The effects of mifepristone on the structure of human decidua and chorion and Bax and Bcl-2 expression at early stage of pregnancy.

BACKGROUND: As a progesterone receptor antagonist, mifepristone combined with misoprostol is widely used to terminate early pregnancy in clinical practice. It has also been reported that mifepristone may cause cell death in decidual cells and result in hemorrhage of the decidua and insufficient blood supply. However, little is known about the histological effects of mifepristone on human decidua and chorion. METHODS: Histological and subcellular structural changes of decidua and chorionic villi from women taking mifepristone at early pregnancy times were examined by Hematoxylin and eosin (H&E) staining and transmission Electron microscope. The expression of apoptosis-related proteins Bax/Bcl-2 was examined by immunohistochemistry. RESULTS: After 48 h of mifepristone administration, the decidua tissue and chorionic villus structures were altered in women within 39-49 days of gestation and displayed varying degrees of degeneration and necrosis-like features. Apoptotic events were observed in the decidua and chorionic villi of early pregnancy, and mifepristone treatment significantly increases the number of apoptotic cells. The increased apoptotic events were concomitant with the increased expression of Bax and decreased expression of Bcl-2. CONCLUSION: This study provides evidence that mifepristone induces histological and subcellular changes in decidua and chorionic villi. Mifepristone modulates the relative ratio of Bax/Bcl-2 and the increased apoptosis contributes to the pregnancy termination at early stage of pregnancy.

The levonorgestrel-releasing intrauterine device induces endometrial decidualisation in women on tamoxifen.

There is conflicting literature on whether the levonorgestrel-releasing intrauterine system (LNG-IUS; Mirena®) induces decidualisation in the tamoxifen-treated endometrium. The expression of the decidualisation marker IGFBP-1 was measured using immunohistochemistry in endometrial biopsies and in serum (using ELISA) of 20 postmenopausal women at the start of tamoxifen-treatment for breast cancer. Ten women were then fitted with LNG-IUS and the other ten received tamoxifen-treatment only and acted as controls. Samples were taken at baseline and after 12 months. At baseline, all endometrial samples were negative for IGFBP-1 and at 12 months, IGFBP-1 was only expressed in the endometria of women fitted with the LNG-IUS, confirming the observed histological features of decidualisation. By contrast, serum IGFBP-1 concentrations were increased by tamoxifen, but not in the group receiving LNG-IUS. In conclusion, tamoxifen induces a rise in serum IGFBP-1 suggesting a systemic, possibly hepatic effect, whilst LNG abrogates this in both the liver and endometrium. Impact statement What is already known on this subject? Previous reports of the use of LNG-IUS in women on tamoxifen have provided conflicting evidence as to whether the endometrium exhibited decidualisation or not. These reports were however based solely on histological examination and lacked supporting biochemical data. What do the results of this study add? After 12 months of treatment with LNG-IUS, the endometria of women on tamoxifen show histological features of decidualisation and the presence of the decidualisation marker IGFBP-1, suggesting that levonorgestrel protects the tamoxifen-treated uterus from additional pathology by causing decidualisation. Serum levels of IGFBP-1 were expected to be a reflection of uterine production, but contrary to expectations, higher levels were identified in women on tamoxifen alone. These data suggest that an inhibition of tamoxifen-induced serum IGFBP-1 production (possibly from a hepatic source) by LNG-IUS occurred and indicates independent systemic effects of both drugs in post menopausal breast cancer patients. What are the implications of these findings for clinical practice and/or further research? This research demonstrated a mechanism for endometrial protection in women on tamoxifen. It also alerts clinicians to the fact that both tamoxifen and LNG-IUS exert systemic effects in this patient group.

Improved ex vivo expansion of mesenchymal stem cells on solubilized acellular fetal membranes.

