IntroductionPregnancy requires coordinated immunometabolic adaptations that allow maternal immune tolerance while preserving tissue remodeling and host defense. Circulating monocytes contribute critically to these processes, yet how gestation shapes their metabolic state and functional specialization remains incompletely defined. MethodsWe investigated the metabolic and functional phenotype of maternal monocytes during earlymid pregnancy (1620 weeks of gestation) and explored the contribution of trophoblast-derived signals using an in vitro macrophage model and trophoblast-conditioned media.ResultsMaternal circulation was enriched in CD14+CD16+ monocytes, accompanied by increased plasma lactate levels and elevated ex vivo lactate secretion by purified monocytes, without changes in mitochondrial mass or membrane potential. Monocytes from pregnant women displayed enhanced long-chain fatty acid uptake and increased expression of the fatty acid transporter CD36, while lipid droplet accumulation remained unchanged. Pregnancy-associated efferocytosis was dependent on fatty acid oxidation (FAO), as pharmacological FAO inhibition abrogated this response. Transcriptional profiling revealed differential regulation of TAM receptors, characterized by increased MERTK and reduced AXL expression, consistent with a homeostatic efferocytic program. Trophoblast-derived conditioned media recapitulated key features of this phenotype in macrophages, inducing fatty acid uptake, lipid dropletmitochondria colocalization, and upregulation of CPT1, DGAT1, LXRa and RARa. In this model, FAO was required to sustain ATP production and M2-like marker expression, while monocarboxylate transport was necessary for efficient efferocytosis and fatty acid uptake. DiscussionTogether, these findings identify a coordinated immunometabolic program in maternal monocytes integrating glycolysis, lactate signaling, and FAO, likely instructed by trophoblast-derived cues, to enhance efferocytic and pro-resolving functions during pregnancy. This metabolic adaptation may represent a systemic mechanism supporting immune tolerance and tissue remodeling in early gestation.

Background: Background: Endometriosis affects 10% of women of reproductive age. Despite the well-known association between endometriosis and infertility, the mechanisms underlying this association remain to be elucidated. Methods: Implantation and pregnancy success rates were evaluated by a retrospective study of patients that underwent IVF using euploid embryos comparing healthy vs. endometriosis patients. To study the early embryo–endometrial dialogue, an interactome network was constructed using public RNAseq data from normal secretory-phase endometrial samples and day-5 blastocyst. Public bulk and single-cell RNAseq data from endometrial samples of endometriosis patients were used to detect alterations in the interactome. Results: Endometriosis patients required significantly more IVF attempts compared to those without endometrial pathologies; however, once pregnancy was achieved, the evolution of both groups was similar. The interactome network between normal endometrium and day-5 blastocyst showed a significant enrichment of pathways associated with tissue remodelling, angiogenesis, and immune regulation, which were altered in endometriosis patients. Endometriosis patients also presented an increased frequency and activation of NK, CD4+, and CD8+ cells, which interfere with embryo–endometrial dialogue. Conclusions: We identified key molecular processes affected by endometriosis specifically involved in the early interaction between the blastocyst, decidual, and resident immune cells, that may underline the reported fertility problems associated with endometriosis.

The placenta has an extraordinary metabolic rate with high oxygen consumption. Extravillous cytotrophoblast cells (EVT) metabolism and function are critical to sustain their invasive phenotype supporting fetal development. Deficient EVT function underlies pregnancy complications as preeclampsia (PE) and fetal growth restriction (FGR). The vasoactive intestinal peptide (VIP) promotes human cytotrophoblast cell migration and invasion through mTOR signaling pathways suggesting its crucial role during placentation. Here we explored fatty acid uptake as well as lipid and glucose metabolism in human-derived cytotrophoblast cell function upon VIP stimulation. We found that VIP induced long chain fatty acid (LCFAs) uptake along with the expression of FATP2 transporter, CPT1 fatty acid oxidation (FAO)-rate limiting step importer, and lipid droplet accumulation. VIP induced the expression of glucose 6-P-dehydrogenase, a rate-limiting enzyme of the pentose phosphate pathway (PPP) and pyruvate dehydrogenase complex enzyme DLAT E2, without altering lactate secretion. This metabolic rewiring of trophoblast cells induced by VIP takes place without compromising mitochondrial function or reactive oxygen species (ROS) production. Moreover, cytotrophoblast cell migration induced by VIP required the three glycolysis, oxidative phosphorylation (OXPHOS) and FAO pathways. Our results provide evidence supporting VIP as a metabolic regulatory peptide in cytotrophoblast cells sustaining proper placentation and fetal growth.

