Search

Macrophages represent the second major type of decidual leukocytes at the fetomaternal interface. Changes in macrophage number and activity are associated with fetal loss and pregnancy complications. Glycodelin-A (GdA) is an abundant glycoprotein in the first-trimester decidua. It is involved in fetomaternal defense and early placental development through its regulatory activities in various immune cells. The N-glycosylation of GdA mediates the binding and therefore the activities of the molecule. In this study, we studied the biological activities of GdA in the functions of human monocytes/macrophages. GdA was purified from amniotic fluid by affinity chromatography. GdA treatment did not affect the viability, cell death, or phagocytic activity of the monocytes/macrophages. GdA, but not recombinant glycodelin without glycosylation, induced IL-6 production as demonstrated by cytokine array, intracellular staining, and ELISA. GdA also induced phosphorylation of ERK in monocytes/macrophages. The involvement of ERKs in IL-6 induction was confirmed using pharmacological inhibitors. Co-immunoprecipitation showed that L-selectin on the monocytes/macrophages was the binding protein of GdA. Treatment with anti-L-selectin antibody reduced GdA binding and GdA-induced IL-6 production. GdA-treated macrophages suppressed IFN-γ expression by co-cultured T-helper cells in an IL-6-dependent manner. These results show that GdA interacts with L-selectin to induce IL-6 production in monocytes/macrophages by activating the ERK signaling pathway. In turn, the increased IL-6 production suppresses IFN-γ expression in T-helper cells, which may play an important role in inducing a Th-2-polarized cytokine environment that flavors the immunotolerance of the fetoplacental unit.

Background: The maternal-fetal interface has a unique immunological response towards the implanting placenta. It is generally accepted that a T-helper type-2 (Th-2) cytokine prevailing environment is important in pregnancy. The proportion of Th-2 cells in the peripheral blood and decidua is significantly higher in pregnant women in the first trimester than in non-pregnant women. Glycodelin-A (GdA) is a major endocrine-regulated decidual glycoprotein thought to be related to fetomaternal defence. Yet the relationship between its immunoregulatory activities and the shift towards Th-2 cytokine profile during pregnancy is unclear., Methods: GdA was immunoaffinity purified from human amniotic fluid. T-helper, T-helper type-1 (Th-1) and Th-2 cells were isolated from the peripheral blood. The viability of these cells was studied by XTT assay. Immunophenotyping of CD4/CD294, cell death and GdA-binding were determined by flow cytometry. The mRNA expression, surface expression and secretion of Fas/Fas ligand (FasL) were determined by quantitative polymerase chain reaction, flow cytometry and ELISA, respectively. The activities of caspase-3, -8 and -9 were measured. The phosphorylation of extracellular signal-regulated kinases (ERK), p38 and, c-Jun N-terminal kinase was determined by western blotting., Results: Although GdA bound to both Th-1 and Th-2 cells, it had differential actions on the two cell-types. GdA induced cell death of the Th-1 cells but not the Th-2 cells. The cell death was mediated through activation of caspase -3, -8 and -9 activities. GdA up-regulated the expression of Fas and inhibited ERK activation in the Th-1 cells, which might enhance the vulnerability of the cells to cell death caused by a trophoblast-derived FasL., Conclusions: The data suggest that GdA could be an endometrial factor that contributes to the Th-2/Th-1 shift during pregnancy.

Objective: Gestational diabetes mellitus (GDM) is a common metabolic disorder of pregnancy. Patients with GDM are at risk for high fetal mortality and gestational complications associated with reduced immune tolerance and abnormal carbohydrate metabolism. Glycodelin-A (GdA) is an abundant decidual glycoprotein with glycosylation-dependent immunomodulatory activities. We hypothesized that aberrant carbohydrate metabolism in GDM was associated with changes in glycosylation of GdA, leading to defective immunomodulatory activities., Research Design and Methods: GdA in the amniotic fluid from women with normal (NGdA) and GDM (DGdA) pregnancies was purified by affinity chromatography. Structural analysis of protein glycosylation was preformed by lectin-binding assay and mass spectrometry. Cytotoxicity, cell death, cytokine secretion, and GdA binding of the GdA-treated lymphocytes and natural killer (NK) cells were determined. The sialidase activity in the placental tissue from normal and GDM patients was measured., Results: GDM affected the glycosylation but not the protein core of GdA. Specifically, DGdA had a lower abundance of α2-6-sialylated and high-mannose glycans and a higher abundance of glycans with Sda (NeuAcα2-3[GalNAcβ1-4]Gal) epitopes compared with NGdA. DGdA had reduced immuosuppressive activities in terms of cytotoxicity on lymphocytes, inhibitory activities on interleukin (IL)-2 secretion by lymphocytes, stimulatory activities on IL-6 secretion by NK cells, and binding to these cells. Desialylation abolished the immunomodulation and binding of NGdA. Placental sialidase activity was increased in GDM patients, which may account for the reduced sialic acid content of DGdA., Conclusions: Taken together, this study provides the first direct evidence for altered enzymatic glycosylation and impaired bioactivity of GdA in GDM patients.

Background: The study was conducted to assess the effects of levonorgestrel (LNG) on hormonal behavior and on the secretory pattern of intrauterine glycodelin at the midcycle of ovulatory women., Study Design: Thirty healthy sterilized women with normal ovarian function were studied during one control untreated cycle and one LNG-treated cycle. In the treated cycle, each woman received two doses of 0.75 mg of LNG 12 h apart during the preovulatory phase approximately 2 days before the LH surge. Daily follicle development recordings were performed until follicle rupture was observed, and serum glycodelin, LH, estradiol, estrone and progesterone were measured as well. In addition, glycodelin concentrations were assayed in uterine flushing obtained on Days LH+1 and LH+12., Results: LNG did not modify follicle rupture in 20 of 30 women. In spite of ovulatory progesterone and the occurrence of follicle rupture in these women, luteal phase length was significantly decreased, as well as the serum concentrations of LH, estradiol and estrone in the periovulatory phase. Glycodelin in serum and uterine flushings was significantly elevated in the periovulatory phase when compared to control cycles., Conclusions: LNG taken at the dose used in emergency contraception before the LH surge increased prematurely serum and intrauterine concentrations of glycodelin at the time of ovulation. Since there are well established glycodelin inhibitory effects upon fertilization, these results may represent an additional action of LNG in situations where the intervention did not interfere with ovulation., (Copyright © 2010 Elsevier Inc. All rights reserved.)

