Transgenic rabbits with the integrated human 15-lipoxygenase gene driven by a lysozyme promoter: macrophage-specific expression and variable positional specificity of the transgenic enzyme.
15-Lipoxygenase is expressed in foamy macrophages of atherosclerotic lesions and has been implicated in the oxidative modification of low density lipoprotein during early stages of atherogenesis. To establish an animal model of 15-lipoxygenase overexpression, we created transgenic rabbits that express at high level the human 15-lipoxygenase in monocyte-derived macrophages but not in liver, heart, kidney, lung, or other tissues. The expression level of the enzyme in monocyte-derived macrophages is comparable to that of interleukin 4 (IL4)-treated human monocytes, but more than 20-fold higher than in macrophages of normal rabbits. The transgenic enzyme oxygenates linoleic acid to 13S-hydroperoxy-9, 11 (Z,E)-octadecadienoic acid (13-HODE), and arachidonic acid to a mixture of 12S-hydroperoxy-5, 8, 10, 14 (Z,Z,E,Z)-eicosatetraenoic acid (12S-HETE), and 15S-hydroperoxy-5, 8, 11, 14 (Z,Z,Z,E)-eicosatetraenoic acid (15S-HETE). The 12-HETE/15-HETE ratio varied between 0.3 and 5.4, indicating a remarkable variability in the positional specificity of the transgenic enzyme. Macrophages from normal rabbits consistently produced 12S-HETE as the major oxygenation product. 15-Lipoxygenase-overexpressing rabbits may be used for further mechanistic studies on the implication of lipoxygenase in atherogenesis; they are also an ideal model for testing the in vivo action of 15-lipoxygenase inhibitors.
Department of Cell Biology, Baylor College of Medicine, Houston, Texas 77030, USA.
J
J
Shen
H
H
Kühn
A
A
Petho-Schramm
L
L
Chan
D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; D000818:Animals; D030801:Animals, Genetically Modified; D001093:Arachidonate 15-Lipoxygenase / Q000096:biosynthesis* / Q000235:genetics; D016718:Arachidonic Acid / Q000378:metabolism; D001483:Base Sequence; D004790:Enzyme Induction; D005260:Female; D006801:Humans; D006893:Hydroxyeicosatetraenoic Acids / Q000096:biosynthesis; D019787:Linoleic Acid; D008041:Linoleic Acids / Q000378:metabolism; D008264:Macrophages / Q000201:enzymology*; D008297:Male; D008969:Molecular Sequence Data; D009000:Monocytes / Q000201:enzymology; D009113:Muramidase / Q000235:genetics*; D009928:Organ Specificity; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis*; D013379:Substrate Specificity
D006893:Hydroxyeicosatetraenoic Acids; D008041:Linoleic Acids; D011993:Recombinant Fusion Proteins; D016718:Arachidonic Acid; D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; C025984:15-hydroxy-5,8,11,13-eicosatetraenoic acid; D019787:Linoleic Acid; D001093:Arachidonate 15-Lipoxygenase; D009113:Muramidase