title: Caffeic acid 3,4-dihydroxy-phenethyl ester suppresses receptor activator of NF-κB ligand–induced osteoclastogenesis and prevents ovariectomy-induced bone loss through inhibition of mitogen-activated protein kinase/activator protein 1 and Ca2+–nuclear factor of activated T-cells cytoplasmic 1 signaling pathways.
abstract: Receptor activator of NF-κB ligand (RANKL) stimulation leads to the activation of mitogen-activated protein kinase (MAPK)/AP-1 and Ca2+–nuclear factor of activated T-cells cytoplasmic 1 (NFATc1) signaling pathways in osteoclastogenesis. Targeting these pathways has been an encouraging strategy for bone-related diseases, such as postmenopausal osteoporosis. In this study, we examined the effects of caffeic acid 3,4-dihydroxy-phenethyl ester (CADPE) on osteoclastogenesis. In mouse bone marrow monocytes (BMMs) and RAW264.7 cells, CADPE suppressed RANKL-induced osteoclast differentiation and actin-ring formation in a dose-dependent manner within non–growth inhibitory concentrations at the early stage, while CADPE had no effect on macrophage colony-stimulating factor (M-CSF)-induced proliferation and differentiation. At the molecular level, CADPE inhibited RANKL-induced phosphorylation of MAPKs, including extracellular signal-regulated kinases 1/2 (ERK1/2), p38, and c-Jun N-terminal kinase (JNK), without significantly affecting the NF-κB signaling pathway. CADPE abrogated RANKL-induced activator protein 1 (AP-1)/FBJ murine osteosarcoma viral oncogene homolog (c-Fos) nuclear translocation and activation. Overexpression of c-Fos prevented the inhibition by CADPE of osteoclast differentiation. Furthermore, CADPE suppressed RANKL-induced the tumor necrosis factor receptor associated factor 6 (TRAF6) interaction with c-src tyrosine kinase (c-Src), blocked RANKL-induced the phosphorylation of protein kinase B (AKT), and inhibited RANKL-induced Ca2+ oscillation. As a result, CADPE decreased osteoclastogenesis-related marker gene expression, including NFATc1, TRAP, cathepsin K, and c-Src. To test the effects of CADPE on osteoclast activity in vivo, we showed that CADPE prevented ovariectomy-induced bone loss by inhibiting osteoclast activity. Together, our data demonstrate that CADPE suppresses osteoclastogenesis and bone loss through inhibiting RANKL-induced MAPKs and Ca2+-NFATc1 signaling pathways. CADPE is a novel agent in the treatment of osteoclast-related diseases, such as osteoporosis.
authors.affiliation: Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China.
authors.forename: Xian
authors.initials: X
authors.lastname: Wu
authors.forename: Zhenxi
authors.initials: Z
authors.lastname: Li
authors.forename: Zhengfang
authors.initials: Z
authors.lastname: Yang
authors.forename: Chunbing
authors.initials: C
authors.lastname: Zheng
authors.forename: Ji
authors.initials: J
authors.lastname: Jing
authors.forename: Yihua
authors.initials: Y
authors.lastname: Chen
authors.forename: Xiyun
authors.initials: X
authors.lastname: Ye
authors.forename: Xiaoyuan
authors.initials: X
authors.lastname: Lian
authors.forename: Wenwei
authors.initials: W
authors.lastname: Qiu
authors.forename: Fan
authors.initials: F
authors.lastname: Yang
authors.forename: Jie
authors.initials: J
authors.lastname: Tang
authors.forename: Jianru
authors.initials: J
authors.lastname: Xiao
authors.forename: Mingyao
authors.initials: M
authors.lastname: Liu
authors.forename: Jian
authors.initials: J
authors.lastname: Luo
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D001854:Bone Marrow Cells / Q000473:pathology; D001862:Bone Resorption / Q000201:enzymology / Q000235:genetics / Q000473:pathology / Q000517:prevention & control*; D002109:Caffeic Acids / Q000494:pharmacology*; D002118:Calcium; D020013:Calcium Signaling / Q000187:drug effects / Q000235:genetics; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D016173:Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism; D050778:NFATC Transcription Factors / Q000378:metabolism*; D010006:Osteoblasts / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D010010:Osteoclasts / Q000187:drug effects / Q000201:enzymology / Q000473:pathology; D010012:Osteogenesis / Q000187:drug effects* / Q000235:genetics; D010052:Ovariectomy; D053245:RANK Ligand / Q000494:pharmacology*; D018808:Transcription Factor AP-1 / Q000378:metabolism*
chemical_list: D000199:Actins; D015415:Biomarkers; D002109:Caffeic Acids; D016328:NF-kappa B; D050778:NFATC Transcription Factors; C494005:Nfatc1 protein, mouse; D053245:RANK Ligand; D018808:Transcription Factor AP-1; C548196:caffeic acid 3,4-dihydroxyphenethyl ester; D016173:Macrophage Colony-Stimulating Factor; D020928:Mitogen-Activated Protein Kinases; D002118:Calcium