Cyclin D2 Compensates for the Loss of Cyclin D1 in Estrogen-Induced Mouse Uterine Epithelial Cell Proliferation

2003 ◽  
Vol 17 (7) ◽  
pp. 1368-1381 ◽  
Author(s):  
Bo Chen ◽  
Jeffrey W. Pollard
Keyword(s):  
Cell Proliferation ◽  
Epithelial Cell ◽  
Cyclin D1 ◽  
Epithelial Cell Proliferation ◽  
Cyclin D2 ◽  
Uterine Epithelial Cell

scholarly journals Progesterone Inhibits the Estrogen-Induced Phosphoinositide 3-Kinase→AKT→GSK-3β→Cyclin D1→pRB Pathway to Block Uterine Epithelial Cell Proliferation

2005 ◽  
Vol 19 (8) ◽  
pp. 1978-1990 ◽  
Author(s):  
Bo Chen ◽  
Haiyan Pan ◽  
Liyin Zhu ◽  
Yan Deng ◽  
Jeffrey W. Pollard
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Epithelial Cell ◽  
Cyclin D1 ◽  
Nuclear Accumulation ◽  
Nuclear Antigen ◽  
Epithelial Cell Proliferation ◽  
Uterine Epithelial Cell ◽  
Gsk 3Β ◽  
Phosphoinositide 3 Kinase

Abstract The mammalian cell cycle is regulated by the cyclin/cyclin-dependent kinase (CDK) phosphorylation of the retinoblastoma (pRB) family of proteins. Cyclin D1 with its CDK4/6 partners initiates the cell cycle and acts as the link between extracellular signals and the cell cycle machinery. Estradiol-17β (E2) stimulates uterine epithelial cell proliferation, a process that is completely inhibited by pretreatment with progesterone (P4). Previously, we identified cyclin D1 localization as a key point of regulation in these cells with E2 causing its nuclear accumulation and P4 retaining it in the cytoplasm with the resultant inhibition of pRB phosphorylation. Here we show that E2 stimulates phosphoinositide 3-kinase to activate phosphokinase B/AKT to effect an inhibitory phosphorylation of glycogen synthase kinase (GSK-3β). This pathway is suppressed by P4. Inhibition of the GSK-3β activity in P4-treated uteri by the specific inhibitor, LiCl, reversed the nuclear accumulation of cyclin D1 and in doing so, caused pRB phosphorylation and the induction of downstream genes, proliferating cell nuclear antigen and Ki67. Conversely, inhibition of phosphoinositide 3 kinase by LY294002 or Wortmanin reversed the E2-induced GSK-3β Ser9 inhibitory phosphorylation and blocked nuclear accumulation of cyclin D1. These data show the reciprocal actions of E2 and P4 on the phosphoinositide 3-kinase through to the GSK-3β pathway that in turn regulates cyclin D1 localization and cell cycle progression. These data reveal a novel signaling pathway that links E2 and P4 action to growth factor-mediated signaling in the uterus.

scholarly journals The molecular basis of tamoxifen induction of mouse uterine epithelial cell proliferation

2005 ◽  
Vol 184 (1) ◽  
pp. 129-140 ◽  
Author(s):  
Haifan Zhang ◽  
Tim McElrath ◽  
Wei Tong ◽  
Jeffrey W Pollard
Keyword(s):  
Cell Proliferation ◽  
Epithelial Cell ◽  
Dna Synthesis ◽  
Cyclin D1 ◽  
Cyclin E ◽  
Cyclin A ◽  
Nuclear Accumulation ◽  
Maximal Response ◽  
Epithelial Cell Proliferation ◽  
Uterine Epithelial Cell

Tamoxifen, a selective estrogen modulator (SERM) that has found clinical utility in the treatment of breast cancer, is an antagonist in the breast and an agonist in the uterus. These agonist actions in the uterus lead to an increased risk of endometrial cancer. In this study in mice we have analyzed the mechanism of action of tamoxifen in inducing cell proliferation in the uterine luminal epithelia. Tamoxifen induces a wave of DNA synthesis in these epithelial cells with kinetics similar to those seen after 17β-estradiol (E2) treatment. However, by these criteria of mitogenicity, it is much less potent and never achieves full estrogenicity. This uterine epithelial cell proliferation is preceded by the mobilization of cyclin D1 from the cytoplasm to the nucleus which, together with CDK4, phosphorylates members of the Rb-retinoblastoma family of proteins, pRb and p107. Subsequent to this initial nuclear accumulation of cyclin D1, cyclin E and then cyclin A are induced that, together with the activation of CDK2, results in enhanced cyclin E- and cyclin A-dependent CDK2 kinase activity and further phosphorylation of pRb and p107. These actions of tamoxifen parallel those of E2. Tamoxifen also induced the classical estrogen water imbibition response. However, in this it was more potent, producing a maximal response at doses that do not affect DNA synthesis. This suggests that the uterotropic response is not an accurate predictor of the compound’s hyperplasia responses. We can conclude that, in its effects on proliferation, tamoxifen acts as a classical impeded estrogen and this suggests that the AF-1 transcription activation domain of the estrogen receptor that is activated upon both E2 and tamoxifen binding to this receptor regulates these responses in the uterus.

