HLA-DR is aberrantly expressed at feto-maternal interface in pre-eclampsia

In normal pregnancy, villous cytotrophoblast and syncytiotrophoblast do not express HLA Class I and Class II molecules, while invasive extravillous trophoblast only express class I HLA-C and the atypical class Ib antigens, HLA-G, -E and -F. Inadequate maternal tolerance of invasive trophoblast has been proposed as a possible immunologic trigger of poor trophoblast invasion and subsequent occurrence of pre-eclampsia. This study aimed to investigate possible aberrant expression of class II HLA-DR on placentae and syncytiotrophoblast-derived extracellular vesicles (STEVs), obtained by dual placental perfusion, from pre-eclampsia (n = 23) and normal pregnant (n = 14) women. Here we demonstrate that HLA-DR can be detected in syncytiotrophoblast from a significant proportion of pre-eclampsia but not control placentae. HLA-DR was also observed, by flow cytometry, on STEVs and associated with placental alkaline phosphatase to validate their placental origin. HLA-DR positive syncytiotrophoblast was detected in placental biopsies from pre-eclampsia but not normal control cases, using immunohistochemistry. The HLA may be fetal or maternal origin. In the latter case a possible mechanism of acquisition is trogocytosis.

Angiogenic factors: potential to change clinical practice in pre-eclampsia?

Pre‐eclampsia is a complex disease with significant maternal and fetal morbidity and mortality. Its syndromic nature makes diagnosis and management difficult. The field is rapidly evolving with the definition of pre‐eclampsia being challenged by some organisations, with proteinuria no longer being essential in the presence of other features. In the last decade, angiogenic factors, in particular soluble fms‐like tyrosine kinase 1 (sFlt‐1), have emerged as important molecules in the pathogenesis of pre‐eclampsia. Here we review the most recent evidence regarding the potential of these factors as biomarkers and therapeutic targets for pre‐eclampsia.

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A review of angiogenic factors, sFlt‐1 and PlGF, in the diagnosis, prediction and management of pre‐eclampsia.

A review of angiogenic factors, sFlt‐1 and PlGF, in the diagnosis, prediction and management of pre‐eclampsia.

Trophoblast Glycoprotein (TPGB/5T4) in Human Placenta: Expression, Regulation, and Presence in Extracellular Microvesicles and Exosomes

BACKGROUND

Many parallels exist between growth and development of the placenta and that of cancer. One parallel is shared expression of antigens that may have functional importance and may be recognized by the immune system. Here, we characterize expression and regulation of one such antigen, Trophoblast glycoprotein (TPGB; also called 5T4), in the placenta across gestation, in placentas of preeclamptic (PE) pregnancies, and in purified microvesicles and exosomes.

METHODS

Trophoblast glycoprotein expression was analyzed by real-time reverse transcription-polymerase chain reaction (RT-PCR), Western blot, and immunohistochemistry. Regulation of 5T4 in cytotrophoblast cells was examined under either differentiating conditions of epidermal growth factor or under varying oxygen conditions. Microvesicles and exosomes were purified from supernatant of cultured and perfused placentas.

RESULTS

Trophoblast glycoprotein expression was prominent at the microvillus surface of syncytiotrophoblast and on the extravillous trophoblast cells, with minimal expression in undifferentiated cytotrophoblasts and normal tissues. Trophoblast glycoprotein expression was elevated in malignant tumors. In cytotrophoblasts, 5T4 was induced by in vitro differentiation, and its messenger RNA (mRNA) was increased under conditions of low oxygen. PE placentas expressed higher 5T4 mRNA than matched control placentas. Trophoblast glycoprotein was prominent within shed placental microvesicles and exosomes.

CONCLUSION

Given the potential functional and known immunological importance of 5T4 in cancer, these studies reveal a class of proteins that may influence placental development and/or sensitize the maternal immune system. In extravillous trophoblasts, 5T4 may function in epithelial-to-mesenchymal transition during placentation. The role of syncytiotrophoblast 5T4 is unknown, but its abundance in shed syncytial vesicles may signify route of sensitization of the maternal immune system.

