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Jiménez-López C, Nadler A. Caged lipid probes for controlling lipid levels on subcellular scales. Curr Opin Chem Biol 2023; 72:102234. [PMID: 36493527 DOI: 10.1016/j.cbpa.2022.102234] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 10/26/2022] [Accepted: 11/07/2022] [Indexed: 12/12/2022]
Abstract
Lipids exert their cellular functions in individual organelles, in some cases on the scale of even smaller, specialized membrane domains. Thus, the experimental capacity to precisely manipulate lipid levels at the subcellular level is crucial for studying lipid-related processes in cell biology. Photo-caged lipid probes which partition into specific cellular membranes prior to photoactivation have emerged as key tools for localized and selective perturbation of lipid concentration in living cells. In this review, we provide an overview of the recent advances in the area and outline which developments are still required for the methodology to be more widely implemented in the wider membrane biology community.
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Affiliation(s)
| | - André Nadler
- Max Planck Institute for Molecular Cell Biology and Genetics, Dresden, Germany.
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2
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Mendoza-Sánchez JE, Rodríguez-Tobón A, Arenas-Ríos E, Orta-Salazar GJ, León-Galván MA, Treviño Santa Cruz CL, Chávez JC. Sperm calcium flux and membrane potential hyperpolarization observed in the Mexican big-eared bat Corynorhinus mexicanus. J Exp Biol 2023; 226:286150. [PMID: 36541225 PMCID: PMC10086540 DOI: 10.1242/jeb.244878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022]
Abstract
Mammalian sperm capacitation involves biochemical and physiological changes, such as an increase in intracellular calcium ion concentration ([Ca2+]i), hyperpolarization of the plasma membrane potential and sperm hyperactivation, among others. These changes provide sperm with the ability to fertilize. In the bat Corynorhinus mexicanus, there is an asynchrony between spermatogenesis and sperm storage in the male with the receptivity of the female. For instance, in C. mexicanus, spermatogenesis occurs before the reproductive season. During the reproductive period, sperm are stored in the epididymis for a few months and the testis undergoes a regression, indicating low or almost null sperm production. Therefore, it is unclear whether the elements necessary for sperm fertilization success undergo maturation or preparation during epididymis storage. Here, we characterized pH-sensitive motility hyperactivation and Ca2+ influx in sperm, regulated by alkalinization and progesterone. In addition, by electrophysiological recordings, we registered currents that were stimulated by alkalinization and inhibited by RU1968 (a CatSper-specific inhibitor), strongly suggesting that these currents were evoked via CatSper, a sperm Ca2+-specific channel indispensable for mammalian fertilization. We also found hyperpolarization of the membrane potential, such as in other mammalian species, which increased according to the month of capture, reaching the biggest hyperpolarization during the mating season. In conclusion, our results suggest that C. mexicanus sperm have functional CatSper and undergo a capacitation-like process such as in other mammals, particularly Ca2+ influx and membrane potential hyperpolarization.
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Affiliation(s)
- José Edwin Mendoza-Sánchez
- Doctorado en Biología Experimental, Universidad Autónoma Metropolitana, Iztapalapa, 09310 Ciudad de México, México
| | - Ahiezer Rodríguez-Tobón
- Laboratorio de Biología y Ecología de Mamíferos, Universidad Autónoma Metropolitana, Iztapalapa, 09310 Ciudad de México, México
| | - Edith Arenas-Ríos
- Laboratorio de Morfofisiología y Bioquímica del Espermatozoide, Universidad Autónoma Metropolitana, Iztapalapa, 09310 Ciudad de México, México
| | - Gerardo J Orta-Salazar
- Consorcio de Fisiología del Espermatozoide, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, 62210 Morelos, México
| | - Miguel A León-Galván
- Laboratorio de Biología y Ecología de Mamíferos, Universidad Autónoma Metropolitana, Iztapalapa, 09310 Ciudad de México, México
| | - Claudia L Treviño Santa Cruz
- Consorcio de Fisiología del Espermatozoide, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, 62210 Morelos, México
| | - Julio C Chávez
- Consorcio de Fisiología del Espermatozoide, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, 62210 Morelos, México
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3
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Kierzek M, Deal PE, Miller EW, Mukherjee S, Wachten D, Baumann A, Kaupp UB, Strünker T, Brenker C. Simultaneous recording of multiple cellular signaling events by frequency- and spectrally-tuned multiplexing of fluorescent probes. eLife 2021; 10:e63129. [PMID: 34859780 PMCID: PMC8700268 DOI: 10.7554/elife.63129] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 12/01/2021] [Indexed: 12/21/2022] Open
Abstract
Fluorescent probes that change their spectral properties upon binding to small biomolecules, ions, or changes in the membrane potential (Vm) are invaluable tools to study cellular signaling pathways. Here, we introduce a novel technique for simultaneous recording of multiple probes at millisecond time resolution: frequency- and spectrally-tuned multiplexing (FASTM). Different from present multiplexing approaches, FASTM uses phase-sensitive signal detection, which renders various combinations of common probes for Vm and ions accessible for multiplexing. Using kinetic stopped-flow fluorimetry, we show that FASTM allows simultaneous recording of rapid changes in Ca2+, pH, Na+, and Vm with high sensitivity and minimal crosstalk. FASTM is also suited for multiplexing using single-cell microscopy and genetically encoded FRET biosensors. Moreover, FASTM is compatible with optochemical tools to study signaling using light. Finally, we show that the exceptional time resolution of FASTM also allows resolving rapid chemical reactions. Altogether, FASTM opens new opportunities for interrogating cellular signaling.
