Cytokine Signaling, Inflammation, Innate Immunity and Preterm Labour – A Workshop Report

Downregulation of SOCS1 increases interferon-induced ISGylation during differentiation of induced-pluripotent stem cells to hepatocytes

Background & Aims

Increased expression of IFN-stimulated gene 15 (ISG15) and subsequently increased ISGylation are key factors in the host response to viral infection. In this study, we sought to characterize the expression of ISG15, ISGylation, and associated enzymes at each stage of differentiation from induced pluripotent stem cells (iPSCs) to hepatocytes.

Methods

To study the regulation of ISGylation, we utilized patient samples and in vitro cell culture models including iPSCs, hepatocytes-like cells, immortalized cell lines, and primary human hepatocytes. Protein/mRNA expression were measured following treatment with poly(I:C), IFNα and HCV infection.

Results

When compared to HLCs, we observed several novel aspects of the ISGylation pathway in iPSCs. These include a lower baseline expression of the ISGylation-activating enzyme, UBE1L, a lack of IFN-induced expression of the ISGylation-conjugation enzyme UBE2L6, an attenuated activation of the transcription factor STAT1 and constitutive expression of SOCS1. ISGylation was observed in iPSCs following downregulation of SOCS1, which facilitated STAT1 activation and subsequently increased expression of UBE2L6. Intriguingly, HCV permissive transformed hepatoma cell lines demonstrated higher intrinsic expression of SOCS1 and weaker ISGylation following IFN treatment. SOCS1 downregulation in HCV-infected Huh 7.5.1 cells led to increased ISGylation.

Conclusions

Herein, we show that high basal levels of SOCS1 inhibit STAT1 activation and subsequently IFN-induced UBE2L6 and ISGylation in iPSCs. Furthermore, as iPSCs differentiate into hepatocytes, epigenetic mechanisms regulate ISGylation by modifying UBE1L and SOCS1 expression levels. Overall, this study demonstrates that the development of cell-intrinsic innate immunity during the differentiation of iPSCs to hepatocytes provides insight into cell type-specific regulation of host defense responses and related oncogenic processes.

Impact and implications

To elucidate the mechanism underlying regulation of ISGylation, a key process in the innate immune response, we studied changes in ISGylation-associated genes at the different stages of differentiation from iPSCs to hepatocytes. We found that high basal levels of SOCS1 inhibit STAT1 activation and subsequently IFN-induced UBE2L6 and ISGylation in iPSCs. Importantly, epigenetic regulation of SOCS1 and subsequently ISGylation may be important factors in the development of cell type-specific host defense responses in hepatocytes that should be considered when studying chronic infections and oncogenic processes in the liver.

Transcriptomic and histochemical analysis reveal the complex regulatory networks in equine Chorioallantois during spontaneous term labor

The equine chorioallantois (CA) undergoes complex physical and biochemical changes during labor. However, the molecular mechanisms controlling these changes are still unclear. Therefore, the current study aimed to characterize the transcriptome of equine CA during spontaneous labor and compare it to that of normal preterm CA. Placental samples were collected postpartum from mares with normal term labor (TL group, n = 4) and from preterm not in labor mares (330 days GA; PTNL group, n = 4). Our study identified 4137 differentially expressed genes (DEGs) (1820 upregulated and 2317 downregulated) in CA during TL as compared to PTNL. TL was associated with the upregulation of several pro-inflammatory mediators (MHC-I, MHC-II, NLRP3, CXCL8, and MIF). Also, TL was associated with the upregulation of matrix metalloproteinase (MMP1, MMP2, MMP3, and MMP9) with subsequent extracellular matrix degradation and apoptosis, as reflected by upregulation of several apoptosis-related genes (ATF3, ATF4, FAS, FOS, and BIRC3). In addition, TL was associated with downregulation of 21 transcripts coding for collagens. The upregulation of proteases, along with the downregulation of collagens, is believed to be implicated in separation and rupture of the CA during TL. Additionally, TL was associated with downregulation of transcripts coding for proteins essential for progestin synthesis (SRD5A1 and AKR1C1) and angiogenesis (VEGFA and RTL1), as well as upregulation of prostaglandin synthesis-related genes (PTGS2 and PTGES), which could reflect the physiological switch in placental endocrinology and function during TL. In conclusion, our findings revealed the equine CA gene expression signature in spontaneous labor at term, which improves our understanding of the molecular mechanisms triggering labor.

Is preterm birth associated with intimate partner violence and maternal malnutrition during pregnancy in Ethiopia? A systematic review and meta analysis

BACKGROUND

Despite remarkable progress in the reduction of under-five mortality, preterm birth associated mortality and morbidity remains a major public health problem in Sub-saharan Africa. In Ethiopia, study findings on the association of preterm birth with intimate partner violence and maternal malnutrition have been inconsistent. Therefore, this systematic review and meta-analysis estimates the pooled effect of intimate partner violence and maternal malnutrition on preterm birth.

METHODS

International databases including PubMed, Web of Science, SCOPUS, CINAHL, PsycINFO, Google Scholar, Science Direct, and the Cochrane Library, were systematically searched. All identified observational studies and/or predictors were included. I2 statistics and Egger's test were used to assess the heterogeneity and publication biases of the studies. A random-effects model was computed to estimate the prevalence and its determinants of preterm birth.

RESULTS

The random effects meta-analysis showed that a pooled national prevalence of preterm birth was 13% (95% CI: 10.0%, 16.0%). The highest prevalence of preterm birth was 25% (95% CI: 21.0%, 30.0%) in Harar, and the lowest prevalence was 8% in Southern Nations Nationalities People of Representatives. The meta-analysis suggested a decrease in preterm birth of up to 61% among women receiving antenatal care [POR = 0.39 (95% CI: 0.21, 0.72)]. Women who experienced intimate partner violence [POR = 2.52 (95% CI: 1.68, 3.78)], malnutrition during pregnancy [POR = 2.00 (95% CI: 1.16, 3.46)], and previous preterm birth [POR = 3.73 (95% CI: 2.37, 5.88)] had significantly higher odds of preterm birth.

