Induction of superoxide dismutase by decidualization in human endometrial stromal cells

The present study was undertaken to investigate the effect of decidualization on superoxide dismutase (SOD) expression in human endometrial stromal cells (ESC). To induce decidualization, isolated ESC were incubated with medroxyprogesterone acetate (MPA, 10(-6) mol/l) and oestradiol (10(-8) mol/l) for 23 days. Insulin-like growth factor-binding protein-1 (IGFBP-1) was used as a marker of decidualization. SOD mRNA in ESC was significantly increased on day 12 of the hormone treatment (P < 0.01), which was concomitant with the onset of IGFBP-1 mRNA expression, and further increased until day 23 of the treatment in a manner similar to the change in IGFBP-1 expression. To examine the synergistic effect of human chorionic gonadotrophin (HCG) with MPA and oestradiol on SOD and IGFBP-1 expression, ESC were incubated with HCG in the presence or absence of MPA and oestradiol. HCG had no synergistic effect on SOD and IGFBP-1 expression. SOD activities in the decidualized endometrial tissue obtained from patients given oestradiol and progesterone for 7-10 days were significantly higher than those in the non-decidualized endometrial tissue from patients without the hormone treatment (P < 0.01). In conclusion, SOD expression in ESC was induced by MPA and oestradiol accompanied by decidualization, suggesting that SOD may play important roles in decidualization of ESC.     

Endometrial stromal cell decidualization inhibits human chorionic gonadotrophin and human placental lactogen secretion by co-cultured trophoblasts

We have developed an in-vitro co-culture system to examine theinteraction between purified first trimester cytotrophoblastsand purified non-pregnant human endometrial stromal cells (ESC).ESC decidualization is an important step in endometrial maturationand may modulate embryo implantation. In order to investigatethe effects of ESC decidualization on trophoblast function,we examined human chorionic gonadotrophin (HCG), human placentallactogen (HPL), progesterone and oestrogen secretion by trophoblastsco-cultured in contact with ESC, either with or without decidualizationinduced by progesterone. Decidualized ESC inhibited basal HCGand HPL secretion for 3 days during the culture for HCG, andfor 5 days during the culture for HPL (P < 0.01 and P <0.03 respectively). After 5 days of co-culture, decidual transformationof ESC as indicated by prolactin production occurred in thecontrol cultures due to progesterone and oestradiol secretionby the co-cultured trophoblasts, but no significant differencesin HCG or HPL secretion were observed between the two groups.Although the type of trophoblast used in the present study isfar from implantation, our results clearly demonstrated thatHCG and HPL secretion by trophoblasts was inhibited by the presenceof co-cultured decidualized ESC, and suggested that ESC decidualizationmay regulate trophoblast function at the human fetal-maternalinterface.     

Different mechanisms for the induction of copper-zinc superoxide dismutase and manganese superoxide dismutase by progesterone in human endometrial stromal cells

BACKGROUND: The present study was undertaken to investigate the cAMP-dependent regulation of copper-zinc superoxide dismutase (Cu,Zn-SOD) and manganese SOD (Mn-SOD) by ovarian steroids in human endometrial stromal cells (ESC). METHODS and RESULTS: To examine the effect of cAMP on SOD expression, ESC were incubated with dibutyryl-cAMP (db-cAMP, 0.5 mmol/l), forskolin (25 micromol/l), or estradiol (E(2), 10(-8) mol/l) + medroxyprogesterone acetate (MPA, 10(-6) mol/l), for 18 days. E(2) + MPA significantly increased Cu,Zn-SOD activity and mRNA concentrations, whereas db-cAMP and forskolin had no effect. On the other hand, Mn-SOD activity and mRNA concentration were significantly increased by all of these treatments. Insulin-like growth factor-binding protein-1, a marker of decidualization, was clearly induced by db-cAMP, forskolin or E(2) + MPA, accompanied by morphological changes characteristic of decidualization. To study whether the increase in Mn-SOD by db-cAMP or E(2) + MPA was mediated by cAMP-dependent protein kinase A (PKA), ESC were incubated with protein kinase inhibitor (PKI) (10 microg/ml), an inhibitor of PKA, in the presence of db-cAMP or E(2) + MPA. The increase in Mn-SOD activity following db-cAMP or E(2) + MPA was completely inhibited by PKI. CONCLUSIONS: In the process of decidualization, E(2) + MPA increases Mn-SOD expression via a cAMP-dependent pathway. Cu,Zn-SOD is also up-regulated by E(2) + MPA, but via a different pathway from that involving cAMP.     