Isolation of syncytiotrophoblast microvesicles and exosomes and their characterisation by multicolour flow cytometry and fluorescence Nanoparticle Tracking Analysis

The human placenta releases multiple types and sizes of syncytiotrophoblast (STB) extracellular vesicles (EV) into the maternal circulation that exhibit diverse biological activities. The placental perfusion technique enables isolation of these STBEV, but conventional flow cytometry can only be used to phenotype EV down to ∼300 nm in size. Fluorescence Nanoparticle Tracking Analysis (fl-NTA) has the potential to phenotype EV down to ∼50 nm, thereby improving current characterisation techniques. The aims of this study were to prepare microvesicle and exosome enriched fractions from human placental perfusate (n=8) and improve fl-NTA STBEV detection. Differential centrifugation and filtration effectively removed contaminating red blood cells from fresh placental perfusates and pelleted a STB microvesicle (STBMV) fraction (10,000×g pellet - 10KP; NTA modal size 395±12 nm), enriched for the STB marker placental alkaline phosphatase (PLAP) and a STB exosome (STBEX) fraction (150,000×g pellet - 150KP; NTA modal size 147±6 nm), enriched for PLAP and exosome markers Alix and CD63. The PLAP positivity of 'standard' 10KP and 150KP pools (four samples/pool), determined by immunobead depletion, was used to optimise fl-NTA camera settings. Individual 10KP and 150KP samples (n=8) were 54.5±5.7% (range 17.8-66.9%) and 30.6±5.6% (range 3.3-51.7%) PLAP positive, respectively. We have developed a reliable method for enriching STBMV and STBEX from placental perfusate. We also standardised fl-NTA settings and improved measurement of PLAP positive EV in STBMV. However, fl-NTA is not as sensitive as anti-PLAP Dynabead capture for STBEX detection, possibly due to STBEX having lower surface expression of PLAP. These important developments will facilitate more detailed studies of the role of STBMV and STBEX in normal and pathological pregnancies.

Illness Identity and the Self-regulatory Model in Recovery from Early Stage Gynaecological Cancer

Women in recovery from early stage gynaecological cancer have extremely good survival and low recurrence rates. Despite this, women continue to feel vulnerable to cancer recurrence for years after treatment. Semi-structured interviews were utilized to explore the factors involved in recovery from gynaecological cancer. This article argues that the illness identity of gynaecological cancer perpetuates a vulnerability to cancer recurrence. The absence of self-diagnosis prior to medical diagnosis is important in the formation of gynaecological cancer illness identity. A lack of self-diagnosis may be due to the 'normalization' of initial symptomatology. It is suggested that illness identity is responsible for maintaining fears of symptom-free cancer recurrence. The self-regulatory model is employed to explore this process, looking in particular at the reinforcement of reassurance needs.

Pre-eclampsia: Definitions, paternal contributions and a four stage model

It is 40 years since I started researching pre-eclampsia. Much has changed but some old problems persist. These include the debate of how to define a syndrome, the inheritance and genetics of pre-eclampsia, why primiparae are so susceptible and is primipaternity important? If it is, in a multiparous pregnancy (after changing partners), the old hypothesis that pre-eclampsia is the outcome of failed maternal immunoregulation to accommodate nature's transplant - the fetus - must be confronted. These points are briefly reviewed and a four stage model of pre-eclampsia derived.

Do women referred for colposcopy receive adequate information from the primary care team?

The objective of this study was to assess whether women had been counselled by their primary health care team and whether or not they had received any information about colposcopy. We also asked where the best information had been obtained. The setting was the colposcopy clinic of a large district general hospital, the design of which was a cross-sectional audit using a questionnaire. The subjects were 100 women attending the colposcopy clinic. The results show that 63% of women were seen by their primary health care team before the colposcopy visit and that counselling was associated with knowledge about colposcopy (P = 0.017). However, 43% of women felt that they knew nothing about colposcopy whilst 19% of women thought that the information they had obtained was not useful. We conclude that there is scope for improving the quality, timing and provision of information for women undergoing colposcopy.

Audit of the views of gynaecological cancer patients regarding follow-up

The purpose of this study was to audit patients opinions on routine follow-up and discharge from the gynaecology clinic. The setting was the gynaecology clinic of a large district general hospital and the design was a cross-sectional audit analysis using a written questionnaire. The subjects were 103 women attending the gynaecological out patients for review following previous treatment for various gynaecological cancers. Ninety patients took part in the study, of these 36 (40%) wished for 'free access', 29 (32%) wished for routine hospital follow-up, and 25 (28%) wished for discharge but with follow-up by their general practitioner. There were no statistically significant differences in choices between cancer groups. The choice of 'free access'seemed to be an important choice for women. We conclude that routine hospital follow-up of women treated for gynaecological cancer is not the desire of the majority and it appears the women may have different inherent psychological characteristics.

