119. IDENTIFICATION AND CHARACTERISATION OF SURFACE PROTEIN COMPLEXES IN HUMAN SPERMATOZOA

2010 ◽  
Vol 22 (9) ◽  
pp. 37 ◽  
Author(s):  
K. A. Redgrove ◽  
B. Nixon ◽  
E. A. McLaughlin ◽  
M. K. O'Bryan ◽  
R. J. Aitken

A unique characteristic of mammalian spermatozoa is that upon ejaculation, they are unable to recognise and bind to an ovulated oocyte. These functional attributes are only realised following the sperms ascent of the female reproductive tract whereupon they undergo a myriad of biochemical and biophysical changes collectively referred to as ‘capacitation’. Since spermatozoa are both transcriptionally and translationally quiescent cells, this functional transformation must be engineered by a combination of post-translational modification and spatial reorganisation of existing sperm proteins. Indeed, evidence from our laboratory suggests that a key attribute of capacitation is the remodeling of the sperm surface architecture leading to the assembly and / or presentation of multimeric sperm-oocyte receptor complex(es). Through the novel application of Blue Native Polyacrylamide Gel Electrophoresis (BN-PAGE), we have secured the first direct evidence that human spermatozoa express a number of these protein complexes on their surface. Furthermore, we have demonstrated that a subset of these complexes harbour putative zona adhesion proteins and display strong affinity for solubilised zona pellucidae. In this study, we have extended our findings through the characterisation of one such complex containing arylsulfatase A (ASA), a protein with recognised affinity for sulfated ligands present within the zona pellucida. Through the application of immunohistochemistry and flow cytometry we revealed that ASA undergoes a capacitation-associated translocation to become expressed on the apical region of the human sperm head, a location compatible with a role in the mediation of sperm-zona pellucida interactions. This dramatic relocation was completely abolished by incubation of capacitating spermatozoa in exogenous cholesterol, suggesting that it may be driven in part by alteration in the membrane fluidity characteristics. Our current research is focused on confirming the role of ASA in human sperm-zona pellucida adhesion and elucidating the precise cellular mechanisms that underpin the proteins translocation to the cell surface.

2009 ◽  
Vol 21 (9) ◽  
pp. 86
Author(s):  
K. A. Redgrove ◽  
E. A. McLaughlin ◽  
M. K. O'Bryan ◽  
R. J. Aitken ◽  
B. Nixon

Upon leaving the testis mammalian spermatozoa are functionally incompetent and are thus unable to fertilize an oocyte. As the spermatozoa ascend the female reproductive tract, functional maturity is achieved through a complex cascade of biophysical and biochemical changes known as capacitation. An important aspect of this final maturation phase is the remodelling of the sperm surface architecture to enable it to interact with the zona pellucida, a glycoprotein matrix that surrounds the oocyte, and initiate fertilisation. While originally thought to be underpinned by a simple lock and key mechanism, emerging evidence has suggested that this interaction may instead be mediated by a multimeric recognition complex that is formed on the sperm surface during capacitation. However, to date the presence and composition of such a complex has yet to be described. Through the application of Blue Native Polyacrylamide Gel Electrophoresis (BN-PAGE), we have provided evidence that human spermatozoa express a number of high molecular weight protein complexes on their surface. Furthermore, the affinity of these surface expressed complexes for the zona pellucida was assessed utilising solubilised human zona pellucida and the technique of Far Western Blotting. Among the complexes that showed affinity for the zona pellucida we identified one comprising 14 subunits of the 20S proteasome. Interestingly, the 20S proteasome has previously been implicated in various aspects of mammalian fertilisation, including zona pellucida penetration and the acrosome reaction, although its precise role in these events has yet to be elucidated. Collectively, these results demonstrate the presence of multimeric protein complexes on the surface of human spermatozoa, and support their putative role in the initial interaction between the sperm and the zona pellucida. Our current research is focused on elucidation of the role of the 20S proteasome in human sperm-zona binding and further investigation of surface expressed protein complexes.


