Influence of Joint Action of Fluid Shear Stress and Signal Transduction Ligand Inhibitor on Osteoclasts´ Differentiation and Maturation

Through observation of the effects of signal transduction ligand inhibitor and fluid shear stress on osteoclasts, search the distinct signal transduction pathway. Exert fluid shear stress of 0.3 dyne/cm to inhibitor-added marrow cells for 0.5 h, and observe the change of osteoclast number, mean optical density of TRAP picture, and RANKL expression level.The amount of osteoclasts, optical density coefficients in TRAP dyeing images, and RANKL expression level reduced significantly; RANKL expression level had significant difference between stress and non-stress exerted groups in Genestein-added group, and in other groups stress- exerting didn´t work. Signal transduction ligand inhibitor KT5720 (cAMP pathway inhibitor) and Genestein (MAPK pathway inhibitor) have depressant effect on differentiation, maturation and enzymatic metabolism of osteoclasts. Reduction of osteoclasts amount and enzyme activity caused by stress attributes to cAMP-PKA pathway but not MAPK one.