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Signorini C, Moretti E, Noto D, Mattioli S, Castellini C, Pascarelli NA, Durand T, Oger C, Galano JM, De Felice C, Lee JCY, Collodel G. F 4-Neuroprostanes: A Role in Sperm Capacitation. Life (Basel) 2021; 11:life11070655. [PMID: 34357027 PMCID: PMC8306804 DOI: 10.3390/life11070655] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 06/24/2021] [Accepted: 07/02/2021] [Indexed: 12/14/2022] Open
Abstract
F4-neuroprostanes (F4-NeuroPs), derived from the oxidative metabolization of docosahexaenoic acid (DHA), are considered biomarkers of oxidative stress in neurodegenerative diseases. Neurons and spermatozoa display a high DHA content. NeuroPs might possess biological activities. The aim of this in vitro study was to investigate the biological effects of chemically synthetized 4-F4t-NeuroP and 10-F4t-NeuroP in human sperm. Total progressive sperm motility (p < 0.05) and linearity (p = 0.016), evaluated by a computer-assisted sperm analyzer, were significantly increased in samples incubated with 7 ng F4-NeuroPs compared to non-supplemented controls. Sperm capacitation was tested in rabbit and swim-up-selected human sperm by chlortetracycline fluorescence assay. A higher percentage of capacitated sperm (p < 0.01) was observed in samples incubated in F4-NeuroPs than in the controls. However, the percentage of capacitated sperm was not different in F4-NeuroPs and calcium ionophore treatments at 2 h incubation. The phosphorylated form of AMPKα was detected by immunofluorescence analysis; after 2 h F4-NeuroP incubation, a dotted signal appeared in the entire sperm tail, and in controls, sperm were labeled in the mid-piece. A defined level of seminal F4-NeuroPs (7 ng) showed a biological activity in sperm function; its addition in sperm suspensions stimulated capacitation, increasing the number of sperm able to fertilize.
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Affiliation(s)
- Cinzia Signorini
- Department of Molecular and Developmental Medicine, University of Siena, Policlinico Santa Maria Alle Scotte, Viale Bracci 14, 53100 Siena, Italy; (C.S.); (D.N.); (N.A.P.); (G.C.)
| | - Elena Moretti
- Department of Molecular and Developmental Medicine, University of Siena, Policlinico Santa Maria Alle Scotte, Viale Bracci 14, 53100 Siena, Italy; (C.S.); (D.N.); (N.A.P.); (G.C.)
- Correspondence: ; Tel.: +39-577-233511
| | - Daria Noto
- Department of Molecular and Developmental Medicine, University of Siena, Policlinico Santa Maria Alle Scotte, Viale Bracci 14, 53100 Siena, Italy; (C.S.); (D.N.); (N.A.P.); (G.C.)
| | - Simona Mattioli
- Department of Agricultural, Environmental, and Food Science, University of Perugia, Borgo XX Giugno 74, 06123 Perugia, Italy; (S.M.); (C.C.)
| | - Cesare Castellini
- Department of Agricultural, Environmental, and Food Science, University of Perugia, Borgo XX Giugno 74, 06123 Perugia, Italy; (S.M.); (C.C.)
| | - Nicola Antonio Pascarelli
- Department of Molecular and Developmental Medicine, University of Siena, Policlinico Santa Maria Alle Scotte, Viale Bracci 14, 53100 Siena, Italy; (C.S.); (D.N.); (N.A.P.); (G.C.)
| | - Thierry Durand
- Institut des Biomolécules Max Mousseron (IBMM), UMR 5247, CNRS, Université de Montpellier, ENSCM, 34090 Montpellier, France; (T.D.); (C.O.); (J.-M.G.)
| | - Camille Oger
- Institut des Biomolécules Max Mousseron (IBMM), UMR 5247, CNRS, Université de Montpellier, ENSCM, 34090 Montpellier, France; (T.D.); (C.O.); (J.-M.G.)