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Affiliation(s)
- Michelina Kierzek
- Centre of Reproductive Medicine and Andrology, University of MünsterMünsterGermany
- CiM-IMPRS Graduate School, University of MünsterMünsterGermany
| | - Parker E Deal
- Department of Chemistry, University of California, BerkeleyBerkeleyUnited States
| | - Evan W Miller
- Department of Chemistry, University of California, BerkeleyBerkeleyUnited States
- Department of Molecular & Cell Biology, University of California, BerkeleyBerkeleyUnited States
- Helen Wills Neuroscience Institute, University of California, BerkeleyBerkeleyUnited States
| | - Shatanik Mukherjee
- Molecular Sensory Systems, Center of Advanced European Studies and ResearchBonnGermany
| | - Dagmar Wachten
- Institute of Innate Immunity, Department of Biophysical Imaging, Medical Faculty, University of BonnBonnGermany
| | - Arnd Baumann
- Institute of Biological Information Processing (IBI-1), Research Center JülichJülichGermany
| | - U Benjamin Kaupp
- Life & Medical Sciences Institute (LIMES), University of BonnBonnGermany
| | - Timo Strünker
- Centre of Reproductive Medicine and Andrology, University of MünsterMünsterGermany
- Cells in Motion Interfaculty Centre, University of MünsterMünsterGermany
| | - Christoph Brenker
- Centre of Reproductive Medicine and Andrology, University of MünsterMünsterGermany
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4
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Li N, Kang H, Peng Z, Wang HF, Weng SQ, Zeng XH. Physiologically detectable bisphenol A impairs human sperm functions by reducing protein-tyrosine phosphorylation. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 221:112418. [PMID: 34146982 DOI: 10.1016/j.ecoenv.2021.112418] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 06/06/2021] [Accepted: 06/08/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND Bisphenol A (BPA), a widely used plastic monomer and plasticizer, is detectable in blood, urine and semen of a healthy people, with concentrations ranging from 0.1 nM to 10 nM. It has been shown that in vitro exposure of BPA as low as 0.001 nM could significantly inhibited mouse sperm motility and acrosome reaction. However, it is still unclear whether BPA at those physiologically detectable concentration affects human sperm. METHODS The effects of different concentrations of BPA (0, 10-3, 10-2, 10-1, 10, 103 nM) on sperm functions were examined, including human sperm viability, kinematic parameters, hyperactivation and capacitation. RESULTS BPA caused a remarkable decline in human sperm viability, motility and progressive motility, hyperactivation, capacitation and progesterone-induced acrosome reaction. Mechanism studies showed that BPA could suppress the protein tyrosine phosphorylation level of human sperm, but had no effect on sperm calcium signaling. CONCLUSIONS Physiologically detectable concentrations of BPA may impair human sperm functions via suppressing protein tyrosine phosphorylation of human sperm, implying that environmental pollution of BPA might be a factor contributing to male infertility.
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Affiliation(s)
- Na Li
- Clinical Medical Research Center, Yichun People's Hospital, Yichun, Jiangxi 336000, PR China; Institute of Life Science, Nanchang University, Nanchang, Jiangxi 330031, PR China; Laboratory Department, Affiliated Reproductive Hospital of Jiangxi University of Traditional Chinese Medicine, Nanchang, Jiangxi 330031, PR China
| | - Hang Kang
- Institute of Life Science, Nanchang University, Nanchang, Jiangxi 330031, PR China
| | - Zhen Peng
- Clinical Medical Research Center, Yichun People's Hospital, Yichun, Jiangxi 336000, PR China; Institute of Life Science, Nanchang University, Nanchang, Jiangxi 330031, PR China
| | - Hua-Feng Wang
- Institute of Life Science, Nanchang University, Nanchang, Jiangxi 330031, PR China
| | - Shi-Qi Weng
- Institute of Life Science, Nanchang University, Nanchang, Jiangxi 330031, PR China
| | - Xu-Hui Zeng
- Institute of Reproductive Medicine, School of Medicine, Nantong University, Nantong, Jiangsu 226000, PR China; Institute of Life Science, Nanchang University, Nanchang, Jiangxi 330031, PR China.
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5
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Mata-Martínez E, Sánchez-Cárdenas C, Chávez JC, Guerrero A, Treviño CL, Corkidi G, Montoya F, Hernandez-Herrera P, Buffone MG, Balestrini PA, Darszon A. Role of calcium oscillations in sperm physiology. Biosystems 2021; 209:104524. [PMID: 34453988 DOI: 10.1016/j.biosystems.2021.104524] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 08/23/2021] [Accepted: 08/24/2021] [Indexed: 10/20/2022]
Abstract
Intracellular Ca2+ is a key regulator of cell signaling and sperm are not the exception. Cells often use cytoplasmic Ca2+ concentration ([Ca2+]i) oscillations as a means to decodify external and internal information. [Ca2+]i oscillations faster than those usually found in other cells and correlated with flagellar beat were the first to be described in sperm in 1993 by Susan Suarez, in the boar. More than 20 years passed before similar [Ca2+]i oscillations were documented in human sperm, simultaneously examining their flagellar beat in three dimensions by Corkidi et al. 2017. On the other hand, 10 years after the discovery of the fast boar [Ca2+]i oscillations, slower ones triggered by compounds from the egg external envelope were found to regulate cell motility and chemotaxis in sperm from marine organisms. Today it is known that sperm display fast and slow spontaneous and agonist triggered [Ca2+]i oscillations. In mammalian sperm these Ca2+ transients may act like a multifaceted tool that regulates fundamental functions such as motility and acrosome reaction. This review covers the main sperm species and experimental conditions where [Ca2+]i oscillations have been described and discusses what is known about the transporters involved, their regulation and the physiological purpose of these oscillations. There is a lot to be learned regarding the origin, regulation and physiological relevance of these Ca2+ oscillations.
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Affiliation(s)
- Esperanza Mata-Martínez
- Laboratorio de Fusión de Membranas y Exocitosis Acrosomal, Instituto de Histología y Embriología Dr. Mario H. Burgos (IHEM) Universidad Nacional de Cuyo, CONICET, Mendoza, Argentina.
| | - Claudia Sánchez-Cárdenas
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología (IBT), Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, Mexico.
| | - Julio C Chávez
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología (IBT), Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, Mexico.
| | - Adán Guerrero
- Laboratorio Nacional de Microscopía Avanzada, IBT, UNAM, Mexico.
| | - Claudia L Treviño
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología (IBT), Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, Mexico.
| | - Gabriel Corkidi
- Departamento de Ingeniería Celular y Biocatálisis, Laboratorio de Imágenes y Visión por Computadora, IBT, UNAM, Mexico.
| | - Fernando Montoya
- Departamento de Ingeniería Celular y Biocatálisis, Laboratorio de Imágenes y Visión por Computadora, IBT, UNAM, Mexico.
| | - Paul Hernandez-Herrera
- Departamento de Ingeniería Celular y Biocatálisis, Laboratorio de Imágenes y Visión por Computadora, IBT, UNAM, Mexico.
| | - Mariano G Buffone
- Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.
| | - Paula A Balestrini
- Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.
| | - Alberto Darszon
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología (IBT), Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, Mexico.
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6
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Occurrence of Calcium Oscillations in Human Spermatozoa Is Based on Spatial Signaling Enzymes Distribution. Int J Mol Sci 2021; 22:ijms22158018. [PMID: 34360784 PMCID: PMC8347727 DOI: 10.3390/ijms22158018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 07/15/2021] [Accepted: 07/21/2021] [Indexed: 11/17/2022] Open
Abstract
In human spermatozoa, calcium dynamics control most of fertilization events. Progesterone, present in the female reproductive system, can trigger several types of calcium responses, such as low-frequency oscillations. Here we aimed to identify the mechanisms of progesterone-induced calcium signaling in human spermatozoa. Progesterone-induced activation of fluorophore-loaded spermatozoa was studied by fluorescent microscopy. Two computational models were developed to describe the spermatozoa calcium responses: a homogeneous one based on a system of ordinary differential equations and a three-dimensional one with added space dimensions and diffusion for the cytosolic species. In response to progesterone, three types of calcium responses were observed in human spermatozoa: a single transient rise of calcium concentration in cytosol, a steady elevation, or low-frequency oscillations. The homogenous model provided qualitative description of the oscillatory and the single spike responses, while the three-dimensional model captured the calcium peak shape and the frequency of calcium oscillations. The model analysis demonstrated that an increase in the calcium diffusion coefficient resulted in the disappearance of the calcium oscillations. Additionally, in silico analysis suggested that the spatial distribution of calcium signaling enzymes governs the appearance of calcium oscillations in progesterone-activated human spermatozoa.
