1
|
Hwang JY, Chung JJ. CatSper Calcium Channels: 20 Years On. Physiology (Bethesda) 2023; 38:0. [PMID: 36512352 PMCID: PMC10085559 DOI: 10.1152/physiol.00028.2022] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 12/12/2022] [Accepted: 12/12/2022] [Indexed: 12/15/2022] Open
Abstract
The flagellar-specific Ca2+ channel CatSper is the predominant Ca2+ entry site in mammalian sperm. CatSper-mediated Ca2+ signaling affects nearly every event that regulates sperm to acquire fertilizing capability. In this review, we summarize some of the main findings from 20 years of CatSper research and highlight recent progress and prospects.
Collapse
Affiliation(s)
- Jae Yeon Hwang
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, Connecticut
| | - Jean-Ju Chung
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, Connecticut
- Department of Gynecology and Obstetrics, Yale School of Medicine, New Haven, Connecticut
| |
Collapse
|
2
|
Subbamanda YD, Bhargava A. Intercommunication between Voltage-Gated Calcium Channels and Estrogen Receptor/Estrogen Signaling: Insights into Physiological and Pathological Conditions. Cells 2022; 11:cells11233850. [PMID: 36497108 PMCID: PMC9739980 DOI: 10.3390/cells11233850] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 11/25/2022] [Accepted: 11/28/2022] [Indexed: 12/05/2022] Open
Abstract
Voltage-gated calcium channels (VGCCs) and estrogen receptors are important cellular proteins that have been shown to interact with each other across varied cells and tissues. Estrogen hormone, the ligand for estrogen receptors, can also exert its effects independent of estrogen receptors that collectively constitute non-genomic mechanisms. Here, we provide insights into the VGCC regulation by estrogen and the possible mechanisms involved therein across several cell types. Notably, most of the interaction is described in neuronal and cardiovascular tissues given the importance of VGCCs in these electrically excitable tissues. We describe the modulation of various VGCCs by estrogen known so far in physiological conditions and pathological conditions. We observed that in most in vitro studies higher concentrations of estrogen were used while a handful of in vivo studies used meager concentrations resulting in inhibition or upregulation of VGCCs, respectively. There is a need for more relevant physiological assays to study the regulation of VGCCs by estrogen. Additionally, other interacting receptors and partners need to be identified that may be involved in exerting estrogen receptor-independent effects of estrogen.
Collapse
|
3
|
Wiesehöfer C, Wiesehöfer M, Dankert JT, Chung JJ, von Ostau NE, Singer BB, Wennemuth G. CatSper and its CaM-like Ca 2+ sensor EFCAB9 are necessary for the path chirality of sperm. FASEB J 2022; 36:e22288. [PMID: 35438819 PMCID: PMC9835897 DOI: 10.1096/fj.202101656rr] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 03/11/2022] [Accepted: 03/17/2022] [Indexed: 01/14/2023]
Abstract
Successful fertilization depends on sperm motility adaptation. Ejaculated and activated sperm beat symmetrically in high frequency, move linearly, and swim with clockwise chirality. After capacitation, sperm beat asymmetrically with lower amplitude and a high lateral head excursion. This motility change called hyperactivation requires CatSper activation and an increase in intracellular Ca2+ . However, whether CatSper-mediated Ca2+ influx participates in controlling the swim path chirality is unknown. In this study, we show that the clockwise path chirality is preserved in mouse sperm regardless of capacitation state but is lost in the sperm either lacking the entire CatSper channel or its Ca2+ sensor EFCAB9. Pharmacological inhibition of CatSper with either mibefradil or NNC 55-0396 leads to the same loss in swim path chirality. Exposure of sperm to the recombinant N-terminal part of the zona pellucida protein 2 randomizes chirality in capacitated cells, but not in non-capacitated ones. We conclude that Ca2+ sensitive regulation of CatSper activity orchestrates clockwise swim path chirality of sperm and any substantial change, such as the physiological stimulus of zona pellucida glycoproteins, results in a loss of chirality.
Collapse
Affiliation(s)
| | - Marc Wiesehöfer
- Department of Anatomy, University Duisburg-Essen, D-45147 Essen, Germany
| | | | - Jean-Ju Chung
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, CT 06510, USA
| | - Nicola Edith von Ostau
- Department of Anatomy, University Duisburg-Essen, D-45147 Essen, Germany,Department of Urology, University Hospital Essen, D-45147 Essen, Germany
| | | | - Gunther Wennemuth
- Department of Anatomy, University Duisburg-Essen, D-45147 Essen, Germany,Correspondence to
| |
Collapse
|
4
|
Li YY, Jia YP, Duan LY, Li KM. Participation of the inositol 1,4,5-trisphosphate-gated calcium channel in the zona pellucida- and progesterone-induced acrosome reaction and calcium influx in human spermatozoa. Asian J Androl 2021; 22:192-199. [PMID: 31169139 PMCID: PMC7155789 DOI: 10.4103/aja.aja_44_19] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The acrosome reaction is a prerequisite for fertilization, and its signaling pathway has been investigated for decades. Regardless of the type of inducers present, the acrosome reaction is ultimately mediated by the elevation of cytosolic calcium. Inositol 1,4,5-trisphosphate-gated calcium channels are important components of the acrosome reaction signaling pathway and have been confirmed by several researchers. In this study, we used a novel permeabilization tool BioPORTER® and first demonstrated its effectiveness in spermatozoa. The inositol 1,4,5-trisphosphate type-1 receptor antibody was introduced into spermatozoa by BioPORTER® and significantly reduced the calcium influx and acrosome reaction induced by progesterone, solubilized zona pellucida, and the calcium ionophore A23187. This finding indicates that the inositol 1,4,5-trisphosphate type-1 receptor antibody is a valid inositol 1,4,5-trisphosphate receptor inhibitor and provides evidence of inositol 1,4,5-trisphosphate-gated calcium channel involvement in the acrosome reaction in human spermatozoa. Moreover, we demonstrated that the transfer of 1,4,5-trisphosphate into spermatozoa induced acrosome reactions, which provides more reliable evidence for this process. In addition, by treating the spermatozoa with inositol 1,4,5-trisphosphate/BioPORTER® in the presence or absence of calcium in the culture medium, we showed that the opening of inositol 1,4,5-trisphosphate-gated calcium channels led to extracellular calcium influx. This particular extracellular calcium influx may be the major process of the final step of the acrosome reaction signaling pathway.
Collapse
Affiliation(s)
- Ying-Ya Li
- Center of Reproductive Medicine, Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai 201204, China
| | - Yan-Ping Jia
- Center of Reproductive Medicine, Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai 201204, China
| | - Li-Yan Duan
- Center of Reproductive Medicine, Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai 201204, China
| | - Kun-Ming Li
- Center of Reproductive Medicine, Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai 201204, China
| |
Collapse
|
5
|
Sperm ion channels and transporters in male fertility and infertility. Nat Rev Urol 2020; 18:46-66. [PMID: 33214707 DOI: 10.1038/s41585-020-00390-9] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/08/2020] [Indexed: 12/16/2022]
Abstract
Mammalian sperm cells must respond to cues originating from along the female reproductive tract and from the layers of the egg in order to complete their fertilization journey. Dynamic regulation of ion signalling is, therefore, essential for sperm cells to adapt to their constantly changing environment. Over the past 15 years, direct electrophysiological recordings together with genetically modified mouse models and human genetics have confirmed the importance of ion channels, including the principal Ca2+-selective plasma membrane ion channel CatSper, for sperm activity. Sperm ion channels and membrane receptors are attractive targets for both the development of contraceptives and infertility treatment drugs. Furthermore, in this era of assisted reproductive technologies, understanding the signalling processes implicated in defective sperm function, particularly those arising from genetic abnormalities, is of the utmost importance not only for the development of infertility treatments but also to assess the overall health of a patient and his children. Future studies to improve reproductive health care and overall health care as a function of the ability to reproduce should include identification and analyses of gene variants that underlie human infertility and research into fertility-related molecules.
Collapse
|
6
|
Finkelstein M, Etkovitz N, Breitbart H. Ca 2+ signaling in mammalian spermatozoa. Mol Cell Endocrinol 2020; 516:110953. [PMID: 32712383 DOI: 10.1016/j.mce.2020.110953] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Revised: 06/08/2020] [Accepted: 07/20/2020] [Indexed: 02/06/2023]
Abstract
Calcium is an essential ion which regulates sperm motility, capacitation and the acrosome reaction (AR), three processes necessary for successful fertilization. The AR enables the spermatozoon to penetrate into the egg. In order to undergo the AR, the spermatozoon must reside in the female reproductive tract for several hours, during which a series of biochemical transformations takes place, collectively called capacitation. An early event in capacitation is relatively small elevation of intracellular Ca2+ (in the nM range) and bicarbonate, which collectively activate the soluble adenylyl cyclase to produce cyclic-AMP; c-AMP activates protein kinase A (PKA), leading to indirect tyrosine phosphorylation of proteins. During capacitation, there is an increase in the membrane-bound phospholipase C (PLC) which is activated prior to the AR by relatively high increase in intracellular Ca2+ (in the μM range). PLC catalyzes the hydrolysis of phosphatidyl-inositol-4,5-bisphosphate (PIP2) to diacylglycerol and inositol-trisphosphate (IP3), leading to activation of protein kinase C (PKC) and the IP3-receptor. PKC activates a Ca2+- channel in the plasma membrane, and IP3 activates the Ca2+- channel in the outer acrosomal membrane, leading to Ca2+ depletion from the acrosome. As a result, the plasma-membrane store-operated Ca2+ channel (SOCC) is activated to increase cytosolic Ca2+ concentration, enabling completion of the acrosome reaction. The hydrolysis of PIP2 by PLC results in the release and activation of PIP2-bound gelsolin, leading to F-actin dispersion, an essential step prior to the AR. Ca2+ is also involved in the regulation of sperm motility. During capacitation, the sperm develops a unique motility pattern called hyper-activated motility (HAM) which is essential for successful fertilization. The main Ca2+-channel that mediates HAM is the sperm-specific CatSper located in the sperm tail.
