Inactivation of prostaglandins in human decidua vera (parietalis) tissue: substrate specificity of prostaglandin dehydrogenase

Prostaglandin dehydrogenase catalyzes the initial reaction in the inactivation of prostaglandin E2 and F2 alpha. To address the potential importance of this enzyme in regulating the tissue levels of active prostaglandins, we evaluated the kinetic properties of prostaglandin dehydrogenase in uterine decidua vera tissue of women. Specifically, we characterized the enzyme activity under optimal in vitro conditions in cytosolic fractions of uterine decidua vera tissue obtained at term and compared the substrate and cosubstrate specificities of prostaglandin dehydrogenase in cytosolic fractions of decidual tissues. The incubation conditions were optimized with either prostaglandin E2 or F2 alpha and nicotinamide-adenine dinucleotide or nicotinamide-adenine dinucleotide phosphate as substrates to ensure linearity of product formation with time of incubation and protein concentration. The apparent Michaelis-Menten constant of nicotinamide-adenine dinucleotide-dependent prostaglandin dehydrogenase for prostaglandin E2 was 5.5 mumol/L. The apparent Michaelis-Menten constant of nicotinamide-adenine dinucleotide phosphate-dependent prostaglandin dehydrogenase for prostaglandin F2 alpha was 15 mumol/L. Prostaglandin E2 serves as a better substrate for prostaglandin dehydrogenase than does prostaglandin F2 alpha, irrespective of the cosubstrate. In cytosolic fractions of decidual tissues, the specific activity (apparent Vmax) of nicotinamide-adenine dinucleotide-dependent prostaglandin dehydrogenase was greater than that of nicotinamide-adenine dinucleotide phosphate-dependent prostaglandin dehydrogenase. In addition, we found that in decidual tissue obtained before or after the onset of labor, the specific activity of prostaglandin dehydrogenase varied widely. In tissues obtained after delivery by cesarean section, no significant differences were apparent in the specific activity of the enzyme before (9.3 to 125.8 nmol/min/mg protein) and after (27.8 to 103.4 nmol/min/mg protein) the onset of labor. In cytosolic fractions of decidual tissue obtained after vaginal delivery, the specific activity of nicotinamide-adenine dinucleotide-dependent prostaglandin dehydrogenase ranged from undetectable levels to 38.4 nmol/min/mg protein. We speculate that nicotinamide-adenine dinucleotide-dependent prostaglandin dehydrogenase in decidua serves to regulate the levels of bioactive prostaglandins in decidua vera tissue and the amounts of prostaglandins (and metabolites) produced in decidua or fetal membranes that reach myometrium and fetal membranes and enter maternal blood and amniotic fluid.     

Ovarian stromal and luteal tissue prostaglandins, 17 beta-estradiol, and progesterone in relation to the phases of the menstrual cycle in women

The concentrations of prostaglandin F2 alpha, prostaglandin E2, the 15-keto-13, 14-dihydro-metabolite of prostaglandin F2 alpha, progesterone, and 17 beta-estradiol were measured in 31 ovarian stromal tissue and 18 luteal tissues. Tissue samples were obtained during abdominal hysterectomy. The ovarian stromal tissue prostaglandin F2 alpha content during the late secretory and early proliferative phases was significantly higher (p less than 0.001) than in tissues obtained during any other phases of the menstrual cycle. The ovarian stromal tissue prostaglandin E2 content was significantly elevated (p less than 0.01) during the late proliferative and early secretory phases. The content of the prostaglandin F2 alpha metabolite also was elevated (p less than 0.001) in ovarian stromal tissues obtained during the late proliferative and early secretory phases. Comparison of the concentrations of prostaglandins and sex steroids in ovarian stromal and luteal tissues indicate the latter to be far more active in terms of steroid and arachidonate metabolism. During the early luteal phase, when the luteal progesterone content was at its highest, both luteal and ovarian stromal tissue contents of prostaglandin E2 were also elevated. The late secretory phase of the menstrual cycle was characterized by lowered luteal progesterone content and a markedly elevated level of prostaglandin F2 alpha in luteal and ovarian stromal tissues. During cyclic ovarian activity in the woman, prostaglandin E2 predominated during the periovulatory phases while the period of luteal death was highlighted by the elevated prostaglandin F2 alpha content in ovarian stromal and luteal tissues.     

