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At least 433 records · Page 24Linked to original sources
PubMed2005

[Mechanism of insulin-like growth factor-I affecting adhesion of trophoblast cells in vitro].

OBJECTIVE: To investigate the mechanism of insulin-like growth factor-I (IGF-I) affecting adhesion of trophoblast cells in vitro. METHODS: Trophoblast cells were obtained from early gestation at artificial abortion to set up the in vitro trophoblast cell adhesion model. The trophoblast cells were incubated with or without 10 nmol/L IGF-I and were divided into three groups (10 nmol/L IGF-I, 10 nmol/L IGF-I + alpha v beta3Ab, and control). The amount of adhered cells was assessed by examining absorbency using enzyme-linked immunoassay. Morphological changes were studied using scanning electron microscopy. The expression of phosphorylated focal adhesion kinase was determined by immunocytochemistry. RESULTS: After serum-starved trophoblast cells were incubated only with IGF-I, the mean absorbency was 0.491 +/- 0.049, obviously higher than control 0.198 +/- 0.022 and the difference was dramatic (P < 0.01). When cells were pre-treated with antibody against alpha v beta3 integrin and then incubated with IGF-I, the mean absorbency was only 0.184 +/- 0.031, distinctly lower than that incubated with IGF-I, and the difference was significant (P < 0.01), however, compared with control, there was no significant difference (P > 0.05). Scanning electron microscopy highlighted a dramatic increase in lamellipodial formation and extension in the IGF-I treated cells compared with control. Immunocytochemistry staining showed phosphorylated focal adhesion kinase was expressed in the trophoblast cells treated with IGF-I. CONCLUSIONS: 10 nmol/L IGF-I can significantly stimulate trophoblast cells adhesion to fibronectin, but antibody against alpha v beta3 integrin obviously blocks its adhesion. IGF-I can stimulate lamellipodial formation and extension at the adhesion sites, and promote adhesion of trophoblast cells to fibronectin by activating phosphorylated focal adhesion kinase.

Adult↗
PubMed1991

The genes for the trophoblast interferons and the related interferon-alpha II possess distinct 5'-promoter and 3'-flanking sequences.

The genes for trophoblast interferons (IFN) bovine trophoblast protein-1 (bTP-1) and ovine trophoblast protein-1 (oTP-1) are expressed massively in the trophectoderm of preimplantation bovine and ovine concepti during the period of maternal recognition of pregnancy. These 172-amino acid IFN are closely related to the IFN-alpha II, a family of "long" IFN expressed in virus-induced leukocytes. Genomic Southern blotting with a full-length bTP-1 cDNA revealed about 15 genes that bind the probe with varying intensities. By using more specific probes for the 3'-ends of the cDNA, we have shown that only four to five of these represent bTP-1 genes, whereas no more than another four are IFN-alpha II. Genes for bTP-1 and IFN-alpha II, all of which are intronless, have been isolated from bovine genomic libraries, and their nucleotide sequences were compared. Additional bTP-1 genes and two distinct oTP-1 genes have been isolated from bovine and ovine genomic DNA by using the polymerase chain reaction procedure in conjunction with specific 3'- and 5'- primers (derived from the bTP-1 gene sequences determined above). The promoter region up to 100 bases upstream from the transcription start sites of the trophoblast IFN are almost completely conserved across different genes and across species, yet show only limited sequence identity with IFN-alpha II. Two putative binding regions for interferon regulatory factor-1 as well as several GAAANN motifs (where N is any nucleotide) that have been implicated in viral responsiveness of alpha 1- and beta-IFN genes are retained at identical positions in all of the trophoblast genes. Putative interferon regulatory factor-1-binding nucleotide hexamers and GAAANN motifs are also present in the IFN-alpha II genes, but these are organized very differently than in the trophoblast IFN genes. A GAAATG motif is present in IFN-alpha II promoters but is absent in trophoblast IFN genes. Based on the evidence presented, it is proposed that the trophoblast interferons constitute a separate subclass of IFN-alpha distinct from IFN-alpha II and IFN-alpha I.

Animals↗
PubMed1989

Murine trophoblast can be killed by lymphokine-activated killer cells.

The ability of fetal trophoblast cells in the placenta to resist cell-mediated lysis may be important for successful pregnancy. Previous studies in this laboratory demonstrated that cultured midterm mouse trophoblast cells are not susceptible to allospecific CTL generated by standard in vitro protocols, to antibody-dependent cell-mediated cytotoxicity, or to naive or IFN-activated NK cells, despite expressing the requisite target structures. However, we now report that murine trophoblast can be killed, in a non-MHC-specific manner, by LAK cells. Normal mouse spleen cells cultured for 4 days in IL-2-containing lymphokine preparations characteristically killed both NK-sensitive (YAC-1) and NK-resistant (EL4, P815) target cells, and mediated significant lysis of both cultured and freshly isolated trophoblast cells (35 to 55%, E/T 100/1). Pretreatment of the LAK cells with anti-ASGM1 antibody and C markedly reduced the lysis of trophoblast and YAC-1 targets, suggesting that the responsible cells belonged to the NK lineage. The ability of IL-2-activated NK cells to kill midterm murine trophoblast cells was confirmed using a population of highly lytic NK cells generated by culturing spleen cells from severe combined immunodeficiency mice in 500 U/ml rIL-2 for 5 days. These effector cells killed YAC-1, EL4 and P815 target cells at much lower E/T ratios than was achieved with the normal splenic LAK cells, and mediated significant lysis of both freshly isolated (45 to 50%, E/T 20/1) and cultured trophoblast cells (68 to 76%, E/T 20/1). The susceptibility of trophoblast to LAK cells and IL-2-activated NK cells supports the need for suppressor mechanisms regulating IL-2 activity at the maternal-fetal interface.

Animals↗
PubMed1987

Murine trophoblast resists cell-mediated lysis. I. Resistance to allospecific cytotoxic T lymphocytes.

Research on the mechanisms of nonrejection of the fetoplacental allograft has focused on the tissues composing the fetomaternal interface, of which the placental trophoblast, the tissue directly confronting the maternal environment, is considered a prime candidate responsible for the survival of the fetus. We recently developed a method for isolating murine trophoblast, and found that a proportion of trophoblast cells from mature placentas, cultured for 2 days, express class I antigens on their surface, and this expression can be enhanced in vitro by interferon-alpha/beta (IFN-alpha/beta). In the present study, it was determined that cultured trophoblast cells from day 14 placentas were resistant to allospecific cytotoxic T lymphocytes (allo-CTL), while being susceptible to alloantibody and complement-mediated lysis. The trophoblast cells remained resistant to allo-CTL-mediated lysis despite IFN-mediated enhanced expression of class I H-2 antigens on their surface and the addition of phytohemagglutinin into the assay. Inhibition of protein synthesis also had no effect. In contrast, fetal fibroblasts, isolated from the same conceptuses, were readily susceptible to allo-CTL-mediated lysis. That the trophoblast cells do interact with the effector cells was shown by their ability to specifically inhibit the lysis of tumor target cells in a dose-dependent manner. Additionally, trophoblast culture supernatants did not inhibit the lytic activity of allo-CTL, even when concentrated 10- to 25-fold, indicating that a soluble suppressor factor was not inactivating the effector cells. These results suggest that trophoblast cells have a protein synthesis-independent mechanism of resistance to lysis by allo-CTL, which could play an important role in protecting the fetoplacental allograft from maternal immune rejection.

Animals↗
PubMed1981

Rat trophoblastic cell antigenicity.

