Focal adhesion kinase signaling controls cyclic tensile strain enhanced collagen I-induced osteogenic differentiation of human mesenchymal stem cells.
Donald F Ward,William A Williams,Nicole E Schapiro,Genevieve L Weber,Samuel R Christy,Megan Salt,Robert F Klees,Adele Boskey,George E Plopper
Molecular & cellular biomechanics : MCB
4
2007
Show Abstract
Focal adhesion kinase (FAK) is a key integrator of integrin-mediated signals from the extracellular matrix to the cytoskeleton and downstream signaling molecules. FAK is activated by phosphorylation at specific tyrosine residues, which then stimulate downstream signaling including the ERK1/2 pathway, leading to a variety of cellular responses. In this study, we examined the effects of FAK point mutations at tyrosine residues (Y397, Y925, Y861, and Y576/7) on osteogenic differentiation of human mesenchymal stem cells exposed to collagen I and cyclic tensile strain. Our results demonstrate that FAK signaling emanating from Y397, Y925, and to a lesser extent Y576/7, but not from Y861, controls osteogenic differentiation through an ERK1/2 pathway, as measured by expression levels of key osteogenesis marker genes and subsequent matrix mineralization. These data indicate that FAK is a critical decision maker in extracellular matrix/strain-enhanced osteogenic differentiation. | 18437915
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