CONCLUSION

One in every eight live births in Ethiopia were preterm. Women who experienced intimate partner violence, malnutrition, and had previous preterm exposure were significantly associated with preterm birth. Thus, improving antenatal care visits and screening women who experience previous preterm birth are key interventions. The Federal Ministry of Health could be instrumental in preventing intimate partner violence and improving the nutritional status of pregnant women through proper and widespread implementation of programs to reduce preterm birth.

Transcriptomic analysis of equine chorioallantois reveals immune networks and molecular mechanisms involved in nocardioform placentitis

Nocardioform placentitis (NP) continues to result in episodic outbreaks of abortion and preterm birth in mares and remains a poorly understood disease. The objective of this study was to characterize the transcriptome of the chorioallantois (CA) of mares with NP. The CA were collected from mares with confirmed NP based upon histopathology, microbiological culture and PCR for Amycolatopsis spp. Samples were collected from the margin of the NP lesion (NPL, n = 4) and grossly normal region (NPN, n = 4). Additionally, CA samples were collected from normal postpartum mares (Control; CRL, n = 4). Transcriptome analysis identified 2892 differentially expressed genes (DEGs) in NPL vs. CRL and 2450 DEGs in NPL vs. NPN. Functional genomics analysis elucidated that inflammatory signaling, toll-like receptor signaling, inflammasome activation, chemotaxis, and apoptosis pathways are involved in NP. The increased leukocytic infiltration in NPL was associated with the upregulation of matrix metalloproteinase (MMP1, MMP3, and MMP8) and apoptosis-related genes, such as caspases (CASP3 and CASP7), which could explain placental separation associated with NP. Also, NP was associated with downregulation of several placenta-regulatory genes (ABCG2, GCM1, EPAS1, and NR3C1), angiogenesis-related genes (VEGFA, FLT1, KDR, and ANGPT2), and glucose transporter coding genes (GLUT1, GLUT10, and GLUT12), as well as upregulation of hypoxia-related genes (HIF1A and EGLN3), which could elucidate placental insufficiency accompanying NP. In conclusion, our findings revealed for the first time, the key regulators and mechanisms underlying placental inflammation, separation, and insufficiency during NP, which might lead to the development of efficacious therapies or diagnostic aids by targeting the key molecular pathways.

Transcriptomic analysis of equine placenta reveals key regulators and pathways involved in ascending placentitis†

Improved understanding of the molecular mechanisms underlying ascending equine placentitis holds the potential for the development of new diagnostic tools and therapies to forestall placentitis-induced preterm labor. The current study characterized the equine placental transcriptome (chorioallantois [CA] and endometrium [EN]) during placentitis (placentitis group, n = 6) in comparison to gestationally-matched controls (control group, n = 6). Transcriptome analysis identified 2953 and 805 differentially expressed genes in CA and EN during placentitis, respectively. Upstream regulator analysis revealed the central role of toll-like receptors (TLRs) in triggering the inflammatory signaling, and consequent immune-cell chemotaxis. Placentitis was associated with the upregulation of matrix metalloproteinase (MMP1, MMP2, and MMP9) and apoptosis-related genes such as caspases (CASP3, CASP4, and CASP7) in CA. Also, placentitis was associated with downregulation of transcripts coding for proteins essential for placental steroidogenesis (SRD5A1 and AKR1C1), progestin signaling (PGRMC1 and PXR) angiogenesis (VEGFA, VEGFR2, and VEGFR3), and nutrient transport (GLUT12 and SLC1A4), as well as upregulation of hypoxia-related genes (HIF1A and EGLN3), which could explain placental insufficiency during placentitis. Placentitis was also associated with aberrant expression of several placenta-regulatory genes, such as PLAC8, PAPPA, LGALS1, ABCG2, GCM1, and TEPP, which could negatively affect placental functions. In conclusion, our findings revealed for the first time the key regulators and mechanisms underlying placental inflammation, separation, and insufficiency during equine placentitis, which might lead to the development of efficacious therapies or diagnostic aids by targeting the key molecular pathways.

Transcriptomic analysis reveals the key regulators and molecular mechanisms underlying myometrial activation during equine placentitis†

The key event in placentitis-induced preterm labor is myometrial activation with the subsequent initiation of labor. However, the molecular mechanisms underlying myometrial activation are not fully understood in the mares. Therefore, the equine myometrial transcriptome was characterized during placentitis (290.0 ± 1.52 days of GA, n = 5) and the prepartum period (330 days of GA, n = 3) in comparison to normal pregnant mares (289.8 ± 2.18 days of GA, n = 4). Transcriptome analysis identified 596 and 290 DEGs in the myometrium during placentitis and the prepartum period, respectively, with 138 DEGs in common. The placentitis DEGs included eight genes (MMP1, MMP8, S100A9, S100A8, PI3, APOBEC3Z1B, RETN, and CXCL2) that are exclusively expressed in the inflamed myometrium. Pathway analysis elucidated that inflammatory signaling, Toll-like receptor signaling, and apoptosis pathways dominate myometrial activation during placentitis. The prepartum myometrium was associated with overexpression of inflammatory signaling, oxidative stress, and 5-hydroxytryptamine degradation. Gene ontology enrichment analysis identified several chemoattractant factors in the myometrium during placentitis and prepartum period, including CCL2, CXCL1, CXCL3, and CXCL6 in common. Upstream regulator analysis revealed 19 potential upstream regulators in placentitis dataset including transcription regulators (E2F1, FOXM1, HIF1A, JUNB, NFKB1A, and STAT1), transmembrane receptors (FAS, ICAM1, SELP, TLR2, and TYROBP), growth factors (HGF and TGFB3), enzymes (PTGS2 and PRKCP), and others (S100A8, S100A9, CD44, and C5AR1). Additionally, three upstream regulators (STAT3, EGR1, and F2R) were identified in the prepartum dataset. These findings revealed the key regulators and pathways underlying myometrial activation during placentitis, which aid in understanding the disease and facilitate the development of efficacious therapies.