Trophoblast cells were isolated from the trophoblast giant cell (TGC) layer associated with the rat parietal yolk sac and from the chorioplacenta. Antisera to these cells were produced in the rabbit and analysed with several test systems. Anti-TGC sera reacted with Reichert's membrane (RM), TGC, and chorioplacental trophoblast cells (CTC) by immunodiffusion, and immunofluorescent localization showed that antisera produced against both preparations of trophoblast cells reacted with antigens present in RM and the maternal and renal glomeruli. There was no localization in the trophoblast cells themselves. The abortifacient effects of trophoblastic antisera, which were previously reported, were not found to be due to antisera produced to specific antigens of the trophoblastic preparations which were utilized. In fact the only abortigenic effect observed could be eliminated if the TGC antisera were absorbed with RM. There are several possibilities to explain the presence of antigens in the TGC and CTC which cross-react with RM, and these are discussed, but it is important to recognize that, in the rat, the preparations of antisera to TGC and CTC may produce abortigenic and embryotoxic effects by their actions not on the chorioplacenta, but on the yolk sac placentae. Both the previous reports of embryotoxicity of trophoblastic antisera and our own findings only raise many new questions that have obviously not been answered by this study. But these studies make it quite apparent that any immunological, embryotoxic or teratological studies in the rodent that deal with antigens of the chorioplacenta must include simultaneous immunological and biological studies involving the yolk sac placentae, since dysfunction in either of these placentae can result in various types of reproductive failure.

Animals↗
PubMed1994

Serum progesterone for the exclusion of early pregnancy in women at risk for recurrent gestational trophoblastic neoplasia.

OBJECTIVE: To evaluate the utility of the serum progesterone level for discriminating pregnancy from gestational trophoblastic neoplasia. METHODS: Serum progesterone levels were measured in 61 women with histories of trophoblastic disease who developed a re-elevation in hCG during surveillance and underwent a work-up to differentiate pregnancy from gestational trophoblastic neoplasia. Progesterone levels were analyzed in the context of diagnostic outcome (pregnancy versus gestational trophoblastic neoplasia) to identify optimal threshold levels of progesterone to be used for classifying outcome. RESULTS: Of the 61 women, 37 proved to be pregnant and 24 had gestational trophoblastic neoplasia. Progesterone less than 2.5 ng/mL was predictive of trophoblastic malignancy, with a sensitivity of 83% (20 of 24 subjects were classified correctly as having gestational trophoblastic neoplasia) and a specificity of 95% (35 of 37 patients with progesterone levels at or above 2.5 ng/mL were correctly classified as pregnant). Progesterone of at least 10 ng/mL was associated with viable pregnancy in 97% of the cases. Furthermore, the progesterone level predicted outcome regardless of the serum hCG value. CONCLUSION: The serum progesterone level is useful for discriminating early pregnancy from gestational trophoblastic neoplasia.

Adolescent↗
PubMed1993

Human immunodeficiency virus type 1 infection of choriocarcinoma-derived trophoblasts.

An in vitro model of placental infection by human immunodeficiency virus type 1 (HIV-1) was established using human choriocarcinoma-derived trophoblast lines exposed to free HIV-1 or HIV-1-infected lymphocytic and monocytic cells. Virus infectivity was evaluated by measuring both the levels of p24 HIV-1 antigen and reverse transcriptase activity either from indicator MT-4 lymphocytes after co-cultivation with infected trophoblasts or directly from trophoblast cultures. None of the tested trophoblast lines were permissive, in a detectable manner, to infection by cell-free virus. Furthermore, there were no signs of infection when trophoblasts were exposed to HIV-1-carrying ACH-2 and U1 cells with impaired adhesion capacity. However, the exposure to MOLT-4/IIIB lymphocytes or U937/YH5 monocytes that adhere to substrate cells resulted invariably in productive infection. The ultrastructure of the trophoblasts suggests endocytosis of HIV-1. It appears that the infection of the host cell results from the escape of virions from degradation in lysosomes. Alternatively, HIV-1 may enter by budding directly from the lymphocyte surface into the cytoplasm of trophoblasts. These results confirm previous studies and suggest that CD4-negative placental trophoblasts--the only foetal cells in direct contact with maternal blood--can be susceptible to HIV-1 infection.