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7
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Jeschke JK, Biagioni C, Schierling T, Wagner IV, Börgel F, Schepmann D, Schüring A, Kulle AE, Holterhus PM, von Wolff M, Wünsch B, Nordhoff V, Strünker T, Brenker C. The Action of Reproductive Fluids and Contained Steroids, Prostaglandins, and Zn 2+ on CatSper Ca 2+ Channels in Human Sperm. Front Cell Dev Biol 2021; 9:699554. [PMID: 34381781 PMCID: PMC8350739 DOI: 10.3389/fcell.2021.699554] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 06/23/2021] [Indexed: 12/16/2022] Open
Abstract
The sperm-specific Ca2+ channel CatSper registers chemical cues that assist human sperm to fertilize the egg. Prime examples are progesterone and prostaglandin E1 that activate CatSper without involving classical nuclear and G protein-coupled receptors, respectively. Here, we study the action of seminal and follicular fluid as well of the contained individual prostaglandins and steroids on the intracellular Ca2+ concentration of sperm from donors and CATSPER2-deficient patients that lack functional CatSper channels. We show that any of the reproductive steroids and prostaglandins evokes a rapid Ca2+ increase that invariably rests on Ca2+ influx via CatSper. The hormones compete for the same steroid- and prostaglandin-binding site to activate the channel, respectively. Analysis of the hormones’ structure–activity relationship highlights their unique pharmacology in sperm and the chemical features determining their effective properties. Finally, we show that Zn2+ suppresses the action of steroids and prostaglandins on CatSper, which might prevent premature prostaglandin activation of CatSper in the ejaculate, aiding sperm to escape from the ejaculate into the female genital tract. Altogether, our findings reinforce that human CatSper serves as a promiscuous chemosensor that enables sperm to probe the varying hormonal microenvironment prevailing at different stages during their journey across the female genital tract.
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Affiliation(s)
- Janice K Jeschke
- Centre of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany
| | - Cristina Biagioni
- Centre of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany
| | - Tobias Schierling
- Institute of Pharmaceutical and Medicinal Chemistry, University of Münster, Münster, Germany
| | - Isabel Viola Wagner
- Centre of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany.,Department of Pediatrics, University Hospital Lübeck, University of Lübeck, Lübeck, Germany
| | - Frederik Börgel
- Institute of Pharmaceutical and Medicinal Chemistry, University of Münster, Münster, Germany
| | - Dirk Schepmann
- Institute of Pharmaceutical and Medicinal Chemistry, University of Münster, Münster, Germany
| | - Andreas Schüring
- UKM Kinderwunschzentrum, University Hospital Münster, Münster, Germany
| | - Alexandra E Kulle
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics, Christian-Albrechts-University, Kiel, Germany
| | - Paul Martin Holterhus
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics, Christian-Albrechts-University, Kiel, Germany
| | - Michael von Wolff
- Division of Gynecological Endocrinology and Reproductive Medicine, University Women's Hospital, Bern, Switzerland
| | - Bernhard Wünsch
- Institute of Pharmaceutical and Medicinal Chemistry, University of Münster, Münster, Germany
| | - Verena Nordhoff
- Centre of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany
| | - Timo Strünker
- Centre of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany.,Cells in Motion Interfaculty Centre, University of Münster, Münster, Germany
| | - Christoph Brenker
- Centre of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany
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Torrezan-Nitao E, Brown SG, Mata-Martínez E, Treviño CL, Barratt C, Publicover S. [Ca2+]i oscillations in human sperm are triggered in the flagellum by membrane potential-sensitive activity of CatSper. Hum Reprod 2021; 36:293-304. [PMID: 33305795 DOI: 10.1093/humrep/deaa302] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 09/22/2020] [Indexed: 12/15/2022] Open
Abstract
STUDY QUESTION How are progesterone (P4)-induced repetitive intracellular Ca2+ concentration ([Ca2+]i) signals (oscillations) in human sperm generated? SUMMARY ANSWER P4-induced [Ca2+]i oscillations are generated in the flagellum by membrane potential (Vm)-sensitive Ca2+-influx through CatSper channels. WHAT IS KNOWN ALREADY A subset of human sperm display [Ca2+]i oscillations that regulate flagellar beating and acrosome reaction. Although pharmacological manipulations indicate involvement of stored Ca2+ in these oscillations, influx of extracellular Ca2+ is also required. STUDY DESIGN, SIZE, DURATION This was a laboratory study that used >20 sperm donors and involved more than 100 separate experiments and analysis of more than 1000 individual cells over a period of 2 years. PARTICIPANTS/MATERIALS, SETTING, METHODS Semen donors and patients were recruited in accordance with local ethics approval from Birmingham University and Tayside ethics committees. [Ca2+]i responses and Vm of individual cells were examined by fluorescence imaging and whole-cell current clamp. MAIN RESULTS AND THE ROLE OF CHANCE P4-induced [Ca2+]i oscillations originated in the flagellum, spreading to the neck and head (latency of 1-2 s). K+-ionophore valinomycin (1 µM) was used to investigate the role of membrane potential (Vm). Direct assessment by whole-cell current-clamp confirmed that Vm in valinomycin-exposed cells was determined primarily by K+ equilibrium potential (EK) and was rapidly 'reset' upon manipulation of [K+]o. Pre-treatment of sperm with valinomycin ([K+]o = 5.4 mM) had no effect on the P4-induced [Ca2+] transient (P = 0.95; eight experiments), but application of valinomycin to P4-pretreated sperm suppressed activity in 82% of oscillating cells (n = 257; P = 5 × 10-55 compared to control) and significantly reduced both the amplitude and frequency of persisting oscillations (P = 0.0001). Upon valinomycin washout, oscillations re-started in most cells. When valinomycin was applied in saline with elevated [K+], the inhibitory effect of valinomycin was reduced and was dependent on EK (P = 10-25). Amplitude and frequency of [Ca2+]i oscillations that persisted in the presence of valinomycin showed similar sensitivity to EK (P < 0.01). The CatSper inhibitor RU1968 (4.8 and 11 µM) caused immediate and reversible arrest of activity in 36% and 96% of oscillating cells, respectively (P < 10-10). Quinidine (300 µM) which blocks the sperm K+ current (IKsper) completely, inhibited [Ca2+]i oscillations. LARGE SCALE DATA N/A. LIMITATIONS, REASONS FOR CAUTION This was an in-vitro study and caution must be taken when extrapolating these results to in-vivo regulation of sperm. WIDER IMPLICATIONS OF THE FINDINGS [Ca2+]i oscillations in human sperm are functionally important and their absence is associated with failed fertilisation at IVF. The data reported here provide new understanding of the mechanisms that underlie the regulation and generation (or failure) of these oscillations. STUDY FUNDING/COMPETING INTEREST(S) E.T.-N. was in receipt of a postgraduate scholarship from the CAPES Foundation (Ministry of Education, Brazil). E.M-M received travel funds from the Programa de Apoyo a los Estudios de Posgrado (Maestria y Doctorado en Ciencias Bioquimicas-Universidad Autonoma de Mexico). SGB and CLRB are recipients of a Chief Scientist Office (NHS Scotland) grant TCS/17/28. The authors have no conflicts of interest.
