Journal of Biomedicine and Biotechnology 
Volume 2004 (2004), Issue 1, Pages 24-34
doi:10.1155/S1110724304306017
Research article

Adhesion to Vitronectin and Collagen I Promotes Osteogenic Differentiation of Human Mesenchymal Stem Cells

Roman M. Salasznyk,1 William A. Williams,1 Adele Boskey,2 Anna Batorsky,1 and George E. Plopper1

 1Department of Biology, Rensselaer Polytechnic Institute, Troy 12180-3596, NY, USA
2Hospital for Special Surgery, New York City 10021, NY, USA
Received 3 June 2003; Revised 9 July 2003; Accepted 9 July 2003

Abstract

The mechanisms controlling human mesenchymal stem cells (hMSC) differentiation are not entirely understood. We hypothesized that the contact with extracellular matrix (ECM) proteins normally found in bone marrow would promote osteogenic differentiation of hMSC in vitro. To test this hypothesis, we cultured hMSC on purified ECM proteins in the presence or absence of soluble osteogenic supplements, and assayed for the presence of well-established differentiation markers (production of mineralized matrix, osteopontin, osteocalcin, collagen I, and alkaline phosphatase expression) over a 16-day time course. We found that hMSC adhere to ECM proteins with varying affinity (fibronectin > collagen I ≥ collagen IV ≥ vitronectin > laminin-1) and through distinct integrin receptors. Importantly, the greatest osteogenic differentiation occurred in cells plated on vitronectin and collagen I and almost no differentiation took place on fibronectin or uncoated plates. We conclude that the contact with vitronectin and collagen I promotes the osteogenic differentiation of hMSC, and that ECM contact alone may be sufficient to induce differentiation in these cells.