补肾、健脾、活血中药对糖皮质激素性骨质疏松症大鼠骨组织Osterix mRNA及蛋白表达的影响

Comparative investigation of effect of reinforcing kidney,strengthening spleen and promoting blood circulation herbs on mRNA and protein expression of Osterix in bone tissue of rats with glucocorticoid-induced osteoporosis

目的:观察糖皮质激素性骨质疏松症(glucocorticoid-induced osteoporosis,GIOP)大鼠模型骨组织成骨细胞特异基因(osterix,Osx)mRNA及蛋白表达,探讨GIOP的发病机制,并比较补肾、健脾、活血中药的疗效及其调控作用。方法:采用后肢肌注地塞米松(2.5mg/kg,每周2次,连续9周)的方法复制GIOP大鼠模型,按体质量分层随机分为正常组、模型空白组、补肾中药组、健脾中药组、活血中药组、骨疏康颗粒阳性对照组。灌胃给药9周。应用XR-26型双能X线骨密度仪测定股骨骨密度,以评价动物模型的成立及药物疗效。实时定量RT-PCR(real-time quantitative,RT-PCR)检测骨组织Osterix mRNA表达,Western Blot检测骨组织Osterix蛋白表达。结果:①股骨骨密度:与正常组比较,模型空白组明显降低(P<0.01);与模型空白组比较,补肾中药组明显升高(P<0.01),骨疏康颗粒阳性对照组明显升高(P<0.05),健脾中药组和活血中药组虽有升高趋势,但无统计学意义。②骨组织Osterix mRNA及蛋白表达:与正常组比较,模型空白组明显降低(P<0.01);与模型空白组比较,补肾中药组明显上调(P<0.01),骨疏康颗粒阳性对照组也有明显上调(P<0.05),健脾中药组和活血中药组虽有所升高,但无统计学意义。结论:①肌注地塞米松可以成功复制GIOP大鼠模型。②骨组织Osterix mRNA及蛋白表达水平降低可能是GIOP的发病机制之一。③补肾中药具有明显防治效果,其作用机制与上调骨组织Osterix mRNA及蛋白表达密切相关。

Objective：To observe the mRNA and protein expression of Osterix in the bone tissue of the rat models with glucocorticoid-induced osteoporosis（GIOP）,discuss the pathogenesis of GIOP and compare the therapeutic effect and adjustable function of the reinforcing the kidney herbs with the strengthening the spleen herbs and the promoting blood circulation herbs.Methods：We established the GIOP rat models by hind limb intramuscular injection of dexamethasone（2.5mg/kg,twice a week,9 weeks continuously）.We stratified all the rats by different body weight and then divided them randomly into normal group,blank model group,reinforcing the kidney herbs group,strengthening the spleen herbs group,promoting blood circulation herbs group and Gushukang granula positive control group.We administrated them by gavage for 9 weeks.We detected the femur bone mineral density by using the XR-26 dual energy X-ray absorptiometry to evaluate the establishment of the animal model and the therapeutic effect of the drugs.We detected the mRNA expression of Osterix in the bone tissue by Real-Time Quantitative RT-PCR and detected its protein expression by Western blot.Results：（1） femur bone mineral density：compared with normal group,blank model group decreased significantly（P0.01）;compared with blank model group,reinforcing the kidney herbs group increased significantly（P0.01）,GUSHUKANG granula positive control group increased significantly（P0.05）,strengthening the spleen herbs group and promoting blood circulation herbs group both tended to increase,but neither of their difference had statistical significance（P0.05）.（2） mRNA and protein expression of Osterix in the bone tissue：compared with normal group,blank model group decreased significantly（P0.01）;compared with blank model group,reinforcing the kidney herbs group up-regulated significantly（P0.01）,Gushukang granula positive control group also up-regulated significantly（P0.05）,strengthening the spleen herbs group and promoting blood circulation herbs group both tended to increase,but neither of their difference had statistical significance（P0.05）.Conclusions：（1） The GIOP rat models can be established successfully by intramuscular injection of dexamethasone.（2） Maybe it is one aspect of the pathogenesis of GIOP that the level of the mRNA and protein expression of Osterix in the bone tissue decreases.（3） The reinforcing the kidney herbs have more evident preventative and therapeutic effect on GIOP by up-regulating the mRNA and protein expression of Osterix in the bone tissue than the strengthening the spleen herbs and the promoting blood circulation herbs.