Myocardial purine metabolism : aspects of myocardial ATP metabolism and pharmacological intervention

The heart is obliged to contract continuously. This implicates for a human with an average heart rate of 70 beats per minute in about 70 years more than 2.5 billions of contractions. For this contraction ATP is needed as the main substrate. As a consequence continuous ATP production by the heart is obligatory. This ATP is mainly produced by the oxygen-dependent oxidative phosphorylation. Disturbances of the oxygen delivery, such as that induced by partial occlusion of one or more coronary arteries can lead to a distortion of the balance between ATP production and consumption. As a res11lt, ATP is dephosphorylated, and subsequently the products adenosine, inosine, hypoxanthine, xanthine and uric acid pass the cellular membrane and appear in the coronary effluent. Because of the importance of adequate ~TP levels for the heart, the following 4 main ::.\'Venues have been investigated in this study, which forms the substance of my thesis

Differential Allelic Expression in the Human Genome: A Robust Approach To Identify Genetic and Epigenetic Cis-Acting Mechanisms Regulating Gene Expression

The recent development of whole genome association studies has lead to the robust identification of several loci involved in different common human diseases. Interestingly, some of the strongest signals of association observed in these studies arise from non-coding regions located in very large introns or far away from any annotated genes, raising the possibility that these regions are involved in the etiology of the disease through some unidentified regulatory mechanisms. These findings highlight the importance of better understanding the mechanisms leading to inter-individual differences in gene expression in humans. Most of the existing approaches developed to identify common regulatory polymorphisms are based on linkage/association mapping of gene expression to genotypes. However, these methods have some limitations, notably their cost and the requirement of extensive genotyping information from all the individuals studied which limits their applications to a specific cohort or tissue. Here we describe a robust and high-throughput method to directly measure differences in allelic expression for a large number of genes using the Illumina Allele-Specific Expression BeadArray platform and quantitative sequencing of RT-PCR products. We show that this approach allows reliable identification of differences in the relative expression of the two alleles larger than 1.5-fold (i.e., deviations of the allelic ratio larger than 60∶40) and offers several advantages over the mapping of total gene expression, particularly for studying humans or outbred populations. Our analysis of more than 80 individuals for 2,968 SNPs located in 1,380 genes confirms that differential allelic expression is a widespread phenomenon affecting the expression of 20% of human genes and shows that our method successfully captures expression differences resulting from both genetic and epigenetic cis-acting mechanisms