Ablation of miR-144 increases vimentin expression and atherosclerotic plaque formation

It has been suggested that miR-144 is pro-atherosclerotic via effects on reverse cholesterol transportation targeting the ATP binding cassette protein. This study used proteomic analysis to identify additional cardiovascular targets of miR-144, and subsequently examined the role of a newly identified regulator of atherosclerotic burden in miR-144 knockout mice receiving a high fat diet. To identify affected secretory proteins, miR-144 treated endothelial cell culture medium was subjected to proteomic analysis including two-dimensional gel separation, trypsin digestion, and nanospray liquid chromatography coupled to tandem mass spectrometry. We identified 5 gel spots representing 19 proteins that changed consistently across the biological replicates. One of these spots, was identified as vimentin. Atherosclerosis was induced in miR-144 knockout mice by high fat diet and vascular lesions were quantified by Oil Red-O staining of the serial sectioned aortic root and from en-face views of the aortic tree. Unexpectedly, high fat diet induced extensive atherosclerosis in miR-144 knockout mice and was accompanied by severe fatty liver disease compared with wild type littermates. Vimentin levels were reduced by miR-144 and increased by antagomiR-144 in cultured cardiac endothelial cells. Compared with wild type, ablation of the miR-144/451 cluster increased plasma vimentin, while vimentin levels were decreased in control mice injected with synthetic miR-144. Furthermore, increased vimentin expression was prominent in the commissural regions of the aortic root which are highly susceptible to atherosclerotic plaque formation. We conclude that miR-144 maybe a potential regulator of the development of atherosclerosis via changes in vimentin signaling.