载脂蛋白E对人干细胞稳态和衰老的调控作用及机制

Aging refers to the process of degeneration including the changes of tissue structure and physiological function increased with years. Stem cell senescence and homeostasis imbalance are the important factors of aging. As one of the important apolipoproteins involved in lipoprotein metabolism, apolipoprotein E (APOE) has been proved to be closely related to aging related diseases, including Alzheimer's disease, atherosclerosis and other diseases. However, few studies have reported the regulatory role and mechanism of APOE on homeostasis maintenance and senescence in human stem cells. In this project, CRISPR/Cas9 mediated gene editing was used to construct APOE knockout and knock-in human embryonic stem cell lines. And these human embryonic stem cell lines were differentiated into neural stem cells, mesenchymal stem cells and vascular endothelial cells in vitro, to explore the effect of APOE gene on the homeostasis maintenance and aging of human pluripotent stem cells. This project is designed to reveal the potential molecular target and regulatory network of APOE in aging intervention, and develop the related intervention strategies of aging.

衰老是机体随着年龄增长而发生的组织结构、生理功能等退行性的变化过程。干细胞衰老以及稳态失衡是引起机体衰老的重要因素。载脂蛋白E（APOE）作为是参与脂蛋白代谢重要的载脂蛋白之一，目前已证实与阿尔兹海默症、动脉粥样硬化等衰老相关疾病的病理过程密切相关。但是APOE对人干细胞稳态维持和衰老的调控作用及机制尚不完全清楚。本项目拟利用CRISPR/Cas9介导的基因编辑技术，产生APOE基因敲除和敲入的人胚胎干细胞系，在体外定向分化为神经干细胞、间充质干细胞和血管内皮细胞等细胞类型后，探究APOE基因对于人多能干细胞稳态维持及衰老的影响，揭示APOE在衰老干预的潜在分子靶标和调控网络，发展相关的预警和干预策略。

载脂蛋白E（APOE）是一种经典的脂质结合蛋白，在脂蛋白代谢中发挥关键作用。APOE的基因多态性与多种退行性疾病密切相关，但其对人干细胞稳态和衰老的调控作用及机制还尚不明确。在本项目中，我们利用CRIPSR/Cas9介导的基因编辑技术，产生APOE基因敲除的人胚胎干细胞系，并定向分化为血管外膜间充质祖细胞。研究发现，在人类干细胞衰老模型中APOE蛋白的表达上调，过表达APOE能够加速人干细胞衰老，而CRISPR/Cas9介导的APOE缺失可以延缓人干细胞衰老。在机制方面，APOE可以通过自噬-溶酶体途径促进了核膜蛋白和异染色质组分的降解，破坏了核周异染色质的稳定性。本项目为揭示APOE在衰老以及衰老相关疾病中的作用及调控机制的研究奠定了理论基础。