51
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Lv MG, Chen WQ, Weng SQ, Chen HY, Cheng YM, Luo T. Rosmarinic acid compromises human sperm functions by an intracellular Ca 2+ concentration-related mechanism. Reprod Toxicol 2018; 81:58-63. [PMID: 30009954 DOI: 10.1016/j.reprotox.2018.07.079] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 06/08/2018] [Accepted: 07/12/2018] [Indexed: 11/25/2022]
Abstract
Rosmarinic acid (RA), a natural phenolic ester, is cytoprotective for male reproduction in animal models. The present study investigated the in vitro actions of RA on human sperm functions. Human sperm were exposed to 1, 10, 100, and 1000 μM RA in vitro and sperm functions were examined. The results showed that although RA did not affect human sperm viability, RA at 10-1000 μM dose-dependently reduced sperm motility, penetration ability, capacitation, and spontaneous acrosome reaction. In addition, the intracellular Ca2+ concentration ([Ca2+]i), which serve as a key regulator of sperm function, was decreased by RA (10-1000 μM) in a dose-dependent manner. Furthermore, the current of the sperm-specific potassium channel, KSPER, which is predominant for Ca2+ influx in sperm, was dose-dependently inhibited by 10-1000 μM RA. Therefore, we conclude that in vitro exposure to RA can compromise human sperm functions by decreasing sperm [Ca2+]i through the suppression of KSPER current.
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Affiliation(s)
- Meng-Ge Lv
- Institute of Life Science and School of Life Science, Nanchang University, Nanchang, Jiangxi 330031, China; Nanchang University Queen Mary School, Jiangxi Medical College of Nanchang University, Nanchang University, Nanchang, Jiangxi 330031, China
| | - Wen-Qiong Chen
- Institute of Life Science and School of Life Science, Nanchang University, Nanchang, Jiangxi 330031, China
| | - Shi-Qi Weng
- Institute of Life Science and School of Life Science, Nanchang University, Nanchang, Jiangxi 330031, China
| | - Hou-Yang Chen
- Reproductive Medical Center, Jiangxi Provincial Maternal and Child Health Hospital, Nanchang, Jiangxi 330006, China
| | - Yi-Min Cheng
- Institute of Life Science and School of Life Science, Nanchang University, Nanchang, Jiangxi 330031, China
| | - Tao Luo
- Institute of Life Science and School of Life Science, Nanchang University, Nanchang, Jiangxi 330031, China; Key Laboratory of Reproductive Physiology and Pathology in Jiangxi Province, Nanchang, Jiangxi 330031, China.
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52
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Brukman NG, Nuñez SY, Puga Molina LDC, Buffone MG, Darszon A, Cuasnicu PS, Da Ros VG. Tyrosine phosphorylation signaling regulates Ca 2+ entry by affecting intracellular pH during human sperm capacitation. J Cell Physiol 2018; 234:5276-5288. [PMID: 30203545 DOI: 10.1002/jcp.27337] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 08/10/2018] [Indexed: 12/23/2022]
Abstract
Capacitation is a mandatory process for the acquisition of mammalian sperm fertilization competence and involves the activation of a complex and still not fully understood system of signaling pathways. Under in vitro conditions, there is an increase in both protein tyrosine phosphorylation (pTyr) and intracellular Ca2+ levels in several species. In human sperm, results from our group revealed that pTyr signaling can be blocked by inhibiting proline-rich tyrosine kinase 2 (PYK2). Based on the role of PYK2 in other cell types, we investigated whether the PYK2-dependent pTyr cascade serves as a sensor for Ca 2+ signaling during human sperm capacitation. Flow cytometry studies showed that exposure of sperm to the PYK2 inhibitor N-[2-[[[2-[(2,3-dihydro-2-oxo-1 H-indol-5-yl)amino]-5-(trifluoromethyl)-4-pyrimidinyl]amino]methyl]phenyl]- N-methyl-methanesulfonamide hydrate (PF431396) produced a significant and concentration-dependent reduction in intracellular Ca 2+ levels during capacitation. Further studies revealed that PF431396-treated sperm exhibited a decrease in the activity of CatSper, a key sperm Ca 2+ channel. In addition, time course studies during capacitation in the presence of PF431396 showed a significant and sustained decrease in both intracellular Ca 2+ and pH levels after 2 hr of incubation, temporarily coincident with the activation of PYK2 during capacitation. Interestingly, decreases in Ca 2+ levels and progressive motility caused by PF431396 were reverted by inducing intracellular alkalinization with NH 4 Cl, without affecting the pTyr blockage. Altogether, these observations support pTyr as an intracellular sensor for Ca 2+ entry in human sperm through regulation of cytoplasmic pH. These results contribute to a better understanding of the modulation of the polymodal CatSper and signaling pathways involved in human sperm capacitation.
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Affiliation(s)
- Nicolás Gastón Brukman
- Instituto de Biología y Medicina Experimental (IByME-CONICET), Ciudad Autónoma de Buenos Aires, Buenos Aires, Argentina
| | - Sol Yanel Nuñez
- Instituto de Biología y Medicina Experimental (IByME-CONICET), Ciudad Autónoma de Buenos Aires, Buenos Aires, Argentina
| | - Lis Del Carmen Puga Molina
- Instituto de Biología y Medicina Experimental (IByME-CONICET), Ciudad Autónoma de Buenos Aires, Buenos Aires, Argentina
| | - Mariano Gabriel Buffone
- Instituto de Biología y Medicina Experimental (IByME-CONICET), Ciudad Autónoma de Buenos Aires, Buenos Aires, Argentina
| | - Alberto Darszon
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, México
| | - Patricia Sara Cuasnicu
- Instituto de Biología y Medicina Experimental (IByME-CONICET), Ciudad Autónoma de Buenos Aires, Buenos Aires, Argentina
| | - Vanina Gabriela Da Ros
- Instituto de Biología y Medicina Experimental (IByME-CONICET), Ciudad Autónoma de Buenos Aires, Buenos Aires, Argentina
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53
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Rennhack A, Schiffer C, Brenker C, Fridman D, Nitao ET, Cheng Y, Tamburrino L, Balbach M, Stölting G, Berger TK, Kierzek M, Alvarez L, Wachten D, Zeng X, Baldi E, Publicover SJ, Benjamin Kaupp U, Strünker T. A novel cross-species inhibitor to study the function of CatSper Ca 2+ channels in sperm. Br J Pharmacol 2018; 175:3144-3161. [PMID: 29723408 PMCID: PMC6031884 DOI: 10.1111/bph.14355] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Revised: 04/14/2018] [Accepted: 04/20/2018] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND AND PURPOSE Sperm from many species share the sperm-specific Ca2+ channel CatSper that controls the intracellular Ca2+ concentration and, thereby, the swimming behaviour. A growing body of evidence suggests that the mechanisms controlling the activity of CatSper and its role during fertilization differ among species. A lack of suitable pharmacological tools has hampered the elucidation of the function of CatSper. Known inhibitors of CatSper exhibit considerable side effects and also inhibit Slo3, the principal K+ channel of mammalian sperm. The compound RU1968 was reported to suppress Ca2+ signaling in human sperm by an unknown mechanism. Here, we examined the action of RU1968 on CatSper in sperm from humans, mice, and sea urchins. EXPERIMENTAL APPROACH We resynthesized RU1968 and studied its action on sperm from humans, mice, and the sea urchin Arbacia punctulata by Ca2+ fluorimetry, single-cell Ca2+ imaging, electrophysiology, opto-chemistry, and motility analysis. KEY RESULTS RU1968 inhibited CatSper in sperm from invertebrates and mammals. The compound lacked toxic side effects in human sperm, did not affect mouse Slo3, and inhibited human Slo3 with about 15-fold lower potency than CatSper. Moreover, in human sperm, RU1968 mimicked CatSper dysfunction and suppressed motility responses evoked by progesterone, an oviductal steroid known to activate CatSper. Finally, RU1968 abolished CatSper-mediated chemotactic navigation in sea urchin sperm. CONCLUSION AND IMPLICATIONS We propose RU1968 as a novel tool to elucidate the function of CatSper channels in sperm across species.