Collapse
Affiliation(s)
| | - Nir Etkovitz
- Sperm Bank, Sheba Hospital, Tel-Hashomer, Israel
| | - Haim Breitbart
- The Mina & Everard Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, 5290002, Israel.
| |
Collapse
|
7
|
Balbach M, Hamzeh H, Jikeli JF, Brenker C, Schiffer C, Hansen JN, Neugebauer P, Trötschel C, Jovine L, Han L, Florman HM, Kaupp UB, Strünker T, Wachten D. Molecular Mechanism Underlying the Action of Zona-pellucida Glycoproteins on Mouse Sperm. Front Cell Dev Biol 2020; 8:572735. [PMID: 32984353 PMCID: PMC7487327 DOI: 10.3389/fcell.2020.572735] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 08/12/2020] [Indexed: 01/10/2023] Open
Abstract
Mammalian oocytes are enveloped by the zona pellucida (ZP), an extracellular matrix of glycoproteins. In sperm, stimulation with ZP proteins evokes a rapid Ca2+ influx via the sperm-specific, pH-sensitive Ca2+ channel CatSper. However, the physiological role and molecular mechanisms underlying ZP-dependent activation of CatSper are unknown. Here, we delineate the sequence of ZP-signaling events in mouse sperm. We show that ZP proteins evoke a rapid intracellular pHi increase that rests predominantly on Na+/H+ exchange by NHA1 and requires cAMP synthesis by the soluble adenylyl cyclase sAC as well as a sufficiently negative membrane potential set by the spem-specific K+ channel Slo3. The alkaline-activated CatSper channel translates the ZP-induced pHi increase into a Ca2+ response. Our findings reveal the molecular components underlying ZP action on mouse sperm, opening up new avenues for understanding the basic principles of sperm function and, thereby, mammalian fertilization.
Collapse
Affiliation(s)
- Melanie Balbach
- Center of Advanced European Studies and Research, Department of Molecular Sensory Systems, Bonn, Germany
| | - Hussein Hamzeh
- Center of Advanced European Studies and Research, Department of Molecular Sensory Systems, Bonn, Germany
| | - Jan F Jikeli
- Institute of Innate Immunity, Department of Biophysical Imaging, Medical Faculty, University of Bonn, Bonn, Germany
| | - Christoph Brenker
- Center of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany
| | - Christian Schiffer
- Center of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany
| | - Jan N Hansen
- Institute of Innate Immunity, Department of Biophysical Imaging, Medical Faculty, University of Bonn, Bonn, Germany
| | - Pia Neugebauer
- Institute of Innate Immunity, Department of Biophysical Imaging, Medical Faculty, University of Bonn, Bonn, Germany
| | | | - Luca Jovine
- Department of Biosciences and Nutrition, Karolinska Institutet, Solna, Sweden
| | - Ling Han
- Department of Biosciences and Nutrition, Karolinska Institutet, Solna, Sweden
| | - Harvey M Florman
- Department of Obstetrics and Gynecology, University of Massachusetts Medical School Worcester, Worcester, MA, United States
| | - U Benjamin Kaupp
- Center of Advanced European Studies and Research, Department of Molecular Sensory Systems, Bonn, Germany.,Life and Medical Sciences Institute, University of Bonn, Bonn, Germany
| | - Timo Strünker
- Center of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany
| | - Dagmar Wachten
- Institute of Innate Immunity, Department of Biophysical Imaging, Medical Faculty, University of Bonn, Bonn, Germany
| |
Collapse
|
8
|
Leemans B, Stout TAE, De Schauwer C, Heras S, Nelis H, Hoogewijs M, Van Soom A, Gadella BM. Update on mammalian sperm capacitation: how much does the horse differ from other species? Reproduction 2020; 157:R181-R197. [PMID: 30721132 DOI: 10.1530/rep-18-0541] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 02/04/2019] [Indexed: 12/21/2022]
Abstract
In contrast to various other mammalian species, conventional in vitro fertilization (IVF) with horse gametes is not reliably successful. In particular, stallion spermatozoa fails to penetrate the zona pellucida, most likely due to incomplete activation of stallion spermatozoa (capacitation) under in vitro conditions. In other mammalian species, specific capacitation triggers have been described; unfortunately, none of these is able to induce full capacitation in stallion spermatozoa. Nevertheless, knowledge of capacitation pathways and their molecular triggers might improve our understanding of capacitation-related events observed in stallion sperm. When sperm cells are exposed to appropriate capacitation triggers, several molecular and biochemical changes should be induced in the sperm plasma membrane and cytoplasm. At the level of the sperm plasma membrane, (1) an increase in membrane fluidity, (2) cholesterol depletion and (3) lipid raft aggregation should occur consecutively; the cytoplasmic changes consist of protein tyrosine phosphorylation and elevated pH, cAMP and Ca2+ concentrations. These capacitation-related events enable the switch from progressive to hyperactivated motility of the sperm cells, and the induction of the acrosome reaction. These final capacitation triggers are indispensable for sperm cells to migrate through the viscous oviductal environment, penetrate the cumulus cells and zona pellucida and, finally, fuse with the oolemma. This review will focus on molecular aspects of sperm capacitation and known triggers in various mammalian species. Similarities and differences with the horse will be highlighted to improve our understanding of equine sperm capacitation/fertilizing events.
Collapse
Affiliation(s)
- Bart Leemans
- Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | - Tom A E Stout
- Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.,Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Catharina De Schauwer
- Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | - Sonia Heras
- Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | - Hilde Nelis
- Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | - Maarten Hoogewijs
- Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | - Ann Van Soom
- Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | - Bart M Gadella
- Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.,Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| |
Collapse
|
9
|
Weiss N, Zamponi GW. Genetic T-type calcium channelopathies. J Med Genet 2020; 57:1-10. [PMID: 31217264 PMCID: PMC6929700 DOI: 10.1136/jmedgenet-2019-106163] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 05/02/2019] [Accepted: 05/18/2019] [Indexed: 12/13/2022]
Abstract
T-type channels are low-voltage-activated calcium channels that contribute to a variety of cellular and physiological functions, including neuronal excitability, hormone and neurotransmitter release as well as developmental aspects. Several human conditions including epilepsy, autism spectrum disorders, schizophrenia, motor neuron disorders and aldosteronism have been traced to variations in genes encoding T-type channels. In this short review, we present the genetics of T-type channels with an emphasis on structure-function relationships and associated channelopathies.
Collapse
Affiliation(s)
- Norbert Weiss
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Praha, Czech Republic
| | - Gerald W Zamponi
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| |
Collapse
|
10
|
Brown SG, Publicover SJ, Barratt CLR, Martins da Silva SJ. Human sperm ion channel (dys)function: implications for fertilization. Hum Reprod Update 2019; 25:758-776. [PMID: 31665287 PMCID: PMC6847974 DOI: 10.1093/humupd/dmz032] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 07/14/2019] [Accepted: 08/13/2019] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Intensive research on sperm ion channels has identified members of several ion channel families in both mouse and human sperm. Gene knock-out studies have unequivocally demonstrated the importance of the calcium and potassium conductances in sperm for fertility. In both species, the calcium current is carried by the highly complex cation channel of sperm (CatSper). In mouse sperm, the potassium current has been conclusively shown to be carried by a channel consisting of the pore forming subunit SLO3 and auxiliary subunit leucine-rich repeat-containing 52 (LRRC52). However, in human sperm it is controversial whether the pore forming subunit of the channel is composed of SLO3 and/or SLO1. Deciphering the role of the proton-specific Hv1 channel is more challenging as it is only expressed in human sperm. However, definitive evidence for a role in, and importance for, human fertility can only be determined through studies using clinical samples. OBJECTIVE AND RATIONALE This review aims to provide insight into the role of sperm ion channels in human fertilization as evidenced from recent studies of sperm from infertile men. We also summarize the key discoveries from mouse ion channel knock-out models and contrast the properties of mouse and human CatSper and potassium currents. We detail the evidence for, and consequences of, defective ion channels in human sperm and discuss hypotheses to explain how defects arise and why affected sperm have impaired fertilization potential. SEARCH METHODS Relevant studies were identified using PubMed and were limited to ion channels that have been characterized in mouse and human sperm. Additional notable examples from other species are included as appropriate. OUTCOMES There are now well-documented fundamental differences between the properties of CatSper and potassium channel currents in mouse and human sperm. However, in both species, sperm lacking either channel cannot fertilize in vivo and CatSper-null sperm also fail to fertilize at IVF. Sperm-lacking potassium currents are capable of fertilizing at IVF, albeit at a much lower rate. However, additional complex and heterogeneous ion channel dysfunction has been reported in sperm from infertile men, the causes of which are unknown. Similarly, the nature of the functional impairment of affected patient sperm remains elusive. There are no reports of studies of Hv1 in human sperm from infertile men. WIDER IMPLICATIONS Recent studies using sperm from infertile men have given new insight and critical evidence supporting the supposition that calcium and potassium conductances are essential for human fertility. However, it should be highlighted that many fundamental questions remain regarding the nature of molecular and functional defects in sperm with dysfunctional ion channels. The development and application of advanced technologies remains a necessity to progress basic and clinical research in this area, with the aim of providing effective screening methodologies to identify and develop treatments for affected men in order to help prevent failed ART cycles. Conversely, development of drugs that block calcium and/or potassium conductances in sperm is a plausible strategy for producing sperm-specific contraceptives.
Collapse
Affiliation(s)
- Sean G Brown
- School of Applied Sciences, Abertay University, Dundee DD11HG, UK
| | | | - Christopher L R Barratt
- Systems Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee DD19SY, UK
| | - Sarah J Martins da Silva
- Systems Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee DD19SY, UK
| |
Collapse
|
11
|
Bondarenko O, Corzo G, Santana FL, Río‐Portilla F, Darszon A, López‐González I. Nonenzymatically oxidized arachidonic acid regulates T‐type Ca
2+
currents in mouse spermatogenic cells. FEBS Lett 2019; 593:1735-1750. [DOI: 10.1002/1873-3468.13448] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 05/14/2019] [Accepted: 05/16/2019] [Indexed: 11/08/2022]
Affiliation(s)
- Olga Bondarenko
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología Universidad Nacional Autónoma de México México México
| | - Gerardo Corzo
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología Universidad Nacional Autónoma de México México México
| | - Félix L. Santana
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología Universidad Nacional Autónoma de México México México
| | - Federico Río‐Portilla
- Departamento de Biomacromoléculas. Instituto de Química Universidad Nacional Autónoma de México México México
| | - Alberto Darszon
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología Universidad Nacional Autónoma de México México México
| | - Ignacio López‐González
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología Universidad Nacional Autónoma de México México México
| |
Collapse
|
12
|
Ritagliati C, Baro Graf C, Stival C, Krapf D. Regulation mechanisms and implications of sperm membrane hyperpolarization. Mech Dev 2018; 154:33-43. [PMID: 29694849 DOI: 10.1016/j.mod.2018.04.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 04/16/2018] [Accepted: 04/18/2018] [Indexed: 12/21/2022]
Abstract
Mammalian sperm are unable to fertilize the egg immediately after ejaculation. In order to gain fertilization competence, they need to undergo a series of biochemical and physiological modifications inside the female reproductive tract, known as capacitation. Capacitation correlates with two essential events for fertilization: hyperactivation, an asymmetric and vigorous flagellar motility, and the ability to undergo the acrosome reaction. At a molecular level, capacitation is associated to: phosphorylation cascades, modification of membrane lipids, alkalinization of the intracellular pH, increase in the intracellular Ca2+ concentration and hyperpolarization of the sperm plasma membrane potential. Hyperpolarization is a crucial event in capacitation since it primes the sperm to undergo the exocytosis of the acrosome content, essential to achieve fertilization of the oocyte.
