Figure 3
Influence of AKB-4924 on intestinal epithelial barrier function and hypoxia-inducible factor (HIF) target gene expression. AKB-4924 (0 or 5.0 mg kg−1 in cyclodextrin vehicle) was administered subcutaneously on day −1 relative to trinitrobenzene sulfonic acid (TNBS) or EtOH intrarectal lavage. Animals were killed on days 2, 3, or 7, and colons were excised and tied off by suture into intestinal sacs. Sacs were loaded with fluorescein isothiocyanate-dextran 4400 (FD-4; 500 μg ml−1) and (a) the apparent permeability (Papp) was assessed. Blood was collected by sterile cardiac puncture and (b) serum assayed for lipopolysaccharide (LPS) content. Colon epithelial mRNA was screened by quantitative PCR for induction of the HIF-target genes CD73 and (c) intestinal trefoil factor (ITF) or (d) β1 integrin (ITGB1). Panel (e) represents western blot analysis for HIF-1α in nuclear isolates from intestinal epithelial cells (IEC) and lamina propria (LP) cells in control and TNBS colitis animals in the presence of AKB-4924. TATA-binding protein was employed as a housekeeper. N=6, *, ^, #P<0.05; **, ^^, ##P<0.01; analysis of variance (a, b, d), two-tailed, Student’s t-test (c).
