Uterine selection of human embryos at implantation

Human embryos frequently harbor large-scale complex chromosomal errors that impede normal development. Affected embryos may fail to implant although many first breach the endometrial epithelium and embed in the decidualizing stroma before being rejected via mechanisms that are poorly understood. Here we show that developmentally impaired human embryos elicit an endoplasmic stress response in human decidual cells. A stress response was also evident upon in vivo exposure of mouse uteri to culture medium conditioned by low-quality human embryos. By contrast, signals emanating from developmentally competent embryos activated a focused gene network enriched in metabolic enzymes and implantation factors. We further show that trypsin, a serine protease released by pre-implantation embryos, elicits Ca2+ signaling in endometrial epithelial cells. Competent human embryos triggered short-lived oscillatory Ca2+ fluxes whereas low-quality embryos caused a heightened and prolonged Ca2+ response. Thus, distinct positive and negative mechanisms contribute to active selection of human embryos at implantation

Selective COX-2 inhibition affects fatty acids, but not COX mRNA expression in patients with FAP

Familial adenomatous polyposis (FAP) provides a model for sporadic colorectal cancer development. Cyclooxygenase (COX) inhibition may ameliorate polyp development, but rofecoxib was withdrawn due to cardiovascular side effects. Although this selective COX-2 inhibitor, like diet, may alter the fatty acid and eicosanoid pattern, data on the potential alteration in tissues after use, are scarce. The aims were to study if rofecoxib might influence the fatty acid distribution in serum phospholipids and duodenal lesions, mRNA for COX-1 and COX-2 in leucocytes and duodenal lesions, and finally plasma levels of PGE2 in a randomized, double-blind, placebo controlled study (n = 38). Significant reductions were found for essential fatty acid index both in serum phospholipids (P = 0.01, 95% CI = −0.9; −0.1), and in duodenal lesions (P = 0.04, 95 CI % = −0.9; −0.1) after treatment. No treatment effects were found on the COX mRNA expression, or in the plasma PGE2 levels. Dietary AA/EPA ratio was inversely associated with all the indicators of EFA status (all P < 0.01). These findings suggest that the effects of COX chemoprevention should be further investigated in FAP and that dietary needs should be included in the treatment of FAP

Control of human endometrial stromal cell motility by PDGF-BB, HB-EGF and trophoblast-secreted factors

Human implantation involves extensive tissue remodeling at the fetal-maternal interface. It is becoming increasingly evident that not only trophoblast, but also decidualizing endometrial stromal cells are inherently motile and invasive, and likely contribute to the highly dynamic processes at the implantation site. The present study was undertaken to further characterize the mechanisms involved in the regulation of endometrial stromal cell motility and to identify trophoblast-derived factors that modulate migration. Among local growth factors known to be present at the time of implantation, heparin-binding epidermal growth factor-like growth factor (HB-EGF) triggered chemotaxis (directed locomotion), whereas platelet-derived growth factor (PDGF)-BB elicited both chemotaxis and chemokinesis (non-directed locomotion) of endometrial stromal cells. Supernatants of the trophoblast cell line AC-1M88 and of first trimester villous explant cultures stimulated chemotaxis but not chemokinesis. Proteome profiling for cytokines and angiogenesis factors revealed neither PDGF-BB nor HB-EGF in conditioned media from trophoblast cells or villous explants, while placental growth factor, vascular endothelial growth factor and PDGF-AA were identified as prominent secretory products. Among these, only PDGF-AA triggered endometrial stromal cell chemotaxis. Neutralization of PDGF-AA in trophoblast conditioned media, however, did not diminish chemoattractant activity, suggesting the presence of additional trophoblast-derived chemotactic factors. Pathway inhibitor studies revealed ERK1/2, PI3 kinase/Akt and p38 signaling as relevant for chemotactic motility, whereas chemokinesis depended primarily on PI3 kinase/Akt activation. Both chemotaxis and chemokinesis were stimulated upon inhibition of Rho-associated, coiled-coil containing protein kinase. The chemotactic response to trophoblast secretions was not blunted by inhibition of isolated signaling cascades, indicating activation of overlapping pathways in trophoblast-endometrial communication. In conclusion, trophoblast signals attract endometrial stromal cells, while PDGF-BB and HB-EGF, although not identified as trophoblast-derived, are local growth factors that may serve to fine-tune directed and non-directed migration at the implantation site

