REGULATION OF EXPRESSION OF HUMAN INTESTINAL BILE ACID-BINDING PROTEIN IN CACO-2 CELLS

摘要: Molecular mechanisms of the bile acid active transport system in ileal enterocytes remain unknown. We examined whether acids affect human enterocyte gene expression intestinal acid-binding protein (I-BABP), a component this system. Differentiated Caco-2 cells were incubated presence bile, or other lipids. The level I-BABP was evaluated by Northern and Western blot analyses. A 24 h incubation medium containing either resulted remarkable 7.5-fold increase mRNA over control level. Neither cholesterol, palmitic acid, phosphatidylcholine nor cholestyramine treated showed any difference from control. Bile treatment increased time- dose-dependent manner. analysis that induction led to cytosolic I-BABP. Chenodeoxycholic deoxycholic greater effects than hydrophilic acids, including their own glycine conjugates. Pretreatment actinomycin D cycloheximide completely inhibited up-regulation acid. especially lipophilic Caco-2-cells, suggesting luminal play an important role regulating expression.