The potential role of prolactin as a modulator of the secretion of proinflammatory mediators in chorioamniotic membranes in term human gestation

OBJECTIVE

To test the effect of prolactin (PRL) on expression of proinflammatory cytokines and matrix metallopeptidase 9 (MMP-9) in vitro.

STUDY DESIGN

Tissue explants were incubated from 4 to 48 hours alone or in the presence of 500 ng/mL PRL, and mRNA expression in tissues and secretion of interleukin (IL)-1β, tumor necrosis factor alpha (TNF-α), MMP-2, and MMP-9 was quantified.

RESULTS

Fetal membranes secreted IL-1β, TNF-α, and MMP-9 in culture with consistent low concentration during the first 24 hours and then increased progressively. The presence of PRL during explant incubation significantly decreased the patterns of IL-1β, TNF-α and MMP-9 secretion along culture (P < .001). MMP-2 secretion was unaffected by PRL. The relative basal expression of IL-1β mRNA (1.2 ± 0.87) was reduced by 80% in the presence of PRL after 32 hours of incubation of the membranes (P = .001). The expression of the TNF-α mRNA was not modified by the presence of PRL (0.06 ± 0.01) compared with the basal expression levels (0.05 ± 0.01). MMP-9 mRNA basal expression (0.018 ± 0.008) was significantly reduced (P = .001) in the presence of PRL after 32 hours (0.002 ± 0.0005).

CONCLUSION

PRL may be a potential candidate as a key signal controlling the expression of signals related to the proinflammatory reaction associated with human labor.

Genome-wide hypermethylation coupled with promoter hypomethylation in the chorioamniotic membranes of early onset pre-eclampsia

Pre-eclampsia is the leading cause of fetal and maternal morbidity and mortality. Early onset pre-eclampsia (EOPE) is a disorder that has severe maternal and fetal outcomes, whilst its etiology is poorly understood. We hypothesize that epigenetics plays an important role to mediate the development of EOPE and conducted a case-control study to compare the genome-wide methylome difference between chorioamniotic membranes from 30 EOPE and 17 full-term pregnancies using the Infinium Human Methylation 450 BeadChip arrays. Bioinformatics analysis tested differential methylation (DM) at CpG site level, gene level, and pathway and network level. A striking genome-wide hypermethylation pattern coupled with hypomethylation in promoters was observed. Out of 385 184 CpG sites, 9995 showed DM (2.6%). Of those DM sites, 91.9% showed hypermethylation (9186 of 9995). Over 900 genes had DM associated with promoters. Promoter-based DM analysis revealed that genes in canonical cancer-related pathways such as Rac, Ras, PI3K/Akt, NFκB and ErBB4 were enriched, and represented biological functional alterations that involve cell cycle, apoptosis, cancer signaling and inflammation. A group of genes previously found to be up-regulated in pre-eclampsia, including GRB2, ATF3, NFKB2, as well as genes in proteasome subunits (PSMA1, PMSE1, PSMD1 and PMSD8), harbored hypomethylated promoters. Contrarily, a cluster of microRNAs, including mir-519a1, mir-301a, mir-487a, mir-185, mir-329, mir-194, mir-376a1, mir-486 and mir-744 were all hypermethylated in their promoters in the EOPE samples. These findings collectively reveal new avenues of research regarding the vast epigenetic modifications in EOPE.

Docosahexaenoic acid supplementation during pregnancy: a potential tool to prevent membrane rupture and preterm labor

Polyunsaturated fatty acids (PUFAs) are required to maintain the fluidity, permeability and integrity of cell membranes. Maternal dietary supplementation with ω-3 PUFAs during pregnancy has beneficial effects, including increased gestational length and reduced risk of pregnancy complications. Significant amounts of ω-3 docosahexaenoic acid (DHA) are transferred from maternal to fetal blood, hence ensuring high levels of DHA in the placenta and fetal bloodstream and tissues. Fetal DHA demand increases exponentially with gestational age, especially in the third trimester, due to fetal development. According to the World Health Organization (WHO) and the Food and Agriculture Organization of the United Nations (FAO), a daily intake of DHA is recommended during pregnancy. Omega-3 PUFAs are involved in several anti-inflammatory, pro-resolving and anti-oxidative pathways. Several placental disorders, such as intrauterine growth restriction, premature rupture of membranes (PROM) and preterm-PROM (pPROM), are associated with placental inflammation and oxidative stress. This pilot study reports on a preliminary evaluation of the significance of the daily DHA administration on PROM and pPROM events in healthy pregnant women. Further extensive clinical trials will be necessary to fully elucidate the correlation between DHA administration during pregnancy and PROM/pPROM occurrence, which is related in turn to gestational duration and overall fetal health.

