Transcription profiling of rat pituitary organ cultures - GnRH-treated and control
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ABSTRACT: Rat pituitary organ cultures were treated with either GnRH at 10nM for 6 hours, or treated with control for 6 h, both groups in triplicate; samples were processed to generate total RNA, which were subsequently analyzed for gene expression using Affymetrix rat 230 2.0 arrays Experiment Overall Design: Comparison of gene expression profiles between GnRH-treated and control rat pituitary organ cultures
Project description:Rat pituitary organ cultures were treated with either GnRH at 10nM for 6 hours, or treated with control for 6 h, both groups in triplicate; samples were processed to generate total RNA, which were subsequently analyzed for gene expression using Affymetrix rat 230 2.0 arrays Keywords: rat pituitary organ culture treated vs control
Project description:Identifying the early gene program induced by GnRH would help understand how GnRH-activated signaling pathways modulate gonadotrope secretory response. We previously analyzed GnRH-induced early genes in LbT2 cells, however these lack GnRH self-potentiation, a physiological attribute of gonadotropes. To minimize cellular heterogeneity, rat primary pituitary cultures were enriched for gonadotropes by 40-60% using a sedimentation gradient. Given the limited number of gonadotropes, RNA was amplified prior to microarray analysis. Thirty-three genes were up-regulated 40 minutes after GnRH stimulation. Real-time PCR confirmed regulation of several transcripts including fosB, c-fos, egr-2 and rap1b, a small GTPase and member of the Ras family. GnRH stimulated rap1b gene expression in gonadotropes, measured by a sensitive single cell assay. Immunocytochemistry revealed increased Rap1 protein in GnRH-stimulated gonadotropes. These data establish rap1b as a novel gene rapidly induced by GnRH and a candidate to modulate gonadotropin secretion in rat gonadotropes. Primary rat gonadotrope cells were exposed to 10 nM GnRH for 40 min, then harvested and processed for RNA extraction using a Qiagen RNeasy mini kit (Qiagen, Valencia, CA). A total of 12 Affymetrix Rat Expression Array 230 v2.0, namely 6 GnRH-treated and 6 vehicle-treated samples, each containing 31,000 gene clusters, were used. Data analysis was performed by Affymetrix GeneChip Operating System (GCOS). A gene was considered to be up-regulated by GnRH if there is at least 50% concordance across multiple pairwise comparisons of GnRH- vs. vehicle-treated microarrays, and if the fold-change was at least 1.50.
Project description:Identifying the early gene program induced by GnRH would help understand how GnRH-activated signaling pathways modulate gonadotrope secretory response. We previously analyzed GnRH-induced early genes in LbT2 cells, however these lack GnRH self-potentiation, a physiological attribute of gonadotropes. To minimize cellular heterogeneity, rat primary pituitary cultures were enriched for gonadotropes by 40-60% using a sedimentation gradient. Given the limited number of gonadotropes, RNA was amplified prior to microarray analysis. Thirty-three genes were up-regulated 40 minutes after GnRH stimulation. Real-time PCR confirmed regulation of several transcripts including fosB, c-fos, egr-2 and rap1b, a small GTPase and member of the Ras family. GnRH stimulated rap1b gene expression in gonadotropes, measured by a sensitive single cell assay. Immunocytochemistry revealed increased Rap1 protein in GnRH-stimulated gonadotropes. These data establish rap1b as a novel gene rapidly induced by GnRH and a candidate to modulate gonadotropin secretion in rat gonadotropes.
Project description:Gonadotrophin-releasing hormone (GnRH) significantly inhibits proliferation of a proportion of cancer cell lines by activating GnRH receptor-G protein signaling. Therefore, manipulation of GnRH receptor signaling may have an under-utilized role in treating certain breast and ovarian cancers. However, the precise signaling pathways necessary for the effect and the features of cellular responses remain poorly defined. We used transcriptomic and proteomic profiling approaches to characterize the effects of GnRH receptor activation in sensitive cells (HEK293-GnRHR, SCL60) in in vitro and in vivo settings, compared to unresponsive HEK293. Analyses of gene expression demonstrated a dynamic SCL60 response to the GnRH super-agonist Triptorelin. Early and mid-phase changes (0.5-1.0 h) comprised mainly transcription factors. Later changes (8-24 h) included a GnRH target gene, CGA, and up or down-regulation of transcripts encoding signaling and cell division machinery. Pathway analysis exposed identified altered mitogen-activated protein kinase and cell cycle pathways, consistent with occurrence of G2/M arrest and apoptosis. NFκB pathway gene transcripts were differentially expressed between control and Triptorelin-treated SCL60 cultures. Reverse phase protein and phospho-proteomic array analyses profiled responses in cultured cells and SCL60 xenografts in vivo during Triptorelin anti-proliferation. Increased phosphorylated NFκB (p65) occurred in SCL60 in vitro, and p-NFκB and IκBε were higher in treated xenografts than controls after 4 days Triptorelin. NFκB inhibition enhanced the anti-proliferative effect of Triptorelin in SCL60 cultures. This study reveals details of pathways interacting with intense GnRH receptor signaling, identifies potential anti-proliferative target genes and implicates the NFκB survival pathway as a node for enhancing GnRH agonist-induced anti-proliferation. 55 samples: 35 SCL60 (15 Control, 20 Treated), 20 HEK293 (12 Control, 8 Treated). Samples collected after 0, 0.5, 1, 2, 8 or 24h after treatment with Triptorelin (100nM) or vehicle control (20% Propylene Glycol solution). SCL60 cells are HEK293 cells stably transfected with a high level of functional rat GnRHR.
