Incomplete development of human spermatozoa is associated with increased creatine phosphokinase concentration and abnormal head morphology

Microfluidics as an emerging paradigm for assisted reproductive technology: A sperm separation perspective

Millions of people are subject to infertility worldwide and one in every six people, regardless of gender, experiences infertility at some period in their life, according to the World Health Organization. Assisted reproductive technologies are defined as a set of procedures that can address the infertility issue among couples, culminating in the alleviation of the condition. However, the costly conventional procedures of assisted reproduction and the inherent vagaries of the processes involved represent a setback for its successful implementation. Microfluidics, an emerging tool for processing low-volume samples, have recently started to play a role in infertility diagnosis and treatment. Given its host of benefits, including manipulating cells at the microscale, repeatability, automation, and superior biocompatibility, microfluidics have been adopted for various procedures in assisted reproduction, ranging from sperm sorting and analysis to more advanced processes such as IVF-on-a-chip. In this review, we try to adopt a more holistic approach and cover different uses of microfluidics for a variety of applications, specifically aimed at sperm separation and analysis. We present various sperm separation microfluidic techniques, categorized as natural and non-natural methods. A few of the recent developments in on-chip fertilization are also discussed.

Impact of calcium and reactive oxygen species on human sperm function: Role of NOX5

NOX5 is introduced as a new therapeutic target for infertility treatment. This study aimed to compare the basal and stimulated reactive oxygen species (ROS) production and sperm function in human teratozoospermic (n = 15) and normozoospermic (n = 17) semen samples following calcium overload and NOX5 activation. Washed spermatozoa incubated for 1 h under five various conditions: control group, adding a calcium ionophore A23187, phorbol myristate acetate (PMA), A23187 + PMA, and diphenylene iodonium (DPI) + A23187 + PMA. ROS generation was measured immediately after treatment for 30 min. Motility, viability, acrosome reaction, and apoptosis were evaluated after 1-h incubation. ROS production significantly increased when A23187 or PMA was added to the sperm medium. DPI had suppressive effects on ROS generation. Progressive and total motility significantly decreased following calcium elevation and NOX5 activation, which was somewhat returned by DPI. Necrotic and live cells in teratozoospermia was, respectively, higher and lower than normozoospermia samples. Incubation with A23187 significantly increased the percentage of early and late apoptosis. Teratozoosperm are more vulnerable than normal spermatozoa, and produce more basal and stimulated ROS. It seems that calcium overload induces apoptosis in spermatozoa and loss of viability through MPT pore opening and increased intracellular ROS.

Zeta and hyaluronic acid assessments, novel sperm selection procedures, in animal model for male infertility

Considering varicocele (VCL)-induced severe, progressive DNA damage, histone-protamine anomalies and low sperm production, in the current study, the experimental VCL was induced and the efficiency of hyaluronic acid (HA)-binding method (HABM) and zeta preparation procedure (ZPP) in selection of appropriate spermatozoa was compared with those spermatozoa from intact animals. Following 2 and 4 months, the histological alterations in testicular tissue, sperm count and viability were assessed to prove the VCL condition. The spermatozoa were undergone simple wash, HABM and ZPP. The chromatin condensation, active caspase-3 expression, DNA fragmentation and apoptosis index were analysed after applying selection techniques and compared with the spermatozoa from intact and VCL-induced animals, which were undergone a simple wash. Observations showed that both HABM and ZPP effectively prepared the spermatozoa with higher chromatin condensation and lower DNA damage. Meanwhile, the ZPP exerted a more preferable effect by preparing the spermatozoa with higher chromatin condensation, and lower caspase-3 expression, and DNA disintegrity versus the HABM, especially after 4 months. In conclusion, ZPP seems to exert much more reliable efficiency in selecting appropriate spermatozoa for ICSI processes, while more studies are needed to find out which one is more useful in the clinical assisted reproductive technique (ART) process.

Novel association between apoptotic sperm biomarkers with seminal biochemical parameters and acetylcholinesterase activity in patients with teratozoospermia

OBJECTIVE

We aimed to determine whether the dysfunction of physiological apoptosis and specific seminal biochemical parameters could be associated with male infertility and sperm morphological defects.

STUDY DESIGN

Ejaculated sperm samples from sixty patients with isolated teratozoospermia and thirty fertile donors were analyzed. The proportion of both viable and dead spermatozoa expressing activated caspases was detected by fluorescence microscopy through the use of different specific carboxyfluorescein-labeled caspase inhibitors FLICA. The different stages of apoptosis in human were qualitatively and quantitatively determined by using the AO/EB fluorescent staining method. The levels of the seminal biochemical parameters (acetylcholinesterase (AChE), lactate dehydrogenase (LDH), creatine phosphokinase (CK), iron (Fe), calcium (Ca), and phosphorus (P)) were evaluated spectrophotometrically.

RESULTS

Patients with teratozoospermia showed significantly higher proportions of dead and live spermatozoa with activated caspases and spermatozoa in the late stage of apoptosis when compared to controls. Among the different studied biochemical seminal parameters, the rates of acetylcholinesterase activity, creatine phosphokinase, iron, and calcium were significantly increased in the patient group. However, the rate of phosphorus was significantly decreased. Interestingly, significant relationships were found between the studied biochemical and apoptotic biomarkers and the rates of atypical sperm forms with the incidences of head, mid-piece, and tail abnormalities. Furthermore, positive correlations were found between P, AChE, Fe, CK, and LDH with apoptotic markers.

CONCLUSIONS

These results emphasize the impact of apoptosis in the pathophysiology of teratozoospermia and suggest that seminal biochemical disturbance may arise such damage.

