[Pathobiology of the microRNA system].

MicroRNAs are approximately 22 nucleotides short, non-protein-coding RNA molecules, which bind semi-complementary to mRNA and have an inhibitory effect on protein expression. Aberrant microRNA expression is part of the molecular pathological damage in several degenerative, inflammatory and neoplastic diseases and deregulation can also be virus-associated. Apart from intracellular regulatory functions, microRNA in platelets and exosomes or bound to extracellular protein complexes can also circulate in the blood. Artificial microRNA analogues (small interference RNA/siRNA) and anti-microRNA (antagomir) are used in molecular pathological research of microRNA/mRNA interaction and it is thought that they will also be used as therapeutic agents in the future.