Perinatal stress, fatigue, depressive symptoms, and immune modulation in late pregnancy and one month postpartum

Stress and fatigue are common complaints of pregnant and postpartum women as is depression. These symptoms may be related to immunomodulation. However, few studies have examined these relationships. The aim of this study was to examine the relationships among stress, fatigue, depression, and cytokines as markers of immune modulation in prenatal and postpartum women. Women completed questionnaires and gave blood samples during late pregnancy and again at 4–6 weeks postpartum. Blood was analyzed for cytokines as measures of immune modulation. Stress, fatigue, and depression were experienced at moderately high levels, with higher levels of fatigue and depression in the postpartum but higher stress in the prenatal period. Levels of several cytokines were increased in the postpartum over the prenatal period. Stress and depression were related in the prenatal period and stress, depression, and fatigue were related in the postpartum. While various cytokines were related to each other in both periods, only stress was related to MIP-1β, a cytokine that may be important for childbirth processes. More studies, especially longitudinal and interventional studies, are needed to increase our knowledge about etiology, patterns, symptoms, factors, and management of maternal distress. The search for reliable biomarkers for at-risk mothers remains a priority.

Air pollution, inflammation and preterm birth: a potential mechanistic link

Preterm birth is a public health issue of global significance, which may result in mortality during the perinatal period or may lead to major health and financial consequences due to lifelong impacts. Even though several risk factors for preterm birth have been identified, prevention efforts have failed to halt the increasing rates of preterm birth. Epidemiological studies have identified air pollution as an emerging potential risk factor for preterm birth. However, many studies were limited by study design and inadequate exposure assessment. Due to the ubiquitous nature of ambient air pollution and the potential public health significance of any role in causing preterm birth, a novel focus investigating possible causal mechanisms influenced by air pollution is therefore a global health priority. We hypothesize that air pollution may act together with other biological factors to induce systemic inflammation and influence the duration of pregnancy. Evaluation and testing of this hypothesis is currently being conducted in a prospective cohort study in Mexico City and will provide an understanding of the pathways that mediate the effects of air pollution on preterm birth. The important public health implication is that crucial steps in this mechanistic pathway can potentially be acted on early in pregnancy to reduce the risk of preterm birth.

Choriodecidual cells from term human pregnancies show distinctive functional properties related to the induction of labor

PROBLEM

Human parturition is associated with an intrauterine pro-inflammatory environment in the choriodecidua. Evidence that some mediators of this signaling cascade also elicit responses leading to labor prompted us to characterize the cellular sources of these mediators in the human choriodecidua.

METHOD OF STUDY

Leukocyte-enriched preparations from human choriodecidua (ChL) and intervillous placental blood leukocytes (PL) were maintained in culture. Secretions of inflammatory cytokines, chemokines, and MMP-9 were documented. Leukocyte phenotype of ChL and PL was determined by flow cytometry using specific fluorochrome-conjugated antibodies.

RESULTS AND CONCLUSIONS

ChL showed a distinct pro-inflammatory secretion pattern of cytokines and chemokines when compared with PL, including higher amounts of TNF-α and IL-6, and decreased secretions of IL-4 and IL-1ra. ChL also secreted more MIP-1α and MCP-1 and MMP-9 than PL. No significant differences were found in leukocytes subsets between compartments. Based on our findings, we propose that ChL isolated from fetal membranes at term are functionally different from PL and may collaborate to modulate the microenvironment linked to induction and progression of human labor.