Collapse
Affiliation(s)
- Carla Ritagliati
- Laboratory of Cell Signal Transduction Networks, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET-UNR), Rosario 2000, Argentina.
| | - Carolina Baro Graf
- Laboratory of Cell Signal Transduction Networks, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET-UNR), Rosario 2000, Argentina
| | - Cintia Stival
- Laboratory of Cell Signal Transduction Networks, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET-UNR), Rosario 2000, Argentina
| | - Dario Krapf
- Laboratory of Cell Signal Transduction Networks, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET-UNR), Rosario 2000, Argentina; Laboratorio de Especialidades Reproductivas, Facultad de Ciencias Bioquimicas y Farmacéuticas, UNR, Rosario 2000, Argentina.
| |
Collapse
|
13
|
Jin SK, Yang WX. Factors and pathways involved in capacitation: how are they regulated? Oncotarget 2018; 8:3600-3627. [PMID: 27690295 PMCID: PMC5356907 DOI: 10.18632/oncotarget.12274] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 09/23/2016] [Indexed: 01/07/2023] Open
Abstract
In mammals, fertilization occurs via a comprehensive progression of events. Freshly ejaculated sperm have yet to acquire progressive motility or fertilization ability. They must first undergo a series of biochemical and physiological changes, collectively known as capacitation. Capacitation is a significant prerequisite to fertilization. During the process of capacitation, changes in membrane properties, intracellular ion concentration and the activities of enzymes, together with other protein modifications, induce multiple signaling events and pathways in defined media in vitro or in the female reproductive tract in vivo. These, in turn, stimulate the acrosome reaction and prepare spermatozoa for penetration of the egg zona pellucida prior to fertilization. In the present review, we conclude all mainstream factors and pathways regulate capacitation and highlight their crosstalk. We also summarize the relationship between capacitation and assisted reproductive technology or human disease. In the end, we sum up the open questions and future avenues in this field.
Collapse
Affiliation(s)
- Shi-Kai Jin
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Wan-Xi Yang
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou, China
| |
Collapse
|
14
|
Tosti E, Ménézo Y. Gamete activation: basic knowledge and clinical applications. Hum Reprod Update 2016; 22:420-39. [PMID: 27278231 PMCID: PMC4917743 DOI: 10.1093/humupd/dmw014] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 04/01/2016] [Indexed: 01/07/2023] Open
Abstract
Background The first clues to the process of gamete activation date back to nearly 60 years ago. The mutual activation of gametes is a crucial event during fertilization. In the testis and ovaries, spermatozoa and oocytes are in a state of meiotic and metabolic quiescence and require reciprocal signals in order to undergo functional changes that lead to competence for fertilization. First, the oocyte activates sperm by triggering motility, chemoattraction, binding and the acrosome reaction, culminating with the fusion of the two plasma membranes. At the end of this cascade of events, collectively known as sperm capacitation, sperm-induced oocyte activation occurs, generating electrical, morphological and metabolic modifications in the oocyte. Objective and rationale The aim of this review is to provide the current state of knowledge regarding the entire process of gamete activation in selected specific animal models that have contributed to our understanding of fertilization in mammals, including humans. Here we describe in detail the reciprocal induction of the two activation processes, the molecules involved and the mechanisms of cell interaction and signal transduction that ultimately result in successful embryo development and creation of a new individual. Search methods We carried out a literature survey with no restrictions on publication date (from the early 1950s to March 2016) using PubMed/Medline, Google Scholar and Web of Knowledge by utilizing common keywords applied in the field of fertilization and embryo development. We also screened the complete list of references published in the most recent research articles and relevant reviews published in English (both animal and human studies) on the topics investigated. Outcomes Literature on the principal animal models demonstrates that gamete activation is a pre-requisite for successful fertilization, and is a process common to all species studied to date. We provide a detailed description of the dramatic changes in gamete morphology and behavior, the regulatory molecules triggering gamete activation and the intracellular ions and second messengers involved in active metabolic pathways in different species. Recent scientific advances suggest that artificial gamete activation may represent a novel technique to improve human IVF outcomes, but this approach requires caution. Wider implications Although controversial, manipulation of gamete activation represents a promising tool for ameliorating the fertilization rate in assisted reproductive technologies. A better knowledge of mechanisms that transform the quiescent oocyte into a pluripotent cell may also provide new insights for the clinical use of stem cells.
Collapse
Affiliation(s)
- Elisabetta Tosti
- Stazione Zoologica Anton Dohrn, Villa Comunale, Naples 80121, Italy
| | - Yves Ménézo
- London Fertility Associates, 104 Harley Street, London WIG7JD, UK
| |
Collapse
|
15
|
López-González I, Treviño CL, Darszon A. Regulation of Spermatogenic Cell T-Type Ca(2+) Currents by Zn(2+): Implications in Male Reproductive Physiology. J Cell Physiol 2016. [PMID: 26222306 DOI: 10.1002/jcp.25112] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Zn(2+) is a trace metal which is important for spermatogenesis progression; its deficiency causes atrophy or malignant growth of the testis. Although testis, epididymis, and prostate contain high Zn(2+) concentrations, the molecular entities which are modulated by this metal are still under study. Interestingly, spermatogenic cells mainly express CaV 3.2-encoded T-type Ca(2+) currents (ICaT) which are positively or negatively modulated by Zn(2+) in other tissues. To explore whether ICaT could be regulated by Zn(2+) and albumin, its main physiological carrier, we performed whole cell electrophysiological recordings of spermatogenic cell ICaT in the absence or presence of different Zn(2+) concentrations. Zn(2+) decreased ICaT in a concentration-dependent manner (IC50 = 2 μM) and this inhibition could only be completely removed in presence of albumin. Differently to previous reports, ICaT did not show a tonic inhibition by Zn(2+) . Further analysis showed that Zn(2+) did not affect the voltage dependency or the kinetics of current activation, but right shifted the steady-state inactivation curve and slowed inactivation and deactivation kinetics. Recovery from inactivation was also altered. However, these apparent alterations in gating properties are not enough to explain the strong ICaT reduction. Using non-stationary fluctuation analysis, we found that Zn(2+) mainly reduced the number of available Ca(2+) channels without changing the single channel current amplitude. ICaT modulation by Zn(2+) could be relevant for spontaneous Ca(2+) oscillations during spermatogenesis and in pathophysiological conditions such as diabetes.
Collapse
Affiliation(s)
- Ignacio López-González
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca Morelos, México
| | - Claudia L Treviño
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca Morelos, México
| | - Alberto Darszon
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca Morelos, México
| |
Collapse
|
16
|
Beltrán C, Treviño CL, Mata-Martínez E, Chávez JC, Sánchez-Cárdenas C, Baker M, Darszon A. Role of Ion Channels in the Sperm Acrosome Reaction. SPERM ACROSOME BIOGENESIS AND FUNCTION DURING FERTILIZATION 2016; 220:35-69. [DOI: 10.1007/978-3-319-30567-7_3] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
17
|
Rossier MF. T-Type Calcium Channel: A Privileged Gate for Calcium Entry and Control of Adrenal Steroidogenesis. Front Endocrinol (Lausanne) 2016; 7:43. [PMID: 27242667 PMCID: PMC4873500 DOI: 10.3389/fendo.2016.00043] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 05/05/2016] [Indexed: 12/03/2022] Open
Abstract
Intracellular calcium plays a crucial role in modulating a variety of functions such as muscle contraction, hormone secretion, gene expression, or cell growth. Calcium signaling has been however shown to be more complex than initially thought. Indeed, it is confined within cell microdomains, and different calcium channels are associated with different functions, as shown by various channelopathies. Sporadic mutations on voltage-operated L-type calcium channels in adrenal glomerulosa cells have been shown recently to be the second most prevalent genetic abnormalities present in human aldosterone-producing adenoma. The observed modification of the threshold of activation of the mutated channels not only provides an explanation for this gain of function but also reminds us on the importance of maintaining adequate electrophysiological characteristics to make channels able to exert specific cellular functions. Indeed, the contribution to steroid production of the various calcium channels expressed in adrenocortical cells is not equal, and the reason has been investigated for a long time. Given the very negative resting potential of these cells, and the small membrane depolarization induced by their physiological agonists, low threshold T-type calcium channels are particularly well suited for responding under these conditions and conveying calcium into the cell, at the right place for controlling steroidogenesis. In contrast, high threshold L-type channels are normally activated by much stronger cell depolarizations. The fact that dihydropyridine calcium antagonists, specific for L-type channels, are poorly efficient for reducing aldosterone secretion either in vivo or in vitro, strongly supports the view that these two types of channels differently affect steroid biosynthesis. Whether a similar analysis is transposable to fasciculata cells and cortisol secretion is one of the questions addressed in the present review. No similar mutations on L-type or T-type channels have been described yet to affect cortisol secretion or to be linked to the development of Cushing syndrome, but several evidences suggest that the function of T channels is also crucial in fasciculata cells. Putative molecular mechanisms and cellular structural organization making T channels a privileged entry for the "steroidogenic calcium" are also discussed.