Choriocarcinoma↗
PubMed1994

Transcriptional activation of cytochrome P450 side chain cleavage enzyme expression during trophoblast cell differentiation.

The purpose of this study was to investigate P450scc expression during trophoblast differentiation. Biochemical characteristics of P450scc protein and mRNA identified in rat trophoblast tissues were similar to those identified in the rat adrenal gland. Furthermore, P450scc was localized to trophoblast giant cells. This observation prompted an examination of progesterone biosynthesis and P450scc expression in Rcho-1 cells. Rcho-1 cells were derived from a transplantable rat choriocarcinoma, their differentiation can be regulated, and they have the capacity to express the trophoblast giant cell phenotype. Progesterone was produced by Rcho-1 cells and increased approximately 100-fold as the cells progressed from proliferation to differentiation. P450scc protein and mRNA accumulation also increased during trophoblast differentiation. P450scc expression within the Rcho-1 cell line was restricted to trophoblast giant cells. To further investigate the regulation of P450scc expression during trophoblast differentiation, we examined a plasmid construct, containing 894 base pairs of DNA 5' upstream from the P450scc transcriptional start site linked to a human growth hormone reporter gene, following stable transfection into Rcho-1 cells. The transfected P450scc regulatory DNA permitted the expression of human growth hormone which paralleled expression of the endogenous P450scc gene. In conclusion, transcriptional activation of the P450scc gene accompanies trophoblast giant cell differentiation.

Allantois↗
PubMed1996

Evidence for the expression of HLAA-C class I mRNA and protein by human first trimester trophoblast.

In this study, evidence is provided that normal human first trimester extravillous trophoblast expresses class I HLA-C molecules in addition to HLA-G. cDNA from highly purified trophoblast cells obtained by flow cytometric sorting was amplified by reverse-transcriptase PCR using HLA locus-specific primers. The identity of the product was confirmed by Southern blotting and hybridization by a second HLA-C-specific oligonucleotide. HLA-C mRNA was clearly demonstrated in all trophoblast samples as well as in JEG-3 and BeWo choriocarcinoma cells. JAR choriocarcinoma cells did not express HLA-C. The presence of HLA-C protein in extravillous trophoblast was investigated using a panel of Abs: L31 is specific for heavy chains of all HLA-C alleles; Q1/28 reacts with all HLA class I products except HLA-G; HC-10 has preferential reactivity with HLA-B and HLA-C heavy chains. We performed 35S metabolic and 125I surface labeling of normal first trimester trophoblast and found abundant HLA-C intracellularly together with low levels of expression of both the beta 2m-associated forms and free heavy chains on the surface. Flow cytometric analysis of normal trophoblast confirmed the expression of a class I HLA molecule distinct from HLA-G by positive reactivity with Q1/28. Immunohistologic studies of first trimester placenta and the implantation site clearly showed expression of HLA-C in all extravillous trophoblast populations. Our results demonstrate the presence of two HLA class I molecules, HLA-G and HLA-C, on the surface of extravillous trophoblast. These results have implications in understanding how maternal uterine lymphocytes, notably the abundant NK-like cells, might recognize the implanting placenta.

Base Sequence↗
PubMedDate not supplied

Mouse trophoblastic cell lines: II--Relationship between invasive potential and proteases.

The specialized interaction between embryonic and maternal tissue is unique to mammalian development. This interaction begins with the invasion of the uterus by the first differentiated embryonic cells, the trophoblasts, and culminates in formation of the placenta. Because of their highly specialized behavior invasive cells must attach to the extracellular matrix proteins, secrete proteinases, capable of degrading matrix, and migrate through the degraded matrix; invasion is partially dependent on the proteinase activity of the cells. The objective, therefore, was to study a vitro system to examine the mechanism(s) of trophoblast cell invasion and its relationship to proteinases. Since little is known about the actual mechanism(s) involved. The mouse trophoblast cell lines established from placentas of different gestational ages were chosen to study their invasive properties in vitro. To begin to understand the biochemical basis of this behavior, the chromogenic assay and the substrate gel technique was used to analyze the cell associated and secreted plasminogen activators. All lines secrete and synthesize both urokinase-type (uPA) and tissue-type (tPA) plasminogen activators. The most invasive line SM9-2, derived from mid-gestation (day 9) placenta showed the highest enzymatic activity in the conditioned medium (CM), whereas in cell extract (CE) SM-10 line derived from late gestation placenta had the highest PAs activity. Four forms of secreted PAs in CM were of 79, 72, 43 and 35 kDa molecular weights, whereas in CE only 79 kDa molecular weight form of PA was detected using substrate SDS-PAGE gels. Additional observations from cells cultured on Marrigel Invasion Chambers also showed secretion of PAs by noninvading and invading cells in a biphasic pattern suggest the involvement of these enzymes in the extracellular proteolysis. The expression of matrix metalloproteinase gelatinase B (MMP-9) and tissue inhibitor of metalloproteinase (TIMP-1) were examined by RT-PCR in all the lines, however MMP-9 and TIMP-1 signals were strongly expressed in SM9-2 and SM-10 lines respectively. CM and CE were characterized by gelatin zymography, and the proteinases secreted by these cells in CM were confirmed to be metalloproteinases with approximate molecular masses between 52 to 92 kDa. Proteinases secreted by noninvading and invading cells cultured on Matrigel Invasion Chambers were not identical suggesting that specialized, temporally regulated metallopro-teinases are involved in trophoblast invasion. Trophoblast cell invasion in Matrigel Invasion Chambers was significantly inhibited in all the lines by using 1, 10-phenanthroline, an inhibitor of metalloproteinases. The results indicated that mouse trophoblast cells have matrix--degrading capabilities through metalloproteinase activity. Similar metalloproteinase activity has been reported to be necessary for human trophoblast invasion, suggesting a similar mechanism of implantation. Trophoblast culture system described here should be useful in studying some of the early events in human placentation.

Animals↗
PubMed1984

Time-dependent inhibition of aromatase in trophoblastic tumor cells in tissue culture.

Human choriocarcinoma trophoblast cells (JAr line) were utilized as whole cell preparations in tissue culture to evaluate the effects of mechanism-based inactivation or "suicide inhibition" of estrogen biosynthesis. A C-19 acetylenic analog (MDL 18,962) of the substrate, androstenedione, was evaluated in competitive and time-dependent assays. Product formation was determined by accumulation of 3H2O resulting from the stereo-specific elimination of 1 beta-tritium from the androgen substrate. Trophoblast cells exhibited initial linear kinetics for at least 3 h following addition of [1-3H]androstenedione. The Km for androstenedione was 35.1 nM with Vmax of 3.7 pmol/h/10(6) trophoblast cells. Kinetic analysis of time-dependent inhibition of aromatase in trophoblast cells revealed an apparent Ki of 0.6 nM for MDL 18,962 and at t 1/2 of inactivation of 26 min at infinite inhibitor concentration. These studies suggest that a suicide aromatase inhibitor can cause irreversible inhibition of estrogen biosynthesis in intact trophoblast cells. In the presence of 1 nM or 10 nM MDL 18,962, trophoblast cells exhibited initial linear kinetics for estrogen biosynthesis during the first hour following co-incubation with inhibitor and 33 nM substrate. During the subsequent 30 min the rate of estrogen biosynthesis precipitously declined from 104 +/- 24 fmol/min/10(6) cells in control cells to 24 +/- 13 and 8 +/- 4 fmol/min/10(6) trophoblasts treated with 1 or 10 nM MDL 18,962, respectively. This significant decrease in aromatase activity (P less than or equal to 0.01) implied irreversible inactivation, which was supported by prolonged inhibition of aromatase activity in trophoblast cells incubated for 6-48 h following removal of medium containing 3 nM or 30 nM MDL 18,962.

Androstenedione↗
PubMed2000

[Gestational trophoblastic diseases. Classification, epidemiology and genetic data].

