Regulatory Circuits Controlling Regenerative Growth

描述（由申请人提供）：多能干细胞为再生医学提供了巨大的希望，但精细控制其活性以 重新构建复杂的器官组织工程已经通过设计合成支架来控制干细胞功能来解决这个问题，但是以这种方式生产真正的组织模拟物是一项艰巨的任务。已经进化出成体组织再生机制的动物提供了一个发现干细胞如何自然地被指示进行胚胎后器官形成的机会。Planarian扁形虫以其通过控制称为neoblasts的多能干细胞的活性来再生任何缺失组织的能力而闻名。由于这些动物可以根据损伤的性质和程度参与多种不同的再生程序，因此它们需要对干细胞的利用进行精确的控制。这种能力可能存在于新的信号通路中，或者存在于对已充分描述的信号通路的独特用途中。该提案描述了一种策略，用于特定的识别调控分子，控制再生生长的干细胞在真涡虫。使用RNA干扰分析这些基因的功能将描述控制再生生长的途径。最终，定量了解干细胞控制再生将是必要的，以有效地适应自然的再生机制，以增强人体组织修复。该提案进一步描述了单分子荧光原位杂交的应用，以定量分析的空间和时间动态的Wnt，BMP和刺猬信号在涡虫再生。这种方法将允许系统水平的识别信号控制机制，通过再生干细胞介导的器官发生的基础。干细胞和组织修复机制很可能是古老的。因此，这些研究有可能鉴定出新的保守蛋白，这些蛋白可以被调节以增强组织修复，并揭示可应用于再生医学的组织修复的基本原理。

DESCRIPTION (provided by applicant): Pluripotent stem cells offer great promise for regenerative medicine, but it remains a significant challenge to finely control their activities to build complex organs de novo. Tissue engineering has approached this problem by designing synthetic scaffolds to control stem cell function, but production of true tissue mimics in this fashion is a daunting task. Animals that have evolved mechanisms of adult tissue regeneration provide an opportunity to discover how stem cells can be naturally instructed to undergo post-embryonic organogenesis. Planarian flatworms are famous for their ability to regenerate any missing tissue by controlling the activity of pluripotent stem cells termed neoblasts. Because such animals can engage a multitude of different regenerative programs dependent on the nature and extent of injury, they require exquisite control over the utilization of stem cells. Thi ability likely either resides in novel signaling pathways or in a unique use for well-described signaling pathways. This proposal describes a strategy for specific identification of the regulatory molecules that control regenerative growth by stem cells in planarians. The analysis of the function of these genes using RNA interference will describe pathways that control regenerative growth. Ultimately, a quantitative understanding of stem cell control in regeneration will be necessary to efficiently adapt natural regenerative mechanisms to the enhancement of human tissue repair. The proposal further describes the application of single-molecule fluorescence in situ hybridization to quantitatively analyze the spatial and temporal dynamics of Wnt, BMP and hedgehog signaling in planarian regeneration. This approach will allow a systems-level identification of signal control mechanisms that underlie stem cell-mediated organogenesis through regeneration. It is likely that stem cells and tissue repair mechanisms are ancient. Therefore, these studies have the potential to identify novel conserved proteins that could be modulated to enhance tissue repair and uncover basic principles of tissue restoration that could be applied to regenerative medicine.