Localised micro-mechanical stiffening in the ageing aorta

Helen K. Graham, Riaz Akhtar, Constantinos Kridiotis, Brian Derby, Tribikram Kundu, Andrew W. Trafford, Michael J. Sherratt

Research output: Contribution to journalArticle

35 Scopus citations

Abstract

Age-related loss of tissue elasticity is a common cause of human morbidity and arteriosclerosis (vascular stiffening) is associated with the development of both fatal strokes and heart failure. However, in the absence of appropriate micro-mechanical testing methodologies, multiple structural remodelling events have been proposed as the cause of arteriosclerosis. Therefore, using a model of ageing in female sheep aorta (young: <18 months, old: >8 years) we: (i) quantified age-related macro-mechanical stiffness, (ii) localised in situ micro-metre scale changes in acoustic wave speed (a measure of tissue stiffness) and (iii) characterised collagen and elastic fibre remodelling. With age, there was an increase in both macro-mechanical stiffness and mean microscopic wave speed (and hence stiffness; young wave speed: 1701±1ms -1, old wave speed: 1710±1ms -1, p<0.001) which was localized to collagen fibril-rich regions located between large elastic lamellae. These micro-mechanical changes were associated with increases in both collagen and elastic fibre content (collagen tissue area, young: 31±2%, old: 40±4%, p<0.05; elastic fibre tissue area, young: 55±3%, old: 69±4%, p<0.001). Localised collagen fibrosis may therefore play a key role in mediating age-related arteriosclerosis. Furthermore, high frequency scanning acoustic microscopy is capable of co-localising micro-mechanical and micro-structural changes in ageing tissues.

Original languageEnglish (US)
Pages (from-to)459-467
Number of pages9
JournalMechanisms of Ageing and Development
Volume132
Issue number10
DOIs
Publication statusPublished - Oct 2011

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Keywords

  • Arteriosclerosis
  • Collagen
  • Elastic fibers
  • Scanning acoustic microscopy
  • Tissue elasticity

ASJC Scopus subject areas

  • Aging
  • Developmental Biology

Cite this

Graham, H. K., Akhtar, R., Kridiotis, C., Derby, B., Kundu, T., Trafford, A. W., & Sherratt, M. J. (2011). Localised micro-mechanical stiffening in the ageing aorta. Mechanisms of Ageing and Development, 132(10), 459-467. https://doi.org/10.1016/j.mad.2011.07.003