A Homeostatic Arid1a-Dependent Permissive Chromatin State Licenses Hepatocyte Responsiveness to Liver-Injury-Associated YAP Signaling.

Abstract

Following injury, differentiated epithelial cells can serve as a stem cell-independent source for tissue regeneration by undergoing reprogramming into other cell types. The intrinsic molecular basis underlying plasticity of differentiated cells remains largely unaddressed. Here we show that Arid1a, a key component of the SWI/SNF chromatin remodeling complex, controls liver regeneration and gene expression associated with emergence of injury-induced liver-progenitor-like cells (LPLCs). Hepatocyte-specific Arid1a ablation reduces LPLC gene expression in several models of periportal liver injury and impairs liver regeneration, leading to organ dysfunction. Arid1a establishes a permissive chromatin state at LPLC-enriched genes during homeostasis, suggesting it endows hepatocytes with competence to respond to injury-induced signals. Consistently, Arid1a facilitates binding of YAP, a critical regeneration signaling pathway, to LPLC-enriched genes, and Arid1a deletion prevents their YAP-associated induction following injury. Together, these findings provide a framework for studying the contributions of injury-induced LPLCs to periportal liver regeneration.