Project description:The potential for xenoestrogens and other environmental chemicals to alter female reproductive function calls for the study of their affects on endogenous hormone-regulated gene expression pathways during uterine tissue remodeling which occurs as part of the menstrual/estrus cycle. However, our knowledge of these pathways is limited. Here, we characterize changes in the CD-1 mouse uterine transcriptome during proestrus and estrus, which are regulated by estrogen and progesterone in preparation of the uterus for pregnancy. Mice were staged beginning at 6 wk of age and uterine horns were harvested after monitoring two estrus cycles. Microarray analysis identified 2,429 genes differentially expressed in estrus compared to proestrus, indicating that the mouse uterus undergoes remarkable remodeling during the estrus cycle, affecting ~10% of all protein-coding genes. Changes in gene expression associated with structural alteration of the uterus include remodeling of the extracellular matrix, changes in cell keratins and adhesion molecules, activation of mitosis, MHC class II presentation, complement and coagulation cascades, and cytochrome P450 expression. Signaling pathways regulated during the estrus cycle, involving ligand-gated channels, Wnt and hedgehog signaling, and several transcription factors with poorly understood roles in reproductive tissues, include several genes and gene networks that have been implicated in pathological states. The information presented here builds a background for understanding of mechanisms involved in uterine tissue response to endocrine disruptors and the development of reproductive tract diseases. Beginning on postnatal day 42, female CD-1 mice were monitored for reproductive stage cycle for 2 consecutive cycles and then total RNA was isolated from uterine horns at estrus or proestrus. Samples were pooled for microarray as follows. Six litters were used to generate 2 tissue pools for estrus and 2 tissue pools for proestrus, with estrus pool 1 and proestrus pool 1 comprised of mice from the same 3 litters, and estrus pool 2 and proestrus pool 2 comprised of mice from the other 3 litters. Each pool was comprised of uterine tissue RNA from n= 4-6 individual mice. Fluorescent labeling of RNA and hybridization of the Alexa 555-labeled (green) and Alexa 647-labeled (red) RNA samples to Agilent-026655 Whole Mouse Genome Microarray 4x44K v2 (Agilent Technology, Palo Alto, CA; catalog # G4846A) were carried out, with dye swapping for each estrus cycle stage comparison.

Project description:Embryo implantation into a receptive endometrium is tightly regulated by a variety of maternal factors, including cytokines, growth factors and transcription factors. Previous studies identified the leukaemia inhibitory factor (LIF), produced in uterine glands, as an essential factor for implantation. It was shown that LIF acts via its cell surface receptor to activate the transcription factor STAT3 in the uterine epithelial cells. However, the mechanisms via which STAT3 promotes uterine receptivity remain unknown. To address the molecular pathways regulated by STAT3 in the uterus, we created mice in which Stat3 gene is conditionally inactivated in uterine epithelium. These mutant mice are infertile due to implantation failure and exhibit a lack of embryo attachment to the luminal epithelium. Gene expression profiling of the epithelial tissue impaired in STAT3 activation revealed dysregulated expression of specific components of junctional complexes, including E-cadherin, M-NM-2-catenin, and claudins, which critically regulate epithelial cell polarity and embryo attachment. Additionally, mice lacking functional epithelial STAT3 showed markedly reduced stromal proliferation and differentiation, indicating that this transcription factor controls stromal function via a paracrine mechanism. The stromal defect arose from a drastic reduction in the production of several members of the epidermal growth factor (EGF) family in luminal epithelium of mutant uteri and consequent lack of activation of EGF receptor signaling and mitotic activity in the stromal cells. Collectively, our results uncovered intricate signaling networks operating downstream of STAT3 in uterine epithelium that regulate epithelial cell polarity, and stromal proliferation and differentiation, which are critical determinants of successful implantation. To identify the downstream targets of STAT3 in mouse uterine epithelial cells during pregnancy, we performed gene expression profling of mouse uterine epithelial cells on day 4 of pregnancy between Stat3 flox control and SW d/d mice. This led to the identification of several junctional molecules (Claudins and Catenins) that are negatively regulated by STAT3 at the time of implantation. Mouse uteirne epithelial cells were isolated from control and knockout mice on the morning of day 4 of pregnancy. (n=3 for each sample), pooled total RNA from these cells was then hybridized to high density affymetrix microarrays according to the Affymetrix protocol (Mouse Genome 430A 2.0 Array) .

Dataset Information

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure