1
|
TRH and TRH-like peptide levels covary with caloric restriction and oral metformin in rat heart and testis. ENDOCRINE AND METABOLIC SCIENCE 2022. [DOI: 10.1016/j.endmts.2022.100121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
|
2
|
Levin RJ. The Clitoris—An Appraisal of its Reproductive Function During the Fertile Years: Why Was It, and Still Is, Overlooked in Accounts of Female Sexual Arousal. Clin Anat 2019; 33:136-145. [DOI: 10.1002/ca.23498] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 09/19/2019] [Indexed: 12/17/2022]
Affiliation(s)
- Roy J. Levin
- Independent Research Investigator Sheffield United Kingdom
| |
Collapse
|
3
|
Maréchal L, Guillemette C, Goupil S, Blondin P, Leclerc P, Richard FJ. Cyclic nucleotide phosphodiesterases in human spermatozoa and seminal fluid: Presence of an active PDE10A in human spermatozoa. Biochim Biophys Acta Gen Subj 2016; 1861:147-156. [PMID: 27836756 DOI: 10.1016/j.bbagen.2016.11.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 10/21/2016] [Accepted: 11/04/2016] [Indexed: 11/16/2022]
Abstract
BACKGROUND Cyclic adenosine monophosphate (cAMP) plays a crucial role as a signaling molecule for sperm functions such as capacitation, motility and acrosome reaction. It is well known that cAMP degradation by phosphodiesterase (PDE) enzyme has a major impact on sperm functions. The present study was undertaken to characterize cAMP-PDE activity in human semen. METHODS cAMP-PDE activity was measured in human sperm and seminal plasma using family specific PDE inhibitors. Three sperm fractionation methods were applied to assess cAMP-PDE activity in spermatozoa. Western blots were used to validate the presence of specific family in sperm and seminal plasma. RESULTS Using three sperm fractionation methods, we demonstrated that in human sperm, the major cAMP-PDE activity is papaverine-sensitive and thus ascribed to PDE10. In seminal plasma, total cAMP-PDE activity was 1.14±0.39fmol of cAMP hydrolyzed per minute per μg of protein. Using specific inhibitors, we showed that the major cAMP-PDE activity found in human seminal plasma is ascribed to PDE4 and PDE11. Western blot analysis, immunoprecipitation with a specific monoclonal antibody, and mass spectrometry confirmed the presence of PDE10 in human spermatozoa. CONCLUSION This study provides the first demonstration of the presence of functional PDE10 in human spermatozoa and functional PDE4 and PDE11 in human seminal plasma. GENERAL SIGNIFICANCE Since the contribution of cyclic nucleotides in several sperm functions is well known, the finding that PDE10 is an active enzyme in human spermatozoa is novel and may lead to new insight into fertility.
Collapse
Affiliation(s)
- Loïze Maréchal
- Centre de recherche en reproduction, développement et santé intergénérationnelle, Département d'obstétrique, gynécologie et reproduction, Centre de recherche du CHU de Québec-Université Laval, 2705 Boul. Laurier, Québec G1V 4G2, Canada
| | - Christine Guillemette
- Centre de recherche en reproduction, développement et santé intergénérationnelle, Département des Sciences Animales, Faculté des sciences de l'agriculture et de l'alimentation, Université Laval, Québec G1V 0A6, Québec, Canada
| | - Serge Goupil
- Centre de recherche en reproduction, développement et santé intergénérationnelle, Département d'obstétrique, gynécologie et reproduction, Centre de recherche du CHU de Québec-Université Laval, 2705 Boul. Laurier, Québec G1V 4G2, Canada
| | - Patrick Blondin
- L'Alliance Boviteq Inc, 19320 Grand rang St-François, Saint-Hyacinthe, Québec J2T 5H1, Canada
| | - Pierre Leclerc
- Centre de recherche en reproduction, développement et santé intergénérationnelle, Département d'obstétrique, gynécologie et reproduction, Centre de recherche du CHU de Québec-Université Laval, 2705 Boul. Laurier, Québec G1V 4G2, Canada
| | - François J Richard
- Centre de recherche en reproduction, développement et santé intergénérationnelle, Département des Sciences Animales, Faculté des sciences de l'agriculture et de l'alimentation, Université Laval, Québec G1V 0A6, Québec, Canada.
| |
Collapse
|
4
|
Bergeron A, Aragon JP, Guillemette C, Hébert A, Sullivan R, Blondin P, Richard FJ. Characterization of cAMP-phosphodiesterase activity in bovine seminal plasma. Andrology 2016; 4:1123-1130. [PMID: 27565610 DOI: 10.1111/andr.12267] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 06/22/2016] [Accepted: 07/14/2016] [Indexed: 12/11/2022]
Abstract
The second messenger cyclic adenosine monophosphate (cAMP) has a central role in sperm physiology. Extracellular cAMP can be sequentially degraded into 5'AMP and adenosine by ecto-phosphodiesterases (ecto-PDE) and ecto-nucleotidases, a phenomenon called extracellular cAMP-adenosine pathway. As cAMP-adenosine pathway is involved in sperm capacitation, we hypothesize that extracellular PDEs are functionally present in seminal plasma. Exclusively measuring cAMP-PDE activity, total activity in bovine seminal plasma was 10.1 ± 1.5 fmoles/min/μg. Using different family-specific PDE inhibitors, we showed that in seminal plasma, the major cAMP-PDE activity was papaverine sensitive (47.5%). These data support the presence of PDE10 in bovine seminal plasma and was further confirmed by western blot. In epididymal fluid, total cAMP-PDE activity was 48.2 ± 14.8 fmoles/min/μg and we showed that the major cAMP-PDE activity was 3-isobutyl-methylxanthine insensitive and thus ascribed to PDE8 family. PDE10A mRNAs were found in the testis, epididymis, and seminal vesicles. cAMP-PDE activity is present in bovine seminal plasma and epididymal fluid. The results suggest a role for ecto-PDEs present in those fluids in the signaling pathways involved in sperm functions.
