正常及炎症状态人牙髓中八聚体结合转录因子4B的表达

Expression of Oct-4B in human normal and inflamed dental pulp cells

目的研究人正常及炎症牙髓组织中八聚体结合转录因子4B(Oct-4B)的表达特点,检测大肠杆菌脂多糖刺激后人牙髓细胞(HDPCs)中Oct-4B的表达水平,以探讨Oct-4B在牙髓炎症中的可能作用。方法采用免疫组织化学和反转录聚合酶链反应(RT-PCR)方法检测正常及炎症牙髓组织中Oct-4B的表达情况。RT-PCR检测1mg/L脂多糖刺激HDPC24、48、72h后Oct-4B和热休克蛋白70(HSP70)表达水平的变化。结果正常牙髓组织中未检测到Oct-4B的表达,炎症牙髓组织病灶处牙髓成纤维细胞和炎症细胞胞质中Oct-4B表达强阳性。炎症牙髓组织中Oct-4BmRNA水平显著高于正常牙髓组织(P<0.05)。脂多糖刺激48、72h后,HDPC中Oct-4B和HSP70mRNA水平同步上调(P<0.05)。结论 Oct-4B在炎症牙髓组织中高表达,且脂多糖刺激可上调牙髓细胞内Oct-4B表达,Oct-4B可能参与牙髓炎症修复过程。

Objective To investigate the expression of Oct-4B in human normal and inflamed dental pulp tissues and the Oct-4B level in HDPC stimulated by lipopolysaccharide,and explore the possible role of Oct-4B in pulpitis.Methods The protein localization and messenger RNA level of Oct-4B in healthy and inflammatory pulps were detected by immunohistochemistry and quantitative real-time polymerase chain reaction（PCR）.In addition,HDPC were collected after stimulated by 1 mg/L lipopolysaccharide for 24,48 and 72 h,then the expression of Oct-4B and 70 000 heat-shock protein（HSP70） in HDPC was evaluated by quantitative real-time PCR.Results Oct-4B was not detected in healthy pulp tissue,but in inflamed pulp tissue,it was strongly stained in cytoplasm of fibroblasts and inflammatory cells.The Oct-4B mRNA level was significantly up-regulated in inflamed pulps compared with healthy pulps（P 0.05）.Moreover,the mRNA levels of Oct-4B and HSP70 in HDPC were concomitantly increased after stimulated with 1 mg/L lipopolysaccharide for 48 and 72 h（P 0.05）.Conclusions This study revealed that a significant increase in the Oct-4B level in inflamed pulp tissue compared with non-inflamed pulp tissue,and up-regulation of Oct-4B expression in HDPC stimulated by lipopolysaccharide.It indicated that Oct-4B might be involved in repair of pulp injury.