plantarum. TER of caco-2 monolayers were maintained 480 Ω·cm2 after being cultured for 7 days. This was in contrast to caco-2 cells infected with EIEC which resulted in an approximately 46.67% decrease of TER
from 480 Ω·cm2 to 256 Ω·cm2. However, when Caco-2 cells were co-incubated simultaneously with EIEC and L. plantarum, the reduction of TER was 39.58% from 480 Ω·cm2 to 290 Ω·cm2. The Caco-2 cells infected with EIEC induced to a substantial decrease of TER to 62.6% of the control values within 24 h (Fig. 1.). Figure 1 L. plantarum attenuates EIEC-induced decrease in TER of Caco-2 cells. (◇) represented control GF120918 group, (■) EIEC group, (▲) L. plantarum group. TER after enteroinvasive E. coli (EIEC) infection was significantly lower than the control after cultured 6 hours during 24 hrs. Each point represented the mean value obtained from 10 to 12 individual Caco-2 monolayers. Error bars showed the standard error. One-way ANOVA was performed with Tukey Kramer post-hoc comparison. * vs control group at different time, P < 0.05; ** vs L. plantarum group at different time, P < 0.05. L. plantarum inhibits increases in macromolecular permeability
of Caco-2 cells in response to EIEC infection Macromolecular find protocol permeability assays with Caco-2 cell monolayers using an infraredsensitive dextran (10-kDa) probe (as measured by the signal intensity for basal medium samples) from apical to basolateral Transwell compartments (relative integrated intensity
[RI] compared to control group, 1.25 ± 0.44, n = 4) demonstrated that EIEC-infected monolayers exhibited a marked increase in the permeability to the dextran probe (RI = 3.59 Fludarabine ± 0.51; n = 4) as compared with control group and L. plantarum group (RI = 2.09 ± 0.45; n = 4), P < 0.01 and P < 0.05, respectively. EIEC-induced increases in the dextran permeability of Caco-2 cell monolayers were reduced when epithelial cells were treated with L. plantarum, P < 0.05 (Fig. 2.). Figure 2 L. plantarum inhibits increases in macromolecular permeability of Caco-2 cells in response to EIEC infection. Macromolecular permeability assays with Caco-2 cell monolayers using an infrared sensitive these dextran (10-kDa) probe. (◇)represented control group, (■) EIEC group, (▲) L. plantarum group. Dextran integrated intensity after EIEC infected was significantly increased than the control group after cultured 60 min during 120 min. One-way ANOVA was performed with Tukey Kramer post-hoc comparison. * vs control group, P < 0.05; ** vs L. plantarum group, P < 0.05. L. plantarum prevents EIEC-induced redistribution of Claudin-1, Occludin, JAM-1 and ZO-1 proteins TJ barrier function can also be affected by changes in the distribution of specific tight junctional proteins or their levels of expression. TJ were located between the adjacent Caco-2 cells, TJs associated proteins were continuously distributed with bright brown spots along membrane of the cells.