唑来膦酸通过抑制Wnt5a介导的软骨下异常骨吸收减轻大鼠膝骨关节炎

Zoledronic acid attenuates osteoarthritis in rat by inhibiting Wnt5a-mediated abnormal subchondral bone resorption

目的 观察唑来膦酸(ZOL)对大鼠膝骨关节炎(OA)的影响,探讨OA早期破骨细胞活化的分子机制。方法 采用内侧半月板失稳法(DMM)建立大鼠膝OA模型。将72只雄性SD大鼠随机平均分为Sham+PBS组、DMM+PBS组和DMM+ZOL组。术后各组大鼠腹腔注射100μg/kg的ZOL或等量的PBS缓冲液,每周2次,连续4周。术后2、4、8、12周用Micro-CT检测软骨下骨结构,番红O-固绿染色评估软骨退变程度。将18只雄性SD大鼠分为相同的3组,术后4周以TRAP染色计数软骨下骨中的破骨细胞,免疫组化和RT-qPCR检测Wnt5a通路的蛋白及mRNA表达水平。结果 与Sham+PBS组比较,DMM+PBS组在术后4周BV/TV降低,术后12周增加(P<0.05);术后4周和12周OARSI评分均增加(P<0.05);术后4周骨吸收活性与破骨细胞表面占比(Oc.S/BS)增加(P<0.05),Wnt5a通路相关的蛋白和mRNA表达增加(P<0.05)。与DMM+PBS组比较,DMM+ZOL组在术后4周BV/TV增加(P<0.05),但与Sham+PBS组比较差异无统计学意义(P>0.05);术后4周和12周AORSI评分均降低但仍高于Sham+PBS组(P<0.05),术后4周Oc.S/BS降低(P<0.05);但与Sham+PBS组比较差异无统计学意义(P>0.05);Wnt5a通路相关的蛋白和mRNA表达均降低(P<0.05)。结论 ZOL可抑制Wnt5a信号介导的软骨下骨吸收,延缓OA进展。

Objective To investigate the effects of zoledronic acid(ZOL)on osteoarthritis(OA)in rats and explored the molecular mechanism of osteoclast activation in early stage of OA.Methods The medial meniscus instability(DMM)was used to establish the knee OA model in rats.Seventy-two male SD rats were randomly divided into Sham+PBS group, DMM+PBS group, and DMM+ZOL group.After operation, the rats in each group were injected intraperitoneally with 100 μg/kg ZOL or PBS,twice weekly for 4 weeks.After 2,4,8 and 12 weeks of OA induction, the subchondral bone structure was detected by using micro-computed tomography and the degree of cartilage degeneration was evaluated by safranin O-fast green staining.Eighteen male SD rats were randomly assigned to the same three groups.Four weeks after surgery, TRAP-stained osteoclasts in subchondral bone were counted, the levels of protein and mRNA of Wnt5a signal pathway in subchondral bone were measured by using IHC and RT-qPCR.Results Compared with Sham+PBS group, the BV/TV in DMM+PBS group was lower at 4 weeks after surgery, but increased at 12 weeks after surgery(P<0.05),the OARSI scores increased at 4 and 12 weeks after surgery(P<0.05),the Oc.S/BS increased at 4 weeks after surgery(P<0.05),and the protein and mRNA levels related to Wnt5a signal pathway increased(P<0.05).Compared with DMM+PBS group, BV/TV in DMM+ZOL group increased at 4 weeks after surgery(P<0.05)and had no statistical difference with Sham+PBS group(P>0.05),The OARSI scores in DMM+ZOL group at 4 weeks and 12 weeks after surgery decreased but were still higher than Sham+PBS group(P<0.05),the Oc.S/BS decreased 4 weeks after surgery(P<0.05)and had no statistical difference with Sham+PBS group(P>0.05),and the protein and mRNA levels related to Wnt5a signal pathway decreased(P<0.05).Conclusion ZOL can suppress bone resorption by inhibiting Wnt5a signal pathway in early OA and delayed the progression of OA.