Coatings produced from extracellular matrixes (ECMs) have emerged as promising surfaces for the improved ex vivo expansion of mesenchymal stem cells (MSCs). However, identifying a readily available source of ECM to generate these coatings is currently the bottleneck of this technology. In this study, we assessed if ECM coatings derived from decellularized fetal membranes were a suitable substrate for MSC expansion. We separated and decellularized the two main components of the fetal membranes, the amnion and the chorion. Characterization of the decellularized membranes revealed that each membrane component has a distinct composition, implying that coatings produced from these materials would have unique biological properties. The membranes were processed further to produce solubilized forms of the decellularized amniotic membrane (s-dAM) and decellularized chorionic membrane (s-dCM). On s-dAM coatings decidual MSCs (DMSC) were more proliferative than those cultured on tissue culture plastic alone or on Matrigel coatings; were smaller in size (a measure of MSC potency); exhibited greater adipogenic differentiation capacity; and improved osteogenic capacity. Additionally, long term culture studies showed late passage DMSCs (passage 8) cultured on s-dAM showed a decrease in cell diameter over three passages. These data support the use of s-dAM as a substrate for improved MSC expansion. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 232-242, 2019.

Selected Case From the Arkadi M. Rywlin International Pathology Slide Club: Peritoneal Lipofuscinosis and Deciduosis in Pregnancy.

Peritoneal lipofuscinosis is a very rarely recognized condition occurring during pregnancy characterized by brown pigmentation of the omentum and peritoneum, a decidual reaction and benign mesothelial cells. The iron negative pigment, which is likely to be confused with hemosiderin in the hematoxylin and eosin stain, is lipofuscin. The seminar case, apparently the third published, arose in a 37-year-old woman who presented in October 2015 at 24 weeks pregnancy with abdominal pain. Investigations revealed a ruptured left ovarian cyst and rising serum carcinoembryonic antige levels. At laparotomy, there was no free intraperitoneal blood but the omentum and uterine serosa were black. Histology showed lipofuscinosis and a decidual reaction. The patient delivered a normal baby in February 2016 and was clinically well after delivery. A left ovarian endometriotic cyst was removed in February 2017. The patient made a good recovery with no clinically apparent symptoms from the liposuscinosis. We postulate that the endometriotic cyst had ruptured and released blood into the peritoneal cavity in 2015. The iron from the red cells breakdown was then rapidly resorbed because of the pregnancy requirements for iron, leaving lipofuscin in peritoneal macrophages.

Decidualization of the canine uterus: From early until late gestational in vivo morphological observations, and functional characterization of immortalized canine uterine stromal cell lines.

The apparent lack of classical mechanisms for maternal recognition of pregnancy is one of the most intriguing features of canine reproduction. Consequently, similar levels of circulating luteal steroids are observed in pregnant and non-pregnant dogs. However, the early pre-implantation canine embryo locally modulates uterine responses to its presence, facilitating the successful onset of pregnancy. As a part of this interaction, the canine uterus undergoes a species-specific decidualization. Maternal stroma-derived decidual cells develop, the only cells of the canine placenta expressing progesterone receptor (PGR). There exists an acute need for an in vitro stable cell line model for canine decidualization. Therefore, herein our goal was to establish, immortalize and characterize such a cell line. We immortalized three monolayer dog uterine stromal (DUS) cell lines by stably transfecting them with SV40Tag oncogene. Cells retained their mesenchymal character for over 30 passages, as evidenced by VIMENTIN staining. Genomic incorporation of the SV40Tag protein was confirmed by immunofluorescence and Western blot analyses. Cells submitted to a classical in vitro decidualization protocol (N6,2'-O-dibutyryladenosine-3',5'-cyclic monophosphate) revealed upregulated gene levels of selected major decidualization markers (e.g. PRLR, PGR, IGF1, PTGES). Additionally, the basic decidualization capability of PGE2 was demonstrated, revealing increased levels of, for example, PGR and PRLR gene expression, thereby implying its involvement in the progesterone-dependent decidualization in the canine uterus. In summary, our in vitro model with immortalized DUS cell line could serve as an ideal and unique model to study the underlying molecular and endocrine mechanisms of canine decidualization.

