Objective To identify the effects of single immunoglobin IL-1 receptor related protein （SIGIRR） on inflammation induced by high mobility group box 1 （HMGB1） in A549 derived from human alveolar epithelial cells.
Methods Eukaryotic expression vectors pCDNA3.1（+） constructed with SIGIRR cDNA were transiently transfected into A549 cells，in which SIGIRR was forced to be over-expressed. Western blot and RT-PCR were applied to detect the expression level of SIGIRR after transfection. After the stimulation by HMGB1，the transcriptional activity of NF-κB in A549 cells was detected by dual-luciferase reporter assay system，and the protein levels of inflammatory cytokine TNF-α and IL-1β were measured by ELISA.
Results The expression level of SIGIRR increased significantly in A549 cells transfected with SIGIRR vectors. The transcriptional activity of NF-κB was enhanced obviously after HMGB1 treatment in A549 cells by dual-luciferase reporter assay system，while the transfection of SIGIRR vectors decreased the activity. The protein levels of TNF-α and IL-1β were down-regulated in A549 cells over-expressing SIGIRR after HMGB1 stimulation compared with the non-transfected cells.
Conclusions Up-regulated SIGIRR expression can inhibit HMGB1-induced proinlammatory cytokine release in A549 cells such as TNF-α and IL-1β. The transcriptional activity of NF-κB is dampened by SIGIRR transfection，implying that the anti-inflammatory effects of SIGIRR may be involved in the regulation of NF-κB.
Citation： HUANG Xun,LIANG Xiaohua,TIAN Feng,JIANG Tao.. Effects of Single Immunoglobin IL-1 Receptor Related Protein on Inflammation Induced by High Mobility Group Box 1 in A549 Cells. Chinese Journal of Respiratory and Critical Care Medicine, 2011, 10(6): 577-580. doi: Copy