Fig. 4

IL6 is a target of let-7b. a Schematic representation of chimeric luciferase constructs. The 3’ UTR sequences containing let-7b binding sites are shown (in green) for IL6. For the mutation of let-7b binding sites in the target 3’UTR, the bases in the seed sequence (in purple) were mutated to the sequence shown in red. Mutations were restricted to the conversion of AUGG to CAAC. b Insertion of let-7b target 3′-UTRs in a luciferase reporter gene constructs leads to reduced relative luciferase activity only in the presence of let-7b target sites. Mutant of let-7b target sequences of two sites in the IL6 3′-UTRs abolished the miRNA-mediated effect on luciferase activity. c Expression levels of IL6 in HaCaT were examined by qRT-PCR and western blotting after transfection. HaCaT were collected 48 h after transfection of let-7b mimic (left) or let-7b inhibitor (right) and scramble control sequences. d IL6 expression was analyzed in healthy (n = 4) and psoriasis lesional skin samples (n = 4) using immunohistochemistry, scale Bar = 100 mm