adjacent to fibroblast subepithelial intestinal fibroblast 2024-09-23T09:59:27Z S2 mesenchymal cells The S2 fibroblast population has been identified as a subset of intestinal fibroblasts located near the epithelial lining. This population is divided into two subtypes: S2a and S2b. S2a is involved in epithelial differentiation, while S2b, located at the top of the crypt, regulates intestinal stem cell proliferation, niche formation, and wound healing. A fibroblast located adjacent to the intestinal epithelium in both the small intestine and colon, specifically around the crypts. This cell is characterized by the expression of PDGFRα and various collagen isoforms, including COL4A5 and COL4A6. It secretes signalling molecules like TGF-β, Wnt ligands, and BMPs, which are crucial for epithelial homeostasis, intestinal stem cell support, and basement membrane formation. S2 fibroblast intestinal epithelium