Dataset Information

Modulation of gonadotropin-releasing hormone-induced extracellular signal-regulated kinase activation by dual-specificity protein phosphatase 1 in LbetaT2 gonadotropes.

ABSTRACT: As the regulator of pituitary reproductive hormone synthesis, the hypothalamic neuropeptide GnRH is the central regulator of reproduction. A hallmark of GnRH action is the differential control of gene expression in pituitary gonadotropes through varied pulsatile stimulation. Among other signaling events, GnRH activation of the ERK family of MAPKs plays a significant role in the transcriptional regulation of the luteinizing hormone ?-subunit gene and regulation of cap-dependent translation. We evaluated the ERK response to different GnRH pulse amplitudes in the gonadotrope cell line L?T2. We found that low-amplitude stimulation with GnRH invokes a rapid and transient ERK activation, whereas high-amplitude stimulation invokes a prolonged activation specifically in the cytoplasm fraction of L?T2 cells. Nuclear and cytoplasmic targets of ERK, Ets-like gene 1, and eukaryotic initiation factor 4E, respectively, are similarly activated. Feedback control of ERK activation occurs mainly through the dual-specificity protein phosphatases (DUSPs). DUSP1 is localized to the nucleus in L?T2 cells but DUSP4, another member implicated in GnRH feedback, exists in both the nucleus and cytoplasm. Manipulation of nuclear DUSP activity through overexpression or knockdown of Dusp1 modulates the ERK response to low and high GnRH pulse amplitudes and activation of the Lhb promoter. Dusp1 overexpression abolishes sustained ERK activation and inhibits Lhb promoter activity induced by high amplitude pulses. Conversely, Dusp1 knockdown enhances ERK activation by low-amplitude stimulation and increases stimulation of Lhb promoter activity. We conclude that DUSP1 feedback activity modulates ERK activation and the transcriptional response to GnRH.

SUBMITTER: Nguyen KA

PROVIDER: S-EPMC2946148 | biostudies-literature | 2010 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Modulation of gonadotropin-releasing hormone-induced extracellular signal-regulated kinase activation by dual-specificity protein phosphatase 1 in LbetaT2 gonadotropes.

Nguyen Kathryn A KA Intriago Rachel E RE Upadhyay Hiral C HC Santos Sharon J SJ Webster Nicholas J G NJ Lawson Mark A MA

Endocrinology 20100804 10

As the regulator of pituitary reproductive hormone synthesis, the hypothalamic neuropeptide GnRH is the central regulator of reproduction. A hallmark of GnRH action is the differential control of gene expression in pituitary gonadotropes through varied pulsatile stimulation. Among other signaling events, GnRH activation of the ERK family of MAPKs plays a significant role in the transcriptional regulation of the luteinizing hormone β-subunit gene and regulation of cap-dependent translation. We ev ...[more]

PMID: 20685880

Similar Datasets

Project description:BACKGROUND:The main objective of the present work was to compare the effects of the gonadotropin-releasing hormone agonist (GnRH-a) and GnRH antagonist (GnRH-ant) on the gene expression profiles of oocytes obtained from Iranian infertile couples undergoing in vitro fertilization (IVF). METHODS:Fifty infertile couples who underwent IVF between June 2012 and November 2013 at the Infertility Center of Tehran Women General Hospital, Tehran University of Medical Sciences, were included in this study. We included women that had undergone IVF treatment because of male factor, tubal factor, or unexplained infertility. The women randomly underwent controlled ovarian stimulation (COS) with either the GnRH-a (n = 26) or the GnRH-ant (n = 24). We obtained 50 germinal vesicle (GV) oocytes donated by women in each group. After the sampling, pool of 50 GV oocytes for each group was separately analyzed by quantitative polymerase chain reaction (qPCR). RESULT:The expression levels of Adenosine triphosphatase 6 (ATPase 6), Bone morphogenetic protein 15 (BMP15), and Neuronal apoptosis inhibitory protein (NAIP) genes were significantly upregulated in the GnRH-ant group compared to the GnRH-a group, with the fold change of 3.990 (SD ± 1.325), 6.274 (SD ± 1.542), and 2.156 (SD ± 1.443), respectively, (P < 0.001). Growth differentiation factor 9 (GDF9) mRNA did not have any expression in the GnRH-a group; however, GDF9 mRNA was expressed in the GnRH-ant group. Finally, it was found that the genes involved in the DNA repairing and cell cycle checkpoint did not have any expression in either group. CONCLUSION:The present study showed, for the first time, the expression levels of genes involved in the cytoplasmic maturity (BMP15, GDF9), adenosine triphosphate production (ATPase 6), and antiapoptotic process (NAIP), in human GV oocytes were significantly higher in the GnRH-anta group than in the GnRH-a group in COS. Higher expression level of these genes when GnRH-ant protocol is applied, this protocol seems to be a more appropriate choice for women with poly cystic ovarian syndrome, because it can probably improve the expression of the aforementioned genes. TRIAL REGISTRATION:Current Controlled Trials: IRCT 2014031112307 N3.

Dataset Information

Modulation of gonadotropin-releasing hormone-induced extracellular signal-regulated kinase activation by dual-specificity protein phosphatase 1 in LbetaT2 gonadotropes.

Publications

Modulation of gonadotropin-releasing hormone-induced extracellular signal-regulated kinase activation by dual-specificity protein phosphatase 1 in LbetaT2 gonadotropes.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure