Creeping fat-derived mechanosensitive fibroblasts drive intestinal fibrosis in Crohn's disease strictures [Mouse scRNA-seq]
A significant complication of Crohn's disease (CD) is intestinal fibrosis, which narrows the bowel lumen to cause a stricture. Creeping fat (CF) is the wrapping of mesenteric adipose tissue (MAT) around inflamed and fibrotic bowel, but its role in stricture progression in CD is unclear. In this study, we explore whether CF-derived fibroblasts, the cells primarily responsible for extracellular matrix (ECM) deposition, directly contribute to stricture progression.  By performing scRNA-seq and Visium on pediatric CD strictures, we identified a CF-associated, mechanosensitive, CTHRC1+ fibroblast enriched for YAP/TAZ signaling that localized to the fibrotic CF-bowel wall interface within the stricture. We developed a novel mouse model of intestinal fibrosis that exhibited CF and used lineage tracing to show that Postn+ mouse fibroblasts, analogous to human CTHRC1+ fibroblasts, infiltrate fibrotic bowel and deposit ECM in a YAP/TAZ-dependent manner through scRNA-seq. Our findings identify mesenteric fat as a key source of pro-fibrotic fibroblasts that can be therapeutically targeted to limit intestinal fibrosis. Overall design: Single cell RNA sequencing of mouse bowel and mesenteric adipose tissue from POD14 colotomy mouse model and sham surgeries