Rationale:
Endothelial inflammation is an early event in the development of atherosclerosis. The microRNA (miR)-146a showed anti-inflammatory effects in cultured endothelial cells. In this study, we investigated the therapeutic role of miR-146a in endothelial function and atherosclerosis in apolipoprotein E (ApoE)-deficient mice.
Methods and Results:
The miR-146a was packaged into a multistage vector (MSV) that was conjugated with an E-selectin-targeting thioaptamer (ESTA) to form an ESTA-MSV microparticle. The ApoE-deficient mice were fed with Western diet and injected through tail vein with 15μg of miR-146a loaded ESTA-MSV microparticles or vehicle vectors biweekly for 12 weeks. The expressions of miR-146a in aortic tissue was increased by five times at two weeks after injection. However, the expressions of miR-146a in heart, lung, liver, spleen, kidney, and skeletal muscle were not increased. The acetylcholine-induced endothelium-dependent relaxations in both carotid arteries and aortas were significantly improved in mice from miR-146a treated group compared with vehicle group. In addition, the endothelium-dependent contractions of carotid arteries were also improved by miR-146a treatment. The en face oil red O staining of whole aortas showed the plaque area was decreased in miR-146a-treated mice. Application of miR-146a also decreased the plaque size, macrophages, and T-lymphocytes, but increased the collagen deposition and vascular smooth muscle cells in the sections of aortic roots. The PCR results showed that expressions of chemokine (C-C motif) ligand (CCL)-2, CCL-5, and CCL-8 were decreased by miR-146a.
Conclusions:
E-selectin-targeting delivery of miR-146a improves endothelial function and inhibits atherosclerosis.
Subphysiologic Apolipoprotein E (ApoE) Plasma Levels Inhibit Neointimal Formation After Arterial Injury in ApoE-Deficient Mice
