Concentration of Glutathione and Expression of Glutathione Peroxidases 1 and 4 in Fresh Sperm Provide a Forecast of the Outcome of Cryopreservation of Human Spermatozoa

Sperm freezing damage: the role of regulated cell death

Substantial progress in research on sperm cryopreservation has occurred since the twentieth century, especially focusing on improving sperm freezing procedures and optimizing semen extenders. However, the cellular biological mechanisms of sperm freezing damage are still unclear, which greatly restricts the promotion and development of sperm cryopreservation. An essential component of sperm freezing damage is the occurrence of cell death. Considering the existence of multiple types of cell death pathways, this review discusses connections between characteristics of regulated cell death (e.g., apoptosis and ferroptosis), and accidental cell death (e.g., intracellular ice crystals) with sperm freezing damage and explores possible future research directions in this field.

The Direct Effects of Climate Change on Tench (Tinca tinca) Sperm Quality under a Real Heatwave Event Scenario

Global aquaculture growth will most probably face specific conditions derived from climate change. In fact, the most severe impacts of these changes will be suffered by aquatic populations in restrictive circumstances, such as current aquaculture locations, which represent a perfect model to study global warming effects. Although the impact of temperature on fish reproduction has been characterized in many aspects, this study was focused on recreating more realistic models of global warming, particularly considering heatwave phenomena, in order to decipher its effects on male gametes (spermatozoa). For this purpose, thermal stress via a heatwave simulation (mimicking a natural occurring heatwave, from 24 to 30 °C) was induced in adult tench (Tinca tinca) males and compared with a control group (55.02 ± 16.44 g of average body wet weight). The impact of the thermal stress induced by this climate change event was assessed using cellular and molecular approaches. After the heatwave recreation, a multiparametric analysis of sperm quality, including some traditional parameters (such as sperm motility) and new ones (focus on redox balance and sperm quality biomarkers), was performed. Although sperm concentration and the volume produced were not affected, the results showed a significant deleterious effect on motility parameters (e.g., reduced progressive motility and total motility during the first minute post-activation). Furthermore, the sperm produced under the thermal stress induced by this heatwave simulation exhibited an increased ROS content in spermatic cells, confirming the negative effect that this thermal stress model (heatwave recreation) might have had on sperm quality. More importantly, the expression of some known sperm quality and fertilization markers was decreased in males exposed to thermal stress. This present study not only unveils the potential effects of climate change in contemporary and future fish farming populations (and their underlying mechanisms) but also provides insights on how to mitigate and/or avoid thermal stress due to heatwave events.

Cryostress induces fragmentation and alters the abundance of sperm transcripts associated with fertilizing competence and reproductive processes in buffalo

The study aimed to assess the influence of cryostress on RNA integrity and functional significance in sperm fertilizing ability. The fresh and post-thawed buffalo sperm (n = 6 each) samples were evaluated for their functional attributes, and sperm total RNA was subjected to transcriptome sequencing followed by validation using real-time PCR and dot blot. Overall, 6911 genes had an expression of FPKM > 1, and among these 431 genes were abundantly expressed (FPKM > 20) in buffalo sperm. These abundantly expressed genes regulate reproductive functions such as sperm motility (TEKT2, SPEM1, and PRM3, FDR = 1.10E-08), fertilization (EQTN, PLCZ1, and SPESP1, FDR = 7.25E-06) and the developmental process involved in reproduction (SPACA1, TNP1, and YBX2, FDR = 7.21E-06). Cryopreservation significantly (p < 0.05) affected the structural and functional membrane integrities of sperm. The expression levels of transcripts that regulate the metabolic activities and fertility-related functions were compromised during cryopreservation. Interestingly, cryostress induces the expression of genes involved (p < 0.05) in chemokine signaling (CX3CL1, CCL20, and CXCR4), G-protein coupled receptor binding (ADRB1, EDN1, and BRS3), translation (RPS28, MRPL28, and RPL18A), oxidative phosphorylation (ND1, ND2, and COX2), response to reactive oxygen species (GLRX2, HYAL2, and EDN1), and immune responses (CX3CL1, CCL26, and TBXA2R). These precociously expressed genes during cryopreservation alter the signaling mechanisms that govern sperm functional competence and can impact fertilization and early embryonic development.

