1
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Li Q, Chen G, Yan J. Transmembrane determinants of voltage-gating differences between BK (Slo1) and Slo3 channels. Biophys J 2024; 123:2154-2166. [PMID: 38637987 PMCID: PMC11309983 DOI: 10.1016/j.bpj.2024.04.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 02/01/2024] [Accepted: 04/15/2024] [Indexed: 04/20/2024] Open
Abstract
Voltage-gated potassium channels are critical in modulating cellular excitability, with Slo (slowpoke) channels forming a unique family characterized by their large conductance and dual regulation by electrical signals and intracellular messengers. Despite their structural and evolutionary similarities, Slo1 and Slo3 channels exhibit significant differences in their voltage-gating properties. This study investigates the molecular determinants that differentiate the voltage-gating properties of human Slo1 and mouse Slo3 channels. Utilizing Slo1/Slo3 chimeras, we pinpointed the selectivity filter region as a key factor in the Slo3 channel's reduced conductance at negative voltages. The S6 transmembrane (TM) segment was identified as pivotal for the Slo3 channel's biphasic deactivation kinetics at these voltages. Additionally, the S4 and S6 TM segments were found to be responsible for the gradual slope in the Slo3 channel's conductance-voltage relationship, while multiple TM regions appear to be involved in the Slo3 channel's requirement of strong depolarization for activation. Mutations in the Slo1's S5 and S6 TM segments revealed three residues (I233, L302, and M304) that likely play a crucial role in the allosteric coupling between the voltage sensors and the pore gate.
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Affiliation(s)
- Qin Li
- Department of Anesthesiology and Perioperative Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas; Molecular & Translational Biology and Neuroscience Programs, MD Anderson UT Health Graduate School of Biomedical Sciences, Houston, Texas
| | - Guanxing Chen
- Department of Anesthesiology and Perioperative Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas; Molecular & Translational Biology and Neuroscience Programs, MD Anderson UT Health Graduate School of Biomedical Sciences, Houston, Texas
| | - Jiusheng Yan
- Department of Anesthesiology and Perioperative Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas; Molecular & Translational Biology and Neuroscience Programs, MD Anderson UT Health Graduate School of Biomedical Sciences, Houston, Texas.
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2
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Sanchez NDRR, Ritagliati C, Kopf GS, Kretschmer S, Buck J, Levin LR. The uniqueness of on-demand male contraception. Mol Aspects Med 2024; 97:101281. [PMID: 38805792 PMCID: PMC11167369 DOI: 10.1016/j.mam.2024.101281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Accepted: 05/21/2024] [Indexed: 05/30/2024]
Abstract
Because nearly half of pregnancies worldwide are unintended, available contraceptive methods are inadequate. Moreover, due to the striking imbalance between contraceptive options available for men compared to the myriad of options available to women, there is an urgent need for new methods of contraception for men. This review summarizes ongoing efforts to develop male contraceptives highlighting the unique aspects particular to on-demand male contraception, where a man takes a contraceptive only when and as often as needed.
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Affiliation(s)
| | - Carla Ritagliati
- Department of Pharmacology, Weill Cornell Medicine, New York, NY, USA
| | | | | | - Jochen Buck
- Department of Pharmacology, Weill Cornell Medicine, New York, NY, USA.
| | - Lonny R Levin
- Department of Pharmacology, Weill Cornell Medicine, New York, NY, USA
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3
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Ku AF, Sharma KL, Ta HM, Sutton CM, Bohren KM, Wang Y, Chamakuri S, Chen R, Hakenjos JM, Jimmidi R, Kent K, Li F, Li JY, Ma L, Madasu C, Palaniappan M, Palmer SS, Qin X, Robers MB, Sankaran B, Tan Z, Vasquez YM, Wang J, Wilkinson J, Yu Z, Ye Q, Young DW, Teng M, Kim C, Matzuk MM. Reversible male contraception by targeted inhibition of serine/threonine kinase 33. Science 2024; 384:885-890. [PMID: 38781365 DOI: 10.1126/science.adl2688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 04/03/2024] [Indexed: 05/25/2024]
Abstract
Men or mice with homozygous serine/threonine kinase 33 (STK33) mutations are sterile owing to defective sperm morphology and motility. To chemically evaluate STK33 for male contraception with STK33-specific inhibitors, we screened our multibillion-compound collection of DNA-encoded chemical libraries, uncovered potent STK33-specific inhibitors, determined the STK33 kinase domain structure bound with a truncated hit CDD-2211, and generated an optimized hit CDD-2807 that demonstrates nanomolar cellular potency (half-maximal inhibitory concentration = 9.2 nanomolar) and favorable metabolic stability. In mice, CDD-2807 exhibited no toxicity, efficiently crossed the blood-testis barrier, did not accumulate in brain, and induced a reversible contraceptive effect that phenocopied genetic STK33 perturbations without altering testis size. Thus, STK33 is a chemically validated, nonhormonal contraceptive target, and CDD-2807 is an effective tool compound.