Women with recurrent spontaneous abortion have decreased 25(OH) vitamin D and VDR at the fetal-maternal interface

Immunological mechanisms have been proposed to underlie the pathogenesis of recurrent spontaneous abortion (RSA). Vitamin D has a potent immunomodulatory effect, which may affect pregnancy outcome. The objective of this study was to investigate 25-hydroxyvitamin D [25(OH) D] concentration and vitamin D receptor (VDR) expression in the decidual tissues of RSA patients. Thirty women with RSA (RSA group) and thirty women undergoing elective abortion (control group) were recruited during 2016 from gynecology outpatient clinics. We measured 25(OH) D, interleukin (IL)-17, IL-23, transforming growth factor β (TGF-β), VDR and 1-α-hydroxylase (CYP27B1) in decidual tissues collected during the abortion procedure. In the RSA group, 25(OH) D and TGF-β were significantly decreased while IL-17 and IL-23 were significantly increased compared with the control group. VDR expression was significantly decreased in the RSA group compared with the control group. Logistic regression analysis showed a significant negative correlation between 25(OH) D in decidual tissues and RSA. These results indicated that vitamin D concentrations in the decidua are associated with inflammatory cytokine production, suggesting that vitamin D and VDR may play a role in the etiology of RSA.

NK cells control HIV-1 infection of macrophages through soluble factors and cellular contacts in the human decidua.

BACKGROUND: During the first trimester of pregnancy, HIV-1 in utero transmission is rare despite the permissivity of the placenta and the decidua (the uterine mucosa during pregnancy) to infection. In the decidua from the first trimester of pregnancy, macrophages (dMs) are the HIV-1 main target cells. Decidual natural killer (dNK) cells account for 70 % of decidual leukocytes. They display distinct phenotype and functions compared to peripheral NK cells. At the periphery, NK cells are involved in the control of HIV-1 infection. In this study, we investigate whether human decidual natural killer (dNK) cells control dM HIV-1 infection. RESULTS: Autologous cocultures of infected dMs with dNK cells reveal that dNK cells strongly inhibit dM HIV-1 infection. The addition of dNK cells to dMs at different times after infection suggests that the control occurs before the complete establishment of the infection. Double chamber cocultures show that cellular contacts are necessary for an optimal control of infection. Nevertheless, soluble factors secreted by dMs and dNK cells in double chamber cocultures partially inhibit dM HIV-1 infection, indicating that soluble factors have also a role in the control of infection. IFN-γ secretion is increased in infected and uninfected cocultures. We show that IFN-γ is involved in the control of dM HIV-1 infection by dNK cells. CONCLUSIONS: These results demonstrate that human dNK cells inhibit efficiently HIV-1 infection in dMs in vitro, and highlight the role of innate immune determinants in the control of HIV-1 transmission.

The effect of 7 days of letrozole pretreatment combined with misoprostol on the expression of progesterone receptor and apoptotic factors of placental and decidual tissues from first-trimester abortion: a randomized controlled trial.

OBJECTIVE: To evaluate if letrozole-induced suppression of estradiol reduces progesterone receptor expression and apoptosis in the first-trimester placenta. STUDY DESIGN: We performed a double-blinded, randomized, placebo-controlled trial. We randomized 20 women requesting first-trimester abortion with gestation up to 63 days to receive either letrozole 10 mg daily or placebo pretreatment for 7 days before administrating 400 mcg of vaginal misoprostol followed by suction abortion. We collected the placental and decidual tissues on which we performed immunohistochemical staining for progesterone receptor and apoptotic markers (active caspase 3, caspase 3, Bcl2, CD95, fas ligand) and determined H-scores of each based on the intensities of staining. We performed terminal deoxynucleotidyl transferase-mediated dUTP-digoxigenin nick end labeling (TUNEL) assay for apoptosis in the samples of four women to confirm the findings from apoptotic markers. RESULTS: We excluded one woman in the letrozole group from the analysis because she had passage of abortus after taking letrozole, leaving 19 women (9 in the letrozole group, 10 in the placebo group) for analysis. There was no significant difference in the H-scorings of progesterone receptor and apoptotic markers, as well as proportion of apoptotic cells on TUNEL assay between the two groups. The H-scores for the progesterone receptor were 8.17 ± 2.67 (mean ± SD) in the letrozole group and 9.01 ± 2.82 in the placebo group (p=0.36). CONCLUSION: We did not detect a difference in the expression of progesterone receptor and apoptotic markers in placental and decidual tissues after letrozole pretreatment for 7 days in first-trimester abortion. IMPLICATIONS: We did not confirm the hypothesis that letrozole reduces progesterone receptor expression and induces apoptosis in the first-trimester placenta. Further studies are required to allow better understanding of the mechanism by which estrogen suppression following the use of letrozole can lead to improved abortion rate in the first trimester.

