Vitamin A prevents round spermatid nuclear damage and promotes the production of motile sperm during in vitro maturation of vitrified pre-pubertal mouse testicular tissue.

STUDY QUESTION: Does vitamin A (retinol, Rol) prevent round spermatid nuclear damage and increase the production of motile sperm during in vitro maturation of vitrified pre-pubertal mouse testicular tissue? SUMMARY ANSWER: The supplementation of an in vitro culture of ~0.75 mm3 testicular explants from pre-pubertal mice with Rol enhances spermatogenesis progression during the first spermatogenic wave. WHAT IS KNOWN ALREADY: The production of functional spermatozoa in vitro has only been achieved in the mouse model and remains a rare event. Establishing an efficient culture medium for vitrified pre-pubertal testicular tissue is now a crucial step to improve the spermatic yield obtained in vitro. The role of Rol in promoting the differentiation of spermatogonia and their entry into meiosis is well established; however, it has been postulated that Rol is also required to support their full development into elongated spermatids. STUDY DESIGN, SIZE, DURATION: A total of 60 testes from 6.5 days post-partum (dpp) mice were vitrified/warmed, cut into fragments and cultured for 30 days: 20 testes were used for light microscopy and histological analyses, 20 testes for DNA fragmentation assessment in round spermatids and 20 testes for induced sperm motility assessment. Overall, 16 testes of 6.5 dpp were used as in vitro fresh tissue controls and 12 testes of 36.5 dpp mice as in vivo controls. Testes were vitrified with the optimal solid surface vitrification procedure and cultured with an in vitro organ culture system until Day 30 (D30). Histological analysis, cell death, degenerating round spermatids, DNA fragmentation in round spermatids and induced sperm motility were assessed. Testosterone levels were measured in media throughout the culture by radioimmunoassay. MAIN RESULTS AND THE ROLE OF CHANCE: At D30, better tissue development together with higher differentiation of spermatogonial stem cells, and higher global cell division ability were observed for vitrified/warmed testicular fragments of ~0.75 mm3 with a culture medium supplemented with Rol compared to controls. During in vitro culture of vitrified pre-pubertal testicular tissue, Rol enhanced and maintained the entry of spermatogonia into meiosis and promoted a higher spermatic yield. Furthermore, decreased round spermatid nuclear alterations and DNA damage combined with induced sperm motility comparable to in vivo highlight the crucial role of Rol in the progression of spermatogenesis during the first wave. LIMITATIONS, REASONS FOR CAUTION: Despite our promising results, the culture media will have to be further improved and adapted within the context of a human application. WIDER IMPLICATIONS OF THE FINDINGS: The results have potential implications for the handling of human pre-pubertal testicular tissues cryopreserved for fertility preservation. However, because some alterations in round spermatids persist after in vitro culture with Rol, the procedure needs to be optimized before human application, bearing in mind that the murine and human spermatogenic processes differ in many respects. LARGE SCALE DATA: None. STUDY FUNDING AND COMPETING INTERESTS: This study was supported by a Ph.D. grant from the Normandy University and a financial support from 'la Ligue nationale contre le cancer' (both awarded to L.D.), funding from Rouen University Hospital, Institute for Research and Innovation in Biomedicine (IRIB) and Agence de la Biomédecine. The authors declare that there is no conflict of interest.

Assessment of the optimal vitrification protocol for pre-pubertal mice testes leading to successful in vitro production of flagellated spermatozoa.

Testicular tissue cryopreservation offers the hope of preserved future fertility to pre-pubertal boys with cancer before exposition to gonadotoxic treatments. The objective of this study was to compare controlled slow freezing (CSF) with five vitrification techniques for cryopreservation of murine pre-pubertal testicular tissue and to evaluate the best protocol that could provide a successful completion of spermatogenesis after in vitro maturation. Testicular tissue from 24 mice at 6.5 days post-partum (dpp) was used to compare several vitrification protocols with one another, as well as with a CSF protocol. Toxicity test using additional 12 mice was performed for all cryopreservation solutions. Fresh tissue (FT) from six mice was used as a control. Once the optimal vitrification protocol was selected [the modified solid surface vitrification No. 1 (mSSV1 )], testes from 18 mice were cultured in vitro for 30 days with (i) fresh, (ii) slow-frozen/thawed and (iii) vitrified/warmed tissues. Testes from six mice at 36.5 dpp were used as controls. At day 30 of in vitro culture, germ cells of the seminiferous tubules showed a high ability to proliferate and elongated spermatids were observed after both freezing techniques, confirming the successful completion of in vitro spermatogenesis. However, after mSSV1 , the morphological alterations and the percentage of pyknotic seminiferous tubules were lower than CSF (4.67 ± 0.53 vs. 10.1 ± 1.12 and 22.7 ± 2.83% vs. 37.3 ± 4.24% respectively). Moreover, the number of flagellated spermatozoa produced per mg of tissue was higher for mSSV1 than for CSF (35 ± 3 vs. 9 ± 4 cells), with amounts of secreted testosterone during the culture close to those of FT. The mSSV1 protocol resulted in success rates better than CSF in maintaining testicular tissue structure, tubular morphology and tissue functions not solely for immediate frozen/thawed tissues but also after a long-term in vitro culture.