LncRNA pathway involved in premature preterm rupture of membrane (PPROM): an epigenomic approach to study the pathogenesis of reproductive disorders

Preterm birth (PTB) is a live birth delivered before 37 weeks of gestation (GW). About one-third of PTBs result from the preterm premature rupture of membranes (PPROM). Up to the present, the pathogenic mechanisms underlying PPROM are not clearly understood. Here, we investigated the differential expression of long chain non-coding RNAs (lncRNAs) in placentas of PTBs with PPROM, and their possible involvement in the pathogenic pathways leading to PPROM. A total number of 1954, 776, and 1050 lncRNAs were identified with a microarray from placentas of PPROM (group A), which were compared to full-term birth (FTB) (group B), PTB (group C), and premature rupture of membrane (PROM) (group D) at full-term, respectively. Instead of investigating the individual pathogenic role of each lncRNA involved in the molecular mechanism underlying PPROM, we have focused on investigating the metabolic pathways and their functions to explore what is the likely association and how they are possibly involved in the development of PPROM. Six groups, including up-regulation and down-regulation in the comparisons of A vs. B, A vs. C, and A vs. D, of pathways were analyzed. Our results showed that 22 pathways were characterized as up-regulated 7 down-regulated in A vs. C, 18 up-regulated and 15 down-regulated in A vs. D, and 33 up-regulated and 7 down-regulated in A vs. B. Functional analysis showed pathways of infection and inflammatory response, ECM-receptor interactions, apoptosis, actin cytoskeleton, and smooth muscle contraction are the major pathogenic mechanisms involved in the development of PPROM. Characterization of these pathways through identification of lncRNAs opened new avenues for further investigating the epigenomic mechanisms of lncRNAs in PPROM as well as PTB.

Prokineticin 1 induces a pro-inflammatory response in murine fetal membranes but does not induce preterm delivery

The mechanisms that regulate the induction of term or preterm delivery (PTD) are not fully understood. Infection is known to play a role in the induction of pro-inflammatory cascades in uteroplacental tissues associated with preterm pathological parturition. Similar but not identical cascades are evident in term labour. In the current study, we used a mouse model to evaluate the role of prokineticins in term and preterm parturition. Prokineticins are multi-functioning secreted proteins that signal through G-protein-coupled receptors to induce gene expression, including genes important in inflammatory responses. Expression of prokineticins (Prok1 and Prok2) was quantified in murine uteroplacental tissues by QPCR in the days preceding labour (days 16-19). Prok1 mRNA expression increased significantly on D18 in fetal membranes (compared with D16) but not in uterus or placenta. Intrauterine injection of PROK1 on D17 induced fetal membrane mRNA expression of the pro-inflammatory mediators Il6, Il1b, Tnf, Cxcl2 and Cxcl5, which are not normally up-regulated until D19 of pregnancy. However, intrauterine injection of PROK1 did not result in PTD. As expected, injection of lipopolysaccharide (LPS) induced PTD, but this was not associated with changes in expression of Prok1 or its receptor (Prokr1) in fetal membranes. These results suggest that although Prok1 exhibits dynamic mRNA regulation in fetal membranes preceding labour and induces a pro-inflammatory response when injected into the uterus on D17, it is insufficient to induce PTD. Additionally, prokineticin up-regulation appears not to be part of the LPS-induced inflammatory response in mouse fetal membranes.

Targeting interleukin-6 receptor inhibits preterm delivery induced by inflammation

Intrauterine infection is still a common trigger of preterm delivery (PTD) and also a determinant risk factor for the subsequent development of neurodevelopmental abnormalities in neonates. In this study, we examined the expressional pattern of various inflammatory cytokines such as interleukin-1β (IL-1β), IL-6 and tumor necrosis factor-α (TNF-α) in placentae complicated with severe chorioamnionitis (CAM) and found that IL-6 is mainly expressed in macrophages in villous mesenchyme by immunohistochemical analysis with anti-CD-68 antibody. Using an experimental lipopolysaccharide (LPS)-induced PTD model, the therapeutic potential of targeting this cytokine was investigated. Anti-IL-6 receptor antibody (MR16-1) was delivered 6 h before LPS treatment. Mice in the MR16-1 group had a significantly lower rate of PTD (17%) than in the controls (53%, P = 0.026). As a result, MR16-1 treatment significantly prolonged the gestational period (control; 18.4 ± 1.7d, MR16-1; 19.8 ± 1.5d, P = 0.007) without any apparent adverse events on the mice and their pups. In primary human amniotic epithelial cells, pretreatment with a humanized anti-human IL-6 receptor antibody, tocilizumab, significantly inhibited the production of prostaglandin E2 induced by IL-6. In conclusion, IL-6 was strongly expressed mainly in macrophages in villous mesenchyme in placentae complicated with CAM. Anti-IL-6R antibody significantly decreased the rate of PTD in LPS-induced inflammatory model in mice, and inhibited PGE2 production from human primary amniotic epithelial cells. Targeting IL-6 signaling could be a promising option for the prevention of PTD and needs to be further explored for future clinical application.

