Normal Trophoblast Invasion Research Articles

Placental growth factor mediates pathological uterine angiogenesis by activating the NFAT5-SGK1 signaling axis in the endometrium: implications for preeclampsia development

After menstruation the uterine spiral arteries are repaired through angiogenesis. This process is tightly regulated by the paracrine communication between endometrial stromal cells (EnSCs) and endothelial cells. Any molecular aberration in these processes can lead to complications in pregnancy including miscarriage or preeclampsia (PE). Placental growth factor (PlGF) is a known contributing factor for pathological angiogenesis but the mechanisms remain poorly understood. In this study, we investigated whether PlGF contributes to pathological uterine angiogenesis by disrupting EnSCs and endothelial paracrine communication. We observed that PlGF mediates a tonicity-independent activation of nuclear factor of activated T cells 5 (NFAT5) in EnSCs. NFAT5 activated downstream targets including SGK1, HIF-1α and VEGF-A. In depth characterization of PlGF - conditioned medium (CM) from EnSCs using mass spectrometry and ELISA methods revealed low VEGF-A and an abundance of extracellular matrix organization associated proteins. Secreted factors in PlGF-CM impeded normal angiogenic cues in endothelial cells (HUVECs) by downregulating Notch-VEGF signaling. Interestingly, PlGF-CM failed to support human placental (BeWo) cell invasion through HUVEC monolayer. Inhibition of SGK1 in EnSCs improved angiogenic effects in HUVECs and promoted BeWo invasion, revealing SGK1 as a key intermediate player modulating PlGF mediated anti-angiogenic signaling. Taken together, perturbed PlGF-NFAT5-SGK1 signaling in the endometrium can contribute to pathological uterine angiogenesis by negatively regulating EnSCs-endothelial crosstalk resulting in poor quality vessels in the uterine microenvironment. Taken together the signaling may impact on normal trophoblast invasion and thus placentation and, may be associated with an increased risk of complications such as PE.

Pathologic maternal and neonatal outcomes associated with programmed embryo transfer: potential etiologies and strategies for prevention.

In the first of two companion papers, we comprehensively reviewed the recent evidence in the primary literature, which addressed the increased prevalence of hypertensive disorders of pregnancy, late-onset or term preeclampsia, fetal overgrowth, postterm birth, and placenta accreta in women conceiving by in vitro fertilization. The preponderance of evidence implicated frozen embryo transfer cycles and, specifically, those employing programmed endometrial preparations, in the higher risk for these adverse maternal and neonatal pregnancy outcomes. Based upon this critical appraisal of the primary literature, we formulate potential etiologies and suggest strategies for prevention in the second article. Comprehensive review of primary literature. Presupposing significant overlap of these apparently diverse pathological pregnancy outcomes within subjects who conceive by programmed autologous FET cycles, shared etiologies may be at play. One plausible but clearly provocative explanation is that aberrant decidualization arising from suboptimal endometrial preparation causes greater than normal trophoblast invasion and myometrial spiral artery remodeling. Thus, overly robust placentation produces larger placentas and fetuses that, in turn, lead to overcrowding of villi within the confines of the uterine cavity which encroach upon intervillous spaces precipitating placental ischemia, oxidative and syncytiotrophoblast stress, and, ultimately, late-onset or term preeclampsia. The absence of circulating corpus luteal factors like relaxin in most programmed cycles might further compromise decidualization and exacerbate the maternal endothelial response to deleterious circulating placental products like soluble fms-like tyrosine kinase-1 that mediate disease manifestations. An alternative, but not mutually exclusive, determinant might be a thinner endometrium frequently associated with programmed endometrial preparations, which could conspire with dysregulated decidualization to elicit greater than normal trophoblast invasion and myometrial spiral artery remodeling. In extreme cases, placenta accreta could conceivably arise. Though lower uterine artery resistance and pulsatility indices observed during early pregnancy in programmed embryo transfer cycles are consistent with this initiating event, quantitative analyses of trophoblast invasion and myometrial spiral artery remodeling required to validate the hypothesis have not yet been conducted. Endometrial preparation that is not optimal, absent circulating corpus luteal factors, or a combination thereof are attractive etiologies; however, the requisite investigations to prove them have yet to be undertaken. Presuming that in ongoing RCTs, some or all adverse pregnancy outcomes associated with programmed autologous FET are circumvented or mitigated by employing natural or stimulated cycles instead, then for women who can conceive using these regimens, they would be preferable. For the 15% or so of women who require programmed FET, additional research as suggested in this review is needed to elucidate the responsible mechanisms and develop preventative strategies.

