中文摘要：

目的通过上调SIGIRR在人气道上皮细胞株H292中的表达,研究SIGIRR对鞭毛蛋白诱导的Toll样受体5（TLR5）表达的影响。方法实验设以下6组：H292组（未给予任何处理的H292细胞）、eH292组（转染空质粒pEGFP-N1的细胞）、sH292组（转染SIGIRR-EGFP真核表达质粒的细胞） ,另设加入鞭毛蛋白（终浓度0.2μg/ ml）的上述各组细胞,分别命名为FH292组、FeH292组和FsH292组。构建SIGIRR-EGFP融和蛋白的真核表达载体,脂质体转染法转染细胞,24h后用荧光显微镜观察融合蛋白的表达情况。Western blotting检测TLR5蛋白表达,ELISA法测定细胞上清中TNF-α浓度。结果转染重组载体的H292细胞可表达SIGIRR-EGFP融和蛋白,其主要分布于细胞质。通过对TLR5蛋白条带的光密度进行观察发现,FH292组（8.06±1.53）较H292组（1.71±0.12）、FeH292组（7.32±0.99）较eH292组（2.32±0.13）、FsH292组（7.01±0.83）较sH292组（2.01±0.07）TLR5蛋白表达明显增加（P〈0.01）。FH292组TNF-α浓度（114.06±10.34）较H292组（43.52±2.84）明显增加,而FsH292组TNF-α浓度（69.56±11.23）较FeH292组（117.76±9.07）显著下降（P〈0.01）。结论 SIGIRR的表达上调可抑制鞭毛蛋白诱导的H292细胞中TNF-α的产生,对TLR5表达无影响。SIGIRR在该信号通路中发挥了＂刹车＂作用,但该作用并不是由TLR5介导的。

英文摘要：

Objective To explore the effects of SIGIRR on the flagellin-induced expression of Toll-like receptor 5 （TLR5） in human air-way epithelial cell H292. Methods Cells were divided into 6 groups： H292 group, ceils without any treatment; eH292 group, cells were transfected with empty plasmid pEGFP-N1; sH292 group, cells were transfected with recombinant plasmid SIGIRR-EGFP. In the other three groups, FH292 group, Fell292 group and FsH292 group, cells were additionally treated with flagellin （final concentration of 0. 2μg/ml）. The eukaryotic expression vector of fusion protein SIGIRR- EGFP was constructed, and then transfected into H292 cells by liposome transfection. The expression of fusion protein was observed with fluorescence microscope 24 hours after transfeetion, the concentration of TNF-α in supernatant was detected by ELISA assay, and the expression of TLR5 protein was detected by Western blotting. Results The fusion protein SIGIRR EGFP was expressed and mainly distributed in the plasma of H292 cell transfected with the recombinant vectors The OD value of TLR5 protein was higher in FH292 group （8. 06±1.53） than in H292 group （1.71±0. 12）, higher in Fell292 group （7.32±0. 99） than in eH292 group （2. 32±0. 13）, and also higher in FsH292 group （7. 01±0. 83） than in sH292 group （2. 01±0. 07, P〈0.01）. The concentration of TNF-α increased significantly （ P〈 0. 01 ） in FH292 group （ 114. 06 ± 10. 34） than in H292 group （43. 52 ± 2. 84 ）, while decreased significantly （P〈0. 01） in FsH292 group （69. 56±11.23） than in H292 group （117.76± 9.07）. Conclusions Up-regulated expression of SIGIRR may inhibit the flagellin-induced release of TNF-α, however it shows no effect on the expression of TLR5. It seerns that the SIGIRR serves as a ＂brake＂ on TLRs signaling, but it is not induced by TLR5.