| | - Jean-Marie Galano
- Institut des Biomolécules Max Mousseron (IBMM), UMR 5247, CNRS, Université de Montpellier, ENSCM, 34090 Montpellier, France; (T.D.); (C.O.); (J.-M.G.)
| | - Claudio De Felice
- Child Neuropsychiatry Unit, Azienda Ospedaliera Universitaria Senese, 53100 Siena, Italy;
- Neonatal Intensive Care Unit, Azienda Ospedaliera Universitaria Senese, 53100 Siena, Italy
| | | | - Giulia Collodel
- Department of Molecular and Developmental Medicine, University of Siena, Policlinico Santa Maria Alle Scotte, Viale Bracci 14, 53100 Siena, Italy; (C.S.); (D.N.); (N.A.P.); (G.C.)
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Ostermeier GC, Cardona C, Moody MA, Simpson AJ, Mendoza R, Seaman E, Travis AJ. Timing of sperm capacitation varies reproducibly among men. Mol Reprod Dev 2018. [PMID: 29521463 PMCID: PMC6001750 DOI: 10.1002/mrd.22972] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Sperm must mature functionally in the process of capacitation to become able to fertilize. Capacitation depends on membrane lipid changes, and can be quantitatively assessed by redistribution of the ganglioside GM1, the basis of the Cap‐Score™ sperm function test. Here, differences in Cap‐Score were compared among and within men at two time points. Ejaculates were liquefied, washed, and incubated for 3 hr under capacitating (Cap) conditions, then fixed and analyzed immediately (Day0); after being incubated 3 hr under Cap conditions then maintained 22–24 hr in fix (Day1‐fix); or after 22–24 hr incubation under Cap conditions prior to fixation (Day1). In all cases, a light fixative previously shown to allow membrane lipid movements was used. Day1‐fix and Day1 Cap‐Scores were greater than Day0 (p < 0.001; n = 25), whereas Day1‐fix and Day1 Cap‐Scores were equivalent (p = 0.43; n = 25). In 123 samples from 52 fertile men, Cap‐Score increased more than 1SD (7.7; calculated previously from a fertile cohort) from Day0 to Day1‐fix in 44% (54/123) of the samples. To test whether timing of capacitation was consistent within an individual, 52 samples from 11 fertile men were classified into either “early” or “late” capacitation groups. The average capacitation group concordance within a donor was 81%. Median absolute deviation (MAD; in Cap‐Score units) was used to assess the tightness of clustering of the difference from Day0 to Day1‐fix within individuals. The average (2.21) and median (1.98) MAD confirmed consistency within individuals. Together, these data show that the timing of capacitation differed among men and was consistent within men.
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Affiliation(s)
| | | | | | | | | | | | - Alexander J. Travis
- Androvia LifeSciencesMountainsideNew Jersey
- Baker Institute for Animal Health, College of Veterinary MedicineCornell UniversityIthacaNew York
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3
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Agarwal A, Ayaz A, Samanta L, Sharma R, Assidi M, Abuzenadah AM, Sabanegh E. Comparative proteomic network signatures in seminal plasma of infertile men as a function of reactive oxygen species. Clin Proteomics 2015; 12:23. [PMID: 26321892 PMCID: PMC4552280 DOI: 10.1186/s12014-015-9094-5] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 08/12/2015] [Indexed: 11/24/2022] Open
Abstract
Background Reactive oxygen species (ROS) plays a major role in the pathology of male infertility. It is an independent biomarker of sperm function. Seminal plasma is a natural reservoir of antioxidants responsible for the nourishment, protection, capacitation, and motility of sperm within the female reproductive tract resulting in successful fertilization and implantation of the embryo. A comparative proteomic analysis of seminal plasma proteins from fertile men and infertile men with varying levels of ROS was carried out to identify signature proteins involved in ROS-mediated reproductive dysfunction. Methods A total of 42 infertile men presenting with infertility and 17 proven fertile donors were enrolled in the study. ROS levels were measured in the seminal ejaculates by chemiluminescence assay. Infertile men were subdivided into Low ROS (0–<93 RLU/s/106 sperm; n = 11), Medium ROS (>93–500 RLU/s/106 sperm; n = 17) and High ROS (>500 RLU/s/106 sperm; n = 14) groups and compared with fertile men (4–50 RLU/s/106 sperm). 