Localization of nuclear factor-kappa B (NF kappa B) and inhibitory factor-kappa B (I kappa B) in human fetal membranes and decidua at term and preterm delivery

Dysregulation of multiple signaling pathways: A possible cause of cerebral palsy

Cerebral palsy (CP) is a lifelong disability characterized by the impairment of brain functions that result in improper posture and abnormal motor patterns. Understanding this brain abnormality and the role of genetic, epigenetic, and non-genetic factors such as signaling pathway dysregulation and cytokine dysregulation in the pathogenesis of CP is a complex process. Hypoxic-ischemic injury and prematurity are two well-known contributors of CP. Like in the case of other neurodevelopmental disorders such as intellectual disability and autism, the genomic constituents in CP are highly complex. The neuroinflammation that is triggered by maternal cytokine response plays a critical role in the pathogenesis of fetal inflammation response, which is one of the contributing factors of CP, and it continues even after the birth of children suffering from CP. Canonical Wnt signaling pathway is important for the development of mammalian fetal brain and it regulates distinct processes including neurogenesis. The glycogen synthase kinase-3 (GSK-3) antagonistic activity in the Wnt signaling pathway plays a crucial role in neurogenesis and neural development. In this review, we investigated several genetic and non-genetic pathways that are involved in the pathogenesis of CP and their regulation, impairment, and implications for causing CP during embryonic growth and developmental period. Investigating the role of these pathways help to develop novel therapeutic interventions and biomarkers for early diagnosis and treatment. This review also helps us to comprehend the mechanical approach of various signaling pathways, as well as their consequences and relevance in the understanding of CP.

Functional changes in decidual mesenchymal stem/stromal cells are associated with spontaneous onset of labour

Ageing and parturition share common pathways, but their relationship remains poorly understood. Decidual cells undergo ageing as parturition approaches term, and these age-related changes may trigger labour. Mesenchymal stem/stromal cells (MSCs) are the predominant stem cell type in the decidua. Stem cell exhaustion is a hallmark of ageing, and thus ageing of decidual MSCs (DMSCs) may contribute to the functional changes in decidual tissue required for term spontaneous labour. Here, we determine whether DMSCs from patients undergoing spontaneous onset of labour (SOL-DMSCs) show evidence of ageing-related functional changes compared with those from patients not in labour (NIL-DMSCs), undergoing Caesarean section. Placentae were collected from term (37-40 weeks of gestation), SOL (n = 18) and NIL (n = 17) healthy patients. DMSCs were isolated from the decidua basalis that remained attached to the placenta after delivery. DMSCs displayed stem cell-like properties and were of maternal origin. Important cell properties and lipid profiles were assessed and compared between SOL- and NIL-DMSCs. SOL-DMSCs showed reduced proliferation and increased lipid peroxidation, migration, necrosis, mitochondrial apoptosis, IL-6 production and p38 MAPK levels compared with NIL-DMSCs (P < 0.05). SOL- and NIL-DMSCs also showed significant differences in lipid profiles in various phospholipids (phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, phosphatidylserine), sphingolipids (ceramide, sphingomyelin), triglycerides and acyl carnitine (P < 0.05). Overall, SOL-DMSCs had altered lipid profiles compared with NIL-DMSCs. In conclusion, SOL-DMSCs showed evidence of ageing-related reduced functionality, accumulation of cellular damage and changes in lipid profiles compared with NIL-DMSCs. These changes may be associated with term spontaneous labour.

Single cell transcriptional signatures of the human placenta in term and preterm parturition

More than 135 million births occur each year; yet, the molecular underpinnings of human parturition in gestational tissues, and in particular the placenta, are still poorly understood. The placenta is a complex heterogeneous organ including cells of both maternal and fetal origin, and insults that disrupt the maternal-fetal dialogue could result in adverse pregnancy outcomes such as preterm birth. There is limited knowledge of the cell type composition and transcriptional activity of the placenta and its compartments during physiologic and pathologic parturition. To fill this knowledge gap, we used scRNA-seq to profile the placental villous tree, basal plate, and chorioamniotic membranes of women with or without labor at term and those with preterm labor. Significant differences in cell type composition and transcriptional profiles were found among placental compartments and across study groups. For the first time, two cell types were identified: 1) lymphatic endothelial decidual cells in the chorioamniotic membranes, and 2) non-proliferative interstitial cytotrophoblasts in the placental villi. Maternal macrophages from the chorioamniotic membranes displayed the largest differences in gene expression (e.g. NFKB1) in both processes of labor; yet, specific gene expression changes were also detected in preterm labor. Importantly, several placental scRNA-seq transcriptional signatures were modulated with advancing gestation in the maternal circulation, and specific immune cell type signatures were increased with labor at term (NK-cell and activated T-cell signatures) and with preterm labor (macrophage, monocyte, and activated T-cell signatures). Herein, we provide a catalogue of cell types and transcriptional profiles in the human placenta, shedding light on the molecular underpinnings and non-invasive prediction of the physiologic and pathologic parturition.

