1
|
Qu H, Zhen Y, Xu M, Huang Y, Wang Y, Ji G, Zhang Y, Li H, Dong Z, Zheng X. Structures of a sperm-specific sodium-hydrogen exchanger. CELL INSIGHT 2024; 3:100177. [PMID: 38957574 PMCID: PMC11214986 DOI: 10.1016/j.cellin.2024.100177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Revised: 05/21/2024] [Accepted: 05/21/2024] [Indexed: 07/04/2024]
Affiliation(s)
- Hongyuan Qu
- Academy of Medical Sciences, Tianjian Laboratory of Advanced Biomedical Sciences, State Key Laboratory of Esophageal Cancer Prevention and Treatment, Zhengzhou University, Zhengzhou, 450001, China
- State Key Laboratory of Molecular Oncology, MOE Key Laboratory of Protein Sciences, SXMU-Tsinghua Collaborative Innovation Center for Frontier Medicine, School of Medicine, Tsinghua University, Beijing, 100084, China
- Beijing Frontier Research Center for Biological Structure and Beijing Advanced Innovation Center for Structural Biology, Beijing, 100084, China
| | - Yi Zhen
- Academy of Medical Sciences, Tianjian Laboratory of Advanced Biomedical Sciences, State Key Laboratory of Esophageal Cancer Prevention and Treatment, Zhengzhou University, Zhengzhou, 450001, China
| | - Mohan Xu
- Academy of Medical Sciences, Tianjian Laboratory of Advanced Biomedical Sciences, State Key Laboratory of Esophageal Cancer Prevention and Treatment, Zhengzhou University, Zhengzhou, 450001, China
| | - Yan Huang
- Academy of Medical Sciences, Tianjian Laboratory of Advanced Biomedical Sciences, State Key Laboratory of Esophageal Cancer Prevention and Treatment, Zhengzhou University, Zhengzhou, 450001, China
- Key Laboratory of Geriatric Nutrition and Health, Beijing Technology and Business University, Beijing, 100048, China
| | - Yashu Wang
- Academy of Medical Sciences, Tianjian Laboratory of Advanced Biomedical Sciences, State Key Laboratory of Esophageal Cancer Prevention and Treatment, Zhengzhou University, Zhengzhou, 450001, China
| | - Gaoyuan Ji
- State Key Laboratory of Molecular Oncology, MOE Key Laboratory of Protein Sciences, SXMU-Tsinghua Collaborative Innovation Center for Frontier Medicine, School of Medicine, Tsinghua University, Beijing, 100084, China
- Beijing Frontier Research Center for Biological Structure and Beijing Advanced Innovation Center for Structural Biology, Beijing, 100084, China
| | - Yuyu Zhang
- Key Laboratory of Geriatric Nutrition and Health, Beijing Technology and Business University, Beijing, 100048, China
| | - Haitao Li
- State Key Laboratory of Molecular Oncology, MOE Key Laboratory of Protein Sciences, SXMU-Tsinghua Collaborative Innovation Center for Frontier Medicine, School of Medicine, Tsinghua University, Beijing, 100084, China
- Beijing Frontier Research Center for Biological Structure and Beijing Advanced Innovation Center for Structural Biology, Beijing, 100084, China
| | - Zigang Dong
- Academy of Medical Sciences, Tianjian Laboratory of Advanced Biomedical Sciences, State Key Laboratory of Esophageal Cancer Prevention and Treatment, Zhengzhou University, Zhengzhou, 450001, China
| | - Xiangdong Zheng
- Academy of Medical Sciences, Tianjian Laboratory of Advanced Biomedical Sciences, State Key Laboratory of Esophageal Cancer Prevention and Treatment, Zhengzhou University, Zhengzhou, 450001, China
| |
Collapse
|
2
|
Fakhro KA, Awwad J, Garibova S, Saraiva LR, Avella M. Conserved genes regulating human sex differentiation, gametogenesis and fertilization. J Transl Med 2024; 22:473. [PMID: 38764035 PMCID: PMC11103854 DOI: 10.1186/s12967-024-05162-2] [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: 03/05/2024] [Accepted: 04/03/2024] [Indexed: 05/21/2024] Open
Abstract
The study of the functional genome in mice and humans has been instrumental for describing the conserved molecular mechanisms regulating human reproductive biology, and for defining the etiologies of monogenic fertility disorders. Infertility is a reproductive disorder that includes various conditions affecting a couple's ability to achieve a healthy pregnancy. Recent advances in next-generation sequencing and CRISPR/Cas-mediated genome editing technologies have facilitated the identification and characterization of genes and mechanisms that, if affected, lead to infertility. We report established genes that regulate conserved functions in fundamental reproductive processes (e.g., sex determination, gametogenesis, and fertilization). We only cover genes the deletion of which yields comparable fertility phenotypes in both rodents and humans. In the case of newly-discovered genes, we report the studies demonstrating shared cellular and fertility phenotypes resulting from loss-of-function mutations in both species. Finally, we introduce new model systems for the study of human reproductive biology and highlight the importance of studying human consanguineous populations to discover novel monogenic causes of infertility. The rapid and continuous screening and identification of putative genetic defects coupled with an efficient functional characterization in animal models can reveal novel mechanisms of gene function in human reproductive tissues.
Collapse
Affiliation(s)
- Khalid A Fakhro
- Research Branch, Sidra Medicine, Doha, Qatar
- Weill Cornell Medicine, Doha, Qatar
- College of Health and Life Sciences, Hamad Bin Khalifa University, Doha, Qatar
| | - Johnny Awwad
- Reproductive Medicine Unit, Sidra Medicine, Doha, Qatar
- Obstetrics & Gynecology, American University of Beirut Medical Center, Beirut, Lebanon
- Vincent Memorial Obstetrics & Gynecology Service, The Massachusetts General Hospital, Boston, MA, USA
| | | | - Luis R Saraiva
- Research Branch, Sidra Medicine, Doha, Qatar
- College of Health and Life Sciences, Hamad Bin Khalifa University, Doha, Qatar
| | - Matteo Avella
- Research Branch, Sidra Medicine, Doha, Qatar.
- College of Health and Life Sciences, Hamad Bin Khalifa University, Doha, Qatar.
- Department of Biomedical Sciences, Qatar University, Doha, Qatar.
| |
Collapse
|
3
|
Chávez JC, Carrasquel-Martínez G, Hernández-Garduño S, Matamoros Volante A, Treviño CL, Nishigaki T, Darszon A. Cytosolic and Acrosomal pH Regulation in Mammalian Sperm. Cells 2024; 13:865. [PMID: 38786087 PMCID: PMC11120249 DOI: 10.3390/cells13100865] [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: 04/19/2024] [Revised: 05/07/2024] [Accepted: 05/09/2024] [Indexed: 05/25/2024] Open
Abstract
As in most cells, intracellular pH regulation is fundamental for sperm physiology. Key sperm functions like swimming, maturation, and a unique exocytotic process, the acrosome reaction, necessary for gamete fusion, are deeply influenced by pH. Sperm pH regulation, both intracellularly and within organelles such as the acrosome, requires a coordinated interplay of various transporters and channels, ensuring that this cell is primed for fertilization. Consistent with the pivotal importance of pH regulation in mammalian sperm physiology, several of its unique transporters are dependent on cytosolic pH. Examples include the Ca2+ channel CatSper and the K+ channel Slo3. The absence of these channels leads to male infertility. This review outlines the main transport elements involved in pH regulation, including cytosolic and acrosomal pH, that participate in these complex functions. We present a glimpse of how these transporters are regulated and how distinct sets of them are orchestrated to allow sperm to fertilize the egg. Much research is needed to begin to envision the complete set of players and the choreography of how cytosolic and organellar pH are regulated in each sperm function.