Influence of distiller's dried grains with solubles on ram lamb growth and reproductive traits

The hypothesis of this experiment was that increasing the inclusion level of distiller's dried grains with solubles (DDGS) in the diets would decrease semen quality but have no negative effects on growth performance. Following the removal of DDGS from the diet, it was hypothesized that the ram lambs would recover and become reproductively sound, independent of treatment. To test this hypothesis, Suffolk and Hampshire ram lambs (n = 112) were allocated to 4 treatments (n = 4 pens per treatment; 7 rams per pen) in a completely randomized design. Dietary treatments were 60% corn, 25% oats, and 15% commercial lamb pellet (CON), 15% of the ration as DDGS substituted for corn (% DM basis; 15DDGS), 30% of the ration as DDGS substituted for corn (% DM basis; 30DDGS), and 45% of the ration as DDGS substituted for corn (% DM basis; 45DDGS). Lambs were fed for 112 d on their respective treatment, after which they were placed on the CON ration until day 168. Lambs were weighed on consecutive d at the beginning (days 0 and 1) and end (days 167 and 168) of the study. Scrotal circumference was measured on all lambs on days 84, 112, 140, and 168. Semen samples were collected on a subset of 64 rams (4 rams per pen) to evaluate semen quality on days 84, 112, 140, and 168. Blood samples were collected on the same subset of rams every 14 d throughout the study. A quadratic effect on BW on day 112 and overall BW (P = 0.03 and P = 0.005, respectively), ADG on day 112 and overall ADG (P = 0.02 and P = 0.02, respectively), DMI (P = 0.007) on day 112, and a cubic effect (P = 0.05) for overall G:F were observed. Overall and day 168 scrotal circumference had a quadratic (P = 0.05) response. A linear increase in spermatozoa concentration on day 168 was observed (P = 0.03) as DDGS concentration increased in the treatment diets, although rams in this stage of the study were no longer receiving DDGS. Overall, testosterone concentrations exhibited a linear decrease (P = 0.005) as DDGS increased in the diet. The linear increase (P = 0.04) on day 168 in morphologically normal sperm as DDGS increased in the diets indicated that all rams, regardless of treatment, would have passed a reproductive soundness exam. In the current study, no negative effects were observed in lamb feedlot or reproductive traits due to increasing DDGS in the diet, indicating that DDGS may be included at levels up to 45% of growing lamb diets.

A new media without animal component for sperm cryopreservation: motility and various attributes affecting paternal contribution of sperm

PURPOSE

Our aim was the development of a safe sperm cryopreservation New Media (NM), composed of consistent and reproducible components devoid of any animal origin, and evaluation of NM in terms of its effect on sperm structure and function as compared to regularly used yolk media (TYM) (Irvine Scientific).

METHODS

We evaluated patient semen samples and cryopreserved them in duplicates in either NM or TYM. The samples were cryopreserved for either a short term of 1 week or long term of 1 month prior to thawing. The parameters investigated include sperm motility via computer-assisted semen analysis (CASA), sperm concentration, and sperm biomarkers that promote paternal contribution of spermatozoa to fertilization including hyaluronic acid binding, chromatin maturity, apoptotic markers, cytoplasmic retention, and sperm DNA integrity.

RESULTS

As compared to TYM, NM was equally capable of sperm cryopreservation with both short-term and long-term storage in media, and after freeze-thaw and gradient processing of sperm. HA binding of sperm was comparable post thaw in both NM and yolk media. There are also no differences observed between the samples cryopreserved in NM or TYM in terms of their aniline blue staining, CK immunocytochemistry, caspase 3 immunostaining, or DNA nick translation.

CONCLUSIONS

NM has the advantage of being xeno-free, yet in preservation of sperm motility and other sperm attributes, the NM is as effective as the TYM.

Cyclic nucleotide phosphodiesterases in human spermatozoa and seminal fluid: Presence of an active PDE10A in human spermatozoa

BACKGROUND

Cyclic adenosine monophosphate (cAMP) plays a crucial role as a signaling molecule for sperm functions such as capacitation, motility and acrosome reaction. It is well known that cAMP degradation by phosphodiesterase (PDE) enzyme has a major impact on sperm functions. The present study was undertaken to characterize cAMP-PDE activity in human semen.

METHODS

cAMP-PDE activity was measured in human sperm and seminal plasma using family specific PDE inhibitors. Three sperm fractionation methods were applied to assess cAMP-PDE activity in spermatozoa. Western blots were used to validate the presence of specific family in sperm and seminal plasma.

RESULTS

Using three sperm fractionation methods, we demonstrated that in human sperm, the major cAMP-PDE activity is papaverine-sensitive and thus ascribed to PDE10. In seminal plasma, total cAMP-PDE activity was 1.14±0.39fmol of cAMP hydrolyzed per minute per μg of protein. Using specific inhibitors, we showed that the major cAMP-PDE activity found in human seminal plasma is ascribed to PDE4 and PDE11. Western blot analysis, immunoprecipitation with a specific monoclonal antibody, and mass spectrometry confirmed the presence of PDE10 in human spermatozoa.

CONCLUSION

This study provides the first demonstration of the presence of functional PDE10 in human spermatozoa and functional PDE4 and PDE11 in human seminal plasma.

GENERAL SIGNIFICANCE

Since the contribution of cyclic nucleotides in several sperm functions is well known, the finding that PDE10 is an active enzyme in human spermatozoa is novel and may lead to new insight into fertility.

Microarray analysis of di-n-butyl phthalate and 17α ethinyl-oestradiol responses in three-spined stickleback testes reveals novel candidate genes for endocrine disruption

Phthalate esters are plasticizers frequently found in wastewater effluents. Previous studies on phthalates have reported anti-androgenic activity in mammals, causing concerns of their potential effects on the reproduction of aquatic organisms. Another group of environmental endocrine disrupters, steroidal estrogens, are known to inhibit steroid biosynthesis in the gonads, but the effects related to spermatogenesis are not well understood in fish. In this study, three-spined sticklebacks were exposed to di-n-butyl phthalate (DBP) and 17α ethinyl-oestradiol (EE2) at nominal concentrations 35μg/L and 40ng/L, respectively, for four days. The aim of the study was to obtain insight into the acute transcriptional responses putatively associated with endocrine disruption. RNA samples from eight individual male fish per treatment (including controls) were used in microarray analysis, covering the expression of approximately 21,000 genes. In the EE2 treatment the results show transcriptional downregulation of genes associated with steroid biosynthesis pathway and up-regulation of genes involved in pathways related to epidermal growth factor signaling and xenobiotic metabolism. The transcriptional response to DBP was in general weaker than to EE2, but based on enrichment analysis, we suggest adverse effects on retinoid metabolism, creatine kinase activity and cell adhesion. Among the genes showing highest fold changes after DBP treatment compared to control was the teleost fish -specific cytochrome P450 17A2. Overall, this study promotes our understanding on molecular responses to anti-androgens and estrogens in fish testes.

