Idiopathic degenerative thoracic aneurysms are associated with increased aortic medial amyloid



Davies, HA, Caamano-Gutierrez, E ORCID: 0000-0001-7737-5941, Chim, Ya Hua, Field, M, Nawaytou, O, Ressel, L ORCID: 0000-0002-6614-1223, Akhtar, R ORCID: 0000-0002-7963-6874 and Madine, J ORCID: 0000-0001-9963-5871
(2019) Idiopathic degenerative thoracic aneurysms are associated with increased aortic medial amyloid. Amyloid: international journal of experimental and clinical investigation, 26 (3). 148 - 155.

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Abstract

Objective: To explore the relationship of aortic medial amyloid with biochemical and micromechanical properties of the aortic wall in aneurysm patients. Methods: Human aortic tissues removed during aneurysm surgery from tricuspid (idiopathic degenerative aneurysm, DA) and bicuspid valve (BAV) patients were subjected to oscillatory nanoindentation experiments to determine localised mechanical properties of the tissue (shear storage modulus, G´ and shear loss modulus, G˝). Collagen, elastin, matrix metalloproteinase 2 and glycosaminoglycans concentrations were determined, along with relative levels of aortic medial amyloid-related factors (medin, milk fat globule-EGF factor 8, oligomers and fibrils). Measurements were combined with clinical data and statistical analyses performed. Results: The DA cohort can be divided based on their phenotype. One group shared similar characteristics with BAV patients, termed bicuspid like phenotype-tricuspid valve. The second group had high amyloid oligomer species present with a significantly lower G´ (p = .01), indicative of reduced elastic response of the tissue, termed amyloid-rich. Conclusions: We identified a group of DA patients with high amyloid oligomers and altered micromechanical and structural properties of the vessel wall. We propose these findings as a cause for aneurysm formation in these patients. Amyloid is not found in BAV patients, suggesting at least two distinct mechanisms for pathogenesis.

Item Type: Article
Uncontrolled Keywords: Aortic medial amyloid, medin, thoracic aortic aneurysm, biomechanics, oligomer, bicuspid valve syndrome
Depositing User: Symplectic Admin
Date Deposited: 19 Jun 2019 08:09
Last Modified: 21 Feb 2021 13:10
DOI: 10.1080/13506129.2019.1625323
Open Access URL: https://www.tandfonline.com/doi/full/10.1080/13506...
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URI: https://livrepository.liverpool.ac.uk/id/eprint/3046449