GnRH-induced PACAP and PAC1 receptor expression in pituitary gonadotrophs: A possible role in the regulation of gonadotropin subunit gene expression
GnRH-induced PACAP and PAC1 receptor expression in pituitary gonadotrophs: A possible role in the regulation of gonadotropin subunit gene expression
复制标题
DOI：
10.1016/j.peptides.2010.05.012
复制
发表时间：
2010-09-01
期刊：
影响因子：
3
通讯作者：
Miyazaki, Kohji
中科院分区：
文献类型：
--
作者：
Purwana, Indri N.;Kanasaki, Haruhiko;Miyazaki, Kohji
我们使用促性腺激素细胞系L β T2检测促性腺激素释放激素（GnRH）刺激后垂体腺苷酸环化酶激活多肽（PACAP）和PACAP 1型受体（PAC 1-R）mRNA的表达。在静止培养中，GnRH刺激增加PACAP和PAC 1-R mRNA的表达。用PAC 1-R表达载体转染后PAC 1-R细胞表面密度的增加显著增加了100 nM PACAP刺激后促性腺激素LH β和FSH β亚基启动子的活性。此外，在PAC-1 R过表达细胞中，PACAP刺激浓度的增加增强了LH β和FSH β的启动子活性。在具有PAC 1-R的细胞中，在存在PACAP的情况下，GnRH的作用进一步增强，LH β和FSH β亚基分别从5.31 +/- 0.93倍增强至9.89 +/- 0.38倍;从单独GnRH的2.58 +/- 0.31倍增强至PACAP的10.90 +/- 2.79倍。GnRH和PACAP联合处理不增加GnRH单独诱导的ERK磷酸化。PACAP增加了cAMP的积聚，并且在存在GnRH的情况下，这种作用显着减弱。在灌流培养中，较低频率的GnRH脉冲（每120分钟）后，PACAP基因表达更为突出。我们的研究结果表明，PACAP和PAC 1-R产生的促性腺激素细胞内的GnRH刺激。随后以自分泌方式影响促性腺激素细胞，并调节促性腺激素亚单位的GnRH脉冲依赖性特异性调节。(C)2010年爱思唯尔公司All rights reserved.
We examined the expression of pituitary adenylate cyclase-activating polypeptide (PACAP) and the PACAP type 1 receptor (PAC1-R) mRNA following gonadotropin-releasing hormone (GnRH) stimulation using the gonadotroph cell line L beta T2. GnRH stimulation increased PACAP and PAC1-R mRNA expression in a static culture. Increase in the cell surface density of the PAC1-R following transfection with PAC1-R expression vectors significantly increased gonadotropin LH beta and FSH beta subunit promoter activities following 100 nM PACAP stimulation. In addition, increasing concentrations of PACAP stimulation augmented the promoter activities for both LH beta and FSH beta in PAC-1R overexpressing cells. In the cells with PAC1-R, the effect of GnRH was further potentiated in the presence of PACAP from 5.31 +/- 0.93 to 9.89 +/- 0.38-fold for LH beta and for FSH beta subunit, respectively; from 2.58 +/- 0.31-fold by GnRH alone to 10.90 +/- 2.79-fold with PACAP. The combination treatment with GnRH and PACAP did not augment the ERK phosphorylation induced by GnRH alone. PACAP expectedly increased cAMP accumulation and this effect was significantly attenuated in the presence of GnRH. PACAP gene expression was more prominent following lower frequency GnRH pulses (every 120 min) in a perifused culture. Our results suggest that PACAP and PAC1-R are produced locally within the gonadotrophs following GnRH stimulation. They subsequently affect the gonadotrophs in an autocrine manner and modulate the GnRH pulse-dependent specific regulation of gonadotropin subunits. (C) 2010 Elsevier Inc. All rights reserved.