Lee Yukyeong, Lee Minseong, Lee Seung-Won, Choi Na Yong, Ham Seokbeom, Lee Hye Jeong, Ko Kisung, Ko Kinarm
Department of Stem Cell Biology, Konkuk University School of Medicine, Seoul, Korea.
Center for Stem Cell Research, Institute of Advanced Biomedical Science, Konkuk University, Seoul, Korea.
Anim Cells Syst (Seoul). 2019 Oct 8;23(6):392-398. doi: 10.1080/19768354.2019.1672578. eCollection 2019.
Spermatogonial stem cells (SSCs) are unipotent adult stem cells, capable of differentiating into sperm cells. SSCs can be cultured for a long time. SSCs expressing Oct4, a pluripotency marker, and are the only adult cells which pluripotency can be induced under defined culture conditions. However, because 2D culture imposes limitations in cell junction formation, cell shape, metabolism, response to stimuli, and cell interface with medium, mechanistic studies on reprogramming of SSCs using feeder cells still have many challenges. Recent studies have shown that a culture system using a bio-matrix can be used in long-term feeder-free SSCs culture and for induction of pluripotency in SSCs. However, the bio-matrix cannot be the optimal micro-environment in mechanistic studies because it creates a physical barrier to growth factors and other signaling molecules. To overcome this effect of the matrix, we reprogrammed SSCs into pluripotent ESC-like cells, so-called germline-derived pluripotent stem cells (gPSCs) by using a 3D scaffold, in which cells are less responsive to external stimuli than in 2D cultures. Thus, we confirm the possibility of SSC reprogramming in the spheroidal state and suggest the utility of 3D scaffolds as a tool for studying the mechanism of SSC reprogramming into gPSCs without a bio-matrix.
精原干细胞（SSCs）是单能成体干细胞，能够分化为精子细胞。SSCs可以长时间培养。表达多能性标志物Oct4的SSCs是唯一在特定培养条件下可诱导多能性的成体细胞。然而，由于二维培养在细胞连接形成、细胞形状、代谢、对刺激的反应以及细胞与培养基的界面方面存在局限性，使用饲养层细胞对SSCs进行重编程的机制研究仍然面临许多挑战。最近的研究表明，一种使用生物基质的培养系统可用于长期无饲养层的SSCs培养以及诱导SSCs的多能性。然而，生物基质在机制研究中并非最佳微环境，因为它对生长因子和其他信号分子形成了物理屏障。为了克服基质的这种影响，我们通过使用三维支架将SSCs重编程为多能性胚胎干细胞样细胞，即所谓的种系来源的多能干细胞（gPSCs），在三维支架中细胞对外界刺激的反应比在二维培养中更不敏感。因此，我们证实了SSCs在球体状态下重编程的可能性，并提出三维支架作为一种工具，可用于研究在没有生物基质的情况下SSCs重编程为gPSCs的机制。