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Affiliation(s)
| | - Sean G Brown
- School of Applied Sciences, Division of Health Sciences, Abertay University, Dundee DD11HG, UK
| | - Esperanza Mata-Martínez
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, México
| | - Claudia L Treviño
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, México
| | - Christopher Barratt
- Systems Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee DD19SY, UK
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9
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Brown SG, Publicover SJ, Barratt CLR, Martins da Silva SJ. Human sperm ion channel (dys)function: implications for fertilization. Hum Reprod Update 2020; 25:758-776. [PMID: 31665287 PMCID: PMC6847974 DOI: 10.1093/humupd/dmz032] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [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.
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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
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10
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Machado SA, Sharif M, Wang H, Bovin N, Miller DJ. Release of Porcine Sperm from Oviduct Cells is Stimulated by Progesterone and Requires CatSper. Sci Rep 2019; 9:19546. [PMID: 31862909 PMCID: PMC6925244 DOI: 10.1038/s41598-019-55834-z] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 11/29/2019] [Indexed: 01/07/2023] Open
Abstract
Sperm storage in the female reproductive tract after mating and before ovulation is a reproductive strategy used by many species. When insemination and ovulation are poorly synchronized, the formation and maintenance of a functional sperm reservoir improves the possibility of fertilization. In mammals, the oviduct regulates sperm functions, such as Ca2+ influx and processes associated with sperm maturation, collectively known as capacitation. A fraction of the stored sperm is released by unknown mechanisms and moves to the site of fertilization. There is an empirical association between the hormonal milieu in the oviduct and sperm detachment; therefore, we tested directly the ability of progesterone to induce sperm release from oviduct cell aggregates. Sperm were allowed to bind to oviduct cells or an immobilized oviduct glycan and then challenged with progesterone, which stimulated the release of 48% of sperm from oviduct cells or 68% of sperm from an immobilized oviduct glycan. The effect of progesterone on sperm release was specific; pregnenolone and 17α-OH-progesterone did not affect sperm release. Ca2+ influx into sperm is associated with capacitation and development of hyperactivated motility. Progesterone increased sperm intracellular Ca2+, which was abrogated by blocking the sperm–specific Ca2+ channel CatSper with NNC 055-0396. NNC 055-0396 also blocked the progesterone-induced sperm release from oviduct cells or immobilized glycan. An inhibitor of the non-genomic progesterone receptor that activates CatSper similarly blocked sperm release. This is the first report indicating that release of sperm from the sperm reservoir is induced by progesterone action through CatSper channels.
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Affiliation(s)
- Sergio A Machado
- Department of Animal Sciences and Institute of Genomic Biology, University of Illinois at Urbana-Champaign, 1207 West Gregory Drive, Urbana, IL, 61801, USA.,Department of Veterinary Medicine, Western Santa Catarina University, Xanxere, Brazil
| | - Momal Sharif
- Department of Animal Sciences and Institute of Genomic Biology, University of Illinois at Urbana-Champaign, 1207 West Gregory Drive, Urbana, IL, 61801, USA.,Department of Obstetrics and Gynecology and Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, 77030, USA
| | - Huijing Wang
- Department of Animal Sciences and Institute of Genomic Biology, University of Illinois at Urbana-Champaign, 1207 West Gregory Drive, Urbana, IL, 61801, USA.,Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Nicolai Bovin
- Shemyakin Institute of Bioorganic Chemistry, Moscow, Russia
| | - David J Miller
- Department of Animal Sciences and Institute of Genomic Biology, University of Illinois at Urbana-Champaign, 1207 West Gregory Drive, Urbana, IL, 61801, USA.
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11
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Light-triggered release of photocaged therapeutics - Where are we now? J Control Release 2019; 298:154-176. [PMID: 30742854 DOI: 10.1016/j.jconrel.2019.02.006] [Citation(s) in RCA: 92] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 02/04/2019] [Accepted: 02/06/2019] [Indexed: 01/02/2023]
Abstract
The current available therapeutics face several challenges such as the development of ideal drug delivery systems towards the goal of personalized treatments for patients benefit. The application of light as an exogenous activation mechanism has shown promising outcomes, owning to the spatiotemporal confinement of the treatment in the vicinity of the diseased tissue, which offers many intriguing possibilities. Engineering therapeutics with light responsive moieties have been explored to enhance the bioavailability, and drug efficacy either in vitro or in vivo. The tailor-made character turns the so-called photocaged compounds highly desirable to reduce the side effects of drugs and, therefore, have received wide research attention. Herein, we seek to highlight the potential of photocaged compounds to obtain a clear understanding of the mechanisms behind its use in therapeutic delivery. A deep overview on the progress achieved in the design, fabrication as well as current and possible future applications in therapeutics of photocaged compounds is provided, so that novel formulations for biomedical field can be designed.
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12
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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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13
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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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14
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López-Torres AS, Chirinos M. Modulation of Human Sperm Capacitation by Progesterone, Estradiol, and Luteinizing Hormone. Reprod Sci 2016; 24:193-201. [PMID: 27071965 DOI: 10.1177/1933719116641766] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Sperm residency in female reproductive tract is essential to undergo functional changes that allow the cell to encounter the oocyte and fertilize it. Those changes, known as capacitation, are modulated by molecules located in the uterotubal surface and fluids. During the fertile window, there is a notable increase in some reproductive hormones such as progesterone, estradiol, and luteinizing hormone in the female reproductive tract, so spermatozoa are exposed to these hormones in an environment that must favor gamete encountering and fusion. This spatiotemporal coincidence suggests that they are suitable candidates to modulate sperm function in order to synchronize the events that ultimately allow the success of fertilization. The presence of receptors for these hormones in the human sperm has been described, but their physiological relevance and mechanisms of action have been either subject of controversy or not properly investigated. This review intends to summarize the evidence that support the participation of these hormones in the regulation of sperm capacitation.
