Gonadotropin-releasing hormone 3 and gonadotropes relationships in female zebrafish pituitary revealed by single-cell transcriptomics
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PROVIDER: PRJNA1138768 | ENA |
REPOSITORIES: ENA
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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.
2024-11-20 | GSE272806 | GEO
Project description:Background: Gonadotropin-releasing hormone (GnRH) neurons play a pivotal role in regulation of the hypothalamic-pituitary gonadal axis in a sex-specific manner. We hypothesized that the differences seen in reproductive functions of males and females are associated with a sexually dimorphic gene expression profile of GnRH neurons. Methods and Results: We compared the transcriptome of GnRH neurons obtained from intact, metestrous female and male GnRH-GFP transgenic mice. About 1500 individual GnRH neurons from each sex were sampled with laser capture microdissection followed by whole transcriptome amplification for gene expression profiling. Under stringent selection criteria (fold change > 1.6, adjusted p-value 0.01), Affymetrix Mouse Genome 430 PM array analysis identified 543 differentially expressed genes. Sexual dimorphism was most apparent in gene clusters associated with synaptic communication, signal transduction, cell adhesion, vesicular transport and cell metabolism. To validate microarray results, 57 genes were selected and 91% of their differential expression was confirmed by real-time PCR. Similarly, 88% of microarray results were confirmed with PCR from independent samples obtained by patch pipette harvesting and pooling of 30 GnRH neurons from each sex. We found significant differences in expression of genes involved in vesicle priming and docking (Syt1, Cplx1), GABAergic (Gabra3, Gabrb3, Gabrg2) and glutamatergic (Gria1, Grin1, Slc17a6) neurotransmission, peptide signaling (Sstr3, Npr2, Cxcr4) and the regulation of intracellular ion homeostasis (Cacna1, Cacnb1, Cacng5, Kcnq2, Kcnc1). Conclusion: The striking sexual dimorphism of the GnRH neuron transcriptome we report here contributes to the better understanding the differences in cellular mechanisms of GnRH neurons in the two sexes.
2021-01-18 | GSE66806 | GEO
Project description:Acquisition of a mature pattern of gonadotropin-releasing hormone (GnRH) secretion from the CNS is a hallmark of the pubertal process. Little is known about GnRH release during sexual maturation, but it is assumed to be minimal before later stages of puberty. We studied spontaneous GnRH secretion in brain slices from male mice during perinatal and postnatal development using fast-scan cyclic voltammetry (FSCV) to detect directly the oxidation of secreted GnRH. There was good correspondence between the frequency of GnRH release detected by FSCV in the median eminence of slices from adults with previous reports of in vivo luteinizing hormone (LH) pulse frequency. The frequency of GnRH release in the late embryonic stage was surprisingly high, reaching a maximum in newborns and remaining elevated in 1-week-old animals despite low LH levels. Early high-frequency GnRH release was similar in wild-type and kisspeptin knock-out mice indicating that this release is independent of kisspeptin-mediated excitation. In vivo treatment with testosterone or in vitro treatment with gonadotropin-inhibitory hormone (GnIH) reduced GnRH release frequency in slices from 1-week-old mice. RF9, a putative GnIH antagonist, restored GnRH release in slices from testosterone-treated mice, suggesting that testosterone inhibition may be GnIH-dependent. At 2-3 weeks, GnRH release is suppressed before attaining adult patterns. Reduction in early life spontaneous GnRH release frequency coincides with the onset of the ability of exogenous GnRH to induce pituitary LH secretion. These findings suggest that lack of pituitary secretory response, not lack of GnRH release, initially blocks downstream activation of the reproductive system.
| S-EPMC4220034 | biostudies-literature
Project description:NR5A1 is expressed in the pituitary gonadotropes and regulates their functional differentiation. In this study, transcriptomes of the pituitary gonadotropes which are sorted from Ad4BP-BAC-EGFP mice were revealed in males and females.
2022-10-28 | GSE216466 | GEO
Project description:Regulatory Architecture of the LβT2 Gonadotrope Cell Underlying the Response to Gonadotropin-Releasing Hormone
| PRJNA397847 | ENA
Project description:The LβT2 mouse pituitary cell line has many characteristics of a mature gonadotrope and is a widely used model system for studying developmental processes and the response to gonadotropin-releasing hormone (GnRH). The global epigenetic landscape, which contributes to cell-specific gene regulatory mechanisms, and the single-cell transcriptome response variation of LβT2 cells have not been previously investigated. Here, we integrate the transcriptome and genome-wide chromatin accessibility state of LβT2 cells during GnRH stimulation. Additionally, we examine cell-to-cell variability in the transcriptional response to GnRH using gel-in-emulsion Drop-seq technology. Analysis of a bulk RNA-seq dataset obtained 45 minutes after exposure to either GnRH or vehicle identified 112 transcripts that were regulated > 4-fold by GnRH (FDR < 0.05). The top regulated transcripts constitute, as determined by Bayesian massive public data integration analysis, a human pituitary-relevant coordinated gene program. Chromatin accessibility (ATAC-seq) datasets generated from GnRH-treated LβT2 cells identified more than 58,000 open chromatin regions, some containing notches consistent with bound transcription factor footprints. Study of the most prominent open regions showed that 75% were in transcriptionally active promoters or introns, supporting their involvement in active transcription. Lhb, Cga, and Egr1 showed significantly open chromatin over their promoters. While Fshb was closed over its promoter, several discrete significantly open regions were found at -40 to -90 kb, which may represent novel upstream enhancers. Chromatin accessibility determined by ATAC-seq was associated with high levels of gene expression determined by RNA-seq. We obtained high quality single-cell gel-in-emulsion Drop-seq transcriptome data, with an average of >4000 expressed genes/cell, from 1992 vehicle- and 1889 GnRH-treated cells. While the individual cell expression patterns showed high cell-to-cell variation, representing both biological and measurement variation, the average expression patterns correlated well with bulk RNA-seq data. Computational assignment of each cell to its precise cell cycle phase showed that the response to GnRH was unaffected by cell cycle. To our knowledge, this study represents the first genome-wide epigenetic and single-cell transcriptomic characterization of this important gonadotrope model. The data have been deposited publicly and should provide a resource for hypothesis generation and further study.
