Single-cell RNA Sequencing Reveals How the Aryl Hydrocarbon Receptor Shapes Cellular Differentiation Potency in the Mouse Colon

Despite recent progress recognizing the importance of aryl hydrocarbon receptor (Ahr)-dependent signaling in suppressing colon tumorigenesis, its role in regulating colonic crypt homeostasis remains unclear. To assess the effects of Ahr on intestinal epithelial cell heterogeneity and functional phenotypes, we utilized single-cell transcriptomics and advanced analytic strategies to generate a high-quality atlas for colonic intestinal crypts from wild-type and intestinal-specific Ahr knockout mice. Here we observed the promotive effects of Ahr deletion on Foxm1-regulated genes in crypt-associated canonical epithelial cell types and subtypes of goblet cells and deep crypt-secretory cells. We also show that intestinal Ahr deletion elevated single-cell entropy (a measure of differentiation potency or cell sternness) and RNA velocity length (a measure of the rate of cell differentiation) in noncycling and cycling Lgr5(+) stem cells. In general, intercellular signaling cross-talk via soluble and membrane-bound factors was perturbed in Ahr-null colonocytes. Taken together, our single-cell RNA sequencing analyses provide new evidence of the molecular function of Ahr in modulating putative stem cell driver genes, cell potency lineage decisions, and cell-cell communication in vivo. Prevention Relevance: Our mouse single-cell RNA sequencing analyses provide new evidence of the molecular function of Ahr in modulating colonic stemness and cell-cell communication in vivo. From a cancer prevention perspective, Ahr should be considered a therapeutic target to recalibrate remodeling of the intestinal stem cell niche.

Automated summary

This study utilized single-cell transcriptomics to analyze colonic intestinal crypts from wild-type and intestinal-specific Ahr knockout mice, revealing the important role of Ahr in regulating colon tumorigenesis. Ahr deletion promoted the expression of Foxm1-regulated genes in specific epithelial cell types and secretory cells, and increased the differentiation potency and rate of cell differentiation in stem cells. Furthermore, Ahr deletion disrupted intercellular signaling. This study provides new evidence of the molecular function of Ahr in vivo and has important implications for cancer prevention.