A Genome-wide CRISPR-Based Screen Identifies KAT7 as a Senescence Driver

Understanding the genetic and epigenetic bases of cellular senescence is instrumental to aging intervention. We performed genome-wide CRISPR/Cas9-based screens in two human mesenchymal precursor cell (hMPC) models of progeroid syndromes and identified hundreds of genes whose deficiency alleviated cellular senescence. Among them, KAT7, a histone acetyltransferase, ranked as a top hit in both models. Inactivation of KAT7 decreased H3 lysine 14 acetylation (H3K14ac), repressed p15INK4b transcription, and rejuvenated both physiologically and pathologically aged cells. Moreover, lentiviral vectors encoding Cas9/sg-Kat7 alleviated liver senescence and extended healthspan and lifespan of mice. Our findings demonstrate that CRISPR/Cas9-based genetic screening is a robust method for systematically uncovering unknown senescence genes, of which KAT7 may represent a new therapeutic target for aging intervention. Overall design: CRISPR screen, RNA-seq, ChIP-seq and Hi-C

阐明细胞衰老的遗传与表观遗传基础，对衰老干预研究具有重要指导价值。我们在两种早衰综合征相关的人间充质前体细胞（human mesenchymal precursor cell, hMPC）模型中开展全基因组CRISPR/Cas9筛选，鉴定出数百个缺失后可缓解细胞衰老的基因。其中，组蛋白乙酰转移酶KAT7在两个模型中均为顶级阳性候选靶点。KAT7功能失活可降低组蛋白H3赖氨酸14乙酰化水平（H3K14ac）、抑制p15INK4b的转录，并使生理性及病理性衰老细胞恢复年轻化状态。此外，搭载Cas9/sg-Kat7的慢病毒载体可缓解小鼠肝脏衰老，延长其健康寿命与总寿命。本研究结果表明，基于CRISPR/Cas9的遗传筛选是系统性发掘未知衰老相关基因的可靠手段，KAT7或可成为衰老干预的全新治疗靶点。实验整体设计：CRISPR筛选、RNA测序（RNA-seq）、染色质免疫共沉淀测序（ChIP-seq）及Hi-C测序