Genetic analyses of a large cohort of infertile patients with globozoospermia, DPY19L2 still the main actor, GGN confirmed as a guest player

Globozoospermia is a rare phenotype of primary male infertility inducing the production of round-headed spermatozoa without acrosome. Anomalies of DPY19L2 account for 50-70% of all cases and the entire deletion of the gene is by far the most frequent defect identified. Here, we present a large cohort of 69 patients with 20-100% of globozoospermia. Genetic analyses including multiplex ligation-dependent probe amplification, Sanger sequencing and whole-exome sequencing identified 25 subjects with a homozygous DPY19L2 deletion (36%) and 14 carrying other DPY19L2 defects (20%). Overall, 11 deleterious single-nucleotide variants were identified including eight novel and three already published mutations. Patients with a higher rate of round-headed spermatozoa were more often diagnosed and had a higher proportion of loss of function anomalies, highlighting a good genotype phenotype correlation. No gene defects were identified in patients carrying < 50% of globozoospermia while diagnosis efficiency rose to 77% for patients with > 50% of globozoospermia. In addition, results from whole-exome sequencing were scrutinized for 23 patients with a DPY19L2 negative diagnosis, searching for deleterious variants in the nine other genes described to be associated with globozoospermia in human (C2CD6, C7orf61, CCDC62, CCIN, DNAH17, GGN, PICK1, SPATA16, and ZPBP1). Only one homozygous novel truncating variant was identified in the GGN gene in one patient, confirming the association of GGN with globozoospermia. In view of these results, we propose a novel diagnostic strategy focusing on patients with at least 50% of globozoospermia and based on a classical qualitative PCR to detect DPY19L2 homozygous deletions. In the absence of the latter, we recommend to perform whole-exome sequencing to search for defects in DPY19L2 as well as in the other previously described candidate genes.

Cryopreservation of Oocytes Retrieved from Ovarian Tissue to Optimize Fertility Preservation in Prepubertal Girls and Women

Human ovarian tissue cryopreservation (OTC) is increasingly used worldwide to preserve female fertility in prepubertal girls and women at risk of premature ovarian insufficiency (POI) in the context of urgent gonadotoxic treatments or ovarian surgery. Fertility preservation is challenging because there is no consensus regarding patient management, preservation fertility strategies, or even technical laboratory protocols, which implies that each procedure must be adapted to the characteristics of the patient profile and its own risk-benefit ratio. During OTC, mature/immature oocytes can be aspirated directly from large/small antral follicles within ovarian tissue samples and/or be released into culture media from growing follicles during ovarian tissue dissection in prepubertal girls and women. In this manuscript, we present a protocol that combines ovarian tissue freezing with the cryopreservation of mature/immature oocytes retrieved from ovarian tissue samples, improving the reproductive potential of fertility preservation. Appropriate collection, handling, and storage of ovarian tissue and oocytes before, during, and after the cryopreservation will be described. The subsequent use and safety of cryopreserved/thawed ovarian tissue samples and oocytes will also be discussed, as well as the optimal timing for in vitro maturation of immature oocytes. We recommend the systematic use of this protocol in fertility preservation of prepubertal girls and women as it increases the whole reproductive potential of fertility preservation (i.e., oocyte vitrification in addition of OTC) and also improves the safety and use of fertility preservation (i.e., thawing of oocytes versus ovarian graft), maximizing the chance of successful childbirth for the patients at risk of POI.

Prokineticin 1 is a new biomarker of human oocyte competence: expression and hormonal regulation throughout late folliculogenesis

CONTEXT

Prokineticin 1 (PROK1) quantification in global follicular fluid (FF) has been recently reported as a predictive biomarker of in vitro fertilization (IVF) outcome. It is now necessary to evaluate its clinical usefulness in individual follicles.

OBJECTIVES

To evaluate the clinical value of PROK1 secretion in individual FF to predict oocyte competence. To determine the impact of follicular size, oocyte maturity, and gonadotropin treatments on PROK1 secretion.

