1
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Buzzatto MV, Berberián MV, Di Bartolo AL, Masone D, Tomes CN. α-Synuclein is required for sperm exocytosis at a post-fusion stage. Front Cell Dev Biol 2023; 11:1125988. [PMID: 37287458 PMCID: PMC10242118 DOI: 10.3389/fcell.2023.1125988] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 05/09/2023] [Indexed: 06/09/2023] Open
Abstract
The sperm acrosome is a large dense-core granule whose contents are secreted by regulated exocytosis at fertilization through the opening of numerous fusion pores between the acrosomal and plasma membranes. In other cells, the nascent pore generated when the membrane surrounding a secretory vesicle fuses with the plasma membrane may have different fates. In sperm, pore dilation leads to the vesiculation and release of these membranes, together with the granule contents. α-Synuclein is a small cytosolic protein claimed to exhibit different roles in exocytic pathways in neurons and neuroendocrine cells. Here, we scrutinized its function in human sperm. Western blot revealed the presence of α-synuclein and indirect immunofluorescence its localization to the acrosomal domain of human sperm. Despite its small size, the protein was retained following permeabilization of the plasma membrane with streptolysin O. α-Synuclein was required for acrosomal release, as demonstrated by the inability of an inducer to elicit exocytosis when permeabilized human sperm were loaded with inhibitory antibodies to human α-synuclein. The antibodies halted calcium-induced secretion when introduced after the acrosome docked to the cell membrane. Two functional assays, fluorescence and transmission electron microscopies revealed that the stabilization of open fusion pores was responsible for the secretion blockage. Interestingly, synaptobrevin was insensitive to neurotoxin cleavage at this point, an indication of its engagement in cis SNARE complexes. The very existence of such complexes during AE reflects a new paradigm. Recombinant α-synuclein rescued the inhibitory effects of the anti-α-synuclein antibodies and of a chimeric Rab3A-22A protein that also inhibits AE after fusion pore opening. We applied restrained molecular dynamics simulations to compare the energy cost of expanding a nascent fusion pore between two model membranes and found it higher in the absence than in the presence of α-synuclein. Hence, our results suggest that α-synuclein is essential for expanding fusion pores.
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Affiliation(s)
- Micaela Vanina Buzzatto
- Instituto de Histología y Embriología de Mendoza (IHEM)-CONICET-Universidad Nacional de Cuyo, Mendoza, Argentina
- Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - María Victoria Berberián
- Instituto de Histología y Embriología de Mendoza (IHEM)-CONICET-Universidad Nacional de Cuyo, Mendoza, Argentina
- Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, Mendoza, Argentina
- Instituto de Ciencias Básicas (ICB)-CONICET-Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Ary Lautaro Di Bartolo
- Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Diego Masone
- Instituto de Histología y Embriología de Mendoza (IHEM)-CONICET-Universidad Nacional de Cuyo, Mendoza, Argentina
- Facultad de Ingeniería, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Claudia Nora Tomes
- Instituto de Histología y Embriología de Mendoza (IHEM)-CONICET-Universidad Nacional de Cuyo, Mendoza, Argentina
- Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, Mendoza, Argentina
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2
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Pinto FM, Odriozola A, Candenas L, Subirán N. The Role of Sperm Membrane Potential and Ion Channels in Regulating Sperm Function. Int J Mol Sci 2023; 24:6995. [PMID: 37108159 PMCID: PMC10138380 DOI: 10.3390/ijms24086995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 04/02/2023] [Accepted: 04/05/2023] [Indexed: 04/29/2023] Open
Abstract
During the last seventy years, studies on mammalian sperm cells have demonstrated the essential role of capacitation, hyperactivation and the acrosome reaction in the acquisition of fertilization ability. These studies revealed the important biochemical and physiological changes that sperm undergo in their travel throughout the female genital tract, including changes in membrane fluidity, the activation of soluble adenylate cyclase, increases in intracellular pH and Ca2+ and the development of motility. Sperm are highly polarized cells, with a resting membrane potential of about -40 mV, which must rapidly adapt to the ionic changes occurring through the sperm membrane. This review summarizes the current knowledge about the relationship between variations in the sperm potential membrane, including depolarization and hyperpolarization, and their correlation with changes in sperm motility and capacitation to further lead to the acrosome reaction, a calcium-dependent exocytosis process. We also review the functionality of different ion channels that are present in spermatozoa in order to understand their association with human infertility.
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Affiliation(s)
- Francisco M. Pinto
- Instituto de Investigaciones Químicas, CSIC-University of Sevilla, Avenida Américo Vespucio 49, 41092 Sevilla, Spain;
| | - Ainize Odriozola
- Department of Physiology, Faculty of Medicine and Nursery, University of the Basque Country (UPV/EHU), 48940 Bizkaia, Spain; (A.O.); (N.S.)
- Biocruces-Bizkaia Health Research Institute, 48903 Barakaldo, Spain
- MEPRO Medical Reproductive Solutions, 20009 San Sebastian, Spain
| | - Luz Candenas
- Instituto de Investigaciones Químicas, CSIC-University of Sevilla, Avenida Américo Vespucio 49, 41092 Sevilla, Spain;
| | - Nerea Subirán
- Department of Physiology, Faculty of Medicine and Nursery, University of the Basque Country (UPV/EHU), 48940 Bizkaia, Spain; (A.O.); (N.S.)
- Biocruces-Bizkaia Health Research Institute, 48903 Barakaldo, Spain
- MEPRO Medical Reproductive Solutions, 20009 San Sebastian, Spain
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3
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Vaquer CC, Suhaiman L, Pavarotti MA, Arias RJ, Pacheco Guiñazú AB, De Blas GA, Belmonte SA. The pair ceramide 1-phosphate/ceramide kinase regulates intracellular calcium and progesterone-induced human sperm acrosomal exocytosis. Front Cell Dev Biol 2023; 11:1148831. [PMID: 37065849 PMCID: PMC10102357 DOI: 10.3389/fcell.2023.1148831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 03/22/2023] [Indexed: 04/03/2023] Open
Abstract
Before fertilization, spermatozoa must undergo calcium-regulated acrosome exocytosis in response to physiological stimuli such as progesterone and zona pellucida. Our laboratory has elucidated the signaling cascades accomplished by different sphingolipids during human sperm acrosomal exocytosis. Recently, we established that ceramide increases intracellular calcium by activating various channels and stimulating the acrosome reaction. However, whether ceramide induces exocytosis on its own, activation of the ceramide kinase/ceramide 1-phosphate (CERK/C1P) pathway or both is still an unsolved issue. Here, we demonstrate that C1P addition induces exocytosis in intact, capacitated human sperm. Real-time imaging in single-cell and calcium measurements in sperm population showed that C1P needs extracellular calcium to induce [Ca2+]i increase. The sphingolipid triggered the cation influx through voltage-operated calcium (VOC) and store-operated calcium (SOC) channels. However, it requires calcium efflux from internal stores through inositol 3-phosphate receptors (IP3R) and ryanodine receptors (RyR) to achieve calcium rise and the acrosome reaction. We report the presence of the CERK in human spermatozoa, the enzyme that catalyzes C1P synthesis. Furthermore, CERK exhibited calcium-stimulated enzymatic activity during the acrosome reaction. Exocytosis assays using a CERK inhibitor demonstrated that ceramide induces acrosomal exocytosis, mainly due to C1P synthesis. Strikingly, progesterone required CERK activity to induce intracellular calcium increase and acrosome exocytosis. This is the first report, implicating the bioactive sphingolipid C1P in the physiological progesterone pathway leading to the sperm acrosome reaction.
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Affiliation(s)
- Cintia C. Vaquer
- Instituto de Histología y Embriología de Mendoza (IHEM) “Dr. Mario H. Burgos”, CONICET, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Laila Suhaiman
- Instituto de Histología y Embriología de Mendoza (IHEM) “Dr. Mario H. Burgos”, CONICET, Universidad Nacional de Cuyo, Mendoza, Argentina
- Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Martín A. Pavarotti
- Instituto de Histología y Embriología de Mendoza (IHEM) “Dr. Mario H. Burgos”, CONICET, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Rodolfo J. Arias
- Instituto de Histología y Embriología de Mendoza (IHEM) “Dr. Mario H. Burgos”, CONICET, Universidad Nacional de Cuyo, Mendoza, Argentina
- LaTIT. Área Farmacología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Anahí B. Pacheco Guiñazú
- Instituto de Histología y Embriología de Mendoza (IHEM) “Dr. Mario H. Burgos”, CONICET, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Gerardo A. De Blas
- Instituto de Histología y Embriología de Mendoza (IHEM) “Dr. Mario H. Burgos”, CONICET, Universidad Nacional de Cuyo, Mendoza, Argentina
- LaTIT. Área Farmacología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Silvia A. Belmonte
- Instituto de Histología y Embriología de Mendoza (IHEM) “Dr. Mario H. Burgos”, CONICET, Universidad Nacional de Cuyo, Mendoza, Argentina
- Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
- *Correspondence: Silvia A. Belmonte, ,
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4
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Flores-Montero K, Berberián MV, Mayorga LS, Tomes CN, Ruete MC. The molecular chaperone cysteine string protein is required for monomeric SNARE proteins to assemble in trans-complexes during human sperm acrosomal exocytosis†. Biol Reprod 2023; 108:229-240. [PMID: 36308432 DOI: 10.1093/biolre/ioac196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Revised: 10/06/2022] [Accepted: 10/24/2022] [Indexed: 11/13/2022] Open
Abstract
Membrane fusion in sperm cells is crucial for acrosomal exocytosis and must be preserved to ensure fertilizing capacity. Evolutionarily conserved protein machinery regulates acrosomal exocytosis. Molecular chaperones play a vital role in spermatogenesis and post-testicular maturation. Cysteine string protein (CSP) is a member of the Hsp40 co-chaperones, and the participation of molecular chaperones in acrosomal exocytosis is poorly understood. In particular, the role of CSP in acrosomal exocytosis has not been reported so far. Using western blot and indirect immunofluorescence, we show that CSP is present in human sperm, is palmitoylated, and predominantly bound to membranes. Moreover, using functional assays and transmission electron microscopy, we report that blocking the function of CSP avoided the assembly of trans-complexes and inhibited exocytosis. In summary, here, we describe the presence of CSP in human sperm and show that this protein has an essential role in membrane fusion during acrosomal exocytosis mediating the trans-SNARE complex assembly between the outer acrosomal and plasma membranes. In general, understanding CSP's role is critical in identifying new biomarkers and generating new rational-based approaches to treat male infertility.
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Affiliation(s)
- Karina Flores-Montero
- Instituto de Histología y Embriología de Mendoza - Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - María Victoria Berberián
- Instituto de Histología y Embriología de Mendoza - Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de Cuyo, Mendoza, Argentina.,Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, Mendoza, Argentina.,Instituto de Ciencias Básicas - Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Luis Segundo Mayorga
- Instituto de Histología y Embriología de Mendoza - Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de Cuyo, Mendoza, Argentina.,Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Claudia Nora Tomes
- Instituto de Histología y Embriología de Mendoza - Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de Cuyo, Mendoza, Argentina.,Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - María Celeste Ruete
- Instituto de Histología y Embriología de Mendoza - Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de Cuyo, Mendoza, Argentina.,Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
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5
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The stallion sperm acrosome: Considerations from a research and clinical perspective. Theriogenology 2023; 196:121-149. [PMID: 36413868 DOI: 10.1016/j.theriogenology.2022.11.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 11/02/2022] [Accepted: 11/07/2022] [Indexed: 11/16/2022]
Abstract
During the fertilization process, the interaction between the sperm and the oocyte is mediated by a process known as acrosomal exocytosis (AE). Although the role of the sperm acrosome on fertilization has been studied extensively over the last 70 years, little is known about the molecular mechanisms that govern acrosomal function, particularly in species other than mice or humans. Even though subfertility due to acrosomal dysfunction is less common in large animals than in humans, the evaluation of sperm acrosomal function should be considered not only as a complementary but a routine test when individuals are selected for breeding potential. This certainly holds true for stallions, which might display lower levels of fertility in the face of "acceptable" sperm quality parameters determined by conventional sperm assays. Nowadays, the use of high throughput technologies such as flow cytometry or mass spectrometry-based proteomic analysis is commonplace in the research arena. Such techniques can also be implemented in clinical scenarios of males with "idiopathic" subfertility. The current review focuses on the sperm acrosome, with particular emphasis on the stallion. We aim to describe the physiological events that lead to the acrosome formation within the testis, the role of very specific acrosomal proteins during AE, the methods to study the occurrence of AE under in vitro conditions, and the potential use of molecular biology techniques to discover new markers of acrosomal function and subfertility associated with acrosomal dysfunction in stallions.
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6
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Ballin M, Griep W, Patel M, Karl M, Mentrup T, Rivera‐Monroy J, Foo B, Schwappach B, Schröder B. The intramembrane proteases
SPPL2a
and
SPPL2b
regulate the homeostasis of selected
SNARE
proteins. FEBS J 2022; 290:2320-2337. [PMID: 36047592 DOI: 10.1111/febs.16610] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 06/28/2022] [Accepted: 08/30/2022] [Indexed: 01/15/2023]
Abstract
Signal peptide peptidase (SPP) and SPP-like (SPPL) aspartyl intramembrane proteases are known to contribute to sequential processing of type II-oriented membrane proteins referred to as regulated intramembrane proteolysis. The ER-resident family members SPP and SPPL2c were shown to also cleave tail-anchored proteins, including selected SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins facilitating membrane fusion events. Here, we analysed whether the related SPPL2a and SPPL2b proteases, which localise to the endocytic or late secretory pathway, are also able to process SNARE proteins. Therefore, we screened 18 SNARE proteins for cleavage by SPPL2a and SPPL2b based on cellular co-expression assays, of which the proteins VAMP1, VAMP2, VAMP3 and VAMP4 were processed by SPPL2a/b demonstrating the capability of these two proteases to proteolyse tail-anchored proteins. Cleavage of the four SNARE proteins was scrutinised at the endogenous level upon SPPL2a/b inhibition in different cell lines as well as by analysing VAMP1-4 levels in tissues and primary cells of SPPL2a/b double-deficient (dKO) mice. Loss of SPPL2a/b activity resulted in an accumulation of VAMP1-4 in a cell type- and tissue-dependent manner, identifying these proteins as SPPL2a/b substrates validated in vivo. Therefore, we propose that SPPL2a/b control cellular levels of VAMP1-4 by initiating the degradation of these proteins, which might impact cellular trafficking.