Influence of boar breeds or hybrid genetic composition on semen quality and seminal plasma biochemical variables

The enzyme concentrations of seminal plasma are important for spermatozoa metabolism and function in boars. The need has arisen for introducing a biochemical evaluation of semen, along with the usual standard semen analyses. There are no data on the influence of boar breeds on the seminal plasma biochemical variables investigated in this study. Therefore, the objective was to determine the influence of breed and hybrid genetic composition of boars on semen quality and seminal plasma biochemical variables. Semen samples of 27 boars (Swedish Landrace, German Landrace, Large White, Pietrain and Pig Improvement Company hybrid-PIC-hybrid), aged between 1.5 and 3 years, were collected. After evaluation of semen quality, the seminal plasma was separated from the spermatozoa by centrifugation of semen. The seminal plasma was subjected to spectrophotometric analysis to determine alkaline phosphatase (ALP), acid phosphatase (ACP), γ-glutamyltransferase (GGT), creatine kinase (CK) and lactate dehydrogenase (LDH) and to atomic absorption spectrophotometric analysis to measure the concentration of calcium and magnesium. Conventional semen quality variables differed depending on breed and PIC-hybrid genetic composition, though these differences were typically insignificant. In the seminal plasma, significant differences were determined in enzyme activity (ALP, GGT, CK and LDH) and in calcium concentration among boars of different breeds. There are, therefore, differences in semen quality and significant differences in the seminal plasma biochemical variables among boars of different breeds and PIC-hybrid genetic composition. The data and differences in semen variables detected in the present study provide knowledge for enhancing evaluation and monitoring of boar reproductive potential, semen quality and explain the potential causes of boar infertility.

Investigation on the Origin of Sperm DNA Fragmentation: Role of Apoptosis, Immaturity and Oxidative Stress

Sperm DNA fragmentation (sDF) represents a threat to male fertility, human reproduction and the health of the offspring. The causes of sDF are still unclear, even if apoptosis, oxidative assault and defects in chromatin maturation are hypothesized. Using multicolor flow cytometry and sperm sorting, we challenged the three hypothesized mechanisms by simultaneously evaluating sDF and signs of oxidative damage (8-hydroxy, 2'-deoxyguanosine [8-OHdG] and malondialdehyde [MDA]), apoptosis (caspase activity and cleaved poly[ADP-ribose] polymerase [cPARP]) and sperm immaturity (creatine phosphokinase [CK] and excess of residual histones). Active caspases and c-PARP were concomitant with sDF in a high percentage of spermatozoa (82.6% ± 9.1% and 53.5% ± 16.4%, respectively). Excess of residual histones was significantly higher in DNA-fragmented sperm versus sperm without DNA fragmentation (74.8% ± 17.5% and 37.3% ± 16.6%, respectively, p < 0.005), and largely concomitant with active caspases. Conversely, oxidative damage was scarcely concomitant with sDF in the total sperm population, at variance with live sperm, where 8-OHdG and MDA were clearly associated to sDF. In addition, most live cells with active caspase also showed 8-OHdG, suggesting activation of apoptotic pathways in oxidative-injured live cells. This is the first investigation on the origin of sDF directly evaluating the simultaneous presence of the signs of the hypothesized mechanisms with DNA breaks at the single cell level. The results indicate that the main pathway leading to sperm DNA breaks is a process of apoptosis, likely triggered by an impairment of chromatin maturation in the testis and by oxidative stress during the transit in the male genital tract. These findings are highly relevant for clinical studies on the effects of drugs on sDF and oxidative stress in infertile men and for the development of new therapeutic strategies.

Cytotoxic and genotoxic effects of titanium dioxide nanoparticles in testicular cells of male wistar rat

Serious concerns have been expressed about potential risks of engineered nanoparticles. Regulatory health risk assessment of such particles has become mandatory for the safe use in consumer products and medicines; also, the potential effects on reproduction and fertility are relevant for this risk evaluation. In the present study, we examined the effects of intravenously injected titanium dioxide nanoparticles (TiO2-NPs; 21 nm), with special emphasis on reproductive system. Antioxidant enzymes such as catalase, glutathione peroxidase, and superoxide dismutase showed a significant decrease, while significant increase in lipid peroxidase was observed. Our results confirmed the bioaccumulation of TiO2-NPs in testicular cells. In TiO2-NPs-treated animals, various functional and pathological disorders, such as reduced sperm count, increase in caspase-3 (a biomarker of apoptosis), creatine kinase activity, DNA damage, and cell apoptosis were observed. Moreover, the testosterone activity was decreased significantly in a dose-dependent manner in the animals treated with TiO2-NPs as compared with control group animals. It is concluded that TiO2-NPs induce oxidative stress, which produce cytotoxic and genotoxic changes in sperms which may affect the fertilizing potential of spermatozoa.

Sperm selection: effect on sperm DNA quality

The selection of spermatozoa without DNA fragmentation and chromosomal diseases prior to assisted reproductive techniques helps to optimize the outcome of the treatment; in particular, sperm selection prior to in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) is crucial. In fact, although ICSI has been successfully and safely applied worldwide for almost 20 years, at the present time we have no real knowledge regarding the hypothetical long-term side effects on ICSI adults, given the increased likelihood of spermatozoa with defective nuclear content fertilizing oocytes.In the case of DNA damage, the basal sperm DNA fragmentation rate can be significantly reduced by some sperm processing procedures that improve the percentage of spermatozoa with normal chromatin structure by filtering out DNA-damaged spermatozoa. After this first step, new advances in micromanipulation can be performed to choose the "ideal" mature spermatozoa for ICSI, reducing potential damage to the gametes. In fact, it is possible to prevent fertilization by DNA-damaged and chromosomal-unbalanced spermatozoa by selecting ICSI sperm by maturation markers such as hyaluronic acid or other zona pellucida receptors. Furthermore, novel noninvasive imaging techniques can be valid tools for helping in the morphological selection of ICSI spermatozoa.

