Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 2 de 2
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Mol Cell Biol ; 28(5): 1770-82, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18172011

RESUMO

The progesterone receptor (PR) plays a critical role during ovulation. Mice lacking the PR gene are anovulatory due to a failure in the rupture of the preovulatory follicles. The pathways that operate downstream of PR to control ovulation are poorly understood. Using gene expression profiling, we identified peroxisome proliferator-activated receptor gamma (PPARgamma) as a target of regulation by PR in the granulosa cells of the preovulatory follicles during the ovulatory process. To investigate the function of PPARgamma during ovulation, we created a conditional knockout mouse in which this gene was deleted via Cre-Lox-mediated excision in granulosa cells. When these mutant mice were subjected to gonadotropin-induced superovulation, the preovulatory follicles failed to rupture and the number of eggs released from the mutant ovaries declined drastically. Gene expression analysis identified endothelin-2, interleukin-6, and cyclic GMP-dependent protein kinase II as novel targets of regulation by PPARgamma in the ovary. Our studies also suggested that cycloxygenase 2-derived metabolites of long-chain fatty acids function as endogenous activating ligands of PPARgamma in the preovulatory follicles. Collectively, these studies revealed that PPARgamma is a key mediator of the biological actions of PR in the granulosa cells and activation of its downstream pathways critically controls ovulation.


Assuntos
Folículo Ovariano/metabolismo , Ovulação/fisiologia , PPAR gama/metabolismo , Progesterona/fisiologia , Anilidas/farmacologia , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Células Cultivadas , Colforsina/farmacologia , Meios de Cultura Livres de Soro , Relação Dose-Resposta a Droga , Feminino , Deleção de Genes , Perfilação da Expressão Gênica , Gonadotropinas/farmacologia , Células da Granulosa/metabolismo , Antagonistas de Hormônios/farmacologia , Imuno-Histoquímica , Hibridização In Situ , Indometacina/farmacologia , Camundongos , Camundongos Knockout , Mifepristona/farmacologia , Modelos Genéticos , Nitrobenzenos/farmacologia , Ovário/metabolismo , Ovulação/efeitos dos fármacos , PPAR gama/genética , Receptores de Progesterona/genética , Receptores de Progesterona/metabolismo , Sulfonamidas/farmacologia , Acetato de Tetradecanoilforbol/farmacologia , Fatores de Tempo
2.
Mol Endocrinol ; 20(11): 2784-95, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16887885

RESUMO

The steroid hormone progesterone (P) plays a pivotal role during ovulation. Mice lacking P receptor (Pgr) gene fail to ovulate due to a defect in follicular rupture. The P receptor (PGR)-regulated pathways that modulate ovulation, however, remain poorly understood. To identify these pathways, we performed gene expression profiling using ovaries from mice subjected to gonadotropin-induced superovulation in the presence and in the absence of CDB-2914, a synthetic PGR antagonist. Prominent among the genes that were down-regulated in response to CDB-2914 was endothelin (ET)-2, a potent vasoactive molecule. ET-2 mRNA was transiently induced in mural granulosa cells of the preovulatory follicles immediately preceding ovulation. This induction was absent in the ovaries of PGR null mice, indicating a critical role of this receptor in ET-2 expression. To investigate the functional role of ET-2 during ovulation, we employed selective antagonists of endothelin receptors, ETR-A and ETR-B. Mice treated with an ETR-B antagonist exhibited a dramatic (>85%) decline in the number of released oocytes. Strong expression of ETR-B was observed in the mural and cumulus granulosa cells of the preovulatory follicles as well as in the capillaries lining the inner border of the theca interna. We also identified cGMP-dependent protein kinase II, a previously reported PGR-regulated gene, as a downstream target of ET-2 during ovulation. Collectively, our studies uncovered a unique pathway in which ET-2, produced by PGR in mural granulosa cells, acts in a paracrine or autocrine manner on multiple cell types within the preovulatory follicle to control the final events leading to its rupture.


Assuntos
Endotelina-2/fisiologia , Ovulação/fisiologia , Receptor de Endotelina B/fisiologia , Receptores de Endotelina/fisiologia , Receptores de Progesterona/fisiologia , Animais , Antagonistas do Receptor de Endotelina B , Antagonistas dos Receptores de Endotelina , Endotelina-2/metabolismo , Feminino , Células da Granulosa/metabolismo , Camundongos , Camundongos Knockout , Modelos Biológicos , Norpregnadienos/administração & dosagem , Folículo Ovariano/metabolismo , Ovário/citologia , Ovário/efeitos dos fármacos , Ovário/metabolismo , Ovulação/efeitos dos fármacos , Progestinas/antagonistas & inibidores , RNA Mensageiro/metabolismo , Receptor de Endotelina B/metabolismo , Receptores de Endotelina/metabolismo , Receptores de Progesterona/genética , Transdução de Sinais/fisiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...