变形链球菌培养上清对EAhy926细胞增殖活性和TLR4表达的影响

Effect of the supernatant of Streptococcus mutans on the proliferation and the TLR4 expression of EAhy926 cells

目的观察变形链球菌培养上清对EAhy926细胞的增殖活性及TLR4表达的影响。方法变形链球菌培养上清作用于EAhy926细胞,MTT法检测EAhy926细胞的增殖活性;RT-PCR法检测EAhy926细胞TLR4 mRNA的表达;流式细胞术检测EAhy926细胞表面TLR4的表达。结果不同浓度的变形链球菌培养上清作用6 h可促进EAhy926细胞的增殖(P<0.05),但12 h后可明显抑制该细胞的生长(P<0.05),呈现显著的时间和剂量依赖性。变形链球菌培养上清作用于EAhy926细胞后,TLR4 mRNA和TLR4蛋白表达量随着作用时间延长而逐渐增高,在16 h达到高峰,24 h后又逐渐下降(P<0.01)。结论变形链球菌培养上清可明显抑制EAhy926细胞的生长,上调该细胞TLR4的表达。

Objective To investigate the effect of the supernatant of Streptococcus mutans on the proliferation and the Toll-like receptor 4（TLR4） expression of EAhy926 cells [a hybridoma of human umbilical vein endothelial cells（HUVEC） and the human epithelial cell line A549,characterized by endothelial phenotype and biology].Methods EAhy926 cells were treated with the supernatant of S.mutans.The proliferation of EAhy926 cells was determined by MTT assay.The mRNA expression of TLR4 in EAhy926 cells was detected by reverse transcription polymerase chain reaction（RT-PCR）.TLR4 was analyzed by flow cytometry.Results The proliferation of EAhy926 cells was significantly enhanced by the supernatant of S.mutans at 6 h（P0.05） and inhibited after 12 h（P0.05） in both a time-and dose-dependent manner.The expression of mRNA and protein for TLR4 in EAhy926 cells increased after stimulation with the supernatant of S.mutans,peaking at 16 h（P0.01） and then decreasing.Conclusion The growth of EAhy926 cells was inhibited by the supernatant of S.mutans.The supernatant of S.mutans markedly upregulated the expression of TLR4 in EAhy926 cells.