Epiregulin enhances periodontal tissue regeneration by promoting bone marrow mesenchymal stem cell functions under inflammatory niches

Figure 3 Epiregulin activated the epidermal growth factor receptor-extracellular signal-regulated kinase 1/2 signaling pathway to promote migration, chemotaxis, and osteogenic differentiation of mouse bone marrow stem cells under inflammatory conditions. A: Expression of mitogen-activated protein kinase signaling pathway were revealed in mouse bone marrow stem cells (mBMSCs) that were cultured in the inflammatory condition by western blotting. β-actin was used as the internal control; B: Expression of phosphorylated extracellular signal-regulated kinase (p-ERK) and ERK were detected in mBMSCs that were cultured in the inflammation condition by western blotting; C and D: Scratch-simulated wound migration assay results (n = 3, one-way analysis of variance [ANOVA]). Scale bar: 500 μm; E and F: Transwell chemotaxis assay results (n = 3, one-way ANOVA). Scale bar: 100 μm; G: Alizarin red staining; H: Expression of osterix (OSX) and osteocalcin (OCN) were revealed in mBMSCs that were cultured in the inflammatory condition by western blotting. Error bars represent standard deviation (n = 3). ^aP ≤ 0.05; ^bP ≤ 0.01. EGFR: Epidermal growth factor receptor; EREG: Epiregulin; JNK: C-Jun N-terminal kinase; MAPK: Mitogen-activated protein kinase.