412. The role of macrophages in regulating uterine epithelial cell proliferation

2008 ◽  
Vol 20 (9) ◽  
pp. 92
Author(s):  
A. S. Care ◽  
W. V. Ingman ◽  
M. J. Jasper ◽  
SA Robertson
Keyword(s):  
Cell Proliferation ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Diphtheria Toxin ◽  
Functional Markers ◽  
Epithelial Cell Proliferation ◽  
Uterine Epithelial Cells ◽  
Uterine Epithelial Cell ◽  
Macrophage Depletion ◽  
Embryo Attachment

During the oestrous cycle, uterine epithelial cells respond to ovarian steroid hormones by producing an array of cytokines and chemokines that cause macrophage recruitment into the uterus and regulate macrophage activation phenotype. In turn, growth factors and cytokines synthesised by macrophages potentially impact epithelial cell proliferation, secretory function and receptivity to embryo attachment. To investigate the hypothesis that uterine macrophages are essential contributors to the proliferation of uterine epithelial cells, we have used an ovariectomy and steroid replacement model in CD11b-DTR ‘Mac-terminator' mice. These mice are engineered for CD11b promoter-driven expression of the monkey diphtheria toxin (DT) receptor, allowing acute systemic ablation of macrophages by administration of human diphtheria toxin (DT). CD11b-DTR mice were ovariectomised, then 2–4 weeks later were primed with E 2, followed by administration of DT (25 ng/g, ip) to effect macrophage depletion, and BrDU to label proliferating cells. Control mice were given PBS instead of DT. Uterine tissues were stained with F4/80 to detect macrophages, and anti-BrDU to detect BrDU+ epithelial cell nuclei. DT treatment was associated with a depletion of >90% of F4/80+ uterine macrophages. However, the numbers of BrDU+ epithelial cells and the architecture of the luminal epithelial surface and abundance of epithelial glands were similar in control and DT-treated uterine tissues. These data suggest that resident macrophages may not be essential for oestrogen-driven uterine epithelial cell proliferation. In ongoing experiments we are assessing the effect of macrophage depletion on epithelial cell expression of functional markers including those involved in regulation of embryo attachment.

scholarly journals Uterine ALK3 is essential during the window of implantation

2015 ◽  
Vol 113 (3) ◽  
pp. E387-E395 ◽  
Author(s):  
Diana Monsivais ◽  
Caterina Clementi ◽  
Jia Peng ◽  
Mary M. Titus ◽  
James P. Barrish ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Epithelial Cell ◽  
Signaling Pathways ◽  
Transforming Growth Factor ◽  
Apical Cell ◽  
Uterine Epithelium ◽  
Conditional Knockout ◽  
Epithelial Cell Proliferation ◽  
Uterine Receptivity ◽  
Uterine Epithelial Cell

The window of implantation is defined by the inhibition of uterine epithelial proliferation, structural epithelial cell remodeling, and attenuated estrogen (E2) response. These changes occur via paracrine signaling between the uterine epithelium and stroma. Because implantation defects are a major cause of infertility in women, identifying these signaling pathways will improve infertility interventions. Bone morphogenetic proteins (BMPs) are TGF-β family members that regulate the postimplantation and midgestation stages of pregnancy. In this study, we discovered that signaling via activin-like kinase 3 (ALK3/BMPR1A), a BMP type 1 receptor, is necessary for blastocyst attachment. Conditional knockout (cKO) of ALK3 in the uterus was obtained by producing Alk3flox/flox-Pgr-cre–positive females. Alk3 cKO mice are sterile and have defects in the luminal uterine epithelium, including increased microvilli density and maintenance of apical cell polarity. Moreover, Alk3 cKO mice exhibit an elevated uterine E2 response and unopposed epithelial cell proliferation during the window of implantation. We determined that dual transcriptional regulation of Kruppel-like factor 15 (Klf15), by both the transforming growth factor β (TGF-β) transcription factor SMAD family member 4 (SMAD4) and progesterone receptor (PR), is necessary to inhibit uterine epithelial cell proliferation, a key step for embryo implantation. Our findings present a convergence of BMP and steroid hormone signaling pathways in the regulation of uterine receptivity.

scholarly journals Sphk1 promotes breast epithelial cell proliferation via NF-κB-p65-mediated cyclin D1 expression

Oncotarget ◽  
2016 ◽  
Vol 7 (49) ◽  
pp. 80579-80585 ◽  
Author(s):  
Shifei Li ◽  
Yan Zhou ◽  
Xiaodong Zheng ◽  
Xiujuan Wu ◽  
Yueyang Liang ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Epithelial Cell ◽  
Cyclin D1 ◽  
Breast Epithelial Cell ◽  
Epithelial Cell Proliferation ◽  
Breast Epithelial
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