title: Coptisine inhibits RANKL-induced NF-κB phosphorylation in osteoclast precursors and suppresses function through the regulation of RANKL and OPG gene expression in osteoblastic cells.
abstract: Excessive receptor activator of NF-κB ligand (RANKL) signaling causes enhanced osteoclast formation and bone resorption. The downregulation of RANKL expression and its downstream signals may be an effective therapeutic approach to the treatment of bone loss diseases such as osteoporosis. Here, we found that coptisine, one of the isoquinoline alkaloids from Coptidis Rhizoma, exhibited inhibitory effects on osteoclastogenesis in vitro. Although coptisine has been studied for its antipyretic, antiphotooxidative, dampness dispelling, antidote, antinociceptive, and anti-inflammatory activities in vitro and in vivo, its effects on osteoclastogenesis have not been investigated. Therefore, we evaluated the effects of coptisine on osteoblastic cells as well as osteoclast precursors for osteoclastogenesis in vitro. The addition of coptisine to cocultures of mouse bone marrow cells and primary osteoblastic cells with 10(-8) M 1α,25(OH)(2)D(3) caused significant inhibition of osteoclast formation in a dose-dependent manner. Reverse transcriptase polymerase chain reaction (RT-PCR) analyses revealed that coptisine inhibited RANKL gene expression and stimulated the osteoprotegerin gene expression induced by 1α,25(OH)(2)D(3) in osteoblastic cells. Coptisine strongly inhibited RANKL-induced osteoclast formation when added during the early stage of bone marrow macrophage (BMM) cultures, suggesting that it acts on osteoclast precursors to inhibit RANKL/RANK signaling. Among the RANK signaling pathways, coptisine inhibited NF-κB p65 phosphorylations, which are regulated in response to RANKL in BMMs. Coptisine also inhibited the RANKL-induced expression of NFATc1, which is a key transcription factor. In addition, 10 μM coptisine significantly inhibited both the survival of mature osteoclasts and their pit-forming activity in cocultures. Thus, coptisine has potential for the treatment or prevention of several bone diseases characterized by excessive bone destruction.
authors.affiliation: Research Institute for Biological Functions, Chubu University, 1200 Matsumoto, Kasugai, Aichi 487-8501, Japan.
authors.forename: Ji-Won
authors.initials: JW
authors.lastname: Lee
authors.forename: Ayumi
authors.initials: A
authors.lastname: Iwahashi
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Hasegawa
authors.forename: Takayuki
authors.initials: T
authors.lastname: Yonezawa
authors.forename: Won Bae
authors.initials: WB
authors.lastname: Jeon
authors.forename: Byung-Yoon
authors.initials: BY
authors.lastname: Cha
authors.forename: Kazuo
authors.initials: K
authors.lastname: Nagai
authors.forename: Je-Tae
authors.initials: JT
authors.lastname: Woo
mesh_terms: D000818:Animals; D001599:Berberine / Q000031:analogs & derivatives* / Q000494:pharmacology; D050071:Bone Density Conservation Agents / Q000494:pharmacology*; D001854:Bone Marrow Cells / Q000187:drug effects* / Q000378:metabolism; D002117:Calcitriol / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D018920:Coculture Techniques; D004305:Dose-Response Relationship, Drug; D005786:Gene Expression Regulation / Q000187:drug effects; D008297:Male; D051379:Mice; D016328:NF-kappa B / Q000378:metabolism*; D050778:NFATC Transcription Factors / Q000378:metabolism; D010006:Osteoblasts / Q000187:drug effects* / Q000378:metabolism; D010010:Osteoclasts / Q000187:drug effects* / Q000378:metabolism; D053244:Osteoprotegerin / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D053245:RANK Ligand / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D051996:Transcription Factor RelA / Q000378:metabolism
chemical_list: D050071:Bone Density Conservation Agents; D016328:NF-kappa B; D050778:NFATC Transcription Factors; C494005:Nfatc1 protein, mouse; D053244:Osteoprotegerin; D053245:RANK Ligand; D012333:RNA, Messenger; C498144:Rela protein, mouse; C506031:Tnfrsf11b protein, mouse; C505689:Tnfsf11 protein, mouse; D051996:Transcription Factor RelA; C034384:coptisine; D001599:Berberine; D002117:Calcitriol