续断皂苷VI调控Wnt/β-Catenin通路对骨质疏松的影响机制

Mechanism of Diposaponin VI Regulating the Influence of Wnt/β-Catenin Pathway on Osteoporosis

目的探讨续断皂苷VI调控Wnt/β-Catenin通路对骨质疏松的影响并分析其作用机制。方法构建SPF级Wistar大鼠骨质疏松症模型与健康大鼠共同饲养形成对照组,将50只雌性大鼠随机分为4组。依次设置为:续断皂苷VI治疗组,模型对照组,假手术组,空白对照组。使用不同双侧卵巢摘除手术法处理实验组大鼠。除空白对照组外,模型对照组与假手术组以及续断皂苷VI处理组的大鼠均制成骨质疏松症大鼠模型,将续断皂苷VI组的大鼠连续给药12周。使用X线骨密度仪骨密度(BMD,bone mineral density)测定法检测各组大鼠BMD,观察给药前后大鼠BMD变化情况;使用生物力学测定仪测定各组大鼠后肢股骨的最大载荷差异;使用RT-PCR实验和Western Blotting实验以检测不同组Wnt3a、β-catenin、LRP5、Runx2、SOST和Osx转录组与蛋白组表达各自发生的差异。结果续断皂苷VI治疗12周可显著提高骨质疏松症大鼠模型股骨的BMD,并提高椎体在最大负荷和弹性模量下的生物力学能力,降低了骨质疏松症在骨组织中造成的致病性。对于组织形态学方面的考察发现,续断皂苷VI治疗组在治疗持续12周后,小梁排列整齐,小梁稍变薄,股骨没有明显的轻微骨折。在进行续断皂苷VI治疗处理的情况下,经典Wnt/β-catenin信号通路中涉及的LRP5、β-catenin、Runx2和Osx的表达显著上调,而在该通路中SOST的表达下调(P<0.05)。结论续断皂苷VI可显著提高骨质疏松模型大鼠的骨密度,其保护机制与激活Wnt/β-catenin信号通路,上调骨质疏松大鼠骨中β-catenin、LRP5的mRNA表达有相关。

Objective To investigate the effect of saponin VI on Wnt/β-catenin pathway on osteoporosis and analyze its mechanism.Methods The osteoporosis model of SPF Wistar rats was constructed and fed with healthy rats to form a control group.50 female rats were randomly divided into 4 groups.They were set as follows:Dipsacus saponin VI treatment group,model control group,sham operation group and blank control group.Different bilateral ovariectomy methods were used to treat the rats in the experimental group.In addition to the blank control group,the rats in the model control group,sham operation group and Dipsacus saponin VI treatment group were made into osteoporosis rat models,and the rats in Dipsacus saponin VI group were administered continuously for 12 weeks.BMD(bone mineral density)was measured by X-ray absorptiometry,and the changes of BMD before and after administration were observed.The maximum load difference of hindlimb femur in each group was measured by biomechanical tester.RT-PCR experiment and Western blotting experiment were used to detect differences in transcriptome and proteome expression of Wnt3a,β-catenin,LRP5,Runx2,SOST and OSX in different groups.Results Dipsacus saponin VI treatment for 12weeks significantly improved the BMD of femur of osteoporosis rat model,improved the biomechanical ability of vertebral body under maximum load and elastic modulus,and reduced the pathogenicity of osteoporosis in bone tissue.According to the investigation of histomorphology,in the Dipsacus saponin VI treatment group,after 12 weeks of treatment,the trabeculae were arranged orderly;the trabeculae were slightly thinner;and there was no obvious slight fracture of femur.In the case of Dipsacus saponin VI treatment,classical Wnt/β-LRP5 involved in catenin signal pathway.The expressions ofβ-catenin,Runx2 and OSX were significantly up-regulated,while the expression of SOST was down-regulated in this pathway(P<0.05).Conclusion Dipsacus saponin VI can significantly improve the bone mineral density of osteoporosis model rats,and its protective mechanism is related to the activation of Wnt/β-Catenin signaling pathway,up-regulated in bone of osteoporotic ratsβ-mRNA expression of catenin and LRP5 was correlated.