The effects of bifidobacterial secretory adhesin on the stress response of intestinal epithelial cells / 中华消化杂志

ABSTRACT

ObjectiveTo observe the effects of bifidobacterial sectory adhesin on NF-κB DNA binding activity,cytoplasm IκB,nuclei NF-κBp65,TNF-α,IL-1β,and IL-8 expression in intestinal epithelial cell post stress response.MethodsThe cultured intestinal epithelial cell line Lovo cells were divided into 5 groups,which included directly stimulated by lypopolysaccharide (LPS) (100 ng/ml) or H2O2 (200 μmol/L) for 3 hours groups,bifidobacterial sectory adhesin (30μg/ml) pre-incubation for 30 minutes and then treated by LPS (100 ng/ml) or H2O2 (200 μmol/L) for 3 hours groups and control group with no treatment.NF-κB DNA binding activity was evaluated by electrophoretic mobility shift assay (EMSA).The cytoplasm IκB and nuclei NF-κBp65 expression were determined by Western blot.The expressions of TNF-α,IL-1β and IL-8 at mRNA level were detected by semi-quantatitive assay of RT-PCR.ResultsThe expressions of NF-κB DNA binding activity [(6.20±0.35) times and (4.16 ± 0.52) times of that of non treated control group,respectively] and nuclei NF-κBp65 [ (0.64±0.05) and (0.67±0.06)] were higher in cells after LPS or H2()2 stimulated,however the cytoplasm IκB expression [ (0.28 ± 0.10) and (0.39 ± 0.12) respectively] was weaker.After bifidobacterial sectory adhesin pre-incubation,the expressions of NF-κB DNA binding activity and nuclei NF-κBp65decreased obviously,but cytoplasm IκB expression increased.After treated with LPS or H2O2,the mRNA expressions of TNF-α,IL-1β and IL-8 were significantly increased [LPS treated group2 (0.92±0.10)、(0.38±0.03)、(1.44±0.25),H2O2 treated group(0.89±0.13)、(0.36±0.06)、(1.42±0.18)].After bifidobacterial sectory adhesin pre-incubation,their expressions decreased.The mRNA expressions of TNF-α,IL-1β and IL-8 have significantly positive correlation with NF-κB DNA binding activity.ConclusionsThere is a significant inhibition role of bifidobacterial sectory adhesin in LPS and H2O2 induced NF-κB DNA binding activity in intestinal epithelia cells.The activation of NFκB may associate with the regulation of TNF-α,IL-1β and IL-8 proinflammatory cytokines expression.