Table 2.

Potential mechanisms of vascular protection in pulmonary circulation.

Biological Activity of HDL	Potential Mechanisms of Vascular Protection
Vasodilatory activity	Stimulation of NO production Prostacyclin release Decreased production of reactive oxygen species
Anti-inflammatory properties	Downregulation of adhesion molecule Inhibition of monocyte activation Downregulation of proinflammatory macrophages Inhibition of NFkB and TNF-alpha signaling in endothelial cells
Antioxidative properties	Protection of LDL from oxidation Inhibition of cellular superoxide production
Cytoprotection	Protection of endothelial cells from apoptosis Modulation of mitochondrial electron transport Reduced cellular superoxide production Antiapoptotic signaling via ABCG1 Protection from extracellular matrix degradation by serpin peptidase inhibitors
Modulation of glucose metabolism	Stimulation of pancreatic insulin secretion Decrease of insulin resistance Modulation of cholesterol homeostasis Modulation of adipocyte metabolism
Regulation of platelet activation	Inhibition of platelet aggregation Anti-thrombotic effects on endothelium Upregulation of NO production Inhibition of calcium release
Regulation of gene expression	Transport of small non-coding microRNA

ABCG1—ATP-binding cassette sub-family G member 1, NFkB—nuclear factor kappa-light-chain-enhancer of activated B cells, NO—nitric oxide, TNF-α—tumor necrosis factor α.