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Affiliation(s)
- Aideé Saray López-Torres
- 1 Departamento de Biología de la Reproducción, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, México DF, Mexico.,2 Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México, Coyoacán, México, DF, Mexico
| | - Mayel Chirinos
- 1 Departamento de Biología de la Reproducción, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, México DF, Mexico
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15
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Zhang Z, Liu J, Meriano J, Ru C, Xie S, Luo J, Sun Y. Human sperm rheotaxis: a passive physical process. Sci Rep 2016; 6:23553. [PMID: 27005727 PMCID: PMC4804285 DOI: 10.1038/srep23553] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 03/02/2016] [Indexed: 12/14/2022] Open
Abstract
A long-standing question in natural reproduction is how mammalian sperm navigate inside female reproductive tract and finally reach the egg cell, or oocyte. Recently, fluid flow was proposed as a long–range guidance cue for sperm navigation. Coitus induces fluid flow from oviduct to uterus, and sperm align themselves against the flow direction and swim upstream, a phenomenon termed rheotaxis. Whether sperm rheotaxis is a passive process dominated by fluid mechanics, or sperm actively sense and adapt to fluid flow remains controversial. Here we report the first quantitative study of sperm flagellar motion during human sperm rheotaxis and provide direct evidence indicating that sperm rheotaxis is a passive process. Experimental results show that there is no significant difference in flagellar beating amplitude and asymmetry between rheotaxis-turning sperm and those sperm swimming freely in the absence of fluid flow. Additionally, fluorescence image tracking shows no Ca2+ influx during sperm rheotaxis turning, further suggesting there is no active signal transduction during human sperm rheotaxis.
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Affiliation(s)
- Zhuoran Zhang
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON, Canada
| | - Jun Liu
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON, Canada
| | - Jim Meriano
- LifeQuest Centre for Reproductive Medicine, Toronto, ON, Canada
| | - Changhai Ru
- Jiangsu Provincial Key Laboratory of Advanced Robotics &Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, China
| | - Shaorong Xie
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON, Canada.,Department of Mechatronic Engineering, Shanghai University, China
| | - Jun Luo
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON, Canada.,Department of Mechatronic Engineering, Shanghai University, China
| | - Yu Sun
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON, Canada.,Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada.,Department of Electrical and Computer Engineering, University of Toronto, Toronto, ON, Canada
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16
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Mukherjee S, Jansen V, Jikeli JF, Hamzeh H, Alvarez L, Dombrowski M, Balbach M, Strünker T, Seifert R, Kaupp UB, Wachten D. A novel biosensor to study cAMP dynamics in cilia and flagella. eLife 2016; 5. [PMID: 27003291 PMCID: PMC4811770 DOI: 10.7554/elife.14052] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Accepted: 03/05/2016] [Indexed: 01/09/2023] Open
Abstract
The cellular messenger cAMP regulates multiple cellular functions, including signaling in cilia and flagella. The cAMP dynamics in these subcellular compartments are ill-defined. We introduce a novel FRET-based cAMP biosensor with nanomolar sensitivity that is out of reach for other sensors. To measure cAMP dynamics in the sperm flagellum, we generated transgenic mice and reveal that the hitherto methods determining total cAMP levels do not reflect changes in free cAMP levels. Moreover, cAMP dynamics in the midpiece and principal piece of the flagellum are distinctively different. The sole cAMP source in the flagellum is the soluble adenylate cyclase (SACY). Although bicarbonate-dependent SACY activity requires Ca2+, basal SACY activity is suppressed by Ca2+. Finally, we also applied the sensor to primary cilia. Our new cAMP biosensor features unique characteristics that allow gaining new insights into cAMP signaling and unravel the molecular mechanisms underlying ciliary function in vitro and in vivo. DOI:http://dx.doi.org/10.7554/eLife.14052.001 Cells can change the way they grow, move or develop in response to information from their environment. This information is first detected at the surface of the cell and then the information is relayed around the interior of the cell by signaling molecules known as “second messengers”. A molecule called cAMP is a well-known second messenger that is involved in many different signaling pathways. Therefore, the levels of cAMP in specific areas of the cell need to be precisely regulated to enable different signaling pathways to be activated at specific times and locations. Some cells have hair-like structures called cilia or flagella on their surface. Cilia and flagella are able to move the fluid that surrounds the cells or even move the cells themselves. The second messenger cAMP plays an essential role in making cilia move, but it is challenging to analyze the dynamics of cAMP – that this, how the levels of this molecule change over time – in these structures. The levels of cAMP in live cells can only be measured using fluorescent biosensors. Introducing these biosensors into specific cell structures is difficult and they are not sensitive enough to respond to low levels of cAMP. Furthermore, it is difficult to measure cAMP activity inside such tiny structures using these biosensors. Mukherjee, Jansen, Jikeli et al. now address some of these challenges by creating a new cAMP biosensor that has several unique features. Most importantly, it can respond to very low levels of cAMP, making it more sensitive than previous biosensors. Mukherjee et al. test this new biosensor in the flagella of sperm cells from mice, which reveals how the production of cAMP is regulated in the flagellum. The new biosensor also shows that different parts of the flagellum can have different cAMP dynamics. In the future, this new biosensor could be used to study cAMP in other structures and compartments within cells. DOI:http://dx.doi.org/10.7554/eLife.14052.002
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Affiliation(s)
- Shatanik Mukherjee
- Department of Molecular Sensory Systems, Center of Advanced European Studies and Research, Bonn, Germany
| | - Vera Jansen
- Minerva Max Planck Research Group, Molecular Physiology, Center of Advanced European Studies and Research, Bonn, Germany
| | - Jan F Jikeli
- Minerva Max Planck Research Group, Molecular Physiology, Center of Advanced European Studies and Research, Bonn, Germany
| | - Hussein Hamzeh
- Minerva Max Planck Research Group, Molecular Physiology, Center of Advanced European Studies and Research, Bonn, Germany
| | - Luis Alvarez
- Department of Molecular Sensory Systems, Center of Advanced European Studies and Research, Bonn, Germany
| | - Marco Dombrowski
- Minerva Max Planck Research Group, Molecular Physiology, Center of Advanced European Studies and Research, Bonn, Germany
| | - Melanie Balbach
- 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.,Centrum für Reproduktionsmedizin und Andrologie, Universitätsklinikum Münster, Münster, Germany
| | - Reinhard Seifert
- Department of Molecular Sensory Systems, Center of Advanced European Studies and Research, Bonn, Germany
| | - U Benjamin Kaupp
- Department of Molecular Sensory Systems, Center of Advanced European Studies and Research, Bonn, Germany
| | - Dagmar Wachten
- Minerva Max Planck Research Group, Molecular Physiology, Center of Advanced European Studies and Research, Bonn, Germany
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17
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Romarowski A, Sánchez-Cárdenas C, Ramírez-Gómez HV, Puga Molina LDC, Treviño CL, Hernández-Cruz A, Darszon A, Buffone MG. A Specific Transitory Increase in Intracellular Calcium Induced by Progesterone Promotes Acrosomal Exocytosis in Mouse Sperm. Biol Reprod 2016; 94:63. [PMID: 26819478 PMCID: PMC4829090 DOI: 10.1095/biolreprod.115.136085] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 01/25/2016] [Indexed: 11/26/2022] Open
Abstract
During capacitation, sperm acquire the ability to undergo the acrosome reaction (AR), an essential step in fertilization. Progesterone produced by cumulus cells has been associated with various physiological processes in sperm, including stimulation of AR. An increase in intracellular Ca2+ ([Ca2+]i) is necessary for AR to occur. In this study, we investigated the spatiotemporal correlation between the changes in [Ca2+]i and AR in single mouse spermatozoa in response to progesterone. We found that progesterone stimulates an [Ca2+]i increase in five different patterns: gradual increase, oscillatory, late transitory, immediate transitory, and sustained. We also observed that the [Ca2+]i increase promoted by progesterone starts at either the flagellum or the head. We validated the use of FM4-64 as an indicator for the occurrence of the AR by simultaneously detecting its fluorescence increase and the loss of EGFP in transgenic EGFPAcr sperm. For the first time, we have simultaneously visualized the rise in [Ca2+]i and the process of exocytosis in response to progesterone and found that only a specific transitory increase in [Ca2+]i originating in the sperm head promotes the initiation of AR.
