred at significantly higher temperatures in membranes of 20 degrees C (13.2 +/- 0.7 degrees C)- than 5 degrees C (7.2 +/- 0.1 degrees C)-acclimated trout. Similarly, acclimation from 5 to 20 degrees C increased both the onset temperature (from 2.0 +/- 0.3 to 7.2 +/- 0.6 degrees C) and the thermal range (from 10.9 +/- 0.5 to 16.0 +/- 1.0) of the gel-fluid transition as assessed by FTIR. The gel-fluid transition midpoint (approximately -2 degrees C) and completion temperatures (-9 degrees C) were unchanged by thermal acclimation. The anisotropy of NBD-PE fluorescence displayed a distinct minimum in membranes of both warm- and cold-acclimated trout (reflecting alterations in lipid packing that in pure lipid membranes ultimately lead to the formation of nonlamellar phases) in the range of 56-58 degrees C; only membranes of 5 degrees C-acclimated trout displayed an additional minimum at significantly lower temperatures (24.5 +/- 1.7 degrees C). Collectively, these data suggest that the regulation of both the temperature at which gel phase lipids begin to form in response to cooling as well as the propensity of membrane lipids to form nonlamellar phases at higher temperatures may be key features of membrane organization subject to adaptive regulation.
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Affiliation(s)
- J R Hazel
- Department of Biology, Arizona State University, Tempe, Arizona 85287, USA
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25
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Wassarman PM, Florman HM. Cellular Mechanisms During Mammalian Fertilization. Compr Physiol 1997. [DOI: 10.1002/cphy.cp140124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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26
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Bell MV, Dick JR, Buda C. Molecular speciation of fish sperm phospholipids: large amounts of dipolyunsaturated phosphatidylserine. Lipids 1997; 32:1085-91. [PMID: 9358435 DOI: 10.1007/s11745-997-0140-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The molecular species compositions of the main diacyl phosphoglyceride classes and ether-linked subclasses from sperm of three species of fish, sea bass Dicentrarchus labrax, Atlantic salmon Salmo salar and Chinook salmon Onchorhynchus tsawytscha, were determined. The phospholipids from sperm were highly unsaturated, dipolyunsaturated fatty acid (diPUFA) molecular species comprised 64.6 to 71.8% of phosphatidylserine (PS), 10.1 to 17.4% of phosphatidylethanolamine (PE), and 3.3 to 10.1% of phosphatidylcholine (PC). In sea bass sperm, di22:6n-3 phospholipid was the predominant diPUFA molecular species, but in both salmon species 22:5n-3/22:6n-3 was also a major constituent of PS. Phospholipids containing 22:6n-3 dominated in sea bass sperm with 16:0/22:6n-3 as a major component of PC and PE, and 18:0/22:6n-3 of PE and PS in addition to di22:6n-3 in the latter two classes. In contrast, both salmon species contained much more 20:5n-3 and less 22:6n-3 so that saturated/20:5n-3 and monounsaturated/20:5n-3 molecular species were more abundant than the corresponding molecules containing 22:6n-3. Ether-linked lipids comprised 11.3-36.3% of choline and ethanolamine phosphoglycerides in each fish species. Molecular species containing 22:6n-3 were the major components of 1-O-alkyl-2-acyl-glycerophosphocholine, especially 16:0a/22:6n-3 in sea bass and 18:1a/22:6n-3 in the two salmon species, while in 1-O-alk-1'-enyl-2-acyl-glycerophosphoethanolamine, 16:0a/22:6n-3 was the major component in both salmon and 18:0a/22:6n-3 in sea bass with 18:1a/22:6n-3 abundant in all three species. In Atlantic salmon 1-O-alkyl-2-acyl-glycerophosphoethanolamine comprised 24.6% of ethanolamine glycerophospholipids which were predominantly 16:0a/22:6n-3 and 18:1a/22:6n-3. Phosphatidylinositol from sperm was dominated by stearoyl/C20 PUFA molecular species, in sea bass overwhelmingly 18:0/20:4n-6, while in both salmon species 18:0/20:4n-6 and 18:0/20:5n-3 were equally abundant.
