Holding our breath: The emerging and anticipated roles of microRNA in pulmonary hypertension

Over the past decade, the importance of non-coding RNA such as microRNA has been established in numerous processes that drive human pathogenesis. These crucial molecular regulators modulate networks of target gene transcripts that, in turn, orchestrate cellular phenotypes such as cell survival, differentiation, proliferation, and metabolism among others and thus affect cardiopulmonary vascular disease conditions. Many of these same pathophenotypes figure prominently in the complex pathogenesis of pulmonary hypertension, an enigmatic vascular disorder characterized by a histological panvasculopathy and driven by disparate upstream triggers such as hypoxia, inflammation, and bone morphogenetic protein signaling. Yet, the importance of just a few microRNAs in pulmonary hypertension has been recognized, and we are only beginning to understand the integrative functions of these molecules in this disease. By combining systems biology with traditional experimental approaches, more direct insight into the pleiotropy of microRNA should not only further reveal the spectrum of molecular pathways that cause pulmonary hypertension, but also offer novel and much needed diagnostic and therapeutic strategies.