Animals study design

The C20:1 and C22:1 fatty acids were in the form of ethyl esters in purified saury oil (Nippon Suisan Kaisha, Tokyo, Japan) and were separated through an octadecylsilyl silica gel column. The fatty acid composition is shown in Supplemental Table 1, and omega-11 LCMUFA isomers are the major components (77% C20:1 n-11 in C20:1 fraction and 96% C22:1 n-11 in C22:1 fraction). Eight-week old female LDLr^−/− mice (the Jackson Laboratory) maintained at 12 h/12 h day/night cycles were treated according to the NIH guidelines and with the approval of the Institutional Animal Care Committee. Animals were randomly assigned to one of three groups (n = 12): Western Adjusted Calories Diet (TD.88137; Teklad, Harlan Laboratories Inc.) supplemented with a final concentration of 5% (w/w) of C20:1 or C22:1 or the control diet (TD.88137) with no fatty acid supplement. The three diets were formulated to be nearly identical in their overall composition (Supplemental Table 2). At the end of the 12-week feeding period, non-fasting blood, aortas and livers were collected at sacrifice. An aliquot of fresh plasma was used for separation of lipoproteins by fast protein liquid chromatography (FPLC) and was analyzed by proteomic analysis as described below. Residual plasma and liver tissue was stored at −80°C for subsequent analysis.