Fig. 4

Knockdown of TFF1 activates NF-κB pathway and promotes high glucose-induced apoptosis in RPE cells. a The relative mRNA levels of TFF1 were measured by qRT-PCR transfection with si-TFF1 reduced the expression of TFF1 in ARPE-19 cells. For (b-d), ARPE-19 cells were divided into four groups: control group, si-NC group, si-TFF1 group and si-TFF1 + BAY11–7082 group. b The relative protein levels of p-p65, p-IκBα and p-IKKα/β were assessed by Western blot, which revealed that si-TFF1 promoted the phosphorylation of NF-κB pathway-associated proteins. c The apoptosis rate was assessed by Annexin V/PI staining and flow cytometry. The data indicated that knockdown of TFF1 significantly promoted HG-induced apoptosis, while BAY 11–7082 (inhibitor of NF-κB pathway) restored the apoptosis rate induced by si-TFF1. d The relative protein levels of cleaved-caspase 3, Bax and Bcl-2 were assessed by Western blot, whose data suggested that si-TFF1 significantly increased the expression of cleaved-caspase 3 and Bax and inhibited Bcl-2 expression, while BAY 11–7082 treatment reversed this effect. Data are presented as mean ± SD. Three replicate wells were used per sample in each experiment and experiments were replicated three times. * P < 0.05; ** P < 0.01