7-Ketocholesterol and 5,6-secosterol induce human endothelial cell dysfunction by differential mechanisms

Area of Science:

• Biochemistry
• Cardiovascular Biology
• Oxidative Stress Research

Background:

• Cholesterol autoxidation products, 7-ketocholesterol and 5,6-secosterol, are implicated in atherosclerosis.
• Endothelial cells are crucial in cardiovascular health, and their dysfunction promotes atherosclerosis.

Purpose of the Study:

• To investigate the effects of 7-ketocholesterol and 5,6-secosterol on endothelial cells and arterial function.
• To elucidate the mechanisms underlying their cellular and functional impacts.

Main Methods:

• Exposure of endothelial cells to 7-ketocholesterol and 5,6-secosterol.
• Assessment of apoptosis, mitochondrial and lysosomal alterations.
• Evaluation of endothelial-dependent arterial relaxation using aortic ring models.

Main Results:

• Both 7-ketocholesterol and 5,6-secosterol induce apoptosis in endothelial cells.
• 5,6-secosterol-induced apoptosis involves PKC and p53 up-regulation.
• 5,6-secosterol inhibits endothelial-dependent arterial relaxation via PKC-dependent pathways.

Conclusions:

• 7-ketocholesterol and 5,6-secosterol are potent inducers of endothelial cell apoptosis.
• 5,6-secosterol exhibits significant endothelial dysfunction, contributing to pro-atherogenic and pro-thrombotic effects.
• Cholesterol autoxidation products play a critical role in cardiovascular disease pathogenesis.