Characterization of human mesenchymal stem cells selected by collagen barrier

Abstract

BACKGROUND: Stem cell therapy is a promising approach for tissue regeneration but there exists a problem of low engraftment rate to the injury site. Our laboratory has shown that human mesenchymal stem cells selected by collagen barrier (3D migrated cells) have higher migration capacity than those remained (3D remained cells). These 3D migrated cells might be hopeful candidate for improving engraftment efficacy. In order to investigate the underlying cause of the superior migratory activities of the selected cells, the cell-extracellular matrix-interacting molecules including matrix metalloproteinases (MMP) and integrins will be characterized in this study. METHODS: Human mesenchymal stem cells were encapsulated as collagen microspheres and allowed to migrate out via plating. Unplated microspheres and unencapsulated cells serve as three-dimensional (3D control) and two-dimensional (2D control) cell culture controls. These cells were characterized with MMP-1, -2, -9, -13, -14 and integrin alpha-2, alpha-v, beta-1 and beta-3 secretion and expression profile. Self-renewal assay, MTT assay for proliferative activity and multiple differentiation potential of these cells were also carried out to ensure their stem cell properties. RESULTS: 3D migrated cells secrete more MMP-1 than other experimental groups and less MMP-2 than 3D remained cells. 3D migrated cells have similar self-renewal capacity with 2D control, but higher proliferative activity than other groups in MTT assay in 72 hrs. CONCLUSION: 3D migrated cells have a different MMP secretion profile from other experimental groups, with higher proliferation rate and without compromising their self-renewing capacity.