Continuous-combined treatment of the menopause with combinations of oestradiol valerate and dienogest - a dose-ranging study

Objectives: To determine the progestational efficacy of continuous treatment with various doses of dienogest, combined with oestradiol valerate, on the basis of endometrial histology, effect on climacteric symptoms and bleeding profile in postmenopausal women. Methods: Patients were randomised to one of five fixed-combination treatments, oestradiol valerate 2.0 mg plus dienogest 0.5, 1.0, 2.0, 3.0 or 4.0 mg. Efficacy was assessed by endometrial biopsy, menstrual charts and change in climacteric symptoms. Results: The endometrium was classified as atrophic in 20.0, 31.3, 25.0, 55.6 and 57.1% of patients in the 0.5, 1.0, 2.0, 3.0 and 4.0 mg dienogest groups, respectively. The frequency of uterine bleeding was dose-dependent. The most favourable bleeding profile was seen in the 3.0 mg dienogest group, whereas the lower doses of dienogest had advantages with respect to the efficacy of the combined preparation. Conclusions: Dienogest 2.0 and 3.0 mg are the optimal doses for combination with 2.0 mg oestradiol valerate for continuous-combined hormone replacement therapy.     

Differential regulation of copper-zinc superoxide dismutase and manganese superoxide dismutase by progesterone withdrawal in human endometrial stromal cells.

The present study was undertaken to investigate the role of estrogen and progesterone in the expression of copper-zinc superoxide dismutase (Cu,Zn-SOD) and manganese SOD (Mn-SOD) in human endometrial stromal cells (ESC). ESC were incubated with estradiol (10(-8) mol/l), medroxyprogesterone acetate (MPA, 10(-6) mol/l), or estradiol + MPA for 18 days. MPA significantly increased Cu,Zn-SOD and Mn-SOD mRNA levels and enzyme activities as well as the mRNA level of insulin-like growth factor-binding protein-1 (IGFBP-1), a marker for decidualization. Estradiol only augmented the effects of MPA on Cu,Zn-SOD activity and IGFBP-1 mRNA level, and estradiol alone had no effect. To study the withdrawal of estrogen and progesterone (EP withdrawal), ESC that had been treated with estradiol + MPA for 12 days were washed and then incubated with or without estradiol + MPA for a further 11 days. Cu,Zn-SOD mRNA levels and activities declined after EP withdrawal, while they were gradually increased by the continuous treatment with estradiol + MPA. In contrast, Mn-SOD mRNA levels and activities were not affected by EP withdrawal. IGFBP-1 mRNA levels were significantly increased 4 days after EP withdrawal and decreased thereafter, whereas they were gradually increased by the continuous treatment with estradiol + MPA. In conclusion, Cu,Zn-SOD, Mn-SOD and IGFBP-1 are differently regulated by estrogen and progesterone in human ESC. The decrease in Cu,Zn-SOD after the ovarian steroid withdrawal may be involved in endometrial breakdown.     

Differentiation of endometrial stromal cells in vitro: down-regulation of suppression of the cell cycle inhibitor p57 by HOXA10?

Decidualization is a critical step during embryo implantation that is characterized by the differentiation of endometrial stromal cells (ESC) into decidua cells. However, the mechanism of differentiation remains largely unknown. Previously, it has been shown that the null function of homeo box A10 (HOXA10) causes defects in both implantation and decidualization, suggesting that the HOXA10 signalling pathway is likely to be involved in uterine decidualization. In the present study, we determined the expression and subcellular distribution of HOXA10 and its downstream molecule, p57, in ESC during in vitro decidualization induced by a combination of 8-bromo-cAMP and medroxyprogesterone acetate. We demonstrated that the HOXA10 was down-regulated while in contrast, p57 was up-regulated in the process of decidualization. Immunocytochemistry and transient expression of the HOXA10 tagged with green fluorescence protein revealed that there were no differences in the HOXA10 subcellular localization between the induced and non-induced ESC. Our results suggest that the down-regulation of HOXA10 may contribute to increased p57 and that up-regulation of p57 likely plays an important role in ESC differentiation in the process of decidualization. The progesterone receptor pathway may participate in promoting ESC to exit the cell cycle and enter differentiation.     

Non-competitive anti-oestrogemc actions of progesterone antagonists in primate endometrium: enhancement of oestrogen and progesterone receptors with blockade of post-receptor proliferative mechanisms

Previous studies have shown that the progesterone antagonists(antiprogestins) inhibit oestrogen-dependent endometrial proliferationin ovariectomized monkeys, without having affinity to the oestrogenreceptor (ER). This study was designed to investigate the effectsof the antiprogestins mifepristone (RU 486) and onapristone(ZK 98,299), on the concentration of ER and progesterone receptor(PR) in the endometrium of long-term ovariectomized cynomolgusmonkeys (Macaca fascicularis). In untreated monkeys, tissuepreparations bound in total 228±68 pmol [³H]-oestradiol/gprotein (ER), and 119±42 pmol [³H]-R5020/g protein (PR).These values were not significantly different from the totalbinding capacities of tissues from monkeys treated with RU 486alone or primates treated with oestradiol plus progesterone.Treatment with oestradiol alone almost doubled the ER and PRconcentrations. Combined treatment with oestradiol and RU 486enhanced the ER and PR concentrations in a dose-dependent manner:1 mg/kg body weight (bw) RU 486/kg increased both ER and PRcontents about 3-fold. The dose of 5 mg/kg bw RU 486 or onapristoneincreased the ER and PR concentrations almost 6- and 5-foldrespectively, compared with the oestradiol-treated controls.Our results demonstrate that RU 486 and onapristone increasedthe endometrial ER and PR concentrations far beyond the physiologicallevel in ovariectomized, oestradiol-treated monkeys. Whetherthe over-expression of ER and PR in the presence of antiprogestinsis causally related to the antiproliferative impact of antiprogestinsin the endometrium (non-competitive anti-oestrogenic effects)or is an independent action is unknown.     

地塞米松对PMA诱导CD18表达的抑制作用

目的:研究GC抑制CD18表达的作用。方法:选用PMA刺激下的U937细胞为实验模型,运用定量RT-PCR、Northern杂交检测U937细胞CD18 mRNA的表达水平。结果:Dex能明显抑制PMA诱导CD18 mRNA的表达,这种抑制作用具有明显的剂量依赖性,GR的拮抗剂RU38486能够明显扭转Dex的抑制作用。结论:Dex通过GR介导能在转录水平上抑制PMA诱导的CD18 mRNA的表达,该作用可能与糖皮质激素受体(GR)在转录水平拮抗NF-κB有关。     

Interleukin 11 advances progesterone-induced decidualization of human endometrial stromal cells

Differentiation of endometrial stromal cells into decidual cells is crucial for embryo implantation and placentation. Interleukin (IL)-11 signalling is essential for adequate decidualization in the mouse uterus. We examined the role of IL-11 during progesterone-induced decidualization of human endometrial stromal cells over a 10-12 day period, using prolactin (PRL) production as a decidual marker. These cells produced biologically active IL-11 and expressed IL-11, IL-11Ralpha and PRL mRNA during decidualization. Neutralization of endogenous IL-11 with an anti-human (hu)IL-11 antibody (AB) reduced production of PRL from day 8 and insulin-like growth factor binding protein (IGFBP)-1, another marker of decidualization, from day 10 of culture. Following AB washout, PRL and IGFBP-1 secretion increased. Addition of recombinant (r)huIL-11 (10 or 100 ng/ml) to endometrial stromal cells increased secretion of PRL from day 4 and IGFBP-1 from day 6 compared with progesterone alone. Morphological signs of differentiation accompanied biochemical differentiation in the progesterone-treated cells and were further induced by exogenous rhuIL-11. Our observations demonstrate that human endometrial stromal cells produce biologically active IL-11, which promotes progesterone-induced decidualization. These results suggest that IL-11 has both paracrine and autocrine actions on human endometrial stromal cells and plays an important role in preparing the human endometrium for implantation.     

Progesterone induces the fibulin-1 expression in human endometrial stromal cells

BACKGROUND: By using microarray analysis with human endometrial stromal cells (ESCs), we previously reported that the mRNA for fibulin-1, an extracellular matrix as well as a plasma glycoprotein, is up-regulated by progesterone. In the present study, we tried to clarify the spatial and temporal regulation mechanism of fibulin-1 in the human endometrium. METHODS AND RESULTS: Quantitative analysis with real-time PCR experiments on human endometrial tissues showed significantly higher fibulin-1 mRNA expressions in secretory phase endometria than in proliferative phase. Immunohistochemical studies revealed that the fibulin-1 protein is expressed in the glandular epithelium in proliferative phase endometria, and that expression switched to the stroma in secretory phase endometria. In culture experiments with ESCs, a significant increase of fibulin-1 mRNA expression was observed in cells treated with 6 alpha-methyl-17 alpha-hydroxy-progesterone acetate (MPA) or 8 bromoadenosine 3':5'-cyclic monophosphate (8-Br-cAMP). MPA stimulated the fibulin-1 mRNA expression in a dose-dependent manner, and a progesterone antagonist, RU-486, inhibited the stimulatory effect almost completely. By contrast, beta-estradiol alone did not increase the fibulin-1 mRNA expression. CONCLUSIONS: These results suggest that fiblin-1 is an important molecule that mediates progesterone action in human ESC differentiation towards implantation.     

Retinoic acid suppresses in-vitro decidualization of human endometrial stromal cells

All-trans retinoic acid (RA) has potent effects on cell differentiationand gene expression. Previous studies have demonstrated thathuman endometrial stromal cells express mRNA for retinoic acidreceptors (RARs) and cellular RA-binding protein-ll (CRABP-II).We examined whether RA regulates stromal cell differentiation(decidualization), a critical process in preparation of theuterus for blastocyst implantation. Decidualization was inducedby incubating cultured stromal cells with medroxyprogesteroneacetate (MPA) and oestradiol. Decidualization was defined bythe induction of prolactin, insulin-like growth factor bindingprotein-1 (IGFBP-1), appearance of a differentiated phenotypeand changes in fibronectin expression. RA treatment significantly(P<0.05) suppressed prolactin and IGFBP-1 production associatedwith stromal cells decidualization. The formation of differentiatedcells was inhibited by RA, and consistent with maintenance ofthe undifferentiated phenotype, fibronectin mRNA content was-3.5-times greater than in the absence of RA. Upon inductionof decidualization, the expression of mRNA for the major RAreceptor sub-types (RAR-     

Corticotrophin-releasing hormone (CRH) interacts with inflammatory prostaglandins and interleukins and affects the decidualization of human endometrial stroma

The hypothalamic neuropeptide, corticotrophin-releasing hormone (CRH), which is also produced by human endometrium, has been shown to induce its decidualization in vitro. This process, induced mainly by progesterone, has characteristics of an aseptic inflammatory reaction, and is modulated by locally produced pro-inflammatory factors. In humans, prostaglandin E(2) (PGE(2)) enhances while interleukin (IL)-1 inhibits the decidualizing effect of progesterone. The aim of the present work was to test the hypothesis that CRH might affect the decidualization of human endometrium interacting with these factors. Therefore, we studied its effects on the production of pro-inflammatory interleukins IL-1, IL-6 and of PGE(2) from human endometrial stromal cells in primary culture. The results strongly suggest that CRH decidualizes stromal cells, as judged by the appearance of cytokeratins and the production of prolactin, two established markers of decidualization. In parallel to its effect on decidualization, CRH also decreased the production of PGE(2), while it increased the production of IL-1 and IL-6. Exposure of endometrial stromal cells to IL-6 also caused decidualization. The data presented here suggest that endometrial CRH regulates the production of local modulators of decidualization, i.e. PGE(2), IL-1 and IL-6. We postulate that, through the regulation of these factors, CRH acts as a local fine-tuner of decidualization initiated by progesterone.     

The presence of platelet-derived endothelial cell growth factor in human endometrium and its characteristic expression during the menstrual cycle and early gestational period

Decidualized tissues are characterized by the intensive outgrowthof the microvasculature. Several angiogenic factors are assumedto be involved during the drastic change in the vasculatureoccurring in the process of decidualization. We examined thepossible role of platelet-derived endothelial cell growth factor(PD-ECGF), a known angiogenic factor, during the process ofearly decidualization in humans. The expression of PD-ECGF inhuman endometrium was demonstrated by Western blot analysis,a marked increase being found in decidualized endometrium. Immunohistochemicalstaining showed that PD-ECGF immunoreactivity was present mainlyin decidualized endometrial stromal cells. We established aprimary cell culture of human endometrial stromal cells whichwere differentiated into decidualized cells in vitro by theaddition of progesterone. In this cell culture system, progesteroneaugmented the expression of PD-ECGF in a dose-dependent fashion.The addition of progesterone also resulted in an increased releaseof prolactin, a well-known marker for decidualization. Thesefindings suggest that PD-ECGF may play a physiological roleas a possible angiogenic factor in the process of decidualizationof human endometrium. angiogenesis/decidualization/human endometrium/PD-ECGF/prolactin     

Akt as a possible intracellular mediator for decidualization in human endometrial stromal cells

To gain an insight into intracellular mechanisms involved in differentiation of human endometrial cells into decidual cells, we examined the presence of Akt, an emerging intracellular mediator in human endometrial stromal cells (ESC). We explored the mechanisms regulating Akt phosphorylation during the process of progesterone-induced decidualization using a primary cell culture system of ESC. Both Akt and phosphorylated Akt (phospho-Akt) were present in ESC. The total Akt level in ESC cultured for 12 days in the absence of ovarian hormones was similar to ESC treated with estradiol (E(2)) at 10 ng/ml, progesterone at 100 ng/ml or E(2) plus progesterone (E(2)progesterone), whereas the levels of phospho-Akt were markedly decreased with progesterone or E(2) progesterone, compared to control cells. Notably, phospho-Akt levels increased during 12 days of culture in parallel with an increase in total Akt in untreated cells. An increase of phospho-Akt in the E(2) progesterone-treated cells was marginal. The level of phospho-Akt in E(2) progesterone-treated cells was markedly reduced compared to control cells at all time points examined. Treatment of the cells with 8-bromo-cAMP decreased the amount of phospho-Akt in ESC in as short a period as 15 min, while no discernible change was observed in the untreated cells. Conversely, H89, an inhibitor of protein kinase A (PKA), significantly increased the amount of phospho-Akt. The addition of H-89 reversed the decrease in the level of phospho-Akt seen in the cells treated with E(2) progesterone. Thus, we demonstrated the presence of Akt and its phosphorylated form in human ESC. We further suggest that Akt phosphorylation through the cAMP/PKA signal transduction pathway may regulate cellular functions coupled with decidualization.     

Reactive oxygen species stimulate prostaglandin F2 alpha production in human endometrial stromal cells in vitro

BACKGROUND: The present study was undertaken to investigatethe effect of reactive oxygen species on prostaglandin F2 (PGF2)production by human endometrial stromal cells (ESC). METHODSAND RESULTS: Isolated ESC were incubated with hydrogen peroxide,which induces lipid peroxidation. Hydrogen peroxide increasedboth intracellular and medium concentrations of PGF2 (P <0.01). A time course study showed that hydrogen peroxide significantlyincreased PGF2 concentrations in the medium after 6 h incubation(P < 0.01), after which no further increase was observed.To study whether the increase in PGF2 production caused by hydrogenperoxide was mediated by cyclooxygenase, ESC were incubatedwith indomethacin (0.5 µg/ml), an inhibitor of cyclooxygenase,in the presence of hydrogen peroxide. Indomethacin significantlyblocked the increases in PGF2 production caused by hydrogenperoxide (P < 0.01). Hydrogen peroxide also increased PGF2production by decidualized ESC (P < 0.01), induced by theincubation with medroxyprogesterone acetate (10^–6 mol/l)and oestradiol (10^–8 mol/l). CONCLUSIONS: Reactive oxygenspecies stimulate PGF2 production in ESC, suggesting that theymight influence endometrial function by regulating PGF2 production.     

Effects of interferon-gamma on cytokine production by endometrial stromal cells

To clarify the role of interferon-gamma (IFN-gamma) in reproduction, we have examined its effects on cytokine production by human endometrial stromal cells (ESC). Concentrations of interleukin (IL)-6, IL-8, monocyte chemoattractant protein-1 (MCP-1), and macrophage colony- stimulating factor (M-CSF) in the culture media of normal ESC and an endometrial stromal sarcoma cell line, MaMi, were measured using an enzyme-linked immunosorbent assay. Both non-stimulated ESC and non- stimulated MaMi cells constitutively secrete IL-6, IL-8, MCP-1, and M- CSF. In a dose-dependent manner, IFN-gamma increased the concentrations of IL-6, MCP-1, and M-CSF and reduced the concentrations of IL-8 in ESC and MaMi cells. These results suggest that IFN-gamma produced by both decidual inflammatory cells and the developing embryo plays a role in the maintenance of early pregnancy by modulating the production of these cytokines by human ESC.      

Oncostatin M inhibits decidualization of normal human endometrial stromal cells

It is well known that oncostatin M binds and activates leukemia inhibitory factor-specific receptors while leukemia inhibitory factor cannot bind oncostatin M-specific receptors. In this study, the differential effects of oncostatin M and leukemia inhibitory factor on cell survival and decidualization of normal human endometrial stromal cells were investigated by using 8-Br-cAMP-induced decidualization assay. Oncostatin M did not affect the viable cell numbers or the prolactin release of unstimulated stromal cells. However, oncostatin M dose-dependently suppressed prolactin releases from 8-Br-cAMP-stimulating stromal cells but enhanced their viable cell numbers. Although oncostatin M significantly enhanced viable cell numbers of 8-Br-cAMP-stimulated stromal cells, it did not affect prolactin secretion from 8-Br-cAMP-induced decidualized cells. Leukemia inhibitory factor significantly enhanced viable cell numbers of 8-Br-cAMP-stimulating cells in a dose-dependent manner as did oncostatin M, while leukemia inhibitory factor did not show any significant suppression of PRL secretion from 8-Br-cAMP-stimulating cells. These results indicate that oncostatin M inhibits the 8-Br-cAMP-induced decidualization process via oncostatin M-specific receptors and that oncostatin M and leukemia inhibitory factor enhance cell survival of 8-Br-cAMP-stimulated prolactin-non-secreting stromal cells mainly via leukemia inhibitory factor receptors. Thus, oncostatin M may autoregulate human endometrial stromal cell survival and decidualization in a paracrine manner.