Cardiovasc Res. 2026 Sep 8:cvag199. doi: 10.1093/cvr/cvag199. Online ahead of print.
ABSTRACT
BACKGROUND: Calcific aortic valve stenosis (AS) affects 3% of older adults and lacks medical treatment. The deacetylase Sirtuin 1 (SIRT1) could be involved in many pathways linked to AS progression. Sodium-glucose co-transporter 2 inhibitors (SGLT2i), glucose-lowering agents, have been shown to reduce cardiovascular events (likely via SIRT1), but their possible benefits in AS are unknown. Our study aims to uncover the role of SIRT1 in AS progression and assess the benefit of SGLT2i to slow down the aortic valve fibro-calcification processes.
METHODS: RNA-seq data of human aortic valve specimens were collected from the ARChS4 database. SIRT1 knockdown (SIRT1 KD) and overexpressing (SIRT1 Over) valve interstitial cells (VIC) were generated by CRISPR/Cas9. Real-time PCR, immunofluorescence, and calcification assays were used to characterise mutant VICs. Conditioned medium experiments were implemented to evaluate SGLT2i effect on cellular cross-talk and calcification. Diabetic patients' data from the Lombardy regional healthcare database, treated with sulphonylureas (SU; no effect on SIRT1) and SGLT2i (acting on SIRT1), were selected and matched 1:1 by age, sex, and multisource comorbidity score. Cumulative incidence of hospitalisation for non-rheumatic aortic valve disease was assessed by Kaplan-Meier and Fine and Gray models were used to estimate subdistribution hazard ratios.
RESULTS: RNA-seq showed that SIRT1 could be an upstream regulator of multiple AS-related pathways. Functional studies on mutant VICs revealed that SIRT1 directly regulates antioxidant processes, extracellular-matrix remodelling, and calcification by modulating key transcription factors. Moreover, calcification assays further support this role, revealing an increased calcification in SIRT1 KD VICs and a concomitant decrease in VIC SIRT1 Over when compared to wild type. Then, exploring SGLT2i impact on calcification, we showed that VICs cultured in SGLT2i-treated-endothelial medium exhibited reduced calcification associated with endothelial-increased nitric oxide levels, while SIRT1 inhibition enhanced VIC calcification. The real-world data analysis revealed that SGLT2i-treated group had a lower incidence of hospitalised patients for non-rheumatic aortic valve disease compared to SU-treated group.
CONCLUSIONS: Our data identify SIRT1 as an upstream regulator of fibro-calcific processes in AS and suggest that SGLT2i may slow the aortic valve degeneration through SIRT1 modulation. These findings support SGLT2i as a potential therapeutic strategy for AS prevention and care.
PMID:42706214 | DOI:10.1093/cvr/cvag199