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Affiliation(s)
- Moritz Ballin
- Biochemical Institute Christian Albrechts University Kiel Kiel Germany
- Institute of Physiological Chemistry Technische Universität Dresden Dresden Germany
| | - Wolfram Griep
- Biochemical Institute Christian Albrechts University Kiel Kiel Germany
- Institute of Physiological Chemistry Technische Universität Dresden Dresden Germany
| | - Mehul Patel
- Institute of Physiological Chemistry Technische Universität Dresden Dresden Germany
| | - Martin Karl
- Institute of Physiological Chemistry Technische Universität Dresden Dresden Germany
| | - Torben Mentrup
- Institute of Physiological Chemistry Technische Universität Dresden Dresden Germany
| | - Jhon Rivera‐Monroy
- Department of Molecular Biology University Medical Center Göttingen Göttingen Germany
| | - Brian Foo
- Department of Molecular Biology University Medical Center Göttingen Göttingen Germany
| | - Blanche Schwappach
- Department of Molecular Biology University Medical Center Göttingen Göttingen Germany
| | - Bernd Schröder
- Institute of Physiological Chemistry Technische Universität Dresden Dresden Germany
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7
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Schiavi-Ehrenhaus LJ, Romarowski A, Jabloñski M, Krapf D, Luque GM, Buffone MG. The early molecular events leading to COFILIN phosphorylation during mouse sperm capacitation are essential for acrosomal exocytosis. J Biol Chem 2022; 298:101988. [PMID: 35487245 PMCID: PMC9142561 DOI: 10.1016/j.jbc.2022.101988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 04/18/2022] [Accepted: 04/20/2022] [Indexed: 12/03/2022] Open
Abstract
The actin cytoskeleton reorganization during sperm capacitation is essential for the occurrence of acrosomal exocytosis (AR) in several mammalian species. Here, we demonstrate that in mouse sperm, within the first minutes of exposure upon capacitating conditions, the activity of RHOA/C and RAC1 is essential for LIMK1 and COFILIN phosphorylation. However, we observed that the signaling pathway involving RAC1 and PAK4 is the main player in controlling actin polymerization in the sperm head necessary for the occurrence of AR. Moreover, we show that the transient phosphorylation of COFILIN is also influenced by the Slingshot family of protein phosphatases (SSH1). The activity of SSH1 is regulated by the dual action of two pathways. On one hand, RHOA/C and RAC1 activity promotes SSH1 phosphorylation (inactivation). On the other hand, the activating dephosphorylation is driven by okadaic acid-sensitive phosphatases. This regulatory mechanism is independent of the commonly observed activating mechanisms involving PP2B and emerges as a new finely tuned modulation that is, so far, exclusively observed in mouse sperm. However, persistent phosphorylation of COFILIN by SSH1 inhibition or okadaic acid did not altered actin polymerization and the AR. Altogether, our results highlight the role of small GTPases in modulating actin dynamics required for AR.
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Affiliation(s)
- Liza J Schiavi-Ehrenhaus
- Instituto de Biología y Medicina Experimental, Consejo Nacional de Investigaciones Científicas y Técnicas (IBYME-CONICET), Buenos Aires, Argentina
| | - Ana Romarowski
- Department of Veterinary and Animal Science, University of Massachusetts, Amherst, Massachusetts, USA
| | - Martina Jabloñski
- Instituto de Biología y Medicina Experimental, Consejo Nacional de Investigaciones Científicas y Técnicas (IBYME-CONICET), Buenos Aires, Argentina
| | - Darío Krapf
- Instituto de Biología Molecular y Celular de Rosario (IBR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Rosario (UNR), Rosario, Argentina
| | - Guillermina M Luque
- Instituto de Biología y Medicina Experimental, Consejo Nacional de Investigaciones Científicas y Técnicas (IBYME-CONICET), Buenos Aires, Argentina.
| | - Mariano G Buffone
- Instituto de Biología y Medicina Experimental, Consejo Nacional de Investigaciones Científicas y Técnicas (IBYME-CONICET), Buenos Aires, Argentina.
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8
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Siu KK, Serrão VHB, Ziyyat A, Lee JE. The cell biology of fertilization: Gamete attachment and fusion. J Cell Biol 2021; 220:e202102146. [PMID: 34459848 PMCID: PMC8406655 DOI: 10.1083/jcb.202102146] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 08/13/2021] [Accepted: 08/16/2021] [Indexed: 02/06/2023] Open
Abstract
Fertilization is defined as the union of two gametes. During fertilization, sperm and egg fuse to form a diploid zygote to initiate prenatal development. In mammals, fertilization involves multiple ordered steps, including the acrosome reaction, zona pellucida penetration, sperm-egg attachment, and membrane fusion. Given the success of in vitro fertilization, one would think that the mechanisms of fertilization are understood; however, the precise details for many of the steps in fertilization remain a mystery. Recent studies using genetic knockout mouse models and structural biology are providing valuable insight into the molecular basis of sperm-egg attachment and fusion. Here, we review the cell biology of fertilization, specifically summarizing data from recent structural and functional studies that provide insights into the interactions involved in human gamete attachment and fusion.
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Affiliation(s)
- Karen K. Siu
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Vitor Hugo B. Serrão
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Ahmed Ziyyat
- Université de Paris, Institut Cochin, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche Scientifique, Paris, France
- Service d’Histologie, d’Embryologie, Biologie de la Reproduction, Assistance Publique - Hôpitaux de Paris, Hôpital Cochin, Paris, France
| | - Jeffrey E. Lee
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
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9
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Aldana A, Carneiro J, Martínez-Mekler G, Darszon A. Discrete Dynamic Model of the Mammalian Sperm Acrosome Reaction: The Influence of Acrosomal pH and Physiological Heterogeneity. Front Physiol 2021; 12:682790. [PMID: 34349664 PMCID: PMC8328089 DOI: 10.3389/fphys.2021.682790] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 05/28/2021] [Indexed: 01/31/2023] Open
Abstract
The acrosome reaction (AR) is an exocytotic process essential for mammalian fertilization. It involves diverse physiological changes (biochemical, biophysical, and morphological) that culminate in the release of the acrosomal content to the extracellular medium as well as a reorganization of the plasma membrane (PM) that allows sperm to interact and fuse with the egg. In spite of many efforts, there are still important pending questions regarding the molecular mechanism regulating the AR. Particularly, the contribution of acrosomal alkalinization to AR triggering physiological conditions is not well understood. Also, the dependence of the proportion of sperm capable of undergoing AR on the physiological heterogeneity within a sperm population has not been studied. Here, we present a discrete mathematical model for the human sperm AR based on the physiological interactions among some of the main components of this complex exocytotic process. We show that this model can qualitatively reproduce diverse experimental results, and that it can be used to analyze how acrosomal pH (pH a ) and cell heterogeneity regulate AR. Our results confirm that a pH a increase can on its own trigger AR in a subpopulation of sperm, and furthermore, it indicates that this is a necessary step to trigger acrosomal exocytosis through progesterone, a known natural inducer of AR. Most importantly, we show that the proportion of sperm undergoing AR is directly related to the detailed structure of the population physiological heterogeneity.
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Affiliation(s)
- Andrés Aldana
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
- Centro de Ciencias de la Complejidad, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Jorge Carneiro
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova, Oeiras, Portugal
| | - Gustavo Martínez-Mekler
- Centro de Ciencias de la Complejidad, Universidad Nacional Autónoma de México, Mexico City, Mexico
- Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Alberto Darszon
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
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10
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Wang Q, Cao Z, Du B, Zhang Q, Chen L, Wang X, Yuan Z, Wang P, He R, Shan J, Zhao Y, Miao L. Membrane contact site-dependent cholesterol transport regulates Na +/K +-ATPase polarization and spermiogenesis in Caenorhabditis elegans. Dev Cell 2021; 56:1631-1645.e7. [PMID: 34051143 DOI: 10.1016/j.devcel.2021.05.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 03/08/2021] [Accepted: 05/06/2021] [Indexed: 10/21/2022]
Abstract
Spermiogenesis in nematodes is a process whereby round and quiescent spermatids differentiate into asymmetric and crawling spermatozoa. The molecular mechanism underlying this symmetry breaking remains uncharacterized. In this study, we revealed that sperm-specific Na+/K+-ATPase (NKA) is evenly distributed on the plasma membrane (PM) of Caenorhabditis elegans spermatids but is translocated to and subsequently enters the invaginated membrane of the spermatozoa cell body during sperm activation. The polarization of NKA depends on the transport of cholesterol from the PM to membranous organelles (MOs) via membrane contact sites (MCSs). The inositol 5-phosphatase CIL-1 and the MO-localized PI4P phosphatase SAC-1 may mediate PI4P metabolism to drive cholesterol countertransport via sterol/lipid transport proteins through MCSs. Furthermore, the NKA function is required for C. elegans sperm motility and reproductive success. Our data imply that the lipid dynamics mediated by MCSs might play crucial roles in the establishment of cell polarity. eGraphical abstract.
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Affiliation(s)
- Qiushi Wang
- Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zheng Cao
- Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
| | - Baochen Du
- Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qi Zhang
- Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lianwan Chen
- Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Xia Wang
- Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Zhiheng Yuan
- Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Peng Wang
- Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ruijun He
- Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Jin Shan
- Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yanmei Zhao
- Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
| | - Long Miao
- Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China; Center for Biological Imaging, Core Facilities for Protein Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
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11
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Suhaiman L, Altamirano KN, Morales A, Belmonte SA. Different Approaches to Record Human Sperm Exocytosis. Methods Mol Biol 2021; 2233:139-168. [PMID: 33222133 DOI: 10.1007/978-1-0716-1044-2_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
Abstract
Acrosome reaction is an exocytic process that enables a sperm to penetrate the zona pellucida and fertilize an egg. The process involves the fenestration and vesiculation of the sperm plasma membrane and outer acrosomal membrane, releasing the acrosomal content. Given the importance of the acrosome secretion in fertilization, many different methods have been developed to detect the acrosome reaction of sperm. In this chapter, we describe detailed practical procedures to assess the acrosomal status of human spermatozoa. To do this, we resorted to light optical and epifluorescence microscopy, flow cytometry, and transmission electron microscopy. We also itemize the protocol for real-time measurements of the acrosome reaction by confocal microscopy. Further, we discuss the level of complexity, costs, and the reasons why a researcher should choose each technique.This chapter is designed to provide the user with sufficient background to measure acrosomal exocytosis in human sperm.
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Affiliation(s)
- Laila Suhaiman
- Instituto Interdisciplinario de Ciencias Básicas (ICB) CONICET. Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Karina Noel Altamirano
- Instituto de Histología y Embriología de Mendoza (IHEM) "Dr. Mario H. Burgos". CONICET. Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Alfonsina Morales
- Instituto de Histología y Embriología de Mendoza (IHEM) "Dr. Mario H. Burgos". CONICET. Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Silvia Alejandra Belmonte
- Instituto de Histología y Embriología de Mendoza (IHEM) "Dr. Mario H. Burgos". CONICET. Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina.
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12
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Mata-Martínez E, Sánchez-Tusie AA, Darszon A, Mayorga LS, Treviño CL, De Blas GA. Epac activation induces an extracellular Ca 2+ -independent Ca 2+ wave that triggers acrosome reaction in human spermatozoa. Andrology 2021; 9:1227-1241. [PMID: 33609309 DOI: 10.1111/andr.12989] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 02/10/2021] [Accepted: 02/17/2021] [Indexed: 01/02/2023]
Abstract
BACKGROUND The signaling pathways of the intracellular second messengers cAMP and Ca2+ play a crucial role in numerous physiological processes in human spermatozoa. One such process is the acrosome reaction (AR), which is necessary for spermatozoa to traverse the egg envelope and to expose a fusogenic membrane allowing the egg-sperm fusion. Progesterone and zona pellucida elicit an intracellular Ca2+ increase that is needed for the AR in the mammalian spermatozoa. This increase is mediated by an initial Ca2+ influx but also by a release from intracellular Ca2+ stores. It is known that intracellular Ca2+ stores play a central role in the regulation of [Ca2+ ]i and in the generation of complex Ca2+ signals such as oscillations and waves. In the human spermatozoa, it has been proposed that the cAMP analog and specific agonist of Epac 8-(p-chlorophenylthio)-2'-O-methyladenosine-3',5'-cyclic monophosphate (2'-O-Me-cAMP) elicits an intracellular Ca2+ release involved in the AR. OBJECTIVE To identify the molecular entities involved in the Ca2+ mobilization triggered by 2'-O-Me-cAMP in human spermatozoa. MATERIALS AND METHODS In capacitated human spermatozoa, we monitored Ca2+ dynamics and the occurrence of the AR in real time using Fluo 3-AM and FM4-64 in a Ca2+ -free medium. RESULTS Epac activation by 2'-O-Me-cAMP induced a Ca2+ wave that started in the midpiece and propagated to the acrosome region. This Ca2+ response was sensitive to rotenone, CGP, xestospongin, NED-19, and thapsigargin, suggesting the participation of different ion transporters (mitochondrial complex I and Na+ /Ca2+ exchanger, inositol 3-phosphate receptors, two-pore channels and internal store Ca2+ -ATPases). DISCUSSION Our results suggest that Epac activation promotes a dynamic crosstalk between three different intracellular Ca2+ stores: the mitochondria, the redundant nuclear envelope, and the acrosome. CONCLUSION The Ca2+ wave triggered by Epac activation is necessary to induce the AR and to enhance the flagellar beat.
