BPIFB1在铜绿假单胞菌引起的炎症反应中的调节作用

Role of BPIFB1 in regulating inflammatory response of RAW264.7 cells infected by P.aeruginosa

目的研究杀菌性/通透性增强蛋白折叠结构1(BPIFB1)在铜绿假单胞菌引起的炎症反应中的作用机制和调节途径。方法应用RNA干涉、特异性蛋白激酶抑制剂阻断法,通过ELISA、Western blot法测定BPIFB1与脂多糖(LPS)共同作用于RAW264.7细胞后膜表面CD14、TLR受体以及胞内相关信号转导通路分子表达水平的变化情况。结果 BPIFB1与LPS作用后RAW264.7细胞表面CD14、TLR4和MyD88的表达水平明显下降;当细胞中MyD88、TRAF6、NF-κB等蛋白分子的表达被各自特异性siRNA所阻断后,BPIFB1与LPS抑制细胞因子TNF-α过表达的能力也被显著抑制;当用BPIFB1与LPS处理过的细胞用相应蛋白激酶抑制剂作用后,细胞内相关通路蛋白p38、pERK1/2、Akt1磷酸化水平被明显抑制。结论 BPIFB1与LPS结合通过阻抑相关胞内细胞因子的表达,降低了铜绿假单胞菌所产生的细胞炎性反应程度。

Objective To demonstrate the mechanisms and regulation pathways of BPIFB1 against P. aeruginosa infection. Methods After treated with 10 ng/mL LPS and 1.28 mg/mL BPIFB1, RAW 246.7 cells were detected for the expression levels of CD14 receptor, TLR4 and MyD88 by ELISA and Western blotting. In addition, using RNAi and specific protease in- hibitor blockade respectively, we observed the changes in the expressions of MyD88, TRAF6, NF-κB and different signaling pathway molecules in RAW 246.7 cells after BPIFB1 and LPS treatment. Results The expression levels of CD14, TLR4 and MyD88 significantly decreased after the RAW264.7 cells were treated with BPIFB1 and LPS. When the expressions of MyD88, TRAF6 and NF-κB were blocked by specific siRNA respectively, there was a significant reduction of TNF-α over- expression induced by BPIFBI and LPS. And when the cells were treated with BPIFB1, LPS and related protease inhibitors, the phosphorylation levels of ERK1/2, p38 and Aktl were evidently inhibited by kinase inhibitors. Conclusion The combina- tion of BPIFBI and LPS can reduce the degree of cell inflammatory responses induced by P. aeruginosa by inhibiting the expressions of relative intracellular cytokines.