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Affiliation(s)
- M V Bell
- Department of Biological and Molecular Sciences, University of Stirling, Scotland.
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27
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Carlini E, Palmerini CA, Cosmi EV, Arienti G. Fusion of sperm with prostasomes: effects on membrane fluidity. Arch Biochem Biophys 1997; 343:6-12. [PMID: 9210640 DOI: 10.1006/abbi.1997.9999] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Prostasomes are membranous vesicles (150-200 nm diameter) present in human semen. They are secreted by the prostate gland and contain large amounts of cholesterol, sphingomyelin, and Ca2+. In addition, some of their proteins are enzymes. Prostasomes enhance the motility of ejaculated sperm and are involved in a number of biological functions. In this work, we study the fusion of prostasomes to sperm by determining the relief of octadecylrhodamine self-quenching and the fluidity of membranes by measuring the fluorescence anisotropy of diphenylhexatriene. We present the following findings: (a) the contact of sperm cells with prostasomes at slightly acidic pH causes the fusion of the membranes; (b) the amount of transferred lipid depends on the prostasome/sperm ratio; (c) the fluidity of sperm is much higher than that of prostasomes; (d) the fusion changes some properties of sperm cells, such as fluidity, which decreases greatly; and (e) the extent of fluidity variations depends on the prostasome to sperm ratio. We propose that the H(+)-dependent fusion of prostasomes to sperm may have physiological consequences. In fact, this process can modify the lipid and protein pattern of sperm plasma membranes.
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Affiliation(s)
- E Carlini
- Istituto di Biochimica e Chimica Medica, Perugia, Italy
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28
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Ladha S, James PS, Clark DC, Howes EA, Jones R. Lateral mobility of plasma membrane lipids in bull spermatozoa: heterogeneity between surface domains and rigidification following cell death. J Cell Sci 1997; 110 ( Pt 9):1041-50. [PMID: 9175700 DOI: 10.1242/jcs.110.9.1041] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Compartmentalization of surface membrane antigens into discrete regions or domains is a characteristic feature of differentiated cells. In mammalian spermatozoa at least 5 surface domains are known, implying the presence of barriers or boundaries within the plasma membrane. Using the technique of fluorescence recovery after photobleaching (FRAP) to measure diffusibility of fluorescent lipid analogues 1,1′-dihexadecyl-3,3,3′3′-tetramethylindocarbocyanine (DiIC[16]) and 5-(N-octa-decanoyl) aminofluorescein (ODAF), we have investigated lipid topology and dynamics in the plasma membrane of ejaculated bull spermatozoa. Contrary to reports in the literature, we have found that DiIC(16) stains only dead or damaged spermatozoa whereas ODAF intercalates into the plasma membrane of both live and dead cells, each type showing a distinctive staining pattern. FRAP analysis with ODAF revealed that diffusion coefficients on live spermatozoa are significantly faster on the acrosome and postacrosome (29.3x10(−9) cm2/second) than on the midpiece and principal piece (11.8x10(−9) cm2/second). Recovery (R) is >90% in all domains. ODAF diffusion also shows regionalized temperature-sensitivity with a 4-fold increase over the sperm head and a 1.8-fold increase on the tail between 20 degrees C and 37 degrees C. Remarkably, dead or permeabilized spermatozoa rapidly develop a large immobile phase (R<25%) over the whole plasma membrane. This rigidification is temperature insensitive and irreversible suggesting major changes in the physical state of membrane lipids. It is concluded that lipid diffusion in the plasma membrane of live bull spermatozoa is rapid and varies significantly between surface domains. Following permeabilization or cell death, however, a large immobile phase develops indicating substantial changes in membrane lipid disposition.
