Spermidine Enhances Mitochondrial Function and Mitigates Aortic Valve Calcification: Implications for DNA...

Area of Science:

• Cardiovascular Biology
• Mitochondrial Medicine
• Cellular Aging

Background:

• Aortic stenosis (AS) is a severe heart valve disease characterized by calcification and fibrosis, often leading to heart failure.
• Mitochondrial dysfunction is increasingly recognized as a key factor in the pathogenesis of AS.
• Current treatments for AS primarily focus on valve replacement, highlighting the need for novel therapeutic strategies.

Purpose of the Study:

• To investigate the role of mitochondrial function in human aortic valve interstitial cells (HAVICs) from AS patients.
• To evaluate the therapeutic potential of spermidine, an autophagy inducer, in mitigating AS.
• To elucidate the molecular pathways involved in spermidine's effects on AS.

Main Methods:

• Isolation and culture of HAVICs from AS patients.
• Treatment of HAVICs and AS mouse models with spermidine.
• Assessment of fibrosis, calcification, and mitochondrial function markers.
• Analysis of the AKT-TP53-DNMT1-PPARG signaling pathway and DNA methylation.
• Inhibition of DNA methyltransferase 1 (DNMT1) using 5-azacytidine.

Main Results:

• Spermidine treatment significantly reduced fibrosis and calcification in HAVICs.
• Spermidine administration improved AS-related features in a mouse model.
• The AKT-TP53-DNMT1-PPARG pathway was identified as a key mediator.
• DNMT1 inhibition by 5-azacytidine promoted mitochondrial biogenesis via reduced mitochondrial DNA hypermethylation.

Conclusions:

• Spermidine demonstrates therapeutic potential for treating aortic stenosis by reducing valvular fibrosis and calcification.
• Targeting DNMT1 and enhancing mitochondrial function represent promising strategies for preventing or treating aortic valve disease.
• The study implicates mitochondrial health as a critical factor in AS progression and identifies novel therapeutic targets.