title: Lactobacillus acidophilus strain suppresses the transcription of proinflammatory-related factors in human HT-29 cells.
abstract: Previous studies have shown that lactic acid bacteria can inhibit inflammatory responses, but the mechanisms are very little known. In this study, transaction and expression of three proinflammatory factors, iNOS, PTGS-2, and IL8, which are closely related to the inflammatory response, were investigated by luciferase reporter assay and RTPCR in HT-29 cells treated by Lactobacillus acidophilus. The results showed that the live L. acidophilus sharply down-regulated the transcription of these three genes. Because there was a NF-κB binding site located at -265 bp, -225 bp, and -95 bp upstream of the iNOS, PTGS-2, and IL8 promoters, respectively, we further addressed the effects of NF-κB on transaction of the three promoters by cotransfection. As was expected, NF-κBs remarkably upregulated the activity of the reporter gene and, no effect of NF-κBs on IL-8 promoter transaction was found after NF-κB binding site mutation of the IL8 promoter in HT-29 cells. In conclusion, the live L. acidophilus decreased the transcriptional activity of NF-κB and, in turn, inhibited the transaction of NF-κB on the three proinflammatory factors mentioned above.
authors: Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Bioengineering, Tianjin University of Science and Technology, Tianjin, China. chenkun97411@163.com
authors: Kun
authors: K
authors: Chen
authors: Nailong
authors: N
authors: Liang
authors: Xuegang
authors: X
authors: Luo
authors: Tong-Cun
authors: TC
authors: Zhang
mesh_terms: D051546:Cyclooxygenase 2 / Q000096:biosynthesis*; D015536:Down-Regulation; D017930:Genes, Reporter; D019073:HT29 Cells; D006801:Humans; D016209:Interleukin-8 / Q000096:biosynthesis*; D007779:Lactobacillus acidophilus / Q000276:immunology*; D008156:Luciferases / Q000032:analysis; D016328:NF-kappa B / Q000096:biosynthesis; D052247:Nitric Oxide Synthase Type II / Q000096:biosynthesis*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic
chemical_list: D016209:Interleukin-8; D016328:NF-kappa B; D008156:Luciferases; C496319:NOS2 protein, human; D052247:Nitric Oxide Synthase Type II; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human