Figure 1.

HDL lifecycle and CETP function.

Notes: Pre-β HDL (lipid-poor apo A-I HDL particles) is converted to spherical HDL₃ by lecithin-cholesterol acyltransferase (LCAT). HDL₃ is converted to HDL₂ by fusion of small HDL particles activated by phospholipid transfer protein (PLTP). The modulator role of CETP transfers cholesteryl esters (CE) between HDL particles to create both larger HDL₂ and smaller pre-β HDL particles (green arrows), which may be an antiatherogenic process. CETP also mediates heterotropic transfer of triglyceride between LDL/VLDL and HDL (orange arrows), as discussed in the text.

Abbreviations: CETP, cholesteryl ester transfer protein; HDL, high-density lipoprotein; LDL, low density lipoprotein; VLDL, very low density lipoprotein.