mir-590 microrna precursor family mir-590 microrna precursor family in molecular biology mir-590 microrna is a short rna molecule. micrornas function to regulate the expression levels of other genes by several mechanisms. mir-590identifierssymbolmir-590rfamrf00928 mirbase familymipf0000418other datarna typemicrornadomain(s)eukaryota;pdb structurespdbe nicotine-induced atrial remodelling downregulation of mir-590 by nicotine has been found to play a key part in the generation of atrial fibrosis by atrial structural remodelling. this downregulation sees the removal of post-transcriptional repression of tgf-β1 and tgf-β receptor type ii (tgf-βrii), and consequent collagen production. mir-590 downregulation has further been shown to be mediated by activation of alpha-7 nicotinic acetylcholine receptors (α7-nachrs).