Decreased Sperm Motility Retarded ICSI Fertilization Rate in Severe Oligozoospermia but Good-Quality Embryo Transfer Had Achieved the Prospective Clinical Outcomes

The Impact of Origanum vulgare Supplementation on Human Asthenozoospermic Sperm Parameter Quality

Male infertility is a complex multifactorial disease and a real health problem; 50% of infertile men have identifiable causes detectable by fundamental sperm analysis. Numerous research studies have shown the possibility of treating abnormal semen samples with some drugs before artificial insemination, yet evidence of the drug's effectiveness remains minimal. In our previous work, we tested the effectiveness of some essential oils, such as eucalyptus (Eucalyptus globulus Labill.), oregano (Origanum vulgare L.), and sage (Salvia officinalis L.) on sperm parameters. The essential oil of oregano showed the best ameliorative effect. In present, we examined the effect of the essential oil of O. vulgare on the physiological parameters and the specific activity of certain antioxidant enzymes such as catalase (CAT), superoxide dismutase (SOD), lipid peroxidation rate (MDA), and GAPDH and antioxidant and metabolic biomarkers, characterizing the quality of human sperm. The results showed that in vitro supplementation of oregano significantly improves the mobility and antioxidant activities, without harmful effects on the integrity of the sperm's DNA, and that the selected concentration of oregano EO is nontoxic and may be considered a therapeutic alternative to heal sperm motility problems in asthenozoospermic patients.

Carob extract induces spermatogenesis in an infertile mouse model via upregulation of Prm1, Plzf, Bcl-6b, Dazl, Ngn3, Stra8, and Smc1b

ETHNOPHARMACOLOGICAL RELEVANCE

Ethnopharmacological studies for drug discovery from natural compounds play an important role for developing current therapeutical platforms. Plants are a group of natural sources which have been served as the basis in the treatment of many diseases for centuries. In this regard, Ceratonia siliqua (carob) is one of the herbal medicine which is traditionally used for male infertility treatments. But so far the main mechanisms for effects of carob are unknown. Here, we intend to investigate the ability of carob extract to induce spermatogenesis in an azoospermia mouse model and determine the mechanisms that underlie its function.

AIM OF THE STUDY

This is a pre-clinical animal model study to evaluate the effect of carob extract in spermatogenesis recovery.

METHODS

We established an infertile mouse model with the intent to examine the ability of carob extract as a potential herbal medicine for restoration of male fertility. Sperm parameters, as well as gene expression dynamics and levels of spermatogenesis hormones, were evaluated 35 days after carob administration.

RESULTS

Significant enhanced sperm parameters (P < 0.05) showed that the carob extract could induce spermatogenesis in the infertile mouse model. Our data suggested an anti-apototic and inducer role in the expressions of cell cycle regulating genes. Carob extract improved the spermatogenesis niche by considerable affecting Sertoli and Leydig cells (P < 0.05). The carob-treated mice were fertile and contributed to healthy offspring that matured. Our data confirmed that this extract triggered the hormonal system, the spermatogenesis-related gene expression network, and signaling pathways to induce and promote sperm production with notable level (P < 0.05). We found that the aqueous extract consisted of a polar and mainly well water-soluble substance. Carob extract might upregulate spermatogenesis hormones via its amino acid components, which were detected in the extract by liquid chromatography-mass spectrometry (LC-MS).

CONCLUSION

Our results strongly suggest that carob extract might be a promising future treatment option for male infertility. This finding could pave the way for clinical trials in infertile men. This is the first study that has provided reliable, strong pre-clinical evidence for carob extract as an effective candidate for fertility recovery in cancer-related azoospermia.

A comprehensive investigation of human endogenous retroviral syncytin proteins and their receptors in men with normozoospermia and impaired semen quality

PURPOSE

The study aims to investigate first the presence of Syncytin 2 and its receptor, MFSD2, in human sperm, and second whether the expressions of Syncytin 1, Syncytin 2, and their receptors, SLC1A5 and MFSD2, differ between normozoospermic, asthenozoospermic, oligozoospermic, and oligoasthenozoospermic human sperm samples.

