Wnt/ß-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/ß-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-ß-catenin reduced, while ß-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/ß-catenin pathway's inhibitor (XAV-939), the protective effects of FDP-Sr on osteoblastic differentiation against oxidative stress were repressed along with inhibited wnt/ß-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/ß-catenin signaling, and FDP in FDP-Sr was able to directly improve the oxidative stress injury through its ROS scavenging ability.

Innegligible musculoskeletal disorders caused by zoledronic acid in adjuvant breast cancer treatment: a meta-analysis.

BACKGROUND: Zoledronic acid (ZOL) is widely used for preventing bone loss in early breast cancer patients. However, the adverse effects caused by ZOL itself should not be neglected. Musculoskeletal disorders were common after ZOL administration and distressing to the patients. Up to now, no precise estimation of musculoskeletal disorders has been made. METHODS: Relevant randomized clinical trials were selected by searching the electronic database PubMed, and a meta-analysis was conducted. RESULTS: Four trials reported musculoskeletal disorders of ZOL treatment versus no ZOL, including 2684 patients treated with ZOL and 2712 patients without ZOL treatment. Compared to patients without ZOL treatment, patients treated with ZOL had a significantly higher risk of arthralgia (risk ratio (RR): 1.162, 95% confidence interval (CI): 1.096-1.232, P = 0.466 for heterogeneity) and bone pain (RR: 1.257, 95% CI: 1.149-1.376, P = 0.193 for heterogeneity). Three clinical trials reported the complications of upfront versus delayed ZOL treatment, including 1091 patients with upfront ZOL and 1110 patients with delayed ZOL. The rate of bone pain in upfront group (119/824) was significantly higher than that in delayed group (74/836) (RR: 1.284, 95% CI: 1.135-1.453, P = 0.460 for heterogeneity). CONCLUSIONS: Our meta-analysis suggested that treatment with ZOL was significantly associated to the occurrence of arthralgia and bone pain. Moreover, higher rate of bone pain was observed in patients treated with upfront ZOL compared with delayed ZOL treatment. More attentions should be paid to patients treated with ZOL, especially for immediate ZOL. For patients with low risk of osteoporosis, immediate ZOL may be not needed due to additional musculoskeletal disorders and little benefit. Or it can be stopped after the occurrence of these adverse events.