Birth and Neonatal Transition in the Guinea Pig: Experimental Approaches to Prevent Preterm Birth and Protect the Premature Fetus

The guinea pig (Cavia porcellus) displays many features of gestational physiology that makes it the most translationally relevant rodent species. Progesterone production undergoes a luteal to placental shift as in human pregnancy with levels rising during gestation and with labor and delivery occurring without a precipitous decline in maternal progesterone levels. In contrast to other laboratory rodents, labor in guinea pigs is triggered by a functional progesterone withdrawal, which involves the loss of uterine sensitivity to progesterone like in women. In both species the amnion membrane is a major source of labor-inducing prostaglandins, which promote functional progesterone withdrawal by modifying myometrial progesterone receptor expression. These similar features appear to result from convergent evolution rather than closer evolutionally relationship to primates compared to other rodents. Nevertheless, the similarities in the production, metabolism and actions of progesterone and prostaglandins allow information gained in pregnant guinea pigs to be extended to pregnant women with confidence. This includes exploring the effects of pregnancy complications including growth restriction and the mechanisms by which stressful conditions increase the incidence of preterm labor. The relatively long gestation of the guinea pig and the maturity of the pups at birth particularly in brain development means that a greater proportion of brain development happens in utero. This allows adverse intrauterine conditions to make a sustained impact on the developing brain like in compromised human pregnancies. In addition, the brain is exposed to a protective neurosteroid environment in utero, which has been suggested to promote development in the guinea pig and the human. Moreover, in utero stresses that have been shown to adversely affect long term neurobehavioral outcomes in clinical studies, can be modeled successfully in guinea pigs. Overall, these parallels to the human have led to increasing interest in the guinea pig for translational studies of treatments and therapies that potentially improve outcomes following adverse events in pregnancy and after preterm birth.

Role of vitamin D in pregnancy and Toll-like receptor pathway

There is a growing concern about the impacts of hypovitaminosis D on the health of pregnant woman, fetal development, childhood, and adult life. Variations in maternal nutrition during gestation and/or lactation play a critical role in the physiological and metabolic development of the fetus and neonate, which can induce phenotypic changes and trigger important consequences throughout life, such as type 2 diabetes, cardiovascular disease, obesity, and hypertension. Vitamin D plays a role in regulating cell proliferation and differentiation and in modulating the innate and adaptive immune response. Also, vitamin D correlates with changes in cytokines, anti and proinflammatory, as well as prevents inflammation induced by changes in myometrial cells mediated by the nuclear factor kappa B pathway. Further investigation is required regarding these relationship.

Finding NEMO in preeclampsia

BACKGROUND

The mechanism of preeclampsia and its way of inheritance are still a mystery. Biochemical and immunochemical studies reveal a substantial increase in tumor necrosis factor alpha, interleukin-1 beta, and interleukin-6 concentrations in the blood of women with preeclampsia. The level of these factors is regulated by nuclear facxtor-kappa B, whose activation in a classical pathway requires inhibitory kappa B kinase gamma (known as NEMO or IKBKG). Moreover, NEMO can schedule between cytoplasma and the nucleus. In the nucleus, IKBKG interacts with other proteins, and thus, it is implicated in the regulation of different gene expressions, which are related to cell cycle progression, proliferation, differentiation, and apoptosis.

OBJECTIVE

This is the first study investigating the association between the level of NEMO gene expression and the presence of preeclampsia. We tested the hypothesis that the simultaneous increase in NEMO gene expression both in the mother and her fetus may be responsible for the preeclampsia development. Moreover, the relationships between clinical risk factors of preeclampsia and the levels of NEMO gene expression in blood, umbilical cord blood, and placentas were investigated.

STUDY DESIGN

A total of 91 women (43 preeclamptic women and 48 controls) and their children were examined. Real-time reverse transcription-polymerase chain reaction was used to assess the amount total NEMO messenger ribonucleic acid (mRNA) content and the mRNA level of each NEMO transcript from exons 1A, 1B, and 1C in maternal blood, umbilical cord blood, and placentas. Univariate analyses and correlation tests were performed to examine the association between NEMO gene expression and preeclampsia.

RESULTS

Newborn weight and height, maternal platelet number, and gestational age (week of delivery) were lower in the group of women with preeclampsia than controls. NEMO gene expression level was found to be almost 7 times higher in the group of women with preeclampsia than healthy controls. The correlation analysis found that a simultaneous increase in the expression level of total NEMO mRNA in maternal blood and the mRNA for total NEMO (Rs = 0.311, P < .05), transcripts 1A (Rs = 0.463, P < .01), 1B (Rs = 0.454, P < .01), and 1C (Rs = 0.563, P < .001) in fetal blood was observed in preeclamptic pregnancies. In addition, the mRNA levels for total NEMO and transcripts 1A, 1B, and 1C were lower in placentas derived from pregnancies complicated by preeclampsia.

