Effect of siRNA silencing apoptosis signal-regulating kinase 1 on inflammatory response of human alveolar epithelial A549 cells induced by lipopolysaccharide / 中国新生儿科杂志

ABSTRACT

Objective To study the effect of small interfering ribonucleic acid (siRNA) silencing apoptosis signal-regulating kinase 1 (ASK1) on inflammatory response of lipopolysaccharide-induced alveolar epithelial A549 cells and its mechanism.Method Cell inflammation model of A549 cells was induced by lipopolysaccharide.The expression of ASK 1 in A549 cells was silenced by liposome transfection of siRNA.The mRNA and expression levels of ASK1,interleukin 6 (IL-6),interleukin 8 (IL-8) and tumor necrosis factor alpha (TNF-α) in A549 cells were detected by immunoblotting,real-time fluorescence quantitative polymerase chain reaction and enzyme-linked immunosorbent assay.Result The expression of IL-6,IL-8 and TNF-α in the experimental group was significantly higher than that in the control group (P＜0.001),which indicated that the inflammatory model of A549 cells was successfully constructed.The mRNA level and expression of ASK1 in the interference group was significantly lower than that in the negative control group and the blank control group (P＜0.01),indicating that silencing ASK1 was also successful.The expressions of IL-6,IL-8 and TNF-α in the interference group (0.37±0.04,0.32±0.04,0.48 ±0.13) were significantly lower than those in the negative control group (1.04±0.11,1.22±0.19,0.93±0.14) and the blank control group (1.01±0.14,1.01 ±0.23,1.02±0.25).The expression of IL-6,IL-8 and TNF-α protein in the interference group (pg/ml) (122.6± 11.0,537.2±42.4,159.2± 19.6) were also significantly lower than those in the negative control group (267.4±20.4,1 289.8±55.3,327.0±26.3) and blank control group (246.6±18.7,1 300.3±35.6,325.2± 18.3),with significant difference (P＜0.05).There was no significant difference in each value between negative control group and blank control group (P＞0.05).Conclusion Silencing ASK1 by siRNA can down-regulate the expression of IL-6,IL-8 and TNF-α in A549 cells,suggesting that ASK 1 may be involved in the regulation of lipopolysaccharide-induced inflammation in A549 cells.