Project description:Affymetrix gene expression profiling in cumulus cells (CC) retrieved from patients undergoing GnRH agonists and GnRH antagonists IVF treatment. Oocytes from three different maturity stages were considered: metaphase I oocytes (MI), nonfertilized metaphase II (MII) oocytes (MII-NF) and MII oocytes developed to blactocyst stage embryo (MII-BL). From 4 GnRH agonist treated patients, CC MI, CC MII-NF and CC MII-BL samples were collected; from 5 GnRH agonist and 6 GnRH antagonist treated patients, CC MII-NF and CC MII-BL samples were collected; and from 2 GnRH agonist and 4 GnRH antagonist treated patients, CC MI and CC MII-BL were collected. Altogether, 10 CC MI, 15 CC MII-NF and 21 CC MII-BL were collected and considered for transcriptome analysis.
Project description:Gonadotropin-releasing hormone (GnRH) governs reproduction in vertebrates by regulating pituitary gonadotropins. Zebrafish, however, is an exception as gnrh3–/– fish, which lack the hypophysiotropic GnRH3, are fertile, suggesting that zebrafish utilizes a Gnrh-independent mechanism to regulate reproduction. To elucidate the role of Gnrh3 and the Gnrh-independent mechanisms that regulate the pituitary gonadotropes, we profiled the gene expression in individual pituitary cells of wild-type and gnrh–/– adult female zebrafish and identified transcriptionally defined cell types. The classical Lh and Fsh gonadotropes expressed both gonadotropin beta subunits with a ratio of 13:1 (lhb:fshb) and 40:1 (fshb:lhb), respectively. We discovered that Lh gonadotropes predominantly express genes encoding receptors for Gnrh (gnrhr2), thyroid hormone, estrogen, dopamine, and steroidogenic factor 1 (SF1). No Gnrh receptor expression was enriched in Fsh gonadotropes, instead, the expression of cholecystokinin receptor (cckrb) and galanin receptor (gal1rb) were enriched in these cells. The hereditary loss of Gnrh3 gene resulted in downregulation of fshb in Lh gonadotropes. Likewise, targeted chemogenetic ablation of Gnrh3 neurons led to a decrease in the number of fshb+/lhb+ cells. Our studies suggest that Gnrh3 directly acts on Lh gonadotropes through Gnrhr2, but the outcome of this interaction is still unknown. Gnrh3 also regulates fshb expression, probably via a non-Gnrh receptor route. Altogether, while Lh secretion and synthesis are likely regulated by multiple factors in a Gnrh-independent manner, Gnrh3 seems to play a role in the cellular organization of the pituitary in zebrafish.
Project description:This SuperSeries is composed of the following subset Series:; GSE4028: Effects of diethylstilbestrol (DES) on the anterior pituitary gland of the ACI, Copenhagen and Brown Norway Rat. GSE4080: Effect of DES-treated Ept congenic rat lines on gene expression in the anterior pituitary gland. GSE4081: Expression QTL (eQTL) mapping in the anterior pituitary gland using DES-treated COPxACI F2 rats. Experiment Overall Design: Refer to individual Series
Project description:DRD2 agonists are effective in treating pituitary tumors. To fathom the β-arresin-dependent mechanisms underlying DRD2-mediated pituitary tumor growth suppression,we applied RNA-seq analysis to rat pituitary MMQ cells treated with a DRD2 β-arresin-biased agoinst, UNC9994.MMQ cells were treated with UNC9994(15μM) or vehecle control for 12 h or 24 h and then subject to RNA-seq analysis.We found oxidative-stress-related genes such as Nqo1 and Hmox1 were upregulated by UNC9994, revealing oxidative stress may be the basis of UNC9994-induced tumor growth suppression. Our study represents the first detailed analysis of transcriptomes in rat pituitary MMQ cells treated with DRD2 β-arresin-biased agonist.The significance of altered expression of specific transcripts will enhance our understanding of DRD2 signaling in pituitary tumor cells.
Project description:Mouse immortalized LbetaT2 gonadotrope cells treated with 100 nM GnRH for 2 h. GnRH treated LbetaT2 cells vs. untreated to assess whether GnRH regulates miRNA expression acutely. Treated and untreated RNA labeled independently then hybridized together to 2-color array. Duplicate arrays run with RNA from independent experiments.