2018-02-15 | GSE102396 | GEO
Project description:The LβT2 mouse pituitary cell line has many characteristics of a mature gonadotrope and is a widely used model system for studying developmental processes and the response to gonadotropin-releasing hormone (GnRH). The global epigenetic landscape, which contributes to cell-specific gene regulatory mechanisms, and the single-cell transcriptome response variation of LβT2 cells have not been previously investigated. Here, we integrate the transcriptome and genome-wide chromatin accessibility state of LβT2 cells during GnRH stimulation. Additionally, we examine cell-to-cell variability in the transcriptional response to GnRH using gel-in-emulsion Drop-seq technology. Analysis of a bulk RNA-seq dataset obtained 45 minutes after exposure to either GnRH or vehicle identified 112 transcripts that were regulated > 4-fold by GnRH (FDR < 0.05). The top regulated transcripts constitute, as determined by Bayesian massive public data integration analysis, a human pituitary-relevant coordinated gene program. Chromatin accessibility (ATAC-seq) datasets generated from GnRH-treated LβT2 cells identified more than 58,000 open chromatin regions, some containing notches consistent with bound transcription factor footprints. Study of the most prominent open regions showed that 75% were in transcriptionally active promoters or introns, supporting their involvement in active transcription. Lhb, Cga, and Egr1 showed significantly open chromatin over their promoters. While Fshb was closed over its promoter, several discrete significantly open regions were found at -40 to -90 kb, which may represent novel upstream enhancers. Chromatin accessibility determined by ATAC-seq was associated with high levels of gene expression determined by RNA-seq. We obtained high quality single-cell gel-in-emulsion Drop-seq transcriptome data, with an average of >4000 expressed genes/cell, from 1992 vehicle- and 1889 GnRH-treated cells. While the individual cell expression patterns showed high cell-to-cell variation, representing both biological and measurement variation, the average expression patterns correlated well with bulk RNA-seq data. Computational assignment of each cell to its precise cell cycle phase showed that the response to GnRH was unaffected by cell cycle. To our knowledge, this study represents the first genome-wide epigenetic and single-cell transcriptomic characterization of this important gonadotrope model. The data have been deposited publicly and should provide a resource for hypothesis generation and further study.
2018-02-15 | GSE102479 | GEO
Project description:Inter-organ communication is a major hallmark of health and is often orchestrated by hormones released by the anterior pituitary gland. Pituitary gonadotropes secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH) to regulate gonadal function and control fertility. Whether FSH and LH also act on organs other than the gonads is debated. Here, we found that gonadotrope depletion in adult female mice triggers profound hypogonadism, obesity, glucose intolerance, fatty liver, and bone loss. The absence of sex steroids precipitates these phenotypes, with the notable exception of fatty liver, which results from ovary-independent actions of FSH. We uncover paracrine FSH action on pituitary corticotropes as a novel mechanism to restrain the production of corticosterone and prevent hepatic steatosis. Our data demonstrate that functional communication of two distinct hormone-secreting cell populations in the pituitary regulates hepatic lipid metabolism.
2023-01-11 | GSE216096 | GEO
Project description:2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) causes the many forms of reproductive toxicity, such as defects in sexual behaviors, in pups of which mother is exposed to this substance at lower doses. However, the mechanism underlying these defects remains to be clarified in spite of many researches conducted so far. Our previous studies have revealed that maternal treatment with TCDD attenuates the production of pituitary gonadotropins [luteinizing hormone (LH) and follicle-stimulating hormone] in the late fetuses, leading to the impairment of sexual behavior in adulthood. To identify the target genes for a fetal reduction in gonadotropin β-subunit, we performed DNA microarray analysis using the fetal pituitary and its regulatory organ, the hypothalamus. The result showed that TCDD induced histone deacetylases (HDACs), and altered the expression of genes including gonadotropin-releasing hormone and activin signaling in the fetal pituitary. Moreover, our data indicated that the increased deacetylation of histone due to HDAC induction plays a critical role for a dioxin-induced attenuation of LHβ in the fetal pituitary. This study suggests a novel molecular mechanism explaining dioxin-produced reproductive toxicity. Pregnant Wistar rats were orally treated with TCDD (1 µg/kg in corn oil) at gestational day (GD)15. Then, the total RNA was extracted from the fetal pituitary and hypothalamus at GD20. To identify the target genes the alteration of which contributes to a reduction in fetal gonadotropin β-subunit, the profile of gene expression was analyzed using the Illumina RatRef-12 Expression BeadChip.
2011-09-30 | E-GEOD-32459 | biostudies-arrayexpress
Project description:NR5A1 is expressed in the pituitary gonadotropes and regulates their functional differentiation. We have previously identified a pituitary-specific enhancer region located in the 6th intron of the Nr5a1 gene. In this study, deletion of the pituitary enhancer by genome editing abolished the expression of NR5A1 in the pituitary gland, confirming the functional importance of the enhancer. Transcriptomic changes in the enhancer-deleted mouse pituitary were revealed in both males and females.
2022-10-28 | GSE216468 | GEO