Understanding stem cell heterogeneity and niche function in intestinal regeneration after irradiation

项目摘要 辐射诱导的胃肠道综合征（RIGS）是由剂量依赖性的，杀细胞作用， 辐射对肠腺细胞的影响目前没有批准的医疗对策来缓解 装备。虽然活性Lgr 5+干细胞被有效消融，但再生从储备、静止、 抗辐射的祖细胞/干细胞。这两个祖先群体之间的确切关系 （放射抵抗和放射敏感）仍然不确定，需要更多的信息来开发治疗方法 治疗RIGS和其他疾病迫切需要一种公正的方法来充分描述 细胞在正常和再生肠，独立的先验知识或纯化测定。工作从 我们的实验室和ISCC已经证明了基质间充质细胞和其他小生境细胞在 调节ISC稳态和再生，但不存在全面的调控模型。矩阵 蛋白质也是生态位的一部分，我们已经能够培养类肠细胞和人类肠道细胞， 组织特异性水凝胶中的类器官。我们的研究人员和合作者已经开发出新的R-spondin 和Wnt激动剂用于体内递送，但用于治疗RIGS的最佳组合尚未确定。 因此，充分了解ISCs和niche细胞之间的串扰信号，以及刺激ISCs和niche细胞的模型， 或替代肠道ISCs，是RIGS治疗进展所必需的。与其他成员合作 我们提出两个具体目标。目标1.肠隐窝的异质性 细胞和邻近的基质细胞在辐射后改变？我们将分析高纯度的隐窝上皮细胞 和基质细胞，并应用 计算工具（MetaVIPER）来开发分层结构和监管模型。目标二。可以 使用小生境因子或干细胞的治疗可用于减轻对 肠子？我们将研究新的因素组合，以减轻RIGS，然后使用组织特异性水凝胶 以及新的因子和细胞，用于体外生长和体内移植人肠类器官以治疗结肠炎， 放射性直肠炎总的来说，这项提案将使用哥伦比亚/爱因斯坦开发的新技术来推进 ISCC的使命是再生人类肠道。

Project Summary The radiation-induced gastrointestinal syndrome (RIGS) results from dose-dependent, cytocidal effects of radiation on intestinal crypt cells. There are currently no approved medical countermeasures to alleviate the RIGS. While active Lgr5+ stem cells are efficiently ablated, regeneration emerges from reserve, quiescent progenitor/stem cells that are radio-resistant. The exact relationship between these two progenitor populations (radio-resistant and radio-sensitive) remains undefined, and more information is needed to develop therapies for RIGS and other disorders. An unbiased approach is critically needed to fully characterize the diversity of cells in normal and regenerating intestine, independent of prior knowledge or purification assays. Work from our lab and the ISCC has demonstrated a key role for the stromal mesenchyme and other niche cells in modulating ISC homeostasis and regeneration, but a comprehensive regulatory model does not exist. Matrix proteins are also part of the niche, and we have been able to grow both enteroids and human intestinal organoids in tissue-specific hydrogels. Our investigators and collaborators have developed novel R-spondin and Wnt agonists for in vivo delivery but the optimal combinations for treatment of RIGS have not been defined. Thus, a full understanding of the cross-talk signals between ISCs and niche cells, and models for stimulating or replacing intestinal ISCs, is needed for advances in therapy for RIGS. In collaboration with other members of the ISCC, we are proposing two specific aims. Aim 1. How does the heterogeneity of intestinal crypt cells and adjacent stromal cells change after radiation? We will analyze highly pure crypt epithelial cells and stromal cells using a novel multiplex scRNA-seq platform before and after radiation, and apply computational tools (metaVIPER) to develop a hierarchical structure and regulatory model. Aim 2. Can therapy with niche factors or stem cells be used to mitigate radiation or inflammatory injury to the intestine? We will study novel combinations of factors to mitigate RIGS, and then use tissue-specific hydrogels and novel factors and cells to grow in vitro and transplant in vivo human intestinal organoids to treat colitis and radiation proctitis. Overall, this proposal will use novel technology developed at Columbia/Einstein to advance collaboratively the ISCC mission to regenerate the human intestine.