动物造模 z-bio 2022-07-07 361

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

　　METHODS: Human brain microvascular endothelial cells (HBMEC) were used to construct an in vitro blood-brain barrier model; Western blotting was used to study whether LGG-CM could inhibit E. - Can CM inhibit bacterial invasion and neutrophil migration; study the expression of adhesion molecule CD44 and tight junction protein ZO-1 by immunoblotting; detect the intracellular distribution of ZO-1 protein by immunofluorescence; establish blood-brain barrier in vitro with Transwell Model, the protective effect of LGG-CM on cell barrier integrity was evaluated by transcellular endothelial electrical resistance (TEER) values and bacterial migration assays.

　　RESULTS: Western blot results showed that LGG-CM could inhibit the activation of NF-κB pathway by E. coli K1, thereby inhibiting the invasion and neutrophil migration of E. coli K1. Meanwhile, LGG-CM could inhibit E. coli K1 from up-regulating CD44 protein and down-regulating tight junction protein ZO-1. In addition, LGG-CM can significantly slow down the decrease of TEER value and inhibit the crossing of E. coli K1 across the blood-brain barrier in vitro.

　　Conclusion: In vitro experiments show that LGG-CM can prevent bacterial encephalitis caused by E. coli K1 by inhibiting the activation of NF-κB pathway, blocking E. coli K1 invasion and neutrophil migration, and maintaining the integrity of the blood-brain barrier.