2008 ◽  
Vol 20 (9) ◽  
pp. 26
Author(s):  
M. D. Dun ◽  
B. Nixon ◽  
R. J. Aitken

Mammalian spermatozoa acquire the ability to fertilise an oocyte as they ascend the female reproductive tract. This process is characterised by a complex cascade of biophysical and biochemical changes collectively known as capacitation. The attainment of a capacitated state is accompanied by a dramatic reorganisation of the surface architecture which renders the spermatozoa competent to recognise the heterogenetic matrix of the zona pellucida surrounding the oocyte and initiate fertilisation. Emerging evidence from our laboratory indicates that this process is facilitated by molecular chaperone-mediated assembly of a multimeric receptor complex on the sperm surface. However, to date the presence and composition of such a complex has yet to be described. Through the novel application of blue native polyacrylamide gel electrophoresis (BN-PAGE), we have provided the first evidence that capacitated mouse spermatozoa express high molecular weight, multimeric protein complexes on their surface. Interestingly, at least two of these complexes contain heat shock protein 1 (HSPD1), a molecular chaperone that has previously been implicated in sperm-zona pellucida interaction. Furthermore, we were able to demonstrate that one of these complexes also possessed an affinity for solubilised zona pellucida as determined by Far-western blotting. 2D BN-PAGE was employed to further delineate the individual constituents of this high molecular weight complex, with several other chaperonin proteins not previously reported in functional sperm indentified. Collectively, these results support the notion the sperm-zona pellucida interaction are mediated by a multimeric receptor complex. Our current work is focussed on the identification of the key zona adhesion molecules that comprise this complex.


2010 ◽  
Vol 22 (9) ◽  
pp. 96
Author(s):  
M. D. Dun ◽  
R. Aitken ◽  
B. Nixon

Mammalian spermatozoa only express their capacity for fertilization following capacitation, a process characterized by a suite of biophysical and biochemical changes that occurs as the cells ascend the female reproductive tract. A key event associated with the attainment of a capacitated state is a dramatic reorganization of the sperm surface architecture to render these cells competent to bind to the protective matrix of the oocyte, the zona pellucida. Our previous analysis of these remodeling events has provided compelling evidence that they include the assembly and/or presentation of multimeric protein complexes on the sperm surface. In addition, we have demonstrated that at least two of these complexes possess strong affinity for solubilized zona pellucida. In our current study we have utilised mass spectrometry analysis to reveal that one of these complexes comprises the eight subunits that form a composite, multimeric structure known as the chaperonin containing TCP-1 (CCT/TRiC) complex. Our collective data suggest that this complex participates indirectly in zona pellucida interaction, possibly through the conveyance of key zona adhesion molecules to the sperm surface during capacitation. Consistent with this notion, we were able to demonstrate that the sperm CCT/TRiC complex releases its bound substrates upon exposure to ATP, and this treatment induced a significant, concomitant reduction in the ability of capacitated sperm to bind to the zona pellucida. Furthermore, the use of immunoprecipitation assays confirmed the interaction of the CCT/TRiC complex with at least one putative zona pellucida receptor candidate, namely zona pellucida binding protein 2 (ZPBP2). Future work is now aimed at identifying additional zona receptors that may reside within this complex and the pathways that regulate its functional assembly.


2010 ◽  
Vol 22 (9) ◽  
pp. 122
Author(s):  
A. L. Anderson ◽  
L. Mitchell ◽  
E. A. McLaughlin ◽  
M. K. O'Bryan ◽  
R. J. Aitken ◽  
...  