CONCLUSION

Simultaneous increase of NEMO gene expression in maternal and fetal blood seems to be relevant for preeclampsia development. The results of our study also suggest that a decreased NEMO gene expression level in preeclamptic placentas may be the main reason for their intensified apoptosis.

Vitamin D regulates contractile profile in human uterine myometrial cells via NF-κB pathway

OBJECTIVE

Infection triggers inflammation that, in turn, enhances the expression of contractile-associated factors in myometrium and increases the risk of preterm delivery. In this study, we assessed vitamin D regulation of inflammatory markers, contractile-associated factors, steroid hormone receptors, and NFκB pathway proteins in human uterine myometrial smooth muscle (UtSM) cells that were cultured in an inflammatory environment.

STUDY DESIGN

Inflammatory environment was simulated for UtSM cells by coculturing them with monocyte lineage (THP1) cells. We measured the expression of inflammatory markers, contractile-associated factors, steroid hormone receptors, and NFκB pathway proteins in UtSM cells that were cultured with THP1 cells in the presence and absence of vitamin D by real time polymerase chain reaction and Western blot analysis.

RESULTS

Monocytes secreted monocyte inflammatory protein-1α and -1β, interleukin (IL)-1β and 6, and tumor necrosis factor-α into the conditioned medium. In the UtSM cells that had been cocultured with THP1 cells, there was a significant (P < .05) increase in the expression of inflammatory markers IL-1β, -6, and -13 and tumor necrosis factor-α; the contractile-associated factors connexin-43, Cox-2, and prostaglandin F2α receptor; the estrogen receptor α, and progesterone receptors A and B. Vitamin D treatment of cocultures decreased (P < .05) the expression of inflammatory markers and contractile-associated factors in UtSM cells. Similarly, vitamin D decreased estrogen receptor α and progesterone receptors A-to-B ratio in UtSM cells that were cocultured with THP1 cells. In addition, vitamin D treatment significantly (P < .05) decreased monocyte-induced p-IκBα in cytosol and NFκB-p65 in the nucleus and increased IκBα in cytosol in UtSM cells.

CONCLUSION

Our results suggest that vitamin D treatment decreases inflammation-induced cytokines and contractile-associated factors in the uterine myometrial smooth muscle cells through the NFκB pathway.

Regulation of GTP-binding protein (Gαs) expression in human myometrial cells: a role for tumor necrosis factor in modulating Gαs promoter acetylation by transcriptional complexes

The onset of parturition is associated with a number of proinflammatory mediators that are themselves regulated by the nuclear factor κB (NF-κB) family of transcription factors. In this context, we previously reported that the RelA NF-κB subunit represses transcription and mRNA expression of the proquiescent Gαs gene in human myometrial cells following stimulation with the proinflammatory cytokine TNF. In the present study, we initially defined the functional consequence of this on myometrial contractility. Here we show that, contrary to our initial expectations, TNF did not induce myometrial contractility but did inhibit the relaxation produced by the histone deacetylase inhibitor trichostatin A, an effect that in turn was abolished by the NF-κB inhibitor N(4)-[2-(4-phenoxyphenyl)ethyl]-4,6-quinazolinediamine. This result suggested a role for TNF in regulating Gαs expression via activating NF-κB and modifying histone acetylation associated with the promoter region of the gene. In this context, we show that the -837 to -618 region of the endogenous Gαs promoter is occupied by cAMP-response element-binding protein (CREB), Egr-1, and Sp1 transcription factors and that CREB-binding protein (CBP) transcriptional complexes form within this region where they induce histone acetylation, resulting in increased Gαs expression. TNF, acting via NF-κB, did not change the levels of CREB, Sp1, or Egr-1 binding to the Gαs promoter, but it induced a significant reduction in the level of CBP. This was associated with increased levels of histone deacetylase-1 and surprisingly an increase in H4K8 acetylation. The latter is discussed herein.

Mice deficient in surfactant protein A (SP-A) and SP-D or in TLR2 manifest delayed parturition and decreased expression of inflammatory and contractile genes

