骨桥蛋白及其受体在人黄韧带骨化标本中的表达及意义

Expressions and significance of osteopontin and its receptors in human ossified ligamentum flavum

目的探讨骨桥蛋白(OPN)及其受体CD44、整合素在人黄韧带骨化(OLF)标本中的表达及意义。方法2014年6月—2016年6月,收集8例在本院接受胸椎后路椎板切除的OLF患者的骨化黄韧带标本以及8例非黄韧带骨化患者的正常黄韧带标本。对所得标本进行脱钙、切片、免疫组织化学染色以及细胞体外培养和蛋白质印迹检测,观察黄韧带标本中OPN及其受体CD44、整合素的表达变化。结果 OLF标本中的弹性纤维排列杂乱无章,同时在骨化层可见大量软骨细胞;正常黄韧带标本中则无上述表现。OLF标本中OPN及其受体CD44呈高表达,且多在骨化区域的软骨细胞周围,而整合素β1的表达较弱;正常黄韧带标本中OPN及其受体呈低表达或不表达状态。通过对体外培养的细胞进行蛋白质印迹检测发现骨化黄韧带细胞OPN的表达较正常黄韧带细胞增加。免疫细胞化学染色发现骨化黄韧带细胞整合素β3染色呈阳性,而正常黄韧带细胞整合素β3的表达呈阴性或弱阳性;蛋白质印迹检测发现骨化黄韧带细胞整合素β3的表达明显高于正常黄韧带细胞。结论 OPN及其受体可能在OLF的发生过程中起关键作用。

Objective To explore the expression and significance of osteopontin（OPN） and its receptors CD44 and integrin in the ossification of the ligamentum flavum（OLF） to pave the way for further study of the pathogenesis of OLF. Methods From June 2014 to June 2016,sections of the thoracic ligamentum flavum were obtained from 8 patients with OLF who underwent posterior thoracic decompression surgery,and from 8 control patients free of OLF. Cultured ligamentum flavum cells were examined with Western blotting for OPN. The harvested sections were examined by immunohistochemistry for the OPN and its receptors. Results The elastic fibers in the OLF samples were disordered,and a large number of chondrocytes were seen in the ossification front,but not in the normal ligamentum flavum samples. OPN and its receptor CD44 were highly expressed in the OLF samples,and mostly around the chondrocytes in the ossification region,while the expression of integrin β1 was weak. The normal ligamentum flavum samples showed low expression or no expression of OPN and its receptors. The expression of the OPN in the OLF cells was higher than the control through the Western blotting. Immunocytochemistry staining showed that the expression of integrin β3 in the OLF cells was significantly higher than that in the normal ligamentum flavum cells,and the same to the Western blotting analysis. Conclusion OPN and its receptors may play a key role in the pathogenic process of OLF.