3 ROLE OF β-DEFENSIN 126 IN PROMOTING SPERM MOTILITY IN CATTLE

2016 ◽  
Vol 28 (2) ◽  
pp. 131
Author(s):  
B. Fernandez-Fuertes ◽  
F. Narciandi ◽  
K. G. Meade ◽  
C. O'Farrelly ◽  
S. Fair ◽  
...  

As immature sperm migrate through the epididymis, they are bathed in region-specific epididymal fluid, which leads to a sequential addition, deletion, and modification of their surface proteins. These changes ultimately result in the acquisition of motility and fertilising abilities. Among the hundreds of proteins secreted by the epididymis, several β-defensins have been identified and correlated with male fertility in multiple species. In cattle, β-defensin 126 (BD126) is exclusively detected in the reproductive tract of pubertal males, with preferential mRNA expression in the epididymis. Both the macaque and human orthologs have been shown to play a role in the ability of sperm to migrate through cervical mucus. The aim of this study was to examine the role of bovine BD126 in sperm function. Western blot revealed that the peptide is uniquely present in both the cauda epididymis sperm and fluid and is absent from sperm recovered from other proximal epididymal regions, or the ejaculate of vasectomised animals. Confocal analysis showed immunofluorescent labelling of BD126 specific to the tail and acrosomal region in cauda sperm only, suggesting a role in motility. We hypothesised that addition of cauda epididymal fluid (CEF) or recombinant BD126 (rBD126) to immature corpus sperm would improve ability to penetrate cervical mucus. Testes from adult bulls were collected at an abattoir, and sperm from the corpus and cauda epididymis, as well as CEF, were recovered. Corpus sperm were incubated for 1 h with CEF in the absence or presence of BD126 antibody, or with different rBD126 concentrations (30 or 60 μg mL–1); untreated corpus and cauda sperm were used as controls. A higher number of cauda than corpus sperm migrated through cervical mucus from oestrus cows (P < 0.001), and addition of CEF increased the number of corpus sperm migrating through this matrix (P < 0.05). The presence of the BD126 antibody in CEF failed to abrogate this effect. Western blot analysis of the sperm samples revealed the antibody was not successful in blocking BD126 from binding onto the sperm surface, which would explain the lack of differences observed. Furthermore, the addition of rBD126 did not increase corpus sperm migration through mucus. In conclusion, we have characterised the expression of bovine BD126 protein in the bovine testis and epididymis. Incubation of sperm from the corpus with CEF from the cauda resulted in enhanced sperm migration through cervical mucus. However, incubation of sperm with rBD126 in the absence of other factors and proteins from the CEF failed to produce the same effect. These results suggest that the role of BD126 in cattle is different from that observed in primates. We are currently investigating other roles of BD126 and related β-defensins in mediating bovine sperm function. This work was supported by a grant from the Irish Department of Agriculture, Food and The Marine under the Research Stimulus Programme (Grant No. 11S 104).

2017 ◽  
Vol 29 (8) ◽  
pp. 1457 ◽  
Author(s):  
D. R. Câmara ◽  
J. P. Kastelic ◽  
J. C. Thundathil

Na+/K+-ATPase was one of the first ion pumps studied because of its importance in maintaining osmotic and ionic balances between intracellular and extracellular environments, through the exchange of three Na+ ions out and two K+ ions into a cell. This enzyme, which comprises two main subunits (α and β), with or without an auxiliary polypeptide (γ), can have specific biochemical properties depending on the expression of associated isoforms (α1β1 and/or α2β1) in the cell. In addition to the importance of Na+/K+-ATPase in ensuring the function of many tissues (e.g. brain, heart and kidney), in the reproductive tract this protein is essential for embryo development because of its roles in blastocoel formation and embryo hatching. In the context of male reproduction, the discovery of a very specific subunit (α4), apparently restricted to male germ cells, only expressed after puberty and able to influence sperm function (e.g. motility and capacitation), opened a remarkable field for further investigations regarding sperm biology. Therefore, the present review focuses on the importance of Na+/K+-ATPase on male reproduction and embryo development.


Reproduction ◽  
2007 ◽  
Vol 133 (5) ◽  
pp. 909-917 ◽  
Author(s):  
David W Erikson ◽  
Amy L Way ◽  
David A Chapman ◽  
Gary J Killian

