Figure 5.

Apoe^−/− and DKO plaques are similar with respect to collagen and macrophage content. A, Picrosirius Red staining for collagen. Representative images (left) and quantitation (right) of Picrosirius Red–positive area in individual plaques. B, CD68 staining for macrophages. Although CD68 expression was similar, CD68⁺ cells were superficial in Apoe^−/− plaques; most staining was beneath a fibrous cap in DKO samples. (Left) Representative of 14 of 14 Apoe^−/− and 11 of 18 DKO animals (excluding DKO animals with no plaque and DKO plaques with no macrophages). (Right) CD68 levels within plaques were assessed by qRT‐PCR. Quantitation of Picrosirius Red area and CD68 gene expression is reported as mean±SEM; each symbol represents a single plaque. n=7 (Apoe^−/−) or 8 (DKO). Significance was evaluated by independent sample t test; groups are not significantly different. Apo indicates apolipoprotein; DKO, double knockout; qRT‐PCR, quantitative real‐time polymerase chain reaction.