Intraleaflet hemorrhage-driven aortic valve stenosis : insights from a multi-model and multi-omics framework
Year: 2026
Type: other
Abstract: Calcific aortic valve disease (CAVD) is characterized by progressive calcium deposition, leading to left ventricular outflow obstruction and heart failure. Neovascularization and intraleaflet hemorrhage frequently occur in stenotic human valves and accelerate disease progression. Ferroptosis, an iron- dependent, phospholipid peroxidation-driven cell death, potentially links iron overload to pathobiology. Yet how erythrocytes contribute to aortic valve calcification remains unknown. This thesis aimed to determine whether erythrocytes extravasated during intraleaflet hemorrhage drive valvular calcification through ferroptosis, identify druggable targets of the lipid peroxidation pathway, and synthesize insights from single-cell transcriptomics on aortic valve cellular heterogeneity. In Study I, whole-mount Perls' staining of 24 surgically excised aortic valves identified non-heme iron deposition in 21 specimens (87.5%), with higher prevalence in bicuspid than tricuspid valves. Co-culture system demonstrated that valvular interstitial cells (VIC) selectively internalized senescent erythrocytes, leading to elevated intracellular ferrous iron and calcification. Under osteogenic conditions, senescent erythrocytes promoted VIC osteogenic transition. Ferrostatin-1 attenuated senescent erythrocyte-induced calcification, linking VIC erythrophagocytosis to valvular calcification via ferroptosis. In Study II, bulk transcriptomics of calcified versus non-calcified valve tissue identified a valve-specific ferroptotic signature enriched in fatty acid peroxidation and oxidative stress, centered on 5-lipoxygenase (ALOX5). Single-cell transcriptomics localized this signature to a VICACSL4+ALOX5+ subcluster co- expressing ALOX5 and acyl-CoA synthetase long-chain family member 4 (ACSL4). Furthermore, ACSL4, ALOX5, and the osteogenic marker BMP2 were upregulated in intraleaflet hemorrhage-positive valve regions. In primary human VIC, pharmacological inhibition of ACSL4 or ALOX5 reduced lipid peroxidation and calcification independent of leukotriene/prostaglandin pathways. In vivo, doxorubicin induced valvular ferroptosis and leaflet thickening, whereas ALOX5 inhibition attenuated leaflet thickening and hemodynamic obstruction in a wire- injury model of aortic stenosis. Finally, plasma arachidonic acid independently associated with valve calcification, incident aortic stenosis, and ferroptosis biomarkers across population cohorts. Study III reviewed single-cell transcriptomic studies spanning aortic valve development, structural cell phenotypes, and immune infiltration, synthesizing a marker-based VIC subcluster framework for CAVD. It highlighted cross-study marker and nomenclature discrepancies, emphasizing spatial transcriptomics, perturbation-based functional screening, and analytical standardization as key prerequisites for single-cell-guided therapeutic target discovery. List of scientific papers I. Qin Z, Bäck M, Franco-Cereceda A, Pawelzik SC. Increased calcification by erythrophagocytosis in aortic valvular interstitial cells. ESC Heart Failure. 2025;12(2):1469-1473. https://doi.org/10.1002/ehf2.15132 II. Qin Z, Haftbaradaran Esfahani P, Pawelzik SC, Shu S, Bosman M, Goovaerts B, De Wilde L, Yang Y, Bergström G, Guns PJ, Franco- Cereceda A, Bäck M. Ferroptosis promotes aortic stenosis through 5-lipoxygenase. European Heart Journal. 2026 Jun 2:ehag397. https://doi.org/10.1093/eurheartj/ehag397 III. Qin Z, Bäck M. Advances in single-cell transcriptomics: unraveling the pathogenesis of calcific aortic valve disease. Cardiovascular Research. 2026 Feb 14;121(18):2838-2859. https://doi.org/10.1093/cvr/cvaf255
DOI: 10.69622/33256218
Author: Zihan Qin
Language: English
Subfield: Cardiology and Cardiovascular Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: gold
OpenAlex ID: W7214575174