Gestational trophoblastic diseases amalgamate several entities with a common denominator which is a hypersecretion of hCG: complete mole, invasive or not, partial mole or triploid syndrome, gestational trophoblastic carcinoma and trophoblastic carcinoma from the implantation site. These entities differ by their origins, their morphology, their evolution and their treatments. Complete moles are diploid and in 80% of cases, chromosomes are only from paternal origin (diandry or dispermy). Their evolution is unpredictable whatever the molecular biology or cytogenetical methods are. Partial moles, generally triploid, are much more frequent (10-20% of miscarriages) than the number of cases diagnosed during the pregnancy. In 85% of cases, two sets of chromosomes are of paternal origin. The gestational trophoblastic carcinoma is diploid and its genetic material comes from both parents. This probably excludes a direct filiation between complete mole and gestational trophoblastic carcinoma. The trophoblastic tumor from the implantation site comes from the trophoblast of the implantation site which explain why its evolution and its prognosis are totally distinct from the previous one. In this report, we successively discuss the natural history of gestational trophoblastic diseases, their epidemiology and the genetic data explaining their origins.

Adult↗
PubMed2003

Extrauterine lesions of intermediate trophoblast.

Lesions of intermediate trophoblast arising in the uterus include exaggerated placental site, placental site nodule, placental site trophoblastic tumor (PSTT), and epithelioid trophoblastic tumor. Only 12 examples of extrauterine lesions of intermediate trophoblast (ELIT) have been previously reported; 7 new cases are described herein. Six lesions were located in the fallopian tube or paratubal region and one in the ovary. The patients were 25 to 47 (average 36) years of age. The lesions ranged from 0.6 to 4 cm in diameter; four were cystic. The four placental site nodules (three tubal, one paratubal) were composed of small, sharply circumscribed nodules of intermediate trophoblast with no mitotic activity. The three PSTTs (two tubal, one ovarian) exhibited irregular stromal infiltration by intermediate trophoblast, mitotic activity, and necrosis. Chronic salpingitis was seen in the six tubal/paratubal cases, and endometriosis was seen in four cases. Immunoreactivity for human placental lactogen, human chorionic gonadotropin, and cytokeratin in two cases was consistent with an origin from intermediate trophoblast. ELITs presumably arise from previous ectopic pregnancies, a history of which was present in two of these patients. Follow-up, available on two of the three patients with PSTT, was uneventful at 6 and 12 years, but study of additional cases is necessary to reliably determine the behavior of extrauterine PSTTs.

Adult↗
PubMed2001

[The c-erbB-related oncoproteins in normal placenta and in gestational trophoblastic diseases (in vitro study)].

In this study the expression of epidermal growth factor receptor (EGFR) and c-erbB-2, c-erbB-3 and c-erbB-4 oncogenes were investigated in gestational trophoblastic diseases and normal first trimester placenta. Furthermore, the possibility that macrophage (IL-1 alpha, IL-1 beta, TNF) and lymphocyte (IL-2, gamma-IFN, GM-CSF) cytokines effects are mediated by changes in EGFR expression were studied. Paraffin sections of 16 cases of partial mole, 25 cases of complete mole, 10 cases of gestational choriocarcinoma and 11 cases of therapeutic abortion were studied immunohistochemically for EGFR, c-erbB-2, c-erbB-3 and c-erbB-4 proteins. The presence of EGFR mRNA was studied using in situ hybridization. JEG-3 human choriocarcinoma cells were incubated with varying concentrations of interleukin 1-alpha, interleukin 1-beta, interleukin 2, gamma-interferon, granulocyte-macrophage colony stimulating factor and tumor necrosis factor-alpha, and the expression of EGFR was measured by radioimmunoassay using a murine monoclonal antibody with specificity for EGFR. Staining for EGFR was detected immunohistochemically in all cell type in gestational trophoblastic diseases and normal placenta. The levels of expression of EGFR in choriocarcinoma and syncytiotrophoblasts and cytotrophoblasts in complete mole were significantly greater than those in syncytiotrophoblasts and cytotrophoblasts in both normal placenta and partial mole (p < 0.01, p < 0.01). The immunoreactivity of c-erbB-2 was significantly stronger in choriocarcinoma and extravillous trophoblast in complete mole than that in extravillous trophoblast in partial mole and normal placenta (p < 0.02, p < 0.01, respectively). Strong immunostaining for EGFR (p = 0.02) and c-erbB-3 (p < 0.01) in extravillous trophoblasts of complete mole was found to be significantly correlated with the development of persistent postmolar gestational trophoblastic tumor. Macrophage-derived cytokines IL-1 alpha, IL-1 beta and TNF significantly suppressed cell growth; this was associated with a significant increase in EGFR expression. The lymphocyte (IL-2, gamma-IFN, GM-CSF) cytokines had no significant effect on either EGFR expression or cell growth. These findings support the concept that cytokines may act as paracrine mediators of autocrine processes involved in choriocarcinoma cell growth regulation by modulating growth factor receptor expression. The EGFR-related family of oncogenes may be important in the pathogenesis and prognosis of gestational trophoblastic diseases.

