Effects of Elastin-Like Peptide on Regulation of Human Mesenchymal Stem Cell Behavior

Abstract

Mesenchymal stem cells (MSCs) have the ability to proliferate and differentiate into different cell types. However, cell behavior has been difficult to fully control. As more is learned about how the surrounding microenvironment in the culture influences cell behavior, the importance of substrate structure and chemistry are realized. Many extracellular matrix proteins have been examined to determine their effects on regulation of cell behavior. In this study, we examined the effect of Arg-Gly-Asp-enriched elastin-like peptide (RGD-ELP), a recombinant peptide containing both elastin repeating units and the RGD adhesion domains, on MSC adhesion, proliferation, cell morphology, and differentiation. To this end, cells were seeded on monolayer or nanofibrous substrates that were coated without any molecule as a negative control, with RGD-ELP, or with fibronectin as a positive control. DNA content was measured 6 h, 3 days, and 7 days after cell seeding. Our results showed that RGD-ELP-coated monolayer substrates were able to support cell proliferation, whereas RGD-ELP-coated nanofibrous substrates were able to enhance cell adhesion but not proliferation, suggesting that substrate topography plays a role in the regulation of cell adhesion and proliferation. Cells cultured on RGD-ELP-coated monolayer or nanofibrous substrates for 2 days demonstrated a more elongated, spread morphology than cells cultured on the uncoated substrates. RGD-ELP-coated monolayer or nanofibrous substrates increased mineral formation in MSC culture compared to both control substrates. The mRNA expression of lineage-specific markers showed that MSCs cultured on RGD-ELP-coated nanofibrous substrates were increasingly induced to differentiate into the osteogenic and adipogenic lineages compared to those cultured on uncoated substrates. Overall, our results suggest that RGD-ELP coating is able to support increased cell adhesion and osteogenesis. Mesenchymal stem cells (MSCs) have been used as a clinical practice to treat patients with graft-versus-host disease. With the potential in regenerative medicine, therapeutic use of the cell recently emerges as a promising strategy to treat degenerative diseases. In fact, a number of clinical trials have been carried out to explore the potential of MSCs for disease treatment. Results of this study suggest that MSC properties can be enhanced through culturing the cell on nanofibrous substrates coated with chemically defined peptides. Our approach using a FDA-approved polymeric substrate along with chemically defined peptides to prepare MSCs for cell therapies can be considered highly translational for clinical applications.