Functional potentiation of leptin-signal transducer and activator of transcription 3 signaling by the androgen receptor.
Endocrinology
; 149(12): 6028-36, 2008 Dec.
Article
em En
| MEDLINE
| ID: mdl-18703637
ABSTRACT
Hypogonadism is associated with increased fat mass and dysregulation of metabolic homeostasis in men. Our previous study revealed that androgen receptor (AR)-null male mice (ARL-/Y) develop late-onset obesity and are leptin-resistant. The present study evaluated how hypothalamic AR contributes to central leptin-signal transducer and activator of transcription 3 (STAT3) signaling. We evaluated leptin action in wild-type and ARL-/Y mice, the anatomic co-relationship between AR and leptin signaling in the hypothalamus, and the effects of AR on leptin-mediated STAT3 transactivation and nuclear translocation. AR deletion in male mice results in a weaker leptin-induced suppression of food intake and body weight drop even before the onset of overt obesity. In wild-type male but not female mice, AR was highly expressed in various hypothalamic nuclei that also expressed the long-form leptin receptor (OBRB) and co-resided with OBRB directly in the arcuate neurons. In vitro, AR significantly enhanced STAT3-mediated transcription of leptin target genes including POMC and SOCS3. This effect relied on the AR N-terminal activation function-1 (AF-1) domain and was specific to AR in that none of the other sex steroid hormone receptors tested showed similar effects. AR enhanced the low concentrations of leptin-induced STAT3 nuclear translocation in vitro, and ARL-/Y mice receiving leptin had impaired STAT3 nuclear localization in the arcuate neurons. These findings indicate that AR in the hypothalamus functions as a regulator of central leptin-OBRB-STAT3 signaling and has a physiological role in energy homeostasis and metabolic regulation in male mice.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Transdução de Sinais
/
Receptores Androgênicos
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Leptina
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Fator de Transcrição STAT3
Limite:
Animals
Idioma:
En
Ano de publicação:
2008
Tipo de documento:
Article