Aorta-specific DNA methylation patterns in cell-free DNA from patients with bicuspid aortic valve-associated aortopathy

Ashna Maredia, David Guzzardi, Mohammad Aleinati, Fatima Iqbal, Arshroop Khaira, Aiswarya Madhu, Xuemei Wang, Alex J. Barker, Patrick M. McCarthy, Paul W.M. Fedak, Steven C. Greenway*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Background: The dilation of the aorta that occurs as a consequence of a congenitally bicuspid aortic valve (BAV) is associated with a risk of dissection, aneurysm or rupture. With progressive aortopathy, surgery is often recommended, but current patient selection strategies have limitations. A blood-based assay to identify those who would most benefit from prophylactic surgery would be an important medical advance. In a proof-of-concept study, we sought to identify aorta-specific differentially methylated regions (DMRs) detectable in plasma cell-free DNA (cfDNA) obtained from patients undergoing surgery for BAV-associated aortopathy. Methods: We used bioinformatics and publicly available human methylomes to identify aorta-specific DMRs. We used data from 4D-flow cardiac magnetic resonance imaging to identify regions of elevated aortic wall shear stress (WSS) in patients with BAV-associated aortopathy undergoing surgery and correlated WSS regions with aortic tissue cell death assessed using TUNEL staining. Cell-free DNA was isolated from patient plasma, and levels of candidate DMRs were correlated with aortic diameter and aortic wall cell death. Results: Aortic wall cell death was not associated with maximal aortic diameter but was significantly associated with elevated WSS. We identified 24 candidate aorta-specific DMRs and selected 4 for further study. A DMR on chromosome 11 was specific for the aorta and correlated significantly with aortic wall cell death. Plasma levels of total and aorta-specific cfDNA did not correlate with aortic diameter. Conclusions: In a cohort of patients undergoing surgery for BAV-associated aortopathy, elevated WSS created by abnormal flow hemodynamics was associated with increased aortic wall cell death which supports the use of aorta-specific cfDNA as a potential tool to identify aortopathy and stratify patient risk.

Original languageEnglish (US)
Article number147
JournalClinical Epigenetics
Volume13
Issue number1
DOIs
StatePublished - Dec 2021
Externally publishedYes

Keywords

  • Apoptosis
  • Bicuspid aortic valve
  • Cell-free DNA
  • DNA methylation
  • Wall shear stress

ASJC Scopus subject areas

  • Molecular Biology
  • Genetics
  • Developmental Biology
  • Genetics(clinical)

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