Metabolomic signature of spermatozoa established during holding time is responsible for differences in boar sperm freezability

Holding at room temperature is the first step in most boar semen cryopreservation protocols. It is well accepted that a holding time (HT) of 24 h increases sperm cryotolerance. However, the effect of HT on ejaculates with different freezability is not entirely clear. The aim of this study was to understand how HT influences spermatic and seminal plasma metabolite profiles of boar ejaculates and how these possible changes affect freezability. Twenty-seven ejaculates were collected and extended to 1:1 (v: v) with BTS and split into two aliquots. The first aliquot was cryopreserved without holding time (0 h), and the second was held at 17°C for 24 h before cryopreservation. Spermatozoa and seminal plasma were collected by centrifugation at two times, before HT (0 h) and after HT (24 h), and subsequently frozen until metabolite extraction and UPLC-MS analysis. After thawing, the semen samples were evaluated for kinetics, membrane integrity, mitochondrial potential, membrane lipid peroxidation, and fluidity. The ejaculates were then allocated into two phenotypes (good ejaculate freezers [GEF] and poor ejaculate freezers [PEF]) based on the percent reduction in sperm quality (%RSQ) as determined by the difference in total motility and membrane integrity between raw and post-thaw samples cryopreserved after 24 h of HT. The metabolic profile of the seminal plasma did not seem to influence ejaculate freezability, but that of the spermatozoa were markedly different between GEF and PEF. We identified a number of metabolic markers in the sperm cells (including inosine, hypoxanthine, creatine, ADP, niacinamide, spermine, and 2-methylbutyrylcarnitine) that were directly related to the improvement of ejaculate freezability during HT; these were components of metabolic pathways associated with energy production. Furthermore, PEF showed an up-regulation in the arginine and proline as well as the glutathione metabolism pathways. These findings help to better understand the effect of holding time on boar sperm freezability and propose prospective metabolic markers that may predict freezability; this has implications in both basic and applied sciences.

Protective Effects of Curcumin on the Outcome of Cryopreservation in Human Sperm

Cryopreservation causes decreased sperm fertility potential due to reactive oxygen species (ROS) production and physical-chemical damage, resulting in reduced sperm viability and motility. The addition of antioxidants to freezing media could protect sperm from cryo-damage, counteracting the harmful effects of ROS. The aim of this study was to assess the effects of curcumin supplementation in freezing medium on preventing cryo-damage in human semen. Semen samples collected from fertile men were cryopreserved in freezing medium supplemented with different concentrations of curcumin (2.5, 5, 10, and 20 μM). After freezing-thawing, sperm parameters, DNA fragmentation, intracellular ROS, and glutathione peroxidase 4 (GPX4) gene expression were evaluated. Supplementation with 20 μM curcumin in freezing medium caused increases in progressive and nonprogressive motility and significant reductions in intracellular ROS and DNA fragmentation in frozen-thawed sperm cells. Following cryopreservation, GPX4 mRNA expression was significantly upregulated in thawed semen supplemented with 20 μM curcumin compared to the control. The results showed that curcumin supplementation in freezing medium was protective against human sperm parameters and sperm DNA, counteracting oxidative damage induced by the freeze-thaw process.

Male reproductive dysfunction in Solea senegalensis: new insights into an unsolved question

Senegalese sole (Solea senegalensis) is a species with a high commercial value that exhibits a reproductive dysfunction in males born and raised in captivity (F1) that hinders their sustainable culture. The present study evaluates the sperm quality and dopaminergic pathway of males born in the wild environment and of F1 males. Traditional sperm analyses were performed, finding only significant differences in curvilinear velocity (VCL) and no significant differences in viability and total motility. No differences in global sperm methylation were observed either in spermatozoa or brain between the two groups (F1 and wild-born males). However, our results point to a different sperm molecular signature between wild fish and fish born in captivity, specifically the differential expression in miR-let7-d and miR-200a-5p between these two groups. miR-let7-d has been correlated with spermatogenesis and sex preferences, whereas the miR-200 family is implied in target innervation of dopaminergic neurons in zebrafish. When we analysed the dopaminergic pathway, no differences were found in terms of different mRNA expression of dopaminergic markers. However, some differences were detected in terms of tyrosine hydroxylase protein expression by western blot analysis, thus suggesting an altered post-transcriptional regulation in F1 males. The results of this study suggest that an altered sperm miRNA signature in F1 males could be one possible mode of transmission of reproductive dysfunction to the progeny.

Inclusion of ovine enriched serum with vitamin E and polyunsaturated fatty acids in the freezing medium: a new strategy to improve human frozen-thawed sperm parameters

The objective was to evaluate the effect of inclusion of 2.5% and 5% ovine serum, enriched with vitamin E (Vit E) and fish oil (FO), in human sperm freezing medium. Serum samples were prepared from sixteen rams (n = 4) feeding on a without supplemented diet, and diets supplemented with Vit E, FO and Vit E + FO. Semen samples, from 60 normozoospermic men, were frozen in: (I) a commercial freezing medium (SpermFreeze™; control medium), (II) the commercial freezing medium containing foetal bovine serum, (III) the commercial freezing medium + nonenriched serum (serum group), (IV) the commercial freezing medium + Vit E enriched serum (Vit E group), (V) the commercial freezing medium + FO enriched serum (FO group) and (VI) the commercial freezing medium + Vit E + FO enriched serum (Vit E + FO group). Sperm total and progressive motility, morphology, viability and plasma membrane integrity were significantly higher (p ≤ .05) in Vit E and Vit E + FO groups compared with the control group. Mitochondrial membrane potential did not differ between treatments (p > .05). It was concluded that ovine serum enriched with vitamin E and vitamin E + FO improved the quality of human spermatozoa but enriched serum containing FO could not improve the sperm cryo-injuries.