Population-Based Estimation of the Preterm Birth Rate in Lilongwe, Malawi: Making Every Birth Count

Objective  The objective of this study was to perform a population-based estimation of the preterm birth (PTB) rate in regions surrounding Lilongwe, Malawi. Study Design  We partnered with obstetrician specialists, community health workers, local midwives, and clinicians in a 50 km region surrounding Lilongwe, Malawi, to perform a population-based estimation of the PTB rate during the study period from December 1, 2012 to May 19, 2015. Results  Of the 14,792 births captured, 19.3% of births were preterm, including preterm early neonatal deaths. Additional PTB risk factors were similarly prevalent including domestic violence, HIV, malaria, anemia, and malnutrition. Conclusion  When performing a population-based estimation of the rate of PTB, including women without antenatal care and women delivering at home, the 19.3% rate of PTB is among the highest recorded globally. This is accompanied by a high rate of risk factors and comorbid conditions.

Fetal exposure to maternal inflammation interrupts murine intestinal development and increases susceptibility to neonatal intestinal injury

Fetal exposure to chorioamnionitis can impact the outcomes of the developing fetus both at the time of birth and in the subsequent neonatal period. Infants exposed to chorioamnionitis have a higher incidence of gastrointestinal (GI) pathology, including necrotizing enterocolitis (NEC); however, the mechanism remains undefined. To simulate the fetal exposure to maternal inflammation (FEMI) induced by chorioamnionitis, pregnant mice (C57BL/6J, IL-6 ^-/-, RAG ^-/- or TNFR1 ^-/-) were injected intraperitoneally on embryonic day (E)15.5 with lipopolysaccharide (LPS; 100 µg/kg body weight). Pups were delivered at term, and reared to postnatal day (P)0, P7, P14, P28 or P56. Serum and intestinal tissue samples were collected to quantify growth, inflammatory markers, histological intestinal injury, and goblet and Paneth cells. To determine whether FEMI increased subsequent susceptibility to intestinal injury, a secondary dose of LPS (100 µg/kg body weight) was given on P5, prior to tissue harvesting on P7. FEMI had no effect on growth of the offspring or their small intestine. FEMI significantly decreased both goblet and Paneth cell numbers while simultaneously increasing serum levels of IL-1β, IL-10, KC/GRO (CXCL1 and CXCL2), TNF and IL-6. These alterations were IL-6 dependent and, importantly, increased susceptibility to LPS-induced intestinal injury later in life. Our data show that FEMI impairs normal intestinal development by decreasing components of innate immunity and simultaneously increasing markers of inflammation. These changes increase susceptibility to intestinal injury later in life and provide novel mechanistic data to potentially explain why preterm infants exposed to chorioamnionitis prior to birth have a higher incidence of NEC and other GI disorders.

A Comprehensive Profile of Chemokine Gene Expression in the Tissues of the Female Reproductive Tract in Mice

Homeostatic leukocyte trafficking into and within the female reproductive tract (FRT) contributes to fertility and reproductive health. It is unclear how this process is regulated in the anatomically distinct reproductive tissues, or whether the genes involved are affected by cyclical changes in reproductive hormones. In tissues such as skin and intestine, mouse studies have defined evolutionarily conserved molecular mechanisms for tissue-specific homing, interstitial positioning, and leukocyte egress. Chemokine family members are invariably involved, with the chemokine expression profile of a tissue regulating leukocyte content. Reproductive tissues (ovary, vagina, cervix, uterine horn) of 8 week old virgin female C57BL/6 mice (n = 20) were collected, and expression of mRNA for leukocyte markers and chemokines conducted by qPCR. Lymphocytic and myeloid cell populations within the uterus, cervix, bone marrow and PALN from virgin C57BL/6 mice were determined by flow cytometric analysis. Variation in leukocyte content between reproductive tissues is evident, with the uterus and cervix containing complex mixtures of lymphocytes and myeloid cells. Twenty-six chemokine genes are expressed in the FRT, many by several component tissues, some preferentially by one. Most striking are Xcl1 and Ccl28, which are restricted to the uterus. Ccl20 and genes encoding CXCR2 ligands are primarily transcribed in cervix and vagina. Ovary shows the lowest expression of most chemokine genes, with the notable exception of Ccl21 and Ccl27. We also identify eight chemokines in the vagina whose expression fluctuates substantially across the oestrous cycle. These data reveal complex chemokine networks within the FRT, and provide a framework for future studies of homeostatic leukocyte trafficking into and within these tissues.Abbreviations: BM: bone marrow; DC: dendritic cell; DN: double negative; FRT: female reproductive tract; FSC: forward scatter; NK: natural killer; PALN: para-aortic lymph node; SSC: side scatter; Tregs: regulatory T cells.

Impact of Metformin and Pioglitazone on Serum Level of Tumor Necrosis Factor-Alpha and Lipid Profiles during Implantation Window in Diabetic Rats

Background

The present study was designed to evaluate serum lipid profile and tumor necrosis factor-alpha (TNF-ɑ) level in diabetic rats at implantation time. Type 2 diabetes mellitus (T2DM) could affect various systems, including innate immune system and it causes chronic low-grade inflammation, increasing level of TNF-ɑ. Furthermore, T2DM is often accompanied by impaired lipid profile. Metformin and pioglitazone are used as the first and second lines of treatment for T2DM.

Materials and Methods

In this experimental study, 35 adult virgin female wistar rats, weighting 175-225 g, were randomly categorized into five groups: i. Control, ii. Sham, iii. Nicotinamide (NA)+streptozotocin (STZ) induced T2DM, iv. Diabetic+pioglitazone (20 mg/kg/day for 28 days oral administration), and v. Diabetic+metformin (100 mg/kg/day for 28 days oral administration). At the time of implantation, TNF-ɑ level in serum of rats was measured by ELISA kit. Glucose was measured using photometric method and lipid profiles were calculated by enzymatic methods.

Results

Level of TNF-ɑ in the diabetic group was significantly higher than other groups (P<0.001). In metformin treated group, TNF-ɑ serum level was also significantly higher than pioglitazone treated group (P<0.001). Fasting blood sugar (FBS) and lipid profiles were significantly higher in diabetic group.

