摘要
本研究的关键科学问题是：1)如何识别不同组织干细胞分化启动关键因子，实现细胞分化命运的操控和谱系重编程；2)如何示踪干细胞在不同组织器官移植后的去向和功能，追踪干细胞在体内的命运转化。整个项目将围绕识别和示踪这两个核心问题，从分子、细胞和整体三个层面进行深入系统的整合性研究。主要研究内容如下：1.用模式生物小鼠和小鼠基因修饰技术，对分裂细胞、各种信号通路、细胞表面分子进行遗传标记，并建立细胞谱系标记技术，跟踪组织干细胞分化过程，阐明组织干细胞的分化网络。分离特定阶段标记细胞进行基因和蛋白质的分析，筛选分化启动的关键因子、鉴定特定组织干细胞的分子指纹图谱、寻找组织干细胞发育分化特定阶段的谱系标志物。2. 研究细胞外基质成分对肝干细胞分化的调控作用，建立部分肝脏切除动物模型、肝细胞凋亡模型以及嵌合肝小鼠模型，分析由肝脏干细胞介导的肝再生的机制；尝试探索通过表观遗传学调控直接进行肝脏细胞谱系重编程为胰腺β细胞的方法。3. 针对发育中心脏组织、肝脏组织的干/祖细胞的基因组表达分析、DNA甲基化及组蛋白乙酰化等分析，揭示不同类型先驱细胞专一性表达的转录因子群体，鉴定到数个在决定分化和转变细胞谱系中起关键作用的主调控基因，阐明其中的表观遗传调控机制。4. 基于干细胞用于临床治疗应用的安全性及有效性，研究四个问题：1. 移植后的干细胞在哪里？2. 移植的干细胞是否能在体内存活？3. 移植的干细胞是否能和宿主整合发挥生理功能？4. 局部注射和静脉系统给予等不同的移植途径对干细胞组织功能重建有什么影响？具体内容包括：探索干细胞体外标记的新方法，研究不同移植途径对干细胞标记示踪的影响，核磁共振影像学结合波谱技术检测脑神经干细胞的研究，活体示踪移植干细胞功能；伦理法规政策允许下，选择符合研究标准的患者入选本研究进行功能恢复评价和安全性评价；开展推广用于其它组织干细胞的示踪研究，初步探索其它组织干细胞的示踪技术体系。上述主要研究内容仅仅围绕关键科学问题，重点集中在组织干细胞发育分化的关键因子识别、细胞谱系示踪的特异性标志物、以及示踪技术的灵敏性、无创性和技术的扩展应用上。There are two key scientific questions to be solved. The first one is how to identify the key differentiation initiating factors in different tissue stem cells, and achieve the manipulation of cell fate and lineage reprogramming. The second one is how to track stem cells in different tissues and organs after transplantation in order to unravel the fate and function changes of stem cells in vivo. The entire project will focus on these two essential issues, identification and tracking, and carry out a deep, integrated research form three different levels, molecualr,cellular and whole system. The main research contents are as follows:1.With the model mouse and mouse gene modification technology, we will label the dividing cells, a variety of signaling pathways, cell surface molecules with genetic markers, establish labeling technique for cell lineage, track stem cell differentiating process, clarify the network during the differentiation of stem cells. 2.We will investigate the regulation mechanism of extracellular matrix on differentiation of hepatic stem cells, establish liver partial resection animal models, liver cell apoptosis animal models, and chimeric liver mouse models to uncover liver stem cell-mediated mechanism for liver regeneration.3.We will perform the gene expression , DNA methylation and histon acetylation analysis in tissue stem/progenitor cells of developing heart and liver in order to reveal the specific transcription factor groups in different progenitor cells, identify several main regulation genes that play a pivotal role in determination of differentiation and transformation of lineage.4.We will investigate four issues based on clinical safety and efficiency stem cell therapy: 1. Where is stem cells after transplantation? 2. Whether the transplanted stem cells survive in vivo? 3. Whether the transplanted stem cells integrate with host and play some physiological function? 4. The effect of different approaches such as local injection and intravenous injection on functional reconstruction of transplanted stem cells. In a word, the main research content is around the key scientific issues, focus on identifying key factors during stem cell development, finding specific markers for lineage tracking, assessing sensitivity and non-invasive of tracking techniques, and clinically applying of tracking techniques.
NSTRS