Viable acrosome-intact human spermatozoa in the ejaculate as a marker of semen quality and fertility status.

Egeberg Palme DL ，Rehfeld A ，Bang AK ，Nikolova KA ，Kjærulff S ，Petersen MR ，Jeppesen JV ，Glensbjerg M ，Juul A ，Skakkebæk NE ，Ziebe S ，Jørgensen N ，Almstrup K ... -  《-》

Improved sperm kinematics in semen samples collected after 2 h versus 4-7 days of ejaculation abstinence.

Does a short abstinence period of only 2 h yield spermatozoa with better motility characteristics than samples collected after 4-7 days? Despite lower semen volume, sperm concentration, total sperm counts and total motile counts, higher percentages of motile spermatozoa with higher velocity and progressiveness were detected in samples obtained after 2 h. Most studies that have assessed the effect of abstinence periods on sperm motility parameters in men with a sperm concentration below 15 million/ml have detected a higher percentage of motile spermatozoa in samples obtained after short abstinence periods. Studies of men with sperm concentrations above 15 million/ml have reported significantly decreased motile sperm counts after 24 h of abstinence compared with longer abstinence periods. This study had a controlled repeated-measures design based on semen samples from 43 male partners, in couples attending for IVF treatment, who had a sperm concentration above 15 million/ml. Data were collected between June 2014 and December 2015 in the Fertility Unit of Aalborg University Hospital (Aalborg, Denmark). Participants provided a semen sample after 4-7 days of abstinence followed by another sample after only 2 h. For both ejaculates, sperm concentration, total sperm counts, motility groups and detailed kinematic parameters were assessed and compared by using the Sperm Class Analyzer (SCA) computer-aided sperm analysis system before and after density gradient selection. The laboratory's local manual method (Makler chamber) was used for comparison. The second raw ejaculate demonstrated lower semen volume (P < 0.0001), sperm concentration (P = 0.003) and sperm counts in all motility sub-groups (P < 0.001) but higher percentages of spermatozoa with higher velocity (P < 0.01), progressiveness (P < 0.001) and hyperactivation (P < 0.001), compared with the first raw ejaculate. The first ejaculate in this study was also used for the IVF/ICSI treatments and therefore only patients with a semen volume ≥2 ml and concentration ≥15 million/ml were included. Further validation in large prospective randomized controlled trials, more purposely directed at normozoospermic males with partners having problems conceiving when there appears to be no female factor, is needed to confirm the potential advantage of using a second semen sample in improving fertilization and pregnancy rates in assisted reproduction. Despite the significantly lower semen volume, sperm concentration and total sperm counts in all motility sub-groups, the significantly higher percentage of spermatozoa with better motility characteristics (velocity, progressiveness and hyperactivation) in the second ejaculate, may provide and allow for a simpler and more effective selection of higher quality spermatozoa. This could prove to be an advantage for ART procedures such as intracytoplasmic sperm injection where a large number of spermatozoa is not needed. It can also be speculated that pooling two consecutive ejaculates obtained after 4-7 days and after 2 h, could be an advantage for intrauterine insemination where a large number of motile spermatozoa are needed. This study was supported by internal grants from the Department of Health Science and Technology, Faculty of Medicine, Aalborg University (Aalborg, Denmark). The SCA® was provided by a grant from 'Ferring Pharmaceuticals' to Aalborg University Hospital (H.I.N). G.V.D.H. is an external senior scientific consultant to Microptic S/L (Barcelona, Spain). H.A. has provided scientific input and presentations for Microptic S/L (Barcelona, Spain) on several occasions. All other authors declare no conflict of interest. N/A.

Alipour H ，Van Der Horst G ，Christiansen OB ，Dardmeh F ，Jørgensen N ，Nielsen HI ，Hnida C ... -  《-》

Characterization of a novel role for the dynamin mechanoenzymes in the regulation of human sperm acrosomal exocytosis.

