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Gonadotropin-releasing hormone positively regulates steroidogenesis via extracellular signal-regulated kinase in rat Leydig cells.
Yao, Bing; Liu, Hai-Yan; Gu, Yu-Chun; Shi, Shan-Shan; Tao, Xiao-Qian; Li, Xiao-Jun; Ge, Yi-Feng; Cui, Ying-Xia; Yang, Guo-Bin.
Afiliação
  • Yao B; Department of Reproduction and Genetics, Nanjing Jingling Hospital, Nanjing 210002, China.
Asian J Androl ; 13(3): 438-45, 2011 May.
Article em En | MEDLINE | ID: mdl-21441942
Gonadotropin-releasing hormone (GnRH) is secreted from neurons within the hypothalamus and is necessary for reproductive function in all vertebrates. GnRH is also found in organs outside of the brain and plays an important role in Leydig cell steroidogenesis in the testis. However, the signalling pathways mediating this function remain largely unknown. In this study, we investigated whether components of the mitogen-activated protein kinase (MAPK) pathways are involved in GnRH agonist (GnRHa)-induced testis steroidogenesis in rat Leydig cells. Primary cultures of rat Leydig cells were established. The expression of 3ß-hydroxysteroid dehydrogenase (3ß-HSD) and the production of testosterone in response to GnRHa were examined at different doses and for different durations by RT-PCR, Western blot analysis and radioimmunoassay (RIA). The effects of GnRHa on ERK1/2, JNK and p38 kinase activation were also investigated in the presence or absence of the MAPK inhibitor PD-98059 by Western blot analysis. GnRHa induced testosterone production and upregulated 3ß-HSD expression at both the mRNA and protein levels; it also activated ERK1/2, but not JNK and p38 kinase. Although the maximum effects of GnRHa were observed at a concentration of 100 nmnol L⁻¹ after 24 h, activation of ERK1/2 by GnRHa reached peak at 5 min and it returned to the basal level within 60 min. PD-98059 completely blocked the activation of ERK1/2, the upregulation of 3ß-HSD and testosterone production. Our data show that GnRH positively regulates steroidogenesis via ERK signalling in rat Leydig cells. ERK1/2 activation by GnRH may be responsible for the induction of 3ß-HSD gene expression and enzyme production, which may ultimately modulate steroidogenesis in rat Leydig cells.
Assuntos

Texto completo: 1 Base de dados: MEDLINE Assunto principal: Hormônio Liberador de Gonadotropina / MAP Quinases Reguladas por Sinal Extracelular / Células Intersticiais do Testículo Limite: Animals Idioma: En Ano de publicação: 2011 Tipo de documento: Article

Texto completo: 1 Base de dados: MEDLINE Assunto principal: Hormônio Liberador de Gonadotropina / MAP Quinases Reguladas por Sinal Extracelular / Células Intersticiais do Testículo Limite: Animals Idioma: En Ano de publicação: 2011 Tipo de documento: Article