Inhibin, activin, follistatin, activin receptors and beta-glycan gene expression in the placental tissue of patients with pre-eclampsia

The objective of this study was to quantify the relative expression of inhibin alpha, inhibin/activin beta(A), beta(B), beta(C), follistatin, activin receptors and beta-glycan genes in placental tissue of term pre-eclamptic patients and controls to investigate if these genes are up-regulated in the placenta in pre-eclampsia. Seven women with pre-eclampsia symptoms were matched with 10 normal pregnant controls for gestational age, maternal age, and parity. Total RNA was isolated from each sample. Complementary DNA samples produced by reverse transcription were used in the real time PCR to quantify the expression of inhibin alpha subunit, inhibin/activin beta(A), beta(B), beta(C) subunits, follistatin, ACTRIA, ACTRIB, ACTRIIA, ACTRIIB, beta-glycan and GAPDH genes. The ratio between the target and GAPDH expression was calculated to provide relative gene expression. Inhibin alpha:GAPDH and inhibin/activin beta(A): GAPDH ratios were significantly higher in placental tissue from women with pre-eclampsia (P = 0.04 and P = 0.01 respectively) compared with matched control placental gene expression. Placental samples from both groups expressed beta(B), beta(C), follistatin, activin receptors and beta-glycan genes. However, there was no significant difference in the relative expression of these genes between the groups. Increases in the placental expression of inhibin alpha and inhibin/activin beta(A) subunit genes could contribute to the rise in circulating levels of inhibin A and activin A in pre-eclampsia. The mechanism(s) involved in increased gene expression in pre-eclampsia is as yet unclear.

Improving outcomes in gynaecological cancer: the impact of centralisation on patient flows and service provision

Responses to a postal questionnaire and cancer registry data were utilised to evaluate the impact of the recent NHS Executive guidelines for the management of gynaecological malignancies on patient flows and service provision in the West Midlands. They were also used to assess the service provision in the west midlands in relation to these guidelines. Eighty-nine per cent (16/18) trusts returned completed questionnaires. Seventy-two per cent (46/64) of recommendations were achieved by all four centres; 18% (10/57) by all 12 units. The cancer registration data revealed 404 cases that would need to be transferred to the cancer centres per annum in order to implement the guidelines. A more detailed analysis for the northern area of the region estimated that a further 120 cases per annum would need to be managed at the main centre. This study has shown that implementation of the guidelines will require significant shifts in patient flows. This will increase workloads for the cancer centre and have an impact on service provision and resource allocation.

Tryptophan degradation by human placental indoleamine 2,3-dioxygenase regulates lymphocyte proliferation

1. The physiological importance of human placental indoleamine 2,3-dioxygenase (EC 1.13.11.42), the first and rate-limiting enzyme in tryptophan metabolism, in regulating feto-maternal immunology has been studied. 2. Concentrations were measured in placental villous explant conditioned media of 14 amino acids that are known to be required for lymphocyte proliferation. In the absence of interferon-gamma only tryptophan and threonine were significantly lowered; in the presence of interferon-gamma (known to stimulate indoleamine 2,3-dioxygenase) tryptophan but not threonine depletion was much greater. 3. Peripheral blood mononuclear cell proliferation determined by measuring thymidine incorporation into DNA following culture in the medium previously conditioned by culture of villous explants was markedly reduced when placental indoleamine 2,3-dioxygenase was stimulated with interferon-gamma. Inhibition of placental indoleamine 2,3-dioxygenase by 1-methyl-tryptophan prevented inhibition of thymidine incorporation. Supplementation of the conditioned medium with tryptophan but no other amino acid completely reversed the inhibition of thymidine incorporation. 4. Flow cytometric analysis showed that CD4-positive T lymphocyte division was specifically suppressed by indoleamine 2,3-dioxygenase-mediated tryptophan depletion. This inhibition of T cell proliferation was due to arrest of cell cycle progression. 5. To study the mechanism of tryptophan sensing we examined the ability of 11 L-tryptophan analogues to support lymphocyte proliferation. Only L-tryptophan methyl and ethyl esters were able to stimulate proliferation in tryptophan-free media. Since both of these molecules are readily degraded to tryptophan by intracellular esterases this suggests that the tryptophan sensor is intracellular. 6. Our results show that mechanisms are present in the human placenta which are able to regulate cellular proliferation of the maternal immune system. This mechanism is dependent both on placental indoleamine 2,3-dioxygenase-mediated tryptophan degradation and on tryptophan sensing systems within lymphocytes.

The pathogenesis of pre-eclampsia

Syncytiotrophoblast normally sheds redundant placental debris into the maternal circulation, a process, which depends on apoptosis. It is renewed from the underlying mononuclear cytotrophoblast. We propose that the continual clearance of this debris from the maternal circulation causes a systemic inflammatory response that is present in all pregnant women in the third trimester. Pre-eclampsia occurs when the systemic inflammatory response decompensates. This may occur if the burden of the debris is abnormally high, or if the woman's response to the process is excessive. There is evidence that oxidative stress in the placenta could lead to an overload of debris by stimulating apoptosis or necrosis or both. Such stress would be most likely with spiral artery disease either from deficient placentation or acute atherosis, In this model, deficient placentation is not the cause of pre-eclampsia but a powerfully predisposing condition.