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Affiliation(s)
- Andreas Rennhack
- Department of Molecular Sensory SystemsCenter of Advanced European Studies and Research (CAESAR)BonnGermany
| | - Christian Schiffer
- University Hospital Münster, Centre of Reproductive Medicine and AndrologyMünsterGermany
| | - Christoph Brenker
- University Hospital Münster, Centre of Reproductive Medicine and AndrologyMünsterGermany
| | - Dmitry Fridman
- Department of Molecular Sensory SystemsCenter of Advanced European Studies and Research (CAESAR)BonnGermany
| | - Elis T Nitao
- School of BiosciencesUniversity of BirminghamBirminghamUK
| | - Yi‐Min Cheng
- Institute of Life Science and School of Life ScienceNanchang UniversityNanchangJiangxiChina
| | - Lara Tamburrino
- Department of Experimental and Clinical Medicine, Center of Excellence DENOTHEUniversity of FlorenceFlorenceItaly
| | - Melanie Balbach
- Department of Molecular Sensory SystemsCenter of Advanced European Studies and Research (CAESAR)BonnGermany
| | - Gabriel Stölting
- Institute of Complex Systems – Zelluläre Biophysik 4, Forschungszentrum JülichJülichGermany
| | - Thomas K Berger
- Department of Molecular Sensory SystemsCenter of Advanced European Studies and Research (CAESAR)BonnGermany
| | - Michelina Kierzek
- University Hospital Münster, Centre of Reproductive Medicine and AndrologyMünsterGermany
| | - Luis Alvarez
- Department of Molecular Sensory SystemsCenter of Advanced European Studies and Research (CAESAR)BonnGermany
| | - Dagmar Wachten
- Max‐Planck Research Group of Molecular Physiology, Center of Advanced European Studies and ResearchBonnGermany
- Institute of Innate ImmunityUniversity Hospital, University of BonnBonnGermany
| | - Xu‐Hui Zeng
- Institute of Life Science and School of Life ScienceNanchang UniversityNanchangJiangxiChina
| | - Elisabetta Baldi
- Department of Experimental and Clinical Medicine, Center of Excellence DENOTHEUniversity of FlorenceFlorenceItaly
| | | | - U Benjamin Kaupp
- Department of Molecular Sensory SystemsCenter of Advanced European Studies and Research (CAESAR)BonnGermany
| | - Timo Strünker
- University Hospital Münster, Centre of Reproductive Medicine and AndrologyMünsterGermany
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54
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Puga Molina LC, Luque GM, Balestrini PA, Marín-Briggiler CI, Romarowski A, Buffone MG. Molecular Basis of Human Sperm Capacitation. Front Cell Dev Biol 2018; 6:72. [PMID: 30105226 PMCID: PMC6078053 DOI: 10.3389/fcell.2018.00072] [Citation(s) in RCA: 135] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 06/19/2018] [Indexed: 12/31/2022] Open
Abstract
In the early 1950s, Austin and Chang independently described the changes that are required for the sperm to fertilize oocytes in vivo. These changes were originally grouped under name of “capacitation” and were the first step in the development of in vitro fertilization (IVF) in humans. Following these initial and fundamental findings, a remarkable number of observations led to characterization of the molecular steps behind this process. The discovery of certain sperm-specific molecules and the possibility to record ion currents through patch-clamp approaches helped to integrate the initial biochemical observation with the activity of ion channels. This is of particular importance in the male gamete due to the fact that sperm are transcriptionally inactive. Therefore, sperm must control all these changes that occur during their transit through the male and female reproductive tracts by complex signaling cascades that include post-translational modifications. This review is focused on the principal molecular mechanisms that govern human sperm capacitation with particular emphasis on comparing all the reported pieces of evidence with the mouse model.
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Affiliation(s)
- Lis C Puga Molina
- Instituto de Biología y Medicina Experimental, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Buenos Aires, Argentina
| | - Guillermina M Luque
- Instituto de Biología y Medicina Experimental, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Buenos Aires, Argentina
| | - Paula A Balestrini
- Instituto de Biología y Medicina Experimental, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Buenos Aires, Argentina
| | - Clara I Marín-Briggiler
- Instituto de Biología y Medicina Experimental, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Buenos Aires, Argentina
| | - Ana Romarowski
- Instituto de Biología y Medicina Experimental, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Buenos Aires, Argentina
| | - Mariano G Buffone
- Instituto de Biología y Medicina Experimental, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Buenos Aires, Argentina
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55
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Windler F, Bönigk W, Körschen HG, Grahn E, Strünker T, Seifert R, Kaupp UB. The solute carrier SLC9C1 is a Na +/H +-exchanger gated by an S4-type voltage-sensor and cyclic-nucleotide binding. Nat Commun 2018; 9:2809. [PMID: 30022052 PMCID: PMC6052114 DOI: 10.1038/s41467-018-05253-x] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 06/15/2018] [Indexed: 11/30/2022] Open
Abstract
Voltage-sensing (VSD) and cyclic nucleotide-binding domains (CNBD) gate ion channels for rapid electrical signaling. By contrast, solute carriers (SLCs) that passively redistribute substrates are gated by their substrates themselves. Here, we study the orphan sperm-specific solute carriers SLC9C1 that feature a unique tripartite structure: an exchanger domain, a VSD, and a CNBD. Voltage-clamp fluorimetry shows that SLC9C1 is a genuine Na+/H+ exchanger gated by voltage. The cellular messenger cAMP shifts the voltage range of activation. Mutations in the transport domain, the VSD, or the CNBD strongly affect Na+/H+ exchange, voltage gating, or cAMP sensitivity, respectively. Our results establish SLC9C1 as a phylogenetic chimaera that combines the ion-exchange mechanism of solute carriers with the gating mechanism of ion channels. Classic SLCs slowly readjust changes in the intra- and extracellular milieu, whereas voltage gating endows the Na+/H+ exchanger with the ability to produce a rapid pH response that enables downstream signaling events. The sperm-specific solute carrier SLC9C1 is a phylogenetic chimaera that carries a voltage-sensing (VSD) and a cyclic nucleotide-binding domain (CNBD). Here authors show by electrophysiology and fluorimetry that SLC9C1 is a genuine Na+/H+ exchanger gated by voltage and cAMP.
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Affiliation(s)
- F Windler
- Center of Advanced European Studies and Research (caesar), Department Molecular Sensory Systems, Ludwig-Erhard-Allee 2, 53175, Bonn, Germany.,Marine Biological Laboratory, 7 MBL Street, Woods Hole, 02543, MA, USA
| | - W Bönigk
- Center of Advanced European Studies and Research (caesar), Department Molecular Sensory Systems, Ludwig-Erhard-Allee 2, 53175, Bonn, Germany
| | - H G Körschen
- Center of Advanced European Studies and Research (caesar), Department Molecular Sensory Systems, Ludwig-Erhard-Allee 2, 53175, Bonn, Germany
| | - E Grahn
- Center of Advanced European Studies and Research (caesar), Department Molecular Sensory Systems, Ludwig-Erhard-Allee 2, 53175, Bonn, Germany
| | - T Strünker
- Center of Advanced European Studies and Research (caesar), Department Molecular Sensory Systems, Ludwig-Erhard-Allee 2, 53175, Bonn, Germany.,Marine Biological Laboratory, 7 MBL Street, Woods Hole, 02543, MA, USA.,University Hospital Münster, Center of Reproductive Medicine and Andrology, Albert-Schweitzer-Campus 1, Geb. D11, 48149, Münster, Germany
| | - R Seifert
- Center of Advanced European Studies and Research (caesar), Department Molecular Sensory Systems, Ludwig-Erhard-Allee 2, 53175, Bonn, Germany. .,Marine Biological Laboratory, 7 MBL Street, Woods Hole, 02543, MA, USA.
| | - U B Kaupp
- Center of Advanced European Studies and Research (caesar), Department Molecular Sensory Systems, Ludwig-Erhard-Allee 2, 53175, Bonn, Germany. .,Marine Biological Laboratory, 7 MBL Street, Woods Hole, 02543, MA, USA. .,University of Bonn, Life & Medical Sciences Institute (LIMES), Carl-Troll-Str. 31, 53115, Bonn, Germany.
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56
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Mundt N, Spehr M, Lishko PV. TRPV4 is the temperature-sensitive ion channel of human sperm. eLife 2018; 7:35853. [PMID: 29963982 PMCID: PMC6051745 DOI: 10.7554/elife.35853] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Accepted: 06/30/2018] [Indexed: 12/15/2022] Open
Abstract
Ion channels control the ability of human sperm to fertilize the egg by triggering hyperactivated motility, which is regulated by membrane potential, intracellular pH, and cytosolic calcium. Previous studies unraveled three essential ion channels that regulate these parameters: (1) the Ca2+ channel CatSper, (2) the K+ channel KSper, and (3) the H+ channel Hv1. However, the molecular identity of the sperm Na+ conductance that mediates initial membrane depolarization and, thus, triggers downstream signaling events is yet to be defined. Here, we functionally characterize DSper, the Depolarizing Channel of Sperm, as the temperature-activated channel TRPV4. It is functionally expressed at both mRNA and protein levels, while other temperature-sensitive TRPV channels are not functional in human sperm. DSper currents are activated by warm temperatures and mediate cation conductance, that shares a pharmacological profile reminiscent of TRPV4. Together, these results suggest that TRPV4 activation triggers initial membrane depolarization, facilitating both CatSper and Hv1 gating and, consequently, sperm hyperactivation.