Galectin-1-Related Modulation of Trophoblast Endothelial Interactions by Integrins α1 and β1.

During normal trophoblast invasion, integrins α6β4 are downregulated, and α1β1 are upregulated in invasive cytotrophoblast cells. In preeclampsia both interstitial and endovascular invasion are shallow and cytotrophoblasts fail to upregulate α1β1 and downregulate α6β4. This study aims to investigate the role of integrins α1β1 and α6β4 on cellular pathways influencing trophoblast integration into endothelial cellular networks in vitro. Red fluorescent-labeled human uterine myometrial microvascular endothelial cells (UtMVECs) were seeded on Matrigel to form endothelial networks. Green fluorescent-labeled trophoblastic HTR-8/SVneo cells pre-incubated with 20μg/ml of neutralizing antibodies (anti-α1, β1, α6, β4, α1+β1, or α6+β4) for 1h were then co-cultured with endothelial networks with the neutralizing antibodies for 24h. Fluorescent images were captured, and quantified utilizing Image J. Cells were retrieved to analyze mRNA expression of galectin-1, TIMP-1, and PAI-1 by quantitative PCR. MMP-2, MMP-9, free sFlt-1, and PlGF from conditioned media were measured by ELISA. The integration of trophoblast cells into endothelial cellular networks was inhibited by anti-β1(- 28± 3%, p< 0.0001), and increased by anti-α6(+ 19± 5%, p< 0.01). Galectin-1 mRNA expression was decreased by anti-α1(- 35± 7%, p< 0.001), anti-β1(-23± 5%, p< 0.05), and anti-α1+β1(- 35± 5%, p< 0.001). The mRNA expression of TIMP-1 was inhibited by anti-α1(- 59 ± 9%, p< 0.01) and anti-β1(- 63± 7%, p< 0.001) while PAI-1 mRNA expression was increased by anti-α1 + β1(+ 285 ± 70%, p< 0.0001). In the conditioned medium, anti-α1 reduced MMP-2(-28± 1%, p< 0.001), MMP-9(-27± 8%, p< 0.01), and sFlt-1(-27± 5%, p< 0.001) production. Anti-β1 reduced MMP-2(- 15± 2%, p< 0.05) production. There were no changes in PlGF. Appropriate integrins α1β1 modulate trophoblast cell integration into endothelial cellular networks in vitro through invasive pathways including galectin-1, TIMP-1, PAI-1, MMP-2, and MMP-9 production.

88. Integrins (α1, β1 and α6, β4) differentially modulate trophoblast-endothelial interaction in vitro

Introduction During normal trophoblast invasion, integrin α6β4 are downregulated and α1β1 are upregulated in invasive cytotrophoblast cells. In preeclampsia, both interstitial and endovascular invasion are shallow and cytotrophoblast fail to upregulate α1β1 and downregulate α6β4. Objective This study aims to investigate role of integrin α1β1 and integrin α6β4 during trophoblast integration into endothelial cellular networks in vitro. Methods Red fluorescent-labeled human uterine myometrial microvascular endothelial cells (UtMVECs) were seeded on Matrigel to form endothelial networks. Green fluorescent-labeled trophoblast HTR-8/SVneo cells pre-incubated with 20 μg/ml of neutralizing antibodies (anti-α1, β1, α6, β4, α1β1 or α6β4) for 1 h were then co-cultured with the endothelial networks with the neutralizing antibody for 24 h. Fluorescent images were captured and quantified by image J. Free soluble fms-like tyrosine kinase-1 (sFlt-1), placenta growth factor (PlGF), matrix metalloproteinases 2 and 9 (MMP-2 and MMP-9) from conditioned media were measured by ELISA. Cells were retrieved to examine mRNA expression of invasion markers of tissue inhibitor of metalloproteinase-1 (TIMP-1) and plasminogen activator inhibitor type 1 (PAI-1) by quantitative PCR. Results The integration of trophoblast cells into endothelial cellular networks was significantly inhibited by anti-β1 (72 ± 3%, p Discussion We have shown that anti-integrin β1, not anti-integrin a1 inhibited and anti-integrin a6, not anti-integrin β4 increased endothelial-trophoblast cellular integration in vitro. The matrix degradation enzymes (MMP-2 and MMP-9) and their associated inhibitors (TIMP-1 and PAI-1) may involve in this process.

