Tumor necrosis factor-alpha and interleukin-1beta regulate interleukin-8 expression in third trimester decidual cells: implications for the genesis of chorioamnionitis

Inflammatory mechanisms of preterm labor and emerging anti-inflammatory interventions

Preterm birth is a major public health concern, requiring a deeper understanding of its underlying inflammatory mechanisms and to develop effective therapeutic strategies. This review explores the complex interaction between inflammation and preterm labor, highlighting the pivotal role of the dysregulation of inflammation in triggering premature delivery. The immunological environment of pregnancy, characterized by a fragile balance of immune tolerance and resistance, is disrupted in preterm labor, leading to a pathological inflammatory response. Feto-maternal infections, among other pro-inflammatory stimuli, trigger the activation of toll-like receptors and the production of pro-inflammatory mediators, promoting uterine contractility and cervical ripening. Emerging anti-inflammatory therapeutics offer promising approaches for the prevention of preterm birth by targeting key inflammatory pathways. From TLR-4 antagonists to chemokine and interleukin receptor antagonists, these interventions aim to modulate the inflammatory environment and prevent adverse pregnancy outcomes. In conclusion, a comprehensive understanding of the inflammatory mechanisms leading to preterm labor is crucial for the development of targeted interventions in hope of reducing the incidence of preterm birth and improving neonatal health outcomes.

The role of neutrophils in chorioamnionitis

Chorioamnionitis, commonly referred to as intrauterine infection or inflammation, is pathologically defined by neutrophil infiltration and inflammation at the maternal-fetal interface. Chorioamnionitis is the common complication during late pregnancy, which lead to a series of serious consequences, such as preterm labor, preterm premature rupture of the fetal membranes, and fetal inflammatory response syndrome. During infection, a large number of neutrophils migrate to the chorio-decidua in response to chemokines. Although neutrophils, a crucial part of innate immune cells, have strong anti-inflammatory properties, over-activating them can harm the body while also eliminating pathogens. This review concentrated on the latest studies on chorioamnionitis-related consequences as well as the function and malfunction of neutrophils. The release of neutrophil extracellular traps, production of reactive oxygen species, and degranulation from neutrophils during intrauterine infection, as well as their pathological roles in complications related to chorioamnionitis, were discussed in detail, offering fresh perspectives on the treatment of chorioamnionitis.

Stromal Interaction Molecule 1 (STIM1) is a Potential Prognostic Biomarker and Correlates with Immune Infiltrates in Solid Tumors

Increasing evidence has shown that stromal interaction molecule 1 (STIM1), a key subunit of store-operated Ca2+ entry (SOCE), is closely associated with tumor growth, development, and metastasis. However, there is no report of a comprehensive assessment of STIM1 in pan-cancer. This study aimed to perform a general analysis of STIM1 in human tumors, including its molecular characteristics, functional mechanisms, clinical significance, and immune infiltrates correlation based on pan-cancer data from The Cancer Genome Atlas (TCGA). Gene expression analysis was investigated using TCGA RNA-seq data, the Tumor Immune Estimation Resource (TIMER). Phosphorylation analysis was undertaken using the Clinical Proteomic Tumor Analysis Consortium (CP-TAC) and the PhosphoNET database. Genetic alterations of STIM1 were analyzed using cBioPortal. Prognostic analysis was via the R package "survival" function and the Kaplan-Meier plotter. Functional enrichment analysis was via by the R package "cluster Profiler" function. The association between STIM1 and tumor-infiltrating immune cells and immune markers was by the R package "GSVA" function and TIMER. STIM1 was differentially expressed and associated with distinct clinical stages in multiple tumors. The phosphorylation of STIM1 at S673 is highly expressed in clear cell renal carcinoma and lung adenocarcinoma tumors compared to normal tissues. STIM1 genetic alterations correlate with poor prognosis in several tumors, including ovarian cancer and lung squamous cell carcinomas. High STIM1 expression is associated with good or poor prognosis across diverse tumors. Overall survival (OS) analysis indicated that STIM1 is a favorable prognostic factor for patients with BRCA, KIRC, LIHC, LUAD, OV, SARC, and UCEC, and is a risk prognostic factor for BLCA, KIRP, STAD, and UVM. There is a close correlation between STIM1 expression and immune cell infiltration, immune-regulated genes, chemokines, and immune checkpoints in a variety of tumors. STIM1 functions differently in diverse tumors, playing an oncogenic or antitumor role. Moreover, It may serve as a prognostic biomarker and an immunotherapy target across multiple tumors.

Regulation of inflammatory genes in decidual cells: Involvement of the bromodomain and extra-terminal family proteins

The decidua undergoes proinflammatory activation in late pregnancy, promoting labor. Bromodomain and Extra-Terminal (BET) family proteins interact with acetylated histones and may control gene expression in inflammation. Here, we assessed whether BETs are involved in inflammatory gene regulation in human decidual cells. We have treated primary cultures of decidual stromal cells (DSCs) from term pregnancies with endotoxin (LPS) and measured the expression of a panel of pro-and anti-inflammatory genes. BET involvement was assessed using the selective BET inhibitors (+)-JQ1 and I-BET-762 or the negative control compound (-)-JQ1. Histone 3 and -4 acetylation and BETs binding at the target gene promoters were determined to assess whether these processes are involved in the actions of LPS, BETs, and BET inhibitors. LPS increased the expression of the proinflammatory (PTGS2, IL6, CXCL8/IL8, TNF) and the anti-inflammatory (IL10, IDO1) genes of the panel. The constitutively expressed inflammatory genes (PTGS1, PTGES) were unaffected. The BET inhibitors, but not the control compound, reduced the basal and LPS-induced expression of PTGS1, PTGS2, IL6, CXCL8/IL8, IL10, and IDO1. TNF expression was not changed by BET inhibition. The dominant BETs were Bromodomain-containing protein -2 (BRD2) and -4L (BRD4L) in DSCs. LPS increased histone 4 acetylation at the CXCL8/IL8 and TNF promoters and histone 3 and -4 acetylation at the IDO1 promoter, while (+)-JQ1 abrogated histone acetylation at several promoters. Overall, histone acetylation and promoter binding of BETs showed no consistent relationship with gene expression across the gene panel and the treatments. BET proteins, predominantly BRD2 and BRD4L, control critical pro- and anti-inflammatory genes in DSCs. TNF induction exemplifies a BET-independent pathway. Changing histone acetylation at the promoters is not a general obligatory requirement for inflammatory gene expression in response to LPS. BETs likely act at chromatin loci separate from the examined promoters. BET inhibitors may block decidual activation at labor.

Spontaneous preterm birth: Involvement of multiple feto-maternal tissues and organ systems, differing mechanisms, and pathways

Survivors of preterm birth struggle with multitudes of disabilities due to improper in utero programming of various tissues and organ systems contributing to adult-onset diseases at a very early stage of their lives. Therefore, the persistent rates of low birth weight (birth weight < 2,500 grams), as well as rates of neonatal and maternal morbidities and mortalities, need to be addressed. Active research throughout the years has provided us with multiple theories regarding the risk factors, initiators, biomarkers, and clinical manifestations of spontaneous preterm birth. Fetal organs, like the placenta and fetal membranes, and maternal tissues and organs, like the decidua, myometrium, and cervix, have all been shown to uniquely respond to specific exogenous or endogenous risk factors. These uniquely contribute to dynamic changes at the molecular and cellular levels to effect preterm labor pathways leading to delivery. Multiple intervention targets in these different tissues and organs have been successfully tested in preclinical trials to reduce the individual impacts on promoting preterm birth. However, these preclinical trial data have not been effectively translated into developing biomarkers of high-risk individuals for an early diagnosis of the disease. This becomes more evident when examining the current global rate of preterm birth, which remains staggeringly high despite years of research. We postulate that studying each tissue and organ in silos, as how the majority of research has been conducted in the past years, is unlikely to address the network interaction between various systems leading to a synchronized activity during either term or preterm labor and delivery. To address current limitations, this review proposes an integrated approach to studying various tissues and organs involved in the maintenance of normal pregnancy, promotion of normal parturition, and more importantly, contributions towards preterm birth. We also stress the need for biological models that allows for concomitant observation and analysis of interactions, rather than focusing on these tissues and organ in silos.

