CXCL10 and IL-6 induce chemotaxis in human trophoblast cell lines

Role of chemokines in regulating luteal and uterine functions in pregnant cows

Pregnancy is intricately regulated by the interactions between various bioactive substances secreted by the conceptus, uterus, and corpus luteum (CL). Interferon-τ, synthesized and secreted by the conceptus, plays a central role in the interaction mechanism of maternal recognition in cows. Chemokines, chemotaxis mediators that are primarily secreted by immune cells, regulate various reproductive responses in various species. Although there are scattered reports on the potential roles of chemokines in the bovine CL and the uterus during the estrous cycle, there is little information on chemokines in these organs during pregnancy. Therefore, in this review, we discuss the possible physiological roles of chemokines in the CL and uterus of pregnant cows, focusing on our recent findings on chemokines and changes in their receptor expression in the CL and endometrium of cows at some stages of pregnancy.

Decidual production of interferon lambda in response to ZIKV persistence: Clinical evidence and in vitro modelling

Zika virus (ZIKV) infections during pregnancy can result in Congenital Zika Syndrome (CZS), a range of severe neurological outcomes in fetuses that primarily occur during early gestational stages possibly due to placental damage. Although some placentas can maintain ZIKV persistence for weeks or months after the initial infection and diagnosis, the impact of this viral persistence is still unknown. Here, we aimed to investigate the immunological repercussion of ZIKV persistence in term placentas. As such, term placentas from 64 pregnant women diagnosed with Zika in different gestational periods were analyzed by ZIKV RT-qPCR, examination of decidua and placental villous histopathology, and expression of inflammation-related genes and IFNL1-4. Subsequently, we explored primary cultures of term decidual Extravillous Trophoblasts (EVTs) and Term Chorionic Villi (TCV) explants, as in vitro models to access the immunological consequences of placental ZIKV infection. Placenta from CZS cases presented low IFNL1-4 expression, evidencing the critical protective role of theses cytokines in the clinical outcome. Term placentas cleared for ZIKV showed increased levels of IFNL1, 3, and 4, whether viral persistence was related with a proinflammatory profile. Conversely, upon ZIKV persistence placentas with decidual inflammation showed high IFNL1-4 levels. In vitro experiments showed that term EVTs are more permissive, and secreted higher levels of IFN-α2 and IFN-λ1 compared to TCV explants. The results suggest that, upon ZIKV persistence, the maternal-skewed decidua contributes to placental inflammatory and antiviral signature, through chronic deciduitis and IFNL upregulation. Although further studies are needed to elucidate the mechanisms underlying the decidual responses against ZIKV. Hence, this study presents unique insights and valuable in vitro models for evaluating the immunological landscape of placentas upon ZIKV persistence.

Impaired secretion of C-X-C motif chemokine ligand 10 by stimulation with a Toll-like receptor 4 ligand in endometrial epithelium of infertile patients with minimal-to-mild endometriosis

Successful embryo implantation requires transient, well-controlled inflammation in decidualizing cells. In mice, Toll-like receptor (TLR) 4 signaling in endometrial epithelial cells (EECs) by stimulation with factors present in seminal fluids has been shown to be a key upstream driver of a controlled inflammatory response. Clinical evidence supports that exposure of the female reproductive tract to seminal plasma promotes implantation success. We investigated the response of EECs to TLR2 (Pam3Csk4), TLR 3 (Poly I:C), and TLR4 (lipopolysaccharides [LPS]) ligands with respect to secretion of C-X-C motif chemokine ligand (CXCL) 10 (CXCL10) and interleukin-6 (IL-6) in infertile patients with minimal-to-mild endometriosis (EECs-endo) (n = 38) and those of healthy, fertile women (EECs-healthy) (n = 30). Stimulation with either Pam3Csk4, Poly I:C or LPS, significantly induced CXCL10 and IL-6 in EECs-healthy (p < 0.05). In EECs-endo, either Pam3Csk4 or Poly I:C significantly induced CXCL10 (p < 0.05), whereas no significant response was observed after stimulation with LPS. Neither LPS, Poly I:C, nor Pam3Csk4 significantly induced IL-6 secretion in EECs-endo. Secretion of CXCL10 in EECs-healthy after stimulation with LPS was significantly higher (p < 0.05) than that in EECs-endo. CXCL10 decreased cell proliferation of EECs from both groups. Activation of nuclear factor kappa light chain enhancer of activated B cells and signal transducer and activator of transcription 3 signalings was not impaired, but activation of p38 mitogen-activated protein kinases signaling by LPS stimulation was impaired in EECs-endo. The present findings suggested that an insufficient response of EECs to a TLR4 ligand may be involved in molecular mechanisms of endometriosis-associated infertility.

A decreased expression of interferon stimulated genes in peri-implantation endometrium of embryo transfer recipient sows could contribute to embryo death

Pig pregnancy succeeds thanks to a well-coordinated system ruling both maternal immune activation and embryonic antigen tolerance. In physiological pregnancies, the maternal immune system should tolerate the presence of hemi-allogeneic conceptuses from the pre-implantation phase to term, while maintaining maternal defence against pathogens. Allogeneic pregnancies, as after embryo transfer (ET), depict high embryo mortality during the attachment phase, calling for studies of the dynamic modifications in immune processes occurring at the maternal-foetal interface, for instance, of interferon (IFN)-stimulated genes (ISGs). These ISGs are generally activated by IFN secreted by the conceptus during the process of maternal recognition of pregnancy (MRP) and responsible for recruiting immune cells to the site of embryo attachment, thus facilitating cell-antigen presentation and angiogenesis. We performed RNA-Seq analysis in peri-implantation (days 18 and 24) endometrial samples retrieved from artificially inseminated sows (hemi-allogeneic embryos (HAL) group) or sows subjected to ET (allogeneic embryos (AL) group) to monitor alterations of gene expression that could be jeopardising early pregnancy. Our results showed that endometrial gene expression patterns related to immune responses differed between hemi- or allogeneic embryo presence, with allogeneic embryos apparently inducing conspicuous modifications of immune-related genes and pathways. A decreased expression (P < 0.05; FC < -2) of several interferon ISGs, such as CXCL8, CXCL10, IRF1, IRF9, STAT1, and B2M, among others was detected in the endometrium of sows carrying allogeneic embryos on day 24 of pregnancy. This severe downregulation of ISGs in allogeneic pregnancies could represent a failure of ET-embryos to signal IFN to the endometrium to warrant the development of adequate immunotolerance mechanisms to facilitate embryo development, thus contributing to elevated embryo death.

Context is key: Maternal immune responses to pig allogeneic embryos

Successful establishment of pregnancy includes the achievement of a state of immune tolerance toward the embryos (and placenta), where the well‐coordinated maternal immune system is capable of recognizing conceptus antigens while maintaining maternal defense against pathogens. In physiological pregnancies, following natural mating or artificial insemination (AI), the maternal immune system is exposed to the presence of hemi‐allogeneic embryos, that is, embryos containing maternal self‐antigens and foreign antigens from the paternal side. In this scenario, the hemi‐allogeneic embryo is recognized by the mother, but the immune system is locally modified to facilitate embryo implantation and pregnancy progression. Pig allogeneic pregnancies (with embryos containing both paternal and maternal material foreign to the recipient female), occur during embryo transfer (ET), with conspicuously high rates of embryonic death. Mortality mainly occurs during the peri‐attachment phase, suggesting that immune responses to allogeneic embryos are more complex and less efficient, hindering the conceptuses to survive to term. Reaching a similar maternal tolerance as in conventional breeding would render ET successful. The present review critically summarizes mechanisms of maternal immune recognition of pregnancy and factors associated with impaired maternal immune response to the presence of allogeneic embryos in the porcine species.

(Dis)similarities between the Decidual and Tumor Microenvironment

Placenta-specific trophoblast and tumor cells exhibit many common characteristics. Trophoblast cells invade maternal tissues while being tolerated by the maternal immune system. Similarly, tumor cells can invade surrounding tissues and escape the immune system. Importantly, both trophoblast and tumor cells are supported by an abetting microenvironment, which influences invasion, angiogenesis, and immune tolerance/evasion, among others. However, in contrast to tumor cells, the metabolic, proliferative, migrative, and invasive states of trophoblast cells are under tight regulatory control. In this review, we provide an overview of similarities and dissimilarities in regulatory processes that drive trophoblast and tumor cell fate, particularly focusing on the role of the abetting microenvironments.

Pregnancy and Tumour: The Parallels and Differences in Regulatory T Cells

Immunological tolerance plays a critical role during pregnancy as semi-allogeneic fetus must be protected from immune responses during the gestational period. Regulatory T cells (Tregs), a subpopulation of CD4+ T cells that express transcription factor Foxp3, are central to the maintenance of immunological tolerance and prevention of autoimmunity. Tregs are also known to accumulate at placenta in uterus during pregnancy, and they confer immunological tolerance at maternal-fetal interface by controlling the immune responses against alloantigens. Thus, uterine Tregs help in maintaining an environment conducive for survival of the fetus during gestation, and low frequency or dysfunction of Tregs is associated with recurrent spontaneous abortions and other pregnancy-related complications such as preeclampsia. Interestingly, there are many parallels in the development of placenta and solid tumours, and the tumour microenvironment is considered to be somewhat similar to that at maternal-fetal interface. Moreover, Tregs play a largely similar role in tumour immunity as they do at placenta- they create a tolerogenic system and suppress the immune responses against the cells within tumour and at maternal-fetal interface. In this review, we discuss the role of Tregs in supporting the proper growth of the embryo during pregnancy. We also highlight the similarities and differences between Tregs at maternal-fetal interface and tumour Tregs, in an attempt to draw a comparison between their roles in these two physiologic and pathologic states.

The Role of Cytokines in Maintaining the Dynamics of Cell-Cell Interaction between Natural Killer Cells and Trophoblast Cells

We analyzed the effect of individual cytokines that are secretory products of placenta typical of the uteroplacental bed. The proinflammatory cytokines IL-6, IFNγ, and IL-1β increased the expression of TGFβR2 molecule by trophoblast cells, while VEGF and PLGF increased the expression of CD45, CD29, and CD54 adhesion molecule by trophoblast cells. The antiinflammatory cytokine IL-4 increased LeptinR expression by trophoblast cells. PMA and TNFα also enhanced the adhesion of NK cells to trophoblast cells. Our findings suggest that NK cells involved CD11a, CD11b, and CD18 molecules during their transmigration through trophoblast, as well as during their transendothelial migration.

Insight on Polyunsaturated Fatty Acids in Endometrial Receptivity

Endometrial receptivity plays a crucial role in fertilization as well as pregnancy outcome in patients faced with fertility challenges. The optimization of endometrial receptivity may help with normal implantation of the embryo, and endometrial receptivity may be affected by numerous factors. Recently, the role of lipids in pregnancy has been increasingly recognized. Fatty acids and their metabolites may be involved in all stages of pregnancy and play a role in supporting cell proliferation and development, participating in cell signaling and regulating cell function. Polyunsaturated fatty acids, in particular, are essential fatty acids for the human body that can affect the receptivity of the endometrium through in a variety of methods, such as producing prostaglandins, estrogen and progesterone, among others. Additionally, polyunsaturated fatty acids are also involved in immunity and the regulation of endometrial decidualization. Fatty acids are essential for fetal placental growth and development. The interrelationship of polyunsaturated fatty acids with these substances and how they may affect endometrial receptivity will be reviewed in this article.

The Role of NF-κB in Uterine Spiral Arteries Remodeling, Insight into the Cornerstone of Preeclampsia

Preeclampsia is one of the three leading causes of maternal morbidity and mortality worldwide. It afflicts 2-8% of pregnancies and is the most common cause of gestational hypertension. This article is focused on nuclear factor kappa B (NF-κB), its role in normal and pathological spiral arteries remodelling and development of preeclampsia, with evaluation if it is a promising therapeutic target. NF-κB is a key mediator of placentation. Since insemination, it stimulates production of proinflammatory cytokines by the uterine epithelium, which leads to activation of macrophages, uterine natural killer cells (uNKs), and other leukocytes. The trophoblast/uNK/macrophage crosstalk is crucial for implantation and spiral arteries remodeling, and NF-κB regulates that process through modification of cytokine expression, as well as cell phenotype and function. In the course of preeclampsia, the remodeling processes is disturbed by excessive inflammation and increased NF-κB activation. The pathological remodeling leads to uteroplacental dysfunction, release of proinflammatory cytokines into the maternal circulation, endothelial stress, and development of preeclampsia. The analysis of genetic and environmental inductors of NF-κB helps to distinguish preeclampsia risk groups. Furthermore, a selective inhibition of NF-κB or NF-κB activating pathways alleviates symptoms of preeclampsia in rat models; therefore, this could be an efficient therapeutic option.

Suboptimal mid-luteal progesterone concentrations are associated with aberrant endometrial gene expression, potentially resulting in implantation failure

RESEARCH QUESTION

What is the difference in endometrial transcriptomics between women with normal and with low mid-luteal progesterone during the implantation window?

DESIGN

An endometrial biopsy and serum progesterone concentration were taken from participants during the mid-luteal phase (LH+7 to LH+9). A total of 12 participants were recruited and categorized into two groups based on their progesterone concentrations: normal progesterone (>15 ng/ml, n = 6) and low progesterone (<15 ng/ml, n = 6). Global endometrial gene expression between the two groups was compared by microarray techniques. Principal component analysis was used to display the gene's expression pattern. Pathway and gene ontology enrichment analysis were performed to determine the biological mechanism of progesterone on the endometrium.

RESULTS

Several key genes related to endometrial receptivity were found to be regulated by progesterone. With regard to gene ontology and pathway analysis, progesterone was shown to be mainly involved in structure morphogenesis predominantly during a process of decidualization, extracellular matrix-receptor interaction and cell adhesion. Distinct differences were observed in the transcriptomic profiles between the two groups, indicating potential impairment of endometrial receptivity in women with suboptimal progesterone concentrations. There was a relatively similar pattern of gene expression between endometrial samples with progesterone concentrations approximately 10 ng/ml and >15 ng/ml. Thus, a progesterone concentration of between 10 and 15 ng/ml appears to be sufficient to induce endometrial receptivity.

