Small-molecule combinationsexpand hematopoietic stem cell ex vivo and in vivo

小分子组合在体外和体内扩增造血干细胞 摘要 造血干细胞(HSCs)具有自我更新和分化为 多个血统。造血干细胞移植(HSCT)是救死扶伤的主要手段。 恶性血液病和低增殖性疾病。非侵入性可及脐带的应用 脐带血(UCB)来源的HSC比骨髓和外周血HSC具有许多优势， 包括对人类白细胞抗原(HLA)配型的要求不那么严格，降低移植物抗宿主病的风险- 宿主病(GVHD)等。然而，脐带血单位中有限的细胞剂量可能会导致严重的问题，如 植入延迟，植入失败，以及严重的感染性并发症。HSC的扩展从 脐带血一直是开发先进细胞疗法以提高移植疗效的重要目标。 并为各种血液病提供潜在的治疗方法。 最近的研究已经实现了使用细胞因子鸡尾酒联合Small体外扩增HSCs 分子，包括嘧啶并吲哚衍生物(UM171)、芳烃受体拮抗剂(SR1)。这个 这些方法的主要缺点是，只有在存在高浓度的 细胞因子。已知细胞因子可诱导分化并影响原始HSC的功能，它们 可能会由于血液系统的扭曲重建而对人类产生长期的有害影响。 含有最少细胞因子的小分子组合将是临床应用的理想选择。我们出版的 研究表明，两种抑制剂(2I)的组合可以在体外维持人和小鼠的生命 长期的造血干细胞，在无细胞因子条件下这样做。两种临床药物的联合用药(锂加 雷帕霉素)可导致体内长期培养的小鼠肝干细胞数量增加。在我们最近的研究中，我们发现2i是有效的 在低细胞因子条件下与SR1协同作用，可显著扩增体外长期功能的HSC。 在本项目中，我们将开展小分子组合方案培养条件的优化研究。 此外，我们还将对体内扩张方法进行测试和优化，这将大大提高成功的 骨髓间充质干细胞移植率。我们的主要目标是开发新的临床方案，以扩大功能性脐带血- 衍生的造血干细胞用于治疗应用。

Small-molecule combinations expand hematopoietic stem cell ex vivo and in vivo Abstract Hematopoietic stem cells (HSCs) are featured by their self-renewal potential and ability to differentiate into multiple blood lineages. Hematopoietic stem cell transplant (HSCT) is a mainstay of life-saving therapy for hematopoietic malignancies and hypoproliferative disorders. The use of noninvasively accessible umbilical cord blood (UCB)-derived HSCs provides many advantages over bone marrow and peripheral blood HSC, including less stringent requirement for human leukocyte antigen (HLA) match, decreased risk of graft-versus- host disease (GVHD), etc. However, limited cell dose in a UCB unit may lead to significant problems such as delayed engraftment, engraftment failure, and severe infectious complications. The expansion of HSCs from UCB has remained an important goal to develop advanced cell therapies for enhancing transplantation efficacy and providing potential cure for various hematological diseases. Recent studies have achieved ex vivo expansion of HSCs using cytokine cocktails combined with small molecules, including pyrimidoindole derivative (UM171), aryl hydrocarbon receptor antagonist (SR1). The major disadvantage with these approaches is that it is only effective in the presence of high concentration of cytokines. Cytokines have been known to induce differentiation and affect the function of primitive HSC, they might have long-term deleterious effect on humans due to skewed reconstitution of the hematopoietic system. The small-molecule combinations with minimal cytokines would be ideal for clinical applications. Our published studies demonstrated a combination of two inhibitors (2i) allows the ex vivo maintenance of human and mouse long-term HSCs and doing so under cytokine-free condition. The combination of two clinical drugs (lithium plus rapamycin) leads to increase of long-term mouse HSCs in vivo. In our recent studies, we found that 2i works synergistically with SR1 under low cytokine condition, significantly expanded long-term functional HSC ex vivo. In this project, we will carry out studies to optimize culture condition of small-molecule combination regimens. Furthermore, we will test and optimize the in vivo expansion method, which will greatly improve the successful rate of HSC transplantation. Our major goal is to develop new clinical protocols for expanding functional UCB- derived HSCs for therapeutic applications.