Hutka Marsida, Kadam Prashant, Van Saen Dorien, Homer Natalie Z M, Onofre Jaime, Wallace W Hamish B, Smith Lee B, Stukenborg Jan-Bernd, Goossens Ellen, Mitchell Rod T
Medical Research Council (MRC) Centre for Reproductive Health, The University of Edinburgh, The Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh EH16 4TJ, UK.
Biology of the Testis, Research Laboratory for Reproduction, Genetics and Regenerative Medicine, Vrije Universiteit Brussel (VUB), Laarbeeklaan 103, 1090 Brussels, Belgium.
Cancers (Basel). 2020 Sep 30;12(10):2830. doi: 10.3390/cancers12102830.
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 ( = 6; aged 1-14 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; = 0.594) and seminal vesicle weights (10.02 vs. 13.93 mg; = 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-Müllerian 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.
儿童癌症幸存者面临长期治疗导致的健康后遗症风险，包括性腺毒性和医源性不育。目前，对于青春期前男孩，尚无可行的临床方法来保留未来的生殖潜力。我们研究了促性腺激素青春期诱导方案对青春期前人睾丸异种移植发育的影响。人睾丸组织取自患有癌症和非恶性血液疾病的患者（n = 6；年龄1 - 14岁），这些患者为保留生育能力而进行了睾丸组织冷冻保存。将新鲜和冻融后的睾丸片段皮下或睾丸内移植到免疫受损小鼠体内。携带移植组织的小鼠每周接受三次载体或外源性促性腺激素注射，即人绒毛膜促性腺激素（hCG，20 IU）和促卵泡激素（FSH，12.5 IU），共注射12周。对于两个移植部位，载体处理组和促性腺激素处理组移植组织的大体形态相似。青春期前人睾丸组织异种移植暴露于外源性促性腺激素后，移植组织的内分泌功能有限，这通过类固醇生成胆固醇侧链裂解酶（CYP11A1）的偶尔表达得以证明。促性腺激素处理组受体小鼠的血浆睾酮浓度（0.13 vs. 0.25 ng/mL；P = 0.594）和精囊重量（10.02 vs. 13.93 mg；P = 0.431）与载体处理组对照组相当。无论移植部位和处理如何，在支持细胞中均观察到雄激素受体（AR）表达的起始和维持，表明其朝着更分化状态发展。然而，无论是外源性促性腺激素（在去势宿主小鼠中）还是内源性睾酮（在完整宿主小鼠中），都不足以抑制与未成熟支持细胞相关的标志物表达，如抗苗勒管激素（AMH）和Ki67，也不足以诱导连接蛋白（连接蛋白43，CX43；闭合蛋白11，CLDN11）重新分布到基底膜附近区域。精原细胞未发生发育进展，而是在睾丸异种移植中保持为最成熟的生殖细胞类型。总体而言，这些发现表明外源性促性腺激素可促进青春期前睾丸异种移植中体细胞环境的部分激活和成熟。然而，需要替代激素方案或其他青春期诱导因素来完成精原干细胞（SSC）微环境的功能成熟。
