Effects of inflammatory cytokines on prostaglandin E(2) production from human amnion cells cultured in serum-free condition

Brucella melitensis Rev1Δwzm: Placental pathogenesis studies and safety in pregnant ewes

One of the main causes of human brucellosis is Brucella melitensis infecting small ruminants. To date, Rev1 is the only vaccine successfully used to control ovine and caprine brucellosis. However, it is pathogenic for pregnant animals, resulting in abortions and vaginal and milk shedding, as well as being infectious for humans. Therefore, there is an urgent need to develop an effective vaccine that is safer than Rev1. In efforts to further attenuate Rev1, we recently used wzm inactivation to generate a rough mutant (Rev1Δwzm) that retains a complete antigenic O-polysaccharide in the bacterial cytoplasm. The aim of the present study was to evaluate the placental pathogenicity of Rev1Δwzm in trophoblastic cells, throughout pregnancy in mice, and in ewes inoculated in different trimesters of pregnancy. This mutant was evaluated in comparison with the homologous 16MΔwzm derived from a virulent strain of B. melitensis and the naturally rough sheep pathogen B. ovis. Our results show that both wzm mutants triggered reduced cytotoxic, pro-apoptotic, and pro-inflammatory signaling in Bewo trophoblasts, as well as reduced relative expression of apoptosis genes. In mice, both wzm mutants produced infection but were rapidly cleared from the placenta, in which only Rev1Δwzm induced a low relative expression of pro-apoptotic and pro-inflammatory genes. In the 66 inoculated ewes, Rev1Δwzm was safe and immunogenic, displaying a transient serological interference in standard RBT but not CFT S-LPS tests; this serological response was minimized by conjunctival administration. In conclusion, these results support that B. melitensis Rev1Δwzm is a promising vaccine candidate for use in pregnant ewes and its efficacy against B. melitensis and B. ovis infections in sheep warrants further study.

A Nested Case-Control Study of the Relationship between Salivary Inflammatory Mediators, Periodontal Parameters, and Preterm Birth in a Chinese Population

Background. To explore whether salivary inflammatory mediators and periodontal indices at different gestational stages can be taken as indicators of preterm birth (PTB). Methods. This nested case-control study enrolled systemically healthy pregnant women at 9 to 36 weeks of gestation. Periodontal indices were measured at the enrollment date, and interleukin-1β (IL-1β), IL-6, tumor necrosis factor (TNF-α), prostaglandin E2 (PGE2), and 8-hydroxy-deoxyguanosine (8-OHdG) in the saliva were determined by enzyme-linked immunosorbent assay (ELISA). The birth outcome was recorded. Results. PTB occurred in 26 women. A total of 104 matched women with full-term birth (FTB) were used as controls. The PTB women enrolled at 24-28 gestational weeks displayed a significantly greater bleeding index (BI), probing pocket depth (PD), $\text{PD}\ge 4\text{mm}$ sites (%), saliva-TNF-α, and saliva-PGE2 ( $P<0.05$ ). BI and PGE2 in the saliva were found to be positively associated with PTB ( $\text{OR}=4.79,P=0.048,95\%\text{CI}=1.014\text{to}22.628;\text{OR}=1.07,P=0.04,95\%\text{CI}=1.004\text{to}1.135$ , respectively). The areas under the receiver operating characteristic curve (ROC) of BI and saliva-PGE2 were 0.82 and 0.78, respectively, and that of the combined detection was 0.91, which was larger than either marker alone, although the differences were not significant ( $P>0.05$ ). Conclusions. The combination of BI and PGE2 in saliva at 24-28 gestational weeks could be a predictor of PTB in asymptomatic women. However, the results should be further explored with larger sample size.

Combined spinal-epidural anesthesia with acupoint injection for labor anesthesia reduces IL-1β/IL-10 ratio in maternal peripheral blood, umbilical cord blood and improves the labor outcomes: A prospective randomized controlled trial

BACKGROUND

This study aimed to investigate the effects of combined spinal-epidural anesthesia (CSEA) with acupoint injection (AI) on the maternal-fetal expression of interleukin-1β (IL-1β), interleukin-10 (IL-10), analgesia effect, and labor outcomes.

METHODS

A total of 360 healthy primiparas were randomized into the CSEA+AI group, the CSEA group, the AI group, and the control group (n = 90, each group) according to the labor analgesia methods.

RESULTS

Compared to the CSEA group, the CSEA+AI group had significantly lower visual analog scale (VAS) scores, adverse events, dose of ropivacaine/sufentanil, and shorter labor durations. The IL-1β/IL-10 ratio in maternal peripheral blood and umbilical cord blood was reduced in the CSEA+AI group compared with the CSEA group.

CONCLUSION

The combination of CSEA and AI can reduce the ratio of IL-1β/ IL-10 in maternal peripheral blood and umbilical cord blood, which can effectively relieve labor pain.

The Potential of Metabolomic Analyses as Predictive Biomarkers of Preterm Delivery: A Systematic Review

SCOPE

as the leading cause of perinatal mortality and morbidity worldwide, the impact of premature delivery is undisputable. Thus far, non-invasive, cost-efficient and accurate biochemical markers to predict preterm delivery are scarce. The aim of this systematic review is to investigate the potential of non-invasive metabolomic biomarkers for the prediction of preterm delivery.

METHODS AND RESULTS

Databases were systematically searched from March 2019 up to May 2020 resulting in 4062 articles, of which 45 were retrieved for full-text assessment. The resulting metabolites used for further analyses, such as ferritin, prostaglandin and different vitamins were obtained from different human anatomical compartments or sources (vaginal fluid, serum, urine and umbilical cord) and compared between groups of women with preterm and term delivery. None of the reported metabolites showed uniform results, however, a combination of metabolomics biomarkers may have potential to predict preterm delivery and need to be evaluated in future studies.

Obstructions in Nanoparticles Conveyance, Nano-Drug Retention, and EPR Effect in Cancer Therapies

In this chapter, the authors first review nano-devices that are mixtures of biologic molecules and synthetic polymers like nano-shells and nano-particles for the most encouraging applications for different cancer therapies. Nano-sized medications additionally spill especially into tumor tissue through penetrable tumor vessels and are then held in the tumor bed because of diminished lymphatic drainage. This procedure is known as the enhanced penetrability and retention (EPR) impact. Nonetheless, while the EPR impact is generally held to improve conveyance of nano-medications to tumors, it in certainty offers not exactly a 2-overlay increment in nano-drug conveyance contrasted with basic ordinary organs, bringing about medication concentration that is not adequate for restoring most malignant growths. In this chapter, the authors likewise review different obstructions for nano-sized medication conveyance and to make the conveyance of nano-sized medications to tumors progressively successful by expanding on the EPR impact..

Exploiting the dynamics of the EPR effect and strategies to improve the therapeutic effects of nanomedicines by using EPR effect enhancers

The enhanced permeability and retention (EPR) effect is a unique phenomenon of solid tumors that is related to their particular anatomical and pathophysiological characteristics, e.g. defective vascular architecture; large gaps between endothelial cells in blood vessels; abundant vascular mediators such as bradykinin, nitric oxide, carbon monoxide, and vascular endothelial growth factor; and impaired lymphatic recovery. These features lead to tumor tissues showing considerable extravasation of plasma components and nanomedicines. These data comprise the basic theory underlying the development of macromolecular agents or nanomedicines. The EPR effect is not necessarily valid for all solid tumors, because tumor blood flow and vascular permeability vary greatly. Tumor blood flow is frequently obstructed as tumor size increases, as often seen clinically; early stage, small tumors show a more uniform EPR effect, whereas advanced large tumor show heterogeneity in EPR effect. Accordingly, it would be very important to apply enhancers of EPR effect in clinical setting to make EPR effect more uniform. In this review, we discuss the EPR effect: its history, factors involved, and dynamics and heterogeneity. Strategies to overcome the EPR effect's heterogeneity may guarantee better therapeutic outcomes of drug delivery to advanced cancers.

Role of NF-κB/GATA3 in the inhibition of lysyl oxidase by IL-1β in human amnion fibroblasts

Preterm premature rupture of membranes (pPROMs) account for one-third of preterm births, a leading cause of neonatal death. Understanding the mechanism of membrane rupture is thus of clinical significance in the prevention of preterm birth. Parturition at both term and preterm is associated with increased abundance of proinflammatory cytokines in the fetal membranes regardless of the presence of infection, which is believed to induce rupture of membranes through activation of the matrix metalloproteinases. It remains unknown whether there are any alternative mechanisms underpinning proinflammatory cytokine-induced rupture of membranes. Here we showed that there were reciprocal increases in interleukin-1β (IL-1β) and decreases in lysyl oxidase (LOX), a collagen crosslinking enzyme, in the human amnion tissue following spontaneous rupture of membrane at term and pPROM. Studies using human amnion tissue explants revealed that IL-1β inhibited the expression of LOX, which can be reproduced in cultured human amnion fibroblasts. Mechanistic study revealed that IL-1β inhibited LOX expression through activation of p38 and Erk1/2 mitogen-activated protein kinase pathways, which resulted in the phosphorylation of the nuclear factor kappa light-chain enhancer of activated B (NF-κB) cell subunit p65 as well as GATA binding protein 3 (GATA3). Subsequently, activated NF-κB interacted with GATA3 at the NF-κB binding site of LOX promoter to inhibit its expression. Conclusively, this study has revealed an alternative mechanism that IL-1β may contribute to the rupture of membranes by attenuating collagen crosslinking through downregulation of LOX expression in amnion fibroblasts.

Nanodrug Delivery: Is the Enhanced Permeability and Retention Effect Sufficient for Curing Cancer?

Nanotechnology offers several attractive design features that have prompted its exploration for cancer diagnosis and treatment. Nanosized drugs have a large loading capacity, the ability to protect the payload from degradation, a large surface on which to conjugate targeting ligands, and controlled or sustained release. Nanosized drugs also leak preferentially into tumor tissue through permeable tumor vessels and are then retained in the tumor bed due to reduced lymphatic drainage. This process is known as the enhanced permeability and retention (EPR) effect. However, while the EPR effect is widely held to improve delivery of nanodrugs to tumors, it in fact offers less than a 2-fold increase in nanodrug delivery compared with critical normal organs, resulting in drug concentrations that are not sufficient for curing most cancers. In this Review, we first overview various barriers for nanosized drug delivery with an emphasis on the capillary wall's resistance, the main obstacle to delivering drugs. Then, we discuss current regulatory issues facing nanomedicine. Finally, we discuss how to make the delivery of nanosized drugs to tumors more effective by building on the EPR effect.

Inhibition of lysyl oxidase by prostaglandin E2 via EP2/EP4 receptors in human amnion fibroblasts: Implications for parturition

The underlying mechanism leading to rupture of the membranes at parturition is not fully understood. Lysyl oxidase (LOX) cross-links collagen fibrils thereby increasing the tensile strength of the membranes. Thus, understanding the regulation of LOX expression may be of crucial importance for elucidation of the process of rupture of the fetal membranes. Prostaglandin E2 (PGE2), mainly produced in the amnion, plays crucial roles during human parturition. However it is not known whether PGE2 regulates LOX expression in the fetal membranes. Using primary human amnion fibroblasts, we showed that addition of PGE2 decreased LOX mRNA and protein levels, which were blocked by inhibition of EP2/EP4 receptors and the receptor-coupled cAMP/PKA pathway. EP2/EP4 receptor agonists and stimulators of the cAMP/PKA pathway consistently decreased LOX expression. Furthermore, PGE2 induced cyclo-oxygenase-2 (COX-2) expression, a key enzyme in PGE2 production, via an EP2 and EP4 receptor-coupled cAMP/PKA pathway. Small interfering RNA-mediated knock-down of COX-2 expression significantly increased the basal expression of LOX. In addition, an increase in COX-2 and a reciprocal decrease in LOX abundance occurred in amnion tissue following labor at term. In conclusion, we have revealed a feed-forward loop of induction of COX-2 and reduction in LOX expression by PGE2 acting via an EP2/EP4 receptor-coupled cAMP/PKA pathway in human amnion fibroblasts toward the end of gestation, which may play a significant role in the rupture of fetal membranes.

Amniotic fluid prostaglandin E2 in pregnancies complicated by preterm prelabor rupture of the membranes

OBJECTIVE

To determine amniotic fluid prostaglandin E2 concentrations in women preterm prelabor rupture of the membranes (PPROM) with respect to microbial invasion of the amniotic cavity (MIAC), intraamniotic inflammation (IAI), microbial-associated IAI, histological chorioamnionitis, and short-term neonatal morbidity.

METHODS

One hundred forty-five women with singleton pregnancies were included in this study. Amniotic fluid samples were obtained by transabdominal amniocentesis and were assayed for prostaglandin E2 concentrations by ELISA. IAI was defined as amniotic fluid interleukin-6 >745 pg/mL. Microbial-associated IAI was defined as the presence of both MIAC and IAI.

RESULT

No differences in prostaglandin E2 concentrations were found between women with and without MIAC (p = 0.27). Women with IAI (p = 0.0008) and microbial-associated IAI (p = 0.01) had higher prostaglandin E2 concentrations than women without these complications. Women with histological chorioamnionitis had higher prostaglandin E2 concentrations only in crude analysis (p = 0.02), but not after adjustment for gestational age at sampling (p = 0.10). No associations between amniotic fluid prostaglandin E2 concentrations and the selected conditions of severe neonatal morbidity were found.

CONCLUSIONS

The intraamniotic inflammatory response either to infectious or to non-infectious stimulus, but not MIAC per se, seems to be a main factor associated with the elevation of the amniotic fluid PGE2 concentrations in women with PPROM.

Umbilical cord prostaglandins in term and preterm parturition

OBJECTIVE

Prostaglandins (PGs) are considered the universal mediators of parturition. Amniotic fluid PGE2 and PGF2α concentrations increase before the onset of spontaneous labor at term, as well as during labor. This study was conducted to determine if the concentrations of umbilical cord PGE2 and PGF2α change with advancing gestational age, spontaneous labor at term, and preterm labor (with and without funisitis).

METHODS

Umbilical cord (UC) tissue samples were obtained from women (N = 158) with singleton pregnancies in the following groups: (1) term deliveries without labor (TNL; n = 20); (2) term deliveries with labor (TIL; n = 20); (3) spontaneous preterm deliveries (sPTD) with (n = 20) and without acute funisitis (n = 20); and (4) preeclampsia without labor (n = 78). The concentrations of PGs were determined in different locations of the UC. PGE2 and PGF2α were measured by specific immunoassays. Non-parametric statistics were used for analysis.

RESULTS

(1) In spontaneous preterm deliveries, the median UC PGE2 concentration was higher in cases with funisitis than in those without funisitis (233.7 pg/µg versus 87.4 pg/µg of total protein, p = 0.001); (2) the median UC PGE2 concentration in sPTD with funisitis was also higher than that obtained from samples who had undergone labor at term (233.7 pg/µg versus 116.1 pg/µg of total protein, p = 0.03); (3) the UC PGE2 and PGF2α concentration increased as a function of advancing gestational age before 36 weeks (PGE2: ρ = 0.59, p < 0.001; PGF2α: ρ = 0.39, p = 0.01), but not after 36 weeks (PGE2: ρ = -0.1, p = 0.5; PGF2α: ρ = -0.2, p = 0.2); (4) the median UC concentrations of PGE2 and PGF2α at term was similar in samples obtained from women with and without labor (PGE2: TNL 133.7 pg/µg versus TIL 116.1 pg/µg of total protein, p = 0.9; PGF2α: TNL 8.4 pg/µg versus TIL 8.1 pg/µg of total protein, p = 0.7); and (5) there was no correlation between UC PG concentration and gestational age at term pregnancy (PGE2: ρ = 0.01, p = 0.9; PGF2α: ρ = 0.07, p = 0.7).

CONCLUSIONS

(1) PGE2 concentrations in the UC are higher in the presence of acute funisitis than in the absence of this lesion; (2) spontaneous labor at term was not associated with a change in the UC concentration of PGE2 and PGF2α; and (3) the UC concentrations of PGE2 and PGF2α increased as a function of gestational age. We propose that UC PGs act as inflammatory mediators generated in the context of fetal systemic inflammation.

Effect of prostaglandin E2 on multidrug resistance transporters in human placental cells

Prostaglandin (PG) E2, a major product of cyclooxygenase (COX)-2, acts as an immunomodulator at the maternal-fetal interface during pregnancy. It exerts biologic function through interaction with E-prostanoid (EP) receptors localized to the placenta. The activation of the COX-2/PGE2/EP signal pathway can alter the expression of the ATP-binding cassette (ABC) transporters, multidrug resistance protein 1 [P-glycoprotein (Pgp); gene: ABCB1], and breast cancer resistance protein (BCRP; gene: ABCG2), which function to extrude drugs and xenobiotics from cells. In the placenta, PGE2-mediated changes in ABC transporter expression could impact fetal drug exposure. Furthermore, understanding the signaling cascades involved could lead to strategies for the control of Pgp and BCRP expression levels. We sought to determine the impact of PGE2 signaling mechanisms on Pgp and BCRP in human placental cells. The treatment of placental cells with PGE2 up-regulated BCRP expression and resulted in decreased cellular accumulation of the fluorescent substrate Hoechst 33342. Inhibiting the EP1 and EP3 receptors with specific antagonists attenuated the increase in BCRP. EP receptor signaling results in activation of transcription factors, which can affect BCRP expression. Although PGE2 decreased nuclear factor κ-light chain-enhancer of activated B activation and increased activator protein 1, chemical inhibition of these inflammatory transcription factors did not blunt BCRP up-regulation by PGE2. Though PGE2 decreased Pgp mRNA, Pgp expression and function were not significantly altered. Overall, these findings suggest a possible role for PGE2 in the up-regulation of placental BCRP expression via EP1 and EP3 receptor signaling cascades.

Macrophages infiltrate the human and rat decidua during term and preterm labor: evidence that decidual inflammation precedes labor

Preterm delivery is the leading cause of perinatal mortality and morbidity. Current tocolytics target myometrial contractions, a late step in the labor cascade. Identifying earlier events in parturition may lead to more effective therapeutic strategies. We hypothesized that inflammatory events in decidua (the maternal-fetal interface), characterized by leucocyte infiltration, are an early event during term and preterm labor (PTL). Leucocyte abundance in decidua of human pregnancies was quantified following term labor and PTL (idiopathic and infection associated), in conjunction with investigation of temporal inflammatory events in rat uterus during the perilabor period and in PTL induced by mifepristone. In human decidua, macrophage numbers were 4-fold higher in term labor (P < 0.01) and 2.5-fold higher in non-infection-associated PTL (P < 0.05) than in term nonlaboring samples. Neutrophil abundance was unchanged with labor but elevated in PTL with infection (5- to 53-fold increase; P < 0.01). T and NK cells were more abundant in idiopathic PTL than TL (P < 0.05). In rat, decidual macrophage infiltration increased 4.5-fold 12 h prior to labor and remained elevated during labor and early postpartum (P < 0.01). Decidual infiltration preceded that of the myometrium and was 4-fold higher (P < 0.01). In rat PTL, decidual macrophage numbers were also elevated (P < 0.01) and exceeded those of the myometrium (P < 0.05). These studies show for the first time that leucocytes infiltrate decidua during labor at term and preterm, supporting a role for leucocyte-derived inflammatory mediators in decidual activation. In the rat, this occurred prior to labor, suggesting it is an early event during parturition and thus a potential target for intervention.

The EPR effect: Unique features of tumor blood vessels for drug delivery, factors involved, and limitations and augmentation of the effect

The enhanced permeability and retention (EPR) effect is a unique phenomenon of solid tumors related to their anatomical and pathophysiological differences from normal tissues. For example, angiogenesis leads to high vascular density in solid tumors, large gaps exist between endothelial cells in tumor blood vessels, and tumor tissues show selective extravasation and retention of macromolecular drugs. This EPR effect served as a basis for development of macromolecular anticancer therapy. We demonstrated methods to enhance this effect artificially in clinical settings. Of great importance was increasing systolic blood pressure via slow angiotensin II infusion. Another strategy involved utilization of NO-releasing agents such as topical nitroglycerin, which releases nitrite. Nitrite is converted to NO more selectively in the tumor tissues, which leads to a significantly increased EPR effect and enhanced antitumor drug effects as well. This review discusses molecular mechanisms of factors related to the EPR effect, the unique anatomy of tumor vessels, limitations and techniques to avoid such limitations, augmenting tumor drug delivery, and experimental and clinical findings.

Amniotic fluid prostaglandin F2 increases even in sterile amniotic fluid and is an independent predictor of impending delivery in preterm premature rupture of membranes

OBJECTIVE

To determine whether amniotic fluid (AF) concentration of prostaglandins (PGs) increases in patients with intra-amniotic inflammation and/or proven AF infection in preterm PROM, and can predict impending delivery.

METHODS

AF PGF2a concentrations were determined by ELISA in 140 singleton pregnancies with preterm premature rupture of membranes (PROM) (< or =35 weeks). AF was cultured for aerobic and anaerobic bacteria, and genital mycoplasmas. Intra-amniotic inflammation was defined as an elevated AF matrix metalloproteinase-8 concentration (>23 ng/ml). Results. (1) Patients with intra-amniotic inflammation and a negative AF culture had a significantly higher median AF PGF2a than those without intra-amniotic inflammation and with a negative culture (p < 0.001); (2) However, there was no difference in the median AF PGF2a between patients with intra-amniotic inflammation with a negative culture and those with culture-proven AF infection (p > 0.1); (3) Patients with an elevated AF PGF2a had a significantly shorter interval-to-delivery than those with a low AF PGF2a (< or =170 pg/mL) (p < 0.001); (4) An elevated AF PGF2a (< or =170 pg/mL) concentration was a significant predictor of the duration of pregnancy after adjusting for gestational age and AF inflammation/infection (p < 0.005). Conclusions. AF PGF2a (> or =170 pg/mL) concentration increased in patients with intra-amniotic inflammation regardless of AF culture results. Moreover, an elevated AF PGF2a concentration was an independent predictor of impending delivery in preterm PROM.

Proinflammatory cytokines found in amniotic fluid induce collagen remodeling, apoptosis, and biophysical weakening of cultured human fetal membranes

The mechanisms by which fetal membranes (FM) rupture during the birth process are unknown. We have recently reported that FM weaken, at least in part, because of a developmental process of extracellular matrix remodeling and apoptosis. We now hypothesize that cytokines that normally increase in amniotic fluid at term induce FM collagen remodeling and apoptosis with concomitant weakening. Full-thickness FM fragments were cultured with (0-100 ng/ml) or without tumor necrosis factor (TNF) or interleukin 1, beta (IL1B). Physical properties were then examined with specially adapted industrial rupture strength testing equipment. Cultured FM were also evaluated for evidence of collagen remodeling and apoptosis. Cytokine-treated FM exhibited a dose-dependent decrease in strength and work to rupture. Compared with controls, the highest TNF dose caused maximal decrease in FM rupture strength (13.2 +/- 1.2 N versus 3.8 +/- 1.5 N; P = 0.0003) and work to rupture (0.035 +/- 0.005 J versus 0.005 +/- 0.002 J; P < 0.0001). The highest IL1B dose also decreased rupture strength (12.9 +/- 3.2 versus 4.6 +/- 1.1 N; P = 0.0027) and work to rupture (0.018 +/- 0.005 J versus 0.005 +/- 0.002 J; P < 0.01). Matrix metalloproteinase 9 (MMP9) protein increased, tissue inhibitor of matrix metalloproteinase 3 (TIMP3) protein decreased, and poly (ADP-ribose) polymerase (PARP1) cleavage increased with increasing TNF or IL1B doses (all P < 0.05), suggesting collagen remodeling and apoptosis. TNF and IL1B cause significant weakening of cultured FM. Both cytokines induce biochemical markers in the FM in a manner characteristic of the weak zone of FM overlying the cervix. TNF and or IL1B may be involved in the development of the weak zone of the FM.

Differential activation of mitogen activated protein kinases and nuclear factor-κB in lipopolysaccharide-treated term and preterm amnion cells

Intrauterine exposure to amniotic sac infection elicits an inflammatory response from the fetus, which is associated with elevated levels of fetal plasma proinflammatory cytokines, i.e. interleukin-6 (IL-6). We have recently demonstrated that the severity of fetal inflammatory response in terms of gestation period is greater in preterm fetuses than in term fetuses. The activation of mitogen activated protein kinases (MAPKs) and nuclear factor kappa B (NF-kappaB) is known to be associated with up-regulation of proinflammatory cytokine gene expression in many cell types. In the present study, therefore, we studied patterns of MAPK and NF-kappaB activation following treatment with bacterial lipopolysaccharide (LPS) in amnion cells obtained from placentas of varying gestational ages to assess whether or not MAPKs and NF-kappaB are differentially regulated during gestation. MAPK phosphorylation was investigated by immunoblot analysis with phosphospecific antibodies. Transient phosphorylations of extracellular signal-regulated kinase (ERK) 1/2 and c-Jun N-terminal kinase (JNK) were observed in LPS-treated amnion cells, with the degree of phosphorylation being more pronounced in preterm cases. The results of NF-kappaB-dependent reporter gene expression and electrophoretic mobility shift assay (EMSA) of NF-kappaB were similar to those of ERK 1/2 and JNK activity. To assess whether the results of in vitro observations reflected in vivo results, we further analyzed amniotic fluid and cord blood IL-6 levels in preterm deliveries with placental inflammation. The analysis also revealed a significantly higher level of IL-6 in cases of </=31 weeks gestation when compared with those of more than 31 weeks (P<0.001). All these findings strongly suggest that there is an inverse relationship between gestational age and fetal inflammatory response during human gestation, and that differences in the intensity of MAPK activation and NF-kappaB-dependent transcription pathways are elements of the major underlying mechanism.

Markedly elevated levels of inflammatory cytokines in maternal serum and peritoneal washing during arrested labor

BACKGROUND

The role of inflammatory cytokines in the pathophysiology of arrested labor is currently unknown. We measured levels of inflammatory cytokines in maternal serum and peritoneal washings in arrested first stage of labor to assess the possible involvement of these mediators in this obstetric disorder.

METHODS

This was a prospective, case-control study involving 15 women who underwent cesarean section for arrested cervical dilatation (group I), 15 controls who were operated during active labor for nonreassuring fetal heart-rate tracing (group II) and 15 controls who were operated electively (group III). Blood samples were drawn from all women shortly before the operation. The presence of peritoneal fluid was assessed and peritoneal washings were obtained during the operation. All samples were assayed for the inflammatory cytokines interleukin (IL)-1beta, IL-6, IL-8 and soluble IL-2 receptor (sIL-2R) by solid-phase enzyme-linked immunosorbent assay (ELISA).

RESULTS

All women from group I and one patient (6.7%) from group II had some degree of peritoneal fluid accumulation, while none from group III had any. Serum samples from group I contained significantly higher IL-1beta, IL-6, IL-8 and IL-2R levels than both control groups. Peritoneal washings from group I contained significantly higher IL-1beta, IL-6 and IL-8 but similar IL-2R levels.

CONCLUSIONS

Arrested first stage of labor is associated with peritoneal fluid accumulation and increased levels of inflammatory cytokines in both serum and peritoneal fluids. Inflammatory cytokines may therefore be involved in the pathophysiology of arrested labor.

Physical properties of the chorioamnion throughout gestation

OBJECTIVE

Our purpose was to assess the tensile strength of the chorioamnion at various gestational ages.

STUDY DESIGN

Segments of chorioamnion were obtained from 35 patients delivered at gestational ages ranging from 17 to 41 weeks. Clinical information including gestational age, chorioamnionitis, premature rupture of membranes, and onset of labor was recorded. Tensile strength (grams to burst and deflection at rupture) was measured on 2 to 16 specimens per patient. Tensile strength of several commercial products was used for comparison.

RESULTS

Tensile strength increases up to 20 weeks of gestation and then plateaus until 39 weeks of gestation, when it falls dramatically. Clinical chorioamnionitis alone did not affect tensile strength, but gross membrane inflammation resulted in reduced tensile strength.

CONCLUSIONS

Tensile strength of the chorioamnion varies with gestational age. This baseline information will be useful in assessing the effects of various conditions and therapies on membrane strength and may provide insight into spontaneous rupture of membranes.

Nuclear factor kappa B regulation of proinflammatory cytokines in human gestational tissues in vitro

Proinflammatory cytokines are implicated in the initiation and progression of human labor and delivery, particularly in relation to infection-induced preterm labor. In nongestational tissues, the nuclear factor kappa B (NF-kappaB) transcription pathway is a key regulator of proinflammatory cytokine release. In these tissues, sulfasalazine (SASP), through its ability to inhibit NF-kappaB activation, inhibits release of interleukin (IL)-2, IL-12, and tumor necrosis factor (TNF)-alpha. Therefore, the aim of this study was to investigate whether or not NF-kappaB activation regulates the formation of proinflammatory cytokines in human gestational tissues. Human placenta, amnion, and choriodecidua (n = 9 separate placentas) were incubated with 10 microg/ml of lipopolysaccharide (LPS) in the absence (control) or presence of SASP (0.1, 1, 5, or 10 mM). After 6 h of incubation, the tissues were collected, and NF-kappaB DNA binding activity in nuclear extracts was assessed by electromobility shift binding assay. The incubation medium was collected and the release of IL-6, IL-8, and TNF-alpha was quantified by ELISA. Treatment of placenta, amnion, and choriodecidua with SASP at concentrations 5 mM or greater significantly inhibited the release of IL-6, IL-8, and TNF-alpha, and NF-kappaB activation (ANOVA, P < 0.05). The data presented in this study demonstrate that the NF-kappaB transcription pathway is a key regulator of LPS-stimulated IL-6, IL-8, and TNF-alpha release from human gestational tissues. The control of NF-kappaB activation may therefore provide an alternative therapeutic strategy for reducing the release of proinflammatory mediators in infection associated preterm labor.

Cytokine imbalance in pregnancies with fetal chromosomal abnormalities

BACKGROUND

The aim of the present study is to investigate the levels of some of the cytokines which may be involved in the mechanisms leading to the impairment of placental perfusion and to the onset of uterine contractions in pregnancies with fetal genetic abnormalities compared with controls.

METHODS

The amniotic fluid and maternal plasma levels of interleukin-6, interleukin-8 and tumour necrosis factor-beta in patients with fetal chromosomal abnormalities were measured, as well as in euploid pregnancies in the seventh week of gestation.

RESULTS

An increase of interleukin-6 (P = 0.034) and a decrease of interleukin-8 (P < or =0.0001) in amniotic fluid, and a decrease of interleukin-6 in the maternal plasma (P = 0.026) was shown in pregnancies with fetal chromosomal abnormalities. A positive correlation was observed between amniotic interleukin-8 and serum interleukin-6 in the presence of fetal aneuploidy (P < 0.006).

CONCLUSION

Further investigations of cytokine imbalance in pregnancies with poor outcome as a consequence of genetic disorders rather than infection is warranted.

Effect of hypoxia, oxidative stress and lipopolysaccharides on the release of prostaglandins and cytokines from human term placental explants

Placental hypoxia, ischaemia, reperfusion and resultant oxidative stress, with the release of various factors into the maternal vasculature acting as mediators of endothelial cell dysfunction, play an important role in the development of pre-eclampsia. Human term placental tissue explants were exposed to different stressors, e.g. hypoxia, oxidative stress and lipopolysaccarides, and the effect on the release of prostanoids and cytokines was determined. The hypoxic environment consisted of 2 per cent O2, 5 per cent CO2and 93 per cent N2. Oxidative stress was induced by addition of xanthine together with xanthine oxidase to the incubation medium. As a third experimental variable, lipopolysaccharide was added to the medium. Prostaglandins (8-iso-PGF(2alpha), or 6-keto-PGF(1alpha)and TXB(2)as stable metabolites of prostacyclin and thromboxane, respectively) and cytokines (TNF-alpha, IL-1alpha, IL-1beta, IL-6) were measured using commercial ELISA assays. Under control conditions, the production of prostaglandins in ng/24 h (mean +/- s.d.) was 6 +/- 3 for 8-iso-PGF(2alpha), 19 +/- 9 for 6-keto-PGF(1alpha)and 5 +/- 2 for TXB2. The production of cytokines was 13 +/- 6 pg for TNF-alpha, 7 +/- 2 pg for IL-1alpha, 5 +/- 3 pg for IL-1beta and 18 +/- 9 ng for IL-6. Under hypoxia the production of prostaglandins remained unchanged and of the cytokines only IL-1beta showed a 15-fold increase. Oxidative stress resulted in an increase in the release of prostaglandins and of cytokines of 4- to 15- and 3- to 130-fold, respectively. Lipopolysaccharides and oxidative stress had a similar effect on the production of prostaglandins, whereas the stimulatory effect of lipopolysaccharides on cytokines was significantly higher than that of oxidative stress.