基质细胞衍生因子1α及其受体CXCR4在牙本质-牙髓复合体损伤修复过程中的表达

摘要

目的:通过构建牙本质-牙髓复合体损伤修复动物模型,研究基质细胞衍生因子1α 及其受体CXCR4(SDF-1α /CXCR4)在其损伤修复过程中的表达.方法:制备大鼠牙本质-牙髓损伤模型,通过免疫组织化学染色、PCR技术分别对损伤后0、6 h和1、3、7 d及正常大鼠牙髓标本中SDF-1α /CXCR4进行检测.结果:正常大鼠组牙髓中没有发现SDF-1α 、CXCR4阳性表达,实验大鼠组损伤6 h后少量的成牙本质细胞和前期牙本质开始出现较弱阳性表达,损伤1 d后成牙本质细胞阳性表达增强,损伤3 d后牙髓成纤维细胞出现阳性表达,损伤7 d后未分化间充质细胞出现阳性表达,大鼠牙髓损伤后SDF-1α 、CXCR4随着时间的增加阳性表达程度明显增强.图像分析结果显示,SD大鼠牙本质-牙髓复合体损伤后牙髓中SDF-1α 、CXCR4的表达(灰度值)除0 h外其余各组均高于对照组(P<0.05).PCR结果显示,损伤后大鼠牙髓中SDF-1α 、CXCR4均符合产物设计大小.其表达(灰度值)除0 h外其余各组均高于对照组(P<0.05).结论:大鼠牙本质-牙髓复合体损伤后,前期牙本质、成牙本质细胞、牙髓成纤维细胞和未分化间充质细胞对SDF-1α 、CXCR4的表达呈时间依赖性,提示SDF-1α 、CXCR4可能参与了修复性牙本质的形成.%AIM : To investigate the expression and effect of stomal ceU derived factor 1 alpha ( SDF-1α) and its receptor CXCR4 in the rehabilitation process of dentin-dental pulp injury by establishing an arumal model of dentin-dental pulp injury rehabilitation.MEIHODS: A rat model of dental pulp-dentin injury was established.SDF-Ia and CXCR4 expression in dental pulp samples at the moment of O h, 6 h, 1 d, 3 d, 7 d after injury and in normal pulp was detected by immunohiscochemical staining (IHC) and RT-PCR.RESULTS : No positive staining of SDF-1α and CXCR4 was detected in normal dental pulp samples by IHC.6 h after injury, weak expression of SDF-Ia and CXCR4 could be detected in a small number of dentin cells and in predentin.Meanwhile, positive staininS was found in fibroblasts and undifferentiated mesenchymal cells during ld to 7d.staining became significantly enhanced with the time course.RT-PCR revealed that SDF -1α and CXCR4 mRNA expression significantly increased time-dependently after pulp injury (P ＜0.05).CONCLUSION: After injury, SDF-1α and CXCR4 expression in rat dental pulp-dentin complex, including predentin, dentin cells,fihroblasts and undifferentiated mesenchymal cells , significantly increased during early phase of repair.The results indicated that SDF-Ia and CXCR4 might participate in the formabon of reparative dentin.