Fig. 6.

miR-1 downregulated HDAC6 and HNF4α by directly binding its 3′-UTR. a, b Downregulated expression of miR-1 led to downregulated protein expression of HDAC, HNF4α and intestinal markers. c, d Upregulated expression of miR-1 resulted in the opposite changes. e, f A schematic representation of the HDAC6 and HNF4α 3′-UTR. Mutations were generated at the predicted miR-1-binding sites. g, h miR-1 luciferase reporter assay. A luciferase reporter was fused with the wild-type or mutant miR-1 targets (HDAC6 and HNF4α), and then transfected into mock-infected or miR-1-infected GES-1 and BGC-823 cells. The luciferase activity of the wild-type luciferase reporters were suppressed by miR-1 significantly. i, j GES-1 cells were transfected with wild-type and mutant miR-1 targets (HDAC6, HNF4α), along with miR-1. HDAC6, HNF4α and intestinal markers expression were detected by immunoblots. k A schematic model of miR-1/HDAC6/HNF4α pathway in gastric cells. Induced by specific concentrations of bile acid, silenced miR-1 stimulates the expression of HDAC6 and HNF4α to activate downstream intestinal markers. *P < 0.05; **P < 0.01. N.S. not significant