Proteomic analysis of preterm premature rupture of membranes in placental tissue

OBJECTION

Preterm premature rupture of membranes (PPROM) is an obstetrics complication and is the leading cause of perinatal mortality and morbidity. PPROM results in critical care emergencies, and nearly all PPROM events are spontaneous and unpredictable. In addition, changes in the proteome in placental tissue during pregnancy that lead to PPROM are not clear.

METHODS

We utilize a proteomics approach to study the molecular mechanisms behind human PPROM. A better understanding of proteome alteration could lead to the identification of better diagnostic/prognostic markers. Human placental tissue was collected in clearly differentiated cases of PPROM and in a healthy term control. Two-dimensional gel polyacrylamide electrophoresis coupled with mass spectrometry and bioinformatics analysis was utilized to identify proteins with altered expression.

RESULTS

In this study, only the most important protein differences were selected for further analysis. Most of the identified proteins were structural/cytoskeletal components of the cell or involved in the regulation of energy metabolism and oxidative stress.

CONCLUSIONS

As a result, this approach has led to the identification of several proteins involved in the underlying pathophysiological mechanisms that can further serve as novel diagnostic tools and targets for rational drug intervention.

Evidence for a role for the adaptive immune response in human term parturition

PROBLEM

Spontaneous labor at term involves leukocyte recruitment and infiltration into the choriodecidua; yet, characterization of these leukocytes and their immunological mediators is incomplete. The purpose of this study was to characterize the immunophenotype of choriodecidual leukocytes as well as the expression of inflammatory mediators in human spontaneous parturition at term.

METHOD OF STUDY

Choriodecidual leukocytes were analyzed by FACS, immunohistochemistry, and RT-PCR in three different groups: (i) preterm gestation delivered for medical indications without labor; (ii) term pregnancy without labor; and (iii) term pregnancy after spontaneous labor.

RESULTS

Two T-cell subsets of memory-like T cells (CD3(+) CD4(+) CD45RO(+) and CD3(+) CD4(-) CD8(-) CD45RO(+) cells) were identified in the choriodecidua of women who had spontaneous labor. Evidence for an extensive immune signaling network composed of chemokines (CXCL8 and CXCL10), chemokine receptors (CXCR1-3), cytokines (IL-1β and TNF-α), cell adhesion molecules, and MMP-9 was identified in these cells during spontaneous labor at term.

CONCLUSIONS

The influx of memory-like T cells in the choriodecidua and the evidence that they are active by producing chemokines and cytokines, and expressing chemokine receptors, cell adhesion molecules, and a matrix-degrading enzyme provides support for the participation of the adaptive immune system in the mechanisms of spontaneous parturition at term.

Pregnancy disorders appear to modify the risk for retinopathy of prematurity associated with neonatal hyperoxemia and bacteremia

OBJECTIVE

To explore (1) whether extremely low gestational age newborns exposed to inflammation-associated pregnancy disorders differ in retinopathy of prematurity (ROP) risk from infants exposed to placenta dysfunction-associated disorders, and (2) whether ROP risk associated with postnatal hyperoxemia and bacteremia differs among infants exposed to these disorders.

METHODS

Pregnancy disorders resulting in preterm birth include inflammation-associated: preterm labor, prelabor premature rupture of membranes (pPROM), cervical insufficiency, and abruption and placenta dysfunction-associated: preeclampsia and fetal indication. The risk of severe ROP associated with pregnancy disorders was evaluated by multivariable analyses in strata defined by potential effect modifiers, postnatal hyperoxemia and bacteremia.

RESULTS

Compared to preterm labor, infants delivered after pPROM were at reduced risk of plus disease (Odds ratio = 0.4, 95% confidence interval: 0.2-0.8) and prethreshold/threshold ROP (0.5, 0.3-0.8). Infants delivered after abruption had reduced risk of zone I ROP (0.2, 0.1-0.8) and prethreshold/threshold ROP (0.3, 0.1-0.7). In stratified analyses, infants born after placenta dysfunction had higher risks of severe ROP associated with subsequent postnatal hyperoxemia and bacteremia than infants born after inflammation-associated pregnancy disorders.