4 subjects from fertile group and 4 each from the Low, Medium and High ROS were pooled. 1D gel electrophoresis followed by in-gel digestion and LC/MS–MS in a LTQ-Orbitrap Elite hybrid mass spectrometer system was used for proteome analysis. Identification of differentially expressed proteins (DEPs), their cellular localization and involvement in different pathways were examined utilizing bioinformatics tools. Results The results indicate that proteins involved in biomolecule metabolism, protein folding and protein degradation are differentially modulated in all three infertile patient groups in comparison to fertile controls. Membrane metallo-endopeptidase (MME) was uniformly overexpressed (>2 fold) in all infertile groups. Pathway involving 35 focus proteins in post-translational modification of proteins, protein folding (heat shock proteins, molecular chaperones) and developmental disorder was overexpressed in the High ROS group compared with fertile control group. MME was one of the key proteins in the pathway. FAM3D was uniquely expressed in fertile group. Conclusion We have for the first time demonstrated the presence of 35 DEPs of a single pathway that may lead to impairment of sperm function in men with Low, Medium or High ROS levels by altering protein turn over. MME and FAM3D along with ROS levels in the seminal plasma may serve as good markers for diagnosis of male infertility. Electronic supplementary material The online version of this article (doi:10.1186/s12014-015-9094-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ashok Agarwal
- American Center for Reproductive Medicine, Department of Urology, Cleveland Clinic, Cleveland, OH 44195 USA
| | - Ahmet Ayaz
- American Center for Reproductive Medicine, Department of Urology, Cleveland Clinic, Cleveland, OH 44195 USA
| | - Luna Samanta
- American Center for Reproductive Medicine, Department of Urology, Cleveland Clinic, Cleveland, OH 44195 USA ; Department of Zoology, School of Life Sciences, Ravenshaw University, Cuttack, Odisha 751003 India
| | - Rakesh Sharma
- American Center for Reproductive Medicine, Department of Urology, Cleveland Clinic, Cleveland, OH 44195 USA
| | - Mourad Assidi
- Center of Excellence in Genomic Medicine Research, King AbdulAziz University, Jeddah, Saudi Arabia ; KACST Technology Innovation Center in Personalized Medicine at King AbdulAziz University, Jeddah, Saudi Arabia
| | - Adel M Abuzenadah
- Center of Excellence in Genomic Medicine Research, King AbdulAziz University, Jeddah, Saudi Arabia ; KACST Technology Innovation Center in Personalized Medicine at King AbdulAziz University, Jeddah, Saudi Arabia
| | - Edmund Sabanegh
- Department of Urology, Cleveland Clinic, Cleveland, OH 44195 USA
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Abstract
Females frequently mate with several males, whose sperm then compete to fertilize available ova. Sperm competition represents a potent selective force that is expected to shape male expenditure on the ejaculate. Here, we review empirical data that illustrate the evolutionary consequences of sperm competition. Sperm competition favors the evolution of increased testes size and sperm production. In some species, males appear capable of adjusting the number of sperm ejaculated, depending on the perceived levels of sperm competition. Selection is also expected to act on sperm form and function, although the evidence for this remains equivocal. Comparative studies suggest that sperm length and swimming speed may increase in response to selection from sperm competition. However, the mechanisms driving this pattern remain unclear. Evidence that sperm length influences sperm swimming speed is mixed and fertilization trials performed across a broad range of species demonstrate inconsistent relationships between sperm form and function. This ambiguity may in part reflect the important role that seminal fluid proteins (sfps) play in affecting sperm function. There is good evidence that sfps are subject to selection from sperm competition, and recent work is pointing to an ability of males to adjust their seminal fluid chemistry in response to sperm competition from rival males. We argue that future research must consider sperm and seminal fluid components of the ejaculate as a functional unity. Research at the genomic level will identify the genes that ultimately control male fertility.