Collapse
Affiliation(s)
- A Bergeron
- Centre de Recherche en Reproduction, Développement et Santé Intergénérationnelle, Université Laval, Québec, QC, Canada.,Département des Sciences Animales, Faculté des Sciences de L'agriculture et de L'alimentation, Université Laval, Québec, QC, Canada
| | - J P Aragon
- Centre de Recherche en Reproduction, Développement et Santé Intergénérationnelle, Université Laval, Québec, QC, Canada.,Département des Sciences Animales, Faculté des Sciences de L'agriculture et de L'alimentation, Université Laval, Québec, QC, Canada
| | - C Guillemette
- Centre de Recherche en Reproduction, Développement et Santé Intergénérationnelle, Université Laval, Québec, QC, Canada.,Département des Sciences Animales, Faculté des Sciences de L'agriculture et de L'alimentation, Université Laval, Québec, QC, Canada
| | - A Hébert
- Centre de Recherche en Reproduction, Développement et Santé Intergénérationnelle, Université Laval, Québec, QC, Canada.,Département des Sciences Animales, Faculté des Sciences de L'agriculture et de L'alimentation, Université Laval, Québec, QC, Canada
| | - R Sullivan
- Centre de Recherche en Reproduction, Développement et Santé Intergénérationnelle, Université Laval, Québec, QC, Canada.,Département Obstétrique, Gynécologie et Reproduction, Faculté de Médecine, Université Laval, Québec, QC, Canada
| | - P Blondin
- Boviteq, Saint-Hyacinthe, QC, Canada
| | - F J Richard
- Centre de Recherche en Reproduction, Développement et Santé Intergénérationnelle, Université Laval, Québec, QC, Canada.,Département des Sciences Animales, Faculté des Sciences de L'agriculture et de L'alimentation, Université Laval, Québec, QC, Canada
| |
Collapse
|
5
|
Agarwal A, Sharma R, Durairajanayagam D, Ayaz A, Cui Z, Willard B, Gopalan B, Sabanegh E. Major protein alterations in spermatozoa from infertile men with unilateral varicocele. Reprod Biol Endocrinol 2015; 13:8. [PMID: 25890347 PMCID: PMC4383193 DOI: 10.1186/s12958-015-0007-2] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 02/11/2015] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND The etiology of varicocele, a common cause of male factor infertility, remains unclear. Proteomic changes responsible for the underlying pathology of unilateral varicocele have not been evaluated. The objective of this prospective study was to employ proteomic techniques and bioinformatic tools to identify and analyze proteins of interest in infertile men with unilateral varicocele. METHODS Spermatozoa from infertile men with unilateral varicocele (n=5) and from fertile men (control; n=5) were pooled in two groups respectively. Proteins were extracted and separated by 1-D SDS-PAGE. Bands were digested and identified on a LTQ-Orbitrap Elite hybrid mass spectrometer system. Bioinformatic analysis identified the pathways and functions of the differentially expressed proteins (DEP). RESULTS Sperm concentration, motility and morphology were lower, and reactive oxygen species levels were higher in unilateral varicocele patients compared to healthy controls. The total number of proteins identified were 1055, 1010 and 1042 in the fertile group, and 795, 713 and 763 proteins in the unilateral varicocele group. Of the 369 DEP between both groups, 120 proteins were unique to the fertile group and 38 proteins were unique to the unilateral varicocele group. Compared to the control group, 114 proteins were overexpressed while 97 proteins were underexpressed in the unilateral varicocele group. We have identified 29 proteins of interest that are involved in spermatogenesis and other fundamental reproductive events such as sperm maturation, acquisition of sperm motility, hyperactivation, capacitation, acrosome reaction and fertilization. The major functional pathways of the 359 DEP related to the unilateral varicocele group involve metabolism, disease, immune system, gene expression, signal transduction and apoptosis. Functional annotations showed that unilateral varicocele mostly affected small molecule biochemistry and post-translational modification proteins. Proteins expressed uniquely in the unilateral varicocele group were cysteine-rich secretory protein 2 precursor (CRISP2) and arginase-2 (ARG2). CONCLUSIONS The expression of these proteins of interest are altered and possibly functionally compromised in infertile men with unilateral varicocele. If validated, these proteins may lead to potential biomarker(s) and help better understand the mechanism involved in the pathophysiology of unilateral varicocele in infertile men.
Collapse
Affiliation(s)
- Ashok Agarwal
- Center for Reproductive Medicine, Glickman Urological & Kidney Institute, Cleveland Clinic, Mail Code X-11, 10681 Carnegie Avenue, Cleveland, OH, 44195, USA.
| | - Rakesh Sharma
- Center for Reproductive Medicine, Glickman Urological & Kidney Institute, Cleveland Clinic, Mail Code X-11, 10681 Carnegie Avenue, Cleveland, OH, 44195, USA.
| | - Damayanthi Durairajanayagam
- Center for Reproductive Medicine, Glickman Urological & Kidney Institute, Cleveland Clinic, Mail Code X-11, 10681 Carnegie Avenue, Cleveland, OH, 44195, USA.
| | - Ahmet Ayaz
- Center for Reproductive Medicine, Glickman Urological & Kidney Institute, Cleveland Clinic, Mail Code X-11, 10681 Carnegie Avenue, Cleveland, OH, 44195, USA.
| | - Zhihong Cui
- Center for Reproductive Medicine, Glickman Urological & Kidney Institute, Cleveland Clinic, Mail Code X-11, 10681 Carnegie Avenue, Cleveland, OH, 44195, USA.
| | - Belinda Willard
- Proteomics Research Core Services, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, USA.
| | - Banu Gopalan
- Proteomics Research Core Services, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, USA.
| | - Edmund Sabanegh
- Center for Reproductive Medicine, Glickman Urological & Kidney Institute, Cleveland Clinic, Mail Code X-11, 10681 Carnegie Avenue, Cleveland, OH, 44195, USA.
| |
Collapse
|
6
|
Karaca E, Buyukkaya R, Pehlivan D, Charng WL, Yaykasli KO, Bayram Y, Gambin T, Withers M, Atik MM, Arslanoglu I, Bolu S, Erdin S, Buyukkaya A, Yaykasli E, Jhangiani SN, Muzny DM, Gibbs RA, Lupski JR. Whole-exome sequencing identifies homozygous GPR161 mutation in a family with pituitary stalk interruption syndrome. J Clin Endocrinol Metab 2015; 100:E140-7. [PMID: 25322266 PMCID: PMC4283017 DOI: 10.1210/jc.2014-1984] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
CONTEXT Pituitary stalk interruption syndrome (PSIS) is a rare, congenital anomaly of the pituitary gland characterized by pituitary gland insufficiency, thin or discontinuous pituitary stalk, anterior pituitary hypoplasia, and ectopic positioning of the posterior pituitary gland (neurohypophysis). The clinical presentation of patients with PSIS varies from isolated growth hormone (GH) deficiency to combined pituitary insufficiency and accompanying extrapituitary findings. Mutations in HESX1, LHX4, OTX2, SOX3, and PROKR2 have been associated with PSIS in less than 5% of cases; thus, the underlying genetic etiology for the vast majority of cases remains to be determined. OBJECTIVE We applied whole-exome sequencing (WES) to a consanguineous family with two affected siblings who have pituitary gland insufficiency and radiographic findings of hypoplastic (thin) pituitary gland, empty sella, ectopic neurohypophysis, and interrupted pitiutary stalk-characteristic clinical diagnostic findings of PSIS. DESIGN AND PARTICIPANTS WES was applied to two affected and one unaffected siblings. RESULTS WES of two affected and one unaffected sibling revealed a unique homozygous missense mutation in GPR161, which encodes the orphan G protein-coupled receptor 161, a protein responsible for transducing extracellular signals across the plasma membrane into the cell. CONCLUSION Mutations of GPR161 may be implicated as a potential novel cause of PSIS.