Background: Glycodelin-A interacts with spermatozoa before fertilization, but its role in modulating sperm functions is not known. Zona pellucida-induced acrosome reaction is crucial to fertilization and its dysfunction is a cause of male infertility. We hypothesized that glycodelin-A, a glycoprotein found in the female reproductive tract, potentiates human spermatozoa for zona pellucida-induced acrosome reaction., Methods: Glycodelin isoforms were immunoaffinity purified. The sperm intracellular cAMP concentration, protein kinase-A (PKA) and extracellular signal-regulated kinase (ERK) activities, and intracellular calcium were measured by ELISA, kinase activity assay kits and Fluo-4AM technique, respectively. The phosphorylation of inositol 1,4,5-trisphosphate type-1 receptor (IP3R1) mediated by ERK was determined by western blotting. Zona pellucida-induced acrosome reaction was detected by Pisum sativum staining., Results: Pretreatment of spermatozoa with glycodelin-A significantly up-regulated adenylyl cyclase/PKA activity and down-regulated the activity of ERK and its phosphorylation of IP3R1, thereby enhancing zona pellucida-induced calcium influx and zona pellucida-induced acrosome reaction. Glycodelin-F or deglycosylated glycodelin-A did not have these actions. Treatment of spermatozoa with a protein kinase inhibitor abolished the priming activity of glycodelin-A, whilst ERK pathway inhibitors mimic the stimulatory effect of glycodelin-A on zona pellucida-induced acrosome reaction., Conclusions: Glycodelin-A in the female reproductive tract sensitizes spermatozoa for zona pellucida-induced acrosome reaction in a glycosylation-specific manner through activation of the adenylyl cyclase/PKA pathway, suppression of extracellular signal-regulated kinase activation and up-regulation of zona pellucida-induced calcium influx. The action of glycodelin-A may be important in vivo to ensure full responsiveness of human spermatozoa to the zona pellucida.

Glycodelin-A increased the secretion of interleukin-6, interleukin-13, and granulocyte-macrophage colony-stimulating factor from natural killer cells in the peripheral blood but does not affect their viability, cell death, and cytotoxicity. These data suggest that glycodelin-A contributes to the cytokine shift in early pregnancy., (Copyright 2010 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.)

Glycodelin is a glycoprotein with 4 known glycoforms, namely glycodelin-S, glycodelin-A, glycodelin-F and glycodelin-C. The glycoforms are present in the female reproductive tract which the spermatozoa must pass through before fertilizing the oocyte. Thus the spermatozoa interact with each of these glycoforms in succession. The glycoforms have different effects on sperm function. Glycodelin-S in the seminal plasma suppresses albumin-induced cholesterol efflux from the spermatozoa and thereby regulates the initiation of capacitation. Glycodelin-A in the oviductal fluid suppresses extracellular signal-regulated kinase making the spermatozoa more sensitive to zona pellucida-induced acrosome reaction. Follicular fluid glycodelin-F suppresses progesterone-induced acrosome reaction and prevents premature acrosome reaction. Glycodelin-A and glycodelin-F also inhibit spermatozoa-zona pellucida binding by interacting with sperm surface fucosyltransferase-5, which also binds to zona pellucida glycoproteins. The physiological implication of this phenomenon remains to be determined. The inhibitory activities of glycodelin-A and glycodelin-F on spermatozoa-zona pellucida binding is removed by glycodelin-C in the cumulus matrix. Glycodelin-C not only displaces sperm-bound glycodelin-A and glycodelin-F, it also enhances spermatozoa-zona pellucida binding. These different biological activities of the glycodelin isoforms are determined by glycosylation of the proteins. Deglycosylation abolishes the binding and therefore the action of the glycodelins on spermatozoa. Knowledge of the mechanism of actions of glycodelins may enable development of novel strategies for fertility regulation.

Glycodelin is a human glycoprotein with four reported glycoforms, namely glycodelin-A (GdA), glycodelin-F (GdF), glycodelin-C (GdC), and glycodelin-S (GdS). These glycoforms have the same protein core and appear to differ in their N-glycosylation. The glycosylation of GdA is completely different from that of GdS. GdA inhibits proliferation and induces cell death of T cells. However, the glycosylation and immunomodulating activities of GdF and GdC are not known. This study aimed to use ultra-high sensitivity mass spectrometry to compare the glycomes of GdA, GdC, and GdF and to study the relationship between the immunological activity and glycosylation pattern among glycodelin glycoforms. Using MALDI-TOF strategies, the glycoforms were shown to contain an enormous diversity of bi-, tri-, and tetra-antennary complex-type glycans carrying Galbeta1-4GlcNAc (lacNAc) and/or GalNAcbeta1-4GlcNAc (lacdiNAc) antennae backbones with varying levels of fucose and sialic acid substitution. Interestingly, they all carried a family of Sda (NeuAcalpha2-3(GalNAcbeta1-4)Gal)-containing glycans, which were not identified in the earlier study because of less sensitive methodologies used. Among the three glycodelins, GdA is the most heavily sialylated. Virtually all the sialic acid on GdC is located on the Sda antennae. With the exception of the Sda epitope, the GdC N-glycome appears to be the asialylated counterpart of the GdA/GdF glycomes. Sialidase activity, which may be responsible for transforming GdA/GdF to GdC, was detected in cumulus cells. Both GdA and GdF inhibited the proliferation, induced cell death, and suppressed interleukin-2 secretion of Jurkat cells and peripheral blood mononuclear cells. In contrast, no immunosuppressive effect was observed for GdS and GdC.

Glycodelin is an endocrine-regulated glycoprotein that has significant effects on immune cells, apoptosis, reproduction, cell adhesion, differentiation and cancer. In reproduction, glycodelin contributes to capacitation and immunoprotection of spermatozoa, and it modulates sperm-oocyte binding, acrosome reaction and implantation. In endocrine-related cancer, the differentiation inducing effects of glycodelin are accompanied by growth restriction of malignant cells, decreased expression of oncogenes, increased expression of tumour suppressor genes and morphological reversion of the malignant phenotype. This review features these properties and clinical connections, highlighting the role of glycosylation in biological actions.

Glycodelin is a lipocalin family glycoprotein expressed mainly in reproductive tissues. It is involved in cell recognition, and its relationship with epithelial differentiation is well established. Glycodelin actually appears to drive epithelial differentiation. The evidence comes from studies employing endometrial and breast cancer cell lines. First, transfection of glycodelin cDNA into glycodelin-negative carcinoma cells results in reduced expression of oncogenes, increased expression of tumor suppressor genes, increased cell differentiation, and reduced carcinoma cell growth. Second, histone deacetylase inhibitors (HDACIs) induce glycodelin synthesis in endometrial cancer cells concomitantly with cell differentiation. This effect is blocked by specific down-regulation of glycodelin by RNA interference, suggesting that the effects of HDACIs are mediated by glycodelin. We recently found that glycodelin not only reduces carcinoma cell growth in vitro, but glycodelin cDNA transfection to MCF-7 breast carcinoma cells also reduces growth of these cells in vivo, demonstrated by xenograft tumor growth in mouse mammary fat pads. These results strongly suggest that glycodelin acts as a tumor suppressor in breast cancer. The findings are compatible with the observations that certain types of glycodelin-expressing ovarian and breast cancers have a more favorable prognosis compared to glycodelin non-expressing tumors. This research has therefore introduced a novel mechanism to control cancer cell growth. In this communication we review the differentiation-related effects of glycodelin.

