MicroRNA regulation in angiogenesis.

The term angiogenesis derives from the Greek words 'angeio' meaning blood vessel, and 'genesis' meaning production or birth, together referring to the creation of blood vessels within the body. This term has been used to generally indicate the growth and remodeling process of the primitive vascular network into a complex network during pre-natal development. After birth, reparative angiogenesis is activated during wound healing and in response to ischemia, while pathological angiogenesis contributes to tumor growth and metastasis, arthritis and ocular diseases, such as diabetic retinopathy. MicroRNAs (miRNAs) are a class of endogenous, small, non-coding RNAs that control gene expression by acting on target mRNAs for promoting either their degradation or translational repression. There is increasing evidence that miRNAs play important roles in vascular development as well as in vascular diseases. In this review, we aim at describing the role of miRNAs in angiogenesis, focusing, in particular, on post-ischemic neovascularization. First, we will describe the regulation and the expression of miRNAs in endothelial cells. Then, we will analyze the role of miRNAs in reparative and pathological angiogenesis. Finally, we will discuss the innovative strategies available to inhibit the level of pathogenic anti-angiogenic miRNAs and to increase expression of therapeutic miRNAs.