High density lipoproteins (HDLs) are a class of lipoproteins characterized by small diameter and high density. Epidemiological studies have demonstrated that HDL cholesterol levels are inversely and independently related to the incidence of coronary heart disease. The mechanisms involved in HDL protection against atherosclerosis are uncertain, but the beneficial effect of HDLs might be the consequence of its properties. The best known of them is related to the “reverse cholesterol transport”, i.e. the transfer of cholesterol from non-hepatic cells to the liver. Second, HDLs exert anti-inflammatory activity by inhibiting the expression of adhesion molecules by endothelial cells and the subsequent transmigration of monocytes. Third, HDLs have antioxidant activity through the anti-oxidative properties of apoprotein A-I, and the presence of enzymes such as paraoxonase, glutathione-peroxidase, and PAF acetylhydrolase. Fourth, HDLs display an anti-thrombotic effect by inhibiting platelets aggregation, reducing von Willebrand factor levels, and enhancing the activity of activated protein C and S. Fifth, HDLs have a beneficial effect on endothelial function by activating endothelial NO synthase and enhancing NO release. Finally, high HDL-C has been associated with “longevity syndrome” while low HDL-C has been related to the “frailty syndrome”, suggesting a possible role of HDL in the phenomenon of successful aging.
The anti-atherogenic properties of HDL particles
ZULIANI, Giovanni;VIGNA, Giovanni Battista;FELLIN, Renato
2007
Abstract
High density lipoproteins (HDLs) are a class of lipoproteins characterized by small diameter and high density. Epidemiological studies have demonstrated that HDL cholesterol levels are inversely and independently related to the incidence of coronary heart disease. The mechanisms involved in HDL protection against atherosclerosis are uncertain, but the beneficial effect of HDLs might be the consequence of its properties. The best known of them is related to the “reverse cholesterol transport”, i.e. the transfer of cholesterol from non-hepatic cells to the liver. Second, HDLs exert anti-inflammatory activity by inhibiting the expression of adhesion molecules by endothelial cells and the subsequent transmigration of monocytes. Third, HDLs have antioxidant activity through the anti-oxidative properties of apoprotein A-I, and the presence of enzymes such as paraoxonase, glutathione-peroxidase, and PAF acetylhydrolase. Fourth, HDLs display an anti-thrombotic effect by inhibiting platelets aggregation, reducing von Willebrand factor levels, and enhancing the activity of activated protein C and S. Fifth, HDLs have a beneficial effect on endothelial function by activating endothelial NO synthase and enhancing NO release. Finally, high HDL-C has been associated with “longevity syndrome” while low HDL-C has been related to the “frailty syndrome”, suggesting a possible role of HDL in the phenomenon of successful aging.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
