Kong Lingbo, Wang Biao, Yang Xiaobin, Guo Hua, Zhang Ke, Zhu Ziqi, Liu Jijun, Hao Dingjun
Cell Physiol Biochem. 2017;43(4):1425-1435. doi: 10.1159/000481874. Epub 2017 Oct 11.
BACKGROUND/AIMS: Osteoporosis is a metabolic bone disorder that tortures about millions of people worldwide. Recent study demonstrated agents derived from picrasma quassioides is a promising drug for targets multiple signaling pathways. However its potential in treatment of bone loss has not been fully understood.
The bone marrow macrophages (BMMs) were cultured and induced with M-CSF and RANKL followed by picrasidine I (PI) treatment. Then the effects of PI on osteoclast formation were evaluated by counting tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells. Moreover, effects of PI on bone resorption activity of mature osteoclast were studied through bone resorption pit counting and actin ring structure analysis. Further, the involved potential signaling pathways cross-talking were investigated by performed Western blotting and quantitative real-time PCR examination.
Results demonstrated PI strongly inhibited RANKL induced osteoclast formation from its precursors. Mechanistically, the inhibitory effect of PI on osteoclast differentiation was due to the suppression of osteoclastogenic transcription factors, c-Fos and NFATc1. Moreover, PI markedly blocked the RANKL-induced osteoclastogenesis by attenuating MAPKs and NF-κB signaling pathways. In addition, PI decreased the ROS generation in osteoclast and osteoblast.
Taken together our data demonstrate that PI has antiosteoclastogenic effect by inhibiting inflammation induced activation of MAPKs, NF-κB and ROS generation followed by suppressing the gene expression of c-Fos and NFATc1 in osteoclast precursors.
背景/目的：骨质疏松症是一种代谢性骨病，折磨着全球约数百万人。最近的研究表明，苦木素衍生的药物是一种有望针对多种信号通路的药物。然而，其在治疗骨质流失方面的潜力尚未完全了解。
培养骨髓巨噬细胞（BMMs），用M-CSF和RANKL诱导，然后用苦木素I（PI）处理。然后通过计数抗酒石酸酸性磷酸酶（TRAP）阳性多核细胞来评估PI对破骨细胞形成的影响。此外，通过骨吸收坑计数和肌动蛋白环结构分析研究了PI对成熟破骨细胞骨吸收活性的影响。进一步通过蛋白质免疫印迹和定量实时PCR检测研究了潜在的信号通路交叉对话。
结果表明，PI强烈抑制RANKL诱导的破骨细胞前体形成。机制上，PI对破骨细胞分化的抑制作用是由于抑制破骨细胞生成转录因子c-Fos和NFATc1。此外，PI通过减弱MAPKs和NF-κB信号通路显著阻断RANKL诱导的破骨细胞生成。此外，PI降低了破骨细胞和成骨细胞中的ROS生成。
综上所述，我们的数据表明，PI通过抑制炎症诱导的MAPKs、NF-κB激活和ROS生成，进而抑制破骨细胞前体中c-Fos和NFATc1的基因表达，具有抗破骨细胞生成作用。