Left-sided grade 3 varicocele may affect the biological function of the epididymis

OBJECTIVE

Varicocele is present in approximately 30-40% of men evaluated for infertility and in 10-20% of the general male population, but the association between varicocele, compromised semen quality and male infertility remains unclear. This indicates that varicocele may impair spermatogenesis or in some other way mitigate sperm quality. Better understanding of criteria for the selection of men who will benefit from varicocele repair would improve the clinical management of men with impaired semen quality and varicocele.

MATERIAL AND METHODS

To further understand the effect of varicocele repair by embolization in men with grade 3 varicocele, 50 men referred for infertility with varicocele were evaluated before and after embolization.

RESULTS

There was a significant improvement in total sperm count (25.5 ± 4.7 million to 78 ± 11 million, p < 0.001) and sperm motility (slowly and rapidly progressive) (31.5 ± 2.9% to 45 ± 2.5%, p < 0.001) after spermatic vein embolization, comparing baseline to 3 month post-treatment follow-up data. Furthermore, alpha-glucosidase (specific epididymis-derived protein) increased from 61.7 ± 5.7 U to 84.7 ± 7.0 U (p < 0.05) and sperm droplets decreased from 14.2 ± 1.5% to 11.0 ± 1.0% (p < 0.05).

CONCLUSION

The results indicate improved epididymal function and suggest that left-sided grade 3 varicocele may affect the epididymis in addition to effects on the testis.

The pattern of tyrosine phosphorylation in human sperm in response to binding to zona pellucida or hyaluronic acid

In mammalian species, acquisition of sperm fertilization competence is dependent on the phenomenon of sperm capacitation. One of the key elements of capacitation is protein tyrosine phosphorylation (TP) in various sperm membrane regions. In previous studies performed, the pattern of TP was examined in human sperm bound to zona pellucida of oocytes. In the present comparative study, TP patterns upon sperm binding to the zona pellucida or hyaluronic acid (HA) were investigated in spermatozoa arising from the same semen samples. Tyrosine phosphorylation, visualized by immunofluorescence, was localized within the acrosomal cap, equatorial head region, neck, and the principal piece. Tyrosine phosphorylation has increased in a time-related manner as capacitation progressed, and the phosphorylation pattern was identical within the principal piece and neck, regardless of the sperm bound to the zona pellucida or HA. Thus, the data demonstrated that the patterns of sperm activation-related TP were similar regardless of the spermatozoa bound to zona pellucida or HA. Further, sperm with incomplete development, as detected by excess cytoplasmic retention, failed to exhibit TP.

[Citogenetic and molecular genetic studies in infertility in eastern Hungary]

INTRODUCTION

In developed countries 10-15% of the couples are affected by infertility. In half of them genetic factors can be identified.

AIMS

We studied genetic alterations in infertility in Hungarian patients.

METHODS

Cyogenetic analyses were performed in 195 females and 305 males. In 17 females FMR1 mutations, in 150 males Y microdeletions, and aneuploidy were studied in the sperm of 28 males. In a carrier male sperm meiotic segregation was studied.

RESULTS

The most common aberrations in females were X chromosome aneuploidia and inversion (3.6%), while the same in males Klinefelter-syndrome (3.3%) and autosomal translocations (2%). In two females FMR1 premutation was found. While Y microdeletions were identified only in azoospermic and severe oligozoospermic men, partial microdeletions could also be detected in normozoospermic males. A higher aberration rate was found in cases with abnormality in both the number and motility of sperm. In a male patient with 46,XY,t(3;6)(q21;q23) karyotype, 53.2% of spem carried unbalanced chromosome assortment.

CONCLUSIONS

Knowledge of abnormalities may help in genetic counseling and choosing the most effective reproduction technique.

Semen Characteristics After Overnight Shipping: Preservation of Sperm Concentrations, HspA2 Ratios, CK Activity, Cytoplasmic Retention, Chromatin Maturity, DNA Integrity, and Sperm Shape

We tested several approaches that can be used to preserve sperm attributes and the objective biochemical markers of sperm maturity and function for assessment in a remote centralized laboratory after overnight shipping of semen samples. Addition of phenyl-methyl-sulfonyl-fluoride (PMSF) to a final concentration of 20 microg/mL semen at 4 degrees C has preserved sperm concentrations and HspA2 isoform ratios, even at room temperature, simulating a shipping delay in moderate ambient temperatures. Regarding the attributes of individual spermatozoa, the patterns of CK-immunocytochemistry (demonstrates cytoplasmic retention in diminished-maturity spermatozoa); aniline blue staining pattern (tests chromatin maturity); sperm shape assessed by both Kruger strict morphology and computer assisted morphometry; and sperm DNA integrity, as tested by DNA nick translation, all remained unchanged. Thus, the PMSF-4 degrees C conditions preserved sperm concentrations and the cytoplasmic and nuclear biomarkers of sperm cellular maturity and function for next-day analysis. This shipping method will facilitate the early detection of subtle changes in semen quality that can affect sperm function, even when there has been no decline in sperm concentrations to signal possible toxic effects. Furthermore, sample preservation will enable investigators to evaluate semen for toxicology studies and for diagnosis of male infertility from remote locations. Home collection of semen should enhance study participation, and semen assessment in centralized laboratories will address concerns regarding interlaboratory variations and quality control.

Intracytoplasmic morphology-selected sperm injection

Approximately 40% of sterility in couples can be attributed to male subfertility and intracytoplasmic sperm injection (ICSI) has become a powerful tool in assisted reproduction to overcome male infertility. Intracytoplasmic morphologically selected sperm injection (IMSI) is an advanced and sophisticated method of ICSI, where prior to sperm injection the morphology of the sperm is evaluated under high magnification. In addition, the IMSI procedure involves a few minor modifications in sperm preparation which are not carried out during the conventional ICSI procedure, such as the use of MSOME criteria, the requirement for a glass-bottomed dish for selection, prolonged sperm manipulation following separation from the seminal fluid, and sperm storage prior to microinjection. These variations are discussed in this chapter.