Collapse
Affiliation(s)
- Michel F. Rossier
- Service of Clinical Chemistry and Toxicology, Hospital of Valais, Sion, Switzerland
- Department of Human Protein Science, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- *Correspondence: Michel F. Rossier,
| |
Collapse
|
18
|
Sperm Capacitation and Acrosome Reaction in Mammalian Sperm. SPERM ACROSOME BIOGENESIS AND FUNCTION DURING FERTILIZATION 2016; 220:93-106. [DOI: 10.1007/978-3-319-30567-7_5] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
|
19
|
Bernhardt ML, Zhang Y, Erxleben CF, Padilla-Banks E, McDonough CE, Miao YL, Armstrong DL, Williams CJ. CaV3.2 T-type channels mediate Ca²⁺ entry during oocyte maturation and following fertilization. J Cell Sci 2015; 128:4442-52. [PMID: 26483387 DOI: 10.1242/jcs.180026] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 10/12/2015] [Indexed: 01/05/2023] Open
Abstract
Initiation of mouse embryonic development depends upon a series of fertilization-induced rises in intracellular Ca(2+). Complete egg activation requires influx of extracellular Ca(2+); however, the channels that mediate this influx remain unknown. Here, we tested whether the α1 subunit of the T-type channel CaV3.2, encoded by Cacna1h, mediates Ca(2+) entry into oocytes. We show that mouse eggs express a robust voltage-activated Ca(2+) current that is completely absent in Cacna1h(-/-) eggs. Cacna1h(-/-) females have reduced litter sizes, and careful analysis of Ca(2+) oscillation patterns in Cacna1h(-/-) eggs following in vitro fertilization (IVF) revealed reductions in first transient length and oscillation persistence. Total and endoplasmic reticulum (ER) Ca(2+) stores were also reduced in Cacna1h(-/-) eggs. Pharmacological inhibition of CaV3.2 in wild-type CF-1 strain eggs using mibefradil or pimozide reduced Ca(2+) store accumulation during oocyte maturation and reduced Ca(2+) oscillation persistence, frequency and number following IVF. Overall, these data show that CaV3.2 T-type channels have prev8iously unrecognized roles in supporting the meiotic-maturation-associated increase in ER Ca(2+) stores and mediating Ca(2+) influx required for the activation of development.
Collapse
Affiliation(s)
- Miranda L Bernhardt
- Reproductive and Developmental Biology Laboratory, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Yingpei Zhang
- Reproductive and Developmental Biology Laboratory, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Christian F Erxleben
- Neurobiology Laboratory, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Elizabeth Padilla-Banks
- Reproductive and Developmental Biology Laboratory, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Caitlin E McDonough
- Reproductive and Developmental Biology Laboratory, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Yi-Liang Miao
- Key Laboratory of Animal Genetics, Breeding, and Reproduction of Ministry of Education, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - David L Armstrong
- Neurobiology Laboratory, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Carmen J Williams
- Reproductive and Developmental Biology Laboratory, National Institutes of Health, Research Triangle Park, NC 27709, USA
| |
Collapse
|
20
|
Abstract
Vertebrate reproduction requires a myriad of precisely orchestrated events-in particular, the maternal production of oocytes, the paternal production of sperm, successful fertilization, and initiation of early embryonic cell divisions. These processes are governed by a host of signaling pathways. Protein kinase and phosphatase signaling pathways involving Mos, CDK1, RSK, and PP2A regulate meiosis during maturation of the oocyte. Steroid signals-specifically testosterone-regulate spermatogenesis, as does signaling by G-protein-coupled hormone receptors. Finally, calcium signaling is essential for both sperm motility and fertilization. Altogether, this signaling symphony ensures the production of viable offspring, offering a chance of genetic immortality.
Collapse
Affiliation(s)
- Sally Kornbluth
- Duke University School of Medicine, Durham, North Carolina 27710
| | - Rafael Fissore
- University of Massachusetts, Amherst, Veterinary and Animal Sciences, Amherst, Massachusetts 01003
| |
Collapse
|
21
|
Sun W, Chen L, Zhang W, Wang R, Goltzman D, Miao D. Active vitamin D deficiency mediated by extracellular calcium and phosphorus results in male infertility in young mice. Am J Physiol Endocrinol Metab 2015; 308:E51-62. [PMID: 25370849 DOI: 10.1152/ajpendo.00076.2014] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We used mice with targeted deletion of 25-hydroxyvitamin D-1 α-hydroxylase [1α(OH)ase(-/-)] to investigate whether 1,25(OH)2D3 deficiency results in male infertility mediated by 1,25(OH)2D3 or extracellular calcium and phosphorus. Male 1α(OH)ase(-/-) and their wild-type littermates fed either a normal diet or a rescue diet from weaning were mated at 6-14 wk of age with female wild-type mice on the same diet. The fertility efficiency of females was analyzed, and the reproductive phenotypes of males were evaluated by histopathological and molecular techniques. Hypocalcemic and hypophosphatemic male 1α(OH)ase(-/-) mice on a normal diet developed infertility characterized by hypergonadotropic hypogonadism, with downregulation of testicular calcium channels, lower intracellular calcium levels, decreased sperm count and motility, and histological abnormalities of the testes. The proliferation of spermatogenic cells was decreased with downregulation of cyclin E and CDK2 and upregulation of p53 and p21 expression, whereas apoptosis of spermatogenic cells was increased with upregulation of Bax and p-caspase 3 expression and downregulation of Bcl-xl expression. When serum calcium and phosphorus were normalized by the rescue diet, the defective reproductive phenotype in the male 1α(OH)ase(-/-) mice, including the hypergonadotropic hypogonadism, decreased sperm count and motility, histological abnormalities of testis, and defective spermatogenesis, was reversed. These results indicate that the infertility seen in male 1,25(OH)2D3-deficient mice is not a direct effect of active vitamin D deficiency on the reproductive system but is an indirect effect mediated by extracellular calcium and phosphorus.
Collapse
Affiliation(s)
- Weiwei Sun
- State Key Laboratory of Reproductive Medicine, Research Center for Bone and Stem Cells, Department of Anatomy, Histology, and Embryology, Nanjing Medical University, Jiangsu, China; and
| | - Lulu Chen
- State Key Laboratory of Reproductive Medicine, Research Center for Bone and Stem Cells, Department of Anatomy, Histology, and Embryology, Nanjing Medical University, Jiangsu, China; and
| | - Wei Zhang
- State Key Laboratory of Reproductive Medicine, Research Center for Bone and Stem Cells, Department of Anatomy, Histology, and Embryology, Nanjing Medical University, Jiangsu, China; and
| | - Rong Wang
- State Key Laboratory of Reproductive Medicine, Research Center for Bone and Stem Cells, Department of Anatomy, Histology, and Embryology, Nanjing Medical University, Jiangsu, China; and
| | - David Goltzman
- Departments of Medicine and Physiology, McGill University, Montreal, Quebec, Canada
| | - Dengshun Miao
- State Key Laboratory of Reproductive Medicine, Research Center for Bone and Stem Cells, Department of Anatomy, Histology, and Embryology, Nanjing Medical University, Jiangsu, China; and
| |
Collapse
|
22
|
López-González I, Torres-Rodríguez P, Sánchez-Carranza O, Solís-López A, Santi CM, Darszon A, Treviño CL. Membrane hyperpolarization during human sperm capacitation. Mol Hum Reprod 2014; 20:619-29. [PMID: 24737063 DOI: 10.1093/molehr/gau029] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Sperm capacitation is a complex and indispensable physiological process that spermatozoa must undergo in order to acquire fertilization capability. Spermatozoa from several mammalian species, including mice, exhibit a capacitation-associated plasma membrane hyperpolarization, which is necessary for the acrosome reaction to occur. Despite its importance, this hyperpolarization event has not been adequately examined in human sperm. In this report we used flow cytometry to show that a subpopulation of human sperm indeed undergo a plasma membrane hyperpolarization upon in vitro capacitation. This hyperpolarization correlated with two other well-characterized capacitation parameters, namely an increase in intracellular pH and Ca(2+) concentration, measured also by flow cytometry. We found that sperm membrane hyperpolarization was completely abolished in the presence of a high external K(+) concentration (60 mM), indicating the participation of K(+) channels. In order to identify, which of the potential K(+) channels were involved in this hyperpolarization, we used different K(+) channel inhibitors including charybdotoxin, slotoxin and iberiotoxin (which target Slo1) and clofilium (a more specific blocker for Slo3). All these K(+) channel antagonists inhibited membrane hyperpolarization to a similar extent, suggesting that both members of the Slo family may potentially participate. Two very recent papers recorded K(+) currents in human sperm electrophysiologically, with some contradictory results. In the present work, we show through immunoblotting that Slo3 channels are present in the human sperm membrane. In addition, we found that human Slo3 channels expressed in CHO cells were sensitive to clofilium (50 μM). Considered altogether, our data indicate that Slo1 and Slo3 could share the preponderant role in the capacitation-associated hyperpolarization of human sperm in contrast to what has been previously reported for mouse sperm, where Slo3 channels are the main contributors to the hyperpolarization event.
Collapse
Affiliation(s)
- I López-González
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, México
| | - P Torres-Rodríguez
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, México
| | - O Sánchez-Carranza
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, México
| | - A Solís-López
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, México
| | - C M Santi
- Department of Anatomy and Neurobiology, Washington University School of Medicine, 660 S Euclid Ave, St. Louis, MO 63110, USA
| | - A Darszon
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, México
| | - C L Treviño
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, México
| |
Collapse
|
23
|
T-type Ca2+ channels in spermatogenic cells and sperm. Pflugers Arch 2014; 466:819-31. [DOI: 10.1007/s00424-014-1478-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 02/08/2014] [Indexed: 12/14/2022]
|
24
|
Mannowetz N, Naidoo NM, Choo SAS, Smith JF, Lishko PV. Slo1 is the principal potassium channel of human spermatozoa. eLife 2013; 2:e01009. [PMID: 24137539 PMCID: PMC3789364 DOI: 10.7554/elife.01009] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Accepted: 09/02/2013] [Indexed: 12/21/2022] Open
Abstract
Mammalian spermatozoa gain competence to fertilize an oocyte as they travel through the female reproductive tract. This process is accompanied by an elevation of sperm intracellular calcium and a membrane hyperpolarization. The latter is evoked by K(+) efflux; however, the molecular identity of the potassium channel of human spermatozoa (hKSper) is unknown. Here, we characterize hKSper, reporting that it is regulated by intracellular calcium but is insensitive to intracellular alkalinization. We also show that human KSper is inhibited by charybdotoxin, iberiotoxin, and paxilline, while mouse KSper is insensitive to these compounds. Such unique properties suggest that the Slo1 ion channel is the molecular determinant for hKSper. We show that Slo1 is localized to the sperm flagellum and is inhibited by progesterone. Inhibition of hKSper by progesterone may depolarize the spermatozoon to open the calcium channel CatSper, thus raising [Ca(2+)] to produce hyperactivation and allowing sperm to fertilize an oocyte. DOI:http://dx.doi.org/10.7554/eLife.01009.001.
