Altered tissue behavior of a non-aneurysmal descending thoracic aorta in the mouse model of Marfan syndrome

Darren Haskett, Jefferson J. Doyle, Connie Gard, Hwu Dau Rw Chen, Corbie Ball, Mark A. Estabrook, Alejandra C. Encinas, Harry C. Dietz, Urs Utzinger, Jonathan P Vande Geest, Mohamad Azhar

Research output: Contribution to journalArticle

18 Scopus citations

Abstract

Aortic aneurysm is predominantly found in the ascending aorta in patients with Marfan syndrome (MFS). However, descending aortic disease has emerged as a problem since people are living longer because of improved medical and surgical management of the ascending aorta. Diagnostic procedures before disease onset and the mechanisms involved in the transition of normal aortic tissue to aneurysm remain unclear. We determined signs of descending aortic disease before disease onset in mice with a mutation in the fibrillin 1 gene (Fbn1 +/C1039G), a validated mouse model of disease susceptibility and progression of aortic aneurysm of MFS. We analyzed a tubular unfixed non-aneurysmal descending thoracic aorta from 8-month-old wild-type and Fbn1+/C1039G mice by a tubular biaxial tester that works in conjunction with a two-photon nonlinear microscope. Fbn1+/C1039G mouse aorta was more compliant in the circumferential direction. Two-photon imaging showed defective organization of adventitial collagen fibers in the pressurized aortas of Fbn1+/C1039G mice. Moreover, disruption in the elastic lamina was noted in the absence of aneurysms in pressurized aortas but not unpressurized aortas of Fbn1+/C1039G mice. At the molecular level, this altered tissue behavior in non-aneurysmal descending aortas of Fbn1+/C1039G mice was accompanied by an increasing trend of canonical but not noncanonical, transforming growth factor-β (TGFβ) signaling. Finally, assays of in vitro collagen lattice formation in mouse wild-type and TGFβ1-deficient embryonic fibroblasts indicate that TGFβ1 can regulate collagen organization. The ability to reveal the presence of altered biomechanics and microstructure coupled with subtle changes in TGFβ signaling provides a novel surrogate measure of tissue susceptibility to aneurysm before disease onset.

Original languageEnglish (US)
Pages (from-to)267-277
Number of pages11
JournalCell & Tissue Research
Volume347
Issue number1
DOIs
Publication statusPublished - Jan 2012

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Keywords

  • Aging
  • Aortic aneurysm
  • Cardiovascular disease
  • Extracellular matrix
  • Fibrillin 1
  • Marfan syndrome
  • Mouse
  • Transforming growth factor-β

ASJC Scopus subject areas

  • Pathology and Forensic Medicine
  • Cell Biology
  • Histology

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