RESUMO
BACKGROUND: Advanced glycation end products (AGEs) that accompany many metabolic disorders including diabetes, obesity, and a wide range of dyslipidemia conditions, are strongly associated with adverse effects on cell and tissue homeostasis. Accordingly, our objective was to investigate the impact of AGE-promoting diets on mouse models, considering both scenarios with and without methylglyoxal (MGO) as a primary precursor of AGEs. MATERIALS AND METHODS: In this experimental study, 5-week-old C57BL/6 mice were split into four groups as a control group (n=5), AGE (n=5), MGO (n=8), and AGE-MGO-diets (n=8). After five weeks the level of fasting blood sugar (FBS), body weight, food intake, sperm parameters, and functional tests were evaluated. Furthermore, testicular superoxide dismutase (SOD) activity, malondialdehyde, and total antioxidant capacity (TAC) were assessed. RESULTS: After five weeks, AGE, AGE-MGO, and MGO groups showed the highest level of body weight and FBS in comparison to the control group. Mean sperm concentration, sperm malondialdehyde, testicular lipid peroxidation, and TAC did not differ significantly among the study groups. While, AGE, MGO, and AGE-MGO groups showed a significant reduction in sperm motility and progressive motility compared to the control group (P<0.05). The greatest increases in abnormal sperm morphology and intracytoplasmic reactive oxygen species (ROS) were observed in the MGO and AGE-MGO groups than in the control group (P<0.05). Sperm protamine deficiency and residual histone were significantly increased in the three treatment groups compared to the control group (P<0.05). Regarding the DNA damage, the AGE and AGE-MGO groups showed the most severe damage. The lowest amount of testicular superoxide dismutases (SOD, P<0.001) was observed in the AGE-MGO group. CONCLUSION: AGEs and MGO have a negative influence on sperm function and reproductive potential. These effects could be possibly attributed to both increased oxidative stress (OS) and inflammation.
RESUMO
This study investigated the deleterious impact of advanced glycation end products (AGEs), commonly present in metabolic disorders like diabetes, obesity, and infertility-related conditions, on sperm structure and function using a mouse model where AGE generation was heightened through dietary intervention. Five-week-old C57BL/6 mice were divided into two groups, one on a regular diet (control) and the other on an AGE-rich diet. After 13 weeks, various parameters were examined, including fasting blood glucose, body weight, food consumption, sperm parameters and function, testicular superoxide dismutase levels, malondialdehyde content, total antioxidant capacity, Johnson score, AGE receptor (RAGE) content, and carboxymethyl lysine (CML) content. The results showed that mice in the AGE group exhibited increased body weight and elevated fasting blood glucose levels. Furthermore, the AGE group displayed adverse effects on sperm, including reduced sperm counts, motility, increased morphological abnormalities, residual histone, protamine deficiency, sperm DNA fragmentation, reduced testicular antioxidant capacity, and higher levels of RAGE and CML proteins. These findings underscore the negative impact of AGEs on male reproductive health, particularly within the context of metabolic disorders, emphasizing the crucial role of the AGE/RAGE axis in male infertility, especially in the context of Western dietary patterns.