Previously we obtained compelling evidence that the fetus provides a critical signal for the initiation of term labor through developmental induction of surfactant protein (SP)-A expression by the fetal lung and secretion into amniotic fluid (AF). We proposed that interactions of AF macrophage (Mϕ) Toll-like receptors (TLRs) with SP-A, at term, or bacterial components, at preterm, result in their activation and migration to the pregnant uterus. Herein the timing of labor in wild-type (WT) C57BL/6 mice was compared with mice homozygous null for TLR2, SP-A, SP-D, or doubly deficient in SP-A and SP-D. Interestingly, TLR2(-/-) females manifested a significant (P < 0.001) delay in timing of labor compared with WT as well as reduced expression of the myometrial contraction-associated protein (CAP) gene, connexin-43, and Mϕ marker, F4/80, at 18.5 d postcoitum (dpc). Whereas in first pregnancies, SP-A(-/-), SP-D(-/-), and SP-A/D(-/-) females delivered at term (∼19.5 dpc), in second pregnancies, parturition was delayed by approximately 12 h in SP-A(-/-) (P = 0.07) and in SP-A/D(-/-) (P <0.001) females. Myometrium of SP-A/D(-/-) females expressed significantly lower levels of IL-1β, IL-6, and CAP genes, connexin-43, and oxytocin receptor at 18.5 dpc compared with WT. F4/80(+) AF Mϕs from TLR2(-/-) and SP-A/D(-/-) mice expressed significantly lower levels of both proinflammatory and antiinflammatory activation markers (e.g. IL-1β, IL-6, ARG1, YM1) compared with gestation-matched WT AF Mϕs. These novel findings suggest that the pulmonary collectins acting via TLR2 serve a modulatory role in the timing of labor; their relative impact may be dependent on parity.

Functional screening of TLRs in human amniotic epithelial cells

Intrauterine infection is a major cause of spontaneous preterm birth. Amniotic epithelial cells represent the first line of defense against intra-amniotic bacteria. We hypothesize that this epithelial cell barrier is able to recognize and respond to pathogens through the function of TLRs, which are crucial regulators of the innate immune system. In this study, we describe the expression of transcripts for TLR1-TLR10 in human amniotic epithelial cells. We show that amniotic epithelial cells express functional TLR5, TLR6/2, and TLR4. Activation by TLR5 and TLR6/2 agonists produces IL-6 and IL-8, concomitantly with the activation of NF-κB signaling pathway, matrix metalloproteinase-9 induction, and PTGS2 expression. In contrast, TLR4 activation reduced amniotic epithelial cell viability and induced cell apoptosis evidenced by an elevated Bax/Bcl-2 ratio and cleavage of caspase-3. These data suggest specific TLR-mediated functions in human amniotic epithelial cells for initiating different immune responses, which ultimately may lead to preterm birth.

Inflammatory gene regulatory networks in amnion cells following cytokine stimulation: translational systems approach to modeling human parturition

A majority of the studies examining the molecular regulation of human labor have been conducted using single gene approaches. While the technology to produce multi-dimensional datasets is readily available, the means for facile analysis of such data are limited. The objective of this study was to develop a systems approach to infer regulatory mechanisms governing global gene expression in cytokine-challenged cells in vitro, and to apply these methods to predict gene regulatory networks (GRNs) in intrauterine tissues during term parturition. To this end, microarray analysis was applied to human amnion mesenchymal cells (AMCs) stimulated with interleukin-1β, and differentially expressed transcripts were subjected to hierarchical clustering, temporal expression profiling, and motif enrichment analysis, from which a GRN was constructed. These methods were then applied to fetal membrane specimens collected in the absence or presence of spontaneous term labor. Analysis of cytokine-responsive genes in AMCs revealed a sterile immune response signature, with promoters enriched in response elements for several inflammation-associated transcription factors. In comparison to the fetal membrane dataset, there were 34 genes commonly upregulated, many of which were part of an acute inflammation gene expression signature. Binding motifs for nuclear factor-κB were prominent in the gene interaction and regulatory networks for both datasets; however, we found little evidence to support the utilization of pathogen-associated molecular pattern (PAMP) signaling. The tissue specimens were also enriched for transcripts governed by hypoxia-inducible factor. The approach presented here provides an uncomplicated means to infer global relationships among gene clusters involved in cellular responses to labor-associated signals.

Pharmacological inhibition of inflammatory pathways for the prevention of preterm birth

The major cause of spontaneous preterm birth (sPTB) at less than 32 weeks of gestation is intrauterine inflammation as a consequence of colonisation of the gestational membranes by pathogenic microorganisms which trigger activation of the local innate immune system. This results in release of inflammatory mediators, leukocytosis (chorioamnionitis), apoptosis, membrane rupture, cervical ripening and onset of uterine contractions. Recent PCR evidence suggests that in the majority of cases of inflammation-driven preterm birth, microorganisms are present in the amniotic fluid, but these are not always cultured by standard techniques. The nature of the organism and its cell wall constituents, residence time in utero, microbial load, route of infection and extent of tissue penetration are all factors which can modulate the timing and magnitude of the inflammatory response and likelihood of progression to sPTB. Administration of anti-inflammatory drugs could be a viable therapeutic option to prevent sPTB and improve fetal outcomes in women at risk of intrauterine inflammation. Preventing fetal inflammation via administration of placenta-permeable drugs could also have significant perinatal benefits in addition to those related to extension of gestational age, as a fetal inflammatory response is associated with a range of significant morbidities. A number of potential drugs are available, effective against different aspects of the inflammatory process, although the pathways actually activated in spontaneous preterm labour have yet to be confirmed. Several pharmacological candidates are discussed, together with clinical and toxicological considerations associated with administration of anti-inflammatory agents in pregnancy.