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Affiliation(s)
- Nadine Mundt
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States.,Department of Chemosensation, Institute for Biology II, RWTH Aachen University, Aachen, Germany
| | - Marc Spehr
- Department of Chemosensation, Institute for Biology II, RWTH Aachen University, Aachen, Germany
| | - Polina V Lishko
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
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57
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Balbach M, Beckert V, Hansen JN, Wachten D. Shedding light on the role of cAMP in mammalian sperm physiology. Mol Cell Endocrinol 2018; 468:111-120. [PMID: 29146556 DOI: 10.1016/j.mce.2017.11.008] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 11/10/2017] [Accepted: 11/10/2017] [Indexed: 12/24/2022]
Abstract
Mammalian fertilization relies on sperm finding the egg and penetrating the egg vestments. All steps in a sperm's lifetime crucially rely on changes in the second messenger cAMP (cyclic adenosine monophosphate). In recent years, it has become clear that signal transduction in sperm is not a continuum, but rather organized in subcellular domains, e.g. the sperm head and the sperm flagellum, with the latter being further separated into the midpiece, principal piece, and endpiece. To understand the underlying signaling pathways controlling sperm function in more detail, experimental approaches are needed that allow to study sperm signaling with spatial and temporal precision. Here, we will give a comprehensive overview on cAMP signaling in mammalian sperm, describing the molecular players involved in these pathways and the sperm functions that are controlled by cAMP. Furthermore, we will highlight recent advances in analyzing and manipulating sperm signaling with spatio-temporal precision using light.
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Affiliation(s)
- Melanie Balbach
- Center of Advanced European Studies and Research (caesar), Department of Molecular Sensory Systems, Bonn, Germany
| | - Vera Beckert
- Institute of Innate Immunity, University Hospital, University of Bonn, Bonn, Germany
| | - Jan N Hansen
- Institute of Innate Immunity, University Hospital, University of Bonn, Bonn, Germany
| | - Dagmar Wachten
- Institute of Innate Immunity, University Hospital, University of Bonn, Bonn, Germany; Center of Advanced European Studies and Research (caesar), Minerva Max Planck Research Group, Molecular Physiology, Bonn, Germany.
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58
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Puga Molina LC, Pinto NA, Torres NI, González-Cota AL, Luque GM, Balestrini PA, Romarowski A, Krapf D, Santi CM, Treviño CL, Darszon A, Buffone MG. CFTR/ENaC-dependent regulation of membrane potential during human sperm capacitation is initiated by bicarbonate uptake through NBC. J Biol Chem 2018; 293:9924-9936. [PMID: 29743243 DOI: 10.1074/jbc.ra118.003166] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 04/29/2018] [Indexed: 12/16/2022] Open
Abstract
To fertilize an egg, sperm must reside in the female reproductive tract to undergo several maturational changes that are collectively referred to as capacitation. From a molecular point of view, the HCO3--dependent activation of the atypical soluble adenylyl cyclase (ADCY10) is one of the first events that occurs during capacitation and leads to the subsequent cAMP-dependent activation of protein kinase A (PKA). Capacitation is also accompanied by hyperpolarization of the sperm plasma membrane. We previously reported that PKA activation is necessary for CFTR (cystic fibrosis transmembrane conductance regulator channel) activity and for the modulation of membrane potential (Em). However, the main HCO3- transporters involved in the initial transport and the PKA-dependent Em changes are not well known nor characterized. Here, we analyzed how the activity of CFTR regulates Em during capacitation and examined its relationship with an electrogenic Na+/HCO3- cotransporter (NBC) and epithelial Na+ channels (ENaCs). We observed that inhibition of both CFTR and NBC decreased HCO3- influx, resulting in lower PKA activity, and that events downstream of the cAMP activation of PKA are essential for the regulation of Em. Addition of a permeable cAMP analog partially rescued the inhibitory effects caused by these inhibitors. HCO3- also produced a rapid membrane hyperpolarization mediated by ENaC channels, which contribute to the regulation of Em during capacitation. Altogether, we demonstrate for the first time, that NBC cotransporters and ENaC channels are essential in the CFTR-dependent activation of the cAMP/PKA signaling pathway and Em regulation during human sperm capacitation.
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Affiliation(s)
- Lis C Puga Molina
- From the Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), C1425FQB Buenos Aires, Argentina
| | - Nicolás A Pinto
- From the Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), C1425FQB Buenos Aires, Argentina
| | - Nicolás I Torres
- From the Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), C1425FQB Buenos Aires, Argentina
| | - Ana L González-Cota
- the Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Guillermina M Luque
- From the Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), C1425FQB Buenos Aires, Argentina
| | - Paula A Balestrini
- From the Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), C1425FQB Buenos Aires, Argentina
| | - Ana Romarowski
- From the Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), C1425FQB Buenos Aires, Argentina
| | - Dario Krapf
- the Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET-UNR, Rosario 2000, Argentina, and
| | - Celia M Santi
- the Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Claudia L Treviño
- the Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, 62210 Morelos, México
| | - Alberto Darszon
- the Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, 62210 Morelos, México
| | - Mariano G Buffone
- From the Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), C1425FQB Buenos Aires, Argentina,
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59
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Alasmari W. Importance of the assessment of intracellular Ca 2+ level as diagnostic tool of dysfunctional sperm. MIDDLE EAST FERTILITY SOCIETY JOURNAL 2017. [DOI: 10.1016/j.mefs.2017.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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60
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Abstract
Fertilization is exceptionally complex and, depending on the species, happens in entirely different environments. External fertilizers in aquatic habitats, like marine invertebrates or fish, release their gametes into the seawater or freshwater, whereas sperm from most internal fertilizers like mammals cross the female genital tract to make their way to the egg. Various chemical and physical cues guide sperm to the egg. Quite generally, these cues enable signaling pathways that ultimately evoke a cellular Ca2+ response that modulates the waveform of the flagellar beat and, hence, the swimming path. To cope with the panoply of challenges to reach and fertilize the egg, sperm from different species have developed their own unique repertoire of signaling molecules and mechanisms. Here, we review the differences and commonalities for sperm sensory signaling in marine invertebrates (sea urchin), fish (zebrafish), and mammals (mouse, human).
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Affiliation(s)
- Dagmar Wachten
- Minerva Max Planck Research Group, Molecular Physiology, Center of Advanced European Studies and Research (caesar), 53175 Bonn, Germany
| | - Jan F Jikeli
- Minerva Max Planck Research Group, Molecular Physiology, Center of Advanced European Studies and Research (caesar), 53175 Bonn, Germany
| | - U Benjamin Kaupp
- Department Molecular Sensory Systems, Center of Advanced European Studies and Research (caesar), 53175 Bonn, Germany
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61
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Wang G. Mechanistic insight into the heme-independent interplay between iron and carbon monoxide in CFTR and Slo1 BK Ca channels. Metallomics 2017; 9:634-645. [PMID: 28474046 DOI: 10.1039/c7mt00065k] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Ion channels have been extensively reported as effectors of carbon monoxide (CO). However, the mechanisms of heme-independent CO action are still not known. Because most ion channels are heterologously expressed on human embryonic kidney cells that are cultured in Fe3+-containing media, CO may act as a small and strong iron chelator to disrupt a putative iron bridge in ion channels and thus to tune their activity. In this review CFTR and Slo1 BKCa channels are employed to discuss the possible heme-independent interplay between iron and CO. Our recent studies demonstrated a high-affinity Fe3+ site at the interface between the regulatory domain and intracellular loop 3 of CFTR. Because the binding of Fe3+ to CFTR prevents channel opening, the stimulatory effect of CO on the Cl- and HCO3- currents across the apical membrane of rat distal colon may be due to the release of inhibitive Fe3+ by CO. In contrast, CO repeatedly stimulates the human Slo1 BKCa channel opening, possibly by binding to an unknown iron site, because cyanide prohibits this heme-independent CO stimulation. Here, in silico research on recent structural data of the slo1 BKCa channels indicates two putative binuclear Fe2+-binding motifs in the gating ring in which CO may compete with protein residues to bind to either Fe2+ bowl to disrupt the Fe2+ bridge but not to release Fe2+ from the channel. Thus, these two new regulation models of CO, with iron releasing from and retaining in the ion channel, may have significant and extensive implications for other metalloproteins.
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Affiliation(s)
- Guangyu Wang
- Department of Physiology and Membrane Biology, University of California School of Medicine, Davis, CA, USA. and Institute of Biophysical Medico-chemistry, Reno, NV, USA
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62
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Geng Y, Ferreira JJ, Dzikunu V, Butler A, Lybaert P, Yuan P, Magleby KL, Salkoff L, Santi CM. A genetic variant of the sperm-specific SLO3 K + channel has altered pH and Ca 2+ sensitivities. J Biol Chem 2017; 292:8978-8987. [PMID: 28377504 DOI: 10.1074/jbc.m117.776013] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 03/21/2017] [Indexed: 11/06/2022] Open
Abstract
To fertilize an oocyte, sperm must first undergo capacitation in which the sperm plasma membrane becomes hyperpolarized via activation of potassium (K+) channels and resultant K+ efflux. Sperm-specific SLO3 K+ channels are responsible for these membrane potential changes critical for fertilization in mouse sperm, and they are only sensitive to pH i However, in human sperm, the major K+ conductance is both Ca2+- and pH i -sensitive. It has been debated whether Ca2+-sensitive SLO1 channels substitute for human SLO3 (hSLO3) in human sperm or whether human SLO3 channels have acquired Ca2+ sensitivity. Here we show that hSLO3 is rapidly evolving and reveal a natural structural variant with enhanced apparent Ca2+ and pH sensitivities. This variant allele (C382R) alters an amino acid side chain at a principal interface between the intramembrane-gated pore and the cytoplasmic gating ring of the channel. Because the gating ring contains sensors to intracellular factors such as pH and Ca2+, the effectiveness of transduction between the gating ring and the pore domain appears to be enhanced. Our results suggest that sperm-specific genes can evolve rapidly and that natural genetic variation may have led to a SLO3 variant that differs from wild type in both pH and intracellular Ca2+ sensitivities. Whether this physiological variation confers differences in fertility among males remains to be established.