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Affiliation(s)
- Angela F Ku
- Center for Drug Discovery, Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Kiran L Sharma
- Center for Drug Discovery, Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Hai Minh Ta
- Center for Drug Discovery, Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX 77030, USA
- Verna and Marrs McLean Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Courtney M Sutton
- Center for Drug Discovery, Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Kurt M Bohren
- Center for Drug Discovery, Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Yong Wang
- Center for Drug Discovery, Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Srinivas Chamakuri
- Center for Drug Discovery, Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Ruihong Chen
- Center for Drug Discovery, Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX 77030, USA
| | - John M Hakenjos
- Center for Drug Discovery, Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Ravikumar Jimmidi
- Center for Drug Discovery, Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Katarzyna Kent
- Center for Drug Discovery, Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Feng Li
- Center for Drug Discovery, Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX 77030, USA
- Verna and Marrs McLean Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jian-Yuan Li
- Center for Drug Discovery, Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Lang Ma
- Center for Drug Discovery, Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Chandrashekhar Madasu
- Center for Drug Discovery, Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Murugesan Palaniappan
- Center for Drug Discovery, Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Stephen S Palmer
- Center for Drug Discovery, Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Xuan Qin
- Center for Drug Discovery, Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX 77030, USA
| | | | - Banumathi Sankaran
- Molecular Biophysics and Integrated Bioimaging, Berkeley Center for Structural Biology, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Zhi Tan
- Center for Drug Discovery, Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX 77030, USA
- Verna and Marrs McLean Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Yasmin M Vasquez
- Center for Drug Discovery, Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jian Wang
- Center for Drug Discovery, Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX 77030, USA
| | | | - Zhifeng Yu
- Center for Drug Discovery, Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Qiuji Ye
- Center for Drug Discovery, Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Damian W Young
- Center for Drug Discovery, Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX 77030, USA
- Verna and Marrs McLean Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Mingxing Teng
- Center for Drug Discovery, Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX 77030, USA
- Verna and Marrs McLean Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Choel Kim
- Center for Drug Discovery, Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX 77030, USA
- Verna and Marrs McLean Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Martin M Matzuk
- Center for Drug Discovery, Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX 77030, USA
- Verna and Marrs McLean Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
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4
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Holdaway J, Georg GI. An emerging target for male contraception. Science 2024; 384:849-850. [PMID: 38781397 DOI: 10.1126/science.adp6432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2024]
Abstract
An inhibitor of a nonhormonal target is identified using a DNA-encoded chemical library.
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Affiliation(s)
| | - Gunda I Georg
- University of Minnesota Twin Cities, Minneapolis, MN, USA
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5
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Balestrini PA, Sulzyk V, Jabloñski M, Schiavi-Ehrenhaus LJ, González SN, Ferreira JJ, Gómez-Elías MD, Pomata P, Luque GM, Krapf D, Cuasnicu PS, Santi CM, Buffone MG. Membrane potential hyperpolarization: a critical factor in acrosomal exocytosis and fertilization in sperm within the female reproductive tract. Front Cell Dev Biol 2024; 12:1386980. [PMID: 38803392 PMCID: PMC11128623 DOI: 10.3389/fcell.2024.1386980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Accepted: 04/24/2024] [Indexed: 05/29/2024] Open
Abstract
Hyperpolarization of the membrane potential (Em), a phenomenon regulated by SLO3 channels, stands as a central feature in sperm capacitation-a crucial process conferring upon sperm the ability to fertilize the oocyte. In vitro studies demonstrated that Em hyperpolarization plays a pivotal role in facilitating the mechanisms necessary for the development of hyperactivated motility (HA) and acrosomal exocytosis (AE) occurrence. Nevertheless, the physiological significance of sperm Em within the female reproductive tract remains unexplored. As an approach to this question, we studied sperm migration and AE incidence within the oviduct in the absence of Em hyperpolarization using a novel mouse model established by crossbreeding of SLO3 knock-out (KO) mice with EGFP/DsRed2 mice. Sperm from this model displays impaired HA and AE in vitro. Interestingly, examination of the female reproductive tract shows that SLO3 KO sperm can reach the ampulla, mirroring the quantity of sperm observed in wild-type (WT) counterparts, supporting that the HA needed to reach the fertilization site is not affected. However, a noteworthy distinction emerges-unlike WT sperm, the majority of SLO3 KO sperm arrive at the ampulla with their acrosomes still intact. Of the few SLO3 KO sperm that do manage to reach the oocytes within this location, fertilization does not occur, as indicated by the absence of sperm pronuclei in the MII-oocytes recovered post-mating. In vitro, SLO3 KO sperm fail to penetrate the ZP and fuse with the oocytes. Collectively, these results underscore the vital role of Em hyperpolarization in AE and fertilization within their physiological context, while also revealing that Em is not a prerequisite for the development of the HA motility, essential for sperm migration through the female tract to the ampulla.
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Affiliation(s)
- Paula A. Balestrini
- Instituto de Biología y Medicina Experimental (IByME)-Consejo Nacional de Investigaciones Científicas y Tícnicas, Buenos Aires, Argentina
| | - Valeria Sulzyk
- Instituto de Biología y Medicina Experimental (IByME)-Consejo Nacional de Investigaciones Científicas y Tícnicas, Buenos Aires, Argentina
| | - Martina Jabloñski
- Instituto de Biología y Medicina Experimental (IByME)-Consejo Nacional de Investigaciones Científicas y Tícnicas, Buenos Aires, Argentina
| | - Liza J. Schiavi-Ehrenhaus
- Instituto de Biología y Medicina Experimental (IByME)-Consejo Nacional de Investigaciones Científicas y Tícnicas, Buenos Aires, Argentina
| | - Soledad N. González
- Instituto de Biología y Medicina Experimental (IByME)-Consejo Nacional de Investigaciones Científicas y Tícnicas, Buenos Aires, Argentina
| | - Juan J. Ferreira
- Department of OB/GYN, Washington University School of Medicine, Saint Louis, MO, United States
| | - Matías D. Gómez-Elías
- Instituto de Biología y Medicina Experimental (IByME)-Consejo Nacional de Investigaciones Científicas y Tícnicas, Buenos Aires, Argentina
| | - Pablo Pomata
- Instituto de Biología y Medicina Experimental (IByME)-Consejo Nacional de Investigaciones Científicas y Tícnicas, Buenos Aires, Argentina
| | - Guillermina M. Luque
- Instituto de Biología y Medicina Experimental (IByME)-Consejo Nacional de Investigaciones Científicas y Tícnicas, Buenos Aires, Argentina
| | - Dario Krapf
- Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas–Universidad Nacional de Rosario, Rosario, Santa Fe, Argentina
| | - Patricia S. Cuasnicu
- Instituto de Biología y Medicina Experimental (IByME)-Consejo Nacional de Investigaciones Científicas y Tícnicas, Buenos Aires, Argentina
| | - Celia M. Santi
- Department of OB/GYN, Washington University School of Medicine, Saint Louis, MO, United States
| | - Mariano G. Buffone
- Instituto de Biología y Medicina Experimental (IByME)-Consejo Nacional de Investigaciones Científicas y Tícnicas, Buenos Aires, Argentina
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6
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Zhang J, Zheng L, Chen Y, Luo T, Zeng X, Kang H. LRRC52 is likely a functional component of human KSper†. Biol Reprod 2024; 110:711-721. [PMID: 38267364 DOI: 10.1093/biolre/ioae004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 07/19/2023] [Accepted: 01/05/2024] [Indexed: 01/26/2024] Open
Abstract
Completion of fertilization is orchestrated by various ion channels in sperm membrane. Hyperpolarization of membrane potential, an indispensable event during the capacitation process, is dominated by sperm potassium channel (KSper). In addition to sperm-specific SLO3, which forms the channel pore, the auxiliary subunit leucine-rich-repeat-containing protein 52 (LRRC52) is required to form mKSper to function under physiological conditions. However, in human sperm, although most evidence supports that hSLO3 is the pore-forming subunit, whether hLRRC52 contributes to hKSper conductance and modulates sperm function remains to be understood. Here, using an extracellular segment that is homologous between mice and humans as an antigen, we developed a polyclonal antibody designed as LID1 that specifically detected mLRRC52 and performed co-immunoprecipitation with mSLO3. Additionally, patch-clamp recordings of mouse sperm showed that, physiological activation of mKSper and sperm functions were dramatically attenuated after treatment with LID1, indicating that LID1 functionally disrupted the regulation of mLRRC52 on mKSper. Next, LID1 was used to investigate the significance of hLRRC52 for hKSper activation. As a result, hLRRC52 was expressed in human sperm and might be assembled with hSLO3. More importantly, LID1 inhibited hKSper currents and depolarized sperm membrane potential, supporting essential modulation of hLRRC52 in hKSper. Ca2+ signaling of human sperm was also compromised in the presence of LID1, which impaired sperm motility and acrosome reaction. Because LID1 specifically inhibited both mKSper and hKSper but not mCatSper or hCatSper, our results suggest that hLRRC52 functions as an important component of hKSper and regulates sperm physiological functions.
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Affiliation(s)
- Jiali Zhang
- Institute of Reproductive Medicine, School of Medicine, Nantong University, Nantong, Jiangsu, China
| | - Liping Zheng
- Institute of Life Science and School of Life Sciences, Nanchang University, Nanchang, Jiangxi, China
| | - Ying Chen
- Institute of Life Science and School of Life Sciences, Nanchang University, Nanchang, Jiangxi, China
| | - Tao Luo
- Institute of Life Science and School of Life Sciences, Nanchang University, Nanchang, Jiangxi, China
| | - Xuhui Zeng
- Institute of Reproductive Medicine, School of Medicine, Nantong University, Nantong, Jiangsu, China
| | - Hang Kang
- Institute of Reproductive Medicine, School of Medicine, Nantong University, Nantong, Jiangsu, China
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7
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Delgado-Bermúdez A, Yeste M, Bonet S, Pinart E. Physiological role of potassium channels in mammalian germ cell differentiation, maturation, and capacitation. Andrology 2024. [PMID: 38436215 DOI: 10.1111/andr.13606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 01/16/2024] [Accepted: 01/29/2024] [Indexed: 03/05/2024]
Abstract
BACKGROUND Ion channels are essential for differentiation and maturation of germ cells, and even for fertilization in mammals. Different types of potassium channels have been identified, which are grouped into voltage-gated channels (Kv), ligand-gated channels (Kligand ), inwardly rectifying channels (Kir ), and tandem pore domain channels (K2P ). MATERIAL-METHODS The present review includes recent findings on the role of potassium channels in sperm physiology of mammals. RESULTS-DISCUSSION While most studies conducted thus far have been focused on the physiological role of voltage- (Kv1, Kv3, and Kv7) and calcium-gated channels (SLO1 and SLO3) during sperm capacitation, especially in humans and rodents, little data about the types of potassium channels present in the plasma membrane of differentiating germ cells exist. In spite of this, recent evidence suggests that the content and regulation mechanisms of these channels vary throughout spermatogenesis. Potassium channels are also essential for the regulation of sperm cell volume during epididymal maturation and for preventing premature membrane hyperpolarization. It is important to highlight that the nature, biochemical properties, localization, and regulation mechanisms of potassium channels are species-specific. In effect, while SLO3 is the main potassium channel involved in the K+ current during sperm capacitation in rodents, different potassium channels are implicated in the K+ outflow and, thus, plasma membrane hyperpolarization during sperm capacitation in other mammalian species, such as humans and pigs. CONCLUSIONS Potassium conductance is essential for male fertility, not only during sperm capacitation but throughout the spermiogenesis and epididymal maturation.
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Affiliation(s)
- Ariadna Delgado-Bermúdez
- Biotechnology of Animal and Human Reproduction (TechnoSperm), Institute of Food and Agricultural Technology, University of Girona, Girona, Spain
- Department of Biology, Faculty of Sciences, Unit of Cell Biology, University of Girona, Girona, Spain
| | - Marc Yeste
- Biotechnology of Animal and Human Reproduction (TechnoSperm), Institute of Food and Agricultural Technology, University of Girona, Girona, Spain
- Department of Biology, Faculty of Sciences, Unit of Cell Biology, University of Girona, Girona, Spain
- Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain
| | - Sergi Bonet
- Biotechnology of Animal and Human Reproduction (TechnoSperm), Institute of Food and Agricultural Technology, University of Girona, Girona, Spain
- Department of Biology, Faculty of Sciences, Unit of Cell Biology, University of Girona, Girona, Spain
| | - Elisabeth Pinart
- Biotechnology of Animal and Human Reproduction (TechnoSperm), Institute of Food and Agricultural Technology, University of Girona, Girona, Spain
- Department of Biology, Faculty of Sciences, Unit of Cell Biology, University of Girona, Girona, Spain
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8
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Gruber FS, Richardson A, Johnston ZC, Myles R, Norcross NR, Day DP, Georgiou I, Sesma-Sanz L, Wilson C, Read KD, Martins da Silva S, Barratt CLR, Gilbert IH, Swedlow JR. Sperm Toolbox-A selection of small molecules to study human spermatozoa. PLoS One 2024; 19:e0297666. [PMID: 38377053 PMCID: PMC10878532 DOI: 10.1371/journal.pone.0297666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 01/11/2024] [Indexed: 02/22/2024] Open
Abstract
Male contraceptive options and infertility treatments are limited, and almost all innovation has been limited to updates to medically assisted reproduction protocols and methods. To accelerate the development of drugs that can either improve or inhibit fertility, we established a small molecule library as a toolbox for assay development and screening campaigns using human spermatozoa. We have profiled all compounds in the Sperm Toolbox in several automated high-throughput assays that measure stimulation or inhibition of sperm motility or the acrosome reaction. We have assayed motility under non-capacitating and capacitating conditions to distinguish between pathways operating under these different physiological states. We also assayed cell viability to ensure any effects on sperm function are specific. A key advantage of our studies is that all compounds are assayed together in the same experimental conditions, which allows quantitative comparisons of their effects in complementary functional assays. We have combined the resulting datasets to generate fingerprints of the Sperm Toolbox compounds on sperm function. The data are included in an on-line R-based app for convenient querying.
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Affiliation(s)
- Franz S. Gruber
- Divisions of Computational Biology and Molecular, Cell and Developmental Biology, and National Phenotypic Screening Centre, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Anthony Richardson
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Zoe C. Johnston
- Division of Systems Medicine, School of Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, United Kingdom
| | - Rachel Myles
- Division of Systems Medicine, School of Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, United Kingdom
| | - Neil R. Norcross
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - David P. Day
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Irene Georgiou
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Laura Sesma-Sanz
- Divisions of Computational Biology and Molecular, Cell and Developmental Biology, and National Phenotypic Screening Centre, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Caroline Wilson
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Kevin D. Read
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Sarah Martins da Silva
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Christopher L. R. Barratt
- Division of Systems Medicine, School of Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, United Kingdom
| | - Ian H. Gilbert
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Jason R. Swedlow
- Divisions of Computational Biology and Molecular, Cell and Developmental Biology, and National Phenotypic Screening Centre, School of Life Sciences, University of Dundee, Dundee, United Kingdom
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9
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Louwagie EJ, Quinn GFL, Pond KL, Hansen KA. Male contraception: narrative review of ongoing research. Basic Clin Androl 2023; 33:30. [PMID: 37940863 PMCID: PMC10634021 DOI: 10.1186/s12610-023-00204-z] [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: 05/05/2023] [Accepted: 07/26/2023] [Indexed: 11/10/2023] Open
Abstract
BACKGROUND Since the release of the combined oral contraceptive pill in 1960, women have shouldered the burden of contraception and family planning. Over 60 years later, this is still the case as the only practical, effective contraceptive options available to men are condoms and vasectomy. However, there are now a variety of promising hormonal and non-hormonal male contraceptive options being studied. The purpose of this narrative review is to provide clinicians and laypeople with focused, up-to-date descriptions of novel strategies and targets for male contraception. We include a cautiously optimistic discussion of benefits and potential drawbacks, highlighting several methods in preclinical and clinical stages of development. RESULTS As of June 2023, two hormonal male contraceptive methods are undergoing phase II clinical trials for safety and efficacy. A large-scale, international phase IIb trial investigating efficacy of transdermal segesterone acetate (Nestorone) plus testosterone gel has enrolled over 460 couples with completion estimated for late 2024. A second hormonal method, dimethandrolone undecanoate, is in two clinical trials focusing on safety, pharmacodynamics, suppression of spermatogenesis and hormones; the first of these two is estimated for completion in December 2024. There are also several non-hormonal methods with strong potential in preclinical stages of development. CONCLUSIONS There exist several hurdles to novel male contraception. Therapeutic development takes decades of time, meticulous work, and financial investment, but with so many strong candidates it is our hope that there will soon be several safe, effective, and reversible contraceptive options available to male patients.
