Résumé
Objective: Cocaine use disorders (CUDs) represent a major public health problem in many countries. To better understand the interaction between the environmental modulations and phenotype, the aim of the present study was to investigate the DNA methylation pattern of CUD patients, who had concomitant cocaine and crack dependence, and healthy controls. Methods: We studied DNA methylation profiles in the peripheral blood of 23 CUD patients and 24 healthy control subjects using the Illumina Infinium HumanMethylation450 BeadChip arrays. Results: Comparison between CUD patients and controls revealed 186 differentially methylated positions (DMPs; adjusted p-value [adjP] < 10-5) related to 152 genes, with a subset of CpGs confirmed by pyrosequencing. DNA methylation patterns discriminated CUD patients and control groups. A gene network approach showed that the EHMT1, EHMT2, MAPK1, MAPK3, MAP2K1, and HDAC5 genes, which are involved in transcription and chromatin regulation cellular signaling pathways, were also associated with cocaine dependence. Conclusion: The investigation of DNA methylation patterns may contribute to a better understanding of the biological mechanisms involved in CUD.
Sujets)
Humains , Mâle , Adulte , Jeune adulte , Crack , Méthylation de l'ADN , Troubles liés à la cocaïne/génétique , Troubles liés à la cocaïne/sang , Étude d'association pangénomique/méthodes , Études cas-témoins , Modèles linéaires , Histone-lysine N-methyltransferase/génétique , Statistique non paramétrique , Mitogen-Activated Protein Kinase 1/génétique , MAP Kinase Kinase 1/génétique , Mitogen-Activated Protein Kinase 3/génétique , Réseaux de régulation génique , Séquençage nucléotidique à haut débit , Antigènes d'histocompatibilité/génétique , Histone deacetylases/génétiqueRésumé
Phenylketonuria is an autosomal recessive disorder caused by a deficiency of phenylalanine hydroxylase. Transthyretin has been implicated as an indicator of nutritional status in phenylketonuria patients. In this study, we report that phenylalanine and its metabolite, phenylpyruvic acid, affect MAPK, changing transthyretin expression in a cell- and tissue-specific manner. Treatment of HepG2 cells with phenylalanine or phenylpyruvic acid decreased transcription of the TTR gene and decreased the transcriptional activity of the TTR promoter site, which was partly mediated through HNF4alpha. Decreased levels of p38 MAPK were detected in the liver of phenylketonuria-affected mice compared with wild-type mice. In contrast, treatment with phenylalanine increased transthyretin expression and induced ERK1/2 activation in PC-12 cells; ERK1/2 activation was also elevated in the brainstem of phenylketonuria-affected mice. These findings may explain between-tissue differences in gene expression, including Ttr gene expression, in the phenylketonuria mouse model.