[Animal experiment]-Lactobacillus rhamnosus culture supernatant prevents E. coli meningitis by inhibiting the NF-κB pathway

  Objective: To investigate whether the supernatant of Lactobacillus rhamnosus (LGG-CM) can block the bacterial meningitis caused by E. coli K1 strain by inhibiting the NF-κB pathway.

  Methods: Human brain microvascular endothelial cells (HBMEC) were used to establish an in vitro blood-brain barrier model, and Western blotting was used to analyze the LGG-CM of the NF-κB pathway through E. coli K1 to study whether it can inhibit activation; invasion and neutrophil migration Research LGG-CM can inhibit bacterial invasion and neutrophil migration; immunoblotting of adhesion molecule CD44 and tight junction protein to study the expression of ZO-1; immunofluorescence to detect the intracellular distribution of ZO-1 protein; use Transwell barrier model The establishment of an in vitro blood brain to ensure the integrity of the cell barrier evaluated the protective effect of LGG-CM through TEER value and bacterial migration experiments.

  Result: The result of immunoblotting showed that LGG-CM inhibited E. coli K1 from activating the NF-κB pathway. The results show that it can inhibit the invasion of E. coli K1 and the migration of neutrophils. Meanwhile, LG G-CM is E. It can inhibit Escherichia coli K1 to inhibit the up-regulation of CD44 protein and down-regulation of tight junction protein ZO-1. In addition, LGG-CM significantly slowed down TEER levels and prevented E. coli K1 from crossing the blood-brain barrier in vitro.

  Conclusion: In vitro experiments show that LGG-CM inhibits the activation of the NF-κB pathway, prevents the entry of E. coli K1 and the migration of neutrophils, and maintains the integrity of the blood-brain barrier. , Showing that it can prevent bacterial encephalitis caused by E. coli K1.