开发单细胞DLO Hi-C技术并解析衰老过程中海马-内嗅皮层神经环路基因组三维构象动态变化

During the aging process, various cells, such as neurons, have different degrees of epigenetic changes. Analyze these changes can better understand the physiological changes during aging process and the mechanisms of aging-related diseases. The brain is the most complex organ in the human body, and different neural circuit have a high degree of heterogeneity. Due to the lack of effective specific neural circuit single-cell isolation technology, traditional brain science research is based on a piece of tissue or a group of cells. It is difficult to accurately isolation specific neural circuit neurons and perform specific expression profiling and epigenetic modification difference analysis. To this end, this project will be based on the pre-established DLO Hi-C technology and specific neural circuit single-cell isolation technology, develop single-cell DLO Hi-C technology and analyze the dynamics of the three-dimensional genome structure of the hippocampal-entorhinal circuitry during aging process, study the relationship between the genome three-dimensional structure and gene expression level, and identification of important transcriptional regulatory elements associated with aging process. This project will provide an efficient method for studying the genome three-dimensional structure of small amount cells or single-cell, and provide a theoretical basis for revealing the epigenetic changes of specific neural circuit during aging process.

衰老过程中各种细胞，如神经细胞都有不同程度表观修饰的变化，解析这些变化可以更好的理解衰老过程生理变化及与衰老相关疾病的发生发展机制。大脑作为人体最复杂的器官，不同环路神经元存在着高度的异质性。由于缺乏有效的特异环路神经元分离技术，传统的脑科学研究都是以一块组织或一群细胞为研究对象，难以精确分离特异神经环路神经元并对其进行特异表达谱分析及表观遗传差异研究。为此，本项目将基于前期构建的DLO Hi-C技术与特异环路神经元分离技术，开发单细胞DLO Hi-C技术并解析衰老过程中海马-内嗅皮层神经环路基因组三维结构的动态变化，研究特异环路神经元基因组三维构象与基因转录的关系，寻找与衰老相关重要转录调控元件。本课题将为研究单细胞及寡量细胞的基因组三维构象提供了一种高效的新方法，并为揭示衰老过程中特异环路神经元表观遗传变化提供理论依据。

大脑的神经元细胞具有高度的异质性，为了解析衰老过程中微量神经元细胞的表观修饰重编程以及染色质三维构象重塑，我们专门开发了针对微量细胞的DLO Hi-C 2.0（并列通讯，Journal of Genetics and Genomics）以及针对单细胞的sciDLO Hi-C（一作，Nature Communications）。利用DLO Hi-C系列技术以及其它表观多组学技术，我们系统的解析了神经元衰老过程，以及巨噬细胞分化及免疫活化过程中染色质空间构象重塑以及表观修饰重编程。在此研究中，结合sciHi-C捕获到的单细胞基因组三维结构信息，我们提出了染色质拓扑结构域（Topologically associated domains，TAD）有序性的概念，并用其来评价TAD的转录活性。最后，通过对GWAS，eQTL，染色质Loop，以及组蛋白表观修饰数据联合分析，我们鉴定了新的疾病易感基因，发掘了新的药物治疗靶点，并寻找到了新的治疗药物。