MicroRNA 181b promotes vascular smooth muscle cells proliferation through activation of XXXX and MAPK pathways.

@entity5447 @entity7504 @entity2308 @entity2508 @entity1373 @entity256 @entity19087 @entity12003 @entity39728 @entity35 @entity731
Vascular smooth muscle cells (VSMCs) @entity1373 is a common feature of pathologic cardiovascular event such as @entity256 and @entity731 . The role and mechanisms of microRNAs (miRs) in VSMCs proliferation are poorly understood. Here, we report that miR-181b promotes VSMCs proliferation and migration. In an animal model, miR-181b was significantly increased in the @entity35 carotid artery after balloon catheter injury. Delivery of miR-181b inhibitor to injured artery exhibited a marked inhibition of neointimal @entity1373 . Transfection of miR-181b with "mimics" to @entity35 cells accelerated cell proliferation, which was accompanied by an increase of cell migration. The induction of @entity35 cells proliferation by miR-181b appeared to be involved in activation of S and G2/M checkpoint, concomitant with decreases in cell-cycle inhibitors @entity7504 and @entity5447 , and increases in cell-cycle activators @entity19087 and @entity12003 . In contract, miR-181b inhibition attenuated @entity35 cells proliferation, inhibited cell migration and arrested cell cycle transition. Moreover, forced miR-181b expression elevated the phosphorylation levels of @entity2308 and @entity2508 , whereas inhibition of miR-181b produced the opposite effects. Additionally, inhibition of @entity39728 and MAPK signaling pathways with specific inhibitors, but not inhibition of JNK pathway, significantly abolished the effects of miR-181b in promoting cell proliferation. These findings demonstrate that miR-181b enhances the proliferation and migration of VSMCs through activation of @entity39728 and MAPK pathways.
