Effect of recombinant human vascular endothelial growth factor on testis tissue xenotransplants from prepubertal boys: a three-case study

Research question Does recombinant human vascular endothelial growth factor (VEGF-165) improve the efficiency of human immature testis tissue (ITT) xenotransplantation? Design ITT fragments from three prepubertal boys were cultured for 5 days with VEGF-165 or without (control) before xenotransplantation into the testes of immunodeficient mice. Xenotransplants were recovered at 4 and 9 months after transplantation, and vascularization, seminiferous tubule integrity, number of spermatogonia and germ cell differentiation were evaluated by histology and immunohistochemistry. Results Transplants from donor 1 and donor 2 treated with VEGF demonstrated higher vascular surface (P = 0.004) and vessel density (P = 0.011) overall and contained more intact seminiferous tubules (P = 0.039) with time, compared with controls. The number of spermatogonia was increased over time (P < 0.001) irrespective of treatment and donor, whereas, for the VEGF-treated transplants, the increase was even higher over time (P = 0.020). At 9 months, spermatocytes were present in the xenotransplants, irrespective of treatment. No transplants could be recovered from donor 3, who had already received treatment with cyclosporine for aplastic anaemia before biopsy. Conclusions In-vitro pre-treatment of human prepubertal testis tissue with VEGF improved transplant vascularization in two out of three cases, resulting in improved seminiferous tubule integrity and spermatogonial survival during xenotransplantation. Although further studies are warranted, we suggest VEGF be considered as a factor for improving the efficiency of immature testis tissue transplantation in the future

Fertility preservation in childhood cancer: Endocrine activity in prepubertal human testis xenografts exposed to a pubertal hormone environment

Survivors of childhood cancer are at risk for long-term treatment-induced health sequelae, including gonadotoxicity and iatrogenic infertility. At present, for prepubertal boys there are no viable clinical options to preserve future reproductive potential. We investigated the effect of a pubertal induction regimen with gonadotrophins on prepubertal human testis xenograft development. Human testis tissue was obtained from patients with cancer and non-malignant haematological disorders (n = 6; aged 1&ndash;14 years) who underwent testis tissue cryopreservation for fertility preservation. Fresh and frozen-thawed testis fragments were transplanted subcutaneously or intratesticularly into immunocompromised mice. Graft-bearing mice received injections of vehicle or exogenous gonadotrophins, human chorionic gonadotrophin (hCG, 20 IU), and follicle-stimulating hormone (FSH, 12.5 IU) three times a week for 12 weeks. The gross morphology of vehicle and gonadotrophin-exposed grafts was similar for both transplantation sites. Exposure of prepubertal human testis tissue xenografts to exogenous gonadotrophins resulted in limited endocrine function of grafts, as demonstrated by the occasional expression of the steroidogenic cholesterol side-chain cleavage enzyme (CYP11A1). Plasma testosterone concentrations (0.13 vs. 0.25 ng/mL; p = 0.594) and seminal vesicle weights (10.02 vs. 13.93 mg; p = 0.431) in gonadotrophin-exposed recipient mice were comparable to vehicle-exposed controls. Regardless of the transplantation site and treatment, initiation and maintenance of androgen receptor (AR) expression were observed in Sertoli cells, indicating commitment towards a more differentiated status. However, neither exogenous gonadotrophins (in castrated host mice) nor endogenous testosterone (in intact host mice) were sufficient to repress the expression of markers associated with immature Sertoli cells, such as anti-M&uuml;llerian hormone (AMH) and Ki67, or to induce the redistribution of junctional proteins (connexin 43, CX43; claudin 11, CLDN11) to areas adjacent to the basement membrane. Spermatogonia did not progress developmentally but remained the most advanced germ cell type in testis xenografts. Overall, these findings demonstrate that exogenous gonadotrophins promote partial activation and maturation of the somatic environment in prepubertal testis xenografts. However, alternative hormone regimens or additional factors for pubertal induction are required to complete the functional maturation of the spermatogonial stem cell (SSC) niche

Spermatogonial stem cells as a source for regenerative medicine

Several researchers have reported the derivation of multipotent cells from both mouse and human spermatogonial stem cells. These spermatogonia-derived stem cells show similarities with embryonic stem cells both for phenotype and functionality, indicating that these cells may be a promising alternative source for stem-cell based therapies in regenerative medicine

Characterisation of testicular function and spermatogenesis in transgender women

STUDY QUESTION: Does gender-affirming treatment prevent full spermatogenesis in transgender women (TW)? SUMMARY ANSWER: Adequate hormonal therapy (Hi) leads to complete suppression of spermatogenesis in most TW, if serum testosterone levels within female reference ranges are obtained. WHAT IS KNOWN ALREADY: Gender-affirming treatment in transgender individuals may involve gender-affirming HT. The effects on spermatogenesis in TW remain unclear. In order to add information from a referral centre for transgender care, we wish to compare results of earlier studies with our population of TW who received a standard hormone treatment. STUDY DESIGN, SIZE, DURATION: This was a prospective cohort study part of the European Network for the Investigation of Gender Incongruence (ENIGI), conducted between 15 February 2010 and 30 September 2015. There were 162 NV were included in the ENIGI study at the Ghent University Hospital in Belgium. Participants are included in ENIGI when they first start HT, and follow-up visits occur over the next 3 years. PARTICIPANTS/MATERIALS, SETTING METHODS: The study included 97 TW who initiated HT with cyproterone acetate (CPA) plus oestrogens and proceeded with gonadectomy at the Ghent University Hospital. Testicular tissue retrieved during gonadectomy was processed and stained for four different germ cell markers by the Biology of the Testis lab at the Vrije Universiteit Brussel. Subsequent immunohistochemical staining was performed for melanoma-associated antigen A4 (MAGE-A4, marker for spermatogonia and early spermatocytes), boule homologue, RNA-binding protein (BOLL, marker for secondary spermatocytes and round spermatids), cAMP-responsive element modulator (CREM, marker for round spermatids) and acrosin (marker for acrosome visualization). Serum levels of sex steroids were measured prior to surgery. MAIN RESULTS AND THE ROLE OF CHANCE: Suppressed testosterone levels (<50 ng/dI) were found in 92% of the participants prior to surgery. The mean time between initiation of HT and surgery was 685 days. In 88% (85/97) of the sections, MAGE-A4 staining was positive. Further staining could not reveal complete spermatogenesis in any participant. LIMITATIONS, REASONS FOR CAUTION: Testicular function of the participants prior to initiation of HT was not assessed, although all participants presented with cisgender male serum testosterone values before initiation of HT. The current study only reports on people using CPA at a fixed dose and may therefore not be applicable to all TW. WIDER IMPLICATIONS OF THE FINDINGS: HT leads to complete suppression of spermatogenesis in most TW, if serum testosterone levels within female reference ranges are obtained. Serum testosterone levels are associated with the sperm maturation rate. It is important to discuss sperm preservation before the start of hormone therapy. If serum testosterone levels remain higher, spermatogenesis may still occur

Is the protein expression window during testicular development affected in patients at risk for stem cell loss?

studyquestion: Is the protein expression windowduring testicular development affected in prepubertal patients at risk for stem cell loss? summary answer: Nuclear ubiquitin carboxyl-terminal esterase L1 (UCHL1) expression in Sertoli cells and interstitial expression of inhibin a (INHA), sex-determining region Y-box 9 (SOX9) and steroidogenic acute regulatory protein (STAR) was affected in patients with Klinefelter syndrome. what is known already: Some patients undergoing testicular tissue banking have already been treated before the testis biopsy is taken. These treatments include chemotherapy or hydroxyurea, which can have an influence on the stem cell number and function. A germinal loss occurs in Klinefelter patients, but its cause is currently unknown. study design, size, duration: Parrafin-embedded testicular tissue from 5 fetuses, 25 prepubertal patients and 5 adultswas used to characterize the spatial and temporal distribution of different testicular marker proteins during testicular development. Expression of the markers was evaluated in germ cells, Sertoli cell and interstitial cells. The integrity of this time window was analyzed in patients at risk for germ cell loss: patients treated with hydroxyurea (n 7), patients treated with chemotherapy (n 6) and patients affected by Klinefelter syndrome (n 5). participants/materials, setting, methods: Immunohistochemistry was performed in normal fetal, prepubertal and adult testicular tissue to set up a timeline for the expression of melanoma antigen family A4 (MAGE-A4), ubiquitin carboxyl-terminal esterase L1 (UCHL1), octamer-binDing transcription factor 4 (OCT4), stage-specific embryonic antigen-4 (SSEA4), homeobox protein NANOG, INHA, anti-Müllerian hormone, androgen receptor (AR), SOX9 and STAR. The established timeline was used to evaluate whether the expression of these markers was altered in patients at risk for germ cell loss (patients treated for sickle cell disease (hydroxyurea) or cancer (chemotherapy) and patients with Klinefelter syndrome). main results and the role of chance: Aprotein expression timeline was created using different markers expressed in different testicular cell types. Less positive tubules and less positive cells per tubule were observed for MAGE-A4 and UCHL1 expression in the KS compared with the non-treated group (P ,0.01). Higher nuclear UCHL1 Sertoli cell expression was observed in the KS group compared with the non-treated group (P ,0.05). Higher interstitial expression of INHA (P ,0.05), SOX9 (P ,0.01) and STAR (P ,0.05) was observed in KS compared with the non-treated group. limitations, reasons for caution: Important age variations exist in the prepubertal groups. Therefore, datawere represented in three age groups. However, owing to the limited access to prepubertal tissue, no statistical comparison was possible between these groups. For the Klinefelter group, tissue was only available from patients older than 12 years. wider implications of the findings: The expression timeline can add knowledge to the process of spermatogenesis and be used to evaluate altered protein patterns in patients undergoing potentially gonadotoxic treatments, to monitor spermatogenesis established in vitro and to unravel causes of germ cell loss in Klinefelter patients.SCOPUS: ar.jSCOPUS: ar.jinfo:eu-repo/semantics/publishe