Project description:Ovarian estrogen (E2) and progesterone (P4) are indispensable for embryo-implantation and endometrial stromal decidualization; however, the molecular mechanisms that underpin these reproductive processes are unclear. Steroid receptor coregulator-2 (SRC-2) belongs to the multifunctional SRC/p160 family which also includes SRC-1 and SRC-3. Sharing strong sequence homology, all three SRCs exert diverse regulatory effects by modulating the transcriptional potency of nuclear receptor family members, including the estrogen and progesterone receptor (ER and PR respectively). Importantly, absence of SRC-2 in PR positive cells in the epithelial, stromal, and myometrial compartments of the murine uterus results in a striking infertility defect. This reproductive phenotype highlights a key role for SRC-2 in uterine function which is not shared with other coregulators. Intriguingly, abrogation of uterine SRC-2 does not block embryo apposition or attachment to the apical surface of luminal epithelial cells of the endometrium but rather prevents P4-dependent local decidualization of the sub-epithelial stroma. Remarkably, epithelial-specific ablation of SRC-2 in the murine uterus does not compromise endometrial functionality, again underscoring the unique importance of stromal derived SRC-2 in uterine function. The stromal decidualization defect resulting from SRC-2 ablation is reflected at the molecular level by a marked attenuation in P4 responsive target genes known to be critical for P4 dependent decidualization (i.e. ERBB receptor feedback inhibitor 1, Follistatin and Fkbp5). Conversely, the induction of E2 or P4 target genes involved in embryo implantation (i.e. leukemia inhibitory factor (LIF) and Indian hedgehog (Ihh) respectively) is not affected by SRC-2’s absence. As with mouse studies, decidualization of primary human stromal cells (HESCs) in culture is blocked by SRC-2 knockdown; however, HESC decidualization is unaffected by knockdown of SRC-1 or SRC-3. As a consequence of SRC-2 knockdown, molecular studies disclose a striking decrease in the induction of a subset of P4 target genes (i.e. WNT4 and FKBP5) which are essential for the stromal-epithelioid transformation step, the cellular hallmark of endometrial decidualization. Collectively, these studies not only showcase the evolutionary importance of SRC-2 in endometrial biology but also suggest that deregulation of this coregulator may underpin a spectrum of hormone-dependent uterine pathologies such as endometriosis and endometrial cancer. Microarray analysis was performed on mouse uteri using eighteen SRC-2flox/flox (SRC-2f/f) and eighteen PRCre/+ SRC-2flox/flox (SRC-2d/d) mice. Mice were ovariectomized at 6 weeks and after 2 weeks mice were either treated with sesame oil (vehicle) or 1 mg of P4. RNA from three mice per genotype per treatment were pooled and assigned as one sample (three samples per genotype per treatment). multiple group comparison

Project description:Ovarian estrogen (E2) and progesterone (P4) are indispensable for embryo-implantation and endometrial stromal decidualization; however, the molecular mechanisms that underpin these reproductive processes are unclear. Steroid receptor coregulator-2 (SRC-2) belongs to the multifunctional SRC/p160 family which also includes SRC-1 and SRC-3. Sharing strong sequence homology, all three SRCs exert diverse regulatory effects by modulating the transcriptional potency of nuclear receptor family members, including the estrogen and progesterone receptor (ER and PR respectively). Importantly, absence of SRC-2 in PR positive cells in the epithelial, stromal, and myometrial compartments of the murine uterus results in a striking infertility defect. This reproductive phenotype highlights a key role for SRC-2 in uterine function which is not shared with other coregulators. Intriguingly, abrogation of uterine SRC-2 does not block embryo apposition or attachment to the apical surface of luminal epithelial cells of the endometrium but rather prevents P4-dependent local decidualization of the sub-epithelial stroma. Remarkably, epithelial-specific ablation of SRC-2 in the murine uterus does not compromise endometrial functionality, again underscoring the unique importance of stromal derived SRC-2 in uterine function. The stromal decidualization defect resulting from SRC-2 ablation is reflected at the molecular level by a marked attenuation in P4 responsive target genes known to be critical for P4 dependent decidualization (i.e. ERBB receptor feedback inhibitor 1, Follistatin and Fkbp5). Conversely, the induction of E2 or P4 target genes involved in embryo implantation (i.e. leukemia inhibitory factor (LIF) and Indian hedgehog (Ihh) respectively) is not affected by SRC-2’s absence. As with mouse studies, decidualization of primary human stromal cells (HESCs) in culture is blocked by SRC-2 knockdown; however, HESC decidualization is unaffected by knockdown of SRC-1 or SRC-3. As a consequence of SRC-2 knockdown, molecular studies disclose a striking decrease in the induction of a subset of P4 target genes (i.e. WNT4 and FKBP5) which are essential for the stromal-epithelioid transformation step, the cellular hallmark of endometrial decidualization. Collectively, these studies not only showcase the evolutionary importance of SRC-2 in endometrial biology but also suggest that deregulation of this coregulator may underpin a spectrum of hormone-dependent uterine pathologies such as endometriosis and endometrial cancer.

Project description:Uterine receptivity implies a dialogue between the hormonally primed maternal endometrium and the free-floating blastocyst. Endometrial stromal cells proliferate, avert apoptosis, and undergo decidualization in preparation for implantation; however, the molecular mechanisms that underlie differentiation into the decidual phenotype remain largely undefined. The Notch family of transmembrane receptors transduce extracellular signals responsible for cell survival, cell-to-cell communication, and trans-differentiation, all fundamental processes for decidualization and pregnancy. Using a murine artificial decidualization model, pharmacological inhibition of Notch signaling by gamma-secretase inhibition resulted in significantly decreased deciduoma. Furthermore, a progesterone receptor (PR)-Cre Notch1 bigenic (Notch1d/d) confirmed a Notch1-dependant hypomorphic decidual phenotype. Microarray and pathway analysis, following Notch1 ablation, demonstrated significantly altered signaling repertoire. Concomitantly, hierarchical clustering demonstrated Notch1-dependent differences in gene expression. Uteri deprived of Notch1 signaling demonstrated decreased cellular proliferation; namely, reduced proliferation-specific antigen, Ki67, altered p21, cdk6, and cyclinD activity, and increased apoptotic-profile, augmented cleaved caspase-3, Bad, and attenuated Bcl2. Demonstrated here, the pre-implantation uterus relies on Notch signaling to inhibit apoptosis of stromal fibroblasts and regulate cell cycle progression, which together promotes successful decidualization. In summary, Notch1 signaling modulates multiple signaling mechanisms crucial for decidualization and we provide greater perspective to the coordination of multiple signaling modalities required during decidualization RNA samples from 3-5 separate mice were extracted. All mRNA quantities were normalized against 18S gene expression. Gene expression levels were measured by real-time RT-PCR SYBR Green analysis using the ABI Prism 7700 Sequence Detector System according to manufacturer’s instructions (Applied Biosystems).

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Transcriptional profiles of decidualized cultured WT vs NELF-B cKO Uterine stromal cells

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