| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 2039778 | Cell Reports | 2016 | 8 Pages |
•Intestinal epithelial stem cells are sensitive to global attenuation of Wnt secretion•Extra-epithelial Wnts maintain the renewal of intestinal epithelial stem cells•Exogenous reconstitution of Wnt/β-catenin signaling promotes intestinal renewal•Gli1 and Acta2 mark the majority of Wnt2b+ subepithelial mesenchymal cells
SummaryTargeting of Wnt signaling represents a promising anti-cancer therapy. However, the consequences of systemically attenuating the Wnt pathway in an adult organism are unknown. Here, we globally prevent Wnt secretion by genetically ablating Wntless. We find that preventing Wnt signaling in the entire body causes mortality due to impaired intestinal homeostasis. This is caused by the loss of intestinal stem cells. Reconstitution of Wnt/β-catenin signaling via delivery of external Wnt ligands prolongs the survival of intestinal stem cells and reveals the essential role of extra-epithelial Wnt ligands for the renewal of the intestinal epithelium. Wnt2b is a key extra-epithelial Wnt ligand capable of promoting Wnt/β-catenin signaling and intestinal homeostasis. Wnt2b is secreted by subepithelial mesenchymal cells that co-express either Gli1 or Acta2. Subepithelial mesenchymal cells expressing high levels of Wnt2b are predominantly Gli1 positive.
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