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Affiliation(s)
- Esperanza Mata-Martínez
- Laboratorio de Fusión de Membranas y Exocitosis Acrosomal, Instituto de Histología y Embriología Dr. Mario H. Burgos (IHEM), Universidad Nacional de Cuyo, CONICET, Mendoza, Argentina
| | - Ana Alicia Sánchez-Tusie
- Laboratorio de Fisiología Celular y Molecular, Departamento de Investigación Biomédica, Facultad de Medicina, Universidad Autónoma de Querétaro, México
| | - Alberto Darszon
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Morelos, México
| | - Luis S Mayorga
- Laboratorio de Fusión de Membranas y Exocitosis Acrosomal, Instituto de Histología y Embriología Dr. Mario H. Burgos (IHEM), Universidad Nacional de Cuyo, CONICET, Mendoza, Argentina.,Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Claudia L Treviño
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Morelos, México
| | - Gerardo A De Blas
- Laboratorio de Fusión de Membranas y Exocitosis Acrosomal, Instituto de Histología y Embriología Dr. Mario H. Burgos (IHEM), Universidad Nacional de Cuyo, CONICET, Mendoza, Argentina.,Laboratorio de Teleanálisis e Investigación Traslacional, Área Farmacología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
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13
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Balestrini PA, Jabloñski M, Schiavi-Ehrenhaus LJ, Marín-Briggiler CI, Sánchez-Cárdenas C, Darszon A, Krapf D, Buffone MG. Seeing is believing: Current methods to observe sperm acrosomal exocytosis in real time. Mol Reprod Dev 2020; 87:1188-1198. [PMID: 33118273 DOI: 10.1002/mrd.23431] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 09/25/2020] [Accepted: 10/14/2020] [Indexed: 01/10/2023]
Abstract
Acrosomal exocytosis (AR) is a critical process that sperm need to undergo to fertilize an egg. The evaluation of the presence or absence of the acrosome is usually performed by using lectins or dyes in fixed cells. With this approach, it is neither possible to monitor the dynamic process of exocytosis and related molecular events while discriminating between live and dead cells, nor to evaluate the acrosomal status while sperm reside in the female reproductive tract. However, over the last two decades, several new methodologies have been used to assess the occurrence of AR in living cells allowing different groups to obtain information that was not possible in the past. These techniques have revolutionized the whole study of this process. This review summarizes current methods available to analyze AR in living cells as well as the important information that emerged from studies using these approaches.
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Affiliation(s)
- Paula A Balestrini
- Instituto de Biología y Medicina Experimental (IBYME-CONICET), Buenos Aires, Argentina
| | - Martina Jabloñski
- Instituto de Biología y Medicina Experimental (IBYME-CONICET), Buenos Aires, Argentina
| | | | | | - Claudia Sánchez-Cárdenas
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, México
| | - Alberto Darszon
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, México
| | - Darío Krapf
- Instituto de Biología Molecular y Celular de Rosario, CONICET-UNR, Rosario, Argentina
| | - Mariano G Buffone
- Instituto de Biología y Medicina Experimental (IBYME-CONICET), Buenos Aires, Argentina
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14
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Itzhakov D, Nitzan Y, Breitbart H. Protein kinase A inhibition induces EPAC-dependent acrosomal exocytosis in human sperm. Asian J Androl 2020; 21:337-344. [PMID: 30632486 PMCID: PMC6628745 DOI: 10.4103/aja.aja_99_18] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
To interact with the egg, the spermatozoon must undergo several biochemical and motility modifications in the female reproductive tract, collectively called capacitation. Only capacitated sperm can undergo acrosomal exocytosis, near or on the egg, a process that allows the sperm to penetrate and fertilize the egg. In the present study, we investigated the involvement of cyclic adenosine monophosphate (cAMP)-dependent processes on acrosomal exocytosis. Inhibition of protein kinase A (PKA) at the end of capacitation induced acrosomal exocytosis. This process is cAMP-dependent; however, the addition of relatively high concentration of the membrane-permeable 8-bromo-cAMP (8Br-cAMP, 0.1 mmol l−1) analog induced significant inhibition of the acrosomal exocytosis. The induction of acrosomal exocytosis by PKA inhibition was significantly inhibited by an exchange protein directly activated by cAMP (EPAC) ESI09 inhibitor. The EPAC selective substrate activated AE at relatively low concentrations (0.02–0.1 μmol l−1), whereas higher concentrations (>5 μmol l−1) were inhibitory to the AE induced by PKA inhibition. Inhibition of PKA revealed about 50% increase in intracellular cAMP levels, conditions under which EPAC can be activated to induce the AE. Induction of AE by activating the actin severing-protein, gelsolin, which causes F-actin dispersion, was inhibited by the EPAC inhibitor. The AE induced by PKA inhibition was mediated by phospholipase C activity but not by the Ca2+-channel, CatSper. Thus, inhibition of PKA at the end of the capacitation process induced EPAC/phospholipase C-dependent acrosomal exocytosis. EPAC mediates F-actin depolymerization and/or activation of effectors downstream to F-actin breakdown that lead to acrosomal exocytosis.
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Affiliation(s)
- Diana Itzhakov
- The Mina and Everard Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Yeshayahu Nitzan
- Department of Clinical Laboratory Science, Zefat Academic College, Zefat 1320611, Israel
| | - Haim Breitbart
- The Mina and Everard Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
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15
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Pini T, Parks J, Russ J, Dzieciatkowska M, Hansen KC, Schoolcraft WB, Katz-Jaffe M. Obesity significantly alters the human sperm proteome, with potential implications for fertility. J Assist Reprod Genet 2020; 37:777-787. [PMID: 32026202 PMCID: PMC7183029 DOI: 10.1007/s10815-020-01707-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 01/30/2020] [Indexed: 11/25/2022] Open
Abstract
PURPOSE In men, obesity may lead to poor semen parameters and reduced fertility. However, the causative links between obesity and male infertility are not totally clear, particularly on a molecular level. As such, we investigated how obesity modifies the human sperm proteome, to elucidate any important implications for fertility. METHODS Sperm protein lysates from 5 men per treatment, classified as a healthy weight (body mass index (BMI) ≤ 25 kg/m2) or obese (BMI ≥ 30 kg/m2), were FASP digested, submitted to liquid chromatography tandem mass spectrometry, and compared by label-free quantification. Findings were confirmed for several proteins by qualitative immunofluorescence and a quantitative protein immunoassay. RESULTS A total of 2034 proteins were confidently identified, with 24 proteins being significantly (p < 0.05) less abundant (fold change < 0.05) in the spermatozoa of obese men and 3 being more abundant (fold change > 1.5) compared with healthy weight controls. Proteins with altered abundance were involved in a variety of biological processes, including oxidative stress (GSS, NDUFS2, JAGN1, USP14, ADH5), inflammation (SUGT1, LTA4H), translation (EIF3F, EIF4A2, CSNK1G1), DNA damage repair (UBEA4), and sperm function (NAPA, RNPEP, BANF2). CONCLUSION These results suggest that oxidative stress and inflammation are closely tied to reproductive dysfunction in obese men. These processes likely impact protein translation and folding during spermatogenesis, leading to poor sperm function and subfertility. The observation of these changes in obese men with no overt andrological diagnosis further suggests that traditional clinical semen assessments fail to detect important biochemical changes in spermatozoa which may compromise fertility.
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Affiliation(s)
- T Pini
- Colorado Center for Reproductive Medicine, Lone Tree, CO, 80124, USA.
| | - J Parks
- Colorado Center for Reproductive Medicine, Lone Tree, CO, 80124, USA
| | - J Russ
- Colorado Center for Reproductive Medicine, Lone Tree, CO, 80124, USA
| | - M Dzieciatkowska
- School of Medicine Biological Mass Spectrometry Facility, University of Colorado, Aurora, CO, 80045, USA
| | - K C Hansen
- School of Medicine Biological Mass Spectrometry Facility, University of Colorado, Aurora, CO, 80045, USA
| | - W B Schoolcraft
- Colorado Center for Reproductive Medicine, Lone Tree, CO, 80124, USA
| | - M Katz-Jaffe
- Colorado Center for Reproductive Medicine, Lone Tree, CO, 80124, USA
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Vaquer CC, Suhaiman L, Pavarotti MA, De Blas GA, Belmonte SA. Ceramide induces a multicomponent intracellular calcium increase triggering the acrosome secretion in human sperm. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1867:118704. [PMID: 32194132 DOI: 10.1016/j.bbamcr.2020.118704] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 03/11/2020] [Accepted: 03/12/2020] [Indexed: 12/17/2022]
Abstract
Exocytosis of spermatozoon's secretory vesicle, named acrosome reaction (AR), is a regulated event that plays a central role in fertilization. It is coupled to a complex calcium signaling. Ceramide is a multitasking lipid involved in exocytosis. Nevertheless, its effect on secretion is controversial and the underlying cellular and molecular mechanisms remain unknown. Human spermatozoa are useful to dissect the role of ceramide in secretion given that the gamete is not capable to undergo any trafficking mechanisms other than exocytosis. We report for the first time, the presence of sphingolipid metabolism enzymes such as neutral-sphingomyelinase and ceramide synthase in sperm. Ceramidases are also present and active. Both the addition of cell-permeable ceramide and the rise of the endogenous one, increase intracellular calcium acting as potent inducers of exocytosis. Ceramide triggers AR in capacitated spermatozoa and enhances the gamete response to progesterone. The lipid induces physiological ultrastructural changes in the acrosome and triggers an exocytosis-signaling cascade involving protein tyrosine phosphatase 1B and VAMP2. Real-time imaging showed an increment of calcium in the cytosol upon ceramide treatment either in the absence or in the presence of extracellular calcium. Pharmacological experiments demonstrate that at early stages the process involves ryanodine receptors, CatSper (calcium channel of sperm), and store-operated calcium channels. We set out the signaling sequence of events that connect ceramide to internal calcium mobilization and external calcium signals during secretion. These results allow the coordination of lipids and proteins in a pathway that accomplishes secretion. Our findings contribute to the understanding of ceramide's role in regulated exocytosis and fertilization.
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Affiliation(s)
- Cintia Celina Vaquer
- Instituto de Histología y Embriología de Mendoza (IHEM) "Dr. Mario H. Burgos", CONICET, Universidad Nacional de Cuyo, 5500 Mendoza, Argentina
| | - Laila Suhaiman
- Instituto Interdisciplinario de Ciencias Básicas (ICB), CONICET, Universidad Nacional de Cuyo, 5500 Mendoza, Argentina
| | - Martín Alejandro Pavarotti
- Instituto de Histología y Embriología de Mendoza (IHEM) "Dr. Mario H. Burgos", CONICET, Universidad Nacional de Cuyo, 5500 Mendoza, Argentina
| | - Gerardo Andrés De Blas
- Instituto de Histología y Embriología de Mendoza (IHEM) "Dr. Mario H. Burgos", CONICET, Universidad Nacional de Cuyo, 5500 Mendoza, Argentina; Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Silvia Alejandra Belmonte
- Instituto de Histología y Embriología de Mendoza (IHEM) "Dr. Mario H. Burgos", CONICET, Universidad Nacional de Cuyo, 5500 Mendoza, Argentina; Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina.
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17
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Tsuru E, Oryu K, Sawada K, Nishihara M, Tsuda M. Complexin 2 regulates secretion of immunoglobulin in antibody-secreting cells. IMMUNITY INFLAMMATION AND DISEASE 2019; 7:318-325. [PMID: 31691534 PMCID: PMC6842823 DOI: 10.1002/iid3.276] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 09/27/2019] [Accepted: 10/17/2019] [Indexed: 12/03/2022]
Abstract
Introduction Complexins (CPLXs), initially identified in neuronal presynaptic terminals, are cytoplasmic proteins that interact with the soluble N‐ethylmaleimide‐sensitive factor attachment protein receptors (SNARE) complex to regulate the fusion of vesicles to the plasma membrane. Although much is known about CPLX function in neuronal synaptic vesicle exocytosis, their distribution and role in immune cells are still unclear. In this study, we investigated CPLX2 knockout (KO) mice to reveal the role of CPLXs in exocytosis of lymphocytes. Methods We examined the expression of CPLXs and SNAREs in lymphocytes. To study the effect of CPLXs on the immune system in vivo, we analyzed the immune phenotype of CPLX2 KO mice. Furthermore, antibodies secretion from the peritoneal cavity, spleen, and bone marrow cells of wild‐type (WT) and CPLX2 KO mice were determined. Results CPLX2 was detected in B cells but not in T cells, while other CPLXs and SNAREs were expressed at a similar level in both B and T cells. To clarify the function of CPLX2 in B lymphocytes, serum concentrations of immunoglobulin G (IgG), IgA, IgM, and IgE were measured in WT and CPLX2 KO mice using enzyme‐linked immunosorbent assay. The level of IgM, which mainly consists of natural antibodies, was higher in KO mice than that in WT mice, while the levels of other antibodies were similar in both types of mice. Additionally, we found that spontaneous secretion of IgM and IgG1 was enhanced from the splenic antibody‐secreting cells (ASCs) of CPLX2 KO mice. Conclusion Our data suggest that CPLX2 inhibits spontaneous secretion of IgM and IgG1 from splenic ASCs. This study provides new insight into the mechanism of antibody secretion of ASCs.