Collapse
Affiliation(s)
- Ender Karaca
- Department of Molecular and Human Genetics (E.K., D.P., W.-L.C., Y.B., T.G., M.W., M.M.A., R.A.G., J.R.L.), Baylor College of Medicine, Houston, Texas 77030; Department of Radiology (R.B.), Duzce University Medical School, 81620 Duzce, Turkey; Department of Medical Biology (K.O.Y.), Kahramanmaras Sutcu Imam University, Medical School, 46100 Kahramanmaras, Turkey; Department of Pediatric Endocrinology (I.A., S.B.), Duzce University Medical School, 81620 Duzce, Turkey; Center for Human Genetic Research (S.E.), Massachussetts General Hospital, Boston, Massachussetts 02114; Department of Radiology (A.B.), Duzce Ataturk Community Hospital, 81620 Duzce, Turkey; Department of Medical Biology and Genetics (E.Y.), Duzce University Institute of Health Science, 81620 Duzce, Turkey; Human Genome Sequencing Center (S.N.J., D.M.M., R.A.G.), Baylor College of Medicine, Houston Texas 77030; Department of Pediatrics (J.R.L.), Baylor College of Medicine, Houston, Texas 77030; and Texas Children's Hospital (J.R.L.), Houston, Texas 77030
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Shpakov AO, Derkach KV. Functional role of membrane-bound adenylyl cyclases and coupled to them receptors and G-proteins in regulation of fertility of spermatozoa. J EVOL BIOCHEM PHYS+ 2014. [DOI: 10.1134/s0022093014040024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
8
|
Chauvin T, Xie F, Liu T, Nicora CD, Yang F, Camp DG, Smith RD, Roberts KP. A systematic analysis of a deep mouse epididymal sperm proteome. Biol Reprod 2012; 87:141. [PMID: 23115268 DOI: 10.1095/biolreprod.112.104208] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Spermatozoa are highly specialized cells that, when mature, are capable of navigating the female reproductive tract and fertilizing an oocyte. The sperm cell is thought to be largely quiescent in terms of transcriptional and translational activity. As a result, once it has left the male reproductive tract, the sperm cell is essentially operating with a static population of proteins. It therefore is theoretically possible to understand the protein networks contained in a sperm cell and to deduce its cellular function capabilities. To this end, we performed a proteomic analysis of mouse sperm isolated from the cauda epididymis and confidently identified 2850 proteins, which to our knowledge is the most comprehensive sperm proteome for any species reported to date. These proteins comprise many complete cellular pathways, including those for energy production via glycolysis, beta-oxidation and oxidative phosphorylation, protein folding and transport, and cell signaling systems. This proteome should prove a useful tool for assembly and testing of protein networks important for sperm function.
Collapse
Affiliation(s)
- Theodore Chauvin
- School of Molecular Biosciences, Washington State University, Spokane, Washington 99201, USA
| | | | | | | | | | | | | | | |
Collapse
|
9
|
Li K, Ni Y, He Y, Chen WY, Lu JX, Cheng CY, Ge RS, Shi QX. Inhibition of sperm capacitation and fertilizing capacity by adjudin is mediated by chloride and its channels in humans. Hum Reprod 2012; 28:47-59. [PMID: 23117128 DOI: 10.1093/humrep/des384] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
STUDY QUESTION Does adjudin disrupt chloride ion (Cl⁻) ion transport function in human sperm and impede sperm capacitation and fertilizing ability in vitro? SUMMARY ANSWER In this study the results indicate that adjudin is a potent blocker of Cl⁻ channels: disrupting Cl⁻ ion transport function results in a decline in sperm capacitation and fertilizing ability in humans in vitro. WHAT IS KNOWN ALREADY Although our previous studies have demonstrated that adjudin exerts its effect by disrupting sertoli-germ cell adhesion junctions, most notably apical ectoplasmic specialization by targeting testin and actin filament bundles that disrupts the actin-based cytoskeleton in sertoli cells, it remains unclear whether adjudin impedes Cl⁻ ion transport function in the human sperm. STUDY DESIGN, SIZE AND DURATION Semen samples were obtained from 45 fertile men (aged 25-32). Spermatozoa were isolated from the semen in the human tube fluid (HTF) medium by centrifugation through a discontinuous Percoll gradient, and incubated with adjudin at 10 nM-10 µM and/or other reagents under capacitating conditions for 0-5 h. PARTICIPANTS/MATERIALS, SETTING, METHODS We evaluated the effect of adjudin and different reagents on sperm functions with which they were incubated at 37 °C. Sperm motility and hyperactivation were analyzed by a computer-assisted sperm analysis (CASA) system. Sperm capacitation and the acrosome reaction were assessed by chlortetracycline fluorescence staining. Sperm fertilizing ability was evaluated by sperm penetration of zona-free hamster egg assay, and cellular cAMP levels in spermatozoa were quantified by the EIA kit. The proteins tyrosine, serine and threonine phosphorylation in the presence or absence of adjudin were analyzed by means of a immunodetection of spermatozoa, especially, compared the effect of adjudin on sperm hyperactivation and capacitation in the complete HTF medium with the Cl⁻-deficient HTF medium as well as the various Cl⁻ channel blockers. MAIN RESULTS AND THE ROLE OF CHANCE Adjudin significantly inhibited sperm hyperactivation but not sperm motility. Adjudin-induced inhibition of sperm capacitation was reversible, and it was found to block the rhuZP₃β- and progesterone-induced acrosome reaction in a dose-dependent manner. Adjudin also blocked sperm penetration of zona-free hamster eggs, and significantly inhibited both forskolin-activated transmembrane adenylyl cyclase and soluble adenylyl cyclase activities leading to a significant decline in the cellular cAMP levels in human spermatozoa. Adjudin failed to reduce sperm protein tyrosine phosphorylation but it did prevent sperm serine and threonine protein phosphorylation. Interestingly, adjudin was found to exert its inhibitory effects on sperm capacitation and capacitation-associated events only in the complete Cl⁻-HTF medium but not Cl⁻-deficient medium, illustrating the likely involvement of Cl⁻. Adjudin inhibits the fertility capacity of human sperm is mediated by disrupting chloride ion and its transport function. LIMITATIONS, REASONS FOR CAUTION This study has examined the effect of adjudin only on human sperm capacitation and fertilizing ability in vitro and thus has some limitations. Further investigations in vivo are needed to confirm adjudin is a potent male contraceptive. WIDER IMPLICATIONS OF THE FINDINGS Our studies demonstrated that adjudin inhibition of capacitation is reversible and its toxicity is low, opening the door for the examination of adjudin as a mediator of male fertility control. Adjudin may be a safe, efficient and reversible male antifertility agent and applicable to initial clinical trials of adjudin as a male antifertility agent in humans. STUDING FUNDING/COMPETING INTEREST(S): This work was supported by the National Basic Research Program of China (2006CB504002), the Nature Science Foundation of China (Nos. 81000244 and 81170554), Zhejiang Project of Science and Technology (2011C23046), the Nature Science Fund of Zhejiang province (Nos.Y2100058 and Y2090236), the key Science and Technology Innovation Team of Zhejiang Province (No.2012R10048-07) and the National Institutes of Health (NICHD U54 HD029990 project 5), USA. The authors declare no conflict of interest.
Collapse
Affiliation(s)
- Kun Li
- Unit of Reproductive Physiology, Zhejiang Academy of Medical Sciences, Hangzhou, Zhejiang 310013, China
| | | | | | | | | | | | | | | |
Collapse
|
10
|
Tapia JA, Macias-Garcia B, Miro-Moran A, Ortega-Ferrusola C, Salido GM, Peña FJ, Aparicio IM. The Membrane of the Mammalian Spermatozoa: Much More Than an Inert Envelope. Reprod Domest Anim 2012; 47 Suppl 3:65-75. [DOI: 10.1111/j.1439-0531.2012.02046.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
11
|
Identification and developmental expression of leucine-rich repeat-containing G protein-coupled receptor 6 (lgr6) in the medaka fish, Oryzias latipes. Dev Genes Evol 2012; 222:217-27. [PMID: 22576653 DOI: 10.1007/s00427-012-0403-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Accepted: 04/25/2012] [Indexed: 10/28/2022]
Abstract
G protein-coupled receptors are critical regulators of diverse developmental processes such as oocyte maturation, fertilization, gastrulation, and organogenesis. To further study the molecular mechanisms underlying these processes, we cloned and characterized the orphan leucine-rich repeat-containing G protein-coupled receptor 6 (LGR6), a stem cell marker in mammalian hair follicles, in medaka fish, Oryzias latipes. To examine the expression pattern of lgr6, we performed whole-mount in situ hybridization (WISH) during embryogenesis. The expression of lgr6 was first detected as a band in the anterior part of the posterior brain vesicle in 0.5-1 day post fertilization (dpf) embryos. This band disappeared by 2 dpf, but new signals appeared in the otic vesicles bordering the original band and also detected in the nasal placode and posterior lateral line primordia. At later stages (3-5 dpf), lgr6 was widely expressed in the brain, otic vesicle, neuromasts, root of the pectoral fin, cranial cartilage, and gut. Then, we conducted more detailed expression analysis of lgr6 in adult gut using WISH and immunohistochemical staining. Lgr6-positive cells were detected in the crypt-like proliferative zone and in parts of the villus. We also performed RT-PCR of mRNAs from different tissues. The lgr6 mRNA was found highest in the kidney and gill. The transcript was also present in the brain, heart, liver, spleen, intestine, skeletal muscle, testis, and ovary, similar to that of mammalian LGR6. These results suggest that medaka lgr6 plays an important role in organ development during embryogenesis and serves as a good molecular marker for future studies of postembryonic organ-specific development in mammals.
