Andriy Dorosh

Effect of zearalenone on reproductive parameters and expression of selected testicular genes in mice

We tested the effect of two different concentrations (150μg/l and 0.15μg/l) of mycotoxin zearalenone (ZEA) on the reproductive parameters and expression of testicular genes in male mice. In adult males, no reduction of body or reproductive organ weight was observed, and the seminiferous tubules were morphologically normal with ongoing spermatogenesis. However, we found decreased sperm concentration, increase of morphologically abnormal spermatozoa and increased binding of apoptotic marker annexin V. This study was also focused on the evaluation of gene expression profiles of 28 genes playing important roles during the processes occurring in the testicular tissue. We detected changes in the expression of genes important for proper spermatogenesis. Surprisingly, we observed a stronger effect after exposure to the lower dose of ZEA.

Effect of estrogens on boar sperm capacitation in vitro

BackgroundMammalian sperm must undergo a series of controlled molecular processes in the female reproductive tract called capacitation before they are capable of penetrating and fertilizing the egg. Capacitation, as a complex biological process, is influenced by many molecular factors, among which steroidal hormone estrogens play their role. Estrogens, present in a high concentration in the female reproductive tract are generally considered as primarily female hormones. However, there is increasing evidence of their important impact on male reproductive parameters. The purpose of this study is to investigate the effect of three natural estrogens such as estrone (E1), 17beta-estradiol (E2) and estriol (E3) as well as the synthetical one, 17alpha-ethynylestradiol (EE2) on boar sperm capacitation in vitro.MethodsBoar sperm were capacitated in vitro in presence of estrogens. Capacitation progress in control and experimental samples was analyzed by flow cytometry with the anti-acrosin monoclonal antibody (ACR.2) at selected times of incubation. Sperm samples were analyzed at 120 min of capacitation by CTC (chlortetracycline) assay, immunocytochemistry and flow cytometry with anti-acrosin ACR.2 antibody. Furthermore, sperm samples and capacitating media were analyzed by immunocytochemistry, ELISA with the ACR.2 antibody, and the acrosin activity assay after induced acrosomal reaction (AR).ResultsEstrogens stimulate sperm capacitation of boar sperm collected from different individuals. The stimulatory effect depends on capacitation time and is highly influenced by differences in the response to estrogens such as E2 by individual animals. Individual estrogens have relatively same effect on capacitation progress. In the boar samples with high estrogen responsiveness, estrogens stimulate the capacitation progress in a concentration-dependent manner. Furthermore, estrogens significantly increase the number of acrosome-reacted sperm after zona pellucida- induced acrosomal reaction.ConclusionsWe demonstrate here the stimulatory effect of four different estrogens on boar sperm capacitation in vitro. According to our results, there is significant difference in the response to tested estrogens at different capacitation time and among individual animals. In animals with a high response to estrogens, there is a concentration-dependent stimulation of capacitation and individual estrogens have relatively the same effect. Effects of individual estrogens, differences in the response to them by individual animals, their time and concentration-dependent outcomes further contribute to our knowledge about steroidal action in sperm.

Expression analysis of MND1/GAJ, SPATA22, GAPDHS and ACR genes in testicular biopsies from non-obstructive azoospermia (NOA) patients

BackgroundHigh-throughput studies provide a wide spectrum of genes for use as predictive markers during testicular sperm extraction (TESE) in combination with ICSI. In this work, we used the specimens from testicular biopsies of men with non-obstructive azoospermia who underwent TESE to investigate the expression of spermatogenesis-related genes MND1, SPATA22, GAPDHS and ACR.MethodsTesticular biopsy specimens were subdivided into three groups: hypospermatogenesis (HS); maturation arrest (MA); and Sertoli cell-only syndrome (SCO). The levels of expression of the spermatogenesis-related genes MND1, SPATA22, GAPDHS and ACR in the testes were compared among these three groups using the reverse transcription polymerase chain reaction (RT-PCR) technique.ResultsAnalysis of the expression of spermatogenic genes in human testes with abnormal spermatogenesis showed different expression patterns in patients from different groups. Fertilization rate for studied set of patients was 66% and pregnancy rate 29%. For HS group fertilization rate was 72% and pregnancy rate 32%, while for MA group fertilization and pregnancy rates were 54% and 26%, respectively. Fertilization rates in relation to the studied genes were uniformly around 70%, pregnancy rates for ACR and GAPDHS genes were surprisingly low at 6% and 8% correspondingly.ConclusionsAnalysis of the expression of genes involved in spermatogenesis can be a fast additional test for the level of spermatogenesis in testicular samples.

Adverse effect of tetracycline and doxycycline on testicular tissue and sperm parameters in CD1 outbred mice

Tetracycline and doxycycline are commonly used antibiotics in acne treatment during puberty in humans. The long-term effect of these antibiotics on male reproductive tract development has not been fully elucidated. For this reason we tested the effect of antibiotics on the reproductive parameters of mice males during puberty with the therapeutic dose used in humans, and with lower and higher doses. The outbred mouse strain CD1 with higher heterozygosity was exposed for 14 days at puberty. Adult males at the age of 70 days were used for the measurements. We observed a significant decrease in anogenital distance and thickness of the seminiferous epithelium in the treated animals. Pathological changes in the testes had an impact on sperm quality; a higher number of sperm positively stained with Annexin V and TUNEL and a lower number of acrosome-intact sperm was detected. In conclusion, the treatment of male mice with antibiotics in puberty led to long-lasting effects on reproductive organs and spermatozoa in adult males.

Acrosin inhibitor detection along the boar epididymis.

Epididymal sperm maturation represents a key step in the reproduction process. Spermatozoa are exposed to epididymal fluid components representing the natural environment essential for their post-testicular maturation. Changes in sperm membrane proteins are influenced by proteolytic, glycosylation and deglycosylation enzymes present in the epididymal fluid. Accordingly, the occurrence of inhibitors of these enzymes in the epididymis is very important for the regulation of sperm membrane protein processing. In the present study, we monitored acrosin inhibitor distribution in boar epididymal fluid and in spermatozoa from different segments of the organ. Using specific polyclonal antibody we registered increasing signal of the acrosin inhibitor (AI) from caput to cauda epididymis. Mass spectroscopy examination of the immunoprecipitated acrosin inhibitor (12 kDa) unequivocally identified sperm-associated acrosin inhibitor (SAAI) in the epididymal tissue. Lectin staining showed N-glycosylation in AI from boar epididymis. Protein detection of AI was supported by the results of semi-quantitative RT-PCR showing the presence of mRNA specifically coding for SAAI and similarly increasing throughout the epididymal duct, from its proximal to distal part. Additionally, the immunofluorescence technique showed the AI localization in the secretory tissue of caput, corpus and cauda epididymis, and in the acrosome region and midpiece of the sperm.

Panel of monoclonal antibodies to sperm surface proteins as a tool for monitoring localization and identification of sperm–zona pellucida receptors

Primary binding of the sperm to the zona pellucida (ZP) is one of the many steps necessary for successful fertilization. Sperm bind ZP by means of membrane receptors which recognize carbohydrate moieties on ZP glycoproteins according to a well-defined sequential process. Primary binding receptors, many of which have been disclosed in various mammals, are localized throughout the acrosomal region of the sperm surface. A panel of monoclonal antibodies against proteins from the sperm surface was prepared. Antibodies were screened by immunofluorescence for protein localization and Western blotting. Proteins localized on the sperm head and simultaneously detected by Western blotting were further studied in terms of immunolocalization in reproductive tissues and fluids, binding to ZP, immunoprecipitation and sequencing. Of 17 prepared antibodies, 8 recognized proteins localized on the sperm head and also detected proteins of interest by Western blotting. Only three other antibodies recognized proteins that also coincided in binding to ZP. These three antibodies were used for immunoprecipitation, and further protein sequencing of immunoprecipitates revealed that these antibodies distinguished acrosin precursor, RAB-2A protein, and lactadherin P47. This is not the first time we have detected acrosin on the surface of ejaculated and capacitated sperm. However, to our knowledge, this is the first time RAB-2A has been detected on the sperm surface. Lactadherin P47 has already been characterized and its physiological function in reproduction has been proposed.