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Affiliation(s)
- Ana Romarowski
- Instituto de Biología y Medicina Experimental (IBYME), National Research Council of Argentina (CONICET), Buenos Aires, Argentina
| | - Claudia Sánchez-Cárdenas
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, México
| | - Héctor V Ramírez-Gómez
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, México
| | - Lis del C Puga Molina
- Instituto de Biología y Medicina Experimental (IBYME), National Research Council of Argentina (CONICET), Buenos Aires, Argentina
| | - Claudia L Treviño
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, México
| | - Arturo Hernández-Cruz
- Departamento de Neurociencia Cognitiva, Instituto de Fisiología Celular, UNAM, Circuito exterior s/n, Ciudad Universitaria, México DF, México
| | - Alberto Darszon
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, México
| | - Mariano G Buffone
- Instituto de Biología y Medicina Experimental (IBYME), National Research Council of Argentina (CONICET), Buenos Aires, Argentina
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18
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Sánchez-Cárdenas C, Servín-Vences MR, José O, Treviño CL, Hernández-Cruz A, Darszon A. Acrosome reaction and Ca²⁺ imaging in single human spermatozoa: new regulatory roles of [Ca²⁺]i. Biol Reprod 2014; 91:67. [PMID: 25100708 DOI: 10.1095/biolreprod.114.119768] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The spermatozoa acrosome reaction (AR) is essential for mammalian fertilization. Few methods allow visualization of AR in real time together with Ca²⁺ imaging. Here, we show that FM4-64, a fluorescent dye used to follow exocytosis, reliably reports AR progression induced by ionomycin and progesterone in human spermatozoa. FM4-64 clearly delimits the spermatozoa contour and reports morphological cell changes before, during, and after AR. This strategy unveiled the formation of moving tubular appendages, emerging from acrosome-reacted spermatozoa, which was confirmed by scanning electron microscopy. Alternate wavelength illumination allowed concomitant imaging of FM4-64 and Fluo-4, a Ca²⁺ indicator. These AR and intracellular Ca²⁺ ([Ca²⁺]i) recordings revealed that the presence of [Ca²⁺]i oscillations, both spontaneous and progesterone induced, prevents AR in human spermatozoa. Notably, the progesterone-induced AR is preceded by a second [Ca²⁺]i peak and ~40% of reacting spermatozoa also manifest a slow [Ca²⁺]i rise ~2 min before AR. Our findings uncover new AR features related to [Ca²⁺]i.
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Affiliation(s)
- Claudia Sánchez-Cárdenas
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, México
| | - Martha Rocio Servín-Vences
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, México
| | - Omar José
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, México
| | - Claudia Lydia Treviño
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, México
| | - Arturo Hernández-Cruz
- Departamento de Neurociencia Cognitiva, Instituto de Fisiología Celular, UNAM, Circuito exterior s/n, Ciudad Universitaria, México DF
| | - Alberto Darszon
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, México
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19
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Sugiyama H, Chandler DE. Sperm guidance to the egg finds calcium at the helm. PROTOPLASMA 2014; 251:461-475. [PMID: 24085342 DOI: 10.1007/s00709-013-0550-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 09/05/2013] [Indexed: 06/02/2023]
Abstract
Sperm respond to multiple cues during guidance to the egg including chemical attractants, temperature, and fluid flow. Of these, sperm chemotaxis has been studied most extensively-over 100 years-but only recently has it started to be understood at the molecular level. The long gestation in this understanding has largely been due to technical limitations that include the detection of calcium signal dynamics in a relatively small structure-the flagellum, measurement of actual chemoattractant gradients, the fact that only subpopulations of sperm respond at any given time, and the diversity in swimming behaviors that sperm exhibit from different species. Today, measurements of flagellar calcium signals on a fast time scale, discovery of the ion channels and organelles that may regulate these signals, and better understanding and quantitation of sperm swimming behaviors involved have given more certainty to our understanding of sperm directional swimming and its control by characteristic, calcium-directed asymmetric flagellar bends. Future research will need to apply these technical advances to other forms of sperm guidance such as thermotaxis and rheotaxis as well as gaining an understanding of how the flagellar apparatus is controlled by calcium.
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Affiliation(s)
- Hitoshi Sugiyama
- Science and Technology Group, Okinawa Institute of Science and Technology, Okinawa, 904-0495, Japan
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20
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Höglinger D, Nadler A, Schultz C. Caged lipids as tools for investigating cellular signaling. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1841:1085-96. [PMID: 24713581 DOI: 10.1016/j.bbalip.2014.03.012] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 03/27/2014] [Accepted: 03/27/2014] [Indexed: 12/21/2022]
Abstract
Lipid derivatives that can be activated by light, often referred to as 'caged' lipids, are useful tools to manipulate intact cells non-invasively. Here we focus on experimental approaches that have made use of caged lipids. Apart from summarizing the recent advances and available tools in the field, we strive to highlight the experimental challenges that arise from lipid-specific biophysical properties and the abundance of an enormous diversity of distinct molecular lipid species in cells. This article is part of a Special Issue entitled Tools to study lipid functions.