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Affiliation(s)
- Yanyan Geng
- the Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, Florida 33136
| | | | | | | | | | - Peng Yuan
- Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri 63110 and
| | - Karl L Magleby
- the Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, Florida 33136
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63
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Vicens A, Andrade‐López K, Cortez D, Gutiérrez RM, Treviño CL. Premammalian origin of the sperm-specific Slo3 channel. FEBS Open Bio 2017; 7:382-390. [PMID: 28286733 PMCID: PMC5337896 DOI: 10.1002/2211-5463.12186] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 12/01/2016] [Accepted: 12/16/2016] [Indexed: 01/05/2023] Open
Abstract
Slo3 is a sperm-specific potassium (K+) channel essential for male fertility. Slo3 channels have so far been considered to be specific to mammals. Through exploratory genomics, we identified the Slo3 gene in the genome of terrestrial (birds and reptiles) and aquatic (fish) vertebrates. In the case of fish, Slo3 has undergone several episodes of gene loss. Transcriptomic analysis showed that vertebrate Slo3 transcript orthologues are predominantly expressed in testis, in concordance with the mammalian Slo3. We conclude that the Slo3 gene arose during the radiation of early vertebrates, much earlier than previously thought. Our findings add to the growing evidence indicating that the phylogenetic profiles of sperm-specific channels are intermittent throughout metazoan evolution, which probably reflects the adaptation of sperm to different ionic milieus and fertilization environments.
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Affiliation(s)
- Alberto Vicens
- Departamento de Genética del Desarrollo y Fisiología MolecularInstituto de BiotecnologíaUniversidad Nacional Autónoma de MéxicoCuernavaca MorelosMéxico
| | - Karla Andrade‐López
- Departamento de Genética del Desarrollo y Fisiología MolecularInstituto de BiotecnologíaUniversidad Nacional Autónoma de MéxicoCuernavaca MorelosMéxico
| | - Diego Cortez
- Centro de Ciencias GenómicasUniversidad Nacional Autónoma de MéxicoCuernavaca MorelosMéxico
| | - Rosa María Gutiérrez
- Departamento de Microbiología MolecularInstituto de BiotecnologíaUniversidad Nacional Autónoma de MéxicoCuernavaca MorelosMéxico
| | - Claudia L. Treviño
- Departamento de Genética del Desarrollo y Fisiología MolecularInstituto de BiotecnologíaUniversidad Nacional Autónoma de MéxicoCuernavaca MorelosMéxico
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64
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Wijerathne TD, Kim J, Yang D, Lee KP. Intracellular calcium-dependent regulation of the sperm-specific calcium-activated potassium channel, hSlo3, by the BK Ca activator LDD175. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2017; 21:241-249. [PMID: 28280418 PMCID: PMC5343058 DOI: 10.4196/kjpp.2017.21.2.241] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Revised: 12/26/2016] [Accepted: 12/27/2016] [Indexed: 11/15/2022]
Abstract
Plasma membrane hyperpolarization associated with activation of Ca2+-activated K+ channels plays an important role in sperm capacitation during fertilization. Although Slo3 (slowpoke homologue 3), together with the auxiliary γ2-subunit, LRRC52 (leucine-rich-repeat–containing 52), is known to mediate the pH-sensitive, sperm-specific K+ current KSper in mice, the molecular identity of this channel in human sperm remains controversial. In this study, we tested the classical BKCa activators, NS1619 and LDD175, on human Slo3, heterologously expressed in HEK293 cells together with its functional interacting γ2 subunit, hLRRC52. As previously reported, Slo3 K+ current was unaffected by iberiotoxin or 4-aminopyridine, but was inhibited by ~50% by 20 mM TEA. Extracellular alkalinization potentiated hSlo3 K+ current, and internal alkalinization and Ca2+ elevation induced a leftward shift its activation voltage. NS1619, which acts intracellularly to modulate hSlo1 gating, attenuated hSlo3 K+ currents, whereas LDD175 increased this current and induced membrane potential hyperpolarization. LDD175-induced potentiation was not associated with a change in the half-activation voltage at different intracellular pHs (pH 7.3 and pH 8.0) in the absence of intracellular Ca2+. In contrast, elevation of intracellular Ca2+ dramatically enhanced the LDD175-induced leftward shift in the half-activation potential of hSlo3. Therefore, the mechanism of action does not involve pH-dependent modulation of hSlo3 gating; instead, LDD175 may modulate Ca2+-dependent activation of hSlo3. Thus, LDD175 potentially activates native KSper and may induce membrane hyperpolarization-associated hyperactivation in human sperm.
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Affiliation(s)
- Tharaka Darshana Wijerathne
- Laboratory of Physiology, College of Veterinary Medicine, Chungnam National University, Daejeon 34134, Korea
| | - Jihyun Kim
- Laboratory of Physiology, College of Veterinary Medicine, Chungnam National University, Daejeon 34134, Korea
| | - Dongki Yang
- Department of Physiology, College of Medicine, Gachon University, Incheon 21936, Korea
| | - Kyu Pil Lee
- Laboratory of Physiology, College of Veterinary Medicine, Chungnam National University, Daejeon 34134, Korea
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65
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Berger TK, Fußhöller DM, Goodwin N, Bönigk W, Müller A, Dokani Khesroshahi N, Brenker C, Wachten D, Krause E, Kaupp UB, Strünker T. Post-translational cleavage of Hv1 in human sperm tunes pH- and voltage-dependent gating. J Physiol 2017; 595:1533-1546. [PMID: 27859356 DOI: 10.1113/jp273189] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 11/08/2016] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS In human sperm, proton flux across the membrane is controlled by the voltage-gated proton channel Hv1. We show that sperm harbour both Hv1 and an N-terminally cleaved isoform termed Hv1Sper. The pH-control of Hv1Sper and Hv1 is distinctively different. Hv1Sper and Hv1 can form heterodimers that combine features of both constituents. Cleavage and heterodimerization of Hv1 might represent an adaptation to the specific requirements of pH control in sperm. ABSTRACT In human sperm, the voltage-gated proton channel Hv1 controls the flux of protons across the flagellar membrane. Here, we show that sperm harbour Hv1 and a shorter isoform, termed Hv1Sper. Hv1Sper is generated from Hv1 by removal of 68 amino acids from the N-terminus by post-translational proteolytic cleavage. The pH-dependent gating of the channel isoforms is distinctly different. In both Hv1 and Hv1Sper, the conductance-voltage relationship is determined by the pH difference across the membrane (∆pH). However, simultaneous changes in intracellular and extracellular pH that leave ΔpH constant strongly shift the activation curve of Hv1Sper but not that of Hv1, demonstrating that cleavage of the N-terminus tunes pH sensing in Hv1. Moreover, we show that Hv1 and Hv1Sper assemble as heterodimers that combine features of both constituents. We suggest that cleavage and heterodimerization of Hv1 represents an adaptation to the specific requirements of pH control in sperm.
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Affiliation(s)
- Thomas K Berger
- Department of Molecular Sensory Systems, Center of Advanced European Studies and Research, Bonn, Germany
| | - David M Fußhöller
- Department of Molecular Sensory Systems, Center of Advanced European Studies and Research, Bonn, Germany
| | - Normann Goodwin
- Department of Molecular Sensory Systems, Center of Advanced European Studies and Research, Bonn, Germany
| | - Wolfgang Bönigk
- Department of Molecular Sensory Systems, Center of Advanced European Studies and Research, Bonn, Germany
| | - Astrid Müller
- Department of Molecular Sensory Systems, Center of Advanced European Studies and Research, Bonn, Germany
| | - Nasim Dokani Khesroshahi
- Department of Molecular Sensory Systems, Center of Advanced European Studies and Research, Bonn, Germany
| | - Christoph Brenker
- Department of Molecular Sensory Systems, Center of Advanced European Studies and Research, Bonn, Germany.,Center of Reproductive Medicine and Andrology, University Hospital Münster, Münster, Germany
| | - Dagmar Wachten
- Max-Planck Research Group Molecular Physiology, Center of Advanced European Studies and Research, Bonn, Germany
| | - Eberhard Krause
- Leibniz-Institute for Molecular Pharmacology, Berlin, Germany
| | - U Benjamin Kaupp
- Department of Molecular Sensory Systems, Center of Advanced European Studies and Research, Bonn, Germany
| | - Timo Strünker
- Department of Molecular Sensory Systems, Center of Advanced European Studies and Research, Bonn, Germany.,Center of Reproductive Medicine and Andrology, University Hospital Münster, Münster, Germany
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66
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Kaczmarek LK, Aldrich RW, Chandy KG, Grissmer S, Wei AD, Wulff H. International Union of Basic and Clinical Pharmacology. C. Nomenclature and Properties of Calcium-Activated and Sodium-Activated Potassium Channels. Pharmacol Rev 2017; 69:1-11. [PMID: 28267675 PMCID: PMC11060434 DOI: 10.1124/pr.116.012864] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024] Open
Abstract
A subset of potassium channels is regulated primarily by changes in the cytoplasmic concentration of ions, including calcium, sodium, chloride, and protons. The eight members of this subfamily were originally all designated as calcium-activated channels. More recent studies have clarified the gating mechanisms for these channels and have documented that not all members are sensitive to calcium. This article describes the molecular relationships between these channels and provides an introduction to their functional properties. It also introduces a new nomenclature that differentiates between calcium- and sodium-activated potassium channels.
