Signal transduction pathways implicated in pathogenesis of vascular remodeling relevant to pulmonary hypertension. Panel A: miR-21 may increase vascular smooth muscle cell number by targeting proteins that regulate cell proliferation (PTEN) and apoptosis (Bcl2). Changes in miR-21 expression have been observed in lung tissues and in vascular smooth muscle in animal models of pulmonary hypertension. Panel B: miR221 promotes vascular smooth muscle cell proliferation by silencing the cell cycle inhibitor p27Kip1. Panel C: miR-204 downregulated in pulmonary hypertension in animals and in human leukocytes can indirectly promote cell proliferation. Derepression of SHP2 expression activates a Src/Stat3 cascade that promotes vascular smooth muscle proliferation.
Additional keywords: microRNA,genetics,proliferation,apoptosis,miR-21