Mammalian spermatozoa attain the ability to fertilize an oocyte as they negotiate the female reproductive tract. This acquisition of functional competence is preceded by an intricate cascade of biochemical and functional changes collectively known as ‘capacitation’. Among the universal correlates of the capacitation process is a remarkable remodeling of the lipid and protein architecture of the sperm plasma membrane. While the fundamental mechanisms that underpin this dynamic reorganization remain enigmatic, emerging evidence has raised the prospect that it may be coordinated, at least in part, by specialized membrane microdomains, or rafts. In the studies described herein we have demonstrated that human spermatozoa express recognized markers of membrane rafts. Further, upon depletion of cellular cholesterol through either physiological (capacitation) or pharmacological (methyl-β-cyclodextrin) intervention, these membrane rafts appear to undergo a polarized redistribution to the peri-acrosomal region sperm head. The polarized targeting of membrane rafts to the sperm head encourages speculation that they represent platforms for the organization of proteins involved in sperm-oocyte interactions. Support for this notion rests with the demonstration that membrane rafts isolated on the basis of their biochemical composition in the form of detergent resistant membranes (DRMs), possess the ability to adhere to homologous zona pellucida. Furthermore a comprehensive proteomic analysis of the DRMs identified a number of proteins known for their affinity for the zona pellucida in addition to other candidates putatively involved in the mediation of downstream binding and/or fusion with the oolemma. Collectively these data afford novel insights into the sub-cellular localization and potential functions of membrane rafts in human spermatozoa.


2018 ◽  
Vol 19 (12) ◽  
pp. 4097 ◽  
Author(s):  
Karl Kerns ◽  
Michal Zigo ◽  
Peter Sutovsky

The importance of zinc for male fertility only emerged recently, being propelled in part by consumer interest in nutritional supplements containing ionic trace minerals. Here, we review the properties, biological roles and cellular mechanisms that are relevant to zinc function in the male reproductive system, survey available peer-reviewed data on nutritional zinc supplementation for fertility improvement in livestock animals and infertility therapy in men, and discuss the recently discovered signaling pathways involving zinc in sperm maturation and fertilization. Emphasis is on the zinc-interacting sperm proteome and its involvement in the regulation of sperm structure and function, from spermatogenesis and epididymal sperm maturation to sperm interactions with the female reproductive tract, capacitation, fertilization, and embryo development. Merits of dietary zinc supplementation and zinc inclusion into semen processing media are considered with livestock artificial insemination (AI) and human assisted reproductive therapy (ART) in mind. Collectively, the currently available data underline the importance of zinc ions for male fertility, which could be harnessed to improve human reproductive health and reproductive efficiency in agriculturally important livestock species. Further research will advance the field of sperm and fertilization biology, provide new research tools, and ultimately optimize semen processing procedures for human infertility therapy and livestock AI.


2015 ◽  
Vol 27 (1) ◽  
pp. 100
Author(s):  
C. Riou ◽  
A. Gargaros ◽  
G. Harichaux ◽  
A. Brionne ◽  
J. Gautron ◽  
...  

Because of prolonged sperm storage in their oviduct, domestic hens can produce fertile eggs for up to 3 weeks following a single AI. The oviduct secretions may have an effect on sperm survival, but its composition during fertilization is unknown. In the present study, we compared the proteomic content of uterine fluid collected from two lines of hens divergent by their duration of fertility period (DFP), which defined sperm-storage duration. The first line displays a shorter period of sperm storage (10 days, line DFP–), whereas the second displays a longer period of sperm storage (21 days, DFP+). The aim was to identify proteins or peptides that may be involved in spermatozoa survival. Uterine fluid was collected 10 h after oviposition either before (n = 5/line) or 24 h after (n = 5/line) AI. Samples were pooled by condition: DFP+ before AI, DFP+ after AI, DFP– before AI, and DFP– after AI. Bottom-up approach using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and nano LC-MS/MS was performed (3 replicates). Data were matched against the NCBInr database (2014) using Mascot, and identifications were validated by the peptide and protein Prophet algorithm using Scaffold software. To determine the differences in protein expression, spectral counting and XIC quantitative methods were employed using Scaffold Q+ (P < 0.05, ratio > 2). Two proteins were up-regulated and one was down-regulated in oviductal secretion of both lines in response to AI. However, AI induced a significantly different abundance between protein content of DFP– and DFP+ fluids. A panel of 8 proteins, included one DFP+-specific protein, was more abundant in DFP+ line than in DFP–. Only one protein was less abundant in DFP+ line than in DFP–. In conclusion, the presence of sperm in the genital tract induced quantitative differences of the protein content of the uterine fluid in DFP– and DFP+ hen lines. These differences imply proteins that are known as male proteins (sperm, seminal plasma, testis). Analysis of sperm protein modifications after storage will help us to understand the functional implication of these candidates.