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Affiliation(s)
- Leonard K Kaczmarek
- Departments of Pharmacology and Cellular and Molecular Physiology, Yale School of Medicine, New Haven, Connecticut (L.K.K.); Center for Learning and Memory and Department of Neuroscience, University of Texas at Austin, Austin, Texas (R.W.A.); Laboratory of Molecular Physiology in the Infection and Immunity Theme, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore (K.G.C.); Institute of Applied Physiology, Ulm University, Ulm, Germany (S.G.); Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington (A.D.W.); and Department of Pharmacology, School of Medicine, University of California, Davis, California (H.W.)
| | - Richard W Aldrich
- Departments of Pharmacology and Cellular and Molecular Physiology, Yale School of Medicine, New Haven, Connecticut (L.K.K.); Center for Learning and Memory and Department of Neuroscience, University of Texas at Austin, Austin, Texas (R.W.A.); Laboratory of Molecular Physiology in the Infection and Immunity Theme, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore (K.G.C.); Institute of Applied Physiology, Ulm University, Ulm, Germany (S.G.); Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington (A.D.W.); and Department of Pharmacology, School of Medicine, University of California, Davis, California (H.W.)
| | - K George Chandy
- Departments of Pharmacology and Cellular and Molecular Physiology, Yale School of Medicine, New Haven, Connecticut (L.K.K.); Center for Learning and Memory and Department of Neuroscience, University of Texas at Austin, Austin, Texas (R.W.A.); Laboratory of Molecular Physiology in the Infection and Immunity Theme, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore (K.G.C.); Institute of Applied Physiology, Ulm University, Ulm, Germany (S.G.); Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington (A.D.W.); and Department of Pharmacology, School of Medicine, University of California, Davis, California (H.W.)
| | - Stephan Grissmer
- Departments of Pharmacology and Cellular and Molecular Physiology, Yale School of Medicine, New Haven, Connecticut (L.K.K.); Center for Learning and Memory and Department of Neuroscience, University of Texas at Austin, Austin, Texas (R.W.A.); Laboratory of Molecular Physiology in the Infection and Immunity Theme, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore (K.G.C.); Institute of Applied Physiology, Ulm University, Ulm, Germany (S.G.); Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington (A.D.W.); and Department of Pharmacology, School of Medicine, University of California, Davis, California (H.W.)
| | - Aguan D Wei
- Departments of Pharmacology and Cellular and Molecular Physiology, Yale School of Medicine, New Haven, Connecticut (L.K.K.); Center for Learning and Memory and Department of Neuroscience, University of Texas at Austin, Austin, Texas (R.W.A.); Laboratory of Molecular Physiology in the Infection and Immunity Theme, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore (K.G.C.); Institute of Applied Physiology, Ulm University, Ulm, Germany (S.G.); Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington (A.D.W.); and Department of Pharmacology, School of Medicine, University of California, Davis, California (H.W.)
| | - Heike Wulff
- Departments of Pharmacology and Cellular and Molecular Physiology, Yale School of Medicine, New Haven, Connecticut (L.K.K.); Center for Learning and Memory and Department of Neuroscience, University of Texas at Austin, Austin, Texas (R.W.A.); Laboratory of Molecular Physiology in the Infection and Immunity Theme, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore (K.G.C.); Institute of Applied Physiology, Ulm University, Ulm, Germany (S.G.); Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington (A.D.W.); and Department of Pharmacology, School of Medicine, University of California, Davis, California (H.W.)
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67
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Kaupp UB, Strünker T. Signaling in Sperm: More Different than Similar. Trends Cell Biol 2016; 27:101-109. [PMID: 27825709 DOI: 10.1016/j.tcb.2016.10.002] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 10/13/2016] [Accepted: 10/14/2016] [Indexed: 11/30/2022]
Abstract
For a given sensory cell type, signaling motifs are rather uniform across phyla. By contrast, sperm from different species use diverse repertoires of sperm-specific signaling molecules and even closely related protein isoforms feature different properties and serve different functions. This surprising diversity has consequences for strategies in fertilization research and it will take some time to get the big picture. We discuss the function of receptors, ion channels, and exchangers embedded in cellular pathways from different sperm species.
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Affiliation(s)
- U B Kaupp
- Center of Advanced European Studies and Research (CAESAR), Department of Molecular Sensory Systems, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany.
| | - T Strünker
- University Hospital Münster, Center of Reproductive Medicine and Andrology, Albert-Schweitzer-Campus 1, Geb. D11, 48149 Münster, Germany
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68
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Lishko PV. Contraception: Search for an Ideal Unisex Mechanism by Targeting Ion Channels. Trends Biochem Sci 2016; 41:816-818. [PMID: 27545067 DOI: 10.1016/j.tibs.2016.08.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 07/22/2016] [Accepted: 08/01/2016] [Indexed: 02/01/2023]
Abstract
Targeting sperm ion channels and other sperm-specific proteins is an effective way to develop unisex contraceptives, as they should have decreased side effects. This Science & Society summarizes the current advances in human sperm physiology in attempts to evaluate what would be appropriate targets for unisex contraceptives.
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Affiliation(s)
- Polina V Lishko
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA.
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69
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Brown SG, Publicover SJ, Mansell SA, Lishko PV, Williams HL, Ramalingam M, Wilson SM, Barratt CLR, Sutton KA, Da Silva SM. Depolarization of sperm membrane potential is a common feature of men with subfertility and is associated with low fertilization rate at IVF. Hum Reprod 2016; 31:1147-57. [PMID: 27052499 PMCID: PMC4871192 DOI: 10.1093/humrep/dew056] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 02/29/2016] [Indexed: 12/17/2022] Open
Abstract
STUDY QUESTION Are significant abnormalities in outward (K+) conductance and resting membrane potential (Vm) present in the spermatozoa of patients undertaking IVF and ICSI and if so, what is their functional effect on fertilization success? SUMMARY ANSWER Negligible outward conductance (≈5% of patients) or an enhanced inward conductance (≈4% of patients), both of which caused depolarization of Vm, were associated with a low rate of fertilization following IVF. WHAT IS KNOWN ALREADY Sperm-specific potassium channel knockout mice are infertile with defects in sperm function, suggesting that these channels are essential for fertility. These observations suggest that malfunction of K+ channels in human spermatozoa might contribute significantly to the occurrence of subfertility in men. However, remarkably little is known of the nature of K+ channels in human spermatozoa or the incidence and functional consequences of K+ channel defects. STUDY DESIGN, SIZE AND DURATION Spermatozoa were obtained from healthy volunteer research donors and subfertile IVF and ICSI patients attending a hospital assisted reproductive techniques clinic between May 2013 and December 2015. In total, 40 IVF patients, 41 ICSI patients and 26 normozoospermic donors took part in the study. PARTICIPANTS/MATERIALS, SETTING, METHODS Samples were examined using electrophysiology (whole-cell patch clamping). Where abnormal electrophysiological characteristics were identified, spermatozoa were further examined for Ca2+ influx induced by progesterone and penetration into viscous media if sufficient sample was available. Full exome sequencing was performed to specifically evaluate potassium calcium-activated channel subfamily M α 1 (KCNMA1), potassium calcium-activated channel subfamily U member 1 (KCNU1) and leucine-rich repeat containing 52 (LRRC52) genes and others associated with K+ signalling. In IVF patients, comparison with fertilization rates was done to assess the functional significance of the electrophysiological abnormalities. MAIN RESULTS AND THE ROLE OF CHANCE Patch clamp electrophysiology was used to assess outward (K+) conductance and resting membrane potential (Vm) and signalling/motility assays were used to assess functional characteristics of sperm from IVF and ICSI patient samples. The mean Vm and outward membrane conductance in sperm from IVF and ICSI patients were not significantly different from those of control (donor) sperm prepared under the same conditions, but variation between individuals was significantly greater (P< 0.02) with a large number of outliers (>25%). In particular, in ≈10% of patients (7/81), we observed either a negligible outward conductance (4 patients) or an enhanced inward current (3 patients), both of which caused depolarization of Vm. Analysis of clinical data from the IVF patients showed significant association of depolarized Vm (≥0 mV) with low fertilization rate (P= 0.012). Spermatozoa with electrophysiological abnormities (conductance and Vm) responded normally to progesterone with elevation of [Ca2+]i and penetration of viscous medium, indicating retention of cation channel of sperm (CatSper) channel function. LIMITATIONS, REASONS FOR CAUTION For practical, technical, ethical and logistical reasons, we could not obtain sufficient additional semen samples from men with conductance abnormalities to establish the cause of the conductance defects. Full exome sequencing was only available in two men with conductance defects. WIDER IMPLICATIONS OF THE FINDINGS These data add significantly to the understanding of the role of ion channels in human sperm function and its impact on male fertility. Impaired potassium channel conductance (Gm) and/or Vm regulation is both common and complex in human spermatozoa and importantly is associated with impaired fertilization capacity when the Vm of cells is completely depolarized. STUDY FUNDING/COMPETING INTEREST(S) The majority of the data were obtained using funding from MRC project grants (#MR/K013343/1, MR/012492/1). Additional funding was provided by NHS Tayside, TENOVUS, Chief Scientist Office NRS Fellowship and University of Abertay. The authors declare that there is no conflict of interest. TRIAL REGISTRATION NUMBER Not applicable.
