Acrosome reaction and chromatin integrity as additional parameters of semen analysis to predict fertilization and blastocyst rates

A combination of biomarkers for predicting stallion sperm fertility

Equine breeding would benefit greatly from reliable biomarkers of stallion or ejaculate fertility. The aim of the study was to investigate how several in vitro sperm characteristics correlate with fertility after artificial insemination, to explore the potential to build a fertility prediction model for stallions. Cooled insemination doses (3-5 per stallion) were obtained from various studs. Sperm membrane integrity, acrosome integrity, chromatin integrity, mitochondrial membrane potential, and reactive oxygen species production were evaluated by flow cytometry 24-30 h after semen collection, and sperm motility was assessed by computer aided sperm analysis. Calcein violet was used to differentiate viable spermatozoa. Per season pregnancy rates for these stallions were available the following year. Positive correlations were found between pregnancy rate and straightness (r = 0.43, p ≤ 0.001), as well as pregnancy rate and the proportion of living hydrogen peroxide positive spermatozoa (r = 0.32, p ≤ 0.05). There were negative correlations between pregnancy rate and amplitude of lateral head displacement (r = -0.26, p ≤ 0.05), and between pregnancy rate and the mean fluorescence of dead superoxide positive spermatozoa (r = -0.46, p < 0.001). Principal component analysis indicated that motility, membrane integrity, DNA fragmentation, and reactive oxygen species production were associated with pregnancy rate. Therefore, a combination of these factors could be used as a biomarker of fertility when assessing ejaculates. However, data from more individuals would be required to construct a model for fertility prediction.

Environmental pollutants and male infertility: Effects on CatSper

Infertility is a growing health concern among many couples worldwide. Men account for half of infertility cases. CatSper, a sperm-specific Ca2+ channel, is expressed on the cell membrane of mammalian sperm. CatSper plays an important role in male fertility because it facilitates the entry of Ca2+ necessary for the rapid change in sperm motility, thereby allowing it to navigate the hurdles of the female reproductive tract and successfully locate the egg. Many pollutants present in the environment have been shown to affect the functions of CatSper and sperm, which is a matter of capital importance to understanding and solving male infertility issues. Environmental pollutants can act as partial agonists or inhibitors of CatSper or exhibit a synergistic effect. In this article, we briefly describe the structure, functions, and regulatory mechanisms of CatSper, and discuss the body of literature covering the effects of environmental pollutants on CatSper.

The GgcxK325Q Mutation Does Not Affect the Calcium Homeostasis of the Epididymis and Male Fertility in Mice

A low-calcium microenvironment is imperative for spermatozoa maturation within the epididymis. Our previous work has shown that γ-glutamyl carboxylase (GGCX), the carboxylation enzyme of the matrix Gla protein (MGP), plays an essential role in epididymal calcium homeostasis and sperm maturation in rats and that the GGCX SNP mutation rs699664 was associated with asthenozoospermia (AZS) in humans. Here, we investigated the expression patterns of GGCX and MGP in the mouse epididymis and generated GgcxK325Q knock-in (KI) mice. We also tested the effects of this mutation on epididymal calcium homeostasis, sperm function, and male fertility in GgcxK325Q-/- mice. The results showed that both GGCX and MGP were enriched in all regions of the mouse epididymis, especially in the initial segment of the epididymis. Double immunofluorescence staining revealed that GGCX colocalized with MGP in the epithelial cells of the initial segment and caput regions as well as in the lumen of the corpus and cauda regions of the mouse epididymis. However, the GgcxK325Q-/- mice were fertile with normal epididymal morphology, sperm functions, and epididymal calcium concentration. Overall, our findings revealed that the GgcxK325Q mutation does not exert any discernible effect on male fertility in mice.

Clinical Utility of Sperm Function Tests in Predicting Male Fertility: A Systematic Review

Routine semen analysis provides considerable information regarding sperm parameters; however, it is not solely adequate to predict male fertility potential. In the past two decades, several advance sperm function tests have been developed. The present systematic review intends to assess the clinical utility of available advance sperm function tests in predicting the male fertility potential. A systematic literature search was conducted as per PRISMA guidelines using PubMed, MEDLINE, Google Scholar, and Cochrane Library. Different keywords either singly or in combination were used to retrieve the relevant articles related to sperm function tests, male fertility, and pregnancy outcomes. A total of 5169 articles were obtained, out of which 110 meeting the selection criteria were included in this review. The majorly investigated sperm function tests are hypo-osmotic swelling test, acrosome reaction test, sperm capacitation test, hemizona binding assay, sperm DNA fragmentation test, seminal reactive oxygen species test, mitochondrial dysfunction tests, antisperm antibody test, nuclear chromatin de-condensation (NCD) test, etc. The different advance sperm function tests analyse different aspects of sperm function. Hence, any one test may not be helpful to appropriately predict the male fertility potential. Currently, the unavailability of high-quality clinical data, robust thresholds, complex protocols, high cost, etc., are the limiting factors and prohibiting current sperm function tests to reach the clinics. Further multi-centric research efforts are required to fulfil the existing lacunas and pave the way for these tests to be introduced into the clinics.

Effects of Nobiletin supplementation on the freezing diluent on porcine sperm cryo-survival and subsequent in vitro embryo development

Nobiletin (NOB) is a bioflavonoid compound isolated from citrus fruit peels. The present study aimed to elucidate whether NOB facilitates the porcine sperm cryosurvival and embryo development after in vitro fertilization (IVF). To this end, spermatozoa were diluted and cryopreserved in a freezing extender supplemented with 0 (control), 50, 100, 150, and 200 μM Nobiletin. The kinematic patterns of frozen-thawed (FT) sperm were assessed after 30 and 90 min incubation using a Sperm Class Analyzer (SCA). Viability, acrosome integrity, and mitochondrial membrane potential (MMP) were measured by fluorescence microscopy 30 min after thawing using SYBR-14/PI, PSA/FITC, and R123/PI, respectively. Lipid peroxidation was determined using MDA assay after incubation for 90 min. The addition of 100 μM and 150 μM NOB to the extender significantly improved sperm progressive motility, and acrosome integrity compared to the control group (P < 0.05). The proportion of viable spermatozoa was significantly higher in the 150 μM NOB group. MDA levels were less in 50 μM and 150 μM NOB treated groups compared to the control. In addition, IVF with FT sperm was used to assess the embryo developmental competence. Treatment with 150 μM NOB before cryopreservation increased the cleavage and blastocyst formation rates compared to the control group. Furthermore, the relative expression of POU5F1 and AMPK, genes related to pluripotency and cell differentiation were significantly upregulated in embryos resulting from NOB-treated sperm compared to the control group. These results suggest that Nobiletin is a functionally novel phytochemical to mitigate oxidative stress during the freezing-thawing of porcine spermatozoa as reflected by improved FT sperm quality and IVF outcome.

Decreased AKAP4/PKA signaling pathway in high DFI sperm affects sperm capacitation

The sperm DNA fragmentation index (DFI) is a metric used to assess DNA fragmentation within sperm. During in vitro fertilization-embryo transfer (IVF-ET), high sperm DFI can lead to a low fertilization rate, poor embryo development, early miscarriage, etc. A kinase anchoring protein (AKAP) is a scaffold protein that can bind protein kinase A (PKA) to subcellular sites of specific substrates and protects the biophosphorylation reaction. Sperm protein antigen 17 (SPA17) can also bind to AKAP. This study intends to explore the reason for the decreased fertilization rate observed in high sperm DFI (H-DFI) patients during IVF-ET. In addition, the study investigates the expression of AKAP, protein kinase A regulatory subunit (PKARII), and SPA17 between H-DFI and low sperm DFI (L-DFI) patients. SPA17 at the transcriptional level is abnormal, the translational level increases in H-DFI patients, and the expression of AKAP4/PKARII protein decreases. H 2 O 2 has been used to simulate oxidative stress damage to spermatozoa during the formation of sperm DFI. It indicates that H 2 O 2 increases the expression of sperm SPA17 protein and suppresses AKAP4/PKARII protein expression. These processes inhibit sperm capacitation and reduce acrosomal reactions. Embryo culture data and IVF outcomes have been documented. The H-DFI group has a lower fertilization rate. Therefore, the results indicate that the possible causes for the decreased fertilization rate in the H-DFI patients have included loss of sperm AKAP4/PKARII proteins, blocked sperm capacitation, and reduced occurrence of acrosome reaction.