Activation antigens during the proliferative and secretory phases of endometrium and early-pregnancy decidua

BACKGROUND: Clarifying the normal distribution of activation antigens will contribute to database construction studies of monoclonal-antibody-based therapies in endometrial disorders. METHODS: In this study, endometrial tissue samples obtained during proliferative and secretory phases and decidual samples of early pregnancies were immunostained by the monoclonal antibodies anti-CD26, anti-CD30, anti-CD70, anti-CD71, and anti-CD98 using the indirect immunoperoxidase method. RESULTS: CD26 is expressed on the glandular epithelium in the endometrium and decidua. Endothelial CD26 is expressed less in the decidua when compared to the endometrium. CD30 is strongly expressed by decidual cells. It is only weakly expressed on endometrial and decidual vessels. Glandular and endothelial CD70 expression is mainly seen in the proliferative phase of the menstrual cycle. Glandular CD71 expression is less in the decidua when compared to the endometrium. Its expression on stromal cells is more in the secretory phase of the menstrual cycle and in early pregnancy deciduae. It is expressed on endometrial vessels but not on decidual vessels. Glandular CD98 is expressed more in the decidua when compared to the endometrium. This antigen exists on endometrial lymphocytes. It is strongly expressed on the endothelium in the endometrium and decidua. CONCLUSION: It seems that CD26 and CD70 are not involved in the functions of endometrial and decidual stromal cells. CD30 and CD71 are thought to be involved in decidualization. Absence of activation antigens other than CD98 on lymphocytes indicated an antigenic profile for large granular lymphocytes that is different from regular lymphocytes.     

Changes in the synthesis and metabolism of prostaglandins by human fetal membranes and decidua at labor

The production of prostaglandins by dispersed cells from human amnion, chorion, and decidua was examined at term before the onset of labor and at spontaneous vaginal delivery. In order to obtain detailed information about relative prostaglandin production rates, the time course of prostaglandin output was examined by incubating the cells for up to 4 hours and measuring the cumulative output of prostaglandin E2, prostaglandin F2 alpha and 13,14-dihydro-15-keto-prostaglandin F2 alpha in the incubation media. The output of all three prostaglandins was low in tissues obtained before the onset of labor. At labor there was an increased production of prostaglandins E2 and F2 alpha in amnion and a small increase in the output of prostaglandin E2, prostaglandin F2 alpha, and 13,14-dihydro-15-keto-prostaglandin F2 alpha in decidua. In contrast, chorionic cells obtained at spontaneous vaginal delivery showed high levels of 13,14-dihydro-15-keto-prostaglandin F2 alpha in the media with no net production of prostaglandin E2 or F2 alpha. These data suggest a high rate of specific in vitro prostaglandin synthesis in amnion and decidua at labor, accompanied by a high rate of prostaglandin metabolism in chorion.     

Decidual activation: abundance and localization of prostaglandin F2alpha receptor (FP) mRNA and protein and uterine activation proteins in human decidua at preterm birth and term birth

OBJECTIVE: To study how the decidua contributes to parturition, we examined prostaglandin F(2alpha) concentrations as well as prostaglandin 15-hydroxy dehydrogenase, prostaglandin F(2alpha) receptor, matrix metalloproteinases 2 and 9, oxytocin receptor, prostaglandin-H synthase-2, and the prostaglandin E(2) receptor expression in human decidua. MATERIALS AND METHODS: Decidual samples were isolated from placentas collected from patients at preterm not in labor (PTNIL), preterm labor (PTL), term not in labor (TNIL), and term labor (TL). For immunohistochemistry, fresh membranes which included chorion, amnion and decidua from term patients were collected. RESULTS: Prostaglandin F(2alpha) receptor mRNA was low in all preterm patients and then significantly increased towards term (p=0.049). Prostaglandin F(2alpha) receptor protein was identified in the amnion epithelium and mesoderm, chorion trophoblasts and decidua by immunohistochemistry, and levels were highest at TNIL (p=0.007) as measured by western blot. Prostaglandin F(2alpha) levels were higher at PTNIL than TNIL. Matrix metalloproteinases 2 and 9 protein and pro-enzyme activities were higher at TL than TNIL. There were no significant changes among the groups for any of the other factors measured. CONCLUSIONS: These results suggest that the induction of Prostaglandin F(2alpha) receptor at term may facilitate the decidua contribution to parturition, and its regulation and role should be examined further.     

