RESUMEN
Recent reports have demonstrated that mice lacking the transcription factor Cited2 die in utero showing various cardiac malformations. We present for the first time functionally relevant mutations of CITED2 in patients with congenital heart defects (CHDs). CITED2 encodes a CREBBP/EP300 interacting transcriptional modulator of HIF1A and TFAP2. To study the potential impact of sequence variations in CITED2 for CHDs in humans, we screened a cohort of 392 well-characterized patients and 192 control individuals using DHPLC, sequencing, and Amplifluor genotyping techniques. We identified 15 CITED2 nucleotide alterations. Seven of these alterations were found only in CHD patients and were not detected in controls, including three mutations leading to alterations of the amino acid sequence (p.Ser170_Gly178del, p.Gly178_Ser179ins9, and p.Ser198_Gly199del). All three of these amino acid changing mutations cluster in the serine-glycine-rich junction of the protein, to which no functionality had heretofore been assigned. Here we show that these mutations significantly reduce the capacity of CITED2 to transrepress HIF1A, and that the p.Ser170_Gly178del mutation significantly diminishes TFAP2C coactivation. This reveals a modifying role for the serine-glycine-rich region in CITED2 function. In summary, the observation of these mutations in patients with septal defects indicates that CITED2 has a causative impact in the development of CHD in humans.
Asunto(s)
Proteínas de Unión al ADN/genética , Cardiopatías Congénitas/genética , Mutación , Proteínas Represoras/genética , Transactivadores/genética , Secuencia de Aminoácidos , Línea Celular , Estudios de Cohortes , Proteínas de Unión al ADN/metabolismo , Proteínas de Unión al ADN/fisiología , Regulación de la Expresión Génica , Frecuencia de los Genes , Pruebas Genéticas , Haplotipos , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Fenotipo , Polimorfismo de Nucleótido Simple , Proteínas Recombinantes de Fusión/análisis , Proteínas Represoras/metabolismo , Proteínas Represoras/fisiología , Transactivadores/metabolismo , Transactivadores/fisiología , Factor de Transcripción AP-2/genética , Factor de Transcripción AP-2/metabolismoRESUMEN
BACKGROUND: We present the first genome-wide cDNA array analysis of human congenitally malformed hearts and attempted to partially elucidate these complex phenotypes. Most congenital heart defects, which account for the largest number of birth defects in humans, represent complex genetic disorders. As a consequence of the malformation, abnormal hemodynamic features occur and cause an adaptation process of the heart. METHODS AND RESULTS: The statistical analysis of our data suggests distinct gene expression profiles associated with tetralogy of Fallot, ventricular septal defect, and right ventricular hypertrophy. Applying correspondence analysis, we could associate specific gene functions to specific phenotypes. Furthermore, our study design allows the suggestion that alterations associated with primary genetic abnormalities can be distinguished from those associated with the adaptive response of the heart to the malformation (right ventricular pressure overload hypertrophy). We provide evidence for the molecular transition of the hypertrophic right ventricle to normal left ventricular characteristics. Furthermore, we present data on chamber-specific gene expression. CONCLUSIONS: Our findings propose that array analysis of malformed human hearts opens a new window to understand the complex genetic network of cardiac development and adaptation. For detailed access, see the online-only Data Supplement.
Asunto(s)
Perfilación de la Expresión Génica , Genoma , Cardiopatías Congénitas/genética , Análisis de Secuencia por Matrices de Oligonucleótidos , Adaptación Fisiológica , Análisis por Conglomerados , Defectos del Tabique Interventricular/genética , Humanos , Hipertrofia Ventricular Derecha/genética , Análisis Multivariante , Fenotipo , Valores de Referencia , Tamaño de la Muestra , Tetralogía de Fallot/genéticaRESUMEN
BACKGROUND: Motivated by a biomedical database set up by our group, we aimed to develop a generic database front-end with embedded knowledge discovery and analysis features. A major focus was the human-oriented representation of the data and the enabling of a closed circle of data query, exploration, visualization and analysis. RESULTS: We introduce a non-task-specific database front-end with a new visualization strategy and built-in analysis features, so called d-matrix. d-matrix is web-based and compatible with a broad range of database management systems. The graphical outcome consists of boxes whose colors show the quality of the underlying information and, as the name suggests, they are arranged in matrices. The granularity of the data display allows consequent drill-down. Furthermore, d-matrix offers context-sensitive categorization, hierarchical sorting and statistical analysis. CONCLUSIONS: d-matrix enables data mining, with a high level of interactivity between humans and computer as a primary factor. We believe that the presented strategy can be very effective in general and especially useful for the integration of distinct data types such as phenotypical and molecular data.