Nuclear factor-kappa B localization and function within intrauterine tissues from term and preterm labor and cultured fetal membranes

BACKGROUND

The objective of this study was to quantify the nuclear localization and DNA binding activity of p65, the major transactivating nuclear factor-kappa B (NF-kappaB) subunit, in full-thickness fetal membranes (FM) and myometrium in the absence or presence of term or preterm labor.

METHODS

Paired full-thickness FM and myometrial samples were collected from women in the following cohorts: preterm no labor (PNL, N = 22), spontaneous preterm labor (PTL, N = 21), term no labor (TNL, N = 23), and spontaneous term labor (STL, N = 21). NF-kappaB p65 localization was assessed by immunohistochemistry, and DNA binding activity was evaluated using an enzyme-linked immunosorbent assay (ELISA)-based method.

RESULTS

Nuclear p65 labeling was rare in amnion and chorion, irrespective of clinical context. In decidua, nuclear p65 labeling was greater in the STL group relative to the TNL cohort, but there were no differences among the TNL, PTL, and PNL cohorts. In myometrium, diffuse p65 nuclear labeling was significantly associated with both term and preterm labor. There were no significant differences in ELISA-based p65 binding activity in amnion, choriodecidual, and myometrial specimens in the absence or presence of term labor. However, parallel experiments using cultured term fetal membranes demonstrated high levels of p65-like binding even the absence of cytokine stimulation, suggesting that this assay may be of limited value when applied to tissue specimens.

CONCLUSIONS

These results suggest that the decidua is an important site of NF-kappaB regulation in fetal membranes, and that mechanisms other than cytoplasmic sequestration may limit NF-kappaB activation prior to term.

Alteration of secretory leukocyte protease inhibitor in human myometrium during labor

OBJECTIVE

Secretory leukocyte protease inhibitor (SLPI) has been shown to have antimicrobial and antiinflammatory properties. The aim of this study was to verify its expression in human myometrium.

STUDY DESIGN

Myometrium was obtained at time of cesarean delivery with (n = 9) or without (n = 11) labor. Expression of SLPI was detected using real-time polymerase chain reaction, enzyme-linked immunosorbent assay, and immunohistochemistry. SLPI expression relative to nuclear factor-kappaB p65 subunit was compared between subjects. SLPI response to inflammatory mediators was studied in myometrial explants.

RESULTS

SLPI was predominantly localized in the nuclei of myocytes and colocalized with CD68(+) macrophages. The nuclear immunoreactivity of SLPI was increased after the onset of labor and was associated with increased nuclear translocation of nuclear factor-kappaB p65 subunit. Treatment with lipopolysaccharide, interleukin-1beta, or tumor necrosis factor-alpha increased SLPI messenger RNA and protein concentrations slightly in myometrium explants.

CONCLUSION

SLPI was expressed in human myometrium and increased after the onset of labor.

Aberrant gene expression patterns in placentomes are associated with phenotypically normal and abnormal cattle cloned by somatic cell nuclear transfer

Transcription profiling of placentomes derived from somatic cell nuclear transfer (SCNT, n = 20), in vitro fertilization (IVF, n = 9), and artificial insemination (AI, n = 9) at or near term development was performed to better understand why SCNT and IVF often result in placental defects, hydrops, and large offspring syndrome (LOS). Multivariate analysis of variance was used to distinguish the effects of SCNT, IVF, and AI on gene expression, taking into account the effects of parturition (term or preterm), sex of fetus, breed of dam, breed of fetus, and pathological finding in the offspring (hydrops, normal, or other abnormalities). Differential expression of 20 physiologically important genes was confirmed with quantitative PCR. The largest effect on placentome gene expression was attributable to whether placentas were collected at term or preterm (i.e., whether the collection was because of disease or to obtain stage-matched controls) followed by placentome source (AI, IVF, or SCNT). Gene expression in SCNT placentomes was dramatically different from AI ( n = 336 genes; 276 >2-fold) and from IVF ( n = 733 genes; 162 >2-fold) placentomes. Functional analysis of differentially expressed genes (DEG) showed that IVF has significant effects on genes associated with cellular metabolism. In contrast, DEG associated with SCNT are involved in multiple pathways, including cell cycle, cell death, and gene expression. Many DEG were shared between the gene lists for IVF and SCNT comparisons, suggesting that common pathways are affected by the embryo culture methods used for IVF and SCNT. However, the many unique gene functions and pathways affected by SCNT suggest that cloned fetuses may be starved and accumulating toxic wastes due to placental insufficiency caused by reprogramming errors. Many of these genes are candidates for hydrops and LOS.

