Experimental cell research
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Adult bone marrow-derived mesenchymal stem cells (MSCs) are able to differentiate into myofibroblasts and be recruited into wound lesions and contribute to wound healing. The cellular and molecular mechanisms responsible for MSC trafficking and differentiation, however, are poorly understood. Local resting resident fibroblasts are activated after injury and play a critical role in recruiting MSCs. ⋯ The regulatory effects of PDGF-B-aFBs are likely to be mediated by basic fibroblast growth factor (bFGF) and epithelial neutrophil activating peptide-78 (ENA-78 or CXCL5) as protein array analysis indicated elevated levels of these two soluble factors in culture supernatant of PDGF-B-aFBs. Blocking antibodies against bFGF and CXCL5 were able to inhibit both trafficking and differentiation of MSCs into 3D collagen gels while supplement of exogenous bFGF and/or CXCL5 promoted invasion/migration of MSCs into 3D collagen gels. Our results reveal that PDGF-B-aFBs play a key role in the recruitment/migration and differentiation of MSCs and implicate a bFGF- and CXCL5-dependent mechanism in mediating these effects.