Dysfunction of Liver Receptor Homolog-1 in Decidua: Possible Relevance to the Pathogenesis of Preeclampsia.

Preeclampsia (PE) is a multisystem disorder unique to Homo sapiens that is known to cause maternal and perinatal mortality and morbidity. Between 5-7% of all pregnancies are affected by PE and it is responsible for approximately 50,000 maternal deaths annually. The pathogenesis of PE remains poorly understood. However, the results of this study indicated that insufficient decidualization plays a significant role. NR5A1 and NR5A2 are orphan members of the Ftz-F1 subfamily of nuclear receptors and are involved in mammal follicular development, female reproduction, steroidogenesis, and decidualization. The expression of NR5A1 and NR5A2 in the human decidua and their functions during decidualization were investigated using in vitro cultured cells by real-time PCR, immunohistochemistry, western blotting, and siRNA techniques. The results demonstrated that the levels of NR5A2 mRNA and protein in the decidual tissues of women with PE were lower than those of normal pregnant women. However, the levels of NR5A1 mRNA and protein did not significantly differ between groups. The expression of NR5A2 was upregulated after in vitro decidualization, but the expression of NR5A1 remained low and showed no difference compared with that of the control cells. Knocking down of NR5A2 in human endometrial stromal cells (hESC) resulted in a significant reduction in their expression of decidualization markers (IGFBP1 and PRL) and signaling pathway molecules (WNT4 and BMP2) (P < 0.05). From these data, we concluded that NR5A2 is pivotal for the decidualization of decidual tissues and cultured human endometrial stromal cells. Disorders of the endometrium in decidual tissues may be associated with the abnormal decidualization thought to cause PE.

Claudin-3, claudin-7, and claudin-10 show different distribution patterns during decidualization and trophoblast invasion in mouse and human.

Implantation of the mammalian embryo requires profound endometrial changes for successful pregnancy, including epithelial-mesenchymal transition of the luminal epithelium and stromal-epithelial transition of the stromal cells resulting in decidualization. Claudins (Cldn) determine the variability in tight junction paracellular permeability and may play a role during these epithelial and decidual changes. We here localized Cldn3, Cldn7 and Cldn10 proteins in the different compartments of murine endometrium up to day 8.5 of pregnancy (dpc) as well as in human endometrium and first trimester decidua. In murine estrous endometrium, luminal and glandular epithelium exhibited Cldn3 and Cldn7, whereas Cldn10 was only detectable in glandular epithelium. At 4.5 dpc, Cldn3 protein shifted to an apical localization, whereas Cldn7 vanished in the epithelium of the implantation chamber. At this stage, there was no stromal signal for Cldn3 and Cldn7, but a strong induction of Cldn10 in the primary decidual zone. Cldn3 proteins emerged at 5.5 dpc spreading considerably from 6.5 dpc onward in the endothelial cells of the decidual blood sinusoids and in the decidual cells of the compact antimesometrial region. In addition to Cldn3, Cldn10 was identified in human endometrial epithelia. Both proteins were not detected in human first trimester decidual cells. Cldn3 was shown in murine trophoblast giant cells as well as in human extravillous trophoblast cells and thus may have an impact on trophoblast invasion in both species. We here showed a specific claudin signature during early decidualization pointing to a role in decidual angiogenesis and regulation of trophoblast invasion.

Novel "omics" approach for study of low-abundance, low-molecular-weight components of a complex biological tissue: regional differences between chorionic and basal plates of the human placenta.