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Affiliation(s)
- Leigh W Simmons
- Centre for Evolutionary Biology, , School of Animal Biology (M092), The University of Western Australia, Crawley, Western Australia 6009, Australia.
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Liu Y, Qu F, Cao X, Chen G, Guo Q, Ying X, Guo W, Lu L, Ding Z. Con A-binding protein Zn-α2-glycoprotein on human sperm membrane is related to acrosome reaction and sperm fertility. ACTA ACUST UNITED AC 2011; 35:145-57. [PMID: 21790656 DOI: 10.1111/j.1365-2605.2011.01195.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Fertilization, the recognition and fusion between spermatozoa and oocyte, involves various molecules on the spermatozoa and oocyte membranes. Concanavalin A (ConA)-binding proteins may be one of the molecules involved in mammal spermatozoa fertilization; however, their structure and function remain largely unknown. Here, we initially identified a ConA-binding protein, Zn-α2-glycoprotein (ZAG), involved in regulating the acrosome reaction (AR) of human spermatozoa. ZAG is localized on the pre-equatorial region covering the acrosome, neck and tail (some parts of middle piece and principal piece respectively) regions of the acrosome intact human spermatozoa, and disappears in the acrosomal region of the acrosome-reacted spermatozoa. Polyclonal antibodies against human recombinant ZAG significantly reduced the AR and sperm capability binding to human zona pellucida or penetration into zona-free hamster oocytes. Furthermore, assessment of the signaling pathways regulated by ZAG revealed that ZAG affects sperm AR through both the cAMP/PKA and PKC pathways. These results indicate that ZAG, which is present on the human sperm membrane, plays a critical role in the AR and subsequently, may be involved in sperm fertility.
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Affiliation(s)
- Y Liu
- Key Laboratory for Reproductive Medicine, Department of Histology and Embryology, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
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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.
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Affiliation(s)
- Lynn R Fraser
- Division of Reproduction and Endocrinology, School of Biomedical and Health Sciences, King's College London, London SE1 1UL, UK.
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7
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Relationship between substances in seminal plasma and Acrobeads Test∗ results. Fertil Steril 2009; 91:179-84. [DOI: 10.1016/j.fertnstert.2007.11.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2007] [Revised: 11/06/2007] [Accepted: 11/06/2007] [Indexed: 11/19/2022]
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Teranishi JI, Ishiguro H, Hoshino K, Noguchi K, Kubota Y, Uemura H. Evaluation of role of angiotensin III and aminopeptidases in prostate cancer cells. Prostate 2008; 68:1666-73. [PMID: 18677709 DOI: 10.1002/pros.20835] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND The aim of this study was to perform a comprehensive evaluation of angiotensin III (Ang-III) and related converting enzymes, aminopeptidase A (APA) and N (APN), in prostate cancer. METHODS We investigated the effects of Ang-III on the in vitro growth of human prostate cancer cells and the expression of APA and APN in cells treated with Ang-III or hormonal agents. Furthermore, we performed real-time quantitative PCR to investigate the expression pattern of APA and APN in 86 prostate tissue samples including normal prostate, untreated and hormone refractory prostate cancer (HRPC). RESULTS Ang-III stimulated cell proliferation, and the proliferative effect was inhibited by olmesartan, an AT(1) receptor blocker (ARB). Western blot analysis showed that phosphorylation of mitogen-activated protein kinase (MAPK) was enhanced by Ang-III and inhibited by olmesartan. APN mRNA level in HRPC was significantly lower than that in normal prostate and untreated prostate cancer tissue. In LNCaP cells, APN expression was augmented by Ang-III, whereas APA expression was not modulated. Hormonal agents, such as estradiol (E2) and dexamethasone (Dex), enhanced APA expression, but did not modulate APN expression in LNCaP cells. CONCLUSIONS Our results suggest that Ang-III and related converting enzymes contribute to cell proliferation of prostate cancer, and may be implicated in cancer progression.