Abstract Background Placental macrophages, Hofbauer cells (HBC) are the only fetal immune cell population within the stroma of healthy placenta along pregnancy. They are central players in maintaining immune tolerance during pregnancy. Immunometabolism emerged a few years ago as a new field that integrates cellular metabolism with immune responses, however, the immunometabolism of HBC has not been explored yet. Here we studied the sex-specific differences in the phenotypic, functional and immunometabolic profile of HBC. Methods HBC were isolated from human term placentas (N = 31, 16 from male and 15 female neonates). Ex vivo assays were carried out to assess active metabolic and endoplasmic reticulum stress pathways by flow cytometry, confocal microscopy, gene expression and in silico approaches. Results HBC from female placentas displayed a stronger M2 phenotype accompanied by high rates of efferocytosis majorly sustained on lipid metabolism. On the other hand, male HBC expressed a weaker M2 phenotype with higher glycolytic metabolism. LPS stimulation reinforced the glycolytic metabolism in male but not in female HBC. Physiological endoplasmic reticulum stress activates IRE-1 differently, since its pharmacological inhibition increased lipid mobilization, accumulation and efferocytosis only in female HBC. Moreover, differential sex-associated pathways accompanying the phenotypic and functional profiles of HBC appeared related to the placental villi environment. Conclusions These results support sex-associated effects on the immunometabolism of the HBC and adds another layer of complexity to the intricate maternal-fetal immune interaction. Graphical abstract

Immunometabolism research is uncovering the relationship between metabolic features and immune cell functions in physiological and pathological conditions. Normal pregnancy entails a fine immune and metabolic regulation of the maternal-fetal interaction to assist the energetic demands of the fetus with immune homeostasis maintenance. Here, we determined the immunometabolic status of monocytes of pregnant women compared with nonpregnant controls and its impact on monocyte anti-inflammatory functions such as efferocytosis. Monocytes from pregnant women (16-20 wk) and nonpregnant age-matched controls were studied. Single cell-based metabolic assays using freshly isolated monocytes from both groups were carried out in parallel with functional assays ex vivo to evaluate monocyte efferocytic capacity. On the other hand, various in vitro metabolic assays with human monocytes or monocyte-derived macrophages were designed to explore the effect of trophoblast cells in the profiles observed. We found that pregnancy alters monocyte metabolism and function. An increased glucose dependency and enhanced efferocytosis were detected in monocytes from pregnant women at resting states, compared with nonpregnant controls. Furthermore, monocytes display a reduced glycolytic response when stimulated with lipopolysaccharide (LPS). The metabolic profiling of monocytes at this stage of pregnancy was comparable with the immunometabolic phenotypes of human monocytes treated in vitro with human first trimester trophoblast cell conditioned media. These findings suggest that immunometabolic mechanisms are involved in the functional shaping of monocytes during pregnancy with a contribution of trophoblast cells. Results provide new clues for future hypotheses regarding pregnancies complicated by metabolic disorders.NEW & NOTEWORTHY Immunometabolism stands as a novel perspective to understand the complex regulation of the immune response and to provide small molecule-based therapies. By applying this approach to study monocytes during pregnancy, we found that these cells have a unique activation pattern. They rely more on glycolysis and show increased efferocytosis/IL-10 production, but they do not have the typical proinflammatory responses. We also present evidence that trophoblast cells can shape monocytes into this distinct immunometabolic profile.

Extracellular vesicles released by the primary pathogen of periodontal disease Porphyromonas gingivalis (Pg), referred to as outer membrane vesicles (OMVs), have been associated with the pathogenesis of systemic diseases like cardiovascular disease, rheumatoid arthritis, and Alzheimer’s disease. A pathogenic role for Pg by disrupting placental homeostasis was proposed in the association between periodontal disease and adverse pregnancy outcomes. On the basis that trophoblast-derived factors modulate endothelial and immune cell profiles in normal pregnancy and the scarce presence of Pg in placenta, we hypothesized that OMVs from Pg affect trophoblast cell phenotype, impairing trophoblast–endothelium and trophoblast–neutrophil interactions. By means of in vitro designs with first-trimester human trophoblast cells, endothelial cells, and freshly isolated neutrophils, we showed that Pg OMVs are internalized by trophoblast cells and modulate the activity and expression of functional markers. Trophoblast cells primed with Pg OMVs enhanced neutrophil chemoattraction and lost their anti-inflammatory effect. In addition, reduced migration with enhanced adhesion of monocytes was found in endothelial cells upon incubation with the media from trophoblast cells pretreated with Pg OMVs. Taken together, the results support a pathogenic role of Pg OMVs at early stages of pregnancy and placentation through disruption of trophoblast contribution to vascular transformation and immune homeostasis maintenance.

In the last 15 years Zika virus (ZIKV) caused several outbreaks of increasing scale in Micronesia, South Pacific islands, and more recently in the Caribbean and South America. The severity of the clinical presentation in neonates from pregnant women infected with ZIKV during the last outbreak supports the relevance of unraveling the mechanism of infection and viral persistence in the placenta with local viral isolates. Here, we investigated the relevance of trophoblast metabolic rewiring for viral multiplication and the role of the vasoactive intestinal peptide (VIP) as an endogenous factor associated with placental restriction to ZIKV infection at early pregnancy. Our in vitro model demonstrated that ZIKV triggers metabolic rewiring in first trimester cytotrophoblast-derived cells by increasing glucose utilization as fuel to sustain its replication, decreasing long-chain polyunsaturated fatty acid uptake, and promoting lipid droplets accumulation to favor its multiplication. Of note, variations in nutrient availability modulated viral spread in trophoblast cultures. The presence of VIP during trophoblast infection impaired ZIKV infective particle production and viral replication, restoring cell migration and metabolism. Moreover, the blockade of endogenous VIP signaling increased viral particle production and the viral entry receptor AXL expression. These results highlight the potential role of VIP as an endogenous antiviral factor related to trophoblast cell permissiveness to ZIKV infection at early pregnancy.

Aberrant promoter methylation of tumor suppressor genes including retinoic acid receptor-β2 (RAR-β2) is frequently detected in hepatitis C virus (HCV)-associated hepatocellular carcinoma; however, the mechanism and its significance are relatively unknown. Here, we showed that HCV Core induced promoter hypermethylation of RAR-β2 to inhibit its expression via up-regulation of DNA methyltransferases 1 and 3b. Under the condition, all-trans retinoic acid (ATRA) failed to activate p16 expression and thus could not inactivate the Rb-E2F pathway. Accordingly, Core-expressing cells exhibited resistance to ATRA-induced growth inhibition. Taken together, HCV Core antagonizes ATRA, a natural anti-cancer compound, to stimulate cell growth via epigenetic down-regulation of RAR-β2.

BACKGROUND:A tight immune and metabolic regulation underlies the early maternal-placental interaction to assist the energetic dynamic demands of the fetus throughout pregnancy. The vasoactive intestinal peptide (VIP) holds biochemical, metabolic and immune properties consistent with a regulatory role during pregnancy.AIM:Here we overview critical aspects of embryo implantation and placental development with special focus on the immune and metabolic effects of VIP expressed by decidual and trophoblast cells.CONTENT:During decidualization, endometrial stromal cells undergo reticular stress and trigger unfolded protein response (UPR) that enable expansion of their endoplasmic reticulum and immunomodulatory factor synthesis. These processes appear differentially affected in recurrent abortion and in vitro fertilization failure suggesting their relevance in reproductive pathologies. Similarly, defective placentation associates with altered immune, vascular and trophoblast interaction resulting in complicated pregnancies that threaten maternal and neonatal health and underlie metabolic programming of adult life. We discuss the most recent research on decidual, trophoblast and immune cell interaction on the light of VIP regulation. Its role in decidualization and UPR associated with a sterile inflammatory response and angiogenesis is discussed. Evidence on VIP modulation of cytotrophoblast cell function, metabolism and immune profile is revised as well as the shaping of decidual leukocyte phenotype and function from decidualization to term.IMPLICATIONS:The broad spectrum of effects of VIP from implantation to term in normal and pathological conditions summarized here might contribute to the identification of novel biomarkers for diagnosis and pharmacological targeting.

