Mifepristone (Ru486) antagonizes monocyte chemotactic protein-3 down-regulation at early mouse pregnancy revealing immunomodulatory events in Ru486 induced abortion

Intrauterine administration of peripheral blood mononuclear cells (PBMCs) improves embryo implantation in mice by regulating local Treg/Th17 cell balance

Immune imbalance of Treg/Th17 cells may contribute to recurrent implantation failure (RIF) during in vitro fertilization and embryo transfer (IVF-ET). In this study, we sought to determine the effect of intrauterine administration of mouse PBMCs prior to embryo implantation on endometrial receptivity and embryo implantation, and examine the underlying mechanism of Treg/Th17 cell balance following intrauterine administration of PBMCs. Pregnant mice were randomly divided into three groups: control group, embryo implantation dysfunction (EID) group, and EID with PBMCs group, and the number of embryo implantation sites was recorded during early pregnancy (Pd7.5). The balance of Treg/Th17 cells in the peripheral blood, spleen, and local implantation sites was detected during the peri-implantation period (Pd4.0) and early pregnancy (Pd7.5). The EID group demonstrated a significant decrease in the number of embryo implantation sites, while the EID with PBMCs group demonstrated higher number of embryo implantation sites compared to the EID group. The balance of Treg/Th17 cells in the peripheral blood and spleen tissues was not significantly different between the aforementioned groups. However, the local uterine ratio of the Treg/Th17 cells increased in the EID with PBMCs group compared to that in the EID group. Collectively, we found that intrauterine administration of PBMCs prior to embryo implantation effectively promotes embryo implantation rates. This may be attributed to the improvement in the local immune balance of Treg and Th17 cells compared with the overall immune balance.

Steroids, Pregnancy and Fetal Development

Maternal glucocorticoids critically rise during pregnancy reaching up to a 20-fold increase of mid-pregnancy concentrations. Concurrently, another steroid hormone, progesterone, increases. Progesterone, which shows structural similarities to glucocorticoids, can bind the intracellular glucocorticoid receptor, although with lower affinity. Progesterone is essential for the establishment and continuation of pregnancy and it is generally acknowledged to promote maternal immune tolerance to fetal alloantigens through a wealth of immunomodulatory mechanisms. Despite the potent immunomodulatory capacity of glucocorticoids, little is known about their role during pregnancy. Here we aim to compare general aspects of glucocorticoids and progesterone during pregnancy, including shared common steroidogenic pathways, plasma transporters, regulatory pathways, expression of receptors, and mechanisms of action in immune cells. It was recently acknowledged that progesterone receptors are not ubiquitously expressed on immune cells and that pivotal features of progesterone induced- maternal immune adaptations to pregnancy are mediated via the glucocorticoid receptor, including e.g., T regulatory cells expansion. We hypothesize that a tight equilibrium between progesterone and glucocorticoids is critically required and recapitulate evidence supporting that their disequilibrium underlie pregnancy complications. Such a disequilibrium can occur, e.g., after maternal stress perception, which triggers the release of glucocorticoids and impair progesterone secretion, resulting in intrauterine inflammation. These endocrine misbalance might be interconnected, as increase in glucocorticoid synthesis, e.g., upon stress, may occur in detriment of progesterone steroidogenesis, by depleting the common precursor pregnenolone. Abundant literature supports that progesterone deficiency underlies pregnancy complications in which immune tolerance is challenged. In these settings, it is largely yet undefined if and how glucocorticoids are affected. However, although progesterone immunomodulation during pregnancy appear to be chiefly mediated glucocorticoid receptors, excess glucocorticoids cannot compensate by progesterone deficiency, indicating that additional und still undercover mechanisms are at play.

