Shikonin mitigates ovariectomy-induced bone loss and RANKL-induced osteoclastogenesis via TRAF6-mediated signaling pathways

作者：Kai Chen, Zijun Yan, Yiran Wang, Yilin Yang, Mengxi Cai, Huang Chunyou, Bo Li, Mingyuan Yang, Xiaoyi Zhou, Xianzhao Wei, Changwei Yang, Kai Chen, Zhai Xiao, Ming Li · 发表于：Biomedicine & Pharmacotherapy · 年份：2020 · DOI：10.1016/j.biopha.2020.110067 · 被引用次数：29 · 研究领域：Bioactive Compounds and Antitumor Agents、Bone Metabolism and Diseases、NF-κB Signaling Pathways

BACKGROUND: Postmenopausal osteoporosis results from estrogen withdrawal and is characterized mainly by bone resorption. Shikonin is a bioactive constitute of Chinese traditional herb which plays a role in antimicrobial and antitumor activities. The study was designed to investigate the role of shikonin on postmenopausal osteoporosis and explore its underlying mechanisms. METHODS: Immunofluorescence staining was performed to evaluate the effects of shikonin on actin ring formation. The expression levels of the nuclear factor kappa-B (NF-κB) and mitogen-activated protein kinase (MAPK) pathway were determined by Western blot analysis. To determine whether shikonin influences the receptor activator of nuclear factor-κB ligand (RANKL)-induced association between receptor activator of NF-κB (RANK) and tumor necrosis factor receptor associated factor 6 (TRAF6), immunofluorescence staining and immunoprecipitation experiments were performed. During our validation model, histomorphometric examination and micro-computed tomography (CT) were conducted to assess the morphology of osteoporosis. RESULTS: Shikonin prevented bone loss by inhibiting osteoclastogenesis in vitro and improving bone loss in ovariectomized mice in vivo. At the molecular level, Western blot analysis indicated that shikonin inhibited the phosphorylation of inhibitor of NF-κB (IκB), P50, P65, extracellular regulated protein kinases (ERK), c-Jun N-terminal kinase (JNK), and P38. Interaction of TRAF6 and RANK was preve...