title: Lipoteichoic acid upregulates NF-κB and proinflammatory cytokines by modulating β-catenin in bronchial epithelial cells.
abstract: Lipoteichoic acid (LTA) is a major cell wall component and virulence factor of gram-positive bacteria. The present study investigated the LTA‑induced inflammatory response of BEAS‑2B human bronchial epithelial cells, and detected the expression levels of proinflammatory cytokines interleukin (IL)‑6, IL‑8, IL‑1β, tumour necrosis factor‑α and monocyte chemotactic protein‑1, the upregulation of NF‑κB, and the phosphorylation and degradation of I‑κB. During the LTA‑induced inflammatory response of the BEAS‑2B human bronchial epithelial cells, the activity levels of the β‑catenin‑dependent promoter, and the protein expression levels of β‑catenin were significantly upregulated, whereas β‑catenin phosphorylation and the expression levels of AXIN were significantly downregulated. Following knockdown of β‑catenin by small interfering (si)RNA transfection, both the LTA-induced protein expression levels of NF‑κB and the LTA-induced activity levels of the NF‑κB‑dependent promoter were significantly reduced. Similarly, a marked reduction in I‑κB phosphorylation and degradation was observed following β‑catenin knockdown. The expression levels of the LTA‑induced proinflammatory cytokines were also significantly reduced following β‑catenin siRNA. These results suggest that β‑catenin has a significant role in the regulation of NF‑κB activity and proinflammatory cytokine expression during the LTA-induced inflammatory response of bronchial epithelial cells.
authors.affiliation: Department of Microbiology, Chung-Ang University College of Medicine, Seoul 156-756, Republic of Korea.
authors.forename: Jaewoong
authors.initials: J
authors.lastname: Jang
authors.affiliation: Department of Microbiology, Chung-Ang University College of Medicine, Seoul 156-756, Republic of Korea.
authors.forename: Wonyong
authors.initials: W
authors.lastname: Kim
authors.affiliation: Department of Microbiology, Chung-Ang University College of Medicine, Seoul 156-756, Republic of Korea.
authors.forename: Kijeong
authors.initials: K
authors.lastname: Kim
authors.affiliation: Department of Microbiology, Chung-Ang University College of Medicine, Seoul 156-756, Republic of Korea.
authors.forename: Sang-In
authors.initials: SI
authors.lastname: Chung
authors.affiliation: College of General Studies, Sangmyung University, Seoul 110-743, Republic of Korea.
authors.forename: Yae Jie
authors.initials: YJ
authors.lastname: Shim
authors.affiliation: School of Mechanical Engineering, Chung-Ang University, Seoul 156-756, Republic of Korea.
authors.forename: Seok-Min
authors.initials: SM
authors.lastname: Kim
authors.affiliation: Department of Microbiology, Chung-Ang University College of Medicine, Seoul 156-756, Republic of Korea.
authors.forename: Yoosik
authors.initials: Y
authors.lastname: Yoon
mesh_terms: D001980:Bronchi / Q000276:immunology / Q000473:pathology; D002460:Cell Line; D016207:Cytokines / Q000235:genetics / Q000378:metabolism*; D004847:Epithelial Cells / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D008070:Lipopolysaccharides / Q000494:pharmacology*; D016328:NF-kappa B / Q000378:metabolism*; D020545:Respiratory Mucosa / Q000276:immunology / Q000473:pathology; D013682:Teichoic Acids / Q000494:pharmacology*; D015854:Up-Regulation; D051176:beta Catenin / Q000235:genetics / Q000378:metabolism*
chemical_list: C495270:CTNNB1 protein, human; D016207:Cytokines; D008070:Lipopolysaccharides; D016328:NF-kappa B; D013682:Teichoic Acids; D051176:beta Catenin; C009900:lipoteichoic acid