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El control de la expresión génica del páncreas y el hígado por los factores de transcripción HNF
Duncan T Odom1, Nora Zizlsperger, D Benjamin Gordon
1Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, MA 02142, USA.
Science (New York, N.Y.)
|February 28, 2004
Resumen
Los investigadores mapearon los reguladores genéticos clave en las células del hígado y el páncreas. Esto revela cómo los factores de transcripción como HNF1alfa, HNF4alfa y HNF6 controlan la diversidad de tejidos y pueden vincular HNF4alfa a la diabetes tipo 2.
Área de la Ciencia:
- La genómica es la genómica.
- Biología Molecular Biología Molecular
- Endocrinología Endocrinología.
Sus antecedentes:
- La diversidad de tejidos humanos surge de complejas redes reguladoras transcripcionales que no se comprenden completamente.
- La identificación de los factores clave de transcripción y sus objetivos es crucial para comprender la expresión génica específica de los tejidos.
Objetivo del estudio:
- Identificar sistemáticamente los genes regulados por HNF1alpha, HNF4alpha y HNF6 en el hígado humano y los islotes pancreáticos.
- Para dilucidar los circuitos reguladores específicos del tejido gobernados por estos factores maestros de transcripción.
- Para explorar el papel potencial de la desregulación de HNF4alfa en la diabetes tipo 2.
Principales métodos:
- La inmunoprecipitación de cromatina (ChIP, por sus siglas en inglés) se empleó para identificar regiones de ADN unidas por factores de transcripción específicos.
- Los microarrays promotores se utilizaron junto con ChIP para identificar genes diana en el hígado humano y las células de los islotes pancreáticos.
- También se evaluó la ocupación de la ARN polimerasa II para mapear la maquinaria transcripcional activa.
Principales resultados:
- Se generó un mapa completo de los genes ocupados por HNF1alpha, HNF4alpha y HNF6 para los islotes hepáticos y pancreáticos.
- Se identificaron circuitos reguladores específicos de los tejidos que involucran estos factores de transcripción y otros cofactores.
- Se confirmó que estos factores funcionan como reguladores maestros que controlan la transcripción génica específica de los hepatocitos y los islotes.
Conclusiones:
- El estudio proporciona nuevos conocimientos sobre los circuitos de transcripción que rigen el desarrollo y la función del hígado humano y los islotes pancreáticos.
- Las redes reguladoras identificadas destacan las funciones críticas de HNF1alpha, HNF4alpha y HNF6 en el mantenimiento de la identidad del tejido.
- La evidencia sugiere un vínculo mecánico entre la desregulación de HNF4alpha y la patogénesis de la diabetes tipo 2.
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