| Summary: | <p>Abstract</p> <p>Background</p> <p>Disturbed cellular cholesterol homeostasis may lead to accumulation of cholesterol in human atheroma plaques. Cellular cholesterol homeostasis is controlled by the sterol regulatory element-binding transcription factor 2 (SREBF-2) and the SREBF cleavage-activating protein (SCAP). We investigated whole genome expression in a series of human atherosclerotic samples from different vascular territories and studied whether the non-synonymous coding variants in the interacting domains of two genes, <it>SREBF-2 </it>1784G>C (rs2228314) and <it>SCAP </it>2386A>G, are related to the progression of coronary atherosclerosis and the risk of pre-hospital sudden cardiac death (SCD).</p> <p>Methods</p> <p>Whole genome expression profiling was completed in twenty vascular samples from carotid, aortic and femoral atherosclerotic plaques and six control samples from internal mammary arteries. Three hundred sudden pre-hospital deaths of middle-aged (33–69 years) Caucasian Finnish men were subjected to detailed autopsy in the Helsinki Sudden Death Study. Coronary narrowing and areas of coronary wall covered with fatty streaks or fibrotic, calcified or complicated lesions were measured and related to the <it>SREBF-2 </it>and <it>SCAP </it>genotypes.</p> <p>Results</p> <p>Whole genome expression profiling showed a significant (p = 0.02) down-regulation of <it>SREBF-2 </it>in atherosclerotic carotid plaques (types IV-V), but not in the aorta or femoral arteries (p = NS for both), as compared with the histologically confirmed non-atherosclerotic tissues. In logistic regression analysis, a significant interaction between the <it>SREBF-2 </it>1784G>C and the <it>SCAP </it>2386A>G genotype was observed on the risk of SCD (p = 0.046). Men with the <it>SREBF-2 </it>C allele and the <it>SCAP </it>G allele had a significantly increased risk of SCD (OR 2.68, 95% CI 1.07–6.71), compared to <it>SCAP </it>AA homologous subjects carrying the <it>SREBF-2 </it>C allele. Furthermore, similar trends for having complicated lesions and for the occurrence of thrombosis were found, although the results were not statistically significant.</p> <p>Conclusion</p> <p>The results suggest that the allelic variants (<it>SREBF-2 </it>1784G>C and <it>SCAP </it>2386A>G) in the cholesterol homeostasis regulating SREBF-SCAP pathway may contribute to SCD in early middle-aged men.</p>
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