title: [Anti-inflammatory mechanism of Lactobacillus rhamnosus GG in lipopolysaccharide- stimulated HT-29 cell].
abstract: OBJECTIVE
  Probiotics are live non-pathogenic organisms that belong to the resident microflora, and confer health benefits by multiple mechanisms. Lactobacillus rhamnosus GG (LGG) is one of the probiotic bacteria that ameliorates intestinal injury and inflammation caused by various stimuli. We aimed to evaluate the anti-inflammatory effect and mechanism of LGG in lipopolysaccharide (LPS)-stimulated HT-29 cells.
  
  
  METHODS
  HT-29 cells were stimulated with interleukin (IL)-1β (2 ng/mL), tumor necrosis factor (TNF)-α (20 ng/mL), and LPS (20 μg/mL) in the presence or absence of LGG (10⁷-10⁹ colony forming units/mL). Production of the pro-inflammatory chemokine IL-8 was measured by ELISA and semi-quantitative PCR. Transcriptional activity of NF-kB-responsive gene was evaluated by luciferase assay with reporter gene. Toll-like receptor 4 (TLR4) mRNA expression was assessed by semi-quantitative PCR. The IκBa degradation was evaluated by western blot and intranuclear translocation of NF-κB was determined by western blot and immunofluorescence.
  
  
  RESULTS
  LGG did not affect the viability of HT-29 cells. Pretreatment of HT-29 cells with LGG significantly blocked TNF-α, and LPS induced IL-8 activation at both mRNA and protein level (p<0.05). Pretreatment of HT-29 cells with LGG attenuated LPS-induced NF-κB nuclear translocation and also blocked LPS-induced IκBα degradation. LGG also down-regulated TLR4 mRNA activated by LPS.
  
  
  CONCLUSIONS
  LGG attenuates LPS induced inflammation, and this may be associated with TLR4/NF-κB down-regulation.
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea.
authors.forename: Sang Kil
authors.initials: SK
authors.lastname: Lee
authors.forename: Kyung Min
authors.initials: KM
authors.lastname: Yang
authors.forename: Jae Hee
authors.initials: JH
authors.lastname: Cheon
authors.forename: Tae Il
authors.initials: TI
authors.lastname: Kim
authors.forename: Won Ho
authors.initials: WH
authors.lastname: Kim
mesh_terms: D002470:Cell Survival / Q000187:drug effects; D015536:Down-Regulation / Q000187:drug effects; D019073:HT29 Cells; D006801:Humans; D020672:I-kappa B Proteins / Q000378:metabolism; D053583:Interleukin-1beta / Q000378:metabolism; D016209:Interleukin-8 / Q000235:genetics / Q000378:metabolism; D052201:Lacticaseibacillus rhamnosus / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000633:toxicity; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000378:metabolism; D019936:Probiotics / Q000494:pharmacology; D051197:Toll-Like Receptor 4 / Q000235:genetics / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism
chemical_list: D020672:I-kappa B Proteins; D053583:Interleukin-1beta; D016209:Interleukin-8; D008070:Lipopolysaccharides; D016328:NF-kappa B; C000606204:NFKBIA protein, human; D051197:Toll-Like Receptor 4; D014409:Tumor Necrosis Factor-alpha; D000072000:NF-KappaB Inhibitor alpha