Preeclampsia is Associated With Reduced ISG15 Levels Impairing Extravillous Trophoblast Invasion

Among several interleukin (IL)-6 family members, only IL-6 and IL-11 require a gp130 protein homodimer for intracellular signaling due to lack of intracellular signaling domain in the IL-6 receptor (IL-6R) and IL-11R. We previously reported enhanced decidual IL-6 and IL-11 levels at the maternal-fetal interface with significantly higher peri-membranous IL-6 immunostaining in adjacent interstitial trophoblasts in preeclampsia (PE) vs. gestational age (GA)-matched controls. This led us to hypothesize that competitive binding of these cytokines to the gp130 impairs extravillous trophoblast (EVT) differentiation, proliferation and/or invasion. Using global microarray analysis, the current study identified inhibition of interferon-stimulated gene 15 (ISG15) as the only gene affected by both IL-6 plus IL-11 vs. control or IL-6 or IL-11 treatment of primary human cytotrophoblast cultures. ISG15 immunostaining was specific to EVTs among other trophoblast types in the first and third trimester placental specimens, and significantly lower ISG15 levels were observed in EVT from PE vs. GA-matched control placentae (p = 0.006). Induction of primary trophoblastic stem cell cultures toward EVT linage increased ISG15 mRNA levels by 7.8-fold (p = 0.004). ISG15 silencing in HTR8/SVneo cultures, a first trimester EVT cell line, inhibited invasion, proliferation, expression of ITGB1 (a cell migration receptor) and filamentous actin while increasing expression of ITGB4 (a receptor for hemi-desmosomal adhesion). Moreover, ISG15 silencing further enhanced levels of IL-1β-induced pro-inflammatory cytokines (CXCL8, IL-6 and CCL2) in HTR8/SVneo cells. Collectively, these results indicate that ISG15 acts as a critical regulator of EVT morphology and function and that diminished ISG15 expression is associated with PE, potentially mediating reduced interstitial trophoblast invasion and enhancing local inflammation at the maternal-fetal interface. Thus, agents inducing ISG15 expression may provide a novel therapeutic approach in PE.

Assessment of IL-1β, IL-6, TNF-α, IL-8, and CCL 5 levels in newly diagnosed Saudi patients with rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis (RA) is a chronic systemic inflammatory disorder which mainly affects small joints, occurs most commonly in middle-aged adults, and can be fatal in severe cases. The exact etiology of RA remains unknown. However, uncontrolled expression of pro-inflammatory cytokines and chemokines can contribute to the pathogenesis of RA.

AIM

In the current study, we assessed the potential of serum concentrations of interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, IL-8, and C-C motif chemokine ligand (CCL)5 as early predictive markers for RA.

METHODS

In addition to clinical examination, blood samples were collected from 100 Saudi patients recently diagnosed with early RA for basic and serological tests, including rheumatoid factor (RF), C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR). Sera of 32 healthy individuals were used as controls. Specific enzyme-linked immunosorbent assay was used to quantify the serum IL-1β, IL-6, TNF-α, IL-8, and CCL5 levels in the samples.

RESULTS

Our results indicated that RF, CRP, and ESR levels were higher in RA patients compared to controls. Furthermore, serum levels of IL-1β, IL-6, IL-8, and CCL5, but not TNF-α, significantly increased in RA patients compared to controls.

CONCLUSION

Overall, the findings suggested that IL-1β, IL-6, IL-8, and CCL5 can be used as biomarkers in the early diagnosis of RA.

Tumor necrosis factor signaling during equine placental infection leads to pro-apoptotic and necroptotic outcomes

Ascending placentitis is the leading cause of abortion in the horse. The pleiotropic cytokine tumor necrosis factor (TNF) is an upstream regulator of this disease, but little is understood regarding its function in pregnancy maintenance or placental infection. To assess this, RNA sequencing was performed on chorioallantois and endometrium of healthy pregnant mares at various gestational lengths (n = 4/gestational age), in addition to postpartum chorioallantois, and diestrus endometrium to assess expression of TNF, TNFR-1, and TNFR-2. Additionally, ascending placentitis was induced via trans-cervical inoculation of S. equi spp. zooepidemicus in pregnant mares (n = 6 infected / n = 6 control) and tissues and serum were collected to evaluate TNF-related transcripts. IHC was performed to confirm protein localization of TNFR-1 and TNFR-2. In healthy pregnancy, TNFR-1 appears to be the predominant TNF-related receptor. Following induction of disease, TNF concentrations increased in maternal serum, but expression did not alter at the tissue level. While both TNFR-1 and TNFR-2 increased following induction of disease, alterations in downstream pathways indicate that TNFR-1 is the dominant receptor in ascending placentitis, and is primarily activated within the chorioallantois, with minimal signaling occurring within the endometrium. In conclusion, TNF appears to be involved in the pathophysiology of ascending placentitis. An increase in this cytokine during disease progression is believed to activate TNFR-1 within the chorioallantois, leading to various pro-apoptotic and necroptotic outcomes, all of which may signal for fetal demise and impending abortion.

Loss of CXC-Chemokine Receptor 1 Expression in Chorioamnionitis Is Associated with Adverse Perinatal Outcomes

Background: Chorioamnionitis complicates about 1−5% of deliveries at term and causes about one-third of stillbirths. CXC-chemokine receptor 1 (CXCR1) binds IL-8 with high affinity and regulates neutrophil recruitment. We aimed to determine the immunoexpression of CXCR1 in placentas with chorioamnionitis, and its association with adverse perinatal outcomes. Methods: A total of 101 cases of chorioamnionitis and 32 cases of non-chorioamnionitis were recruited over a period of 2 years. CXCR1 immunohistochemistry was performed, and its immunoexpression in placentas was evaluated. The adverse perinatal outcomes included intrauterine death, poor APGAR score, early neonatal death, and respiratory complications. Results: Seventeen cases (17/101, 16.8%) with chorioamnionitis presented as preterm deliveries. Lung complications were more common in mothers who were >35 years (p = 0.003) and with a higher stage in the foetal inflammatory response (p = 0.03). Notably, 24 cases (23.8%) of histological chorioamnionitis were not detected clinically. Interestingly, the loss of CXCR1 immunoexpression in the umbilical cord endothelial cells (UCECs) was significantly associated with foetal death (p = 0.009). Conclusion: The loss of CXCR1 expression in UCECs was significantly associated with an increased risk of adverse perinatal outcomes and could be used as a biomarker to predict adverse perinatal outcomes in chorioamnionitis. Further study is warranted to study the pathophysiology involved in the failure of CXCR1 expression in these cells.

miR-21 differentially regulates IL-1β and IL-10 expression in human decidual cells infected with streptococcus B

Intrauterine infections caused by bacteria like group B streptococcus (GBS) and the subsequent activation of the maternal inflammatory response have been long suspected to be the underlying cause of preterm labor. The inflammatory network triggered by maternal decidua has been widely described and includes the secretion of pro- and anti-inflammatory cytokines as IL-1β and IL-10; however, the mechanisms that regulate their secretion have not been completely elucidated. MicroRNAs (miRNAs) are critical modulators of the inflammatory response by regulating cytokine expression in several cell types. Here, we explored the role of miR-21 in the expression of IL-1β and IL-10 in human decidual stromal cells (DSCs) exposed in vitro to GBS. We observed that IL1B and IL10 expression at the mRNA level was increased in DSCs after GBS infection. IL-10 but not IL-1β secretion was detected in the culture supernatants. We found a higher miR-21 expression (22-fold) in infected DSCs as compared with non-infected cells. miR-21 functional analysis revealed that DSCs transfected with an antagomiR vs. miR-21 significantly increased the secretion of IL-1β but decreased that of IL-10 in DSCs cells infected with GBS. Our results suggest that miR-21 participates in balancing the inflammatory response in infected decidua through at least IL-1β and IL-10 regulation. This is the first study attributing a functional role of miR-21 in the regulation of key molecules involved in the inflammatory response in infected DSCs, providing new insights into the epigenetic control of human decidual inflammation.

The pivotal roles of the NOD-like receptors with a PYD domain, NLRPs, in oocytes and early embryo development†

Nucleotide-binding oligomerization domain (NOD)-like receptors with a pyrin domain (PYD), NLRPs, are pattern recognition receptors, well recognized for their important roles in innate immunity and apoptosis. However, several NLRPs have received attention for their new, specialized roles as maternally contributed genes important in reproduction and embryo development. Several NLRPs have been shown to be specifically expressed in oocytes and preimplantation embryos. Interestingly, and in line with divergent functions, NLRP genes reveal a complex evolutionary divergence. The most pronounced difference is the human-specific NLRP7 gene, not identified in rodents. However, mouse models have been extensively used to study maternally contributed NLRPs. The NLRP2 and NLRP5 proteins are components of the subcortical maternal complex (SCMC), which was recently identified as essential for mouse preimplantation development. The SCMC integrates multiple proteins, including KHDC3L, NLRP5, TLE6, OOEP, NLRP2, and PADI6. The NLRP5 (also known as MATER) has been extensively studied. In humans, inactivating variants in specific NLRP genes in the mother are associated with distinct phenotypes in the offspring, such as biparental hydatidiform moles (BiHMs) and preterm birth. Maternal-effect recessive mutations in KHDC3L and NLRP5 (and NLRP7) are associated with reduced reproductive outcomes, BiHM, and broad multilocus imprinting perturbations. The precise mechanisms of NLRPs are unknown, but research strongly indicates their pivotal roles in the establishment of genomic imprints and post-zygotic methylation maintenance, among other processes. Challenges for the future include translations of findings from the mouse model into human contexts and implementation in therapies and clinical fertility management.