Conclusion

Metformin and pioglitazone have similar effects on glucose, lipid profiles and TNF-ɑ serum levels. Among these drugs, pioglitazone has more efficient influence on TNF-α serum level, in comparison with metformin.

Quantitative Proteomics by SWATH-MS of Maternal Plasma Exosomes Determine Pathways Associated With Term and Preterm Birth

Exosomes are membrane-bound nanovesicles that transport molecular signals between cells. This study determined changes in maternal plasma exosome proteomics contents in term and preterm births. Maternal plasma (MP) samples were collected from group 1: term not in labor (TNIL, n = 13); group 2: term in labor (TL, n = 11); group 3: preterm premature rupture of membranes (pPROM, n = 8); and group 4: preterm birth (PTB, n = 13). Exosomes isolated from plasma by differential density centrifugation followed by size exclusion chromatography were characterized by morphology (electron microscopy), quantity and size (nanoparticle tracking analysis), and markers (western blot). A quantitative, information-independent acquisition [sequential windowed acquisition of all theoretical mass spectra (SWATH-MS)] approach was used to determine the protein profile in exosomes. Ingenuity Pathway Analysis determined pathways associated with the protein profile identified in exosomes. MP exosomes were spherical, had a mean diameter of 120 nm, and were positive for exosomal proteins CD63 and TSG101 irrespective of pregnancy status. No distinct changes in exosome quantities were seen in maternal circulation across the groups. SWATH-MS identified 72 statistically significant proteins across the groups studied. Bioinformatics analysis showed the proteins within the exosomes in TNIL, TL, pPROM, and PTB target pathways mainly associated with inflammatory and metabolic signals. Exosomal data suggest that homeostatic imbalances, specifically inflammatory and endocrine signaling, might disrupt pregnancy maintenance resulting in labor-related changes both at term and preterm. Reflection of physiologic changes in exosomes is suggestive of its usefulness as biomarkers and cellular function indicators.

Qualitative assessment of knowledge transfer regarding preterm birth in Malawi following the implementation of targeted health messages over 3 years

Background

In 2012, we performed a needs assessment and gap analysis to qualitatively assess providers’ and patients’ knowledge and perceptions regarding preterm birth (PTB). During the study, we identified knowledge gaps surrounding methods to reduce the risk of occurrence of PTB and management options if preterm labor/birth occur. We targeted health messages toward these gaps. The objective of the present study was to assess the impact of our community health worker-based patient education program 3 years after it was implemented.

Methods

Fifteen focus groups including 70 participants were included in the study. The groups comprised either patients/patient couples or health providers. A minimum of two facilitators led each group using 22 a priori designed and standardized lead-in prompts for participants with four additional prompts for providers only. A single researcher recorded responses, and transcript notes were reviewed by the facilitators and interpreters immediately following each group discussion to ensure accuracy.

Results

The understanding of term vs preterm gestation was generally accurate. Every participant knew of women who had experienced PTB, and the general perception was that two to three women out of every ten had this experience. The majority of respondents thought that women should present to their local health clinic if they experience preterm contractions; few were aware of the use of antenatal steroids for promoting fetal lung maturity, but many acknowledged that the neonate may be able to receive life-sustaining treatment if born at a higher level of care facility. The majority of participants were aware that PTB could recur in subsequent pregnancies. All respondents were able to list ways that women could potentially reduce the risk of PTB.

Conclusion

After employing targeted health messages, the majority of participants expressed improved understanding of the definition of PTB, methods to prevent risk of PTB, and management options for preterm labor or PTB.

Regulation of CXCL1 chemokine and CSF3 cytokine levels in myometrial cells by the MAFF transcription factor

Cytokines play key roles in a variety of reproductive processes including normal parturition as well as preterm birth. Our previous data have shown that MAFF, a member of the MAF family of bZIP transcription factors, is rapidly induced by pro‐inflammatory cytokines in PHM1‐31 myometrial cells. We performed loss‐of‐function studies in PHM1‐31 cells to identify MAFF dependent genes. We showed that knockdown of MAFF significantly decreased CXCL1 chemokine and CSF3 cytokine transcript and protein levels. Using chromatin immunoprecipitation analyzes, we confirmed CXCL1 and CSF3 genes as direct MAFF targets. We also demonstrated that MAFF function in PHM1‐31 myometrial cells is able to control cytokine and matrix metalloproteinase gene expression in THP‐1 monocytic cells in a paracrine fashion. Our studies provide valuable insights into the MAFF dependent transcriptional network governing myometrial cell function. The data suggest a role of MAFF in parturition and/or infection‐induced preterm labour through modulation of inflammatory processes in the microenvironment.

Lipopolysaccharide-induced maternal inflammation induces direct placental injury without alteration in placental blood flow and induces a secondary fetal intestinal injury that persists into adulthood

PROBLEM

Premature birth complicates 10%-12% of deliveries. Infection and inflammation are the most common etiologies and are associated with increased offspring morbidity and mortality. We hypothesize that lipopolysaccharide (LPS)-induced maternal inflammation causes direct placenta injury and subsequent injury to the fetal intestine.

METHOD OF STUDY

Pregnant C57Bl6 mice were injected intraperitoneally on day 15.5 with 100 μg/kg LPS or saline. Maternal serum, amniotic fluid, placental samples, and ileal samples of offspring were obtained assessed for inflammation and/or injury. Maternal placental ultrasounds were performed. Placental DNA was isolated for microbiome analysis.

RESULTS

Maternal injection with LPS caused elevated IL-1β, IL-10, IL-6, KC-GRO, and TNF. Placental tissue showed increased IL-1β, IL-6, and KC-GRO and decreased IL-10, but no changes were observed in amniotic fluid. Placental histology demonstrated LPS-induced increases in mineralization and necrosis, but no difference in placental blood flow. Most placentas had no detectable microbiome. Exposure to maternal LPS induced significant injury to the ilea of the offspring.

CONCLUSION

Lipopolysaccharide causes a maternal inflammatory response that is mirrored in the placenta. Placental histology demonstrates structural changes; however, placental blood flow is preserved. LPS also induces an indirect intestinal injury in the offspring that lasts beyond the neonatal period.