The adenylate cyclase system and prostaglandin production in human decidua parietalis.

We studied the beta-adrenergic system in the human decidua and its effect on prostaglandin E2 and F2a release from dispersed decidual cells in culture. Beta-adrenergic receptors in decidual membranes were partially characterized using (+)[125I]HYP. Specific binding was demonstrated with maximum binding capacity (Bmax) of 70 +/- 10.6 fmol/mg and an affinity (KD) of 20.85 +/- 1.86 pmol. cAMP dependent phosphoproteins in decidual cytosol were also identified. Two phosphoproteins of M(r) 42,000 and 22,000 were seen in all preparations. Three others (M(r) 39,000, 23,000 and 21,000) were identified in only some of the preparations. Phosphoproteins of similar M(r) to those seen in cytosol prepared from decidual homogenates were also identified in cytosol of cultured decidual cells. Phosphorylation of the 42,000 M(r) and 22,000 M(r) proteins was maximal (3.04 +/- 0.35-fold and 5.7 +/- 0.68-fold) with 10(-6) M cAMP. Cultured decidual cells produced prostaglandin E2 and F2a which increased in a dose-dependent manner in response to dbcAMP, forskolin or isoproterenol. The decidua contains an intact beta-adrenergic system that, when activated, is capable of phosphorylating specific proteins and modulating prostaglandin release.     

雌、孕激素对人子宫内膜Pbx2蛋白表达的影响

目的:探讨人子宫内膜腺上皮细胞和基质细胞中雌、孕激素对Pbx2蛋白表达的影响。方法:采用免疫组织化学链霉菌抗生物素蛋白-过氧化物酶(SP)连接法检测人增生期、分泌中期和蜕膜期子宫内膜中Pbx2的表达和分布;体外培养人子宫内膜基质细胞和高分化子宫内膜癌细胞Ishikawa,分别加入雌激素、孕激素、雌、孕激素联合刺激48 h,并以不加雌、孕激素的基质细胞核和Ishikawa细胞为对照组,采用免疫组织化学、免疫印迹法测定各种条件下Ishikawa细胞中Pbx2蛋白的表达。结果:①在人各期子宫内膜组织中,Pbx2表达于腺上皮细胞和基质细胞的细胞核中;Pbx2在分泌中期和蜕膜期基质细胞中的表达显著高于增生期,但在腺上皮细胞中增生期组织的表达高于分泌中期和蜕膜期,差异均具有统计学意义(P<0.05)。②Western blotting结果显示,在孕激素和雌、孕激素联合处理Ishikawa细胞组中,Pbx2的表达显著低于对照组(P<0.05),雌激素处理后Pbx2的表达与其他各组间的表达无显著性差异(P>0.05),在人子宫内膜基质细胞(ESC)中,Pbx2的表达在雌、孕激素处理各组间比较均无统计学差异(P>0.05)。结论:在人子宫内膜腺上皮Ishikawa细胞中孕激素对Pbx2的表达具有下调作用,在人子宫内膜基质细胞中,Pbx2的调控可能是非雌、孕激素依赖性的。     

Steroid synthetic and prostaglandin metabolizing activity is present in different cell populations from human fetal membranes and decidua

