RESUMEN
Increased cortisol levels in humans are often observed in patients suffering from mood disorders. In this study human fetal brain aggregates were exposed to cortisol at 500 nM for 3 weeks, as an in-vitro model of chronic cortisol exposure. Microarray analysis on extracted mRNA using the Affymetrix U133A platform was then performed. Our results demonstrated a significant effect of cortisol on 1648 transcripts; 736 up-regulated and 912 down-regulated genes. The most differentially regulated biological categories were: RNA processing, protein metabolism, and cell growth. Within these categories we observed a down-regulation of fibroblast growth factor 2 (FGF2) (-1.5-fold) and aquaporin4 (AQP4) (-1.7-fold), alongside an up-regulation of fibroblast growth factor 9 (FGF9) (+1.7-fold) and vesicle associated membrane protein2 (VAMP2) (+1.7-fold). FGF2, FGF9, AQP4 and VAMP2 changes were confirmed at the protein level by immunohistochemistry. Alterations in FGF transcripts are in keeping with recent literature demonstrating such effects in patients with mood disorders.
Asunto(s)
Encéfalo/metabolismo , Hidrocortisona/metabolismo , Sistema Hipotálamo-Hipofisario/fisiopatología , Trastornos del Humor/metabolismo , Proteínas del Tejido Nervioso/genética , Estrés Psicológico/metabolismo , Encéfalo/efectos de los fármacos , Encéfalo/fisiopatología , Células Cultivadas , Perfilación de la Expresión Génica , Regulación de la Expresión Génica/efectos de los fármacos , Regulación de la Expresión Génica/genética , Sustancias de Crecimiento/genética , Humanos , Hidrocortisona/farmacología , Sistema Hipotálamo-Hipofisario/metabolismo , Proteínas de la Membrana/genética , Trastornos del Humor/genética , Trastornos del Humor/fisiopatología , Análisis de Secuencia por Matrices de Oligonucleótidos , ARN Mensajero/efectos de los fármacos , ARN Mensajero/metabolismo , Estrés Psicológico/genética , Estrés Psicológico/fisiopatología , Activación Transcripcional/efectos de los fármacos , Activación Transcripcional/genéticaRESUMEN
The kinetics of global changes in transcription patterns during competence development in Streptococcus pneumoniae was analysed with high-density arrays. Four thousand three hundred and one clones of a S. pneumoniae library, covering almost the entire genome, were amplified by PCR and gridded at high density onto nylon membranes. Competence was induced by the addition of CSP (competence stimulating peptide) to S. pneumoniae cultures grown to the early exponential phase. RNA was extracted from samples at 5 min intervals (for a period of 30 min) after the addition of CSP. Radiolabelled cDNA was generated from isolated total RNA by random priming and the probes were hybridized to identical high density arrays. Genes whose transcription was induced or repressed during competence were identified. Most of the genes previously known to be competence induced were detected together with several novel genes that all displayed the characteristic transient kinetics of competence-induced genes. Among the newly identified genes many have suggested functions compatible with roles in genetic transformation. Some of them may represent new members of the early or late competence regulons showing competence specific consensus sequences in their promoter regions. Northern experiments and mutational analysis were used to confirm some of the results.