[In vitro spermatogenesis new horizon to restore fertility?]. / Spermatogenèse in vitro nouvel horizon pour restaurer la fertilité ?

The survival of the young boy after cancer has considerably progressed in recent years due to the efficiency of chemo/radiotherapy against the tumor cells. However, this treatment causes adverse effects on healthy tissues, including fertility. Freezing testicular tissue before highly gonadotoxic treatment is a prerequisite for preserving fertility in prepubertal boys that do not produce sperm yet. But which strategy proposes to restore fertility from frozen-thawed testicular tissue? One potential solution would be to consider an in vitro maturation of spermatogonial stem cells. In this article we trace the chronological development of in vitro spermatogenesis that resulted in mouse sperm production in vitro and give an overview of new challenges for the future.

The feasibility of fertility preservation in adolescents with Klinefelter syndrome.

STUDY QUESTION: Is fertility preservation feasible after the onset of puberty in adolescents with Klinefelter syndrome (KS)? SUMMARY ANSWER: Fertility preservation counseling should be an integral part of the care of XXY adolescents. Frozen ejaculated or testicular spermatozoa and even frozen immature germ cells can give them the potential to conceive their genetic progeny. However, no biological or clinical parameters were predictive of mature or immature germ cell retrieval. WHAT IS KNOWN ALREADY: KS is the commonest sex chromosome disorder observed in azoospermic infertile males. Testicular sperm extraction success decreases with age and after testosterone therapy. Arguably, spermatozoa should be retrieved from KS males at the onset of puberty and before testosterone therapy to increase the chance of success. STUDY DESIGN, SIZE, DURATION: A retrospective study was performed in eight KS adolescents, aged between 15 and 17 years, who were referred for counseling about their future fertility to the center CECOS (Centre d'Etude et de Conservation des Oeufs et du Sperme humain) at Rouen University Hospital between October 2008 and December 2011. PARTICIPANTS/MATERIALS, SETTING, METHODS: The patients were first seen with their parents and then separately. It was proposed to them that they should provide a semen sample, if this was azoospermic, two other semen samples spaced by 3 months were collected. If azoospermia was confirmed, a bilateral testicular biopsy was proposed for sperm retrieval and testicular tissue preservation. Each adolescent met the psychologist before undergoing testicular biopsy. Paraffin-embedded testicular tissue was evaluated after staining with hematoxylin-eosin and saffron and immunostaining using vimentin, anti-Müllerian hormone, androgen receptor and MAGE-A4 antibodies. Sertoli cell maturity, germ cell identification and lamina propria alteration were assessed on seminiferous tubules. MAIN RESULTS AND THE ROLE OF CHANCE: KS adolescents were not deeply concerned about their future fertility and only became involved in the process of fertility preservation after at least three medical consultations. The parents agreed immediately that fertility preservation should be attempted. Seven non-mosaic XXY adolescents presented with azoospermia and one XXY/XY adolescent had oligozoospermia. Increased plasma levels of FSH and LH as well as bilateral testicular hypotrophy were observed in all patients. The XXY/XY adolescent banked four semen samples before testosterone replacement therapy. Two patients refused testicular biopsy. Five patients accepted a bilateral testicular biopsy. Spermatozoa were retrieved in one patient, elongated spermatids and spermatocytes I in a second patient. LIMITATIONS, REASONS FOR CAUTION: The number of patients enrolled in our study was low because the diagnosis of KS is only rarely made before or at the onset of puberty. Most XXY males are diagnosed in adulthood within the context of male infertility. WIDER IMPLICATIONS OF THE FINDINGS: Spermatozoa can be retrieved in semen sample and in testicular tissue of adolescent Klinefelter patients. Furthermore, the testis may also harbor spermatogonia and incompletely differentiated germ cells. However, the physician should discuss with the patient and his parents over a period of several months before collecting a semen sample and performing bilateral testicular biopsy. Fertility preservation might best be proposed to adolescent Klinefelter patients just after the onset of puberty when it is possible to collect a semen sample and when the patient is able to consider alternative options to achieve fatherhood and also to accept the failure of spermatozoa or immature germ cell retrieval.

[Male gamete spermatozoon or spermatid?]. / Gamète mâle un spermatozoïde ou une spermatide?

Normal spermatogenesis results from a balance between process of cell proliferation, cell differentiation and apoptosis that concern somatic cells and germ cells. Dysfunction of spermatogenesis may be the result of constitutional or acquired abnormalities of spermatogonia stem cells or somatic cells. To overcome these problems, it seems necessary to implement preventive measures for germ stem cell preservation or substitute measures to replace them, the objective being to replicate in vivo or in vitro the process of spermatozoa production. This article will discuss the different experimental strategies for considering the in vivo or in vitro production of spermatozoa, outside the physiological process.

