基于OPG/RANKL/RANK信号通路探讨傣药肾叶山蚂蝗的抗骨质疏松作用

Anti-Osteoporosis Effect of Desmodium Renifolium(Linn.)Schindl Based on OPG/RANKL/RANK Pathway

目的探讨傣药肾叶山蚂蝗对去卵巢骨质疏松大鼠模型的作用及其机制。方法60只雌性SD大鼠随机分为假手术组、模型组、仙灵骨葆组(0.24 g·kg^(-1))、肾叶山蚂蝗低(1.35 g·kg^(-1))、中(2.70 g·kg^(-1))和高剂量组(5.40 g·kg^(-1))。采用双侧卵巢切除术建立骨质疏松模型,药物干预14周后,检测血清中骨钙素(Bone gamma-carboxyglutamic-acid-containing Proteins,BGP)、骨保护素(Ostoeprotegerin,OPG)和碱性磷酸酶(Alkaline phosphatase,ALP)的含量,苏木精-伊红(HE)染色法观察骨组织中骨小梁的变化;实时荧光定量PCR(qPCR)检测大鼠胫骨中OPG/RANKL/RANK信号通路相关基因的表达。另取破骨细胞前体细胞株RAW264.7,分为阴性对照组、核因子κB受体活化因子配体(RANKL)组、仙灵骨葆组、肾叶山蚂蝗低、中、高剂量组。阴性对照组不加RANKL,其余各组使用50 ng·mL^(-1) RANKL诱导,药物组同时分别加入不同浓度的仙灵骨葆和肾叶山蚂蝗含药血清进行干预。10天后进行抗酒石酸酸性磷酸酶(TRAP)染色,观察破骨细胞分化情况,qPCR测定OPG/RANKL/RANK信号通路相关基因的表达。结果与假手术组比较,模型组血清中OPG含量显著降低(P<0.01),ALP和BGP显著升高(P<0.01),骨小梁显著减少,断裂,排列稀疏,骨小梁之间间距大,胫骨组织OPG mRNA表达显著减少(P<0.01),RANKL、肿瘤坏死因子受体相关蛋白6(TRAF6)、活化T-细胞核因子1(NFATc1)、组织蛋白酶K(CTK)和降钙素受体(CalcR)mRNA水平的表达升高(P<0.01),肾叶山蚂蝗干预后能显著改善以上指标。RAW264.7培养10天后,与阴性对照组比较,RANKL组破骨细胞明显增多,肾叶山蚂蝗能显著降低破骨细胞的数量,OPG/RANKL/RANK通路相关基因表达趋势和动物实验一致。结论肾叶山蚂蝗能有效改善去卵巢大鼠模型的骨质疏松,其作用机制可能是通过抑制破骨细胞增殖分化,调节OPG/RANKL/RANK信号通路来实现。

Objective To investigate the effect and potential mechanism of Desmodium renifolium(Linn.)Schindl on ovariectomized osteoporosis rat model.Methods Sixty 3-month-old female SD rats were randomly divided into Sham group,model group,Xianlin Gubao group(0.24 g·kg^(-1)),Desmodium renifolium low-dose group(1.35 g·kg^(-1)),mediumdose group(2.7 g·kg^(-1))and high-dose group(5.4 g·kg^(-1)).Osteoporosis was induced by performing double ovariectomy in rats.After 14 weeks treatment,the contents of osteocalcin(BGP),osteoprotectin(OPG)and alkaline phosphatase(ALP)in serum were determined.Hematoxylin-eosin(HE)staining was used to observe the changes of bone trabeculae.The osteoclast progenitor-cell line RAW264.7 was divided into negative control group,Receptor activator of nuclear factor-κB ligand(RANKL)group,Xianlin Gubao group,Desmodium renifolium low-dose,medium-dose and high-dose drug groups.The RANKL group and drug groups were induced with 50 ng·mL^(-1) RANKL.Meanwhile,Xianlin Gubao group and different concentrations of drug-containing serum of Desmodium renifolium,were added for intervention.Tartrateresistant acid phosphatase(TRAP)staining was performed 10 days after intervention to observe the differentiation of osteoclasts,and quantitative real-time PCR(qPCR)was used to determine the mRNA expression.Results Compared with Sham group,the contents of OPG in serum of model group were significantly decreased(P<0.01),while ALP and BGP were significantly increased(P<0.01),bone trabeculae were significantly reduced,broken,sparsely arranged,and the space between bone trabeculae was large,the OPG mRNA expression in model group were significantly decreased(P<0.01),and the mRNA expression of receptor activator of nuclear factor-κB ligand(RANKL),TNF receptor associated factor 6(TRAF6),nuclear factor of activated t-cells,cytoplasmic 1(NFATC1),cathepsin K(CTK)and calcitonin receptor(CALCR)in model group were significantly increased(P<0.01),all these aspects showed remarkable improvement after Desmodium renifolium intervention.After 10 days of RAW264.7 culture,no osteoclasts were found in the Control group.Compared with the negative control group,osteoclasts in RANKL group were significantly increased,treatment with Desmodium renifolium markedly decreased osteoclast number,the result of RANKL/RANK/OPG signaling mRNA expression were consistent with the animal experiments.Conclusion Desmodium renifolium exerts effects on osteoporosis in ovariectomized rats,its mechanism might be realized by inhibiting osteoclast proliferation and differentiation,and regulating OPG/RANKL/RANK signaling pathway.