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Affiliation(s)
- Sean G Brown
- School of Science, Engineering and Technology, Abertay University, Dundee DD11HG, UK
| | | | - Steven A Mansell
- Reproductive and Developmental Biology, School of Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee DD19SY, UK Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - Polina V Lishko
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - Hannah L Williams
- Reproductive and Developmental Biology, School of Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee DD19SY, UK
| | - Mythili Ramalingam
- Reproductive and Developmental Biology, School of Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee DD19SY, UK
| | - Stuart M Wilson
- Wolfson Research Institute, School of Medicine, Pharmacy and Health, University of Durham, Queen's Campus, Stockton on Tees TS17 6BH, UK
| | - Christopher L R Barratt
- Reproductive and Developmental Biology, School of Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee DD19SY, UK
| | - Keith A Sutton
- Reproductive and Developmental Biology, School of Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee DD19SY, UK
| | - Sarah Martins Da Silva
- Reproductive and Developmental Biology, School of Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee DD19SY, UK
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70
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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]
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71
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Fechner S, Alvarez L, Bönigk W, Müller A, Berger TK, Pascal R, Trötschel C, Poetsch A, Stölting G, Siegfried KR, Kremmer E, Seifert R, Kaupp UB. A K(+)-selective CNG channel orchestrates Ca(2+) signalling in zebrafish sperm. eLife 2015; 4:e07624. [PMID: 26650356 PMCID: PMC4749565 DOI: 10.7554/elife.07624] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 12/09/2015] [Indexed: 01/03/2023] Open
Abstract
Calcium in the flagellum controls sperm navigation. In sperm of marine invertebrates and mammals, Ca(2+) signalling has been intensely studied, whereas for fish little is known. In sea urchin sperm, a cyclic nucleotide-gated K(+) channel (CNGK) mediates a cGMP-induced hyperpolarization that evokes Ca(2+) influx. Here, we identify in sperm of the freshwater fish Danio rerio a novel CNGK family member featuring non-canonical properties. It is located in the sperm head rather than the flagellum and is controlled by intracellular pH, but not cyclic nucleotides. Alkalization hyperpolarizes sperm and produces Ca(2+) entry. Ca(2+) induces spinning-like swimming, different from swimming of sperm from other species. The "spinning" mode probably guides sperm into the micropyle, a narrow entrance on the surface of fish eggs. A picture is emerging of sperm channel orthologues that employ different activation mechanisms and serve different functions. The channel inventories probably reflect adaptations to species-specific challenges during fertilization.
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Affiliation(s)
- Sylvia Fechner
- Abteilung Molekulare Neurosensorik, Center of Advanced European Studies and Research, Bonn, Germany
| | - Luis Alvarez
- Abteilung Molekulare Neurosensorik, Center of Advanced European Studies and Research, Bonn, Germany
| | - Wolfgang Bönigk
- Abteilung Molekulare Neurosensorik, Center of Advanced European Studies and Research, Bonn, Germany
| | - Astrid Müller
- Abteilung Molekulare Neurosensorik, Center of Advanced European Studies and Research, Bonn, Germany
| | - Thomas K Berger
- Abteilung Molekulare Neurosensorik, Center of Advanced European Studies and Research, Bonn, Germany
| | - Rene Pascal
- Abteilung Molekulare Neurosensorik, Center of Advanced European Studies and Research, Bonn, Germany
| | | | - Ansgar Poetsch
- Lehrstuhl Biochemie der Pflanzen, Ruhr-Universität Bochum, Bochum, Germany
| | - Gabriel Stölting
- Institute of Complex Systems 4, Forschungszentrum Jülich, Jülich, Germany
| | - Kellee R Siegfried
- Biology Department, University of Massachusetts Boston, Boston, United States
| | - Elisabeth Kremmer
- Institut für Molekulare Immunologie, Helmholtz-Zentrum München, München, Germany
| | - Reinhard Seifert
- Abteilung Molekulare Neurosensorik, Center of Advanced European Studies and Research, Bonn, Germany
| | - U Benjamin Kaupp
- Abteilung Molekulare Neurosensorik, Center of Advanced European Studies and Research, Bonn, Germany
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72
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Williams HL, Mansell S, Alasmari W, Brown SG, Wilson SM, Sutton KA, Miller MR, Lishko PV, Barratt CLR, Publicover SJ, Martins da Silva S. Specific loss of CatSper function is sufficient to compromise fertilizing capacity of human spermatozoa. Hum Reprod 2015; 30:2737-46. [PMID: 26453676 PMCID: PMC4643530 DOI: 10.1093/humrep/dev243] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2015] [Accepted: 09/07/2015] [Indexed: 12/26/2022] Open
Abstract
STUDY QUESTION Are significant abnormalities of CatSper function present in IVF patients with normal sperm concentration and motility and if so what is their functional significance for fertilization success? SUMMARY ANSWER Sperm with a near absence of CatSper current failed to respond to activation of CatSper by progesterone and there was fertilization failure at IVF. WHAT IS KNOWN ALREADY In human spermatozoa, Ca2+ influx induced by progesterone is mediated by CatSper, a sperm-specific Ca2+ channel. A suboptimal Ca2+ influx is significantly associated with, and more prevalent in, men with abnormal semen parameters, and is associated with reduced fertilizing capacity. However, abnormalities in CatSper current can only be assessed directly using electrophysiology. There is only one report of a CatSper-deficient man who showed no progesterone potentiated CatSper current. A CatSper 2 genetic abnormality was present but there was no information on the [Ca2+]i response to CatSper activation by progesterone. Additionally, the semen samples had indicating significant abnormalities (oligoasthenoteratozoospermia) multiple suboptimal functional responses in the spermatozoon. As such it cannot be concluded that impaired CatSper function alone causes infertility or that CatSper blockade is a potential safe target for contraception. STUDY DESIGN, SIZE, DURATION Spermatozoa were obtained from donors and subfertile IVF patients attending a hospital assisted reproductive techniques clinic between January 2013 and December 2014. In total 134 IVF patients, 28 normozoospermic donors and 10 patients recalled due to a history of failed/low fertilization at IVF took part in the study. PARTICIPANTS/MATERIALS, SETTING, METHODS Samples were primarily screened using the Ca2+ influx induced by progesterone and, if cell number was sufficient, samples were also assessed by hyperactivation and penetration into viscous media. A defective Ca2+ response to progesterone was defined using the 99% confidence interval from the distribution of response amplitudes in normozoospermic donors. Samples showing a defective Ca2+ response were further examined in order to characterize the potential CatSper abnormalities. In men where there was a consistent and robust failure of calcium signalling, a direct assessment of CatSper function was performed using electrophysiology (patch clamping), and a blood sample was obtained for genetic analysis. MAIN RESULTS AND THE ROLE OF CHANCE A total of 101/102 (99%) IVF patients and 22/23 (96%) donors exhibited a normal Ca2+ response. The mean (±SD) normalized peak response did not differ between donors and IVF patients (2.57 ± 0.68 [n = 34 ejaculates from 23 different donors] versus 2.66 ± 0.68 [n = 102 IVF patients], P = 0.63). In recall patients, 9/10 (90%) showed a normal Ca2+ response. Three men were initially identified with a defective Ca2+ influx. However, only one (Patient 1) had a defective response in repeat semen samples. Electrophysiology experiments on sperm from Patient 1 showed a near absence of CatSper current and exon screening demonstrated no mutations in the coding regions of the CatSper complex. There was no increase in penetration of viscous media when the spermatozoa were stimulated with progesterone and importantly there was failed fertilization at IVF. LIMITATIONS, REASONS FOR CAUTION A key limitation relates to working with a specific functional parameter (Ca2+ influx induced by progesterone) in fresh sperm samples from donors and patients that have limited viability. Therefore, for practical, technical and logistical reasons, some men (∼22% of IVF patients) could not be screened. As such the incidence of significant Ca2+ abnormalities induced by progesterone may be higher than the ∼1% observed here. Additionally, we used a strict definition of a defective Ca2+ influx such that only substantial abnormalities were selected for further study. Furthermore, electrophysiology was only performed on one patient with a robust and repeatable defective calcium response. This man had negligible CatSper current but more subtle abnormalities (e.g. currents present but significantly smaller) may have been present in men with either normal or below normal Ca2+ influx. WIDER IMPLICATIONS OF THE FINDINGS These data add significantly to the understanding of the role of CatSper in human sperm function and its impact on male fertility. Remarkably, these findings provide the first direct evidence that CatSper is a suitable and specific target for human male contraception. STUDY FUNDING/COMPETING INTEREST(S) Initial funding was from NHS Tayside, Infertility Research Trust, TENOVUS, Chief Scientist Office NRS Fellowship, the Wellcome Trust, University of Abertay. The majority of the data were obtained using funding from a MRC project grant (# 4190). The authors declare that there is no conflict of interest. TRIAL REGISTRATION NUMBER Not applicable.
