Research Paper Advance Articles

Figure 3. Evaluation of the collagen component within the aging aortic wall (n = 5–10, red) and young (n = 5–10, blue). (A) Decision tree allowing the evaluation of collagen. (B) mRNA expression of collagen (1a) type I. (C) Quantification of total collagen on the whole aorta. (D) Histological staining with picrosirius red and visualization in polarized or non-polarized light (left panel). Quantification of colorized collagen as a function of image area using ImageJ Software (right panel). (E) Quantification of the different crosslinks formed within collagen fibers such as hydroxylysyl pyridinoline (HP), hydroxylysinonorleucine (HLNL), dehydroxylysinonorleucine (DHLNL), histidinohydroxymerodesmosine (HHMD) in the thoracic aorta. (F) mRNA expression of lysyl-oxidase (LOX) and lysyl-oxidase like 1 to 4 (LOXL1, −2, −3, −4). (G) mRNA expression of metalloproteinases 1, 2, 13 and 8 (MMP1, −2, −13, −8). Statistical test: Mann-Whitney. Mean +/− SEM. Significant differences (^*p < 0.05, ^**p < 0.001, ^***p < 0.0001, Mann-Whitney).