Collapse
Affiliation(s)
- Nadja Mannowetz
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Natasha M Naidoo
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Seung-A Sara Choo
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - James F Smith
- Department of Urology, University of California, San Francisco, San Francisco, United States
| | - Polina V Lishko
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| |
Collapse
|
25
|
Balderas E, Sánchez-Cárdenas C, Chávez J, de la Vega Beltrán J, Gómez-Lagunas F, Treviño C, Darszon A. The anti-inflammatory drug celecoxib inhibits t-type Ca2+
currents in spermatogenic cells yet it elicits the acrosome reaction in mature sperm. FEBS Lett 2013; 587:2412-9. [DOI: 10.1016/j.febslet.2013.05.068] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Revised: 05/28/2013] [Accepted: 05/30/2013] [Indexed: 11/27/2022]
|
26
|
Gallo A, Russo GL, Tosti E. T-type Ca2+ current activity during oocyte growth and maturation in the ascidian Styela plicata. PLoS One 2013; 8:e54604. [PMID: 23349937 PMCID: PMC3551846 DOI: 10.1371/journal.pone.0054604] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Accepted: 12/14/2012] [Indexed: 11/19/2022] Open
Abstract
Voltage-dependent calcium currents play a fundamental role during oocyte maturation, mostly L-type calcium currents, whereas T-type calcium currents are involved in sperm physiology and cell growth. In this paper, using an electrophysiological and pharmacological approach, we demonstrated, for the first time in oocytes, that T-type calcium currents are present with functional consequences on the plasma membrane of growing immature oocytes of the ascidian Styela plicata. We classified three subtypes of immature oocytes at the germinal vesicle stage on the basis of their size, morphology and accessory cellular structures. These stages were clearly associated with an increased activity of T-type calcium currents and hyperpolarization of the plasma membrane. We also observed that T-type calcium currents oscillate in the post-fertilization embryonic stages, with minimal amplitude of the currents in the zygote and maximal at 8-cell stage. In addition, chemical inhibition of T-type calcium currents, obtained by applying specific antagonists, induced a significant reduction in the rate of cleavage and absence of larval formation. We suggest that calcium entry via T-type calcium channels may act as a potential pacemaker in regulating cytosolic calcium involved in fertilization and early developmental events.
Collapse
Affiliation(s)
- Alessandra Gallo
- Animal Physiology and Evolution Laboratory, Stazione Zoologica Anton Dohrn, Napoli, Italy
| | - Gian Luigi Russo
- Animal Physiology and Evolution Laboratory, Stazione Zoologica Anton Dohrn, Napoli, Italy
- Institute of Food Sciences, National Research Council, Avellino, Italy
| | - Elisabetta Tosti
- Animal Physiology and Evolution Laboratory, Stazione Zoologica Anton Dohrn, Napoli, Italy
| |
Collapse
|
27
|
Affiliation(s)
- Regina M Turner
- Department of Clinical Studies, Center for Animal Transgenesis, Germ Cell Research, University of Pennsylvania School of Veterinary Medicine, Kennett Square, USA
| |
Collapse
|
28
|
Abstract
To succeed in fertilization, spermatozoa must decode environmental cues which require a set of ion channels. Recent findings have revealed that K(+) and Cl(-) channels participate in some of the main sperm functions. This work reviews the evidence indicating the involvement of K(+) and Cl(-) channels in motility, maturation, and the acrosome reaction, and the advancement in identifying their molecular identity and modes of regulation. Improving our insight on how these channels operate will strengthen our ability to surmount some infertility problems, improve animal breeding, preserve biodiversity, and develop selective and secure male contraceptives.
Collapse
|
29
|
De La Vega-Beltran JL, Sánchez-Cárdenas C, Krapf D, Hernandez-González EO, Wertheimer E, Treviño CL, Visconti PE, Darszon A. Mouse sperm membrane potential hyperpolarization is necessary and sufficient to prepare sperm for the acrosome reaction. J Biol Chem 2012; 287:44384-93. [PMID: 23095755 DOI: 10.1074/jbc.m112.393488] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Mammalian sperm are unable to fertilize the egg immediately after ejaculation; they acquire this capacity during migration in the female reproductive tract. This maturational process is called capacitation and in mouse sperm it involves a plasma membrane reorganization, extensive changes in the state of protein phosphorylation, increases in intracellular pH (pH(i)) and Ca(2+) ([Ca(2+)](i)), and the appearance of hyperactivated motility. In addition, mouse sperm capacitation is associated with the hyperpolarization of the cell membrane potential. However, the functional role of this process is not known. In this work, to dissect the role of this membrane potential change, hyperpolarization was induced in noncapacitated sperm using either the ENaC inhibitor amiloride, the CFTR agonist genistein or the K(+) ionophore valinomycin. In this experimental setting, other capacitation-associated processes such as activation of a cAMP-dependent pathway and the consequent increase in protein tyrosine phosphorylation were not observed. However, hyperpolarization was sufficient to prepare sperm for the acrosome reaction induced either by depolarization with high K(+) or by addition of solubilized zona pellucida (sZP). Moreover, K(+) and sZP were also able to increase [Ca(2+)](i) in non-capacitated sperm treated with these hyperpolarizing agents but not in untreated cells. On the other hand, in conditions that support capacitation-associated processes blocking hyperpolarization by adding valinomycin and increasing K(+) concentrations inhibited the agonist-induced acrosome reaction as well as the increase in [Ca(2+)](i). Altogether, these results suggest that sperm hyperpolarization by itself is key to enabling mice sperm to undergo the acrosome reaction.
Collapse
Affiliation(s)
- Jose Luis De La Vega-Beltran
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, México
| | | | | | | | | | | | | | | |
Collapse
|
30
|
Reid AT, Lord T, Stanger SJ, Roman SD, McCluskey A, Robinson PJ, Aitken RJ, Nixon B. Dynamin regulates specific membrane fusion events necessary for acrosomal exocytosis in mouse spermatozoa. J Biol Chem 2012; 287:37659-72. [PMID: 22977254 DOI: 10.1074/jbc.m112.392803] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Mammalian spermatozoa must complete an acrosome reaction prior to fertilizing an oocyte. The acrosome reaction is a unique exocytotic event involving a series of prolonged membrane fusions that ultimately result in the production of membrane vesicles and release of the acrosomal contents. This event requires the concerted action of a large number of fusion-competent signaling and scaffolding proteins. Here we show that two different members of the dynamin GTPase family localize to the developing acrosome of maturing mouse germ cells. Both dynamin 1 and 2 also remain within the periacrosomal region of mature mouse spermatozoa and are thus well positioned to regulate the acrosome reaction. Two pharmacological inhibitors of dynamin, dynasore and Dyngo-4a, blocked the in vitro induction of acrosomal exocytosis by progesterone, but not by the calcium ionophore A23187, and elicited a concomitant reduction of in vitro fertilization. In vivo treatment with these inhibitors also resulted in spermatozoa displaying reduced acrosome reaction potential. Dynamin 1 and 2 phosphorylation increased on progesterone treatment, and this was also selectively blocked by dynasore. On the basis of our collective data, we propose that dynamin could regulate specific membrane fusion events necessary for acrosomal exocytosis in mouse spermatozoa.
Collapse
Affiliation(s)
- Andrew T Reid
- School of Environmental and Life Sciences, Discipline of Biological Sciences, The University of Newcastle, University Drive, Callaghan, New South Wales 2308, Australia
| | | | | | | | | | | | | | | |
Collapse
|
31
|
Balderas E, Ateaga-Tlecuitl R, Rivera M, Gomora JC, Darszon A. Niflumic acid blocks native and recombinant T-type channels. J Cell Physiol 2012; 227:2542-55. [PMID: 21898399 DOI: 10.1002/jcp.22992] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Voltage-dependent calcium channels are widely distributed in animal cells, including spermatozoa. Calcium is fundamental in many sperm functions such as: motility, capacitation, and the acrosome reaction (AR), all essential for fertilization. Pharmacological evidence has suggested T-type calcium channels participate in the AR. Niflumic acid (NA), a non-steroidal anti-inflammatory drug commonly used as chloride channel blocker, blocks T-currents in mouse spermatogenic cells and Cl(-) channels in testicular sperm. Here we examine the mechanism of NA blockade and explore if it can be used to separate the contribution of different Ca(V)3 members previously detected in these cells. Electrophysiological patch-clamp recordings were performed in isolated mouse spermatogenic cells and in HEK cells heterologously expressing Ca(V)3 channels. NA blocks mouse spermatogenic cell T-type currents with an IC(50) of 73.5 µM, without major voltage-dependent effects. The NA blockade is more potent in the open and in the inactivated state than in the closed state of the T-type channels. Interestingly, we found that heterologously expressed Ca(V)3.1 and Ca(V)3.3 channels were more sensitive to NA than Ca(V)3.2 channels, and this drug substantially slowed the recovery from inactivation of the three isoforms. Molecular docking modeling of drug-channel binding predicts that NA binds preferentially to the extracellular face of Ca(V)3.1 channels. The biophysical characteristics of mouse spermatogenic cell T-type currents more closely resemble those from heterologously expressed Ca(V)3.1 channels, including their sensitivity to NA. As Ca(V)3.1 null mice maintain their spermatogenic cell T-currents, it is likely that a novel Ca(V)3.2 isoform is responsible for them.
