| The complex spatiotemporal organization of cellular and molecular interactions dictates the physiological function of cells. These behaviors are indicative of an integrated response to a mechanistic cellular environment and anchored in cell. Here, we are able to control interconnected structural, mechanical, and chemical stimuli by dictating the cellular environment through chemical surface modifications, soft lithography, and mechanical deformation. Control of these variables is obtained through the use a novel Pressure-controlled Cell Stretching devices (PreCS) chemically modified for cell adhesion. The PreCS generates a pattern of forces similar to those encountered in physiological environments. Further, the integration of lithographic methods and chemical patterning allows the introduction of space and time dependent parameters by combining mechanical stimulation, biochemical regulation, and scaffolding design.; Mechanotransduction has been a highly-studied response in cellular and molecular biology with a focus on integrins as the transmembrane molecular initiation point (Discher, Janmey et al. 2005; Shemesh, Geiger et al. 2005; Wang, Botvinick et al. 2005). Although much has been learned about integrin regulated signal initiation, researchers have hypothesized that alternate transmembrane activation molecules could be present. Here, we demonstrate the existence of a novel initiation molecule, syndecan-4, and the independence of this transmembrane protein from integrin-binding based mechanotransduction signaling. The mechanical stretching of NIH-3T3 cells adhered solely to syndecan-4 antibodies, enabled by our chemical and pressure based techniques, results in an increase in extracellular signal-regulated kinase phosphorylation that is known to occur during mechanotransduction. The role of syndecans as integrators of extracellular signals as well as their ability to bind to both extracellular and cytoplasmic proteins (Zimmermann and David 1999; Denhez, Wilcox-Adelman et al. 2002) supports the finding that these proteins could be an alternative activation initiator. |
