体外诱导人多能干细胞形成雄性生殖细胞的研究

Aspermatogenesis is a severe impairment of spermatogenesis in which germ cells are completely lacking or present in an immature form, which results in sterility in approximately 25%-50% of patients and the only option currently available for these patients is adoption or artificial insemination using donor sperm. Researchers have been trying to establish an in vitro system to recapitulate the in vivo process of germ cell formation and differentiation in order to study the underline genetic and epigenetic mechanisms and to develop clinical applications of male infertility treatment. However, the clinical application of this technology is still an unreachable goal because of the uncontrolled induction method and the low efficiency of acquiring functional gametes. Consequently, I set the following specific goals for my research: 1. To establish a new in vitro procedure for primordial germ cells induction from human pluripotent stem cells; 2. To convert induced primordial germ cells into germline stem cells, which can be amplified by self-renewal proliferation; 3. To increase the efficiency of haploid cell induction from induced germline stem cells. The realization of these goals would markedly increase the efficiency of germ cell induction from human pluripotent stem cells, and would build a solid foundation for developing treatment of male infertility based on induced germ cells.

无精症在临床上被定义为由于睾丸病变或精子细胞完全缺失而引起的无精子生成。这些男性病人大约占到男科病例的25%到50%。目前为止他们获得后代的唯一选择就是收养或接受捐赠者的精子进行人工授精。为了深入研究精子发生过程并为临床无精症患者提供治愈的可能，多年来人们一直尝试建立体外诱导生殖细胞形成和发育的研究系统。2003年以来，该领域已经取得了一些进展。然而，由于很难控制体外分化过程并高效获得有功能的配子，该技术离临床应用还有很大距离。本研究的目标是：1，建立将人的多能干细胞诱导形成原始生殖细胞的新的技术手段；2，通过体外培养将形成的原始生殖细胞转化为生殖干细胞进行扩增；3，探索将诱导的生殖干细胞进一步分化成为单倍体生殖细胞的方法。通过这些目标的实现，我们将提高把人多能性干细胞诱导成为生殖细胞的效率，也为获得具有受精能力的生殖细胞奠定基础。

无精症在临床上被定义为由于睾丸病变或精子细胞完全缺失而引起的无精子生成。这些男性病人大约占到男科病例的25%到50%。目前为止他们获得后代的唯一选择就是收养或接受捐赠者的精子进行人工授精。为了深入研究精子发生过程并为临床无精症患者提供治愈的可能，多年来人们一直尝试建立体外诱导生殖细胞形成和发育的研究系统。本项研究建立了稳定高效的小鼠体外诱导生殖细胞的实验条件，对实验获得的单倍体细胞进行了系统的鉴定。在此基础上，探索了人精原干细胞的培养方法。尽管目前全世界范围内还没有建立稳定培养的人精原干细胞系，我们还是收集了志愿者的睾丸曲细精管组织进行了培养条件摸索。未来，本项研究将在小鼠实验的基础上，深入探索人多能干细胞和精原干细胞诱导分化产生配子的过程，也为获得具有受精能力的生殖细胞奠定基础。