C/T conversion alters interleukin-1A promoter function in a human astrocyte cell line.

Recently, association of an interleukin-1A promoter polymorphism (-889, thymine/thymine (T/T)) with Alzheimer's disease was reported, suggesting that this cytokine may play an important role in disease development. To understand the mechanism underlying the interleukin-1A promoter's role in Alzheimer's disease, a study comparing promoter function of an interleukin-1A polymorphism was performed in the SVG astroglia cell line. The effects of thymine and cytosine on transcriptional activity of the interleukin-1A promoter were analyzed by testing luciferase-reporter activity in transfected SVG cells. Our results demonstrate that cytosine/thymine conversion increases activity of the interleukin-1A promoter in SVG cells. Both sodium salicylate and lovastatin are able to block induced promoter activities in astroglial cells. Induced promoter activity by the polymorphism (T/T) may result in the upregulation of interleukin-1alpha protein and "cytokine cycle" amplification, which may promote disease development.