Takamatsu Akira, Ohkawara Bisei, Ito Mikako, Masuda Akio, Sakai Tadahiro, Ishiguro Naoki, Ohno Kinji
Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya, Japan; Department of Orthopaedic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan.
Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya, Japan.
PLoS One. 2014 Mar 21;9(3):e92699. doi: 10.1371/journal.pone.0092699. eCollection 2014.
In past years, the canonical Wnt/β-catenin signaling pathway has emerged as a critical regulator of cartilage development and homeostasis. FRZB, a soluble antagonist of Wnt signaling, has been studied in osteoarthritis (OA) animal models and OA patients as a modulator of Wnt signaling. We screened for FDA-approved drugs that induce FRZB expression and suppress Wnt/β-catenin signaling. We found that verapamil, a widely prescribed L-type calcium channel blocker, elevated FRZB expression and suppressed Wnt/β-catenin signaling in human OA chondrocytes. Expression and nuclear translocation of β-catenin was attenuated by verapamil in OA chondrocytes. Lack of the verapamil effects in LiCl-treated and FRZB-downregulated OA chondrocytes also suggested that verpamil suppressed Wnt signaling by inducing FRZB. Verapamil enhanced gene expressions of chondrogenic markers of ACAN encoding aggrecan, COL2A1 encoding collagen type II α1, and SOX9, and suppressed Wnt-responsive AXIN2 and MMP3 in human OA chondrocytes. Verapamil ameliorated Wnt3A-induced proteoglycan loss in chondrogenically differentiated ATDC5 cells. Verapamil inhibited hypertrophic differentiation of chondrocytes in the explant culture of mouse tibiae. Intraarticular injection of verapamil inhibited OA progression as well as nuclear localizations of β-catenin in a rat OA model. We propose that verapamil holds promise as a potent therapeutic agent for OA by upregulating FRZB and subsequently downregulating Wnt/β-catenin signaling.
在过去几年中，经典的Wnt/β-连环蛋白信号通路已成为软骨发育和体内平衡的关键调节因子。FRZB是一种Wnt信号的可溶性拮抗剂，已在骨关节炎（OA）动物模型和OA患者中作为Wnt信号的调节剂进行了研究。我们筛选了可诱导FRZB表达并抑制Wnt/β-连环蛋白信号传导的FDA批准药物。我们发现，维拉帕米是一种广泛使用的L型钙通道阻滞剂，可提高人OA软骨细胞中FRZB的表达并抑制Wnt/β-连环蛋白信号传导。维拉帕米可减弱OA软骨细胞中β-连环蛋白的表达和核转位。在LiCl处理和FRZB下调的OA软骨细胞中缺乏维拉帕米效应也表明，维拉帕米通过诱导FRZB抑制Wnt信号。维拉帕米增强了编码聚集蛋白聚糖的ACAN、编码II型胶原α1的COL2A1和SOX9等软骨生成标志物的基因表达，并抑制了人OA软骨细胞中Wnt反应性AXIN2和MMP3。维拉帕米改善了Wnt3A诱导的软骨分化的ATDC5细胞中蛋白聚糖的丢失。维拉帕米在小鼠胫骨外植体培养中抑制软骨细胞的肥大分化。在大鼠OA模型中，关节内注射维拉帕米可抑制OA进展以及β-连环蛋白的核定位。我们认为，维拉帕米有望通过上调FRZB并随后下调Wnt/β-连环蛋白信号传导而成为一种有效的OA治疗药物。
