Fig. 3
CREBH enhances the expression of intestinal integrity associated tight junction proteins impaired by inflammatory cytokines. Four groups of WT or CREBH-KO mice (n = 5–6/group) were treated with either TNFα (60 ng/g body weight) or vehicle (Veh, saline) for 5 h. Ileum tissues were collected for protein and RNA extraction for the following analyses: A mRNA expression of CLDN5 and CLDN8 in the ileums measured by qRT-PCR. B Immunoblotting analysis of CLDN2 and β-actin in the ileums of the KO mice treated with TNFα or Veh. C Immunofluorescent confocal microscopic images of IPEC-J2 cells treated with Veh (H2O) or TNFα (20 ng/mL) for 24 h followed by stained with anti-CREBH antibody or Hoescht 33,342 as described in the Additional file 1: Supplemental Methods. D qRT-PCR analysis of mRNA expression of CLDN8 and CLDN2 in IPEC-J2 cells treated with Veh (H2O) or TNFα (20 ng/mL) for 12 or 24 h. E IPEC-J2 cells were transfected with mock (empty vector) or an active CREBH (N-terminal CREBH, constitutively active) plasmid for 48 h. Total RNAs were extracted for measurement of mRNA expression of CLDN2, 5, 8, and ZO-1 by qRT-PCR. Results represent the means ± SD. The two-tailed Student’s t-test was used for statistical analyses of two-group comparisons. *P < 0.05 and **P < 0.01 versus controls