Leukemia Inhibitory Factor (LIF) Inhibition during Mid-Gestation Impairs Trophoblast Invasion and Spiral Artery Remodelling during Pregnancy in Mice.

The placenta forms the interface between the maternal and fetal circulation and is critical for the establishment of a healthy pregnancy. Trophoblast cell proliferation, migration and invasion into the endometrium are fundamental events in the initiation of placentation. Leukemia inhibitory factor (LIF) has been shown to promote trophoblast invasion in vitro, however its precise role in trophoblast invasion in vivo is unknown. We hypothesized that LIF would be required for normal trophoblast invasion and spiral artery remodeling in mice. Both LIF and its receptor (LIFRα) co-localized with cytokeratin-positive invasive endovascular extravillous trophoblasts (EVT) in mouse implantation sites during mid-gestation. Temporally blocking LIF action during specific periods of placental development via administration of our unique LIFRα antagonist, PEGLA, resulted in abnormal trophoblast invasion and impaired spiral artery remodeling compared to PEG control. PEGLA-treated mouse decidual vessels were characterized by retention of α-smooth muscle actin (αSMA)-positive vascular smooth muscle cells (VSMCs), while PEG control decidual vessels were remodelled by cytokeratin-positive trophoblasts. LIF blockade did not alter F4/80-positive decidual macrophage numbers between treatment groups, but resulted in down-regulation of decidual transcript levels of monocyte chemoattractant protein-1 (MCP-1) and interleukin-10 (IL-10), which are important immune cell activation factors that promote spiral artery remodeling during pregnancy. Our data suggest that LIF plays an important role in trophoblast invasion in vivo and may facilitate trophoblast-decidual-immune cell cross talk to enable adequate spiral artery remodeling.

Vascular endothelial growth factor role in predicting vascular disorders in pregnant with fetal growth restriction syndrome

The review covers the up-to-date data of vascular endothelial growth factor role in forming of placental blood circulation in non-complicated pregnancy and in fetal growth retardation syndrome. It is shown that the normal trophoblast invasion to the spiral arteries wall in the myometrium and adequate remodeling of spiral arteries are essential for the normal fetal growth and development. The processes of blood vessels formation - vasculogenesis and angiogenesis - are described in detail. The process of angiogenesis regulation by growth factors and their receptors is reviewed. The importance of angiogenic and antiangiogenic factors coordinated action for the adequate placental microvasculature formation and normal fetal development is described. The growth factor complexes and their receptors formation processes and competition for receptor binding, as well as the role of placental growth factor in uteroplacental complex angiogenesis are analyzed. It is shown that the serum growth factors represent the mechanisms of pathologic reactions in placental insufficiency and fetal growth restriction syndrome. Special attention is given to the family of vascular endothelial growth factor as for the most important angiogenesis regulator. To determine the physiological role of vascular endothelial growth factor and to assess the its influence on angiogenesis and adequate uteroplacental and fetoplacental blood circulation formation, the features of vascular endothelial growth factor chemical structure are described. Determining the vascular endothelial growth factor in blood may be used to assess the mother-placenta-fetus system formation. The need for developing the criteria for choosing the optimal delivery term in pregnant with fetal growth restriction syndrome is discussed.

Morphological analysis of the pancreatic beta cells of diabetic female rats at different ages of life