We examined whether different cell subpopulations from human fetal membranes and decidua produce steroids (estrone and progesterone) and metabolize prostaglandins (prostaglandin F2 alpha to 13, 14-dihydro-15-keto-prostaglandin F2 alpha and if these changed with labor. Amnion, chorion, and decidua were obtained at elective cesarean section at term or at spontaneous labor. Cells were dispersed with collagenase and separated by density on discontinuous Percoll gradients. At cesarean section there was a major broad band of cells from amnion and chorion. This band contained most of the estrone sulfatase (estrone sulfate to estrone) activity. The 3 beta-hydroxysteroid dehydrogenase (pregnenolone to progesterone conversion) and prostaglandin F2 alpha metabolizing activities were present in these cells and those that migrated at greater Percoll densities. Amnion and chorion obtained after spontaneous labor had two major bands of cells. Estrone sulfatase was present in cells from both hands, whereas progesterone output from pregnenolone and prostaglandin F2 alpha metabolism predominated in the second band of cells with greater density. This pattern was particularly apparent in chorion. Dispersed cells from decidua tended to migrate throughout the gradient. In general, estrone sulfate to estrone conversion predominated in lighter cells whereas progesterone output from pregnenolone and prostaglandin F2 alpha metabolism predominated in cells of greater density. The output of progesterone from pregnenolone was significantly lower in cell preparations from chorion and decidua at spontaneous labor compared with cesarean section. We conclude that human amnion, chorion, and decidua contain distinct cell subpopulations based on Percoll migration and that in the membranes these change between cesarean section and spontaneous labor. Partial separation of estrone sulfatase from 3 beta-hydroxysteroid dehydrogenase and prostaglandin F2 alpha metabolizing activities has been demonstrated, which raises the possibility of paracrine interactions in vivo.     

An inhibitor of type-1 cyclo-oxygenase in tissues from human pregnancy.

BACKGROUND: Previous work has shown that first trimester human decidua contains a protein which directly inhibits the activity of type-1 cyclo-oxygenase (COX-1). METHODS: Activity assays for cyclo-oxygenase types I and II were developed. Cell cytosol was prepared from a number of different sources: human placenta and decidua (first and third trimester), two placental cell-lines (BeWo and TCL-1), an endometrial stromal cell-line and K562 erythroleukemia cells. The effects of all cytosols on activity of type I cyclo-oxygenase, and of cytosols from BeWo choriocarcinoma and decidual cells on type II enzyme, were tested. RESULTS: Cytosols from first trimester human placenta, two placental cell-lines, an endometrial stromal cell-line and K562 erythroleukemia cells all inhibited the type I enzyme. The inhibitor protein could not be detected in third trimester human decidual cells after labor, and was present only at very low levels in third trimester decidua prior to the onset of labor. Cytosols from BeWo and decidual cells had no effect on the activity of the type-2 cyclo-oxygenase enzyme. CONCLUSIONS: The inhibitor of type I cyclo-oxygenase was not specific to pregnancy-related tissues, and may be a general regulator of this enzyme. Lower levels of inhibitor were present at term, but the physiological significance of this is unclear. The cytosolic inhibitor appears to be specific to the type I enzyme.     

Augmented PLA2 activity in pre-eclamptic decidual tissue--a key player in the pathophysiology of 'acute atherosis' in pre-eclampsia?

Decidual acute atherosis is associated with pre-eclampsia, but the underlying mechanism is still unclear. We have previously demonstrated elevated level of the oxidative stress marker 8-isoprostaglandin F(2 alpha)(8-isoprostane) and lipids in pre-eclamptic decidual tissue. Arachidonic acid (AA) in tissue phospholipids is a source for 8-isoprostane generation, and 8-isoprostane is liberated from tissue phospholipids by phospholipase A(2)(PLA(2)). The aims of this study were to explore whether AA content or PLA(2)expression in pre-eclamptic decidual tissue differed from controls. Decidua basalis tissues were obtained by vacuum aspiration at Caesarean delivery in pre-eclamptic and control pregnancies. We demonstrated a statistically significantly higher total PLA(2)activity in pre-eclamptic decidua compared to control tissue. On the other hand, no differences in AA content of tissue phospholipids or protein expression of secretory and cytosolic PLA(2)between pre-eclamptic and control decidual tissue were found. In conclusion, the elevated level of free 8-isoprostane in pre-eclamptic decidual tissue could be caused by augmented PLA(2)activity. We speculate that an elevated PLA(2)enzyme activity in pre-eclamptic decidual tissue could be of importance in the pathogenesis of 'acute atherosis', comparable to the atherogenesis in cardiovascular diseases.     