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Affiliation(s)
- Eli J Louwagie
- University of South Dakota Sanford School of Medicine, 1400 W 22nd St, Sioux Falls, SD, 57105, USA.
| | - Garrett F L Quinn
- University of South Dakota Sanford School of Medicine, 1400 W 22nd St, Sioux Falls, SD, 57105, USA
| | - Kristi L Pond
- University of South Dakota Sanford School of Medicine, 1400 W 22nd St, Sioux Falls, SD, 57105, USA
| | - Keith A Hansen
- Chair and Professor, Dept. of Obstetrics and Gynecology, University of South Dakota Sanford School of Medicine; Reproductive Endocrinologist, Sanford Fertility and Reproductive Medicine, 1500 W 22nd St Suite 102, Sioux Falls, SD, 57105, USA
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10
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Amory JK. Male Contraception. Semin Reprod Med 2023; 41:279-286. [PMID: 38113922 DOI: 10.1055/s-0043-1777757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
Approximately 40 to 50% of pregnancies are unintended. Contraceptive use significantly reduces the risk of unintended pregnancy. Approximately 70% of couples' contraceptive use is female and 30% is male, attributable to the reliance on condoms and vasectomies. Unfortunately, many women cannot use currently available contraceptives due to medical contraindications or side effects. At the same time, men want additional safe and effective contraceptive methods. Because of this, work to develop novel, safe, and effective male contraceptives is underway. This review will briefly discuss the pros and cons of condoms and vasectomies, and then describe research into the development of novel methods of male contraception, by the mechanism of action of the contraceptive. First, we will discuss male contraceptives that block sperm transmission. Next, we will discuss male contraceptives that impair sperm production. Lastly, we will discuss male contraceptives that impair sperm function.
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Affiliation(s)
- John K Amory
- Department of Medicine, The Center for Research in Reproduction and Contraception, University of Washington, Seattle, Washington
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Gardner CC, James PF. Na +/H + Exchangers (NHEs) in Mammalian Sperm: Essential Contributors to Male Fertility. Int J Mol Sci 2023; 24:14981. [PMID: 37834431 PMCID: PMC10573352 DOI: 10.3390/ijms241914981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 10/03/2023] [Accepted: 10/04/2023] [Indexed: 10/15/2023] Open
Abstract
Na+/H+ exchangers (NHEs) are known to be important regulators of pH in multiple intracellular compartments of eukaryotic cells. Sperm function is especially dependent on changes in pH and thus it has been postulated that NHEs play important roles in regulating the intracellular pH of these cells. For example, in order to achieve fertilization, mature sperm must maintain a basal pH in the male reproductive tract and then alkalize in response to specific signals in the female reproductive tract during the capacitation process. Eight NHE isoforms are expressed in mammalian testis/sperm: NHE1, NHE3, NHE5, NHE8, NHA1, NHA2, NHE10, and NHE11. These NHE isoforms are expressed at varying times during spermatogenesis and localize to different subcellular structures in developing and mature sperm where they contribute to multiple aspects of sperm physiology and male fertility including proper sperm development/morphogenesis, motility, capacitation, and the acrosome reaction. Previous work has provided evidence for NHE3, NHE8, NHA1, NHA2, and NHE10 being critical for male fertility in mice and NHE10 has recently been shown to be essential for male fertility in humans. In this article we review what is known about each NHE isoform expressed in mammalian sperm and discuss the physiological significance of each NHE isoform with respect to male fertility.
