The collective influence of 1, 25-dihydroxyvitamin D3 with physiological fluid shear stress on osteoblasts

1, 25-dihydroxyvitamin D-3 (1, 25 (OH)(2) D-3) and mechanical stimuli in physiological environment contributes greatly to osteoporosis pathogenesis. Wide investigations have been conducted on how 1, 25-dihydroxyvitamin D-3 and mechanical stimuli separately impact osteoblasts. This study reports the collective influences of 1, 25dihydroxyvitamin D-3 and flow shear stress (FSS) on biological functions of osteoblasts. 1, 25 (OH)(2) D-3 were prepared in various kinds of concentrations (0, 1, 10, 100 nmmol/L), while physiological fluid shear stress (12 dynes/cm(2)) was produced by using a parallel-plate fluid flow system. 1, 25 (OH)(2) D-3 affects the responses of ROBs to FSS, including the inhibition of NO release and cell proliferation as well as the promotion of PGE2 release and cell differentiation. These findings provide a possible mechanism by which 1, 25(OH)(2) D-3 influences osteoblasts' responses to FSS, thus most probably providing guidance for the selection of 1, 25(OH)(2) D-3 concentration and mechanical loading in order to produce functional bone tissues in vitro.