Spontaneous preterm birth: advances toward the discovery of genetic predisposition

Evidence from family and twin-based studies provide strong support for a significant contribution of maternal and fetal genetics to the timing of parturition and spontaneous preterm birth. However, there has been only modest success in the discovery of genes predisposing to preterm birth, despite increasing sophistication of genetic and genomic technology. In contrast, DNA variants associated with other traits/diseases have been identified. For example, there is overwhelming evidence that suggests that the nature and intensity of an inflammatory response in adults and children are under genetic control. Because inflammation is often invoked as an etiologic factor in spontaneous preterm birth, the question of whether spontaneous preterm birth has a genetic predisposition in the case of pathologic inflammation has been of long-standing interest to investigators. Here, we review various genetic approaches used for the discovery of preterm birth genetic variants in the context of inflammation-associated spontaneous preterm birth. Candidate gene studies have sought genetic variants that regulate inflammation in the mother and fetus; however, the promising findings have often not been replicated. Genome-wide association studies, an approach to the identification of chromosomal loci responsible for complex traits, have also not yielded compelling evidence for DNA variants predisposing to preterm birth. A recent genome-wide association study that included a large number of White women (>40,000) revealed that maternal loci contribute to preterm birth. Although none of these loci harbored genes directly related to innate immunity, the results were replicated. Another approach to identify DNA variants predisposing to preterm birth is whole exome sequencing, which examines the DNA sequence of protein-coding regions of the genome. A recent whole exome sequencing study identified rare mutations in genes encoding for proteins involved in the negative regulation (dampening) of the innate immune response (eg, CARD6, CARD8, NLRP10, NLRP12, NOD2, TLR10) and antimicrobial peptide/proteins (eg, DEFB1, MBL2). These findings support the concept that preterm labor, at least in part, has an inflammatory etiology, which can be induced by pathogens (ie, intraamniotic infection) or "danger signals" (alarmins) released during cellular stress or necrosis (ie, sterile intraamniotic inflammation). These findings support the notion that preterm birth has a polygenic basis that involves rare mutations or damaging variants in multiple genes involved in innate immunity and host defense mechanisms against microbes and their noxious products. An overlap among the whole exome sequencing-identified genes and other inflammatory conditions associated with preterm birth, such as periodontal disease and inflammatory bowel disease, was observed, which suggests a shared genetic substrate for these conditions. We propose that whole exome sequencing, as well as whole genome sequencing, is the most promising approach for the identification of functionally significant genetic variants responsible for spontaneous preterm birth, at least in the context of pathologic inflammation. The identification of genes that contribute to preterm birth by whole exome sequencing, or whole genome sequencing, promises to yield valuable population-specific biomarkers to identify the risk for spontaneous preterm birth and potential strategies to mitigate such a risk.

In vivo immune signatures of healthy human pregnancy: Inherently inflammatory or anti-inflammatory?

Changes in maternal innate immunity during healthy human pregnancy are not well understood. Whether basal immune status in vivo is largely unaffected by pregnancy, is constitutively biased towards an inflammatory phenotype (transiently enhancing host defense) or exhibits anti-inflammatory bias (reducing potential responsiveness to the fetus) is unclear. Here, in a longitudinal study of healthy women who gave birth to healthy infants following uncomplicated pregnancies within the Canadian Healthy Infant Longitudinal Development (CHILD) cohort, we test the hypothesis that a progressively altered bias in resting innate immune status develops. Women were examined during pregnancy and again, one and/or three years postpartum. Most pro-inflammatory cytokine expression, including CCL2, CXCL10, IL-18 and TNFα, was reduced in vivo during pregnancy (20-57%, p<0.0001). Anti-inflammatory biomarkers (sTNF-RI, sTNF-RII, and IL-1Ra) were elevated by ~50-100% (p<0.0001). Systemic IL-10 levels were unaltered during vs. post-pregnancy. Kinetic studies demonstrate that while decreased pro-inflammatory biomarker expression (CCL2, CXCL10, IL-18, and TNFα) was constant, anti-inflammatory expression increased progressively with increasing gestational age (p<0.0001). We conclude that healthy resting maternal immune status is characterized by an increasingly pronounced bias towards a systemic anti-inflammatory innate phenotype during the last two trimesters of pregnancy. This is resolved by one year postpartum in the absence of repeat pregnancy. The findings provide enhanced understanding of immunological changes that occur in vivo during healthy human pregnancy.

Protection against maternal infection-associated fetal growth restriction: proof-of-concept with a microbial-derived immunomodulator

Infection-associated inflammatory stress during pregnancy is the most common cause of fetal growth restriction and/or miscarriage. Treatment strategies for protection of at-risk mothers are limited to a narrow range of vaccines, which do not cover the bulk of the common pathogens most frequently encountered. Using mouse models, we demonstrate that oral treatment during pregnancy with a microbial-derived immunomodulator (OM85), currently used clinically for attenuation of infection-associated airway inflammatory symptoms in infants-adults, markedly reduces risk for fetal loss/growth restriction resulting from maternal challenge with bacterial lipopolysaccharide or influenza. Focusing on LPS exposure, we demonstrate that the key molecular indices of maternal inflammatory stress, notably high levels of RANTES, MIP-1α, CCL2, KC, and G-CSF (granulocyte colony-stimulating factor) in gestational tissues/serum, are abrogated by OM85 pretreatment. Systems-level analyses conducted in parallel using RNASeq revealed that OM85 pretreatment selectively tunes LPS-induced activation in maternal gestational tissues for attenuated expression of TNF, IL1, and IFNG-driven proinflammatory networks, without constraining Type1-IFN-associated networks central to first-line antimicrobial defense. This study suggests that broad-spectrum protection-of-pregnancy against infection-associated inflammatory stress, without compromising capacity for efficient pathogen eradication, represents an achievable therapeutic goal.

