title: [Lactobacillus rhamnosus GG conditioned medium prevents E. coli meningitis by inhibiting nuclear factor-κB pathway].
abstract: To investigate whether Lactobacillus rhamnosus GG conditioned medium(LGG-CM)has preventive effect against E. coli K1-induced neuropathogenicity in vitro by inhibiting nuclear factor-κB (NF-κB) signaling pathway.
  
  
  
  An in vitro blood-brain barrier (BBB) model was constructed using human brain microvascular endothelial cells (HBMECs). The effect of LGG-CM on E. coli-actived NF-κB signaling pathway was assayed using Western blotting. Invasion assay and polymorphonuclear leukocyte (PMN) transmigration assay were performed to explore whether LGG-CM could inhibit E. coli invasion and PMN transmigration across the BBB in vitro. The expressions of ZO-1 and CD44 were detected using Western blotting and immunofluorescence. The changes of trans-epithelial electric resistance (TEER) and bacterial translocation were determined to evaluate the BBB permeability.
  
  
  
  Pre-treament with LGG-CM inhibited E. coli-activated NF-κB signaling pathway in HBMECs and decreased the invasion of E. coli K1 and transmigration of PMN. Western blotting showed that LGG-CM could alleviate E. coli-induced up-regulation of CD44 and down-regulation of ZO-1 expressions in HBMECs. In addition, pre-treatment with LGG-CM alleviated E. coli K1-induced reduction of TEER and suppressed bacterial translocation across the BBB in vitro.
  
  
  
  LGG-CM can block E. coli-induced activation of NF-κB signaling pathway and thereby prevents E. coli K1-induced neuropathogenicity by decreasing E. coli K1 invasion rates and PMN transmigration.
authors.affiliation: Department of Microbiology, School of Public healthy, Southern Medical University, Guangzhou 510515, China.E-mail: 870686982@qq.com.
authors.forename: Qing
authors.initials: Q
authors.lastname: Zeng
authors.forename: Xiao-Long
authors.initials: XL
authors.lastname: He
authors.forename: Han-Sheng
authors.initials: HS
authors.lastname: Xiao
authors.forename: Lei
authors.initials: L
authors.lastname: Du
authors.forename: Yu-Jing
authors.initials: YJ
authors.lastname: Li
authors.forename: Le-Cheng
authors.initials: LC
authors.lastname: Chen
authors.forename: Hui-Wen
authors.initials: HW
authors.lastname: Tian
authors.forename: Sheng-He
authors.initials: SH
authors.lastname: Huang
authors.forename: Hong
authors.initials: H
authors.lastname: Cao
mesh_terms: D018407:Bacterial Physiological Phenomena / Q000187:drug effects; D001812:Blood-Brain Barrier; D017077:Culture Media, Conditioned / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D052201:Lacticaseibacillus rhamnosus; D020814:Meningitis, Escherichia coli / Q000517:prevention & control*; D016328:NF-kappa B / Q000037:antagonists & inhibitors* / Q000378:metabolism; D009504:Neutrophils / Q000502:physiology; D057705:Transendothelial and Transepithelial Migration / Q000187:drug effects / Q000502:physiology
chemical_list: D017077:Culture Media, Conditioned; D016328:NF-kappa B