Effect of Total Flavones from Cuscuta Chinensis on Anti-Abortion via the MAPK Signaling Pathway

For centuries, the Chinese herb Cuscuta chinensis has been applied clinically for abortion prevention in traditional Chinese medicine (TCM). Total flavones extracted from Cuscuta chinensis (TFCC) are one of the active components in the herb and also display anti-abortion effect similar to the unprocessed material. However, how TFCC exerts the anti-abortion effect remains largely unknown. In this study, we aim at characterizing the anti-abortion effects of TFCC and its underlying molecular mechanism in vitro and in vivo using human primary decidua cells and a mifepristone-induced abortion model in rat, respectively. The damage to the decidua caused by mifepristone in vivo was reversed by TFCC treatment in a dosage-dependent manner. High dosage of TFCC significantly upregulated the expression of estrogen receptor (ER), progesterone receptor (PR), and prolactin receptor (PRLR) in decidua tissue but downregulated the expression of p-ERK. Furthermore, we detected higher level of p-ERK and p-p38 in primary decidua cells from spontaneous abortion while treatment by TFCC downregulated their expression. Our results suggest TFCC mediates its anti-abortion effect by interfering with MAPK signaling pathway.

Shenghua Decoction reduces uterine bleeding and regulates T-cell paradigm in human deciduas of RU486 medical abortion

ETHNOPHARMACOLOGICAL RELEVANCE

Excessive uterine bleeding is the most common and problematic side effect of RU486 medical abortion. Shenghua Decoction (SHD) is a well-known traditional Chinese herbal prescription for reducing uterine bleeding induced by RU486 medical abortion. However, its therapeutic mechanism still remains unclear. The Th1/Th2/Th17/Treg paradigm plays an important role in achieving maternal-fetal immunotolerance and its bias participates in RU486-induced abortion. Our previous research on mice demonstrated that the uterine bleeding volume is negatively related to the proportions of Th1 and Th17 cells whereas positively related to the proportions of Th2 and Treg cells. Additionally, Th1-type cytokine inducing effect was identified in our previous study. Therefore, it was hypothesized that SHD reduced the uterine bleeding in RU486 medical abortion by inducing Th1/Th2/Th17/Treg paradigm bias. The purpose of this study was to determine the regulatory effect and the mechanism of SHD on human decidual Th1/Th2/Th17/Treg paradigm for alleviating uterine bleeding in RU486 medical abortion.

MATERIALS AND METHODS

90 women within seven weeks of a normal intrauterine pregnancy, who elected for termination of pregnancy, were divided into three groups; vacuum aspiration group, RU486 group, and SHD-RU486 group. Duration of uterine bleeding was recorded and volume of uterine bleeding was measured by the method of alkaline hematin photometric. To determine the regulatory effect of SHD on Th1/Th2/Th17/Treg paradigm, the proportions of Th1/Th2/Th17/Treg cells in the decidua of different groups were analyzed using a FACS calibur. Correlation was analyzed in order to demonstrate the relationship between the Th1/Th2/Th17/Treg paradigm and the uterine bleeding in RU486 medical abortion. Moreover, to elucidate the mechanism underlying the T-cell paradigm regulating of SHD, the mRNA and protein expressions of subset-specific transcription factors (T-bet, GATA-3, RORγt, and Foxp3) for the differentiation of Th1/Th2/Th17/Treg paradigm in human decidual CD4(+) T cells were detected by reverse transcription-polymerase chain reaction (RT-PCR) assay and western blot analysis respectively. Moreover, the mRNA expression of the characteristic cytokines of Th1/Th2/Th17/Treg paradigm (IFNγ, IL-4, IL-17A, TGF-β) were analyzed by RT-PCR assay.

RESULT

Compared with RU486 group, both the uterine bleeding volume and duration reduced significantly in SHD-RU486 group. Both the duration and the volume of the uterine bleeding demonstrated negative correlation with the proportions of Th1 and Th17 cells, whereas showed positive correlation with Th2 and Treg cells. SHD increased the proportions of Th1 and Th17 cells whereas decreased those of Th2 and Treg cells. Thus, the ratios of Th1/Th2 and Th17/Treg cells elevated markedly after SHD treatment. SHD promoted the mRNA as well as the protein expressions of subset-specific transcription factors for the differentiation of Th1 and Th17 subsets (T-bet and RORγt) while inhibited those of Th2 and Treg cells (GATA-3 and Foxp3). Moreover, the mRNA expression of Th1- and Th17- type cytokines (IFNγ and IL-17A) was up-regulated while that of Th2-type and Treg-produced cytokines (IL-4 and TGF-β) was down-regulated significantly after SHD administration.

CONCLUSION

Th1/Th2/Th17/Treg paradigm bias was involved in RU486 medical abortion. SHD reduced the uterine bleeding efficiently by inducing Th1 and Th17 skews in the maternal-fetal of RU486 medical abortion patients. The regulatory effect of SHD on Th1/Th2/Th17/Treg paradigm in RU486 medical abortion is attributed to the modulation of transcription and protein expression of subset-specific transcription factors for T-cell subsets differentiation and their characteristic cytokines.

Pro-inflammatory profile of preeclamptic placental mesenchymal stromal cells: new insights into the etiopathogenesis of preeclampsia

The objective of the present study was to evaluate whether placental mesenchymal stromal cells (PDMSCs) derived from normal and preeclamptic (PE) chorionic villous tissue presented differences in their cytokines expression profiles. Moreover, we investigated the effects of conditioned media from normal and PE-PDMSCs on the expression of pro-inflammatory Macrophage migration Inhibitory Factor (MIF), Vascular Endothelial Growth Factor (VEGF), soluble FMS-like tyrosine kinase-1 (sFlt-1) and free β-human Chorionic Gonadotropin (βhCG) by normal term villous explants. This information will help to understand whether anomalies in PE-PDMSCs could cause or contribute to the anomalies typical of preeclampsia.

METHODS

Chorionic villous PDMSCs were isolated from severe preeclamptic (n = 12) and physiological control term (n = 12) placentae. Control and PE-PDMSCs's cytokines expression profiles were determined by Cytokine Array. Control and PE-PDMSCs were plated for 72 h and conditioned media (CM) was collected. Physiological villous explants (n = 48) were treated with control or PE-PDMSCs CM for 72 h and processed for mRNA and protein isolation. MIF, VEGF and sFlt-1 mRNA and protein expression were analyzed by Real Time PCR and Western Blot respectively. Free βhCG was assessed by immunofluorescent.

RESULTS

Cytokine array showed increased release of pro-inflammatory cytokines by PE relative to control PDMSCs. Physiological explants treated with PE-PDMSCs CM showed significantly increased MIF and sFlt-1 expression relative to untreated and control PDMSCs CM explants. Interestingly, both control and PE-PDMSCs media induced VEGF mRNA increase while only normal PDMSCs media promoted VEGF protein accumulation. PE-PDMSCs CM explants released significantly increased amounts of free βhCG relative to normal PDMSCs CM ones.

CONCLUSIONS

Herein, we reported elevated production of pro-inflammatory cytokines by PE-PDMSCs. Importantly, PE PDMSCs induced a PE-like phenotype in physiological villous explants. Our data clearly depict chorionic mesenchymal stromal cells as central players in placental physiopathology, thus opening to new intriguing perspectives for the treatment of human placental-related disorders as preeclampsia.

Contraceptive vaccines targeting factors involved in establishment of pregnancy

Current methods of contraception lack specificity and are accompanied with serious side effects. A more specific method of contraception is needed. Contraceptive vaccines can provide most, if not all, the desired characteristics of an ideal contraceptive. This article reviews several factors involved in the establishment of pregnancy, focusing on those that are essential for successful implantation. Factors that are both essential and pregnancy-specific can provide potential targets for contraception. Using database search, 76 factors (cytokines/chemokines/growth factors/others) were identified that are involved in various steps of the establishment of pregnancy. Among these factors, three, namely chorionic gonadotropin (CG), leukemia inhibitory factor (LIF), and pre-implantation factor (PIF), are found to be unique and exciting molecules. Human CG is a well-known pregnancy-specific protein that has undergone phase I and phase II clinical trials, in women, as a contraceptive vaccine with encouraging results. LIF and PIF are pregnancy-specific and essential for successful implantation. These molecules are intriguing and may provide viable targets for immunocontraception. A multiepitope vaccine combining factors/antigens involved in various steps of the fertilization cascade and pregnancy establishment may provide a highly immunogenic and efficacious modality for contraception in humans.

Progesterone increases systemic and local uterine proportions of CD4+CD25+ Treg cells during midterm pregnancy in mice

Mechanisms maintaining the growth of a "semi-foreign" fetus within the maternal uterus via immune tolerance remain unclear. CD4(+)CD25(+) regulatory T (Treg) cells have been implicated in the maintenance of maternal-fetal immune tolerance. Additionally, 17β-estradiol (E2) is able to initiate immune suppression through CD4(+)CD25(+) Treg cells during early pregnancy. Little is known, however, regarding the relationship between progesterone (P4) and immune tolerance during midterm pregnancy, an important period, characterized by higher levels of P4 but lower levels of E2 in the serum. Here, we examined the effects of P4 on the expansion and function of systemic and local uterine CD4(+)CD25(+) Treg cells during midterm pregnancy in mice. Using in vivo and in vitro models, we provide the first evidence that P4 not only increases the proportion of CD4(+)CD25(+) Treg cells and IL-10 expression but also enhances their suppressive function. Moreover, at physiological doses relevant to midterm pregnancy, P4, but not E2, converts CD4(+)CD25(-) T cells into CD4(+)CD25(+) Treg cells. This conversion was inhibited in vitro by the nuclear P4 receptors antagonist RU 486 and in vivo in P4-treated ovariectomized and pseudopregnant mice models, suggesting that P4 expands Treg populations via nuclear P4 receptors. Furthermore, RU 486 significantly reduced the quantity and function of Treg cells in the fetal-maternal interface before the onset of induced abortion. Interestingly, with decreasing Foxp3, proinflammatory factors increased. Together, the present results demonstrate that P4 is an important regulator of systemic and local CD4(+)CD25(+) Treg cells, which are involved in maintaining maternal-fetal immune tolerance during midterm pregnancy.

Differential Expression of Alternatively Spliced Transcripts of HLA-G in Human Preimplantation Embryos and Inner Cell Masses

It has been reported that preimplantation human embryos secrete HLA-G, and the levels may be predictive of their ability to implant. However, it is not known which of the membrane-bound (HLA-G 1-4) and soluble (HLA-G 5-6) alternatively spliced forms are present, nor the developmental stage at which they appear. Therefore, we have investigated HLA-G mRNA isoform expression on single embryos at the two-, four-, six-, and eight-cell, morula, and blastocyst stages. The percentage of embryos expressing each HLA-G isoform mRNA increased with developmental stage, but contrary to expectation, HLA-G5 mRNA was not detected in single two- to eight-cell embryos and was only expressed by 20% of morulae and blastocysts. Similarly, soluble HLA-G6 mRNA was not detected until the blastocyst stage and then in only one-third of embryos. In contrast, labeling with MEM G/9 Ab (specific for HLA-G1 and -G5) was observed in 15 of 20 two- to eight-cell embryos and 5 of 5 blastocysts. This disparity between mRNA and protein may be due to HLA-G protein remaining from maternal oocyte stores produced before embryonic genome activation and brings into question the measurement of soluble HLA-G for clinical evaluation of embryo quality. Although HLA-G is expressed in the preimplantation embryo, later it is primarily expressed in the invasive trophoblast of the placenta rather than the fetus. Therefore, we have investigated whether down-regulation of HLA-G first occurs in the inner cell mass (precursor fetal cells) of the blastocyst and, in support of this concept, have shown the absence HLA-G1 and -G5 protein and mRNA.