ABSTRACT
Objective In the present study, we investigated the effects of advanced oxidation protein products(AOPP) on reactive oxygen species(ROS) production in murine osteoblastic MC3T3-E1 cells by NADPH oxidase enzymes pathway. Methods Experiments were divided into three groups, including control group, rats albumin(RSA) group, and AOPP group. Different concentrations of AOPP were added to the osteoblastic MC3T3-E1 cells culture medium. The production of ROS in MC3T3-E1 cells was measured by the fluorescence intensity of intracellular fluoroprobe ( DCFD ) . In order to verify the effect of enzyme of the production of ROS, the specific inhibitors of corresponding enzymes were added in the MC3T3-E1 cells which were cultured in the medium with AOPP. Finally, western blot and immunofluorescence were used to observe the changes of NADPH oxidase enzymes subunits. Results Different concentrations of AOPP (50,100,200μg/ml) induced MC3T3-E1 cells to produce different amount of ROS. The higher concentrations of AOPP were added, the more ROS were produced. Furthermore,200μg/ml AOPP induced the maximum amount of ROS production(P<0. 05). Meanwhile, AOPP induced MC3T3-E1 cells to produce different amount of ROS with a time-dependent manner. The peak amount of ROS production in MC3T3-E1 cells was observed in 3h when AOPP were added (P<0. 05). In addition, when specific inhibitors of corresponding enzymes were added in the MC3T3-E1 cells, the production of ROS were significantly suppressed by C-SOD, DPI, and apocynin(P<0. 05). On the other hand, AOPP can up-regulate the expression of Nox4 protein of the MC3T3-E1 cells, which is one of the subunits of NADPH oxidase enzymes. Meanwhile, AOPP can also induce the membrane migration of p47phox subunit. Conclusion AOPP induces osteoblastic MC3T3-E1 cells to produce ROS by NADPH oxidase enzymes pathway, and which may be one of the pathogenesis of AOPP involved in osteoporosis.