Unitat de Biologia Cel·lular i Genètica Mèdica, Departament de Biologia Cel·lular, Fisiologia i Immunologia, Facultat de Medicina, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.
Genes (Basel). 2019 Jan 31;10(2):105. doi: 10.3390/genes10020105.
Reproductive diseases have become a growing worldwide problem and male factor plays an important role in the reproductive diagnosis, prognosis and design of assisted reproductive treatments. Sperm cell holds the mission of carrying the paternal genetic complement to the oocyte in order to contribute to an euploid zygote with proper DNA integrity. Sperm DNA fragmentation had been used for decades as a male fertility test, however, its usefulness have arisen multiple debates, especially around Intracytoplasmic Sperm Injection (ICSI) treatments. In the recent years, it has been described that different types of sperm DNA breaks (single and double strand DNA breaks) cause different clinical reproductive effects. On one hand, single-strand DNA breaks are present extensively as a multiple break points in all regions of the genome, are related to oxidative stress and cause a lack of clinical pregnancy or an increase of the conception time. On the other hand, double-strand DNA breaks are mainly localized and attached to the sperm nuclear matrix as a very few break points, are possibly related to a lack of DNA repair in meiosis and cause a higher risk of miscarriage, low embryo quality and higher risk of implantation failure in ICSI cycles. The present work also reviews different studies that may contribute in the understanding of sperm chromatin as well as treatments to prevent sperm DNA damage.
生殖疾病已成为全球性日益严重的问题，男性因素在生殖诊断、预后和辅助生殖治疗方案的设计中起着重要作用。精子细胞肩负着将父系遗传物质传递给卵子的使命，以促进具有适当 DNA 完整性的整倍体受精卵形成。几十年来，精子 DNA 碎片化一直被用作男性生育力检测，但它的有用性引发了诸多争议，尤其是在胞浆内单精子注射（ICSI）治疗方面。近年来，人们已经描述了不同类型的精子 DNA 断裂（单链和双链 DNA 断裂）会导致不同的临床生殖效果。一方面，单链 DNA 断裂广泛存在于基因组的所有区域，表现为多个断裂点，与氧化应激有关，导致临床妊娠率降低或受孕时间延长。另一方面，双链 DNA 断裂主要定位于精子核基质并附着于其上，表现为少量断裂点，可能与减数分裂中 DNA 修复不足有关，导致流产风险增加、胚胎质量降低以及 ICSI 周期中着床失败风险增加。本研究还综述了一些可能有助于了解精子染色质以及预防精子 DNA 损伤的治疗方法的研究。