Developmental selenium exposure and health risk in daily foodstuffs: A systematic review and meta-analysis

Selenium (Se) is a trace mineral and an essential nutrient of vital importance to human health in trace amounts. It acts as an antioxidant in both humans and animals, immunomodulator and also involved in the control of specific endocrine pathways. The aim of this work is to provide a brief knowledge on selenium content in daily used various foodstuffs, nutritional requirement and its various health consequences. In general, fruits and vegetables contain low content of selenium, with some exceptions. Selenium level in meat, eggs, poultry and seafood is usually high. For most countries, cereals, legumes, and derivatives are the major donors to the dietary selenium intake. Low level of selenium has been related with higher mortality risk, dysfunction of an immune system, and mental failure. Selenium supplementation or higher selenium content has antiviral outcomes and is necessary for effective reproduction of male and female, also decreases the threat of chronic disease (autoimmune thyroid). Generally, some advantages of higher content of selenium have been shown in various potential studies regarding lung, colorectal, prostate and bladder cancers risk, nevertheless results depicted from different trials have been diverse, which perhaps indicates the evidence that supplementation will merely grant advantage if the intakes of a nutrient is deficient. In conclusion, the over-all people should be advised against the usage of Se supplements for prevention of cardiovascular, hepatopathies, or cancer diseases, as advantages of Se supplements are still ambiguous, and their haphazard usage could result in an increased Se toxicity risk. The associations among Se intake/status and health, or disease risk, are complicated and need exposition to notify medical practice, to improve dietary recommendations, and to develop adequate communal health guidelines.

Solea senegalensis sperm cryopreservation: New insights on sperm quality

Cryopreservation of Senegalese sole sperm can represent an alternative to overcome some reproductive problems of this species. However, it is important to guarantee the safe use of cryopreserved sperm by selecting an appropriate protocol according to a high demand quality need to be ensured. It has been demonstrated that traditional assays such as motility and viability do not provide enough information to identify specific damage caused by cryopreservation process (freezing and thawing). Specific tests, including lipid peroxidation and DNA damage, should be performed. In the present study, motility and lipid peroxidation were performed as specific tests allowing us to discard cryopreservation conditions such as methanol as internal cryoprotectant and bovine serum albumin as external cryoprotectant. In addition, a caspase 3/7 detection by flow cytometry was performed to analyze apoptosis activity in the best selected conditions. Moreover, new highly sensitive tests based on transcript number detection have recently been described in fish sperm cryopreservation. For this reason, a transcript level detection assay was performed on certain oxidative and chaperone genes related to fertilization ability and embryo development (hsp70, hsp90BB, hsp90AA, gpx) to select the best cryopreservation conditions. DMSO+ egg yolk proved to be the best cryoprotectant combination in terms of transcript level. This study describes an optimized cryopreservation protocol for Solea senegalensis sperm demonstrating for the first time that transcript degradation is the most sensitive predictor of cell status in this species after cryopreservation.

Selenium in the Therapy of Neurological Diseases. Where is it Going?

Selenium (₃₄Se), an antioxidant trace element, is an important regulator of brain function. These beneficial properties that Se possesses are attributed to its ability to be incorporated into selenoproteins as an amino acid. Several selenoproteins are expressed in the brain, in which some of them, e.g. glutathione peroxidases (GPxs), thioredoxin reductases (TrxRs) or selenoprotein P (SelP), are strongly involved in antioxidant defence and in maintaining intercellular reducing conditions. Since increased oxidative stress has been implicated in neurological disorders, including Parkinson’s disease, Alzheimer’s disease, stroke, epilepsy and others, a growing body of evidence suggests that Se depletion followed by decreased activity of Se-dependent enzymes may be important factors connected with those pathologies. Undoubtedly, the remarkable progress that has been made in understanding the biological function of Se in the brain has opened up new potential possibilities for the treatment of neurological diseases by using Se as a potential drug. However, further research in the search for optimal Se donors is necessary in order to achieve an effective and safe therapeutic income.

Posttesticular sperm maturation, infertility, and hypercholesterolemia

Cholesterol is a key molecule in the mammalian physiology of especial particular importance for the reproductive system as it is the common precursor for steroid hormone synthesis. Cholesterol is also a recognized modulator of sperm functions, not only at the level of gametogenesis. Cholesterol homeostasis regulation is crucial for posttesticular sperm maturation, and imbalanced cholesterol levels may particularly affect these posttesticular events. Metabolic lipid disorders (dyslipidemia) affect male fertility but are most of the time studied from the angle of endocrine/testicular consequences. This review will focus on the deleterious effects of a particular dyslipidemia, i.e., hypercholesterolemia, on posttesticular maturation of mammalian spermatozoa.

Gene expression changes for antioxidants pathways in the mouse cochlea: relations to age-related hearing deficits

Age-related hearing loss - presbycusis - is the number one neurodegenerative disorder and top communication deficit of our aged population. Like many aging disorders of the nervous system, damage from free radicals linked to production of reactive oxygen and/or nitrogen species (ROS and RNS, respectively) may play key roles in disease progression. The efficacy of the antioxidant systems, e.g., glutathione and thioredoxin, is an important factor in pathophysiology of the aging nervous system. In this investigation, relations between the expression of antioxidant-related genes in the auditory portion of the inner ear - cochlea, and age-related hearing loss was explored for CBA/CaJ mice. Forty mice were classified into four groups according to age and degree of hearing loss. Cochlear mRNA samples were collected and cDNA generated. Using Affymetrix® GeneChip, the expressions of 56 antioxidant-related gene probes were analyzed to estimate the differences in gene expression between the four subject groups. The expression of Glutathione peroxidase 6, Gpx6; Thioredoxin reductase 1, Txnrd1; Isocitrate dehydrogenase 1, Idh1; and Heat shock protein 1, Hspb1; were significantly different, or showed large fold-change differences between subject groups. The Gpx6, Txnrd1 and Hspb1 gene expression changes were validated using qPCR. The Gpx6 gene was upregulated while the Txnrd1 gene was downregulated with age/hearing loss. The Hspb1 gene was found to be downregulated in middle-aged animals as well as those with mild presbycusis, whereas it was upregulated in those with severe presbycusis. These results facilitate development of future interventions to predict, prevent or slow down the progression of presbycusis.

Concentration, activity and biochemical characterization of myeloperoxidase in fresh and post-thaw equine semen and their implication on freezability

Myeloperoxidase (MPO) is a pro-oxidant enzyme associated with decreased motility in thawed equine semen. This study aimed to describe MPO concentration, activity and subunits in raw and thawed semen and to correlate these data with motilities in raw and thawed semen. Semen samples from five stallions were collected four times. Motilities were assessed in raw and thawed semen. MPO assays were performed in raw seminal plasma, raw sperm-rich pellet and thawed semen. Total and active MPO concentrations were, respectively, assayed by enzyme-linked immunosorbent assay and specific immunological extraction followed by enzymatic detection. MPO subunits present in semen were characterized by Western blot. Purified active MPO was added in saline solution and freezing extender to control its activity during freezing procedure. Differences between medians were determined using Kruskal-Wallis test, and correlations were determined using Spearman's test for nonparametric data. Active MPO concentration was low in seminal plasma and thawed semen, but high in pellet (p = 0.0058), as the opposite relation was observed for total MPO concentration (p < 0.0001). In seminal plasma and post-thaw semen, inactive 86-kDa MPO precursor was mainly observed. Purified MPO activity was decreased in the extender (p = 0.0286). MPO activity in pellet was highly correlated with thawed progressive motility (r = -0.5576, p = 0.0086). Inactive MPO precursor and unknown low molecular weight inactive MPO precursor subunits explain low MPO activity in semen. Major MPO activity was observed in pellet, and post-thaw loss of activity is partially explained by MPO inactivation in extender. Thawed semen motility was negatively correlated with MPO activity in pellet, becoming a potential freezability predictor.

Y chromosome microdeletions, sperm DNA fragmentation and sperm oxidative stress as causes of recurrent spontaneous abortion of unknown etiology

BACKGROUND

The aim of the present study was to evaluate the implication of male factor, in terms of sperm DNA oxidation and fragmentation, and Y chromosome microdeletions in recurrent spontaneous abortion (RSA) of unknown origin in a strictly selected cohort.

METHODS

A prospective cohort study was carried out in a private university-affiliated setting. Three groups, each comprised of 30 males, were compared. The first was formed by healthy and fertile sperm donors (SD) with normal sperm parameters (control group), the second by men presenting severe oligozoospermia (SO) without RSA history, and the third by men from couples who had experienced idiopathic RSA. Frequency of Y chromosome microdeletions and mean sperm DNA fragmentation and oxidation were determined.

RESULTS

Y chromosome microdeletions were not detected in any of the males enrolled in the study. Moreover, sperm DNA oxidation measurements were not demonstrated to be relevant to RSA. Interestingly, sperm DNA fragmentation was higher in the SO group than in the RSA and the SD groups, and also higher in the RSA group compared with the SD group, but lacked an adequate predictive power to be employed as a discriminative test of RSA condition.

CONCLUSIONS

Sperm DNA features and Y chromosome microdeletions do not seem to be related to RSA of unknown origin. Other molecular features of sperm should be studied to determine their possible influence on RSA. Clinicaltrials.gov reference: NCT00447395.

