Soft-tissue cells are surprisingly sensitive to the elasticity of their microenvironment, suggesting that traditional culture plastic and glass are less relevant to tissue regeneration and chemotherapeutics than might be achieved. Cells grown on gels that mimic the elasticity of tissue reveal a significant influence of matrix elasticity on adhesion, cytoskeletal organization, and even the differentiation of human adult derived stem cells. Cellular forces and feedback are keys to how cells feel their mechanical microenvironment, but detailed molecular mechanisms are still being elucidated. This review summarizes our initial findings for multipotent stem cells and also the elasticity-coupled effects of drugs on cancer cells and smooth muscle cells. The drugs include the contractility inhibitor blebbistatin, the proliferation inhibitor mitomycin C, an apoptotis-inducing antibody against CD47, and the translation inhibitor cycloheximide. The differential effects not only lend insight into mechano-sensing of the substrate by cells, but also have important implications for regeneration and molecular therapies.

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Proteomic analysis of the human body is a significant recent scientific endeavour. In this study, we investigated the proteomic profile of human dentin using modern analytical and mass spectrometric techniques. Five healthy permanent human molars from five adults were cut, pulverized, denaturated with guanidine buffer, and demineralized with EDTA buffer. The extracted proteins were analysed by gel electrophoresis (SDS-PAGE and two-dimensional gel electrophoresis), digested with trypsin, and separated by liquid chromatography/high-resolution tandem mass spectrometry. We identified 289 proteins with high confidence, 90 of which had not been previously detected in human dentin. Nine (currently hypothetical) proteins were identified for the first time in an actual human sample. The proteins have a variety of functions, including calcium-ion binding, formation of the extracellular matrix, formation of the cytoskeleton, cytoskeletal protein binding, immune response, and transport. In conclusion, this is the first use of two-dimensional electrophoresis for investigating human dentin.