Colonic healing requires Wnt produced by epithelium as well as Tagln+ and Acta2+ stromal cells

• DOI: 10.1242/dev.199587
• Publication Date: 2021-12-15T09:45:43Z
• Authors: Soumyashree Das; Qiang Feng; Iyshwarya Balasub...; Xiang Lin; Haoran Liu; Oscar Pellón-Card...; Shiyan Yu; Xiao Zhang; Yue Liu; Zhi Wei; Edward M. Bonder; Michael P. Verzi; Wei Hsu; Lanjing Zhang; Timothy C. Wang; Nan Gao
• Keywords: 0301 basic medicine; Wound Healing; Colon; Stem Cells; Microfilament Proteins; Muscle Proteins; Pancreatitis-Associated Proteins; Actins; Receptors, G-Protein-Coupled; Mice, Inbred C57BL; Mice; 03 medical and health sciences; Wnt3A Protein; Animals; Colitis, Ulcerative; Intestinal Mucosa; Cells, Cultured

ABSTRACT Although Wnt signaling is clearly important for the intestinal epithelial homeostasis, the relevance of various sources of Wnt ligands themselves remains incompletely understood. Blocking the release of Wnt in distinct stromal cell types suggests obligatory functions of several stromal cell sources and yields different observations. The physiological contribution of epithelial Wnt to tissue homeostasis remains unclear. We show here that blocking epithelial Wnts affects colonic Reg4+ epithelial cell differentiation and impairs colonic epithelial regeneration after injury in mice. Single-cell RNA analysis of intestinal stroma showed that the majority of Wnt-producing cells were contained in transgelin (Tagln+) and smooth muscle actin α2 (Acta2+) expressing populations. We genetically attenuated Wnt production from these stromal cells using Tagln-Cre and Acta2-CreER drivers, and found that blockage of Wnt release from either epithelium or Tagln+ and Acta2+ stromal cells impaired colonic epithelial healing after chemical-induced injury. Aggregated blockage of Wnt release from both epithelium and Tagln+ or Acta2+ stromal cells drastically diminished epithelial repair, increasing morbidity and mortality. These results from two uncharacterized stromal populations suggested that colonic recovery from colitis-like injury depends on multiple Wnt-producing sources.