Temephos, an organophosphate larvicide for residential use: a review of its toxicity

Temephos (O,O,O',O'-tetramethyl O,O'-thiodi-p-phenylene bis(phosphorothioate)) is a larvicide belonging to the family of organophosphate pesticides used for the control of different vectors of diseases, such as dengue, Zika, chikungunya, and dracunculiasis. The aim of this review was to discuss the available published information about temephos toxicokinetics and toxicity in mammals. Temephos is quickly absorbed in the gastrointestinal tract, distributed to all organs, and then it accumulates mainly in adipose tissue. It is metabolized by S-oxidation, oxidative desulfuration, and hydrolysis reactions, with the possible participation of cytochrome P450 (CYP). Temephos is mainly eliminated by feces, whereas some of its metabolites are eliminated by urine. The World Health Organization classifies it as class III: slightly dangerous with a NOAEL (no-observed adverse effect level) of 2.3 mg/kg/day for up to 90 days in rats, based on brain acetylcholinesterase (AChE) inhibition. A LOAEL (lowest observable adverse effect level) of 100 mg/kg/day for up to 44 days in rats was proposed based on cholinergic symptoms. However, some studies have shown that temephos causes toxic effects in mammals. The inhibition of the enzyme acetylcholinesterase (AChE) is one of its main demonstrated effects; however, this larvicide has also shown genotoxic effects and some adverse effects on male reproduction and fertility, as well as liver damage, even at low doses. We performed an extensive review through several databases of the literature about temephos toxicokinetics, and we recommend to revisit current assessment of temephos with the new available data.

Supplementation of melatonin to cooling and freezing extenders improves canine spermatozoa quality measures

Background

Sperm freezing and cold storage are the two most common assisted reproductive technologies in the canine breeding industry. The freeze-thawing process causes significant detrimental changes in both sperm cell structure and function. Previous research has confirmed that excessive accumulation of un-scavenged free radicals (oxidative stress) plays an important role in the cryopreservation-induced damage to sperm cells. Also, the gradual accumulation of the free radicals during cold storage leads to a decline in the sperm quality markers. Melatonin is an endogenous neurohormone synthesized from tryptophan amino acid by pineal glands. Besides its several well-known physiologic roles, melatonin has a significant antioxidant potential through direct free radical scavenging properties. Therefore, the current study was designed to evaluate the potential in vitro protective properties of melatonin (0.5, 1, and 2 mM) on canine sperm cells after freezing or during long-term cold storage (9 days, 5 °C) on most important sperm in vitro fertility markers.

Results

Melatonin at 0.5, 1- or 2-mM concentrations could preserve significantly higher sperm total motility after 4 days of cold storage. However, only the 1- and 2 mM melatonin concentrations could result in better TM and PM values after 7 days of cold storage. Furthermore, melatonin supplementation could preserve higher sperm viability and acrosome integrity after 7 days of storage. Also, it could have significant protective effects on the cooled sperm DNA integrity. In the freezing section of the current research, melatonin at either 1- or 2-mM concentrations could not improve the sperm post-thaw TM and PM, whereas they improved sperm DNA integrity. Also, the post-thaw plasma membrane functional integrity and sperm velocity parameters were not affected by the treatment. Although DMSO (Dimethyl Sulfoxide) as the melatonin solvent could reduce the level of sperm lipid peroxidation and even improve the post-thaw sperm DNA integrity compared to the negative control, it reduced the post-thaw sperm progressive motility. However, the negative effects were reversed by concurrent melatonin supplementation at 1- and 2-mM concentrations.

Conclusion

The addition of 1- or 2-mM melatonin to the canine sperm freezing and cooling media could improve sperm motility, viability, acrosome, and DNA integrity.

Prolonged exposure of human spermatozoa in polyvinylpyrrolidone has detrimental effects on sperm biological characteristics

Polyvinylpyrrolidone (PVP) has been utilized in intracytoplasmic sperm injection (ICSI) for immobilization and manipulation of spermatozoa. This study aims to determine the suitable time that sperm cells could be safely exposed to PVP during ICSI procedure. Twenty-five normal semen samples were prepared using the swim-up method and then were exposed to 10% PVP at different time intervals (15, 30 and 60 min). The effect of PVP on sperm parameters (viability and morphology), DNA fragmentation index (sperm chromatin dispersion test), chromatin quality (aniline blue, toluidine blue and chromomycin A3 staining), acrosome reaction, mitochondrial membrane potential and sperm ultrastructure was assessed at different time intervals. Our results showed that prolonged sperm exposure in PVP for 15, 30 and 60 min significantly affects viability and morphology with a concomitant increase in DNA fragmentation and abnormal chromatin structure, while the percentage of acrosome-reacted spermatozoa was additionally increased. In addition, the spermatozoa with high mitochondrial membrane potential were significantly decreased compared to unexposed spermatozoa to PVP. In conclusion, the detrimental effects of PVP were increased significantly following sperm exposure in PVP after 15 min. Therefore, the sperm exposure to PVP should be limited to less than 15 min during ICSI procedure.

Effects of nonoxynol-9 (N-9) on sperm functions: systematic review and meta-analysis

Objective

To summarize the currently available phase I and II clinical trials of the effects of nonoxynol-9 (N-9) on human sperm structure and functions.

Methods

A systematic review and meta-analysis aiming to evaluate the spermicidal activity of N-9 on motility, was conducted in PubMed, EMBASE, and Cochrane databases by 10 March 2021. The counted numbers of progressive motile (PR) sperm in cervical mucus and the vanguard sperm penetration distances were analyzed. Other effects on sperm structures and physiological activities were reviewed as well.

Results

In the pooled results, percentages or counted numbers of PR sperm decreased after the treatment of N-9. Vanguard sperm penetration distance was shortened in treated groups. N-9 has been confirmed to damage the structures of sperm, as well as other organelles like acrosome and mitochondria. The physiological activities such as generation of reactive oxygen species, superoxide dismutase activity, acrosin activity, and hemizona binding were all inhibited in the reviewed studies.

Conclusions

N-9 has several impacts on sperm owing to its potency in reducing sperm motility and cervical mucus penetration, as well as other functional competencies.

Lay summary

Nonoxynol-9 (N-9) has been used worldwide as a spermicide to kill sperm for more than 60 years but can cause side effects including vaginal irritation and can increase the rate of contraceptive failure. A detailed analysis of published literature aiming to evaluate the spermicidal activity of N-9 on sperm was carried out. In the pooled results, N-9 reduced the number of active sperm and the distance they traveled. It also caused damage to the structures of sperm and to the way the sperm acted and interacted with the egg. In conclusion, N-9 impacts on sperm in a number of ways that lead to sperm death and dysfunction.

Using Deep Learning Algorithm: The Study of Sperm Head Vacuoles and Its Correlation with Protamine mRNA Ratio

Objective

It is necessary to evaluate fertility effective agents to predict assisted reproduction outcomes. This study was designed to examine sperm vacuole characteristics, and its association with sperm chromatin status and protamine-1 (PRM1) to protamine-2 (PRM2) ratio, to predict assisted pregnancy outcomes.

Materials and Methods

In this experimental study, ninety eight semen samples from infertile men were classified based on Vanderzwalmen’s criteria as follows: grade I: no vacuoles; grade II: <2 small vacuoles; grade III: <1 large vacuole and grade IV: large vacuole with other abnormalities. The location, frequency and size of vacuoles were assessed using high magnification, a deep learning algorithm, and scanning electron microscopy (SEM). The chromatin integrity, condensation, viability and acrosome integrity, and protamination status were evaluated for vacuolated samples by toluidine blue (TB) staining, aniline blue, triple staining, and CMA3 staining, respectively. Also, Protamine-1 and protamine-2 genes expression was analysed by reverse transcription-quantitative polymerase chain reaction (PCR). The assisted reproduction outcomes were also followed for each cycle.

Results

The results show a significant correlation between the vacuole size (III and IV) and abnormal sperm chromatin condensation (P=0.03 and P=0.02, respectively), and also, protamine-deficient (P=0.04 and P=0.03, respectively). The percentage of reacting acrosomes was significantly higher in the grades III and IV spermatozoa in comparison with normal group. The vacuolated spermatozoa with grade IV showed a high protamine mRNA ratio (PRM-2 was underexpressed, P=0.01). In the IVF cycles, we observed a negative association between sperm head vacuole and fertilization rate (P=0.01). This negative association was also significantly observed in pregnancy and live birth rate in the groups with grade III and IV (P=0.04 and P=0.03, respectively).

