伊班膦酸钠干预骨关节炎模型大鼠丝裂原活化蛋白激酶信号通路的变化

背景:丝裂原活化蛋白激酶信号通路参与成骨细胞与破骨细胞的分化,与软骨下骨重建过程密切相关,在骨关节炎的发生发展中起重要作用。双膦酸盐作为骨吸收抑制剂,主要用于骨质疏松的治疗。目的:探讨伊班膦酸钠对大鼠骨关节炎的治疗效果,以及其对丝裂原活化蛋白激酶信号通路的影响。方法:实验方案经南华大学附属第一医院动物实验伦理委员会批准。30只雌性SD大鼠随机分为假手术组、模型组、治疗组。模型组和治疗组行双侧去卵巢及前交叉韧带切断术,假手术组大鼠只切除卵巢周围与卵巢大小相仿的脂肪组织,切开双侧膝关节腔,但不切断前交叉韧带。术后1周,治疗组予以腹腔注射伊班膦酸钠10μg/kg,模型组予以腹腔注射等量生理盐水,假手术组不作干预。12周以后,处死实验动物,进行关节软骨的组织形态学观察及Mankin评分,软骨下骨的Micro-CT扫描及骨组织显微结构定量分析,检测丝裂原活化蛋白激酶信号通路中细胞外信号调节蛋白激酶(ERK1)和c-Jun氨基酸末端激酶(JNK)的mRNA表达量及蛋白表达水平。结果与结论:①模型组软骨结构明显破坏,Mankin评分较假手术组明显增高,而治疗组的Mankin评分较模型组显著降低(P<0.01);②与假手术组比较,模型组中的骨密度、骨体积分数、骨小梁数量降低,骨小梁分离度显著增高(P<0.01);与模型组相比,治疗组的骨密度、骨体积分数、骨小梁数量增加,骨小梁分离度明显下降(P<0.01);③模型组中的ERK1、JNK mRNA表达和蛋白表达较假手术组明显增加(P<0.05,P<0.01);与模型组相比,治疗组中的ERK1、JNK mRNA表达和蛋白表达显著降低(P<0.05);④结果说明,伊班膦酸钠可能通过抑制ERK1、JNK丝裂原活化蛋白激酶信号通路的表达改善膝骨关节炎大鼠的软骨下骨的微结构,抑制软骨的退变。

Effect of ibandronate on mitogen-activated protein kinase signaling pathway in rat models of osteoarthritis

BACKGROUND:Mitogen-activated protein kinase signaling pathway participates in the differentiation of osteoblasts and osteoclasts,closely related to subchondral bone reconstruction and play a key role in the occurrence and development of osteoarthritis.Bisphosphonates as bone resorption inhibitor is used to treat osteoporosis.OBJECTIVE:To observe the effect of sodium ibandronate on the knee osteoarthritis in rats,and changes of mitogen-activated protein kinase signaling pathway.METHODS:The study was approved by the Laboratory Animal Ethical Committee of the First Affiliated Hospital of South China University.Thirty female Sprague-Dawley rats were randomly divided into sham,model,and treatment groups.The rats in the latter two groups underwent ovariectomy bilaterally,and anterior cruciate ligament resection,and rats in the sham group received the fatty tissue surrounding the ovaries removed only.After 1 week of surgery,the rats in the treatment group were given intraperitoneal injection of 10μg/kg sodium ibandronate,rats in the model group were injected with normal saline,and the sham group received no intervention.Twelve weeks late,the rats were killed to perform histological examination of cartticular cartilage and Mankin scores were detected.Micro-CT of subchondral bone and quantitative analysis of the bone microstructure were conducted.The protein and mRNA expression levels of extracellular signal regulated protein kinase and c-Jun N-terminal kinase in mitogen-activated protein kinase signaling pathway were measured.RESULTS AND CONCLUSION:(1)The cartilage structure in the model group was significantly damaged,the Mankin score was significantly higher than that in the sham group,and the Mankin score in the treatment group was significantly lower than that in the model group(P<0.01).(2)The bone mineral density,trabecular bone volume ratio,trabecular number in the model group were significantly lower than those in the sham group(P<0.01),and trabecular separation was higher than that in the sham group(P<0.01).Compared with the model group,the treatment group had higher bone mineral density,trabecular bone volume ratio,trabecular number,and lower trabecular separation(P<0.01).(3)The mRNA and protein expression levels of extracellular signal regulated protein kinase and c-Jun N-terminal kinase in the model group were significantly higher than those in the sham group(P<0.05,P<0.01),and the levels in the treatment group were significantly lower than those in the model group(P<0.05).(4)To conclude,sodium ibandronate may inhibit subchondral bone loss and articular cartilage degeneration in rat models of osteoarthritis by inhibiting extracellular signal regulated protein kinase and c-Jun N-terminal kinase in mitogen-activated protein kinase signaling pathway.