CONCLUSION

Infants exposed to placenta dysfunction have an increased risk of severe ROP following postnatal hyperoxemia and bacteremia compared to infants exposed to inflammation-associated pregnancy disorders.

Maternal circulating leukocytes display early chemotactic responsiveness during late gestation

BACKGROUND

Parturition has been widely described as an immunological response; however, it is unknown how this is triggered. We hypothesized that an early event in parturition is an increased responsiveness of peripheral leukocytes to chemotactic stimuli expressed by reproductive tissues, and this precedes expression of tissue chemotactic activity, uterine activation and the systemic progesterone/estradiol shift.

METHODS

Tissues and blood were collected from pregnant Long-Evans rats on gestational days (GD) 17, 20 and 22 (term gestation). We employed a validated Boyden chamber assay, flow cytometry, quantitative real time-polymerase chain reaction, and enzyme-linked immunosorbent assays.

RESULTS

We found that GD20 maternal peripheral leukocytes migrated more than those from GD17 when these were tested with GD22 uterus and cervix extracts. Leukocytes on GD20 also displayed a significant increase in chemokine (C-C motif) ligand 2 (Ccl2) gene expression and this correlated with an increase in peripheral granulocyte proportions and a decrease in B cell and monocyte proportions. Tissue chemotactic activity and specific chemokines (CCL2, chemokine (C-X-C motif) ligand 1/CXCL1, and CXCL10) were mostly unchanged from GD17 to GD20 and increased only on GD22. CXCL10 peaked on GD20 in cervical tissues. As expected, prostaglandin F2α receptor and oxytocin receptor gene expression increased dramatically between GD20 and 22. Progesterone concentrations fell and estradiol-17β concentrations increased in peripheral serum, cervical and uterine tissue extracts between GD20 and 22.

CONCLUSION

Maternal circulating leukocytes display early chemotactic responsiveness, which leads to their infiltration into the uterus where they may participate in the process of parturition.

Risk of preterm delivery in non-diabetic women with polycystic ovarian syndrome

OBJECTIVE

To examine the risk and etiology of preterm delivery in women with polycystic ovary syndrome (PCOS).

STUDY DESIGN

Retrospective cohort study comparing preterm delivery rate among non-diabetic PCOS and non-PCOS women with singleton pregnancy. Multivariable logistic regression was used to identify predictors of preterm delivery among PCOS women.

RESULT

Among 908 PCOS women with singleton pregnancy, 12.9% delivered preterm compared with 7.4% among non-PCOS women (P<0.01). Causes of preterm delivery among PCOS women included preterm labor (41%), cervical insufficiency (11%), hypertensive complications (20%), preterm premature rupture of membranes (15%), fetal-placental concerns (9%) and intrauterine fetal demise (5%). Maternal age, race/ethnicity and nulliparity were significant predictors of preterm delivery in PCOS, whereas body mass index and fertility medications were not.

CONCLUSION

A higher proportion of PCOS women delivered preterm (12.9%) compared with non-PCOS women, with the majority of cases due to spontaneous preterm birth. Future studies should explore etiologies and strategies to improve pregnancy outcomes in PCOS.

Possible roles of proinflammatory and chemoattractive cytokines produced by human fetal membrane cells in the pathology of adverse pregnancy outcomes associated with influenza virus infection

Pregnant women are at an increased risk of influenza-associated adverse outcomes, such as premature delivery, based on data from the latest pandemic with a novel influenza A (H1N1) virus in 2009-2010. It has been suggested that the transplacental transmission of influenza viruses is rarely detected in humans. A series of our study has demonstrated that influenza virus infection induced apoptosis in primary cultured human fetal membrane chorion cells, from which a factor with monocyte differentiation-inducing (MDI) activity was secreted. Proinflammatory cytokines, such as interleukin (IL)-6, tumor necrosis factor (TNF)-α, and interferon (IFN)-β, were identified as a member of the MDI factor. Influenza virus infection induced the mRNA expression of not only the proinflammatory cytokines but also chemoattractive cytokines, such as monocyte chemoattractant protein (MCP)-1, regulated on activation, normal T-cell expressed and secreted (RANTES), macrophage inflammatory protein (MIP)-1β, IL-8, growth-regulated oncogene (GRO)-α, GRO-β, epithelial cell-derived neutrophil-activating protein (ENA)-78, and interferon inducible protein (IP)-10 in cultured chorion cells. These cytokines are postulated to associate with human parturition. This paper, therefore, reviews (1) lessons from pandemic H1N1 2009 in pregnancy, (2) production of proinflammatory and chemoattractive cytokines by human fetal membranes and their functions in gestational tissues, and (3) possible roles of cytokines produced by human fetal membranes in the pathology of adverse pregnancy outcomes associated with influenza virus infection.

Prostaglandin E2 represses interleukin 1 beta-induced inflammatory mediator output from pregnant human myometrial cells through the EP2 and EP4 receptors

Inflammatory mediators, including prostaglandins, cytokines, and chemokines, are strongly implicated in the mechanism of human labor, though their precise roles remain unknown. Here we demonstrate that interleukin 1 beta (IL-1beta) significantly increased the expression and release of interleukin-8 (CXCL8), monocyte chemotactic protein-1 (CCL2), and granulocyte macrophage colony-stimulating factor (CSF2) by primary human myometrial cells. However, this effect was repressed by prostaglandin E(2) (PGE(2)). As PGE(2) can activate four distinct PGE(2) receptors (EP(1), EP(2), EP(3), and EP(4)) to elicit various responses, we sought to define the EP receptor(s) responsible for this repression. Using selective EP receptor agonists and a selective EP(4) antagonist, we show that PGE(2) mediates the repression of IL-1beta-induced release of CXCL8, CCL2, and CSF2 via activation of the EP(2) and EP(4) receptors. The use of siRNA gene-specific knockdown further confirmed a role for both receptors. Real-time RT-PCR demonstrated that EP(2) was the most highly expressed of all four EP receptors at the mRNA level in human myometrial cells, and immunocytochemistry showed that EP(2) protein is abundantly present throughout the cells. Interestingly, PGE(2) does not appear to reduce mRNA expression of CXCL8, CCL2, and CSF2. Our results demonstrate that PGE(2) can elicit anti-inflammatory responses via activation of the EP(2) and EP(4) receptors in lower segment term pregnant human myometrial cells. Further elucidation of the EP receptor-mediated signaling pathways in the pregnant human uterus may be beneficial for optimizing the maintenance of pregnancy, induction of labor or indeed treatment of preterm labor.

Extracellular matrix dynamics and fetal membrane rupture

The extracellular matrix (ECM) plays an important role in determining cell and organ function: (1) it is an organizing substrate that provides tissue tensile strength; (2) it anchors cells and influences cell morphology and function via interaction with cell surface receptors; and (3) it is a reservoir for growth factors. Alterations in the content and the composition of the ECM determine its physical and biological properties, including strength and susceptibility to degradation. The ECM components themselves also harbor cryptic matrikines, which when exposed by conformational change or proteolysis have potent effects on cell function, including stimulating the production of cytokines and matrix metalloproteinases (MMPs). Collectively, these properties of the ECM reflect a dynamic tissue component that influences both tissue form and function. This review illustrates how defects in ECM synthesis and metabolism and the physiological process of ECM turnover contribute to changes in the fetal membranes that precede normal parturition and contribute to the pathological events leading to preterm premature rupture of membranes (PPROM).

Amniotic fluid chemokines and autism spectrum disorders: an exploratory study utilizing a Danish Historic Birth Cohort

INTRODUCTION

Elevated levels of chemokines have been reported in plasma and brain tissue of individuals with Autism Spectrum Disorders (ASD). The aim of this study was to examine chemokine levels in amniotic fluid (AF) samples of individuals diagnosed with ASD and their controls.

MATERIAL AND METHODS

A Danish Historic Birth Cohort (HBC) kept at Statens Serum Institute, Copenhagen was utilized. Using data from Danish nation-wide health registers, a case-control study design of 414 cases and 820 controls was adopted. Levels of MCP-1, MIP-1α and RANTES were analyzed using Luminex xMAP technology. Case-control differences were assessed as dichotomized at below the 10th percentile or above the 90th percentile cut-off points derived from the control biomarker distributions (logistic regression) or continuous measures (tobit regression).

RESULTS AND CONCLUSION

AF volume for 331 cases and 698 controls was sufficient for Luminex analysis. Including all individuals in the cohort yielded no significant differences in chemokine levels in cases versus controls. Logistic regression analyses, performed on individuals diagnosed using ICD-10 only, showed increased risk for ASD with elevated MCP-1 (elevated 90th percentile adjusted OR: 2.32 [95% CI: 1.17-4.61]) compared to controls. An increased risk for infantile autism with elevated MCP-1 was also found (adjusted OR: 2.28 [95% CI: 1.16-4.48]). Elevated levels of MCP-1 may decipher an etiologic immunologic dysfunction or play rather an indirect role in the pathophysiology of ASD. Further studies to confirm its role and to identify the potential pathways through which MCP-1 may contribute to the development of ASD are necessary.

Dynamics of regulatory T-cells during pregnancy: effect of HIV infection and correlations with other immune parameters

Objectives

Regulatory T cells (Treg) increase in the context of HIV infection and pregnancy. We studied Treg subpopulations in HIV-infected and uninfected women during pregnancy and their relationship with inflammation, activation and cell-mediated immunity (CMI).

Design and Methods

Blood obtained from 20 HIV-infected and 18 uninfected women during early and late gestation was used to measure Treg and activated T cells (Tact) by flow cytometry; plasma cytokines and inflammatory markers by ELISA and chemoluminescence; and CMI against varicella-zoster virus (VZV) by lymphocyte proliferation.

Results and Conclusions

Compared with uninfected women, HIV-infected participants had higher frequencies of Treg subpopulations in early pregnancy, including CD4+CD25+FoxP3+%, CD8+CD25+FoxP3+%, CD4+TGFβ+% and CD4+IL10+%. In contrast, Treg frequencies were lower during late pregnancy in HIV-infected compared with uninfected women, including CD8+TGFβ+%, CD4+CTLA4+% and CD8+CTLA4+%. VZV-CMI, which was lower in HIV-infected compared with uninfected pregnant women, was inversely correlated with CD4+FoxP3+%, CD8+FoxP3+% and CD8+TGFβ+% in HIV-infected, but not in uninfected pregnant women. β_2-microglobulin, neopterin, IL1, IL4, IL8, IL10, IFNγ and TNFα plasma concentrations as well as Tact were higher in HIV-infected compared with uninfected women throughout pregnancy. In HIV-infected, but not in uninfected women, inflammatory, Th1, Th2 and regulatory cytokines increased with higher Treg%, suggesting that inflammation and regulation have a common pathophysiologic origin in the context of HIV infection. In HIV-infected and more commonly in uninfected pregnant women, higher Treg% correlated with lower Tact%. We conclude that Treg have different dynamics during pregnancy in HIV-infected and uninfected women. Higher levels of inflammatory cytokines and lower Treg% during late pregnancy in HIV-infected women may contribute to their increased incidence of maternal-fetal morbidity.

Prokineticin 1 induces inflammatory response in human myometrium: a potential role in initiating term and preterm parturition

The infiltration of human myometrium and cervix with leukocytes and the formation of a pro-inflammatory environment within the uterus have been associated with the initiation of both term and preterm parturition. The mechanism regulating the onset of this pro-inflammatory cascade is not fully elucidated. We demonstrate that prokineticin 1 (PROK1) is up-regulated in human myometrium and placenta during labor. The expression of PROK1 receptor remains unchanged during labor and is abundantly expressed in the myometrium. Gene array analysis identified 65 genes up-regulated by PROK1 in human myometrium, mainly cytokines and chemokines, including IL-1β, chemokine C-C motif ligand 3, and colony-stimulating factor 3. In addition, we demonstrate that PROK1 increases the expression of chemokine C-C motif ligand 20, IL-6, IL-8, prostaglandin synthase 2, and prostaglandin E(2) and F(2α) secretion. The treatment of myometrial explants with 100 ng/mL of lipopolysaccharide up-regulates the expression of PROK1, PROK1 receptor, and inflammatory mediators. The infection of myometrial explants with lentiviral microRNA targeting PROK1, preceding treatment with lipopolysaccharide, reduces the expression of inflammatory genes. We propose that PROK1 is a novel inflammatory mediator that can contribute to the onset of human parturition at term and partially mediate premature onset of inflammatory pathways during bacterial infection.

Specific inflammatory microenvironments in the zones of the fetal membranes at term delivery

OBJECTIVE

The purpose of this study was to examine the histologic and immunologic differences between fetal membrane zones after membrane rupture at term delivery.