Expression of glucose transporter 1 in human endometrial and decidual tissue

Regulation of endometrial glucose transport is important for the decidualization process. Therefore ,we have examined the expression of the glucose transporter protein isoform 1 (GLUT1) in endometrial samples during the menstrual cycle and in decidual tissue by immunohistochemistry ,and GLUT1 mRNA by RNase protection assays. GLUT1 protein was not detected in proliferative endometrial samples ,but was highly expressed in decidual tissue. Placental tissue was highly positive. GLUT1 mRNA could be detected in endometrial samples with an increase in endometria of the late secretory phase (day 25–28) and maximum concentration in the decidua of the 9th–10th week of gestation. Our results show that GLUT1 is differentially expressed in the different phases of the human endometrium with a maximum in the human decidua. Therefore ,GLUT1 may be an important marker for endometrial differentiation.     

Expression of glucose transporter 1 in human endometrial and decidual tissue.

Regulation of endometrial glucose transport is important for the decidualization process. Therefore, we have examined the expression of the glucose transporter protein isoform 1 (GLUT1) in endometrial samples during the menstrual cycle and in decidual tissue by immunohistochemistry, and GLUT1 mRNA by RNase protection assays. GLUT1 protein was not detected in proliferative endometrial samples, but was highly expressed in decidual tissue. Placental tissue was highly positive. GLUT1 mRNA could be detected in endometrial samples with an increase in endometria of the late secretory phase (day 25-28) and maximum concentration in the decidua of the 9th-10th week of gestation. Our results show that GLUT1 is differentially expressed in the different phases of the human endometrium with a maximum in the human decidua. Therefore, GLUT1 may be an important marker for endometrial differentiation.     

Plasma prostaglandin metabolite levels after use of prostaglandin E2 gel for cervical ripening

An ideal agent for cervical ripening should produce an increase in cervical scores without stimulating myometrial contractions. Currently used methods of preinduction ripening with prostaglandin E2 are frequently associated with contractions, limiting their use in high-risk patients. To discriminate between a direct effect of absorbed prostaglandin E2 and a triggering of the intrinsic mechanisms of labor, we measured circulating levels of stable metabolites of prostaglandin E2 and prostaglandin F2 alpha. Prostaglandin E2 gel insertion followed by a rise in prostaglandin E2 metabolite but not prostaglandin F2 alpha metabolite implies that contractions are secondary to absorbed prostaglandin E2.     

Plasma concentrations of prostaglandin F2 alpha and prostaglandin E2 metabolites after transabdominal and transvaginal cervical cerclage

Circulating prostaglandin metabolites 13,14-dihydro-15-keto-prostaglandin F2 alpha and the bicyclo derivative of prostaglandin E2 were measured in maternal plasma by radioimmunoassay after transabdominal cervicoisthmic cerclage and after transvaginal cerclage (Shirodkar and McDonald procedures) performed in the first and second trimesters. Statistically significant elevations in prostaglandin E2 metabolite or 13,14-dihydro-15-keto-prostaglandin F2 alpha occurred after transabdominal cervicoisthmic and transvaginal cerclage; they returned to control levels within 6 to 24 hours after surgery and were associated with good fetal outcome. Increases in 13,14-dihydro-15-keto-prostaglandin F2 alpha were proportionately greater than in prostaglandin E2 metabolite. Mean basal levels and the rise in prostaglandin metabolites were not related to cerclage type, trimester of pregnancy, or cervical status (dilatation less than or equal to 3 cm; effacement less than or equal to 60%). Highest basal and postcerclage 13,14-dihydro-15-keto-prostaglandin F2 alpha and prostaglandin E2 metabolite levels were associated with advanced cervical changes, uterine irritability, membrane prolapse or rupture, and premature delivery. Routine administration of prostaglandin synthetase inhibitors is not indicated for transvaginal cerclage or transabdominal cervicoisthmic cerclage; plasma prostaglandin metabolite levels may identify patients not suitable for cerclage.     

Studies in the involvement of prostaglandins in uterine symptomatology and pathology.