Clinical chorioamnionitis at term II: the intra-amniotic inflammatory response

OBJECTIVE

Recent studies indicate that clinical chorioamnionitis is a heterogeneous condition and only approximately one-half of the patients have bacteria in the amniotic cavity, which is often associated with intra-amniotic inflammation. The objective of this study is to characterize the nature of the inflammatory response within the amniotic cavity in patients with clinical chorioamnionitis at term according to the presence or absence of 1) bacteria in the amniotic cavity and 2) intra-amniotic inflammation.

MATERIALS AND METHODS

A retrospective cross-sectional case-control study was conducted to examine cytokine and chemokine concentrations in the amniotic fluid (AF). Cases consisted of women with clinical chorioamnionitis at term (n=45). Controls were women with uncomplicated pregnancies at term who did not have intra-amniotic inflammation and were in labor (n=24). Women with clinical chorioamnionitis were classified according to the results of AF cultures, broad-range polymerase chain reaction coupled with electrospray ionization mass spectrometry, and AF concentration of interleukin-6 (IL-6) into those: 1) without intra-amniotic inflammation, 2) with microbial-associated intra-amniotic inflammation, and 3) with intra-amniotic inflammation without detectable bacteria. The AF concentrations of 29 cytokines/chemokines were determined using sensitive and specific V-PLEX immunoassays.

RESULTS

1) The AF concentrations of pro- and anti-inflammatory cytokines/chemokines such as interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), interleukin-4 (IL-4), macrophage inflammatory protein-1 beta (MIP-1β), and interleukin-8 (IL-8) (except Eotaxin-3) were significantly higher in women with clinical chorioamnionitis at term than in controls (term labor without intra-amniotic inflammation); 2) patients with microbial-associated intra-amniotic inflammation, and those with intra-amniotic inflammation without detectable bacteria, had a dramatic differential expression of cytokines and chemokines in AF compared to patients with spontaneous labor without intra-amniotic inflammation. However, no difference could be detected in the pattern of the intra-amniotic inflammatory response between patients with intra-amniotic inflammation with and without detectable bacteria; and 3) in patients with clinical chorioamnionitis at term but without intra-amniotic inflammation, the behavior of cytokines and chemokines in the AF was similar to those in spontaneous labor at term.

CONCLUSIONS

Patients with clinical chorioamnionitis who had microbial-associated intra-amniotic inflammation or intra-amniotic inflammation without detectable bacteria had a dramatic upregulation of the intra-amniotic inflammatory response assessed by amniotic fluid concentrations of cytokines. A subset of patients with term clinical chorioamnionitis does not have intra-amniotic infection/inflammation, as demonstrated by elevated AF concentrations of inflammation-related proteins, when compared to women in term labor with uncomplicated pregnancies, suggesting over-diagnosis. These observations constitute the first characterization of the cytokine/chemokine network in the amniotic cavity of patients with clinical chorioamnionitis at term.

Infertility and reproductive disorders: impact of hormonal and inflammatory mechanisms on pregnancy outcome

BACKGROUND

Reproductive disorders and infertility are associated with the risk of obstetric complications and have a negative impact on pregnancy outcome. Affected patients often require assisted reproductive technologies (ART) to conceive, and advanced maternal age is a further confounding factor. The challenge is to dissect causation, correlation and confounders in determining how infertility and reproductive disorders individually or together predispose women to poor pregnancy outcomes.

METHODS

The published literature, to June 2015, was searched using PubMed, summarizing all evidences concerning the perinatal outcome of women with infertility and reproductive disorders and the potential mechanisms that may influence poor pregnancy outcome.

RESULTS

Reproductive disorders (endometriosis, adenomyosis, polycystic ovary syndrome and uterine fibroids) and unexplained infertility share inflammatory pathways, hormonal aberrations, decidual senescence and vascular abnormalities that may impair pregnancy success through common mechanisms. Either in combination or alone, these disorders results in an increased risk of preterm birth, fetal growth restriction, placental pathologies and hypertensive disorders. Systemic hormonal aberrations, and inflammatory and metabolic factors acting on endometrium, myometrium, cervix and placenta are all associated with an aberrant milieu during implantation and pregnancy, thus contributing to the genesis of obstetric complications. Some of these features have been also described in placentas from ART.

CONCLUSIONS

Reproductive disorders are common in women of childbearing age and rarely occur in isolation. Inflammatory, endocrine and metabolic mechanisms associated with these disorders are responsible for an increased incidence of obstetric complications. These patients should be recognized as 'high risk' for poor pregnancy outcomes and monitored with specialized follow-up. There is a real need for development of evidence-based recommendations about clinical management and specific obstetric care pathways for the introduction of prompt preventative care measures.

A point of care test for the determination of amniotic fluid interleukin-6 and the chemokine CXCL-10/IP-10

OBJECTIVE

Intra-amniotic inflammation is a mechanism of disease implicated in preterm labor, preterm prelabor rupture of membrane, cervical insufficiency, a short cervix, and idiopathic vaginal bleeding. Determination of interleukin (IL)-6 with immunoassays has been proven for more than two decades to be an excellent method for the detection of intra-amniotic inflammation. However, assessment of IL-6 for this indication has been based on immunoassays which are not clinically available, and this has been an obstacle for the implementation of this test in clinical practice. It is now possible to obtain results within 20 min with a point of care (POC) test which requires minimal laboratory support. This test is based on lateral flow-based immunoassay. The objective of this study was to compare amniotic fluid (AF) IL-6 and interferon-γ - inducible protein 10 (IP-10 or CXCL-10) concentrations determined using lateral flow-based immunoassay or POC test and standard enzyme-linked immunosorbent assay (ELISA) techniques.

MATERIAL AND METHODS

AF samples were collected from patients with singleton gestations and symptoms of preterm labor (n = 20). AF IL-6 and IP-10 concentrations were determined by lateral flow-based immunoassay and ELISA. Intra-amniotic inflammation was defined as AF IL-6 ≥ 2.6 ng/ml. AF IL-6 and IP-10 concentrations between two assays were compared.

RESULTS

(1) Lateral flow-based immunoassay POC AF IL-6 and IP-10 test results were strongly correlated with concentrations of this cytokine/chemokine determined by ELISA (Spearman's ρ = 0.92 and 0.83, respectively, both p < 0.0001); (2) AF IL-6 concentrations determined by the lateral flow-based immunoassay test were, on average, 30% lower than those determined by ELISA, and the median difference was statistically significant (p < 0.0001); and (3) in contrast, AF IP-10 concentrations determined by the lateral flow-based immunoassay test were, on average, only 7% lower than those determined by ELISA, and the median difference was not statistically significant (p = 0.81).

CONCLUSION

AF IL-6 and IP-10 concentrations determined using a lateral flow-based immunoassay POC are strongly correlated with concentrations determined by conventional ELISA. This justifies further studies about the diagnostic indices and predictive values of this POC test.

Sterile and microbial-associated intra-amniotic inflammation in preterm prelabor rupture of membranes

OBJECTIVE

The objectives of this study were to: (1) determine the amniotic fluid (AF) microbiology of patients with preterm prelabor rupture of membranes (PROM); and (2) examine the relationship between intra-amniotic inflammation with and without microorganisms (sterile inflammation) and adverse pregnancy outcomes in patients with preterm PROM.

METHODS

AF samples obtained from 59 women with preterm PROM were analyzed using cultivation techniques (for aerobic and anaerobic bacteria as well as genital mycoplasmas) and with broad-range polymerase chain reaction coupled with electrospray ionization mass spectrometry (PCR/ESI-MS). AF concentration of interleukin-6 (IL-6) was determined using ELISA. Results of both tests were correlated with AF IL-6 concentrations and the occurrence of adverse obstetrical/perinatal outcomes.

RESULTS

(1) PCR/ESI-MS, AF culture, and the combination of these two tests each identified microorganisms in 36% (21/59), 24% (14/59) and 41% (24/59) of women with preterm PROM, respectively; (2) the most frequent microorganisms found in the amniotic cavity were Sneathia species and Ureaplasma urealyticum; (3) the frequency of microbial-associated and sterile intra-amniotic inflammation was overall similar [ 29% (17/59)]: however, the prevalence of each differed according to the gestational age when PROM occurred; (4) the earlier the gestational age at preterm PROM, the higher the frequency of both microbial-associated and sterile intra-amniotic inflammation; (5) the intensity of the intra-amniotic inflammatory response against microorganisms is stronger when preterm PROM occurs early in pregnancy; and (6) the frequency of acute placental inflammation (histologic chorioamnionitis and/or funisitis) was significantly higher in patients with microbial-associated intra-amniotic inflammation than in those without intra-amniotic inflammation [93.3% (14/15) versus 38% (6/16); p = 0.001].

CONCLUSIONS

(1) The frequency of microorganisms in preterm PROM is 40% using both cultivation techniques and PCR/ESI-MS; (2) PCR/ESI-MS identified microorganisms in the AF of 50% more women with preterm PROM than AF culture; and (3) sterile intra-amniotic inflammation was present in 29% of these patients, and it was as or more common than microbial-associated intra-amniotic inflammation among those presenting after, but not before, 24 weeks of gestation.

The preterm placental microbiome varies in association with excess maternal gestational weight gain

OBJECTIVE

Although a higher maternal body mass index is associated with preterm birth, it is unclear whether excess gestational weight gain (GWG) or obesity drives increased risk. We and others have shown that the placenta harbors microbiota, which is significantly different among preterm births. Our aim in this study was to investigate whether the preterm placental microbiome varies by virtue of obesity or alternately by excess GWG.

STUDY DESIGN

Placentas (n=320) were collected from term and preterm pregnancies. Genomic DNA was extracted and subjected to metagenomic sequencing. Data were analyzed by clinical covariates that included the 2009 Institute of Medicine's GWG guideline and obesity.

RESULTS

Analysis of 16S recombinant RNA-based metagenomics revealed no clustering of the microbiome by virtue of obesity (P=.161). Among women who spontaneously delivered preterm, there was again no clustering by obesity (P=.480), but there was significant clustering by excess GWG (P=.022). Moreover, among preterm births, detailed analysis identified microbial genera (family and genus level) and bacterial metabolic gene pathways that varied among pregnancies with excess GWG. Notably, excess GWG was associated with decreased microbial folate biosynthesis pathways and decreased butanoate metabolism (linear discriminate analysis, >3.0-fold).

CONCLUSION

Although there were no significant alterations in the microbiome by virtue of obesity per se, excess GWG was associated with an altered microbiome and its metabolic profile among those women who experienced a preterm birth.

Rhododendron album Blume inhibits iNOS and COX-2 expression in LPS-stimulated RAW264.7 cells through the downregulation of NF-κB signaling

Rhododendron album Blume (RA) has traditionally been used as an herbal medicine and is considered to have anti-inflammatory properties. In the present study, we screened RA extracts with anti-inflammatory properties. The biological effects of an RA methanol extract (RAME) on inflammation were investigated in lipopolysaccharide (LPS)-stimulated mouse RAW264.7 cells. We investigated the effects of RAME on the production of nitric oxide (NO) and prostaglandin E2 (PGE2) in LPS-stimulated RAW264.7 cells. To explore the anti-inflammatory mechanisms of RAME, we measured the mRNA and protein expression of pro-inflammatory mediators induced by RAME in the LPS-stimulated RAW264.7 cells by RT-PCR and western blot analysis, respectively. RAME significantly inhibited the production of NO, PGE2, interleukin (IL)-6, IL-1β and tumor necrosis factor (TNF)-α in the LPS-stimulated RAW264.7 cells. It also suppressed the mRNA and protein expression of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2) and mitogen-activated protein kinases (MAPKs) with a concomitant decrease in the nuclear translocation of nuclear factor-κB (NF-κB) in the LPS-stimulated RAW264.7 cells. These results indicate that RAME inhibits LPS-induced inflammatory responses. These effects were considered to be strongly associated with the suppression of NF-κB activation. We therefore suggest that RAME may be prove to be an effective therapeutic agent for the treatment of inflammatory diseases.

Early elevations of the complement activation fragment C3a and adverse pregnancy outcomes

OBJECTIVE

To estimate whether elevations of complement C3a early in pregnancy are predictive of the subsequent development of adverse pregnancy outcomes.

