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Vinod H. Nargund - One of the best experts on this subject based on the ideXlab platform.
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Effects of psychological stress on Male Fertility
Nature Reviews Urology, 2015Co-Authors: Vinod H. NargundAbstract:Psychological stress has been perceived clinically as a potential risk factor for Male inFertility, although to what extent it affects human Male Fertility is difficult to study and evaluate Clinical studies demonstrate an inverse relationship between psychological stress and semen parameters The paraventricular nucleus (PVN) in the hypothalamus regulates stress responses and activates the sympathetic–adrenal system (SAS), and the hypothalamic–pituitary–gonadal (HPG) and hypothalamic–pituitary–adrenal (HPA) axes Activation of HPG and HPA axes leads to a fall in testosterone levels in the testes, affecting Sertoli cells and the blood—testis barrier Psychological stress can be defined as any uncomfortable 'emotional experience' accompanied by predictable biochemical, physiological and behavioural changes or responses. Many clinical studies looking at the effects of psychological stress on Male Fertility have shown that stress is associated with reduced paternity and abnormal semen parameters. Enough scientific evidence exists to suggest that psychological stress could severely affect spermatogenesis, mainly as a result of varying testosterone secretion. The hypothalamic–pituitary–adrenal axis has a direct inhibitory action on the hypothalamic–pituitary–gonadal (HPG) axis and Leydig cells in the testes. The newly discovered hormone, gonadotropin-inhibitory hormone (GnIH), also has an inhibitory effect on the HPG axis. Inhibition of the HPG axis results in a fall in testosterone levels, which causes changes in Sertoli cells and the blood–testis barrier, leading to the arrest of spermatogenesis. Germ cells also become vulnerable to gonadotoxins and oxidation. However, the extent and severity of the effects of psychological stress on human testes is difficult to study and data mostly come from animal models. Despite this limitation, stress as a causative factor in Male inFertility cannot be ignored and patients should be made aware of its effects on testicular function and Fertility and helped to manage them. Many clinical studies looking at the effects of psychological stress on Male Fertility have shown that stress is associated with reduced paternity and abnormal semen parameters. This Review by Nargund describes the possible effects of psychological stress on testosterone secretion and spermatogenesis.
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Effects of psychological stress on Male Fertility
Nature Reviews Urology, 2015Co-Authors: Vinod H. NargundAbstract:Many clinical studies looking at the effects of psychological stress on Male Fertility have shown that stress is associated with reduced paternity and abnormal semen parameters. This Review by Nargund describes the possible effects of psychological stress on testosterone secretion and spermatogenesis.
Myung-geol Pang - One of the best experts on this subject based on the ideXlab platform.
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Mitochondrial Functionality in Male Fertility: From Spermatogenesis to Fertilization.
Antioxidants (Basel Switzerland), 2021Co-Authors: Yoo-jin Park, Myung-geol PangAbstract: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.
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Peroxiredoxin activity is a major landmark of Male Fertility.
Scientific reports, 2017Co-Authors: Do-yeal Ryu, Saidur Rahman, Woo-sung Kwon, Ki-uk Kim, Amena Khatun, Myung-geol PangAbstract:Peroxiredoxins (PRDXs) are important antioxidant enzymes reported to have a role in sperm function and Male Fertility. However, how PRDXs affects Male Fertility remain fundamental unanswered questions. We therefore sought to investigate the role of these enzymes in sperm function and fertilisation. In this in vitro trial, mouse spermatozoa were incubated with different concentrations of conoidin A (1, 10, or 100 µM), a specific inhibitor of PRDXs. Our results demonstrated that inhibition of PRDXs by conoidin A significantly decreased the oxidized form of peroxiredoxins (PRDXs-SO3) in spermatozoa. Decreased PRDX activity was associated with a significant reduction in sperm motility parameters, viability, and intracellular ATP, whereas ROS levels, DNA fragmentation, and loss of mitochondrial membrane potential were increased. Simultaneously capacitation and the acrosome reaction were also significantly inhibited perhaps as a consequence of decreased tyrosine phosphorylation and protein kinase-A activity. In addition, fertilisation and early embryonic development were adversely affected following PRDXs inhibition in spermatozoa. Taken together, our data demonstrate that decreased PRDX activity directly affects Male Fertility due to negative effects on important functions and biochemical properties of spermatozoa, ultimately leading to poor fertilisation and embryonic development.
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Prediction of Male Fertility using capacitation-associated proteins in spermatozoa.
Molecular Reproduction and Development, 2017Co-Authors: Saidur Rahman, Woo-sung Kwon, Myung-geol PangAbstract:InFertility and subFertility account for huge economic losses in the animal industry; indeed, 50% of animal breeding failure is associated with Male inFertility. Approximately 70% of cattle and 90% of pig livestock are currently produced by artificial insemination. Therefore, breeding-Male selection is extremely important for the genetic benefits of progeny. Although conventional semen analysis provides an initial measure of Male Fertility, its clinical value is questionable. Proteomics approaches recently identified candidate protein markers in spermatozoa for evaluating Male Fertility. Fertility-related proteins in capacitated boar spermatozoa were shown to predict boar Fertility more precisely then those detected in ejaculated spermatozoa, which motivated the development of more accurate and sensitive tools for the assessment of Male Fertility in relation to sperm function and fertilization. Although protein markers in spermatozoa are capable of discriminating fertile and infertile Males, clinical trials are required to validate their predictive utility. This review outlines recent findings regarding the capacitation-related proteome of spermatozoa, and discusses how these proteins may be utilized to better understand the Fertility of domestic animals.
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Increased Male Fertility using Fertility-related biomarkers.
Scientific Reports, 2015Co-Authors: Woo-sung Kwon, Saidur Rahman, Yoo-jin Park, Do-yeal Ryu, Myung-geol PangAbstract:Conventional semen analyses are used to evaluate Male factor Fertility/inFertility in humans and other animals. However, their clinical value remains controversial. Therefore, new tools that more accurately assess Male Fertility based on sperm function and fertilization mechanism are of interest worldwide. While protein markers in spermatozoa that might help differentiate fertile and infertile sperm have been identified, studies are in their infancy, and the markers require validation in field trials. In the present study, to discover more sensitive biomarkers in spermatozoa for predicting Male Fertility, we assessed protein expression in capacitated spermatozoa. The results demonstrated that cytochrome b-c1 complex subunit 2 (UQCRC2) was abundantly expressed in high-litter size spermatozoa (>3-fold). On the other hand, equatorin, beta-tubulin, cytochrome b-c1 complex subunit 1 (UQCRC1), speriolin, Ras-related protein Rab-2A (RAB2A), spermadhesin AQN-3, and seminal plasma sperm motility inhibitor were abundantly expressed in low-litter size spermatozoa (>3-fold). Moreover, RAB2A and UQCRC1 expression negatively correlated with litter size, while UQCRC2 expression positively correlated with litter size. Finally, the putative biomarkers predicted litter size in field trials. Our study suggests that biomarkers present in spermatozoa after capacitation can help differentiate superior Male Fertility from below-average Fertility with high sensitivity.
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Proteomic Revolution to Improve Tools for Evaluating Male Fertility in Animals
Journal of Proteome Research, 2013Co-Authors: Yoo-jin Park, Jin Kim, Young-ah You, Myung-geol PangAbstract:Artificial insemination has been used as a common breeding technique for the rapid dissemination of important genes to improve livestock quality. However, inFertility or subFertility in the Male leads to the disintegration of the breeding system and large economic losses. Therefore, the development of an accurate diagnostic protocol for Male Fertility is of critical importance. To this end, many basic laboratory assays have been developed on the basis of semen analysis. Although these assays may provide a preliminary estimate of Male Fertility, their accuracies are often unacceptably low. Therefore, it is vital to develop new semen analyses that are simple to use and accurate. Proteomic approaches will shed light on understanding sperm physiology and help in developing new diagnostic tools for Male Fertility. The aim of this study was to review the retrospective semen analyses and prospective proteomic studies of Male Fertility determination and usefulness of proteomic approaches in diagnosing Male fertil...
Reini W. Bretveld - One of the best experts on this subject based on the ideXlab platform.
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The impact of pesticides on Male Fertility.
Current opinion in obstetrics & gynecology, 2008Co-Authors: Nel Roeleveld, Reini W. BretveldAbstract:PURPOSE OF REVIEW: Observations in several Western countries point toward a decline in semen quality which may be associated with exposure to environmental endocrine disruptors such as several frequently used pesticides. The scarce literature on the effects of pesticides on Male Fertility will be reviewed with a focus on semen quality and time-to-pregnancy. RECENT FINDINGS: The majority of studies published since 2000 reported some effects of pesticide exposure on semen quality or time-to-pregnancy. The results are not consistent, however, with some studies showing reduced sperm concentrations and others showing low percentages of morphologically normal and/or motile sperm. In time-to-pregnancy studies, reduced Male Fertility measured as prolonged time-to-pregnancy related to pesticide exposure was observed for first pregnancies only. Some of the inconsistencies may be explained by heterogeneity in populations, pesticide exposure, and study design. SUMMARY: Despite this heterogeneity, the conclusion can be drawn that pesticide exposure may affect spermatogenesis leading to poor semen quality and reduced Male Fertility. More research is needed to unravel the pathophysiological mechanisms and the role of endocrine disruption.
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Influence of pesticides on Male Fertility
Scandinavian journal of work environment & health, 2007Co-Authors: Reini W. Bretveld, Marijn M. Brouwers, Inge Ebisch, Nel RoeleveldAbstract:Several studies have shown a decline in human semen quality and increased risks of Male subFertility. This paper provides an overview of the mechanisms of pesticide-induced reproductive toxicity and the effects on Male Fertility since exposure to pesticides may be one of the causes of these disorders. Pesticides may directly damage spermatozoa, alter Sertoli cell or Leydig cell function, or disrupt the endocrine function in any stage of hormonal regulation (hormone synthesis, release, storage, transport, and clearance; receptor recognition and binding; thyroid function; and the central nervous system). These mechanisms are described with respect to the effects of pesticide exposure in vitro and in vivo. In epidemiologic studies, effects on sperm quality and time to pregnancy are reviewed. Clear effects on Male Fertility have been demonstrated for some pesticides [eg, dibromochloropropane, ethylene dibromide]. But results from more recent studies are inconsistent, and no uniform conclusion can be drawn about the effects of pesticides on Male reproduction.
Nel Roeleveld - One of the best experts on this subject based on the ideXlab platform.
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The impact of pesticides on Male Fertility.
Current opinion in obstetrics & gynecology, 2008Co-Authors: Nel Roeleveld, Reini W. BretveldAbstract:PURPOSE OF REVIEW: Observations in several Western countries point toward a decline in semen quality which may be associated with exposure to environmental endocrine disruptors such as several frequently used pesticides. The scarce literature on the effects of pesticides on Male Fertility will be reviewed with a focus on semen quality and time-to-pregnancy. RECENT FINDINGS: The majority of studies published since 2000 reported some effects of pesticide exposure on semen quality or time-to-pregnancy. The results are not consistent, however, with some studies showing reduced sperm concentrations and others showing low percentages of morphologically normal and/or motile sperm. In time-to-pregnancy studies, reduced Male Fertility measured as prolonged time-to-pregnancy related to pesticide exposure was observed for first pregnancies only. Some of the inconsistencies may be explained by heterogeneity in populations, pesticide exposure, and study design. SUMMARY: Despite this heterogeneity, the conclusion can be drawn that pesticide exposure may affect spermatogenesis leading to poor semen quality and reduced Male Fertility. More research is needed to unravel the pathophysiological mechanisms and the role of endocrine disruption.
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Influence of pesticides on Male Fertility
Scandinavian journal of work environment & health, 2007Co-Authors: Reini W. Bretveld, Marijn M. Brouwers, Inge Ebisch, Nel RoeleveldAbstract:Several studies have shown a decline in human semen quality and increased risks of Male subFertility. This paper provides an overview of the mechanisms of pesticide-induced reproductive toxicity and the effects on Male Fertility since exposure to pesticides may be one of the causes of these disorders. Pesticides may directly damage spermatozoa, alter Sertoli cell or Leydig cell function, or disrupt the endocrine function in any stage of hormonal regulation (hormone synthesis, release, storage, transport, and clearance; receptor recognition and binding; thyroid function; and the central nervous system). These mechanisms are described with respect to the effects of pesticide exposure in vitro and in vivo. In epidemiologic studies, effects on sperm quality and time to pregnancy are reviewed. Clear effects on Male Fertility have been demonstrated for some pesticides [eg, dibromochloropropane, ethylene dibromide]. But results from more recent studies are inconsistent, and no uniform conclusion can be drawn about the effects of pesticides on Male reproduction.
Stefano Lorenzetti - One of the best experts on this subject based on the ideXlab platform.
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The role of the prostate in Male Fertility, health and disease
Nature Reviews Urology, 2016Co-Authors: Paolo Verze, Stefano LorenzettiAbstract:The prostate gland is the major Male reproductive gland involved in Male Fertility. In this Review, the authors discuss the reproductive function of the prostate gland, summarizing physiological and molecular mechanisms that connect prostate homeostasis with Male Fertility and describing how these mechanisms are associated with prostatic diseases. They highlight the central role of Zn^2+and citrate in regulating activities of the prostate epithelium, discuss the influence of bacteria-related prostate inflammation on Male Fertility, and note the potential role of prostatic inflammation in the development of prostatic hyperplastic growth and prostate carcinogenesis. Male Fertility is controlled by a Zn^2+-dependent short circuit of the Krebs cycle within prostate epithelial cells Homeostasis of the prostate epithelium is reliant on the intracellular androgen-dependent accumulation of Zn^2+ and citrate Sperm motility requires the coordinated action of the components of the two main fluids in the human seminal plasma: the prostatic fluid, which is enriched with Zn^2+, citrate and kallikreins, and the semenogelin-enriched seminal vesicle secretion The prostate is the direct target for a number of benign and malignant diseases that are potentially linked to impaired Fertility status Prostatitis might be directly linked with changes in Fertility Ejaculation is a synchronized cascade of events that has the ultimate goal of activating sperm and enabling them to reach an egg for fertilization. The seminal plasma contains a complex mixture of fluids that is secreted from the testes, epididymis and Male accessory glands. The prostate gland has a pivotal role in this process, as prostatic fluid enriched in Zn^2+, citrate and kallikreins is crucial for the molecular synchronization of the functional cascade triggered by ejaculatory stimuli. The prostate is the target of a number of common diseases that can affect Male Fertility at different ages. In both young and aged men, prostatic diseases or an unhealthy prostate can affect spermatozoa functioning and, therefore, Male Fertility. Consideration of prostate physiology emphasizes a number of points: the central role of Zn^2+ and citrate in the regulation of prostate epithelium homeostasis and in ejaculation; the influence of bacteria-related prostatic inflammation on Male Fertility; and the potential role of prostatic inflammation in promoting the development of prostatic hyperplastic growth and carcinogenesis.
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The role of the prostate in Male Fertility, health and disease
Nature reviews. Urology, 2016Co-Authors: Paolo Verze, T. Tony Cai, Stefano LorenzettiAbstract:Ejaculation is a synchronized cascade of events that has the ultimate goal of activating sperm and enabling them to reach an egg for fertilization. The seminal plasma contains a complex mixture of fluids that is secreted from the testes, epididymis and Male accessory glands. The prostate gland has a pivotal role in this process, as prostatic fluid enriched in Zn(2+), citrate and kallikreins is crucial for the molecular synchronization of the functional cascade triggered by ejaculatory stimuli. The prostate is the target of a number of common diseases that can affect Male Fertility at different ages. In both young and aged men, prostatic diseases or an unhealthy prostate can affect spermatozoa functioning and, therefore, Male Fertility. Consideration of prostate physiology emphasizes a number of points: the central role of Zn(2+) and citrate in the regulation of prostate epithelium homeostasis and in ejaculation; the influence of bacteria-related prostatic inflammation on Male Fertility; and the potential role of prostatic inflammation in promoting the development of prostatic hyperplastic growth and carcinogenesis.