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Affiliation(s)
- Jun-ichi Teranishi
- Department of Urology, Yokohama City University Medical Center, Minami-ku, Yokohama, Japan
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9
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Qu F, Ying X, Guo W, Guo Q, Chen G, Liu Y, Ding Z. The role of Zn-alpha2 glycoprotein in sperm motility is mediated by changes in cyclic AMP. Reproduction 2007; 134:569-76. [PMID: 17890292 DOI: 10.1530/rep-07-0145] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Sperm motility is essential for male reproduction or natural fertilization. The cyclic AMP (cAMP)/cAMP-dependent protein kinase A (PKA) signaling pathway is generally recognized as one of the significant signaling pathways in the regulation of mammalian spermatozoan motility. Since Zn-alpha2-glycoprotein (ZAG) activity in mammalian adipose tissue is mediated via the beta(3)-adrenoreceptor, with upregulation of the cAMP pathway, we hypothesize that ZAG may play the same role in sperm motility regulation, a new factor of regulation of sperm motility. Therefore, the gene encoding human ZAG was cloned and polyclonal antibodies were generated, and then laser scanning confocal microscopy and flow cytometry were employed to identify this protein in human spermatozoa. The results showed that ZAG protein was mostly localized on the pre-equatorial region covering the acrosome, neck, and middle piece of the flagellum of spermatozoa. Furthermore, using computer-assisted sperm analysis, we found that anti-human ZAG antibodies could significantly reduce the motility of human swim-up spermatozoa after 90- or 120-min incubation (P<0.05 and P<0.01 respectively), together with the decreasing of intracellular cAMP and PKA levels. In conclusion, these data suggest that ZAG is present in human spermatozoa and may be involved in the regulation of sperm motility via the cAMP/PKA signaling pathway.
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Affiliation(s)
- Fei Qu
- Shanghai Key Laboratory for Reproductive Medicine, Department of Histology and Embryology, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
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10
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Duncan MW, Thompson HS. Proteomics of semen and its constituents. Proteomics Clin Appl 2007; 1:861-75. [DOI: 10.1002/prca.200700228] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2007] [Indexed: 01/23/2023]
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Uemura H, Hasumi H, Ishiguro H, Teranishi JI, Miyoshi Y, Kubota Y. Renin-angiotensin system is an important factor in hormone refractory prostate cancer. Prostate 2006; 66:822-30. [PMID: 16482568 DOI: 10.1002/pros.20407] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
BACKGROUND The aim of this study was to perform a comprehensive evaluation of the renin-angiotensin system (RAS) in prostate cancer. METHODS We investigated the expression of RAS components in prostate cancer cells treated with hormonal agents. Real-time PCR data showed the expression of the AT1 receptor, angiotensin I converting enzyme (ACE), and angiotensin I/II (Ang-I/II) precursor in all 87 prostate tissue samples. RESULTS Expression of these genes in hormone refractory prostate cancer (HRPC) was significantly higher than that in normal prostate tissue and untreated prostate cancer tissue. Western blot showed that protein expression of the AT1 receptor and Ang-I/II was enhanced in LNCaP cells cultivated in steroid-free medium. When LNCaP cells were stimulated with dihydrotestosterone (DHT), estradiol (E2), dexamethasone (DEX), or anti-androgen drugs, protein expression of the AT1 receptor and Ang-I/II was augmented. CONCLUSIONS The present data suggest that prostatic RAS is overexpressed in HRPC tissue, and expression of its components is influenced by several kinds of hormonal stimulation.