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Affiliation(s)
- Hannah L Williams
- Reproductive and Developmental Biology, Medical School, Ninewells Hospital, University of Dundee, Dundee DD1 9SY, UK Assisted Conception Unit, NHS Tayside, Ninewells Hospital, Dundee DD1 9SY, UK
| | - Steven Mansell
- Reproductive and Developmental Biology, Medical School, Ninewells Hospital, University of Dundee, Dundee DD1 9SY, UK Department of Molecular and Cell Biology, University of California, Berkeley, USA
| | - Wardah Alasmari
- Reproductive and Developmental Biology, Medical School, Ninewells Hospital, University of Dundee, Dundee DD1 9SY, UK
| | | | - Stuart M Wilson
- Reproductive and Developmental Biology, Medical School, Ninewells Hospital, University of Dundee, Dundee DD1 9SY, UK Wolfson Research Institute, School of Medicine, Pharmacy and Health, Queen's Campus, University Of Durham, Stockton on Tees TS17 6BH, UK
| | - Keith A Sutton
- Reproductive and Developmental Biology, Medical School, Ninewells Hospital, University of Dundee, Dundee DD1 9SY, UK
| | - Melissa R Miller
- Department of Molecular and Cell Biology, University of California, Berkeley, USA
| | - Polina V Lishko
- Department of Molecular and Cell Biology, University of California, Berkeley, USA
| | - Christopher L R Barratt
- Reproductive and Developmental Biology, Medical School, Ninewells Hospital, University of Dundee, Dundee DD1 9SY, UK Assisted Conception Unit, NHS Tayside, Ninewells Hospital, Dundee DD1 9SY, UK
| | | | - Sarah Martins da Silva
- Reproductive and Developmental Biology, Medical School, Ninewells Hospital, University of Dundee, Dundee DD1 9SY, UK Assisted Conception Unit, NHS Tayside, Ninewells Hospital, Dundee DD1 9SY, UK
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73
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Wrighton DC, Muench SP, Lippiat JD. Mechanism of inhibition of mouse Slo3 (KCa 5.1) potassium channels by quinine, quinidine and barium. Br J Pharmacol 2015; 172:4355-63. [PMID: 26045093 PMCID: PMC4556473 DOI: 10.1111/bph.13214] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Revised: 05/13/2015] [Accepted: 05/26/2015] [Indexed: 12/21/2022] Open
Abstract
Background and Purpose The Slo3 (KCa5.1) channel is a major component of mammalian KSper (sperm potassium conductance) channels and inhibition of these channels by quinine and barium alters sperm motility. The aim of this investigation was to determine the mechanism by which these drugs inhibit Slo3 channels. Experimental Approach Mouse (m) Slo3 (KCa5.1) channels or mutant forms were expressed in Xenopus oocytes and currents recorded with 2-electrode voltage-clamp. Gain-of-function mSlo3 mutations were used to explore the state-dependence of the inhibition. The interaction between quinidine and mSlo3 channels was modelled by in silico docking. Key Results Several drugs known to block KSper also affected mSlo3 channels with similar levels of inhibition. The inhibition induced by extracellular barium was prevented by increasing the extracellular potassium concentration. R196Q and F304Y mutations in the mSlo3 voltage sensor and pore, respectively, both increased channel activity. The F304Y mutation did not alter the effects of barium, but increased the potency of inhibition by both quinine and quinidine approximately 10-fold; this effect was not observed with the R196Q mutation. Conclusions and Implications Block of mSlo3 channels by quinine, quinidine and barium is not state-dependent. Barium inhibits mSlo3 outside the cell by interacting with the selectivity filter, whereas quinine and quinidine act from the inside, by binding in a hydrophobic pocket formed by the S6 segment of each subunit. Furthermore, we propose that the Slo3 channel activation gate lies deep within the pore between F304 in the S6 segment and the selectivity filter.
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Affiliation(s)
- David C Wrighton
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Stephen P Muench
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Jonathan D Lippiat
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, UK
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74
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Miller MR, Mansell SA, Meyers SA, Lishko PV. Flagellar ion channels of sperm: similarities and differences between species. Cell Calcium 2015; 58:105-13. [DOI: 10.1016/j.ceca.2014.10.009] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 10/16/2014] [Accepted: 10/20/2014] [Indexed: 10/24/2022]
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75
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Correia J, Michelangeli F, Publicover S. Regulation and roles of Ca2+ stores in human sperm. Reproduction 2015; 150:R65-76. [PMID: 25964382 PMCID: PMC4497595 DOI: 10.1530/rep-15-0102] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 05/11/2015] [Indexed: 12/16/2022]
Abstract
[Ca(2)(+)]i signalling is a key regulatory mechanism in sperm function. In mammalian sperm the Ca(2)(+)-permeable plasma membrane ion channel CatSper is central to [Ca(2)(+)]i signalling, but there is good evidence that Ca(2)(+) stored in intracellular organelles is also functionally important. Here we briefly review the current understanding of the diversity of Ca(2)(+) stores and the mechanisms for the regulation of their activity. We then consider the evidence for the involvement of these stores in [Ca(2)(+)]i signalling in mammalian (primarily human) sperm, the agonists that may activate these stores and their role in control of sperm function. Finally we consider the evidence that membrane Ca(2)(+) channels and stored Ca(2)(+) may play discrete roles in the regulation of sperm activities and propose a mechanism by which these different components of the sperm Ca(2)(+)-signalling apparatus may interact to generate complex and spatially diverse [Ca(2)(+)]i signals.
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Affiliation(s)
- Joao Correia
- School of BiosciencesUniversity of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | | | - Stephen Publicover
- School of BiosciencesUniversity of Birmingham, Edgbaston, Birmingham B15 2TT, UK
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76
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Strünker T, Alvarez L, Kaupp UB. At the physical limit - chemosensation in sperm. Curr Opin Neurobiol 2015; 34:110-6. [PMID: 25768273 DOI: 10.1016/j.conb.2015.02.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Revised: 02/18/2015] [Accepted: 02/18/2015] [Indexed: 12/15/2022]
Abstract
Many cells probe their environment for chemical cues. Some cells respond to picomolar concentrations of neuropeptides, hormones, pheromones, or chemoattractants. At such low concentrations, cells encounter only a few molecules. The mechanistic underpinnings of single-molecule sensitivity are not known for any eukaryotic cell. Sea urchin sperm offer a unique model to unveil in quantitative terms the principles underlying chemosensation at the physical limit. Here, we discuss the mechanisms of such exquisite sensitivity and the computational operations performed by sperm during chemotactic steering. Moreover, we highlight commonalities and differences between signalling in sperm and photoreceptors and among sperm from different species.
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Affiliation(s)
- T Strünker
- Center of Advanced European Studies and Research (caesar), Ludwig-Erhard-Allee 2, Bonn 53175, Germany
| | - L Alvarez
- Center of Advanced European Studies and Research (caesar), Ludwig-Erhard-Allee 2, Bonn 53175, Germany
| | - U B Kaupp
- Center of Advanced European Studies and Research (caesar), Ludwig-Erhard-Allee 2, Bonn 53175, Germany.
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77
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SLO3 auxiliary subunit LRRC52 controls gating of sperm KSPER currents and is critical for normal fertility. Proc Natl Acad Sci U S A 2015; 112:2599-604. [PMID: 25675513 DOI: 10.1073/pnas.1423869112] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Following entry into the female reproductive tract, mammalian sperm undergo a maturation process termed capacitation that results in competence to fertilize ova. Associated with capacitation is an increase in membrane conductance to both Ca(2+) and K(+), leading to an elevation in cytosolic Ca(2+) critical for activation of hyperactivated swimming motility. In mice, the Ca(2+) conductance (alkalization-activated Ca(2+)-permeable sperm channel, CATSPER) arises from an ensemble of CATSPER subunits, whereas the K(+) conductance (sperm pH-regulated K(+) current, KSPER) arises from a pore-forming ion channel subunit encoded by the slo3 gene (SLO3) subunit. In the mouse, both CATSPER and KSPER are activated by cytosolic alkalization and a concerted activation of CATSPER and KSPER is likely a common facet of capacitation-associated increases in Ca(2+) and K(+) conductance among various mammalian species. The properties of heterologously expressed mouse SLO3 channels differ from native mouse KSPER current. Recently, a potential KSPER auxiliary subunit, leucine-rich-repeat-containing protein 52 (LRRC52), was identified in mouse sperm and shown to shift gating of SLO3 to be more equivalent to native KSPER. Here, we show that genetic KO of LRRC52 results in mice with severely impaired fertility. Activation of KSPER current in sperm lacking LRRC52 requires more positive voltages and higher pH than for WT KSPER. These results establish a critical role of LRRC52 in KSPER channels and demonstrate that loss of a non-pore-forming auxiliary subunit results in severe fertility impairment. Furthermore, through analysis of several genotypes that influence KSPER current properties we show that in vitro fertilization competence correlates with the net KSPER conductance available for activation under physiological conditions.
