MicroRNAs: promising therapeutic targets for the treatment of pulmonary arterial hypertension.

INTRODUCTION: MicroRNAs (miRNAs) are small noncoding RNAs that not only regulate gene expression during normal development but can also be active players in several diseases. To date, several studies have demonstrated a possible role for specific miRNAs in the regulation of pulmonary vascular homeostasis suggesting that novel therapeutic agents which target these modulators of gene expression could serve to treat pulmonary arterial hypertension (PAH). AREAS COVERED: The characterization of miRNA-mediated gene modulation in the pulmonary circulation is expanding very rapidly. This review summarizes current relevant findings on the role of miRNAs in the pathogenesis of PAH and expands on the potential use of agents that target these molecules as future disease-modifying therapies. EXPERT OPINION: Further understanding of miRNA biology and function in the pulmonary circulation will serve to further enhance our understanding of their contribution to the pathogenesis of PAH. The implementation of a systems biology approach will help accelerate the discovery of miRNAs that influence angiogenesis and cellular responses to vascular injury. Experimental characterization of these miRNAs using in vitro and in vivo methods will be required to validate the biological roles of these miRNAs prior to the consideration of their use as therapeutic targets in future clinical trials.