2020 ◽  
Vol 6 (31) ◽  
pp. eaba5168 ◽  
Author(s):  
Hermes Gadêlha ◽  
Paul Hernández-Herrera ◽  
Fernando Montoya ◽  
Alberto Darszon ◽  
Gabriel Corkidi

Flagellar beating drives sperm through the female reproductive tract and is vital for reproduction. Flagellar waves are generated by thousands of asymmetric molecular components; yet, paradoxically, forward swimming arises via symmetric side-to-side flagellar movement. This led to the preponderance of symmetric flagellar control hypotheses. However, molecular asymmetries must still dictate the flagellum and be manifested in the beat. Here, we reconcile molecular and microscopic observations, reconnecting structure to function, by showing that human sperm uses asymmetric and anisotropic controls to swim. High-speed three-dimensional (3D) microscopy revealed two coactive transversal controls: An asymmetric traveling wave creates a one-sided stroke, and a pulsating standing wave rotates the sperm to move equally on all sides. Symmetry is thus achieved through asymmetry, creating the optical illusion of bilateral symmetry in 2D microscopy. This shows that the sperm flagellum is asymmetrically controlled and anisotropically regularized by fast-signal transduction. This enables the sperm to swim forward.


Development ◽  
2008 ◽  
Vol 135 (22) ◽  
pp. 3677-3686 ◽  
Author(s):  
G. Machado-Oliveira ◽  
L. Lefievre ◽  
C. Ford ◽  
M. B. Herrero ◽  
C. Barratt ◽  
...  

2021 ◽  
Vol 13 (606) ◽  
pp. eabd5219
Author(s):  
Bhawana Shrestha ◽  
Alison Schaefer ◽  
Yong Zhu ◽  
Jamal Saada ◽  
Timothy M. Jacobs ◽  
...  

Many women risk unintended pregnancy because of medical contraindications or dissatisfaction with contraceptive methods, including real and perceived side effects associated with the use of exogenous hormones. We pursued direct vaginal delivery of sperm-binding monoclonal antibodies (mAbs) that can limit progressive sperm motility in the female reproductive tract as a strategy for effective nonhormonal contraception. Here, motivated by the greater agglutination potencies of polyvalent immunoglobulins but the bioprocessing ease and stability of immunoglobulin G (IgG), we engineered a panel of sperm-binding IgGs with 6 to 10 antigen-binding fragments (Fabs), isolated from a healthy immune-infertile woman against a unique surface antigen universally present on human sperm. These highly multivalent IgGs (HM-IgGs) were at least 10- to 16-fold more potent and faster at agglutinating sperm than the parent IgG while preserving the crystallizable fragment (Fc) of IgG that mediates trapping of individual spermatozoa in mucus. The increased potencies translated into effective (>99.9%) reduction of progressively motile sperm in the sheep vagina using as little as 33 μg of the 10-Fab HM-IgG. HM-IgGs were produced at comparable yields and had identical thermal stability to the parent IgG, with greater homogeneity. HM-IgGs represent not only promising biologics for nonhormonal contraception but also a promising platform for engineering potent multivalent mAbs for other biomedical applications.


Andrology ◽  
2015 ◽  
Vol 3 (6) ◽  
pp. 1068-1075 ◽  
Author(s):  
C. M. Zumoffen ◽  
E. Massa ◽  
A. M. Caille ◽  
M. J. Munuce ◽  
S. A. Ghersevich

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