Tissue proteomics has relied heavily on two-dimensional gel electrophoresis, for protein separation and quantification, then single protein isolation, trypsin digestion, and mass spectrometric protein identification. Such methods are predominantly used for study of high-abundance, full-length proteins. Tissue peptidomics has recently been developed but is still used to study the most highly abundant species, often resulting in observation and identification of dozens of peptides only. Tissue lipidomics is likewise new, and reported studies are limited. We have developed an "omics" approach that enables over 7,000 low-molecular-weight, low-abundance species to be surveyed and have applied this to human placental tissue. Because the placenta is believed to be involved in complications of pregnancy, its proteomic evaluation is of substantial interest. In previous research on the placental proteome, abundant, high-molecular-weight proteins have been studied. Application of large-scale, global proteomics or peptidomics to the placenta have been limited, and would be challenging owing to the anatomic complexity and broad concentration range of proteins in this tissue. In our approach, involving protein depletion, capillary liquid chromatography, and tandem mass spectrometry, we attempted to identify molecular differences between two regions of the same placenta with only slightly different cellular composition. Our analysis revealed 16 species with statistically significant differences between the two regions. Tandem mass spectrometry enabled successful sequencing, or otherwise enabled chemical characterization, of twelve of these. The successful discovery and identification of regional differences between the expression of low-abundance, low-molecular weight biomolecules reveals the potential of our approach.

Prostaglandin pathway gene expression in human placenta, amnion and choriodecidua is differentially affected by preterm and term labour and by uterine inflammation.

BACKGROUND: Elucidation of the biochemical pathways involved in activation of preterm and term human labour would facilitate the development of effective management and inform judgements regarding the necessity for preterm tocolysis and post-term induction. Prostaglandins act at all stages of human reproduction, and are potentially activators of labour. METHODS: Expression of 15 genes involved in prostaglandin synthesis, transport and degradation was measured by qPCR using tissue samples from human placenta, amnion and choriodecidua at preterm and full-term vaginal and caesarean delivery. Cellular localisation of eight prostaglandin pathway proteins was determined by immunohistochemistry. RESULTS: Expression of prostaglandin pathway genes was differentially affected by factors including gestational age at delivery, and the incidence and duration of labour. Chorioamnionitis/deciduitis was associated with upregulation of PTGS2 (prostaglandin-endoperoxide synthase 2 (prostaglandin G/H synthase and cyclooxygenase)), along with the inflammatory genes IL8 (interleukin 8), S100A8 (S100 calcium binding protein A8) and TLR2 (toll-like receptor 2), in amnion and choriodecidua, and with downregulation of CBR1 (carbonyl reductase 1) and HPGD (hydroxyprostaglandin dehydrogenase 15-(NAD)) in choriodecidua. Protein localisation differed greatly between the various maternal and fetal cell types. CONCLUSIONS: Preterm and term labour are associated with distinct prostaglandin pathway expression profiles; inflammation provokes specific changes, unrelated to the presence of labour; spontaneous and induced term labour are indistinguishable.

Florid diffuse peritoneal deciduosis mimicking carcinomatosis in a primigravida patient: a case report and review of the literature.

A case of a 27 year old G1P0 female with a dichorionic, diamniotic twin pregnancy presenting with premature rupture of membranes found to have omental caking and diffuse yellow-tan peritoneal nodules, clinically suspicious for carcinomatosis. The case work-up showed this to be an example of florid-diffuse peritoneal deciduosis mimicking carcinomatosis which has since resolved 4 months postpartum.

Compartmentalization of pro-inflammatory cytokine levels in renal-transplanted pregnant women.

OBJECTIVE: We evaluated whether chronic exposure to immunosuppression in transplant recipients modulate the placental inflammatory cytokine levels associated to gestational tolerance mechanisms. METHODS: Serum samples were collected from 12 renal transplanted pregnant under immunosuppressive regimen treatment and 10 healthy women in second/third trimester of gestation. Term placental tissues (decidua and chorionic villi) were also obtained after elective caesarean. Serum IL-1ß, IL-6, IL-8, IL-12p70 and TNF-α were measured, as also in placental homogenates, by Cytometric Bead Array (CBA) combined with flow cytometry and, TGF-ß and IL-18 were measured by ELISA. RESULTS: Serum levels of IL-6 (p = 0.0001) and TNF-α (0.0112) were higher in the 2nd and 3rd trimesters and in decidua the spectrum of increased pro inflammatory cytokines was wider: IL-1ß (p = 0.0001), IL-6 (p = 0.0001), IL-8 (p = 0.0001), IL-12p70 (p = 0.0001), TGF-ß (p = 0.0089) and TNF-α (p = 0.0002). TGF-ß1 was particularly increased in decidual compartment (p = 0.001). In the chorionic villous, pro inflammatory profile also were maintained. High IL-1ß (p = 0.0001), IL-6 (p = 0.0001), IL-8 (p = 0.0001) and TNF-α (p = 0.0001) levels establish a similar pattern to that seem in decidua. CONCLUSION: Immunosuppressors may impair the immune response, but when associated with pregnancy the cytokine levels seems to shift a proinflammatory profile in placental compartments, which might also impact on the gestational outcomes in transplanted mothers.

Endopolyploid and proliferating trophoblast cells express different patterns of intracellular cytokeratin and glycogen localization in the rat placenta.

The presence of keratin intermediate filaments is a characteristic of trophoblast differentiation. Meantime, their intracellular localization in the functionally different subtypes of placental trophoblast is poorly investigated in rodent, whereas their placentae are being broadly investigated in recent years as a model of the feto-maternal interaction. The purpose was to study the intracellular distribution of cytokeratin filaments in correlation with glycogen deposits, both being important constituents of the trophoblast cells in rat placenta. Different rat trophoblast cell populations exhibited different patterns of cytokeratin immunolocalization. The most intensive immunostaining was observed in the highly endopolyploid SGTCs (secondary giant trophoblast cells) at the border with decidua basalis. The most prominent cytokeratin-positive threads were found at the periphery of cytoplasm and in the extensive system of cytoplasmic sprouts by which the SGTC connect each other. Similar cytokeratin intensity and distribution was detected in the TSC (trabecular spongiotrophoblast cells) of the junctional zone of placenta that line the lacunae with the maternal blood. Clusters of highly proliferative pre-glycogen as well as glycogen cells showed some weaker cytokeratin signals mostly in the perinuclear and peripheral zones of cytoplasm. At the 11.5th to the 13.5th day of gestation, the interstitial and endovascular invasive endopolyploid TGTCs (tertiary giant trophoblast cells) prove the intensive cytokeratin staining throughout the cytoplasm and its sprouts. Meantime, the TGTCs were glycogen negative. By contrast, glycogen was heavily accumulated in the glycogen cells that belong both to the junctional zone of placenta and the cuff of the central arterial channel underlying the monolayer of endovascularly invading TGTCs. Thus, the TGTCs that are first to penetrate into the depth of the uterine wall do not contain glycogen but are accompanied by the glycogen-rich cells. The SGTC also contained the prominent deposits of glycogen at the periphery of cytoplasm and in the cytoplasmic sprouts. At the 16th day of gestation, an extensive interstitial invasion of the cytokeratin-positive glycogen trophoblast cells from the junctional zone was observed. The patterns of cytokeratin and glycogen intracellular localization are specific for each subtype of the rat trophoblast; that is, most probably, accounted for by the functional diversity of different trophoblast populations, i.e. patterns of invasion/phagocytosis and their involvement in a barrier at the feto-maternal interface.

Progesterone receptors in the human pregnancy uterus: do they hold the key to birth timing?

The process and timing of human parturition involves a complex hormonal dialogue between maternal and fetal systems that transforms the uterine muscle into the laboring state. Progesterone, through specific progesterone receptors (PRs) in uterine tissues, is key player in this process. For most of pregnancy, progesterone promotes myometrial relaxation and its withdrawal initiates parturition. In women, a functional progesterone withdrawal occurs by changes in PR isoform expression and/or function in myometrial cells. Research in the last 10 to 20 years has shown that progesterone actions are mediated by a variety of PRs including the classic nuclear PRs, PR-A and PR-B that mediate genomic actions, and a family of membrane-bound PRs that mediate non-genomic actions. Herein, we review current understanding of the PRs expressed in the human pregnancy uterus, the pathways through which they mediate progesterone actions, and their roles in controlling myometrial contractility and the parturition process.

