Lepr+ mesenchymal cells sense diet to modulate intestinal stem cells via the Leptin-Igf1-Igf1r axis

We demonstrated that Lepr+ mesenchymal cells surround intestinal crypts where ISCs and transit-amplifying (TA) cells localize. The abundance of these cells increased upon administration of a high-fat diet (HFD) but dramatically decreased upon fasting. Depletion of Lepr+ mesenchymal cells resulted in fewer ISCs, compromised architecture of crypt-villi axis and impaired intestinal regeneration. Furthermore, Lepr+ cell-derived Igf1 has been identified as an important effector that promotes the proliferation of ISCs and TA cells. Deletion of Igf1 in Lepr+ cells partially recapitulated Lepr+ cell-ablated intestinal phenotypes during both homeostasis and regeneration. Overall, Lepr+ mesenchymal cells sense diet alteration and function as a novel niche for ISCs via the stromal Igf1 - epithelial Igf1r axis, which is critical for intestinal homeostasis and regeneration. These findings revealed that Lepr+ mesenchymal cells are an important mediator that links diet to ISC function and might provide a novel therapeutic target for gut diseases. Overall design: Examination of the whole mesenchymal cells and Lepr+ cells in intestine.