Cíl studie: Jednou z příčin mužské neplodnosti je snížená motilita spermií. Ukazuje se, že ve vývoji této poruchy může hrát roli snížená efektivita respirační aktivity mitochondrií. Cílem naší studie bylo komplexní stanovení respirační aktivity mitochondrií spermií s normální a sníženou pohyblivostí. Typ studie: Prospektivní studie. Název a sídlo pracoviště: Ústav histologie a embryologie, LF UK, Plzeň; Ústav fyziologie, LF UK, Plzeň; Institut reprodukční medicíny a endokrinologie, IVF Centrum Prof. Zecha, Plzeň. Metodika: Ejakuláty byly získány od 14 mužů z IVF Centra Prof. Zecha v Plzni. Podle klasifikace World Health Organization byli muži rozděleni do skupiny normozoospermatiků (n = 7) a astenozoospermatiků (n = 7). Respirační aktivitu spermií jsme měřili na dvoukanálovém oxygrafu Oroboros. Výsledky: V astenozoospermatických vzorcích byla nalezena signifikantně snížená aktivita komplexu I(p = 0,007), zvýšená respirace po aplikaci inhibitoru ATP-syntázy oligomycinu (ukazující na zvýšené rozpřažení oxidace a fosforylace; p = 0,046). Inhibice komplexu I rotenonem ukázala, že příspěvek komplexu I k celkové kapacitě oxidační fosforylace byl i u zdravých spermií relativně nižší, než je tomu typicky v somatických buňkách. Závěr: V naší studii jsme měřili respirační aktivitu mitochondrií lidských spermií permeabilizovaných digitoninem vysokoúčinnou oxygrafií, která umožňuje stanovení spotřeby kyslíku z nejmenšího možného množství zárodečných buněk. Výsledky studie potvrzují sníženou aktivitu komplexu I u astenozoospermatiků a naznačují, že na snížené pohyblivosti spermií by se mohl podílet i zvýšený únik protonů z mitochondriální matrix, který vede ke snížené efektivitě fosforylačního procesu. Lepší charakterizace mužských zárodečných buněk, ať zcela zdravých, či s postiženou motilitou, nám pomůže lépe pochopit proces fyziologického oplodnění a zároveň pomůže i ve výběru té nejvíce životaschopné spermie pro léčbu neplodnosti metodami asistované reprodukce.
Objective: One of causes of male infertility is reduced sperm motility. It turns out that the reduced efficiency of the mitochondrial respiratory activity may play a role in the development of this disorder. The aim of our study was to comprehensively determine mitochondrial respiratory activity of sperm with normal and reduced motility. Design: Prospective study. Setting: Department of Histology and Embryology, Faculty of Medicine in Pilsen, Charles University in Prague; Department of Physiology, Faculty of Medicine in Pilsen, Charles University in Prague; Institute of Reproductive Medicine and Endocrinology, IVF Centers Prof. Zech, Plzeň. Methods: Ejaculates of 14 men were obtained from IVF Center Prof. Zech, Pilsen. According to the World Health Organization classification, samples were divided into normozoospermatic (n = 7) and asthenozoospermatic(n = 7) groups. Respiratory activity of sperm was measured on two-chamber oxygraph Oroboros. Results: In asthenozoospermatic samples, significantly reduced activity of complex I (p = 0.007) and increased respiration after application of ATP-synthase inhibitor oligomycin (showing increased uncoupled oxidation and phosphorylation, p = 0.046) were found. Inhibition of complex I by rotenone showed that complex I contribution to the total capacity of oxidative phosphorylation of healthy sperm was relatively lower than it is typical for somatic cells. Conclusion: In our study, we measured mitochondrial respiratory activity of human sperm, permeabilized by digitonin, by high-resolution oxygraphy, which allows the determination of oxygen consumption from the smallest possible number of germ cells. The study results confirm reduced activity of complex I in asthenozoospermatics and suggest that increased leakage of protons from the mitochondrial matrix, which leads to reduced efficiency of phosphorylating process, could participate in the reduced sperm motility. Better characterization of male germ cells, either completely healthy or with affected motility, will help us to understand better the physiological process of fertilization and also to choose the most viable sperm for infertility treatment by methods of assisted reproduction.
- MeSH
- Asthenozoospermia metabolism MeSH
- Clinical Laboratory Techniques MeSH
- Humans MeSH
- Mitochondrial Proteins * physiology metabolism MeSH
- Sperm Motility physiology MeSH
- Infertility, Male MeSH
- Cell Membrane Permeability MeSH
- Policy MeSH
- Reactive Oxygen Species * metabolism MeSH
- Semen * metabolism MeSH
- Spermatozoa * physiology pathology MeSH
- Oxygen Consumption MeSH
- Statistics as Topic MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
The LINC (LInker of Nucleoskeleton and Cytoskeleton) complex is localized within the nuclear envelope and consists of SUN (Sad1/UNc84 homology domain-containing) proteins located in the inner nuclear membrane and KASH (Klarsicht/Anc1/Syne1 homology domain-containing) proteins located in the outer nuclear membrane, hence linking nuclear with cytoplasmic structures. While the nucleoplasm-facing side acts as a key player for correct pairing of homolog chromosomes and rapid chromosome movements during meiosis, the cytoplasm-facing side plays a pivotal role for sperm head development and proper acrosome formation during spermiogenesis. A further complex present in spermatozoa is involved in head-to-tail coupling. An intact LINC complex is crucial for the production of fertile sperm, as mutations in genes encoding for complex proteins are known to be associated with male subfertility in both mice and men. The present review provides a comprehensive overview on our current knowledge of LINC complex subtypes present in germ cells and its central role for male reproduction. Future studies on distinct LINC complex components are an absolute requirement to improve the diagnosis of idiopathic male factor infertility and the outcome of assisted reproduction.
- MeSH
- Models, Biological MeSH
- Cell Nucleus metabolism MeSH
- Humans MeSH
- Multiprotein Complexes metabolism MeSH
- Infertility, Male metabolism pathology MeSH
- Spermatozoa metabolism MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
BACKGROUND: Sperm proteins are important for the sperm cell function in fertilization. Some of them are involved in the binding of sperm to the egg. We characterized the acrosomal sperm protein detected by a monoclonal antibody (MoAb) (Hs-8) that was prepared in our laboratory by immunization of BALB/c mice with human ejaculated sperms and we tested the possible role of this protein in the binding assay. METHODS: Indirect immunofluorescence and immunogold labelling, gel electrophoresis, Western blotting and protein sequencing were used for Hs-8 antigen characterization. Functional analysis of GAPDHS from the sperm acrosome was performed in the boar model using sperm/zona pellucida binding assay. RESULTS: Monoclonal antibody Hs-8 is an anti-human sperm antibody that cross-reacts with the Hs-8-related protein in spermatozoa of other mammalian species (boar, mouse). In the immunofluorescence test, Hs-8 antibody recognized the protein localized in the acrosomal part of the sperm head and in the principal piece of the sperm flagellum. In immunoblotting test, MoAb Hs-8 labelled a protein of 45 kDa in the extract of human sperm. Sequence analysis identified protein Hs-8 as GAPDHS (glyceraldehyde 3-phosphate dehydrohenase-spermatogenic). For this reason, commercial mouse anti-GAPDHS MoAb was applied in control tests. Both antibodies showed similar staining patterns in immunofluorescence tests, in electron microscopy and in immunoblot analysis. Moreover, both Hs-8 and anti-GAPDHS antibodies blocked sperm/zona pellucida binding. CONCLUSION: GAPDHS is a sperm-specific glycolytic enzyme involved in energy production during spermatogenesis and sperm motility; its role in the sperm head is unknown. In this study, we identified the antigen with Hs8 antibody and confirmed its localization in the apical part of the sperm head in addition to the principal piece of the flagellum. In an indirect binding assay, we confirmed the potential role of GAPDHS as a binding protein that is involved in the secondary sperm/oocyte binding.
- MeSH
- Acrosome metabolism MeSH
- Energy Metabolism MeSH
- Flagella metabolism MeSH
- Glyceraldehyde-3-Phosphate Dehydrogenases analysis genetics physiology MeSH
- Sperm-Ovum Interactions MeSH
- Humans MeSH
- Sperm Motility MeSH
- Mice, Inbred BALB C MeSH
- Mice MeSH
- Swine metabolism MeSH
- Spermatogenesis MeSH
- Spermatozoa metabolism MeSH
- Zona Pellucida metabolism MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Spontaneous polyploidy has been frequently documented in various fish species. This process may lead to disruption in testicular development and function. In the present study, sperm morphology and motility, elements critical to male fertility, were characterized in the naturally occurring triploid (3n) and tetraploid (4n) European weatherfish, Misgurnus fossilis L. (Teleostei, Cobitidae) inhabiting the upper reaches of the Lužnice River in the Czech Republic. Sperm with smaller heads, shorter flagella, and a lower number of mitochondria was observed in 3n specimens compared with 4n, but no differences were observed in size of midpiece or ultrastructure of sperm. Similar to most teleosts, the European weatherfish spermatozoon lacked an acrosome and consisted of a head (containing DNA), a midpiece (containing mitochondria and proximal and distal centrioles), and a flagellum with 9 + 2 microtubular structure. Sperm velocity was significantly lower in individuals with 4n compared with 3n, whereas no difference in sperm motility was observed. The stepwise linear regression reported significant negative correlations between sperm velocity and length of sperm head (r = -0.92, P < 0.01). In conclusion, the data reported no effect of polyploidy on sperm ultrastructure and motility in the European weatherfish, although it can affect sperm velocity, possibly through differences in head size and the number of mitochondria, which provide ATP for sperm movement.
In many taxa, odour cues mediate mating decisions. A key question is what these odours comprise, where they are produced, and what they signal. Using rose bitterling, fish that spawn in the gills of freshwater mussels, we investigated the role of sperm cues on female oviposition decisions using individuals of known MHC genotype. Male bitterling frequently released sperm prior to female oviposition and females responded with an increased probability of oviposition and released a greater number of eggs, particularly if males had a dissimilar MHC genotype. These mating preferences by females were shown to be adaptive, with MHC dissimilarity of males and females correlated positively with embryo survival. These results support a role for indirect benefits to rose bitterling mate choice, and we propose that sperm acts as a releaser pheromone in bitterling, functioning as a sexual ornament signalling male quality as a mate.
- MeSH
- Major Histocompatibility Complex genetics MeSH
- Cypriniformes genetics physiology MeSH
- Gene Expression Regulation MeSH
- Mating Preference, Animal * MeSH
- Spermatozoa physiology MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
In the last two decades, a school of thought emerged that perceives male reproductive health, testicular function, and sperm output as a sentry for general, somatic health. Large-scale epidemiologic studies have already linked the reduced sperm count to increased risk of chronic somatic disease (e.g., cancer, cardiovascular, neurological and bone diseases), yet most of these studies have not taken full advantage of advanced andrological analysis. Altered proteostasis, i.e., the disbalance between protein synthesis and turnover, is a common denominator of many diseases, including but not limited to cancer and neurodegenerative diseases. This chapter introduces the concept of cellular proteostasis as a measure of sperm structural and functional integrity and an endpoint of varied impacts on spermiogenesis and sperm maturation, including heritability, general health, lifestyle, and occupational and environmental reprotoxic exposure. Special consideration is given to small molecule protein modifiers, sperm-binding seminal plasma proteins, zinc-interacting proteins, and redox proteins responsible for the maintenance of protein structure and the protection of spermatozoa from oxidative damage. While the main focus is on human male infertility, serious consideration is given to relevant animal models, and in particular to male food animals with extensive records of fertility from artificial insemination services. Altogether, the proteostatic biomarker discovery and validation studies set the stage for the integration of proteomics of sperm proteostasis with genomic and high throughput phenomic approaches to benefit both human and animal reproductive medicine.
- MeSH
- Fertility * physiology MeSH
- Proteostasis * physiology MeSH
- Humans MeSH
- Infertility, Male * metabolism genetics pathology physiopathology MeSH
- Spermatogenesis * MeSH
- Spermatozoa * metabolism pathology physiology MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
Testicular cancer is the most common form of cancer in young men of reproductive age and its incidence is increasing globally. With the currently successful treatment and 95% survival rate, there is a need for deeper understanding of testicular cancer-related infertility. Most patients with testicular cancer experience semen abnormalities prior to cancer therapy. However, the exact mechanism of the effect of testicular cancer on sperm anomalies is not known. Mitochondria are organelles that play a crucial role in both tumorigenesis and spermatogenesis and their malfunction may be an important factor resulting in sperm abnormalities in testicular cancer patients. Within the scope of this review, we will discuss current knowledge of testicular cancer-related alterations in the ATP production pathway, a possible pathophysiological switch from oxidative phosphorylation (OXPHOS) to glycolysis, as well as the role of oxidative stress promoting sperm dysfunction. In this regard, the review provides a summary of the impact of testicular cancer on sperm quality as a possible consequence of impaired mitochondrial function including the energy metabolic pathways that are known to be altered in the sperm of testicular cancer patients.
- MeSH
- Semen Analysis MeSH
- Neoplasms, Germ Cell and Embryonal * MeSH
- Humans MeSH
- Mitochondrial Diseases * metabolism MeSH
- Semen metabolism MeSH
- Spermatozoa MeSH
- Testicular Neoplasms * metabolism MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
Seminal plasma (SP) is the natural environment for spermatozoa and contains a number of components, especially proteins important for successful sperm maturation and fertilization. Nevertheless, in standard frozen stallion insemination doses production, SP is completely removed and is replaced by a semen extender. In the present study, we analyzed the effects of the selected seminal plasma protein groups that might play an important role in reducing the detrimental effects on spermatozoa during the cryopreservation process. SP proteins were separated according to their ability to bind to heparin into heparin-binding (Hep+) and heparin-non-binding (Hep-) fractions. The addition of three concentrations-125, 250, and 500 µg/mL-of each protein fraction was tested. After thawing, the following parameters were assessed: sperm motility (by CASA), plasma membrane integrity (PI staining), and acrosomal membrane integrity (PNA staining) using flow cytometry, and capacitation status (anti-phosphotyrosine antibody) using imaging-based flow cytometry. Our results showed that SP protein fractions had a significant effect on the kinematic parameters of spermatozoa and on a proportion of their subpopulations. The 125 µg/mL of Hep+ protein fraction resulted in increased linearity (LIN) and straightness (STR), moreover, with the highest values of sperm velocities (VAP, VSL), also this group contained the highest proportion of the fast sperm subpopulation. In contrast, the highest percentage of slow subpopulation was in the groups with 500 µg/mL of Hep+ fraction and 250 µg/mL of Hep- fraction. Interestingly, acrosomal membrane integrity was also highest in the groups with Hep+ fraction in concentrations of 125 µg/mL. Our results showed that the addition of protein fractions did not significantly affect the plasma membrane integrity and capacitation status of stallion spermatozoa. Moreover, our results confirmed that the effect of SP proteins on the sperm functionality is concentration-dependent, as has been reported for other species. Our study significantly contributes to the lack of studies dealing with possible use of specific stallion SP fractions in the complex puzzle of the improvement of cryopreservation protocols. It is clear that improvement in this field still needs more outputs from future studies, which should be focused on the effect of individual SP proteins on other sperm functional parameters with further implication on the success of artificial insemination in in vivo conditions.
- MeSH
- Horses MeSH
- Cryopreservation veterinary MeSH
- Serum Albumin, Human metabolism MeSH
- Seminal Plasma Proteins metabolism MeSH
- Serum Globulins metabolism MeSH
- Spermatozoa physiology MeSH
- Semen Preservation methods veterinary MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Sperm capacitation, one of the key events during successful fertilization, is associated with extensive structural and functional sperm remodeling, beginning with the modification of protein composition within the sperm plasma membrane. The ubiquitin-proteasome system (UPS), a multiprotein complex responsible for protein degradation and turnover, participates in capacitation events. Previous studies showed that capacitation-induced shedding of the seminal plasma proteins such as SPINK2, AQN1, and DQH from the sperm surface is regulated by UPS. Alterations in the sperm surface protein composition also relate to the porcine β-microseminoprotein (MSMB/PSP94), seminal plasma protein known as immunoglobulin-binding factor, and motility inhibitor. MSMB was detected in the acrosomal region as well as the flagellum of ejaculated boar spermatozoa, while the signal disappeared from the acrosomal region after in vitro capacitation (IVC). The involvement of UPS in the MSMB degradation during sperm IVC was studied using proteasomal interference and ubiquitin-activating enzyme (E1) inhibiting conditions by image-based flow cytometry and Western blot detection. Our results showed no accumulation of porcine MSMB either under proteasomal inhibition or under E1 inhibiting conditions. In addition, the immunoprecipitation study did not detect any ubiquitination of sperm MSMB nor was MSMB detected in the affinity-purified fraction containing ubiquitinated sperm proteins. Based on our results, we conclude that UPS does not appear to be the regulatory mechanism in the case of MSMB and opening new questions for further studies. Thus, the capacitation-induced processing of seminal plasma proteins on the sperm surface may be more complex than previously thought, employing multiple proteolytic systems in a non-redundant manner.
- MeSH
- Sperm Capacitation physiology MeSH
- Swine MeSH
- Proteasome Endopeptidase Complex metabolism MeSH
- Prostatic Secretory Proteins metabolism MeSH
- Spermatozoa metabolism physiology MeSH
- Ubiquitin metabolism MeSH
- Ubiquitination MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
After being historically considered as noxious agents, nitric oxide (NO) and hydrogen sulfide (H2S) are now listed as gasotransmitters, gaseous molecules that play a key role in a variety of cellular functions. Both NO and H2S are endogenously produced, enzymatically or non-enzymatically, and interact with each other in a range of cells and tissues. In spite of the great advances achieved in recent decades in other biological systems, knowledge about H2S function and interactions with NO in sperm biology is in its infancy. Here, we aim to provide an update on the importance of these molecules in the physiology of the male gamete. Special emphasis is given to the most recent advances in the metabolism, mechanisms of action, and effects (both physiological and pathophysiological) of these gasotransmitters. This manuscript also illustrates the physiological implications of NO and H2S observed in other cell types, which might be important for sperm function. The relevance of these gasotransmitters to several signaling pathways within sperm cells highlights their potential use for the improvement and successful application of assisted reproductive technologies.
- MeSH
- Gasotransmitters chemistry metabolism MeSH
- Humans MeSH
- Nitric Oxide metabolism MeSH
- Oxidation-Reduction MeSH
- Oxidative Stress MeSH
- Reactive Nitrogen Species chemistry metabolism MeSH
- Sulfur chemistry metabolism MeSH
- Spermatozoa chemistry enzymology metabolism physiology MeSH
- Hydrogen Sulfide metabolism MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
