MicroRNA 497 modulates interleukin 1 signalling via the MAPK/ERK pathway.

The MAPK/ERK signalling pathway has been described to mediate IL-1 induction of target genes and is known to be regulated by microRNAs (miRNA). We describe a novel miRNA regulating the expression of the MEK1 gene and how it impacts IL-1 induced IL-6 transcription. miR-497 was predicted to target MEK1 3'UTR using bioinformatic tools. Transfection of miR-497 into HeLa cells inhibited MEK1 protein expression by 50%. In transient transfection experiments, the luciferase activity of a MEK1 3'UTR luciferase reporter construct was reduced in the presence of miR-497, and mutation of the predicted miR-497 binding site restored activity. miR-497 also decreased protein levels of RAF1 and ERK1 but not ERK2. Addition of miR-497 was further shown to inhibit IL-1 induced IL-6 gene transcription.