Project description:Ovariectomized WT, KIKO (DNA-binding deficient ERα) or αERKO female mice were injected (ip) with saline (vehicle), estradiol (E2; 250 ng), bisphenol A (BPA; 750 µg) or 2,2-bis(p-hydroxyphenyl)-1,1,1-trichloroethane (HPTE; 750 µg) and uteri were collected after 2 or 24 hours. Uterine profiles were compared and indicated the early (2 hour) responses to E2 were highly correlated to the BPA and HPTE profiles. KIKO patterns included overlap with WT but also included distinct responses. Later (24 hour) responses in the KIKO were weaker, indicating DNA binding is needed to maintain the estrogenic response. BPA and HPTE also showed a weakened late response in the WT, suggesting they are impeded estrogens.
Project description:To uncover genes regulated by mTORC1 and estradiol in uterine Tsc2-null LAM like cells, we performed RNAseq on uteri from 12-week old wild-type (WT) and uterine-specific Tsc2-null (KO) mice that were either untreated (intact), oopherectomized (ovx) or oopherectomized + treated with 17β-estradiol pellets (E2) for 8 weeks. We identified genes that were both estradiol- and TSC2-mediated. Uterine mRNA profiles of 12 week old wild type (WT) and uterine-specific Tsc2-null (KO) mice in the presence or absence of estradiol were generated using Illumina HiSeq2500
Project description:At birth, all female mice, including those that either lack estrogen receptor α (ERα-knockout) or that express mutated forms of ERα (AF2ERKI), have a hypoplastic uterus. However, uterine growth and development that normally accompanies pubertal maturation does not occur in ERα-knockout or AF2ERKI mice, indicating ERα mediated estrogen signaling is essential for this process. Mice that lack Cyp19 (aromatase, ArKO mice), an enzyme critical for estrogen (E2) synthesis, are unable to make E2, and lack pubertal uterine development. A single injection of E2 into ovariectomized adult (10 weeks old) females normally results in uterine epithelial cell proliferation, however, we observe that, although ERα is present in the ArKO uterine cells, no proliferative response is seen. We assessed the impact of exposing ArKO mice to E2 during pubertal and post-pubertal windows and observed that E2 exposed ArKO mice acquired growth responsiveness. Analysis of differential gene expression between unexposed ArKO samples and samples from animals exhibiting the ability to mount an E2-induced uterine growth response (WT or E2 exposed ArKO) revealed activation of EZH2 and HAND2 signaling and inhibition of GLI1 responses. EZH2 and HAND2 are known inhibit uterine growth, and GLI1 is involved in IHH signaling, which is a positive mediator of uterine response. Finally, we show that exposure of ArKO females to dietary phytoestrogens results in their acquisition of uterine growth competence. Altogether our findings suggest that pubertal levels of endogenous and exogenous estrogens impact biological function of uterine cells later in life via ERα-dependent mechanisms. We compared uterine RNA from ovariectomized adult aromatase knockout mice (ARKO) mice that were untreated to WT mice and to ARKO that were administered estradiol benzoate (EB) to induce uterine epithelial cell growth competence
Project description:To uncover genes regulated by mTORC1 and estradiol in uterine Tsc2-null LAM like cells, we performed RNAseq on uteri from 12-week old wild-type (WT) and uterine-specific Tsc2-null (KO) mice that were either untreated (intact), oopherectomized (ovx) or oopherectomized + treated with 17β-estradiol pellets (E2) for 8 weeks. We identified genes that were both estradiol- and TSC2-mediated.
Project description:ChIP-seq from mice with DNA binding mutations in Esr1 (KIKO mouse). Estrogen Receptor α (ERα) interacts with DNA, directly, or indirectly via other transcription factors, referred to as “tethering”. Evidence for tethering is based on in vitro studies and a widely used “KIKO” mouse model containing mutations that prevent direct estrogen response element (ERE) DNA-binding. KIKO mice are infertile, due in part to the inability of estrogen (E2) to induce uterine epithelial proliferation. To elucidate the molecular events that prevent KIKO uterine growth, regulation of the pro-proliferative E2 target gene Klf4, and of Klf15, a progesterone (P4) target gene that opposes KLF4’s pro-proliferative activity, were evaluated. Klf4 induction was impaired in KIKO uteri; however, Klf15 was induced by E2 rather than by P4. Whole uterine ChIP-seq revealed enrichment of KIKO ERα binding to hormone response elements (HRE), motifs. KIKO binding to HRE motifs was verified using reporter gene and DNA-binding assays. Because the KIKO ERα has HRE DNA-binding activity, we evaluated the “EAAE” ERα, which has more severe DBD mutations, and demonstrated lack of ERE or HRE reporter gene induction or DNA binding. The EAAE mouse has an ERα-null like phenotype, with impaired uterine growth and transcriptional activity. Our findings demonstrate that the KIKO mouse model, which has been used by numerous investigators, cannot be used to establish biological functions for ERα tethering, as KIKO ERα effectively stimulates transcription using HRE motifs. The EAAE-ERα DBD mutant mouse demonstrates that ERα DNA-binding is crucial for biological and transcriptional processes in reproductive tissues, and that ERα-tethering may not contribute to estrogen-responsiveness in vivo.
Project description:Estrogens stimulate hypertrophy and hyperplasia in the uterus and exert their activity through estrogen receptor α (ERα). A uterine epithelial ERα conditional knockout mouse model (Wnt7aCre+;Esr1f/f or cKO) demonstrated that ERα in the epithelial cells was dispensable for an early uterine proliferative response to 17β-estradiol (E2), but required for subsequent uterine biological responses. We compared the gene expression profile in the uterus after E2 treatment in the cKO samples with WT samples. We found that approximately 25% of the genes differentially expressed at 2 h were epithelial ERα independent, as they were preserved in the cKO, indicating they are mediated from the stroma and sufficient to promote initial proliferative responses. However, more than 90% of the differentially expressed transcripts at 24 h were absent in the cKO, indicating the majority of later transcriptional regulation required epithelial ERα and suggesting the loss of regulation of these later transcripts results in the blunted growth response 3 days after treatment. These transcription profiles correlate with our previous biological responses, in which the initial proliferative response is independent of epithelial ERα but dependent on stromal ERα, yet epithelial ERα is essential for subsequent tissue responsiveness. These analyses are now allowing for in vivo determination of the cell specific actions of ERα in the female reproductive tract.
Project description:To evaluate the ability of a DNA binding deficient ERa to mediate transcriptional responses in the mouse uterus, ovariectomized mice were injected with 100 ul of saline or 250 ng of estradiol (E2) in 100 ul saline, uterine tissue was collected 2 hours filllowing the injection, and RNA was isolated
Project description:To advance understanding of mechanisms leading to biological and transcriptional endpoints related to estrogen action in the mouse uterus, we have mapped ERα and RNA polymerase II binding sites using chromatin immunoprecipitation (ChIP) followed by sequencing of enriched chromatin fragments (ChIP-seq). In the absence of hormone, 5184 ERα binding sites were apparent in the vehicle treated ovariectomized uterine chromatin, while 17240 were seen one hour after estrogen (E2) treatment, indicating that some sites are occupied by unliganded ERα, and that ERα binding is increased by E2. Approximately 15% of the uterine ERα binding sites were adjacent to (<10 KB) annotated transcription start sites and many sites are found within genes or are found more than 100 KB distal from mapped genes; however, the density (sites per bp) of ERα binding sites is significantly greater adjacent to promoters. An increase in quantity of sites but no significant positional differences were seen between vehicle and E2 treated samples in the overall locations of ERα binding sites either distal from, adjacent to or within genes. Analysis of the PolII data revealed the presence of poised promoter proximal PolII on some highly upregulated genes. Additionally, co-recruitment of PolII and ERα to some distal enhancer regions was observed. A de novo motif analysis of sequences in the ERα bound chromatin confirmed that estrogen response elements (EREs) were significantly enriched. Interestingly, in areas of ERα binding without predicted ERE motifs, homeodomain transcription factor (Hox) binding motifs were significantly enriched. The integration of the ERα and PolII binding sites from our uterine ChIP-seq data with transcriptional responses revealed in our uterine microarrays has the potential to greatly enhance our understanding of mechanisms governing estrogen response in uterine and other estrogen target tissues.
Project description:RNA-seq: Gene expression profiling in MCF-7 cells treated with vehicle (0), estradiol (E2), the Selective ER Modulator 4-hydroxytamoxifen (OHT), or the pure antiestrogen fulvestrant (ICI). ChIP-seq: Genome-wide DNA binding profile of ERα and SUMO2/3 in MCF-7 cells treated with vehicle, E2 or ICI.
Project description:Estrogen (E2) signaling through its nuclear receptor, estrogen receptor α (ERα) increases insulin-like growth factor 1 (IGF1) in the rodent uterus, which then initiates further signals via the IGF1 receptor (IGF1R). Directly administering IGF1 results in similar biological and transcriptional uterine responses. Our studies using global ERα-null mice demonstrated a loss of uterine biological responses of the uterus to E2 or IGF1 treatment, while maintaining transcriptional responses to IGF1. To address this discrepancy in the need for uterine ERα in mediating the IGF1 transcriptional vs. growth responses, we assessed the IGF1 transcriptional responses in PgrCre+Esr1f/f (called ERαUtcKO) mice, which selectively lack ERα in progesterone receptor (PGR) expressing cells, including all uterine cells, while maintaining ERα expression in other tissues and cells that do not express Pgr. Additionally, we profiled IGF1-induced ERα binding sites in uterine chromatin using ChIP-seq. Herein, we explore the transcriptional and molecular signaling that underlies our findings to refine our understanding of uterine IGF1 signaling and identify ERα-mediated and ERα-independent uterine transcriptional responses. Defining these mechanisms in vivo in whole tissue and animal contexts provides details of nuclear receptor mediated mechanisms that impact biological systems and have potential applicability to reproductive processes of humans, livestock and wildlife.