Conclusion

The results of our study highlight the importance sperm parameters such as sperm head vacuole characteristics, particularly those parameters with the potency of reflecting protamine-deficiency and in vitro fertilization/ intracytoplasmic sperm injection (IVF/ICSI) outcomes predicting.

CD147 deficiency is associated with impairedsperm motility/acrosome reaction and offersa therapeutic target for asthenozoospermia

Patients with asthenozoospermia often present multiple defects in sperm functions apart from a decrease in sperm motility. However, the etiological factors underlying these multifaceted defects remain mostly unexplored, which may lead to unnecessary treatment and unsatisfactory assisted reproductive technologies (ART) outcome. Here, we show that the protein levels of CD147 were lowered in sperm obtained from asthenozoospermic infertile patients exhibiting defects in both sperm motility and the acrosome reaction. Whereas CD147 maintained sperm motility before capacitation, female tract-derived soluble CD147 interacted with sperm-bound CD147 to induce an acrosome reaction in capacitated sperm. Soluble CD147 treatment restored the acrosome reaction and improved the fertility of sperm from patients with asthenozoospermia. Mechanistically, CD147 promotes sperm motility and acrosome reaction (AR) by eliciting Ca²⁺ influx through soluble CD147 binding to sperm-bound CD147. Notably, the level of soluble CD147 in seminal plasma was positively correlated with the fertilization rate and pregnancy outcome in infertile couples undergoing in vitro fertilization. Our study has identified a marker for the diagnosis and a therapeutic target for the defective AR capability in asthenozoospermia and a candidate for the prediction of in vitro fertilization outcomes for male infertile patients that facilitates the development of precision medicine in ART.

Temephos decreases sperm quality and fertilization rate and is metabolized in rat reproductive tissues at low dose exposure

Temephos is an organophosphorus (OP) pesticide used in control campaigns against vectors that transmit diseases, including dengue, a public health concern. The WHO classifies temephos in category III and its safe concentration (LOAEL) in male rats is 100 mg/kg/day for up to 44 days. Temephos inhibits acetylcholinesterase (AChE) and is metabolized in different tissues, probably by mixed-function oxidases; one of its metabolites is bisphenol S (BPS), which is considered an endocrine disruptor. The aim of this study was to evaluate the effects of temephos on sperm function and its biotransformation in the testis, epididymis, and other tissues to explore its toxicity in rats treated with 100 mg/kg/day/5 or 7 days (gavage). AChE activity was inhibited 70% starting on day 3 and 13 or 41% mortality was observed at 5 or 7 days, respectively. After 7 days, temephos significantly decreased sperm motility (30%) and viability (10%) and increased (10%) lipoperoxidation, and the sperm DNA exhibited no damage. Temephos was distributed and metabolized in all tissues, with the highest levels observed in the adipose tissue and temephos levels were 16-fold higher in the epididymis than in the testis. Notably, BPS was observed in the testis. At 5 days, decreased sperm motility (12.5%) and viability (5.7%) were observed and sperm fertilization decreased (30%). These results suggest that temephos decreases sperm quality and fertilization capacity at recommended safe concentrations and that it is metabolized in male reproductive tissues. This pesticide places the reproductive health of exposed people at risk, suggesting the need to reevaluate its toxicity.

Predictive Significance of Sperm DNA Fragmentation Testing in Early Pregnancy Loss in Infertile Couples Undergoing Intracytoplasmic Sperm Injection

Objective

This study aimed to determine the role of sperm DNA fragmentation as a marker that could predict early pregnancy loss (EPL), either independently or in combination with another marker or markers, after intracytoplasmic sperm injection (ICSI) cycles.

Methods

This prospective descriptive cohort study retrieved data from 162 couples who underwent their first ICSI cycles at the Center for Reproductive Endocrinology and Infertility of Hue University Hospital in Vietnam from May 2018 to December 2019. General characteristics, semen parameters, sperm DNA fragmentation index (DFI), fertilization, embryo development, pregnancy rates, and EPL were assessed. The receiver-operating characteristic (ROC) method was performed to identify the threshold of DFI in EPL. Multivariate analysis was used to demonstrate the relationship between the sperm DNA fragmentation level and EPL.

Results

Of 162 ICSI cycles, 23 (14.2%) involved EPL. There was no significant difference between the sperm DNA fragmentation rate and the overall rate of pregnancy loss, although the negative pregnancy outcome group had a median DFI that was higher than that of the positive pregnancy outcome group (20% vs 17.8%). The ROC analysis indicated that a sperm DNA fragmentation rate of 16.6% was the priority cut-off that could be used to distinguish EPL with a sensitivity of 73.9% (95% confidence interval [CI], 67.15-80.67) and specificity of 47.48% (95% CI, 39.79-55.17). The multivariate analysis confirmed that in female factors such as age, body mass index (BMI), and sperm DNA fragmentation level affected the EPL rate. However, a combination of the sperm DNA fragmentation level and female age or female BMI could not sufficiently predict EPL.

Conclusion

EPL can be affected by multiple factors including sperm DNA fragmentation; however, there is no sufficient evidence indicating that sperm DNA fragmentation, both as a single marker and combined with other markers, is a good predictor of EPL.

Effects of Pulsed-Wave Photobiomodulation Therapy on Human Spermatozoa

BACKGROUND AND OBJECTIVES

Previous studies reported that photobiomodulation (PBM) positively affects the mitochondrial respiratory chain in sperm, resulting in improved motility and velocity. As laser settings are not yet fully established, the present study aimed at optimizing PBM on human sperm. In addition, possible side-effects of PBM on sperm DNA fragmentation level and acrosomal integrity have been analyzed.

STUDY DESIGN/MATERIALS AND METHODS

A pulsed laser-probe (wavelength 655 nm, output power 25 mW/cm², impulse duration 200 nanoseconds) was used. Native fresh liquefied semen samples underwent radiation with energy doses of 0 (control), 4, 6, and 10 J/cm². Sperm parameters were assessed at 0, 30, 60, 90, and 120 minutes after radiation using a computer-assisted sperm analysis system. Motility and velocity of sperm from asthenozoospermic patients (n = 42) and normozoospermic controls (n = 22) were measured. The amount of DNA strand breaks was analyzed using ligation-mediated quantitative polymerase chain reaction in patients with asthenozoospermia (n = 18) and normozoospermia (n = 13). Post-irradiance acrosomal integrity was investigated using flow cytometry based on CD46 protein expression (n = 7).

RESULTS

Exposure to laser energy-doses of 4 and 6 J/cm² improved sperm motility and velocity in asthenozoospermic patients. PBM exhibited no significant effect on DNA fragmentation level and expression of CD46 serving as a biomarker for acrosome integrity.

CONCLUSION

PBM improves sperm motility parameters by maintaining DNA and acrosome integrity and, therefore, represents a promising new tool for assisted reproductive therapy. In particular, improving sperm motility in asthenozoospermic patients by PBM in future may contribute to increasing the chance for successful intrauterine insemination. The present trial has no clinical registration number, as only in vitro studies were performed. The study was approved by the local ethics committee and performed according to the Declaration of Helsinki. Lasers Surg. Med. © 2021 The Authors. Lasers in Surgery and Medicine published by Wiley Periodicals LLC.

Sperm Cholesterol Content Modifies Sperm Function and TRPV1-Mediated Sperm Migration

Transient receptor potential channels-vanilloid receptor 1 (TRPV1) regulates thermotaxis in sperm-oriented motility. We investigated the role of membrane cholesterol (Chol) on TRPV1-mediated human sperm migration. Semen samples were obtained from five normozoospemic healthy volunteers. Sperm membrane Chol content, quantified by liquid chromatography-mass spectrometry, was modified by incubating cells with 2-hydroxypropyl-ß-cyclodextrin (CD) or the complex between CD and Chol (CD:Chol). The effect on sperm migration on a 10 μM capsaicin gradient (CPS), a TRPV1 agonist, was then investigated. Motility parameters were evaluated by Sperm Class Analyser. Intracellular calcium concentration and acrosome reaction were measured by staining with calcium orange and FITC-conjugated anti-CD46 antibody, respectively. TRPV1-Chol interaction was modelled by computational molecular-modelling (MM). CD and CD:Chol, respectively, reduced and increased membrane Chol content in a dose-dependent manner, resulting in a dose-dependent increase and reduction of sperm migration in a CPS gradient. MM confirmed a specific interaction of Chol with a TRPV1 domain that appeared precluded to the Chol epimer epicholesterol (Epi-Chol). Accordingly, CD:Epi-Chol was significantly less efficient than CD:Chol, in reducing sperm migration under CPS gradient. Chol inhibits TRPV1-mediated sperm function by directly interacting with a consensus sequence of the receptor.

Clinical implications of sperm DNA damage in IVF and ICSI: updated systematic review and meta-analysis

The clinical effect of sperm DNA damage in assisted reproduction has been a controversial topic during recent decades, leading to a variety of clinical practice recommendations. While the latest European Society of Human Reproduction and Embryology (ESHRE) position report concluded that DNA damage negatively affects assisted reproduction outcomes, the Practice Committee of the American Society for Reproductive Medicine (ASRM) does not recommend the routine testing of DNA damage for in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). Herein, our aim was to perform a systematic review and meta-analysis of studies investigating whether sperm DNA damage affects clinical outcomes in IVF and ICSI, in order to contribute objectively to a consistent clinical recommendation. A comprehensive systematic search was conducted according to PRISMA guidelines from the earliest available online indexing year until March 2020, using the MEDLINE-PubMed and EMBASE databases. We included studies analysing IVF and/or ICSI treatments performed in infertile couples in which sperm DNA damage was well defined and assessed. Studies also had to include information about pregnancy, implantation or live birth rates as primary outcomes. The NHLBI-NIH quality assessment tool was used to assess the quality of each study. Meta-analyses were conducted using the Mantel-Haenszel method with random-effects models to evaluate the Risk Ratio (RR) between high-DNA-damage and control groups, taking into account the 95% confidence intervals. Heterogeneity among studies was evaluated using the I² statistic. We also conducted sensitivity analyses and post-hoc subgroup analyses according to different DNA fragmentation assessment techniques. We identified 78 articles that met our inclusion and quality criteria and were included in the qualitative analysis, representing a total of 25639 IVF/ICSI cycles. Of these, 32 articles had sufficient data to be included in the meta-analysis, comprising 12380 IVF/ICSI cycles. Meta-analysis revealed that, considering IVF and ICSI results together, implantation rate (RR = 0.74; 95% CI = 0.61-0.91; I²  = 69) and pregnancy rate (RR = 0.83; 0.73-0.94; I²  = 58) are negatively influenced by sperm DNA damage, although after adjustment for publication bias the relationship for pregnancy rate was no longer significant. The results showed a non-significant but detrimental tendency (RR = 0.78; 0.58-1.06; I²  = 72) on live birth rate. Meta-analysis also showed that IVF outcomes are negatively influenced by sperm DNA damage, with a statistically significant impact on implantation (RR = 0.68; 0.52-0.89; I²  = 50) and pregnancy rates (RR = 0.72; 0.55-0.95; I²  = 72), although the latter was no longer significant after correction for publication bias. While it did not quite meet our threshold for significance, a negative trend was also observed for live birth rate (RR = 0.48; 0.22-1.02; I²  = 79). In the case of ICSI, non-significant trends were observed for implantation (RR = 0.79; 0.60-1.04; I²  = 72) or pregnancy rates (RR = 0.89; 0.78-1.02; I²  = 44), and live birth rate (RR = 0.92; 0.67-1.27; I²  = 70). The current review provides the largest evidence to date supporting a negative association between sperm DNA damage and conventional IVF treatments, significantly reducing implantation and pregnancy rates. The routine use of sperm DNA testing is therefore justified, since it may help improve the outcomes of IVF treatments and/or allow a given couple to be advised on the most suitable treatment. Further well-designed controlled studies on a larger number of patients are required to allow us to reach more precise conclusions, especially in the case of ICSI treatments.

