Generation of liver assembloids and mechanoregulation of liver regeneration

Abstract

Liver has been known to be capable of regenerating its cell population upon damage. Upon persistent liver damage such as fibrosis, coupled with the impairment of hepatocyte proliferation, cholangiocyte population shows a leniency to acquire an expression profile resembling hepatocytes. However, this leniency is mainly shown in animal models and has not yet been demonstrated in an organoid system without the external regulation of the pathways to push cells to hepatic fate. Liver cells also have been shown to respond to mechanical stimuli upon changes in the micro-environment including fibrosis but the response of cholangiocytes to mechanical cues is a topic that requires further investigation. In this study, we take advantage of the bi-phenotypic nature of cholangiocytes to generate hepatocyte-like organoids from ductal organoids isolated from both TAA and control livers. By assembling these organoids in a kinetic culture system, a novel attempt to generate a liver assembloid model that recapitulates native liver architecture is performed. Here,we propose a novel mechanotransduction pathway in cholangiocytes, mediated by PIEZO1, that orchestrates liver tissue organization. We demonstrate that PIEZO1 which is localized in the primary cilium regulates YAP1 signaling, influencing cellular responses to fibrosis and guiding cholangiocyte-driven tissue remodeling. Employing both in vitro fibrosis organoid cultures and in vivo fibrosis models, we reveal distinct expression profiles in fibrotic versus control conditions. This study advances our understanding of hepatic cell plasticity and offers a powerful platform for therapeutic exploration in liver disease.