Abnormal uterine bleeding as a presentation of metastatic breast disease in a patient with advanced breast cancer.

BACKGROUND: Extragenital carcinomas secondarily involving the uterus are very rare and they usually occur as a manifestation of widespread disease. When the metastases involve the endometrium in a diffuse, permeative pattern, sparing the glands, they may cause problems in the diagnosis. CASE: A case of metastatic carcinoma to the endometrium with a decidua-like pattern is reported. The patient had a history of breast carcinoma and presented with vaginal bleeding. The pathologic findings in the uterine curettings raised the differential diagnosis between metastatic breast carcinoma and non-neoplastic stromal lesions. The presence of nuclear atypia and mitotic activity along with the appropriate immunohistochemical findings revealed the neoplastic nature of the endometrial lesion and confirmed its origin from the breast. CONCLUSION: Unusual uterine bleeding in a patient with breast cancer should alert the gynecologist to the possibility of metastatic breast disease. Furthermore, the metastasis to the uterus and to other organs of the genital tract can be considered as a preterminal event.

Human trophoblast cells express the immunomodulator progesterone-induced blocking factor.

Progesterone-induced blocking factor (PIBF) is an immunomoduatory factor with anti-abortive properties. In this study, we present evidence that PIBF is synthesized in the human placenta and determine its cellular source. Expression of PIBF was analysed with polyclonal rabbit anti-human PIBF antibodies against recombinant N-terminal 48kDa PIBF in first trimester and term placental tissues and in the choriocarcinoma cell line JAR by means of immunohistochemistry, confocal laser scanning microscopy of double immunofluorescence labelling, and Western blotting; RT-PCR was performed for analysis of PIBF mRNA in isolated trophoblast cells. PIBF protein is present in human first trimester and term placenta. Double immunofluorescence labelling localised PIBF to the extravillous cytotrophoblast. PIBF is also expressed heterogeneously by syncytiotrophoblast and part of the villous cytotrophoblast. Full-length PIBF mRNA encoded by exons 1-18 is present in isolated first trimester and term villous trophoblast and in the choriocarcinoma cell line JAR. The corresponding 90kDa protein is expressed by JAR cells, first trimester and term villous trophoblast cells. In addition, these cells express PIBF proteins of 50 and 34kDa. Trophoblast is a source of PIBF; its tissue distribution suggests a role both in systemic and local (decidual) immunoregulation.

Expression of BAFF in the trophoblast and decidua of normal early pregnant women and patients with recurrent spontaneous miscarriage.

BACKGROUND: BAFF, the B cell activation factor, is a member of the tumor necrosis factor (TNF) ligand family that binds to BCMA, TACI, and BAFF-R. Previous studies have shown that members of the TNF family are detected in human placental trophoblast cells, but the expression patterns of BAFF involved in human decidua and the differential expression of BAFF between normal pregnancy and miscarriage are still incompletely documented or unknown. This study was designed to investigate the expression of BAFF and BAFF-R in the trophoblast and decidua of normal early pregnant women and recurrent spontaneous abortion (RSA) patients. METHODS: Forty-five patients with RSA and 45 normal pregnant women were included in this study. By reverse transcriptase-polymerase chain reaction (RT-PCR), Western blotting and immunohistochemical experiments, we explored the expression of BAFF and BAFF-R in the maternal-fetal interface of normal early pregnant women and RSA patients. RESULTS: Analysis by RT-PCR and Western blotting revealed that BAFF was detected in both trophoblast and decidua of all the samples, and the expression level was higher in the tissues of normal early pregnant women (P<0.05) than that of recurrent spontaneous abortion patients under the same gestational weeks. Messages for BAFF-R were absent. Immunohistochemical experiments showed that expression of BAFF was cell-specific which was localized to villous cytotrophoblast and syncytiotrophoblast cells in trophoblast and to stromal cells in decidua. Whereas BAFF was prominent on the trophoblast and decidua of normal early pregnant women, it was decreased in the tissues of RSA patients. CONCLUSIONS: BAFF might steer maternal leukocytes away from a harmful immune response and toward a favorable one and play a potentially vital role for successful pregnancy.