Wnt/β-catenin signaling plays an important role in the protective effects of FDP-Sr against oxidative stress induced apoptosis in MC3T3-E1 cell

Strontium fructose 1,6-diphosphate (FDP-Sr) is a new strontium-containing compound. The primary aim of this study was to clarify whether the structure component of FDP-Sr, FDP could benefit the protective effect of Sr (II) against oxidative stress induced apoptosis, and meanwhile to further explore the important role of Wnt/beta-catenin signaling in the anti-apoptosis effect of FDP-Sr in response to oxidative stress induced by H2O2 in an osteoblastic MC3T3-E1 cell line. Results showed that FDP-Sr could improve the osteoblastic differentiation under oxidative stress with induced cell proliferation and improved mineralization. The inhibition effect of FDP-Sr on cell apoptosis induced by H2O2 was proved by reduced reactive oxygen species production and activated caspase3. Under oxidative stress, mRNA and protein levels of phospho-beta-catenin reduced, while beta-catenin increased in the FDP-Sr treatment cell, leaded to the up-regulations of Runx2 and OPG at both mRNA and protein levels, finally improved the differentiation of osteoblasts. By the engagement of Wnt/beta-catenin pathway's inhibitor (XAV-939), the protective effects of FDP-Sr on osteoblastic differentiation against oxidative stress were repressed along with inhibited wnt/beta-catenin signaling and reduced mRNA and protein levels of Runx2 and OPG. In conclusion, FDP-Sr was demonstrated to protect osteoblast differentiation from oxidative damage induced by H2O2 through up-regulation of Wnt/beta-catenin signaling, and FDP in FDP-Sr was able to directly improve the oxidative stress injury through its ROS scavenging ability. (C) 2016 Elsevier Ltd. All rights reserved.