Endogenous estradiol and inflammation biomarkers: potential interacting mechanisms of obesity-related disease

PURPOSE

Disentangling the effects of endogenous estrogens and inflammation on obesity-related diseases requires a clearer understanding of how the two biological mechanisms relate to each other.

METHODS

We studied 155 healthy postmenopausal women not taking menopausal hormone therapy enrolled in the Prostate Lung Colorectal and Ovarian (PLCO) screening cancer trial. From a baseline blood draw, we measured endogenous estradiol and 69 inflammation biomarkers: cytokines, chemokines, adipokines, angiogenic factors, growth factors, acute phase proteins, and soluble receptors. We evaluated the estradiol-inflammation relationship by assessing associations across different models (linear, ordinal logistic, and binary logistic) using a variety of estradiol classifications. We additionally investigated the estradiol-inflammation relationship stratified by baseline obesity status (BMI < 30 stratum and BMI > 30 stratum).

RESULTS

Associations of estradiol with 7 inflammation biomarkers met p < 0.05 statistical significance in linear and ordinal models: C-reactive protein (CRP), adiponectin, chemokine (C-X-C motif) ligand-6, thymus activation-regulated chemokine, eosinophil chemotactic protein, plasminogen activator inhibitor-1, and serum amyloid A. The positive association between estradiol and CRP was robust to model changes. Each standard deviation increase in endogenous estradiol doubled a woman's odds of having CRP levels higher than the study median (odds ratio 2.29; 95% confidence interval 1.28, 4.09). Estradiol was consistently inversely associated with adiponectin. Other estradiol-inflammation biomarker associations were not robust to model changes.

CONCLUSIONS

Endogenous estradiol appears to be associated with CRP and adiponectin; the evidence is limited for other inflammation biomarkers.

The feto-maternal immune response to equine placentitis

PROBLEM

Ascending placentitis is one of the leading causes of abortion in the horse. Minimal work has focused on its effect on fetal fluids or the antenatal immune response of the fetus.

METHODOLOGY

Placentitis was induced via transcervical inoculation of Streptococcus equi ssp Zooepidemicus, and fluids/serum/tissues were collected 4-6 days later following euthanasia. Cytokine concentrations were detected using a multiplex immunoassay within fetal fluids (amniotic and allantoic) and serum (maternal and fetal) in inoculated and control mares. In addition, tissues from fetal (spleen, liver, lung, umbilicus, amnioallantois) and maternal (spleen, liver, lung, chorioallantois, endometrium) origin were analyzed in inoculated and control mares utilizing qPCR for expression of cytokines.

RESULTS

No difference in cytokine concentrations in maternal or fetal serum was noted between inoculated and control mares. Concentrations of IL-1β, IL-6, IL-10, and GRO were upregulated in the amniotic fluid following inoculation, with a trend toward higher IL-6 concentration in allantoic fluid. The amnioallantoic tissue separating the two fluids had higher expression of IL-1β and IL-6 following inoculation, while chorioallantois and endometrium upregulated IL-1β and IL-8 expression. IL-1β was upregulated in the maternal spleen following inoculation. Fetal spleens were upregulated in expression of IL-1β, GRO, and IL-6, while IL-6 was higher in fetal liver after inoculation than in controls.

CONCLUSION

The maternal response to placentitis is primarily pro-inflammatory while the fetus appears to play a regulatory role in this inflammation. Additionally, amniotic fluid sampling may be more diagnostic of ascending placentitis than circulating cytokines.

CXCR2 Blockade Mitigates Neural Cell Injury Following Preclinical Chorioamnionitis

Minimizing central nervous system (CNS) injury from preterm birth depends upon identification of the critical pathways that underlie essential neurodevelopmental and CNS pathophysiology. While chorioamnionitis (CHORIO), is a leading cause of preterm birth, the precise mechanism linking prenatal brain injury and long-term CNS injury is unknown. The chemokine (C-X-C motif) ligand 1 (CXCL1) and its cognate receptor, CXCR2, are implicated in a variety of uterine and neuropathologies, however, their role in CNS injury associated with preterm birth is poorly defined. To evaluate the putative efficacy of CXCR2 blockade in neural repair secondary to CHORIO, we tested the hypothesis that transient postnatal CXCR2 antagonism would reduce neutrophil activation and mitigate cerebral microstructural injury in rats. To this end, a laparotomy was performed on embryonic day 18 (E18) in Sprague Dawley rats, with uterine arteries transiently occluded for 60 min, and lipopolysaccharide (LPS, 4 μg/sac) injected into each amniotic sac. SB225002, a CXCR2 antagonist (3 mg/kg), was administered intraperitoneally from postnatal day 1 (P1)-P5. Brains were collected on P7 and P21 and analyzed with western blot, immunohistochemistry and ex vivo diffusion tensor imaging (DTI). Results demonstrate that transient CXCR2 blockade reduced cerebral neutrophil activation (myeloperoxidase expression/MPO) and mitigated connexin43 expression, indicative of reduced neuroinflammation at P7 (p < 0.05 for all). CXCR2 blockade also reduced alpha II-spectrin calpain-mediated cleavage, improved pNF/NF ratio, and minimized Iba1 and GFAP expression consistent with improved neuronal and axonal health and reduced gliosis at P21. Importantly, DTI revealed diffuse white matter injury and decreased microstructural integrity following CHORIO as indicated by lower fractional anisotropy (FA) and elevated radial diffusivity (RD) in major white matter tracts (p < 0.05). Early postnatal CXCR2 blockade also reduced microstructural abnormalities in white matter and hippocampus at P21 (p < 0.05). Together, these data indicate that transient postnatal blockade of CXCR2 ameliorates perinatal abnormalities in inflammatory signaling, and facilitates neural repair following CHORIO. Further characterization of neuroinflammatory signaling, specifically via CXCL1/CXCR2 through the placental-fetal-brain axis, may clarify stratification of brain injury following preterm birth, and improve use of targeted interventions in this highly vulnerable patient population.

Toll-like receptor 9, maternal cell-free DNA and myometrial cell response to CpG oligodeoxynucleotide stimulation

PROBLEM

Among mechanisms triggering onset of parturition, it has been recently postulated that Toll-Like Receptor (TLR)9 engagement by cell-free DNA (cfDNA) triggers inflammation, myometrial contractions, and labor in absence of infection. The current study evaluated whether direct (myometrial) or indirect (decidual) TLR9 engagement enhances human myometrial contractility.

METHOD OF STUDY

Toll-like receptor 9 expression and cellular localization were surveyed by immunohistochemistry of placenta, fetal membranes, and myometrium in term (gestational age [GA]: >37 weeks) labor (TL, n = 7) or term non-labor (TNL, n = 7) tissues. Non-pregnant myometrium (n = 4) served as reference. TLR9 mRNA expression relative to other TLRs was evaluated through the mining of an RNA-seq dataset and confirmed by RT-PCR. Immortalized human myometrial cells (hTERT-HM) were treated with incremental concentrations of TLR9 agonist ODN2395, TNF-α, or LPS. Secreted cytokines were quantified by multiplex immunoassay, and contractility was assessed by an in-gel cell contraction assay (n = 9). Induction of hTERT-HM contractility was also evaluated indirectly following exposure to conditioned media from primary term decidual cells (n = 4) previously stimulated with ODN2395.

RESULTS

Toll-like receptor 9 immunostaining in placenta and amniochorion was strongest in decidual cells, but unrelated to labor. TLR9 staining intensity was significantly decreased in TL compared with TNL myometrium (P = 0.002). Although total cfDNA in maternal circulation increased in TL (P = 0.025 vs TNL), difference in cffDNA was non-significant. Myometrial TLR9 mRNA levels were unaffected by contractile status and far less abundant than other pro-inflammatory TLRs. hTERT-HM contractility was enhanced by LPS (P = 0.002) and TNF-α (P = 0.003), but not by ODN2395 (P = 0.345) or supernatant of TLR9-stimulated decidual cells.

CONCLUSION

Myometrial and decidual TLR9 are unlikely to directly regulate human parturition.