Malignant growth is characterized by loss of cell differentiation, uncontrolled proliferation and resistance to apoptosis. Many tumor suppressor genes that protect cells against malignant transformation regulate cell differentiation. Here, we show for the first time that glycodelin, a differentiation-related protein, reduces breast cancer tumor growth in vivo. We found that glycodelin cDNA-transfected MCF-7 breast cancer cells showed a differentiated phenotype and produced smaller tumors in mouse mammary fat pads compared with control-transfected cells. Glycodelin-induced differentiation was associated with reduced expression of oncogenes and increased expression of tumor suppressor genes. Our results suggest that glycodelin acts as a tumor suppressor in breast cancer. This may explain its reported association with a more favorable prognosis in some cancers., ((c) 2008 Wiley-Liss, Inc.)

Glycodelin is an example of a glycoprotein whose complex-type glycans mediate biological actions in human reproduction and immune reactions. Being attached to an identical protein backbone, glycodelin oligosaccharides vary significantly from one reproductive tissue to another and have an effect on its own secretion and role in cell communication. For instance, uterine glycodelin-A inhibits sperm-oocyte interaction by binding on the sperm head. This is a glycosylation-dependent phenomenon, in which fucosyltransferase-5 plays a key role. Glycodelin-S from seminal plasma binds evenly around the sperm head and maintains an uncapacitated state in the spermatozoa, until the isoform is detached during sperm passage through the cervix. Glycodelin-F from follicular fluid and Fallopian tube binds to the acrosomal region of the sperm head, thereby inhibiting both the sperm-oocyte binding and premature progesterone-induced acrosome reaction. The cumulus cells surrounding the oocyte can capture glycodelin-A and -F from the surrounding environment and convert these isoforms to a cumulus cell isoform, glycodelin-C. It differs by glycosylation from the other isoforms, and it too attaches on the sperm head, with the highest density in the equatorial region. Glycodelin-C is capable of detaching the sperm-bound inhibitory isoforms so that the sperm-oocyte binding is enhanced. Glycodelin-A also has immunosuppressive actions directed to cellular, humoral and innate immunity. Although these actions depend mainly on the protein backbone, glycosylation also plays a part. Glycosylated glycodelin may be involved in the protection of spermatozoa against maternal immune reactions, and glycodelin also has apoptogenic activity. Some glycosylation patterns of glycodelin may mask its apoptogenic domain. This review updates the recent research and clinical associations of glycodelin, highlighting the role of glycosylation.

Objective: To test the hypothesis that glycodelin is localized on pinopodes and correlates with temporal immunostaining of leukemia inhibitory factor (LIF), LIF receptor (LIFR), and progesterone receptor B (PRB)., Design: Prospective clinical study., Setting: Hospital-based reproductive health unit and research laboratories., Patient(s): Twenty-five healthy fertile women with normal menstrual cycles., Intervention(s): Endometrial biopsy specimens were obtained from healthy fertile women in the luteal phase of the menstrual cycle., Main Outcome Measure(s): Immunohistochemical staining of glycodelin, ultrastructural immunostaining of glycodelin, and double staining of glycodelin and PRB., Result(s): Glycodelin is present in the glands when pinopodes appear. Glycodelin is localized on pinopodes but is also secreted from luminal epithelial cells regardless of pinopode formation. There was a negative correlation between glycodelin secretion from the glands and PRB staining. A weak correlation between the presence of LIFR (but not LIF) and glycodelin was found., Conclusion(s): Pinopode appearance, intense staining of LIFR in pinopodes and glycodelin staining in the glands are synchronized events. Down-regulation of PRB in the endometrium is concomitant with the presence of glycodelin in the endometrium, suggesting interaction.

Objective: Glycodelin is a major secretory glycoprotein of differentiated endometrial epithelium, rarely expressed in proliferative endometrium or endometrial cancer. We aimed to elucidate its role in growth and gene expression of endometrial adenocarcinoma cells, and hypothesized that glycodelin affects cell growth and tumor-associated gene expression., Study Design: Endometrial adenocarcinoma HEC-1B cells were transfected with glycodelin cDNA in both antisense and sense orientations. Cellular morphology, cell proliferation, and gene expression were compared between native and transfected cells., Results: Compared with native and antisense-transfected carcinoma cells, sense-transfected, glycodelin-producing carcinoma cells showed reduced proliferation, morphologic changes, and altered expression of cancer-related genes. Notably, anti-apoptotic Bcl-XL and MUC1 genes were down-regulated., Conclusion: Reduction by glycodelin transfection of carcinoma cell proliferation and expression of MUC1 and Bcl-XL is significant because these genes are often overexpressed in human cancers--MUC1 is linked to invasive growth and metastases, and both confer resistance to chemotherapy. These results suggest a novel mechanism whereby malignant growth of endometrial adenocarcinoma cells is regulated.

Objective: Treatment with metformin, an insulin-lowering agent, increases serum glycodelin, a progesterone-regulated lipocalin protein of the reproductive axis that may play a role in foeto-maternal defence mechanisms. This finding led to the hypothesis that insulin might decrease serum glycodelin concentration., Design, Patients and Measurements: Euglycaemic hyperinsulinaemic clamp experiments (n = 50) were carried out on 28 women of reproductive age (range 25-47 years; mean +/- SEM 39 +/- 1.0 years), and the results were analysed with respect to their baseline serum progesterone (< 10 or > or = 10 nmol/l) and glycodelin (< 10 or > or = 10 microg/l, equivalent to < 357 or > or = 357 pmol/l) concentrations at the onset of the clamp. Ten clamp experiments were performed on five women wearing a levonorgestrel-releasing intrauterine device (IUD), and these were analysed as a separate group., Results: Contrary to the hypothesis, no acute glycodelin-lowering effect of insulin was found in any of the groups studied. All the small rises in glycodelin levels detected during acute hyperinsulinaemia occurred in the comparisons of medians and not means, and all such changes took place within the limits seen in the women with no progesterone exposure. In the group with low progesterone/low glycodelin (n = 21), glycodelin showed a small but significant increase at 30 and 90 min of the clamp (P < 0.01). In the group with elevated progesterone/low glycodelin (n = 11), there was a slight glycodelin increase at 30 min (P < 0.05), whereas no increase was found in the group with elevated glycodelin levels (n = 8). In the clamp experiments on women with levonorgestrel-releasing IUD, the basal glycodelin level was low in all cases and, as in the other women with low glycodelin levels, glycodelin was slightly increased at 30, 60 and 90 min of hyperinsulinaemia (P < 0.01)., Conclusions: The results rule out any acute glycodelin-reducing effects of insulin, although indirect long-term effects mediated by insulin on glycodelin secretion cannot be excluded.