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Affiliation(s)
| | - Paul F. James
- Department of Biology, Miami University, Oxford, OH 45056, USA;
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12
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Wang C, Meriggiola MC, Amory JK, Barratt CLR, Behre HM, Bremner WJ, Ferlin A, Honig S, Kopa Z, Lo K, Nieschlag E, Page ST, Sandlow J, Sitruk-Ware R, Swerdloff RS, Wu FCW, Goulis DG. Practice and development of male contraception: European Academy of Andrology and American Society of Andrology guidelines. Andrology 2023. [PMID: 37727884 DOI: 10.1111/andr.13525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 08/31/2023] [Indexed: 09/21/2023]
Abstract
BACKGROUNDS Despite a wide spectrum of contraceptive methods for women, the unintended pregnancy rate remains high (45% in the US), with 50% resulting in abortion. Currently, 20% of global contraceptive use is male-directed, with a wide variation among countries due to limited availability and lack of efficacy. Worldwide studies indicate that >50% of men would opt to use a reversible method, and 90% of women would rely on their partner to use a contraceptive. Additional reasons for novel male contraceptive methods to be available include the increased life expectancy, sharing the reproductive risks among partners, social issues, the lack of pharma industry involvement and the lack of opinion makers advocating for male contraception. AIM The present guidelines aim to review the status regarding male contraception, the current state of the art to support the clinical practice, recommend minimal requirements for new male contraceptive development and provide and grade updated, evidence-based recommendations from the European Society of Andrology (EAA) and the American Society of Andrology (ASA). METHODS An expert panel of academicians appointed by the EAA and the ASA generated a consensus guideline according to the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) system. RESULTS Sixty evidence-based and graded recommendations were produced on couple-centered communication, behaviors, barrier methods, semen analysis and contraceptive efficacy, physical agents, surgical methods, actions before initiating male contraception, hormonal methods, non-hormonal methods, vaccines, and social and ethical considerations. CONCLUSION As gender roles transform and gender equity is established in relationships, the male contribution to family planning must be facilitated. Efficient and safe male-directed methods must be evaluated and introduced into clinical practice, preferably reversible, either hormonal or non-hormonal. From a future perspective, identifying new hormonal combinations, suitable testicular targets, and emerging vas occlusion methods will produce novel molecules and products for male contraception.
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Affiliation(s)
- Christina Wang
- Division of Endocrinology, Department of Medicine and Clinical and Translational Science Institute, The Lundquist Insitute and Harbor-UCLA Medical Center, Torrance, California, USA
| | - Maria Cristina Meriggiola
- Division of Gynecology and Human Reproduction Physiopathology, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - John K Amory
- Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
| | - Christopher L R Barratt
- Division of Systems and Cellular Medicine, Medical School, Ninewells Hospital, University of Dundee, Dundee, Scotland
| | - Hermann M Behre
- Center for Reproductive Medicine and Andrology, University Medicine Halle, Halle, Germany
| | - William J Bremner
- Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
| | - Alberto Ferlin
- Unit of Andrology and Reproductive Medicine, Department of Medicine, University of Padova, Padova, Italy
| | - Stanton Honig
- Division of Reproductive and Sexual Medicine, Department of Urology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Zsolt Kopa
- Department of Urology, Andrology Centre, Semmelweis University, Budapest, Hungary
| | - Kirk Lo
- Division of Urology, Department of Surgery, University of Toronto, Toronto, Canada
| | - Eberhard Nieschlag
- Center of Reproductive Medicine and Andrology, University Hospital, Münster, Germany
| | - Stephanie T Page
- Division of Metabolism, Endocrinology and Nutrition, UW Medicine Diabetes Institute, University of Washington School of Medicine, Seattle, Washington, USA
| | - Jay Sandlow
- Department of Urology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Regine Sitruk-Ware
- Center for Biomedical Research, Population Council, New York, New York, USA
| | - Ronald S Swerdloff
- Division of Endocrinology, Department of Medicine, The Lundquist Institute and Harbor-UCLA Medical Center, Torrance, California, USA
| | - Frederick C W Wu
- Division of Endocrinology, Diabetes and Gastroenterology, Faculty of Biology, Medicine and Health, School of Medical Sciences, University of Manchester, Manchester, UK
| | - Dimitrios G Goulis
- First Department of Obstetrics and Gynecology, Unit of Reproductive Endocrinology, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece
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13
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Mariani NAP, Silva JV, Fardilha M, Silva EJR. Advances in non-hormonal male contraception targeting sperm motility. Hum Reprod Update 2023; 29:545-569. [PMID: 37141450 DOI: 10.1093/humupd/dmad008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 03/23/2023] [Indexed: 05/06/2023] Open
Abstract
BACKGROUND The high rates of unintended pregnancy and the ever-growing world population impose health, economic, social, and environmental threats to countries. Expanding contraceptive options, including male methods, are urgently needed to tackle these global challenges. Male contraception is limited to condoms and vasectomy, which are unsuitable for many couples. Thus, novel male contraceptive methods may reduce unintended pregnancies, meet the contraceptive needs of couples, and foster gender equality in carrying the contraceptive burden. In this regard, the spermatozoon emerges as a source of druggable targets for on-demand, non-hormonal male contraception based on disrupting sperm motility or fertilization. OBJECTIVE AND RATIONALE A better understanding of the molecules governing sperm motility can lead to innovative approaches toward safe and effective male contraceptives. This review discusses cutting-edge knowledge on sperm-specific targets for male contraception, focusing on those with crucial roles in sperm motility. We also highlight challenges and opportunities in male contraceptive drug development targeting spermatozoa. SEARCH METHODS We conducted a literature search in the PubMed database using the following keywords: 'spermatozoa', 'sperm motility', 'male contraception', and 'drug targets' in combination with other related terms to the field. Publications until January 2023 written in English were considered. OUTCOMES Efforts for developing non-hormonal strategies for male contraception resulted in the identification of candidates specifically expressed or enriched in spermatozoa, including enzymes (PP1γ2, GAPDHS, and sAC), ion channels (CatSper and KSper), transmembrane transporters (sNHE, SLC26A8, and ATP1A4), and surface proteins (EPPIN). These targets are usually located in the sperm flagellum. Their indispensable roles in sperm motility and male fertility were confirmed by genetic or immunological approaches using animal models and gene mutations associated with male infertility due to sperm defects in humans. Their druggability was demonstrated by the identification of drug-like small organic ligands displaying spermiostatic activity in preclinical trials. WIDER IMPLICATIONS A wide range of sperm-associated proteins has arisen as key regulators of sperm motility, providing compelling druggable candidates for male contraception. Nevertheless, no pharmacological agent has reached clinical developmental stages. One reason is the slow progress in translating the preclinical and drug discovery findings into a drug-like candidate adequate for clinical development. Thus, intense collaboration among academia, private sectors, governments, and regulatory agencies will be crucial to combine expertise for the development of male contraceptives targeting sperm function by (i) improving target structural characterization and the design of highly selective ligands, (ii) conducting long-term preclinical safety, efficacy, and reversibility evaluation, and (iii) establishing rigorous guidelines and endpoints for clinical trials and regulatory evaluation, thus allowing their testing in humans.