s / Placenta 36 (2015) 469e521 490 pregnancy morbidity plus vascular thrombosis (PM/VT), pregnancy morbidity without aPL (PM/aPL-) or healthy women (NHS). Drugs were added at the same time with IgG at previous established concentrations. After 24 h, the inserts were removed and trophoblast cell migration across the Matrigel coated membrane was determined using a colorimetric assay. The relative cell invasion value was assessed by comparing the optical densities with no treatment control. STAT-3 activation was determined at same conditions of invasion assays using Western blots. Results: IgGs from patients with APS-associated pregnancy morbidity (PM, PM/VT) induce a significantly decreased invasion in comparison with IgGs from the NHS and PM/aPLgroups. Enoxaparin, aspirin and ATL restore the aPL-decreased invasion and, moreover, ATL has a receptormediated effect as demonstrated by application of its antagonist Boc-2, which reverses the ATL-restored invasion. Additionally, phosphorylation of STAT-3 is reduced by IgGs from PM patients. Conclusion: We show here that some of drugs used in APS-related pregnancy morbidity treatment are involved in the modulation of trophoblast function. They possibly restore some processes essential for normal trophoblast invasion. Moreover, ATL effects may explain the benefits of aspirin treatment observed in patients with obstetric APS. Since STAT-3 is an intracellular signalling molecule involved in migration and invasion processes, our results support the view that aPL from patients with pregnancy morbidity alter the proper function of this pathway. Financial support: CODIUniversidad de Antioquia Grant 91515; Estrategia de sostenibilidad Grupo Reproducci on 2014-2015; Programa de Cooperaci on Cientifica Internacional-Proyectos de Intercambio: Colciencias-Colombia Convocatoria 614-2013, y CONICYT-Chile PCCI 130017. AMA is a fellow of Colciencias. PA.7. MORPHOLOGICAL ANALYSIS OF THE PANCREATIC BETA CELLS OF DIABETIC FEMALE RATS AT DIFFERENT AGES OF LIFE F.Q. Gallego , Y.K. Sinzato , B. Dallaqua , I.L. Iessi , R.L. Amorim , C.E. Fonseca , I.M.P. Calderon , M.V.C. Rudge , D.C. Damasceno . 1 Laboratory of Experimental Research on Gynecology and Obstetrics, Graduate Program on Gynecology, Obstetrics and Mastology, Botucatu Medical School, Brazil; Department of Pathology, Botucatu Veterinary and Zootechnology Medical School, Univ. Estadual Paulista_Unesp, Botucatu, S~ ao Paulo, Brazil Background: Recent studies have shown regeneration of pancreatic islets in physiological and pathological circumstances. We hypothesized that diabetes disturbs insulin-producing b-cell regeneration in laboratory animals. Aim: The objective was to understand the proliferation and death mechanism of pancreatic b-cells in non-diabetic and neonatally streptozotocininduced mild diabetic rats at different stages of life and during pregnancy. Methods: The rats were randomly assigned into the following groups: Non-diabetic (Control1⁄4C, glycemia<120 mg/dL) or Mild diabetes (MD) (n1⁄415/group). The mild diabetes group was induced at birth by the b-cell cytotoxic agent e Streptozotocin (STZ 100 mg/kg b.w., sc.). On postnatal days (PND) 5, 15 and 90 and on day 18.5 of pregnancy, the different groups of rats were killed to collect blood samples for insulin and glycated hemoglobin measurements; pancreas samples were processed for histological and immunohistochemical analysis for cell proliferation, apoptosis and insulin. In addition, on day 18.5 of pregnancy, the uterine corns were exposed for evaluation of reproductive outcomes. p<0.05 was considered as the significant statistical limit. Results: On PND5, the diabetic rats showed pancreatic islet morphological alterations as decreased insulin and apoptosis immunostaining, and increased cell proliferation. On PND15, cell proliferationwas lower than on PND5 in diabetic rats. In adulthood (PND90 and pregnancy), diabetic rats presented increased glycated hemoglobin levels and glucose intolerance, and no changes in pancreatic islets morphology were observed in relation to the control group. On day 18.5 of pregnancy, MD dams presented an increased number of embryonic death and rate of preimplantation losses when compared with the control group. Conclusion: Our results showed that after administration of streptozotocin pancreatic b-cells were able to regenerate partially by an increase in proliferation and a decrease in apoptosis. However, this was insufficient to reverse the diabetic status in adulthood leading to impairment of the reproductive function in diabetic mothers. Acknowledgement: FAPESP/Brazil (Process Numbers: 2011/18519-7; 2011/15606-6). PA.8. LEPTIN IS INVOLVED IN HUMAN TROPHOBLAST MIGRATION AND INVASION A. Toro , R. Sampayo , A. P erez-P erez , B. Maskin , V. S anchezMargalet , M. Simian , C. Varone . Dpto. de Quimica Biol ogica, FCENUBA, IQUIBICEN CONICET, Buenos Aires, Argentina; 2 Area de Investigaciones, Instituto de Oncologia “ Angel H. Roffo”, Buenos Aires, Argentina; Dpto. de Bioquimica M edica y Biologia Molecular. Universidad de Sevilla, Sevilla, Spain; Hospital Nacional “A. Posadas”, Buenos Aires,

Treatment of poor placentation and the prevention of associated adverse outcomes--what does the future hold?

