The aim of our study was to investigate interactions of mesenchymal progenitor cells (MPCs) with collagen matrices.Methods
Human bone-marrow-derived MPCs were cultivated in collagen type I gels with and without inhibition of β1-integrin by a specific antibody. Collagen gel contraction, cell morphology, expression of integrin subunits and several genes related to matrix synthesis and turnover as well as MPC differentiation were analyzed over 14 days.Results
Human MPCs markedly contracted free-floating collagen gels. Contraction was nearly completely inhibited by blocking β1-integrin. Cellular morphology was elongated in the absence and mostly round in the presence of the antibody. Expression of integrin α1, α2 and β1 subunits showed several changes partly dependent on β1-integrin blocking. Expression of matrix metalloproteinase-1 was elevated irrespective of β1-integrin blocking and tenascin-C was subsequently induced during gel contraction. Spontaneous induction of chondrogenic, osteogenic or adipogenic differentiation was observed neither in the presence nor in the absence of the β1-integrin antibody.Conclusion
Our results indicate that the interaction of human MPCs with fibrillar collagen type I involves β1- and α-integrin subunits and induces changes in gene expression related to extracellular matrix synthesis and turnover but not differentiation to the chondrogenic, osteogenic or adipogenic phenotype.