microRNA or miRNA is an ultra short chain RNA produced by eukoryotic cells for epigenetic post transcriptional silencing of mRNA by binding to complementary regions. miRNA-7 downregulation may lead to excessive expression of Type I collagen leading to localised scleroderma and keloids. In comparison with the normal skin tissues, miRNAs were aberrantly expressed in limited cutaneous scleroderma and diffuse cutaneous scleroderma skin tissues as well. Supplementation of the microRNA results in the decrease of collagen expression in scleroderma fibroblasts.
|Overview of microRNA processing in animals, from transcription to the formation of the effector complex. Enzymes: Pol II (transcription) and associated proteins Drosha, Pasha (pri-miRNA → pre-miRNA) RAN-GTP, Exportin-5 (export from nucleus) Dicer (pre-miRNA → miRNA) RISC (effector complex) Abbrevations: pri-miRNA = primary microRNA transcript pre-miRNA = precursor microRNA miRNA = microRNA miRNA* = antisense microRNA miRISC = microRNA-induced silencing complex (Photo credit: Wikipedia)|
microRNA-7 down-regulation mediates excessive collagen expression in localized scleroderma. (http://www.springerlink.com/content/c7l2t83l21686382/)