The polycystic ovary syndrome (PCOS) is associated with an increased rate of early pregnancy loss (EPL). Hyperinsulinemia is an independent risk factor for EPL and has been found to decrease levels of glycodelin and IGF binding protein-1 (IGFBP-1), two major endometrial proteins. We hypothesized that serum glycodelin IGFBP-1 concentrations would be reduced in women with PCOS during the first trimester of pregnancy. Fasting serum insulin, glycodelin, and IGFBP-1 were measured, and oral glucose tolerance tests were performed in 72 women with PCOS and 62 normal women. Each woman was seen once and assigned to one of three gestational groups: wk 3-5, 6-8, and 9-11. The insulin sensitivity index during oral glucose tolerance test was lower in women with PCOS compared with normal women throughout the first trimester (P < 0.0001). Both serum glycodelin and IGFBP-1 were markedly lower in women with PCOS (for glycodelin: wk 3-5, P < 0.0001; wk 6-8, P = 0.03; wk 9-11, P = 0.19; and for IGFBP-1: wk 3-5 and 6-8, P < 0.0001; wk 9-11, P = 0.0003). Comparing women with PCOS who experienced EPL with those who did not, serum glycodelin was significantly lower during wk 3-8 (P < 0.02) and serum IGFBP-1 during wk 9-11 (P = 0.003). During the first trimester, serum glycodelin and IGFBP-1 concentrations are markedly decreased in PCOS, implicating endometrial epithelial and stromal dysfunction during periimplantation and early pregnancy as a possible mechanism for EPL in PCOS. These decreases are likely to be secondary to hyperinsulinemia and reduced insulin sensitivity.

Ovarian cancer consists of many subtypes, serous carcinoma being the most common of them. In addition to the histopathological subtype, grading, clinical staging, and the amount of residual tumor, a great number of putative prognostic markers have been introduced. This study addresses in ovarian serous carcinoma the role of glycodelin, the major progesterone-regulated lipocalin protein of the reproductive axis with diverse actions in cell recognition and differentiation. Glycodelin expression was determined by immunohistochemistry of tissue microarrays in ovarian serous carcinomas from 460 patients, and the results were analyzed with respect to progesterone receptor subtype A (PRA) and progesterone receptor subtype B (PRB), clinical parameters, and survival. Glycodelin was localized to the cytoplasm of tumor cells, whereas vascular endothelium in tumor tissue was glycodelin-negative. Glycodelin expression was more frequent in well-differentiated (grade I, 79%) than in poorly differentiated carcinomas (grade III, 51%; P < 0.0001), and it was also more frequent in early-stage compared with advanced-stage carcinomas (P = 0.002). Nuclear PRA and PRB were often coexpressed with cytoplasmic glycodelin. Although this was not consistent in all tumors, there was a positive correlation between the presence of glycodelin and PRs in the tumor (P < 0.02), but not between the presence of, or the absence of, glycodelin in tumor and the CA-125 serum concentration. Although in multivariate analysis glycodelin was not an independent variable, the patients with glycodelin-expressing tumors showed a higher 5-year overall survival compared with those with glycodelin-negative tumors (55 versus 39%; P < 0.0001; hazard ratio in univariate analysis, 0.57; confidence interval, 0.44-0.74). This difference was notable in patients with grade I tumors and stage III disease. In the latter group, the 10-year survival probability of patients with glycodelin-positive tumors was more than twice as high as that in women with glycodelin-negative tumors. This was also found within well-defined clinical categories, e.g., stage III/grade II and stage III/grade III carcinomas, in which patients with glycodelin-positive tumors carried significantly better 10-year overall survival compared with those with glycodelin-negative tumors. It is concluded that, in ovarian serous carcinoma, glycodelin expression portends better prognosis, probably because of its differentiation-related disposition.

Glycodelin is a glycoprotein that belongs to the lipocalin superfamily. Depending on glycosylation, glycodelin appears in various isoforms. In the uterus, glycodelin-A is the major progesterone-regulated glycoprotein secreted into uterine luminal cavity by secretory/decidualized endometrial glands. The other tissues expressing glycodelin include fallopian tubes, ovary, breast, seminal vesicle, bone marrow, and eccrine glands. Glycodelin-A potently and dose-dependently inhibits human sperm-egg binding, whereas differently glycosylated glycodelin-S from seminal plasma has no such effect. Absence of contraceptive glycodelin-A in the uterus during periovulatory midcycle is consistent with an open "fertile window." Glycodelin induced by local or systemic administration of progestogens may potentially reduce the fertilizing capacity of sperm in any phase of the menstrual cycle. Glycodelin also has immunosuppressive activity. Its high concentration at the fetomaternal interface may contribute to protection of the embryonic semiallograft. Besides being an epithelial differentiation marker, glycodelin appears to play a role in glandular morphogenesis, as transfection of glycodelin cDNA into a glycodelin-negative breast cancer cells resulted in formation of gland-like structures, restricted proliferation, and induction of other epithelial markers. These various properties, as well as the chemistry, biology, and clinical aspects of glycodelin, continue to be areas of active investigation reviewed in this communication.

Aim: Few studies address decidual function in abnormal pregnancies, due obviously to shortage of appropriate markers. Glycodelin is produced by epithelial cells of pregnancy decidua. We investigated whether serum glycodelin concentrations are altered in premature rupture of membranes (PROM)., Methods: Serum glycodelin concentrations were measured in 32 women with PROM and in 27 gestational age-matched healthy women. Serum C-reactive protein (CRP) concentrations were measured to indicate infection., Results: Glycodelin concentrations were similar in PROM patients and control subjects. No difference was found in glycodelin concentrations between the 17 PROM patients with CRP > 12 mg/l and controls, or between the 15 PROM patients with CRP < or = 12 mg/l and controls. There was no correlation between the highest antepartum glycodelin level and the interval from PROM to delivery. A negative correlation between the last glycodelin concentration and the birth weight of the newborns was found in the PROM patients (rs = -0.369, p = 0.038)., Conclusions: Decidual epithelial cell function does not seem to be compromised in PROM. The inverse correlation between serum glycodelin and the birth weight of the newborns in PROM may be explained by the normally occurring decline of serum glycodelin with advancing pregnancy in the third trimester.

Objective: To determine whether subdermal levonorgestrel implants induce endometrial expression of glycodelin., Design: Cross-sectional, blinded study., Setting: University clinic., Patient(s): One hundred and eight women with subdermal implants and 19 postmenopausal women., Intervention(s): Endometrial biopsies, curettages, and hysterectomies., Main Outcome Measure(s): Endometrial glycodelin expression was examined through immunohistochemistry, in situ hybridization, and morphologic endometrial dating., Result(s): Overall, 80% of the endometrial specimens obtained from women with subdermal levonorgestrel implants stained positive for glycodelin. Endometrial morphology of these women showed proliferative (71%), inactive/weakly proliferative (19%), menstrual or regenerating (6.5%), and other patterns (2.8%). Of these, 79%, 71%, 100%, and 100% were glycodelin positive, respectively. Nineteen specimens were obtained during the midcycle when glycodelin is not normally expressed: of these, 89% stained positive for glycodelin. Implant-related amenorrhea was associated with endometrial glycodelin expression in 58% of the women, whereas the endometrium specimens obtained from women with postmenopausal hypoestrogenic amenorrhea contained no detectable glycodelin., Conclusion(s): Subdermal levonorgestrel implant use is often associated with endometrial expression of glycodelin. Because glycodelin has been shown to inhibit sperm-egg binding, the induction of glycodelin may contribute to the contraceptive activity of the implant.