ABSTRACTPoor placentation, which manifests as pre-eclampsia and fetal growth restriction, is a major pregnancy complication. The underlying cause is a deficiency in normal trophoblast invasion of the spiral arteries, associated with placental inflammation, oxidative stress, and an antiangiogenic state. Peripartum therapies, such as prenatal maternal corticosteroids and magnesium sulphate, can prevent some of the adverse neonatal outcomes, but there is currently no treatment for poor placentation itself. Instead, management relies on identifying the consequences of poor placentation in the mother and fetus, with iatrogenic preterm delivery to minimise mortality and morbidity. Several promising therapies are currently under development to treat poor placentation, to improve fetal growth, and to prevent adverse neonatal outcomes. Interventions such as maternal nitric oxide donors, sildenafil citrate, vascular endothelial growth factor gene therapy, hydrogen sulphide donors, and statins address the underlying pathology, while maternal melatonin administration may provide fetal neuroprotection. In the future, these may provide a range of synergistic therapies for pre-eclampsia and fetal growth restriction, depending on the severity and gestation of onset.

Uric acid attenuates trophoblast invasion and integration into endothelial cell monolayers

Hyperuricemia develops as early as 10 wk of gestation in women who later develop preeclampsia. At this time the invasive trophoblast cells are actively remodeling the uterine spiral arterioles, integrating into and finally replacing the vascular endothelial lining. In the nonpregnant population uric acid has several pathogenic effects on vascular endothelium. We therefore sought to examine the effects of uric acid (0-7 mg/dl) on trophoblast cell invasion through an extracellular matrix using an in vitro Matrigel invasion assay. We also assessed trophoblast integration into a uterine microvascular endothelial cell monolayer in a trophoblast-endothelial cell coculture model. Additionally, we addressed the importance of redox signaling and trophoblast-induced endothelial cell apoptosis. Uric acid elicited a concentration-dependent attenuation of trophoblast invasion and integration into a uterine microvascular endothelial cell monolayer. The attenuated trophoblast integration appeared to be the result of reduced trophoblast-induced endothelial cell apoptosis, likely through the intracellular antioxidant actions of uric acid. In a test of relevance, pooled serum (5% vol/vol) from preeclamptic women attenuated the ability of trophoblast cells to integrate into the endothelial cell monolayers compared with pooled serum from healthy pregnant controls, and this response was partially rescued when endogenous uric acid was previously removed with uricase. Taken together these data support the hypothesis that elevations in circulating uric acid in preeclamptic women contribute to the pathogenesis of the disorder, in part, through attenuation of normal trophoblast invasion and spiral artery vascular remodeling.

Tumor Necrosis Factor‐α in the Placenta is not Elevated in Pre‐eclamptic Patients Despite its Elevation in Peripheral Blood

Tumor necrosis factor-alpha (TNF-alpha) is present in human placental and uterine cells at the early and late stages of gestation and promotes the regulation of trophoblast growth and invasion. We evaluated whether TNF-alpha levels in the placenta and blood of pre-eclamptic women differed from those with normal pregnancies. The subjects were 39 pregnant women carrying single fetuses (21 normal-pregnant and 18 pre-eclamptic patients). Their average gestational age at entry was 38-39 weeks. Peripheral blood was collected before the onset of labor and separated serum was stored at -20 degrees C. A tissue segment of the placenta was cut and frozen in liquid nitrogen immediately after delivery at -80 degrees C. The frozen placental tissue was added to phosphate-buffered saline. The tissue was fully homogenized and centrifuged. Separated supernatant was stored at -80 degrees C. TNF-alpha levels in separated serum and TNF-alpha and total protein (TP) levels in separated supernatant were measured. The presence of TNF-alpha in the placenta was evaluated by immunohistochemistry in five pre-eclamptic and five normal-pregnant patients. Serum TNF-alpha levels were higher in pre-eclampsia than in normal pregnancies. However, TNF-alpha/TP levels in the placenta did not differ significantly between the two groups. As for TNF-alpha immunostaining of trophoblastic cells in the placenta, it was weak in three and moderate in two of the normal pregnancies, while it was absent in two, weak in one, and moderate in two in the pre-eclampsia group. We demonstrated no significant increase in TNF-alpha/TP levels in the placenta in pre-eclampsia despite a significant increase in serum TNF-alpha levels. There was no strong immunostaining for TNF-alpha detected by immunohistochemistry in the pre-eclampsia group. These findings suggest that TNF-alpha in the placenta is not a key cytokine to interfere with normal trophoblast invasion into the myometrium in pre-eclampsia, and that sources other than the placenta may contribute to the elevated levels of TNF-alpha found in the circulation of pre-eclamptic patients.