Choriocarcinoma↗
PubMed2000

Effect of imiquimod on cytokine induction in first trimester trophoblasts.

OBJECTIVES: Imiquimod (IQ) is used clinically for the topical treatment of external genital warts. IQ is an immune response modifier and induces the expression of interferon-alpha and other cytokines in human Peripheral Blood Monocytes (PBMC). Trophoblasts have been previously shown to express inflammatory cytokines upon lipopolysaccharide (LPS) stimulation. The objective of this study was to evaluate the ability of IQ to induce transcription of cytokines in trophoblasts. METHODS: A transformed human first trimester trophoblast cell line, HTR-8/SVneo, was cultured in DMEM containing IQ at concentrations of 0 to 5.0 microg/ml. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) viability assays were conducted to control for any drug-induced cell death. Total RNA was isolated from trophoblasts at 0, 8 and 24 hours of culture and Reverse Transcription-Polymerase Chain Reaction (RT-PCR) was conducted using specific amplimers for the inflammatory cytokines interleukin (IL)-1alpha, IL-1beta, IL-6 and IL-8. RT-PCR of beta-actin was performed to control for equal RNA loading. RESULTS: RT-PCR was unable detect an increase in either IL-1alpha, IL-1beta, IL-6 or IL-8 mRNA in first trimester trophoblasts cultured in the presence of 0 to 5.0 microg/mL of IQ for up to 24 hours. RT-PCR confirmed equal RNA loading and MTT viability assays did not show loss of cell viability at concentrations of IQ up to 5.0 microg/ml. CONCLUSIONS: IQ, at the concentrations tested, did not induce the transcriptional expression of inflammatory cytokines in human first trimester trophoblasts. These data suggest that IQ would not induce the expression of inflammatory cytokines in placental trophoblasts.

Aminoquinolines↗
PubMed1993

Decreased expression of epidermal growth factor and its receptor in the malignant transformation of trophoblasts.