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Affiliation(s)
- Emi Tsuru
- Institute for Laboratory Animal Research, Science Research Center, Kochi University, Kochi, Japan
| | - Kohei Oryu
- Institute for Laboratory Animal Research, Science Research Center, Kochi University, Kochi, Japan
| | - Ken Sawada
- Kokorono Support Center, Kochi Health Sciences Center, Kochi, Japan
| | - Makoto Nishihara
- Center for Interdisciplinary Pain, Aichi Medical University, Aichi, Japan
| | - Masayuki Tsuda
- Institute for Laboratory Animal Research, Science Research Center, Kochi University, Kochi, Japan
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18
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Mayorga L, Altamirano K, Zanni Ruiz E, Pavarotti M. Human sperm capacitation is necessary for SNARE assembly in neurotoxin-resistant complexes. Andrology 2019; 8:442-449. [PMID: 31509646 DOI: 10.1111/andr.12706] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 08/20/2019] [Accepted: 09/02/2019] [Indexed: 11/28/2022]
Abstract
BACKGROUND Capacitation is not a well-defined process, required for the acrosome reaction triggered by physiological stimuli. In vitro, capacitation is achieved by sperm incubation in artificial media supplemented with HCO3 - , Ca2+ , and albumin. The role of capacitation in the membrane fusion machinery required for acrosomal exocytosis is not well-known. SNARE proteins are fundamental for intracellular membrane fusion and acrosomal exocytosis. We have previously shown that in capacitated spermatozoa, the fusion machinery is maintained in an inactive state until the acrosome reaction is initiated. In particular, SNARE proteins are assembled in neurotoxin-resistant complexes. OBJECTIVE This work aimed to study the dynamic changes of SNARE complexes during capacitation. MATERIALS AND METHODS The light chain of tetanus and botulinum neurotoxin has been widely used to study the configuration of SNARE proteins. For this purpose, we developed a recombinant light chain of tetanus neurotoxin linked to a polyarginine peptide. This membrane-permeant protein was able to cleave cytosolic VAMP2 (a SNARE protein required for acrosome reaction) when present in a monomeric configuration. RESULTS The results show that the VAMP2 is cleaved by the membrane-permeant tetanus neurotoxin in non-capacitated spermatozoa, indicating that, before capacitation, SNAREs are not assembled in stable toxin-resistant complexes. However, 2 h of incubation in a capacitation medium containing albumin was sufficient to render VAMP2 insensitive to the toxin. DISCUSSION We conclude that during capacitation, the SNARE proteins become engaged in stable fully assembled cis-SNARE complexes. This step is likely essential to prevent untimely activation of the membrane fusion machinery. CONCLUSION We propose that capacitation promotes the stabilization of the membrane fusion machinery required for acrosomal exocytosis in preparation for the stimulus-triggered acrosome reaction.
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Affiliation(s)
- L Mayorga
- Laboratorio de Fusión de Membranas y Exocitosis Acrosomal, Instituto de Histologia y Embriologia Mendoza Dr Mario H Burgos, Mendoza, Argentina.,Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina.,Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, Mendoza, Argentina.,Consejo Nacional de Investigaciones Cientificas y Tecnicas, Buenos Aires, Argentina.,Laboratorio de Lípidos y Exocitosis Acrosomal, Instituto de Histologia y Embriologia Mendoza Dr Mario H Burgos, Mendoza, Argentina.,Universidad Nacional de Cuyo, Mendoza, Argentina
| | - K Altamirano
- Consejo Nacional de Investigaciones Cientificas y Tecnicas, Buenos Aires, Argentina.,Laboratorio de Lípidos y Exocitosis Acrosomal, Instituto de Histologia y Embriologia Mendoza Dr Mario H Burgos, Mendoza, Argentina.,Universidad Nacional de Cuyo, Mendoza, Argentina
| | - E Zanni Ruiz
- Laboratorio de Fusión de Membranas y Exocitosis Acrosomal, Instituto de Histologia y Embriologia Mendoza Dr Mario H Burgos, Mendoza, Argentina.,Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, Mendoza, Argentina.,Universidad Nacional de Cuyo, Mendoza, Argentina
| | - M Pavarotti
- Laboratorio de Fusión de Membranas y Exocitosis Acrosomal, Instituto de Histologia y Embriologia Mendoza Dr Mario H Burgos, Mendoza, Argentina.,Consejo Nacional de Investigaciones Cientificas y Tecnicas, Buenos Aires, Argentina.,Universidad Nacional de Cuyo, Mendoza, Argentina
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19
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Ruete MC, Zarelli VEP, Masone D, de Paola M, Bustos DM, Tomes CN. A connection between reversible tyrosine phosphorylation and SNARE complex disassembly activity of N-ethylmaleimide-sensitive factor unveiled by the phosphomimetic mutant N-ethylmaleimide-sensitive factor-Y83E. ACTA ACUST UNITED AC 2019; 25:344-358. [DOI: 10.1093/molehr/gaz031] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 05/16/2019] [Accepted: 06/03/2019] [Indexed: 12/26/2022]
Abstract
Abstract
N-ethylmaleimide-sensitive factor (NSF) disassembles fusion-incompetent cis soluble-NSF attachment protein receptor (SNARE) complexes making monomeric SNAREs available for subsequent trans pairing and fusion. In most cells the activity of NSF is constitutive, but in Jurkat cells and sperm it is repressed by tyrosine phosphorylation; the phosphomimetic mutant NSF–Y83E inhibits secretion in the former. The questions addressed here are if and how the NSF mutant influences the configuration of the SNARE complex. Our model is human sperm, where the initiation of exocytosis (acrosome reaction (AR)) de-represses the activity of NSF through protein tyrosine phosphatase 1B (PTP1B)-mediated dephosphorylation. We developed a fluorescence microscopy-based method to show that capacitation increased, and challenging with an AR inducer decreased, the number of cells with tyrosine-phosphorylated PTP1B substrates in the acrosomal domain. Results from bioinformatic and biochemical approaches using purified recombinant proteins revealed that NSF–Y83E bound PTP1B and thereupon inhibited its catalytic activity. Mutant NSF introduced into streptolysin O-permeabilized sperm impaired cis SNARE complex disassembly, blocking the AR; subsequent addition of PTP1B rescued exocytosis. We propose that NSF–Y83E prevents endogenous PTP1B from dephosphorylating sperm NSF, thus maintaining NSF’s activity in a repressed mode and the SNARE complex unable to dissociate. The contribution of this paper to the sperm biology field is the detection of PTP1B substrates, one of them likely being NSF, whose tyrosine phosphorylation status varies during capacitation and the AR. The contribution of this paper to the membrane traffic field is to have generated direct evidence that explains the dominant-negative role of the phosphomimetic mutant NSF–Y83E.
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Affiliation(s)
- María Celeste Ruete
- Instituto de Histología y Embriología de Mendoza Dr Mario H. Burgos–CONICET, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Valeria Eugenia Paola Zarelli
- Instituto de Histología y Embriología de Mendoza Dr Mario H. Burgos–CONICET, Universidad Nacional de Cuyo, Mendoza, Argentina
- Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Diego Masone
- Instituto de Histología y Embriología de Mendoza Dr Mario H. Burgos–CONICET, Universidad Nacional de Cuyo, Mendoza, Argentina
- Facultad de Ingeniería, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Matilde de Paola
- Instituto de Histología y Embriología de Mendoza Dr Mario H. Burgos–CONICET, Universidad Nacional de Cuyo, Mendoza, Argentina
- Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
- Instituto de Medicina y Biología Experimental de Cuyo–Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Diego Martín Bustos
- Instituto de Histología y Embriología de Mendoza Dr Mario H. Burgos–CONICET, Universidad Nacional de Cuyo, Mendoza, Argentina
- Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Claudia Nora Tomes
- Instituto de Histología y Embriología de Mendoza Dr Mario H. Burgos–CONICET, Universidad Nacional de Cuyo, Mendoza, Argentina
- Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
- Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, Mendoza, Argentina
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Romarowski A, Velasco Félix ÁG, Torres Rodríguez P, Gervasi MG, Xu X, Luque GM, Contreras-Jiménez G, Sánchez-Cárdenas C, Ramírez-Gómez HV, Krapf D, Visconti PE, Krapf D, Guerrero A, Darszon A, Buffone MG. Super-resolution imaging of live sperm reveals dynamic changes of the actin cytoskeleton during acrosomal exocytosis. J Cell Sci 2018; 131:jcs.218958. [PMID: 30301778 DOI: 10.1242/jcs.218958] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 09/25/2018] [Indexed: 01/14/2023] Open
Abstract
Filamentous actin (F-actin) is a key factor in exocytosis in many cell types. In mammalian sperm, acrosomal exocytosis (denoted the acrosome reaction or AR), a special type of controlled secretion, is regulated by multiple signaling pathways and the actin cytoskeleton. However, the dynamic changes of the actin cytoskeleton in live sperm are largely not understood. Here, we used the powerful properties of SiR-actin to examine actin dynamics in live mouse sperm at the onset of the AR. By using a combination of super-resolution microscopy techniques to image sperm loaded with SiR-actin or sperm from transgenic mice containing Lifeact-EGFP, six regions containing F-actin within the sperm head were revealed. The proportion of sperm possessing these structures changed upon capacitation. By performing live-cell imaging experiments, we report that dynamic changes of F-actin during the AR occur in specific regions of the sperm head. While certain F-actin regions undergo depolymerization prior to the initiation of the AR, others remain unaltered or are lost after exocytosis occurs. Our work emphasizes the utility of live-cell nanoscopy, which will undoubtedly impact the search for mechanisms that underlie basic sperm functions.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Ana Romarowski
- Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires C1428ADN, Argentina
| | - Ángel G Velasco Félix
- Laboratorio Nacional de Microscopía Avanzada, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos 62210, México
| | - Paulina Torres Rodríguez
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos 62210, México
| | - María G Gervasi
- Department of Veterinary and Animal Science, Paige Labs, University of Massachusetts, Amherst, MA 01003, USA
| | - Xinran Xu
- Department of Electrical and Computer Engineering, School of Biomedical Engineering, 1301 Campus Delivery, Fort Collins, CO 80523, USA
| | - Guillermina M Luque
- Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires C1428ADN, Argentina
| | - Gastón Contreras-Jiménez
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos 62210, México
| | - Claudia Sánchez-Cárdenas
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos 62210, México
| | - Héctor V Ramírez-Gómez
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos 62210, México
| | - Diego Krapf
- Department of Electrical and Computer Engineering, School of Biomedical Engineering, 1301 Campus Delivery, Fort Collins, CO 80523, USA
| | - Pablo E Visconti
- Department of Veterinary and Animal Science, Paige Labs, University of Massachusetts, Amherst, MA 01003, USA
| | - Dario Krapf
- Instituto de Biología Molecular y Celular de Rosario (CONICET-UNR), Rosario, Santa Fe S2000EZP, Argentina
| | - Adán Guerrero
- Laboratorio Nacional de Microscopía Avanzada, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos 62210, México
| | - Alberto Darszon
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos 62210, México
| | - Mariano G Buffone
- Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires C1428ADN, Argentina
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21
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Simons J, Fauci L. A Model for the Acrosome Reaction in Mammalian Sperm. Bull Math Biol 2018; 80:2481-2501. [PMID: 30094771 DOI: 10.1007/s11538-018-0478-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Accepted: 07/23/2018] [Indexed: 12/31/2022]
Abstract
The acrosome reaction is a complex, calcium-dependent reaction that results in an exocytotic event required for successful fertilization of the egg. It has long been thought that the acrosome reaction occurs upon sperm binding to the zona pellucida, a viscoelastic layer surrounding the oocyte. Recent studies have suggested that the reaction may even occur before the sperm encounters the zona, perhaps mediated by progesterone or some other agonist. It has been particularly difficult to understand differences between progesterone-induced and zona-induced reactions experimentally and whether one substance is the more biologically relevant trigger. Until this present work, there has been little effort to mathematically model the acrosome reaction in sperm as a whole. Instead, attention has been paid to modeling portions of the pathways involved in other cell types. Here we present a base model for the acrosome reaction which characterizes the known biochemical reactions and behaviors of the system. Our model allows us to analyze several pathways that may act as a stabilizing mechanism for avoiding sustained oscillatory calcium responses often observed in other cell types. Such an oscillatory regime might otherwise prevent acrosomal exocytosis and therefore inhibit fertilization. Results indicate that the acrosome reaction may rely upon multiple redundant mechanisms to avoid entering an oscillatory state and instead maintain a high resting level of calcium, known to be required for successful acrosomal exocytosis and, ultimately, fertilization of the oocyte.
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Affiliation(s)
- Julie Simons
- Department of Sciences and Mathematics, California Maritime Academy, 200 Maritime Academy Dr., Vallejo, CA, 95490-8181, USA.
| | - Lisa Fauci
- Department of Mathematics and Center for Computational Science, Tulane University, 6823 St. Charles Ave., New Orleans, LA, 70118, USA
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22
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Puga Molina LC, Luque GM, Balestrini PA, Marín-Briggiler CI, Romarowski A, Buffone MG. Molecular Basis of Human Sperm Capacitation. Front Cell Dev Biol 2018; 6:72. [PMID: 30105226 PMCID: PMC6078053 DOI: 10.3389/fcell.2018.00072] [Citation(s) in RCA: 135] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 06/19/2018] [Indexed: 12/31/2022] Open
Abstract
In the early 1950s, Austin and Chang independently described the changes that are required for the sperm to fertilize oocytes in vivo. These changes were originally grouped under name of “capacitation” and were the first step in the development of in vitro fertilization (IVF) in humans. Following these initial and fundamental findings, a remarkable number of observations led to characterization of the molecular steps behind this process. The discovery of certain sperm-specific molecules and the possibility to record ion currents through patch-clamp approaches helped to integrate the initial biochemical observation with the activity of ion channels. This is of particular importance in the male gamete due to the fact that sperm are transcriptionally inactive. Therefore, sperm must control all these changes that occur during their transit through the male and female reproductive tracts by complex signaling cascades that include post-translational modifications. This review is focused on the principal molecular mechanisms that govern human sperm capacitation with particular emphasis on comparing all the reported pieces of evidence with the mouse model.
