HDL and endothelial protection: examining evidence from HDL inherited disorders

Epidemiological studies have clearly demonstrated that plasma concentrations of HDL cholesterol are strongly and inversely associated with cardiovascular risk. Besides playing a major role in reverse cholesterol transport, the process by which excess cholesterol in the arterial wall is removed by HDL and delivered to the liver for excretion, HDL have other atheroprotective functions. In particular, HDL can contribute to the maintenance of endothelial cell homeostasis by inhibiting cell adhesion molecule expression, by promoting the release of bioactive molecules such as nitric oxide and prostacyclin, and by regulating cell proliferation and migration. HDL inherited disorders represent a unique tool to understand the relationship between HDL concentration, HDL function and HDL–mediated atheroprotection.