Osteopontin (OPN) is a secreted extracellular matrix phosphoprotein identified in various tissues and fluids including those of the male and female reproductive tracts. OPN was previously identified as a 55 kDa high fertility marker in Holstein bull seminal plasma, produced by the ampulla and the vesicular gland. The objectives of this study were to characterize OPN on ejaculated and cauda epididymal sperm using immunofluorescence and western blot analysis, and to assess the role of sperm OPN in fertilization. Solubilized sperm membrane proteins from ejaculated and cauda epididymal sperm were separated by 1D SDS-PAGE, transferred to nitrocellulose, and probed with an antibody to bovine milk OPN. A 35 kDa protein was detected by this antibody in both ejaculated and cauda epididymal sperm membranes. Analyses also recognized OPN at 55 and 25 kDa in cauda epididymal fluid and testicular parenchyma homogenates respectively. Immunofluorescent analysis of ejaculated and cauda epididymal sperm showed OPN localization in a well-defined band in the postacrosomal region of the sperm head and also on the midpiece. Results ofin vitrofertilization experiments showed that sperm treated with an antibody to OPN fertilized fewer oocytes than sperm treated with control medium while increasing incidence of polyspermy, suggesting a role of sperm-associated OPN in fertilization and a block to polyspermy. These studies demonstrate that OPN exists at multiple molecular weight forms in the bull reproductive tract and its presence on ejaculated sperm may signal its importance in fertilization by interacting with integrins or other proteins on the oocyte plasma membrane.


2021 ◽  
Vol 22 (21) ◽  
pp. 11809
Author(s):  
Veronika Merc ◽  
Michaela Frolikova ◽  
Katerina Komrskova

In mammals, integrins are heterodimeric transmembrane glycoproteins that represent a large group of cell adhesion receptors involved in cell–cell, cell–extracellular matrix, and cell–pathogen interactions. Integrin receptors are an important part of signalization pathways and have an ability to transmit signals into and out of cells and participate in cell activation. In addition to somatic cells, integrins have also been detected on germ cells and are known to play a crucial role in complex gamete-specific physiological events, resulting in sperm-oocyte fusion. The main aim of this review is to summarize the current knowledge on integrins in reproduction and deliver novel perspectives and graphical interpretations presenting integrin subunits localization and their dynamic relocation during sperm maturation in comparison to the oocyte. A significant part of this review is devoted to discussing the existing view of the role of integrins during sperm migration through the female reproductive tract; oviductal reservoir formation; sperm maturation processes ensuing capacitation and the acrosome reaction, and their direct and indirect involvement in gamete membrane adhesion and fusion leading to fertilization.


2021 ◽  
Vol 26 (1) ◽  
Author(s):  
Olugbemi T. Olaniyan ◽  
Ayobami Dare ◽  
Gloria E. Okotie ◽  
Charles O. Adetunji ◽  
Babatunde O. Ibitoye ◽  
...  

Abstract Background Studies have shown that olfactory receptor genes are the largest in the human genome, which are significantly expressed in olfactory and non-olfactory tissues such as the reproductive systems where they perform many important biological functions. Main body There is growing evidence that bioactive metabolites from the ovary, follicular fluid, and other parts of the female reproductive tract signal the sperm through a series of signal transduction cascades that regulate sperm migration, maturation, and fertilization processes. Several studies have highlighted the role of G-protein-coupled receptors in these cellular processes. Thus, we aimed to summarize the existing evidence describing the physiological role of most prominent exogenous and endogenous biomolecules found in the female reproductive organ in enhancing the chemotaxis behavior of spermatozoa during migration, maturation, and fertilization and also to elucidate the pathological implications of its dysfunctions and the clinical significance in human fertility. Short conclusion In the future, drugs and molecules can be designed to activate these receptors on sperm to facilitate fertility among infertile couples and use as contraceptives.


Author(s):  
Nikolaos Sofikitis ◽  
Aris Kaltsas ◽  
Fotios Dimitriadis ◽  
Jens Rassweiler ◽  
Nikolaos Grivas ◽  
...  

The therapeutic range of cyclic nucleotide phosphodiesterase 5 inhibitors (PDE5) inhibitors is getting wider in the last years. This review study focuses on the potential employment of PDE5 inhibitors as an adjunct tool for the therapeutic management of male infertility. The literature tends to suggest a beneficial effect of PDE5 inhibitors on Leydig and Sertoli cells secretory function. It also appears that PDE5 inhibitors play a role in the regulation of the contractility of the testicular tunica albuginea and the epididymis. Moreover scientific data suggest that PDE5 inhibitors enhance the prostatic secretory function leading to an improvement in sperm motility. Other studies additionally demonstrate a role of PDE5 inhibitors in the regulation of sperm capacitation process. Placebo-controlled, randomized, blind studies are necessary to unambiguously incorporate PDE5 inhibitors as an adjunct tool for the pharmaceutical treatment of semen disorders and male infertility.


Reproduction ◽  
2013 ◽  
Vol 146 (2) ◽  
pp. 119-133 ◽  
Author(s):  
Barbara Ambruosi ◽  
Gianluca Accogli ◽  
Cécile Douet ◽  
Sylvie Canepa ◽  
Géraldine Pascal ◽  
...  

Oviductal environment affects preparation of gametes for fertilization, fertilization itself, and subsequent embryonic development. The aim of this study was to evaluate the effect of oviductal fluid and the possible involvement of deleted in malignant brain tumor 1 (DMBT1) on IVF in porcine and equine species that represent divergent IVF models. We first performed IVF after pre-incubation of oocytes with or without oviductal fluid supplemented or not with antibodies directed against DMBT1. We showed that oviductal fluid induces an increase in the monospermic fertilization rate and that this effect is canceled by the addition of antibodies, in both porcine and equine species. Moreover, pre-incubation of oocytes with recombinant DMBT1 induces an increase in the monospermic fertilization rate in the pig, confirming an involvement of DMBT1 in the fertilization process. The presence of DMBT1 in the oviduct at different stages of the estrus cycle was shown by western blot and confirmed by immunohistochemical analysis of ampulla and isthmus regions. The presence of DMBT1 in cumulus–oocyte complexes was shown by western blot analysis, and the localization of DMBT1 in the zona pellucida and cytoplasm of equine and porcine oocytes was observed using immunofluorescence analysis and confocal microscopy. Moreover, we showed an interaction between DMBT1 and porcine spermatozoa using surface plasmon resonance studies. Finally, a bioinformatic and phylogenetic analysis allowed us to identify the DMBT1 protein as well as a DMBT1-like protein in several mammals. Our results strongly suggest an important role of DMBT1 in the process of fertilization.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xiaoqing Fan ◽  
Haoran Yang ◽  
Chenggang Zhao ◽  
Lizhu Hu ◽  
Delong Wang ◽  
...  

Abstract Background A large number of preclinical studies have shown that local anesthetics have a direct inhibitory effect on tumor biological activities, including cell survival, proliferation, migration, and invasion. There are few studies on the role of local anesthetics in cancer stem cells. This study aimed to determine the possible role of local anesthetics in glioblastoma stem cell (GSC) self-renewal and the underlying molecular mechanisms. Methods The effects of local anesthetics in GSCs were investigated through in vitro and in vivo assays (i.e., Cell Counting Kit 8, spheroidal formation assay, double immunofluorescence, western blot, and xenograft model). The acyl-biotin exchange method (ABE) assay was identified proteins that are S-acylated by zinc finger Asp-His-His-Cys-type palmitoyltransferase 15 (ZDHHC15). Western blot, co-immunoprecipitation, and liquid chromatograph mass spectrometer-mass spectrometry assays were used to explore the mechanisms of ZDHHC15 in effects of local anesthetics in GSCs. Results In this study, we identified a novel mechanism through which local anesthetics can damage the malignant phenotype of glioma. We found that local anesthetics prilocaine, lidocaine, procaine, and ropivacaine can impair the survival and self-renewal of GSCs, especially the classic glioblastoma subtype. These findings suggest that local anesthetics may weaken ZDHHC15 transcripts and decrease GP130 palmitoylation levels and membrane localization, thus inhibiting the activation of IL-6/STAT3 signaling. Conclusions In conclusion, our work emphasizes that ZDHHC15 is a candidate therapeutic target, and local anesthetics are potential therapeutic options for glioblastoma.


2021 ◽  
Vol 7 (10) ◽  
pp. eabf2403
Author(s):  
Pierre Nottelet ◽  
Laure Bataille ◽  
Geraldine Gourgues ◽  
Robin Anger ◽  
Carole Lartigue ◽  
...  

Mycoplasma immunoglobulin binding (MIB) and mycoplasma immunoglobulin protease (MIP) are surface proteins found in the majority of mycoplasma species, acting sequentially to capture antibodies and cleave off their VH domains. Cryo–electron microscopy structures show how MIB and MIP bind to a Fab fragment in a “hug of death” mechanism. As a result, the orientation of the VL and VH domains is twisted out of alignment, disrupting the antigen binding site. We also show that MIB-MIP has the ability to promote the dissociation of the antibody-antigen complex. This system is functional in cells and protects mycoplasmas from antibody-mediated agglutination. These results highlight the key role of the MIB-MIP system in immunity evasion by mycoplasmas through an unprecedented mechanism, and open exciting perspectives to use these proteins as potential tools in the antibody field.


Cancers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1361
Author(s):  
Zoia Razumova ◽  
Husam Oda ◽  
Igor Govorov ◽  
Eva Lundin ◽  
Ellinor Östensson ◽  
...  

Endometrial cancer (EC) is the most common gynecologic malignancy in Sweden and it has various prognostic factors. The LRIG family is a group of three integral surface proteins with a similar domain organization. The study aimed to explore LRIG family as prognostic factor proteins in EC. The initial study cohort included 100 women with EC who were treated at the Department of Women’s and Children’s Health, Karolinska University Hospital Solna, between 2007 and 2012. We assessed the associations between LRIG protein expression and type, grade, and stage of EC, as well as progression-free and overall survival. Immunohistochemistry results revealed that most women in the analytical sample had >50% LRIG1-, LRIG2- and LRIG3-positive cells. A statistically significant association was observed between having a high number of LRIG3-positive cells and superior overall survival (incidence rate ratio = 0.977; 95% confidence interval: 0.958–0.996, p = 0.019). Moreover, positive LRIG3 staining of the cell membrane was associated with reducing in the risk of death (hazard ratio = 0.23; 95% confidence interval: 0.09–0.57). Our results show that LRIG3 expression might be a prognostic factor in EC. The role of LRIG1 and LRIG2 expression remains to be further investigated.


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