High-density lipoprotein, mitochondrial dysfunction and cell survival mechanisms

Area of Science:

• Cardiology
• Mitochondrial Biology
• Cellular Signaling

Background:

• Ischemia/reperfusion (I/R) injury is a major complication following cardiac events and procedures.
• Mitochondrial dysfunction, driven by reactive oxygen species (ROS) and opening of the mitochondrial permeability transition pore (mPTP), is central to I/R injury.
• Ischemic conditioning protocols (preconditioning and postconditioning) protect the heart by activating RISK and SAFE pathways.

Purpose of the Study:

• To review the role of high-density lipoprotein (HDL) and its components in mitigating myocardial I/R injury.
• To elucidate the mechanisms by which HDL-associated mediators activate cardioprotective signaling cascades.
• To highlight apolipoprotein A-I (apoA-I) and sphingosine 1-phosphate (S1P) as key players in HDL-mediated cardioprotection.

Main Methods:

• Review of clinical and experimental studies on I/R injury and cardioprotective strategies.
• Analysis of signaling pathways involved in cell survival, including RISK and SAFE pathways.
• Investigation of the molecular targets of HDL components, such as ROS production and mPTP opening.

Main Results:

• HDL mimics the protective effects of ischemic conditioning against myocardial I/R injury.
• HDL activates the Reperfusion Injury Salvage Kinase (RISK) and Survivor Activating Factor Enhancement (SAFE) pathways.
• Apolipoprotein A-I (apoA-I) and sphingosine 1-phosphate (S1P) mediate infarct-sparing effects by inhibiting ROS-dependent damage and mPTP opening.

Conclusions:

• HDL, through apoA-I and S1P, represents a promising therapeutic strategy for attenuating myocardial I/R injury.
• Targeting HDL-mediated signaling offers a novel approach to enhance cardiomyocyte survival and preserve cardiac function post-ischemia.
• Understanding the interplay between HDL, mitochondria, and cell survival pathways is crucial for developing effective treatments for ischemic heart disease.