Decreased LIN28B in preeclampsia impairs human trophoblast differentiation and migration

Preeclampsia (PE) is a common cause of maternal morbidity, characterized by impaired trophoblast invasion and spiral artery transformation resulting in progressive uteroplacental hypoxia. Given the primary role of LIN28A and LIN28B in modulating cell metabolism, differentiation, and invasion, we hypothesized that LIN28A and/or LIN28B regulates trophoblast differentiation and invasion, and that its dysregulation may contribute to PE. Here we show that LIN28B is expressed ∼1300-fold higher than LIN28A in human term placenta and is the predominant paralog expressed in primary human trophoblast cultures. The expression of LIN28B mRNA and protein levels are significantly reduced in gestational age-matched preeclamptic vs. normal placentas, whereas LIN28A expression is not different. First trimester human placental sections displayed stronger LIN28B immunoreactivity in extravillous (invasive) cytotrophoblasts and syncytial sprouts vs. villous trophoblasts. LIN28B overexpression increased HTR8 cell proliferation, migration, and invasion, whereas LIN28B knockdown in JEG3 cells reduced cell proliferation. Moreover, LIN28B knockdown in JEG3 cells suppressed syncytin 1 (SYN-1), apelin receptor early endogenous ligand (ELABELA), and the chromosome 19 microRNA cluster, and increased mRNA expression of ITGβ4 and TNF-α. Incubation of BeWo and JEG3 cells under hypoxia significantly decreased expression of LIN28B and LIN28A, SYN-1, and ELABELA, whereas TNF-α is increased. These results provide the first evidence that LIN28B is the predominant paralog in human placenta and that decreased LIN28B may play a role in PE by reducing trophoblast invasion and syncytialization, and by promoting inflammation.-Canfield, J., Arlier, S., Mong, E. F., Lockhart, J., VanWye, J., Guzeloglu-Kayisli, O., Schatz, F., Magness, R. R., Lockwood, C. J., Tsibris, J. C. M., Kayisli, U. A., Totary-Jain, H. Decreased LIN28B in preeclampsia impairs human trophoblast differentiation and migration.

A Role for the Inflammasome in Spontaneous Preterm Labor With Acute Histologic Chorioamnionitis

Inflammasomes are cytosolic multiprotein complexes that orchestrate inflammation in response to pathogens and endogenous danger signals. Herein, we determined whether the chorioamniotic membranes from women in spontaneous preterm labor with acute histologic chorioamnionitis (1) express major inflammasome components; (2) express caspase (CASP)-1 and CASP-4 as well as their active forms; (3) exhibit apoptosis-associated speck-like protein containing a CARD (ASC)/CASP-1 complex formation; and (4) release the mature forms of interleukin (IL)-1β and IL-18. We utilized quantitative reverse transcription polymerase chain reaction, enzyme-linked immunosorbent assay, immunoblotting, and immunohistochemistry to determine the messenger RNA (mRNA) and protein expression of major inflammasome components, nucleotide-binding oligomerization domain (NOD) proteins, and the pro- and mature/active forms of CASP-1, CASP-4, IL-1β, and IL-18. The ASC/CASP-1 complex formation was determined using an in situ proximity ligation assay. When comparing the chorioamniotic membranes from women in spontaneous preterm labor with acute histologic chorioamnionitis to those without this placental lesion, we found that (1) the mRNA of NLR family pyrin domain-containing protein ( NLRP) 1, NLRP3, NLR family CARD domain-containing protein 4 ( NLRC4), and NOD2 were higher; (2) the NLRP3 protein was increased; (3) the mRNA and active form (p10) of CASP-1 were greater; (4) the mRNA and active form of CASP-4 were increased; (5) the mRNA and mature form of IL-1β were higher; (6) the mature form of IL-18 was elevated; and (7) ASC/CASP-1 complex formation was increased. In conclusion, spontaneous preterm labor with acute histologic chorioamnionitis is characterized by an upregulation of NLRP3 and the active form of CASP-4, as well as increased ASC/CASP-1 complex formation, which may participate in the activation of CASP-1 and the maturation of IL-1β and IL-18 in the chorioamniotic membranes. These findings provide the first evidence that supports a role for the inflammasome in the pathological inflammation implicated in spontaneous preterm labor with acute histologic chorioamnionitis.

Matrix Metalloprotease-1 and Elastase Are Novel Uterotonic Agents Acting Through Protease-Activated Receptor 1

Matrix metalloproteinase-1 (MMP-1) and neutrophil elastase are proteolytic enzymes involved in tissue remodeling, but a role for them as uterotonic agents has not been considered. However, both these proteases activate protease-activated receptor 1 (PAR-1) that mediates thrombin-induced contractions. Matrix metalloproteinase-1 and elastase are products of neutrophils that infiltrate intrauterine tissues at the time of labor, so we tested the hypothesis that these proteases might be novel uterotonic agents acting via PAR-1. Decidual tissue was collected from fetal membranes of term not-in-labor (TNL), term labor (TL), and preterm labor (PTL) women and analyzed for gene and protein expression of MMP-1 and neutrophil elastase. Contractile effects of MMP-1 and elastase were tested with uterine strips of day 19 and 20 gestation rats. Expression of MMP-1 and neutrophil elastase was increased in TL and PTL as compared to TNL. Expression of both the pro- and active enzymes of MMP-1 increased progressively from TNL to TL to PTL. Tumor necrosis factor-α, a neutrophil product, increased MMP-1 in decidual and myometrial cells. Both MMP-1 and elastase stimulated strong contractions of myometrial strips, which were prevented by inhibition of PAR-1 and inhibition of inositol trisphosphate receptor or calcium channel blockade. Indomethacin did not prevent protease-induced contractions. These data suggest that MMP-1 and neutrophil elastase may be important but heretofore unrecognized players in stimulating uterine contractions at the time of labor, and they may explain why indomethacin delays, but does not prevent, PTL because indomethacin inhibits the prostaglandin component but not the protease component of labor.

A Role for the Inflammasome in Spontaneous Labor at Term with Acute Histologic Chorioamnionitis

Inflammasomes are cytosolic signaling platforms that regulate the activation of caspase (CASP)-1, which induces the maturation of interleukin (IL)-1β and IL-18. Herein, we determined whether the chorioamniotic membranes from women in spontaneous labor at term with acute histologic chorioamnionitis express major inflammasome components and whether these changes are associated with the activation of CASP-1 and CASP-4 and the release of mature IL-1β and IL-18. When comparing the chorioamniotic membranes from women in spontaneous labor at term with acute histologic chorioamnionitis to those without this placental lesion, we found that (1) the messenger RNA (mRNA) abundance of NLR family pyrin domain containing 3 ( NLRP3), NLR family CARD domain containing 4 ( NLRC4), absent in melanoma 2 ( AIM2), and nucleotide binding oligomerization domain 2 ( NOD2) was higher; (2) the NLRP3 and NLRC4 protein quantities were increased; (3) the mRNA and protein expressions of CASP-1 and its active forms were greater; (4) CASP-4 was increased at the mRNA level only; (5) the mRNA and protein expressions of IL-1β and its mature form were higher; and (6) a modest increase in the total protein concentration and abundance of the mature form of IL-18 was observed. In vitro incubation of the chorioamniotic membranes with the CASP-1 inhibitor, VX765, decreased the release of endotoxin-induced IL-1β and IL-18 (2-fold) but not IL-6 or tumor necrosis factor α. In conclusion, spontaneous labor at term with acute histologic chorioamnionitis is characterized by an upregulation of inflammasome components which, in turn, may participate in the activation of CASP-1 and lead to the release of mature IL-1β by the chorioamniotic membranes. These results support a role for the inflammasome in the mechanisms responsible for spontaneous labor at term with acute histologic chorioamnionitis.

Dynamics of Base Excision Repair at the Maternal-Fetal Interface in Pregnancies Complicated by Preeclampsia

Preeclampsia (PE) (gestational proteinuric hypertension) is the leading cause of maternal and perinatal mortality worldwide. Although placental endothelial dysfunction and oxidative stress are known to contribute to PE, the exact pathological basis for this disorder remains unclear. Previously, we demonstrated that DNA damage at the maternal-fetal interface is more common in the placentas of women with PE than normotensive controls. In this study, we utilized an in vivo comparative study, including 20 preeclamptic women and 8 healthy control subjects, and an in vitro hypoxia/reperfusion model to mimic the effects of oxidative stress at the maternal-fetal interface. We tracked the spatial pattern of expression of 2 base excision repair proteins, 8-oxoguanine glycosylase (OGG1) and apurinic/apyrimidinic endonuclease-1 (APE1), at the maternal-fetal interface in response to oxidative stress. In vivo, we found a significant increase in OGG1 and APE1 concentrations in PE placental tissues as compared to normotensive controls ( P < .0001). Further, our in vitro study revealed that OGG1 and APE1 expression is much greater in maternal cells (decidua) than in fetal cells (cytotrophoblasts) of placental tissue subjected to oxidative stress ( P < .0001). Our results suggest that OGG1 and APE1 likely protect decidual cells from oxidative base damage.

