Wyns C, Abu-Ghannam G, Poels J
Service de gynécologie-andrologie, cliniques universitaires Saint-Luc, avenue Hippocrate, 10, 1200 Bruxelles, Belgique.
Gynecol Obstet Fertil. 2013 Sep;41(9):558-61. doi: 10.1016/j.gyobfe.2013.07.005. Epub 2013 Aug 16.
Preservation of reproductive health is a major concern for patient long-term quality of life. While sperm freezing has proven to be effective to preserve fertility after puberty, cryopreservation of immature testicular tissue (ITT) is emerging as a promising approach for fertility preservation in young boys. Slow-freezing (SF) is the conventional method used to preserve ITT and has resulted in the birth of mice offspring. In humans, methods to preserve ITT are still at the research stage. Controlled SF using dimethyl sulfoxide showed preservation of proliferative spermatogonia after thawing in a xenotransplantation model used to evaluate the efficiency of freezing and thawing procedures. However, spermatogonial recovery was low and normal differentiation could not be achieved. Both freezing/thawing and the environment of the xenotransplantation model may be implicated. Indeed, with SF, ice crystal formation could damage tissue and cells. For this reason, vitrification, leading to solidification of a liquid without crystallization, may be a promising alternative. ITT vitrification has been investigated in different species and shown spermatogonial survival and differentiation to the round or elongated spermatids stage. Offspring were also recently obtained after vitrification and allotransplantation in avians, confirming the potential of vitrification for fertility preservation. In humans, vitrification appears to be as efficient as SF in terms of spermatogonial survival and initiation of differentiation after xenotransplantation. However, before validation of such fertility preservation methods, completion of normal spermatogenesis and the fertilization capacity of sperm retrieved from cryopreserved and transplanted tissue should be fully investigated.
生殖健康的保护是患者长期生活质量的主要关注点。虽然精子冷冻已被证明在青春期后保留生育能力方面有效，但未成熟睾丸组织（ITT）的冷冻保存正成为年轻男孩生育力保存的一种有前景的方法。慢速冷冻（SF）是用于保存ITT的传统方法，并已使小鼠后代出生。在人类中，保存ITT的方法仍处于研究阶段。在用于评估冷冻和解冻程序效率的异种移植模型中，使用二甲亚砜进行的控制性SF显示解冻后增殖性精原细胞得以保存。然而，精原细胞的恢复率较低，无法实现正常分化。冷冻/解冻以及异种移植模型的环境可能都有影响。事实上，采用SF时，冰晶形成可能会损害组织和细胞。因此，玻璃化（导致液体固化而不结晶）可能是一种有前景的替代方法。已在不同物种中对ITT玻璃化进行了研究，并显示精原细胞存活并分化至圆形或延长型精子细胞阶段。最近在禽类中经玻璃化和同种异体移植后也获得了后代，证实了玻璃化在生育力保存方面的潜力。在人类中，就异种移植后精原细胞存活和分化启动而言，玻璃化似乎与SF一样有效。然而，在验证此类生育力保存方法之前，应充分研究从冷冻保存和移植组织中获取的精子完成正常精子发生和受精能力的情况。
