细胞焦亡相关蛋白在钽融合器松动周围组织中的表达及意义

Expression and significance of pyroptosis associated protein in peripheral tissues with tantalum cage loosening

背景:钽融合器植入椎间隙后如何影响其周围细胞最终导致骨溶解,发生无菌性松动,其机制有待阐明。目的:探索细胞焦亡在钽所致椎间骨溶解中的作用。方法:选择2015年1月至2021年12月江西省人民医院骨科收治的患者,观察组(n=19)为腰椎融合钽融合器松动并行翻修病例,对照组(n=11)为自体骨植骨腰椎融合、其他材料融合器融合后内固定取出及钽融合器植入邻近节段退变需要延长固定融合节段病例,术中收集两组患者融合器周围及融合节段周围界膜组织,进行扫描电镜、免疫荧光染色及qRT-PCR检测。结果与结论:①扫描电镜下可见,观察组钽融合器周围及融合节段界膜组织内可见大量纤维组织增生,同时可见部分钽脱落不规则颗粒物存在,对照组纤维组织增生不明显,未见有不规则颗粒物存在;②苏木精-伊红染色显示,观察组钽融合器周围及融合节段界膜组织中可见大量纤维组织增生,成骨细胞不明显;对照组界膜组织中纤维组织增生不明显,可见成骨细胞分布在骨组织周围;③免疫荧光染色显示,观察组界膜组织细胞焦亡相关蛋白GSDMD、NLRP3、Caspase1表达高于对照组(P<0.05);④qRT-PCR检测显示,观察组界膜组织GSDMD、NLRP3、Caspase1的mRNA表达高于对照组(P<0.05);⑤结果表明,细胞焦亡相关蛋白(GSDMD、NLRP3、Caspase1)在钽融合器松动病例中表达明显升高,说明细胞焦亡参与了钽所致椎间骨溶解的病理生理过程。

BACKGROUND:The mechanism of how the fusion cage affects its surrounding cells and eventually leads to osteolysis with aseptic loosening after implantation of the tantalum(Ta)fusion device into the intervertebral space remains to be elucidated.OBJECTIVE:To explore the effect of pyroptosis in tantalum(Ta)induced intervertebral osteolysis.METHODS:Patients admitted to the Department of Orthopedics,Jiangxi Provincial People’s Hospital from January 2015 to December 2021 were selected in this study.The observation group(n=19)contained the cases of lumbar fusion tantalum cage loosening and revision.The control group(n=11)consisted of autologous bone graft lumbar fusion,internal fixation removal after fusion of other material cages,and degeneration of adjacent segments implanted with tantalum cages requiring extended fixation of the fusion segment.During the operation,the limiting membrane tissue around the cage and around the fusion segment of the two groups was collected for scanning electron microscopy,immunofluorescence staining and qRT-PCR detection.RESULTS AND CONCLUSION:(1)Electron microscopy showed that a large amount of fibrous tissue proliferation was observed around the tantalum(Ta)fusion vessel and within the boundary membrane tissue of the fused segment in the observation group.Meanwhile,irregular particles on tantalum shedding could be observed partially,but fibrous tissue proliferation was not obvious in the control group,and no irregular particles were found.(2)Hematoxylin and eosin staining showed that a large amount of fibrous tissue proliferation with indistinct osteoblasts was observed in the boundary membrane tissue around the fusions and in the fused segments,and osteoblasts were not obvious in the observation group.Fibrous tissue proliferation was not obvious in the limiting membrane tissue of the control group,and osteoblasts were seen distributed around the bone tissue.(3)Immunofluorescence examination showed that the expression of pyroptosis-related proteins GSDMD,NLRP3 and Caspase 1 in the limiting membrane tissue in the observation group was higher than that in the control group(P<0.05).(4)qRT-PCR assay showed that mRNA expression levels of GSDMD,Caspase 1 and NLRP3 in the observation group were higher than those in the control group(P<0.05).(5)These results showed that the expression of pyroptosis related proteins(GSDMD,NLRP3,and Caspase 1)was remarkably increased in tantalum(Ta)fusion loosening cases,indicating that pyroptosis was involved in the pathophysiology of tantalum(Ta)induced intervertebral osteolysis.