ABSTRACT
Objective To apply iTRAQ technology to observe changes in protein expression group in the process of inducing C2C12 cells differentiation towards osteoblast by BMP-2.Methods The myoblast C2C12 cells were seeded in BMP-2 induced differentiation system for differentiation induction.In the 7th day,differentiation protein was extracted and labeled with iTRAQ reagent.Then,mass spectrometric detection,data analysis of differentially expressed proteins,and analysis of biological information were carried out.Results 23 significantly differentially expressed protein spots were screened by BMP-2-induced myoblast C2C12 differentiated cell protein expression profile analysis,where the protein was labeled with iTRAQ reagent.8 protein points were up-regulated,and 15 protein points were down-regulated.Trend classification found that the above differential protein had differential expression in each period of C2C12 cell osteogenic differentiation (1-7 days).Part of up-regulated protein in the early differentiation period showed high expression level;part of up-regulated protein in the late differentiation period showed high expression level;similarly,part of down-regulated protein in the early differentiation period presented low expression level;part of down-regulated protein in the late differentiation period showed low expression level.Preliminary identification showed SERCA3,Cytochrome bS,S100A4,ATPase inhibitor and ATPIF1 presented dynamic changes,which suggests that these proteins may be related to inducing osteogenic differentiation mechanism.Conclusion The results of differential protein expression trend show the necessity of full monitoring of C2C 12 cells osteogenic differentiation and indicate that iTRAQ technology is an effective method of studying protein changes of cellular molecule.Five proteins including SERCA3,Cytochrome b5,S100A4,ATPase inhibitor and ATPIF1 can be used as candidate targets for osteogenic differentiation mechanism research.
ABSTRACT
<p><b>OBJECTIVE</b>To assess the optimal configuration of double-screw fixation for subtalar arthrodesis using finite element analysis.</p><p><b>METHODS</b>Three-dimensional finite element double-screw models of subtalar arthrodesis were reconstructed using Mimics 13.0, Geomagic 10.0 and solid works software based on the 3-D images of the volunteer's right foot. The external and internal rotation torques of 4 N·m were applied, and the micromotion at the bone-to-bone interface were measured to evaluate the initial stability of subtalar arthrodesis.</p><p><b>RESULTS</b>A neck screw plus an anterolateral dome screw was the most stable model. The peak micromotion at the fusion site of this fixation configuration were 41.67mnplus;0.49 and 42.64mnplus;0.75 µm in response to the respectively. A neck screw plus a posteromedial dome screw was the least stable model, with peak micromotion at the bone-to-bone interface of 61.76mnplus;1.00 and 62.32mnplus;0.90 µm, respectively.</p><p><b>CONCLUSION</b>A neck screw plus an anterolateral dome screw is the best fixation configuration while a neck screw plus a posteromedial screw provides the least stability of subtalar arthrodesis. Three-dimensional finite element models allow effective preoperative planning of the screw number and placement.</p>