脂多糖诱导牙髓细胞DNA双链断裂的研究

doi:10.13701/j.cnki.kqyxyj.2017.03.001

摘要/Abstract

摘要： 目的:探讨低剂量条件下脂多糖诱导牙髓细胞DNA损伤方法,为研究脂多糖诱导牙髓细胞DNA双链断裂及DNA修复提供实验模型。方法:10 μg/L脂多糖连续刺激牙髓细胞1、3、6次后,采取MTT及TUNEL分别检测其对牙髓细胞增殖及凋亡的作用;采用q-PCR及免疫印迹检测γ-H2A.X的mRNA及蛋白水平的表达;使用免疫荧光及免疫组化法观测γ-H2A.X在体内、外牙髓细胞的表达。结果:与对照组相比,10 μg/L脂多糖连续刺激对牙髓细胞增殖及凋亡均无显著性差异;脂多糖连续刺激6次后细胞免疫荧光显示在细胞核检测到γ-H2A.X的阳性表达,且蛋白及mRNA水平的表达较对照组有显著性增加(P<0.05);免疫组化结果表明在脂多糖诱导4、6、8 d后,γ-H2A.X在大鼠牙髓组织较对照组表达水平显著升高(P<0.05)。结论:低剂量脂多糖连续刺激可诱导牙髓细胞产生DNA双链断裂。

关键词: 脂多糖, 牙髓细胞, DNA双链断裂, γ-H2A.X

Abstract: Objective: To investigate whether low dose of lipopolysaccharide (LPS) induces DNA damage in dental pulp cells, and to provide an experimental model for studying the DNA double-strand breaks and DNA repair. Methods: Ten μg/L LPS was added to dental pulp cells constantly once, three times, and six times, respectively. Cell proliferation was detected by MTT assay. Cell apoptosis was detected by TUNEL assay. The mRNA and protein expression levels of γ-H2A.X were investigated by q-PCR and Western blot. The expressions of γ-H2A. X in vivo or vitro were detected by immunofluorescence and immunohistochemistry. Results: Compared with the control group, the repeated stimulation of 10μg/L LPS had no significantinfluence on cell proliferation or on cell apoptosis. After repeated stimulation of 10μg/L LPS for six times,immunofluorescence revealed the positive expression of γ-H2A.X in cell nucleus. Moreover, compared with control groups, the mRNA and protein expression levels of γ-H2A.X increased significantly (P<0.05). Immunohistochemistry showed γ-H2A.X expression level increased remarkably after being induced by LPS for 4, 6 and 8days, respectively (P<0.05). Conclusion: The repeated stimulation of low dose of LPS may induce the occurrence of DNA double-strand breaks in dental pulp cells.

Key words: Lipopolysaccharide , Dental pulp cell, DNA double-strand breaks , γ-H2A.X

中图分类号:

R780.1

黄叶全，孟柳燕，乔玮玮，边专. 脂多糖诱导牙髓细胞DNA双链断裂的研究[J]. 口腔医学研究, 2017, 33(3): 235-239.

HUANG Ye-quan, MENG Liu-yan, QIAO Wei-wei, BIAN Zhuan. Lipopolysaccharide Stimulation Induces DNA Double-strand Breaks in Dental Pulp Cells.[J]. Journal of Oral Science Research, 2017, 33(3): 235-239.

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