Chromatin remodelling in damaged intestinal crypts orchestrates redundant TGFβ and Hippo signalling to drive regeneration

Abstract

Cell state dynamics underlying successful tissue regeneration are undercharacterized. In the intestine, damage prompts epithelial reprogramming into revival stem cells (revSCs) that reconstitute Lgr5⁺ intestinal stem cells (ISCs). Here single-nuclear multi-omics of mouse crypts regenerating from irradiation shows revSC chromatin accessibility overlaps with ISCs and differentiated lineages. While revSC genes themselves are accessible throughout homeostatic epithelia, damage-induced remodelling of chromatin in the crypt converges on Hippo and the transforming growth factor-beta (TGFβ) signalling pathway, which we show is transiently activated and directly induces functional revSCs. Combinatorial gene expression analysis further suggests multiple sources of revSCs, and we demonstrate TGFβ can reprogramme enterocytes, goblet and paneth cells into revSCs and show individual revSCs form organoids. Despite this, loss of TGFβ signalling yields mild regenerative defects, whereas interference in both Hippo and TGFβ leads to profound defects and death. Intestinal regeneration is thus poised for activation by a compensatory system of crypt-localized, transient morphogen cues that support epithelial reprogramming and robust intestinal repair.