NRF2 modulates aryl hydrocarbon receptor signaling: influence on adipogenesis.
Mol Cell Biol
; 27(20): 7188-97, 2007 Oct.
Article
en En
| MEDLINE
| ID: mdl-17709388
ABSTRACT
The NF-E2 p45-related factor 2 (NRF2) and the aryl hydrocarbon receptor (AHR) are transcription factors controlling pathways modulating xenobiotic metabolism. AHR has recently been shown to affect Nrf2 expression. Conversely, this study demonstrates that NRF2 regulates expression of Ahr and subsequently modulates several downstream events of the AHR signaling cascade, including (i) transcriptional control of the xenobiotic metabolism genes Cyp1a1 and Cyp1b1 and (ii) inhibition of adipogenesis in mouse embryonic fibroblasts (MEFs). Constitutive expression of AHR was affected by Nrf2 genotype. Moreover, a pharmacological activator of NRF2 signaling, CDDO-IM {1-[2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oyl]imidazole}, induced Ahr, Cyp1a1, and Cyp1b1 transcription in Nrf2+/+ MEFs but not in Nrf2-/- MEFs. Reporter analysis and chromatin immunoprecipitation assay revealed that NRF2 directly binds to one antioxidant response element (ARE) found in the -230-bp region of the promoter of Ahr. Since AHR negatively controls adipocyte differentiation, we postulated that NRF2 would inhibit adipogenesis through the interaction with the AHR pathway. Nrf2-/- MEFs showed markedly accelerated adipogenesis upon stimulation, while Keap1-/- MEFs (which exhibit higher NRF2 signaling) differentiated slowly compared to their congenic wild-type MEFs. Ectopic expression of Ahr and dominant-positive Nrf2 in Nrf2-/- MEFs also substantially delayed differentiation. Thus, NRF2 directly modulates AHR signaling, highlighting bidirectional interactions of these pathways.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Transducción de Señal
/
Regulación de la Expresión Génica
/
Receptores de Hidrocarburo de Aril
/
Factor 2 Relacionado con NF-E2
/
Adipogénesis
Límite:
Animals
Idioma:
En
Revista:
Mol Cell Biol
Año:
2007
Tipo del documento:
Article
País de afiliación:
Estados Unidos