Collapse
Affiliation(s)
- Enrique Balderas
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Avenida Universidad 2001, Col. Chamilpa, Cuernavaca Mor., Mexico
| | | | | | | | | |
Collapse
|
32
|
Escoffier J, Krapf D, Navarrete F, Darszon A, Visconti PE. Flow cytometry analysis reveals a decrease in intracellular sodium during sperm capacitation. J Cell Sci 2012; 125:473-85. [PMID: 22302997 DOI: 10.1242/jcs.093344] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Mammalian sperm require time in the female tract in order to be able to fertilize an egg. The physiological changes that render the sperm able to fertilize are known as capacitation. Capacitation is associated with an increase in intracellular pH, an increase in intracellular calcium and phosphorylation of different proteins. This process is also accompanied by the hyperpolarization of the sperm plasma membrane potential. Recently, we presented evidence showing that epithelial Na+ channels (ENaC) are present in mature sperm and that ENaCs are blocked during capacitation. In the present work, we used flow cytometry to analyze changes in intracellular Na+ concentration ([Na+](i)) during capacitation in individual cells. Our results indicate that capacitated sperm have lower Na+ concentrations. Using sperm with green fluorescent protein in their acrosomes, it was shown that the lower [Na+](i) concentration only occurs in sperm having intact acrosomes. ENaC inhibition has been shown in other cell types to depend on the activation of cystic fibrosis transmembrane conductance regulator (CFTR). In non-capacitated sperm, amiloride, an ENaC inhibitor, and genistein, a CFTR activator, caused a decrease in [Na+](i), suggesting that also in these cells [Na+](i) is dependent on the crosstalk between ENaC and CFTR. In addition, PKA inhibition blocked [Na+](i) decrease in capacitated sperm. Altogether, these data are consistent with the hypothesis that the capacitation-associated hyperpolarization involves a decrease in [Na+](i) mediated by inhibition of ENaC and regulated by PKA through activation of CFTR channels.
Collapse
Affiliation(s)
- Jessica Escoffier
- Department of Veterinary and Animal Science, Integrated Sciences Building, University of Massachusetts, Amherst, MA, USA
| | | | | | | | | |
Collapse
|
33
|
Buffone MG, Ijiri TW, Cao W, Merdiushev T, Aghajanian HK, Gerton GL. Heads or tails? Structural events and molecular mechanisms that promote mammalian sperm acrosomal exocytosis and motility. Mol Reprod Dev 2011; 79:4-18. [PMID: 22031228 DOI: 10.1002/mrd.21393] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2010] [Accepted: 08/23/2011] [Indexed: 11/11/2022]
Abstract
Sperm structure has evolved to be very compact and compartmentalized to enable the motor (the flagellum) to transport the nuclear cargo (the head) to the egg. Furthermore, sperm do not exhibit progressive motility and are not capable of undergoing acrosomal exocytosis immediately following their release into the lumen of the seminiferous tubules, the site of spermatogenesis in the testis. These cells require maturation in the epididymis and female reproductive tract before they become competent for fertilization. Here we review aspects of the structural and molecular mechanisms that promote forward motility, hyperactivated motility, and acrosomal exocytosis. As a result, we favor a model articulated by others that the flagellum senses external signals and communicates with the head by second messengers to affect sperm functions such as acrosomal exocytosis. We hope this conceptual framework will serve to stimulate thinking and experimental investigations concerning the various steps of activating a sperm from a quiescent state to a gamete that is fully competent and committed to fertilization. The three themes of compartmentalization, competence, and commitment are key to an understanding of the molecular mechanisms of sperm activation. Comprehending these processes will have a considerable impact on the management of fertility problems, the development of contraceptive methods, and, potentially, elucidation of analogous processes in other cell systems.
Collapse
Affiliation(s)
- Mariano G Buffone
- Center for Research on Reproduction and Women's Health, Department of Obstetrics and Gynecology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | | | | | | | | |
Collapse
|
34
|
Lishko PV, Kirichok Y, Ren D, Navarro B, Chung JJ, Clapham DE. The control of male fertility by spermatozoan ion channels. Annu Rev Physiol 2011; 74:453-75. [PMID: 22017176 DOI: 10.1146/annurev-physiol-020911-153258] [Citation(s) in RCA: 246] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Ion channels control the sperm ability to fertilize the egg by regulating sperm maturation in the female reproductive tract and by triggering key sperm physiological responses required for successful fertilization such as hyperactivated motility, chemotaxis, and the acrosome reaction. CatSper, a pH-regulated, calcium-selective ion channel, and KSper (Slo3) are core regulators of sperm tail calcium entry and sperm hyperactivated motility. Many other channels had been proposed as regulating sperm activity without direct measurements. With the development of the sperm patch-clamp technique, CatSper and KSper have been confirmed as the primary spermatozoan ion channels. In addition, the voltage-gated proton channel Hv1 has been identified in human sperm tail, and the P2X2 ion channel has been identified in the midpiece of mouse sperm. Mutations and deletions in sperm-specific ion channels affect male fertility in both mice and humans without affecting other physiological functions. The uniqueness of sperm ion channels makes them ideal pharmaceutical targets for contraception. In this review we discuss how ion channels regulate sperm physiology.
Collapse
Affiliation(s)
- Polina V Lishko
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, USA
| | | | | | | | | | | |
Collapse
|
35
|
Darszon A, Nishigaki T, Beltran C, Treviño CL. Calcium Channels in the Development, Maturation, and Function of Spermatozoa. Physiol Rev 2011; 91:1305-55. [DOI: 10.1152/physrev.00028.2010] [Citation(s) in RCA: 243] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
A proper dialogue between spermatozoa and the egg is essential for conception of a new individual in sexually reproducing animals. Ca2+ is crucial in orchestrating this unique event leading to a new life. No wonder that nature has devised different Ca2+-permeable channels and located them at distinct sites in spermatozoa so that they can help fertilize the egg. New tools to study sperm ionic currents, and image intracellular Ca2+ with better spatial and temporal resolution even in swimming spermatozoa, are revealing how sperm ion channels participate in fertilization. This review critically examines the involvement of Ca2+ channels in multiple signaling processes needed for spermatozoa to mature, travel towards the egg, and fertilize it. Remarkably, these tiny specialized cells can express exclusive channels like CatSper for Ca2+ and SLO3 for K+, which are attractive targets for contraception and for the discovery of novel signaling complexes. Learning more about fertilization is a matter of capital importance; societies face growing pressure to counteract rising male infertility rates, provide safe male gamete-based contraceptives, and preserve biodiversity through improved captive breeding and assisted conception initiatives.
Collapse
Affiliation(s)
- Alberto Darszon
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Takuya Nishigaki
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Carmen Beltran
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Claudia L. Treviño
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| |
Collapse
|
36
|
Molecular and cellular mechanisms of mammalian cell fusion. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2011; 713:33-64. [PMID: 21432013 DOI: 10.1007/978-94-007-0763-4_4] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The fusion of one cell with another occurs in development, injury and disease. Despite the diversity of fusion events, five steps in sequence appear common. These steps include programming fusion-competent status, chemotaxis, membrane adhesion, membrane fusion, and post-fusion resetting. Recent advances in the field start to reveal the molecules involved in each step. This review focuses on some key molecules and cellular events of cell fusion in mammals. Increasing evidence demonstrates that membrane lipid rafts, adhesion proteins and actin rearrangement are critical in the final step of membrane fusion. Here we propose a new model for the formation and expansion of membrane fusion pores based on recent observations on myotube formation. In this model, membrane lipid rafts first recruit adhesion molecules and align with opposing membranes, with the help of a cortical actin "wall" as a rigid supportive platform. Second, the membrane adhesion proteins interact with each other and trigger actin rearrangement, which leads to rapid dispersion of lipid rafts and flow of a highly fluidic phospholipid bilayer into the site. Finally, the opposing phospholipid bilayers are then pushed into direct contact leading to the formation of fusion pores by the force generated through actin polymerization. The actin polymerization generated force also drives the expansion of the fusion pores. However, several key questions about the process of cell fusion still remain to be explored. The understanding of the mechanisms of cell fusion may provide new opportunities in correcting development disorders or regenerating damaged tissues by inhibiting or promoting molecular events associated with fusion.
Collapse
|
37
|
Kirichok Y, Lishko PV. Rediscovering sperm ion channels with the patch-clamp technique. Mol Hum Reprod 2011; 17:478-99. [PMID: 21642646 DOI: 10.1093/molehr/gar044] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Upon ejaculation, mammalian spermatozoa have to undergo a sequence of physiological transformations within the female reproductive tract that will allow them to reach and fertilize the egg. These include initiation of motility, hyperactivation of motility and perhaps chemotaxis toward the egg, and culminate in the acrosome reaction that permits sperm to penetrate the protective vestments of the egg. These physiological responses are triggered through the activation of sperm ion channels that cause elevations of sperm intracellular pH and Ca(2+) in response to certain cues within the female reproductive tract. Despite their key role in sperm physiology and their absolute requirement for the process of fertilization, sperm ion channels remain poorly understood due to the extreme difficulty in application of the patch-clamp technique to spermatozoa. This review covers the topic of sperm ion channels in the following order: first, we discuss how the intracellular Ca(2+) and pH signaling mediated by sperm ion channels controls sperm behavior during the process of fertilization. Then, we briefly cover the history of the methodology to study sperm ion channels, which culminated in the recent development of a reproducible whole-cell patch-clamp technique for mouse and human cells. We further discuss the main approaches used to patch-clamp mature mouse and human spermatozoa. Finally, we focus on the newly discovered sperm ion channels CatSper, KSper (Slo3) and HSper (H(v)1), identified by the sperm patch-clamp technique. We conclude that the patch-clamp technique has markedly improved and shifted our understanding of the sperm ion channels, in addition to revealing significant species-specific differences in these channels. This method is critical for identification of the molecular mechanisms that control sperm behavior within the female reproductive tract and make fertilization possible.
Collapse
Affiliation(s)
- Yuriy Kirichok
- Department of Physiology, University of California San Francisco UCSF Mail Code 2140, Genentech Hall Room N272F 600 16th Street, San Francisco, CA 94158, USA.
| | | |
Collapse
|
38
|
Olson SD, Fauci LJ, Suarez SS. Mathematical modeling of calcium signaling during sperm hyperactivation. Mol Hum Reprod 2011; 17:500-10. [PMID: 21606121 DOI: 10.1093/molehr/gar040] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Mammalian sperm must hyperactivate in order to fertilize oocytes. Hyperactivation is characterized by highly asymmetrical flagellar bending. It serves to move sperm out of the oviductal reservoir and to penetrate viscoelastic fluids, such as the cumulus matrix. It is absolutely required for sperm penetration of the oocyte zona pellucida. In order for sperm to hyperactivate, cytoplasmic Ca(2+) levels in the flagellum must increase. The major mechanism for providing Ca(2+) to the flagellum, at least in mice, are CatSper channels in the plasma membrane of the principal piece of the flagellum, because sperm from CatSper null males are unable to hyperactivate. There is some evidence for the existence of other types of Ca(2+) channels in sperm, but their roles in hyperactivation have not been clearly established. Another Ca(2+) source for hyperactivation is the store in the redundant nuclear envelope of sperm. To stabilize levels of cytoplasmic Ca(2+), sperm contain Ca(2+) ATPase and exchangers. The interactions between channels, Ca(2+) ATPases, and exchangers are poorly understood; however, mathematical modeling can help to elucidate how they work together to produce the patterns of changes in Ca(2+) levels that have been observed in sperm. Mathematical models can reveal interesting and unexpected relationships, suggesting experiments to be performed in the laboratory. Mathematical analysis of Ca(2+) dynamics has been used to develop a model for Ca(2+) clearance and for CatSper-mediated Ca(2+) dynamics. Models may also be used to understand how Ca(2+) patterns produce flagellar bending patterns of sperm in fluids of low and high viscosity and elasticity.
