脂多糖上调人牙髓细胞B细胞淋巴瘤-2蛋白及其相关X蛋白的表达

Lipopolysaccharides upregulated the expression of B-cell lymphoma-2 and its associated X protein in human dental pulp cells

目的探讨脂多糖(LPS)作用于人牙髓细胞后,B细胞淋巴瘤-2(Bc1-2)蛋白、Bcl-2相关X蛋白(Bax)在正常人牙髓和炎症牙髓中的表达,探讨其在牙髓炎症过程中的作用机制。方法在体外用不同质量浓度LPS刺激人牙髓细胞后,采用免疫细胞化学染色方法在不同的时间点检测Bcl-2、Bax的表达,用图像分析系统Simple PCI version 5.1分析。结果正常人牙髓细胞中Bcl-2、Bax表达量不高,而在牙髓炎症过程中两者均增强,但是随着LPS质量浓度的增加,Bcl-2的表达量开始下降,而Bax的表达则持续增强。结论内毒素能使人牙髓细胞膜上的Bcl-2、Bax表达增强,但Bax的表达强于Bcl-2,内毒素可能通过两者介导的信号传导途径引起细胞凋亡。

Objective To study the effects of lipopolysaccharides（LPS） on B-cell lymphoma-2（Bcl-2） protein and Bcl-2-associated X protein（Bax） expression of human dental pulp cells. Methods In vitro model of human dental pulp cells apoptosis was established by LPS. The protein expression of Bcl-2 and Bax in human dental pulp celI（HDPC） after induction of LPS with different concentrations at different times was determined by immunocytochemical method. The result was analyzed using Simple PCI version 5.1. Results A small number of Bcl-2 and Bax positive cells were observed in normal dental pulp. By contrast, Bcl-2 and Bax showed enhanced expression in inflammatory dental pulp and some pulp cells in the inflammatory area. Bax was furtherexpressedas the LPS increased, whereas Bcl-2 showeda weakened shift. Conclusion The apoptosis in dental pulp induced by Bcl-2 and Bax may play a role in pulpitis. Endotoxin may change the expression of Bcl-2 and Bax on human dental pulp cell membrane and induces cell apoptosis through Bcl-2 and Bax- mediated signal pathway.