Angiopoietin like‐2 increases with aging and atherosclerosis

Circulating Angiopoietin like‐2 (Angptl2) has been reported to be a regulator of inflammatory diseases such as diabetes and to promote adhesion of monocytes. We hypothesized that Angptl2 levels increase in atherosclerosis. Plasma levels of Angptl2 were measured by enrichment of samples using ProteoMiner Protein Enrichment Kits followed by Western blot. In C57Bl/6 control mice, Angptl2 plasma levels increased from 2.9±0.2 ng/ml at 6 months to 14.2±4.4 ng/ml at 12 months of age, while tissue aorta levels increased by 230±32% with age. In atherosclerotic mice (hApoB+/+/LDLr−/−; ATX), levels were higher (P<0.05) than in control mice both in the plasma (3 folds) and the aorta (2 folds), and they further rose with age (P<0.05). Recombinant Angpltl2 stimulated by 205±21% adhesion of leukocytes to the native endothelium of ATX mice, while it reduced by 48±7% adhesion in control mice. In atherosclerotic patients, circulating levels of Angptl2 where elevated (96±19 ng/ml, n=18; P<0.05) compared to healthy volunteers (39±5ng/ml, n=10). Notably, circulating levels of Angptl2 were positively correlated (r2=0.32, p=0.0188) with the duration of the disease. Altogether, our data strongly suggest that Angptl2 is a positive biomarker of atherosclerosis. Supported by CIHR (MOP14496).