Deletion of Gαq/11 or Gαs Proteins in Gonadotropes Differentially Affects Gonadotropin Production and Secretion in Mice.
Endocrinology
; 163(2)2022 02 01.
Article
em En
| MEDLINE
| ID: mdl-34864945
ABSTRACT
Gonadotropin-releasing hormone (GnRH) regulates gonadal function via its stimulatory effects on gonadotropin production by pituitary gonadotrope cells. GnRH is released from the hypothalamus in pulses and GnRH pulse frequency differentially regulates follicle-stimulating hormone (FSH) and luteinizing hormone (LH) synthesis and secretion. The GnRH receptor (GnRHR) is a G protein-coupled receptor that canonically activates Gαâq/11-dependent signaling on ligand binding. However, the receptor can also couple to Gαâs and in vitro data suggest that toggling between different G proteins may contribute to GnRH pulse frequency decoding. For example, as we show here, knockdown of Gαâs impairs GnRH-stimulated FSH synthesis at low- but not high-pulse frequency in a model gonadotrope-derived cell line. We next used a Cre-lox conditional knockout approach to interrogate the relative roles of Gαâq/11 and Gαâs proteins in gonadotrope function in mice. Gonadotrope-specific Gαâq/11 knockouts exhibit hypogonadotropic hypogonadism and infertility, akin to the phenotypes seen in GnRH- or GnRHR-deficient mice. In contrast, under standard conditions, gonadotrope-specific Gαâs knockouts produce gonadotropins at normal levels and are fertile. However, the LH surge amplitude is blunted in Gαâs knockout females and postgonadectomy increases in FSH and LH are reduced both in males and females. These data suggest that GnRH may signal principally via Gαâq/11 to stimulate gonadotropin production, but that Gαâs plays important roles in gonadotrope function in vivo when GnRH secretion is enhanced.
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MEDLINE
Assunto principal:
Cromograninas
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Subunidades alfa Gs de Proteínas de Ligação ao GTP
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Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP
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Gonadotrofos
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Gonadotropinas
Idioma:
En
Ano de publicação:
2022
Tipo de documento:
Article