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Affiliation(s)
- Lis C Puga Molina
- Instituto de Biología y Medicina Experimental, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Buenos Aires, Argentina
| | - Guillermina M Luque
- Instituto de Biología y Medicina Experimental, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Buenos Aires, Argentina
| | - Paula A Balestrini
- Instituto de Biología y Medicina Experimental, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Buenos Aires, Argentina
| | - Clara I Marín-Briggiler
- Instituto de Biología y Medicina Experimental, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Buenos Aires, Argentina
| | - Ana Romarowski
- Instituto de Biología y Medicina Experimental, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Buenos Aires, Argentina
| | - Mariano G Buffone
- Instituto de Biología y Medicina Experimental, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Buenos Aires, Argentina
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23
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Yavuz H, Kattan I, Hernandez JM, Hofnagel O, Witkowska A, Raunser S, Walla PJ, Jahn R. Arrest of trans-SNARE zippering uncovers loosely and tightly docked intermediates in membrane fusion. J Biol Chem 2018; 293:8645-8655. [PMID: 29666192 PMCID: PMC5986196 DOI: 10.1074/jbc.ra118.003313] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Indexed: 12/03/2022] Open
Abstract
Soluble N-ethylmaleimide–sensitive factor attachment protein receptor (SNARE) proteins mediate intracellular membrane fusion in the secretory pathway. They contain conserved regions, termed SNARE motifs, that assemble between opposing membranes directionally from their N termini to their membrane-proximal C termini in a highly exergonic reaction. However, how this energy is utilized to overcome the energy barriers along the fusion pathway is still under debate. Here, we have used mutants of the SNARE synaptobrevin to arrest trans-SNARE zippering at defined stages. We have uncovered two distinct vesicle docking intermediates where the membranes are loosely and tightly connected, respectively. The tightly connected state is irreversible and independent of maintaining assembled SNARE complexes. Together, our results shed new light on the intermediate stages along the pathway of membrane fusion.
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Affiliation(s)
| | - Iman Kattan
- Biomolecular Spectroscopy and Single-Molecule Detection Research Group, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Javier M Hernandez
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | - Oliver Hofnagel
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | | | - Stefan Raunser
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | - Peter J Walla
- Biomolecular Spectroscopy and Single-Molecule Detection Research Group, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany.,Biomolecular Spectroscopy and Single-Molecule Detection Research Group, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
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Abstract
The evolutionary origin of synapses and neurons is an enigmatic subject that inspires much debate. Non-bilaterian metazoans, both with and without neurons and their closest relatives already contain many components of the molecular toolkits for synapse functions. The origin of these components and their assembly into ancient synaptic signaling machineries are particularly important in light of recent findings on the phylogeny of non-bilaterian metazoans. The evolution of synapses and neurons are often discussed only from a metazoan perspective leaving a considerable gap in our understanding. By taking an integrative approach we highlight the need to consider different, but extremely relevant phyla and to include the closest unicellular relatives of metazoans, the ichthyosporeans, filastereans and choanoflagellates, to fully understand the evolutionary origin of synapses and neurons. This approach allows for a detailed understanding of when and how the first pre- and postsynaptic signaling machineries evolved.
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Affiliation(s)
- Pawel Burkhardt
- Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth, United Kingdom
| | - Simon G Sprecher
- Institute of Cell and Developmental Biology, Department of Biology, University of Fribourg, Fribourg, Switzerland
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25
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Sharif M, Silva E, Shah STA, Miller DJ. Redistribution of soluble N-ethylmaleimide-sensitive-factor attachment protein receptors in mouse sperm membranes prior to the acrosome reaction. Biol Reprod 2017; 96:352-365. [PMID: 28203732 DOI: 10.1095/biolreprod.116.143735] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 12/12/2016] [Accepted: 01/10/2017] [Indexed: 02/03/2023] Open
Abstract
Formation of complexes between soluble N-ethylmaleimide-sensitive-factor attachment protein receptor (SNARE) proteins on opposing membranes is the minimal requirement for intracellular membrane fusion. The SNARE, syntaxin 2, is found on the sperm plasma membrane and a second SNARE, vesicle associated membrane protein 2 (VAMP2, also known as synaptobrevin 2, SYB2), is on the apposing outer acrosomal membrane. During the acrosome reaction, the outer acrosomal membrane fuses at hundreds of points with the plasma membrane. We hypothesized that syntaxin 2 and VAMP2 redistribute within their respective membranes prior to the acrosome reaction to form trans-SNARE complexes and promote membrane fusion. Immunofluorescence and superresolution structured illumination microscopy were used to localize syntaxin 2 and VAMP2 in mouse sperm during capacitation. Initially, syntaxin 2 was found in puncta throughout the acrosomal region. At 60 and 120 min of capacitation, syntaxin 2 was localized in puncta primarily in the apical ridge. Although deletion of bicarbonate during incubation had no effect, syntaxin 2 puncta were relocated in the restricted region in less than 20% of sperm incubated without albumin. In contrast, VAMP2 was already found in puncta within the apical ridge prior to capacitation. The puncta containing syntaxin 2 and VAMP2 did not precisely co-localize at 0 or 60 min of capacitation time. In summary, syntaxin 2 shifted its location to the apical ridge on the plasma membrane during capacitation in an albumin-dependent manner but VAMP2 was already localized to the apical ridge. Puncta containing VAMP2 did not co-localize with those containing syntaxin 2 during capacitation; therefore, formation of trans-SNARE complexes containing these SNAREs does not occur until after capacitation, immediately prior to acrosomal exocytosis.
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Affiliation(s)
- Momal Sharif
- Institute of Animal Sciences, University of Agriculture, Faisalabad, Pakistan
| | - Elena Silva
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, 1207 West Gregory Drive, Urbana, IL, USA
| | - Syed Tahir Abbas Shah
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, 1207 West Gregory Drive, Urbana, IL, USA
| | - David J Miller
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, 1207 West Gregory Drive, Urbana, IL, USA
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26
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Quevedo MF, Lucchesi O, Bustos MA, Pocognoni CA, De la Iglesia PX, Tomes CN. The Rab3A-22A Chimera Prevents Sperm Exocytosis by Stabilizing Open Fusion Pores. J Biol Chem 2016; 291:23101-23111. [PMID: 27613869 DOI: 10.1074/jbc.m116.729954] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Indexed: 11/06/2022] Open
Abstract
At the final stage of exocytotis, a fusion pore opens between the plasma and a secretory vesicle membranes; typically, when the pore dilates the vesicle releases its cargo. Sperm contain a large dense-core secretory granule (the acrosome) whose contents are secreted by regulated exocytosis at fertilization. Minutes after the arrival of the triggering signal, the acrosomal and plasma membranes dock at multiple sites and fusion pores open at the contact points. It is believed that immediately afterward, fusion pores dilate spontaneously. Rab3A is an essential component of human sperm exocytotic machinery. Yet, recombinant, persistently active Rab3A halts calcium-triggered secretion when introduced after docking into streptolysin O-permeabilized cells; so does a Rab3A-22A chimera. Here, we applied functional assays, electron and confocal microscopy to show that the secretion blockage is due to the stabilization of open fusion pores. Other novel findings are that sperm SNAREs engage in α-SNAP/NSF-sensitive complexes at a post-fusion stage. Complexes are disentangled by these chaperons to achieve vesiculation and acrosomal contents release. Thus, post-fusion regulation of the pores determines their expansion and the success of the acrosome reaction.
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Affiliation(s)
- María F Quevedo
- From the IHEM, Universidad Nacional de Cuyo, CONICET, Facultad de Ciencias Médicas, CC56. 5500 Mendoza, Argentina
| | - Ornella Lucchesi
- From the IHEM, Universidad Nacional de Cuyo, CONICET, Facultad de Ciencias Médicas, CC56. 5500 Mendoza, Argentina
| | - Matías A Bustos
- From the IHEM, Universidad Nacional de Cuyo, CONICET, Facultad de Ciencias Médicas, CC56. 5500 Mendoza, Argentina
| | - Cristian A Pocognoni
- From the IHEM, Universidad Nacional de Cuyo, CONICET, Facultad de Ciencias Médicas, CC56. 5500 Mendoza, Argentina
| | - Paola X De la Iglesia
- From the IHEM, Universidad Nacional de Cuyo, CONICET, Facultad de Ciencias Médicas, CC56. 5500 Mendoza, Argentina
| | - Claudia N Tomes
- From the IHEM, Universidad Nacional de Cuyo, CONICET, Facultad de Ciencias Médicas, CC56. 5500 Mendoza, Argentina
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Hirohashi N. Site of Mammalian Sperm Acrosome Reaction. ADVANCES IN ANATOMY EMBRYOLOGY AND CELL BIOLOGY 2016; 220:145-58. [DOI: 10.1007/978-3-319-30567-7_8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
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28
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Cupertino RB, Kappel DB, Bandeira CE, Schuch JB, da Silva BS, Müller D, Bau CHD, Mota NR. SNARE complex in developmental psychiatry: neurotransmitter exocytosis and beyond. J Neural Transm (Vienna) 2016; 123:867-83. [DOI: 10.1007/s00702-016-1514-9] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 01/20/2016] [Indexed: 12/31/2022]
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29
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Sosa CM, Zanetti MN, Pocognoni CA, Mayorga LS. Acrosomal Swelling Is Triggered by cAMP Downstream of the Opening of Store-Operated Calcium Channels During Acrosomal Exocytosis in Human Sperm. Biol Reprod 2016; 94:57. [PMID: 26792943 DOI: 10.1095/biolreprod.115.133231] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 01/15/2016] [Indexed: 11/01/2022] Open
Abstract
Acrosomal exocytosis in mammalian sperm is a regulated secretion with unusual characteristics. One of its most striking features is the postfusion loss of the outer acrosomal membrane and the overlying plasma membrane as hybrid vesicles. We have previously reported in human sperm that, by preventing the release of calcium from the acrosome, the exocytic process can be arrested at a stage where the acrosomes are profusely swollen, with invaginations of the outer acrosomal membrane. In this report, we show by transmission electron microcopy swelling with similar characteristics without arresting the exocytic process. Acrosomal swelling was observed when secretion was promoted by pharmacological and physiological inducers of the acrosome reaction that trigger exocytosis by different mechanisms. We show that progesterone- and thapsigargin-induced swelling depended on a calcium influx from the extracellular medium through store-operated calcium channels. However, calcium was dispensable when sperm were stimulated with cAMP analogs. KH7, an inhibitor of the soluble adenylyl cyclase, blocked progesterone-induced swelling. Our results indicate that swelling is a required process for acrosomal exocytosis triggered by activation of an adenylyl cyclase downstream of the opening of store-operated calcium channels.
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Affiliation(s)
- Claudia M Sosa
- Instituto de Histología y Embriología de Mendoza (IHEM/CONICET-UNCuyo), School of Medicine, National University of Cuyo, Mendoza, Argentina
| | - M Natalia Zanetti
- Instituto de Histología y Embriología de Mendoza (IHEM/CONICET-UNCuyo), School of Medicine, National University of Cuyo, Mendoza, Argentina
| | - Cristian A Pocognoni
- Instituto de Histología y Embriología de Mendoza (IHEM/CONICET-UNCuyo), School of Medicine, National University of Cuyo, Mendoza, Argentina
| | - Luis S Mayorga
- Instituto de Histología y Embriología de Mendoza (IHEM/CONICET-UNCuyo), School of Medicine, National University of Cuyo, Mendoza, Argentina
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30
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Characterization of VAMP2 in Schistosoma japonicum and the Evaluation of Protective Efficacy Induced by Recombinant SjVAMP2 in Mice. PLoS One 2015; 10:e0144584. [PMID: 26641090 PMCID: PMC4671580 DOI: 10.1371/journal.pone.0144584] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2015] [Accepted: 11/20/2015] [Indexed: 11/25/2022] Open
Abstract
Background The outer-tegument membrane covering the schistosome is believed to maintain via the fusion of membranous vesicles. Fusion of biological membranes is a fundamental process in all eukaryotic cells driven by formation of trans-SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) complexes through pairing of vesicle associated v-SNAREs (VAMP) with complementary t-SNAREs on target membranes. The purpose of this study was to characterize Schistosoma japonicum vesicle-associated membrane protein 2 (SjVAMP2) and to investigate its potential as a candidate vaccine against schistosomiasis. Methodology/Principal Findings The sequence of SjVAMP2 was analyzed, cloned, expressed and characterized. SjVAMP2 is a member of the synaptobrevin superfamily harboring the v-SNARE coiled-coil homology domain. RT–PCR analysis revealed that significantly higher SjVAMP2 levels were observed in 14-, 28- and 42-day-old worms, and SjVAMP2 expression was much higher in 42-day-old female worms than in those male worms. Additionally, the expression of SjVAMP2 was associated with membrane recovery in PZQ-treated worms. Immunostaining assay showed that SjVAMP2 was mainly distributed in the sub-tegument of the worms. Western blotting revealed that rSjVAMP2 showed strong immunogenicity. Purified rSjVAMP2 emulsified with ISA206 adjuvant induced 41.5% and 27.3% reductions in worm burden, and 36.8% and 23.3% reductions in hepatic eggs in two independent trials. Besides, significantly higher rSjVAMP2-specific IgG, IgG1, IgG2a levels were detected in rSjVAMP2-vaccinated mice. Conclusion Our study indicated that SjVAMP2 is a potential vaccine candidate against S. japonicum and provided the basis for further investigations into the biological function of SjVAMP2.
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31
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Pocognoni CA, Berberián MV, Mayorga LS. ESCRT (Endosomal Sorting Complex Required for Transport) Machinery Is Essential for Acrosomal Exocytosis in Human Sperm1. Biol Reprod 2015; 93:124. [DOI: 10.1095/biolreprod.115.132001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Accepted: 10/09/2015] [Indexed: 12/31/2022] Open
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32
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Kongmanas K, Kruevaisayawan H, Saewu A, Sugeng C, Fernandes J, Souda P, Angel JB, Faull KF, Aitken RJ, Whitelegge J, Hardy D, Berger T, Baker MA, Tanphaichitr N. Proteomic Characterization of Pig Sperm Anterior Head Plasma Membrane Reveals Roles of Acrosomal Proteins in ZP3 Binding. J Cell Physiol 2015; 230:449-63. [PMID: 25078272 DOI: 10.1002/jcp.24728] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 07/25/2014] [Indexed: 11/12/2022]
Abstract
The sperm anterior head plasma membrane (APM) is the site where sperm first bind to the zona pellucida (ZP). This binding reaches the maximum following the sperm capacitation process. To gain a better understanding of the sperm-ZP binding mechanisms, we compared protein profiles obtained from mass spectrometry of APM vesicles isolated from non-capacitated and capacitated sperm. The results revealed that ZP-binding proteins were the most abundant group of proteins, with a number of them showing increased levels in capacitated sperm. Blue native gel electrophoresis and far-western blotting revealed presence of high molecular weight (HMW) protein complexes in APM vesicles of both non-capacitated and capacitated sperm, but the complexes (∼750-1300 kDa) from capacitated sperm possessed much higher binding capacity to pig ZP3 glycoprotein. Proteomic analyses indicated that a number of proteins known for their acrosome localization, including zonadhesin, proacrosin/acrosin and ACRBP, were components of capacitated APM HMW complexes, with zonadhesin being the most enriched protein. Our immunofluorescence results further demonstrated that a fraction of these acrosomal proteins was transported to the surface of live acrosome-intact sperm during capacitation. Co-immunoprecipitation indicated that zonadhesin, proacrosin/acrosin and ACRBP interacted with each other and they may traffic as a complex from the acrosome to the sperm surface. Finally, the significance of zonadhesin in the binding of APM HMW complexes to pig ZP3 was demonstrated; the binding ability was decreased following treatment of the complexes with anti-zonadhesin antibody. Our results suggested that acrosomal proteins, especially zonadhesin, played roles in the initial sperm-ZP binding during capacitation.
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Affiliation(s)
- Kessiri Kongmanas
- Chronic Disease Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.,Department of Biochemistry/Microbiology/Immunology, University of Ottawa, Ontario, Canada
| | - Hathairat Kruevaisayawan
- Chronic Disease Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.,Department of Anatomy, Faculty of Medical Sciences, Naresuan University, Phitsanulok, Thailand
| | - Arpornrad Saewu
- Chronic Disease Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.,Department of Biochemistry/Microbiology/Immunology, University of Ottawa, Ontario, Canada
| | - Clarissa Sugeng
- Chronic Disease Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.,Department of Biochemistry/Microbiology/Immunology, University of Ottawa, Ontario, Canada
| | - Jason Fernandes
- Chronic Disease Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.,Department of Biochemistry/Microbiology/Immunology, University of Ottawa, Ontario, Canada
| | - Puneet Souda
- Pasarow Mass Spectrometry Laboratory, University of California, Los Angeles, California
| | - Jonathan B Angel
- Chronic Disease Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.,Department of Biochemistry/Microbiology/Immunology, University of Ottawa, Ontario, Canada.,Division of Infectious Diseases, Ottawa Hospital-General Campus, Ottawa, Ontario, Canada
| | - Kym F Faull
- Pasarow Mass Spectrometry Laboratory, University of California, Los Angeles, California
| | - R John Aitken
- The ARC Centre of Excellence in Biotechnology and Development, School of Environmental and Life Sciences, University of Newcastle, Callaghan, New South Wales, Australia
| | - Julian Whitelegge
- Pasarow Mass Spectrometry Laboratory, University of California, Los Angeles, California
| | - Daniel Hardy
- Department of Cell Biology and Biochemistry, Health Sciences Center, Texas Tech University, Texas
| | - Trish Berger
- Department of Animal Science, University of California, Davis, California
| | - Mark A Baker
- The ARC Centre of Excellence in Biotechnology and Development, School of Environmental and Life Sciences, University of Newcastle, Callaghan, New South Wales, Australia
| | - Nongnuj Tanphaichitr
- Chronic Disease Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.,Department of Biochemistry/Microbiology/Immunology, University of Ottawa, Ontario, Canada.,Department of Obstetrics and Gynaecology, University of Ottawa, Ontario, Canada
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Romarowski A, Battistone MA, La Spina FA, Puga Molina LDC, Luque GM, Vitale AM, Cuasnicu PS, Visconti PE, Krapf D, Buffone MG. PKA-dependent phosphorylation of LIMK1 and Cofilin is essential for mouse sperm acrosomal exocytosis. Dev Biol 2015; 405:237-49. [PMID: 26169470 DOI: 10.1016/j.ydbio.2015.07.008] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Revised: 07/01/2015] [Accepted: 07/09/2015] [Indexed: 02/06/2023]
Abstract
Mammalian sperm must acquire their fertilizing ability after a series of biochemical modifications in the female reproductive tract collectively called capacitation to undergo acrosomal exocytosis, a process that is essential for fertilization. Actin dynamics play a central role in controlling the process of exocytosis in somatic cells as well as in sperm from several mammalian species. In somatic cells, small GTPases of the Rho family are widely known as master regulators of actin dynamics. However, the role of these proteins in sperm has not been studied in detail. In the present work we characterized the participation of small GTPases of the Rho family in the signaling pathway that leads to actin polymerization during mouse sperm capacitation. We observed that most of the proteins of this signaling cascade and their effector proteins are expressed in mouse sperm. The activation of the signaling pathways of cAMP/PKA, RhoA/C and Rac1 is essential for LIMK1 activation by phosphorylation on Threonine 508. Serine 3 of Cofilin is phosphorylated by LIMK1 during capacitation in a transiently manner. Inhibition of LIMK1 by specific inhibitors (BMS-3) resulted in lower levels of actin polymerization during capacitation and a dramatic decrease in the percentage of sperm that undergo acrosomal exocytosis. Thus, we demonstrated for the first time that the master regulators of actin dynamics in somatic cells are present and active in mouse sperm. Combining the results of our present study with other results from the literature, we have proposed a working model regarding how LIMK1 and Cofilin control acrosomal exocytosis in mouse sperm.
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Affiliation(s)
- Ana Romarowski
- Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - María A Battistone
- Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Florenza A La Spina
- Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Lis del C Puga Molina
- Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Guillermina M Luque
- Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Alejandra M Vitale
- Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Patricia S Cuasnicu
- Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Pablo E Visconti
- Department of Veterinary and Animal Science, Paige Labs, University of Massachusets, Amherst, MA 01003, USA
| | - Darío Krapf
- Instituto de Biología Molecular y Celular de Rosario (CONICET-UNR), Rosario 2000 Argentina
| | - Mariano G Buffone
- Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.
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Correia J, Michelangeli F, Publicover S. Regulation and roles of Ca2+ stores in human sperm. Reproduction 2015; 150:R65-76. [PMID: 25964382 PMCID: PMC4497595 DOI: 10.1530/rep-15-0102] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 05/11/2015] [Indexed: 12/16/2022]
Abstract
[Ca(2)(+)]i signalling is a key regulatory mechanism in sperm function. In mammalian sperm the Ca(2)(+)-permeable plasma membrane ion channel CatSper is central to [Ca(2)(+)]i signalling, but there is good evidence that Ca(2)(+) stored in intracellular organelles is also functionally important. Here we briefly review the current understanding of the diversity of Ca(2)(+) stores and the mechanisms for the regulation of their activity. We then consider the evidence for the involvement of these stores in [Ca(2)(+)]i signalling in mammalian (primarily human) sperm, the agonists that may activate these stores and their role in control of sperm function. Finally we consider the evidence that membrane Ca(2)(+) channels and stored Ca(2)(+) may play discrete roles in the regulation of sperm activities and propose a mechanism by which these different components of the sperm Ca(2)(+)-signalling apparatus may interact to generate complex and spatially diverse [Ca(2)(+)]i signals.
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Affiliation(s)
- Joao Correia
- School of BiosciencesUniversity of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | | | - Stephen Publicover
- School of BiosciencesUniversity of Birmingham, Edgbaston, Birmingham B15 2TT, UK
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Abstract
Exocytosis is a highly regulated process that consists of multiple functionally, kinetically and/or morphologically definable stages such as recruitment, targeting, tethering and docking of secretory vesicles with the plasma membrane, priming of the fusion machinery and calcium-triggered membrane fusion. After fusion, the membrane around the secretory vesicle is incorporated into the plasma membrane and the granule releases its contents. The proteins involved in these processes belong to several highly conserved families: Rab GTPases, SNAREs (soluble NSF-attachment protein receptors), α-SNAP (α-NSF attachment protein), NSF (N-ethylmaleimide-sensitive factor), Munc13 and -18, complexins and synaptotagmins. In the present article, the molecules of exocytosis are reviewed, using human sperm as a model system. Sperm exocytosis is driven by isoforms of the same proteinaceous fusion machinery mentioned above, with their functions orchestrated in a hierarchically organized and unidirectional signalling cascade. In addition to the universal exocytosis regulator calcium, this cascade includes other second messengers such as diacylglycerol, inositol 1,4,5-trisphosphate and cAMP, as well as the enzymes that synthesize them and their target proteins. Of special interest is the cAMP-binding protein Epac (exchange protein directly activated by cAMP) due in part to its enzymatic activity towards Rap. The activation of Epac and Rap leads to a highly localized calcium signal which, together with assembly of the SNARE complex, governs the final stages of exocytosis. The source of this releasable calcium is the secretory granule itself.
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Bustos MA, Roggero CM, De la Iglesia PX, Mayorga LS, Tomes CN. GTP-bound Rab3A exhibits consecutive positive and negative roles during human sperm dense-core granule exocytosis. J Mol Cell Biol 2015; 6:286-98. [PMID: 25053757 DOI: 10.1093/jmcb/mju021] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Exocytosis of mammalian sperm dense-core secretory granule relies on the same fusion molecules as all other secretory cells; one such molecule is the small GTPase Rab3A. Here, we report an in-depth biochemical characterization of the role of Rab3A in secretion by scrutinizing the exocytotic response of streptolysin O-permeabilized human sperm to the acute application of a number of Rab3A-containing constructs and correlating the findings with those gathered with the endogenous protein. Full length, geranylgeranylated, and active Rab3A elicited human sperm exocytosis per se. With Rab3A/Rab22A chimeric proteins, we demonstrated that the carboxy-terminal domain of the Rab3A molecule was necessary and sufficient to promote exocytosis, whereas its amino-terminus prevented calcium-triggered secretion. Interestingly, full length Rab3A halted secretion when added after the docking of the acrosome to the plasma membrane. This effect depended on the inability of Rab3A to hydrolyze GTP. We combined modified immunofluorescence and acrosomal staining protocols to detect membrane fusion and the activation status of endogenous Rab3 simultaneously in individual cells, and found that GTP hydrolysis on endogenous Rab3 was mandatory for fusion pores to open. Our findings contribute to establishing that Rab3 modulates regulated exocytosis differently depending on the nucleotide bound and the exocytosis stage under study.
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Affiliation(s)
- Matías A Bustos
- Instituto de Histología y Embriología, IHEM-CONICET, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Carlos M Roggero
- Instituto de Histología y Embriología, IHEM-CONICET, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina Present address: Department of Biophysics, UT Southwestern Medical Center, Dallas, TX, USA
| | - Paola X De la Iglesia
- Instituto de Histología y Embriología, IHEM-CONICET, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina Present address: Servicio de Patología, Hospital Italiano de Buenos Aires, Buenos Aires, Argentina
| | - Luis S Mayorga
- Instituto de Histología y Embriología, IHEM-CONICET, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Claudia N Tomes
- Instituto de Histología y Embriología, IHEM-CONICET, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
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Reid AT, Anderson AL, Roman SD, McLaughlin EA, McCluskey A, Robinson PJ, Aitken RJ, Nixon B. Glycogen synthase kinase 3 regulates acrosomal exocytosis in mouse spermatozoa via dynamin phosphorylation. FASEB J 2015; 29:2872-82. [PMID: 25808536 DOI: 10.1096/fj.14-265553] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 03/09/2015] [Indexed: 11/11/2022]
Abstract
The dynamin family of GTPases has been implicated as novel regulators of the acrosome reaction, a unique exocytotic event that is essential for fertilization. Dynamin activity during the acrosome reaction is accompanied by phosphorylation of key serine residues. We now tested the hypothesis that glycogen synthase kinase 3 (GSK3) is the protein kinase responsible for dynamin phosphorylation at these phosphosites in mouse spermatozoa. Pharmacologic inhibition of GSK3 in mature mouse spermatozoa (CHIR99021: IC50 = 6.7 nM) led to a significant reduction in dynamin phosphorylation (10.3% vs. 27.3%; P < 0.001), acrosomal exocytosis (9.7% vs. 25.7%; P < 0.01), and in vitro fertilization (53% vs. 100%; P < 0.01). GSK3 was shown to be present in developing germ cells where it colocalized with dynamin in the peri-acrosomal domain. However, additional GSK3 was acquired by maturing mouse spermatozoa within the male reproductive tract, via a novel mechanism involving direct interaction of sperm heads with extracellular structures known as epididymal dense bodies. These data reveal a novel mode for the cellular acquisition of a protein kinase and identify a key role for GSK3 in the regulation of sperm maturation and acrosomal exocytosis.
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Affiliation(s)
- Andrew T Reid
- *School of Environmental and Life Sciences, Discipline of Biological Sciences, and School of Environmental and Life Sciences, Discipline of Chemistry, The University of Newcastle, Callaghan, New South Wales, Australia; and Children's Medical Research Institute, The University of Sydney, Westmead, New South Wales, Australia
| | - Amanda L Anderson
- *School of Environmental and Life Sciences, Discipline of Biological Sciences, and School of Environmental and Life Sciences, Discipline of Chemistry, The University of Newcastle, Callaghan, New South Wales, Australia; and Children's Medical Research Institute, The University of Sydney, Westmead, New South Wales, Australia
| | - Shaun D Roman
- *School of Environmental and Life Sciences, Discipline of Biological Sciences, and School of Environmental and Life Sciences, Discipline of Chemistry, The University of Newcastle, Callaghan, New South Wales, Australia; and Children's Medical Research Institute, The University of Sydney, Westmead, New South Wales, Australia
| | - Eileen A McLaughlin
- *School of Environmental and Life Sciences, Discipline of Biological Sciences, and School of Environmental and Life Sciences, Discipline of Chemistry, The University of Newcastle, Callaghan, New South Wales, Australia; and Children's Medical Research Institute, The University of Sydney, Westmead, New South Wales, Australia
| | - Adam McCluskey
- *School of Environmental and Life Sciences, Discipline of Biological Sciences, and School of Environmental and Life Sciences, Discipline of Chemistry, The University of Newcastle, Callaghan, New South Wales, Australia; and Children's Medical Research Institute, The University of Sydney, Westmead, New South Wales, Australia
| | - Phillip J Robinson
- *School of Environmental and Life Sciences, Discipline of Biological Sciences, and School of Environmental and Life Sciences, Discipline of Chemistry, The University of Newcastle, Callaghan, New South Wales, Australia; and Children's Medical Research Institute, The University of Sydney, Westmead, New South Wales, Australia
| | - R John Aitken
- *School of Environmental and Life Sciences, Discipline of Biological Sciences, and School of Environmental and Life Sciences, Discipline of Chemistry, The University of Newcastle, Callaghan, New South Wales, Australia; and Children's Medical Research Institute, The University of Sydney, Westmead, New South Wales, Australia
| | - Brett Nixon
- *School of Environmental and Life Sciences, Discipline of Biological Sciences, and School of Environmental and Life Sciences, Discipline of Chemistry, The University of Newcastle, Callaghan, New South Wales, Australia; and Children's Medical Research Institute, The University of Sydney, Westmead, New South Wales, Australia
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Pelletán LE, Suhaiman L, Vaquer CC, Bustos MA, De Blas GA, Vitale N, Mayorga LS, Belmonte SA. ADP ribosylation factor 6 (ARF6) promotes acrosomal exocytosis by modulating lipid turnover and Rab3A activation. J Biol Chem 2015; 290:9823-41. [PMID: 25713146 DOI: 10.1074/jbc.m114.629006] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Indexed: 11/06/2022] Open
Abstract
Regulated secretion is a central issue for the specific function of many cells; for instance, mammalian sperm acrosomal exocytosis is essential for egg fertilization. ARF6 (ADP-ribosylation factor 6) is a small GTPase implicated in exocytosis, but its downstream effectors remain elusive in this process. We combined biochemical, functional, and microscopy-based methods to show that ARF6 is present in human sperm, localizes to the acrosomal region, and is required for calcium and diacylglycerol-induced exocytosis. Results from pulldown assays show that ARF6 exchanges GDP for GTP in sperm challenged with different exocytic stimuli. Myristoylated and guanosine 5'-3-O-(thio)triphosphate (GTPγS)-loaded ARF6 (active form) added to permeabilized sperm induces acrosome exocytosis even in the absence of extracellular calcium. We explore the ARF6 signaling cascade that promotes secretion. We demonstrate that ARF6 stimulates a sperm phospholipase D activity to produce phosphatidic acid and boosts the synthesis of phosphatidylinositol 4,5-bisphosphate. We present direct evidence showing that active ARF6 increases phospholipase C activity, causing phosphatidylinositol 4,5-bisphosphate hydrolysis and inositol 1,4,5-trisphosphate-dependent intra-acrosomal calcium release. We show that active ARF6 increases the exchange of GDP for GTP on Rab3A, a prerequisite for secretion. We propose that exocytic stimuli activate ARF6, which is required for acrosomal calcium efflux and the assembly of the membrane fusion machinery. This report highlights the physiological importance of ARF6 as a key factor for human sperm exocytosis and fertilization.
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Affiliation(s)
- Leonardo E Pelletán
- From the Instituto de Histología y Embriología, CONICET, Facultad de Ciencias Médicas, CC56, Universidad Nacional de Cuyo, 5500 Mendoza, Argentina and
| | - Laila Suhaiman
- From the Instituto de Histología y Embriología, CONICET, Facultad de Ciencias Médicas, CC56, Universidad Nacional de Cuyo, 5500 Mendoza, Argentina and
| | - Cintia C Vaquer
- From the Instituto de Histología y Embriología, CONICET, Facultad de Ciencias Médicas, CC56, Universidad Nacional de Cuyo, 5500 Mendoza, Argentina and
| | - Matías A Bustos
- From the Instituto de Histología y Embriología, CONICET, Facultad de Ciencias Médicas, CC56, Universidad Nacional de Cuyo, 5500 Mendoza, Argentina and
| | - Gerardo A De Blas
- From the Instituto de Histología y Embriología, CONICET, Facultad de Ciencias Médicas, CC56, Universidad Nacional de Cuyo, 5500 Mendoza, Argentina and
| | - Nicolas Vitale
- the Département Neurotransmission et Sécrétion Neuroendocrine, Institut des Neurosciences Cellulaires et Intégratives (UPR 3212), CNRS et Université de Strasbourg, 5 Rue Blaise Pascal, 67084 Strasbourg, France
| | - Luis S Mayorga
- From the Instituto de Histología y Embriología, CONICET, Facultad de Ciencias Médicas, CC56, Universidad Nacional de Cuyo, 5500 Mendoza, Argentina and
| | - Silvia A Belmonte
- From the Instituto de Histología y Embriología, CONICET, Facultad de Ciencias Médicas, CC56, Universidad Nacional de Cuyo, 5500 Mendoza, Argentina and
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Sosa CM, Pavarotti MA, Zanetti MN, Zoppino FCM, De Blas GA, Mayorga LS. Kinetics of human sperm acrosomal exocytosis. Mol Hum Reprod 2014; 21:244-54. [PMID: 25452326 DOI: 10.1093/molehr/gau110] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The acrosome reaction is a unique event in the lifespan of sperm characterized by the exocytosis of the acrosomal content and the release of hybrid vesicles formed by patches of the outer acrosomal membrane and the plasma membrane. This unique regulated exocytosis is mediated by essentially the same membrane fusion machinery present in neuroendocrine cells. However, whereas secretion in neuroendocrine cells occurs in less than a second, the acrosome reaction is normally assessed after several minutes of incubation with inducers. In this report, we measured the kinetics of human sperm exocytosis triggered by two stimuli (calcium ionophore and progesterone) by using electron microscopy and three different approaches based on the incorporation of fluorescent Pisum sativum agglutinin into the acrosome upon opening of fusion pores connecting the extracellular medium with the acrosomal lumen. The results with the different methods are consistent with a slow kinetics (t½ = 14 min). We also manipulated the system to measure different steps of the process. We observed that cytosolic calcium increased with a relatively fast kinetics (t½ = 0.1 min). In contrast, the swelling of the acrosomal granule that precedes exocytosis was a slow process (t½ = 13 min). When swelling was completed, the fusion pore opening was fast (t½ = 0.2 min). The results indicate that acrosomal swelling is the slowest step and it determines the kinetics of the acrosome reaction. After the swelling is completed, the efflux of calcium from intracellular stores triggers fusion pores opening and the release of hybrid vesicles in seconds.
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Affiliation(s)
- C M Sosa
- IHEM (CONICET-UNCuyo), School of Medicine, National University of Cuyo, 5500 Mendoza, Argentina
| | - M A Pavarotti
- IHEM (CONICET-UNCuyo), School of Medicine, National University of Cuyo, 5500 Mendoza, Argentina
| | - M N Zanetti
- IHEM (CONICET-UNCuyo), School of Medicine, National University of Cuyo, 5500 Mendoza, Argentina Present address: Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
| | - F C M Zoppino
- IHEM (CONICET-UNCuyo), School of Medicine, National University of Cuyo, 5500 Mendoza, Argentina Present address: Laboratory of Oncology, Institute of Experimental Medicine and Biology of Cuyo (IMBECU - CONICET), 5500 Mendoza, Argentina
| | - G A De Blas
- IHEM (CONICET-UNCuyo), School of Medicine, National University of Cuyo, 5500 Mendoza, Argentina
| | - L S Mayorga
- IHEM (CONICET-UNCuyo), School of Medicine, National University of Cuyo, 5500 Mendoza, Argentina
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Ruete MC, Lucchesi O, Bustos MA, Tomes CN. Epac, Rap and Rab3 act in concert to mobilize calcium from sperm's acrosome during exocytosis. Cell Commun Signal 2014; 12:43. [PMID: 25159528 PMCID: PMC4156617 DOI: 10.1186/s12964-014-0043-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Accepted: 06/19/2014] [Indexed: 11/11/2022] Open
Abstract
Background Exocytosis of sperm’s single secretory granule or acrosome (acrosome reaction, AR) is a highly regulated event essential for fertilization. The AR begins with an influx of calcium from the extracellular milieu and continues with the synthesis of cAMP and the activation of its target Epac. The cascade bifurcates into a Rab3-GTP-driven limb that assembles the fusion machinery and a Rap-GTP-driven limb that mobilizes internal calcium. Results To understand the crosstalk between the two signaling cascades, we applied known AR inhibitors in three experimental approaches: reversible, stage-specific blockers in a functional assay, a far-immunofluorescence protocol to detect active Rab3 and Rap, and single cell-confocal microscopy to visualize fluctuations in internal calcium stores. Our model system was human sperm with their plasma membrane permeabilized with streptolysin O and stimulated with external calcium. The inhibition caused by reagents that prevented the activation of Rap was reversed by mobilizing intracellular calcium pharmacologically, whereas that caused by AR inhibitors that impeded Rab3’s binding to GTP was not. Both limbs of the exocytotic cascade joined at or near the stage catalyzed by Rab3 in a unidirectional, hierarchical connection in which the intra-acrosomal calcium mobilization arm was subordinated to the fusion protein arm; somewhere after Rab3, the pathways became independent. Conclusions We delineated the sequence of events that connect an external calcium signal to internal calcium mobilization during exocytosis. We have taken advantage of the versatility of the sperm model to investigate how cAMP, calcium, and the proteinaceous fusion machinery coordinate to accomplish secretion. Because the requirement of calcium from two different sources is not unique to sperm and fusion proteins are highly conserved, our findings might contribute to elucidate mechanisms that operate in regulated exocytosis in other secretory cell types. Electronic supplementary material The online version of this article (doi:10.1186/s12964-014-0043-0) contains supplementary material, which is available to authorized users.
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Sánchez-Cárdenas C, Servín-Vences MR, José O, Treviño CL, Hernández-Cruz A, Darszon A. Acrosome reaction and Ca²⁺ imaging in single human spermatozoa: new regulatory roles of [Ca²⁺]i. Biol Reprod 2014; 91:67. [PMID: 25100708 DOI: 10.1095/biolreprod.114.119768] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The spermatozoa acrosome reaction (AR) is essential for mammalian fertilization. Few methods allow visualization of AR in real time together with Ca²⁺ imaging. Here, we show that FM4-64, a fluorescent dye used to follow exocytosis, reliably reports AR progression induced by ionomycin and progesterone in human spermatozoa. FM4-64 clearly delimits the spermatozoa contour and reports morphological cell changes before, during, and after AR. This strategy unveiled the formation of moving tubular appendages, emerging from acrosome-reacted spermatozoa, which was confirmed by scanning electron microscopy. Alternate wavelength illumination allowed concomitant imaging of FM4-64 and Fluo-4, a Ca²⁺ indicator. These AR and intracellular Ca²⁺ ([Ca²⁺]i) recordings revealed that the presence of [Ca²⁺]i oscillations, both spontaneous and progesterone induced, prevents AR in human spermatozoa. Notably, the progesterone-induced AR is preceded by a second [Ca²⁺]i peak and ~40% of reacting spermatozoa also manifest a slow [Ca²⁺]i rise ~2 min before AR. Our findings uncover new AR features related to [Ca²⁺]i.
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Affiliation(s)
- Claudia Sánchez-Cárdenas
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, México
| | - Martha Rocio Servín-Vences
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, México
| | - Omar José
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, México
| | - Claudia Lydia Treviño
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, México
| | - Arturo Hernández-Cruz
- Departamento de Neurociencia Cognitiva, Instituto de Fisiología Celular, UNAM, Circuito exterior s/n, Ciudad Universitaria, México DF
| | - Alberto Darszon
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, México
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Chiu PCN, Lam KKW, Wong RCW, Yeung WSB. The identity of zona pellucida receptor on spermatozoa: an unresolved issue in developmental biology. Semin Cell Dev Biol 2014; 30:86-95. [PMID: 24747367 DOI: 10.1016/j.semcdb.2014.04.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Revised: 04/04/2014] [Accepted: 04/07/2014] [Indexed: 11/29/2022]
Abstract
Mammalian oocytes are surrounded by an acellular zona pellucida (ZP). Fertilization begins when a capacitated spermatozoon binds to the ZP. Defective sperm-ZP interaction is a cause of male infertility and reduced fertilization rates in clinical assisted reproduction treatment. Despite the importance of spermatozoa-ZP binding, the mechanisms and regulation of the interaction are unclear partly due to the failure in the identification of ZP receptor on spermatozoa. Most of the previous studies assumed that the sperm ZP receptor is a single molecular species, and a number of potential candidates had been suggested. Yet none of them can be considered as the sole sperm ZP receptor. Accumulated evidence suggested that the sperm ZP receptor is a dynamic multi-molecular structure requiring coordinated action of different proteins that are assembled into a functional complex during post-testicular maturation and capacitation. The complex components may include carbohydrate-binding, protein-binding and acrosomal matrix proteins which work as a suite to mediate spermatozoa-ZP interaction. This article aims to review the latest insights in the identification of the sperm ZP receptor. Continued investigation of the area will provide considerable understanding of the regulation of fertilization that will be useful for practical application in human contraception and reproductive medicine.
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Affiliation(s)
- Philip C N Chiu
- Department of Obstetrics and Gynaecology, University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Hong Kong, China; Centre of Reproduction, Development and Growth, LKS Faculty of Medicine, University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Hong Kong, China
| | - Kevin K W Lam
- Department of Obstetrics and Gynaecology, University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Hong Kong, China
| | - Rachel C W Wong
- Department of Obstetrics and Gynaecology, University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Hong Kong, China
| | - William S B Yeung
- Department of Obstetrics and Gynaecology, University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Hong Kong, China; Centre of Reproduction, Development and Growth, LKS Faculty of Medicine, University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Hong Kong, China.