Collapse
Affiliation(s)
- S D Olson
- Department of Mathematics, Tulane University, New Orleans, LA 70115 USA
| | | | | |
Collapse
|
39
|
Visconti PE, Krapf D, de la Vega-Beltrán JL, Acevedo JJ, Darszon A. Ion channels, phosphorylation and mammalian sperm capacitation. Asian J Androl 2011; 13:395-405. [PMID: 21540868 PMCID: PMC3739340 DOI: 10.1038/aja.2010.69] [Citation(s) in RCA: 227] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Revised: 03/11/2011] [Accepted: 03/14/2011] [Indexed: 12/17/2022] Open
Abstract
Sexually reproducing animals require an orchestrated communication between spermatozoa and the egg to generate a new individual. Capacitation, a maturational complex phenomenon that occurs in the female reproductive tract, renders spermatozoa capable of binding and fusing with the oocyte, and it is a requirement for mammalian fertilization. Capacitation encompasses plasma membrane reorganization, ion permeability regulation, cholesterol loss and changes in the phosphorylation state of many proteins. Novel tools to study sperm ion channels, image intracellular ionic changes and proteins with better spatial and temporal resolution, are unraveling how modifications in sperm ion transport and phosphorylation states lead to capacitation. Recent evidence indicates that two parallel pathways regulate phosphorylation events leading to capacitation, one of them requiring activation of protein kinase A and the second one involving inactivation of ser/thr phosphatases. This review examines the involvement of ion transporters and phosphorylation signaling processes needed for spermatozoa to achieve capacitation. Understanding the molecular mechanisms leading to fertilization is central for societies to deal with rising male infertility rates, to develop safe male gamete-based contraceptives and to preserve biodiversity through better assisted fertilization strategies.
Collapse
Affiliation(s)
- Pablo E Visconti
- Department of Veterinary and Animal Science, Paige Labs, University of Massachusets, Amherst, MA 01003, USA
| | | | | | | | | |
Collapse
|
40
|
Abstract
During mammalian fertilisation, the zona pellucida (ZP) matrix surrounding the oocyte is responsible for the binding of the spermatozoa to the oocyte and induction of the acrosome reaction (AR) in the ZP-bound spermatozoon. The AR is crucial for the penetration of the ZP matrix by spermatozoa. The ZP matrix in mice is composed of three glycoproteins designated ZP1, ZP2 and ZP3, whereas in humans, it is composed of four (ZP1, ZP2, ZP3 and ZP4). ZP3 acts as the putative primary sperm receptor and is responsible for AR induction in mice, whereas in humans (in addition to ZP3), ZP1 and ZP4 also induce the AR. The ability of ZP3 to induce the AR resides in its C-terminal fragment. O-linked glycans are critical for the murine ZP3-mediated AR. However, N-linked glycans of human ZP1, ZP3 and ZP4 have important roles in the induction of the AR. Studies with pharmacological inhibitors showed that the ZP3-induced AR involves the activation of the G(i)-coupled receptor pathway, whereas ZP1- and ZP4-mediated ARs are independent of this pathway. The ZP3-induced AR involves the activation of T-type voltage-operated calcium channels (VOCCs), whereas ZP1- and ZP4-induced ARs involve both T- and L-type VOCCs. To conclude, in mice, ZP3 is primarily responsible for the binding of capacitated spermatozoa to the ZP matrix and induction of the AR, whereas in humans (in addition to ZP3), ZP1 and ZP4 also participate in these stages of fertilisation.
Collapse
|
41
|
Ren D, Xia J. Calcium signaling through CatSper channels in mammalian fertilization. Physiology (Bethesda) 2010; 25:165-75. [PMID: 20551230 DOI: 10.1152/physiol.00049.2009] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The molecular mechanisms underlying Ca(2+) entry into sperm are now much more well defined thanks to direct recordings of mature sperm cells. This article reviews the function of a sperm-specific ion channel, CatSper. CatSpers have a clearly defined function in sperm's hyperactivated motility and are essential for male fertility. We propose that physiological stimuli such as zona pellucida and cyclic nucleotides induce Ca(2+) entry through CatSper channels instead of acting on Ca(V) and CNG channels as previously thought.
Collapse
Affiliation(s)
- Dejian Ren
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
| | | |
Collapse
|
42
|
Hermo L, Pelletier RM, Cyr DG, Smith CE. Surfing the wave, cycle, life history, and genes/proteins expressed by testicular germ cells. Part 4: intercellular bridges, mitochondria, nuclear envelope, apoptosis, ubiquitination, membrane/voltage-gated channels, methylation/acetylation, and transcription factors. Microsc Res Tech 2010; 73:364-408. [PMID: 19941288 DOI: 10.1002/jemt.20785] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
As germ cells divide and differentiate from spermatogonia to spermatozoa, they share a number of structural and functional features that are common to all generations of germ cells and these features are discussed herein. Germ cells are linked to one another by large intercellular bridges which serve to move molecules and even large organelles from the cytoplasm of one cell to another. Mitochondria take on different shapes and features and topographical arrangements to accommodate their specific needs during spermatogenesis. The nuclear envelope and pore complex also undergo extensive modifications concomitant with the development of germ cell generations. Apoptosis is an event that is normally triggered by germ cells and involves many proteins. It occurs to limit the germ cell pool and acts as a quality control mechanism. The ubiquitin pathway comprises enzymes that ubiquitinate as well as deubiquitinate target proteins and this pathway is present and functional in germ cells. Germ cells express many proteins involved in water balance and pH control as well as voltage-gated ion channel movement. In the nucleus, proteins undergo epigenetic modifications which include methylation, acetylation, and phosphorylation, with each of these modifications signaling changes in chromatin structure. Germ cells contain specialized transcription complexes that coordinate the differentiation program of spermatogenesis, and there are many male germ cell-specific differences in the components of this machinery. All of the above features of germ cells will be discussed along with the specific proteins/genes and abnormalities to fertility related to each topic.
Collapse
Affiliation(s)
- Louis Hermo
- Department of Anatomy and Cell Biology, Faculty of Medicine, McGill University, 3640 University Street, Montreal, QC Canada H3A 2B2.
| | | | | | | |
Collapse
|
43
|
Bhandari B, Bansal P, Talwar P, Gupta SK. Delineation of downstream signalling components during acrosome reaction mediated by heat solubilized human zona pellucida. Reprod Biol Endocrinol 2010; 8:7. [PMID: 20096131 PMCID: PMC2832785 DOI: 10.1186/1477-7827-8-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2009] [Accepted: 01/23/2010] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Human egg is enveloped by a glycoproteinaceous matrix, zona pellucida (ZP), responsible for binding of the human spermatozoa to the egg and induction of acrosomal exocytosis in the spermatozoon bound to ZP. In the present manuscript, attempts have been made to delineate the downstream signalling components employed by human ZP to induce acrosome reaction. METHODS Heat-solubilized human ZP (SIZP) was used to study the induction of acrosome reaction in capacitated human spermatozoa using tetramethylrhodamine isothiocyanate conjugated Pisum sativum agglutinin (TRITC-PSA) in absence or presence of various pharmacological inhibitors. In addition, intracellular calcium ([Ca2+]i) levels in sperm using Fluo-3 acetoxymethyl ester as fluorescent probe were also estimated in response to SIZP. RESULTS SIZP induces acrosomal exocytosis in capacitated human sperm in a dose dependent manner accompanied by an increase in [Ca2+]i. Human SIZP mediated induction of acrosome reaction depends on extracellular Ca2+ and involves activation of Gi protein-coupled receptor, tyrosine kinase, protein kinases A & C and phosphoinositide 3 (PI3)- kinase. In addition, T-type voltage operated calcium channels and GABA-A receptor associated chloride (Cl-) channels play an important role in SIZP mediated induction of acrosome reaction. CONCLUSIONS Results described in the present study provide a comprehensive account of the various downstream signalling components associated with human ZP mediated acrosome reaction.
Collapse
Affiliation(s)
- Beena Bhandari
- Reproductive Cell Biology Laboratory, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi-110 067, India
| | - Pankaj Bansal
- Reproductive Cell Biology Laboratory, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi-110 067, India
| | - Pankaj Talwar
- Assisted Reproduction Technology Centre, Army Hospital Research & Referral, Delhi Cantonment, Delhi-110 010, India
| | - Satish K Gupta
- Reproductive Cell Biology Laboratory, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi-110 067, India
| |
Collapse
|
44
|
|
45
|
Xia J, Ren D. Egg coat proteins activate calcium entry into mouse sperm via CATSPER channels. Biol Reprod 2009; 80:1092-8. [PMID: 19211808 DOI: 10.1095/biolreprod.108.074039] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
During mammalian fertilization, the contact between sperm and egg triggers increases in intracellular Ca(2+) concentration ([Ca(2+)](i)) in sperm. Voltage-gated Ca(2+) channels (Ca(V)s) are believed to mediate the initial phase of [Ca(2+)](i) increases in sperm induced by egg coat (zona pellucida [ZP]) glycoproteins, while store depletion-activated Ca(2+) entry is thought to mediate the sustained phase. Using patch-clamp recording and Ca(2+) imaging, we show herein that Ca(V) channel currents, while found in spermatogenic cells, are not detectable in epididymal sperm and are not essential for the ZP-induced [Ca(2+)](i) changes. Instead, CATSPER channels localized in the distal portion of sperm (the principal piece) are required for the ZP-induced [Ca(2+)](i) increases. Furthermore, the ZP-induced [Ca(2+)](i) increase starts from the sperm tail and propagates toward the head.
