Simvastatin Attenuates H₂O₂-Induced Endothelial Cell Dysfunction by Reducing Endoplasmic Reticulum Stress.

Area of Science:

• Cardiovascular Biology
• Cellular Biology
• Pharmacology

Background:

• Atherosclerosis, a primary cause of cardiovascular disease, involves endothelial dysfunction.
• Simvastatin demonstrates anti-atherosclerosis properties, necessitating a deeper understanding of its mechanisms.

Purpose of the Study:

• To evaluate simvastatin's protective effects on endothelial cells under oxidative stress.
• To elucidate the underlying molecular mechanisms of simvastatin's action.

Main Methods:

• Utilized hydrogen peroxide (H₂O₂) to induce oxidative stress in human umbilical vein endothelial cells (HUVECs).
• Investigated the Wnt/β-catenin pathway activation using lithium chloride.
• Assessed intracellular cholesterol deposition, endoplasmic reticulum (ER) stress, and LRP6 expression/phosphorylation.

Main Results:

• Simvastatin attenuated H₂O₂-induced HUVEC dysfunction and inhibited the Wnt/β-catenin pathway.
• Activating the Wnt/β-catenin pathway enhanced endothelial dysfunction.
• Simvastatin reduced intracellular cholesterol and inhibited ER stress, which in turn inhibited the Wnt/β-catenin pathway.

Conclusions:

• Simvastatin ameliorates endothelial dysfunction by reducing intracellular cholesterol accumulation and inhibiting ER stress.
• This mechanism subsequently blocks intracellular Wnt/β-catenin signaling, offering a protective effect against atherosclerosis.
• Simvastatin's action appears independent of transmembrane Wnt/β-catenin signaling components like LRP6.