DESIGN AND SETTING

Prospective cohort study from May 2015 to May 2017 at the University Hospital of Grenoble.

PATIENTS

A total of 69 infertile couples underwent IVF.

INTERVENTION(S)

Collection of 298 individual FF from 44 women undergoing IVF; 52 individual cumulus cell (CC) samples and 15 CC primary cultures from 25 women undergoing IVF-intracytoplasmic sperm injection (ICSI).

MAIN OUTCOME MEASURE(S)

Oocyte competence was defined as the ability to sustain embryo development to the blastocyst stage. Follicular size was measured by 2D-sonography. PROK1 concentration was quantified by ELISA assay.

RESULTS

PROK1 concentration was correlated to follicular size (r = 0.85, P = 2.2 × 10-16). Normalized PROK1 concentration in FF was predictive of subsequent oocyte competence (AUROC curve = 0.76 [95% CI, 0.69-0.83]; P = 1.7 × 10-9), irrespectively of day-2 embryo morphokinetic parameters. The expression and secretion of PROK1 were increased in FF and CC of mature oocytes (P < 0.01). Follicle Stimulating Hormone and hCG up-regulated PROK1 secretion in CC primary cultures (P < 0.01; P < 0.05), probably through the cAMP pathway (P < 0.01).

CONCLUSIONS

PROK1 quantification in individual FF could constitute a new predictive biomarker of oocyte competence in addition with embryo morphokinetic parameters.

TRIAL REGISTRATION NUMBER

none.

Is sperm FISH analysis still useful for Robertsonian translocations? Meiotic analysis for 23 patients and review of the literature

Background

Robertsonian translocations (RobT) are common structural chromosome rearrangements where carriers display a majority of chromosomally balanced spermatozoa from alternate segregation mode. According to some monotony observed in the rates of balanced segregation, is sperm FISH analysis obsolete for RobT carriers?

Methods

Retrospective cohort research study on 23 patients analyzed in our center from 2003 to 2017 and compared to the data of 187 patients in literature from 1983 to 2017.

Robertsonian translocation carriers were divided in six groups according to the chromosomes involved in the translocation: 9 patients from our center and 107 from literature carrying 45,XY,der(13;14) karyotype, 3 and 35 patients respectively with 45,XY,der(14;21), 5 and 11 patients respectively with 45,XY,der(13;15), 4 and 7 patients respectively with 45,XY,der(14;15), 1 and 4 patients respectively with 45,XY,der(13;22),and 1 and 10 patients respectively with 45,XY,der(14;22).

Results

Alternate segregation mode is predominant in our group of Robertsonian translocation carriers with 73.45% ±8.05 of balanced spermatozoa (min 50.92%; max 89.99%). These results are compliant with the data from literature for all translocations types (p > 0.05) and are consistent among the different types of Robertsonian translocations (p > 0.05) except for der(13;15) that exhibit lower balanced spermatozoa rates (p < 0.05 versus der(13;14), der(14;21), (13;21) and der(15;22)). Normozoospermic patients also display a significantly (p < 0.01) higher rate of balanced sperm cells than patients with abnormal seminograms whatever the defect implied.

Conclusions

According to the discrepancies observed between der(13;15) and all the other Rob T carriers, the differences observed among patients presenting normal and abnormal sperm parameters and the input in genetical counselling, sperm FISH does not seem obsolete for these patients. Moreover, it seems important to collect more data for rare RobT.

Spermaurin, an La1-like peptide from the venom of the scorpion Scorpio maurus palmatus, improves sperm motility and fertilization in different mammalian species

STUDY QUESTION

Is it possible to identify original compounds that are able to enhance sperm motility from the venom of the scorpion Scorpio maurus palmatus?