Collapse
Affiliation(s)
- Julio C. Chávez
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología (IBT), Universidad Nacional Autónoma de México (UNAM), Cuernavaca 62210, Morelos, Mexico; (J.C.C.); (G.C.-M.)
| | - Gabriela Carrasquel-Martínez
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología (IBT), Universidad Nacional Autónoma de México (UNAM), Cuernavaca 62210, Morelos, Mexico; (J.C.C.); (G.C.-M.)
- CITMER, Medicina Reproductiva, México City 11520, Mexico
| | - Sandra Hernández-Garduño
- Departamento de Morfología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México (UNAM), México City 04510, Mexico;
| | - Arturo Matamoros Volante
- Department of Electrical and Computer Engineering and School of Biomedical Engineering, Colorado State University, Fort Collins, CO 80523, USA;
| | - Claudia L. Treviño
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología (IBT), Universidad Nacional Autónoma de México (UNAM), Cuernavaca 62210, Morelos, Mexico; (J.C.C.); (G.C.-M.)
| | - Takuya Nishigaki
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología (IBT), Universidad Nacional Autónoma de México (UNAM), Cuernavaca 62210, Morelos, Mexico; (J.C.C.); (G.C.-M.)
| | - Alberto Darszon
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología (IBT), Universidad Nacional Autónoma de México (UNAM), Cuernavaca 62210, Morelos, Mexico; (J.C.C.); (G.C.-M.)
| |
Collapse
|
4
|
Liang M, Ji N, Song J, Kang H, Zeng X. Flagellar pH homeostasis mediated by Na+/H+ exchangers regulates human sperm functions through coupling with CatSper and KSper activation. Hum Reprod 2024; 39:674-688. [PMID: 38366201 DOI: 10.1093/humrep/deae020] [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: 09/02/2023] [Revised: 01/19/2024] [Indexed: 02/18/2024] Open
Abstract
STUDY QUESTION Whether and how do Na+/H+ exchangers (NHEs) regulate the physiological functions of human sperm? SUMMARY ANSWER NHE-mediated flagellar intracellular pH (pHi) homeostasis facilitates the activation of the pH-sensitive, sperm-specific Ca2+ channel (CatSper) and the sperm-specific K+ channel (KSper), which subsequently modulate sperm motility, hyperactivation, flagellar tyrosine phosphorylation, and the progesterone (P4)-induced acrosome reaction. WHAT IS KNOWN ALREADY Sperm pHi alkalization is an essential prerequisite for the acquisition of sperm-fertilizing capacity. Different sperm functions are strictly controlled by particular pHi regulatory mechanisms. NHEs are suggested to modulate sperm H+ efflux. STUDY DESIGN, SIZE, DURATION This was a laboratory study that used samples from >50 sperm donors over a period of 1 year. To evaluate NHE action on human sperm function, 5-(N,N-dimethyl)-amiloride (DMA), a highly selective inhibitor of NHEs, was utilized. All experiments were repeated at least five times using different individual sperm samples or cells. PARTICIPANTS/MATERIALS, SETTING, METHODS By utilizing the pH fluorescent indicator pHrodo Red-AM, we detected alterations in single-cell pHi value in human sperm. The currents of CatSper and KSper in human sperm were recorded by the whole-cell patch-clamp technique. Changes in population and single-cell Ca2+ concentrations ([Ca2+]i) of human sperm loaded with Fluo 4-AM were measured. Membrane potential (Vm) and population pHi were quantitatively examined by a multimode plate reader after sperm were loaded with 3,3'-dipropylthiadicarbocyanine iodide and 2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein, acetoxymethyl ester, respectively. Sperm motility parameters were assessed by a computer-assisted semen analysis system. Tyrosine phosphorylation was determined by immunofluorescence, and sperm acrosome reaction was evaluated by Pisum sativum agglutinin-FITC staining. MAIN RESULTS AND THE ROLE OF CHANCE DMA-induced NHEs inhibition severely acidified the human sperm flagellar pHi from 7.20 ± 0.04 to 6.38 ± 0.12 (mean ± SEM), while the effect of DMA on acrosomal pHi was less obvious (from 5.90 ± 0.13 to 5.57 ± 0.12, mean ± SEM). The whole-cell patch-clamp recordings revealed that NHE inhibition remarkably suppressed alkalization-induced activation of CatSper and KSper. As a consequence, impairment of [Ca2+]i homeostasis and Vm maintenance were detected in the presence of DMA. During the capacitation process, pre-treatment with DMA for 2 h potently decreased sperm pHi, which in turn decreased sperm motility and kinetic parameters. Sperm capacitation-associated functions, including hyperactivation, tyrosine phosphorylation, and P4-induced acrosome reaction, were also compromised by NHE inhibition. LARGE SCALE DATA N/A. LIMITATIONS, REASONS FOR CAUTION This was an in vitro study. Caution should be taken when extrapolating these results to in vivo applications. WIDER IMPLICATIONS OF THE FINDINGS This study revealed that NHEs are important physiological regulators for human CatSper and KSper, which are indispensable for human sperm fertility, suggesting that malfunction of NHEs could be an underlying mechanism for the pathogenesis of male infertility. FUNDING/COMPETING INTEREST(S) This work was supported by the National Natural Science Foundation of China (32271167 and 81871202 to X.Z.), Jiangsu Innovation and Entrepreneurship Talent Plan (JSSCRC20211543 to X.Z.), the Social Development Project of Jiangsu Province (No. BE2022765 to X.Z.), the Society and livelihood Project of Nantong City (No. MS22022087 to X.Z.), and the Natural Science Foundation of Jiangsu Province (BK20220608 to H.K.). The authors have no competing interests to declare.
Collapse
Affiliation(s)
- Min Liang
- Institute of Reproductive Medicine, Medical School of Nantong University, Nantong, China
| | - Nanxi Ji
- Institute of Reproductive Medicine, Medical School of Nantong University, Nantong, China
| | - Jian Song
- Department of Obstetrics and Gynecology, Center of Reproductive Medicine, Affiliated Hospital of Nantong University, Nantong, China
| | - Hang Kang
- Institute of Reproductive Medicine, Medical School of Nantong University, Nantong, China
| | - Xuhui Zeng
- Institute of Reproductive Medicine, Medical School of Nantong University, Nantong, China
| |
Collapse
|
5
|
Novero AG, Rodríguez PT, De la Vega Beltrán JL, Schiavi-Ehrenhaus LJ, Luque GM, Carruba M, Stival C, Gentile I, Ritagliati C, Santi CM, Nishigaki T, Krapf D, Buffone MG, Darszon A, Treviño CL, Krapf D. The sodium-proton exchangers sNHE and NHE1 control plasma membrane hyperpolarization in mouse sperm. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.04.583310. [PMID: 38496535 PMCID: PMC10942401 DOI: 10.1101/2024.03.04.583310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
Sperm capacitation, crucial for fertilization, occurs in the female reproductive tract and can be replicated in vitro using a medium rich in bicarbonate, calcium, and albumin. These components trigger the cAMP-PKA signaling cascade, proposed to promote hyperpolarization of the mouse sperm plasma membrane through activation of SLO3 K+ channel. Hyperpolarization is a hallmark of capacitation: proper membrane hyperpolarization renders higher in vitro fertilizing ability, while Slo3 KO mice are infertile. However, the precise regulation of SLO3 opening remains elusive. Our study challenges the involvement of PKA in this event and reveals the role of Na+/H+ exchangers. During capacitation, calcium increase through CatSper channels activates NHE1, while cAMP directly stimulates the sperm-specific NHE, collectively promoting the alkalinization threshold needed for SLO3 opening. Hyperpolarization then feeds back Na+/H+ activity. Our work is supported by pharmacology, and a plethora of KO mouse models, and proposes a novel pathway leading to hyperpolarization.
Collapse
Affiliation(s)
- Analia G Novero
- Instituto de Biología Molecular y Celular de Rosario, CONICET-UNR, and Laboratorio de Medicina Reproductiva, Facultad de Ciencias Bioquímicas y Farmacéuticas, UNR, Rosario SF2000, Argentina
| | | | | | - Liz J Schiavi-Ehrenhaus
- Instituto de Bíologia y Medicina Experimental (IBYME-CONICET), Ciudad Autónoma de Buenos Aires, Argentina
| | - Guillermina M Luque
- Instituto de Bíologia y Medicina Experimental (IBYME-CONICET), Ciudad Autónoma de Buenos Aires, Argentina
| | - Micaela Carruba
- Instituto de Biología Molecular y Celular de Rosario, CONICET-UNR, and Laboratorio de Medicina Reproductiva, Facultad de Ciencias Bioquímicas y Farmacéuticas, UNR, Rosario SF2000, Argentina
| | - Cintia Stival
- Instituto de Biología Molecular y Celular de Rosario, CONICET-UNR, and Laboratorio de Medicina Reproductiva, Facultad de Ciencias Bioquímicas y Farmacéuticas, UNR, Rosario SF2000, Argentina
| | - Iñaki Gentile
- Instituto de Biología Molecular y Celular de Rosario, CONICET-UNR, and Laboratorio de Medicina Reproductiva, Facultad de Ciencias Bioquímicas y Farmacéuticas, UNR, Rosario SF2000, Argentina
| | - Carla Ritagliati
- Instituto de Biología Molecular y Celular de Rosario, CONICET-UNR, and Laboratorio de Medicina Reproductiva, Facultad de Ciencias Bioquímicas y Farmacéuticas, UNR, Rosario SF2000, Argentina
| | - Celia M Santi
- Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis Missouri 63110, USA
| | | | - Diego Krapf
- Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, CO 80526, USA
| | - Mariano G Buffone
- Instituto de Bíologia y Medicina Experimental (IBYME-CONICET), Ciudad Autónoma de Buenos Aires, Argentina
| | | | | | - Dario Krapf
- Instituto de Biología Molecular y Celular de Rosario, CONICET-UNR, and Laboratorio de Medicina Reproductiva, Facultad de Ciencias Bioquímicas y Farmacéuticas, UNR, Rosario SF2000, Argentina
| |
Collapse
|
6
|
Gardner CC, Abele JA, Winkler TJ, Reckers CN, Anas SA, James PF. Common as well as unique methylation-sensitive DNA regulatory elements in three mammalian SLC9C1 genes. Gene 2024; 893:147897. [PMID: 37832806 PMCID: PMC10841394 DOI: 10.1016/j.gene.2023.147897] [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: 08/09/2023] [Revised: 10/04/2023] [Accepted: 10/10/2023] [Indexed: 10/15/2023]
Abstract
The SLC9C1 gene (which encodes the NHE10 protein) is essential for male fertility in both mice and humans, however the epigenetic mechanisms regulating its testis/sperm-specific gene expression have yet to be studied. Here we identify and characterize DNA regulatory elements of the SLC9C1 gene across three mammalian species: mouse, rat, and human. First, in silico analysis of these mammalian SLC9C1 genes identified a CpG island located upstream of the transcription start site in the same relative position in all three genes. Further analysis reveals that this CpG island behaves differently, with respect to gene regulatory activity, in the mouse SLC9C1 gene than it does in the rat and human SLC9C1 gene. The mouse SLC9C1 CpG island displays strong promoter activity by itself and seems to have a stronger gene regulatory effect than either the rat or human SLC9C1 CpG islands. While the function of the upstream SLC9C1 CpG island may be divergent across the three studied species, it appears that the promoters of these three mammalian SLC9C1 genes share similar DNA methylation-sensitive regulatory mechanisms. All three SLC9C1 promoter regions are differentially methylated in lung and testis, being more hypermethylated in lung relative to the testis, and DNA sequence alignments provide strong evidence of primary sequence conservation. Luciferase assays reveal that in vitro methylation of constructs containing different elements of the three SLC9C1 genes largely exhibit methylation-sensitive promoter activity (reduced promoter activity when methylated) in both HEK 293 and GC-1spg cells. In total, our data suggest that the DNA methylation-sensitive elements of the mouse, rat, and human SLC9C1 promoters are largely conserved, while the upstream SLC9C1 CpG island common to all three species seems to perform a different function in mouse than it does in rat and human. This work provides evidence that while homologous genes can all be regulated by DNA methylation-dependent epigenetic mechanisms, the location of the specific cis-regulatory elements responsible for this regulation can differ across species.
Collapse
Affiliation(s)
| | - Jason A Abele
- Department of Biology, Miami University, Oxford, OH 45056, USA
| | | | | | - Sydney A Anas
- Department of Biology, Miami University, Oxford, OH 45056, USA
| | - Paul F James
- Department of Biology, Miami University, Oxford, OH 45056, USA.
| |
Collapse
|
7
|
Arcos-Hernández C, Nishigaki T. Ion currents through the voltage sensor domain of distinct families of proteins. J Biol Phys 2023; 49:393-413. [PMID: 37851173 PMCID: PMC10651576 DOI: 10.1007/s10867-023-09645-z] [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: 04/28/2023] [Accepted: 09/11/2023] [Indexed: 10/19/2023] Open
Abstract
The membrane potential of a cell (Vm) regulates several physiological processes. The voltage sensor domain (VSD) is a region that confers voltage sensitivity to different types of transmembrane proteins such as the following: voltage-gated ion channels, the voltage-sensing phosphatase (Ci-VSP), and the sperm-specific Na+/H+ exchanger (sNHE). VSDs contain four transmembrane segments (S1-S4) and several positively charged amino acids in S4, which are essential for the voltage sensitivity of the protein. Generally, in response to changes of the Vm, the positive residues of S4 displace along the plasma membrane without generating ionic currents through this domain. However, some native (e.g., Hv1 channel) and mutants of VSDs produce ionic currents. These gating pore currents are usually observed in VSDs that lack one or more of the conserved positively charged amino acids in S4. The gating pore currents can also be induced by the isolation of a VSD from the rest of the protein domains. In this review, we summarize gating pore currents from all families of proteins with VSDs with classification into three cases: (1) pathological, (2) physiological, and (3) artificial currents. We reinforce the model in which the position of S4 that lacks the positively charged amino acid determines the voltage dependency of the gating pore current of all VSDs independent of protein families.
Collapse
Affiliation(s)
- César Arcos-Hernández
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62210, Mexico.
| | - Takuya Nishigaki
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62210, Mexico
| |
Collapse
|
8
|
Yeo H, Mehta V, Gulati A, Drew D. Structure and electromechanical coupling of a voltage-gated Na +/H + exchanger. Nature 2023; 623:193-201. [PMID: 37880360 PMCID: PMC10620092 DOI: 10.1038/s41586-023-06518-2] [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: 04/18/2023] [Accepted: 08/04/2023] [Indexed: 10/27/2023]
Abstract
Voltage-sensing domains control the activation of voltage-gated ion channels, with a few exceptions1. One such exception is the sperm-specific Na+/H+ exchanger SLC9C1, which is the only known transporter to be regulated by voltage-sensing domains2-5. After hyperpolarization of sperm flagella, SLC9C1 becomes active, causing pH alkalinization and CatSper Ca2+ channel activation, which drives chemotaxis2,6. SLC9C1 activation is further regulated by cAMP2,7, which is produced by soluble adenyl cyclase (sAC). SLC9C1 is therefore an essential component of the pH-sAC-cAMP signalling pathway in metazoa8,9, required for sperm motility and fertilization4. Despite its importance, the molecular basis of SLC9C1 voltage activation is unclear. Here we report cryo-electron microscopy (cryo-EM) structures of sea urchin SLC9C1 in detergent and nanodiscs. We show that the voltage-sensing domains are positioned in an unusual configuration, sandwiching each side of the SLC9C1 homodimer. The S4 segment is very long, 90 Å in length, and connects the voltage-sensing domains to the cytoplasmic cyclic-nucleotide-binding domains. The S4 segment is in the up configuration-the inactive state of SLC9C1. Consistently, although a negatively charged cavity is accessible for Na+ to bind to the ion-transporting domains of SLC9C1, an intracellular helix connected to S4 restricts their movement. On the basis of the differences in the cryo-EM structure of SLC9C1 in the presence of cAMP, we propose that, upon hyperpolarization, the S4 segment moves down, removing this constriction and enabling Na+/H+ exchange.
Collapse
Affiliation(s)
- Hyunku Yeo
- Department of Biochemistry and Biophysics, Science for Life Laboratory, Stockholm University, Stockholm, Sweden
| | - Ved Mehta
- Department of Biochemistry and Biophysics, Science for Life Laboratory, Stockholm University, Stockholm, Sweden
| | - Ashutosh Gulati
- Department of Biochemistry and Biophysics, Science for Life Laboratory, Stockholm University, Stockholm, Sweden
| | - David Drew
- Department of Biochemistry and Biophysics, Science for Life Laboratory, Stockholm University, Stockholm, Sweden.
| |
Collapse
|
9
|
Orlowski J. An ion transporter in sperm that has features of a channel. Nature 2023; 623:38-40. [PMID: 37880527 DOI: 10.1038/d41586-023-03154-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2023]
|
10
|
Kalienkova V, Peter MF, Rheinberger J, Paulino C. Structures of a sperm-specific solute carrier gated by voltage and cAMP. Nature 2023; 623:202-209. [PMID: 37880361 PMCID: PMC10620091 DOI: 10.1038/s41586-023-06629-w] [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: 06/27/2023] [Accepted: 09/08/2023] [Indexed: 10/27/2023]
Abstract
The newly characterized sperm-specific Na+/H+ exchanger stands out by its unique tripartite domain composition1,2. It unites a classical solute carrier unit with regulatory domains usually found in ion channels, namely, a voltage-sensing domain and a cyclic-nucleotide binding domain1,3, which makes it a mechanistic chimera and a secondary-active transporter activated strictly by membrane voltage. Our structures of the sea urchin SpSLC9C1 in the absence and presence of ligands reveal the overall domain arrangement and new structural coupling elements. They allow us to propose a gating model, where movements in the voltage sensor indirectly cause the release of the exchanging unit from a locked state through long-distance allosteric effects transmitted by the newly characterized coupling helices. We further propose that modulation by its ligand cyclic AMP occurs by means of disruption of the cytosolic dimer interface, which lowers the energy barrier for S4 movements in the voltage-sensing domain. As SLC9C1 members have been shown to be essential for male fertility, including in mammals2,4,5, our structure represents a potential new platform for the development of new on-demand contraceptives.
Collapse
Affiliation(s)
- Valeria Kalienkova
- Groningen Biomolecular Sciences and Biotechnology, University of Groningen, Groningen, The Netherlands
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Martin F Peter
- Groningen Biomolecular Sciences and Biotechnology, University of Groningen, Groningen, The Netherlands
- Biochemistry Center, Heidelberg University, Heidelberg, Germany
| | - Jan Rheinberger
- Biochemistry Center, Heidelberg University, Heidelberg, Germany
| | - Cristina Paulino
- Groningen Biomolecular Sciences and Biotechnology, University of Groningen, Groningen, The Netherlands.
- Biochemistry Center, Heidelberg University, Heidelberg, Germany.
| |
Collapse
|
11
|
Chowdhury S, Pal K. Architecture and rearrangements of a sperm-specific Na +/H + exchanger. RESEARCH SQUARE 2023:rs.3.rs-3396005. [PMID: 37886505 PMCID: PMC10602139 DOI: 10.21203/rs.3.rs-3396005/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2023]
Abstract
The sperm-specific sodium hydrogen exchanger, SLC9C1, underlies hyperpolarization and cyclic nucleotide stimulated proton fluxes across sperm membranes and regulates their hyperactivated motility. SLC9C1 is the first known instance of an ion transporter that uses a canonical voltage-sensing domain (VSD) and an evolutionarily conserved cyclic nucleotide binding domain (CNBD) to influence the dynamics of its ion-exchange domain (ED). The structural organization of this 'tripartite transporter' and the mechanisms whereby it integrates physical (membrane voltage) and chemical (cyclic nucleotide) cues are unknown. In this study, we use single particle cryo-electron microscopy to determine structures of a metazoan SLC9C1 in different conformational states. We find that the three structural domains are uniquely organized around a distinct ring-shaped scaffold that we call the 'allosteric ring domain' or ARD. The ARD undergoes coupled proton-dependent rearrangements with the ED and acts as a 'signaling hub' enabling allosteric communication between the key functional modules of sp9C1. We demonstrate that binding of cAMP causes large conformational changes in the cytoplasmic domains and disrupts key ARD-linked interfaces. We propose that these structural changes rescue the transmembrane domains from an auto-inhibited state and facilitate their functional dynamics. Our study provides a structural framework to understand and further probe electrochemical linkage in SLC9C1.
