1. Department of Biology, Western Carolina University, Cullowhee, NC 28723, USA.
2. Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA.
Background: Dermatopontin (DPT) is a 22-kDa tyrosine-rich extracellular matrix (ECM) protein that is found at high levels in demineralized bone matrix and cartilage and may play an important role in skeletal tissue function. In the current study, we investigate whether DPT in the ECM plays a role in the enhanced osteogenic differentiation of adipose-derived stem cells (ADSCs).
Methods: In order to determine whether DPT modulates osteogenesis, we overexpressed the DPT gene in ADSC using stable lentiviral infection, induced the DPT-overexpressing cells to differentiate, and isolated the ECM secreted by these cells during osteogenesis. Using the secreted ECM with "higher than normal" levels of DPT embedded within as a substrate for cell growth, we assessed the extent to which the excess DPT modulated osteogenic marker expression during osteogenic differentiation of naive ADSC.
Results: We found that ADSC cultured on the DPT-enriched ECM differentiated towards an osteogenic phenotype more robustly, as measured by expression of osteogenic marker genes.
Conclusions: This may indicate an important role for DPT in the induction of stem cells toward an osteoblast phenotype during skeletal wound healing. DPT may present a novel candidate for future studies of stem cell osteogenesis and the development of more biologically relevant biomaterial substrates for bone regeneration.
Keywords: Dermatopontin, adipose-derived stem cells, extracellular matrix, osteogenesis, overexpression, matricellular proteins