Multidimensional genomic signature of human liver growth and hypertrophy

背景：正常人类肝脏具有显著的可塑性和再生能力：在肿瘤手术或活体供肝移植的背景下，高达60%的肝脏被常规切除。然而，关于肝细胞类型，如肝细胞、血管细胞、免疫细胞、星状细胞和肝细胞干细胞区室及其潜在的基因组程序在这一过程中的作用和合作的关键问题-特别是在人类肝脏中-仍然没有答案。在肝脏手术和肝硬化器官损伤的背景下，迫切需要新的治疗方法来增强肝脏再生。目的：利用独特的临床基础设施，我们旨在通过深入的单细胞和表观遗传学分析来了解人类肝脏再生过程的细胞程序和起源。本人正在进行的工作：申请人在肝脏表观遗传学和功能基因组学方面拥有专业知识，并建立了独特的分析管道。工作计划：申请人将在肿瘤肝切除术前通过门静脉栓塞原位分裂手术治疗性诱导肝再生的临床设置。来自同一个体的肥大肝脏和对照肝脏-从而为个体间变异提供固有的控制-将对新分离的肝细胞和非实质细胞进行单细胞RNA和NOMe测序。这些数据将由新鲜冷冻肝脏样本的核RNA测序和激光捕获的分区实质细胞和主要非实质细胞区室的低温显微解剖产生的空间信息进行补充。特异的基因组特征将通过免疫组织化学和RNA原位杂交进一步验证。生物信息学整合将最终提供肝脏生长和肥大的细胞和组织基因组程序的空间分辨和动态地图。结论：该项目提供了一个独特的机会，在临床相关、控制良好、伦理合理的环境下，在单细胞和组织水平上研究人体器官（即肝脏）的再生。该结果将为人类肝脏生物学提供深刻的新见解，并指出治疗解决肝脏再生和重塑的机制。

Background: Normal human liver has remarkable plasticity and regenerative capacity: Resections of up to 60% of the liver are routinely performed in the context of oncological surgery or living donor liver transplantation. However, key questions regarding the roles and the cooperation of hepatic cell types such as hepatocytes, vascular, immune, stellate and hepatocyte stem cell compartments and their underlying genomic programs in this process – particularly in human liver – remain unanswered. There is pressing medical need for novel therapeutic approaches to enhance liver regeneration in the context of liver surgery and in cirrhotic organ damage.Aims: Using a unique clinical infrastructure, we aim to understand the cellular programs and origins of regenerative processes in human liver using deep single cell and epigenetic analyses.Own proceeding work: The applicants build on their expertise in liver epigenetics and functional genomics and have established a unique analysis pipeline.Work plan: The applicants will use the clinical setting of therapeutically induced liver regeneration through portal vein embolization and in-situ split surgery before oncological liver resection. Hypertrophied and control liver from the same individual – thereby providing an inherent control for interindividual variation – will undergo single cell RNA and NOMe sequencing of freshly isolated hepatocytes and non-parenchymal cells. This data will be complemented by nuclear RNA sequencing from fresh frozen liver samples and by spatial information generated from laser capture cryo-microdissection of zonated parenchymal and major non-parenchymal cell compartments. Characteristic genomic signatures will further be verified by immunohistochemistry and RNA in situ hybridization. Bioinformatic integration will ultimately provide a spatially resolved and dynamic map of the cellular and tissue genomic programs of liver growth and hypertrophy. Conclusion: This project provides a unique opportunity to study the regeneration of a human organ (i.e. liver) on a single cell and tissue level in a clinically relevant, well controlled and ethically sound setting. The results will provide profound new insights into human liver biology and point out mechanisms to therapeutically tackle liver regeneration and remodeling.