Table 1.
Crypt epithelial stem cells | Subepithelial (pericryptal) myofibroblasts-local stem cell niche | BM-MSCs | |
Origin | Pericryptal myofibroblasts | Subepithelial CD34+ fibroblasts, perivascular smooth muscle cells, adipocytes, endothelial- and epithelial cells (via EMT), BM-MSCs | Bone marrow |
Daughter cells | Enterocytes, goblet cells, endocrine cells, paneth cells | Follicular dendritic cells, crypt epithelial stem cells, pericytes | Subepithelial myofibroblasts, fibrocytes, pericytes, adipocytes, crypt epithelial stem cells |
Main regulator pathways of differentiation and/or homing | Wnt/β-catenin, Lgr-5, integrins, growth factor receptors (EGFR, HGFR, I1GFR) | TGF-β1, cytokines (IL-1, -6, -10, TNFα), growth factors (TGFα, GM-CSF, PDGF-AA, -BB, bFGF, KGF, HGF), chemokines (IL-8, MCP1, MIP-1α,-2), inflammatory mediators (PGE2, PAF, PGI2) | Chemokine receptors (CCR-1,-2,-7,-8,-9; CXCR-1,-2,-4,-5,-6), cell adhesion molecules involved in extravasation (VCAM, ICAM, selectins), proinflammatory cytokines (TNFα, IL-8), von Willebrand factor |
Physiological function | Epithelial renewal | Growth, repair | Growth, repair, wound healing |
Pathological function | Tumorigenesis, ulcer development | Tumorigenesis, cancer progression, inflammation, fibrosis | Tumorigenesis, inflammation, fibrosis |
Cell type specific markers | Positive markers: Lgr-5, Musashi-1, CDX-2 | Negative markers: smoothelin, caldesmon, desmin | Negative markers: CD13, -14, -45, c-Kit, MHC class I and II |
Positive markers: α-SMA, vimentin, SMM, prolyl 4-hydroxylase, CD90 | Positive markers: CD54,-90,-133,-146,-166, Flk-1, Sca-1, stage-specific antigen I, musashi-1, HLA class I | ||
References | 1-6, 35, 50 | 12, 15, 25, 37, 48, 49 | 8, 9, 11, 20, 26, 29, 35, 37, 41, 58 |
Lgr-5: Leucine-rich repeat-containing G-protein coupled receptor 5; EGFR: Epithelial growth factor receptor; HGFR: Hepatocyte growth factor receptor; I1GFR: Insulin-like growth factor receptor-1; CDX2: Caudal type homeobox transcription factor 2; EMT: Epithelial-to-mesenchymal transition; TGF: Transforming growth factor; IL: Interleukin; TNF: Tumor necrosis factor; GM-CSF: Granulocyte macrophage colony-stimulating factor; PDGF: Platelet-derived growth factor; bFGF: Basic fibroblast growth factor; KGF: Keratinocyte growth factor; HGF: Hepatocyte growth factor; MCP1: Monocyte chemotactic protein 1; MIP: Macrophage inflammatory protein; PGE2: Prostaglandin E2; PAF: Platelet-activating factor; PGI2: Prostacyclin; SMA: Smooth muscle actin; SMM: Smooth muscle myosin; CCR: Chemokine receptor; CXCR: Chemokine CXC motif receptor; VCAM: Vascular cell adhesion molecule; ICAM: Intercellular cell adhesion molecule; MHC: Major histocompatibility complex; Flk-1: Fetal liver kinase-1; Sca-1: Stem cell antigen-1; HLA: Human leukocyte antigen.