Collapse
|
12
|
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.
Collapse
Affiliation(s)
| | - Paul F. James
- Department of Biology, Miami University, Oxford, OH 45056, USA;
| |
Collapse
|
13
|
Benko F, Urminská D, Ďuračka M, Tvrdá E. Signaling Roleplay between Ion Channels during Mammalian Sperm Capacitation. Biomedicines 2023; 11:2519. [PMID: 37760960 PMCID: PMC10525812 DOI: 10.3390/biomedicines11092519] [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: 07/30/2023] [Revised: 08/31/2023] [Accepted: 09/06/2023] [Indexed: 09/29/2023] Open
Abstract
In order to accomplish their primary goal, mammalian spermatozoa must undergo a series of physiological, biochemical, and functional changes crucial for the acquisition of fertilization ability. Spermatozoa are highly polarized cells, which must swiftly respond to ionic changes on their passage through the female reproductive tract, and which are necessary for male gametes to acquire their functional competence. This review summarizes the current knowledge about specific ion channels and transporters located in the mammalian sperm plasma membrane, which are intricately involved in the initiation of changes within the ionic milieu of the sperm cell, leading to variations in the sperm membrane potential, membrane depolarization and hyperpolarization, changes in sperm motility and capacitation to further lead to the acrosome reaction and sperm-egg fusion. We also discuss the functionality of selected ion channels in male reproductive health and/or disease since these may become promising targets for clinical management of infertility in the future.
Collapse
Affiliation(s)
- Filip Benko
- Institute of Biotechnology, Faculty of Biotechnology and Food Sciences, Slovak University of Agriculture in Nitra, Tr. A. Hlinku 2, 949 76 Nitra, Slovakia; (D.U.); (E.T.)
| | - Dana Urminská
- Institute of Biotechnology, Faculty of Biotechnology and Food Sciences, Slovak University of Agriculture in Nitra, Tr. A. Hlinku 2, 949 76 Nitra, Slovakia; (D.U.); (E.T.)
| | - Michal Ďuračka
- AgroBioTech Research Centre, Slovak University of Agriculture in Nitra, Tr. A. Hlinku 2, 949 76 Nitra, Slovakia;
| | - Eva Tvrdá
- Institute of Biotechnology, Faculty of Biotechnology and Food Sciences, Slovak University of Agriculture in Nitra, Tr. A. Hlinku 2, 949 76 Nitra, Slovakia; (D.U.); (E.T.)
| |
Collapse
|
14
|
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.
Collapse
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
| |
Collapse
|
15
|
Sahoo B, Gupta MK. Effect of arginine-induced motility and capacitation on RNA population in goat spermatozoa. Vet Res Commun 2023; 47:1427-1444. [PMID: 37162640 DOI: 10.1007/s11259-023-10092-3] [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: 12/01/2022] [Accepted: 02/26/2023] [Indexed: 05/11/2023]
Abstract
INTRODUCTION In vitro capacitation is essential in assisted reproductive technologies (ART) for embryo production. Recently, arginine has been proven to enhance capacitation in mammalian spermatozoa. However, the detailed mechanism of action of arginine remains elusive. AIM This study investigated the effect of arginine-induced capacitation and motility enhancement on the spermatozoal RNA (spRNA) population in goats. MATERIAL AND METHODS Goat spermatozoa were treated with arginine for up to six hours and compared with non-treated or PHE (penicillamine, hypotaurine, and epinephrine)-treated spermatozoa at different intervals (0, 1, 2, 4, and 6 hours). Sperm parameters, including viability, individual motility, capacitation, acrosome reaction, and ROS production, were evaluated. The spRNA population was analyzed by short-read RNA sequencing (RNA-seq). RESULTS The percentage of capacitated (73.21 ± 4.22%) and acrosome reacted (18.35 ± 0.56%) spermatozoa was highest in arginine treatment, while PHE treatment showed the highest percentage (79.82 ± 4.31%) of motile spermatozoa from 0 to 4 hours of incubation. RNA-seq analysis identified 1,321 differentially expressed genes (DEGs) in arginine-treated spermatozoa compared to the control. The PGK2, RNASE10, ODF1, and ROPN1L genes involved in sperm motility and ACR, DKKL1, KCNJ11, and PRND genes involved in the capacitation process were upregulated in arginine-treated spermatozoa. The DEGs regulate sperm capacitation-related cAMP-PKA, PI3-Akt, calcium, and MAPK signaling pathways. CONCLUSION The arginine-induced capacitation and enhanced sperm motility were associated with the upregulation of several genes involved in sperm motility and capacitation pathways. The comparative study also suggests that arginine may be used in lieu of PHE for motility enhancement and in vitro capacitation of goat spermatozoa.
Collapse
Affiliation(s)
- Bijayalaxmi Sahoo
- Gene Manipulation Laboratory, Centre for Bioinformatics and Computational Biology, Department of Biotechnology and Medical Engineering, National Institute of Technology Rourkela, Rourkela, Odisha, 769 008, India
| | - Mukesh Kumar Gupta
- Gene Manipulation Laboratory, Centre for Bioinformatics and Computational Biology, Department of Biotechnology and Medical Engineering, National Institute of Technology Rourkela, Rourkela, Odisha, 769 008, India.
| |
Collapse
|
16
|
Gardner CC, Abele JA, Winkler TJ, Reckers CN, Anas SA, James PF. Common as well as unique methylation-sensitive DNA regulatory elements in three mammalian SLC9C1 genes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.29.555319. [PMID: 37693488 PMCID: PMC10491193 DOI: 10.1101/2023.08.29.555319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
The SLC9C1 gene (which encodes the NHE10 protein) is essential for male fertility in both mice and humans, however the epigenetic mechanisms regulating its testis/sperm-specific gene expression have yet to be studied. Here we identify and characterize DNA regulatory elements of the SLC9C1 gene across three mammalian species: mouse, rat, and human. First, in silico analysis of these mammalian SLC9C1 genes identified a CpG island located upstream of the transcription start site in the same relative position in all three genes. Further analysis reveals that this CpG island behaves differently, with respect to gene regulatory activity, in the mouse SLC9C1 gene than it does in the rat and human SLC9C1 gene. The mouse SLC9C1 CpG island displays strong promoter activity by itself and seems to have a stronger gene regulatory effect than either the rat or human SLC9C1 CpG islands. While the function of the upstream SLC9C1 CpG island may be divergent across the three studied species, it appears that the promoters of these three mammalian SLC9C1 genes share similar DNA methylation-sensitive regulatory mechanisms. All three SLC9C1 promoter regions are differentially methylated in lung and testis, being more hypermethylated in lung relative to the testis, and DNA sequence alignments provide strong evidence of primary sequence conservation. Luciferase assays reveal that in vitro methylation of constructs containing different elements of the three SLC9C1 genes largely exhibit methylation-sensitive promoter activity (reduced promoter activity when methylated) in both HEK 293 and GC-1spg cells. In total, our data suggest that the DNA methylation-sensitive elements of the mouse, rat, and human SLC9C1 promoters are largely conserved, while the upstream SLC9C1 CpG island common to all three species seems to perform a different function in mouse than it does in rat and human. This work provides evidence that while homologous genes can all be regulated by DNA methylation-dependent epigenetic mechanisms, the location of the specific cis-regulatory elements responsible for this regulation can differ across species.
