82 research outputs found
Numerical Chromosome Abnormalities in Sperm From Oligoasthenoteratozoospermic Patients and Fertile Males
Artificial fertilization protocols have been developed which bypass natural barriers for reproduction. One aspect of infertility which has received little attention is the potential importance of aneuploidy in sperm. To more clearly understand the cytogenetic make-up of sperm from OAT patients, multi-probe, multi-color FISH was performed to determine aneuploidy.
The introduction of intracytoplasmic sperm injection (ICSI) has revolutionized protocols used in in vitro fertilization centers. The pregnancies resulting from ICSI suggest an increased frequency of sex chromosome aneuploidy in livebirths. Preliminary data by others\u27 suggest that sperm tail swelling patterns following hypo-osmotic swelling (HOST) can be predictive of fertilizing ability. To clarify the relationship between sperm tail swelling patterns, aneuploidy, and fertilizing ability, we developed a technique combining HOST and FISH.
Using multi-probe, multi color FISH and developed formulae, we determined total aneuploidy in sperm from proven fertile donors and OAT patients. In controls, the total aneuploidy ranged between 4.1 and 7.7%. For OAT patients, the total aneuploidy was between 43 and 69%. Diploidy was found in 0.04% of sperm in controls and ranged between 0.4 and 9.6% in OAT patients.
To determine if sperm selection by swim-up can separate haploid from aneuploid sperm, we used three-probe, three-color FISH on sperm in the swim-up and pellet fractions. Between 35 and 52% of sperm from OAT patients in the swim-up fraction and 36 to 49% from the pellet were aneuploid. No significant difference was observed. However, the percent of diploid sperm predominantly resided within the pellet for all OAT and proven fertile donors.
We performed HOST and FISH on sperm from OAT patients undergoing ICSI. Data suggests that sperm tail swelling patterns A, B, D, E, F and G may be aneuploid in OAT patients. No aneuploidy was found in sperm with a C type tail swelling pattern in either OAT or normal controls. Diploid sperm in controls and OAT patients were only found in types A and G tail swelling patterns. Preliminary data suggests that there may be a correlation between HOST and aneuploidy for OAT patients.
Of the 30 OAT patients studied, 26 series of ICSI were performed. Sixty-eight percent of oocytes fertilized (165 embryos/242 oocytes). Following fresh embryo transfer, 1 preclinical abortion, 1 first trimester loss, and 2 term deliveries (2/26, 7.7%) occurred.
Our data show significant increases in the frequencies of diploidy, autosomal disomy, autosomal nullisomy, sex chromosome number, and total cytogenetic abnormalities in sperm from OAT patients versus controls. The data suggest that meiotic errors occur at highly elevated frequencies in the germ cells of severely affected OAT patients
Sperm Proteomics: Road to Male Fertility and Contraception
Spermatozoa are highly specialized cells that can be easily obtained and purified. Mature spermatozoa are transcriptionally and translationally inactive and incapable of protein synthesis. In addition, spermatozoa contain relatively higher amounts of membrane proteins compared to other cells; therefore, they are very suitable for proteomic studies. Recently, the application of proteomic approaches such as the two-dimensional polyacrylamide gel electrophoresis, mass spectrometry, and differential in-gel electrophoresis has identified several sperm-specific proteins. These findings have provided a further understanding of protein functions involved in different sperm processes as well as of the differentiation of normal state from an abnormal one. In addition, studies on the sperm proteome have demonstrated the importance of spermatozoal posttranslational modifications and their ability to induce physiological changes responsible for fertilization. Large-scale proteomic studies to identify hundreds to thousands of sperm proteins will ultimately result in the development of novel biomarkers that may help to detect fertility, the state of complete contraception, and beyond. Eventually, these protein biomarkers will allow for a better diagnosis of sperm dysfunctions and aid in drug development. This paper reviews the recent scientific publications available from the PubMed database to address sperm proteomics and its potential application to characterize male fertility and contraception
The effect of male circumcision on sexuality