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Affiliation(s)
- S Ladha
- Department of Food Biophysics, Institute of Food Research, Norwich Research Park, UK
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29
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Hazel J. Thermal Adaptation in Biological Membranes: Beyond Homeoviscous Adaptation. THERMOBIOLOGY 1997. [DOI: 10.1016/s1569-2558(08)60075-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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30
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Harrison RA, Ashworth PJ, Miller NG. Bicarbonate/CO2, an effector of capacitation, induces a rapid and reversible change in the lipid architecture of boar sperm plasma membranes. Mol Reprod Dev 1996; 45:378-91. [PMID: 8916050 DOI: 10.1002/(sici)1098-2795(199611)45:3<378::aid-mrd16>3.0.co;2-v] [Citation(s) in RCA: 215] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Bicarbonate/CO2 is believed to be the key in vitro effector of sperm capacitation, a process which induces major changes in the sperm plasma membrane in preparation for fertilization. In a flow cytometric study, we examined the effect of bicarbonate on boar spermatozoa using merocyanine, an impermeant lipophilic probe which binds to plasma membranes with increasing affinity as their lipid components become more disordered. We found that bicarbonate causes a rapid increase in the ability of live boar spermatozoa to bind merocyanine. First detected about 100 sec after exposure to bicarbonate and largely complete by 300 sec, this increase appears to result from individual cells within the sperm population switching from a low merocyanine-binding state to a high binding state. The majority of live spermatozoa are capable of responding in this way, and do so in proportion to bicarbonate concentration, half-maximal response being induced by about 3 mM bicarbonate; however, overall population response varies greatly between ejaculates. Increased merocyanine stainability is observed over the whole surface area of the cell, and is reversible both with respect to temperature (it is only manifested above 30 degrees C) and with respect to presence of bicarbonate. A similar effect can be induced by phosphodiesterase inhibitors such as isobutylmethylxanthine, and enhanced by a permeant cyclic nucleotide analogue. We conclude that bicarbonate causes a major alteration in sperm plasma membrane lipid architecture, apparently by perturbing enzymic control processes. This novel action of bicarbonate may represent an initial permissive event in the capacitation sequence.
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Affiliation(s)
- R A Harrison
- Department of Signalling, Babraham Institute, Cambridge, UK
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31
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Schram V, Lin HN, Thompson TE. Topology of gel-phase domains and lipid mixing properties in phase-separated two-component phosphatidylcholine bilayers. Biophys J 1996; 71:1811-22. [PMID: 8889158 PMCID: PMC1233650 DOI: 10.1016/s0006-3495(96)79382-7] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The influence of the lipid mixing properties on the lateral organization in a two-component, two-phase phosphatidylcholine bilayer was investigated using both an experimental (fluorescence recovery after photobleaching (FRAP)) and a simulated (Monte Carlo) approach. With the FRAP technique, we have examined binary mixtures of 1-stearoyl-2-capryl-phosphatidylcholine/1,2-distearoyl-phosphat idylcholine (C18C10PC/DSPC), and 1-stearoyl-2-capryl-phosphatidylcholine/1,2-dipalmitoyl-phospha tid ylcholine (C18C10PC/DPPC). Comparison with the 1,2-dimyristoyl-phosphatidylcholine/1,2-distearoyl-phosphatidylcholine (DMPC/DSPC) previously investigated by FRAP by Vaz and co-workers (Biophys. J., 1989, 56:869-876) shows that the gel phase domains become more effective in restricting the diffusion coefficient when the ideality of the mixture increases (i.e., in the order C18C10PC/DSPC-->C18C10PC/DPPC-->DMPC/DSPC). However, an increased lipid miscibility is accompanied by an increasing compositional dependence: the higher the proportion of the high-temperature melting component, the less efficient the gel phase is in compartmentalizing the diffusion plane, a trend that is best accounted for by a variation of the gel phase domain shape rather than size. Computer-simulated fluorescence recoveries obtained in a matrix obstructed with obstacle aggregates of various fractal dimension demonstrate that: 1) for a given obstacle size and area fraction, the relative diffusion coefficient increases linearly with the obstacle fractal dimension and 2) aggregates with a lower fractal dimension are more efficient in compartmentalizing the diffusion plane. Comparison of the simulated with the experimental mobile fractions strongly suggests that the fractal dimension of the gel phase domains increases with the proportion of high-temperature melting component in DMPC/DSPC and (slightly) in C18C10PC/DPPC.