CONCLUSIONS

Abnormally low progesterone below the threshold of 10-15 ng/ml during the implantation window results in aberrant endometrial gene expression that may affect implantation potential.

Peri-implantation cytokine profile differs between singleton and twin IVF pregnancies

PROBLEM

It is unknown whether maternal cytokine production differs between twin and singleton gestations in the implantation phase. A difference in maternal serum cytokine concentrations in twins would imply a dose-response to the invading embryos, as opposed to a general immune reaction.

METHOD OF STUDY

A prospective longitudinal cohort of women aged 18-45 at an academic fertility center undergoing in vitro fertilization and embryo transfer (IVF-ET) underwent routine collection of serial serum samples starting 9 days after ET and then approximately every 48 hours thereafter. Cryopreserved aliquots of these samples were assayed for interleukin-10 (IL-10), tumor necrosis factor-alpha (TNF-α), and C-X-C motif chemokine ligand 10 (CXCL10) using the SimplePlex immunoassay platform. Pregnancies were followed until delivery. Serial measures of serum concentrations of IL-10, CXCL10, and TNF-α in singleton or di-di twin pregnancies from 9 to 15 days after IVF-ET were compared.

RESULTS

Maternal serum levels of CXCL10 are significantly lower in women with di-di twin pregnancies in early implantation compared to those with singleton gestation (day 9-11, P = .02). Serum levels of TNF-α and IL-10 were comparable at all studied time points (P > .05).

CONCLUSION

Maternal serum levels of CXCL10 are significantly lower in the earliest implantation phase in di-di twins compared to singleton conceptions. Given the known anti-angiogenic role of CXCL10, we hypothesize that lower CXCL10 levels in twin implantations allow an environment that is conducive for the greater vascularization required for the establishment of dual placentation in di-di twins.

Expression profile of proinflammatory mediators in the placenta of mares during physiological detachment and retention of fetal membranes

Physiological parturition is characterized by sterile, inflammatory-like processes. During parturition, the placenta expresses various proinflammatory mediators, such as chemokines and IL-17. Nevertheless, inflammatory processes present in the parturient mare are poorly characterized. The aim of this study was to investigate the expression of selected chemokines and IL-17 in the allantochorion and the endometrium of mares that retained fetal membranes (RFM) and expelled them physiologically. We hypothesized that the expression of these mediators may be altered in the placenta of mares with RFM and result in RFM occurrence. Differences in mRNA expression in the placenta of investigated groups of mares were detected for CCL2, CCL3, CCL4, CCL8, CXCL1, CXCL8, CXCL10, CX3CL1 and IL-17. There were no differences in mRNA expression of CCL5 and CXCL6. Gene ontology network analysis showed enrichment in genes related to leukocyte migration, cell chemotaxis and response to chemokine in tissues of RFM mares. Analysis of association network suggested denotations between CXCL6, CXCL8, CXCL1, CCL5, CCL4, CX3CL1 and CXCL10. Moreover, possible inhibition of CXCL10 by IL-17A and prostaglandin peroxide synthase 2 (PTGS2) by CXCL1 was detected. Our results suggest that, based on differences in chemokines and IL-17 expression, recruited subsets of leukocytes might differ between the analyzed groups of mares, which in turn may impair the separation of fetal membranes in the group of RFM mares. In addition, the results of the expression analysis suggest that macrophages might be one of the most abundant cells infiltrating the equine placenta during the expulsion of fetal membranes. Furthermore, we suspect that the synthesis of PTGS2 might be inhibited in mares with RFM.

Cytotrophoblast extracellular vesicles enhance decidual cell secretion of immune modulators via TNFα

The placenta releases large quantities of extracellular vesicles (EVs) that likely facilitate communication between the embryo/fetus and the mother. We isolated EVs from second trimester human cytotrophoblasts (CTBs) by differential ultracentrifugation and characterized them using transmission electron microscopy, immunoblotting and mass spectrometry. The 100,000  g pellet was enriched for vesicles with a cup-like morphology typical of exosomes. They expressed markers specific to this vesicle type, CD9 and HRS, and the trophoblast proteins placental alkaline phosphatase and HLA-G. Global profiling by mass spectrometry showed that placental EVs were enriched for proteins that function in transport and viral processes. A cytokine array revealed that the CTB 100,000  g pellet contained a significant amount of tumor necrosis factor α (TNFα). CTB EVs increased decidual stromal cell (dESF) transcription and secretion of NF-κB targets, including IL8, as measured by qRT-PCR and cytokine array. A soluble form of the TNFα receptor inhibited the ability of CTB 100,000  g EVs to increase dESF secretion of IL8. Overall, the data suggest that CTB EVs enhance decidual cell release of inflammatory cytokines, which we theorize is an important component of successful pregnancy.

Differential gene expression elicited by ZIKV infection in trophoblasts from congenital Zika syndrome discordant twins

Zika virus (ZIKV) causes congenital Zika syndrome (CZS), which is characterized by fetal demise, microcephaly and other abnormalities. ZIKV in the pregnant woman circulation must cross the placental barrier that includes fetal endothelial cells and trophoblasts, in order to reach the fetus. CZS occurs in ~1-40% of cases of pregnant women infected by ZIKV, suggesting that mothers' infection by ZIKV during pregnancy is not deterministic for CZS phenotype in the fetus. Therefore, other susceptibility factors might be involved, including the host genetic background. We have previously shown that in three pairs of dizygotic twins discordant for CZS, neural progenitor cells (NPCs) from the CZS-affected twins presented differential in vitro ZIKV susceptibility compared with NPCs from the non-affected. Here, we analyzed human-induced-pluripotent-stem-cell-derived (hiPSC-derived) trophoblasts from these twins and compared by RNA-Seq the trophoblasts from CZS-affected and non-affected twins. Following in vitro exposure to a Brazilian ZIKV strain (ZIKVBR), trophoblasts from CZS-affected twins were significantly more susceptible to ZIKVBR infection when compared with trophoblasts from the non-affected. Transcriptome profiling revealed no differences in gene expression levels of ZIKV candidate attachment factors, IFN receptors and IFN in the trophoblasts, either before or after ZIKVBR infection. Most importantly, ZIKVBR infection caused, only in the trophoblasts from CZS-affected twins, the downregulation of genes related to extracellular matrix organization and to leukocyte activation, which are important for trophoblast adhesion and immune response activation. In addition, only trophoblasts from non-affected twins secreted significantly increased amounts of chemokines RANTES/CCL5 and IP10 after infection with ZIKVBR. Overall, our results showed that trophoblasts from non-affected twins have the ability to more efficiently activate genes that are known to play important roles in cell adhesion and in triggering the immune response to ZIKV infection in the placenta, and this may contribute to predict protection from ZIKV dissemination into fetuses' tissues.

