Zhou Long, Song Hanyi, Zhang Yiqi, Ren Zhaozhou, Li Minghe, Fu Qin
Department of Orthopedics, Shengjing Hospital of China Medical University, No. 36 Sanhao Street, Heping District, Shenyang, 110004, Liaoning Province, China.
Department of Gastroenterology, Shengjing Hospital of China Medical University, Shenyang, China.
BMC Musculoskelet Disord. 2020 Feb 19;21(1):112. doi: 10.1186/s12891-020-3077-z.
Osteoporosis is a worldwide severe bone disease. This study aimed to evaluate the effect of polyphyllin VII on the genesis of osteoclasts from bone marrow macrophages (BMMs) and its potentiality as a therapeutic drug for osteoporosis.
BMMs were induced to differentiate into osteoclasts by RANKL and M-CSF. The cells were then treated with various concentrations of polyphyllin VII. Intracellular reactive oxygen species (ROS) measurement assay, resorption pit formation assay, tartrate-resistant acid phosphatase (TRAP) staining and TRAP activity assessment, cell viability assay, active GTPase pull-down assay, immunofluorescent staining, immunoblotting, and RT-PCR were performed.
RANKL + M-CSF significantly increased TRAP activity, number of osteoclasts, number and area of lacunae, intracellular content of ROS, protein levels of Nox1, TRAF6, c-Src and p-PI3K, as well as the content of activated GTP-Rac1, which were significantly blocked by polyphyllin VII in a concentration-dependent manner.
These findings suggested that polyphyllin VII inhibited differentiation of BMMs into osteoclasts through suppressing ROS synthesis, which was modulated by TRAF6-cSrc-PI3k signal transduction pathway including GTP-Rac1 and Nox1. Polyphyllin VII could be a therapeutic drug for osteoporosis.
骨质疏松症是一种全球性的严重骨病。本研究旨在评估重楼皂苷VII对骨髓巨噬细胞（BMMs）向破骨细胞分化的影响及其作为骨质疏松症治疗药物的潜力。
用RANKL和M-CSF诱导BMMs分化为破骨细胞。然后用不同浓度的重楼皂苷VII处理细胞。进行细胞内活性氧（ROS）测量分析、吸收陷窝形成分析、抗酒石酸酸性磷酸酶（TRAP）染色和TRAP活性评估、细胞活力分析、活性GTP酶下拉分析、免疫荧光染色、免疫印迹和RT-PCR。
RANKL + M-CSF显著增加了TRAP活性、破骨细胞数量、陷窝数量和面积、细胞内ROS含量、Nox1、TRAF6、c-Src和p-PI3K的蛋白水平，以及活化的GTP-Rac1的含量，而重楼皂苷VII以浓度依赖的方式显著阻断了这些作用。
这些发现表明，重楼皂苷VII通过抑制ROS合成来抑制BMMs向破骨细胞的分化，ROS合成受包括GTP-Rac1和Nox1在内的TRAF6-cSrc-PI3k信号转导通路调控。重楼皂苷VII可能是一种治疗骨质疏松症的药物。
