MicroRNAs mediate metabolic stresses and angiogenesis.

MicroRNAs are short endogenous RNA molecules that are able to regulate (mainly inhibiting) gene expression at the post-transcriptional level. The MicroRNA expression profile is cell-specific, but it is sensitive to perturbations produced by stresses and diseases. Endothelial cells subjected to metabolic stresses, such as calorie restriction, nutrients excess (glucose, cholesterol, lipids) and hypoxia may alter their functionality. This is predictive for the development of pathologies like atherosclerosis, diabetes, and hypertension. Moreover, cancer cells can activate a resting endothelium by secreting pro-angiogenic factors, in order to promote neoangiogenesis, which is essential for tumor growth. Endothelial altered phenotype is mirrored by altered mRNA, microRNA, and protein expression, with a microRNA being able to control pathways by regulating the expression of multiple mRNAs. In this review we will consider the involvement of microRNAs in modulating the response of endothelial cells to metabolic stresses and their role in promoting or halting angiogenesis.