Effect of genistein supplementation of thawing medium on characteristics of frozen human spermatozoa

In this study, we evaluated the effects of genistein supplementation of the thawing extender on frozen-thawed human semen parameters. We analyzed the effect of supplementation on sperm motility, capacitation (membrane lipid disorder), reactive oxygen species (ROS) generation, chromatin condensation and DNA damage. Using this preliminary information, it maybe possible to improve the cryopreservation process and reduce the cellular damage. We have confirmed that the isoflavone genistein (10 micromol L(-1)) has antioxidant properties on the frozen-thawed spermatozoa. This results in a decreased ROS production that shows a slight improvement in the sperm motility, and decreases the membrane lipid disorder and DNA damage caused by cryopreservation. These results suggest an effect of genistein on sperm functionality that could be of interest for assisted reproduction treatments using frozen-thawed human spermatozoa, but further studies will be necessary to confirm our findings and to evaluate the possible clinical applications.

The effects of methanolic extracts of ginger (Zingiber officinale) on human sperm parameters; an in vitro study

This study was conducted on Zingiber officinale or ginger on motility, grading and morphological aspects of human sperm. Thirty human semen samples were obtained from the local hospital. The samples were swim up by Ham's F10. The samples (0.9 mL) were treated by 0.1 mL of ginger methanolic extracts (0.1, 0.2, 0.4 and 0.6% concentration). Sperm motility, grading and morphology parameters were assessed using light microscope at 0, 2, 4, 8 and 24 h after treatment. Dose and time-dependent decreases in motility accompanied by concomitant decrease in grading 3 and 4 were noticed. Morphologic profiles of the sperms were changed under different doses of ginger on the basis of time of assess. These data indicate that some exhibits a lower percentage of motility and grading when methanolic ginger is added to semen fluid. According to the results it would be concluded that ginger can induce the toxic effects on sperm parameters.

Chenopodium album seed extract-induced sperm cell death: exploration of a plausible pathway

BACKGROUND

This study was conducted for to explore the plausible pathway of Chenopodium album seed extract (CAE)-mediated sperm cell death.

STUDY DESIGN

The role of CAE for its spermicidal action was assessed by (a) measuring lipid peroxidation, protein carbonyl content and intracellular glutathione content in CAE exposed sperm cells; (b) assaying antioxidant enzymes like catalase and superoxide dismutase (SOD); (c) analyzing protein expressions by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot analysis; (d) fluorimetric measurement of intracellular H(2)O(2) level and generation of reactive oxygen species (ROS) in CAE-treated sperm cells; and (e) DNA ladder formation study.

RESULTS

CAE-induced sperm death is due to (a) lipid peroxidation of the sperm cell membrane, oxidation of some critical cellular proteins and depletion of intracellular reduced gluthathione, indicating production of ROS; (b) activation of Mn-SOD and inactivation of catalase favoring endogenous accumulation of H(2)O(2); (c) generation of O(2)(*-) at an enhanced rate during oxidative stress as evidenced by increased Mn-SOD activity and protein expression; (d) accumulation of ROS in spermatozoa reflected in the fluorimetric experiments; and (e) increased production of O(2)(*-) and H(2)O(2) induced apoptosis-like death in sperm cells as observed by DNA ladder formation.

CONCLUSION

The sperm death mediated by CAE is due to oxidative damage of cellular macromolecules by in situ generation of ROS.

The significance of sperm DNA oxidation in embryo development and reproductive outcome in an oocyte donation program: a new model to study a male infertility prognostic factor

OBJECTIVE

One byproduct resulting from free radical damage is the DNA hydroxylation also known as DNA oxidation. Our aim with this work was to determine the relevance of sperm DNA oxidation on embryo quality in oocyte donation cycles.

DESIGN

We prospectively studied pairs of oocyte donation cycles, i.e., the same oocyte donors, donating to two recipients, where the only difference between the two treatments was the use of a different sperm sample.

SETTING

University-affiliated private IVF setting.

PATIENT(S)

Infertile male partners from couples undergoing oocyte donation cycles (n = 38): 76 semen aliquots analyzed before and after semen processing by swim up.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

We measured sperm DNA oxidation by flow cytometry using the OxiDNA assay and correlated it with embryo quality parameters, implantation, and pregnancy outcome.

RESULT(S)

A positive correlation was seen between embryo fragmentation and DNA oxidation of capacitated samples at 48 hours and 72 hours after fertilization. However, when we analyzed the differences in the IVF outcome parameters of the couples who shared the oocyte cohort (same donor) with the differences in the OxiDNA values, we observed increased and further relationships with cell embryo division 48 hours after fertilization. A negative association with blastocyst formation was also detected.

CONCLUSION(S)

Oxidative damage in the DNA is clearly increased in samples with lower sperm motility. An association between early and late embryo quality and sperm DNA oxidation supports the relevance of the hydroxylation of 8-oxoguanine as a biomarker of sperm quality reflecting the free radical damage in human sperm.

Human immunodeficiency type-1 virus (HIV-1) infection in serodiscordant couples (SDCs) does not have an impact on embryo quality or intracytoplasmic sperm injection (ICSI) outcome

OBJECTIVE

To evaluate the embryo quality in our program for human immunodeficiency type-1 virus (HIV-1) serodiscordant couples (SDCs) with the male infected in comparison with a tubal-factor infertility control group.

DESIGN

Retrospective case-control study.

SETTING

Instituto Valenciano de Infertilidad, Valencia, Spain.

PATIENT(S)

Thirty SDC and 79 control couples without HIV-1 infection attending for intracytoplasmic sperm injection (ICSI). Only first cycles were considered.

INTERVENTION(S)

Controlled ovarian hyperstimulation and ICSI in both groups; sperm wash, nested polymerase chain reaction (PCR) in semen sample, and capacitation by swim-up after thawing the semen sample in the SDC group; and sperm capacitation by swim-up after thawing the semen sample in the control group.

MAIN OUTCOME MEASURE(S)

ICSI procedure and embryo characteristics (fertilization, cleavage, embryo morphology, and development) and cycle outcome (ongoing pregnancy and miscarriage rates).

RESULT(S)

Fertilization and cleavage rates were similar between the groups. On days 2 and 3 of embryo development, very similar embryo features were found between the groups. There was no difference in mean number of optimal embryos on day 3. When embryos were cultured up to 5-6 days, a significant increase in embryo blockage was found in the SDC group compared with the control group. The mean number of optimal blastocysts on day 6 was comparable in both groups. No difference was found regarding the number of cryopreserved and transferred embryos or implantation, pregnancy, multiple pregnancy, or miscarriage rates between the groups.

CONCLUSION(S)

HIV-1 infection in SDCs with infected males does not appear to have a significantly negative impact on embryo development or ICSI outcome.

MUC1 in human testis and ejaculated spermatozoa and its relationship to male fertility status

MUC1 is a cell surface glycoprotein with a previously described antiadhesive role involved in different aspects of reproductive function. We found MUC1 expressed in male germ cell line and within the ejaculated sperm, but its presence in mature sperm does not seem to be related to male fertility. This was confirmed after analysis of results from assisted reproduction techniques with oocyte donation related with MUC1, although higher MUC1 expression is related to sperm recovery after preparation.

Sperm indexes obtained using computer-assisted morphometry provide a forecast of the freezability of canine sperm

Sperm morphometric indexes obtained after principal component analysis were used to investigate its value as diagnostic tests for freezability. Semen from six dogs was frozen-thawed following a standard protocol. Before freezing, computer-assisted analysis of sperm morphometry (CASMA) was performed. The principal component analysis (a statistical technique for simplifying a dataset, by reducing multidimensional datasets to lower dimensions for analysis) performed in the data obtained after the CASMA analysis gave four morphometric indexes. After thawing, ejaculates were evaluated for early changes in sperm membranes using the combination of two fluorescent probes, YO-PRO-1 and ethidium homodimer and flow cytometry. Significant differences in the percentages of intact membranes post-thaw were observed among dogs (p < 0.01). Significant non-parametric correlations were found between index 3 and the percentage of intact membranes after thawing (R = 0.432 p < 0.05). Receiving operating system curves demonstrate a good diagnostic value for indexes 2 and 3 in the prediction of freezability, with areas under the curve of 0.798 and 0.786, respectively.

Effect of sperm glutathione peroxidases 1 and 4 on embryo asymmetry and blastocyst quality in oocyte donation cycles

OBJECTIVE

To prospectively determine the impact of concrete components of the sperm oxidative glutathione stress system in terms of enzymatic activity and mitochondrial RNA (mRNA) expression on embryo quality and reproductive outcome. Human spermatozoa use the glutathione system to inactivate reactive oxygen metabolites, and there is a close correlation between some components of the glutathione system and male fertility. However, very few data are published regarding this system in sperm cells and its effect on fertilization ability and embryo development in human beings.

DESIGN

An oocyte-donation model, used to homogenize the female factor.

SETTING

University-affiliated private IVF setting.

PATIENT(S)

Semen samples from infertile males (n = 43) of couples undergoing oocyte-donation cycles (n = 43).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Gene expression and activity of glutathione peroxidases (GPXs) 1 and 4, glutathione reductase, and intracellular glutathione (GSH) by fluorescent quantitative polymerase chain reaction and spectrophotometry, respectively.

RESULT(S)

Fertilization rate, pronuclear number, asymmetry, and pronuclear body distribution were not correlated with any sperm glutathione parameters that were considered. When day 3 embryo parameters were evaluated, only GPX4 mRNA expression in sperm cells was statistically significantly lower when asymmetric embryos were observed. Also, worst embryo development and morphology on day 5 was statistically significantly correlated with lower sperm GPX1 activity (101.07 vs. 258.8 IU/mg protein). Glutathione system analysis in fresh sperm was not statistically significantly different in patients achieving pregnancy compared with those who not, and we did not find any correlation with implantation rate.

CONCLUSION(S)

We have been able to correlate embryo morphology on day 3 with the sperm expression of GPX family members. The results indicate that sperm-derived mRNA may condition human embryo quality and persist even to blastocyst stage. The correlation of the sperm GPX family mRNA expression with embryo health appears quite promising for discovery of molecular causes of male infertility.

Within and between breed differences in freezing tolerance and plasma membrane fatty acid composition of boar sperm

The response of sperm to cryopreservation and the fertility of frozen-thawed semen varies between species. Besides species differences in sperm physiology, structure and biochemistry, factors such as sperm transport and female reproductive tract anatomy will affect fertility of frozen-thawed semen. Therefore, studying differences in sperm cryotolerance between breeds and individuals instead of between species may reveal sources of variability in sperm cryotolerance. In the present study, the effect of cooling, re-warming and freezing and thawing on plasma membrane and acrosome integrity of sperm within and between Norwegian Landrace and Duroc breeds was studied. Furthermore, the relation between post-thaw survival rate and fatty acid composition of the sperm plasma membranes was investigated. Flow cytometry assessments of plasma membrane and acrosome integrity revealed no significant differences between breeds; however there were significant male-to-male variations within breeds in post-thaw percentages of live sperm (plasma membrane intact). The most abundant fatty acids in the plasma membranes from both breeds were palmitic acid (16:0), stearic acid (18:0), oleic acid (18:1, n-9), docosapentaenoic acid (22:5, n-6) and docosahexaenoic acid (22:6, n-3). The ratio of sigma operator 22:5, n-6 and 22:6, n-3/ sigma operator all other membrane fatty acids was significantly related to survival rate (plasma membrane integrity) of sperm for both Norwegian Landrace (correlation coefficient (r(s)) = 0.64, P < 0.05) and Duroc (r(s) = 0.67, P < 0.05) boars. In conclusion, male-to-male differences in sperm survival rate after freezing and thawing may be partly related to the amount of long-chain polyunsaturated fatty acids in the sperm plasma membranes.

Sperm cryopreservation in oncological patients: a 14-year follow-up study

OBJECTIVE

Oncologic treatments can destroy spermatogenic dividing cells and cause azoospermia which could be irreversible. Sperm banking is the best option to preserve male fertility after these treatments. It is easy, inexpensive, and safe. To date, few clinical data are available about large series of cancer patients. Our objective was to determine the usefulness of these preventive sperm freezing protocols.

DESIGN

Prospective study.

SETTING

University-affiliated private fertility center.

PATIENT(S)

One hundred eighty-six cancer patients who banked sperm samples at our center before surgery or chemo- or radiotherapy treatments from 1991 to 2004.

INTERVENTION(S)

Conjugal status, age, type of cancer, treatment, and future use (if any) of the cryopreserved sperm samples for assisted reproduction technology (ART), and cycle results were recorded, analyzed, and compared with a control group.

MAIN OUTCOME MEASURE(S)

Basic sperm analysis of semen samples from cancer patients prior to freezing, after thawing, and after capacitation for ART.

RESULT(S)

A total of 320 semen samples were frozen before antineoplasic treatment. Six months later, 27% of the males recovered normal sperm production. From all frozen samples, 8.7% were discarded; the reasons were pregnancy achievement (55%), normal sperm production (28%), and patient death (18%). Finally, 5 IUI cycles and 30 ICSI cycles were done from frozen samples, with 1 and 15 pregnancies, respectively; results were comparable with those obtained in a control group.

CONCLUSION(S)

A significant number of males who cryopreserved semen samples before receiving antitumoral treatments have employed them. The results obtained showed that this is the strategy of choice, aiming to preserve fertility for the future, because the cost/benefit ratio is favorable. Patients should be counseled accordingly.

Value of the sperm deoxyribonucleic acid fragmentation level, as measured by the sperm chromatin dispersion test, in the outcome of in vitro fertilization and intracytoplasmic sperm injection

OBJECTIVE

To determine the prognostic value of sperm DNA fragmentation levels, as measured by the sperm chromatin dispersion (SCD) test, in predicting IVF and ICSI outcome.

DESIGN

Double-blind prospective study.

SETTING

University-affiliated private IVF setting.

PATIENT(S)

A total of 85 couples undergoing infertility treatment with IVF/ICSI.

INTERVENTION(S)

Analysis of DNA fragmentation by the SCD test in 170 aliquots obtained from the ejaculate and from the processed semen used for assisted reproductive technologies (ART).

MAIN OUTCOME MEASURE(S)

Percentage of spermatozoa with fragmented DNA was statistically correlated with embryo quality and reproductive success.