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Affiliation(s)
- Noemia A P Mariani
- Department of Biophysics and Pharmacology, Institute of Biosciences of Botucatu, São Paulo State University, Botucatu, Brazil
| | - Joana V Silva
- Department of Medical Sciences, Institute of Biomedicine (iBiMED), University of Aveiro, Aveiro, Portugal
- QOPNA & LAQV, Department of Chemistry, University of Aveiro, Aveiro, Portugal
- Multidisciplinary Research in Biomedicine (UMIB), Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Porto, Portugal
| | - Margarida Fardilha
- Department of Medical Sciences, Institute of Biomedicine (iBiMED), University of Aveiro, Aveiro, Portugal
| | - Erick J R Silva
- Department of Biophysics and Pharmacology, Institute of Biosciences of Botucatu, São Paulo State University, Botucatu, Brazil
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14
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Lyon MD, Ferreira JJ, Li P, Bhagwat S, Butler A, Anderson K, Polo M, Santi CM. SLO3: A Conserved Regulator of Sperm Membrane Potential. Int J Mol Sci 2023; 24:11205. [PMID: 37446382 DOI: 10.3390/ijms241311205] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 07/03/2023] [Accepted: 07/05/2023] [Indexed: 07/15/2023] Open
Abstract
Sperm cells must undergo a complex maturation process after ejaculation to be able to fertilize an egg. One component of this maturation is hyperpolarization of the membrane potential to a more negative value. The ion channel responsible for this hyperpolarization, SLO3, was first cloned in 1998, and since then much progress has been made to determine how the channel is regulated and how its function intertwines with various signaling pathways involved in sperm maturation. Although Slo3 was originally thought to be present only in the sperm of mammals, recent evidence suggests that a primordial form of the gene is more widely expressed in some fish species. Slo3, like many reproductive genes, is rapidly evolving with low conservation between closely related species and different regulatory and pharmacological profiles. Despite these differences, SLO3 appears to have a conserved role in regulating sperm membrane potential and driving large changes in response to stimuli. The effect of this hyperpolarization of the membrane potential may vary among mammalian species just as the regulation of the channel does. Recent discoveries have elucidated the role of SLO3 in these processes in human sperm and provided tools to target the channel to affect human fertility.
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Affiliation(s)
- Maximilian D Lyon
- Department of Obstetrics and Gynecology, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Juan J Ferreira
- Department of Obstetrics and Gynecology, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Ping Li
- Department of Obstetrics and Gynecology, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Shweta Bhagwat
- Department of Obstetrics and Gynecology, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Alice Butler
- Department of Obstetrics and Gynecology, Washington University in St. Louis, St. Louis, MO 63110, USA
- Department of Neuroscience, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Kelsey Anderson
- Department of Obstetrics and Gynecology, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Maria Polo
- Department of Obstetrics and Gynecology, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Celia M Santi
- Department of Obstetrics and Gynecology, Washington University in St. Louis, St. Louis, MO 63110, USA
- Department of Neuroscience, Washington University in St. Louis, St. Louis, MO 63110, USA
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15
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Cong S, Zhang J, Pan F, Pan L, Zhang A, Ma J. Research progress on ion channels and their molecular regulatory mechanisms in the human sperm flagellum. FASEB J 2023; 37:e23052. [PMID: 37352114 DOI: 10.1096/fj.202300756r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 06/06/2023] [Accepted: 06/09/2023] [Indexed: 06/25/2023]
Abstract
The ion channels in sperm tail play an important role in triggering key physiological reactions, e.g., progressive motility, hyperactivation, required for successful fertilization. Among them, CatSper and KSper have been shown to be important ion channels for the transport of Ca2+ and K+ . Moreover, the voltage-gated proton channel Hv1, the sperm-specific sodium-hydrogen exchanger (sNHE), the epithelial sodium channel (ENaC), members of the temperature-sensitive TRP channel family, and the cystic fibrosis transmembrane regulator (CFTR) are also found in the flagellum. This review focuses on the latest advances in ion channels located at the flagellum, describes how they affect sperm physiological function, and summarizes some primary mutual regulation mechanism between ion channels, including PH, membrane potential, and cAMP. These ion channels may be promising targets for clinical application in infertility.
