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L'apolipoproteina C-I regola il trasporto del colesterolo

Nell'uomo, l'apo C-I anche in concentrazioni fisiologiche, riduce il trasporto degli esteri di colesterolo attraverso l'inibizione dell'attività del CETP.

Apolipoprotein CI is a physiological regulator of cholesteryl ester transfer protein activity in human plasma, but not in Rabbit plasma.

Pais de Barros JP, Boualam A, Gautier T, Dumont L, Vergès B, Masson D, Lagrost L.

J Lipid Res 2009;50:1842-51

Plasma cholesteryl ester transfer protein (CETP) activity is high in rabbits, intermediate in humans, and non-detectable in rodents. Human apolipoprotein (apo) CI was found to be a potent inhibitor of CETP. The aim of the present study was to compare the ability of rabbit and human apoCI to modulate the interaction of CETP with high density lipoproteins (HDL) and to evaluate to which extent apoCI contributes to plasma cholesteryl ester transfer rate in normolipidemic humans and rabbits. Rabbit apoCI gene was cloned and sequenced, rabbit and human apoCI were purified to homogeneity, and their ability to modify the surface charge properties and the CETP inhibitory potential of HDL were compared. It is demonstrated that unlike human apoCI, rabbit apoCI does not modulate cholesteryl ester transfer rate in total plasma. Whereas both human and rabbit apoCI readily associate with HDL, only human apoCI was found to modify the electrostatic charge of HDL. In humans, both CETP and apoCI at normal, physiological levels contribute significantly to the plasma cholesteryl ester transfer rate. In contrast, CETP is the sole major determinant of cholesteryl ester transfer in normolipidemic rabbit plasma as a result of the inability of rabbit apoCI to change HDL electronegativity.