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Affiliation(s)
- V Schram
- Department of Biochemistry, University of Virginia, Charlottesville, 22908, USA
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32
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Yu W, So PT, French T, Gratton E. Fluorescence generalized polarization of cell membranes: a two-photon scanning microscopy approach. Biophys J 1996; 70:626-36. [PMID: 8789081 PMCID: PMC1224964 DOI: 10.1016/s0006-3495(96)79646-7] [Citation(s) in RCA: 107] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
We use the lipophilic fluorescence probe Laurdan to study cell membranes. The generalized polarization (GP) of Laurdan-labeled cells contains useful information about membrane fluidity and polarity. A high GP is usually associated with low fluidity, low polarity, or high cholesterol content of the membranes, and a low GP is the opposite. We have combined the GP method and two-photon fluorescence microscopy to provide an alternative approach to study cell membranes. Using two-photon excitation in a conventional microscope offers great advantages for studying biological samples. These advantages include efficient background rejection, low photodamage, and improved depth discrimination. We performed GP measurements on mouse fibroblast cells and observed that both intensity and GP images are not spatially uniform. We tested for possible GP artifacts arising from cellular autofluorescence and lifetime quenching, using a procedure for background fluorescence subtraction and by direct lifetime measurements in the microscope. GP measured in a single cell displays a broad distribution, and the GP of 40 different cells grown on the same cover glass is also statistically distributed. The correlations between intensity and GP images were analyzed, and no monotonic dependence between the two was found. By digitally separating high and low GP values, we found that high GP values often associate with the regions of the plasma membrane and low GP values link with the nuclear membranes. Our results also show local GP variations within the plasma and nuclear membranes.
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Affiliation(s)
- W Yu
- Department of Physics, University of Illinois at Urbana-Champaign, Illinois 61801, USA.
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33
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Nolan JP, Magargee SF, Posner RG, Hammerstedt RH. Flow cytometric analysis of transmembrane phospholipid movement in bull sperm. Biochemistry 1995; 34:3907-15. [PMID: 7696254 DOI: 10.1021/bi00012a006] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Fluorescent phospholipids are useful to investigate phospholipid dynamics in biological membranes. We used flow cytometry to investigate transbilayer phospholipid movement in live sperm cells. Acyl-labeled N-4-nitrobenzo-2-oxa-1,3-diazole (NBD) -phosphatidylcholine (-PC), -phosphatidylethanolamine (-PE), or -phosphatidylserine (-PS) were incorporated into sperm cells, and the transbilayer location was determined by extraction of probe from cell with excess bovine serum albumin (BSA) or by chemical destruction of probe by sodium dithionite. Using these methods, we have measured the head group specific outer leaflet to inner leaflet movement (flip) of the aminophospholipids NBD-PS and NBD-PE. The fluorescent phospholipids moved inward across the plasma membrane with half-times of 1.8, 2.5, and 11.2 min, for NBD-PS, NBD-PE, and NBD-PC and reached apparent equilibrium levels of 88%, 94%, and 32% inside, respectively. The inward movement of NBD-PE was inhibited by sulfhydryl reagents, elevated intracellular Ca2+, and depletion of cellular ATP. Analysis of the kinetics of NBD-PE and -PS extraction by BSA allows determination of the rates for outward movement (flop) across the plasma membrane. Half-times for flop were 4.7 and 4.5 min for NBD-PS and -PE, respectively. Based on these measurements, a simple model of NBD-phospholipid equilibria was developed and fit to the kinetic data. Computer-generated fits reflected major features of the experimental data and provide a potential tool for predicting the dynamics of endogenous lipids.
