RESUMO
INTRODUCTION: Current scientific evidence guiding the decision whether men with an active desire to become a father should be treated with methotrexate (MTX) remains controversial. We aimed to prospectively evaluate the testicular toxicity profile of MTX focusing on several markers of male fertility, including semen parameters and sperm DNA fragmentation index (sDFI). As a secondary outcome, we aimed to evaluate whether MTX-polyglutamates can be detected in spermatozoa and seminal plasma and to evaluate the enzymatic activity in spermatozoa of folylpolyglutamate synthetase (FPGS). METHODS: In a prospective cohort study, men ≥18 years who started therapy with MTX were invited to participate (MTX-starters). Participants were instructed to produce two semen samples (a pre-exposure and a post-exposure sample after 13 weeks). Healthy men ≥18 years were invited to participate as controls. Conventional semen analyses, male reproductive endocrine axis and sDFI were compared between groups. FPGS enzymatic activity and MTX-PG1-5 concentrations were determined by mass spectrometry analytical methods. RESULTS: In total, 20 MTX-starters and 25 controls were included. The pre-exposure and postexposure semen parameters of MTX-starters were not statistically significant different. Compared with healthy controls, the conventional semen parameters and the sDFI of MTX-starters were not statistically significant different. These data were corroborated by the marginal accumulation of MTX-PGs in spermatozoa, consistent with the very low FPGS enzymatic activity associated with the expression of an alternative FPGS splice-variant. DISCUSSION: Treatment with MTX is not associated with testicular toxicity, consistent with the very low concentration of intracellular MTX-PG. Therefore, therapy with MTX can be safely started or continued in men and with a wish to become a father.
Assuntos
Metotrexato , Sêmen , Masculino , Humanos , Metotrexato/efeitos adversos , Estudos Prospectivos , Sêmen/metabolismo , Biomarcadores , PaiRESUMO
Infertility affects approximately 15% of the couples wanting to conceive. In 30 - 40% of the cases the aetiology of male infertility remains unknown and is called idiopathic male infertility. When assisted reproductive technologies are used to obtain pregnancy, an adequate (epi)genetic diagnosis of male infertility is of major importance to evaluate if a genetic abnormality will be transmitted to the offspring. In addition, there is need for better diagnostic seminal biomarkers to assess the success rates of these assisted reproductive technologies. This review investigated the possible causes and molecular mechanisms underlying male idiopathic infertility by extensive literature searches of: (i) causal gene mutations; (ii) proteome studies of spermatozoa from idiopathic infertile men;(iii) the role of epigenetics; (iv) post-translational modifications; and (v) sperm DNA fragmentation in infertile men. In conclusion, male infertility is a complex, multi-factorial disorder and the underlying causes often remain unknown. Further research on the (epi)genetic and molecular defects in spermatogenesis and sperm function is necessary to improve the diagnosis and to develop more personalized treatments of men with idiopathic infertility.
Assuntos
Epigenômica , Infertilidade Masculina/fisiopatologia , Mutação , Proteoma/análise , Espermatogênese , Animais , Humanos , MasculinoRESUMO
Semen parameters are unable to inform on the function or fertilizing capacity of the male gamete. Standardized methods are provided by the WHO but, the lower reference limits have reduced sensitivity to predict chances of conception. Subfertile men may be falsely classified as "normal" and a male factor contributing to genome instability may be overlooked. Semen parameters, sperm DNA fragmentation (SDF), sperm chromatin maturity and stability, and sperm aneuploidy were assessed in fertile (F), subfertile normozoospermic (SN) and subfertile non-normozoospermic males (SN-N). Standardized assays employing flow cytometry were used to detect genome instability. Sperm DNA fragmentation did not differ significantly whether the semen samples were from a fertile (F), subfertile normozoospermic (SN) or subfertile non-normozoospermic male (SN-N). Chromatin decondensation was significantly reduced and hyperstability significantly increased in the SN group as compared to the F group. The frequency of diploidy was significantly different in the three study groups with significance between F and SN and between F and SN-N groups. Subfertile men with normal semen parameters are often excluded from extensive genetic testing. Genome instability might be an independent attribute of semen quality detecting problems not seen with semen analysis alone.
Assuntos
Infertilidade Masculina , Sêmen , Masculino , Humanos , Análise do Sêmen , Cromatina , Instabilidade Genômica , Organização Mundial da SaúdeRESUMO
Antioxidant therapy should be reserved for infertile patients who actually exhibit signs of oxidative stress (OS). Nevertheless, there is no consensus regarding the measure of the primary endpoint and the assay that should be used. The formation of 8-hydroxy-2'-deoxyguanosine (8-OHdG), an early marker of sperm DNA oxidation (SDO), was analyzed using flow cytometry, in men at a University hospital setup for infertility treatment. Similar to conventional semen parameters, 8-OHdG assay was validated on fresh semen samples to reduce the variability of results. SDO was associated with semen volume, sperm concentration, leucocytes and round cells, but not with age, body mass index, sperm DNA fragmentation (SDF) or OS. Whether the semen samples were normal or subnormal according to the WHO criteria, the expression of 8-OHdG was not different. Receiver operating characteristic curve analysis could discriminate two independent populations. Both SDF and SDO were independently expressed. A high SDF did not reveal a high SDO and vice versa. The thresholds for SDO have been established, but vary with the techniques used. The methodology for SDO needs to be further validated and optimized on a larger clinically defined patient population before the outcome measure is fit to monitor antioxidant therapy in male infertility.
RESUMO
Intrauterine insemination with donor sperm (IUI-D) requires multiple in vitro manipulations such as sperm selection and cryopreservation during which spermatozoa may be exposed to oxidative stress (OS) and other insults that may produce potential damage including sperm DNA fragmentation (SDF). High levels of SDF, referring to damage or breaks in the genetic material of sperm cells, are linked to an increased risk of reproductive failure. This retrospective, observational study set out to evaluate whether SDF assessment could predict clinical outcome in an IUI-D program, where sperm donors are selected on strict conventional semen parameters. A total of 18 donors and 106 recipients were matched for IUI-D. Out of 429 cycles, 100 (23.3%) resulted in clinical pregnancy. We counted 78 live births (18.2% of cycles), while 20 pregnancies ended in miscarriage (4.7% of cycles), 1 in extra-uterine pregnancy and 1 in stillbirth. Female age significantly influenced clinical pregnancy and miscarriage rates. SDF increased after cryopreservation (26.3 ± 14.5%; p < 0.001) and more so after post-thaw density gradient (34.9 ± 22.1%; p = 0.04) without affecting clinical pregnancy (OR [95% CI] 1.01 [0.99; 1.02]; p = 0.27), live birth (1.00 [0.99; 1.02]; p = 0.72) and miscarriage rates (1.02 [1.00; 1.05]; p = 0.08). The implications of our findings extend to a better selection of sperm donors and a better sperm preparation technique tailored to the donor semen's properties in order to maximize the chances of a favorable treatment outcome.
RESUMO
The biological variability of semen and sperm DNA fragmentation (SDF) parameters in a longitudinal intrauterine insemination (IUI) trial over multiple IUI cycles was investigated. A TUNEL assay was used for SDF testing, both before and after density gradient centrifugation. A significant age effect was observed: while semen parameters deteriorated with advancing age, on average, higher SDF values were observed for older males. There was quite some variability observed for both semen and SDF variables. Using fertile threshold values, three patient categories were distinguished: those with a high SDF in all samples, those with low SDF in all samples and those who fluctuated between high and low during the whole IUI trial. Density gradient centrifugation increases SDF. However, the three patient categories react differently after semen processing. A large percentage of those with high SDF retain their high SDF even after gradient centrifugation. The SDF fluctuaters react with a high SDF after gradient centrifugation. The low SDF category, on the contrary, distributes itself evenly between the three categories after gradient centrifugation. SDF testing after semen processing might be indispensable for therapeutic purposes, probably influencing medical decision-making. In order to isolate fluctuaters, a second SDF testing might be advocated in certain cases. SDF after semen processing is indispensable for therapeutic management.
RESUMO
Endogenous and exogenous factors can severely affect the integrity of genetic information by inducing DNA damage and impairing genome stability. The extent to which men with and without subfertility are exposed to several adverse lifestyle factors and the impact on sperm DNA fragmentation (SDF), sperm chromatin maturity (condensation and decondensation), stability (hypo- and hypercondensation) and sperm aneuploidy are assessed in this study. Standardized assays employing flow cytometry were used to detect genome instability in 556 samples. Semen parameters deteriorated with age, BMI, increased physical activity and smoking. Age and BMI were associated with increased SDF. Increased BMI was associated with increased hypocondensed chromatin and decreased decondensed chromatin. Increase in age also caused an increase in sex chromosome aneuploidy in sperms. Surprisingly, alcohol abuse reduced chromatin hypercondensation and drug abuse reduced SDF. Although genome instability was more pronounced in the subfertile population as compared to the fertile group, the proportion of men with at least one lifestyle risk factor was the same in both the fertile and subfertile groups. While one in three benefited from nutritional supplementation, one in five showed an increase in SDF after supplementation. Whilst the message of 'no smoking, no alcohol, no drugs, but a healthy diet' should be offered as good health advice, we are a long way from concluding that nutritional supplementation would be beneficial for male fertility.
Assuntos
Infertilidade Masculina , Sêmen , Aneuploidia , Cromatina , Fragmentação do DNA , Instabilidade Genômica , Humanos , Infertilidade Masculina/genética , Estilo de Vida , Masculino , EspermatozoidesRESUMO
Multiple technologies exploring chromatin structure anomalies have been applied during the last decade to evaluate fertility disorders and to increase the predictive value of sperm analysis for procreation in vivo and in vitro. Our aim was to implement sperm nuclear maturity and nuclear chromatin stability as a functional test for male infertility diagnosis and to compare it with a fertile group. As semen processing is an integral part of assisted reproductive technologies the impact of density gradient centrifugation in selecting sperm based on nuclear maturity and stability was also analyzed. Flow cytometry combined with fluorescent dyes exhibiting affinity for DNA was implemented. Both nuclear parameters correlated significantly with semen parameters. The control fertile group had significantly higher mean condensed population and a significantly lower hypocondensed and hypercondensed fractions as compared to the subfertile study group. Density gradient centrifugation succeeded in selecting the condensed population in both the control and study groups, while reducing the hypocondensed percentage. The hypercondensed population which was ten-fold higher in the study group remained unchanged after selection, in both the control and the study groups. Sperm nuclear maturity and chromatin stability appears to be homogenous in the fertile sperm donors and heterogeneous in subfertile patients. Sperm preparation for assisted reproduction should aim to minimize the risk of abnormal spermatozoa being used for fertilization.
Assuntos
Cromatina , Infertilidade Masculina/diagnóstico , Análise do Sêmen/métodos , Espermatozoides , Adulto , Estudos de Casos e Controles , Núcleo Celular/química , Centrifugação com Gradiente de Concentração , Humanos , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
The present study evaluated the effects of field metal contamination on sperm motility and the RNA/DNA ratio in echinoderms. Populations of Asterias rubens and Echinus acutus that occur naturally along a contamination gradient of sediments by cadmium, copper, lead, and zinc in a Norwegian fjord (the Sørfjord) were studied. Sperm motility, a measure of sperm quality, was quantified using a computer-assisted sperm analysis system. The RNA/DNA ratio, a measure of protein synthesis, was assessed by a one-dye (ethidium bromide)/one-enzyme (RNase), 96-well microplate fluorometric assay. Although both species accumulate metals at high concentrations, neither sperm motility parameters in A. rubens nor the RNA/DNA ratio in both species were affected. The Sørfjord is still one of the most metal-contaminated marine sites in Europe, but even so, populations of A. rubens and E. acutus are able to endure under these conditions.