METHODS

The localization patterns and expression levels of syncytins and their receptors were evaluated in normozoospermic (concentration = 88.9 ± 5.5 × 10⁶, motility = 79.2 ± 3.15%, n = 30), asthenozoospermic (concentration = 51.7 ± 7.18 × 10⁶, motility = 24.0 ± 3.12%, n = 15), mild oligozoospermic (concentration = 13.5 ± 2.17 × 10⁶, motility = 72.1 ± 6.5%, n = 15), moderate oligozoospermic (concentration = 8.4 ± 3.21 × 10⁶, motility = 65.1 ± 8.9%, n = 15), severe oligozoospermic (concentration = 2.1 ± 1.01 × 10⁶, motility = 67.5 ± 3.2%, n = 15), and oligoasthenozoospermic (concentration = 5.5 ± 3.21 × 10⁶, motility = 18.5 ± 1.2%, n = 15) samples by immunofluorescence staining and western blot.

RESULTS

Syncytins and their receptors visualized by immunofluorescence showed similar staining patterns with slight staining of the tail in all spermatozoa regardless of normozoospermia, asthenozoospermia, oligozoospermia, or oligoasthenozoospermia. The localization patterns were categorized as equatorial segment, midpiece region, acrosome, and post-acrosomal areas. The combined staining patterns were also detected as acrosomal cap plus post acrosomal region, the midpiece plus equatorial segment, and midpiece plus acrosomal region. However, some sperm cells were categorized as non-stained. Both syncytin proteins were most intensely localized in the midpiece region, while their receptors were predominantly present in the midpiece plus acrosomal region. Conspicuously, syncytins and their receptors showed decreased expression in asthenozospermic, oligozoospermic, and oligoasthenozoospermic samples compared to normozoospermic samples.

CONCLUSION

The expression patterns of HERV-derived syncytins and their receptors were identical regardless of the spermatozoa in men with normozoospermia versus impaired semen quality. Further, asthenozoospermia, oligozoospermia, and oligoasthenozoospermia as male fertility issues are associated with decreased expression of both syncytins and their receptors.

The Need for a Framework Addressing the Temporal Aspects of Fish Sperm Motility Leading to Community-Level Standardization

Motility is a widely available parameter that can be used to assess sperm quality of aquatic species. Sperm from fishes with external fertilization usually undergo a dynamic and short-lived period of motility after activation. The common practice of assigning a single value at an arbitrary peak of motility presents challenges for reproducibility, community-level standardization, and comparisons across studies. This study aimed to explore statistical approaches to standardize motility reporting, and to develop an initial framework for community-level standards. Sperm samples from 14 zebrafish (Danio rerio) with a total of 21,705 cells were analyzed by use of computer-assisted sperm analysis with data collection starting at 10 s after activation at 5-s intervals for 50 s. Four common motility variables were selected for analyses: curvilinear velocity, straight-line velocity, beat cross frequency, and amplitude of lateral head displacement. Cluster analysis was used to evaluate sperm subpopulations within and among males over time, least-square means was used to explore temporal aspects, and the first derivative of the regression equations was used to calculate the rate of change for the motility parameters. Cluster analysis proved informative, but overlapping ephemeral clusters were not valuable for providing standardization options. Analysis of temporal aspects and rate of change indicated opportunities for standardization by reporting the overall motility-time functions or reporting during stable time windows instead of peak motility or at random times. These approaches could minimize the inconsistencies caused by male-to-male variation and dynamic changes of subpopulations while providing comparable information. An overall temporal framework was identified for motility reporting along the collection-processing-cryopreservation-thawing sequence to provide a basis to support efforts of community-level standardization.

