Biochemical investigation of possible lesions in human aorta that predispose to dissecting aneurysms: pyridinoline crosslinks

Abstract

Pyridinoline, a collagen specific covalent crosslink, was quantified in acid hydrolysates of human aorta using a non-equilibrium inhibition ELISA. The study was based on specimens from seven cases of aortic dissection and from seven control subjects whose death was unrelated to thoracic aortic dissection. There were no significant differences in the amounts or concentrations of pyridinoline in aortas with dissecting aneurysms compared with normal tissue, thus excluding the possibility of a causative relation between the degree of pyridinoline crosslinking of collagen molecules and dissection of the thoracic aorta. In all cases, however, the number of pyridinoline crosslinks per molecule of collagen in the ascending aorta and arch approached the theoretical maximum for lysyl derivatives and was as high as that present in cartilage. Thus in this region of the vessel pyridinoline represents the major stabilising crosslink of collagen. In contrast, the number of pyridinoline crosslinks per collagen molecule decreased maximally by a factor of 10 between the arch and the proximal regions of the descending thoracic aorta. This suggests a possible correlation between the rigidity of collagen fibres and the forces exerted on the aortic wall during diastole and systole.

Biochemical Study of Collagen and Its Crosslinks in the Anterior Cruciate Ligament and the Tissues Used as a Graft for Reconstruction of the Anterior Cruciate Ligament

“…With regard to the age-relationship of crosslinks in the tissues, Pyr most definitely increases in tissue from birth to maturation. However, from maturation to old age, levels have been shown to slightly increase, decrease or remain the same depending upon tissue type and species [23][24][25][26]. In our previous There was no significant correlation between pyridinoline and age in all tissues by Spearman correlation rank test.…”

Alteration of Elastin, Collagen and their Cross-links in Abdominal Aortic Aneurysms

“…The behaviour of PYR and DPD in aortic walls was studied by Watanabe, 20 who assessed its content relatively to age in autoptic controls; he found a direct correlation between their content and age. Whittle 21 assessed the difference in cross-links between desiccated and normal aortas and observed a progressive decrease going from aortic root towards descending aorta.…”

Pathogenesis of Aortic Dissection: Elastic Fiber Abnormalities and Aortic Medial Weakness

“…For example, the composition of collagen fibers has been reported to vary with the location of the aorta. 31) Among glycosaminoglycans, the content of dermatan sulfate and hyaluronate has been reported to be increased in the areas of aortic dissection, suggesting that these localized increases are related to the development of aortic dissection. 32) In electron microscopic and immunohistochemical studies of cases of aortic dissection, Ishii et al observed the presence of spirally thickened collagen fibers, thinning and loss of the basement membrane of smooth muscle cells, and marked expression of MMP-1, -2, and -9 and tissue inhibitors of metalloproteinase (TIMP)-1 and -2, suggesting that overall changes in extracellular matrix components have an important significance in the development of aortic dissection.…”