Assessment of freezing procedures for rat immature testicular tissue.

Fertility preservation has been included in the management of childhood cancer treatment. Cryopreservation of immature testicular tissue is the only available solution for pre-pubertal boys. Different freezing protocols have been developed in several species but without a clearly identified procedure. We tried to evaluate several protocols for cryopreservation of rat immature testicular tissue. Twelve different freezing protocols using different (i) cryoprotectant (dimethylsulphoxide [DMSO] or 1,2-propanediol [PROH]), (ii) cryoprotectant concentration (1.5M or 3M), (iii) equilibration time (30 or 60 min), (iv) equilibration temperature (4 °C or room temperature), (v) size of testicular fragment (7.5mg or 15 mg), (vi) package (straws or cryovials), were compared using cord morphological damage evaluation. A testicular tissue piece of 7.5mg cryopreserved in cryovial using 1.5M DMSO, an equilibration time of 30 min at 4 °C showed fewer morphological alterations than the other protocols tested. The selected freezing protocol was able to maintain rat immature testicular tissue architecture, functionality after testicular pieces organotypic culture, and could be proposed in a human application.

Percutaneous internal fixation combined with kyphoplasty for neurologically intact thoracolumbar fractures: a prospective cohort study of 24 patients with one year of follow-up.

INTRODUCTION AND HYPOTHESIS: Neurologically intact lumbar and thoracolumbar fractures are frequent but their treatment is not codified. The purpose of this study was to evaluate the effectiveness of minimally invasive treatment of such fractures by percutaneous fixation associated with balloon kyphoplasty. PATIENTS AND METHODS: Between November 2008 and July 2010, 24 patients were treated. There were 12 men and 12 women, with a mean age of 53 years (range 20-88 years). Fractures were classified as one Magerl lesion type A1, one type A2, 19 A3 (five A31, 10 A32, four A33), and three type B2. The treatment was kyphoplasty of the fractured vertebra followed by percutaneous fixation of the vertebra above and below the fracture. Patient follow-up included an analysis of pain using the visual analogic score, the Oswestry score, and functional X-ray and CT analysis. RESULTS: Surgery lasted a mean 99 minutes. At the last follow-up, the mean pain was scored at 0.9 and the Oswestry score was 13.2. Reduction of vertebral kyphosis was 8.6° and reduction of the corrected regional angle was 7.1°. The gain in vertebral height was 17%. All pedicle screws were positioned correctly and no neurological, septic, or thromboembolic complications were observed. DISCUSSION AND CONCLUSION: Percutaneous osteosynthesis combined with balloon kyphoplasty is a valuable surgical technique in the treatment of thoracolumbar and lumbar fractures with no neurologic deficit. The clinical results are good and the technique allows the patient to return home earlier without having to wear a corset. The X-ray result scores are very encouraging, with corrections similar to conventional surgery in terms of vertebral height and kyphosis. This technique can be an alternative to conventional open surgery. LEVEL OF EVIDENCE: IV: Prospective observational study.

Rapid screening of cryopreservation protocols for murine prepubertal testicular tissue by histology and PCNA immunostaining.

Numerous parameters have to be tested to identify optimal conditions for prepubertal testicular tissue banking. Our study evaluated 19 different cryopreservation conditions for immature testicular tissue using a rapid screening method. Immature mice testes were cryopreserved using either 1,2-propanediol (PROH) or dimethyl sulfoxide (DMSO) at a concentration of 0.75 or 1.5 M using a controlled slow-cooling rate protocol with (S+) or without seeding (S+). Equilibration was performed either at room temperature or at 4°C for 15 or 30 minutes. Seminiferous cord cryodamage was determined by scoring morphologic alterations. Cell proliferation ability was evaluated using a proliferating cell nuclear antigen (PCNA) antibody. Testes cryopreserved with optimal conditions were grafted into immunodeficient mice. The highest proportions of PCNA-positive nuclei and lowest morphologic alterations were observed with 1.5 M DMSO. Tissues were more altered with 0.75 M DMSO or PROH. Complete germ cell maturation was observed after allografting of testicular pieces previously frozen with 1.5 M DMSO, S+, 30 minutes. The 1.5 M DMSO, S+ or S+ protocol preserved prepubertal mice testicular tissue architecture and germ cell and Sertoli cell proliferation potential. Allografting of thawed testis fragments into immunodeficient mice confirmed that the 1.5 M DMSO, S+, 30 minutes protocol maintained testicular somatic and germ cell functions. Postthaw histologic evaluation and PCNA immunostaining are useful to rapidly test numerous freeze-thaw parameters. They may also be efficient tools to control human prepubertal frozen testis quality, within the context of a clinical application.