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Peri-implantation Period (peri-implantation + period)
Selected AbstractsIdentification and characterization of a novel progesterone receptor-binding element in the mouse prostaglandin E receptor subtype EP2 geneGENES TO CELLS, Issue 9 2003Sohken Tsuchiya Background:, Gene expression of prostaglandin E receptor EP2 is induced in the luminal epithelium of the mouse uterus during peri-implantation period (day-5 of pseudopregnancy), suggesting the involvement of progesterone and its receptor (PR) in this expression. However it remains unclear whether PR affects EP2 gene expression through its binding. Results:, We investigated transcriptional regulation of EP2 gene expression with reporter gene analysis using HeLa cells with or without expression of the PR. The 5,-flanking region (,3260 to ,27, upstream of the translation initiation site) exhibited progesterone-induced promoter activation and basal promoter activity in the presence of PR. Using successive deletion analysis, we determined the six regulatory regions in the EP2 gene. Three regions were found to be involved in progesterone-induced promoter activation, whereas the other three regions were involved in basal promoter activity in the presence of PR. We identified a novel PR-binding sequence, 5,-G(G/A)CCGGA-3,, in the two basal promoter regions and Sp1- and Sp3-binding in the other basal promoter region. Conclusions:, We identified a novel PR-binding sequence, which may be involved in the regulation of basal promoter activity in the EP2 gene. [source] Expression and downregulation of WNT signaling pathway genes in rhesus monkey oocytes and embryosMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 6 2006Ping Zheng Abstract Mammalian WNT genes encode secreted glycoproteins that are conserved homologues of the Drosophila Wingless gene, which plays a crucial role in Drosophila development. Recently, WNT pathway signaling has been implicated in ovarian development, oogenesis, and early development. We sought to evaluate whether these genes may contribute to the formation of healthy human oocytes or embryos, and whether the expression of these genes could provide informative markers of human oocyte and embryo quality. To do this, we employed the primate embryo gene expression resource (PREGER; www.preger.org) to examine expression of mRNAs encoding 38 components of the WNT signaling pathway in rhesus monkey oocytes and embryos as a nonhuman primate model. We observed considerable conservation between rhesus monkey and mouse of expression of WNT, FZD, and effector gene mRNAs, and a generalized downregulation of genes encoding key components of the WNT signaling pathway during preimplantation development. Our results support a role for WNT signaling during oocyte growth or maturation, but not during preimplantation development. Additionally, we observed differences between in vitro cultured and in vivo developing blastocysts, indicating possible effects of culture on WNT signaling during the peri-implantation period. Mol. Reprod. Dev. © 2006 Wiley-Liss, Inc. [source] Uterine secretion of ISP1 & 2 tryptases is regulated by progesterone and estrogen during pregnancy and the endometrial cycleMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 3 2004Colleen M. O'Sullivan Abstract We have described two novel implantation serine proteinase (ISP) genes that are expressed during the implantation period. The ISP1 gene may encode the embryo-derived enzyme strypsin, which is necessary for blastocyst hatching in vitro and the initiation of invasion. The ISP2 gene, which encodes a related tryptase, is expressed in endometrial glands and is regulated by progesterone during the peri-implantation period. Based on similarities between ISP2 gene expression and that of a progesterone-regulated lumenal serine proteinase activity associated with lysis of the zona pellucida, we have suggested that the strypsin related protein, ISP2, may encode a zona lysin proteinase. Recently strypsin has also been found within uterine fluid, suggesting a second potential role in hatching. Consistently, we have discovered that ISP1 is also expressed in the uterine secretory gland at the time of hatching. In this study we demonstrate that both ISP1 and ISP2 are secreted together into the uterine lumen at peri-implantation, and that the appearance of ISP protein is regulated positively at the transcriptional level by progesterone and negatively at the posttranscriptional level by estrogen. This negative regulation by estrogen may be overridden in pregnancy as ISP protein expression is restored during oil-induced decidualization. ISP1 and ISP2 proteins are also expressed in proestrous suggesting additional roles in the endometrial cycle. Mol. Reprod. Dev. 69: 252,259, 2004. © 2004 Wiley-Liss, Inc. [source] ORIGINAL ARTICLE: Lipopolysaccharide Alters the Vaginal Electrical Resistance in Cycling and Pregnant MiceAMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 2 2009Varkha Agrawal Problem, Lipopolysaccharide (LPS) has been postulated to exert harmful biologic effects during pregnancy. The objective of present investigation is to measure the vaginal electrical resistance (VER) in LPS-treated normal cycling and pregnant female mice. Method of study, Minimum dose (MD) of LPS (250 ,g/kg body weight) was injected in pregnant female mice through i.p. route on day 0.5 of pregnancy. VER was measured during different phases of reproductive cycle in female mice, which were pre-exposed to LPS and in untreated cycling female mice. VER