Dataset Information

Effects of estradiol and growth hormone on liver transcriptome in hypothyroid-orquiectomized rats

ABSTRACT: E2 and GH are critical regulators of growth and intermediate metabolism in mammals. Hypothyroidism causes endocrine and metabolic disturbances in the liver with features that mimic deficiencies of E2 or GH signalling. In this work, we used the hypothyroid-orchiectomized (TXOX) adult rat model to evaluate the influence of E2 and GH on the liver in terms of global changes in gene expression. This study shows the changes in hepatic transcriptome that were provoked by E2 benzoate (50 ug/kg; sc; 5 days per week x 27 days), intermittent GH administration (0.3 mg/kg/day;sc injection divided into two daily injections x 7 days) or the combination of E2 plus GH in TXOX rats. E2 influenced the liver transcriptome, particularly genes involved in metabolism of lipids and endo-xenobiotics, and the GH-regulated endocrine, metabolic, gender, and immune responses. E2 did not prevent the inhibitory effects of GH on urea and amino acid metabolism-related genes. Notably, the combination of E2 and GH caused deleterious effects on transcriptional immune response. These results highlight the role of E2 as a critical regulator of liver metabolism in mammals and provide insights into the functional interplay between E2 and GH in the liver.

ORGANISM(S): Rattus norvegicus

PROVIDER: GSE50014 | GEO | 2014/02/28

SECONDARY ACCESSION(S): PRJNA215808

REPOSITORIES: GEO

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Project description:E2 and GH are critical regulators of growth and intermediate metabolism in mammals. Hypothyroidism causes endocrine and metabolic disturbances in the liver with features that mimic deficiencies of E2 or GH signalling. In this work, we used the hypothyroid-orchiectomized (TXOX) adult rat model to evaluate the influence of E2 and GH on the liver in terms of global changes in gene expression. This study shows the changes in hepatic transcriptome that were provoked by E2 benzoate (50 ug/kg; sc; 5 days per week x 27 days), intermittent GH administration (0.3 mg/kg/day;sc injection divided into two daily injections x 7 days) or the combination of E2 plus GH in TXOX rats. E2 influenced the liver transcriptome, particularly genes involved in metabolism of lipids and endo-xenobiotics, and the GH-regulated endocrine, metabolic, gender, and immune responses. E2 did not prevent the inhibitory effects of GH on urea and amino acid metabolism-related genes. Notably, the combination of E2 and GH caused deleterious effects on transcriptional immune response. These results highlight the role of E2 as a critical regulator of liver metabolism in mammals and provide insights into the functional interplay between E2 and GH in the liver. Groups=4; Biological replicates = 4 per group; Samples=16; Reference samples=TXOX group. Adult (3 months old) male Sprague-Dawley rats (n=4 per group) were used throughout these experiments. The generation of TXOX was performed by adding methimazole (MMI; 0.05%) to the drinking water for 5 weeks starting on postnatal day (PND) 59 until sacrifice on PND94. Two weeks after starting MMI administration, male rats were castrated (OX) to make TXOX rats. Four days after OX, we began treatment with E2 benzoate (TXOXE2) or vehicle (TXOX) to TXOX rats for 20 days followed for 7 days by either vehicle plus GH (TXOXGH) or by E2 plus GH (TXOXE2GH). Twenty-four hours (in the case of E2) or twelve hours (in the case of GH) after the last injection, the animals were killed by exsanguinations. Portions of the liver were snap frozen in liquid nitrogen and stored at -80C until processed for mRNA analysis.

Project description:17alpha-ethinylestradiol (EE2) is one of the most potent estrogens that have the ability to interfere with the endocrine system of fish. The objective was to investigate the effects and mechanisms of action caused by 60 days of dietary exposure to 0.2 mg EE2/kg and 0.07 mg EE2/kg feed in female largemouth bass (LMB) during the reproductive season. Microarrays and pathway analyses were performed on hepatic tissues to identify genes and biological processes altered in female LMB by EE2 exposure. The hypothesis was that the two concentrations of EE2 would produce dose-response changes in sensitive genes. Body and ovary weights were measured and blood was collected for measurement of plasma steroid hormones (17beta-estradiol (E2), testosterone (T)) and vitellogenin (VTG) using ELISA. The 0.2 mg EE2/kg feed exposure reduced the gonadosomatic index (GSI) by 75%, and plasma levels of E2 and T were reduced by over 90%. Plasma VTG was increased by approximately 100% (from 4 to 8mg/ml) by the 0.2 mg/kg treatment. T levels, from the 0.07 mg EE2/kg feed, reduced GSI by approximately 30% and circulating E2 and T by ~80% but did not affect VTG concentrations. We found 1,594 and 1,165 genes were significantly affected (p<0.05) by the 0.07 mg EE2/kg feed and 0.2 mg EE2/kg feed, respectively. Gene ontology (GO) analysis revealed that there were different biological processes regulated by the two concentrations of EE2. Pathway analysis showed that the 0.07 mg EE2/kg feed exposure caused differential regulation of genes associated with fatty acid biosynthesis and glycolysis, indicating some metabolic effects. In contrast, the 0.2 mg EE2/kg feed exposure altered transcription of genes involved in immune response and apoptosis, suggesting a toxic response at this concentration. These results suggest that the two concentrations demonstrated distinct physiological responses, with the higher concentration inducing complete endocrine disruption in LMB. These findings demonstrate the usefulness of microarrays to identify possible biomarkers and modes of toxic action to dietary exposure in LMB. Two concentrations of EE2 would produce dose-response changes in sensitive genes. Female LMB were fed 5 days per week for 60 days with floating pellets that contained 0.07 or 0.2 mg/kg of EE2.