Assuntos
Produtos Finais de Glicação Avançada , Camundongos Endogâmicos C57BL , Receptor para Produtos Finais de Glicação Avançada , Motilidade dos Espermatozoides , Espermatozoides , Animais , Masculino , Produtos Finais de Glicação Avançada/metabolismo , Espermatozoides/metabolismo , Camundongos , Receptor para Produtos Finais de Glicação Avançada/metabolismo , Contagem de Espermatozoides , Testículo/metabolismo , Glicemia/metabolismo , Lisina/análogos & derivados , Lisina/metabolismo , Estresse Oxidativo , Fragmentação do DNARESUMO
BACKGROUND: Severe acute syndrome coronavirus 2 can invade a variety of tissues, including the testis. Even though this virus is scarcely found in human semen polymerase chain reaction tests, autopsy studies confirm the viral presence in all testicular cell types, including spermatozoa and spermatids. OBJECTIVE: To investigate whether the severe acute syndrome coronavirus 2 is present inside the spermatozoa of negative polymerase chain reaction-infected men up to 3 months after hospital discharge. MATERIALS AND METHODS: This cross-sectional study included 13 confirmed moderate-to-severe COVID-19 patients enrolled 30-90 days after the diagnosis. Semen samples were obtained and examined with real-time polymerase chain reaction for RNA detection and by transmission electron microscopy. RESULTS: In moderate-to-severe clinical scenarios, we identified the severe acute syndrome coronavirus 2 inside spermatozoa in nine of 13 patients up to 90 days after discharge from the hospital. Moreover, some DNA-based extracellular traps were reported in all studied specimens. DISCUSSION AND CONCLUSION: Although severe acute syndrome coronavirus 2 was not present in the infected men's semen, it was intracellularly present in the spermatozoa till 3 months after hospital discharge. The Electron microscopy (EM) findings also suggest that spermatozoa produce nuclear DNA-based extracellular traps, probably in a cell-free DNA-dependent manner, similar to those previously described in the systemic inflammatory response to COVID-19. In moderate-to-severe cases, the blood-testes barrier grants little defence against different pathogenic viruses, including the severe acute syndrome coronavirus 2. The virus could also use the epididymis as a post-testicular route to bind and fuse to the mature spermatozoon and possibly accomplish the reverse transcription of the single-stranded viral RNA into proviral DNA. These mechanisms can elicit extracellular cell-free DNA formation. The potential implications of our findings for assisted conception must be addressed, and the evolutionary history of DNA-based extracellular traps as preserved ammunition in animals' innate defence might improve our understanding of the severe acute syndrome coronavirus 2 pathophysiology in the testis and spermatozoa.
RESUMO
BACKGROUND: Sperm DNA integrity is increasingly seen as a critical characteristic determining reproductive success, both in natural reproduction and in assisted reproductive technologies (ART). Despite this awareness, sperm DNA and nuclear integrity tests are still not part of routine examinations for either infertile men or fertile men wishing to assess their reproductive capacity. This is not due to the unavailability of DNA and sperm nuclear integrity tests. On the contrary, several relevant but distinct tests are available and have been used in many clinical trials, which has led to conflicting results and confusion. The reasons for this are mainly the lack of standardization between different clinics and between the tests themselves. In addition, the small number of samples analyzed in these trials has often weakened the value of the analyses performed. In the present work, we used a large cohort of semen samples, covering a wide age range, which were simultaneously evaluated for sperm DNA fragmentation (SDF) using two of the most frequently used SDF assays, namely the TUNEL assay and the sperm chromatin structure assay (SCSA®). At the same time, as standard seminal parameters (sperm motility, sperm morphology, sperm count) were available for these samples, correlations between age, SDF and conventional seminal parameters were analyzed. RESULTS: We show that the SCSA® and TUNEL assessments of SDF produce concordant data. However, the SDF assessed by TUNEL is systematically lower than that assessed by SCSA®. Regardless of the test used, the SDF increases steadily during aging, while the HDS parameter (High DNA stainability assessed via SCSA®) remains unchanged. In the cohort analyzed, conventional sperm parameters do not seem to discriminate with aging. Only sperm volume and motility were significantly lower in the oldest age group analyzed [50-59 years of age]. CONCLUSIONS: In the large cohort analyzed, SDF is an age-dependent parameter, increasing linearly with aging. The SCSA® assessment of SDF and the flow cytometry-assisted TUNEL assessment are well correlated, although TUNEL is less sensitive than SCSA®. This difference in sensitivity should be taken into account in the final assessment of the true level of fragmentation of the sperm nucleus of a given sample. The classical sperm parameters (motility, morphology, sperm count) do not change dramatically with age, making them inadequate to assess the fertility potential of an individual.