Collapse
|
12
|
Levin RJ. Can the Controversy About the Putative Role of the Human Female Orgasm in Sperm Transport be Settled with Our Current Physiological Knowledge of Coitus? J Sex Med 2011; 8:1566-78. [DOI: 10.1111/j.1743-6109.2010.02162.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
|
13
|
Chiu PCN, Liao S, Lam KKW, Tang F, Ho JCM, Ho PC, O WS, Yao YQ, Yeung WSB. Adrenomedullin regulates sperm motility and oviductal ciliary beat via cyclic adenosine 5'-monophosphate/protein kinase A and nitric oxide. Endocrinology 2010; 151:3336-47. [PMID: 20444935 DOI: 10.1210/en.2010-0077] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Cilium and flagellum beating are important in reproduction and defects in their motion are associated with ectopic pregnancy and infertility. Adrenomedullin (ADM) is a polypeptide present in the reproductive system. This report demonstrates a novel action of ADM in enhancing the flagellar/ciliary beating of human spermatozoa and rat oviductal ciliated cells. At the concentration found in the seminal plasma, it increases the progressive motility of spermatozoa. ADM binds to its classical receptor, calcitonin receptor-like receptor/receptor activity-modifying protein complex on spermatozoa. ADM treatment increases the protein kinase A activities, the cyclic adenosine monophosphate, and nitric oxide levels of spermatozoa and oviductal cells. Pharmacological activators and inhibitors confirmed that the ADM-induced flagella/ciliary beating was protein kinase A dependent. Whereas nitric oxide donors had no effect on sperm motility, they potentiated the motility-inducing action of protein kinase A activators, demonstrating for the first time the synergistic action of nitric oxide and protein kinase A signaling in flagellar/ciliary beating. The ADM-induced motility enhancement effect in spermatozoa also depended on the up-regulation of intracellular calcium, a known key regulator of sperm motility and ciliary beating. In conclusion, ADM is a common activator of flagellar/ciliary beating. The study provides a physiological basis on possible use of ADM as a fertility regulation drug.
Collapse
Affiliation(s)
- Philip C N Chiu
- Department of Obstetrics and Gynaecology, Li Ka Shing Faculty of Medicine, University of Hong Kong, Queen Mary Hospital, Hong Kong, China
| | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Fraser LR. The "switching on" of mammalian spermatozoa: molecular events involved in promotion and regulation of capacitation. Mol Reprod Dev 2010; 77:197-208. [PMID: 19908247 DOI: 10.1002/mrd.21124] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Following the discovery of mammalian sperm capacitation and its fundamental importance for the acquisition of fertilizing potential, it has gradually become possible to identify some specific molecules and molecular events that play pivotal roles in the "switching on" of spermatozoa. These are discussed in the context of the promotion and regulation of capacitation, emphasizing differences between commonly used conditions in vitro and the environment in vivo where spermatozoa normally undergo capacitation. Although typical culture media used in vitro do support capacitation, they do not prevent capacitated cells from undergoing spontaneous acrosome reactions and so losing fertilizing potential. This is not a problem in vitro, but could be in vivo where few spermatozoa reach the site of fertilization. Several small molecules, known to be present in vivo, have been shown in vitro to bind to spermatozoa and to regulate capacitation, first accelerating capacitation and then inhibiting spontaneous acrosome reactions, by regulating cAMP production. Since spermatozoa would contact these molecules during and after ejaculation, it is plausible that they serve a similar function in vivo. The mechanisms whereby the presence or absence of decapacitation factors might alter plasma membrane architecture and so alter functionality of a number of membrane-associated enzymes involved in capacitation are also considered. Finally, several unresolved issues relating to events during capacitation are discussed.
Collapse
Affiliation(s)
- Lynn R Fraser
- Division of Reproduction and Endocrinology, School of Biomedical and Health Sciences, King's College London, London SE1 1UL, UK.
| |
Collapse
|
15
|
Piña-Guzmán B, Sánchez-Gutiérrez M, Marchetti F, Hernández-Ochoa I, Solís-Heredia M, Quintanilla-Vega B. Methyl-parathion decreases sperm function and fertilization capacity after targeting spermatocytes and maturing spermatozoa. Toxicol Appl Pharmacol 2009; 238:141-9. [DOI: 10.1016/j.taap.2009.05.008] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2009] [Revised: 04/29/2009] [Accepted: 05/04/2009] [Indexed: 11/29/2022]
|
16
|
Effects of nonylphenol on motility and subcellular elements of epididymal rat sperm. Reprod Toxicol 2009; 28:542-9. [PMID: 19539023 DOI: 10.1016/j.reprotox.2009.06.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2008] [Revised: 05/20/2009] [Accepted: 06/05/2009] [Indexed: 01/28/2023]
Abstract
Nonylphenol (NP) is an important environmental toxicant and potential endocrine disrupting chemical. The objective of these studies was to determine the effects of NP on epididymal rat sperm in vitro. Epididymal sperm samples from Sprague-Dawley rats were incubated in 1, 10, 100, 250, and 500 microg/ml NP for 1, 2, 3, or 4h. Computer-assisted sperm analysis was used to determine motility. Epifluorescent microscopy was used to determine acrosomal status and flow cytometry was used to determine mitochondrial membrane potential (MMP) and chromatin integrity. Exposure of epididymal rat sperm to 250 or 500 microg/ml NP was highly detrimental to motility (P<0.05), with complete loss of motility observed after exposure to 500 microg/ml NP (P<0.05). The acrosomal integrity of sperm was significantly reduced with the lowest concentration (1 microg/ml) of NP, and higher concentrations resulted in a dose-dependent induction of the acrosomal reaction (P<0.05). Similarly, the percentage of sperm with high MMP declined dramatically after exposure to 100, 250, and 500 microg/ml NP (P<0.05). Duration of NP exposure did not have any effect on motility or MMP and NP did not appear to have detrimental effects on chromatin integrity (P>0.05). These results indicate that major mechanism of action of NP on rat sperm is by adversely affecting their acrosomal integrity. However, NP-induced impaired sperm motility, decreased mitochondrial membrane potential also likely to play an important role in destruction of sperm function.