Nuclear factor-kappa B regulates inducible prostaglandin E synthase expression in human amnion mesenchymal cells

The human amnion is a major intrauterine source of prostaglandin (PG) E(2), a potent mediator of uterine contractions and cervical ripening. During parturition, inflammatory cytokines promote PGE(2) production through increased prostaglandin-endoperoxide synthase-2 (PTGS2, also known as cyclooxygenase-2) expression. This is mediated, in part, through activation of the transcription factor nuclear factor kappa B (NFkappaB). Prostaglandin E synthase (PTGES, also known as microsomal PGE synthase-1) acts downstream of PTGS2 and is inducibly expressed in most systems. We hypothesized that NFkappaB might regulate cytokine-induced PTGES expression in amnion cells. With amnion mesenchymal cells, we found that proinflammatory cytokines coordinately upregulated PTGS2 and PTGES mRNA expression. In parallel, increased expression of the PTGS2 and PTGES proteins was observed. In comparison, the expression of two other PGE synthases (PTGES2 and PTGES3) was unmodified. PTGES induction was blocked both in the presence of pharmacological NFkappaB inhibitors and following adenovirus-mediated overexpression of a dominant-negative NFkappaB pathway protein. In cells transiently transfected with a luciferase reporter bearing a portion (-597/+33) of the human PTGES gene promoter, interleukin-1beta (IL1B) produced a moderate increase in luciferase activity; this effect was abrogated in the presence of an indirect NFkappaB inhibitor (MG-132). Finally, a kappaB-like regulatory element was identified that, when mutated, markedly attenuated IL1B-responsive PTGES promoter activity. In conclusion, our results support a role for NFkappaB in cytokine-induced PTGES expression in amnion mesenchymal cells in vitro. By coordinately regulating PTGS2 and PTGES, NFkappaB may contribute to an inducible PGE(2) biosynthesis pathway during human parturition.

Changes of nuclear factor kappa B (NF-κB), cyclooxygenase-2 (COX-2) and matrix metalloproteinase-9 (MMP-9) in human myometrium before and during term labor

OBJECTIVE

To investigate the changes of nuclear factor kappa B (NF-kappaB), cyclooxygenase-2 (COX-2) and matrix metalloproteinase-9 (MMP-9) in human term myometrium before and during term labor.

STUDY DESIGN

Myometrium was obtained from women undergoing cesarean delivery at term before (n=16) and after labor (n=12). Immunostaining of NF-kappaB subunits (p65/p50) and Western blot analysis of NF-kappaB subunits, MMP-9 and COX-2 proteins were compared. Human term myocyte cultures were stimulated with IL-1beta. Activation of NF-kappaB was assessed by evaluating changes in the inhibitory protein IkappaB; regulation of COX-2 and MMP-9 levels was studied using Western blot analysis and gelatin zymography.

RESULTS

In contrast to a significant increase in the level of COX-2 and MMP-9 proteins, p65 and p50 decreased significantly in the after-labor group compared to the before-labor group. After treatment with IL-1beta, IkappaB was degraded by almost 90% within 5 min and became undetectable by 15 min. IL-1beta stimulation increased the levels of COX-2 protein and the gelatinolytic activities of MMP-9, both of which were inhibited by NF-kappaB inhibitors.

CONCLUSIONS

Human term labor is associated with changes in NF-kappaB and increased expression of COX-2 and MMP-9 in the myometrium. NF-kappaB pathway activation and subsequent increments of COX-2 and MMP-9 were observed in human term myocyte cultures.

Pre-B-cell Colony-enhancing Factor (PBEF/Visfatin) Gene Expression is Modulated by NF-κB and AP-1 in Human Amniotic Epithelial Cells

A localized intrauterine inflammatory response is often associated with the initiation of normal human parturition, whereas infection causes a similar but more florid response initiating preterm labor. Pre-B-cell colony-enhancing factor (PBEF) is expressed in the human fetal membranes and is up-regulated by labor, severe infection and inflammatory stimuli. The aim of this study was to determine the involvement of the transcription factors NF-kappaB and AP-1 in the response of PBEF to an inflammatory stimulus and compare it with IL-8. The results showed that this treatment of amniotic epithelial-like cells (WISH) and primary amniotic epithelial cells increased expression of PBEF and IL-8, but IL-8 responded 100-fold more than PBEF. IL-1beta treatment together with a panel of NF-kappaB and AP-1 inhibitors demonstrated the involvement of these transcription factors in the up-regulation of PBEF. These data show that an inflammatory stimulus in the fetal membranes inducing NF-kappaB and AP-1 would up-regulate PBEF as well as IL-8.