Glycodelin is a major glycoprotein that is synthesized in the endometrium in response to progesterone and relaxin exposure. Endometrium-derived glycodelin-A has contraceptive and immunosuppressive properties. Glycodelin is absent from the endometrium during the fertile periovulatory phase, but is synthesized in this tissue during the peri-implantation phase and is abundant during the last week of the luteal phase. Changes in local and/or circulating glycodelin concentrations have been observed in women with reproductive disorders. The chemical modification of glycodelins has resulted in compounds with antiviral activity.

We hypothesized that hyperinsulinemia contributes to early pregnancy loss in the polycystic ovary syndrome by adversely affecting endometrial function and environment. Serum glycodelin, a putative biomarker of endometrial function, is decreased in women with early pregnancy loss. Insulin-like growth factor-binding protein-1 may also play an important role in pregnancy by facilitating adhesion processes at the feto-maternal interface. We studied 48 women with polycystic ovary syndrome before and after 4 weeks of administration of 500 mg metformin (n = 26) or placebo (n = 22) 3 times daily. Oral glucose tolerance tests were performed, and serum glycodelin and insulin-like growth factor-binding protein-1 were measured during the follicular and clomiphene-induced luteal phases of menses. In the metformin group, the mean (+/-SE) area under the serum insulin curve after glucose administration decreased from 62 +/- 6 to 19 +/- 2 nmol/L.min (P < 0.001). Follicular phase serum glycodelin concentrations increased 20-fold from 150 +/- 46 to 2813 +/- 1192 pmol/L (P < 0.001), and serum insulin-like-growth factor-binding protein-1 concentrations increased from 936 +/- 152 to 2396 +/- 300 pmol/L (P < 0.001). Similarly, luteal phase serum glycodelin concentrations increased 3-fold from 3434 +/- 1299 to 10624 +/- 1803 pmol/L (P < 0.001), and serum insulin-like growth factor-binding protein-1 concentrations increased from 1220 +/- 136 to 4916 +/- 596 pmol/L (P < 0.001). Uterine vascular penetration also increased in the metformin group, as did blood flow of spiral arteries, as demonstrated by a 20% decrease in the resistance index from 0.71 +/- 0.02 to 0.57 +/- 0.03 (P < 0.001). These variables did not change in the placebo group. We conclude that insulin reduction with metformin increases follicular and luteal phase serum glycodelin and insulin-like growth factor-binding protein-1 concentrations and enhances luteal phase uterine vascularity and blood flow in the polycystic ovary syndrome. These changes may reflect an improved endometrial milieu for the establishment and maintenance of pregnancy.

Endometrium-derived glycodelin-A inhibits sperm-egg binding, whereas differentially glycosylated seminal plasma glycodelin-S does not. The difference has been ascribed to the specific type of glycosylation of glycodelin-A. We studied whether the total glycodelin concentration or the relative glycodelin-A concentration in seminal plasma are related to the in vitro fertilization rate of oocytes. We found that total glycodelin levels were significantly higher in a quartile of men with the lowest in vitro fertilization rate compared with the remaining 3 quartiles combined (P = .01). However, for predicting low fertilization capacity of sperm, combining the glycodelin and sperm concentrations by logistic regression analysis did not significantly increase the information obtained from sperm concentration alone. We used specific lectin-immunoassays to determine whether increased glycodelin-A-type glycosylation in seminal plasma would be related to failure to fertilize. No difference was found between the groups with high fertilization and no fertilization in vitro. It is concluded that, although high seminal plasma total glycodelin level has a tendency of being associated with a lower fertilization rate, the difference has limited value to predict fertilization in vitro.

We have produced human recombinant glycodelin in human kidney 293 cells and in Chinese hamster ovary (CHO) cells. Structural analyses by lectin immunoassays and fast atom bombardment mass spectrometry showed that recombinant human glycodelin produced in CHO cells contains only typical CHO-type glycans and is devoid of any of the N, N'-diacetyllactosediamine (lacdiNAc)-based chains previously identified in glycodelin-A (GdA). By contrast, human kidney 293 cells produced recombinant glycodelin with the same type of carbohydrate structures as GdA. The presence of a beta1-->4-N-acetylgalactosaminyltransferase functioning in the synthesis of lacdiNAc-based glycans in human kidney 293 cells is concluded to be the cause of the occurrence of lacdiNAc-based glycans on glycodelin produced in these cells. Furthermore, human kidney 293 cells were found to be particularly suited for the production of recombinant glycodelin when they were cultured in high glucose media. Lowering the glucose concentration and the addition of glucosamine resulted in higher relative amounts of oligomannosidic-type glycans and complex glycans with truncated antennae. Human glycodelin is an attractive candidate for the development of a contraceptive agent, and this study gives valuable information for selecting the proper expression system and cell culture conditions for the production of a correctly glycosylated recombinant form.

Glycodelin is a 28 kDa glycoprotein with structural homology to beta-lactoglobulins, particularly expressed in steroid-responsive tissues of the female reproductive tract. We previously found that transfection of glycodelin cDNA into MCF-7 breast cancer cells induces differentiation into organized acinar epithelium and up-regulation of epithelial markers. In this study, we used immunohistochemistry, Northern blotting and reverse transcription-polymerase chain reaction (RT-PCR) analyses to study glycodelin expression in normal and in malignant breast tissues. The results were compared with the expression of estrogen (ER) and progesterone receptors (PR) and p53 tumor suppressor protein. Glycodelin was found in ductal and lobular epithelium of 6/6 normal breast tissues, 27/29 morphologically normal breast tissues from breast cancer patients, 6/6 benign lactating adenomas, 21/35 ductal carcinomas, 9/9 tubular carcinomas, 9/9 mucinous carcinomas, 3/3 mixed ductal/tubular carcinomas and 7/11 lobular carcinomas. In the latter, of particular interest was the presence of glycodelin in paranucleolar vacuoles of carcinoma cells. Northern blot analysis of fresh frozen tissues revealed the normal full length 0.9 kb mRNA of glycodelin in ductal breast carcinoma. Using RT-PCR analysis, glycodelin messenger ribonucleic acid was found in 13/13 ductal and in 3/3 tubular tumor tissues. We also detected a splicing variant lacking exon 4, which includes the nucleotide sequence encoding the potential N-glycosylation site at Asn-85. Our results demonstrate the synthesis of glycodelin in normal breast and breast cancer. In addition, we show that the paranuclear vacuole, characteristically present in lobular breast cancer cells, contains abundant amounts of glycodelin.

Studies published in recent years have elucidated the role of glycodelins in early human reproduction and the biological actions of glycodelins relative to their structure. New information has also emerged on the regulation of glycodelin synthesis and on the effects of glycodelin transfection on cellular growth and the expression of other epithelial markers.