Collapse
|
17
|
|
18
|
Leung T, Humbert JE, Stauffer AM, Giger KE, Chen H, Tsai HJ, Wang C, Mirshahi T, Robishaw JD. The orphan G protein-coupled receptor 161 is required for left-right patterning. Dev Biol 2008; 323:31-40. [PMID: 18755178 DOI: 10.1016/j.ydbio.2008.08.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2008] [Revised: 07/28/2008] [Accepted: 08/01/2008] [Indexed: 11/18/2022]
Abstract
Gpr161 (also known as RE2) is an orphan G protein-coupled receptor (GPCR) that is expressed during embryonic development in zebrafish. Determining its biological function has proven difficult due to lack of knowledge regarding its natural or synthetic ligands. Here, we show that targeted knockdown of gpr161 disrupts asymmetric gene expression in the lateral plate mesoderm, resulting in aberrant looping of the heart tube. This is associated with elevated Ca(2+) levels in cells lining the Kupffer's vesicle and normalization of Ca(2+) levels, by over-expression of ncx1 or pmca-RNA, is able to partially rescue the cardiac looping defect in gpr161 knockdown embryos. Taken together, these data support a model in which gpr161 plays an essential role in left-right (L-R) patterning by modulating Ca(2+) levels in the cells surrounding the Kupffer's vesicle.
Collapse
MESH Headings
- Amino Acid Sequence
- Animals
- Animals, Genetically Modified
- Body Patterning/genetics
- Body Patterning/physiology
- Calcium/metabolism
- Calcium Signaling
- Embryo, Nonmammalian/metabolism
- Embryo, Nonmammalian/physiology
- Gene Expression Regulation, Developmental
- In Situ Hybridization
- Models, Biological
- Molecular Sequence Data
- Oligonucleotides, Antisense/pharmacology
- Protein Structure, Tertiary
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Receptors, G-Protein-Coupled/physiology
- Sequence Homology, Amino Acid
- Zebrafish/embryology
- Zebrafish/genetics
- Zebrafish/metabolism
- Zebrafish Proteins/antagonists & inhibitors
- Zebrafish Proteins/genetics
- Zebrafish Proteins/metabolism
- Zebrafish Proteins/physiology
Collapse
Affiliation(s)
- Tinchung Leung
- Weis Center for Research, Geisinger Clinic, Danville, PA 17822, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Fini C, Coli M, Angelini A, Brusco G, Pasqualucci P, Tiziani F. 5'-Nucleotidase activity is decreased in seminal plasma and spermatozoa from varicocele patients. J Endocrinol Invest 2008; 31:666-71. [PMID: 18787389 DOI: 10.1007/bf03345622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
5'-Nucleotidase is involved in sperm capacitation via the cAMP-adenosine pathway and in sperm motility via direct adenosine production from AMP. Since these functions are reduced in varicocele, the aim of this study was to investigate whether the enzyme levels were altered in sperm from varicocele patients. The mean (SD) international units (IU) of 5'-nucleotidase activity in seminal plasma from 35 varicocele III patients was 0.16(0.09) IU ml(-1) vs 0.35(0.13) IU ml(-1) in 53 controls, this decrease being statistically significant at p < or = 0.001. A significant decrease in activity, expressed as international units per mg of protein concentration in spermatozoa homogenates, was also observed with spermatozoa: 0.0018(0.0017) IU mg(-1) in varicocele III vs 0.0081(0.0060) IU mg(-1) in controls, at p < or = 0.001. Compared to controls, the activity decrease observed both in spermatozoa and seminal plasma from 45 men with varicocele I was not statistically significant at p < or = 0.05. To determine the diagnostic value of 5'-nucleotidase in assessing sperm fertility in varicocele III, we used the likelihood ratios method and best cut-offs were identified in receiver operating characteristic curves. With a prevalence of 36%, the post-test probability of infertility was 91% in spermatozoa and 78% in seminal plasma. The cut-off values of 5'-nucleotidase activity discriminating for fertile/unfertile semen were 0.2 IU ml(-1) in seminal plasma and 0.003 IU mg(-1) of protein in spermatozoa. Overall, determination of 5'-nucleotidase activity, especially in spermatozoa, can be useful to characterize different varicocele degrees as well as the sperm fertility potential.
Collapse
Affiliation(s)
- C Fini
- Department of Internal Medicine, 06126 Perugia, Italy.
| | | | | | | | | | | |
Collapse
|
20
|
Baker MA, Reeves G, Hetherington L, Müller J, Baur I, Aitken RJ. Identification of gene products present in Triton X-100 soluble and insoluble fractions of human spermatozoa lysates using LC-MS/MS analysis. Proteomics Clin Appl 2007; 1:524-32. [PMID: 21136703 DOI: 10.1002/prca.200601013] [Citation(s) in RCA: 139] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2006] [Indexed: 11/09/2022]
Abstract
A comprehensive analysis of the proteins found in human spermatozoa is essential for understanding the events leading up to, and including, fertilization and development. Proteomics offers a platform for investigating this process, provided that the dynamic range is relatively low. In this report, spermatozoa from a number of human sperm ejaculates were isolated in a pure state using discontinuous Percoll gradient centrifugation. Triton X-100 soluble and insoluble proteins were recovered and separated by SDS-PAGE. The separation lanes were dissected into 96 fractions and analyzed individually by LC-MS(n) . A comprehensive protocol, involving LC-MS/MS analysis eventually down to the ninth most intense peak found in the MS-survey scan, was performed. Analysis of purified human sperm populations resulted in the identification of 1056 gene products, of which approximately 8% have not previously been characterized. The data were supported by the large number of proteins represented by expressed sequence tags in the testis. Bioinformatic analysis demonstrated that 437 of the gene products were involved in various metabolic pathways including glycolysis and oxidative phosphorylation. The inventory of proteins present in the human sperm proteome includes a number of notable discoveries including the first description of a nicotinamide adenine dinucleotide phosphate oxidase, dual-oxidase 2, finally laying to rest any doubts about the presence of such enzymes in spermatozoa. Furthermore, a number of different classes of receptor have also been detected in these cells and are potential regulators of sperm function. This list includes at least six seven-pass transmembrane receptors, six tyrosine kinase receptors, a tyrosine phosphatase receptor, glutamate-gated ion channel receptors, transient receptor potential cation channels, and a non-genomic progesterone receptor. This is the first published list of identified proteins in human spermatozoa using LC-MS/MS analysis.
Collapse
Affiliation(s)
- Mark A Baker
- The ARC Centre of Excellence in Biotechnology and Development, Reproductive Science Group, School of Environmental and Life Sciences, University of Newcastle, Newcastle, Australia
| | | | | | | | | | | |
Collapse
|
21
|
Fehr J, Meyer D, Widmayer P, Borth HC, Ackermann F, Wilhelm B, Gudermann T, Boekhoff I. Expression of the G-protein α-subunit gustducin in mammalian spermatozoa. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2006; 193:21-34. [PMID: 17021831 DOI: 10.1007/s00359-006-0168-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2006] [Revised: 08/09/2006] [Accepted: 08/18/2006] [Indexed: 10/24/2022]
Abstract
Although chemotaxis has been proposed to guide sperm to egg throughout the animal kingdom, sperm attractants released from mammalian eggs have not been identified. Since the G protein subunit alpha-gustducin is accepted as a marker of chemosensitive cells, attempts were made to explore whether alpha-gustducin is also expressed in spermatozoa of mammals. Immunohistochemical approaches using an anti-alpha-gustducin-specific antibody revealed the most intense immunoreactivity in differentiating spermatids. Further evidence for the alpha-gustducin expression was obtained analyzing testicular and sperm-derived tissue preparations in western blot analyses. To elucidate whether alpha-gustducin is retained in mature spermatozoa, epididymal mouse and rat sperm were subjected to immunocytochemistry as well as immunogold electron microscopy. A specific staining was obtained within the circumference of the midpiece-localized mitochondria, on the axoneme and the outer dense fibers surrounding the microtubules of this region, whereas no labeling was detectable in the end piece regions. The analysis of ejaculated bovine and human sperm revealed a comparable segmental distribution pattern for alpha-gustducin. Although a possible function for alpha-gustducin has yet to be determined, the axonemal-associated localization within the midpiece and principal piece of different mammalian spermatozoa raises the possibility that this G protein alpha-subunit may process intracellular signals controlling sperm motility.
