Biomimetic Artificial Niche for Hematopoietic Stem Cell Expansion

描述(申请人提供)：每年有超过30,000名患有白血病、淋巴瘤、多发性骨髓瘤和严重再生障碍性贫血等血液病的患者接受大剂量化疗后进行造血干细胞移植。造血干细胞在移植后重建所有血统的能力可以拯救这些患者的生命。然而，他们的需求严重超过了他们的可用性 由于很难找到合适的供体匹配，再加上它们在体外的低扩张潜力。已评估了多种培养条件用于体外扩增HSCs，但由于分化增加、干性丧失和促进培养中的细胞周期异常而取得的成功有限。因此，本项目旨在开发新型仿生生物材料底物，并利用共存的利基细胞的固有能力来促进HSC的体外扩增。目的1将开发一种生物材料基质，以模拟天然的骨髓细胞外基质环境，促进HSC的体外扩增。目的2将研究是否存在Nestin阳性的MSCs的替代来源，这些来源可以用于体外扩增HSCs。最后，目标3将确定额外的候选利基细胞在促进HSC体外扩增中的作用。这项建议将通过分析细胞表面受体、细胞骨架变化、可溶性因子、遗传变化和相关的细胞内途径来表征HSC在与HSC共同培养时由于生物材料或其他候选生态位细胞的影响而导致HSC扩张的分子机制。促进HSC扩增的创新方法可用于挽救生命的移植，显著影响恶性血液病患者的预后。此外，该系统还可以作为研究利基细胞-细胞相互作用、细胞-基质相互作用、药物筛选和遗传病的模型。这些研究将对骨髓微环境的知识基础做出重大贡献，并可能导致新的患者疗法的开发，从而使他们能够活得更长、更有成就感。

DESCRIPTION (provided by applicant): Each year, over 30,000 patients suffering from hematological diseases such as leukemia, lymphoma, multiple myeloma, and severe aplastic anemia are treated with high-dose chemotherapy followed by hematopoietic stem cell (HSC) transplantations. The ability of HSCs to reconstitute all blood lineages post transplantation can be life-saving for these patients. However, their need is severely outweighed by their availability due to the difficulty in finding a suitable donor match coupled with their low expansion potential ex-vivo. A variety of culture conditions have been evaluated for in vitro expansion of HSCs but have yielded limited success due to an increase in differentiation, loss of stemness and promotion of cell cycle abnormalities in culture. Thus, this project aims to develop novel biomimetic biomaterial substrates and harbor the innate ability of co-existing niche cells to promote HSC expansion in vitro. Aim 1 will develop a biomaterial substrate to emulate the native bone marrow extracellular matrix environment and promote HSC expansion in vitro. Aim 2 will investigate if alternative sources of Nestin positive MSCs exist, which can be harnessed towards the expansion of HSCs in vitro. Finally, Aim 3 will determine the role of additional candidate niche cells in promoting HSC expansion in vitro. This proposal will characterize the molecular mechanisms behind HSC expansion due to the effects of the biomaterial or other candidate niche cells in culture with HSCs by analyzing cell surface receptors, cytoskeleton changes, soluble factors, genetic changes and associated intracellular pathways. Innovative methods for promoting HSC expansion could be used for life-saving transplantations to significantly impact the prognosis of patients with hematological malignancies. Additionally, this system can serve as a model for studying niche cell-cell interactions, cell-matrix interactions, drug screening and genetic diseases. These studies will significantly contribute to the knowledge base of the bone marrow niche microenvironment and potentially lead to the development of new patient therapies so they can live longer and more fulfilling lives.