RéSUMé: CONTEXTE: l'intégrité de l'ADN des spermatozoïdes est de plus en plus considérée comme une caractéristique essentielle déterminant le succès de la reproduction, tant dans la reproduction naturelle que dans les techniques de reproduction assistée (AMP). Malgré cette prise de conscience, les tests d'intégrité nucléaire des spermatozoïdes ne font toujours pas partie des examens de routine pour les hommes infertiles ou fertiles souhaitant évaluer leur capacité de reproduction. Cette situation n'est pas due à l'indisponibilité des tests. Au contraire, plusieurs tests pertinents mais distincts sont disponibles et ont été utilisés dans de nombreux essais cliniques, ce qui a donné lieu à des résultats contradictoires et à une certaine confusion. Les raisons en sont principalement le manque de normalisation entre les différentes cliniques et entre les tests eux-mêmes. En outre, le petit nombre d'échantillons analysés dans ces essais a souvent affaibli la valeur des analyses effectuées. Dans le présent travail, nous avons utilisé une vaste cohorte d'échantillons, couvrant une large tranche d'âge, évalués simultanément pour la fragmentation de l'ADN des spermatozoïdes à l'aide de deux des tests les plus fréquemment utilisés, à savoir le test TUNEL et le test de la structure de la chromatine des spermatozoïdes (SCSA®). Parallèlement, comme les paramètres séminaux standard (motilité, morphologie, numération) étaient disponibles pour ces échantillons, les corrélations entre l'âge, le niveau de fragmentation et les paramètres séminaux conventionnels ont été analysées. RéSULTATS: Nous montrons que les évaluations SCSA® et TUNEL produisent des données concordantes. Cependant, le SDF évalué par TUNEL est systématiquement plus faible que celui évalué par SCSA®. Quel que soit le test utilisé, la fragmentation augmente régulièrement au cours du vieillissement, alors que le paramètre HDS (« High DNA stainability¼ évalué par le test SCSA®) reste inchangé. Dans la cohorte analysée, les paramètres spermatiques conventionnels ne semblent pas varier avec le vieillissement. Seuls le volume et la mobilité des spermatozoïdes étaient significativement plus faibles dans le groupe d'âge le plus élevé analysé [5059 ans]. CONCLUSIONS: Dans la grande cohorte analysée, la fragmentation de l'ADN spermatique est un paramètre dépendant de l'âge, augmentant linéairement avec le vieillissement. L'évaluation du SDF par SCSA® et l'évaluation via le test TUNEL assistée par cytométrie de flux sont bien corrélées, bien que le TUNEL soit moins sensible que le SCSA®. Cette différence de sensibilité doit être prise en compte dans l'évaluation finale du niveau réel de fragmentation du noyau des spermatozoïdes d'un échantillon donné. Les paramètres classiques du sperme (motilité, morphologie, nombre de spermatozoïdes) ne changent pas de façon spectaculaire avec l'âge, ce qui les rend inadéquats pour évaluer le potentiel de fertilité d'un individu.
RESUMO
In mammals, especially rodents, social behaviours, such as parenting, territoriality or mate attraction, are largely based on olfactory communication through chemosignals. These behaviours are mediated by species-specific chemosignals, including small organic molecules and proteins that are secreted in the urine or in various fluids from exocrine glands. Chemosignal detection is mainly ensured by olfactory neurons in two specific sensory organs, the vomeronasal organ (VNO) and the main olfactory epithelium (MOE). This study aimed to characterise the olfactory communication in the fossorial ecotype of the water voles, Arvicola terrestris. We first measured the olfactory investigation of urine and lateral scent gland secretions from conspecifics. Our results showed that water voles can discriminate the sex of conspecifics based on the smell of urine, and that urinary male odour is attractive for female voles. Then, we demonstrated the ability of the VNO and MOE to detect volatile organic compounds (VOCs) found in water vole secretions using live-cell calcium imaging in dissociated cells. Finally, we evaluated the attractiveness of two mixtures of VOCs from urine or lateral scent glands in the field during a cyclical outbreak of vole populations.
RESUMO
Testicular dysfunction, whether linked to varicocele, obesity, diabetes, aging, inflammation, or lifestyle or environmental issues, is frequently accompanied by an accumulation of unfolded or misfolded proteins, indicating impaired endoplasmic reticulum (ER) function. In this review, we examined the Google Scholar, Scopus and PubMed databases (from 2011 to 2022) to support the association of ER stress with defective spermatogenesis in animal models and humans. ER stress, whether in its pro-survival or pro-apoptotic aspect, appears to be closely linked to each studied situation. Several studies have demonstrated a significant increase in oxidative stress (OS) levels in infertile men compared to fertile individuals, which is associated with poor spermatogenesis quality. OS is likely the result of the interplay between ER stress and spermatogenesis defects. These findings suggest that therapeutic strategies aimed at mitigating both ER stress and OS could be of interest in restoring male reproductive function.
RESUMO
BACKGROUND: Infertility affects one couple out of six worldwide. Male infertilty can result from congenital or acquired factors, of which pathogens that reach the genital tract through sexual contact or blood dissemination. The impact of major viral, bacterial and parasitic infections on the male genital tract and fertility has been summarized. RESULTS AND CONCLUSIONS: A systematic review of articles published in the Google Scholar and PubMed databases was conducted. It turns out that viruses, as well as bacteria and parasites are major inducers of male genital tract infections and ensuing infertility through damage to the organs and subsequent loss of function and/or through direct damage to the sperm cells. Moreover, not only male infertility results from such infections but these can also be transmitted to women and even to the offspring, thus highlighting the need to efficiently detect, treat and prevent them.
RéSUMé: CONTEXTE: L'infertilité affecte un couple sur six dans le monde. L'infertilité masculine peut être due à des facteurs congénitaux ou acquis, parmi lesquels des pathogènes qui atteignent le tractus génital par contact sexuel ou dissémination par voie sanguine. Cette revue présente les principaux pathogènes d'origine virale, bactérienne et parasitaire qui affectent le tractus génital masculin et leur impact sur la fertilité. RéSULTATS ET CONCLUSION: Une revue systématique de la littérature a été conduite à partir de Google Scholar et de PubMed. Il apparaît que les virus, au même titre que les bactéries ou les parasites, sont des facteurs majeurs d'infection du tractus génital masculin et d'infertilité. Cette dernière découle de dommages aux organes reproducteurs et à leur perte de fonction et/ou d'atteintes directes aux spermatozoïdes. De plus, ces infections n'impactent pas seulement la fertilité masculine, mais elles peuvent également être transmises aux partenaires féminines et même à la descendance, ce qui souligne l'importance de les détecter, de les traiter et de les prévenir efficacement.
RESUMO
PURPOSE: Several clinical scenarios regulate the final ejaculated semen, which is pivotal to reproductive success. Sperm motility and plasma membrane fusogenic activity primarily rely on the peculiar sperm lipid composition, influenced by the patient's metabolism, genetics, nutritional, environmental status, and concomitant clinical entities such as varicocele. This study aimed to determine the relationship between serum lipid profile and testicular function (semen quality and testosterone levels). METHODS: This retrospective study uses medical charts of 278 infertile men who attended andrological care between 2000 and 2019. Seminal analysis data, lipid profile, and total serum testosterone were collected. A multiple linear regression analysis was performed to evaluate the influence of the lipid parameters on the seminal variables. Statistical analyses were carried out with p ≤ 0.05 considered statistically significant. RESULTS: Seminal creatine kinase activity (p = 0.024) is negatively related to HDL (p = 0.032) and triglycerides (p = 0.037), while total testosterone (p < 0.0001) and seminal volume (p = 0.046) appeared both to be negatively related to triglycerides (p = 0.030 and p = 0.033, respectively). CONCLUSION: Medical advice commonly advocated to prevent endothelial dysfunction and cardiovascular disease and improve HDL-cholesterol and triglyceride levels in dyslipidemic patients should also be given to infertile men. Physicians should give patients a thorough assessment, including the blood lipid profile, hormonal status, and routine seminal examinations. We propose a more comprehensive men´s health check-up for the infertile male population, not limited to a simple evaluation of basic sperm parameters.
Assuntos
Infertilidade Masculina , Análise do Sêmen , Masculino , Humanos , Sêmen , Saúde do Homem , Contagem de Espermatozoides , Estudos Retrospectivos , Motilidade dos Espermatozoides/fisiologia , Lipídeos , Triglicerídeos , TestosteronaRESUMO
BACKGROUND: The scientific and clinical communities now recognize that sperm DNA integrity is crucial for successful fertilization, good embryo development, and offspring quality of life. Despite the apparent unanimity, this criterion is rarely evaluated in clinical practice. We evaluated the sperm DNA fragmentation index of nearly 1200 sperm samples and its connections based on the patient's age, body mass index, the season of sperm collection, geographical location, medical history, and addictive behaviors. METHODS: A cohort of 1503 patients who were referred to the Royan Institute between July 2018 and March 2020 was examined. Only 1191 patient records with demographic data, complete semen analysis, and DNA fragmentation index measurements were included in the final cohort. Documents were classified, incorporated into statistical models, and analyzed. RESULTS: The results confirmed previous findings that the sperm DNA fragmentation index was significantly higher in aging men. The sperm DNA fragmentation index and high DNA stainability levels were significantly higher in spring and summer samples than in those of other seasons. No correlation was found between semen DNA fragmentation index and patient body mass index, although the study cohort was significantly overweight. Contrary to what might be expected, we observed that the sperm DNA fragmentation index was higher in rural than in urban patients. Intriguingly, epileptic patients exhibited significantly higher sperm DNA fragmentation index levels. DISCUSSION AND CONCLUSION: Age is the factor that is most strongly associated with sperm DNA fragmentation index levels. Our analysis of 1191 samples indicates that between the ages of 19 and 59, the sperm DNA fragmentation index increases by an average of 2% each year. Intriguingly, from an epidemiological perspective, the warm season (spring/summer) is associated with a higher sperm DNA fragmentation index in the study population, possibly due to the deleterious effect of temperature on sperm quality. Some neurological diseases, such as epilepsy, are associated with decreased sperm DNA integrity. This observation could be related to the iatrogenic effects of associated therapies. In the study cohort, body mass index did not appear to be correlated with the DNA fragmentation index.
Assuntos
Infertilidade Masculina , Sêmen , Humanos , Masculino , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Estudos Retrospectivos , Fragmentação do DNA , Qualidade de Vida , Espermatozoides , Análise do Sêmen , DNARESUMO
Long considered an accessory tubule of the male reproductive system, the epididymis is proving to be a key determinant of male fertility. In addition to its secretory role in ensuring functional maturation and survival of spermatozoa, the epididymis has a complex immune function. Indeed, it must manage both peripheral tolerance to sperm antigens foreign to the immune system and the protection of spermatozoa as well as the organ itself against pathogens ascending the epididymal tubule. Although our knowledge of the immunobiology of this organ is beginning to accumulate at the molecular and cellular levels, the organization of blood and lymphatic networks of this tissue, important players in the immune response, remains largely unknown. In the present report, we have taken advantage of a VEGFR3:YFP transgenic mouse model. Using high-resolution three-dimensional (3D) imaging and organ clearing coupled with multiplex immunodetections of lymphatic (LYVE1, PDPN, PROX1) and/or blood (PLVAP/Meca32) markers, we provide a simultaneous deep 3D view of the lymphatic and blood epididymal vasculature in the mature adult mouse as well as during postnatal development.
Assuntos
Epididimo , Imageamento Tridimensional , Masculino , Animais , Camundongos , Sêmen , Espermatozoides , Camundongos TransgênicosRESUMO
Routine exposure to chemicals omnipresent in the environment, particularly the so-called endocrine-disrupting chemicals (EDCs), has been associated with decreased sperm quality and increased anomalies in testis. The decline in semen quality and testicular abnormalities have been attributed to the disruption of endocrine signaling as well as oxidative stress. The present study set out to examine the effect of short-term exposure of two common EDCs widely used in the plastic industry: Dibutyl Phthalate (DBP) and Bisphenol AF (BPAF). Our research objective was to focus on the post-testicular compartment of the epididymis, where spermatozoa acquire their functional capacity and are stored. The data obtained indicated no significant effect for either chemicals on sperm viability, motility or acrosome integrity. Neither of the EDCs had a noticeable effect on the structures of the testis and epididymis. However, substantial impact on the integrity of the sperm nucleus and DNA structure was evidenced by a significant increase in nuclear decondensation and DNA base oxidation. The damage observed was postulated to arise from the pro-oxidant properties of the EDCs generating excess of reactive oxygen species (ROS) and triggering a state of oxidative stress. This hypothesis was confirmed when the observed damage was largely blocked by co-administering EDCs with an evidenced-based antioxidant formulation.