Activation of the IL-1β/CXCL1/MMP-10 axis in chorioamnionitis induced by inactivated Group B Streptococcus

Infection or inflammation during pregnancy is known to lead to maternal immune activation triggering a fetal inflammatory response syndrome associated with deleterious effects, such as brain injury and neurodevelopmental disabilities. Group B Streptococcus (GBS) - one of the most common bacterium colonizing pregnant women - can be responsible for chorioamnionitis. Given that interleukin (IL)-1β has a major role in anti-GBS host defense, we hypothesized that IL-1β-driven innate immune response is implicated in GBS-induced chorioamnionitis. Using a rat model of GBS-induced chorioamnionitis, this study showed that inflammatory response to this pathogen was associated with maternal and placental IL-1β hyper expression. Following placental chemokine (C-X-C motif) ligand 1 (CXCL1) production, polymorphonuclear leukocytes (PMN) placental infiltration started at 24 h post-GBS exposure, and MMP-10 was released within these placentas. At 72 h, PMN infiltration extended to membranes and to membranes' arteries. This was associated with IL-1β release within the fetus blood at 72 h. Such a GBS-associated inflammatory cascade might be deleterious for fetal organs. These results pave the way toward targeted placento-protective anti-inflammatory strategies against GBS-induced chorioamnionitis.

The role of decidual cells in uterine hemostasis, menstruation, inflammation, adverse pregnancy outcomes and abnormal uterine bleeding

BACKGROUND

Human pregnancy requires robust hemostasis to prevent hemorrhage during extravillous trophoblast (EVT) invasion of the decidualized endometrium, modification of spiral arteries and post-partum processes. However, decidual hemorrhage (abruption) can occur throughout pregnancy from poorly transformed spiral arteries, causing fetal death or spontaneous preterm birth (PTB), or it can promote the aberrant placentation observed in intrauterine growth restriction (IUGR) and pre-eclampsia; all leading causes of perinatal or maternal morbidity and mortality. In non-fertile cycles, the decidua undergoes controlled menstrual bleeding. Abnormal uterine bleeding (AUB) accompanying progestin-only, long-acting, reversible contraception (pLARC) accounts for most discontinuations of these safe and highly effective agents, thereby contributing to unwanted pregnancies and abortion. The aim of this study was to investigate the role of decidual cells in uterine hemostasis, menstruation, inflammation, adverse pregnancy outcomes and abnormal uterine bleeding.

METHODS

We conducted a critical review of the literature arising from PubMed searches up to December 2015, regarding in situ and in vitro expression and regulation of several specific proteins involved in uterine hemostasis in decidua and cycling endometrium. In addition, we discussed clinical and molecular mechanisms associated with pLARC-induced AUB and pregnancy complications with abruptions, chorioamnionitis or pre-eclampsia.

RESULTS

Progestin-induced decidualization of estradiol-primed human endometrial stromal cells (HESCs) increases in vivo and in vitro expression of tissue factor (TF) and type-1 plasminogen activator inhibitor (PAI-1) while inhibiting plasminogen activators (PAs), matrix metalloproteinases (MMPs), and the vasoconstrictor, endothelin-1 (ET-1). These changes in decidual cell-derived regulators of hemostasis, fibrinolysis, extracellular matrix (ECM) turnover, and vascular tone prevent hemorrhage during EVT invasion and vascular remodeling. In non-fertile cycles, progesterone withdrawal reduces TF and PAI-1 while increasing PA, MMPs and ET-1, causing menstrual-associated bleeding, fibrinolysis, ECM degradation and ischemia. First trimester decidual hemorrhage elicits later adverse outcomes including pregnancy loss, pre-eclampsia, abruption, IUGR and PTB. Decidual hemorrhage generates excess thrombin that binds to decidual cell-expressed protease-activated receptors (PARs) to induce chemokines promoting shallow placentation; such bleeding later in pregnancy generates thrombin to down-regulate decidual cell progesterone receptors and up-regulate cytokines and MMPs linked to PTB. Endometria of pLARC users display ischemia-induced excess vasculogenesis and progestin inhibition of spiral artery vascular smooth muscle cell proliferation and migration leading to dilated fragile vessels prone to bleeding. Moreover, aberrant TF-derived thrombin signaling also contributes to the pathogenesis of endometriosis via induction of angiogenesis, inflammation and cell survival.

CONCLUSION

Perivascular decidualized HESCs promote endometrial hemostasis during placentation yet facilitate menstruation through progestational regulation of hemostatic, proteolytic, and vasoactive proteins. Pathological endometrial hemorrhage elicits excess local thrombin generation, which contributes to pLARC associated AUB, endometriosis and adverse pregnancy outcomes through several biochemical mechanisms.

In vitro progesterone modulation on bacterial endotoxin-induced production of IL-1β, TNFα, IL-6, IL-8, IL-10, MIP-1α, and MMP-9 in pre-labor human term placenta

BACKGROUND

During human pregnancy, infection/inflammation represents an important factor that increases the risk of developing preterm labor. The purpose of this study was to determine if pre-treatment with progesterone has an immunomodulatory effect on human placenta production of endotoxin-induced inflammation and degradation of extracellular matrix markers.

METHODS

Placentas were obtained under sterile conditions from pregnancies delivered at term before the onset of labor by cesarean section. Explants from central cotyledons of 10 human placentas were pre-treated with different concentrations of progesterone (0.01, 01, 1.0 μM) and then stimulated with 1000 ng/mL of LPS of Escherichia coli. Cytokines TNFα, IL-1β, IL-6, IL-8, MIP-1α, IL-10 concentrations in the culture medium were then measured by specific ELISA. Secretion profile of MMP-9 was evaluated by ELISA and zymogram. Statistical differences were determined by one-way ANOVA followed by the appropriate ad hoc test; P < 0.05 was considered statistically significant.

RESULTS

In comparison to the explants incubated with vehicle, the LPS treatment led to a significant increase in the level of all cytokines. In comparison to the explants treated only with LPS, pre-treatment with 0.01-1.0 μM progesterone significantly blunted (73, 56, 56, 75, 25, 48 %) the secretion of TNF-α, IL-1β, IL-6, IL-8, MIP-1α, IL-10, respectively. The MMP-9 induced by LPS treatment was inhibited only with the highest concentration of progesterone. Mifepristone (RU486) blocked the immunosuppressive effect of progesterone.

CONCLUSIONS

The present results support the concept that progesterone could be part of the compensatory mechanism that limits the inflammation-induced cytotoxic effects associated with an infection process during gestation.

A toll-like receptor 9 (rs352140) variant is associated with placental inflammation in newborn infants

OBJECTIVE

Chorioamnionitis contributes to premature birth and associated postnatal morbidity. The genetic basis of altered immune responses underlying placental inflammation (PI) remains understudied. The aim of this study was to evaluate the relationship among TLR signaling pathway polymorphisms and different patterns of PI.

METHODS

Prospective cohort study in infants involving cord blood collection and placental examination for PI. One hundred and fifty-nine infants enrolled in study out of which 28 were term (eight with PI) and 131 preterm (47 with PI). DNA from blood was genotyped for SNPs in TLR2, 4, 5, 9, NFKBI, NFKBIA, TIRAP, and IRAK1 genes using multiplexed single base extension assay.

RESULTS

While there were no differences in BW, GA, gender, race, and SPL among infants with or without PI, there was a higher incidence of PPROM, maternal smoking, drug use, and clinical chorioamnionitis among infants with PI. Out of nine TLR variants, only CT and/or TT genotypes of the TLR9 variant (rs352140) were significantly associated (p = 0.004) with any PI and maternal pattern of inflammation (p = 0.012) both by univariate analysis and logistic regression.

CONCLUSIONS

The presence of a variant T allele in a common SNP (rs352140) in the TLR9 gene whose product recognizes bacterial DNA is associated with increased PI.

Mechanisms of chorioamnionitis-associated preterm birth: interleukin-1β inhibits progesterone receptor expression in decidual cells

In chorioamnionitis (CAM), a major cause of preterm birth (PTB), maternal-fetal inflammation of the decidua and amniochorion cause the release of cytokines that elicit cervical ripening, fetal membrane rupture and myometrial activation. We posit that this inflammatory milieu triggers PTB by inhibiting progesterone receptor (PR) expression and increasing decidual prostaglandin (PG) production. Immunohistochemical staining of decidua detected significantly lower PR levels in decidual cells (DCs) from CAM-complicated PTB. Incubation of DCs with IL-1β decreased PR expression and significantly increased PGE2 and PGF2α production and COX-2 expression. The addition of PGF2α to DC cultures also suppressed PR expression. However, the COX inhibitor, indomethacin, did not reverse IL-1β suppression of PR expression in DC cultures. Although IL-1β treatment activated the NF-KB, ERK1/2 and p38 MAPK signalling cascades in DCs, inhibition of ERK1/2 MAPK signalling alone was sufficient to completely reverse the suppression of PR levels by IL-1β. These findings suggest that CAM-associated PTB is induced at least in part by IL-1β-mediated functional progesterone withdrawal.