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Affiliation(s)
- J P Nolan
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park 16802
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34
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Gadella BM, Lopes-Cardozo M, van Golde LM, Colenbrander B, Gadella TW. Glycolipid migration from the apical to the equatorial subdomains of the sperm head plasma membrane precedes the acrosome reaction. Evidence for a primary capacitation event in boar spermatozoa. J Cell Sci 1995; 108 ( Pt 3):935-46. [PMID: 7622622 DOI: 10.1242/jcs.108.3.935] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In order to extend the static information of immunolabelling sulphogalactolipids in fixed boar spermatozoa, a fluorescent sulphogalactolipid analogue, galactose(3-sulphate)-beta 1–1′[(N-lissamine rhodaminyl)-12-aminodode-canoyl]-sphingosine, was incorporated into plasma membranes of living spermatozoa and its lateral distribution over the sperm head was studied. The fluorescent lipid was enriched in the apical ridge subdomain of freshly ejaculated sperm cells. After sperm binding to the zona pellucida the lipid redistributed to the equatorial segment of the sperm surface. A similar shift occurred during capacitation in vitro with 2 mM CaCl2 or with 4% (w/v) bovine serum albumin. The desulphated derivative galactose-beta 1–1′[(N-lissamine rhodaminyl)-12-aminododecanoyl]-sphingosine was also incorporated into the plasma membrane of freshly ejaculated sperm cells and clearly stained the apical ridge subdomain and the (pre)-equatorial subdomains of the sperm heads. The desulphogalactolipid analogue showed a slightly faster migration to the equatorial segment of the sperm plasma membrane than did its sulphated counterpart. The measured fluorescence intensity distributions correlated linearly with the spatial probe distribution, which was checked by fluorescence lifetime imaging microscopy. The observed migration of the incorporated glycolipids precedes the acrosome reaction and is one of the underlying molecular events likely to be important in the process of sperm capacitation. The results of this study suggest that lipid phase segregation is an important driving force for the organization of the sperm head plasma membrane into subdomains.
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Affiliation(s)
- B M Gadella
- Laboratory of Veterinary Biochemistry, Utrecht University, The Netherlands
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35
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Abstract
Mammalian sperm have unusual plasma membranes compared to those of somatic cells. After leaving the testes, sperm cease plasma membrane lipid and protein systhesis. A major fraction of mammalian sperm plasma membranes are lipid linked. A large fraction of their lipid chains are highly unsaturated. Biophysical studies reveal that lipids are regionalized on the sperm surface and are highly immobile. This immobile fraction evolves with sperm development. This non-diffusing fraction is also observed in bilayers reconstituted from lipid extracts of sperm head plasma membranes, suggesting the existence of gel phase domains in these membranes. This hypothesis is further supported by differential scanning calorimetry, which shares at least two relatively broad phase transitions with physiological temperature falling between these major transitions.
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Affiliation(s)
- D E Wolf
- Worcester Foundation for Experimental Biology, Shrewsbury, MA 01545, USA
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36
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Westbrook-Case VA, Winfrey VP, Olson GE. Characterization of two antigenically related integral membrane proteins of the guinea pig sperm periacrosomal plasma membrane. Mol Reprod Dev 1994; 39:309-21. [PMID: 7534094 DOI: 10.1002/mrd.1080390308] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The periacrosomal plasma membrane of mammalian spermatozoa functions both in recognition and in binding of the egg's zona pellucida and in the acrosome reaction. This study characterizes two antigenically related proteins with molecular weights of 35 kD (PM35) and 52 kD (PM52) of the guinea pig sperm periacrosomal plasma membrane. Polyclonal antisera were prepared against electrophoretically purified PM35 or PM52. Each antiserum recognized both the 35-kD and 52-kD polypeptides on Western blots, indicating that they are structurally related. This conclusion was supported by peptide mapping experiments demonstrating comparably sized fragments of both PM35 and PM52. Both PM35 and PM52 behave as integral membrane proteins during phase-separation analysis with Triton X-114. Electron microscopic immunocytochemistry and differential fractionation of sperm membranes established that both PM35 and PM52 are exclusively localized to the periacrosomal plasma membrane. Three different antisera were used for ultrastructural studies, and each specifically bound the cytoplasmic but not the extracellular membrane surface. The electrophoretic mobilities of the PM35 and PM52 polypeptides were unchanged during sperm maturation and during the ionophore-induced acrosome reaction. The localization of PM35 and PM52 suggests a potential role for these integral plasma membrane proteins in signal transduction or membrane fusion events of the acrosome reaction.