Human glycodelin, a lipocalin with a high amino acid similarity to beta-lactoglobulins, appears as various glycoforms with different biological activities in endometrium (glycodelin-A) and seminal plasma (glycodelin-S). We found that the structures of these glycodelins and beta-lactoglobulin are similar. Despite this structural similarity, unlike beta-lactoglobulin, glycodelin-A binds neither retinoic acid nor retinol. It was impossible to detect any endogenous retinoids or steroids in any of the two purified glycodelins. Both their glycoforms share similar thermodynamic parameters of reversible denaturation suggesting that native folding of glycodelin-A and glycodelin-S is not influenced by the differences in glycosylation or by ligand binding.

Human endometrium is the major organ that produces glycodelin A (GdA). The production of endometrial GdA causes a fluctuation of the peripheral glycodelin concentrations in women during the menstrual cycle and pregnancy. It has recently been reported that the rise of plasma concentrations of glycodelin is correlated with relaxin during the late luteal phase and early pregnancy. In addition, administration of relaxin increases glycodelin plasma concentrations, suggesting that relaxin induces GdA production in endometrium. To investigate whether relaxin regulates the GdA synthesis, human endometrial glandular epithelial cells were isolated and cultured with or without relaxin for up to 4 days. Western blot showed that GdA synthesized and secreted from epithelial glands had a major molecular weight of 28 kDa, i.e. the same as the GdA isolated from amniotic fluid. Cells incubated with relaxin consistently increased in GdA production rate (2-6-fold). The GdA mRNA concentrations increased 2-11-fold in cells incubated with relaxin for 2-4 days, as determined by solution hybridization/ribonuclease protection assay. The increase of the mRNA concentration indicates that relaxin activates GdA transcription.

One of the most abundant protein products of human secretory endometrium is glycodelin, a glycoprotein previously referred to as PP14. Although the precise function of this protein is unknown, its unique glycosylation pattern is believed to affect immunomodulatory activity during human embryonic implantation and inhibition of sperm-egg binding after ovulation. Having confirmed the expression of glycodelin in secretory endometrial glands, we used purified endometrial epithelial cell cultures to demonstrate the hormonal regulation of glycodelin synthesis and secretion. The findings were corroborated by transiently transfecting glycodelin gene promoter-reporter constructs into human epithelioid HeLa and Ishikawa cells. Our results indicate that glycodelin protein production by endometrial epithelial cells is directly up-regulated 4- to 9-fold by progestins and antiprogestins in vitro. Transcriptional regulation of the glycodelin gene promoter expressed in HeLa cells is progesterone receptor-dependent. As observed in the primary endometrial cells, progestins and antiprogestins both act as agonists on the in vitro expression of this endometrial gene. Our findings provide insight into the regulation of this abundant endometrial protein and raise interesting questions about the physical nature of the interaction of agonist- and antagonist-bound progesterone receptors with the glycodelin gene promoter.

Glycodelins are glycoproteins synthesized in various glands, with sequence homology to beta-lactoglobulins, and named according to their unique oligosaccharide structures. We purified, cloned and sequenced endometrium- and seminal plasma-derived glycodelins (GdA and GdS respectively) and found that they are involved in various types of cell-cell communications. These include interactions between the spermatozoon and the egg, and between immune cells and their targets. Endometrial GdA inhibits sperm-egg binding, whereas the differently glycosylated GdS in seminal plasma does not. These observation are of interest for reproductive physiology, detection of causes of infertility, and they also may have potential for contraceptive development.

Glycodelins are 28 to 30-kD glycoproteins synthesized in various glands, notably those of the male and female reproductive organs. Depending on the site of origin, the same protein backbone is glycosylated in different ways, yielding glycodelins with different biological actions. Thus, human endometrium-derived glycodelin-A is temporally expressed in the latter half of the menstrual cycle, consists of unique sialylated and fucosylated lacdiNAc oligosaccharide sequences, and inhibits sperm-egg binding. By contrast, glycodelin-S from seminal vesicles has no such oligosaccharide sequences and no contraceptive activity. Glycodelin-A also has potent immunosuppressive properties, and its chemically modified forms inhibit transmission of HIV in vitro. Studies are reviewed suggesting that glycoforms dictate the function of human glycodelins, and that some of the oligosaccharide recognition sites present in the human gametes and immune cells have converged.

Intrauterine devices (IUDs) exert contraceptive action by interfering with sperm transport, ovum development, fertilization and implantation. Glycodelin A (GdA) is a uterine glycoprotein that has local contraceptive activity by inhibiting sperm-egg binding. GdA is normally absent from endometrium during the fertile midcycle and it is not expressed until the fifth postovulatory day. The phase of menstrual cycle addressed in this study covers the phase when conception is most likely to follow an unprotected intercourse and when GdA is normally absent. We present here evidence that levonorgestrel-releasing IUD (LNg-IUD) is accompanied by 'inappropriate' expression of GdA in endometrium between days 7 and 16 of the menstrual cycle (six out of six cases). The same was also found in copper-releasing IUD (Cu-IUD)-wearing women, but less frequently (four out of 11 cases, P < 0.0345, Fisher's exact test). In-situ hybridization localized GdA mRNA into endometrial glands in the midcycle endometrium, confirming the cellular site of synthesis. Based on the potent inhibitory activity of GdA on sperm-egg binding, the presence of GdA in uterine glands of IUD wearers may lead to prior exposure of sperm to contraceptive GdA, thus contributing to the contraceptive activity of the IUD.

Glycodelin, a 28-kd human glycoprotein found in glandular epithelial cells of endometrium and seminal vesicle, was originally considered specific for the reproductive tract. Glycodelin has significant amino-acid sequence homology with beta-lactoglobulins from various species. We report herein the expression of glycodelin in normal and neoplastic glandular epithelia outside the reproductive tract including breast, sweat glands, parabronchial glands, hidradenoma, and pancreatic cystadenoma. The localization of glycodelin in highly differentiated acinar epithelia led us to investigate a possible role for glycodelin in epithelial organization. Transfection of glycodelin cDNA into MCF-7 breast cancer cells induced a dramatically altered growth behavior with formation of acinar configurations and an inability to grow in semisolid media because of apoptosis. The glycodelin-expressing cells also displayed strongly up-regulated expression of markers of organized epithelia, such as cytokeratins 8 and 18 as well as E-cadherin, and changes in intracellular distribution of beta-catenin. The rate of proliferation was also suppressed. These results show that, besides being a product of glandular epithelial cells, expression of glycodelin is accompanied by the acquisition of a phenotype of organized glandular epithelium.

