MicroRNA Regulation of SIRT1

SIRT1 is an NAD-dependent deacetylase that regulates stress response pathways. By deacetylating transcription factors and co-factors, SIRT1 modulates metabolism, inflammation, hypoxic responses, circadian rhythms, cell survival, and longevity. Since SIRT1 plays a key role in regulating pathways involved in cardiovascular diseases and metabolic diseases cancer, the regulation of SIRT1 has received intense scrutiny. The post-transcriptional regulation of SIRT1 is mediated by two classes of molecules, RNA-binding proteins (RBPs) and non-coding small RNAs. MicroRNAs (miRNAs) are short non-coding RNAs that regulate target gene expression in a post-transcriptional manner. More than 16 miRNAs modulate SIRT1 expression, including miR-34a. miR-34a induces colon cancer apoptosis through SIRT1, and miR-34a also promotes senescence in endothelial cells via SIRT1. This review describes the impact of miRNAs on SIRT1. The background of SIRT1 and miRNAs will be summarized, followed by the mechanism by which several key miRNAs alter SIRT1 levels, and how the RBP HuR regulates SIRT1. MicroRNA regulation of SIRT1 might affect a wide variety of pathways in humans, from metabolic diseases such as diabetes to cardiovascular diseases and cancer.