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MESH Headings
- Androgen Antagonists/pharmacology
- Angiotensin I/analysis
- Angiotensin I/genetics
- Angiotensin II/analysis
- Angiotensin II/genetics
- Antineoplastic Agents, Hormonal/therapeutic use
- Blotting, Western
- Cell Line, Tumor
- Dexamethasone/pharmacology
- Dihydrotestosterone/pharmacology
- Drug Resistance, Neoplasm
- Estradiol/pharmacology
- Gene Expression Regulation, Neoplastic/drug effects
- Humans
- Male
- Peptidyl-Dipeptidase A/analysis
- Peptidyl-Dipeptidase A/genetics
- Prostate/chemistry
- Prostate/drug effects
- Prostate/physiology
- Prostatic Neoplasms/chemistry
- Prostatic Neoplasms/drug therapy
- Prostatic Neoplasms/genetics
- Prostatic Neoplasms/physiopathology
- RNA, Messenger/analysis
- RNA, Messenger/genetics
- Receptor, Angiotensin, Type 1/analysis
- Receptor, Angiotensin, Type 1/genetics
- Renin-Angiotensin System/genetics
- Renin-Angiotensin System/physiology
- Reverse Transcriptase Polymerase Chain Reaction
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Affiliation(s)
- Hiroji Uemura
- Department of Urology, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
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12
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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.
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Affiliation(s)
- Rhona W Baxendale
- Reproduction and Rhythms Group, School of Biomedical Sciences, King's College London, London, United Kingdom
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13
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Adeoya-Osiguwa SA, Gibbons R, Fraser LR. Identification of functional alpha2- and beta-adrenergic receptors in mammalian spermatozoa. Hum Reprod 2006; 21:1555-63. [PMID: 16488904 DOI: 10.1093/humrep/del016] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND A recent study of several compounds, structurally related to amphetamine, provided evidence that mammalian spermatozoa might have adrenergic receptors able to regulate cAMP production. The present study investigated this possibility using physiological and immunochemical analyses of mouse and human spermatozoa. METHODS Antibodies specific for different receptor subtypes were used for Western blotting of mouse and human sperm lysates and for immunocytochemical evaluation of whole mouse and human spermatozoa. Uncapacitated and capacitated mouse spermatozoa were incubated with specific agonists and antagonists for alpha2-, beta1-, beta2- and beta3-adrenergic receptors for approximately 35 min and then assessed using chlortetracycline (CTC) fluorescence. RESULTS Western blotting revealed proteins of the correct size for all these receptors; immunolocalization indicated their presence on the head, especially acrosomal and neck regions, and flagellum of both mouse and human spermatozoa. CTC results indicated significant responses to agonists for all of the beta-receptors in uncapacitated cells, with agonist effectiveness being beta1 > beta2 > beta3; relevant antagonists blocked responses. In contrast, an agonist and antagonist for alpha2-receptors acted only on capacitated spermatozoa. CONCLUSION These experiments provide the first good evidence that mammalian spermatozoa have both beta-adrenergic receptors, known to stimulate cAMP production by membrane-associated adenylyl cyclases (mACs), and alpha2-adrenergic receptors, known to inhibit cAMP production by mACs. Responses are capacitation state dependent and provide a mechanism for inhibiting spontaneous acrosome reactions and helping to maintain fertilizing ability. These results suggest that the use of amphetamine-related compounds, either for medical or for social reasons, might have an unexpected positive impact on fertility.
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14
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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.
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Affiliation(s)
- Lynn R Fraser
- Reproduction and Rhythms Group, School of Biomedical and Health Sciences, King's College London, London, UK.