Collapse
|
17
|
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.
Collapse
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
| |
Collapse
|
18
|
Abstract
Reproduction involves a wide range of biological processes, including organ formation and development, neuroendocrine regulation, hormone production, and meiosis and mitosis. Infertility, the failure of reproduction, has become a major issue for human reproductive health and affects up to one in seven couples worldwide. Here, we review various aspects of human infertility, including etiology, mechanisms, and treatments, with a particular emphasis on genetics. We focus on gamete production and gamete quality, which is the core of successful reproduction. We also discuss future research opportunities and challenges to further expand our understanding of human infertility and improve patient care by providing precision diagnosis and personalized treatments.
Collapse
Affiliation(s)
- Qing Sang
- Institute of Pediatrics, Children's Hospital of Fudan University and Institutes of Biomedical Sciences, the State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Medical Epigenetics, Fudan University, Shanghai 200032, China
| | - Pierre F Ray
- Université Grenoble Alpes, INSERM U1209, CNRS UMR 5309, Team Genetics Epigenetics and Therapies of Infertility, Institute for Advanced Biosciences, 380000 Grenoble, France
| | - Lei Wang
- Institute of Pediatrics, Children's Hospital of Fudan University and Institutes of Biomedical Sciences, the State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Medical Epigenetics, Fudan University, Shanghai 200032, China
| |
Collapse
|
19
|
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.
Collapse
|
20
|
How to study a highly toxic protein to bacteria: A case of voltage sensor domain of mouse sperm-specific sodium/proton exchanger. Protein Expr Purif 2023; 201:106172. [DOI: 10.1016/j.pep.2022.106172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 08/30/2022] [Accepted: 09/09/2022] [Indexed: 11/21/2022]
|
21
|
Cordero-Martínez J, Jimenez-Gutierrez GE, Aguirre-Alvarado C, Alacántara-Farfán V, Chamorro-Cevallos G, Roa-Espitia AL, Hernández-González EO, Rodríguez-Páez L. Participation of signaling proteins in sperm hyperactivation. Syst Biol Reprod Med 2022; 68:315-330. [DOI: 10.1080/19396368.2022.2122761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Affiliation(s)
- Joaquín Cordero-Martínez
- Laboratorio de Bioquímica Farmacológica, Departamento de Bioquímica, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México, Mexico
| | | | - Charmina Aguirre-Alvarado
- Laboratorio de Bioquímica Farmacológica, Departamento de Bioquímica, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México, Mexico
- Unidad de Investigación Médica en Inmunología e Infectología Centro Médico Nacional La Raza, IMSS, Ciudad de México, Mexico
| | - Verónica Alacántara-Farfán
- Laboratorio de Bioquímica Farmacológica, Departamento de Bioquímica, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México, Mexico
| | - Germán Chamorro-Cevallos
- Laboratorio de Toxicología Preclínica Departamento de Farmacia Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México, Mexico
| | - Ana L. Roa-Espitia
- Departamento de Biología Celular Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional, Instituto Politécnico Nacional, México City, Mexico
| | - Enrique O. Hernández-González
- Departamento de Biología Celular Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional, Instituto Politécnico Nacional, México City, Mexico
| | - Lorena Rodríguez-Páez
- Laboratorio de Bioquímica Farmacológica, Departamento de Bioquímica, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México, Mexico
| |
Collapse
|
22
|
Prokaryotic Na+/H+ Exchangers—Transport Mechanism and Essential Residues. Int J Mol Sci 2022; 23:ijms23169156. [PMID: 36012428 PMCID: PMC9408914 DOI: 10.3390/ijms23169156] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 08/09/2022] [Accepted: 08/13/2022] [Indexed: 11/16/2022] Open
Abstract
Na+/H+ exchangers are essential for Na+ and pH homeostasis in all organisms. Human Na+/H+ exchangers are of high medical interest, and insights into their structure and function are aided by the investigation of prokaryotic homologues. Most prokaryotic Na+/H+ exchangers belong to either the Cation/Proton Antiporter (CPA) superfamily, the Ion Transport (IT) superfamily, or the Na+-translocating Mrp transporter superfamily. Several structures have been solved so far for CPA and Mrp members, but none for the IT members. NhaA from E. coli has served as the prototype of Na+/H+ exchangers due to the high amount of structural and functional data available. Recent structures from other CPA exchangers, together with diverse functional information, have allowed elucidation of some common working principles shared by Na+/H+ exchangers from different families, such as the type of residues involved in the substrate binding and even a simple mechanism sufficient to explain the pH regulation in the CPA and IT superfamilies. Here, we review several aspects of prokaryotic Na+/H+ exchanger structure and function, discussing the similarities and differences between different transporters, with a focus on the CPA and IT exchangers. We also discuss the proposed transport mechanisms for Na+/H+ exchangers that explain their highly pH-regulated activity profile.
Collapse
|
23
|
Hernández-Garduño S, Chavez JC, Matamoros-Volante A, Sánchez-Guevara Y, Torres P, Treviño CL, Nishigaki T. Hyperpolarization induces cytosolic alkalization of mouse sperm flagellum probably through sperm Na+/H+ exchanger. Reproduction 2022; 164:125-134. [PMID: 35900329 DOI: 10.1530/rep-22-0101] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 07/19/2022] [Indexed: 11/08/2022]
Abstract
The sperm-specific sodium/proton exchanger (sNHE) is an indispensable protein for male fertility in mammals. Nevertheless, it is still unknown how mammalian sNHE is regulated. Evidence obtained from sea urchin sNHE indicates that hyperpolarization of plasma membrane potential (Vm), which is a hallmark of mammalian capacitation, positively regulates the sNHE. Therefore, we explored the activity of sNHE in mouse and human sperm by fluorescence imaging of intracellular pH (pHi) with a ratiometric dye, SNARF-5F. A valinomycin-induced Vm hyperpolarization elevated sperm flagellar pHi of wild-type mouse, but not in sNHE-KO mouse. Moreover, this pHi increase was inhibited in a high K+ (40 mM) medium. These results support the idea that mouse sNHE is activated by Vm hyperpolarization. Interestingly, we observed different types of kinetics derived from valinomycin-induced alkalization, including some (30 %) without any pHi changes. Our quantitative pHi determinations revealed that unresponsive cells had a high resting pHi (> 7.5), suggesting that the activity of mouse sNHE is regulated by the resting pHi. On the other hand, valinomycin did not increase the pHi of human sperm in the head or the flagellum, regardless of their resting pHi values. Our findings suggest that the regulatory mechanisms of mammalian sNHEs are probably distinct depending on the species.
