# Embryologic Origins of Aortopathy: Biomechanical Characterization of Aortic Aneurysms in the NOTCH1 Mutant Model

> **NIH NIH F32** · OHIO STATE UNIVERSITY · 2021 · $73,062

## Abstract

PROJECT ABSTRACT
Aortic aneurysmal disease is a leading causes of death in the US. Ascending aortic aneurysms (AscAA) are
associated with aortic dissection and rupture causing significant morbidity and mortality due to a lack of
symptoms and limited non-surgical therapies. AscAA are frequently found with congenital heart defects (CHD),
specifically bicuspid aortic valve (BAV) and tetralogy of Fallot (TOF). However, the molecular mechanism of
CHD-associated AscAA is poorly understood and there is growing evidence that the mechanism of aneurysm
formation and progression is heterogeneous. As such, disease progression and risk of developing an acute aortic
event is poorly predicted and subsequent clinical guidelines are inadequate. A better understanding of the aortic
biomechanical properties is needed to bridge this knowledge gap, identify disease-specific indicators to guide
therapy, and produce more effective therapeutics.
Mutations in NOTCH1 have been linked to BAV and TOF and we previously described a novel mouse model in
which Notch1 haploinsufficiency is sufficient to cause AscAA. Our previously published data suggests that
differentiation defects of vascular smooth muscle cell (SMC)-precursors during development contribute to
abnormal SMCs in the Notch1+/- adult aorta predisposing to AscAA and implicating an embryologic origin of
CHD-associate aortopathy. We hypothesize that loss of NOTCH1 signaling leads to an abnormal tissue response
to hemodynamic stress and results in increased wall stiffness. This in turn leads to an increase in wall strain and
risk of aortic dissection. The goal of this project is to further investigate the biomechanical properties of the
proximal aortic wall in CHD-associated AscAA.
We will test our hypothesis by (1) assessing the effects of loss of Notch1 on smooth muscle cell phenotype in
response to injury, (2) assessing the biomechanical properties of the smooth muscle cells within the ascending
aortas of NOTCH1 haploinsufficent mice, and(3) assessing the biomechanical properties within the proximal
ascending aorta of pediatric TOF patients. Successful completion of these aims will help to bridge the current
knowledge gap regarding pathogenesis of CHD-associated AscAA disease, assist in improving clinical
guidelines, and create opportunities for new therapeutic targets.

## Key facts

- **NIH application ID:** 10314596
- **Project number:** 1F32HL160059-01
- **Recipient organization:** OHIO STATE UNIVERSITY
- **Principal Investigator:** Ruth Ackah
- **Activity code:** F32 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $73,062
- **Award type:** 1
- **Project period:** 2021-09-01 → 2023-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10314596

## Citation

> US National Institutes of Health, RePORTER application 10314596, Embryologic Origins of Aortopathy: Biomechanical Characterization of Aortic Aneurysms in the NOTCH1 Mutant Model (1F32HL160059-01). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10314596. Licensed CC0.

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