The collective influence of 1, 25-dihydroxyvitamin D3with physiological fluid shear stress on osteoblasts

1, 25-dihydroxyvitamin D 3 (1, 25 (OH) 2 D 3 ) and mechanical stimuli in physiological environment play an important role in the pathogenesis of osteoporosis. The effects of 1, 25-dihydroxyvitamin D 3 alone and mechanical stimuli alone on osteoblasts have been widely investigated. This study reports the collective influences of 1, 25-dihydroxyvitamin D 3 and flow shear stress (FSS) on biological functions of osteoblasts. 1, 25 (OH) 2 D 3 were constructed in various kinds of concentration (0, 1, 10, 100 nmmol/L), while physiological fluid shear stress (12 dynes/cm 2 ) were 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 releases and cell proliferation as well as the promotion of PGE 2 releases and cell differentiation. These findings provide a possible mechanism by which 1, 25(OH) 2 D 3 influences osteoblasts responses to FSS and may provide guidance for the selection of 1, 25(OH) 2 D 3 concentration and mechanical loading in order to in vitro produce functional bone tissues.