Methodology of aniline blue staining of chromatin and the assessment of the associated nuclear and cytoplasmic attributes in human sperm

In this chapter, the laboratory methods for detection of sperm biomarkers that are aimed at identifying arrested sperm development are summarized. These probes include sperm staining with aniline blue for persistent histones, representing a break in the histone-transition protein-protamine sequence, immunocytochemistry with cytoplasmic sperm proteins, highlighting cytoplasmic retention during spermiogenesis, DNA nick translation testing for DNA chain fragmentation due to various reasons, for instance low HspA2 chaperone protein levels, and consequential diminished DNA repair. Finally, we briefly provide references on our work on sperm hyaluronan binding, abnormal Tybergerg sperm morphology, and the increased levels of chromosomal aneuploidies in sperm with developmental arrest. A very interesting aspect of the biomarker field is the discovery (Sati et al, Reprod Biomed Online 16:570-579, 2008) that the various nuclear and cytoplasmic defects detected by the biomarkers are related, and may simultaneously occur within the same spermatozoa as evidenced by a combination of biomarkers, such as aniline blue staining (persistent histones) coupled with cytoplasmic retention, DNA fragmentation, Caspase-3, Tygerberg abnormal morphology, and increased levels of chromosomal aneuploidies. We show examples of this >80% overlap in staining patterns within the same spermatozoa.

Use of hyaluronan in the selection of sperm for intracytoplasmic sperm injection (ICSI): significant improvement in clinical outcomes--multicenter, double-blinded and randomized controlled trial

STUDY QUESTION

Does the selection of sperm for ICSI based on their ability to bind to hyaluronan improve the clinical pregnancy rates (CPR) (primary end-point), implantation (IR) and pregnancy loss rates (PLR)?

SUMMARY ANSWER

In couples where ≤65% of sperm bound hyaluronan, the selection of hyaluronan-bound (HB) sperm for ICSI led to a statistically significant reduction in PLR.

WHAT IS KNOWN AND WHAT THIS PAPER ADDS

HB sperm demonstrate enhanced developmental parameters which have been associated with successful fertilization and embryogenesis. Sperm selected for ICSI using a liquid source of hyaluronan achieved an improvement in IR. A pilot study by the primary author demonstrated that the use of HB sperm in ICSI was associated with improved CPR. The current study represents the single largest prospective, multicenter, double-blinded and randomized controlled trial to evaluate the use of hyaluronan in the selection of sperm for ICSI.

DESIGN

Using the hyaluronan binding assay, an HB score was determined for the fresh or initial (I-HB) and processed or final semen specimen (F-HB). Patients were classified as >65% or ≤65% I-HB and stratified accordingly. Patients with I-HB scores ≤65% were randomized into control and HB selection (HYAL) groups whereas patients with I-HB >65% were randomized to non-participatory (NP), control or HYAL groups, in a ratio of 2:1:1. The NP group was included in the >65% study arm to balance the higher prevalence of patients with I-HB scores >65%. In the control group, oocytes received sperm selected via the conventional assessment of motility and morphology. In the HYAL group, HB sperm meeting the same visual criteria were selected for injection. Patient participants and clinical care providers were blinded to group assignment.

PARTICIPANTS AND SETTING

Eight hundred two couples treated with ICSI in 10 private and hospital-based IVF programs were enrolled in this study. Of the 484 patients stratified to the I-HB > 65% arm, 115 participants were randomized to the control group, 122 participants were randomized to the HYAL group and 247 participants were randomized to the NP group. Of the 318 patients stratified to the I-HB ≤ 65% arm, 164 participants were randomized to the control group and 154 participants were randomized to the HYAL group.

MAIN RESULTS AND THE ROLE OF CHANCE

HYAL patients with an F-HB score ≤65% demonstrated an IR of 37.4% compared with 30.7% for control [n = 63, 58, P > 0.05, (95% CI of the difference −7.7 to 21.3)]. In addition, the CPR associated with patients randomized to the HYAL group was 50.8% when compared with 37.9% for those randomized to the control group (n = 63, 58, P > 0.05). The 12.9% difference was associated with a risk ratio (RR) of 1.340 (RR 95% CI 0.89–2.0). HYAL patients with I-HB and F-HB scores ≤65% revealed a statistically significant reduction in their PLR (I-HB: 3.3 versus 15.1%, n = 73, 60, P = 0.021, RR of 0.22 (RR 95% CI 0.05–0.96) (F-HB: 0.0%, 18.5%, n = 27, 32, P = 0.016, RR not applicable due to 0.0% value) over control patients. The study was originally planned to have 200 participants per arm providing 86.1% power to detect an increase in CPR from 35 to 50% at α = 0.05 but was stopped early for financial reasons. As a pilot study had demonstrated that sperm preparation protocols may increase the HB score, the design of the current study incorporated a priori collection and analysis of the data by both the I-HB and the F-HB scores. Analysis by both the I-HB and F-HB score acknowledged the potential impact of sperm preparation protocols.

BIAS, CONFOUNDING AND OTHER REASONS FOR CAUTION

Selection bias was controlled by randomization. Geographic and seasonal bias was controlled by recruiting from 10 geographically unique sites and by sampling over a 2-year period. The potential for population effect was controlled by adjusting for higher prevalence rates of >65% I-HB that naturally occur by adding the NP arm and to concurrently recruit >65% and ≤65% I-HB subjects. Monitoring and site audits occurred regularly to ensure standardization of data collection, adherence to the study protocol and subject recruitment. Subgroup analysis based on the F-HB score was envisaged in the study design.

GENERALIZABILITY TO OTHER POPULATIONS

The study included clinics using different sperm preparation methods, located in different regions of the USA and proceeded in every month of the year. Therefore, the results are widely applicable.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by Biocoat, Inc., Horsham, PA, USA. The statistical analysis plan and subsequent analyses were performed by Sherrine Eid, a biostatistician. The manuscript was prepared by Kathryn C. Worrilow, Ph.D. and the study team members. Biocoat, Inc. was permitted to review the manuscript and suggest changes, but the final decision on content was exclusively retained by the authors. K.C.W is a scientific advisor to Biocoat, Inc. S.E. is a consultant to Biocoat, Inc. D.W. has nothing to disclose. M.P., S.S., J.W., K.I., C.K. and T.E. have nothing to disclose. G.D.B. is a consultant to Cooper Surgical and Unisense. J.L. is on the scientific advisory board of Origio.

TRIAL REGISTRATION NUMBER

NCT00741494.