Premature placental aging is implicated in a number of complications of pregnancy including preeclampsia. A placenta knockout mouse model has shown a relationship between SIRT1, aging and placental dysfunction. The role of SIRT1 in cellular senescence has been extensively studied in various cell types, but its role in trophoblast senescence is almost unknown.Human placental samples were obtained from preeclampsia-affected women and healthy controls. The placental aging profiles were assessed by Doppler ultrasound, placental histopathology, and evaluation of senescence- and ECM-related markers. The SIRT1 expression pattern relevant to placental aging profiles was studied in premature aging placenta with preeclampsia (32–37 weeks gestation, n = 10) and healthy controls (37–40 weeks gestation, n = 10). Using cell culture, the effects of activation and knockdown of SIRT1 or its downstream target molecules in syncytialized BeWo cells were evaluated.SIRT1 was expressed by syncytiotrophoblast across normal gestation. In preeclamptic premature aging placentas, SIRT1 was significantly downregulated, while senescence- and extracellular matrix (ECM) -related protein levels were upregulated compared to controls. Immunohistochemistry showed these changes to be confined to syncytiotrophoblast. In vitro, SIRT1 activation in response to resveratrol (RSV) abrogated senescence in forskolin-induced syncytialization of BeWo cells via regulation of senescence- and ECM-related proteins, and filamentous actin (F-actin). These effects were restored by SIRT1 siRNA.The downregulation of SIRT1 may accelerate senescence of syncytiotrophoblast via targets contributing to regulation of the cell cycle, ECM production and cytoskeleton reorganization leading to premature placental aging observed in preeclampsia.

Zika virus (ZIKV) re-emerged after circulating almost undetected for many years and the last spread in 2015 was the major outbreak reported. ZIKV infection was associated with congenital fetal growth anomalies such as microcephaly, brain calcifications, and low birth weight related to fetal growth restriction. In this study, we investigated the effect of ZIKV infection on first trimester trophoblast cell function and metabolism. We also studied the interaction of trophoblast cells with decidual immune populations. Results presented here demonstrate that ZIKV infection triggered a strong antiviral response in first trimester cytotrophoblast-derived cells, impaired cell migration, increased glucose uptake and GLUT3 expression, and reduced brain derived neurotrophic factor (BDNF) expression. ZIKV infection also conditioned trophoblast cells to favor a tolerogenic response since an increased recruitment of CD14+ monocytes bearing an anti-inflammatory profile, increased CD4+ T cells and NK CD56Dim and NK CD56Bright populations and an increment in the population CD4+ FOXP3+ IL-10+ cells was observed. Interestingly, when ZIKV infection of trophoblast cells occurred in the presence of the vasoactive intestinal peptide (VIP) there was lower detection of viral RNA and reduced toll-like receptor-3 and viperin messenger RNA expression, along with reduced CD56Dim cells trafficking to trophoblast conditioned media. The effects of ZIKV infection on trophoblast cell function and immune-trophoblast interaction shown here could contribute to defective placentation and ZIKV persistence at the fetal-maternal interface. The inhibitory effect of VIP on ZIKV infection of trophoblast cells highlights its potential as a candidate molecule to interfere ZIKV infection during early pregnancy.

Glucose uptake by the placenta and its transfer to the fetus is a finely regulated process required for placental and fetal development. Deficient placentation is associated with pregnancy complications such as fetal growth restriction (FGR). The vasoactive intestinal peptide (VIP) has embryotrophic effects in mice and regulates human cytotrophoblast metabolism and function. Here we compared glucose uptake and transplacental transport in vivo by VIP-deficient placentas from normal or VIP-deficient maternal background. The role of endogenous VIP in placental glucose and amino acid uptake was also investigated. Wild type C57BL/6 (WT) or VIP+/− (VIP HT) females were mated with WT, VIP knock-out (VIP KO) or VIP HT males. Glucose uptake and transplacental transport were evaluated by the injection of the fluorescent d-glucose analogue 2-NBDG in pregnant mice at gestational day (gd) 17.5. Glucose and amino acid uptake in vitro by placental explants were measured with 2-NBDG or 14C-MeAIB respectively. In normal VIP maternal background, fetal weight was reduced in association with placental VIP deficiency, whereas placental weight was unaltered. Paradoxically, VIP+/− placentas presented higher glucose uptake and higher gene expression of GLUT1 and mTOR than VIP+/+ placentas. However, in a maternal VIP-deficient environment placental uptake and transplacental transport of glucose increased while fetal weights were unaffected, regardless of feto-placental genotype. Results point to VIP-deficient pregnancy in a normal background as a suitable FGR model with increased placental glucose uptake and transplacental transport. The apparently compensatory actions are unable to sustain normal fetal growth and could result in complications later in life.

AIM:To explore the functional profile of circulating monocytes and decidual macrophages at term human pregnancy and their contribution to tissue repair upon stimulation ex vivo with decidual factors and the vasoactive intestinal peptide (VIP).METHODS:Peripheral blood monocytes were isolated from pregnant and non-pregnant volunteers and tested in vitro with decidual explants from term placenta and VIP. The effect of VIP on decidual explants and the effect of its conditioned media on monocytes or decidual macrophages isolated by magnetic beads was carried out by RT-qPCR and ELISA for cytokines expression and release. Migration assays were performed in transwell systems. Efferocytosis was assessed in monocytes or decidual macrophages with CFSE-labelled autologous apoptotic neutrophils and quantified by flow cytometry. Monocyte and decidual macrophages wound healing capacity was evaluated using human endometrial stromal cell monolayers. Immunohistochemistry was performed in serial tissue sections of different placentas.RESULTS:VIP is expressed in the villi as well as in trophoblast giant cells distributed within the decidua of term placenta. VIP induced the expression of antiinflmammatory markers and monocyte chemoattractant CCL2 and CCL3 in decidual tissues. Monocytes presented higher migration towards decidual explants than CD4 and CD8 cells. VIP-conditioned monocytes displayed an enhanced efferocytosis and wound healing capacity comparable to that of decidual macrophages. Moreover limited efferocytosis of pregnant women monocytes was restored by VIP-induced decidual factors.CONCLUSION:Results show the conditioning of monocytes by decidual factors and VIP to sustain processes required for tissue repair and homeostasis maintenance in term placenta.

Porphyromonas gingivalis (Pg) is one of the pathogenic bacteria that cause periodontal diseases, lipopolysaccharide (LPS) is the key factor that triggers alveolar bone absorption. This study explored the action of Axin 1 on Pg-LPS-induced osteoblasts injury, so as to search a possible treatment for periodontal diseases.Rat osteoblasts were dealt with Pg-LPS and Axin 1 knockdown alone or in combination. The effect of Pg-LPS and Axin 1 on osteoblast viability and apoptosis were detected by Cell Counting Kit-8 and flow cytometry. The expressions of alkaline phosphatase (ALP) and Axin 1 in processed osteoblasts were measured by western blot (WB) and quantitative real-time polymerase chain reaction (qRT-PCR) assays. Furthermore, the role of Axin 1 knockdown in the levels of inflammatory cytokines and apoptosis-related proteins were also determined.Pg-LPS inhibited the viability of osteoblasts and promote apoptosis with concentration and time dependence. ALP expression in Pg-LPS-treated osteoblasts was reduced, while Axin 1 expression was increased. On the one hand, Axin 1 knockdown reversed the Pg-LPS-induced reduction of cell activity and pro-apoptosis effect. On the other hand, Axin 1 knockdown not only improved the ALP activity of Pg-LPS-treated cells, but also reduced the elevation of inflammatory cytokines (TNF-α, IL-1β and IL-6) caused by Pg-LPS. Moreover, Pg-LPS increased the expressions of cleaved Caspase-3 and Bax, and inhibited Bcl-2 expressed, which was rescued by Axin 1 knockdown.Axin 1 knockdown inhibited Pg-LPS-induced osteoblastic apoptosis by regulating the levels of inflammatory cytokines, which may be helpful for the treatment of periodontal diseases.

A network of cell-cell communications through contact and soluble factors supports the maternal-placental interaction and provides a suitable environment for fetal growth. Trophoblast cells take center stage at these loops: they interact with maternal leukocytes to sustain the varying demands of gestation, and they synthesize hormones, cytokines among other factors that contribute to the maintenance of immune homeostasis. Here, we discuss vasoactive intestinal peptide (VIP) and its potential as a regulatory neuropeptide in pregnancy. VIP is synthesized by trophoblast cells; it regulates trophoblast cell function and interaction with the major immune cell populations present in the pregnant uterus. VIP activity produces an anti-inflammatory microenvironment by modulating the functional profile of monocytes, macrophages, and regulatory T cells. Trophoblast VIP inhibits neutrophil extracellular trap formation and accelerates neutrophil apoptosis, enabling their silent clearance by phagocytic cells. The effects of VIP on the trophoblast-immune interaction are consistent with its regulatory role throughout pregnancy for immune homeostasis maintenance. These observations may provide new clues for pharmacological targeting of pregnancy complications associated with exacerbated inflammation.

We evaluated the association between plasma soluble endoglin (sENG) and maternal vascular malperfusion (MVM) lesions of the placenta in women with preeclampsia. We measured sENG (sCD105) by ELISA in N = 70 women diagnosed with preeclampsia (median [IQR] GA at sampling = 36.4 [6.0] weeks) and available placental pathology. Placental pathology reports were reviewed for evidence of MVM based on the presence of ≥1 of the following: villous infarct, decidual vasculopathy, accelerated villous maturation, intervillous fibrin deposition, and/or low placental weight (<10th percentile for GA). We categorized plasma sENG concentrations into tertiles and used a modified Poisson regression approach to estimate the prevalence of MVM associated with sENG. We separately estimated the association between sENG and accelerated villous maturation, villous infarct, and low placental weight, the three most frequent lesions in the sample. We adjusted all models for age, parity, pre-pregnancy obesity, smoking, and infant sex. The prevalence of MVM in our sample of women with preeclampsia was 74%. Women in the highest sENG tertile had a higher prevalence of MVM (aPR[adjusted prevalence ratio] 1.70, 95% CI 1.15–2.52), low placental weight (aPR 3.26, 95% CI 1.25–8.50), and villous infarcts (aPR 2.93, 95% CI 1.27–6.73) compared with women in the lowest sENG tertile, after adjusting for covariates. Medium (aPR 2.57, 95% CI 1.17–5.66) and high (aPR 3.14, 95% CI 1.47–6.70) tertile concentrations of sENG were associated with higher accelerated villous maturation. Our results suggest that sENG may mark a more severe placental phenotype of preeclampsia, although findings should be replicated in larger cohorts.

Background and PurposeExtravillous trophoblast (EVT) cells are responsible for decidual stromal invasion, vascular transformation, and the recruitment and functional modulation of maternal leukocytes in the first‐trimester pregnant uterus. An early disruption of EVT function leads to placental insufficiency underlying pregnancy complications such as preeclampsia and fetal growth restriction. Vasoactive intestinal peptide (VIP) is a vasodilating and immune modulatory factor synthesized by trophoblast cells. However, its role in first‐trimester placenta has not been explored. Here, we tested the hypothesis that VIP is involved in first‐trimester EVT outgrowth, spiral artery remodelling, balancing angiogenesis, and maintenance of immune homeostasis.Experimental ApproachFirst‐trimester placental tissue (five to nine weeks of gestation) was collected, and was used for EVT outgrowth experiments, immunofluorescence, isolation of decidual natural killer (dNK) cells and decidual macrophages (dMA), and functional assays. Peripheral blood monocytes were differentiated with GM‐CSF and used for angiogenesis assays.Key ResultsIn decidua basalis, VIP+ EVT were observed sprouting from cell columns and lining spiral arterioles. EVT migrating from placental explants were also VIP+. VIP increased EVT outgrowth and IL‐10 release, whereas it decreased pro‐inflammatory cytokine production in EVT, dNK cells, and dMA. VIP disrupted endothelial cell networks, both directly and indirectly via an effect on macrophages.Conclusion and ImplicationsThe results suggest that VIP assists the progress of EVT invasion and vessel remodelling in first‐trimester placental bed in an immunologically “silent” milieu. The effects of VIP in the present ex vivo human placental model endorse its potential as a therapeutic candidate for deep placentation disorders.

Normal placentation entails highly regulated interactions of maternal leukocytes with vascular and trophoblast cells to favor vascular transformation. Neutrophil activation and neutrophil extracellular trap (NET) formation associate with poor placentation and severe pregnancy complications. To deepen into the mechanisms of trophoblast-neutrophil interaction, we explored the effects of NETs on trophoblast cell function and, conversely, whether trophoblast cell-derived factors condition neutrophils to favor angiogenesis and anti-inflammatory signals required for fetal growth. NETs isolated from activated neutrophils hindered trophoblast cell migration. Trophoblast conditioned media prevented the effect as well as the vasoactive intestinal peptide (VIP) known to regulate trophoblast and neutrophil function. On the other hand, factors released by trophoblast cells and VIP shaped neutrophils to a proangiogenic profile with increased vascular endothelial growth factor synthesis and increased capacity to promote vascular transformation. Results presented here provide novel clues to reconstruct the interaction of trophoblast cells and neutrophils in vivo during placentation in humans.