Placental transcriptome profile of women with sickle cell disease reveals differentially expressed genes involved in migration, trophoblast differentiation and inflammation

Sickle cell disease (SCD) is a group of disorders whose common characteristic is the presence of hemoglobin (Hb) S in erythrocytes. The main consequence of this abnormality is vaso-occlusion, which can affect almost all organs including the placenta. This study aimed to evaluate the gene expression profile in placentas of women with SCD by means of total RNA sequencing. For this, we proposed a case-control study, with three groups of pregnant women: HbSS (n = 10), HbSC (n = 14) and HbAA (n = 21). The results showed differences in expression in a number of genes such as NOS2 (fold change, FC = 4.52), HLAG (FC = 5.56), ASCL2 (FC = 3.61), CXCL10 (FC = -3.66) and IL1R2 (FC = 3.92) for the HbSC group and S100A8 (FC = -3.82), CPXM2 (FC = 4.57), CXCL10 (FC = -4.59), CXCL11 (FC = -3.72) and CAMP (FC = -4.55) for the HbSS group. Differentially expressed genes are mainly associated with migration, trophoblast differentiation and inflammation. The causes leading to altered gene expression in placentas of sickle cell patients are not fully understood, but the presence of intravascular hemolysis and vaso-occlusion, with cycles of ischemia and reperfusion, may contribute to the emergence of an environment which can be very harmful for placental physiology, altering the nutrient supply and metabolic exchange for fetal growth.

New Insights into the Process of Placentation and the Role of Oxidative Uterine Microenvironment

For a successful pregnancy to occur, a predecidualized receptive endometrium must be invaded by placental differentiated cells (extravillous trophoblast cells (EVTs)) and, at the same time, continue decidualization. EVT invasion is aimed at anchoring the placenta to the maternal uterus and ensuring local blood supply increase necessary to provide normal placental and foetal development. The first is achieved by migrating through the maternal endometrium and deeper into the myometrium, while the second by transforming uterine spiral arteries into large vessels. This process is a tightly regulated battle comprising interests of both the mother and the foetus. Invading EVTs are required to perform a scope of functions: move, adhere, proliferate, differentiate, interact, and digest the extracellular matrix (ECM); tolerate hypoxia; transform the maternal spiral arteries; and die by apoptosis. All these functions are modulated by their surrounding microenvironment: oxygen, soluble factors (e.g., cytokines, growth factors, and hormones), ECM proteins, and reactive oxygen species. A deeper comprehension of oxidative uterine microenvironment contribution to trophoblast function will be addressed in this review.

Variable chemokine expression in porcine trophoblasts and endometrium during the peri-implantation period

Successful embryo implantation and its further development depends on appropriate endometrial remodelling. Porcine early pregnancy is associated with intensive endometrial angiogenesis and establishment of an immunotolerant environment for the embryo. An increasing number of factors are believed to participate in endometrial remodelling. The aim of this study was to elucidate the involvement of selected chemokines at the porcine maternal-foetal interface during the peri-implantation period. Real-time PCR analysis revealed several upregulated chemokines during the time of implantation, and Western blot/ELISA analyses and immunohistochemical staining confirmed their presence at the protein level. The gene expression of several chemokines and receptors was also confirmed in early porcine trophoblasts. The results indicated that IFNG, a porcine trophoblast signal, positively influenced the expression of some chemokines in endometrial cells. In conclusion, we suggest that some of the examined chemokines may be involved in endometrial communication with the trophoblast (CCL2, CCL5, CCL11, CXCL12), whereas others are implicated in the recruitment of immune cells and establishment of an immunotolerant environment for the embryo (CXCL9, CXCL10).

Gene expression of CCL8 and CXCL10 in peripheral blood leukocytes during early pregnancy in cows

Background

The aim of the present study was to evaluate CCL8 and CXCL10 expression and its regulatory mechanism in peripheral blood leukocytes (PBLs) at the time of maternal recognition in cows. Blood samples were collected on 14, 15, 16, 17 and 18 d after artificial insemination (AI). Based on the day of return of estrus, cows were divided into three groups, pregnant (n = 5), early embryonic mortality (EEM; n = 5) and late embryonic mortality (LEM; n = 5). The gene expression levels in PBLs were assessed with quantitative real-time reverse transcription PCR.

Results

The expression of CCL8 and CXCL10 mRNA in PBLs gradually increased from 14 to 18 d of pregnant cows and significant differences were observed on 18 d (P < 0.05), whereas no significant changes were observed both in EEM and LEM cows. Interferon-stimulated protein 15 kDa (ISG15), myxovirus-resistance gene (MX) 1 and MX2 mRNA expression in PBLs increased from 14 to 18 d which was significant on 18 d of pregnant cows as well as in LEM cows (P < 0.05), but no changes were observed in EEM cows. To determine whether the expression of CCL8 and CXCL10 in PBLs was regulated by pregnancy-related substances or not, expression level was assessed after exposure to interferon-τ (IFNT) and CCL16. Monocytes, granulocytes and lymphocytes were obtained using density-gradient centrifugation and flow cytometry. The addition of IFNT (100 ng/mL) and CCL16 (100 ng/mL) to cultured PBLs increased the expression of CCL8 and CXCL10 mRNA (P < 0.05). The expression of ISG15, MX1 and MX2 mRNA in PBLs was also stimulated by IFNT and CCL16 (P < 0.05).

Conclusions

The expression of CCL8 and CXCL10 genes increased in PBLs during early pregnancy. Since IFNT stimulated CCL8 and CXCL10 expression in cultured PBLs, the increase of CCL8 and CXCL10 might be pregnancy-dependent events. The expression of both CCL8 and CXCL10 in PBLs was stimulated by CCL16 as well as IFNT, suggesting a chemokine interaction that at least includes CCL8, CXCL10 and CCL16, and may play a role in regulating maternal recognition in cows.

Decidual cell regulation of trophoblast is altered in pregnancies at risk of pre-eclampsia

Successful implantation and placentation are dependent on the interaction between decidual stromal cells (DSC) and extravillous trophoblast (EVT) cells. The extent of trophoblast invasion relies on communication between the placenta and maternal decidua. The cyclical process of decidualisation induces a transformation of endometrial fibroblasts to secretory DSC; these secreted products have many functions including the control of trophoblast invasion. Inadequate trophoblast invasion and remodelling of the uterine vessels (the spiral arteries) are associated with pregnancy disorders such as pre-eclampsia. Uterine artery Doppler resistance index (RI) in the first trimester of pregnancy can be used as a proxy measure of remodelling. DSC were isolated from pregnancies with normal (normal RI) or impaired (high RI) spiral artery remodelling. Following isolation, DSC were re-decidualised using cAMP and MPA and secretion of the decidualisation markers IGFBP-1 and prolactin assessed. We examined the impact of DSC-secreted factors on trophoblast cell function, using the EVT cell line SGHPL-4. We demonstrated that DSC exposed to decidual factors were able to re-decidualise in vitro and that the chemoattraction of trophoblasts by DSC is impaired in pregnancies with high RI. This study provides new insights into the role that DSC play in regulating EVT functions during the first trimester of pregnancy. This is the first study to demonstrate that DSC from pregnancies with impaired vascular remodelling in the first trimester secrete factors that inhibit the directional movement of trophoblast cells. This finding may be important in understanding aberrant trophoblast invasion in pregnancies where vascular remodelling is impaired.

The role of NFκB in the three stages of pregnancy - implantation, maintenance, and labour: a review article

The transcription factor nuclear factor kappa B (NFκB) controls the expression of over 400 genes, some of which are associated with reproductive events. During implantation, immune cells accumulate in the maternal-fetal interface; they secrete inflammatory mediators under the control of NFĸB, the level of which also rises. NFĸB is then downregulated to maintain gestation, but its level rises again before birth to manage prostaglandin, cytokine, and chemokine synthesis, and to stimulate uterine contraction. This review summarises the current state of knowledge about NFκB and its role in the molecular regulation of processes related to pregnancy development.

TWEETABLE ABSTRACT

This review examines the current state of knowledge about role of NFκB in the development of pregnancy.

Decreased Human Leukocyte Antigen-G Expression by miR-133a Contributes to Impairment of Proinvasion and Proangiogenesis Functions of Decidual NK Cells

Human leukocyte antigen (HLA)-G plays a crucial role in conferring fetal–maternal tolerance and ensuring a successful pregnancy. CD56^bright natural killer (NK) cells accumulate at the maternal decidua in large numbers during pregnancy and are found in direct contact with fetal trophoblasts. There are increasing evidences that decidual NK (dNK) cells are crucial for pregnancy. However, the regulation of dNK cells is mostly unknown. Here, we provide evidences that the secretion function of dNK cells in recurrent spontaneous abortion was impaired, which led to the impairment of the proinvasion and proangiogenesis functions of dNK cells. Decreased HLA-G expression induced by the transfection of miR-133a mimics in HTR-8/SVneo affected the secretory functions of dNK cells. Thus, our data revealed that the functions of dNK cells could be suppressed by the decreased expression of HLA-G and suggest a possible mechanism of recurrent miscarriage.

Identification of genes dysregulated by elevation of microRNA-210 levels in human trophoblasts cell line, Swan 71

PROBLEM

Preeclampsia is a serious pregnancy disorder characterized by gestational hypertension and proteinuria. miR-210 is significantly overexpressed in the placentas of preeclampsia patients.

METHOD OF STUDY

Swan 71 cells, first-trimester human trophoblastic cell line, were transfected with hsa-miR-210-3p oligonucleotides by electroporation. Altered transcriptome was analyzed using microarray technique. Differentially expressed genes (DEGs) were clustered into Gene Ontology annotation biological processes. The extent of physical interaction between miR-210 and IGFBP3 mRNA was assessed via ribonucleoprotein immunoprecipitation.

RESULTS

Microarray analysis showed 408 DEGs by elevated levels of miR-210 in Swan 71 cells. These genes were enriched in several biological processes involved in the pathogenesis of preeclampsia. IGFBP3, a gene associated with preeclampsia pathophysiology, was validated as a target gene of miR-210.

CONCLUSION

We have demonstrated that elevated miR-210 levels in human trophoblast alter the expression profile of known preeclampsia-associated genes, and of gene targets involved in various biological processes essential to preeclampsia progression.

Niche matters: The comparison between bone marrow stem cells and endometrial stem cells and stromal fibroblasts reveal distinct migration and cytokine profiles in response to inflammatory stimulus

Objective

Intrinsic inflammatory characteristics play a pivotal role in stem cell recruitment and homing through migration where the subsequent change in niche has been shown to alter these characteristics. The bone marrow mesenchymal stem cells (bmMSCs) have been demonstrated to migrate to the endometrium contributing to the stem cell reservoir and regeneration of endometrial tissue. Thus, the aim of the present study was to compare the inflammation-driven migration and cytokine secretion profile of human bmMSCs to endometrial mesenchymal stem cells (eMSCs) and endometrial fibroblasts (eSFs).

Materials and methods

The bmMSCs were isolated from bone marrow aspirates through culturing, whereas eMSCs and eSFs were FACS-isolated. All cell types were tested for their surface marker, proliferation profiles and migration properties towards serum and inflammatory attractants. The cytokine/chemokine secretion profile of 35 targets was analysed in each cell type at basal level along with lipopolysaccharide (LPS)-induced state.

Results

Both stem cell types, bmMSCs and eMSCs, presented with similar stem cell surface marker profiles as well as possessed high proliferation and migration potential compared to eSFs. In multiplex assays, the secretion of 16 cytokine targets was detected and LPS stimulation expanded the cytokine secretion pattern by triggering the secretion of several targets. The bmMSCs exhibited higher cytokine secretion of vascular endothelial growth factor (VEGF)-A, stromal cell-derived factor-1 alpha (SDF)-1α, interleukin-1 receptor antagonist (IL-1RA), IL-6, interferon-gamma inducible protein (IP)-10, monocyte chemoattractant protein (MCP)-1, macrophage inflammatory protein (MIP)1α and RANTES compared to eMSCs and/or eSFs after stimulation with LPS. The basal IL-8 secretion was higher in both endometrial cell types compared to bmMSCs.

Conclusion

Our results highlight that similar to bmMSCs, the eMSCs possess high migration activity while the differentiation process towards stromal fibroblasts seemed to result in loss of stem cell surface markers, minimal migration activity and a subtler cytokine profile likely contributing to normal endometrial function.

Possible Roles of CC- and CXC-Chemokines in Regulating Bovine Endometrial Function during Early Pregnancy

The aim of the present study was to determine the possible roles of chemokines in regulating bovine endometrial function during early pregnancy. The expression of six chemokines, including CCL2, CCL8, CCL11, CCL14, CCL16, and CXCL10, was higher in the endometrium at 15 and 18 days of pregnancy than at the same days in non-pregnant animals. Immunohistochemical staining showed that chemokine receptors (CCR1, CCR2, CCR3, and CXCR3) were expressed in the epithelial cells and glandular epithelial cells of the bovine endometrium as well as in the fetal trophoblast obtained from a cow on day 18 of pregnancy. The addition of interferon-τ (IFNT) to an endometrial tissue culture system increased CCL8 and CXCL10 expression in the tissues, but did not affect CCL2, CCL11, and CCL16 expression. CCL14 expression by these tissues was inhibited by IFNT. CCL16, but not other chemokines, clearly stimulated interferon-stimulated gene 15 (ISG15) and myxovirus-resistance gene 1 (MX1) expression in these tissues. Cyclooxygenase 2 (COX2) expression decreased after stimulation with CCL8 and CCL14, and oxytocin receptor (OTR) expression was decreased by CCL2, CCL8, CCL14, and CXCL10. Collectively, the expression of chemokine genes is increased in the endometrium during early pregnancy. These genes may contribute to the regulation of endometrial function by inhibiting COX2 and OTR expression, subsequently decreasing prostaglandin production and preventing luteolysis in cows.

Role of Human Corneal Stroma-Derived Mesenchymal-Like Stem Cells in Corneal Immunity and Wound Healing

Corneal tissue regeneration is of crucial importance for maintaining normal vision. We aimed to isolate and cultivate human corneal stroma-derived mesenchymal stem-like cells (CSMSCs) from the central part of cadaver corneas and study their phenotype, multipotency, role in immunity and wound healing. The isolated cells grew as monolayers in vitro, expressed mesenchymal- and stemness-related surface markers (CD73, CD90, CD105, CD140b), and were negative for hematopoietic markers as determined by flow cytometry. CSMSCs were able to differentiate in vitro into fat, bone and cartilage. Their gene expression profile was closer to bone marrow-derived MSCs (BMMSCs) than to limbal epithelial stem cells (LESC) as determined by high-throughput screening. The immunosuppressive properties of CSMSCs were confirmed by a mixed lymphocyte reaction (MLR), while they could inhibit proliferation of activated immune cells. Treatment of CSMSCs by pro-inflammatory cytokines and toll-like receptor ligands significantly increased the secreted interleukin-6 (IL-6), interleukin-8 (IL-8) and C-X-C motif chemokine 10 (CXCL-10) levels, as well as the cell surface adhesion molecules. CSMSCs were capable of closing a wound in vitro under different stimuli. These cells thus contribute to corneal tissue homeostasis and play an immunomodulatory and regenerative role with possible implications in future cell therapies for treating sight-threatening corneal diseases.