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Affiliation(s)
- Doris Höglinger
- European Molecular Biology Laboratory (EMBL), Cell Biology & Biophysics Unit, Meyerhofstr. 1, 69117 Heidelberg, Germany
| | - André Nadler
- European Molecular Biology Laboratory (EMBL), Cell Biology & Biophysics Unit, Meyerhofstr. 1, 69117 Heidelberg, Germany
| | - Carsten Schultz
- European Molecular Biology Laboratory (EMBL), Cell Biology & Biophysics Unit, Meyerhofstr. 1, 69117 Heidelberg, Germany.
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21
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Brenker C, Zhou Y, Müller A, Echeverry FA, Trötschel C, Poetsch A, Xia XM, Bönigk W, Lingle CJ, Kaupp UB, Strünker T. The Ca2+-activated K+ current of human sperm is mediated by Slo3. eLife 2014; 3:e01438. [PMID: 24670955 PMCID: PMC3966514 DOI: 10.7554/elife.01438] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Sperm are equipped with a unique set of ion channels that orchestrate fertilization. In mouse sperm, the principal K+ current (IKSper) is carried by the Slo3 channel, which sets the membrane potential (Vm) in a strongly pHi-dependent manner. Here, we show that IKSper in human sperm is activated weakly by pHi and more strongly by Ca2+. Correspondingly, Vm is strongly regulated by Ca2+ and less so by pHi. We find that inhibitors of Slo3 suppress human IKSper, and we identify the Slo3 protein in the flagellum of human sperm. Moreover, heterologously expressed human Slo3, but not mouse Slo3, is activated by Ca2+ rather than by alkaline pHi; current–voltage relations of human Slo3 and human IKSper are similar. We conclude that Slo3 represents the principal K+ channel in human sperm that carries the Ca2+-activated IKSper current. We propose that, in human sperm, the progesterone-evoked Ca2+ influx carried by voltage-gated CatSper channels is limited by Ca2+-controlled hyperpolarization via Slo3. DOI:http://dx.doi.org/10.7554/eLife.01438.001 A sperm that has been ejaculated into the female reproductive tract must complete a number of tasks to pass on its genes to the next generation. First it must travel along a meandering route to encounter an egg, before pushing through a jelly-like coating that surrounds the egg and then, finally, fusing with the egg’s surface membrane. In order to complete these steps and fertilise the egg, a sperm must undergo a process called ‘capacitation’. This process, and a variety of other sperm functions, involves the controlled flux of positive ions into and out of the sperm via specific ion channels that are located in the cell membrane. The properties of the ion channels that allow protons and calcium ions to move into and out of human sperm are well understood, but less is known about the channels that control the movement of potassium ions. In mice, a channel called Slo3 allows potassium ions to flow out of the sperm and makes the membrane voltage of these cells more negative. Also, in mice, this channel is essential for the sperm to function correctly, and for fertilization. However, in humans, it is unclear if the Slo3 channel is present in sperm and if it performs the same role. Now, Brenker et al. have shown that the flow of potassium ions out of human sperm occurs via the Slo3 channel, and that human Slo3 is responsible for setting the membrane voltage of these cells. However, whereas the mouse Slo3 channel is opened in response to a decrease in the concentration of protons within the sperm (i.e., an increase of the pH inside the cell), human Slo3 is largely controlled by changes in the levels of calcium ions. An increase in the calcium concentration within the cell opens the human Slo3 channel, more than a decrease in the proton concentration does. Altogether, Brenker et al. identify Slo3 as the principal potassium channel in human sperm and reveal more fundamental differences between human sperm and mouse sperm. Thereby, this work further stresses the need to be cautious about using mice as a model of male fertility in humans. DOI:http://dx.doi.org/10.7554/eLife.01438.002
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Affiliation(s)
- Christoph Brenker
- Department of Molecular Sensory Systems, Center of Advanced European Studies and Research, Bonn, Germany
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22
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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]
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Alasmari W, Barratt CLR, Publicover SJ, Whalley KM, Foster E, Kay V, Martins da Silva S, Oxenham SK. The clinical significance of calcium-signalling pathways mediating human sperm hyperactivation. Hum Reprod 2013; 28:866-76. [PMID: 23406974 PMCID: PMC3600839 DOI: 10.1093/humrep/des467] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
STUDY QUESTION What is the prevalence of defects in the Ca2+-signalling pathways mediating hyperactivation (calcium influx and store mobilization) among donors and sub-fertile patients and are they functionally significant, i.e. related to fertilization success at IVF? SUMMARY ANSWER This study identifies, for the first time, the prevalence of Ca2+ store defects in sperm from research donors, IVF and ICSI patients. It highlights the biological role and importance of Ca2+ signalling (Ca2+ store mobilization) for fertilization at IVF. WHAT IS KNOWN ALREADY Sperm motility and hyperactivation (HA) are important for fertility, mice with sperm incapable of HA are sterile. Recently, there has been significant progress in our knowledge of the factors controlling these events, in particular the generation and regulation of calcium signals. Both pH-regulated membrane Ca2+ channels (CatSper) and Ca2+ stores (potentially activating store-operated Ca2+ channels) have been implicated in controlling HA. STUDY DESIGN, SIZE, AND DURATION This was a prospective study examining a panel of 68 donors and 181 sub-fertile patients attending the Assisted Conception Unit, Ninewells Hospital Dundee for IVF and ICSI. Twenty-five of the donors gave a second sample (∼4 weeks later) to confirm consistency/reliability of the recorded responses. Ca2+ signalling was manipulated using three agonists, NH4Cl (activates CatSper via pH), progesterone (direct activation of CatSper channels, potentially enhancing mobilization of stored Ca2+ by CICR) and 4-aminopyridine (4-AP) (effect on pH equivalent to NH4Cl and mobilizes stored Ca2+). The broad-spectrum phosphodiesterase inhibitor 3-isobutyl-1-methyxanthine (IBMX), a potent activator of HA was also used for comparison. For patient samples, an aliquot surplus to requirements for IVF/ICSI treatment was examined, allowing direct comparison of Ca2+ signalling and motility data with functional competence of the sperm. MATERIALS, SETTING, METHODS The donors and sub-fertile patients were screened for HA (using CASA) and changes in intracellular Ca2+ were assessed by loading with Fura-2 and measuring fluorescence using a plate reader (FluoStar). MAIN RESULTS AND THE ROLE OF CHANCE The relative efficacy of the stimuli in inducing HA was 4-AP >> IBMX > progesterone. NH4Cl increased [Ca2+]i similarly to 4-AP and progesterone but did not induce a significant increase in HA. Failure of samples to generate HA (no significant increase in response to stimulation