Inhibition of MicroRNA-92 alleviates atherogenesis by regulation of macrophage polarization through targeting KLF4

Atherosclerosis is a chronic inflammatory disease in which macrophage polarization plays an important role in contribution to atherosclerotic plaque formation and stability. Here we tested the effect of miR-92 regulation on the development of atherosclerosis beyond tumorigenesis and explored the potential mechanism.In the present study, bone marrow derived macrophages (BMDMs), mouse peritoneal macrophages (MPMs), and human macrophages were used to test the expression of miR-92. Here we noticed miR-92 levels were enhanced in classic M1 macrophage but decreased in alternative M2 macrophage, respectively. In vitro, we demonstrated that macrophages transfected with miR-92 inhibitor attenuated proinflammatory cytokine secretion represented by polarized M1 markers but promoted anti-inflammatory state that was indicative of an M2 phenotype. Mechanistically, miR-92 was found to directly interact with KLF4 and we further identified a requirement role of KLF4 in mediating the effect of miR-92 silencing macrophage polarization. Concomitantly, miR-92 inhibition treated ApoE-/- mice promoted macrophage polarization toward alternative M2 macrophage, thus protecting against atherosclerotic plaque formation and preventing a vulnerable phenotype.miR-92 inhibition promoted alternative macrophage activation and attenuated atherosclerosis regression partially regulated in a KLF4-dependent manner, which indicated that miR-92/KLF4 axis may serve as a promising strategy for prevention of atherosclerotic diseases.