OBJECTIVE To prospectively study, using a questionnaire, the sexuality of men circumcised as adults compared to uncircumcised men, and to compare their sex lives before and after circumcision. SUBJECTS AND METHODS The study included 373 sexually active men, of whom 255 were circumcised and 118 were not. Of the 255 circumcised men, 138 had been sexually active before circumcision, and all were circumcised at > 20 years of age. As the Brief Male Sexual Function Inventory does not specifically address the quality of sex life, questions were added to compare sexual and masturbatory pleasure before and after circumcision. RESULTS There were no significant differences in sexual drive, erection, ejaculation, and ejaculation latency time between circumcised and uncircumcised men. Masturbatory pleasure decreased after circumcision in 48% of the respondents, while 8% reported increased pleasure. Masturbatory difficulty increased after circumcision in 63% of the respondents but was easier in 37%. About 6% answered that their sex lives improved, while 20% reported a worse sex life after circumcision. CONCLUSION There was a decrease in masturbatory pleasure and sexual enjoyment after circumcision, indicating that adult circumcision adversely affects sexual function in many men, possibly because of complications of the surgery and a loss of nerve endings
Mitochondrial Functionality in Male Fertility: From Spermatogenesis to Fertilization
Mitochondria are structurally and functionally distinct organelles that produce adenosine triphosphate (ATP) through oxidative phosphorylation (OXPHOS), to provide energy to spermatozoa. They can also produce reactive oxidation species (ROS). While a moderate concentration of ROS is critical for tyrosine phosphorylation in cholesterol efflux, sperm–egg interaction, and fertilization, excessive ROS generation is associated with male infertility. Moreover, mitochondria participate in diverse processes ranging from spermatogenesis to fertilization to regulate male fertility. This review aimed to summarize the roles of mitochondria in male fertility depending on the sperm developmental stage (from male reproductive tract to female reproductive tract). Moreover, mitochondria are also involved in testosterone production, regulation of proton secretion into the lumen to maintain an acidic condition in the epididymis, and sperm DNA condensation during epididymal maturation. We also established the new signaling pathway using previous proteomic data associated with male fertility, to understand the overall role of mitochondria in male fertility. The pathway revealed that male infertility is associated with a loss of mitochondrial proteins in spermatozoa, which induces low sperm motility, reduces OXPHOS activity, and results in male infertility
Role of Antioxidants in Alleviating Bisphenol A Toxicity
Bisphenol A (BPA) is an oestrogenic endocrine disruptor widely used in the production of certain plastics, e.g., polycarbonate, hard and clear plastics, and epoxy resins that act as protective coating for food and beverage cans. Human exposure to this chemical is thought to be ubiquitous. BPA alters endocrine function, thereby causing many diseases in human and animals. In the last few decades, studies exploring the mechanism of BPA activity revealed a direct link between BPA-induced oxidative stress and disease pathogenesis. Antioxidants, reducing agents that prevent cellular oxidation reactions, can protect BPA toxicity. Although the important role of antioxidants in minimizing BPA stress has been demonstrated in many studies, a clear consensus on the associated mechanisms is needed, as well as the directives on their efficacy and safety. Herein, considering the distinct biochemical properties of BPA and antioxidants, we provide a framework for understanding how antioxidants alleviate BPA-associated stress. We summarize the current knowledge on the biological function of enzymatic and non-enzymatic antioxidants, and discuss their practical potential as BPA-detoxifying agents
Determination of Highly Sensitive Biological Cell Model Systems to Screen BPA-Related Health Hazards Using Pathway Studio
Bisphenol-A (BPA) is a ubiquitous endocrine-disrupting chemical. Recently, many issues have arisen surrounding the disease pathogenesis of BPA. Therefore, several studies have been conducted to investigate the proteomic biomarkers of BPA that are associated with disease processes. However, studies on identifying highly sensitive biological cell model systems in determining BPA health risk are lacking. Here, we determined suitable cell model systems and potential biomarkers for predicting BPA-mediated disease using the bioinformatics tool Pathway Studio. We compiled known BPA-mediated diseases in humans, which were categorized into five major types. Subsequently, we investigated the differentially expressed proteins following BPA exposure in several cell types, and analyzed the efficacy of altered proteins to investigate their associations with BPA-mediated diseases. Our results demonstrated that colon cancer cells (SW480), mammary gland, and Sertoli cells were highly sensitive biological model systems, because of the efficacy of predicting the majority of BPA-mediated diseases. We selected glucose-6-phosphate dehydrogenase (G6PD), cytochrome b-c1 complex subunit 1 (UQCRC1), and voltage-dependent anion-selective channel protein 2 (VDAC2) as highly sensitive biomarkers to predict BPA-mediated diseases. Furthermore, we summarized proteomic studies in spermatozoa following BPA exposure, which have recently been considered as another suitable cell type for predicting BPA-mediated diseases
