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目的:观察低强度脉冲超声(LIPUS)对磷酸三钙(tricalcium phosphate,TCP)磨损颗粒诱导的假体周围骨细胞(osteocyte)损伤的影响,并探讨其可能作用机理.方法:取6～8周龄ICR雄性小鼠30只,随机分为正常组、模型组和LIPUS治疗组,每组10只.模型组和LIPUS治疗组小鼠分别于第1、3、5、7、9和第11周向颅顶注射TCP磨损颗粒建立小鼠颅骨溶解模型.正常组小鼠颅顶皮肤仅接受阴性超声探头按压处理,治疗组小鼠颅顶皮肤接受LIPUS干预治疗3个月,实验结束后取颅骨.采用Micro-CT分析各组小鼠颅骨TCP磨损颗粒植入部位周围溶解情况;应用HE染色比较各组假体周围骨细胞活性;通过流式细胞术定量检测各组假体周围骨细胞凋亡情况;采用免疫印迹技术检测各组假体周围骨细胞牙本质基质蛋白(DMP-1)、骨硬化蛋白(SOST)、葡萄糖调节蛋白78(GRP78)、肌醇依赖酶1α(IRE1α)、X盒结合蛋白(XBP1s)、c-Jun氨基末端激酶(JNK)及磷酸化JNK(p-JNK)等蛋白表达水平.结果:与正常组比较,模型组小鼠假体周围骨细胞活性明显降低,细胞凋亡显著(P＜0.05),其特征蛋白DMP-1显著下调,SOST明显上调,造成DMP-1/SOST增加(P＜0.05),且内质网应激通路蛋白GRP78、IRE1α、XBP1s和p-JNK表达水平显著增加(P＜0.05).而LIPUS治疗组假体周围骨细胞损伤及内质网应激反应显著减弱,表现为假体周围骨细胞活性、数量和DMP-1/SOST明显增加(P＜0.05),且IRE1α-XBP1-JNK通路的活化被显著抑制(P＜0.05).结论:LIPUS可阻止TCP磨损颗粒诱导的假体周围骨细胞损伤,其作用机制可能与抑制IRE1α-XBP1-JNK信号通路介导的内质网应激反应密切相关.“,”Objectives To observe the effect of low intensity pulsed ultrasound (LIPUS) on osteocyte injuries induced by the tricalcium phosphate(TCP) wear particles in the calvaria of mice.Methods Thirty ICR male mice of 6 to 8 weeks were randomly divided into a normal control group(n=10),a model group (n=10) and a LIPUS-treated group(n=10).A murine calvarial model of osteolysis was established in the model and LIPUS-treated groups through injecting TCP particles onto the surface of bilateral parietal bones at week 1,3,5,7 and 11.Mice in the normal group received negative ultrasound probe pressing,while those in the LIPUS-treated received LIPUS radiation.Three months later,the calvarias were obtained.The micro-CT,HE staining,flow cytometry and Western blotting were performed to estimate the calvarial osteolysis,osteocyte death,apoptosis and proteins expression of the dentin matrix protein 1 (DMP-1),sclerosis protein (SOST),glucose-regulated protein78 (GRP78),inositol-requiring enzyme(IRE 1 α),spliced X-box binding protein 1 (XBP1 s),c-Jun N-terminal kinase (JNK) and phosphorylated c-Jun N-terminal kinase(p-JNK) respectively.Results Compared with the normal control group,in the model group the viability of prosthetic osteocytes decreased significantly,and cell apoptosis was more obvious(P＜0.05);the osteocytic marker protein DMP-1 down-regulated significantly,but another marker protein SOST up-regulated significantly,which caused the decline in DMP-1/SOST(P＜0.05).Moreover,the expression levels of GRP78,IRE1,XBPls and p-JNK of the model group increased significantly(P＜0.05) in the calvaria osteocytes compared to the control group.However,in the LIPUS treatment group,osteocyte injuries and endoplasmic reticulum(ER) stress both decreased significantly,shown by a significant increase in the number and activity of osteocytes,DMP-1/SOST,and significant inhibition of the IRE1α-XBP1-JNK activation(P＜0.05).Conclusion LIPUS prevents osteocyte injuries induced by TCP wear particles in the calvaria of mice,which may be due to the inhibition of IRE1α-XBP1-JNK pathway activation through ER stress reaction.