Evidence for cytokine regulation of cholesterol metabolism in herpesvirus-infected arterial cells by the lipoxygenase pathway.
Cytokines such as tumor necrosis factor (TNF), interleukin-1 (IL-1), and gamma-interferon (IF) are produced by activated hematopoietic cells. They possess antiviral activity and have other biological activities such as induction of cell proliferation and hemorrhagic necrosis of tumors. Since herpes simplex virus (HSV) infection of human vascular cells is known to produce a biochemical and cytopathological effect virtually indistinguishable from atherosclerosis, we hypothesized that these cytokines many prevent cholesteryl ester (CE) accumulation in arterial smooth muscle cells (SMC) that is seen with herpesvirus infection. We now report that TNF and IL-1 but not gamma-IF prevent CE accumulation in HSV-infected arterial SMC by induction of cyclic AMP-dependent CE hydrolysis. This effect is mediated through the arachidonate 12-lipoxygenase pathway via 12-HETE since pretreatment of cells with several lipoxygenase inhibitors abolishes the antiviral effect and 12-HETE is the major (greater than 99%) lipoxygenase metabolite produced by these cells. This conclusion is further based on our observations that TNF and IL-1 enhance 12-HETE production in SMC and that 12-HETE significantly increases both intracellular cyclic AMP and lysosomal CE hydrolysis. Moreover, dibutyryl cyclic AMP restored a normal phenotype in these virally infected cells. Collectively, these findings identify for the first time a biochemical mechanism involved in the reduction of lipid accumulation in virally infected arterial SMC by these potent cytokines.
Etingin
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Department of Medicine, Cornell University Medical College, New York, NY 10021.
Hajjar
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D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; D000818:Animals; D001092:Arachidonate 12-Lipoxygenase / Q000378:metabolism*; D001091:Arachidonate Lipoxygenases / Q000378:metabolism*; D001161:Arteriosclerosis / Q000209:etiology; D001685:Biological Factors / Q000494:pharmacology*; D002478:Cells, Cultured; D002784:Cholesterol / Q000378:metabolism*; D016207:Cytokines; D003588:Cytopathogenic Effect, Viral / Q000187:drug effects; D004347:Drug Interactions; D006561:Herpes Simplex / Q000150:complications / Q000378:metabolism*; D006893:Hydroxyeicosatetraenoic Acids / Q000378:metabolism; D007371:Interferon-gamma / Q000494:pharmacology; D007375:Interleukin-1 / Q000494:pharmacology; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism / Q000382:microbiology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D001685:Biological Factors; D016207:Cytokines; D006893:Hydroxyeicosatetraenoic Acids; D007375:Interleukin-1; D014409:Tumor Necrosis Factor-alpha; D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; D007371:Interferon-gamma; D002784:Cholesterol; D001091:Arachidonate Lipoxygenases; D001092:Arachidonate 12-Lipoxygenase