Unravel the Epigenetic Mechanisms of Cellular Rejuvenation and Identify Universal Rejuvenating Transcription Factors

PROJECT SUMMARY Aging is a complex process characterized by many hallmarks, such as DNA instability, epigenetic changes, and loss of protein homeostasis. Cellular rejuvenation, which aims to restore cells to a youthful state, offers hope to counteract aging and its associated diseases. Recent advances in epigenetic reprogramming using Yamanaka factors (a set of four transcription factors) have rejuvenated aged cells to youthful states and extended lifespan in mice. However, the clinical use of Yamanaka factors is limited due to their tumorigenic risk and full reprogramming potential. Therefore, it is important to find new rejuvenating transcription factors that are safer and more potent than the Yamanaka factors. The Li lab has recently developed a systematic approach and identified ~30 potential rejuvenation transcription factors. They have identified ~30 transcription factors that can restore youthful gene expression patterns in aged human fibroblasts in vitro. Critically, they also validated a few top hits with cellular and molecular phenotyping of aging hallmarks. However, the underlying mechanisms by which these transcription factors/chromatin modifiers rejuvenate aged cells, and the ability of these transcription factors to rejuvenate other types of aged cells (such as post-mitotic cells) are unknown. To better prepare me for such research, I propose to continue my training in cell/molecular biology by investigating how BRWD3 regulates DNA replication and epigenetic modifications (F99 Aims). This will not only enhance my comprehensive skill set for mechanistic studies, but also deepen my understanding and investigative strategies for chromatin-associated proteins, which are central to my proposed F00 aging research. During the K00 phase, I will leverage my molecular research expertise and the Li lab's system-level approaches to advance our understanding of cellular rejuvenation. I propose to dissect the mechanism of a top rejuvenation candidate and identify its key targets responsible for rejuvenation (K00 Aim 2.1). I will also use the induced neurons with the system-level approaches developed by the Li lab to explore the rejuvenation potential of the top 30 transcription factors in aged neurons (post-mitotic). Collectively, these experiments will not only deepen our understanding of the rejuvenation mechanism, but also shed light on rejuvenation approaches for overlooked post-mitotic cells, leading to the discovery of safer and more universal rejuvenation solutions for both mitotic and post-mitotic cells.