Calcium Influx and Male Fertility in the Context of the Sperm Proteome: An Update
Freshly ejaculated spermatozoa are incapable or poorly capable of fertilizing an oocyte. The fertilization aptness of spermatozoa depends on the appropriate and time-dependent acquisition of hyperactivation, chemotaxis, capacitation, and the acrosome reaction, where calcium (Ca2+) is extensively involved in almost every step. A literature review showed that several ion channel proteins are likely responsible for regulation of the Ca2+ uptake in spermatozoa. Therefore, manipulation of the functions of channel proteins is closely related to Ca2+ influx, ultimately affecting male fertility. Recently, it has been shown that, together with different physiological stimuli, protein-protein interaction also modifies the Ca2+ influx mechanism in spermatozoa. Modern proteomic analyses have identified several sperm proteins, and, therefore, these findings might provide further insight into understanding the Ca2+ influx, protein functions, and regulation of fertility. The objective of this review was to synthesize the published findings on the Ca2+ influx mechanism in mammalian spermatozoa and its implications for the regulation of male fertility in the context of sperm proteins. Finally, Pathway Studio (9.0) was used to catalog the sperm proteins that regulate the Ca2+ influx signaling by using the information available from the PubMed database following a MedScan Reader (5.0) search
Bioinformatics Annotation of Human Y Chromosome-Encoded Protein Pathways and Interactions
We performed a comprehensive analysis
of human Y chromosome-encoded
proteins, their pathways, and their interactions using bioinformatics
tools. From the NCBI annotation release 107 of human genome, we retrieved
a total of 66 proteins encoded on Y chromosome. Most of the retrieved
proteins were also matched with the proteins listed in the core databases
of the Human Proteome Project including neXtProt, PeptideAtlas, and
the Human Protein Atlas. When we examined the pathways of human Y-encoded
proteins through KEGG database and Pathway Studio software, many of
proteins fall into the categories related to cell signaling pathways.
Using the STRING program, we found a total of 49 human Y-encoded proteins
showing strong/medium interaction with each other. While using the
Pathway studio software, we found that a total of 16 proteins interact
with other chromosome-encoded proteins. In particular, the SRY protein
interacted with 17 proteins encoded on other chromosomes. Additionally,
we aligned the sequences of human Y-encoded proteins with the sequences
of chimpanzee and mouse Y-encoded proteins using the NCBI BLAST program.
This analysis resulted in a significant number of orthologous proteins
between human, chimpanzee, and mouse. Collectively, our findings provide
the scientific community with additional information on the human
Y chromosome-encoded proteins
Optimization of sperm RNA processing for developmental research
Abstract Recent studies have demonstrated the significance of sperm RNA function as a transporter of important information directing the course of life. To determine the message contained in sperm RNA, it is necessary to optimize transcriptomic research tools. The current study was performed to optimize the processing of sperm RNA from sample storage to quantitative real-time PCR and assess the corresponding method with to evaluate male fertility and its representative markers, equatorin (EQTN) and peroxiredoxin (PRDX). Following successive steps of the Minimum Information for Publication of Quantitative Real-Time PCR Experiments guidelines, several options were compared using boar spermatozoa. To evaluate the optimized procedures, the relationship between mRNA expression of EQTN and PRDX in spermatozoa and the fertility (litter size) of 20 individual boars was assessed. Unexpectedly, DNase treatment during RNA isolation had the deleterious effect by decreasing the RNA concentration by 56% and eliminating the correlation between EQTN and PRDX4 mRNA expression and male fertility. Moreover, when sperm RNA was processed using the corresponding method, the results showed the highest exon sequence expression, male fertility prediction power, and consistency. This optimized protocol for predicting male fertility can be used to study the transport of messages directing the life course from spermatozoon to offspring
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