HSP90-Mediates Liraglutide Preconditioning-Induced Cardioprotection by Inhibiting C5a and NF-κB

Area of Science:

• Cardiology
• Molecular Biology
• Immunology

Background:

• Heat shock protein 90 (HSP90) is known to inhibit complement C5a, contributing to cardioprotection.
• Liraglutide has demonstrated cardioprotective effects, but the underlying molecular mechanisms require further elucidation.

Purpose of the Study:

• To investigate the role of HSP90-mediated inhibition of complement C5a/nuclear factor-kappa B (NF-κB) signaling in liraglutide-induced cardioprotection.
• To determine if targeting this pathway can enhance the protective effects of liraglutide.

Main Methods:

• Rat hearts subjected to 30 minutes of ischemia and 2 hours of reperfusion.
• Groups included ischemia/reperfusion (I/R), sham, liraglutide preconditioning (LP), LP with HSP90 inhibitor (geldanamycin), and LP with C5a receptor antagonist (PMX53).
• Assessed cardiac injury, C5a/NF-κB activation, and inflammatory markers.

Main Results:

• Liraglutide preconditioning significantly reduced cardiomyocyte apoptosis, infarct size, and cardiac enzyme release.
• These protective effects correlated with decreased C5a levels, suppressed NF-κB signaling, and reduced inflammation, alongside increased HSP90 levels.
• Inhibition of HSP90 abolished liraglutide's cardioprotection, while C5a antagonism enhanced it, confirming the pathway's involvement.

Conclusions:

• HSP90 plays a critical role in liraglutide-mediated cardioprotection by inhibiting inflammatory responses and C5a/NF-κB signaling.
• This mechanism attenuates ischemia/reperfusion-induced cardiomyocyte apoptosis by modulating pro-apoptotic (Bax) and anti-apoptotic (Bcl2) factors.
• Targeting the HSP90/C5a/NF-κB pathway presents a promising therapeutic strategy for protecting the heart during ischemic events.