Characterization of Atherosclerosis Formation in a Murine Model of Type IIa Human Familial Hypercholesterolemia

Figure 11

Plaque characteristics in a representative 72-week-old L/A mouse at 2 different depths, one slice containing an endothelium completely covered by a plaque and the other containing an intact endothelium. (a, b) H&E stains, showing the general morphology of the aortic sinus. (c) Endothelial discontinuity is demonstrated as a disruption in endothelial cell staining on the most luminal surface of the plaque (blue arrowheads). Fragmented debris from the plaque is also observed in the lumen of the sinus (red arrowhead). An intact area of endothelium is also noted (green arrowhead). (d) Several cells on the surface of the aortic wall are stained positive for endothelial cells (blue arrowheads). (e) Dense fibrin deposits are observed on the cap (blue arrowheads), which colocalize with ruptured areas identified from endothelial cell staining. Diffuse fibrin is also present in the remaining part of the plaque core (yellow arrowheads). (f) Continued presence of fibrin in the plaque body. (g) Anti-SMA immunostains (red coloration) in a plaque area illustrating a small number of cells are positively stained (red arrowheads) in the cap area. No positive stains are observed in the aortic wall (blue arrowheads). (h) Intense anti-SMA-staining in the aortic wall (blue arrowheads) is observed in an endothelium not covered by plaque. (i) Anti-SMemb immunostaining in a plaque area showing cap (red arrowheads) and aortic wall (blue arrowheads) features. (j) Anti-SMemb immunostains are negative in aortic wall areas not covered by plaques (blue arrowheads). Original magnification, 100X.

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