Collapse
Affiliation(s)
- Sandra Hernández-Garduño
- S Hernández-Garduño, Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología UNAM, Cuernavaca, Mexico
| | - Julio C Chavez
- J Chavez, Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología UNAM, Cuernavaca, Mexico
| | - Arturo Matamoros-Volante
- A Matamoros-Volante, Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología UNAM, Cuernavaca, Mexico
| | - Yoloxochitl Sánchez-Guevara
- Y Sánchez-Guevara, Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología UNAM, Cuernavaca, Mexico
| | - Paulina Torres
- P Torres, Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología UNAM, Cuernavaca, Mexico
| | - Claudia L Treviño
- C Treviño, Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología UNAM, Cuernavaca, Mexico
| | - Takuya Nishigaki
- T Nishigaki, Genetica del Desarrollo y Fisiologia Molecular, Instituto de Biotecnologia UNAM, Cuernavaca, 62210, Mexico
| |
Collapse
|
24
|
Delgado-Bermúdez A, Yeste M, Bonet S, Pinart E. A Review on the Role of Bicarbonate and Proton Transporters during Sperm Capacitation in Mammals. Int J Mol Sci 2022; 23:ijms23116333. [PMID: 35683013 PMCID: PMC9180951 DOI: 10.3390/ijms23116333] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 06/01/2022] [Accepted: 06/05/2022] [Indexed: 12/14/2022] Open
Abstract
Alkalinization of sperm cytosol is essential for plasma membrane hyperpolarization, hyperactivation of motility, and acrosomal exocytosis during sperm capacitation in mammals. The plasma membrane of sperm cells contains different ion channels implicated in the increase of internal pH (pHi) by favoring either bicarbonate entrance or proton efflux. Bicarbonate transporters belong to the solute carrier families 4 (SLC4) and 26 (SLC26) and are currently grouped into Na+/HCO3− transporters and Cl−/HCO3− exchangers. Na+/HCO3− transporters are reported to be essential for the initial and fast entrance of HCO3− that triggers sperm capacitation, whereas Cl−/HCO3− exchangers are responsible for the sustained HCO3− entrance which orchestrates the sequence of changes associated with sperm capacitation. Proton efflux is required for the fast alkalinization of capacitated sperm cells and the activation of pH-dependent proteins; according to the species, this transport can be mediated by Na+/H+ exchangers (NHE) belonging to the SLC9 family and/or voltage-gated proton channels (HVCN1). Herein, we discuss the involvement of each of these channels in sperm capacitation and the acrosome reaction.
Collapse
Affiliation(s)
- Ariadna Delgado-Bermúdez
- Biotechnology of Animal and Human Reproduction (TechnoSperm), Institute of Food and Agricultural Technology, University of Girona, ES-17003 Girona, Spain; (A.D.-B.); (M.Y.); (S.B.)
- Unit of Cell Biology, Department of Biology, Faculty of Sciences, University of Girona, ES-17003 Girona, Spain
| | - Marc Yeste
- Biotechnology of Animal and Human Reproduction (TechnoSperm), Institute of Food and Agricultural Technology, University of Girona, ES-17003 Girona, Spain; (A.D.-B.); (M.Y.); (S.B.)
- Unit of Cell Biology, Department of Biology, Faculty of Sciences, University of Girona, ES-17003 Girona, Spain
- Catalan Institution for Research and Advanced Studies (ICREA), ES-08010 Barcelona, Spain
| | - Sergi Bonet
- Biotechnology of Animal and Human Reproduction (TechnoSperm), Institute of Food and Agricultural Technology, University of Girona, ES-17003 Girona, Spain; (A.D.-B.); (M.Y.); (S.B.)
- Unit of Cell Biology, Department of Biology, Faculty of Sciences, University of Girona, ES-17003 Girona, Spain
| | - Elisabeth Pinart
- Biotechnology of Animal and Human Reproduction (TechnoSperm), Institute of Food and Agricultural Technology, University of Girona, ES-17003 Girona, Spain; (A.D.-B.); (M.Y.); (S.B.)
- Unit of Cell Biology, Department of Biology, Faculty of Sciences, University of Girona, ES-17003 Girona, Spain
- Correspondence: ; Tel.: +34-972-419-514
| |
Collapse
|
25
|
Gao AYL, Lourdin-De Filippis E, Orlowski J, McKinney RA. Roles of Endomembrane Alkali Cation/Proton Exchangers in Synaptic Function and Neurodevelopmental Disorders. Front Physiol 2022; 13:892196. [PMID: 35547574 PMCID: PMC9081726 DOI: 10.3389/fphys.2022.892196] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 03/30/2022] [Indexed: 12/25/2022] Open
Abstract
Endomembrane alkali cation (Na+, K+)/proton (H+) exchangers (eNHEs) are increasingly associated with neurological disorders. These eNHEs play integral roles in regulating the luminal pH, processing, and trafficking of cargo along the secretory (Golgi and post-Golgi vesicles) and endocytic (early, recycling, and late endosomes) pathways, essential regulatory processes vital for neuronal development and plasticity. Given the complex morphology and compartmentalization of multipolar neurons, the contribution of eNHEs in maintaining optimal pH homeostasis and cargo trafficking is especially significant during periods of structural and functional development and remodeling. While the importance of eNHEs has been demonstrated in a variety of non-neuronal cell types, their involvement in neuronal function is less well understood. In this review, we will discuss their emerging roles in excitatory synaptic function, particularly as it pertains to cellular learning and remodeling. We will also explore their connections to neurodevelopmental conditions, including intellectual disability, autism, and attention deficit hyperactivity disorders.
Collapse
Affiliation(s)
- Andy Y L Gao
- Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada.,Department of Pharmacology & Therapeutics, McGill University, Montreal, QC, Canada
| | | | - John Orlowski
- Department of Physiology, McGill University, Montreal, QC, Canada
| | - R Anne McKinney
- Department of Pharmacology & Therapeutics, McGill University, Montreal, QC, Canada
| |
Collapse
|
26
|
Cavarocchi E, Whitfield M, Saez F, Touré A. Sperm Ion Transporters and Channels in Human Asthenozoospermia: Genetic Etiology, Lessons from Animal Models, and Clinical Perspectives. Int J Mol Sci 2022; 23:ijms23073926. [PMID: 35409285 PMCID: PMC8999829 DOI: 10.3390/ijms23073926] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/29/2022] [Accepted: 03/30/2022] [Indexed: 12/18/2022] Open
Abstract
In mammals, sperm fertilization potential relies on efficient progression within the female genital tract to reach and fertilize the oocyte. This fundamental property is supported by the flagellum, an evolutionarily conserved organelle that provides the mechanical force for sperm propulsion and motility. Importantly several functional maturation events that occur during the journey of the sperm cells through the genital tracts are necessary for the activation of flagellar beating and the acquisition of fertilization potential. Ion transporters and channels located at the surface of the sperm cells have been demonstrated to be involved in these processes, in particular, through the activation of downstream signaling pathways and the promotion of novel biochemical and electrophysiological properties in the sperm cells. We performed a systematic literature review to describe the currently known genetic alterations in humans that affect sperm ion transporters and channels and result in asthenozoospermia, a pathophysiological condition defined by reduced or absent sperm motility and observed in nearly 80% of infertile men. We also present the physiological relevance and functional mechanisms of additional ion channels identified in the mouse. Finally, considering the state-of-the art, we discuss future perspectives in terms of therapeutics of asthenozoospermia and male contraception.
Collapse
Affiliation(s)
- Emma Cavarocchi
- Institute for Advanced Biosciences, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, 38000 Grenoble, France; (E.C.); (M.W.)
| | - Marjorie Whitfield
- Institute for Advanced Biosciences, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, 38000 Grenoble, France; (E.C.); (M.W.)
| | - Fabrice Saez
- UMR GReD Institute (Génétique Reproduction & Développement) CNRS 6293, INSERM U1103, Team «Mécanismes de L’Infertilité Mâle Post-Testiculaire», Université Clermont Auvergne, 63000 Clermont-Ferrand, France
- Correspondence: (F.S.); (A.T.)
| | - Aminata Touré
- Institute for Advanced Biosciences, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, 38000 Grenoble, France; (E.C.); (M.W.)
- Correspondence: (F.S.); (A.T.)
| |
Collapse
|
27
|
Yeste M, Recuero S, Maside C, Salas-Huetos A, Bonet S, Pinart E. Blocking NHE Channels Reduces the Ability of In Vitro Capacitated Mammalian Sperm to Respond to Progesterone Stimulus. Int J Mol Sci 2021; 22:ijms222312646. [PMID: 34884450 PMCID: PMC8657634 DOI: 10.3390/ijms222312646] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 11/12/2021] [Accepted: 11/22/2021] [Indexed: 11/24/2022] Open
Abstract
Few data exist about the presence and physiological role of Na+/H+ exchangers (NHEs) in the plasma membrane of mammalian sperm. In addition, the involvement of these channels in the ability of sperm to undergo capacitation and acrosomal reaction has not been investigated in any mammalian species. In the present study, we addressed whether these channels are implicated in these two sperm events using the pig as a model. We also confirmed the presence of NHE1 channels in the plasma membrane of ejaculated sperm by immunofluorescence and immunoblotting. The function of NHE channels during in vitro capacitation was analyzed by incubating sperm samples in capacitating medium for 300 min in the absence or presence of a specific blocker (DMA; 5-(N,N-dimethyl)-amiloride) at different concentrations (1, 5, and 10 µM); acrosome exocytosis was triggered by adding progesterone after 240 min of incubation. Sperm motility and kinematics, integrity of plasma and acrosome membranes, membrane lipid disorder, intracellular calcium and reactive oxygen species (ROS) levels, and mitochondrial membrane potential (MMP) were evaluated after 0, 60, 120, 180, 240, 250, 270, and 300 min of incubation. NHE1 localized in the connecting and terminal pieces of the flagellum and in the equatorial region of the sperm head and was found to have a molecular weight of 75 kDa. During the first 240 min of incubation, i.e., before the addition of progesterone, blocked and control samples did not differ significantly in any of the parameters analyzed. However, from 250 min of incubation, samples treated with DMA showed significant alterations in total motility and the amplitude of lateral head displacement (ALH), acrosomal integrity, membrane lipid disorder, and MMP. In conclusion, while NHE channels are not involved in the sperm ability to undergo capacitation, they could be essential for triggering acrosome exocytosis and hypermotility after progesterone stimulus.
Collapse
Affiliation(s)
- Marc Yeste
- Biotechnology of Animal and Human Reproduction (TechnoSperm), Institute of Food and Agricultural Technology, University of Girona, ES-17003 Girona, Spain; (M.Y.); (S.R.); (C.M.); (A.S.-H.); (S.B.)
- Unit of Cell Biology, Department of Biology, Faculty of Sciences, University of Girona, ES-17003 Girona, Spain
| | - Sandra Recuero
- Biotechnology of Animal and Human Reproduction (TechnoSperm), Institute of Food and Agricultural Technology, University of Girona, ES-17003 Girona, Spain; (M.Y.); (S.R.); (C.M.); (A.S.-H.); (S.B.)
- Unit of Cell Biology, Department of Biology, Faculty of Sciences, University of Girona, ES-17003 Girona, Spain
| | - Carolina Maside
- Biotechnology of Animal and Human Reproduction (TechnoSperm), Institute of Food and Agricultural Technology, University of Girona, ES-17003 Girona, Spain; (M.Y.); (S.R.); (C.M.); (A.S.-H.); (S.B.)
- Unit of Cell Biology, Department of Biology, Faculty of Sciences, University of Girona, ES-17003 Girona, Spain
| | - Albert Salas-Huetos
- Biotechnology of Animal and Human Reproduction (TechnoSperm), Institute of Food and Agricultural Technology, University of Girona, ES-17003 Girona, Spain; (M.Y.); (S.R.); (C.M.); (A.S.-H.); (S.B.)
- Unit of Cell Biology, Department of Biology, Faculty of Sciences, University of Girona, ES-17003 Girona, Spain
- Department of Nutrition, Harvard T.H. Chan School of Public Health, Harvard University, Boston, MA 02115, USA
- Consorcio CIBER, M.P., Fisiopatología de la Obesidad y Nutrición (ciBeRobn), Instituto de Salud Carlos III (ISCIII), ES-28029 Madrid, Spain
| | - Sergi Bonet
- Biotechnology of Animal and Human Reproduction (TechnoSperm), Institute of Food and Agricultural Technology, University of Girona, ES-17003 Girona, Spain; (M.Y.); (S.R.); (C.M.); (A.S.-H.); (S.B.)
- Unit of Cell Biology, Department of Biology, Faculty of Sciences, University of Girona, ES-17003 Girona, Spain
| | - Elisabeth Pinart
- Biotechnology of Animal and Human Reproduction (TechnoSperm), Institute of Food and Agricultural Technology, University of Girona, ES-17003 Girona, Spain; (M.Y.); (S.R.); (C.M.); (A.S.-H.); (S.B.)
- Unit of Cell Biology, Department of Biology, Faculty of Sciences, University of Girona, ES-17003 Girona, Spain
- Correspondence: ; Tel.: +34-972-419-514
| |
Collapse
|