Project description:Sex-dependent pituitary growth hormone (GH) secretory patterns determine the sex-biased expression of >1,000 genes in mouse and rat liver, affecting lipid and drug metabolism, inflammation and disease. A fundamental biological question is how robust differential expression can be achieved for hundreds of sex-biased genes simply based on the GH input signal pattern: pulsatile GH stimulation in males vs. near-continuous GH exposure in females. STAT5 is an essential transcriptional mediator of the sex-dependent effects of GH in the liver, but the mechanisms that underlie its sex-dependent actions are obscure. Here we elucidate the dynamic, sex-dependent binding of STAT5 and the GH/STAT5-regulated repressor BCL6 to mouse liver chromatin, revealing the counteractive interplay between these two regulators of liver sex-specificity. Our findings establish a close correlation between sex-dependent STAT5 binding and sex-biased target gene expression. Moreover, sex-dependent STAT5 binding correlated positively with sex-biased DNase hypersensitivity and H3-K4me1 and H3-K4me3 (activating) marks, correlated negatively with sex-biased H3-K27me3 (repressive) marks, and was associated with sex-differentially enriched motifs for HNF6/CDP factors. Importantly, BCL6 binding was preferentially associated with repression of female-biased STAT5 targets in male liver. Furthermore, BCL6 and STAT5 common targets but not BCL6 unique targets showed strong enrichment for lipid and drug metabolism. These findings provide a comprehensive, genome-wide view of the mechanisms whereby these two GH-regulated transcription factors establish and maintain sex differences affecting liver physiology and disease. The approaches used here to characterize sex-dependent STAT5 and BCL6 binding can be applied to other condition-specific regulatory factors and binding sites and their interplay with co-operative chromatin-binding factors. Mouse livers were excised from individual male and female mice killed at either a peak of STAT5 binding activity, or during the growth hormone (GH) interpulse interval, when STAT5 activity is either low (females) or essentially undetectable (males). Sonicated, cross-linked liver nuclear chromatin was then used to identify STAT5 binding sites by ChIP-Seq.

Project description:MicroRNAs (miRNAs) are extensively in diverse biological processes. However, very little is known about the role of miRNAs in mediating thyroid hormones (TH) action. Maintenance of appropriate TH levels is known to be critically important for development, differentiation and maintenance of metabolic balance in mammals. We induced transient hypothyroidism in juvenile mice by short term exposure to methimazole and perchlorate from post natal day (PND) 12 to 15. The expression of miRNAs in the liver was analyzed with the Taqman Low Density Array (containing up to 600 rodent microRNAs). We found the expression of 40 miRNAs was significantly altered in the liver of hypothyroid mice compared to euthyroid controls. Among the miRNAs, miR-1/206/133 exhibited a massive increase in expression (50 – 500 folds). To further explore TH effect on miR-1/206/133, we treated mouse hepatocyte AML 12 cells with 10 nm T3 for 1 hr and 24 hrs. TH treatment induced the down-regulation of miR-1/206/133b at both time points, reaching statistical significance at 24 hrs. To identify the genes targeted by these miRNAs, DNA microarrays were used to examine hepatic mRNA levels in the hypothyroid mouse model alongside controls. We found transcripts from 92 known genes were significantly altered in hypothyroid mice. Web-based target predication softwares (TargetScan and Microcosm) identified 14 of these transcripts as targets of miR-1/106/133. The vast majority of these mRNA targets were significantly down-regulated in hypothyroid mice, corresponding well with the up-regulation of miR-1/206/133 in hypothyroid mouse liver. The results suggest that TH regulation of these genes may occur secondarily via the reduced repression consequent to TH-induced down-regulation of miR-1/206/133. These studies provide novel insight into the role of miRNAs in mediating TH regulation of gene expression. Agilent two-color microarray were used to perform gene expression profile in euthyroid and hypothyroid male mouse livers, 5 biological replicates. TLDA (Taqman microRNA Array) was used to explore the miRNA expression profile in euthyroid and hypothyroid male mouse livers, 4 biological replicates.

Dataset Information

Effects of estradiol and growth hormone on liver transcriptome in hypothyroid-orquiectomized rats

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets