miRNAs associated with endoplasmic reticulum stress and unfolded protein response during decidualization.

RESEARCH QUESTION: Do microRNAs (miRNAs) play a role in regulating endoplasmic reticulum stress (ERS) and unfolded protein response (UPR) in decidualized cells and endometrium associated with reproductive failures? DESIGN: Endometrial stromal cell line St-T1b was decidualized in vitro with 8-Br-cAMP over 5 days, or treated with the ERS inducer thapsigargin. Expression of ERS sensors, UPR markers and potential miRNA regulators was analysed by quantitative PCR. Endometrial biopsies from patients with recurrent pregnancy loss (RPL) and recurrent implantation failure (RIF) were investigated for the location of miRNA expression. RESULTS: Decidualization of St-T1b cells resulted in increased expression of ERS sensors including ATF6α, PERK and IRE1α, and the UPR marker, CHOP. TXNIP, which serves as a link between the ERS pathway and inflammation, as well as inflammasome NLRP3 and interleukin 1ß expression increased in decidualized cells. An in-silico analysis identified miR-17-5p, miR-21-5p and miR-193b-3p as miRNAs potentially involved in regulation of the ERS/UPR pathways and inflammation associated with embryo implantation. Their expression decreased significantly (P ≤ 0.0391) in non-decidualized cells in the presence of thapsigargin. Finally, expression of the selected miRNAs was localized by in-situ hybridization in stromal and glandular epithelial cells in endometrial samples from patients with RPL and RIF. Expression in stroma cells from patients with RPL was lower in comparison with stroma cells from patients with RIF. CONCLUSIONS: Decidualization in St-T1b cells is accompanied by ERS/UPR processes, associated with an inflammatory response that is potentially influenced by miR-17-5p, miR-21-5p and miR-193b-3p. These miRNAs are expressed differentially in stromal cells from patients with RPL and RIF, indicating an alteration in regulation of the ERS/UPR pathways.

Host-pathogen interactions mediated by extracellular vesicles in Toxoplasma gondii infection during pregnancy.

Molecular communication between a pathogen and its host is crucial for a successful interplay. Extracellular vesicles (EVs) act as mediators for the delivery of molecular signals among pathogens or between pathogens and the host. Toxoplasma gondii (T. gondii), an intracellular parasite with a worldwide presence, produces EVs itself, or induces the secretion of EVs from infected host cells potentially having capacities to modulate the host immune response. T. gondii infection is particularly important during pregnancy. Depending on the gestational age at the time of infection, the parasite can be transmitted through the placenta to the fetus, causing clinical complications such as jaundice, hepatosplenomegaly, chorioretinitis, cranioencephalic abnormalities, or even death. T. gondii infection is related to a pro-inflammatory immune response in both mother and fetus, which may enhance parasite transmission, but the implication of EV signaling in this process remains unclear. In this review, we summarize the current knowledge on EV release from T. gondii and its human host cells in regard to the immunological consequences and the passage through the placenta.

Splenic B1 B Cells Acquire a Proliferative and Anti-Inflamatory Profile During Pregnancy in Mice.

B cells are a heterogeneous cell population with differential ontogeny, anatomical location, and functions. B1 B cells are a distinct subpopulation characterized by their unique capacity of self-renewal, the production of large quantities of IL-10, and the ability to secrete protective, anti-inflammatory natural antibodies (NAbs), presumably upon down-regulation of CD1d expression. Although natural antibodies are thought to be protective, due to their polyreactivity, their participation in certain autoimmune diseases has been suggested. In the context of pregnancy, the role of B1 B cells has been discussed controversially. While in human pregnancies B1 B cells and natural/polyreactive antibodies they produce are involved in the development of preeclampsia, in mice they promote healthy gestation and fetal protection. In this work, we aimed to functionally characterize the splenic B1 B cell population during pregnancy in mice. Functional enrichment analysis using only up-regulated transcripts from a transcriptomic profile performed on total splenic B cells from pregnant compared to non-pregnant mice showed augmented cell cycle and DNA replication pathways. Proliferation studies by flow cytometry showed augmented Ki-67 proliferation marker expression and percentages of B1 B cells. Furthermore, B1 B cells produced higher levels of IL-10 and lower levels of TNF-α leading to an increased IL-10/TNF-α ratio and showing an immunoregulatory phenotype. Finally, we observed lower expression of CD1d on B1 B cells, suggesting a higher capacity to produce NAbs in the context of pregnancy. In summary, our results showed not only an expanded and proliferative splenic B1 B cell population during pregnancy but also the acquisition of immunomodulatory capacities suggesting its critical role in the intricate process of pregnancy tolerance.

Involvement of STAT1 in proliferation and invasiveness of trophoblastic cells.

Trophoblast proliferation and invasion are controlled by cytokines and growth factors present at the implantation site. Members of the Interleukin-6 (IL-6) family of cytokines trigger their effects through activation of intracellular cascades including the Janus Kinase/Signal Transducer and Activator of Transcription (JAK-STAT) pathway. Functions of several STAT molecules in trophoblast cells have been described, but the role of STAT1 remained unclear. Here, potential functions of STAT1 and its activation by Oncostatin M (OSM) have been investigated in an in vitro model. STAT1 expression and phosphorylation were analyzed in human term placenta tissue by immunohistochemistry. HTR-8/SVneo cells (immortalized human extravillous trophoblast cells) were stimulated with OSM, IL-6, IL-11, Leukemia Inhibitory Factor (LIF) and Granulocyte Macrophage Colony-Stimulating Factor. Expression and phosphorylation of STAT1 were analyzed by Western blotting and immunocytochemistry. Fludarabine and STAT1 siRNA were employed for STAT1 depletion. STAT1 transcriptional activity was evaluated by DNA-binding capacity assay. Cell viability and invasion were assessed by MTS and Matrigel assays, respectively. STAT1 was expressed in villous and extravillous trophoblast cells. Low phosphorylation was detectable exclusively in extravillous trophoblast cells. Only OSM and LIF induced phosphorylation of STAT1 in the in vitro model. Challenge with OSM increased cell invasion but not proliferation. Inhibition of STAT1 by fludarabine treatment or STAT1 siRNA transfection reduced cell viability and invasiveness in presence and absence of OSM. These results indicate the potential involvement of STAT1 in the regulation of trophoblast behavior. Furthermore, STAT 1 functions are more efficiently inhibited by blocking its expression than its phosphorylation.

Serum Protein Profile in Women With Pregnancy Morbidity Associated With Antiphospholipid Syndrome.

CONTEXT: Antiphospholipid antibodies (aPL) are related with a high risk of pregnancy morbidity (PM) and also of vascular thrombosis. On the basis of recent studies, we expect that in women with PM associated with antiphospholipid syndrome (APS), further factors may be deregulated and involved in pathophysiology of the disease. Such factors may have the potential to become novel biomarkers for APS and its stages. SETTINGS AND DESIGN: Descriptive study from a recurrent pregnancy loss program. AIMS: To study the protein expression in sera from women with PM with or without aPL. MATERIALS AND METHODS: Protein profiles were determined by surface enhanced laser desorption and ionization - time of flight mass spectrometry (SELDI-TOF MS) in the serum samples from women with PM, 10 of them with aPL and 12 without aPL. On the basis of the mass-to-charge ratio (m/z) of the protein, signals differentially expressed between the two groups were compared with data banks to approach candidate proteins. STATISTICAL ANALYSIS USED: To determine the differential expression of each protein, a no paired t-test was performed using Ciphergen Express Client 3.1 software. RESULTS: SELDI-TOF analysis makes it possible to discriminate between several proteins in women with PM with and without aPL, although it does not allow protein identification. Nine proteins were found in significantly higher levels in aPL-positive women. CONCLUSION: The results underline that further factors beyond autoantibodies are involved in PM associated with APS and might lead to the development of new biomarkers.

Modulation of antiphospholipid antibodies-induced trophoblast damage by different drugs used to prevent pregnancy morbidity associated with antiphospholipid syndrome.