SUMMARY ANSWER

We identified a potent disulfide-rich peptide (DRP) of 73 amino acids that significantly improved the motility of fresh and frozen-thawed sperm in different mammalian species, including human, and improved fertilization outcome in mouse IVF experiments.

WHAT IS KNOWN ALREADY

Any disturbance of sperm motility has a strong impact on fertilization and can lead to subfertility or infertility. Significant efforts have, therefore,  been made to identify pharmacological drugs that might improve sperm motility. Such compounds are particularly useful in azoospermia to improve testicular sperm extraction and in the domain of cryopreservation because the motility of frozen-thawed sperm is reduced.

STUDY DESIGN, SIZE, DURATION

This was a basic science/medical research study aimed at identifying original compounds from a library of venoms able to enhance mammalian sperm motility, including human. We first identified in the venom of a scorpion S. m. palmatus a fraction able to potently activate sperm motility. We next purified and characterized the compound by liquid chromatography, mass spectrometry and peptide synthesis. Finally, the potency and toxicity of both purified and synthetic versions of the identified compound on sperm motility were assessed using different in vitro tests in different mammalian species.

PARTICIPANTS/MATERIALS, SETTING, METHODS

For human sperm, biological samples were collected from normozoospermic donors and subfertile patients attending a reproduction department for diagnostic semen analysis. Testicular sperm was collected from cynomolgus monkeys (Macaca fascicularis) euthanized for the needs of specific authorized research projects. The peptide was also tested on bovine and mouse epidydimal sperm. We measured different sperm motility parameters with a computer-assisted sperm analysis system in the presence or absence of the peptide.

MAIN RESULTS AND THE ROLE OF CHANCE

Size exclusion chromatography enabled us to isolate a fraction of the venom of S. m. palmatus able to increase sperm motility. By liquid chromatography and mass spectrometry, a peptide comprising 73 amino acids with 4 disulfide bridges was identified as responsible for the biological activity and called 'spermaurin'. The identity of spermaurin was confirmed by chemical synthesis. We showed that the peptide increased the motility of fresh and frozen-thawed human sperm. We observed that the potency of the peptide was higher on fresh ejaculated spermatozoa with a low motility, achieving a 100% increase of curvilinear velocity in poorly performing sperm. We also demonstrated that peptide is effective on bovine and mouse fresh epididymal, bovine frozen-thawed ejaculated and fresh non-human primate testicular sperm. Finally, in mouse IVF, the production of 2-cell embryos was increased by 24% when sperm were treated with the peptide.

LIMITATIONS, REASONS FOR CAUTION

This work is an in vitro evaluation of the ability of spermaurin to improve sperm motility parameters. Another limitation of this study is the small number of human sperm samples tested with the natural (n = 36) and synthetic (n = 12) peptides. Moreover, the effect of the peptide on IVF outcome was only tested in mouse and further tests with human and bovine gametes are required to confirm and extend this result in other mammalian species.

WIDER IMPLICATIONS OF THE FINDINGS

This work confirms our initial study showing that venoms represent an interesting source of molecules that are able to modify sperm physiology. Moreover, this work presents the first demonstrated biological action of a venom peptide from the scorpion S. m. palmatus with sequence similarities to La1 peptide from Liocheles australasiae (Wood scorpion), a widespread family of DRPs.

LARGE SCALE DATA

Not applicable.

STUDY FUNDING/COMPETING INTEREST(S)

This work is part of the project 'LAB COM-14 LAB7 0004 01-LIPAV', funded by the program LabCom 2014 from the French Research Agency (ANR). Dr Arnoult reports grants from IMV Technologies during the conduct of the study. In addition, Drs Arnoult, Martinez, Ray and Schmitt have a patent EP16305642.7 pending containing some of the information presented in this manuscript.

PROK1 Level in the Follicular Microenvironment: A New Noninvasive Predictive Biomarker of Embryo Implantation

CONTEXT

Prokineticin 1 (PROK1), also called endocrine gland-derived vascular endothelial growth factor, is a well-established regulator of endometrial receptivity and placental development. However, its clinical usefulness as a noninvasive predictive biomarker of embryo implantation is yet to be validated.

OBJECTIVE

The main objective of this article was to determine the relationship between PROK1 levels in the follicular fluid (FF) and fertilization culture media (FCM) and the reproductive outcome in patients who received a first conventional in vitro fertilization-embryo transfer. The secondary objective was to characterize the expression of PROK1 and its receptors (PROKRs) in the human follicular microenvironment.

DESIGN AND SETTING

We conducted a prospective study between January 2013 and June 2015 at the University Hospital of Grenoble.

PATIENTS

A total of 135 infertile in vitro fertilization patients and 10 women undergoing ovarian tissue cryopreservation were included.

INTERVENTIONS

The PROK1 concentration was measured by ELISA in FF and FCM collected on the day of oocyte retrieval and the day of the oocyte denudation step, respectively. Follicular expression of the PROK1/PROKR system was determined by immunohistochemistry, RT-quantitative PCR, and ELISA.

MAIN OUTCOME MEASURE

Assessment of the clinical pregnancy rates was the main outcome.

RESULTS

FF and FCM PROK1 levels were significantly higher in the embryo implantation group (P < .001) and were predictive of subsequent embryo implantation (area under the receiver operating characteristic curve, 0.91 [95% confidence interval, 0.81-1.00], P = .001; and 0.88 [0.72-1.00], P = .001, respectively). FF and FCM PROK1 levels remain similar irrespective of the embryo morphokinetic parameters (P = .71 and P = .83, respectively). The PROK1/PROKR system is expressed during human folliculogenesis.

CONCLUSIONS

PROK1 levels in FF and FCM could constitute new predictive noninvasive markers of successful embryo implantation in conventional in vitro fertilization-embryo transfer.

In cryptozoospermia or severe oligozoospermia is sperm freezing useful?

Background

Intracytoplasmic Sperm Injection (ICSI) is an Assisted Reproduction Technique (ART) which offers the chance to conceive to patients presenting very low sperm counts (cryptozoospermia/severe oligozoospermia). Sperm freezing before the oocyte pick-up, can prevent from a lack of spermatozoa on the day of the ICSI. It can avoid the cancellation of the ICSI or the use of TESE (Testicular sperm extraction). The objective of this study was to analyse the practice of sperm freezing for these patients in our center over 8 years and the rate of use of these frozen sperms. We also compared the outcome of ICSIs with frozen versus ejaculated sperm.

Material and methods

We performed a retrospective epidemiological study between 2004 and 2011. We recruited all the patients having a sperm count below 1 Million/mL and who were waiting for their first ICSI attempt.

Results

169 patients were recruited: 84 cryopreserved their sperm before the ICSI (secured ICSI) while 85 did not (non-secured ICSI). Both groups were split in cryptozoospermia (<10³ spermatozoa/ml): 19 and 17 patients respectively, very severe oligozoospermia (10³–10⁵/ml): 37 and 13 patients, and severe oligozoospermia (10⁵–10⁶/ml): 28 and 55 patients. The part of secured ICSI significantly increased from 29% during 2004–2007 to 74% during 2008–2011(p = 0.0029) and the frozen sperm was used in 5.9% of the cases. Median age was significantly higher in the non secured ICSI group (33.57 vs 35.52 for men, p = 0.0069 and 30.45 vs 32.26 for women, p = 0.025) but no significant difference was found in the outcome of the ICSI between frozen-thawed sperm and fresh ejaculated sperm.

Conclusion

Sperm freezing before ICSI for severe oligozoospermic and cryptozoospermic patients significantly increased in our practice but the rate of use remain very low. This encourages to define more accurate criteria leading to sperm freezing.

Electronic supplementary material

The online version of this article (doi:10.1186/2051-4190-24-15) contains supplementary material, which is available to authorized users.