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Affiliation(s)
- V A Westbrook-Case
- Department of Cell Biology, Vanderbilt University, Nashville, Tennessee 37232
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37
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Müller K, Pomorski T, Müller P, Zachowski A, Herrmann A. Protein-dependent translocation of aminophospholipids and asymmetric transbilayer distribution of phospholipids in the plasma membrane of ram sperm cells. Biochemistry 1994; 33:9968-74. [PMID: 8061006 DOI: 10.1021/bi00199a020] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We have investigated the transbilayer movement of phospholipids in the plasma membrane of ram sperm cells using spin- and fluorescence-labeled lipid analogues. After incorporation into the outer leaflet, phosphatidylcholine (PC) and sphingomyelin (SM) moved slowly to the inner cytoplasmic leaflet, whereas phosphatidylserine (PS) and phosphatidylethanolamine (PE) rapidly disappeared from the exoplasmic monolayer. Variation of the initial velocity of the relocation kinetics vs the amount of analogue incorporated into the membrane suggests a saturability of the transbilayer movement of aminophospholipids. ATP depletion or pretreatment with N-ethylmaleimide of ram sperm cells reduced the fast inward motion of PS and PE, indicating a protein-mediated aminophospholipid translocation. The results suggest for the plasma membrane of ram sperm cells the presence of an aminophospholipid translocase and an asymmetric transversal lipid distribution with aminophospholipids preferentially located in the inner leaflet and choline-containing phospholipids in the outer leaflet. The relevance of the transversal segregation of phospholipids for membrane fusion processes occurring during fertilization is discussed.
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Affiliation(s)
- K Müller
- Institut für Fortpflanzung landwirtschaftlicher Nutztiere Schönow e.V., Schönow
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38
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Gadella BM, Gadella TW, Colenbrander B, van Golde LM, Lopes-Cardozo M. Visualization and quantification of glycolipid polarity dynamics in the plasma membrane of the mammalian spermatozoon. J Cell Sci 1994; 107 ( Pt 8):2151-63. [PMID: 7983174 DOI: 10.1242/jcs.107.8.2151] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Seminolipid (sulphogalactosylalkylacylglycerol), the glycolipid that is specific for mammalian germ cells, is located exclusively in the outer leaflet of the sperm plasma membrane. In this study the lateral distribution of seminolipid on sperm heads has been investigated by indirect immunofluorescence labelling and detection with digital imaging fluorescence microscopy. In freshly ejaculated sperm cells this glycolipid was present primarily at the apical ridge subdomain of the plasma membrane of the sperm head. After binding the sperm cells to zona-coated coverslips seminolipid migrated, in 40 minutes, from the apical ridge to the equatorial subdomain of the plasma membrane. A similar redistribution of seminolipid was observed during capacitation of sperm cells in vitro induced by Ca2+ or bovine serum albumin. Comparable migration of seminolipid was also found after prolonged storage of ejaculated sperm cells, albeit at a much slower rate. Addition of arylsulphatase A, an enzyme present in seminal plasma that desulphates seminolipid, significantly enhanced the migration of seminolipid during storage of sperm cells. Its breakdown product desulphoseminolipid (galactosylalkylacylglycerol) appeared highly specifically at the equatorial segment. The measured fluorescence intensity over the sperm head surface correlated linearly with the spatial probe distribution as was checked by fluorescence lifetime imaging microscopy. This paper demonstrates and quantifies for the first time the polarity of seminolipid on the surface of the sperm cell and the dynamic alterations that occur in this polarity during post-ejaculatory events.
