LSR Targets YAP to Modulate Intestinal Paneth Cell Differentiation

Lipolysis-stimulated lipoprotein receptor (LSR) is a multi-functional protein that is best known for its roles in assembly of epithelial tricellular tight junctions and hepatic clearance of lipoproteins. Here, we investigated whether LSR contributes to intestinal epithelium homeostasis and pathogenesis of intestinal disease. By using multiple conditional deletion mouse models and ex vivo cultured organoids, we find that LSR elimination in intestinal stem cells results in disappearance of Paneth cell without affecting the differentiation of other cell lineages. Mechanistic studies reveal that LSR deficiency increases abundance and nuclear localization of YAP by modulating its phosphorylation and proteasomal degradation. Using gain- and loss-of-function studies we show that LSR protects against necrotizing enterocolitis through enhancement of Paneth cell differentiation in small intestinal epithelium. Thus, this study identifies LSR as an upstream negative regulator of YAP activity, an essential factor for Paneth cell differentiation, and a potential novel therapeutic target for inflammatory bowel disease. ### Competing Interest Statement The authors have declared no competing interest.