The relationship between reactive oxygen species, DNA fragmentation, and sperm parameters in human sperm using simplified sucrose vitrification with or without triple antioxidant supplementation

Objective

This study examined whether the addition of triple antioxidants (3A)—10 µM acetyl-L-carnitine, 10 µM N-acetyl-L-cysteine, and 5 µM α-lipoic acid—in freezing-thawing medium during human sperm cryopreservation using the sucrose vitrification (SuV) and liquid nitrogen vapor (Vapor) techniques could improve post-thaw survival of spermatozoa.

Methods

We analyzed 30 samples from healthy human sperm donors. Each sample was allocated into one of five groups: fresh control, SuV, SuV+3A, Vapor, and Vapor+3A. The sperm motility, morphology, viability, intracellular and extracellular reactive oxygen species (ROS) levels, and sperm DNA fragmentation (SDF) were evaluated.

Results

The cryopreserved spermatozoa had significantly reduced percentages of motility (p<0.05) and viability (p<0.05). Antioxidant supplementation non-significantly improved these parameters (p>0.05). No significant differences were found in sperm morphology between the fresh and frozen-thawed groups (p>0.05). After freezing, the extracellular ROS levels in the frozen-thawed groups were significantly higher (p<0.05) than in the fresh group. However, we did not find any differences in intracellular ROS parameters among these groups (p>0.05). The SDF was higher in the SuV and Vapor groups than in the fresh group, but without statistical significance (p=0.075 and p=0.077, respectively).

Conclusion

Cryopreservation had detrimental effects on sperm motility, viability, and extracellular ROS levels, without changing the morphology or intracellular ROS levels. Antioxidant supplementation was slightly effective in preventing SDF in frozen-thawed spermatozoa.

An Update on Semen Physiology, Technologies, and Selection Techniques for the Advancement of In Vitro Equine Embryo Production: Section II

Simple Summary

In order to improve fertilization and pregnancy rates within artificial insemination or in vitro fertilization techniques in horses, producers may choose to select the best sperm within an ejaculate. In this paper, we review conventional and novel methods of sperm selection.

Abstract

As the use of assisted reproductive technologies (ART) and in vitro embryo production (IVP) expand in the equine industry, it has become necessary to further our understanding of available semen selection techniques. This segment of our two-section review will focus on the selection of spermatozoa based on quality and sex for equine intracytoplasmic sperm injection (ICSI), as well as current and future developments in sperm sorting technologies. Ultimately, novel methods of semen selection will be assessed based on their efficacy in other species and their relevance and future application towards ARTs in the horse.

The outcome of intra-cytoplasmic sperm injection (ICSI): do the sperm concentration and motility matter?

OBJECTIVES

The male-factor subfertility was reported to be 30% globally; thus, the intracytoplasmic sperm injection (ICSI) procedure was implemented to improve the overall in vitro fertilization (IVF) rates. Nevertheless, at least 10% of fertilization failure still occurs. Concerning this issue, we explored the association of sperm concentration and motility with the quality of embryo development and pregnancy outcome in IVF-ICSI cycles.

METHODS

Retrospective analysis of 109 couples with male factor were done over 14 months in a tertiary university hospital in Malaysia. The data were divided into four groups; Group I: normal sperm parameters, Group II: normal sperm concentration but reduced total sperm motility, Group III: reduced sperm concentration and motility, Group IV: reduced sperm concentration but normal sperm motility. Only fresh semen samples and fresh embryo transfers were included. The fertilization, cleavage rate, embryo quality and pregnancy outcome were assessed.

RESULTS

Overall, group I had the highest oocytes yield and ICSI attempted; (10.12 + 6.50), whereas the lowest was in group IV; (7.00 + 2.82). Group II revealed the highest fertilization and cleavage rates; (54.14 + 25.36), (55.16 + 26.06), thus not surprisingly resulting in the highest number of good embryos and highest clinical pregnancy rates. The lowest cleavage and pregnancy rates were seen in group IV. However, all the outcomes were not statically significant (p>0.05).

CONCLUSIONS

Similar fertilization rate and comparable pregnancy outcome was seen among couples with normal and reduced sperm concentration and motility.

Assessment of correlation between asthenozoospermia and mitochondrial DNA mutations in Egyptian infertile men

BACKGROUND

Asthenozoospermia is a chief reason for male seminal pathologies with an impression of around 19% of infertile patients. Spermatozoa mitochondrial DNA variations seem to link with low sperm motility. The objective of the study was to assess the relation between mitochondrial mutations and male sterility, especially in asthenozoospermia. The patient semen samples were investigated by studying the sperm physical characters; motility, viability, and morphological parameters were then classified into normozoospermia and asthenozoospermia. In addition, the level of malondialdehyde (MDA) as a bio-indicator of lipid peroxidation, seminal fructose, and total antioxidant capacity (TAC) were estimated. For molecular analysis, DNA from the semen samples was extracted using a DNA extraction kit. ND1, ND2, and ATPase6 genes were amplified by using a specific primer. After the purification procedure, each PCR product was sequenced to identify the single nucleotide polymorphisms (SNPs) in selected genes.

RESULTS

A significant negative correlation between seminal plasma malondialdehyde levels and sperm motility was detected. Meanwhile, TAC analysis revealed significantly lower activity (p ≤ 0.05) in the sample of asthenozoospermic than in normozoospermic men. As regards the seminal plasma fructose, there was no significant difference in the fructose level of normozoospermia and asthenozoospermia cases. At the molecular level, 31 diverse nucleotide substitutions were recognized in mitochondrial DNA. Only ten (10) mutations led to amino acid transformation: four have deleterious effects, four are benign, and the other two have conflicting effectiveness.

CONCLUSIONS

This study is the first in Egypt that is concerned with studying the relationship between the mitochondrial DNA mutations in human spermatozoa of asthenozoospermic patients and fertility. The results displayed scientific indications evidenced that there is an association between mitochondrial mutations and male infertility.

Abnormal fertilization in ICSI and its association with abnormal semen parameters: a retrospective observational study on 1855 cases

Intracytoplasmic sperm injection (ICSI) efficiently addresses male factor infertility. However, the occurrence of abnormal fertilization, mainly characterized by abnormal pronuclei (PN) patterns, merits investigation. To investigate abnormal fertilization patterns following ICSI and identify their respective associations with abnormal parameters in semen analysis (SA), a retrospective observational study including 1855 cycles was performed. Male infertility diagnosis relied on the 2010 WHO criteria. The population was divided into groups based on their SA results. The presence of 2PNs and extrusion of the second polar body (PB) indicated normal fertilization. A Kruskal–Wallis test along with a Wilcoxon post hoc evaluation and Bonferroni correction was employed for comparison among the groups. For the pregnancy rate, logistic regression was employed. No correlation was established between the SA abnormalities and the 1PN or 3PN formation rates. The highest and lowest 0PN rates were reported for the oligoasthenoteratozoospermic and normal groups, respectively. The lowest cleavage formation rates were identified in the oligoasthenozoospermic and oligoasthenoteratozoospermic groups. The aforementioned groups along with the oligoteratozoospermic group similarly presented the lowest blastocyst formation rates. For the clinical pregnancy rate, no statistically significant difference was observed. In conclusion, the incidence of two or more abnormal SA parameters – with the common denominator being oligozoospermia – may jeopardize normal fertilization, cleavage, and blastocyst rates. Once the developmental milestone of achieving blastocyst stage status was achieved, only oligoasthenozoospermia and oligoasthenoteratozoospermia were associated with lower rates. Interestingly, following adjustment for the number of blastocysts, no statistically significant differences were observed.

Cryopreservation of Mauritian Cynomolgus Macaque (Macaca fascicularis) Sperm in Chemically Defined Medium

The objective of this study was to optimize cryopreservation of sperm from Mauritian cynomolgus macaques (MCM) in defined conditions. Sperm viability and motility were compared between sperm cryopreserved in chemically-defined freezing media with variable osmolarity and the presence of either ethylene glycol or glycerol. The highest percentage viability (after freeze-thaw) was seen in sperm samples that were cryopreserved in medium with an osmolarity of 310 mOsm, while higher osmolarities markedly decreased sperm viability. Ethylene glycol and glycerol at concentrations of 4.6% and 5%, respectively, preserved sperm viability to an equivalent degree. Although higher motility rates and higher straight-line velocities were observed in sperm samples frozen in glycerol compared with ethylene glycol, these differences were not statistically significant. Thawed sperm frozen in defined conditions with glycerol were capable of fertilizing MCM oocytes in vitro, with development to the blastocyst stage. The protocol described here provides an effective method for cryopreservation of sperm to facilitate subsequent in vitro fertilization and genome editing of embryos in MCM species.

Sperm origins and concentration do not impact the clinical outcomes in intracytoplasmic sperm injection cycles

In the present study, we evaluated the impact of sperm origins and concentration on the clinical outcomes of intracytoplasmic sperm injection (ICSI) cycles. A total of 1201 ICSI cycles were retrospectively analyzed for male azoospermia or oligozoospermia between January 2015 and December 2015 in the Peking University Third Hospital. Patients were divided into three groups (Group 1 vs Group 2/3; surgically extracted sperm vs ejaculated sperms): Group 1 included 343 ICSI cycles and Group 2 analyzed 388 cycles on semen with sperm concentration <5 × 10⁶ ml⁻¹ (severe oligozoospermia group). Group 3 included 470 cycles with sperm concentration between 5 × 10⁶ ml⁻¹ and 15 × 10⁶ ml⁻¹ (mild oligozoospermia group). Fertilization rates, clinical pregnancy rates, and live birth rates were analyzed and compared among groups of different semen origins and concentrations on the oocyte retrieval day. Group 2 showed a lower fertilization rate than Group 3 (62.9% ± 21.6% vs 66.8% ± 22.1%,P < 0.05). There were no statistically significant differences in clinical pregnancy rate per transfer (51.3%, 46.7%, and 50.0%, respectively), live birth rate per transfer (44.4%, 40.9%, and 41.4%, respectively), accumulative live birth rate (58.3%, 51.0%, and 52.1%, respectively), twin birth rate (18.4%, 10.6%, and 12.6%, respectively), and birth defects rate (0, 0.3%, and 0.2%, respectively) among three groups. The results of this study indicated that sperm origins and concentration do not impact the clinical outcomes in ICSI cycles.

How general semen quality influences the blastocyst formation rate: Analysis of 4205 IVF cycles

Objective

To select embryos with higher implantation potential, the extended culture has been the most frequently applied strategy worldwide, and consequently leads to higher live birth rates per transfer. Sperm quality is a determining feature, and it may influence the outcomes of IVF from fertilization to embryo development. Therefore, we hypothesize that blastocyst formation may also be impaired by general semen quality.

Methods

We analyzed 4205 IVF cycles. Four study groups were designed according to semen quality: normal, mild alteration, severe alteration and epididymis. All cycles were intended to extend embryo culture until the blastocyst stage, and embryo development was evaluated.

Results

Regarding cleavage rate, the normal and mild alteration semen groups were equivalent, and the severe alteration and epididymis semen groups were equivalent to each other. The blastocyst formation rate decreased with semen quality. At least one blastocyst formed in 79.9% of cycles for the normal semen group, whereas the percentage of cycles with the formation of at least one blastocyst was slightly lower for the mild alteration (75.6%), severe alteration (76.4%) and epididymis (76.8%) semen groups. A multivariate logistic regression showed that for each additional cleaved embryo on day 3, the chance of having at least one blastocyst doubles. Additionally, the chance of having at least one blastocyst decreased when semen presented mild or severe alterations.

Conclusion

The general quality of sperm is a good predictor of blastocyst formation, significantly affecting the likelihood of having at least one blastocyst at the end of the cycle. Based on our findings, it is necessary to consider general semen quality and the number of cleaved embryos when forecasting the possibility of blastocyst formation and transfer in an extended culture system.