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Affiliation(s)
- B M Gadella
- Laboratory of Veterinary Biochemistry, Utrecht University, The Netherlands
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39
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Perry AC, Hall L, Bell AE, Jones R. Sequence analysis of a mammalian phospholipid-binding protein from testis and epididymis and its distribution between spermatozoa and extracellular secretions. Biochem J 1994; 301 ( Pt 1):235-42. [PMID: 8037677 PMCID: PMC1137167 DOI: 10.1042/bj3010235] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The cellular origin of a soluble phospholipid-binding protein (PBP) in rat testicular and epididymal secretions has been investigated genetically and immunologically. PBP is ubiquitous in tissue cytosols but is not present in blood serum, lymph or milk. The relatively large amounts present in cauda epididymal plasma (CEP) and rete testis fluid suggested therefore that it may be secreted specifically by these tissues. However, when PBP cDNAs from testis and epididymis were cloned and sequenced, they did not contain a signal peptide and only one size of transcript was obtained on Northern blots of RNAs from liver, brain, placenta, testis and epididymis. Moreover, PBP could not be detected in sperm-free CEP from castrated, androgen-stimulated animals or in medium from Sertoli cell cultures. Spermatozoa, on the other hand, contained significant amounts of PBP that could be solubilized by washing cells in dissociating reagents or high-salt solutions. These results indicate that, contrary to previous interpretations, PBP is not secreted by classical pathways in either the testis or epididymis but that its presence in CEP and rete testis fluid is attributable largely to release from spermatozoa. Thus, spermatozoa have a significant influence on the composition of CEP as well as on the secretory and absorptive activity of the epididymal epithelium. A possible role for PBP in membrane biogenesis and maintenance of antigen segregation in spermatozoa is discussed.
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Affiliation(s)
- A C Perry
- Department of Biochemistry, University of Bristol School of Medical Sciences, UK
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40
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Wolf DE. Microheterogeneity in Biological Membranes. CURRENT TOPICS IN MEMBRANES 1994. [DOI: 10.1016/s0070-2161(08)60980-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/31/2023]
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41
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Terzaghi A, Tettamanti G, Masserini M. Interaction of glycosphingolipids and glycoproteins: thermotropic properties of model membranes containing GM1 ganglioside and glycophorin. Biochemistry 1993; 32:9722-5. [PMID: 8373775 DOI: 10.1021/bi00088a026] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
High-sensitivity differential scanning calorimetry (DSC) was used to study the mutual interactions between a glycoprotein (human glycophorin, GPA) and a glycosphingolipid (GM1 ganglioside) embedded in large unilamellar vesicles composed of dimyristoylphosphatidylcholine (DMPC). The DSC thermograms exhibited by DMPC/GM1 vesicles, either in the presence or in the absence of GPA, are resolvable into two components. The relative contribution of the minor component, centered at higher temperature, to the total enthalpy and its transition temperature increase with the concentration of the glycolipid embedded in the vesicles. This minor peak, undetectable in the absence of ganglioside, is indicative of the occurrence of lateral phase separation and suggests that GM1 ganglioside-enriched domains are present within the bilayer. At a given concentration of GM1 embedded in the vesicles, the proportion of the phase-separated peak is higher in the presence of GPA, suggesting that the glycoprotein enhances the tendency of GM1 to segregate. Experiments investigating the thermotropic behavior of GPA show that the temperature of irreversible thermal unfolding of the glycoprotein inserted in DMPC vesicles, centered at 65.9 degrees C in the absence of GM1, is shifted to 57.6 degrees C when GM1 is present in the bilayer. These results indicate that, at least in this experimental system, on the one hand, GPA enhances the tendency of the glycolipid to segregate within the membrane, and on the other hand, the glycolipid clusters affect the protein conformation and oligomerization in the membrane.
