NCK Associated Protein 1 Modulated by miRNA‐214 Determines Vascular Smooth Muscle Cell Migration, Proliferation, and Neointima Hyperplasia

Abstract

Background MicroRNA miR‐214 has been implicated in many biological cellular functions, but the impact of miR‐214 and its target genes on vascular smooth muscle cell ( VSMC ) proliferation, migration, and neointima smooth muscle cell hyperplasia is unknown. Methods and Results Expression of miR‐214 was closely regulated by different pathogenic stimuli in VSMC s through a transcriptional mechanism and decreased in response to vascular injury. Overexpression of miR‐214 in serum‐starved VSMC s significantly decreased VSMC proliferation and migration, whereas knockdown of miR‐214 dramatically increased VSMC proliferation and migration. Gene and protein biochemical assays, including proteomic analyses, showed that NCK associated protein 1 ( NCKAP 1)—a major component of the WAVE complex that regulates lamellipodia formation and cell motility—was negatively regulated by miR‐214 in VSMC s. Luciferase assays showed that miR‐214 substantially repressed wild‐type but not the miR‐214 binding site mutated version of NCKAP 1 3′ untranslated region luciferase activity in VSMC s. This result confirmed that NCKAP 1 is the functional target of miR‐214 in VSMC s. NCKAP 1 knockdown in VSMC s recapitulates the inhibitory effects of miR‐214 overexpression on actin polymerization, cell migration, and proliferation. Data from cotransfection experiments also revealed that inhibition of NCKAP 1 is required for miR‐214–mediated lamellipodia formation, cell motility, and growth. Importantly, locally enforced expression of miR‐214 in the injured vessels significantly reduced NCKAP 1 expression levels, inhibited VSMC proliferation, and prevented neointima smooth muscle cell hyperplasia after injury. Conclusions We uncovered an important role of miR‐214 and its target gene NCKAP 1 in modulating VSMC functions and neointima hyperplasia. Our findings suggest that miR‐214 represents a potential therapeutic target for vascular diseases.