Enhanced Human Decidual Cell-Expressed FKBP51 May Promote Labor-Related Functional Progesterone Withdrawal

Sustained plasma progesterone (P4) levels suggest initiation of human term labor by functional P4 withdrawal, reflecting reduced progesterone receptor (PR) and/or glucocorticoid receptor (GR) expression or activity. The steroid-induced immunophilin cochaperone FKBP51 inhibits PR- and GR-mediated transcription, suggesting a labor-initiating role. Gestational age-matched decidual sections were immunostained for FKBP51 and decidual cell (DC) and interstitial trophoblast (IT) markers, vimentin and cytokeratin, respectively. Term DC cultures were incubated with vehicle (control), estradiol (E2) with or without medroxyprogesterone acetate, dexamethasone (Dex), or Organon 2058. FKBP51 histologic scoring was significantly higher in DC nuclei during labor versus prelabor decidua, whereas FKBP51 immunostaining was undetected in interstitial trophoblasts (P < 0.05). In term DC cultures, E2 + medroxyprogesterone acetate or E2 + Dex enhanced FKBP51 expression (P < 0.01), whereas E2 + Organon 2058 inhibited PR expression (P < 0.05), and E2 + Dex inhibited GR expression (P < 0.05). Unlike term DCs, FKBP51 was undetected in control or Dex-treated cultured third-trimester trophoblasts. Electrophoretic mobility shift assays revealed that FKPB51 overexpression or silencing in cultured DCs altered PR-DNA binding. Increased FKBP51 levels in term DCs during labor complement our prior in situ observations of significantly lower PR in labor versus prelabor DCs. In a milieu of sustained plasma P4 levels, these reciprocal changes will amplify functional P4 withdrawal in DCs via FKBP51-mediated PR resistance coupled with declining PR levels, whereas the lack of FKBP51 expression in interstitial trophoblasts suggests unopposed constitutive GR action.

IL-1β and TGF-β weaken the placental barrier through destruction of tight junctions: an in vivo and in vitro study

INTRODUCTION

Chorioamnionitis is a gestational pathological condition characterized by acute inflammation of the amniochorionic membranes and placentas leading to high concentrations of IL-1β, Il-6, Il-8 and TGF-β in the amniotic fluid. In normal conditions, the permeability of foeto-maternal barrier is due to the assembly and maintenance of different cellular junctional domains.

METHODS

In the present study, first we aimed to evaluate the protein expression (by immunohistochemistry and western blotting) and mRNA (by real time PCR) levels of the molecular components of tight junctions (Zonula occludens-1 and occludin), and of adherent junctions (VE-cadherin and β-catenin) in placentas from chorioamnionitis compared to that in normal pregnancies.

RESULTS

Western blotting results showed a significant down-regulation of occludin in placentas affected with chorioamnionitis. No differences were detected for the other proteins analysed. We evaluated whether occludin expression was regulated by IL-1β, IL-6, IL-8 and TGF-β by means of in vitro studies using HUVEC cultures and demonstrated a key role of IL-1β and TGF-β in the disappearance of occludin at cellular border.

CONCLUSIONS

We conclude by suggesting a pivotal role of these two cytokines in facilitating intra-placental infection via para-cellular way due to the disassembly of tight junctions at trophoblastic and endothelial cells in placental tissues.

In vivo and in vitro evidence for placental DNA damage in preeclampsia

Preeclampsia (PE) is an idiopathic multisystem disease affecting 5–7% of pregnant women. Placental oxidative stress is a characteristic feature of PE and occurs when the production of reactive oxygen species (ROS) within the placenta overwhelms the intrinsic anti-oxidant defenses. We hypothesize that excessive oxidative DNA damage at the fetal-maternal interface coupled with a defective DNA damage/repair response is causally related to PE. Here we demonstrate that γH2AX (a sensitive marker of DNA damage) is expressed in the maternal decidua but not trophoblast of normal placentas, and that expression is significantly higher in PE placental tissues in vivo. Using primary in vitro cultures of maternal decidual stromal cells (DSCs) and fetal cytotrophoblast cells (CTs), we show an increase in γH2AX foci in DSCs cultured with vs without H₂O₂ (70.6% vs 11.6%; P<0.0001) or under hypoxia-reperfusion vs normoxia (20- vs 3-fold; P = 0.01); no foci were seen in CTs. We further demonstrate that Base Excision Repair (BER) intermediates are significantly increased in DSCs (not CTs) under these same conditions. Our data show that DNA damage is significantly more common in PE placentas, and that this DNA damage is localized to the maternal and not fetal side of the placenta. CTs may be selectively resistant to DNA damage in an effort to protect the fetus.

Abruption-induced preterm delivery is associated with thrombin-mediated functional progesterone withdrawal in decidual cells

Plasma progesterone levels remain elevated throughout human pregnancy, suggesting that reduced reproductive-tract progesterone receptor (PR) initiates labor. Placental abruption and excess thrombin generation elicit preterm delivery (PTD). PR, glucocorticoid receptor (GR), and total and p-ERK1/2 in decidual cells (DCs) and interstitial trophoblasts (IT) were assessed via immunohistochemical staining in abruption-associated PTD versus gestational-age matched control placentas, and in cultured DCs incubated with estradiol (E2) ± medroxyprogesterone acetate (MPA) ± thrombin. Immunostaining for PR was lower in DC nuclei in abruption versus control decidua and was absent from ITs; GR was higher in IT than DCs, with no abruption-related changes in either cell type; p-ERK1/2 was higher in DCs in abruption than control decidua, with total ERK 1/2 unchanged. Immunoblotting of cultured DCs demonstrated strong E2, weak MPA, and intermediate E2+MPA mediated elevation of PR-A and PR-B levels, with constitutive GR expression. In cultured DCs, thrombin inhibited PR but not GR mRNA levels, reduced PR binding to DNA and [(3)H]progesterone binding to PR, and enhanced phosphorylated but not total ERK1/2 levels. Coincubation with a specific p-ERK1/2 inhibitor reversed thrombin-enhanced p-ERK1/2 and lowered PR levels. Thus, abruption-associated PTD is initiated by functional progesterone withdrawal, as indicated by significantly reduced DC nuclear expression of PR-A and PR-B. Functional withdrawal of progesterone results in increased p-ERK1/2, and is thus one pathway initiating abruption-associated PTD.

Preserved ex vivo inflammatory status in decidual cells from women with preterm labor and subclinical intrauterine infection

Objective

To compare the inflammatory response preserved ex vivo by decidual cells isolated from women who experienced preterm labor with and without subclinical intrauterine infection.

Methods

Fetal membranes were obtained after cesarean section from 35 women who delivered before 37 weeks of gestation following spontaneous preterm labor, with no clinical evidence of intrauterine infection. Decidua was microbiologically tested and cultured. Concentrations of anti-inflammatory cytokines (IL-2, IL-4, IL-10), pro-inflammatory cytokines (IL-6, IL-8, IL-1β and TNF-α), and matrix metalloproteinases (MMP-1, MMP-2, MMP-3, MMP-7, MMP-8, MMP-9) were measured in the supernatants using Bio-Plex, and prostaglandin E₂ (PGE₂) was measured by enzyme immunoassay.

Results

Subclinical infection was confirmed in 10 women (28.5%). Microorganisms isolated were Ureaplasma urealyticum (4), group B streptococci (3), Gardnerella vaginalis (1), and Escherichia coli (2). We found a significant increase of pro-inflammatory cytokines and a significant decrease of anti-inflammatory cytokines in supernatants from decidual cells obtained from women with preterm labor and subclinical intrauterine infection compared to women without infection. Secretion of MMP-1, MMP-8, MMP-9 and PGE₂ was significantly higher in infected women. Secretion of IL-8 by decidual cells from infected women persisted upon repeated in vitro culture passages.

Conclusions

Almost 30% of idiopathic preterm labor cases were associated with subclinical intrauterine infection, and decidual cells isolated from these cases preserved an ex vivo inflammatory status after in vivo bacterial exposure.

Innate immunity, decidual cells, and preeclampsia

Preeclampsia (PE) manifested by hypertension and proteinuria complicates 3% to 8% of pregnancies and is a leading cause of fetal-maternal morbidity and mortality worldwide. It may lead to intrauterine growth restriction, preterm delivery, and long-term sequelae in women and fetuses, and consequently cause socioeconomic burden to the affected families and society as a whole. Balanced immune responses are required for the maintenance of successful pregnancy. Although not a focus of most studies, decidual cells, the major resident cell type at the fetal-maternal interface, have been shown to modulate the local immune balance by interacting with other cell types, such as bone marrow derived-immune cells, endothelial cells, and invading extravillous trophoblasts. Accumulating evidence suggests that an imbalanced innate immunity, facilitated by decidual cells, plays an important role in the pathogenesis of PE. Thus, this review will discuss the role of innate immunity and the potential contribution of decidual cells in the pathogenesis of PE.