Hyaluronidase-based swim-up for semen selection in patients with human papillomavirus semen infection

Infection by human papillomavirus (HPV) represents one of the most common sexually transmitted diseases in both men and women worldwide. Recently, the detection of HPV virions in the semen of a large percentage of sexually active men has been associated with detrimental effects on both sperm parameters and on assisted reproductive technologies (ART) treatment outcomes. Conventional semen washing procedure used in ART have proved to be ineffective in removing HPV bound to sperm, requiring the identification of more effective and specific methods. In the present study, we assessed the possible use of hyaluronidase for the detachment of HPV from sperm cell surface. Semen samples from five normozoospermic control subjects (CTRL) were incubated with HPV virus-like particles (HPV-VLP) and treated with hyaluronidase by both a modified swim-up procedure (M-SU) and single-cell approach (SCA). The treatment with hyaluronidase was associated with the complete loss of HPV-VLP signal on sperms by both M-SU and SCA. In addition, semen samples from 12 HPV-positive infertile patients were treated with hyaluronidase 80 IU/mL by M-SU, resulting in the complete loss of HPV-DNA signal from sperm surface. Finally, the possible impact of hyaluronidase treatment on sperm parameters was assessed on both sperms from the five CTRL subjects and on further five oligo-astheno-terato-zoospermic (OAT) patients, both HPV negative. The treatment with hyaluronidase was equally associated with a slight reduction of sperm viability and progressive motility in both CTRL and OAT. In conclusion, the treatment with hyaluronidase removed efficiently and safely HPV virions bound to spermatozoa.

Predictive value of the sperm DNA fragmentation index for low or failed IVF fertilization in men with mild-to-moderate asthenozoospermia

INTRODUCTION

It has been observed that there is an increased incidence of total fertilization failure (TFF) and a low fertilization rate (LFR, <25 %) during conventional in vitro fertilization (IVF) treatments involving men with poor sperm motility. These men also exhibit a high sperm DNA fragmentation index (DFI), which has adverse effects on various IVF outcomes. However, the relationship between a high DFI and an increased TFF or LFR during IVF cycles has not been elucidated. Here, we aimed to investigate the association between the sperm DFI and TFF or LFR in IVF cycles involving men with mild-to-moderate asthenozoospermia and normozoospermia.

MATERIALS AND METHODS

This retrospective study included 116 men diagnosed as mild-to-moderate asthenozoospermia, and 407 men with normozoospermia. The sperm DFI was assessed using the sperm chromatin dispersion (SCD) test.

RESULTS

Men in the asthenozoospermia group had a significantly higher incidence of cycles with a TFF or LFR (9.5 % vs 2.7 %, P = 0.01), and these were associated significantly with an increased DFI (P < 0.01). After adjustment for confounding factors, a TFF or LFR was to correlate significantly with the DFI (odds ratio: 1.188; 95 % confidence interval, 1.035-1.363; P = 0.014). Area under the receiver operating characteristic curve was 0.772. No similar relationships between the DFI and IVF outcomes were observed in the normozoospermia group.

CONCLUSIONS

For men with mild-to-moderate asthenozoospermia, a high sperm DFI is associated with a decreased fertilization rate and an increased risk of a TFF or LFR. Additional prospectively-designed studies are warranted to confirm our results.

A Novel Approach to Improving the Reliability of Manual Semen Analysis: A Paradigm Shift in the Workup of Infertile Men

Conventional semen analysis (SA) is an essential component of the male infertility workup, but requires laboratories to rigorously train and monitor technicians as well as regularly perform quality assurance assessments. Without such measures there is room for error and, consequently, unreliable results. Furthermore, clinicians often rely heavily on SA results when making diagnostic and treatment decisions, however conventional SA is only a surrogate marker of male fecundity and does not guarantee fertility. Considering these challenges, the last several decades have seen the development of many advances in SA methodology, including tests for sperm DNA fragmentation, acrosome reaction, and capacitation. While these new diagnostic tests have improved the scope of information available to clinicians, they are expensive, time-consuming, and require specialized training. The latest advance in laboratory diagnostics is the measurement of seminal oxidation-reduction potential (ORP). The measurement of ORP in an easy, reproducible manner using a new tool called the Male Infertility Oxidative Stress System (MiOXSYS) has demonstrated ORP's potential as a feasible adjunct test to conventional SA. Additionally, the measurement of ORP by this device has been shown to be predictive of both poor semen quality and male infertility. Assessing ORP is a novel approach to both validating manual SA results and identifying patients who may benefit from treatment of male oxidative stress infertility.