Spermidine Suppresses Development of Experimental Abdominal Aortic Aneurysms

Area of Science:

• Cardiovascular Research
• Molecular Biology
• Pharmacology

Background:

• Polyamines show protective effects in cardiovascular disease.
• The role of spermidine in abdominal aortic aneurysm (AAA) remains uninvestigated.
• This study explores spermidine's impact on experimental AAA.

Purpose of the Study:

• To investigate the effects of spermidine on experimental AAA.
• To elucidate the potential mechanisms underlying spermidine's influence on AAA.

Main Methods:

• Experimental AAAs were induced in mice using porcine pancreatic elastase.
• Spermidine was administered orally.
• Aortic tissues and blood samples were analyzed using immunostaining, flow cytometry, Western blot, and electron microscopy.
• Human aortic samples were used to assess autophagic function.

Main Results:

• Spermidine treatment prevented AAA formation and preserved medial elastin and smooth muscle cells.
• Spermidine significantly reduced inflammatory cell infiltration (macrophages, T cells, neutrophils) in the aorta.
• Leukocyte infiltration and circulating inflammatory cells were decreased by spermidine.
• Spermidine promoted autophagy-related proteins in experimental AAAs.
• Human aneurysmal aortae showed dysregulated autophagy compared to non-aneurysmal segments.

Conclusions:

• Spermidine supplementation limits experimental AAA formation.
• Spermidine preserves aortic structural integrity and attenuates inflammatory responses.
• Increased autophagy is associated with spermidine treatment in AAA.
• Spermidine shows potential as a therapeutic agent for AAA disease.