Progression of duodenal adenomatosis in familial adenomatous polyposis: due to ageing of subjects and advances in technology

Familial adenomatous polyposis patients are at risk of duodenal cancer. Surveillance is indicated and the extent of duodenal polyposis is quantified by the Spigelman staging system. We noticed an impressive increase in high Spigelman stages over the years and therefore decided to investigate whether this increase might be due to the time-lapse since the inception of surveillance or related to improvements in endoscopic imaging and/or changes in dysplasia-reporting. Patients who were investigated by the same endoscopist since 1980 in at least 2 different episodes of technical improvements were eligible. The period 1980–2009 was divided into 4 episodes using the following landmarks: replacement of fibre-endoscopes by video-endoscopes in 1987, change in processors in 1995, change in image resolution in 2000, and change in dysplasia-reporting in 2006. An increase in Spigelman stages from low stages (0–II 100%) to high stages (III 28.1%, IV 43.8%) was seen (median follow-up: 19.5 years). In patients who progressed, a median of 4 years elapsed before progression by one stage occurred and 7 years to progress by two stages. In a mixed-model analysis, both time-lapse and technical improvements were determinant factors for duodenal disease progression. When both factors were introduced in the model, the time-lapse as well as the change in image resolution and dysplasia-ranking contributed consistently in increasing Spigelman scores and stages. The impressive increase in severity of duodenal polyposis is determined by time-lapse, technological advances and change in dysplasia-reporting. These results might call for a revised Spigelman classification

Genetic polymorphisms in the cyclooxygenase-2 gene, use of nonsteroidal anti-inflammatory drugs, and breast cancer risk

INTRODUCTION: The association between use of nonsteroidal anti-inflammatory drugs (NSAIDs) and breast cancer risk remains unclear. Inconsistencies in previously reported findings may be partly due to differences in expression of cyclooxygenase (COX)-2. We hypothesized that genetic polymorphisms (COX-2 .926, COX-2 .5209, and COX-2 .8473) may reduce overall breast cancer risk or risk for subtypes of breast cancer by modulating the inflammatory response and may interact with aspirin or any NSAID use. METHODS: We conducted a population-based, case-control study in which we genotyped 1,067 breast cancer cases and 1,110 control individuals included in the Long Island Breast Cancer Study Project. RESULTS: No major effects of the three COX-2 variant alleles on breast cancer risk were found. A total of eight distinct haplotypes and 18 diplotypes were observed in the population. Overall, no significant associations between COX-2 haplotypes/diplotypes and breast cancer risk were observed. Among women who used aspirin or any NSAID there was little evidence for an interaction with the at-risk COX-2 genotypes, with one exception. Among women with hormone receptor positive breast cancer, the reduced risk for any NSAID use was only evident among those who had at least one variant C allele of COX-2 .8473 (odds ratio = 0.7, 95% confidence interval = 0.5 to 1.0; P for the interaction = 0.02). There was no corresponding interaction for aspirin use, possibly because of limited power. CONCLUSION: These data provide modest evidence that the C allele of COX-2 .8473 may interact with NSAIDs to reduce risk for hormone receptor positive breast cancer

Regulation of human endometrial function: mechanisms relevant to uterine bleeding

This review focuses on the complex events that occur in the endometrium after progesterone is withdrawn (or blocked) and menstrual bleeding ensues. A detailed understanding of these local mechanisms will enhance our knowledge of disturbed endometrial/uterine function – including problems with excessively heavy menstrual bleeding, endometriosis and breakthrough bleeding with progestin only contraception. The development of novel strategies to manage these clinically significant problems depends on such new understanding as does the development of new contraceptives which avoid the endometrial side effect of breakthrough bleeding

Full-length human placental sFlt-1-e15a isoform induces distinct maternal phenotypes of preeclampsia in mice