Collapse
Affiliation(s)
- Johanna Fehr
- Department of Pharmacology and Toxicology, Philipps-University Marburg, Karl-von-Frisch-Strasse 1, 35032, Marburg, Germany
| | | | | | | | | | | | | | | |
Collapse
|
22
|
Fraser LR, Adeoya-Osiguwa SA. The potential impact of novel investigational compounds on human fertility. Expert Opin Investig Drugs 2006; 15:1179-89. [PMID: 16989595 DOI: 10.1517/13543784.15.10.1179] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
There is considerable concern that the incidence of infertility in humans may be increasing, in some instances due to the action of bioactive xenobiotic compounds found in our environment; for example, high concentrations of xenobiotics with estrogenic activity can interfere with normal testicular function and fertility. However, recent studies have shown that very low concentrations of several estrogenic xenobiotics can have subtle, unexpected effects on sperm function. When tested in vitro, these compounds stimulate spermatozoa to become fertile very quickly, but continued stimulation causes them to burn out and lose fertilising ability; similar responses occurring in vivo could reduce fertility. In contrast, several other compounds, structurally related to amfetamine, have been shown to act on spermatozoa in vitro in a positive manner, stimulating cells to 'switch on' quickly and then preventing burnout so that they maintain fertilising potential; similar responses occurring in vivo could enhance fertility. These results could have implications for either reducing or enhancing natural fertility.
Collapse
Affiliation(s)
- Lynn R Fraser
- King's College London, Division of Reproduction and Endocrinology, School of Biomedical and Health Sciences, London SE1 1UL, UK.
| | | |
Collapse
|
23
|
Baxendale RW, Fraser LR. Mammalian sperm phosphodiesterases and their involvement in receptor-mediated cell signaling important for capacitation. Mol Reprod Dev 2006; 71:495-508. [PMID: 15856425 DOI: 10.1002/mrd.20265] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
This study investigated the presence and function of intracellular cyclic nucleotide phosphodiesterases (PDEs) in mature mouse spermatozoa. PCR analysis detected gene transcripts for most of the 11 known PDE families in whole testis, but mainly for PDEs 1, 3, 6, and 8 in spermatozoa. Using specific antibodies, the strongest evidence was obtained for PDE proteins 1, 4, 6, 8, 10, and 11 in both sperm lysates and intact cells. These showed a range of subcellular localizations, with PDE 1A being primarily in the flagellum but PDEs 4D and 10A being in both the acrosomal region and the flagellum, similar to specific G proteins and adenylyl cyclases implicated in cAMP regulation during capacitation. In live spermatozoa, inhibitors selective for PDE 1 (MMPX) and 4 (rolipram) significantly increased cAMP over control levels but only rolipram significantly stimulated capacitation and in-vitro fertilizing ability; this suggests that compartmentalization has functional implications since only PDE 4 was abundant in both head and flagellum. Treatment of spermatozoa with CGS 21680, a stimulatory adenosine receptor agonist, significantly reduced cAMP-PDE activity at the same time-point when it causes increased cAMP. Thus, certain receptor-regulated cAMP processes in spermatozoa may be controlled by changes in both PDE and cyclase activities. In addition to demonstrating for the first time that some of the more recently discovered PDE isoforms, including PDE 6 (usually associated with the retina), are present in mature spermatozoa, this study provides clear evidence that the intracellular location of specific PDEs has important functional significance during capacitation and fertilization.
Collapse
Affiliation(s)
- Rhona W Baxendale
- Reproduction and Rhythms Group, School of Biomedical Sciences, King's College London, London, United Kingdom
| | | |
Collapse
|
24
|
Brewis IA, Moore HD, Fraser LR, Holt WV, Baldi E, Luconi M, Gadella BM, Ford WCL, Harrison RAP. Molecular mechanisms during sperm capacitation. HUM FERTIL 2006; 8:253-61. [PMID: 16393825 DOI: 10.1080/14647270500420178] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Ian A Brewis
- Biostatistics and Bioinformatics Unit & Department of Medical Biochemistry and Immunology, School of Medicine, Cardiff University, Cardiff, UK.
| | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Fraser LR, Beyret E, Milligan SR, Adeoya-Osiguwa SA. Effects of estrogenic xenobiotics on human and mouse spermatozoa. Hum Reprod 2006; 21:1184-93. [PMID: 16459350 DOI: 10.1093/humrep/dei486] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
OBJECTIVE To investigate human sperm responsiveness to the estrogenic xenobiotic genistein and seek further information regarding the mechanism of action of estrogenic xenobiotics using mouse spermatozoa. METHODS Uncapacitated human spermatozoa were incubated with genistein and assessed using chlortetracycline (CTC) fluorescence. CTC was also used to evaluate mouse sperm responses to daidzein and combinations of genistein, 8-prenylnaringenin and nonylphenol. Several steroids were tested to determine structure-function relationships, and possible involvement of cAMP and G proteins in responses was also investigated. RESULTS Genistein significantly accelerated capacitation and acrosome loss in human spermatozoa, with 1, 10 and 100 nmol/l being equally effective. In mouse spermatozoa, daidzein produced significant responses, and combinations of xenobiotics at low concentrations were more effective than used singly. The compounds appear to act at the cell surface, and responses to three different steroids were nonidentical. A protein kinase-A inhibitor blocked responses to xenobiotics, while genistein and nonylphenol significantly stimulated cAMP production. Pertussis toxin and dideoxyadenosine blocked responses, suggesting involvement of inhibitory G proteins and membrane-associated adenylyl cyclases. CONCLUSION Human and mouse sperm responses to genistein are very similar, but human gametes appear to be even more sensitive. The mechanism of action may involve unregulated stimulation of cAMP production, leading to significant acrosome loss, undesirable because already acrosome-reacted cells are nonfertilizing. Xenobiotics were even more effective in combination. Since simultaneous exposure to low concentrations of multiple xenobiotics is likely to occur in animals and humans, further investigation is needed to determine whether this could impair fertility.
Collapse
Affiliation(s)
- Lynn R Fraser
- Reproduction and Rhythms Group, School of Biomedical and Health Sciences, King's College London, London, UK.
| | | | | | | |
Collapse
|
26
|
Gibbons R, Adeoya-Osiguwa SA, Fraser LR. A mouse sperm decapacitation factor receptor is phosphatidylethanolamine-binding protein 1. Reproduction 2005; 130:497-508. [PMID: 16183867 DOI: 10.1530/rep.1.00792] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Capacitation is a pivotal event for mammalian spermatozoa, involving the loss of surface proteins known as decapacitation factors (DF) and consequent acquisition of fertilizing ability. Earlier studies showed that a mouse sperm DF binds to a receptor, DF-R, whose attachment to the sperm plasma membrane appears to involve a glycosylphosphatidylinositol (GPI) anchor. In the present study, purification and subsequent sequencing of DF-R has identified this ~23 kDa protein as phosphatidyletha-nolamine-binding protein 1 (PEBP 1). To obtain functional evidence that supports sequence homology data, purified recombinant PEBP 1 and PEBP 2 were evaluated for biological activity. While PEBP 1 was able to remove DF activity in solution at concentrations above ~1 nmol/l, PEBP 2 was ineffective, even at 600 nmol/l; this confirmed that DF-R is PEBP 1. Anti-PEBP 1 antiserum recognized recombinant PEBP 1 and a ~23 kDa protein in both mouse and human sperm lysates. Immunolocalization studies revealed that DF-R/PEBP 1 is located on the acrosomal cap, the post-acrosomal region and the flagellum of both mouse and human spermatozoa, with epitope accessibility being capacitation state-dependent and reversible. Treatment of cells with a phospholipase able to cleave GPI anchors essentially abolished immunostaining, thus confirming the extracellular location of DF-R/PEBP 1. We suggest that DF-R/PEBP 1 plays its fundamental role in capacitation by causing alterations in the sperm plasma membrane in both head and flagellum, with functional consequences for membrane-associated proteins. Obtaining more detail about DF ↔ DF-R interactions could lead to useful applications in both fertility treatments and new contraceptive approaches.
Collapse
Affiliation(s)
- Rachel Gibbons
- Reproduction and Rhythms Group, School of Biomedical Sciences, King's College London, Guy's Campus, London SE1 1UL, UK
| | | | | |
Collapse
|
27
|
Fraser LR, Adeoya-Osiguwa S, Baxendale RW, Mededovic S, Osiguwa OO. First messenger regulation of mammalian sperm function via adenylyl cyclase/cAMP. J Reprod Dev 2005; 51:37-46. [PMID: 15750295 DOI: 10.1262/jrd.51.37] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
When released into an appropriate environment, mammalian spermatozoa begin to capacitate and then continue until fully capacitated and able to fertilize. During capacitation in vitro, some cells 'over-capacitate' and undergo spontaneous acrosome reactions; this would be highly undesirable in vivo since already acrosome-reacted spermatozoa are non-fertilizing. Recent studies have revealed that seminal plasma contains several small molecules that bind to specific receptors on the sperm plasma membrane and act as 'first messengers', causing biologically important changes in availability of the 'second messenger' cAMP. Fertilization promoting peptide (FPP), calcitonin and adenosine all regulate cAMP production, stimulating it in uncapacitated spermatozoa and then inhibiting it in capacitated cells; in contrast, angiotensin II stimulates cAMP throughout capacitation. The molecules that regulate cAMP appear to do so via G protein-modulated changes in membrane associated adenylyl cyclases (mACs). Both mouse and human spermatozoa have been shown to have Galphas and Galphai2, as well as several isoforms of mAC, located in the same regions as the specific receptors. Thus spermatozoa possess the required elements for several separate signal transduction pathways, many of which regulate mAC/cAMP and so maintain sperm fertilizing ability. In vivo, such responses could increase the chances of successful fertilization.
Collapse
Affiliation(s)
- Lynn R Fraser
- Reproduction and Rhythms Group, Centre for Reproduction, Endocrinology and Diabetes, School of Biomedical Sciences, King's College London, Guy's Campus, London, UK.
| | | | | | | | | |
Collapse
|
28
|
Abstract
Angiotensin II (AII) stimulates capacitation and fertilizing ability in mammalian spermatozoa, with the binding of AII to its receptors resulting in stimulation of cAMP production in both uncapacitated and capacitated cells. This study investigated possible mechanisms whereby AII affects cAMP availability. The first question was whether extracellular Ca2+ is required for responses in mouse spermatozoa and, using chlortetracycline fluorescence analysis, it was clear that cells responded to AII only when the medium contained CaCl2, with both 90 microM and 1.80 mM supporting a significant acceleration of capacitation. Consistent with those results, AII significantly stimulated cAMP production in both CaCl2-containing media tested, the response being greater in that containing 1.80 mM. Several different agents that might affect the signalling pathway stimulated by AII were then evaluated in uncapacitated suspensions. Chlortetracycline analysis revealed that pertussis toxin abolished responses to AII, suggesting the involvement of an inhibitory Galpha subunit; dideoxyadenosine, a specific membrane-associated adenylyl cyclase (mAC) P-site inhibitor, also blocked responses, suggesting involvement of an mAC. cAMP determinations confirmed that both reagents also abolished AII's stimulation of cAMP. In contrast, nifedipine, a Ca2+ channel blocker, did not inhibit AII's effects on spermatozoa. Finally, in capacitated suspensions, both pertussis toxin and dideoxyadenosine were again shown to block AII's stimulation of cAMP. These results suggest that responses to AII involve an inhibitory G protein and an mAC, but it is likely that AII-receptor coupling does not stimulate directly mAC but rather does so in an indirect manner, perhaps by altering the intracellular Ca2+ concentration.
Collapse
Affiliation(s)
- Samra Mededovic
- Centre for Reproduction, Endocrinology and Diabetes, School of Biomedical Sciences, King's College London, Guy's Campus, London Bridge, London SE1 1UL, UK
| | | |
Collapse
|
29
|
Fraser LR, Adeoya-Osiguwa SA. New insights into possible factors contributing to male subfertility. Reprod Med Biol 2005. [PMID: 29699209 DOI: 10.1111/j.1447-0578.2005.00089.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Male subfertility contributes significantly to fertility problems in couples. Although semen analysis may identify abnormalities in sperm numbers, morphology and/or motility that might contribute to subfertility, in other instances the semen parameters may appear to be normal, but the spermatozoa might be dysfunctional. A number of endogenous and exogenous factors have now been identified that can significantly affect sperm function in vitro and it is possible that they may have similar effects in vivo. Some endogenous factors maintain the spermatozoa in a non-fertilizing state, to avoid them 'burning out' and losing fertility before they reach an oocyte, while others stimulate spermatozoa to become fertile and then hold them in a state of readiness to fertilize. Exogenous environmental molecules, referred to as xenobiotics, have been shown to continuously stimulate spermatozoa so that they become fertile quickly, but then 'burn out'. Defects relating to the endogenous molecules could result in spermatozoa either never becoming fertile or becoming fertile too quickly and so losing fertilizing potential. By understanding the mechanisms involved in promoting sperm fertilizing ability, it may be possible to develop new therapeutic treatments to overcome such defects. (Reprod Med Biol 2005; 4: 45-53).
Collapse
Affiliation(s)
- Lynn R Fraser
- Reproduction and Rhythms Group, School of Biomedical Sciences, King's College London, Guy's Campus, London, UK
| | - Susan A Adeoya-Osiguwa
- Reproduction and Rhythms Group, School of Biomedical Sciences, King's College London, Guy's Campus, London, UK
| |
Collapse
|
30
|
Fraser LR, Adeoya-Osiguwa SA. New insights into possible factors contributing to male subfertility. Reprod Med Biol 2005; 4:45-52. [PMID: 29699209 PMCID: PMC5904685 DOI: 10.1007/bf03016136] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Male subfertility contributes significantly to fertility problems in couples. Although semen analysis may identify abnormalities in sperm numbers, morphology and/or motility that might contribute to subfertility, in other instances the semen parameters may appear to be normal, but the spermatozoa might be dysfunctional. A number of endogenous and exogenous factors have now been identified that can significantly affect sperm function in vitro and it is possible that they may have similar effects in vivo. Some endogenous factors maintain the spermatozoa in a non-fertilizing state, to avoid them 'burning out' and losing fertility before they reach an oocyte, while others stimulate spermatozoa to become fertile and then hold them in a state of readiness to fertilize. Exogenous environmental molecules, referred to as xenobiotics, have been shown to continuously stimulate spermatozoa so that they become fertile quickly, but then 'burn out'. Defects relating to the endogenous molecules could result in spermatozoa either never becoming fertile or becoming fertile too quickly and so losing fertilizing potential. By understanding the mechanisms involved in promoting sperm fertilizing ability, it may be possible to develop new therapeutic treatments to overcome such defects. (Reprod Med Biol 2005; 4: 45-53).
