Mesenchymal stem cell integrin-associated complexes

The composition and stiffness of the extracellular matrix (ECM) environment that surrounds Multipotent mesenchymal stem cells (MSCs) stem cells dictates transcriptional programming, thereby affecting stem cell lineage decision-making. Cells sense force between themselves and their microenvironment controlling the capability of MSCs to differentiate into adipocytes, osteocytes and chondrocytes. Force sensing is transmitted by integrin receptors and their associated adhesion signalling complexes. To identify regulators of MSC force sensing we sought to catalogue MSC adhesion complex composition. Therefore we isolated integrin-associated adhesion complexes formed in MSCs plated on the ECM ligand fibronectin. We identifed proteins using mass spectrometry that define a MSC specific subset of adhesion complex proteins consisting of key linkages to the actin cytoskeleton together with integrin signalling and force sensing components.