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78
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Seifert R, Flick M, Bönigk W, Alvarez L, Trötschel C, Poetsch A, Müller A, Goodwin N, Pelzer P, Kashikar ND, Kremmer E, Jikeli J, Timmermann B, Kuhl H, Fridman D, Windler F, Kaupp UB, Strünker T. The CatSper channel controls chemosensation in sea urchin sperm. EMBO J 2014; 34:379-92. [PMID: 25535245 DOI: 10.15252/embj.201489376] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Sperm guidance is controlled by chemical and physical cues. In many species, Ca(2+) bursts in the flagellum govern navigation to the egg. In Arbacia punctulata, a model system of sperm chemotaxis, a cGMP signaling pathway controls these Ca(2+) bursts. The underlying Ca(2+) channel and its mechanisms of activation are unknown. Here, we identify CatSper Ca(2+) channels in the flagellum of A. punctulata sperm. We show that CatSper mediates the chemoattractant-evoked Ca(2+) influx and controls chemotactic steering; a concomitant alkalization serves as a highly cooperative mechanism that enables CatSper to transduce periodic voltage changes into Ca(2+) bursts. Our results reveal intriguing phylogenetic commonalities but also variations between marine invertebrates and mammals regarding the function and control of CatSper. The variations probably reflect functional and mechanistic adaptations that evolved during the transition from external to internal fertilization.
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Affiliation(s)
- Reinhard Seifert
- Center of Advanced European Studies and Research (Caesar), Abteilung Molekulare Neurosensorik, Bonn, Germany Marine Biological Laboratory, Woods Hole, MA, USA
| | - Melanie Flick
- Center of Advanced European Studies and Research (Caesar), Abteilung Molekulare Neurosensorik, Bonn, Germany
| | - Wolfgang Bönigk
- Center of Advanced European Studies and Research (Caesar), Abteilung Molekulare Neurosensorik, Bonn, Germany
| | - Luis Alvarez
- Center of Advanced European Studies and Research (Caesar), Abteilung Molekulare Neurosensorik, Bonn, Germany
| | | | - Ansgar Poetsch
- Ruhr-Universität Bochum Lehrstuhl Biochemie der Pflanzen, Bochum, Germany
| | - Astrid Müller
- Center of Advanced European Studies and Research (Caesar), Abteilung Molekulare Neurosensorik, Bonn, Germany
| | - Normann Goodwin
- Marine Biological Laboratory, Woods Hole, MA, USA Laboratory of Molecular Signalling, Babraham Institute, Cambridge, UK
| | - Patric Pelzer
- Marine Biological Laboratory, Woods Hole, MA, USA Institut für Anatomie und Zellbiologie, Abteilung für Funktionelle Neuroanatomie, Universität Heidelberg, Heidelberg, Germany
| | - Nachiket D Kashikar
- Marine Biological Laboratory, Woods Hole, MA, USA Sussex Neuroscience, School of Life Sciences, University of Sussex, Falmer, Brighton, UK
| | - Elisabeth Kremmer
- Helmholtz-Zentrum München, Institut für Molekulare Immunologie, München, Germany
| | - Jan Jikeli
- Center of Advanced European Studies and Research (Caesar), Abteilung Molekulare Neurosensorik, Bonn, Germany
| | | | - Heiner Kuhl
- Max-Planck-Institut für Molekulare Genetik, Berlin, Germany
| | - Dmitry Fridman
- Center of Advanced European Studies and Research (Caesar), Abteilung Molekulare Neurosensorik, Bonn, Germany Marine Biological Laboratory, Woods Hole, MA, USA
| | - Florian Windler
- Center of Advanced European Studies and Research (Caesar), Abteilung Molekulare Neurosensorik, Bonn, Germany Marine Biological Laboratory, Woods Hole, MA, USA
| | - U Benjamin Kaupp
- Center of Advanced European Studies and Research (Caesar), Abteilung Molekulare Neurosensorik, Bonn, Germany Marine Biological Laboratory, Woods Hole, MA, USA
| | - Timo Strünker
- Center of Advanced European Studies and Research (Caesar), Abteilung Molekulare Neurosensorik, Bonn, Germany Marine Biological Laboratory, Woods Hole, MA, USA
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79
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Chávez JC, Ferreira JJ, Butler A, De La Vega Beltrán JL, Treviño CL, Darszon A, Salkoff L, Santi CM. SLO3 K+ channels control calcium entry through CATSPER channels in sperm. J Biol Chem 2014; 289:32266-32275. [PMID: 25271166 DOI: 10.1074/jbc.m114.607556] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Here we show how a sperm-specific potassium channel (SLO3) controls Ca(2+) entry into sperm through a sperm-specific Ca(2+) channel, CATSPER, in a totally unanticipated manner. The genetic deletion of either of those channels confers male infertility in mice. During sperm capacitation SLO3 hyperpolarizes the sperm, whereas CATSPER allows Ca(2+) entry. These two channels may be functionally connected, but it had not been demonstrated that SLO3-dependent hyperpolarization is required for Ca(2+) entry through CATSPER channels, nor has a functional mechanism linking the two channels been shown. In this study we show that Ca(2+) entry through CATSPER channels is deficient in Slo3 mutant sperm lacking hyperpolarization; we also present evidence supporting the hypothesis that SLO3 channels activate CATSPER channels indirectly by promoting a rise in intracellular pH through a voltage-dependent mechanism. This mechanism may work through a Na(+)/H(+) exchanger (sNHE) and/or a bicarbonate transporter, which utilizes the inward driving force of the Na(+) gradient, rendering it intrinsically voltage-dependent. In addition, the sperm-specific Na(+)/H(+) exchanger (sNHE) possess a putative voltage sensor that might be activated by membrane hyperpolarization, thus increasing the voltage sensitivity of internal alkalization.
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Affiliation(s)
- Julio César Chávez
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri 63110 and; Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), 62210 Cuernavaca, México
| | - Juan José Ferreira
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri 63110 and
| | - Alice Butler
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri 63110 and
| | | | - Claudia L Treviño
- Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), 62210 Cuernavaca, México
| | - Alberto Darszon
- Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), 62210 Cuernavaca, México
| | - Lawrence Salkoff
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri 63110 and
| | - Celia M Santi
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri 63110 and
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80
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Nishigaki T, José O, González-Cota AL, Romero F, Treviño CL, Darszon A. Intracellular pH in sperm physiology. Biochem Biophys Res Commun 2014; 450:1149-58. [PMID: 24887564 PMCID: PMC4146485 DOI: 10.1016/j.bbrc.2014.05.100] [Citation(s) in RCA: 122] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Accepted: 05/22/2014] [Indexed: 10/25/2022]
Abstract
Intracellular pH (pHi) regulation is essential for cell function. Notably, several unique sperm ion transporters and enzymes whose elimination causes infertility are either pHi dependent or somehow related to pHi regulation. Amongst them are: CatSper, a Ca(2+) channel; Slo3, a K(+) channel; the sperm-specific Na(+)/H(+) exchanger and the soluble adenylyl cyclase. It is thus clear that pHi regulation is of the utmost importance for sperm physiology. This review briefly summarizes the key components involved in pHi regulation, their characteristics and participation in fundamental sperm functions such as motility, maturation and the acrosome reaction.
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Affiliation(s)
- Takuya Nishigaki
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62210, Mexico
| | - Omar José
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62210, Mexico
| | - Ana Laura González-Cota
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62210, Mexico
| | - Francisco Romero
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62210, Mexico
| | - Claudia L Treviño
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62210, Mexico
| | - Alberto Darszon
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62210, Mexico.
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81
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Abstract
Recent work in humans and mouse has confirmed the involvement of the host defence β-defensin peptides in male fertility. We discuss here the work that has implicated β-defensins in sperm function including the identification of the epididymis as the predominant site of expression of the peptides and the in vivo consequences of mutation and deletion. The potential dual role of these peptides in the regulation of infection and control of sperm maturation is compelling and may combine their antimicrobial activity with the ability of these molecules to interact with cell membrane receptors and modulate ion transport.
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Affiliation(s)
- Julia R Dorin
- MRC Human Genetics Unit, MRC IGMM, University of Edinburgh, Western General Hospital, Edinburgh, UK
| | - Christopher L R Barratt
- Reproductive and Developmental Biology, Medical School, University of Dundee, Ninewells Hospital, Dundee, UK
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