with 4-AP) was seen in just 2% of research donors but occurred in 10% of IVF patients (P = 0.025). All donor samples generated a significant [Ca2+]i increase when stimulated with 4-AP but 3.3% of IVF and 28.6% of ICSI patients failed to respond. Amplitudes of HA and [Ca2+]i responses to 4-AP were correlated with fertilization rate at IVF (P= 0.029; P = 0.031, respectively). Progesterone reliably induced [Ca2+]i responses (97% of donors, 100% of IVF patients) but was significantly less effective than 4-AP in inducing HA. Twenty seven per cent of ICSI patients failed to generate a [Ca2+]i response to progesterone (P= 0.035). Progesterone-induced [Ca2+]i responses were correlated with fertilization rate at IVF (P= 0.037) but induction of HA was not. In donor samples examined on more than one occasion consistent responses for 4-AP-induced [Ca2+]i (R2 = 0.97) and HA (R2 = 0.579) were obtained. In summary, the data indicate that defects in Ca2+ signalling leading to poor HA do occur and that ability to undergo Ca2+ -induced HA affects IVF fertilizing capacity. The data also confirm that release of stored Ca2+ is the crucial component of Ca2+ signals leading to HA and that Ca2+ store defects may therefore underlie HA failure. LIMITATIONS, REASONS FOR CAUTION This is an in vitro study of sperm function. While the repeatability of the [Ca2+]i and HA responses in samples from the same donor were confirmed, data for patients were from 1 assessment and thus the robustness of the failed responses in patients’ needs to be established. The focus of this study was on using 4AP, which mobilizes stored Ca2+ and is a potent inducer of HA. The n values for other agonists, especially calcium assessments, are smaller. WIDER IMPLICATIONS OF THE FINDINGS Previous studies have shown a significant relationship between basal levels of HA, calcium responses to progesterone and IVF fertilization rates. Here, we have systematically investigated the ability/failure of human sperm to generate Ca2+ signals and HA in response to targeted pharmacological challenge and, related defects in these responses to IVF success. [Ca2+]i signalling is fundamental for sperm motility and data from this study will lead to assessment of the nature of these defects using techniques such as single-cell imaging and patch clamping. STUDY FUNDING/COMPETING INTEREST(S) Resources from a Wellcome Trust Project Grant (#086470, Publicover and Barratt PI) primarily funded the study. The authors have no competing interests.
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Affiliation(s)
- Wardah Alasmari
- Reproductive and Developmental Biology, Medical School, Ninewells Hospital, University of Dundee, Dundee DD1 9SY, UK
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Alasmari W, Costello S, Correia J, Oxenham SK, Morris J, Fernandes L, Ramalho-Santos J, Kirkman-Brown J, Michelangeli F, Publicover S, Barratt CLR. Ca2+ signals generated by CatSper and Ca2+ stores regulate different behaviors in human sperm. J Biol Chem 2013; 288:6248-58. [PMID: 23344959 PMCID: PMC3585060 DOI: 10.1074/jbc.m112.439356] [Citation(s) in RCA: 112] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
[Ca2+]i signaling regulates sperm motility, enabling switching between functionally different behaviors that the sperm must employ as it ascends the female tract and fertilizes the oocyte. We report that different behaviors in human sperm are recruited according to the Ca2+ signaling pathway used. Activation of CatSper (by raising pHi or stimulating with progesterone) caused sustained [Ca2+]i elevation but did not induce hyperactivation, the whiplash-like behavior required for progression along the oviduct and penetration of the zona pellucida. In contrast, penetration into methylcellulose (mimicking penetration into cervical mucus or cumulus matrix) was enhanced by activation of CatSper. NNC55-0396, which abolishes CatSper currents in human sperm, inhibited this effect. Treatment with 5 μm thimerosal to mobilize stored Ca2+ caused sustained [Ca2+]i elevation and induced strong, sustained hyperactivation that was completely insensitive to NNC55-0396. Thimerosal had no effect on penetration into methylcellulose. 4-Aminopyridine, a powerful modulator of sperm motility, both raised pHi and mobilized Ca2+ stored in sperm (and from microsomal membrane preparations). 4-Aminopyridine-induced hyperactivation even in cells suspended in Ca2+-depleted medium and also potentiated penetration into methylcellulose. The latter effect was sensitive to NNC55-039, but induction of hyperactivation was not. We conclude that these two components of the [Ca2+]i signaling apparatus have strikingly different effects on sperm motility. Furthermore, since stored Ca2+ at the sperm neck can be mobilized by Ca2+-induced Ca2+ release, we propose that CatSper activation can elicit functionally different behaviors according to the sensitivity of the Ca2+ store, which may be regulated by capacitation and NO from the cumulus.
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Affiliation(s)
- Wardah Alasmari
- From the Reproductive and Developmental Biology, Medical School, University of Dundee, Ninewells Hospital, Dundee DD1 9SY, Scotland, United Kingdom
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Abstract
Ca2+i signalling is pivotal to sperm function. Progesterone, the best-characterized agonist of human sperm Ca2+i signalling, stimulates a biphasic [Ca2+]i rise, comprising a transient and subsequent sustained phase. In accordance with recent reports that progesterone directly activates CatSper, the [Ca2+]i transient was detectable in the anterior flagellum (where CatSper is expressed) 1–2 s before responses in the head and neck. Pre-treatment with 5 μM 2-APB (2-aminoethoxydiphenyl borate), which enhances activity of store-operated channel proteins (Orai) by facilitating interaction with their activator [STIM (stromal interaction molecule)] ‘amplified’ progesterone-induced [Ca2+]i transients at the sperm neck/midpiece without modifying kinetics. The flagellar [Ca2+]i response was unchanged. 2-APB (5 μM) also enhanced the sustained response in the midpiece, possibly reflecting mitochondrial Ca2+ accumulation downstream of the potentiated [Ca2+]i transient. Pre-treatment with 50–100 μM 2-APB failed to potentiate the transient and suppressed sustained [Ca2+]i elevation. When applied during the [Ca2+]i plateau, 50–100 μM 2-APB caused a transient fall in [Ca2+]i, which then recovered despite the continued presence of 2-APB. Loperamide (a chemically different store-operated channel agonist) enhanced the progesterone-induced [Ca2+]i signal and potentiated progesterone-induced hyperactivated motility. Neither 2-APB nor loperamide raised pHi (which would activate CatSper) and both compounds inhibited CatSper currents. STIM and Orai were detected and localized primarily to the neck/midpiece and acrosome where Ca2+ stores are present and the effects of 2-APB are focussed, but store-operated currents could not be detected in human sperm. We propose that 2-APB-sensitive channels amplify [Ca2+]i elevation induced by progesterone (and other CatSper agonists), amplifying, propagating and providing spatio-temporal complexity in [Ca2+]i signals of human sperm.
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