BACKGROUND: Gestational trophoblastic neoplasms comprise the neoplastic spectrum of nonmalignant hydatidiform mole, invasive hydatidiform mole, and truly malignant choriocarcinoma. Increasing evidence indicates that epidermal growth factor (EGF) acts as an enhancer of trophoblast function to produce human chorionic gonadotropin and that EGF and its receptor may provide a growth advantage to certain carcinoma cells. The current study was undertaken to evaluate a possible link between malignant transformation of trophoblast and expression of EGF and EGF receptor. METHODS: Cytologic localization and cellular levels of expression of EGF and EGF receptor in hydatidiform mole, invasive hydatidiform mole, and choriocarcinoma tissue specimens were examined by the avidin-biotin immunoperoxidase techniques with monoclonal antibodies against EGF and EGF receptor. RESULTS: EGF in hydatidiform mole and invasive mole was localized in syncytiotrophoblasts, whereas cytologic localization of EGF receptor in hydatidiform mole and invasive mole was observed in both cytotrophoblasts and syncytiotrophoblasts. By contrast, EGF and EGF receptor in choriocarcinoma were exhibited in cytotrophoblastic and syncytiotrophoblastic elements. Most (72%) hydatidiform moles immunostained intensely for EGF and EGF receptor, whereas most (78%) choriocarcinomas immunostained slightly for EGF and EGF receptor. Invasive mole occupied the middle position in the staining intensity for EGF and EGF receptor, between hydatidiform mole and choriocarcinoma, with 50% of the cases exhibiting moderate staining. CONCLUSIONS: The simultaneous expression of EGF and EGF receptor in the neoplastic trophoblasts implies that EGF may act in an autocrine-paracrine manner in trophoblastic neoplasms. Furthermore, the results obtained suggest that cytologic expression of EGF and EGF receptor in trophoblastic neoplasms decreases in the malignant transformation of trophoblast.

Cell Transformation, Neoplastic↗
PubMed1985

The early development of the sheep trophoblast and the involvement of cell death.

During the period of rapid elongation prior to the initiation of placental attachment (days 12-16 of gestation), the ovine blastocyst consists of a single layer (primarily) of roughly cuboidal trophoblastic cells with an inner lining of flattened endodermal cells. Well-developed spot desmosomes link the adjacent cell borders in both the trophoblastic and endodermal layers. The trophoblastic cells contain acid phosphatase-positive, lysosomelike organelles, the mean diameter of which increases greatly between days 12 and 16 and whose contents vary during development. Also during the developmental period studied, trophoblast cells accumulate lipid; and periodic acid-Schiff-positive binucleate cells appear within the trophoblast layer. A consistent observation throughout the 5 days of rapid growth and differentiation of the blastocyst was the death and disintegration of some trophoblast cells. These disintegrating cells are usually singly dispersed within the trophoblast, although occasionally groups of four or five are observed. The cell death may indicate overall remodelling of the blastocyst, or the cells may represent genetically deficient cells which are unable to respond to the appropriate signal to differentiate.

Animals↗
PubMed1994

Mouse trophoblast cell invasion of extracellular matrix purified from endometrial tissue: a model for peri-implantation development.

We have investigated the invasive activity of mouse trophoblast cells during embryo implantation in vitro by culturing blastocysts with extracellular matrix (ECM) purified from mouse endometrium obtained on day 4 of pregnancy. Endometrium was dissected from lyophilized mouse uteri, and intact ECM was isolated by sequential precipitation in nonionic detergent and high salt. Electron microscopic examination of the ECM revealed typical collagen fibers plus an amorphous material resembling basement membrane. Electrophoretic analysis of the ECM revealed an enrichment of high molecular weight proteins, and immunoblotting indicated the presence of fibronectin, laminin, entactin, and type IV collagen, but not the intracellular proteins 2',3'-cyclic nucleotide-3'-phosphodiesterase or vimentin. Mouse blastocysts cultured with this ECM attached to it within 3 days, and the trophoblast cells began to migrate through the matrix in a manner resembling trophoblast invasion in utero. Unlike blastocysts cultured on plastic surfaces, the trophoblast did not flatten and become disorganized, but retained a polarized, spherical structure. Fluorescent microscopy with fluorescein isothiocyanate-labeled phalloidin revealed a high degree of microfilament organization and established that actin was absent from the ECM preparation. In the presence of a serum substitute, differentiation continued through yolk sac formation. Without serum components, yolk sac did not form; however, light and electron microscopic examination indicated that the invasive behavior of trophoblast cells persisted and was comparable to that of trophoblasts cultured in the presence of the serum substitute. A three-dimensional model for investigating trophoblast behavior in ECM from the endometrium should be of great value in elucidating the cellular and molecular events surrounding the process of blastocyst implantation.

Animals↗