Correlation study between sperm concentration, hyaluronic acid-binding capacity and sperm aneuploidy in Hungarian patients

Infertile men with low sperm concentration and/or less motile spermatozoa have an increased risk of producing aneuploid spermatozoa. Selecting spermatozoa by hyaluronic acid (HA) binding may reduce genetic risks such as chromosomal rearrangements and numerical aberrations. Fluorescence in-situ hybridization (FISH) has been used to evaluate the presence of aneuploidies. This study examined spermatozoa of 10 oligozoospermic, 9 asthenozoospermic, 9 oligoasthenozoospermic and 17 normozoospermic men by HA binding and FISH. Mean percentage of HA-bound spermatozoa in the normozoospermic group was 81%, which was significantly higher than in the oligozoospermic (P<0.001), asthenozoospermic (P<0.001) and oligoasthenozoospermic (P<0.001) groups. Disomy of sex chromosomes (P=0.014) and chromosome 17 (P=0.0019), diploidy (P=0.03) and estimated numerical chromosome aberrations (P=0.004) were significantly higher in the oligoasthenozoospermic group compared with the other groups. There were statistically significant relationships (P<0.001) between sperm concentration and HA binding (r=0.658), between sperm concentration and estimated numerical chromosome aberrations (r=-0.668) and between HA binding and estimated numerical chromosome aberrations (r=-0.682). HA binding and aneuploidy studies of spermatozoa in individual cases allow prediction of reproductive prognosis and provision of appropriate genetic counselling. Infertile men with normal karyotypes and low sperm concentrations and/or less motile spermatozoa have significantly increased risks of producing aneuploid (diminished mature) spermatozoa. Selecting spermatozoa by hyaluronic acid (HA) binding, based on a binding between sperm receptors for zona pellucida and HA, may reduce the potential genetic risks such as chromosomal rearrangements and numerical aberrations. In the present study we examined sperm samples of 45 men with different sperm parameters by HA-binding assay and fluorescence in-situ hybridization (FISH). Mean percentage of HA-bound spermatozoa in the normozoospermic group was significantly higher than the oligozoospermic, the asthenozoospermic and the oligoasthenozoospermic groups. Using FISH, disomy of sex chromosomes and chromosome 17, diploidy and estimated numerical chromosome aberration frequencies were significantly higher in the oligoasthenozoospermic group compared with the three other groups. A significant positive correlation was found between the sperm concentration and the HA-binding capacity, and significant negative correlations between the sperm concentration and the estimated numerical chromosomes aberrations as well as between the HA-binding ability and the estimated numerical chromosome aberrations were identified. We conclude that HA-binding assay and sperm aneuploidy study using FISH may help to predict the reproductive ability of selected infertile male patients and to provide appropriate genetic counselling.

Effect of abamectin exposure on semen parameters indicative of reduced sperm maturity: a study on farmworkers in Antalya (Turkey)

Environmental exposure to pesticides may cause serious health risks including fertility and reproductive function. The aim of this study was to highlight whether there is a relationship between exposure to abamectin and male fertility parameters of farmworkers. Twenty male farmworkers who were using abamectin and 20 men not exposed to pesticides were recruited as experimental and control groups, respectively. Semen analysis, molecular markers of sperm maturity and serum reproductive hormone levels were evaluated. In experimental group, high plasma abamectin levels were detected. These men have decreased sperm motility. Moreover, diminished molecular markers of sperm maturity, such as decreased hyaluronic acid (HA) binding of sperm, increased numbers of aniline blue positive sperm and increased percentage of creatine kinase (CK) positive sperm, were observed in abamectin-exposed men. Their serum testosterone, LH and FSH levels did not change significantly. We conclude that exposure to abamectin may impair male fertility by effecting semen quality.

Clinical management of male infertility in assisted reproduction: ICSI and beyond

The advent of in vitro fertilization and its augmentation with intracytoplasmic sperm injection (ICSI) has allowed a large number of couples suffering from moderate to severe male infertility, and also presenting with female pathologies, to achieve their reproductive dreams. Notwithstanding the existence of fundamental questions about the pathophysiological mechanisms leading to sperm dysfunction, and still unanswered concerns about health risks following ICSI, it appears that overall ICSI is safe and here to stay. Although on one hand ICSI possibly hampered advances of the knowledge in some areas of gamete biology and interaction, on the other it definitely gave impulse to studies designed to unveil the sperm contributions during and beyond fertilization, including the normalcy of the DNA/chromatin as well as molecular mechanisms of genetic/epigenetic control and nuclear organization status. In all, almost entering the fourth decade of assisted reproductive technologies, we should continue monitoring the safety of the technique and long-term development of offspring, whereas at the same time prioritizing areas of research addressing these fundamental questions.

The therapeutic effect of a pulsed electromagnetic field on the reproductive patterns of male Wistar rats exposed to a 2.45-GHz microwave field

INTRODUCTION

Environmental exposure to man-made electromagnetic fields has been steadily increasing with the growing demand for electronic items that are operational at various frequencies. Testicular function is particularly susceptible to radiation emitted by electromagnetic fields.

OBJECTIVES

This study aimed to examine the therapeutic effects of a pulsed electromagnetic field (100 Hz) on the reproductive systems of male Wistar rats (70 days old).

METHODS

The experiments were divided into five groups: microwave sham, microwave exposure (2.45 GHz), pulsed electromagnetic field sham, pulsed electromagnetic field (100 Hz) exposure, and microwave/pulsed electromagnetic field exposure. The animals were exposed for 2 hours/day for 60 days. After exposure, the animals were sacrificed, their sperm was used for creatine and caspase assays, and their serum was used for melatonin and testosterone assays.

RESULTS

The results showed significant increases in caspase and creatine kinase and significant decreases in testosterone and melatonin in the exposed groups. This finding emphasizes that reactive oxygen species (a potential inducer of cancer) are the primary cause of DNA damage. However, pulsed electromagnetic field exposure relieves the effect of microwave exposure by inducing Faraday currents.

CONCLUSIONS

Electromagnetic fields are recognized as hazards that affect testicular function by generating reactive oxygen species and reduce the bioavailability of androgen to maturing spermatozoa. Thus, microwave exposure adversely affects male fertility, whereas pulsed electromagnetic field therapy is a non-invasive, simple technique that can be used as a scavenger agent to combat oxidative stress.

