GENETIC-CONTROL OF INFLAMMATORY GENE INDUCTION AND NF-KAPPA-B-LIKE TRANSCRIPTION FACTOR ACTIVATION IN RESPONSE TO AN ATHEROGENIC DIET IN MICE

A high fat, high cholesterol ''atherogenic'' diet induced considerably greater hepatic levels of conjugated dienes and expression of several inflammatory and oxidative stress responsive genes (JE, the mouse homologue of monocyte chemotactic protein-1, colony-stimulating factors, heme oxygenase, and members of the serum amyloid A family) in fatty streak susceptible C57BL/6 mice compared to fatty streak resistant C3H/HeJ mice. Since serum amyloid A proteins bind exclusively to HDL and influence the properties of HDL, serum amyloid A expression may contribute to the decrease in HDL levels seen in the susceptible strains. Induction of a similar set of genes was observed upon injection of minimally oxidized low density lipoprotein. The transcription factor NF-kappaB is known to be activated by oxidative stress and is involved in the transcriptional regulation of several of these genes. On the atherogenic diet the susceptible C57BL/6 mice exhibited significant NF-kappaB-like activation whereas the resistant C3H / HeJ mice exhibited little or no activation. These results are consistent with the hypothesis that the atherogenic diet resulted in the accumulation of oxidized lipids in certain tissues (e.g., liver and arteries) and the resulting inflammatory response to this oxidative stress was genetically determined.