Chlamydia pneumoniae Infection Exacerbates Atherosclerosis in ApoB100only/LDLR^−/− Mouse Strain

Figure 4

Comparative quantitative assessment of atherosclerosis in ApoB100only/LDLR^−/− and ApoE^−/− mice. Atherosclerosis development was assessed by histological and morphometric analyses in the aorta sinus and descending aorta of ApoB100only/LDLR^−/− and ApoE^−/− mice without and with 3 Cpn infections, 12 weeks after the first infection kept on normal diet. (a) Photo of representative hematoxylin and eosin-stained cross sections of the noninfected and Cpn-infected ApoB100only/LDLR^−/− mice and noninfected and Cpn-infected ApoE^−/− mice (scale bar: 500 μm). Arrows point to atherosclerotic lesions. (b) The percentage length of the aortic luminal surface (perimeter) covered by atherosclerotic plaque (PAP/AP × 100); (c) percentage of aortic lumen area occupied by atherosclerotic plaques (PLA/LA × 100) in 8 sections of aortic root from noninfected (), Cpn-infected () ApoB100only/LDLR^−/−, and noninfected () and Cpn-infected () ApoE^−/− mice. Average percentage values from individual mice and mean percentages in groups are shown. (d) In situ microscopic pictures of en face proximal aorta of noninfected and Cpn-infected ApoB100only/LDLR^−/− and ApoE^−/− mice, respectively. (e) Plaque size was measured on the length of the luminal surface of the descending aorta of 6–8 mice, and the percentage of total aorta area covered by plaques was calculated. Percentage values in individual mice and mean percentages in groups are shown. Data demonstrate the results of one of two independent experiments. For comparison of groups independent-samples -test was used, . PAP: plaque-covered aorta perimeter; AP: aorta perimeter; PLA: plaque-occupied lumen area; LA: aorta lumen area; 3x: three intranasal Cpn infections.