AKT and ERK1/2 activation via remote ischemic preconditioning prevents Kcne2-dependent sudden cardiac death

Area of Science:

• Cardiology
• Molecular Biology
• Genetics

Background:

• Sudden cardiac death (SCD) is a leading global cause of mortality.
• SCD is often caused by cardiac ischemia reperfusion (IR) injury or genetic ion channel defects.
• Effective preventative strategies for ventricular arrhythmias linked to SCD are needed.

Purpose of the Study:

• To investigate the efficacy of remote ischemic preconditioning (RIPC) of the limb versus the liver in reducing ventricular arrhythmias.
• To explore the underlying molecular mechanisms of RIPC-mediated cardioprotection in a mouse model of SCD.

Main Methods:

• Utilized a mouse model lacking the Kcne2 gene, predisposing to Long QT syndrome.
• Induced cardiac IR injury via coronary ligation.
• Administered limb or liver RIPC prior to IR injury.
• Assessed ventricular arrhythmias and SCD incidence.
• Performed biochemical and pharmacological analyses to investigate signaling pathways.

Main Results:

• Cardiac IR injury induced ventricular arrhythmias in all untreated mice and SCD in 33% of cases.
• Both limb and liver RIPC significantly reduced ventricular arrhythmia incidence and severity.
• RIPC completely prevented SCD in all treated mice.
• RIPC-induced cardioprotection was dependent on ERK1/2 and/or AKT phosphorylation.
• GSK-3β phosphorylation was not altered, suggesting a non-conventional RISK pathway.

Conclusions:

• Remote ischemic preconditioning (limb or liver) is a highly effective strategy for preventing SCD and ventricular arrhythmias in a mouse model.
• RIPC-mediated cardioprotection involves ERK1/2 and/or AKT signaling.
• Limb RIPC offers a potential noninvasive, nonpharmacological therapeutic approach for SCD prevention in humans, particularly those with ischemia or channelopathies.