Endometrial gene expression in high- and low-fertility heifers in the late luteal phase of the estrous cycle and a comparison with midluteal gene expression

Embryonic mortality is a major constraint to improving reproductive efficiency and profitability in livestock enterprises. We previously reported differential expression of genes with identified roles in cellular growth and proliferation, lipid metabolism, endometrial remodeling, inflammation, angiogenesis, and metabolic exchange in endometrial tissue on day 7 of the estrous cycle (D7), between heifers ranked as either high (HF) or low (LF) for fertility. The aim of the current study was to further elucidate the underlying molecular mechanisms contributing to early embryo loss by examining differential endometrial gene expression in HF or LF heifers at a later stage of the estrous cycle;day 14(D14). A second objective was to compare these expression profiles with those from midluteal HF and LF endometrium. Using the same animal model as employed in the previous study, we slaughtered HF and LF animals on D14, harvested endometrial tissue, and carried out global gene expression analysis using the Affymetrix Bovine GeneChip. Microarray analysis detected 430 differentially expressed genes (DEG) between HF and LF animals. Ingenuity Pathway Analysis revealed enrichment for a host of biological pathways including lipid metabolism, molecular transport, immune response, cell morphology and development, and cell growth and proliferation. Important DEG includedALB, BMPR2, CCL28, COL4A3/4, FADS1, ITGA6, LDLR, PLCB3, PPARG, PTGS2, and SLC27A4 Furthermore, DEG expressed on both D7 and D14 included:PCCB,SLC25A24,DAP, and COL4A4 This study highlights some of the pathways and mechanisms underpinning late luteal bovine endometrial physiology and endometrial-related conception rate variance.

Changes in Functional Activity of JEG-3 Trophoblast Cell Line in the Presence of Factors Secreted by Placenta

BACKGROUND AND AIMS

Cells in the maternal-fetal interface secrete cytokines that regulate proliferation, migration, and trophoblast invasion during the first trimester of pregnancy and the limitation of these processes during the third trimester. The aim of the study was to evaluate the influence of factors secreted by human placenta during the first and third trimester of pregnancy on cytokine receptor expression and proliferative and migratory activity of JEG-3 trophoblast cells.

METHODS

The research was conducted using the explant conditioned media of placentas obtained from healthy women with elective termination of pregnancy at 9-11 weeks and placentas of women whose pregnancy progressed without complications at 38-39 weeks. Assessment of surface molecule expression was performed using FACS Canto II flow cytometer (BD, USA). The proliferative activity of JEG-3 trophoblast cells was evaluated by dyeing with crystal violet vital dye. The migration activity of JEG-3 was evaluated using 24-well insert plates with polycarbonate inserts (pore size 8 microns).

RESULTS

Expression of CD116, CD118, CD119, IFNγ-R2, CD120b, CD183, CD192, CD295, EGFR, and TGFβ-R2 on JEG-3 was higher when the cells were incubated in the presence of the third trimester placental factors in comparison with the first trimester placental factors. Factors secreted by the placenta during the third trimester of pregnancy had more pronounced stimulatory effect on the proliferation and migration of trophoblast in comparison with baseline levels and with the effect of the first trimester placental factors.

CONCLUSIONS

The findings suggest that the behavior of trophoblasts in vitro might not be representative of in vivo behavior in the absence of additional local factors that influence the trophoblast in vivo.

Biopsy-induced inflammatory conditions improve endometrial receptivity: the mechanism of action

A decade ago, we first reported that endometrial biopsy significantly improves the success of pregnancy in IVF patients with recurrent implantation failure, an observation that was later confirmed by others. Recently, we have demonstrated that this treatment elevated the levels of endometrial pro-inflammatory cytokines and increased the abundance of macrophages (Mac) and dendritic cells (DCs). We therefore hypothesised that the biopsy-related successful pregnancy is secondary to an inflammatory response, and aimed at deciphering its mechanism of action. Supporting our hypothesis, we found that the pro-inflammatory TNFα stimulated primary endometrial stromal cells to express cytokines that attracted monocytes and induced their differentiation into DCs. These monocyte-derived DCs stimulated endometrial epithelial cells to express the adhesive molecule SPP1 (osteopontin (OPN)) and its receptors ITGB3 and CD44, whereas MUC16, which interferes with adhesion, was downregulated. Other implantation-associated genes, such as CHST2, CCL4 (MIP1B) and GROA, were upregulated by monocyte-derived Mac. These findings suggest that uterine receptivity is mediated by the expression of molecules associated with inflammation. Such an inflammatory milieu is not generated in some IVF patients with recurrent implantation failure in the absence of local injury provoked by the biopsy treatment.

Endometrial CXCL13 expression is cycle regulated in humans and aberrantly expressed in humans and Rhesus macaques with endometriosis

C-X-C ligand 13 (CXCL13), a regulator of mucosal immunity, is secreted by human endometrial epithelium and may be involved in embryo implantation. However, cyclic expression of human endometrial CXCL13 in health and disease is not well studied. This study examines cycle stage-specific endometrial CXCL13 expression in normal humans when compared to those with biopsy-confirmed, stage 1 to 4 endometriosis using real-time reverse transcriptase, real-time polymerase chain reaction and immunohistochemistry. Eutopic endometrial CXCL13 expression was also compared between normal, control Rhesus macaques, and macaques with advanced endometriosis. In healthy women, CXLC13 messenger RNA expression was minimal in the proliferative phase and maximal in the secretory phase. However, in the presence of endometriosis, proliferative-phase endometrial expression markedly increased in both humans and rhesus subjects (P < .05). The cross-species and cross-stage concordance suggests a pathophysiologic role for CXCL13 in endometriosis and its use as a biomarker for disease.

The role of inflammation for a successful implantation

Approximately half of all human embryo implantations result in failed pregnancy. Multiple factors may contribute to this failure, including genetic or metabolic abnormalities of the embryo. However, many of these spontaneous early abortion cases are attributed to poor uterine receptivity. Furthermore, although many fertility disorders have been overcome by a variety of assisted reproductive techniques, implantation remains the rate-limiting step for the success of the in vitro fertilization (IVF) treatments. We, as well as others, have demonstrated that endometrial biopsies performed either during the spontaneous, preceding cycle, or during the IVF cycle itself, significantly improve the rate of implantation, clinical pregnancies, and live births. These observations suggest that mechanical injury of the endometrium may enhance uterine receptivity by provoking the immune system to generate an inflammatory reaction. In strong support of this idea, we recently found that dendritic cells (DCs), an important cellular component of the innate immune system, play a critical role in successful implantation in a mouse model. In this review, we discuss the hypothesis that the injury-derived inflammation in the biopsy-treated patients generates a focus for uterine DCs and Mac accumulation that, in turn, enhance the endometrial expression of essential molecules that facilitate the interaction between the embryo and the uterine epithelium.