Does dynamin regulate human sperm acrosomal exocytosis? Our studies of dynamin localization and function have implicated this family of mechanoenzymes in the regulation of progesterone-induced acrosomal exocytosis in human spermatozoa. Completion of an acrosome reaction is a prerequisite for successful fertilization in all studied mammalian species. It follows that failure to complete this unique exocytotic event represents a common aetiology in the defective spermatozoa of male infertility patients that have failed IVF in a clinical setting. Recent studies have implicated the dynamin family of mechanoenzymes as important regulators of the acrosome reaction in murine spermatozoa. The biological basis of this activity appears to rest with the ability of dynamin to polymerize around newly formed membrane vesicles and subsequently regulate the rate of fusion pore expansion. To date, however, the dynamin family of GTPases have not been studied in the spermatozoa of non-rodent species. Here, we have sought to examine the presence and functional significance of dynamin in human spermatozoa. Dynamin expression was characterized in the testis and spermatozoa of several healthy normozoospermic individuals. In addition, we assessed the influence of selective dynamin inhibition on the competence of human spermatozoa to undergo a progesterone-induced acrosome reaction. A minimum of five biological and technical replicates were performed to investigate both inter- and intra-donor variability in dynamin expression and establish statistical significance in terms of the impact of dynamin inhibition. The expression and the localization of dynamin in the human testis, epididymis and mature spermatozoa were determined through the application of immunofluorescence, immunoblotting and/or electron microscopy. Human semen samples were fractionated via density gradient centrifugation and the resultant populations of good and poor quality spermatozoa were induced to capacitate and acrosome react in the presence or absence of selective dynamin inhibitors. The acrosome integrity of live spermatozoa was subsequently assessed via the use of fluorescently conjugated Arachis hypogea lectin (PNA). The influence of dynamin phosphorylation and the regulatory kinase(s) responsible for this modification in human spermatozoa were also assessed via the use of in situ proximity ligation assays and pharmacological inhibition. In all experiments, ≥100 spermatozoa were assessed/treatment group and all graphical data are presented as the mean values ± SEM, with statistical significance being determined by ANOVA. Dynamin 1 (DNM1) and DNM2, but not DNM3, were specifically localized to the acrosomal region of the head of human spermatozoa, an ideal position from which to regulate acrosomal exocytosis. In keeping with this notion, pharmacological inhibition of DNM1 and DNM2 was able to significantly suppress the rates of acrosomal exocytosis stimulated by progesterone. Furthermore, our comparison of dynamin expression in good and poor quality spermatozoa recovered from the same ejaculate, revealed a significant reduction in the amount of DNM2 in the latter subpopulation of cells. In contrast, DNM1 was detected at equivalent levels in both subpopulations of spermatozoa. Such findings are of potential significance given that the poor quality spermatozoa proved refractory to the induction of a progesterone stimulated acrosome reaction. In seeking to identify the regulatory influence of progesterone on DNM2 function, we were able to establish that the protein is a substrate for CDK1-dependent phosphorylation. The functional significance of DNM2 phosphorylation was illustrated by the fact that pharmacological inhibition of CDK1 elicited a concomitant suppression of both DNM2-Ser764 phosphorylation and the overall rates of progesterone-induced acrosomal exocytosis. N/A. This was an in vitro study performed mainly on ejaculated human spermatozoa. This experimental paradigm necessarily eliminates the physiological contributions of the female reproductive tract that would normally support capacitation and acrosomal responsiveness. This study identifies a novel causative link between dynamin activity and the ability of human spermatozoa to complete a progesterone-induced acrosome reaction. Such findings encourage a more detailed analysis of the contribution of dynamin dysregulation as an underlying aetiology in infertile males whose spermatozoa are unable to penetrate the zona pellucida. This research was supported by a National Health and Medical Research Council of Australia Project Grant (APP1103176) awarded to B.N. and E.A.M. The authors report no conflict of interest.

Zhou W ，Anderson AL ，Turner AP ，De Iuliis GN ，McCluskey A ，McLaughlin EA ，Nixon B ... -  《-》

A novel copy number variation in CATSPER2 causes idiopathic male infertility with normal semen parameters.

Are genetic abnormalities in CATSPER (cation channel of sperm) genes associated with idiopathic male infertility with normal semen parameters and, if so, how do they affect male fertility? A novel copy number variation (CNV) in CATSPER2 causes idiopathic male infertility with normal semen parameters by disrupting the ability of sperm to penetrate viscous media, undergo hyperactivation and respond to progesterone. CATSPER is the principle Ca2+ channel mediating extracellular Ca2+ influx into spermatozoa. Although several case reports have suggested a causal relationship between CATSPER disruption and human male infertility, whether genetic abnormalities in CATSPER genes are associated with idiopathic male infertility with normal semen parameters remains unclear. Spermatozoa were obtained from men attending the reproductive medical center at Jiangxi Provincial Maternal and Child Health Hospital, Nanchang, Jiangxi, China between January 2014 and June 2016. In total, 120 men from infertile couples and 20 healthy male donors were selected to take part in the study, based on their normal semen parameters. CATSPER and KSPER currents were assessed using the whole-cell patch-clamp technique. Whole-genome sequencing and TaqMan® CNV assays were performed to identify genetic variations. The expression levels of genes encoding the CATSPER complex were measured by quantitative real-time PCR and Western blot. Sperm motion characteristics and hyperactivation were examined with a computer-aided sperm analysis (CASA) system. Sperm responses to progesterone, assessed as increases in CATSPER current and intercellular Ca2+ concentrations ([Ca2+]i), as well as inducement of penetration ability and acrosome reaction, were examined by means of whole-cell patch-clamp technique, single-sperm [Ca2+]i imaging, penetration into methylcellulose assay and chlortetracycline staining, respectively. An infertile man with complete disruption of CATSPER current was identified. This individual has a novel CNV which disrupts one gene copy in the region 43894500-43950000 in chromosome 15 (GRCh37.p13 Primary Assembly, nsv3067119), containing the whole DNA sequence of CATSPER2. This CNV affected the expression of CATSPER2, resulting in dramatically reduced levels of CATSPER2 proteins in the individual's spermatozoa. Although this individual exhibited normal semen parameters, his spermatozoa showed impaired penetration ability, deficient hyperactivation, and did not respond to progesterone, in terms of monovalent current potentiation, [Ca2+]i increase, penetration ability enhancement and acrosome reaction inducement, which may explain the individual's idiopathic infertility. N/A. Our novel findings require more cases to support the CATSPER2 CNV identified in this study as a common cause of idiopathic male infertility in patients with normal semen parameters. Therefore, caution must be taken when extrapolating the use of this CNV as a potential biomarker for idiopathic male infertility. The findings from the unique human CATSPER 'knockout' model in this study not only confirm the essential roles of CATSPER in mediating progesterone response and regulating hyperactivation in human spermatozoa but also reveal that disruption of CATSPER current is a significant factor causing idiopathic male infertility. This study was funded by National Natural Science Foundation of China (81771644 and 31400996 to T.L.; 31230034 to X.Z.); National Basic Research Program of China (973 Program, 2015CB943003 to X.Z.); National Key Research and Development Program of China (2016YFC1000905 to T.L.); Natural Science Foundation of Jiangxi, China (20121BBG70021 and GJJ12015 to X.Z.; 20161BAB204167 and 20171ACB21006 to T.L.) and the open project of National Population and Family Planning Key Laboratory of Contraceptives and Devices Research (No. 2016KF07 to T.L.). The authors have no conflicts of interest to declare.

Luo T ，Chen HY ，Zou QX ，Wang T ，Cheng YM ，Wang HF ，Wang F ，Jin ZL ，Chen Y ，Weng SQ ，Zeng XH ... -  《-》

Semen quality impairment is associated with sexual dysfunction according to its severity.

Is sexual dysfunction associated with severity of semen quality impairment in men with couple infertility? In males of infertile couples the prevalence of erectile dysfunction (ED) increases as a function of semen quality impairment severity. Infertile men are at a higher risk for sexual dysfunction, psychopathological and general health disorders. However, it has never been systematically investigated if these problems are associated with severity of semen quality impairment. Cross-sectional analysis of a first-time evaluation of 448 males of infertile couples attending an outpatient clinic from September 2010 to November 2015. In addition, 74 age-matched healthy, fertile men from an ultrasound study on male fertility were studied for comparison. All subjects underwent a complete physical, biochemical, scrotal and flaccid penile colour-Doppler ultrasound evaluation and semen analysis. Patients had already undergone at least one semen analysis; therefore, the majority were aware of their sperm quality before taking part in the study. Validated tools, such as the International Index of Sexual Function-15 (IIEF-15), Premature Ejaculation Diagnostic Tool (PEDT), Middlesex Hospital Questionnaire (MHQ), National Institutes of Health-Chronic Prostatitis Symptom Index (NIH-CPSI), International Prostate Symptom Score and Chronic Disease Score (CDS), were used to evaluate, respectively, sexual dysfunction, premature ejaculation (PE), psychopathological traits, prostatitis-like symptoms, lower urinary tract symptoms and general health status. Among men with couple infertility, 96 showed azoospermia (Group #1), 245 at least one sperm abnormality (Group #2) and 107 normozoospermia (Group #3). Fertile men were considered as a control group (Group #4). After adjusting for age, we observed a higher prevalence of ED (IIEF-15-erectile function domain score <26) (18.3% versus 0%; P = 0.006) and PE (PEDT score >8) (12.9% versus 4.1%; P = 0.036) in males of infertile couples compared with fertile men. The ED prevalence increases as a function of semen quality impairment severity (P < 0.0001), even after adjusting for confounders (age, CDS, MHQ and NIH-CPSI total score), despite similar hormonal, glyco-metabolic and penile vascular status. Compared to fertile men, all three groups of males with couple infertility showed a poorer erectile function, associated with an overall psychopathological burden (MHQ total score), particularly with somatized anxiety (MHQ-S). Azoospermic men showed the worst erectile function and general health: in this group, erectile function was negatively associated not only with psychopathological disturbances (MHQ total and MHQ-S scores; P < 0.0001) but also with a less healthy phenotype (higher CDS; P = 0.015). In addition, azoospermic men reported higher PE prevalence and lower sexual desire and orgasmic function when compared to fertile men (all P < 0.05), all of which were related to psychopathological symptoms. The cross-sectional nature of the study represents its main limitation. A possible selection bias concerning the control group of healthy, fertile men recruited into an ultrasound study might have occurred. Finally, causality cannot be inferred in this type of study design and hence there should be some caution in interpreting the results. Investigation of male sexual function, general health and psychological status in infertile couples, especially if azoospermic, is advisable, in order to improve not only reproductive but also general and sexual health. Grants were received from the Ministry of University and Scientific Research (SIR project to F.L., protocol number: RBSI14LFMQ). There are no conflicts of interest. None.

Lotti F ，Corona G ，Castellini G ，Maseroli E ，Fino MG ，Cozzolino M ，Maggi M ... -  《-》