STUDY DESIGN

Fetal membrane explants from postrupture zones (periplacental, middle, rupture) were obtained from women following spontaneous vaginal delivery at term (n = 5). Tissues for histology, protein extracts, and RNA were isolated.

RESULTS

The collagen distribution decreased and the leukocyte density increased from the periplacental zone to the rupture zone. T cells were mainly present in the rupture zone and granulocytes in the middle zone. CXCL10, CXCR1, ICAM-1, -2, PSEL, tumor necrosis factor alpha, and matrix metalloproteinase-9 levels were higher in the middle zone than in the rupture zone and periplacental zone (P < .021). Interleukin-1beta and CXCL8 levels were higher in the rupture zone than in the middle zone and periplacental zone (P = .018 and P < .0001).

CONCLUSION

During labor specific immunologic microenvironments are created in the zones of the fetal membrane that may be involved in their rupture at the end of gestation.

The effects of thrombin and cytokines upon the biomechanics and remodeling of isolated amnion membrane, in vitro

Abruption-induced thrombin generation and inflammation/infection induced cytokine production have both been associated with fetal membrane (FM) weakening and preterm premature rupture of the fetal membranes (PPROM). Using our in vitro model system we have demonstrated that thrombin, and separately the cytokines, tumor necrosis factor-alpha (TNFα) and interleukin-1-beta (IL-1β), remodel and weaken full thickness FM. Additionally, we have reported that the anti-oxidant and NFκB inhibitor, alpha-lipoic acid (LA), blocks these thrombin and cytokine induced effects. The purpose of these studies was to determine whether thrombin and cytokines directly weaken the amnion membrane (AM), the major load-bearing component of FM. Isolated AM or full thickness FM fragments from unlabored Cesarean deliveries were incubated with thrombin, TNFα, or IL-1β, for 48 h. Rupture strength (breaking force) of each fragment was thereafter determined using our published methodology. Biochemical evidence of remodeling and apoptosis; immunoreactive Matrix Metalloproteinase 9 (MMP9), Tissue Inhibitor of Matrix Metalloproteinase 3 (TIMP3) and cleaved poly (ADP-ribose) polymerase (C-PARP) levels in tissue extracts, were determined by western blot and densitometry. Thrombin induced a dose-dependent weakening of isolated AM (P < 0.001) coupled with dose dependent increases in PARP cleavage, and reciprocal increases and decreases, respectively, in MMP9 and TIMP3 protein (all P < 0.01). Thrombin receptor activating peptide-6 (TRAP) also weakened isolated AM. Neither TNFα nor IL-1β weakened isolated AM. However, both cytokines weakened AM when it was incubated together with the choriodecidua as part of full thickness FM (P < 0.001). Cytokine-conditioned choriodecidua medium also weakened isolated AM (P < 0.001). Under conditions in which cytokines weakened the AM, the changes in MMP9, TIMP3 and PARP cleavage were consistent with those seen after thrombin incubation. LA blocked the FM weakening and remodeling effects. In summary, thrombin weakens AM directly whereas cytokines weaken AM indirectly by causing the release of soluble intermediates from the choriodecidua.

Choriodecidua and amnion exhibit selective leukocyte chemotaxis during term human labor

OBJECTIVE

The purpose of this study was to compare the chemotactic activity of the choriodecidua and amnion, and to identify the phenotype of the leukocytes chemoattracted by each tissue.

STUDY DESIGN

Amnion, choriodecidua and whole fetal membranes extracts were obtained from women at term (>37 weeks of gestation) with or without labor (n = 5 each). Extracts were assayed for leukocyte chemotactic activity, and the number and phenotype of the chemoattracted leukocytes were characterized by flow cytometry.

RESULTS

Although all of the extracts exhibited chemotactic activity, more leukocytes were chemoattracted by the choriodecidua and the whole fetal membranes during labor compared with no labor (P = .010, .008). During labor the choriodecidua is responsible for granulocyte, T-lymphocyte, monocyte, and natural killer-cell chemoattraction, and the amnion is responsible for B-lymphocyte chemoattraction.

CONCLUSION

Choriodecidua and amnion exhibit chemotactic activity for selective leukocytes and thus, each fetal membrane differentially regulates leukocyte chemotactic activity during labor.