Hippo signaling is an evolutionarily conserved pathway that restricts organ growth during development and suppresses regeneration in mature organs 1-3 . Using a high-throughput phenotypic screen, we have identified a potent, non-toxic, and reversible inhibitor of Hippo signaling. An ATP-competitive inhibitor of Lats kinases, the compound causes Yapdependent proliferation of murine supporting cells in the inner ear, murine cardiomyocytes, and human Müller glia in retinal organoids. RNA sequencing indicates that the substance fosters both the G1-S and G2-M checkpoint transitions and yields supporting cells capable of transdifferentiation. Upon withdrawal of the compound, a subset of supporting cells move their nuclei into the hair-cell layer and express genes characteristic of hair cells. Viral transfection of Atoh1 induces the expression of hair cellspecific proteins in progeny. The compound promotes the initial stages of the proliferative regeneration of hair cells, a process thought to be permanently suppressed in the adult mammalian inner ear. This project was made possible by the dedicated personnel of two service facilities. At Rockefeller University's High-Throughput Screening Resource Center directed by Fraser Glickman, Carolina Adura Alcaino helped design assays for enzyme activity. assisted with assay design and Rui Liang performed chemical syntheses.
Declaration of InterestsKG, NK, TA, AAP, and AJH are parties to an application for patent protection of derivatives of the Lats inhibitor presented here.