ATP-binding cassette transporter expression in human placenta as a function of pregnancy condition

Fetal drug exposure is determined by the type and concentration of placental transporters, and their regulation is central to the development of new treatments and delivery strategies for pregnant women and their fetuses. We tested the expression of several clinically important transporters in the human placenta associated with various pregnancy conditions (i.e., labor, preeclampsia, and preterm labor-inflammation). Placentas were obtained from five groups of women at the time of primary cesarean section: 1) term no labor; 2) term labor; 3) preterm no labor (delivered for severe preeclampsia); 4) preterm labor without inflammation (PTLNI); and 5) preterm labor with inflammation (PTLI). Samples were analyzed by Western blot and immunohistochemistry to identify changes in protein expression. Relative mRNA expression was determined by quantitative real-time polymerase chain reaction. A functional genomic approach was used to identify placental gene expression and elucidate molecular events that underlie the given condition. Placental expression of ATP-binding cassette transporters from women in labor and women with preeclampsia was unaltered. Multidrug resistance protein 1 (MDR1) and breast cancer resistance protein (BCRP) and mRNA expression increased in placentas of women with preterm labor with inflammation. Molecular pathways of genes up-regulated in PTLI samples included cytokine-cytokine receptor interactions and inflammatory response compared with those in the PTLNI group. The mRNA expression of MDR1 and BCRP was correlated with that of interleukin-8, which also increased significantly in PTLI samples. These data suggest that the transfer of drugs across the placenta may be altered in preterm pregnancy conditions associated with inflammation through changes in MDR1 and BCRP.

Intra-amniotic infection upregulates neutrophil gelatinase-associated lipocalin (NGAL) expression at the maternal-fetal interface at term: implications for infection-related preterm birth

OBJECTIVE

Neutrophil gelatinase-associated lipocalin (NGAL) is a ubiquitous lipocalin that serves as a critical component of innate immunity and a transport shuttle for numerous substances (retinoids, arachidonic acid, prostaglandins, fatty acids, steroids, iron, and MMPs). Despite the well-documented association between intra-amniotic infection/inflammation (IAI) and preterm birth, NGAL expression in the uterus has not previously been examined. This study investigates NGAL expression at the maternal-fetal interface in vivo and in vitro.

METHODS

Neutrophil gelatinase-associated lipocalin expression in term placenta with/without IAI was examined by immunohistochemistry. Trophoblast and decidual stromal cells were retrieved from elective cesarean, purified, and depleted of leukocytes. On days 1 (cytotrophoblast cells) and 4 (syncytiotrophoblast), cells were stimulated with/without interleukin 1β (IL-1β; 1 ng/mL), tumor necrosis factor α (TNF-α; 1 ng/mL), or lipopolysaccharide (LPS; 1 μg/mL). Neutrophil gelatinase-associated lipocalin messenger RNA (mRNA) and protein expression were measured by immunocytochemistry/Western blot and RT-qPCR, respectively.

RESULTS

Under basal conditions, NGAL is expressed in trophoblast, but not decidua. Trophoblast NGAL is significantly upregulated in tissues with evidence of IAI vs controls. NGAL expression was increased after stimulation with all 3 pro-inflammatory mediators in day 1 (cytotrophoblast) but not day 4 cells (syncytiotrophoblast). IL-1β and TNF-α (not LPS) upregulated NGAL gene expression in cytotrophoblast (not syncytiotrophoblast) cells.

CONCLUSIONS

Intra-amniotic infection/inflammation is associated with increased expression of NGAL in trophoblast tissues in vivo. IL-1β, TNF-α, and LPS stimulated NGAL in cytotrophoblast cells (not syncytiotrophoblast and decidua) in vitro. These data suggest that, in keeping with its role as a mediator of innate immunity, NGAL may have a central role to play in IAI-induced preterm birth.

Focal increases of fetal macrophages in placentas from pregnancies with histological chorioamnionitis: potential role of fibroblast monocyte chemotactic protein-1

PROBLEM

 Histopathological chorioamnionitis (HCA) is caused by microbial-driven infiltration of leukocytes to the maternal-fetal interface resulting in adverse neonatal outcomes in a subset of pregnancies. The role of placental villus macrophages (i.e. Hofbauer cells, HBCs) in the pathophysiology of HCA is unelucidated.

METHOD OF STUDY

 The number of HBCs in human term placental villi in HCA and control groups was compared using immunohistochemistry. Levels of monocyte chemotactic protein (MCP-1) expression were measured in primary cultures of syncytioytrophoblasts (SCTs) and fibroblasts (FIBs) treated with bacterial compounds [lipopolysaccharide (LPS) and peptidoglycan] and pro-inflammatory cytokines (TNF-α and IL-1β) using ELISA and quantitative real-time PCR.

RESULTS

 Immunohistochemistry revealed a focal increase in HBCs in HCA. Treatment of FIBs with LPS, IL-1β, and TNF-α significantly increased MCP-1 mRNA and protein expression. Conversely, MCP-1 mRNA and protein levels were virtually undetectable in treated and untreated SCTs.

CONCLUSION

 These results demonstrate cell-type-specific regulation of MCP-1 expression in human placenta. A model is presented in which bacterial products and inflammatory cytokines initiate a fibroblast-driven cytokine cascade resulting in recruitment of fetal monocytes to placenta which focally increases levels of HBCs in pregnancies complicated by HCA.

Regulation of interleukin-6 expression in human decidual cells and its potential role in chorioamnionitis

Chorioamnionitis frequently precedes both genital tract and placental inflammation and is both a primary cause of maternal morbidity and a major antecedent of preterm premature rupture of the membranes (PPROM) as well as preterm delivery (PTD). In most cases of chorioamnionitis, neutrophils dominate the decidua. In a subset of these cases, a predominance of monocytes is uniquely associated with both neonatal intraventricular hemorrhage and death. The multifunctional cytokine, interleukin-6, promotes local monocyte dominance via several mechanisms. In this study, immunostaining of placental sections revealed significantly higher interleukin-6 HSCOREs in decidual cells (DCs) but not in interstitial trophoblasts, in chorioamnionitis versus gestational age-matched control placentas (P < 0.05). In confluent leukocyte-free term DCs, secreted interleukin-6 levels in incubations with estradiol-17β were increased 2500-fold by IL-1β (P < 0.05). This up-regulation was inhibited by more than 50% in parallel incubations that included medroxyprogesterone acetate (n = 12, P < 0.05). Western blotting data confirmed these enzyme-linked immunosorbent assay results; quantitative RT-PCR findings demonstrated corresponding changes in interleukin-6 mRNA levels. Specific inhibitors of signaling for both nuclear factor-κB activation and p38-mitogen-activated protein kinase, but not for protein kinase C, significantly decreased IL-1β-enhanced interleukin-6 expression levels in cultured DCs. In conclusion, in situ and in vitro results indicate that significantly enhanced interleukin-6 expression levels in DCs during chorioamnionitis could be pivotal in skewing decidual monocyte differentiation to macrophages.

Human labor is associated with reduced decidual cell expression of progesterone, but not glucocorticoid, receptors

CONTEXT

Unchanging plasma progesterone (P4) levels suggest that human labor is initiated by reduced P4 receptor (PR) expression, which elicits functional P4 withdrawal. The glucocorticoid receptor (GR) is also implicated in this process.

OBJECTIVE

Our objective was to compare PR and GR staining in human decidual cells (DCs) and interstitial trophoblasts (ITs) of gestational age-matched pre- and postcontraction specimens and to evaluate steroid effects on PR and GR expression in human DC cultures.

INTERVENTIONS AND MAIN OUTCOME MEASURES

Decidua basalis and parietalis sections were immunostained for PR or GR and then for the cytoplasmic DC and IT markers vimentin and cytokeratin. Western blotting measured PR and GR levels in nuclear extracts of cultured leukocyte-free term DCs after incubation with estradiol-17beta (E2) with or without medroxyprogesterone acetate (MPA).

RESULTS

PR histological scores (HSCOREs) were significantly higher in DC nuclei from pre- vs. post-uterine-contraction decidua basalis and parietalis sections with PR immunostaining absent from ITs. In contrast, immunoreactive GR was localized in IT and DC nuclei. GR HSCORES were significantly higher in ITs than DCs but similar in pre- vs. post-uterine-contraction specimens. In term DC monolayers, PR-A and PR-B were enhanced by E2 and inhibited by MPA, whereas E2 plus MPA produced intermediate PR expression. The GR was constitutively expressed.