The concentrations of prostaglandin E2 and F2alpha were measured by radioimmunoassay in samples of endometrial tissue from 155 women. The results showed that the concentration of prostaglandins E2 (ng/100 mg of wet tissue; mean +/- SD) in tissue from apparently healthy women with regular menstrual cycles was 79-3 +/- 9-9 during the menstrual period. The level in the proliferative and early secretory phases fell to 11-8 +/- 4-0 and 13-3 +/- 8-3 respectively. During the late secretory phase there was a significant increase to 20-1 +/- 10-8. The corresponding values from patients with fibromyomata and without menorrhagia were similar. However, the concentration in tissue from patients with fibromyomata and menorrhagia was significantly higher (63-9 +/- 17-9) during the secretory phase of the uterine cycle. In addition, the amount was significantly higher in the groups with dysmenorrhoea (19-0 +/- 4-5 proliferative; 68-0 +/-18-15 secretory) and irregular uterine bleeding (78-3 +/- 59-0 proliferative; 87-4 +/- 64-9 secretory). The mean concentration was higher in cases of endometriosis, and significantly elevated in endometrial carcinoma. The results for prostaglandin F2alpha showed a similar pattern, but the changes were less marked in patients with irregular dysfunctional bleeding. The findings are discussed.     

Estrogen, progesterone, prolactin, prostaglandin E2, prostaglandin F2 alpha, 13,14-dihydro-15-keto-prostaglandin F2 alpha, and 6-keto-prostaglandin F1 alpha gradients across the uterus in women in labor and not in labor

Before or during labor in humans, changes in peripheral levels of estrogen and progesterone are not evident. Local alterations of estrogen, progesterone, and prolactin concentrations may be present and be accompanied by prostaglandin changes. The purpose of this study was to investigate the differences in concentrations of these hormones across the uterus and to evaluate their interrelationships in patients at term gestation with and without labor. Blood samples were obtained from a radial artery and a uterine vein in 22 women without and in 10 with labor. The difference between levels in the two blood vessels was designated as the gradient. Neither levels nor gradients were different between the two groups for estrone, estradiol, estriol, progesterone, or prolactin. The plasma levels of prostaglandin F2 alpha, 13,14-dihydro-15-keto-prostaglandin F2 alpha, and prostaglandin E2 were significantly increased in labor. Prostacyclin levels, as indicated by the 6-keto-prostaglandin F1 alpha metabolite, were not altered. The gradients for prostaglandin F2 alpha and E2 were significantly increased in labor. The results of the study also suggested that, in gestation at term, serum prolactin is produced mainly by the pituitary and that estrone may originate from peripheral conversion of estradiol. We conclude that in humans prostaglandin gradients of the E and F groups are increased in labor. These increases are not associated with changes in sex steroids or prolactin. Prostacyclin metabolite gradients also appear not to be altered in labor, suggesting that some prostaglandins are selectively increased in early labor either by enhanced production or decreased metabolism or both.     

Ultrastructural studies of tumors transplanted into nude mice using the TTK-1 cell lines derived from normal human early decidual tissue

Tumors transplanted into nude mice using the TTK-1 cell lines [TTK-1(E) and TTK-1(F)] derived from normal human early decidual tissue were studied morphologically. The epithelial-like cell line TTK-1(E) and the fibroblast-like cell line TTK-1(F) were maintained in culture through one hundred and ten subcultures since July 1979. Rapidly growing tumor nodules formed at the implantation sites. The incidence of tumor growth was 100% for both cell lines. Histologically the tumors were composed of poorly-differentiated cells arranged in a cord-like structure and showed typical malignant characteristics. Immunohistochemical studies, electron microscopy and immunocytochemical studies revealed that the tumors from the two cell lines differed in many respects. The tumors formed by TTK-1(E) showed epithelial characteristics and the tumors formed by TTK-1(F) showed both epithelial and mesenchymal characteristics. Therefore, TTK-1(E) might be useful as an in vitro model of endometrial cancer and TTK-1(F) as an in vitro model of both endometrial cancer and endometrial stromal tumor (containing mixed mesodermal tumor). These tumors will be valuable for future studies of the tumorigenicity and therapy of uterine malignant tumors. They may reflect the various functions of decidual tissue.