Research on Small Doses of Lipopolysaccharide Induced Vascular Endothelial Cells Expression of Toll Like Receptor 4

Objective To investigate the expression of Toll like receptor 4(TLR4)on human umbilical vein endothelial cells (HUVEC) induced by small doses of lipopolysaccharide (LPS).Methods The ECV304 belonging to HUVEC was cultured in vitro.and hatched with LPS and LPS + antibody of TLR4(anti-TLR4) respectively.Cell proliferation activity was detected by MTT.The effect of LPS on change of the cell surface of TLR4 was observed with immunohistochemical staining method.The expression of TLR4-mRNA and of IL-8mRNA were evaluated by Fluorescence Detection Quantitative Polymerase Chain Reaction (PCR).Results ECV304 cells stimulated by LPS of(10-50)ng/mL within 24 h,MTT detection showed no apparent change (P 0.05);but with 100 ng/mL LPS stimulated the cells 24 h,the number of cells reduced significantly (P 0.05),under the circumstances,anti-TLR4 didn't withstand evidently.The 10 ng/mL LPS stimulated ECV304 in 24 h,the expression of TLR4 was elevatory;and with 50 ng/mL LPS stimulation,the expression of TLR4 was significantly increased in 6-24 h (P 0.05),with 50 ng/mL LPS stimulating ECV304 cells in 4 h and 8 h.The expression of TLR4-mRNA in LPS group and LPS+anti-TLR4 group increased significantly as compared with the normal control group (P 0.05),but LPS+anti-TLR4 group only in 8 h lower than LPS group;the expression of IL-8mRNA in LPS group and LPS+anti-TLR4 evaluated obviously as compared with the normal control group only in 8 h,which did not affect with anti-TLR4.Conclusion Small doses of LPS can induce ECV304 cells expressing TLR4 and cause cell activation,and anti-TLR4 can inhibit TLR4 expression,but can't restrain cell activation.