Controlling endothelial fate and vascular assembly from pluripotent stem cells

 描述（由申请人提供）：创建功能性血管的能力是血管治疗和组织工程的关键一步。目前，我们仍然没有完全控制和理解血管分化，包括内皮细胞（EC）和周细胞，从人类诱导多能干细胞（hiPSC）。在胚胎发生过程中，血管发生产生原始丛，随后是血管生成，其中EC发芽，伸长，管腔化和合并形成管。同时，这些新生的EC管通过血管周围细胞的募集而稳定。传统上，体外功能性微血管结构的工程化涉及将EC和周细胞的两种不同细胞来源嵌入三维（3D）支架材料内。我们的实验室已经建立了一种新的贴壁培养系统，从hiPSC中获得早期血管细胞（EVC）的双细胞群体。这些EVC由VEcad+和PDGFR细胞组成，它们可以分别成熟为EC和周细胞，并且可以在水凝胶支架中自组织成3D多细胞血管网络。这种方法为研究hiPSC血管分化过程中的命运决定提供了很好的机会。它还有助于临床应用的血管结构的构建。我们的目标是：（1）建立无饲养层的贴壁培养系统，以从hiPSC获得EC与周细胞的高比率;（2）剖析EC和周细胞分化的空间和时间动力学;和（3）分析真实的-时间细胞相互作用和功能 自我组织的血管网络。为了实现我们的目标，建议的研究策略结合干细胞和血管生物工程技术。这些目标的成功完成对于改善血管治疗具有相当大的临床影响，并将拓宽我们对血管发育和修复的理解。

 DESCRIPTION (provided by applicant): The ability to create functional vasculatures is a crucial step towards vascular therapy and tissue engineering. Currently, we still do not have full control and understanding of vascular differentiation including endothelial cells (ECs) and pericytes, from human induced pluripotent stem cells (hiPSCs). During embryogenesis, vasculogenesis gives rise to the primitive plexus followed by angiogenesis where ECs sprout, elongate, lumenize and coalesce to form tubes. Concurrently, these nascent ECs tubes are stabilized via the recruitment of perivascular cells. Traditionally, engineering of functional microvasculature constructs in vitro involves embedding two distinct cell sources of ECs and pericytes within a three-dimensional (3D) scaffold material. Our lab has established a novel adherent culture system to derive a bi-cellular population of early vascular cells (EVCs) from hiPSCs. These EVCs are composed of VEcad+ and PDGFR¿¿ cells that can mature to ECs and pericytes respectively, and can self-organize to a 3D multicellular vascular network in a hydrogel scaffold. This approach provides great opportunities to study fate decisions during vascular differentiation of hiPSCs. It also contributes to the construction of vascular structures for clinical applications. Our aims are: (1) Establish a feeder free, adherent culture system to obtain high ratio of EC to pericyte from hiPSCs; (2) Dissect the spatial and temporal kinetics of EC and pericyte differentiation; and (3) Analyze real- time cellular interactions and functionality of self-organized vascular networks. To achieve our aims, the proposed research strategy combines techniques in stem cell and vascular biology engineering. Successful completion of these aims has considerable clinical impact with respect to improved vascular therapeutics and will broaden our understanding of vascular development and repair.