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Affiliation(s)
- Shengnan Cong
- Obstetrics and Gynecology Department, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, P.R. China
- Women's Hospital of Nanjing Medical University (Nanjing Maternity and Child Health Care Hospital), Nanjing, P.R. China
| | - Jingjing Zhang
- Women's Hospital of Nanjing Medical University (Nanjing Maternity and Child Health Care Hospital), Nanjing, P.R. China
| | - Feng Pan
- Women's Hospital of Nanjing Medical University (Nanjing Maternity and Child Health Care Hospital), Nanjing, P.R. China
| | - Lianjun Pan
- Women's Hospital of Nanjing Medical University (Nanjing Maternity and Child Health Care Hospital), Nanjing, P.R. China
| | - Aixia Zhang
- Women's Hospital of Nanjing Medical University (Nanjing Maternity and Child Health Care Hospital), Nanjing, P.R. China
| | - Jiehua Ma
- Obstetrics and Gynecology Department, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, P.R. China
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16
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Cooray A, Kim J, Nirujan BR, Jayathilake NJ, Lee KP. Pharmacological Evidence Suggests That Slo3 Channel Is the Principal K + Channel in Boar Spermatozoa. Int J Mol Sci 2023; 24:ijms24097806. [PMID: 37175513 PMCID: PMC10178124 DOI: 10.3390/ijms24097806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 04/20/2023] [Accepted: 04/23/2023] [Indexed: 05/15/2023] Open
Abstract
Sperm ion channels are associated with the quality and type of flagellar movement, and their differential regulation is crucial for sperm function during specific phases. The principal potassium ion channel is responsible for the majority of K+ ion flux, resulting in membrane hyperpolarization, and is essential for sperm capacitation-related signaling pathways. The molecular identity of the principal K+ channel varies greatly between different species, and there is a lack of information about boar K+ channels. We aimed to determine the channel identity of boar sperm contributing to the primary K+ current using pharmacological dissection. A series of Slo1 and Slo3 channel modulators were used for treatment. Sperm motility and related kinematic parameters were monitored using a computer-assisted sperm analysis system under non-capacitated conditions. Time-lapse flow cytometry with fluorochromes was used to measure changes in different intracellular ionic concentrations, and conventional flow cytometry was used to determine the acrosome reaction. Membrane depolarization, reduction in acrosome reaction, and motility parameters were observed upon the inhibition of the Slo3 channel, suggesting that the Slo3 gene encodes the main K+ channel in boar spermatozoa. The Slo3 channel was localized on the sperm flagellum, and the inhibition of Slo3 did not reduce sperm viability. These results may aid potential animal-model-based extrapolations and help to ameliorate motility and related parameters, leading to improved assisted reproductive methods in industrial livestock production.
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Affiliation(s)
- Akila Cooray
- Department of Physiology, College of Veterinary Medicine, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Jeongsook Kim
- Department of Physiology, College of Veterinary Medicine, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Beno Ramesh Nirujan
- Department of Physiology, College of Veterinary Medicine, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Nishani Jayanika Jayathilake
- Department of Physiology, College of Veterinary Medicine, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Kyu Pil Lee
- Department of Physiology, College of Veterinary Medicine, Chungnam National University, Daejeon 34134, Republic of Korea
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The SLC9C2 Gene Product (Na+/H+ Exchanger Isoform 11; NHE11) Is a Testis-Specific Protein Localized to the Head of Mature Mammalian Sperm. Int J Mol Sci 2023; 24:ijms24065329. [PMID: 36982403 PMCID: PMC10049371 DOI: 10.3390/ijms24065329] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 03/02/2023] [Accepted: 03/07/2023] [Indexed: 03/14/2023] Open
Abstract
Na+/H+ exchangers (NHEs) are a family of ion transporters that regulate the pH of various cell compartments across an array of cell types. In eukaryotes, NHEs are encoded by the SLC9 gene family comprising 13 genes. SLC9C2, which encodes the NHE11 protein, is the only one of the SLC9 genes that is essentially uncharacterized. Here, we show that SLC9C2 exhibits testis/sperm-restricted expression in rats and humans, akin to its paralog SLC9C1 (NHE10). Similar to NHE10, NHE11 is predicted to contain an NHE domain, a voltage sensing domain, and finally an intracellular cyclic nucleotide binding domain. An immunofluorescence analysis of testis sections reveals that NHE11 localizes with developing acrosomal granules in spermiogenic cells in both rat and human testes. Most interestingly, NHE11 localizes to the sperm head, likely the plasma membrane overlaying the acrosome, in mature sperm from rats and humans. Therefore, NHE11 is the only known NHE to localize to the acrosomal region of the head in mature sperm cells. The physiological role of NHE11 has yet to be demonstrated but its predicted functional domains and unique localization suggests that it could modulate intracellular pH of the sperm head in response to changes in membrane potential and cyclic nucleotide concentrations that are a result of sperm capacitation events. If NHE11 is shown to be important for male fertility, it will be an attractive target for male contraceptive drugs due to its exclusive testis/sperm-specific expression.
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SLO3 in the fast lane: The latest male contraceptive target with a promising small-molecule inhibitor. Proc Natl Acad Sci U S A 2023; 120:e2221758120. [PMID: 36791103 PMCID: PMC9974486 DOI: 10.1073/pnas.2221758120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023] Open
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