Collapse
Affiliation(s)
- Jingsheng Xia
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | | |
Collapse
|
46
|
Krapf D, O'Brien ED, Cabada MO, Visconti PE, Arranz SE. Egg water from the amphibian Bufo arenarum modulates the ability of homologous sperm to undergo the acrosome reaction in the presence of the vitelline envelope. Biol Reprod 2009; 80:311-9. [PMID: 18923159 PMCID: PMC2804820 DOI: 10.1095/biolreprod.108.071076] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2008] [Revised: 07/09/2008] [Accepted: 10/08/2008] [Indexed: 11/01/2022] Open
Abstract
Sperm from the toad Bufo arenarum must penetrate the egg jelly before reaching the vitelline envelope (VE), where the acrosome reaction is triggered. When the jelly coat is removed, sperm still bind to the VE, but acrosomal exocytosis is not promoted. Our previous work demonstrated that diffusible substances of the jelly coat, termed "egg water" (EW), triggered capacitation-like changes in B. arenarum sperm, promoting the acquisition of a transient fertilizing capacity. In the present work, we correlated this fertilizing capacity with the ability of the sperm to undergo the acrosome reaction, further substantiating the role of the jelly coat in fertilization. When sperm were exposed to the VE, only those preincubated in EW for 5 or 8 min underwent an increase in the intracellular Ca(2+) concentration ([Ca(2+)](i)), which led to acrosomal exocytosis. Responsiveness to the VE was not acquired on preincubation in EW for 2 or 15 min or in Ringer solution regardless of the preincubation time. In contrast, depletion of intracellular Ca(2+) stores (induced by thapsigargin) promoted [Ca(2+)](i) rise and the acrosome reaction even in sperm that were not exposed to EW. Acrosomal exocytosis was blocked by the presence of Ca(2+) chelators independent of whether a physiological or pharmacological stimulus was used. However, Ni(2+) and mibefradil prevented [Ca(2+)](i) rise and the acrosome reaction of sperm exposed to the VE but not of sperm exposed to thapsigargin. These data suggest that the acrosomal responsiveness of B. arenarum sperm, present during a narrow period, is acquired during EW incubation and involves the modulation of a voltage-dependent Ca(2+) channel.
Collapse
Affiliation(s)
- Darío Krapf
- Institute of Molecular and Cell Biology of Rosario (Consejo Nacional de Investigaciones Científicas y Técnicas [CONICET]) and Área Biología, Facultad de Ciencias Biológicas y Farmacéuticas, Universidad Nacional de Rosario, S2002LRK Rosario, Argentina
| | - Emma D. O'Brien
- Institute of Molecular and Cell Biology of Rosario (Consejo Nacional de Investigaciones Científicas y Técnicas [CONICET]) and Área Biología, Facultad de Ciencias Biológicas y Farmacéuticas, Universidad Nacional de Rosario, S2002LRK Rosario, Argentina
| | - Marcelo O. Cabada
- Institute of Molecular and Cell Biology of Rosario (Consejo Nacional de Investigaciones Científicas y Técnicas [CONICET]) and Área Biología, Facultad de Ciencias Biológicas y Farmacéuticas, Universidad Nacional de Rosario, S2002LRK Rosario, Argentina
| | - Pablo E. Visconti
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, Massachusetts 01003
| | - Silvia E. Arranz
- Institute of Molecular and Cell Biology of Rosario (Consejo Nacional de Investigaciones Científicas y Técnicas [CONICET]) and Área Biología, Facultad de Ciencias Biológicas y Farmacéuticas, Universidad Nacional de Rosario, S2002LRK Rosario, Argentina
| |
Collapse
|
47
|
Effects of Copper on T-Type Ca2+ Channels in Mouse Spermatogenic Cells. J Membr Biol 2009; 227:87-94. [DOI: 10.1007/s00232-008-9148-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2008] [Accepted: 12/04/2008] [Indexed: 10/21/2022]
|
48
|
Jankowska A, Burczyńska B, Duda T, Warchol JB. Rod outer segment membrane guanylate cyclase type 1 (ROS-GC1) calcium-modulated transduction system in the sperm. Fertil Steril 2008; 93:904-12. [PMID: 19111294 DOI: 10.1016/j.fertnstert.2008.10.048] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2008] [Revised: 10/21/2008] [Accepted: 10/27/2008] [Indexed: 10/21/2022]
Abstract
OBJECTIVE Evaluation of the presence of a Ca(2+)-regulated membrane guanylate cyclase signal transudation system in the spermatozoa. DESIGN Experimental study. SETTING Research university laboratory. PATIENT(S) Human sperm obtained from healthy donors who met the criteria of the World Health Organization for normozoospermia and bovine semen collected from bulls of proven fertility. INTERVENTION(S) Radioimmunoassay and immunohistochemistry of human and bovine spermatozoa. MAIN OUTCOME MEASURE(S) The membrane guanylate cyclase activity and the presence of membrane guanylate cyclase transduction machinery components in the spermatozoa. RESULT(S) The identity of a Ca(2+)-modulated membrane guanylate cyclase transduction machinery in human and bovine spermatozoa has been documented. The machinery is both inhibited and stimulated within nanomolar to semimicromolar range of free Ca(2+). The transduction component of this machinery is the rod outer segment membrane guanylate cyclase type 1 (ROS-GC1). The enzyme coexists with three Ca(2+)-dependent modulators: guanylate cyclase activating protein type 1 (GCAP1), S100B and neurocalcin delta. ROS-GC1 and its modulators are present in the heads and tails of both species' spermatozoa. CONCLUSION(S) The coexpression of ROS-GC1 and its activators in spermatozoa suggests that the Ca(2+)-modulated ROS-GC1 transduction system may be a part of the fertilization machinery.
Collapse
Affiliation(s)
- Anna Jankowska
- Department of Cell Biology, Poznan University of Medical Sciences, Rokietnicka 5D, 60-806 Poznan, Poland.
| | | | | | | |
Collapse
|
49
|
Tao J, Zhang Y, Li S, Sun W, Soong TW. Tyrosine kinase-independent inhibition by genistein on spermatogenic T-type calcium channels attenuates mouse sperm motility and acrosome reaction. Cell Calcium 2008; 45:133-43. [PMID: 18789523 DOI: 10.1016/j.ceca.2008.07.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2008] [Revised: 06/19/2008] [Accepted: 07/24/2008] [Indexed: 01/19/2023]
Abstract
Although the protein tyrosine kinase (PTK) inhibitor, genistein, has been widely used to investigate the possible involvement of PTK during reproductive functions, it is unknown whether it modulates sperm calcium channel activity. In the present study, we recorded T-type calcium currents (I(Ca,T)) in mouse spermatogenic cells using whole-cell patch clamp and found that extracellular application of genistein reversibly decreased I(Ca,T) in a concentration-dependent manner (IC(50) approximately 22.7 microM). To determine whether TK activity is required for I(Ca,T) inhibition, we found that peroxovanadate, a tyrosine phosphatase inhibitor, was ineffective in preventing the inhibitory effect of genistein. Furthermore, intracellular perfusion of the cells with ATP-gamma-S also did not alter the inhibitory effect of genistein. To further reveal the direct inhibitory mechanism of genistein on I(Ca,T), we applied into the bath lavendustin A, a PTK inhibitor structurally unrelated to genistein, and found that the current amplitude remained unchanged. Moreover, daidzein, an inactive structural analog of genistein, robustly inhibited the currents. The inhibitory effect of genistein on T-type calcium channels was associated with a hyperpolarizing shift in the voltage-dependence of inactivation. Genistein was observed to decrease sperm motility and to significantly inhibit sperm acrosome reaction (AR) evoked by zona pellucida. Using transfected HEK293 cells system, only Cav3.1 and Cav3.2, instead of Cav3.3, channels were inhibited by genistein. Since T-type calcium channels are the key components in the male reproduction, such as in AR and sperm motility, our data suggest that this PTK-independent inhibition of genistein on I(Ca,T) might be involved in its anti-reproductive effects.
Collapse
Affiliation(s)
- Jin Tao
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore
| | | | | | | | | |
Collapse
|
50
|
Escoffier J, Boisseau S, Serres C, Chen CC, Kim D, Stamboulian S, Shin HS, Campbell KP, De Waard M, Arnoult C. Expression, localization and functions in acrosome reaction and sperm motility of Ca(V)3.1 and Ca(V)3.2 channels in sperm cells: an evaluation from Ca(V)3.1 and Ca(V)3.2 deficient mice. J Cell Physiol 2007; 212:753-63. [PMID: 17450521 DOI: 10.1002/jcp.21075] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
In spermatozoa, voltage-dependent calcium channels (VDCC) have been involved in different cellular functions like acrosome reaction (AR) and sperm motility. Multiple types of VDCC are present and their relative contribution is still a matter of debate. Based mostly on pharmacological studies, low-voltage-activated calcium channels (LVA-CC), responsible of the inward current in spermatocytes, were described as essential for AR in sperm. The development of Ca(V)3.1 or Ca(V)3.2 null mice provided the opportunity to evaluate the involvement of such LVA-CC in AR and sperm motility, independently of pharmacological tools. The inward current was fully abolished in spermatogenic cells from Ca(V)3.2 deficient mice. This current is thus only due to Ca(V)3.2 channels. We showed that Ca(V)3.2 channels were maintained in sperm by Western-blot and immunohistochemistry experiments. Calcium imaging experiments revealed that calcium influx in response to KCl was reduced in Ca(V)3.2 null sperm in comparison to control cells, demonstrating that Ca(V)3.2 channels were functional. On the other hand, no difference was noticed in calcium signaling induced by zona pellucida. Moreover, neither biochemical nor functional experiments, suggested the presence of Ca(V)3.1 channels in sperm. Despite the Ca(V)3.2 channels contribution in KCl-induced calcium influx, the reproduction parameters remained intact in Ca(V)3.2 deficient mice. These data demonstrate that in sperm, besides Ca(V)3.2 channels, other types of VDCC are activated during the voltage-dependent calcium influx of AR, these channels likely belonging to high-voltage activated Ca(2+) channels family. The conclusion is that voltage-dependent calcium influx during AR is due to the opening of redundant families of calcium channels.
Collapse
Affiliation(s)
- Jessica Escoffier
- INSERM U836 Equipe 3, Laboratoire Canaux Calciques Fonctions et Pathologies, CEA/Grenoble, iRTSV, Université Joseph Fourier, Grenoble, France
| | | | | | | | | | | | | | | | | | | |
Collapse
|