Bovine beta-lactoglobulin chemically modified with 3-hydroxyphthalic anhydride (3HP) was recently shown, at nanomolar concentrations, to block the binding site on CD4 for the HIV surface glycoprotein (gp120), potentially inhibiting HIV transmission. Human glycodelin has sequence homology with bovine beta-lactoglobulin and appears as different glycoforms in endometrium (GdA) and seminal plasma (GdS). We studied the anti-HIV effects of chemically modified GdA and GdS on both the infection of MT-2 cells by HIV-1IIIB, and the infection of peripheral blood mononuclear cells by the primary HIV isolate THA/93/051 belonging to subtype E. Whereas the native proteins were inactive when tested at physiologic concentrations, nanomolar concentrations of either 3HP-GdA or 3HP-GdS inhibited the production of HIV nucleocapsid p24, cytopathic effects of HIV-1IIIB, and infection of peripheral blood mononuclear cells by the primary HIV isolate THA/93/051. Moreover, both modified proteins inhibited gp120-CD4 binding, 3HP-GdS being more potent than 3HP-GdA (p = 0.0042). Because GdA and GdS have the same major protein core, the observed difference in gp120-CD4 binding must depend on the specific glycoform. In view of the previously reported contraceptive activity of GdA, the observed anti-HIV activity induced by its chemical modification should be of special interest in the development of antiviral strategies that may also have contraceptive effects.

Glycodelin-A is a human endometrium-derived glycoprotein with contraceptive and immunosuppressive activities. Recently, we found that seminal plasma contains immunoreactive glycodelin (GdS) that is differentially glycosylated and has no contraceptive activity. We now report localization and variant forms of GdS in the male genital tract. Northern blot and reverse transcription-PCR analyses showed that GdS mRNA is expressed in the seminal vesicles and ampulla of the vas deferens. Immunohistochemical staining localized GdS to the epithelial cells and lumen of glands in the seminal vesicles and ampullary part of the vas deferens. The same tissues and cells contained glycodelin mRNA as localized by in situ hybridization. Whereas the major reverse transcription-PCR products were identical to the glycodelin-A cDNA from decidual expression library, there were also several splicing variants of GdS mRNA. Seminal plasma also contained smaller immunoreactive forms of the GdS protein. Some of them were posttranslational cleavage products of GdS, because incubation of 125I-labeled GdS in seminal plasma resulted in smaller molecular weight cleavage products. Based on these results, we concluded that multiple forms of glycodelin mRNA are expressed in the male genital tract, including those lacking the coding sequences for the glycosylation sites, and that seminal plasma has proteolytic activity that cleaves GdS.

Glycodelin-A is a human amniotic fluid-derived glycoprotein with contraceptive and immunosuppressive activities. An immunoreactive form of glycodelin was detected in seminal plasma over a decade ago, but definitive characterization of this glycoprotein was not pursued. We considered it unlikely that the seminal plasma of fertile men would contain an appreciable amount of contraceptive glycodelin-A. To address this issue we purified seminal plasma glycodelin (glycodelin-S) and performed comparative studies with glycodelin-A. Glycodelin-S behaved differently when compared with glycodelin-A during sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and isoelectric focusing but identically after enzymatic deglycosylation. N-terminal sequencing of glycodelin-A and glycodelin-S gave identical results, and digestion with trypsin gave identical peptide fragments. The glycoproteins were also found to be indistinguishable from each other based upon immunological analyses. These results indicate that glycodelin-S and glycodelin-A have similar overall protein structure, suggesting the likelihood that these glycoproteins are differentially glycosylated forms of very similar proteins. This latter possibility is supported by lectin binding studies indicating that, unlike glycodelin-A, glycodelin-S does not manifest any affinity for lectins from Wisteria floribunda or Sambucus nigra. The results of sugar analysis and neuraminidase digestion also lead us to conclude that glycodelin-S and glycodelin-A are differentially glycosylated forms of similar proteins. Our evidence indicates that glycodelin-A mediated its biological activities via its unusual oligosaccharide sequences that are not associated with glycodelin-S. In lectin-immunoassay no appreciable amount of contraceptive glycodelin-A was found in the 22 seminal plasma samples studied.

Glycodelin is a glycoprotein with potent immunosuppressive and contraceptive activities. It reacts with antibodies against placental protein 14, or progesterone-associated endometrial protein, and has a unique carbohydrate structure. Previous nomenclature is misleading, because glycodelin is neither synthesized in the placenta nor is it endometrium specific. No ovarian synthesis of glycodelin has been demonstrated. We present evidence for glycodelin synthesis in the human ovary and ovarian tumors. In follicular phase, immunoperoxidase staining of microwave-treated tissue sections employing affinity-purified polyclonal antibodies localized glycodelin to areas of stromal cell condensation in ovarian cortex, theca interna, and the granulosa. In luteal phase, cortical stroma was negative or only weakly positive, whereas glycodelin was present in theca interna of the corpus luteum and luteinized granulosa cells and also in corpus albicans and Leydig cells of the ovarian hilus. In situ hybridization gave negative results for glycodelin mRNA in normal ovary, whereas in ovarian tumors strong expression of both the glycodelin mRNA and the protein were found in benign and malignant serous cystadenomas, mucinous ovarian tumors being negative. We conclude that glycodelin is synthesized in human ovarian tumors, and its occurrence in normal human ovary may represent either synthesis or a site of glycodelin action.

Objective: To study the potential for dissemination of endometrial tissue substances during transcervical resection of the endometrium (TCRE)., Design: Prospective study., Setting: One university and two county hospitals., Participants: Forty-eight women with dysfunctional bleeding., Interventions: The serum levels of two endometrial proteins, insulin-like growth factor binding protein-1 (IGFBP-1) and placental protein 14 (PP14), were measured before and every 10 min during the operations. Blood loss was also measured by a photometer together with absorption of the irrigating fluid containing glycine 1.5% and ethanol 1% by expired-breath tests, and serum sodium and volumetric fluid balances., Main Outcome Measures: Linear correlations between changes in IGFBP-1 and PP14 during TCRE and operating parameters such as operating time, blood loss and fluid absorption., Results: The baseline levels of IGFBP-1 were normal but PP14 could only be detected in one third of the patients, which was due, in part, to pre-operative treatment with danazol. The highest levels of IGFBP-1 and PP14 during surgery correlated positively with the baseline concentrations. Fluid absorption (median 405 ml, range 0-2177) was the only surgical factor associated with increasing serum levels of endometrial proteins., Conclusion: Absorption of the solution used to irrigate the uterus is associated with dissemination of endometrial products in the bloodstream during TCRE.

Objective: To study serum levels of placental protein 14 (PP14) in relation to endometrial function in women with a history of habitual abortion., Design: Prospective study., Setting: Departments I and II of Obstetrics and Gynecology, University Central Hospital of Helsinki, Helsinki, Finland., Patients: Fifty patients (26 primary and 24 secondary habitual aborters) and 38 controls without a history of abortion studied during a regular cycle., Results: Habitual aborters as a whole or when subgrouped into those with normal cycles (n = 40) or with a luteal phase defect (LPD; n = 10) and control women demonstrated a distinct increase in PP14 levels from late follicular to late luteal phases. In the luteal phase, serum PP14 levels were lower in the patients than in the controls (27.2 +/- 3.1 versus 48.5 +/- 10.1 micrograms/L), but the differences in PP14 levels between habitual aborters with or without LPD was not significant (16.3 +/- 4.3 versus 29.9 +/- 3.7 micrograms/L)., Conclusions: Habitual aborters exhibit lower serum PP14 levels in the late luteal phase compared with normal fertile women.