The preterm parturition syndrome

The implicit paradigm that has governed the study and clinical management of preterm labour is that term and preterm parturition are the same processes, except for the gestational age at which they occur. Indeed, both share a common pathway composed of uterine contractility, cervical dilatation and activation of the membranes/decidua. This review explores the concept that while term labour results from physiological activation of the components of the common pathway, preterm labour arises from pathological signalling and activation of one or more components of the common pathway of parturition. The term "great obstetrical syndromes" has been coined to reframe the concept of obstetrical disease. Such syndromes are characterised by: (1) multiple aetiology; (2) long preclinical stage; (3) frequent fetal involvement; (4) clinical manifestations that are often adaptive in nature; and (5) gene-environment interactions that may predispose to the syndromes. This article reviews the evidence indicating that the pathological processes implicated in the preterm parturition syndrome include: (1) intrauterine infection/inflammation; (2) uterine ischaemia; (3) uterine overdistension; (4) abnormal allograft reaction; (5) allergy; (6) cervical insufficiency; and (7) hormonal disorders (progesterone related and corticotrophin-releasing factor related). The implications of this conceptual framework for the prevention, diagnosis, and treatment of preterm labour are discussed.

The role and regulation of the nuclear factor kappa B signalling pathway in human labour

Within the discipline of reproductive biology, our understanding of one of the most fundamental biological processes is lacking--the cellular and molecular mechanisms that govern birth. This lack of understanding limits our ability to reduce the incidence of labour complications. The incidence of labour complications including: preterm labour; cervical incompetence; and post-date pregnancies has not diminished in decades. The key to improving the management of human labour and delivery is an understanding of how the multiple processes that are requisite for a successful labour and delivery are coordinated to achieve a timely birth. Processes of human labour include the formation of: contraction associated proteins; inflammatory mediators (e.g. cytokines); uterotonic phospholipid metabolites (e.g. prostaglandins); and the induction of extracellular matrix (ECM) remodelling. Increasingly, it is becoming evident that labour onset and birth are the result of cross-talk between multiple components of an integrated network. This hypothesis is supported by recent data implicating various upstream regulatory pathways in the control of key labour-associated processes, including the activity of enzymes involved in the formation of prostaglandins and extracellular matrix remodelling, and mediators of inflammation. Clearly, the biochemical pathways involved in the formation of these mediators represent potential sites for intervention that may translate to therapeutic interventions to delay or prevent preterm labour and delivery. Available data strongly implicate the nuclear factor-kappaB (NF-kappaB) family as candidate upstream regulators of multiple labour-associated processes. Not only do these data warrant further detailed analysis of the involvement of these pathways in the process of human labour but also promise new insights into the key mechanisms that trigger birth and the identification of new therapeutic interventions that will improve the management of labour.

Lipopolysaccharide and TNF-α Activate the Nuclear Factor Kappa B Pathway in the Human Placental JEG-3 Cells

Up-regulation of pro-inflammatory cytokines, cyclooxygenase (COX-2) and prostaglandins is a critical factor driving human term labour and inflammation-associated preterm labour. Nuclear factor kappa B (NF-kappaB) is activated in response to a number of inflammatory mediators, including cytokines and lipopolysaccharide (LPS). The aim of this study was (i) to investigate if TNF-alpha and LPS activate the NF-kappaB pathway; and (ii) to use short interfering RNA (siRNA) against inhibitor kappaB kinase (IKK)-beta to confirm the role of the NF-kappaB pathway in the regulation of pro-inflammatory mediators in human placental JEG-3 cells. JEG-3 cells (3 independent experiments) were (i) incubated in the presence or absence of 10 microg/ml LPS or 20 ng/ml TNF-alpha, or (ii) transfected with 100 nM IKK-beta siRNA. Incubation of JEG-3 cells with LPS and TNF-alpha increased the expression of cytoplasmic IKK-beta and phosphorylated IkappaB-alpha, and nuclear NF-kappaB proteins p50 and p65. This was associated with a concurrent increase in COX-2 protein, and IL-6 and PGF2alpha release from JEG-3 cells. Treatment of cells with BAY 11-7082 at 50 microM significantly inhibited basal, LPS- and TNF-alpha-induced NF-kappaB and COX-2 expression, and IL-6 and PGF2alpha release. Transfection of JEG-3 cells with IKK-beta siRNA significantly decreased IL-6 and PGF2alpha release. The data presented in this study demonstrate that pro-inflammatory mediators regulate the NF-kappaB transcription pathway in human JEG-3 cells, and the IKK-beta/NF-kappaB pathway is a regulator of inflammatory mediators in placental JEG-3 cells.

Dexamethasone Fails to Inhibit the Induction of Cytosolic Phospholipase A2 Expression by Interleukin-1β in Cultured Primary Human Amnion Fibroblasts

OBJECTIVE

To investigate the interaction of dexamethasone and interleukin-1beta (IL-1beta) on the expression of cytosolic phospholipase A(2) (cPLA(2)), the enzyme catalyzing the first reaction in the formation of prostaglandins, in cultured primary human amnion fibroblasts.

DESIGN AND METHODS

Human amnion fibroblasts were prepared from fetal amnion collected at term and were treated with dexamethasone with or without interleukin-1beta for 24h. Prostaglandin E(2) (PGE(2)) output and cPLA(2) expression in cultured amnion fibroblasts were measured with radioimmunoassay, quantitative real-time polymerase chain reaction, Western blotting and cPLA(2) promoter-driven luciferase reporter gene activity.

RESULTS

Both dexamethasone and IL-1beta caused a significant increase in prostaglandin E(2) output, cPLA(2) mRNA and protein expression in cultured human amnion fibroblasts. Both dexamethasone and IL-1beta stimulated cPLA(2) promoter-driven luciferase reporter gene activity. There was no obvious antagonistic or synergistic effect of combined treatment of dexamethasone and IL-1beta on PGE(2) output, cPLA(2) expression or cPLA(2) promoter-driven luciferase reporter gene activity in cultured human amnion fibroblasts.

CONCLUSION

The above findings suggest that paradoxically dexamethasone is a stimulator for both prostaglandin synthesis and cPLA(2) expression in human amnion fibroblasts. The interaction between dexamethasone and IL-1beta on prostaglandin synthesis and cPLA(2) expression is neither synergistic nor conventionally antagonistic.

Activation of nuclear factor-kappaB and its proinflammatory mediator cascade in the infarcted rat heart

Nuclear transcription factor (NF)-kappaB regulates inflammatory and immune responses by increasing the expression of specific inflammatory genes in various tissues. Whether the infarcted heart includes the activation of NF-kappaB and a proinflammatory mediator cascade that it regulates has not been fully explored. Herein, we monitored the temporal and spatial activation of NF-kappaB, together with expression of tumor necrosis factor (TNF)-alpha, vascular cell adhesion molecule-1 (VCAM-1), and transforming growth factor (TGF)-beta(1), in the infarcted rat heart at and remote to MI from day 3 to day 28 following left coronary artery ligation. Compared to the normal heart, we observed NF-kappaB activation, together with the elevated expression of VCAM-1 in endothelial cells, TNF-alpha and TGF-beta(1) in inflammatory cells at sites of repair in the infarcted heart, which started on day 3, peaked on day 7, and gradually declined thereafter. Our findings suggest NF-kappaB activation and its proinflammatory mediator cascade are contributory to the inflammatory response and remodeling that appear at various sites of repair in the infarcted rat heart.

Transcriptional regulation of genes for enzymes of the prostaglandin biosynthetic pathway

Numerous studies over the years have demonstrated changes in prostaglandin (PG) levels in intrauterine tissues in association with labour, and PG administration has long been used to induce delivery. While it is now widely accepted that PGs play a major role in human parturition, the complex regulation of their levels is still being elucidated, with the focus on the transcriptional control of the enzymes responsible for the various steps in PG biosynthesis and catabolism.

Cytokines, prostaglandins and parturition--a review

The elaboration of cytokines, chemokines and immunomodulatory proteins in the placenta and gestational membranes has been extensively investigated in the context of both normal and abnormal pregnancy and delivery. Patterns of expression of cytokines in the foetal membranes and decidua suggest that inflammatory activation occurs modestly with term labour, but much more robustly in preterm delivery, particularly in the presence of intrauterine infection. Enhanced chemokine expression, particularly evident in deliveries with an infected amniotic cavity, is presumably responsible for recruiting infiltrating leukocytes into the membranes thereby amplifying the inflammatory process and hastening membrane rupture and delivery. Anti-inflammatory cytokines suppress inflammatory reactions in the placenta, but under some circumstances may act in a pro-inflammatory fashion in the membranes. Intracellular signalling by cytokines is modulated by proteins such as SOCS (Silencer Of Cytokine Signalling)-1, -2 and -3. Changes in the abundance of these proteins occur with term labour, implicating them as modulators of cytokine actions around the time of parturition. Prostaglandins, released by the membranes in response to stretch and the actions of pro-inflammatory cytokines, act not only upon the myometrium and cervix, but may also exert paracrine/autocrine effects on cell viability and matrix protein integrity. The localization and regulation of prostanoid isomerases, responsible for converting PGH(2) (derived from prostaglandin H synthase-1 and -2) to bioactive prostanoids, are being studied in these tissues, particularly in the context of cytokine interactions. Although the gestational tissues are known to be sources of PGD(2), PGJ(2) and its derivatives, the regulation of production of these prostaglandins has yet to be studied in any detail and their actions, which may include apoptosis and suppression of inflammation, remain poorly defined. A more complete understanding of these aspects of cytokine-prostaglandin interactions in pregnancy and parturition will, no doubt, unfold as current studies come to fruition.