MicroRNAs and liver disease.

Posttranscriptional regulation of gene expression is now recognized as an important contributor to disease pathogenesis, whose mechanisms include alterations in the function of stability and translational elements within both coding and noncoding regions of messenger RNA. A major component in this regulatory paradigm is the binding both to RNA stability as well as to translational control elements by microRNAs (miRNAs). miRNAs are noncoding endogenously transcribed RNAs that undergo a well-characterized series of processing steps that generate short single-stranded (∼20-22) RNA fragments that bind to complementary regions within a range of targets and in turn lead to mRNA degradation or attenuated translation as a result of trafficking to processing bodies. This article will highlight selected advances in the role of miRNAs in liver disease including nonalcoholic fatty liver disease, viral hepatitis, and hepatocellular carcinoma and will briefly discuss the utility of miRNAs as biomarkers of liver injury and neoplasia.