MicroRNA-155 Promotes Atherosclerosis Inflammation via Targeting SOCS1

Aims: Accumulating evidence suggests that atherosclerotic progression depends on persistent and chronic inflammation in the arterial walls. MicroRNA-155 is reportedly involved in cardiovascular disease and has been implicated as a pro-inflammation regulator. Although some researchers have focused on microRNA-155 as an atherosclerosis regulator, the mechanisms by which microRNA-155 functions as a putative pro-atherosclerosis microRNA are largely unknown. This study aims to analyze microRNA-155's effects on atherosclerotic inflammation and to explore its mechanism. Methods: MicroRNA-155's effects on atherosclerotic inflammation were observed along with the expression and activity levels of SOCS1, STAT3 and NF-κB though microRNA-155 inhibition or overexpression. Results: Highly expressions of microRNA-155 in oxLDL-stimulated macrophages and atherosclerosis mice were inversely correlated with SOCS1 expression. Ectopic microRNA-155 overexpression significantly promoted inflammatory cytokine and chemokine production and atherosclerosis progression. We then observed microRNA-155's functional role in the atherosclerotic pathophysiological process in vivo and in vitro. The observation revealed that by enhancing STAT3 and NF-κB signaling and facilitating immune inflammation by targeting SOCS1, microRNA-155 plays a promotable role in atherosclerosis progression. Conclusions: microRNA-155 works as a promoter in the atherosclerotic procession. Its mechanism may include enhancing inflammatory response in atherosclerosis by increasing STAT3 and NF-κB signaling via targeting SOCS1.