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Bjerregaard B, Lemmen JG, Petersen MR, Østrup E, Iversen LH, Almstrup K, Larsson LI, Ziebe S. Syncytin-1 and its receptor is present in human gametes. J Assist Reprod Genet 2014; 31:533-9. [PMID: 24687878 DOI: 10.1007/s10815-014-0224-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 03/14/2014] [Indexed: 12/11/2022] Open
Abstract
MAIN PURPOSE AND RESEARCH QUESTION To determine whether the true fusogen Syncytin-1 and its receptor (ASCT-2) is present in human gametes using qRT-PCR, immunoblotting and immunofluorescence. METHODS Donated oocytes and spermatozoa, originating from a fertility center in tertiary referral university hospital, underwent qRT-PCR, immunoblotting and immunofluorescence analyzes. RESULTS Quantitative RT-PCR of sperm samples from sperm donors showed that syncytin-1 is present in all samples, however, protein levels varied between donors. Syncytin-1 immunoreactivity predominates in the sperm head and around the equatorial segment. The receptor ASCT-2 is expressed in the acrosomal region and in the sperm tail. Moreover, ASCT-2, but not syncytin-1, is expressed in oocytes and the mRNA level increases with increasing maturity of the oocytes. CONCLUSIONS Syncytin and its receptor are present in human gametes and localization and temporal appearance is consistent with a possible role in fusion between oocyte and sperm.
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Affiliation(s)
- B Bjerregaard
- Faculty of Life Science, University of Copenhagen, Copenhagen, Denmark
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44
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Buffone MG, Hirohashi N, Gerton GL. Unresolved questions concerning mammalian sperm acrosomal exocytosis. Biol Reprod 2014; 90:112. [PMID: 24671881 DOI: 10.1095/biolreprod.114.117911] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
In recent years, the study of mammalian acrosomal exocytosis has produced some major advances that challenge the long-held, general paradigms in the field. Principally, the idea that sperm must be acrosome-intact to bind to the zona pellucida of unfertilized eggs, based largely on in vitro fertilization studies of mouse oocytes denuded of the cumulus oophorus, has been overturned by experiments using state-of-the-art imaging of cumulus-intact oocytes and fertilization experiments where eggs were reinseminated by acrosome-reacted sperm recovered from the perivitelline space of zygotes. In light of these results, this minireview highlights a number of unresolved questions and emphasizes the fact that there is still much work to be done in this exciting field. Future experiments using recently advanced technologies should lead to a more complete and accurate understanding of the molecular mechanisms governing the fertilization process in mammals.
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Affiliation(s)
- Mariano G Buffone
- Instituto de Biologia y Medicina Experimental, National Research Council of Argentina (CONICET), Buenos Aires, Argentina
| | - Noritaka Hirohashi
- Oki Marine Biological Station, Education and Research Center for Biological Resources, Shimane University, Shimane, Japan
| | - George L Gerton
- Center for Research on Reproduction and Women's Health, Department of Obstetrics and Gynecology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
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Shi L, Zhang Q, Xu B, Jiang X, Dai Y, Zhang CY, Zen K. Sustained high protein-tyrosine phosphatase 1B activity in the sperm of obese males impairs the sperm acrosome reaction. J Biol Chem 2014; 289:8432-41. [PMID: 24519936 DOI: 10.1074/jbc.m113.517466] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Evidence of a causal link between male obesity and subfertility or infertility has been demonstrated previously. However, the mechanism underlying this link is incompletely understood. Here, we report that sustained high protein-tyrosine phosphatase 1B (PTP1B) activity in sperm of obese donors plays an essential role in coupling male obesity and subfertility or infertility. First, PTP1B level and activity were significantly higher in sperm from ob/ob mice than in wild-type littermates. High PTP1B level and activity in sperm was also observed in obese patients compared with non-obese donors. The enhanced sperm PTP1B level and activity in ob/ob mice and obese patients correlated with a defect of the sperm acrosome reaction (AR). Second, treating sperm from male ob/ob mice or obese men with a specific PTP1B inhibitor largely restored the sperm AR. Finally, blockade of sperm AR by enhanced PTP1B activity in male ob/ob mice or obese men was due to prolonged dephosphorylation of N-ethylmaleimide-sensitive factor by PTP1B, leading to the inability to reassemble the trans-SNARE complexes, which is a critical step in sperm acrosomal exocytosis. In summary, our study demonstrates for the first time that a sustained high PTP1B level or activity in the sperm of obese donors causes a defect of sperm AR and that PTP1B is a novel potential therapeutic target for male infertility treatment.
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Affiliation(s)
- Lei Shi
- From the Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, Jiangsu 210093, China and
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46
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Arndt L, Castonguay J, Arlt E, Meyer D, Hassan S, Borth H, Zierler S, Wennemuth G, Breit A, Biel M, Wahl-Schott C, Gudermann T, Klugbauer N, Boekhoff I. NAADP and the two-pore channel protein 1 participate in the acrosome reaction in mammalian spermatozoa. Mol Biol Cell 2014; 25:948-64. [PMID: 24451262 PMCID: PMC3952862 DOI: 10.1091/mbc.e13-09-0523] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
A TPCN1 gene–deficient mouse strain is used to show that two convergent working NAADP-dependent pathways with nonoverlapping activation and self-inactivation profiles for distinct NAADP concentrations drive acrosomal exocytosis, by which TPC1 is central for the pathway activated by low-micromolar NAADP concentrations. The functional relationship between the formation of hundreds of fusion pores during the acrosome reaction in spermatozoa and the mobilization of calcium from the acrosome has been determined only partially. Hence, the second messenger NAADP, promoting efflux of calcium from lysosome-like compartments and one of its potential molecular targets, the two-pore channel 1 (TPC1), were analyzed for its involvement in triggering the acrosome reaction using a TPCN1 gene–deficient mouse strain. The present study documents that TPC1 and NAADP-binding sites showed a colocalization at the acrosomal region and that treatment of spermatozoa with NAADP resulted in a loss of the acrosomal vesicle that showed typical properties described for TPCs: Registered responses were not detectable for its chemical analogue NADP and were blocked by the NAADP antagonist trans-Ned-19. In addition, two narrow bell-shaped dose-response curves were identified with maxima in either the nanomolar or low micromolar NAADP concentration range, where TPC1 was found to be responsible for activating the low affinity pathway. Our finding that two convergent NAADP-dependent pathways are operative in driving acrosomal exocytosis supports the concept that both NAADP-gated cascades match local NAADP concentrations with the efflux of acrosomal calcium, thereby ensuring complete fusion of the large acrosomal vesicle.
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Affiliation(s)
- Lilli Arndt
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians University, 81377 München, Germany Department of Pharmacy, Ludwig-Maximilians University, 81377 München, Germany Institute for Experimental and Clinical Pharmacology and Toxicology, Albert-Ludwigs-University, 79104 Freiburg, Germany Institute for Anatomy, University of Duisburg-Essen, 45141 Essen, Germany
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Abstract
Fertilization is the process by which eggs and spermatozoa interact, achieve mutual recognition, and fuse to create a zygote, which then develops to form a new individual, thus allowing for the continuity of a species. Despite numerous studies on mammalian fertilization, the molecular mechanisms underpinning the fertilization event remain largely unknown. However, as I summarize here, recent work using both gene-manipulated animals and in vitro studies has begun to elucidate essential sperm and egg molecules and to establish predictive models of successful fertilization.
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Affiliation(s)
- Masaru Okabe
- Center for Genetic Analysis for Biological Responses Research Institute for Microbial Diseases Osaka University, Yamadaoka 3-1, Suita, Osaka 565-0871, Japan
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48
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Shang Y, Chen L, Liu Z, Wang X, Ma X, Miao L. Cytosolic Ca(2+) as a multifunctional modulator is required for spermiogenesis in Ascaris suum. Protein Cell 2013; 4:456-66. [PMID: 23686736 DOI: 10.1007/s13238-013-3019-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 04/07/2013] [Indexed: 10/26/2022] Open
Abstract
The dynamic polar polymers actin filaments and microtubules are usually employed to provide the structural basis for establishing cell polarity in most eukaryotic cells. Radially round and immotile spermatids from nematodes contain almost no actin or tubulin, but still have the ability to break symmetry to extend a pseudopod and initiate the acquisition of motility powered by the dynamics of cytoskeleton composed of major sperm protein (MSP) during spermiogenesis (sperm activation). However, the signal transduction mechanism of nematode sperm activation and motility acquisition remains poorly understood. Here we show that Ca(2+) oscillations induced by the Ca(2+) release from intracellular Ca(2+) store through inositol (1,4,5)-trisphosphate receptor are required for Ascaris suum sperm activation. The chelation of cytosolic Ca(2+) suppresses the generation of a functional pseudopod, and this suppression can be relieved by introducing exogenous Ca(2+) into sperm cells. Ca(2+) promotes MSP-based sperm motility by increasing mitochondrial membrane potential and thus the energy supply required for MSP cytoskeleton assembly. On the other hand, Ca(2+) promotes MSP disassembly by activating Ca(2+)/calmodulin-dependent serine/threonine protein phosphatase calcineurin. In addition, Ca(2+)/camodulin activity is required for the fusion of sperm-specifi c membranous organelle with the plasma membrane, a regulated exocytosis required for sperm motility. Thus, Ca(2+) plays multifunctional roles during sperm activation in Ascaris suum.
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Affiliation(s)
- Yunlong Shang
- Laboratory of Noncoding RNA, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
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49
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Bromfield EG, Nixon B. The function of chaperone proteins in the assemblage of protein complexes involved in gamete adhesion and fusion processes. Reproduction 2013; 145:R31-42. [PMID: 23166368 DOI: 10.1530/rep-12-0316] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The remarkable complexity of the molecular events governing adhesion and fusion of the male and female gametes is becoming apparent. Novel research suggests that these highly specific cellular interactions are facilitated by multiprotein complexes that are delivered to and/or assembled on the surface of the gametes by molecular chaperones in preparation for sperm-egg interaction. While the activation of these molecular chaperones and the mechanisms by which they shuttle proteins to the surface of the cell remain the subject of ongoing investigation, a compelling suggestion is that these processes are augmented by dynamic membrane microdomains or lipid rafts that migrate to the apical region of the sperm head after capacitation. Preliminary studies of the oocyte plasma membrane have also revealed the presence of lipid rafts comprising several molecular chaperones, raising the possibility that similar mechanisms may be involved in the activation of maternal fusion machinery and the regulation of oocyte plasma membrane integrity. Despite these findings, the analysis of oocyte surface multiprotein complexes is currently lacking. Further analyses of the intermediary proteins that facilitate the expression of key players in sperm-egg fusion are likely to deliver important insights into this unique event, which culminates in the cytoplasmic continuity of the male and female gametes.
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Affiliation(s)
- Elizabeth G Bromfield
- Priority Research Centre in Reproductive Science, School of Environmental and Life Sciences, Discipline of Biological Sciences, The University of Newcastle, Callaghan, New South Wales 2308, Australia
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50
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Raudsepp T, McCue ME, Das PJ, Dobson L, Vishnoi M, Fritz KL, Schaefer R, Rendahl AK, Derr JN, Love CC, Varner DD, Chowdhary BP. Genome-wide association study implicates testis-sperm specific FKBP6 as a susceptibility locus for impaired acrosome reaction in stallions. PLoS Genet 2012; 8:e1003139. [PMID: 23284302 PMCID: PMC3527208 DOI: 10.1371/journal.pgen.1003139] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Accepted: 10/18/2012] [Indexed: 01/07/2023] Open
Abstract
Impaired acrosomal reaction (IAR) of sperm causes male subfertility in humans and animals. Despite compelling evidence about the genetic control over acrosome biogenesis and function, the genomics of IAR is as yet poorly understood, providing no molecular tools for diagnostics. Here we conducted Equine SNP50 Beadchip genotyping and GWAS using 7 IAR–affected and 37 control Thoroughbred stallions. A significant (P<6.75E-08) genotype–phenotype association was found in horse chromosome 13 in FK506 binding protein 6 (FKBP6). The gene belongs to the immunophilins FKBP family known to be involved in meiosis, calcium homeostasis, clathrin-coated vesicles, and membrane fusions. Direct sequencing of FKBP6 exons in cases and controls identified SNPs g.11040315G>A and g.11040379C>A (p.166H>N) in exon 4 that were significantly associated with the IAR phenotype both in the GWAS cohort (n = 44) and in a large multi-breed cohort of 265 horses. All IAR stallions were homozygous for the A-alleles, while this genotype was found only in 2% of controls. The equine FKBP6 was exclusively expressed in testis and sperm and had 5 different transcripts, of which 4 were novel. The expression of this gene in AC/AG heterozygous controls was monoallelic, and we observed a tendency for FKBP6 up-regulation in IAR stallions compared to controls. Because exon 4 SNPs had no effect on the protein structure, it is likely that FKBP6 relates to the IAR phenotype via regulatory or modifying functions. In conclusion, FKBP6 was considered a susceptibility gene of incomplete penetrance for IAR in stallions and a candidate gene for male subfertility in mammals. FKBP6 genotyping is recommended for the detection of IAR–susceptible individuals among potential breeding stallions. Successful use of sperm as a source of DNA and RNA propagates non-invasive sample procurement for fertility genomics in animals and humans. Impaired acrosomal reaction (IAR) of sperm causes male subfertility in humans and animals, and currently the molecular causes of the condition are not known. Here we report the mapping, identification, and functional analysis of a susceptibility locus for IAR in stallions. The candidate region was mapped to horse chromosome 13 by SNP genotyping and GWAS of 7 IAR affected and 44 control Thoroughbred stallions. Re-sequencing and case-control analysis of functionally relevant candidate genes in the region identified FKBP6 gene as a significantly associated locus. The association was confirmed by genotyping 265 male horses of multiple breeds. FKBP6 belongs to the immunophilins FKBP family known to be involved in meiosis, calcium homeostasis, clathrin-coated vesicles, and membrane fusions. We showed that the equine FKBP6 is exclusively and monoallelically expressed in testis and sperm and has 5 different transcripts, of which 4 were novel. Overall, FKBP6 was considered a susceptibility gene of incomplete penetrance for IAR in stallions and a candidate gene for male subfertility in other mammals. Successful use of sperm as a source of DNA and RNA propagates non-invasive sample procurement for fertility genomics in animals and humans.
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Affiliation(s)
- Terje Raudsepp
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, USA.
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