Hypercholesterolemia promotes a CD36-dependent and endothelial nitric-oxide synthase-mediated vascular dysfunction

Area of Science:

• Cardiovascular Science
• Molecular Biology
• Hypertension Research

Background:

• Hypertension is linked to CD36 presence/absence.
• Hypercholesterolemia impairs nitric oxide-induced vasodilation, increasing blood pressure.

Purpose of the Study:

• To test if diet-induced hypercholesterolemia disrupts nitric oxide generation and vasodilation in a CD36-dependent manner.
• To investigate the role of CD36 in hypercholesterolemia-mediated vascular dysfunction.

Main Methods:

• Mice models (C57BL/6, apoE null, CD36 null, apoE/CD36 null) were fed chow or high-fat diets.
• Vascular responsiveness to acetylcholine was measured.
• Caveolae integrity and endothelial nitric-oxide synthase localization were analyzed.
• Low-density lipoprotein (LDL) fraction and cyclodextrin effects were examined.

Main Results:

• ApoE null mice on high-fat diet lost acetylcholine-induced vasodilation; CD36 null mice did not.
• High-fat diet depleted caveolae of cholesterol and endothelial nitric-oxide synthase in apoE null mice.
• Plasma LDL fraction and cyclodextrin mimicked these effects, impairing nitric oxide production.

Conclusions:

• Ablation of CD36 prevents hypercholesterolemia's negative impact on nitric oxide-mediated vasodilation.
• CD36 is directly linked to early events in hypercholesterolemia-induced hypertension.
• Mechanisms involve CD36, nitric oxide synthase, caveolae integrity, and blood pressure regulation.