<div><p>Objective</p><p>Most anti-angiogenic preeclampsia models in rodents utilized the overexpression of a truncated soluble fms-like tyrosine kinase-1 (sFlt-1) not expressed in any species. Other limitations of mouse preeclampsia models included stressful blood pressure measurements and the lack of postpartum monitoring. We aimed to 1) develop a mouse model of preeclampsia by administering the most abundant human placental sFlt-1 isoform (hsFlt-1-e15a) in preeclampsia; 2) determine blood pressures in non-stressed conditions; and 3) develop a survival surgery that enables the collection of fetuses and placentas and postpartum (PP) monitoring.</p><p>Methods</p><p>Pregnancy status of CD-1 mice was evaluated with high-frequency ultrasound on gestational days (GD) 6 and 7. Telemetry catheters were implanted in the carotid artery on GD7, and their positions were verified by ultrasound on GD13. Mice were injected through tail-vein with adenoviruses expressing hsFlt-1-e15a (n = 11) or green fluorescent protein (GFP; n = 9) on GD8/GD11. Placentas and pups were delivered by cesarean section on GD18 allowing PP monitoring. Urine samples were collected with cystocentesis on GD6/GD7, GD13, GD18, and PPD8, and albumin/creatinine ratios were determined. GFP and hsFlt-1-e15a expression profiles were determined by qRT-PCR. Aortic ring assays were performed to assess the effect of hsFlt-1-e15a on endothelia.</p><p>Results</p><p>Ultrasound predicted pregnancy on GD7 in 97% of cases. Cesarean section survival rate was 100%. Mean arterial blood pressure was higher in hsFlt-1-e15a-treated than in GFP-treated mice (∆MAP = 13.2 mmHg, p = 0.00107; GD18). Focal glomerular changes were found in hsFlt-1-e15a -treated mice, which had higher urine albumin/creatinine ratios than controls (109.3±51.7μg/mg vs. 19.3±5.6μg/mg, p = 4.4x10^-2; GD18). Aortic ring assays showed a 46% lesser microvessel outgrowth in hsFlt-1-e15a-treated than in GFP-treated mice (p = 1.2x10^-2). Placental and fetal weights did not differ between the groups. One mouse with liver disease developed early-onset preeclampsia-like symptoms with intrauterine growth restriction (IUGR).</p><p>Conclusions</p><p>A mouse model of late-onset preeclampsia was developed with the overexpression of hsFlt-1-e15a, verifying the <i>in vivo</i> pathologic effects of this primate-specific, predominant placental sFlt-1 isoform. HsFlt-1-e15a induced early-onset preeclampsia-like symptoms associated with IUGR in a mouse with a liver disease. Our findings support that hsFlt-1-e15a is central to the terminal pathway of preeclampsia, and it can induce the full spectrum of symptoms in this obstetrical syndrome.</p></div

Breast Cancer Epigenetics: From DNA Methylation to microRNAs

Both appropriate DNA methylation and histone modifications play a crucial role in the maintenance of normal cell function and cellular identity. In cancerous cells these “epigenetic belts” become massively perturbed, leading to significant changes in expression profiles which confer advantage to the development of a malignant phenotype. DNA (cytosine-5)-methyltransferase 1 (Dnmt1), Dnmt3a and Dnmt3b are the enzymes responsible for setting up and maintaining DNA methylation patterns in eukaryotic cells. Intriguingly, DNMTs were found to be overexpressed in cancerous cells, which is believed to partly explain the hypermethylation phenomenon commonly observed in tumors. However, several lines of evidence indicate that further layers of gene regulation are critical coordinators of DNMT expression, catalytic activity and target specificity. Splice variants of DNMT transcripts have been detected which seem to modulate methyltransferase activity. Also, the DNMT mRNA 3′UTR as well as the coding sequence harbors multiple binding sites for trans-acting factors guiding post-transcriptional regulation and transcript stabilization. Moreover, microRNAs targeting DNMT transcripts have recently been discovered in normal cells, yet expression of these microRNAs was found to be diminished in breast cancer tissues. In this review we summarize the current knowledge on mechanisms which potentially lead to the establishment of a DNA hypermethylome in cancer cells