Národní úložiště šedé literatury Nalezeno 104 záznamů.  začátekpředchozí72 - 81dalšíkonec  přejít na záznam: Hledání trvalo 0.01 vteřin. 
Effect of diabetes mellitus on reproductive parameters in mice
Margaryan, Hasmik ; Elzeinová, Fatima ; Kubátová, Alena ; Strolená, Eva ; Pěknicová, Jana
The decrease in population fertility has become a major concern in many developed countries. Recent studies show that infertility is affecting an estimated 15% of all couples (World Health Organization, WHO, 2010). Male infertility is the primary or contributing cause in 60% of cases. Male infertility is caused by a number of factors, such as genetic background, various environmental factors and disease. Diabetes mellitus (DM), a serious health problem on its own, is also suspected to be a contributing factor to male infertility. The aim of this project was to analyze the cellular, molecular and genetic effects of diabetic environment on spermatogenesis and sperm quality and to determine the impact of DM on the in vivo reproduction, using the mouse model (Mus musculus) inbred FVB. Diabetes was induced using streptozotocin. We used our knowledge and tools (unique monoclonal antibodies developed by our group) to determine the status of reproductive organs, anogenital distance, and the quality of sperms. Genetic analysis was performed by a quantitative Reverse Transcription Polymerase Chain Reaction (qPCR). We tested selected genes which are expressed in testicular tissue and thus can influence process of spermatogenesis and consequently the sperm quality. Our preliminary data strongly suggest that DM impairs male fertility. We have found significant changes in the body and reproductive organ weight of mice with DM. We have identified qualitative and quantitative changes in the expression of proteins in epididymal fluid and sperms. We have also detected an increased number of apoptotic cells in sperm of diabetic mice compared to the control group. To our knowledge, there is no study assessing the correlation between DM and “unexplained infertility”. In view of this, it is essential to analyze the effects of DM on male fertility, sperm quality, and reproduction parameters.
Expression of estrogen receptor beta (ERβ) In murine male reproductive tract and sperm
Dostálová, Pavla ; Děd, Lukáš ; Dorosh, Andriy ; Elzeinová, Fatima ; Pěknicová, Jana
Estrogens are steroid hormones that play an important role in reproduction of both sexes. In male, the main source of estrogens are testes where both somatic and germ cells are responsible for testosteron conversion to estrogens. Estrogens are involved in control of spermatogenesis, fluid reabsorption in rete testis and epididymis, and in later maturation steps that sperm undergo in female genital tract (capacitation, acrosome reaction). Generally, estrogen action is mediated through binding to estrogen receptors (ERs) which than lead to classical genomic or rapid non-genomic signaling. Nowadays, two classical estrogen receptors are known – ERα and ERβ. ERβ is a predominant variant in testes, while ERα is more abundant in rete testis and initial segment of epididymis. In addition to classical ERs, several splice variants that can differ in their ligand- or DNA-binding properties were detected in different tissues and cell lines. ERs mostly work as a dimer (homo- and hetero-) and splice variants often „only“ modulate function of classical full-length ERs. Therefore, estrogen action seems to be a very complex. To contribute to understanding of estrogen action in male, we detected ERβ and its potential splice variants in mice testis, epididymis and sperm. According to our results, two variants are present in all analysed tissues and cells. These variants differ in one exon in ligand binding domain which leads to different affinity for estrogens. To analyse these variants also at a protein level, we prepared specific monoclonal antibodies recognizing particular variant of ERβ. Both atibodies detected band(s) in protein extracts from testes or epididymis. Taking together, there are at least two variants of ERβ in mice testes, epididymis and sperm and it seems that both variants are similar in abundance within the same organ or sperm.
Effect of exposure to bisphenol A on gene expression in the testicular tissue in male mice
Dorosh, Andriy ; Elzeinová, Fatima ; Žatecká, Eva ; Kubátová, Alena ; Pěknicová, Jana
Laboratory of Reproductive Biology, Institute of Biotechnology, Academy of Sciences of the Czech Republic, v.v.i., Prague, Czech Republic Bisphenol A (BPA) is a synthetic, endocrine-disrupting compound able to directly bind estrogen receptors. Free BPA has been detected in human samples indicating that humans are internally exposed to BPA. The purpose of this study was to analyse the effect of BPA on the male reproductive system and testicular gene expression in germ cells. We studied the influence of long-term low concentration BPA exposition on male fertility in vivo in a two-generation study in C57BL/6 mouse strain. In this work, BPA was added with water at two environmentally relevant concentrations: 0, 4 and 4 µg/l. We measured the reproductive organs weight and sperm cells morphology and quality. Expression of genes involved in endocrine regulation and energy metabolism in testis was analysed after BPA exposure. Next, the epigenetic mechanisms of gene expression and regulation during the germ cell differentiation and effect of BPA will be analysed.
The effect of tetrabromobisphenol a on protamination and DNA quality of mouse sperm
Žatecká, Eva ; Castillo, J. ; Elzeinová, Fatima ; Kubátová, Alena ; Děd, Lukáš ; Pěknicová, Jana ; Oliva, R.
Tetrabromobisphenol (TBBPA) is a widely used brominated flame retardant, currently its consumption is 210,000 tons / year and is still growing. In our previous multigenerational in vivo study we have demonstrated that TBBPA is able to induce apoptosis of testicular cells and changes in the expression of genes important for proper spermatogenesis. However the potential effect of TBBPA on epidydimal spermatozoa had not yet been investigated. Therefore, we performed further study to evaluate the effect of on sperm DNA integrity and on the protamines as the major nuclear proteins. C57Bl/6J mice pups (n=10) were exposed to TBBPA (experimental group) during the gestation, lactation, pre-pubertal and pubertal periods up to the age of 70 days and compared control mice pups (n= 10) which were not exposed. Our results demonstrate that TBBPA treatment results in a significantly decreased P1/P2 ratio, increased total protamine/DNA ratio and increased DNA fragmentation observed between TBBPA and control mice, respectively. Protamines have recently been connected to the epigenetic marking of sperm chromatin in human and mouse spermatozoa. Thus, our findings suggest that TBBPA exposure, in addition to result in increased sperm DNA damage, may also alter the epigenetic marking of sperm chromatin.
Flow cytometry (FCM) sperm assessment In normozoospermic and asthenozoospermic men using monoclonal antibodies against sperm proteins
Čapková, Jana ; Kubátová, Alena ; Děd, Lukáš ; Teplá, O. ; Pěknicová, Jana
Recent studies have shown that infertility affects an estimated 15% of all couples. Male infertility is the primary or contributing cause in 60% of these cases. Consequently, application of methods of assisted reproduction is increasing. These methods would benefit from extended evaluation of the sperm quality. For this purpose, we analyzed sperm proteins in men with normal spermiograms and with asthenozoospermia. Ejaculates of both groups were tested with a set of well-characterized monoclonal antibodies (MoAbs) to human sperm. No statistically significant differences were found between normospermics and asthenospermics in the expression of sperm surface proteins clusterin, evaluated by Hs-3 MoAb, and semenogelin, evaluated by Hs-9 MoAb. On the other hand, flow cytometry revealed quantitative differences between normozoospermic and asthenozoospermic men in GAPDHS (glyceraldehyde phosphate dehydrogenase human sperm-specific glycolytic enzyme), evaluated by Hs-8 MoAb, VCP (valosin-containing protein), detected with Hs-14 MoAb, and PRKAR2A (cAMP-dependent protein kinase type II – alpha regulatory subunit) detected by MoAb Hs-36. Asthenozoospermic men displayed significantly reduced expression of intra-acrosomal proteins with a likely decrease in sperm quality, and thus a negative impact on successful reproduction.
Book of abstract XVIIIth Symposium of Czech Reproductive Immunologist with international participation
Pěknicová, Jana ; Elzeinová, Fatima ; Kubátová, Alena
Book of abstract XVIIth Symposium of Czech Reproductive Immunologist with international participation contains abstracts of lectures which focuse on immunology and physiology of reproduction.
Book of abstract XVIIth Symposium of Czech Reproductive Immunologist with international participation
Pěknicová, Jana ; Elzeinová, Fatima ; Cozlová, Nina
Book of abstract XVIIth Symposium of Czech Reproductive Immunologist with international participation contains abstracts of lectures which focuse on immunology and physiology of reproduction.

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