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

1, 25-dihydroxyvitamin D3 (1, 25 (OH)2 D3) and mechanical stimuli in physiological environment play an important role in the pathogenesis of osteoporosis. The effects of 1, 25-dihydroxyvitamin D3 alone and mechanical stimuli alone on osteoblasts have been widely investigated. This study reports the collective influences of 1, 25-dihydroxyvitamin D3 and flow shear stress (FSS) on biological functions of osteoblasts. 1, 25 (OH)2 D3 were constructed in various kinds of concentration (0, 1, 10, 100 nmmol/L), while physiological fluid shear stress (12 dynes/cm2) were produced by using a parallel-plate fluid flow system. 1, 25 (OH)2 D3 affects the responses of ROBs to FSS, including the inhibition of NO releases and cell proliferation as well as the promotion of PGE2 releases and cell differentiation. These findings provide a possible mechanism by which 1, 25(OH)2 D3 influences osteoblasts responses to FSS and may provide guidance for the selection of 1, 25(OH)2 D3 concentration and mechanical loading in order to in vitro produce functional bone tissues.