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Affiliation(s)
- A Terzaghi
- Department of Medical Chemistry and Biochemistry, Medical School, University of Milan, Italy
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42
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Lee GM, Zhang F, Ishihara A, McNeil CL, Jacobson KA. Unconfined lateral diffusion and an estimate of pericellular matrix viscosity revealed by measuring the mobility of gold-tagged lipids. J Cell Biol 1993; 120:25-35. [PMID: 8416991 PMCID: PMC2119481 DOI: 10.1083/jcb.120.1.25] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Nanovid (video-enhanced) microscopy was used to determine whether lateral diffusion in the plasma membrane of colloidal gold-tagged lipid molecules is confined or is unrestricted. Confinement could be produced by domains within the plane of the plasma membrane or by filamentous barriers within the pericellular matrix. Fluorescein-phosphatidylethanolamine (F1-PE), incorporated into the plasma membranes of cultured fibroblasts, epithelial cells and keratocytes, was labeled with 30-nm colloidal gold conjugated to anti-fluorescein (anti-F1). The trajectories of the gold-labeled lipids were used to compute diffusion coefficients (DG) and to test for restricted motion. On the cell lamella, the gold-labeled lipids diffused freely in the plasma membrane. Since the gold must move through the pericellular matrix as the attached lipid diffuses in the plasma membrane, this result suggests that any extensive filamentous barriers in the pericellular matrix are at least 40 nm from the plasma membrane surface. The average diffusion coefficients ranged from 1.1 to 1.7 x 10(-9) cm2/s. These values were lower than the average diffusion coefficients (DF) (5.4 to 9.5 x 10(-9) cm2/s) obtained by FRAP. The lower DG is partially due to the pericellular matrix as demonstrated by the result that heparinase treatment of keratocytes significantly increased DG to 2.8 x 10(-9) cm2/s, but did not affect DF. Pericellular matrix viscosity was estimated from the frictional coefficients computed from DG and DF and ranged from 0.5 to 0.9 poise for untreated cells. Heparinase treatment of keratocytes decreased the apparent viscosity to approximately 0.1 poise. To evaluate the presence of domains or barriers, the trajectories and corresponding mean square displacement (MSD) plots of gold-labeled lipids were compared to the trajectories and MSD plots resulting from computer simulations of random walks within corrals. Based on these comparisons, we conclude that, if there are domains limiting the diffusion of F1-PE, most are larger than 5 microns in diameter.
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Affiliation(s)
- G M Lee
- Department of Cell Biology and Anatomy, University of North Carolina, Chapel Hill 27599
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43
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McKinnon CA, Weaver FE, Yoder JA, Fairbanks G, Wolf DE. Cross-linking a maturation-dependent ram sperm plasma membrane antigen induces the acrosome reaction. Mol Reprod Dev 1991; 29:200-7. [PMID: 1878227 DOI: 10.1002/mrd.1080290216] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
ESA152 is a highly hydrophobic 18 kDa sialoglycoprotein, which becomes expressed on ram sperm in the proximal cauda epididymis. ESA 152 is expressed on all regions of the sperm surface, most strongly on the posterior region of the head, most weakly on the anterior region of the head. In this paper, we show that induction of the acrosome reaction with Ca2+ ionophore causes ESA152 to be redistributed from the posterior to the anterior region of the head plasma membrane. Cross-linking ESA152 with bivalent antibody causes similar redistribution and induces the acrosome reaction. Induction of the acrosome reaction with ESA152 antibody requires Ca2+ but is insensitive to (10 ng/ml) pertussis toxin.
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Affiliation(s)
- C A McKinnon
- Worcester Foundation for Experimental Biology, Shrewsbury, Massachusetts 01545
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