CONCLUSIONS

In post- vs. pre-uterine-contraction specimens, significantly lower HSCOREs in DC nuclei, but not IT, and unchanging GR levels in DCs and ITs suggest that functional P4 withdrawal may occur in DCs and is unlikely to involve the GR. Nuclear extracts from DC monolayer cultures express steroid-regulated PR-A and PR-B and constitutive GR.

Cord blood biomarkers of the fetal inflammatory response

OBJECTIVE

In current, neonatal practice, clinical signs of intrauterine infection (IUI) are often non-specific. From a large panel of immune biomarkers, we seek to identify cord blood markers that are most strongly associated with the fetal inflammatory response (FIR), a specific placental lesion associated with serious neonatal complications.

METHODS

We used multiplex immunoassay to measure 27 biomarkers, selected as part of an NIH-funded study of preterm birth, according to gestational age (GA) and extent of placental inflammation: involvement of chorion, amnion, decidua (maternal inflammatory response, MIR); extension to umbilical cord or chorionic plate (FIR). We used false-discovery rate (FDR < 5%, P < 0.001) to account for multiple comparisons.

RESULTS

Among 506 births (GA 23-42 weeks), IL-1 beta increased with FIR among preterm subgroups (P = 0.0001 for <32 weeks; P = 0.0009 for 33-36 weeks). IL-6 and IL-8 increased with FIR among preterm and full-term infants (P < 0.0001). P-trend for IL-6 and IL-8 with MIR versus FIR was <0.0001. Comparison with respect to clinical IUI yielded persistent elevation with FIR even when clinical signs were absent. The remaining 24 markers were not significantly associated.

CONCLUSION

We conclude that among 27 cord blood biomarkers, IL-1 beta, IL-6 and IL-8 are selectively associated with FIR. These markers may be clinically useful indicators of extensive IUI associated with poor neonatal outcome.

Progestin and thrombin regulate tissue factor expression in human term decidual cells

CONTEXT

Perivascular cell membrane-bound tissue factor (TF) initiates hemostasis via thrombin generation. The identity and potential regulation of TF-expressing cells at the human maternal-fetal interface that confers hemostatic protection during normal and preterm delivery is unclear.

OBJECTIVES

The objective of the study were to identify TF-expressing cells at the maternal-fetal interface in term and preterm decidual sections by immunohistochemistry and evaluate progestin, thrombin, TNF-alpha, and IL-1beta effects on TF expression by cultured human term decidual cells (DCs).

INTERVENTIONS AND MAIN OUTCOME MEASURES

Serial placental sections were immunostained for TF. Leukocyte-free term DC monolayers were incubated with 10(-8) M estradiol (E2) or E2 plus 10(-7) M medroxyprogestrone acetate (MPA) +/- thrombin or TNF-alpha or IL-1beta. ELISA and Western blotting assessed TF in cell lysates. Quantitative real-time RT-PCR measured TF mRNA levels.

RESULTS

Immunolocalized TF in DC membranes in preterm and term placental sections displayed higher Histologic Scores than villous mesenchymal cells (P < 0.05). TF was undetected in interstitial or extravillous trophoblasts. Compared with DCs incubated with E2, MPA and 2.5 U/ml thrombin each doubled TF levels (P < 0.05) and E2 + MPA + thrombin further doubled TF levels (P < 0.05), whereas TNF-alpha and IL-1beta were ineffective. Western blotting confirmed the ELISA results. Quantitative RT-PCR revealed corresponding changes in TF mRNA levels.

CONCLUSIONS

In human term placental sections, DC-expressed TF exceeds that of other cell types at the maternal-fetal interface and is localized at the cell membranes in which it can bind to factor VII and meet the hemostatic demands of labor and delivery via thrombin formation. Unlike the general concept that TF is constitutive in cells that highly express it, MPA and thrombin significantly enhanced TF expression in term DC monolayers.

Intra-amniotic infection upregulates decidual cell vascular endothelial growth factor (VEGF) and neuropilin-1 and -2 expression: implications for infection-related preterm birth

Intra-amniotic infection/inflammation (IAI) is a major cause of preterm birth, but the mechanisms responsible are not well understood. This study investigates the effects of IAI on vascular endothelial growth factor (VEGF) as well as VEGF receptor (Flt1, KDR2) and coreceptor (neuropilin-1 and -2) messenger RNA (mRNA) and protein expression at the maternal-fetal interface, both in vitro and in vivo. Decidual stromal cells (DSCs) were isolated from term placentae, purified, and treated with 10(-8) mol/L estradiol (E(2)), 10( -7) mol/L medroxyprogesterone acetate (MPA), both, or vehicle for 7 days. Vascular endothelial growth factor expression in cultured DSCs increased in response to stimulation with interleukin 1 beta (IL-1 beta; 0.01-10 ng/mL)--but not tumor necrosis factor alpha (TNF-alpha; 1 ng/mL)--in a concentration-dependent fashion irrespective of the hormonal milieu. This effect appears to be mediated at the level of gene transcription because stimulation with IL-1 beta (but not TNF-alpha) increased expression of VEGF mRNA as measured by real-time quantitative reverse transcriptase-polymerase chain reaction (RT-qPCR); a similar increase was seen in neuropilin-1/-2 (but not Flt1 and KDR2) mRNA. Immunohistochemical studies confirmed these observations in vivo. Immunostaining for VEGF and neuropilin-1/-2 (but not Flt1 or KDR2) was increased in serial tissue sections of decidua from women with clinical and histological evidence of IAI versus noninfected controls, and in cultured term DSCs exposed to IL-1 beta. The novel observations that IL-1 beta stimulates VEGF and neuropilin-1/-2 mRNA and protein expression in term DSCs in vitro along with confirmatory in vivo data using immunohistochemistry provide a mechanism by which IAI can alter vascular permeability, thereby facilitating leukocyte trafficking and increasing the risk of abruption, both of which are associated with preterm birth.

Mechanisms of leukocyte accumulation and activation in chorioamnionitis: interleukin 1 beta and tumor necrosis factor alpha enhance colony stimulating factor 2 expression in term decidua

Chorioamnionitis is a major cause of prematurity as well as perinatal morbidity and mortality. The present study observed a marked increase in immunohistochemical staining for Colony Stimulating Factor 2 (CSF2; also known as granulocyte macrophage-colony stimulating factor), a potent neutrophil and macrophage chemoattractant and activator, in the decidua of patients with CAM compared with controls (n = 8; P = .001). To examine the regulation of this CSF2, cultured decidual cells primed with estradiol (E2) or E2 plus medroxyprogesterone acetate, were exposed to tumor necrosis factor-alpha or interleukin-1beta and secreted CSF2 measured by ELISA. Levels of CSF2 in E2 plus MPA-treated cultures increased 18- and 245-fold following treatment with TNF or IL1B (n = 7, P < .05). Quantitative RT-PCR demonstrated parallel changes in mRNA levels. This study reveals that CSF2 is strongly expressed in decidua from patients with CAM and indicates TNF or IL1B as important regulators of CAM-related decidual leukocyte infiltration and activation.

Inducible nitric oxide synthase (iNOS) gene polymorphism in pre-eclampsia: a pilot study in North India

BACKGROUND

Pre-eclampsia is one of the most frequent complications of pregnancy, however, little is known about its aetiology.

AIMS

The objective of this study was to investigate the association between inducible nitric oxide synthase (iNOS) genotypes and pre-eclampsia. We also measured the concentrations of tumour necrosis factor-alpha (TNF-alpha), nitric oxide (NO) and superoxide dismutase (SOD) in patients with pre-eclampsia to evaluate their relations to the single nucleotide polymorphisms (SNPs) observed.

METHODS

This cross-sectional study included 30 pregnant women with pre-eclampsia and 30 healthy pregnant women. They were screened at 28th, 36th weeks of gestation and just after delivery (within 48 h), and their blood samples were analysed for NO, SOD, TNF-alpha and iNOS gene polymorphism.

RESULTS

Patients with pre-eclampsia at 36 weeks gestation showed significantly increased serum NO levels (P=0.007), whereas SOD activity was decreased significantly (P=0.004). A doublefold increase was observed in TNF-alpha levels at 36 weeks in patients with pre-eclampsia (P=0.003) which decreased significantly (P=0.001) after delivery. A total of four SNPs were observed, of which two (G300A exon 8 and G274T exon 16) showed statistically significant association with pre-eclampsia. When compared, G274T exon 16 SNP also showed association with TNF-alpha levels and SOD activity in pre-eclamptic patients.

CONCLUSION

As pre-eclampsia is a disease of multifactorial aetiopathology, NO, TNF-alpha, SOD activity and NOS2A polymorphism might play an intermingled role in its development.