Comparison of upstream regulators in human ex vivo cultured cornea limbal epithelial stem cells and differentiated corneal epithelial cells

Background

The surface of the human eye is covered by corneal epithelial cells (CECs) which regenerate from a small population of limbal epithelial stem cells (LESCs). Cell therapy with LESCs is a non-penetrating treatment for preventing blindness due to LESC deficiency or dysfunction. Our aim was to identify new putative molecular markers and upstream regulators in the LESCs and associated molecular pathways.

Results

Genome-wide microarray transcriptional profiling was used to compare LESCs to differentiated human CECs. Ingenuity-based pathway analysis was applied to identify upstream regulators and pathways specific to LESCs. ELISA and flow cytometry were used to measure secreted and surface expressed proteins, respectively. More than 2 fold increase and decrease in expression could be found in 1830 genes between the two cell types. A number of molecules functioning in cellular movement (381), proliferation (567), development (552), death and survival (520), and cell-to-cell signaling (290) were detected having top biological functions in LESCs and several of these were confirmed by flow cytometric surface protein analysis. Custom-selected gene groups related to stemness, differentiation, cell adhesion, cytokines and growth factors as well as angiogenesis could be analyzed. The results show that LESCs play a key role not only in epithelial differentiation and tissue repair, but also in controlling angiogenesis and extracellular matrix integrity. Some pro-inflammatory cytokines were found to be important in stemness-, differentiation- and angiogenesis-related biological functions: IL-6 and IL-8 participated in most of these biological pathways as validated by their secretion from LESC cultures.

Conclusions

The gene and molecular pathways may provide a more specific understanding of the signaling molecules associated with LESCs, therefore, help better identify and use these cells in the treatment of ocular surface diseases.

Decidual natural killer cell interactions with trophoblasts are impaired in pregnancies at increased risk of preeclampsia

Transformation of the uterine spiral arteries (SAs) during pregnancy is critical to support the developing fetus, and is impaired in some pregnancy disorders, including preeclampsia. Decidual natural killer (dNK) cells play a role in SA remodeling, although their interactions with fetal trophoblast remain unclear. A uterine artery Doppler resistance index (RI) in the first trimester of pregnancy can be used as a proxy measure of the extent of SA remodeling; we have used this technique to characterize dNK cells from pregnancies with normal (normal RI) and impaired (high RI) SA remodeling, which display least and highest risk of developing preeclampsia, respectively. We examined the impact of dNK cell secreted factors on trophoblast motility, chemoattraction, and signaling pathways to determine the contribution of dNK cells to SA transformation. We demonstrated that the chemoattraction of the trophoblast by dNK cells is impaired in pregnancies with high RI, as is the ability to induce trophoblast outgrowth from placental villous explants. These processes are dependent on activation of the extracellular signal-regulated kinase 1/2 and phosphatidylinositol 3-kinase-Akt signaling pathways, which were altered in trophoblasts incubated with secreted factors from dNK cells from high RI pregnancies. Therefore, by characterizing pregnancies using uterine artery Doppler RI before dNK cell isolation, we have identified that impaired dNK-trophoblast interactions may lead to poor placentation. These findings have implications for pregnancy pathological conditions, such as preeclampsia.

Control of extravillous trophoblast function by the eotaxins CCL11, CCL24 and CCL26

STUDY QUESTION

What are the effects of the eotaxin group of chemokines (CCL11, CCL24 and CCL26) on extravillous trophoblast (EVT) functions important during uterine decidual vessel remodelling?

SUMMARY ANSWER

CCL11, CCL24 and CCL26 can regulate EVT migration, invasion and adhesion, highlighting a potential regulatory role for these chemokines during uterine decidual spiral arteriole remodelling in the first trimester of human pregnancy.

WHAT IS KNOWN ALREADY

A successful human pregnancy depends on adequate remodelling of the uterine decidual spiral arterioles, a process carried out by EVT which invade from the placenta. The invasion by EVT into the maternal uterine decidual vessels is regulated by the interaction of many factors including members of the chemokine subfamily of cytokines.

STUDY DESIGN, SIZE, DURATION

This study used the HTR8/SVneo cell line as a model for invasive EVT. All experiments were repeated on at least three separate occasions.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The effect of recombinant human CCL11, CCL24 and CCL26 on EVT migration and invasive potential was measured using the xCELLigence real-time system, wound-healing and Matrigel invasion assays, zymography to measure MMP activity and reverse zymography to measure TIMP activity. A commercially available adhesion assay was used to assess EVT adhesion to extracellular matrix proteins.

MAIN RESULTS AND THE ROLE OF CHANCE

All the three eotaxins were found to significantly stimulate migration of the EVT-derived cell line HTR8/SVneo (P < 0.05) with no significant changes in cell number following treatment with each chemokine (P > 0.05). All the three eotaxins significantly increased HTR8/SVneo invasion (P < 0.05) and MMP2 activity (P < 0.05) without any effects on TIMP2 activity (P > 0.05). All the three eotaxins significantly increased HTR8/SVneo cell binding to collagen IV (P < 0.05) and fibronectin (P < 0.05).

LIMITATIONS, REASONS FOR CAUTION

This work has been conducted in vitro with a commonly used cell line model of EVT, HTR8/SVneo.

WIDER IMPLICATIONS OF THE FINDINGS

This study is the first to comprehensively examine the effects of the eotaxin group of chemokines on EVT functions and demonstrates that all the three eotaxins have the ability to regulate EVT functions critical to their role in vessel remodelling. This identifies a new role for the eotaxin group of chemokines during placentation.

Identification of chemokines associated with the recruitment of decidual leukocytes in human labour: potential novel targets for preterm labour

Current therapies for preterm labour (PTL) focus on arresting myometrial contractions but are largely ineffective, thus alternative therapeutic targets need to be identified. Leukocytes infiltrate the uterus around the time of labour, and are in particularly abundant in decidua (maternal-fetal interface). Moreover, decidual inflammation precedes labour in rat pregnancies and thus may contribute to initiation of labour. We hypothesized that chemokines mediate decidual leukocyte trafficking during preterm labour (PTL) and term labour (TL), thus representing potential targets for preventing PTL. Women were recruited into 4 groups: TL, term not in labour (TNL), idiopathic PTL and PTL with infection (PTLI). Choriodecidual RNA was subjected to a pathway-specific PCR array for chemokines. Differential expression of 12 candidate chemokines was validated by real time RT-PCR and Bioplex assay, with immunohistochemistry to confirm cellular origin. 25 chemokines were upregulated in choriodecidua from TL compared to TNL. A similar pattern was detected in PTL, however a distinct profile was observed in PTLI consistent with differences in leukocyte infiltration. Upregulation of CCL2, CCL4, CCL5, CXCL8 and CXCL10 mRNA and protein was confirmed in TL, with CCL8 upregulated in PTL. Significant correlations were detected between these chemokines and decidual leukocyte abundance previously assessed by immunohistochemical and image analysis. Chemokines were primarily expressed by decidual stromal cells. In addition, CXCL8 and CCL5 were significantly elevated in maternal plasma during labour, suggesting chemokines contribute to peripheral inflammatory events during labour. Differences in chemokine expression patterns between TL and idiopathic PTL may be attributable to suppression of chemokine expression by betamethasone administered to women in PTL; this was supported by in vitro evidence of chemokine downregulation by clinically relevant concentrations of the steroid. The current study provides compelling evidence that chemokines regulate decidual leukocyte recruitment during labour. The 6 chemokines identified represent potential novel therapeutic targets to block PTL.

Glycodelin-A stimulates interleukin-6 secretion by human monocytes and macrophages through L-selectin and the extracellular signal-regulated kinase pathway

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.

Possible roles of proinflammatory and chemoattractive cytokines produced by human fetal membrane cells in the pathology of adverse pregnancy outcomes associated with influenza virus infection

Pregnant women are at an increased risk of influenza-associated adverse outcomes, such as premature delivery, based on data from the latest pandemic with a novel influenza A (H1N1) virus in 2009-2010. It has been suggested that the transplacental transmission of influenza viruses is rarely detected in humans. A series of our study has demonstrated that influenza virus infection induced apoptosis in primary cultured human fetal membrane chorion cells, from which a factor with monocyte differentiation-inducing (MDI) activity was secreted. Proinflammatory cytokines, such as interleukin (IL)-6, tumor necrosis factor (TNF)-α, and interferon (IFN)-β, were identified as a member of the MDI factor. Influenza virus infection induced the mRNA expression of not only the proinflammatory cytokines but also chemoattractive cytokines, such as monocyte chemoattractant protein (MCP)-1, regulated on activation, normal T-cell expressed and secreted (RANTES), macrophage inflammatory protein (MIP)-1β, IL-8, growth-regulated oncogene (GRO)-α, GRO-β, epithelial cell-derived neutrophil-activating protein (ENA)-78, and interferon inducible protein (IP)-10 in cultured chorion cells. These cytokines are postulated to associate with human parturition. This paper, therefore, reviews (1) lessons from pandemic H1N1 2009 in pregnancy, (2) production of proinflammatory and chemoattractive cytokines by human fetal membranes and their functions in gestational tissues, and (3) possible roles of cytokines produced by human fetal membranes in the pathology of adverse pregnancy outcomes associated with influenza virus infection.

Interleukin-6 in pregnancy and gestational disorders

IL6 is a multifunctional cytokine with pivotal roles in the inflammatory response and in directing T cell differentiation in adaptive immunity. IL6 is widely expressed in the female reproductive tract and gestational tissues, and exerts regulatory functions in embryo implantation and placental development, as well as the immune adaptations required to tolerate pregnancy. Here, we summarise the current understanding of how membrane-bound and soluble receptors mediate IL6 signalling to regulate leukocytes and non-haemopoietic cells. We review the published literature regarding the expression and actions of IL6 in the uterus, decidua and placenta, and studies implicating this cytokine in pregnancy disorders. Elevated IL6 is frequently evident in the altered cytokine profiles characteristic of unexplained infertility, recurrent miscarriage, preeclampsia and preterm delivery. Notably, there is compelling evidence indicating altered systemic IL6 trans-signalling in women prone to recurrent miscarriage, with excessive IL6 bioavailability potentially inhibiting generation of CD4+ T regulatory cells required for pregnancy tolerance. Insufficient local IL6 may also contribute to fetal loss, since IL6 expression is reduced in the endometrium of women with recurrent miscarriage, and in the fetal-placental tissue of CBA×DBA/2 mice. Consistent with the role of IL6 in key reproductive events, Il6 null mutant mice exhibit elevated fetal resorption and delayed parturition. Investigation of the association between IL6 signalling components and T cell responses in pregnant women, as well as detailed analysis of the maternal immune response in IL6-deficient mice, is now required to define the mechanisms by which this cytokine exerts influence on reproductive success.

Chemokines at mucosal barriers and their impact on HIV infection

Aside from representing a physical barrier and providing an unfavorable chemical milieu to viral and bacterial infections, mucosae of gut and female genital tract also contain organized lymphoid structures that support the initiation of anti-microbial immune responses, and more diffuse lymphoid tissues that represent immune effector mucosal sites. Local expression of specific chemokines orchestrates lymphoid cell trafficking and positioning in the mucosa-associated lymphoid tissues, leading to their efficient priming during antigenic stimulations as well as their specific homing back where they were primed. This review examines productions and roles of mucosae-specific chemokines in healthy and pathological conditions, as well as their possible positive and deleterious effects during mucosal HIV infection.

Endometrial gene expression during early pregnancy differs between fertile and subfertile dairy cow strains

A receptive uterine environment is a key component in determining a successful reproductive outcome. We tested the hypothesis that endometrial gene expression patterns differ in fertile and subfertile dairy cow strains. Twelve lactating dairy cattle of strains characterized as having fertile (n = 6) and subfertile (n = 6) phenotypes underwent embryo transfer on day 7 of the reproductive cycle. Caruncular and intercaruncular endometrial tissue was obtained at day 17 of pregnancy, and microarrays used to characterize transcriptional profiles. Statistical analysis of microarray data at day 17 of pregnancy revealed 482 and 1,021 differentially expressed transcripts (P value < 0.05) between fertile and subfertile dairy cow strains in intercaruncular and caruncular tissue, respectively. Functional analysis revealed enrichment for several pathways involved in key reproductive processes, including the immune response to pregnancy, luteolysis, and support of embryo growth and development, and in particular, regulation of histotroph composition. Genes implicated in the process of immune tolerance to the embryo were downregulated in subfertile cows, as were genes involved in preventing luteolysis and genes that promote embryo growth and development. This study provides strong evidence that the endometrial gene expression profile may contribute to the inferior reproductive performance of the subfertile dairy cow strain.

A signature of immune function genes associated with recurrence-free survival in breast cancer patients

The clinical significance of tumor-infiltrating immune cells has been reported in a variety of human carcinomas including breast cancer. However, molecular signature of tumor-infiltrating immune cells and their prognostic value in breast cancer patients remain elusive. We hypothesized that a distinct network of immune function genes at the tumor site can predict a low risk versus high risk of distant relapse in breast cancer patients regardless of the status of ER, PR, or HER-2/neu in their tumors. We conducted retrospective studies in a diverse cohort of breast cancer patients with a 1-5 year tumor relapse versus those with up to 7 years relapse-free survival. The RNAs were extracted from the frozen tumor specimens at the time of diagnosis and subjected to microarray analysis and real-time RT-PCR. Paraffin-embedded tissues were also subjected to immunohistochemistry staining. We determined that a network of immune function genes involved in B cell development, interferon signaling associated with allograft rejection and autoimmune reaction, antigen presentation pathway, and cross talk between adaptive and innate immune responses were exclusively upregulated in patients with relapse-free survival. Among the 299 genes, five genes which included B cell response genes were found to predict with >85% accuracy relapse-free survival. Real-time RT-PCR confirmed the 5-gene prognostic signature that was distinct from an FDA-cleared 70-gene signature of MammaPrint panel and from the Oncotype DX recurrence score assay panel. These data suggest that neoadjuvant immunotherapy in patients with high risk of relapse may reduce tumor recurrence by inducing the immune function genes.