Previous studies suggest that, in pregnancies after in-vitro fertilization (IVF) and embryo transfer following pituitary down-regulation with a gonadotrophin-releasing hormone analogue (buserelin) and ovulation induction with human gonadotrophins, the serum placental protein 14 (PP14) concentration is lower than in normally conceived pregnancies. We studied serum PP14 concentrations in two groups of women: (i) in 17 infertile women whose pregnancy followed IVF and embryo transfer using buserelin (long protocol) and human menopausal gonadotrophin for ovulation induction; (ii) in 15 women whose pregnancy followed transfer of frozen-thawed embryos. Similar PP14 concentrations were found in both groups on days 9-10, 14-15 and 70-77 after human chorionic gonadotrophin administration (buserelin, IVF/embryo transfer) or spontaneous luteinizing hormone surge (frozen-thawed embryo transfer). Our results show that PP14 secretion is not compromised by pituitary down-regulation with buserelin in infertile women with functional ovaries.

Progesterone-associated endometrial protein (PAEP/PP14) is a 28-kD glycoprotein with sequence homology to beta-lactoglobulins containing a retinol-binding motif. PAEP/PP14 is present at nanomolar concentrations in human serum. It is produced by secretory and decidualized endometrium in women and by seminal vesicle epithelium in men. We report here that PAEP mRNA is constitutively expressed in normal hematopoietic tissue. Western immunoblotting of bone marrow cells with rabbit antibodies to PAEP gave a band at 28 kD, and immunocytochemical staining with monoclonal antibodies localized PAEP into the cytoplasm of erythroid precursors representing different stages of the normoblast series. PAEP was not detected in mature red blood cells, platelets, or in cells of the myeloid lineage. Untreated K562 leukemia cells did not contain PAEP, whereas treatment of the cells with tetradecanoylphorbol acetate (TPA) induced strong expression of PAEP mRNA and synthesis of the intact protein that was found both in the cytoplasm of the differentiating cells and in the supernatant of TPA-treated cultures. These findings add a new member to the growing family of genes that are constitutively expressed both in the reproductive tract and in the hematopoietic system.

A large number of proteins and peptides have been identified in the endometrium where they are likely to exert local biological effects. These substances may be enzymes, their inhibitors, proteinases, proteinase inhibitors, hormones, or bioactive peptides with diverse functions. Endometrial function and embryo-endometrial interactions require synchronized actions between endocrine and local factors. As examples of local factors recent studies on the insulin-like growth factor (IGF) system and placental protein 14 (PP14) are reviewed. IGF binding protein-1 (IGFBP-1) and PP14 are products of the secretory phase endometrium: IGFBP-1 is produced by decidualized stromal cells and PP14 by glandular epithelial cells. IGFBP-1 may inhibit the action of IGFs at the endometrial-trophoblastic interphase, and it may also have a role in stromal-epithelial interaction. PP14 has immunosuppressive properties, and recent findings indicate that it may play a part in the fertilization process by inhibiting binding of spermatozoa to the zona.

The purpose of this study was to investigate whether endometrium with retarded development differs, functionally, from endometrium with normal 'in-phase' development. Precisely timed endometrial biopsies were obtained from 24 women suffering from unexplained infertility at 4, 7, 10 and 13 days following the luteinizing hormone (LH) surge. Frozen sections were labelled with an anti-placental protein (PP) 14 monoclonal antibody using an avidin-biotin peroxidase technique and semi-quantification of endometrial PP14 was performed using a Quantimet 970 image analyser. Serum PP14 and saliva progesterone were measured for each patient. Data were analysed using one- and two-way analysis of variance. Normal and retarded endometrium were identified in 16 (group I) and eight (group II) women respectively. Both groups demonstrated a significant increase of the area of precipitate measured for PP14 from day LH + 4 to LH + 13. However, two-way analysis of variance showed that endometrial PP14 was significantly (P < 0.05) lower in the retarded endometrium group at LH + 10 and LH + 13. Serum PP14 was also significantly lower (P < 0.01) in women with retarded endometrial development at LH + 13. Women with normal endometrial development had a significantly higher (P < 0.05) concentration of cumulative saliva progesterone from LH + 3 to LH + 5. This study indicates that there are functional differences between normal and retarded endometrium. These differences may adversely affect uterine receptivity during implantation and the early placentation stage.

The effects of RU 486 combined with tamoxifen and tamoxifen alone on hormonal parameters and endometrial development at the time of implantation were studied. Measurements of cytosolic oestrogen and progesterone receptors in endometrium and placental protein 14 (PP14) in plasma were also included. Three dosage schedules were used: single oral dose of 40 mg tamoxifen alone and in combination with 200 mg RU 486, and 40 mg tamoxifen for three consecutive days starting on the first day after the luteinizing hormone (LH) surge. The combined treatment prolonged the luteal phase (P < 0.05) and increased the plasma levels of progesterone. A single dose of tamoxifen did not affect the bleeding pattern and plasma hormone levels, but raised plasma oestradiol and LH with the 3-day treatment. The endometrium was retarded after the combined and the 3-day treatment with tamoxifen. Concentrations of cytosolic progesterone receptors were higher after the combined therapy, but were unaffected after tamoxifen only. PP14 levels were higher (P < 0.05) after repeated tamoxifen doses than in controls, but were lower with combined treatment. Progesterone and oestrogen are evidently necessary for endometrial maturation during the secretory phase of the menstrual cycle. PP14 levels in plasma cannot be used for clinical assessments of endometrial function because high levels coincide with disturbed endometrial development.

Progesterone-associated endometrial protein (PAEP) has been isolated from human decidualized endometrium. In-situ hybridization histochemistry was employed to determine the cellular localization of PAEP mRNA in decidua during pregnancy. PAEP mRNA was found to be expressed in the glandular epithelium of decidua spongiosa throughout pregnancy. Substantial variations in the amount of PAEP mRNA during the course of pregnancy were observed, and it was most abundant at the end of the first trimester. We also found that the PAEP gene was expressed in endometriosis and in a borderline endometrioid adenoma. As in decidual tissues, PAEP mRNA in endometriosis was abundant in the glandular compartment.

Placental protein 14 (PP14) and human chorionic gonadotrophin (HCG) were analysed in patients participating in an in-vitro fertilization-embryo transfer programme which did not include any kind of luteal support. Women with normal pregnancies, spontaneous abortions, ectopic pregnancies, biochemical pregnancies and non-pregnant women were compared. A combination of HCG and PP14 analyses distinguished between normal and abnormal implantation as early as 15 days after oocyte retrieval. The product of HCG (IU/l) and PP14 (micrograms/l) concentrations differed significantly between normal pregnancy, spontaneous abortion and ectopic pregnancy (P = 0.0248). It is concluded that both endometrial (PP14) and trophoblastic (HCG) markers, when used in combination, exhibit changes in abnormal implantation which may be clinically useful.