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

Abstract

While Wnt signaling is clearly important for the intestinal epithelial homeostasis, the relevance of various sources of Wnt ligands themselves remains incompletely understood. Wnt blockage in distinct stromal cell types suggested obligatory functions of several stromal cell sources and yielded different observations. The physiological contribution of epithelial Wnt to tissue homeostasis remains unclear. We show here that blocking epithelial Wnts affected colonic Reg4+ epithelial cell differentiation, and impaired colonic epithelial regeneration after injury. Single cell RNA analysis of intestinal stroma showed that the majority of Wnt-producing cells were contained in transgelin (Tagln+) and smooth muscle actin alpha 2 (Acta2+) expressing populations. We genetically attenuated Wnt production from these stromal cells using Tagln-Cre and Acta2-CreER drivers, and found that Wnt blockage from either epithelium or Tagln+ and Acta2+ stromal cells impaired colonic epithelial healing after chemical-induced injury. Aggregated Wnt blockage 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.

Histone deacetylase inhibitor belinostat regulates metabolic reprogramming in killing KRAS‐mutant human lung cancer cells

“…To further confirm the metabolic effect of belinostat, stable isotope tracer was introduced by preparing different concentrations of the drug in methionine‐free RPMI medium supplemented with 2 mM l ‐methionine (methyl‐ 13 C) as described previously 37‐39 . Briefly, 1 × 10 6 cells were seeded in a 6‐cm cell culture dish overnight.…”

“…To further confirm the metabolic effect of belinostat, stable isotope tracer was introduced by preparing different concentrations of the drug in methionine-free RPMI medium supplemented with 2 mM L-methionine (methyl-13 C) as described previously. [37][38][39] Briefly, 1 × 10 6 cells were seeded in a 6-cm cell culture dish overnight. The cells were then serum starved for 24 h followed by treatment with 0.1% DMSO and 80 μM belinostat for 3 and 24 h. Cell metabolites were then collected and analyzed by LC-MS, as described in the previous section.…”

Subepithelial Stromal Cells: Their Roles and Interactions with Intestinal Epithelial Cells during Gut Mucosal Homeostasis and Regeneration

“…[44,45]. For example, knocking out Porcupine and Wntless, the essential mediators of Wnt secretion, greatly reduced the ISC population [18,43,46]. Similarly, the adenoviral delivery of the Wnt signaling antagonist, Dkk1, inhibited the intestinal proliferative marker, Ki67, and the Wnt/β-catenin target genes, CD44 and EpbB2 [47].…”

Subepithelial Stromal Cells: Their Roles and Interactions with Intestinal Epithelial Cells during Gut Mucosal Homeostasis and Regeneration

“…As demonstrated in previous studies, canonical Wnt (or Wnt/β-catenin) signaling is crucial for ISC self-renewal maintenance [ 44 , 45 ]. For example, knocking out Porcupine and Wntless, the essential mediators of Wnt secretion, greatly reduced the ISC population [ 18 , 43 , 46 ]. Similarly, the adenoviral delivery of the Wnt signaling antagonist, Dkk1, inhibited the intestinal proliferative marker, Ki67, and the Wnt/β-catenin target genes, CD44 and EpbB2 [ 47 ].…”