The use of nanovibration to discover specific and potent bioactive metabolites that stimulate osteogenic differentiation in mesenchymal stem cells
Tom Hodgkinson, Penelope M. Tsimbouri, Virginia Llopis-Hernández, Paul Campsie, David J. Scurr, Peter Childs, David J. Phillips, Sam Donnelly, Julia Wells, Fergal J. O’Brien, Manuel Salmerón‐Sánchez, Karl Burgess, Morgan R. Alexander, Massimo Vassalli, Richard O. C. Oreffo, S. Reid, David J. France, Matthew J. Dalby
Abstract
Bioactive metabolites have wide-ranging biological activities and are a potential source of future research and therapeutic tools. Here, we use nanovibrational stimulation to induce osteogenic differentiation of mesenchymal stem cells, in the absence of off-target, nonosteogenic differentiation. We show that this differentiation method, which does not rely on the addition of exogenous growth factors to culture media, provides an artifact-free approach to identifying bioactive metabolites that specifically and potently induce osteogenesis. We first identify a highly specific metabolite, cholesterol sulfate, an endogenous steroid. Next, a screen of other small molecules with a similar steroid scaffold identified fludrocortisone acetate with both specific and highly potent osteogenic-inducing activity. Further, we implicate cytoskeletal contractility as a measure of osteogenic potency and cell stiffness as a measure of specificity. These findings demonstrate that physical principles can be used to identify bioactive metabolites and then enable optimization of metabolite potency can be optimized by examining structure-function relationships.