骨质疏松症大鼠模型生物力学性能和OPG/RANKL/RANK信号通路研究

Study on biomechanical properties and OPG/RANKL/RANK signal pathway of osteoporosis rat model

目的研究针刺对骨质疏松症(osteoporosis,OP)模型大鼠生物力学性能和骨保护素(OPG)/核因子-κB受体活化因子(RANKL)/核因子-κB受体活化因子受体(RANK)信号通路的影响,探讨针刺防治OP的作用机制。方法选取50只雌性SD大鼠,通过摘除卵巢建立OP大鼠模型,分为假手术组、模型组、针刺低剂量组、针刺高剂量组、阿仑膦酸钠组,每组10只。成功建立模型并对大鼠进行适应性喂养2个月后,连续灌胃给药12周,再进行腹主动脉取血并处死大鼠。通过双能X射线仪测定各组大鼠右侧下肢股骨骨矿含量;用酶联免疫吸附法测定法检测血清钙(Ca^(2+))、磷(P)和OPG、RANKL、RANK的水平;采用AG-IX万能实验机检测股骨的生物力学性能;采用蛋白质印迹法检测骨组织OPG、RANKL、RANK蛋白的表达。结果与假手术组比较,模型组大鼠骨组织中骨矿含量、血清Ca^(2+)、P、OPG的表达、股骨组织中OPG蛋白含量和股骨最大载荷、刚度及弹性模量均明显降低(P<0.01);血清RANKL和RANK的表达及股骨组织中RANKL、RANK蛋白含量明显升高(P<0.01)。与模型组比较,针刺低剂量组和针刺高剂量组以及阿仑膦酸钠组上述指标均有明显改善(P<0.05或P<0.01),且针刺的作用具有剂量依赖性(P<0.05或P<0.01)。结论针刺具有明显的抗OP作用,可能与其改善骨组织生物力学特性以及调控OPG/RANKL/RANK通路有关。

Objective To investigate the effects of acupuncture on the biomechanical properties of osteoporosis model rats and the signaling pathway of bone protectin(OPG)/nuclear factor-B receptor activator(RANKL)/nuclear factor-B receptor activator receptor(RANK),so as to explore the mechanism of acupuncture in the prevention and treatment of osteoporosis.Methods Fifty female SD rats were selected to establish OP model by removing their ovaries.They were divided into sham operation group,model group,acupuncture low-dose group,acupuncture high-dose group and alendronate sodium group,with 10 rats in each group.The model was successfully established and the rats were adaptively fed for 2 months.After continuous intragastric administration for 12 weeks,the blood was taken from the abdominal aorta and the rats were killed.The bone mineral content of femur in the right lower limb of rats in each group was measured by dual energy X-ray absorptiometry;The levels of serum calcium(Ca^(2+)),phosphorus(P),OPG,RANKL and rank were measured by enzyme-linked immunosorbent assay;The biomechanical properties of femur were measured on ag-ix biomechanical universal experimental machine;Western blot was used to detect the expression of OPG,RANKL and rank proteins in bone tissue.Results Compared with the sham operation group,the bone mineral content in bone tissue,the expression of serum Ca^(2+),P and OPG,the content of OPG protein in femur,the maximum load,stiffness and elastic modulus of femur in the model group were significantly lower(P<0.01);The expression of RANKL and rank in serum and the contents of RANKL and rank protein in femoral tissue increased significantly(P<0.01).Compared with the model group,the above indexes were significantly improved in the low-dose acupuncture group,high-dose acupuncture group and alendronate group(P<0.05 or P<0.01),and the effect of acupuncture was dose-dependent(P<0.05 or P<0.01).Conclusion Acupuncture has obvious anti osteoporosis effect,which may be related to improving the biomechanical properties of bone tissue and regulating OPG/RANKL/rank pathway.