Etiology and Pathogenesis of Preeclampsia

The etiology of preeclampsia is unknown. At present, 4 hypotheses are the subject of extensive investigation, as follows: (1) Placental ischemia-Increased trophoblast deportation, as a consequence of ischemia, may inflict endothelial cell dysfunction. (2) Very low-density lipoprotein versus toxicity-preventing activity-In compensation for increased energy demand during pregnancy, nonesterified fatty acids are mobilized. In women with low albumin concentrations, transporting extra nonesterified fatty acids from adipose tissues to the liver is likely to reduce albumin's antitoxic activity to a point at which very-low density lipoprotein toxicity is expressed. (3) Immune maladaptation-Interaction between decidual leukocytes and invading cytotrophoblast cells is essential for normal trophoblast invasion and development. Immune maladaptation may cause shallow invasion of spiral arteries by endovascular cytotrophoblast cells and endothelial cell dysfunction mediated by an increased decidual release of cytokines, proteolytic enzymes, and free radical species. (4) Genetic imprinting-Development of preeclampsia-eclampsia may be based on a single recessive gene or a dominant gene with incomplete penetrance. Penetrance may be dependent on fetal genotype. The possibility of genetic imprinting should be considered in future genetic investigations of preeclampsia.

Etiology and pathogenesis of preeclampsia: Current concepts

The etiology of preeclampsia is unknown. At present, 4 hypotheses are the subject of extensive investigation, as follows: (1) Placental ischemia—Increased trophoblast deportation, as a consequence of ischemia, may inflict endothelial cell dysfunction. (2) Very low-density lipoprotein versus toxicity-preventing activity—In compensation for increased energy demand during pregnancy, nonesterified fatty acids are mobilized. In women with low albumin concentrations, transporting extra nonesterified fatty acids from adipose tissues to the liver is likely to reduce albumin’s antitoxic activity to a point at which very-low density lipoprotein toxicity is expressed. (3) Immune maladaptation—Interaction between decidual leukocytes and invading cytotrophoblast cells is essential for normal trophoblast invasion and development. Immune maladaptation may cause shallow invasion of spiral arteries by endovascular cytotrophoblast cells and endothelial cell dysfunction mediated by an increased decidual release of cytokines, proteolytic enzymes, and free radical species. (4) Genetic imprinting—Development of preeclampsia-eclampsia may be based on a single recessive gene or a dominant gene with incomplete penetrance. Penetrance may be dependent on fetal genotype. The possibility of genetic imprinting should be considered in future genetic investigations of preeclampsia. (Am J Obstet Gynecol 1998;179:1359-75.)

Interleukin-1 beta regulates human cytotrophoblast metalloproteinase activity and invasion in vitro.

During early human pregnancy, fetal cytotrophoblasts rapidly invade the uterus. This process has many similarities to tumor invasion, except that the extent and the timing of cytotrophoblast invasion are carefully regulated. Therefore, this system is particularly useful for studying mechanisms that regulate invasive processes. Previously, we showed that production and activation of the 92-kDa type IV collagenase (matrix metalloproteinase(MMP)-9) is necessary for cytotrophoblast invasion in vitro. In other systems, interleukin (IL)-1 beta is an important regulator of matrix-degrading metalloproteinases. Therefore, we investigated trophoblast production of IL-1 beta and its receptors, as well as the effects of this cytokine on cytotrophoblast metalloproteinase activity and invasion. The results showed that release of IL-1 beta parallels the invasive potential of the cytotrophoblasts; the highest levels are produced by first trimester cells and the lowest levels by term cells. Immunoprecipitation showed that cytotrophoblasts express the 80-kDa type I IL-1 receptor, suggesting that autocrine effects are possible. IL-1 beta stimulated trophoblast MMP-9 secretion (by a mechanism that required nascent mRNA and protein synthesis) as well as metalloproteinase activity and invasion of Matrigel. Increasing (by lipopolysaccharide treatment) or decreasing (by glucocorticoid treatment) IL-1 beta production had parallel effects on MMP-9 secretion, metalloproteinase activity, and invasion. Because IL-1 beta and corticosteroids are present in high concentrations at the maternal-fetal interface, normal trophoblast invasion may be regulated, in part, by their opposing actions. In contrast, stimulation of cytotrophoblast IL-1 beta secretion by lipopolysaccharide may play a role in the sequela of infected fetal membranes.