RESUMO
BACKGROUND: The optimization of spermatozoa preparation techniques in order to obtain cell fractions enriched with structurally and functionally "superior" spermatozoa is a key objective of the assisted reproduction industry. OBJECTIVES: The purpose of this study was to evaluate a recent development of an electrophoretic spermatozoa separation device (Felix™, Memphasys Ltd, Sydney, Australia) and to compare its performance with conventional spermatozoa preparation by density gradient centrifugation (DGC). Particular attention was paid to the evaluation of sperm DNA/nuclear integrity. MATERIALS & METHODS: A cohort of 29 human semen samples was studied. Semen samples were analyzed fresh and after DGC or Felix™ preparation. Semen parameters monitored included sample volume, sperm count, total motility, progressive motility, sperm DNA fragmentation using the Sperm Chromatin Structure Assay and sperm DNA oxidation. RESULTS: Spermatozoa preparation with Felix™ resulted in significantly improved spermatozoa fractions with higher progressive motility, lower sperm DNA fragmentation, and lower sperm DNA oxidation compared with raw semen and DGC-prepared spermatozoa. DISCUSSION & CONCLUSION: The data collected in this study support the preparation of spermatozoa by the Felix™ system as it allows selection of spermatozoa with the highest progressive motility as well as the lowest nuclear/DNA damage. These improved sperm parameters, along with the fact that the Felix™ separation process is very fast and highly standardized, should be of great interest to the assisted reproduction technologies industry.
Assuntos
Sêmen , Espermatozoides , Humanos , Masculino , Sêmen/fisiologia , Separação Celular/métodos , Centrifugação com Gradiente de Concentração , Espermatozoides/fisiologia , Dano ao DNA , DNA , Motilidade dos Espermatozoides/fisiologiaRESUMO
Depression in mammals is known to be associated with poor reproductive capacity. In males, it has been associated with decreased efficiency of spermatogenesis as well as the production of spermatozoa of reduced structural and functional integrity. Although antidepressants are effective in correcting depressive states, there is controversy regarding their effectiveness in restoring male reproductive function. Here, using an animal model of depression induced by a forced swim test, we confirmed that depression is accompanied by impaired male reproductive function. We further show that administration of a conventional antidepressant of the serotonin reuptake inhibitor class (paroxetine) impairs male reproductive performance in terms of sperm production and quality when administered to healthy animals. Intriguingly, when paroxetine is administered to "depressed" animals, it resulted in a complete restoration of the animal's ability to produce sperm that appears to be as capable of meeting the parameters evaluated here as those of control animals. The one-carbon cycle (1CC) is one of the most important metabolic cycles that include the methionine and folate cycles and plays a major role in DNA synthesis, amino acids, and also the production of antioxidants. Our results show that depression affects the main components of this cycle and paroxetine on healthy mice increases homocysteine levels, decreases glycine and vitamin B12, while in depressed mice, it increases folate levels and decreases vitamin B12. Thus, paroxetine exerts negative impacts on male reproductive function when administered to healthy animals and it well correlate with the altered sperm parameters and functions of depressed animals, and its mechanism remains to be explored.
Assuntos
Paroxetina , Sêmen , Masculino , Camundongos , Animais , Paroxetina/farmacologia , Paroxetina/uso terapêutico , Modelos Animais , Espermatozoides , Vitamina B 12 , Ácido Fólico , MamíferosRESUMO
Marijuana is one of the most consumed drugs worldwide. There is increasing evidence of an association between marijuana and male infertility. This study intends to assess the repercussion of marijuana smoking and other habits (sedentary lifestyle, alcohol, and tobacco use) in the testicular function of infertile men seeking andrological evaluation. A retrospective study was performed using medical records data of men aged 18-59 years from 2009 to 2017. Complete semen analyses, sperm functional tests, SHBG, and hormonal levels, testosterone-to-estradiol ratio (T/E2), and testis volume were evaluated. Exclusion criteria included cryptorchidism, infertility caused by genetic or infectious diseases, and cancer. A multiple linear regression analysis was performed to investigate which habit could predict certain parameters using the software SPSS 23.0 (P < 0.05). In a sample of 153 men, semen parameters, testosterone levels, and testis volume were not significantly influenced. Marijuana use had the broader hormonal changes since it influences estradiol (P = 0.000; B = -11.616), prolactin (P = 0.000; B = 3.211), SHBG levels (P = 0.017; B = 7.489), and T/E2 (P = 0.004; B = 14.030). Sedentary lifestyle (P = 0.028; B = 1.279) and tobacco smoking (P = 0.031; B = -2.401) influenced the prolactin levels. Marijuana is associated with hormonal imbalance in this infertile cohort by lowering estradiol levels and inhibiting aromatase function.
RESUMO
Biomedical science is rapidly developing in terms of more transparency, openness and reproducibility of scientific publications. This is even more important for all studies that are based on results from basic semen examination. Recently two concordant documents have been published: the 6th edition of the WHO Laboratory Manual for the Examination and Processing of Human Semen, and the International Standard ISO 23162:2021. With these tools, we propose that authors should be instructed to follow these laboratory methods in order to publish studies in peer-reviewed journals, preferable by using a checklist as suggested in an Appendix to this article.
Assuntos
Análise do Sêmen , Sêmen , Humanos , Reprodutibilidade dos Testes , Análise do Sêmen/métodos , Revisão por Pares , EditoraçãoRESUMO
In brief: Oxidative stress is recognized as an underlying driving factor of both telomere dysfunction and human subfertility/infertility. This review briefly reassesses telomere integrity as a fertility biomarker before proposing a novel, mechanistic rationale for the role of oxidative stress in the seemingly paradoxical lengthening of sperm telomeres with aging. Abstract: The maintenance of redox balance in the male reproductive tract is critical to sperm health and function. Physiological levels of reactive oxygen species (ROS) promote sperm capacitation, while excess ROS exposure, or depleted antioxidant defenses, yields a state of oxidative stress which disrupts their fertilizing capacity and DNA structural integrity. The guanine moiety is the most readily oxidized of the four DNA bases and gets converted to the mutagenic lesion 8-hydroxy-deoxyguanosine (8-OHdG). Numerous studies have also confirmed oxidative stress as a driving factor behind accelerated telomere shortening and dysfunction. Although a clear consensus has not been reached, clinical studies also appear to associate telomere integrity with fertility outcomes in the assisted reproductive technology setting. Intriguingly, while sperm cellular and molecular characteristics make them more susceptible to oxidative insult than any other cell type, they are also the only cell type in which telomere lengthening accompanies aging. This article focuses on the oxidative stress response pathways to propose a mechanism for the explanation of this apparent paradox.
Assuntos
Antioxidantes , Infertilidade Masculina , Masculino , Humanos , Espécies Reativas de Oxigênio/metabolismo , Antioxidantes/metabolismo , Infertilidade Masculina/metabolismo , Sêmen/metabolismo , Espermatozoides/metabolismo , Estresse Oxidativo , Telômero/metabolismo , Guanina/metabolismo , DNA , Desoxiguanosina/metabolismo , Biomarcadores/metabolismoRESUMO
Vitamin D (VD) deficiency reduces the chances of successful fertilization; however, it remains to be validated whether this effect is dependent or not on calcium. To address this question, we generated several situation using a mouse model in which VD content was either increased or decreased in a normo or hypocalcemia context. After the measurement of serum 25-hydroxyvitamin D2, calcium and phosphorus levels, an analysis was carried out in terms of oocytes maturation as well as reproductive performance. VD overdose, despite the fact that it resulted in an increased number of mature oocytes, reduced developmental competence and offspring survival. VD deficiency (VDD), on the contrary, reduced the number and percentage of mature oocytes, blastocyst rate, as well as fertility rate and offspring survival. Hypo-calcemia when VD levels were normal, had a similar effect than VDD. The effects of VDD were reversed by a diet that corrected calcium level. Therefore, both VD overdose (in a context of normal calcium level) VD deficiency as well as hypo-calcemia have an effect on female reproductive function. In conclusion, although closely related, VD and calcium act in part independently of each other in defining the "optimum" for female reproductive performance.
Assuntos
Cálcio , Deficiência de Vitamina D , Cálcio da Dieta , Feminino , Humanos , Vitamina D , Deficiência de Vitamina D/complicações , VitaminasRESUMO
BACKGROUND: Infertility related to varicocele, infections, metabolic dysfunctions, oxidative stress and environmental toxicants is also associated with inflammatory processes that ultimately lead to the activation of the inflammasome pathway (IP). IP is classically activated by DAMPs, MAMPs or LAMPs, which stand for Damage-, Microbe- or Lifestyle-Associated Molecular Patterns, respectively. The most important player in IP activation is the NLRP3 (NOD[Nuclear oligomerization domain]-, LRR[Leucine rich repeat]- and pyrin domain-containing protein 3) which functions as an intracellular sensor of D/M/L-AMPs resulting in activation of caspase-1, promotion of apoptosis, pyroptosis and generation of inflammatory cytokines. This review addresses the question of whether IP activation might be associated with male infertility situations. RESULTS & CONCLUSIONS: We conducted a systematic review of articles published in the Google Scholar, and PubMed databases through October 2021. It turns out that inflammasome activation and its consequences including cytokine storms, apoptosis and pyroptosis could be associated with the reduced sperm count as well as the structural and functional sperm defects recorded in several situations associated with male infertility suggesting that anti-inflammatory therapeutic strategies could be possibly considered to restore male fertility in future research.
RéSUMé: CONTEXTE: L'infertilité liée à la varicocèle, aux infections, aux dysfonctionnements métaboliques, au stress oxydant et aux toxiques environnementaux est. également associée à des processus inflammatoires qui conduisent finalement à l'activation de la voie de l'inflammasome (IP). Cette voie est. classiquement activée par des DAMPs, MAMPs ou LAMPs, qui signifient respectivement Damage-, Microbe- ou Lifestyle-Associated Molecular Patterns. L'acteur le plus important dans l'activation de l'inflammasome est. la protéine NLRP3 (NOD[Nuclear Oligomerization Domain]-, LRR[Leucine Rich Repeat]- and pyrin domain-containing protein 3) qui fonctionne comme un capteur intracellulaire de D/M/L-AMPs résultant en l'activation de la caspase-1, la promotion de l'apoptose, la pyroptose et la génération de cytokines inflammatoires. Cette revue aborde la question de savoir si l'activation de l'inflammasome pourrait être associée à des situations d'infertilité masculine. RéSULTATS ET CONCLUSIONS: Nous avons réalisé une revue systématique des articles publiés dans les bases de données Google Scholar, et PubMed jusqu'en octobre 2021. Il s'avère que l'activation de l'inflammasome et ses conséquences, y compris les "orages" de cytokines, l'apoptose et la pyroptose, pourraient être associées à la réduction du nombre de spermatozoïdes ainsi qu'aux défauts structurels et fonctionnels des spermatozoïdes enregistrés dans plusieurs situations associées à l'infertilité masculine, ce qui suggère que des stratégies thérapeutiques anti-inflammatoires pourraient être éventuellement envisagées pour restaurer la fertilité masculine dans les recherches futures.
RESUMO
A unique opportunity to conduct a longitudinal analysis of semen quality in a male subject immediately before, during and after COVID-19 infection, has revealed new insights into the impact of this virus on male reproductive function. A moderate COVID infection that did not require hospitalization resulted in a state of azoospermia that persisted for 4 weeks. Given that the duration of spermatogenesis and epididymal sperm maturation in the human is 78 days, we calculate that a viral attack on the germ line was initiated at or before the patient was symptomatic and may have been signalled by a sudden reduction in sperm count and motility, several weeks earlier. Before the virus had been fully cleared, reinitiation of spermatogenesis occurred as evidenced by spermatozoa reappearing in the ejaculate exhibiting high levels of motility but significant levels of oxidative DNA damage as measured by a modified 8-OHdG assay protocol. These unique data indicate that even a moderate COVID-19 infection is capable of rapidly inducing a state of azoospermia that rapidly reverses as the infection wanes.
RESUMO
Reactive oxygen species (ROS) play a critical role in defining the functional competence of human spermatozoa. When generated in moderate amounts, ROS promote sperm capacitation by facilitating cholesterol efflux from the plasma membrane, enhancing cAMP generation, inducing cytoplasmic alkalinization, increasing intracellular calcium levels, and stimulating the protein phosphorylation events that drive the attainment of a capacitated state. However, when ROS generation is excessive and/or the antioxidant defences of the reproductive system are compromised, a state of oxidative stress may be induced that disrupts the fertilizing capacity of the spermatozoa and the structural integrity of their DNA. This article focusses on the sources of ROS within this system and examines the circumstances under which the adequacy of antioxidant protection might become a limiting factor. Seminal leukocyte contamination can contribute to oxidative stress in the ejaculate while, in the germ line, the dysregulation of electron transport in the sperm mitochondria, elevated NADPH oxidase activity, or the excessive stimulation of amino acid oxidase action are all potential contributors to oxidative stress. A knowledge of the mechanisms responsible for creating such stress within the human ejaculate is essential in order to develop better antioxidant strategies that avoid the unintentional creation of its reductive counterpart.