Flow cytometric measurement of intracellular Th1 and Th2 cytokine production by human villous and extravillous cytotrophoblast

A wide variety of cytokines are present at the maternal-fetal interface, but the extreme cellular complexity of the placenta has made it difficult to determine which cytokines are produced by which cells. Hence novel flow cytometric methods have been applied to determine intracellular cytokine production by specific cell-types in placental cell suspensions. Cell suspensions were prepared from first and third trimester chorionic villi and third trimester amniochorion by enzymatic digestion and Percoll density gradient centrifugation. After overnight incubation in the presence of monensin, cells were fixed, permeabilized and labelled with antibodies for villous cytotrophoblast (cytokeratin+, MHC class I-), extravillous cytotrophoblast (cytokeratin+, MHC class 1+) and leucocytes (CD45+). These cell types were further characterized by their expression of EGFR (proliferative cytotrophoblast) and c-erbB2 (invasive cytotrophoblast). Production of IL-4, IL-10, TNF-alpha, IFN-gamma and IL-12 was determined by simultaneous labelling with the appropriate monoclonal antibodies. Only IL-4 was detected consistently in all samples of cytotrophoblast. IL-10 was not detected but IL-10 mRNA was demonstrated in third trimester chorionic villus digests by RT-PCR. Although IL-4 secretion has not been demonstrated, these data suggest that, in vivo there may be a "Th2 type cytokine bias" orchestrated by the trophoblast. It is proposed that other cytokines (including IL-10 and TNF-alpha) are produced by decidual leukocytes, and not cytotrophoblast, at the maternal-fetal interface.

Expression of inflammatory cytokines in placentas from women with preeclampsia

It is postulated that inadequate remodeling of the uterine spiral arteries in preeclampsia leads to focal ischemia and generation of inflammatory cytokines, such as tumor necrosis factor (TNF alpha) and interleukins (ILs), by the placenta. Our objective was to compare TNF alpha, IL-1 alpha, IL-1 beta, and IL-6 levels in placentas from patients with preeclampsia and normal term pregnancies. Because the placenta is a large heterogeneous organ, we analyzed multiple sites per placenta. On the average, there was a 3-fold variation in cytokine protein levels across the eight sites analyzed for each placenta. However, there were no significant overall differences among the normal term, preeclamptic, and preterm placentas from women without preeclampsia. There were also no significant differences in TNF alpha messenger ribonucleic acid between the normal term and preeclamptic placentas, although TNF alpha messenger ribonucleic acid levels were lower in placentas from preterm patients without diagnosis of preeclampsia than in the normal term placentas. In vitro, hypoxia stimulated the production of TNF alpha, IL-1 alpha and IL-1 beta, but not that of IL-6, by placental villous explants from both groups of patients, and this was not exaggerated in preeclampsia. Finally, although peripheral and uterine venous levels of TNF alpha were elevated in preeclamptic women compared with normal term patients, the ratio of uterine to peripheral venous TNF alpha levels was not significantly different from 1.0 for either patient group. Taken together, these results suggest that sources other than the placenta contribute to the elevated concentrations of TNF alpha and IL-6 found in the circulation of preeclamptic women.

Glutathione S-transferase GSTM1 and GSTT1 genotypes in ovarian cancer: association with p53 expression and survival

The objective of this study was to determine whether the association between GSTM1 null/GSTTI null and survival in ovarian cancer is mediated by the influence of these genes on p53 expression. In 81 women with pure invasive ovarian cancer, GSTM1 null and GSTT1 null genotypes were identified using polymerase chain reaction and p53 expression was assessed using immunohistochemistry. The association of these factors with survival was examined using Cox's proportional hazards regression models. Performance status (P < 0.001), operative stage (P = 0.004), residual disease (P = 0.001), histologic subtype (P = 0.05), tumor grade (P = 0.007), and the combined GSTMI null/GSTTl null genotype (P = 0.023) were all individually associated with survival. p53 expression was not associated with survival (P = 0.45). In a multivariate analysis, the effects of GSTM1 null/GSTT1 null on survival were lost when residual disease and tumor grade were included. The effects of p53 expression on survival were unchanged when residual disease, tumor grade, operative stage, and performance score were included. GSTM1 null/GSTT1null did not influence the effects of p53 expression on survival and vice versa. The GSTM1 null/GSTT1 null genotype was associated with response to primary chemotherapy (P = 0.007) but p53 expression was not. We conclude that the association of GSTM1 null/GSTTl null with survival appears to be mediated through different mechanisms to p53 expression in ovarian cancer and in addition, may be a better predictor of outcome.