Collapse
Affiliation(s)
- Lynn R Fraser
- Reproduction and Rhythms Group, School of Biomedical Sciences, King's College London, Guy's Campus, London, UK
| | - Susan A Adeoya-Osiguwa
- Reproduction and Rhythms Group, School of Biomedical Sciences, King's College London, Guy's Campus, London, UK
| |
Collapse
|
31
|
Adeoya-Osiguwa SA, Fraser LR. Cathine and norephedrine, both phenylpropanolamines, accelerate capacitation and then inhibit spontaneous acrosome loss. Hum Reprod 2004; 20:198-207. [PMID: 15513978 DOI: 10.1093/humrep/deh566] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Cathinone, released when Catha edulis leaves (khat) are chewed, has euphoric, stimulatory properties. It is metabolized to the phenylpropanolamines (PPAs) cathine and norephedrine. This study investigated whether PPAs affect mammalian sperm function, using primarily mouse, but also human, spermatozoa. METHODS Uncapacitated sperm suspensions were treated with cathine, norephedrine, adrenaline and noradrenaline, then assessed using chlortetracycline (CTC) fluorescence. Cathine and adrenaline were also evaluated using in vitro fertilization. Capacitated suspensions were treated with PPAs+/-progesterone and+/-pertussis toxin. Finally, cAMP production was evaluated in uncapacitated and capacitated suspensions. RESULTS In uncapacitated mouse spermatozoa, cathine, norephedrine, adrenaline and noradrenaline all significantly accelerated capacitation; uncapacitated human spermatozoa responded similarly to cathine. Consistent with these results, cathine- and adrenaline-treated suspensions were significantly more fertile than controls. In capacitated spermatozoa, both PPAs inhibited spontaneous acrosome reactions (ARs) but progesterone could over-ride this inhibition. Pertussis toxin abolished cathine's inhibition of ARs, suggesting G protein involvement. Finally, cathine and adrenaline significantly stimulated cAMP production in uncapacitated suspensions, but significantly inhibited it in capacitated suspensions. CONCLUSIONS This is the first demonstration that PPAs can directly affect mammalian sperm function, accelerating capacitation and inhibiting spontaneous ARs. These responses correlated with initial stimulation and subsequent inhibition of cAMP production. Adrenaline/noradrenaline elicited similar responses, suggesting the presence of adrenergic receptors. Therefore, regulation of adenylyl cyclase/cAMP in a G protein-mediated fashion by PPAs may possibly involve adrenergic receptors. These results suggest that PPAs, at appropriate doses, might provide a novel approach to enhance natural fertility.
Collapse
Affiliation(s)
- Susan A Adeoya-Osiguwa
- Centre for Reproduction Endocrinology and Diabetes School of Biomedical Sciences, King's College London, Guy's Campus, London SE1 1UL, UK
| | | |
Collapse
|
32
|
Valdivia A, Irazusta J, Fernández D, Múgica J, Ochoa C, Casis L. Pyroglutamyl peptidase I and prolyl endopeptidase in human semen: increased activity in necrozoospermia. ACTA ACUST UNITED AC 2004; 122:79-84. [PMID: 15380924 DOI: 10.1016/j.regpep.2004.05.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2004] [Revised: 05/21/2004] [Accepted: 05/21/2004] [Indexed: 11/16/2022]
Abstract
Thyrotropin-releasing hormone (TRH) and its analogues have been reported to have important functions in human semen. In the present paper, we have characterized the activity of the TRH-degrading enzymes pyroglutamyl peptidase I and prolyl endopeptidase in the fluid and prostasomes of human semen and in subcellular fractions of the corresponding sperm. Enzymatic activities were measured fluorimetrically using beta-naphthylamine derivatives as substrate. Activity associated with both enzymes was detected in seminal fluid and in the prostasome fraction, as well as in soluble and particulate sperm subcellular fractions. Pyroglutamyl-peptidase I activity presented highest levels in the particulate sperm fraction, whereas the activity of prolyl endopeptidase was maximal in the soluble sperm fraction. In addition, we compared the activity of both enzymes in different seminal fractions in normozoospermic, fertile men and in subfertile patients with different abnormalities revealed by spermiogram analysis (astenozoospermia, necrozoospermia and teratozoospermia). The activities of pyroglutamyl peptidase I and prolyl endopeptidase in necrozoospermia were found to be higher in the corresponding soluble and particulate sperm fractions, respectively, with respect to those measured in normozoospermic semen. The results of the present study indicate that these enzymes may participate in regulating the levels of seminal TRH analogues and in mediating sperm death associated with necrozoospermia.
Collapse
Affiliation(s)
- Asier Valdivia
- Department of Physiology, Faculty of Medicine and Dentistry, University of the Basque Country, P.O. Box 699 Bilbao, Bizkaia, Spain.
| | | | | | | | | | | |
Collapse
|
33
|
Luconi M, Porazzi I, Ferruzzi P, Marchiani S, Forti G, Baldi E. Tyrosine phosphorylation of the a kinase anchoring protein 3 (AKAP3) and soluble adenylate cyclase are involved in the increase of human sperm motility by bicarbonate. Biol Reprod 2004; 72:22-32. [PMID: 15342355 DOI: 10.1095/biolreprod.104.032490] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Mammalian testicular spermatozoa are immotile, thus, to reach the oocyte, they need to acquire swimming ability under the control of different factors acting during the sperm transit through the epididymis and the female genital tract. Although bicarbonate is known to physiologically increase motility by stimulating soluble adenylate cyclase (sAC) activity of mammalian spermatozoa, no extensive studies in human sperm have been performed yet to elucidate the additional molecular mechanisms involved. In this light, we investigated the effect of in vitro addition of bicarbonate to human spermatozoa on the main intracellular signaling pathways involved in regulation of motility, namely, intracellular cAMP production and protein tyrosine phosphorylation. Bicarbonate effects were compared with those of the phosphatidyl-inositol-3 kinase inhibitor, LY294002, previously demonstrated to be a pharmacological stimulus for sperm motility. Bicarbonate addition to spermatozoa results in a significant increase in sperm motility as well as in several hyperactivation parameters. This stimulatory effect of bicarbonate and LY294002 is mediated by an increase in cAMP production and tyrosine phosphorylation of the A kinase anchoring protein, AKAP3. The specificity of bicarbonate effects was confirmed by inhibition with 4,4'-di-isothiocyanostilbene-2,2'-disulfonic acid. We remark that, in human spermatozoa, bicarbonate acts primarily through activation of sAC to stimulate tyrosine phosphorylation of AKAP3 and sperm motility because both effects are blunted by the sAC inhibitor 2OH-estradiol. In conclusion, our data provide the first evidence that bicarbonate stimulates human sperm motility and hyperactivation through activation of sAC and tyrosine phosphorylation of AKAP3, finally leading to an increased recruitment of PKA to AKAP3.
Collapse
Affiliation(s)
- M Luconi
- Department of Clinical Physiopathology, Center for Research, Transfer and High Education MCIDNENT, University of Florence, 1-50139 Florence, Italy.
| | | | | | | | | | | |
Collapse
|