Functional blockage of EMMPRIN ameliorates atherosclerosis in apolipoprotein E-deficient mice

BackgroundExtracellular matrix metalloproteinase inducer (EMMPRIN), a 58-kDa cell surface glycoprotein, has been identified as a key receptor for transmitting cellular signals mediating metalloproteinase activities, as well as inflammation and oxidative stress. Clinical evidence has revealed that EMMPRIN is expressed in human atherosclerotic plaque; however, the relationship between EMMPRIN and atherosclerosis is unclear. To evaluate the functional role of EMMPRIN in atherosclerosis, we treated apolipoprotein E-deficient (ApoE−/−) mice with an EMMPRIN function-blocking antibody.Methods and resultsEMMPRIN was found to be up-regulated in ApoE−/− mice fed a 12-week high-fat diet in contrast to 12 weeks of normal diet. Administration of a function-blocking EMMPRIN antibody (100 μg, twice per week for 4 weeks) to ApoE−/− mice, starting after 12 weeks of high-fat diet feeding caused attenuated and more stable atherosclerotic lesions, less reactive oxygen stress generation on plaque, as well as down-regulation of circulating interleukin-6 and monocyte chemotactic protein-1 in ApoE−/− mice. The benefit of EMMPRIN functional blockage was associated with reduced metalloproteinases proteolytic activity, which delayed the circulating monocyte transmigrating into atherosclerotic lesions.ConclusionEMMPRIN antibody intervention ameliorated atherosclerosis in ApoE−/− mice by the down-regulation of metalloproteinase activity, suggesting that EMMPRIN may be a viable therapeutic target in atherosclerosis.