Increased expression of genes that control ionic homeostasis, second messenger signaling and metabolism in the carotid plaques from patients with symptomatic stroke.

The molecular mechanisms that render a carotid atherosclerotic plaque symptomatic have not yet been identified. Using an Affymetrix Human GeneChip set, we analyzed the gene expression patterns of 44 862 mRNA transcripts in surgically removed carotid artery plaques from six patients with symptomatic stroke and four non-symptomatic patients. The age, body mass index and the degree of stenosis were similar in the two groups. Some 236 transcripts (approximately 0.5% of the total transcripts analyzed) were expressed more abundantly in the symptomatic than the asymptomatic group. Of these, 61 transcripts are those that participate in ionic homeostasis, signal transduction and metabolism. The other groups of transcripts up-regulated in the symptomatic plaques include oncogenes, growth factors, tumor markers, angiogenesis promoters, transcription factors, and RNA splicing and processing factors. This study indicates that the higher metabolic activity in some atherosclerotic plaques leads to their faster growth and precipitation of stroke symptoms. The implications of these findings are that both diagnosis and prevention of stroke symptoms may become possible at the genetic level.