RESULT(S)

Fertilization rate was inversely correlated with DNA fragmentation (r = -0.245 P = .045). Higher DNA fragmentation rate gave an increased proportion of zygotes showing asynchrony between the nucleolar precursor bodies of zygote pronuclei (73.8% vs. 28.8% P < .001). In addition, the slower embryo development and worst morphology on day 6 was correlated with higher sperm DNA fragmentation (47.7% vs. 29.4% P = .044). We also observed a negative correlation between DNA fragmentation and the implantation rate (r = -0.250 P = .042). However, SCD test values were not statistically different in cycles that resulted in a pregnancy compared with those that did not (33.2 vs. 28.2 and 32.4 vs. 34.7).

CONCLUSION(S)

This is the first report that describes a correlation between sperm DNA integrity, as measured by the SCD test, and fertilization rate, embryo quality, and implantation rate in IVF/ICSI. The degree of DNA fragmentation was inversely correlated with fertilization rate, synchrony of the nucleolar precursor bodies' pattern in pronuclei, embryo ability to achieve blastocyst stage, and embryo morphological quality. Because SCD test values were correlated with embryo quality and blastocyst rate, the lack of correlation between sperm DNA fragmentation and pregnancy outcome in IVF might be due to embryo selection before transfer. The ability of the SCD test to predict the blastocyst rate after IVF/ICSI warrants further study.

Value of the sperm chromatin dispersion test in predicting pregnancy outcome in intrauterine insemination: a blind prospective study

BACKGROUND

Sperm DNA integrity has been used as a new marker of sperm quality in the prediction of pregnancy. Nevertheless, no previous study has been performed by analysing the same samples that were employed in assisted reproduction. The main objective of this work was to correlate sperm chromatin dispersion (SCD), measured by the SCD test, with semen parameters and pregnancy outcome in intrauterine insemination (IUI).

METHODS

A total of 100 semen samples obtained from males of couples undergoing IUI were analysed by the SCD test before and after swim-up, and the results were correlated with semen parameters and pregnancy outcome.

RESULTS

SCD was negatively correlated with sperm motility in both ejaculated and processed semen. Sperm recovered by swim-up did not show a significant improvement in DNA integrity. No correlation was found between SCD and pregnancy outcome in IUI.

CONCLUSIONS

DNA dispersion, as measured by the SCD test, is not correlated with pregnancy outcome in IUI.

GPX5 orthologs of the mouse epididymis-restricted and sperm-bound selenium-independent glutathione peroxidase are not expressed with the same quantitative and spatial characteristics in large domestic animals

We report here on the cloning of cDNAs coding bovine and equine orthologs of mouse epididymis-restricted and sperm-bound glutathione peroxidase 5 (GPX5), a selenium-independent member of the multigenic GPX family in mammals. The complete sequence of bovine GPX5 as well as a partial sequence of the equine GPX5 were characterized, conceptually translated and aligned with other known mammalian GPX5 proteins. Using Northern blotting assays, we show that the level of expression of GPX5 is high in bovine but low in equine and that in both species the regionalization of GPX5 expression in epididymis is not totally identical to what was reported for rodent mouse GPX5. An antibody was produced against GPX5 and used in Western blot assays as well as in immunohistochemistry assays on bovine epididymis sections. It shows that the protein is essentially present in the cytoplasmic compartment of the caput segment 2 epithelium of the bovine epididymis. Unlike in the mouse model, bovine GPX5 seems to be poorly secreted and does not seem to be present on cauda epididymal spermatozoa.

Relationship among standard semen parameters, glutathione peroxidase/glutathione reductase activity, and mRNA expression and reduced glutathione content in ejaculated spermatozoa from fertile and infertile men

OBJECTIVE

To determine the expression and enzymatic activity of glutathione peroxidase (GPX)-1, GPX-4, and glutathione reductase together with glutathione (GSH) concentrations in spermatozoa from fertile and infertile men.

DESIGN

Prospective study.

SETTING

University-affiliated private center.

PATIENT(S)

Fifty-four infertile men undergoing assisted reproduction techniques and 55 fertile sperm donors with pregnancies and newborns by artificial insemination.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Analysis of gene expression by fluorescent quantitative polymerase chain reaction and an analysis of enzymatic activity and GSH concentration by controlled biochemical reactions and spectrophotometry.

RESULT(S)

GPX-4 activity but not mRNA expression is directly related to sperm morphology (strict criteria) and is more compromised with a low percentage of normal sperm. These differences are also demonstrated when fertile and infertile men were compared. In addition, intracellular GSH concentrations are lower when sperm morphology is severely impaired, but no differences were found between fertile and infertile men.

CONCLUSION(S)

Intracellular sperm GSH system components GPX-4 and GSH are altered in infertile men, and these alterations seem to be linked to sperm morphology.