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15
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Uemura H, Ishiguro H, Nagashima Y, Sasaki T, Nakaigawa N, Hasumi H, Kato S, Kubota Y. Antiproliferative activity of angiotensin II receptor blocker through cross-talk between stromal and epithelial prostate cancer cells. Mol Cancer Ther 2006; 4:1699-709. [PMID: 16275991 DOI: 10.1158/1535-7163.mct-04-0295] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We showed previously that angiotensin II activated the proliferation of prostate cancer cells and that angiotensin II receptor blockers (ARB) could inhibit it. Here, we investigated whether angiotensin II exerts mitogenic effects on the cross-talk between stromal and cancer cells and whether an ARB can inhibit tumor growth through actions on stromal cells. Cell proliferation and interleukin-6 secretion of prostate stromal PrSC cells stimulated with angiotensin II, tumor necrosis factor-alpha, or epidermal growth factor were examined in the absence and presence of ARB. We examined the effect of ARB on mitogen-activated protein kinase (MAPK) phosphorylation of PrSC and PC-3 cells treated with conditioned medium of PrSC cells and determined the effect of ARB on tumor growth induced by paracrine factors from PrSC cells. Angiotensin II activated the cell proliferation and interleukin-6 secretion of PrSC cells, and ARB inhibited it. Angiotensin II, tumor necrosis factor-alpha, or epidermal growth factor induced MAPK phosphorylation in PrSC cells, and this phosphorylation was inhibited by ARB. Conditioned medium of PrSC cells with angiotensin II activated MAPK phosphorylation in PC-3 cells, and ARB-treated conditioned medium of PrSC cells inhibited it. The tumor growth and angiogenesis of a mixture of PC-3 with PrSC were inhibited by ARB administration, whereas those of PC-3 xenografts were not inhibited. ARB exerted an antiproliferative effect on prostate cancer through paracrine factors from stromal cells. Because prostate stromal cells are thought to be involved in the initiation and development of prostate cancer, the present data suggest the possibility that ARBs are a novel therapeutic class of agents for prostate cancer.
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Affiliation(s)
- Hiroji Uemura
- Department of Urology, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan.
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16
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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.
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Affiliation(s)
- Rachel Gibbons
- Reproduction and Rhythms Group, School of Biomedical Sciences, King's College London, Guy's Campus, London SE1 1UL, UK
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17
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Chiu PCN, Chung MK, Tsang HY, Koistinen R, Koistinen H, Seppala M, Lee KF, Yeung WSB. Glycodelin-S in Human Seminal Plasma Reduces Cholesterol Efflux andInhibits Capacitation ofSpermatozoa. J Biol Chem 2005; 280:25580-9. [PMID: 15883155 DOI: 10.1074/jbc.m504103200] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Tight control of sperm capacitation is important for successful fertilization. Glycodelin-S is one of the most abundant glycoproteins in the human seminal plasma. However, its function is unclear. We investigated the role of glycodelin-S on capacitation of human spermatozoa. Binding kinetics experiments demonstrated the presence of two saturable and reversible binding sites of glycodelin-S on human spermatozoa. Differently glycosylated other isoforms of glycodelin, glycodelin-A and -F, did not compete with glycodelin-S for these binding sites, suggesting that the glycodelin-S binding sites are different from those of the other isoforms. Indirect immunofluorescent staining revealed specific binding of glycodelin-S around the sperm head. This immunoreactivity was greatly reduced in spermatozoa that had migrated through the cervical mucus surrogates. Glycodelin-S at physiological concentrations significantly reduced the bovine serum albumin and cyclodextrin-induced cholesterol efflux and down-regulated the adenylyl cyclase/protein kinase A/tyrosine kinase signaling pathway, resulting in suppression of capacitation. Deglycosylation abolished glycodelin-S binding and the effect of glycodelin-S on bovine serum albumin-induced capacitation. This indicates that the carbohydrate moiety of glycodelin-S is critical for the function of the molecule. It is concluded that glycodelin-S in seminal plasma maintains the uncapacitated state of human spermatozoa.