PROBLEM: Women with antiphospholipid antibodies (aPLs) present a risk of pregnancy morbidity (PM), vascular thrombosis (VT), or both (PM/VT). aPLs affect trophoblast function, and the aim of this study was to determine the modulation of this aPL-induced damage by different drugs. METHOD OF STUDY: IgG was obtained from women with PM and PM/VT positive to aPLs. Binding of IgG to trophoblastic cells, proliferation, mitochondrial membrane integrity, and trophoblast invasion were assessed. The effect of enoxaparin, aspirin, and aspirin-triggered lipoxin (ATL) were evaluated as well as signal transducer and activator of transcription 3 (STAT3) phosphorylation. RESULTS: IgG from women with aPLs strongly binds to trophoblastic cells. Integrity of mitochondrial membrane was reduced, and proliferation was increased by IgG-PM/VT. Both IgG-PM and IgG-PM/VT decreased trophoblast invasion, which was restored by enoxaparin, aspirin, and ATL. IgG-PM triggered reduction in STAT3 phosphorylation. CONCLUSION: Some drugs used to prevent aPL-induced PM modulated the alteration of trophoblast function.

Prevention and treatment of allergic asthma in pregnancy: from conventional drugs to new therapeutical approaches.

Different conventional anti-asthmatic and anti-allergic drugs are commonly used in pregnancy, including inhaled corticosteroids, long- and short-acting ß-agonists, leukotriene modifiers, cromolyn, and theophylline. Alternatively, immunotherapy with allergens before and during pregnancy is accepted as a causal treatment of allergies, but the allergy specifity and severity in combination with a variety of application protocols and procedures cause wide heterogenity of this treatment principle. Furthermore, the pharmacokinetic characteristics and the US Food and Drug Administration (FDA) classification of conventional anti-allergic drugs and immunological implications of immunotherapy are summarized in this review, and insights on fetal programming of allergies are introduced. We propose a potential perspective of treatment with anti-inflammatory and pro-resolving mediators, such as lipoxins, resolvins and protectins; these are lipid mediators physiologically generated during the immune response from arachidonic acid, eicosapentaenoic acid and docosahexaenoic acid. This proposal fits with the recently appreciated approaches to allergy prevention for the newborn child by a balanced maternal nutrition and omega-3 long-chain polyunsaturated fatty acid consumption.

Ovarian stimulation affects the levels of regulatory endometrial NK cells and angiogenic cytokine VEGF.

PROBLEM: Endometrial NK cells play a critical role in uterine vascularization producing angiogenic factors. Impact of ovarian stimulation on endometrial expression of NK cells and VEGF in normal fertile oocyte donors and the effect of endometrial injury treatment on these parameters have been investigated. METHOD OF STUDY: Endometrial tissue was obtained from oocyte donors during natural and stimulated cycles. NK cell subsets were measured by flow cytometry. VEGF was determined by ELISA and flow cytometry. Endometrial angiogenic parameters were determined by ultrasound Doppler. Local injury was induced by scratching endometrial tissue previous to implantation window. RESULTS: Ovarian stimulation decreased endometrial levels of NK cells and vascularization index but increased VEGF levels. Local injury normalized only the CD56(+) NK cell count. CONCLUSION: Hormonal therapy for ovarian stimulation may be associated with poor endometrial vascularization. Local injury before the implantation window seems not to influence endometrial angiogenic parameters altered by ovarian stimulation.

Role of regulatory and angiogenic cytokines in invasion of trophoblastic cells.

PROBLEM: Trophoblast invasion is a temporally and locally restricted process, which regulates implantation and oxygen arrival to the embryo through the dialog with spiral artery endothelium. Trophoblast factors with angiogenic potential are activated by hypoxia. Their capacities to induce proliferation, migration, and invasion of trophoblastic cells have been investigated. METHOD OF STUDY: The expression of interleukin (IL)-6, CD126, CD130, vascular endothelial growth factor (VEGF), and hypoxia inducible factor-1alpha (HIF-1alpha) has been silenced in JEG-3 choriocarcinoma cells by using siRNA. Silencing efficacy has been assessed by ELISA, PCR or Western blotting. Proliferation has been measured by flow cytometry, migration by a transwell assay, and invasion by a Matrigel assay. RESULTS: Proliferation was significantly reduced by silencing of CD126 or CD130, migration by silencing of IL-6, VEGF, or HIF-1alpha, and invasion by silencing of IL-6 and HIF-1alpha. CONCLUSION: The expression of IL-6, VEGF, and HIF-1alpha in trophoblastic cells is involved in the control of trophoblast invasion and migration.