The role of lipoxygenase-isoforms in atherogenesis.

Lipoxygenases (LOXs) form a heterogeneous family of lipid-peroxidizing enzymes, and several LOX-isoforms (12/15-LOX, 5-LOX) have been implicated in atherogenesis. However, the precise role of these enzymes is still a matter of discussion. 12/15-LOXs are capable of oxidizing lipoproteins (low-density lipoprotein (LDL), high-density lipoprotein (HDL)) to atherogenic forms, and functional inactivation of this enzyme in murine atherosclerosis models slows down lesion formation.

Expression of 12/15-lipoxygenase attenuates intracellular lipid deposition during in vitro foam cell formation.

Objective: Lipoxygenases with different positional specificity have been implicated in atherogenesis, but the precise roles of the various isoforms remain unclear. Because of its capability of oxidizing low-density lipoprotein (LDL) to an atherogenic form, 12/15-lipoxygenases have been suggested to initiate LDL oxidation in vivo; thus, these enzymes may exhibit pro-atherogenic activities. However, in several rabbit atherosclerosis models, the enzyme appears to act atheroprotective.