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Affiliation(s)
- Philip C N Chiu
- Department of Obstetrics and Gynaecology, University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Hong Kong, China
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18
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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.
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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.
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19
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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.
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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
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20
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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).
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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
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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).
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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
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22
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O'Mahony OA, Barker S, Puddefoot JR, Vinson GP. Synthesis and secretion of angiotensin II by the prostate gland in vitro. Endocrinology 2005; 146:392-8. [PMID: 15448113 DOI: 10.1210/en.2004-0565] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The renin angiotensin system has been shown to have tissue-related functions that are distinct from its systemic roles. We showed that angiotensin II type 1 (AT1) receptors are present in mammalian sperm, and angiotensin II stimulates sperm motility and capacitation. In addition, angiotensin II is present in human seminal plasma at concentrations higher than found in blood. In testing the possibility that the prostate may be the source of seminal plasma angiotensin II, mRNA coding for angiotensinogen, (pro)renin, and angiotensin-converting enzyme were identified by RT-PCR in rat and human prostate and in prostate LNCaP cells, as well as the angiotensin receptors types 1 and 2 (AT1 and AT2) in human tissues and AT1 in rat. In human tissue, immunocytochemistry showed cellular colocalization of renin with the AT1 receptor in secretory epithelial cells. Confirmation of the capacity of the prostate to secrete angiotensin II was shown by the detection of immunoreactive angiotensin in media removed from rat prostate organ cultures and LNCaP cells. Rat prostate angiotensin secretion was enhanced by dihydrotestosterone, but LNCaP angiotensin was stimulated by estradiol. This stimulation was blocked by tamoxifen. Rat prostate AT1 receptor expression was much greater in prepuberal than in postpuberal rats but was not affected by a low-sodium diet. It was, however, significantly enhanced by captopril pretreatment. These findings all suggest the independence of prostate and systemic renin angiotensin system regulation. The data presented here suggest that the prostate may be a source of the secreted angiotensin II found in seminal plasma.
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Affiliation(s)
- Orla A O'Mahony
- School of Biological Sciences, Queen Mary, University of London, London E1 4NS, United Kingdom
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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.
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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
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24
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Mededovic S, Fraser LR. Angiotensin II stimulates cAMP production and protein tyrosine phosphorylation in mouse spermatozoa. Reproduction 2004; 127:601-12. [PMID: 15129016 DOI: 10.1530/rep.1.00062] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Angiotensin II (AII), found in seminal plasma, has been shown to stimulate capacitation in uncapacitated mammalian spermatozoa. The present study investigated the location of AII receptors on spermatozoa and AII's mechanism of action. AT1 type receptors for AII are present on the acrosomal cap region and along the whole of the flagellum of both mouse and human spermatozoa. Because combinations of low concentrations of AII and either calcitonin or fertilization-promoting peptide (FPP), both known to regulate the adenylyl cyclase (AC)/cAMP signal transduction pathway, elicited a significant response, this study investigated the hypothesis that these peptides act on the same pathway. AII was shown to significantly stimulate cAMP production in both uncapacitated and capacitated mouse spermatozoa and this was associated with increases in protein tyrosine phosphorylation. Using an anti-phosphotyrosine antibody to visualize the location of tyrosine phosphoproteins within individual cells, AII significantly stimulated phosphorylation within 20 min in both the head, especially in the acrosomal cap region, and the flagellum, especially in the principal piece, of uncapacitated mouse spermatozoa; combined AII + FPP was stimulatory within 5 min. In addition, Western blotting revealed that AII stimulation increased phosphorylation in a number of tyrosine phosphoproteins in both uncapacitated and capacitated mouse spermatozoa, with some being altered only in the latter category of cells. These results support the hypothesis that AII stimulates AC/cAMP in mammalian spermatozoa.
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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
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