Kokkinaki Maria, Djourabtchi Ardalan, Golestaneh Nady
Georgetown University School of Medicine, Department of Biochemistry and Molecular & Cellular Biology ; Lombardi Comprehensive Cancer Center, Georgetown University School of Medicine.
Georgetown University School of Medicine, Department of Biochemistry and Molecular & Cellular Biology.
J Stem Cell Res Ther. 2011 Nov 11;2(2). doi: 10.4172/2157-7633.S2-003.
Recently we and two other groups have shown that human spermatogonial stem cells (SSCs) have the potential to become pluripotent in defined culture conditions and to differentiate into cells of the three embryonic germ layers. This discovery could open new avenues for autologous cell-based therapy in degenerative diseases, bypassing the ethical and immunological problems related to the human embryonic stem cells. In addition, human SSCs could be used to treat infertility in cancer survival children. However, in order to reprogram SSCs into pluripotency, or to preserve them for repopulation of infertile testes, the first and limiting step is to have access to a highly purified human SSC population that could be multiplied and efficiently cultured maintaining their molecular and cellular characteristics. Although various studies have attempted to identify molecular markers of human SSCs, to date there is still limited information related to the specific markers that could be used for their isolation and optimized purification that allows long-term culture of isolated human SSCs. Here using SSEA-4 as an optimal marker for isolation of a subpopulation of SSCs, we show that SSEA-4 positive cells express the highest level of SSC genes compared to other subpopulations isolated with different markers, and can be maintained in culture for over 14 passages which we were unable to obtain with other SSCs markers including GPR125 and ITGA6. In addition, we have established a new technology for cell sorting and long-term culture of human SSC-SSEA-4 positive cells that maximizes the purity and viability of the sorted cells. Our findings are crucial and could be used for the most efficient isolation, purification and long-term culture of SSCs for clinical applications in regenerative medicine, or for preparation of human SSCs for autologous treatment of infertility in cancer survival children.
最近，我们和其他两个研究小组表明，人类精原干细胞（SSCs）在特定培养条件下具有成为多能细胞的潜力，并能分化为三个胚胎胚层的细胞。这一发现可能为退行性疾病的自体细胞疗法开辟新途径，绕过与人类胚胎干细胞相关的伦理和免疫问题。此外，人类精原干细胞可用于治疗癌症存活儿童的不孕症。然而，为了将精原干细胞重编程为多能性，或将它们保存下来用于不育睾丸的再殖，首要的且具有限制性的步骤是获得高度纯化的人类精原干细胞群体，该群体能够增殖并高效培养，同时保持其分子和细胞特征。尽管各种研究试图鉴定人类精原干细胞的分子标志物，但迄今为止，关于可用于其分离和优化纯化的特定标志物的信息仍然有限，而这种优化纯化能够实现分离出的人类精原干细胞的长期培养。在这里，我们使用阶段特异性胚胎抗原-4（SSEA-4）作为分离精原干细胞亚群的最佳标志物，结果表明，与用不同标志物分离出的其他亚群相比，SSEA-4阳性细胞表达精原干细胞基因的水平最高，并且可以在培养中维持超过14代传代，而我们用包括GPR125和整合素α6（ITGA6）在内的其他精原干细胞标志物无法做到这一点。此外，我们已经建立了一种用于人类精原干细胞-SSEA-4阳性细胞分选和长期培养的新技术，该技术可使分选细胞的纯度和活力最大化。我们的研究结果至关重要，可用于最有效地分离、纯化和长期培养精原干细胞，以用于再生医学的临床应用，或用于制备人类精原干细胞以自体治疗癌症存活儿童的不孕症。