was also measured in control pregnant female mice (saline-treated mice) through whole pregnancy and LPS-treated female mice in early stages of pregnancy. Results, Vaginal electrical resistance was significantly higher during proestrous or early estrous stage as compared with any other stages of reproductive cycle in mouse. One peak of VER was observed during peri-implantation period of pregnancy in control female mice. The significant differences in the pattern of VER were found between LPS-treated and control female mice during peri-implantation period of pregnancy, and between cycling female mice, which were pre-exposed to LPS and untreated cycling female mice during proestrus. Conclusion, The presented results demonstrate, for the first time, that LPS exposure during pregnancy may be determined by measuring VER in mothers without any adverse effect on ongoing pregnancy and may help in refining the assisted reproduction techniques. [source] Distributions of Endometrial NK Cells, B Cells, T Cells, and Th2/Tc2 Cells Fail to Predict Pregnancy Outcome Following Recurrent AbortionAMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 4 2002TOSHIHIKO MICHIMATA PROBLEM: To evaluate the ability of immunophenotypes of endometrial leukocytes from patients with histories of recurrent abortion to predict outcome of subsequent pregnancy. METHODS OF STUDY: Seventeen women with two successive spontaneous abortions with normal karyotype in the conceptus and 15 women with male-factor infertility were studied. Subsequent pregnancy outcomes in 17 recurrent abortion patients were noted; 11 had live birth, while six aborted in the first trimester. All of 15 women with male-factor infertility became pregnant after therapy, resulting in live birth in all cases. Endometrium was sampled during the peri-implantation period before subsequent pregnancy. We immunostained paraffin-embedded sections for lymphocyte markers including natural killer (NK) cell markers, CD56 and CD16, a B-cell marker CD20, T-cell markers CD3 and CD8, and a specific T-helper(Th)2 and T-cytotoxic (Tc)2 marker termed `chemoattractant receptor-homologous molecule expressed on Th2 cells' (CRTH2). Immunoreactive cells for these antigens were counted and positivity ratios to CD45- or CD3-positive cells were calculated. These parameter were compared between 17 patients with histories of recurrent abortion and 15 control women and also compared between 11 patients whose subsequent pregnancy was successful and six patients whose subsequent pregnancy was a failure. RESULTS: Numbers of CD45+, CD56+, CD16+, CD20+, CD3+, CD8+, and CRTH2+ cells in recurrent abortion patients resembled those in controls. No significant difference in lymphocyte subset numbers or ratios was noted between patients whose subsequent pregnancy was successful and those who again aborted. CONCLUSION: We could not predict pregnancy outcome by immunophenotypic analysis of endometrium in women with recurrent abortion. [source] TH1/TH2,3 Imbalance due to Cytokine-Producing NK, ,, T and NK-,, T Cells in Murine Pregnancy Decidua in Success or Failure of PregnancyAMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 5 2001DAVID A. CLARK PROBLEM: Recurrent spontaneous abortion in DBA/2-mated CBA/J mice has been attributed to the production of Th1 cytokines (tumor necrosis factor [TNF]-, and interferon [IFN]-,) by asialoGM1+ natural killer (NK) cells and V,1.1,6.3+ T cells that infiltrate decidua by day 6.5, during the peri-implantation period. Abortions can be prevented by a second population of V,1.1,6.3 cells, which infiltrate on day 8.5 of gestation, and produce the Th2 cytokine interleukin (IL)-10 and Th3 cytokine transforming growth factor (TGF)-,2. In low abortion rate immunocompetent mice, most of the TGF-,2 is derived from ,, T cells. However, TGF-,2-producing cells are present in the decidua of pregnant severe combined immune deficient (SCID) mice, which lack ,, T cells. METHODS: The cells in day 13.5 decidua of CBA×DBA/2 matings and SCID×SCID matings were identified using flow cytometry and combined surface staining for ,, and/or asialoGM1, and intracellular cytokine staining for TNF-,, IFN-,, and TGF-,2,3. RESULTS: TGF-,2 and TNF-, were found in asialoGM1+ NK cells in SCID mouse decidua. In CBA×DBA/2 mated mice, two major and one minor subsets of cytokine-positive cells were identified: -,,-only T cells, double positive asialoGM1+,,+ (NK-,, T) cells, and a small number of asialoGM1+,,, NK-only cells. The NK-only and NK-,, T subsets showed a greater Th1/Th2,3 pattern of intracellular staining compared with the ,,-only subset. In the CBA×DBA/2 and SCID×SCID systems, Th1/Th2,3 ratios could not predict actual observed abortion rates but did correlate with susceptibility to abortions (if exposed to an additional stimulus such as stress). The known effect of in vivo administration of anti-asialoGM1 antibody on abortion rates within groups of mice exposed to such stresses could also be predicted. CONCLUSION: ,,+ cells in decidua (e.g. V,1+ cells which can recognize trophoblasts) differ based on the presence or absence of the NK marker-asialo-GM1. NK-,, T cells may be quite important in the Th1 response in early pregnancy that predisposes to abortions in CBA×DBA/2 matings, whereas ,, T-only cells appear to be protective. In pregnant SCID mice, the TNF-,+/TGF-,2+ NK population is greatly expanded. An activating stimulus (such as stress or endotoxin) appears to be as important in triggering abortions, as is the Th1/Th2,3 ratio at the feto,maternal interface. [source] | ||||||||||