The expression pattern of SEPT7 correlates with sperm morphology

PURPOSE

To investigate the expression pattern of the SEPT7 protein during spermatogenesis and its potential role in sperm function.

METHODS

We first investigated the expression pattern of SEPT7 during different steps of mouse spermiogenesis using an immunofluorescence assay (IFA). IFA was also applied to study the expression pattern of SEPT7 in human ejaculated spermatozoa. Nine fertile men with normal semen parameters were used as the control group, and 21 infertile men with asthenozoospermia were recruited as the patient group. We assessed the frequency of the SEPT7 signal in the various morphological subgroups.

RESULTS

In humans, the frequency of a defective SEPT7 signal was significantly increased in men with asthenozoospermia. The absence of a SEPT7 signal was more prevalent in sperm containing morphological defects of various types.

CONCLUSIONS

The expression pattern of SEPT7 suggested that this protein may be involved in the regulation of subcellular-compartment formation during spermiogenesis in the mouse. The absence of a SEPT7 signal correlated with multiple sperm defects.

Tests to measure the quality of spermatozoa at spermiation

This commentary is to critique the revised World Health Organization (WHO) semen analysis manual as it pertains to characteristics of a spermatozoon at spermiation. The aims of the revised WHO manual include improving the 'quality of semen analysis' without any restriction to clinical use. Furthermore, the manual states that semen analysis may be useful for (a) 'investigating male fertility status' and (b) 'monitoring spermatogenesis during and following male fertility regulation.' However, if the analysis of ejaculated spermatozoa is intended for the purposes described in (b), then cells that are abnormal at spermiation must be identified. This paper takes the position that the manual does not identify methods to estimate the quality of spermatozoa at spermiation. Instead, it uses a 'gold standard' of sperm passing through the cervical mucus or arriving near the site of fertilization. Although this standard is appropriate for drawing conclusions regarding the probability that an individual could impregnate his partner, it is not appropriate for studying illness of the testes per se. Herein, the measures of sperm quality presented in the WHO manual are critiqued with respect to the detection of spermatozoa that were abnormal at spermiation vs. those that became abnormal subsequently. Quality assessments based on the percentage of motile or 'viable' spermatozoa are meaningless. Alternative quality attributes defining spermatozoa at spermiation are presented in this paper. In conclusion, assessment of spermatozoal quality at spermiation, on the basis of quality attributes of individual ejaculated spermatozoa, is best achieved through application of (a) a new paradigm for the morphological evaluation of sperm quality and (b) modern analytical techniques to evaluate, in an adequate sample, several appropriate independent attributes in each spermatozoon in order to more accurately identify the proportion of abnormal spermatozoa.

The role of sperm creatine kinase in the assessment of male fertility

The lack of reliable methods to assess sperm fertilizing potential has been a long-standing problem for infertile couples and for their physicians. The most widely used tests, the measurements of sperm concentrations, motility, velocity and morphology in the ejaculate, are of limited utility. Indeed, following intrauterine insemination, a treatment that compensates for low motile sperm concentrations, there were no significant differences found in semen parameters among those who did or did not achieve pregnancies. Other available assays probing for selected sperm functions, such as membrane integrity, acrosome enzyme activity, bovine cervical mucus penetration test, zona-free hamster oocyte penetration test and sperm binding to various carbohydrates,10–13 have all failed thus far to consistently predict male fertility. It became increasingly obvious that there was a need to identify cellular markers of sperm quality and fertilizing potential.

Semen characteristics and sperm morphology of serow (Capricornis sumatraensis)

The serow (Capricornis sumatraensis) is a critically endangered species. The objectives of this study were to evaluate ejaculate quality in captive males, and to investigate and characterize sperm morphology. Semen was collected using electroejaculation. Mean (+/-S.D.) seminal characteristics were: semen volume 2.3+/-0.8 mL, pH 7.8+/-0.4, and osmolality 329.9+/-32.9mOsmol/kg; sperm concentration 515.8+/-263.1 x 10(6) cells/mL; wave motion score (1-5) 3.9+/-0.4; motile sperm 60.5+/-22%; viable sperm 68.3+/-9.4%; morphologically normal sperm 70.8+/-19.3%; and an opacity that was yellowish to milky-white. Sperm head length, width, degree of elongation, area, and perimeter were 6.0+/-0.6 microm, 4.3+/-0.3 microm, 71.7+/-8.6%, 19.8+/-2.5 microm(2), and 17.9+/-2.1 microm. Based on these measurements, we categorized sperm head morphometry as small, medium, or large. In addition, sperm morphology was examined by light and scanning electron microscopy; overall, morphologically normal and abnormal sperm were similar to those reported for other bovidae. In summary, this study provided baseline data regarding semen characteristics of C. sumatraensis, which should be of value in the preservation of this endangered species.

Evaluation of sperm selection procedure based on hyaluronic acid binding ability on ICSI outcome

PURPOSE

To compare the efficiency of routine sperm selection method with HA-selection procedure for fertilization rate, embryo development, implantation and pregnancy rates as well as evaluating the relationship between HA-binding ability with sperm protamine deficiency and DNA fragmentation.

METHODS

Semen samples were obtained from the 50 couples undergoing ICSI. The percentage of fertilization rate, cleavage and quality of embryos compared between two procedures (routine sperm selection and HA-binding selection). The semen samples were assessed for DNA fragmentation and protamine deficiency by sperm chromatin dispersion (SCD) test and Chromomycin A3 (CMA3) staining, respectively.

RESULTS

A significant inverse correlation was observed between percentage of HA binding with protamine deficiency, DNA fragmentation and abnormal sperm morphology (P < 0.05). Furthermore, in current study, oocytes inseminated by HA sperm selection procedure had significantly higher fertilization rate (P < 0.05). While the pregnancy and implantation rates were insignificantly increased.

CONCLUSION

The results suggest that normal sperm have higher chance to bind HA and therefore, HA sperm selection procedure may select sperm with normal protamine content and low DNA fragmentation, but to confirm the effect of HA sperm selection on the ICSI outcome requires further studies.

Fertility testing and ICSI sperm selection by hyaluronic acid binding: clinical and genetic aspects

The testis-expressed chaperone protein, HspA2 (previously creatine kinase M isoform) was established as a measure of human sperm cellular maturity, function and fertility. The presence of HspA2 in the synaptonemal complex is likely to link low HspA2 expression and increased frequency of chromosomal aneuploidies in arrested-maturity spermatozoa. A relationship also exists between HspA2 expression in elongating spermatids and the associated spermatogenetic events, including plasma membrane remodelling and the formation of zona pellucida and hyaluronic acid (HA) binding sites. The HA receptor of mature spermatozoa, when coupled with HA-coated slides and/or Petri dishes, allows visual observation of sperm-HA binding, providing a basis for sperm maturity testing, a major improvement in semen evaluation, and selection of mature spermatozoa for intracytoplasmic sperm injection (ICSI). Thus, in HA-selected spermatozoa the frequency of chromosomal disomy and diploidy is reduced 4- to 6-fold compared with semen sperm fractions. This reduction is similar to the increase in numerical chromosomal aberrations in ICSI children. Combined studies of sperm shape and chromosome probes demonstrated that sperm morphology does not aid selection of haploid spermatozoa. The HA-mediated sperm selection is a novel and efficient technique that may alleviate potential problems related to ICSI fertilization with visually selected spermatozoa.

Hyaluronic acid binding ability of human sperm reflects cellular maturity and fertilizing potential: selection of sperm for intracytoplasmic sperm injection

PURPOSE OF REVIEW

The current concepts of sperm biochemical markers and the central role of the HspA2 chaperone protein, a measure of sperm cellular maturity and fertilizing potential, are reviewed.

RECENT FINDINGS

Because HspA2 is a component of the synaptonemal complex, low HspA2 levels and increased frequency of chromosomal aneuploidies are related in diminished maturity sperm. We also suggest a relationship between HspA2 expression in elongating spermatids and events of late spermiogenesis, such as cytoplasmic extrusion and plasma membrane remodeling that aid the formation of the zona pellucida binding and hyaluronic acid binding sites. The presence of hyaluronic acid receptor on the plasma membrane of mature sperm, coupled with hyaluronic acid coated glass or plastic surfaces, facilitates testing of sperm function and selection of single mature sperm for intracytoplasmic sperm injection. The frequencies of sperm with chromosomal disomy are reduced approximately fourfold to fivefold in hyaluronic acid selected sperm compared with semen sperm, comparable to the increase in such abnormalities in intracytoplasmic sperm injection offspring. Hyaluronic acid binding also excludes immature sperm with cytoplasmic extrusion, persistent histones, and DNA chain breaks.

SUMMARY

Hyaluronic acid mediated sperm selection is a novel technique that is comparable to sperm zona pellucida binding. Hyaluronic acid selected sperm will also alleviate the risks related to intracytoplasmic sperm injection fertilization with sperm of diminished maturity that currently cause worldwide concern.

Glycolysis and sperm motility: does a spoonful of sugar help the flagellum go round?

It is doubtful that diffusion can deliver sufficient ATP from the mitochondria to sustain activity at the distal end of the sperm flagellum. Glycolytic enzymes bound to the fibrous sheath could provide energy along the flagellum at the point it is required. An obligatory role for glycolysis is supported by the lack of progressive motility in sperm from mice where the gene for sperm-specific glyceraldehyde-3-phosphate dehydrogenase (GAPDHs) had been 'knocked out'. Here, I review some evidence against this idea. First, pure diffusion from the mitochondrion is likely to be adequate in species with smaller sperm, and it is possible that rapid ATP delivery required in larger sperm could be achieved by an adenylate kinase shuttle. Second, experience with alpha-chlorohydrin demonstrates that sperm can remain motile with normal ATP concentrations despite inhibition of GAPDHs; adverse effects only occur if glucose is added and high levels of glycolytic intermediates accumulate. These observations undermine the GAPDHs knockout mouse as evidence for an essential role of local glycolysis. Third, sperm from many species can remain motile for long periods in sugar-free media and excepting dog sperm, evidence that gluconeogenesis is a possible explanation, is weak. In most species, it is unlikely that local glycolysis is the only way that ATP can be supplied to the distal flagellum.

Intracytoplasmic sperm injection: a novel selection method for sperm with normal frequency of chromosomal aneuploidies

OBJECTIVE

To test a newly invented intracytoplasmic sperm injection (ICSI) sperm selection method based on sperm hyaluronic acid (HA) binding.

DESIGN

Comparison of chromosomal disomy and diploidy frequencies in sperm arising from semen and in HA-bound sperm.

SETTING

Academic andrology laboratory.

PATIENT(S)

Men presenting for semen analysis.

INTERVENTION(S)

Washed sperm fractions of 32 semen samples were applied to Petri dishes or glass slides coated with immobilized HA. The unbound sperm were rinsed gently, and the HA-bound sperm were removed with an ICSI pipette. The control sperm population was the unselected sperm. Both HA-selected and unselected sperm were treated with fluorescence in situ hybridization with centromeric probes for the X, Y, and 17 chromosomes.

MAIN OUTCOME MEASURE(S)

Chromosomal disomy and diploidy frequencies.

RESULT(S)

In the HA-bound sperm (495-2,079 per man, 41,670 in all) compared with unselected sperm (4,770 per man, 162,210 in all), the chromosomal disomy frequencies were reduced to 0.16% from 0.52%, diploidy to 0.09% from 0.51%, and sex chromosome disomy to 0.05% from 0.27% (a 5.4-fold reduction vs. 4-fold respective increase in ICSI offspring).

CONCLUSION(S)

The HA sperm selection method for ICSI, which is based on a relationship between sperm receptors for zona pellucida and HA, will likely reduce the potential genetic complications and adverse public health effects of ICSI.

Cytoplasmic droplets: the good, the bad or just confusing?

The term cytoplasmic droplets is used to mean two different structures by basic scientists and clinicians. The literature on the presence, position and loss of cytoplasmic droplets and their relationship to infertility in animal species is reviewed. It is proposed that a change in terminology is required: 'cytoplasmic droplet' should be used to describe normal droplets associated with functional sperm produced by normal spermatogenesis and 'excess residual cytoplasm' is suggested to describe abnormal droplets associated with dysfunctional sperm that are products of faulty spermatogenesis.