小肠干细胞通过和Niche细胞"对话"精细调控Wnt 和 Notch等关键信号通路来维持其增殖分化平衡，但这些信号通路在辐射后干细胞再生、重建中的调控机制还远未阐明。通过前期探索，我们建立了高通量细胞流式分选方法，可以分离、富集正常和辐射后不同时期的小肠上皮干细胞和相关Niche细胞，将通过转录组测序等技术明确干细胞和Niche细胞来源调控因子在辐射前后的动态表达。另外，以往研究大多关注Niche细胞来源调控信号，忽略了干细胞自主性分泌的调控因子，因此我们将在干细胞和Niche细胞对话网络中侧重分析后者的角色和作用，并将在体外培养的肠类器官中通过干预相关信号通路来分析其对干细胞分化以及辐射后损伤修复的影响。本课题预期将首次明确小肠干细胞和多种Niche细胞在辐射损伤修复中的"对话"模式，并明确干细胞自主性分泌的调控因子在生理和病理条件下对干细胞调控的相关分子机制。

The crosstalk between intestinal stem cells (ISCs) and niche cells regulate several critical signal pathways activated in stem cells including Wnt and Notch, dominating the proliferation and differentiation status of intestinal stem cells . However, it remains obscure how these critical pathways are regulated in the tissue damage response and regeneration because of the challenge from isolating and enriching survival ISCs in damaged tissue. We have established a serial of methods for relatively enriching Lgr5+ ISCs and other niche cells from intestinal tissue during damage response and early tissue regeneration. So we will analyze the gene expression level of secretory factors derived from stem cells and Niche cells by using RNAseq. In addition, we will focus on the automatic regulation of ISC and interrogate the role of secertory factors derived from ISC on ISC proliferation, differentiation and regeneration in the 3D organoid culture system by manipulating their expression. In summary, we expect to get the primary cross talk pattern between ISC and Niche cells during irradiation damage and repair and also understand the mechanism of ISC automatic regulation under physiological and stress conditions.