METHODS

A plasma sample was obtained from each enrolled pregnant woman before 20 weeks of gestation. The cohort (n=1,002) was evaluated for the development of adverse pregnancy outcomes defined as hypertensive diseases of pregnancy (gestational hypertension or preeclampsia), preterm birth (before 37 weeks of gestation), premature rupture of the membranes, pregnancy loss (during the embryonic and fetal period), intrauterine growth restriction, and the composite outcome of any adverse outcome.

RESULTS

One or more adverse pregnancy outcomes occurred in 211 (21%) of the cohort. The mean levels (ng/mL) of C3a in early pregnancy were significantly (P=<.001) higher among women with one or more adverse outcomes (858±435) compared with women with an uncomplicated pregnancy (741±407). Adjusted for parity and prepregnancy body mass index, women with levels of C3a in the upper quartile in early pregnancy were three times more likely to have an adverse outcome later in pregnancy compared with women in the lowest quartile (95% confidence interval, 1.8-4.8; P<.001). The link between early elevated C3a levels and adverse pregnancy outcomes was driven primarily by individual significant (P<.05) associations of C3a with hypertensive diseases of pregnancy, preterm birth, and premature rupture of the membranes.

CONCLUSION

Elevated C3a as early as the first trimester of pregnancy is an independent predictive factor for adverse pregnancy outcomes, suggesting that complement-related inflammatory events in pregnancy contribute to the subsequent development of poor outcomes at later stages of pregnancy.

LEVEL OF EVIDENCE

II.

Psychosocial stress in pregnancy and preterm birth: associations and mechanisms

AIMS

Psychosocial stress during pregnancy (PSP) is a risk factor of growing interest in the etiology of preterm birth (PTB). This literature review assesses the published evidence concerning the association between PSP and PTB, highlighting established and hypothesized physiological pathways mediating this association.

METHOD

The PubMed and Web of Science databases were searched using the keywords "psychosocial stress", "pregnancy", "pregnancy stress", "preterm", "preterm birth", "gestational age", "anxiety", and "social support". After applying the exclusion criteria, the search produced 107 articles.

RESULTS

The association of PSP with PTB varied according to the dimensions and timing of PSP. Stronger associations were generally found in early pregnancy, and most studies demonstrating positive results found moderate effect sizes, with risk ratios between 1.2 and 2.1. Subjective perception of stress and pregnancy-related anxiety appeared to be the stress measures most closely associated with PTB. Potential physiological pathways identified included behavioral, infectious, neuroinflammatory, and neuroendocrine mechanisms.

CONCLUSIONS

Future research should examine the biological pathways of these different psychosocial stress dimensions and at multiple time points across pregnancy. Culture-independent characterization of the vaginal microbiome and noninvasive monitoring of cholinergic activity represent two exciting frontiers in this research.

Periodontitis in pregnant baboons: systemic inflammation and adaptive immune responses and pregnancy outcomes in a baboon model

BACKGROUND/OBJECTIVES

Chronic periodontal infections have been suggested to contribute to the risk of adverse pregnancy outcomes.

MATERIAL AND METHODS

This study describes the relationship of patterns of systemic inflammatory mediators and IgG antibody to 20 oral bacteria in pregnant female baboons (Papio anubis) coupled with clinical features of ligature-induced periodontitis, as risk indicators for adverse pregnancy outcomes. Animals showing a preterm delivery and/or low birth weight newborns, as well as those pregnancies resulting in spontaneous abortion, stillbirth, or fetal demise were tabulated as adverse pregnancy outcomes.

RESULTS

A significantly greater frequency of the periodontitis group neonates had a low birth weight (18.1%; p = 0.008) and decreased gestational age (9.8%). Spontaneous abortion/stillbirth/fetal demise were increased in the periodontitis (8.7%) versus the control group (3.8%) (p = 0.054). The baseline oral clinical presentation of the experimental animals did not relate to the adverse pregnancy outcomes. Animals with the greatest extent/severity of periodontitis progression during the initial ½ of gestation (ie. to mid-pregnancy) had the greatest risk for adverse pregnancy outcomes. Baseline biological parameters indicating historical responses of the animals to periodontal challenge demonstrated individual variation in selected mediators, some of which became more differential during ligature-induced periodontitis. The relationship of clinical parameters to systemic inflammatory responses was consistent with a temporal contribution to adverse pregnancy outcomes in a subset of the animals.

CONCLUSIONS

These results support a link between periodontitis and adverse pregnancy outcomes in the baboons and provide a prospective experimental model for delineating the biologic parameters that contribute to a causal relationship between chronic oral infections and birth events.

Demystifying animal models of adverse pregnancy outcomes: touching bench and bedside

This represents an overview of the use of animal models to study the adverse pregnancy outcomes seen in humans. The purpose is to entice clinicians to utilize some of this information to seek out the literature and have more meaningful and profitable discussions with their academic colleagues and enhance transdisciplinary research in reproductive health.

Systemic inflammatory responses in progressing periodontitis during pregnancy in a baboon model

This study tested the hypothesis that pregnant female baboons exhibit increased levels of various inflammatory mediators in serum resulting from ligature-induced periodontitis, and that these profiles would relate to periodontal disease severity/extent in the animals. The animals were sampled at baseline (B), mid-pregnancy (MP; two quadrants ligated) and at delivery (D; four quadrants ligated). All baboons developed increased plaque, gingival inflammation and bleeding, pocket depths and attachment loss following placement of the ligatures. By MP, both prostaglandin E(2) (PGE(2)) and bactericidal permeability inducing factor (BPI) were greater than baseline, while increased levels of interleukin (IL)-6 occurred in the experimental animals by the time of delivery. IL-8, MCP-1 and LBP all decreased from baseline through the ligation phase of the study. Stratification of the animals by baseline clinical presentation demonstrated that PGE(2), LBP, IL-8 and MCP-1 levels were altered throughout the ligation interval, irrespective of baseline clinical values. IL-6, IL-8 and LBP were significantly lower in the subset of animals that demonstrated the least clinical response to ligation, indicative of progressing periodontal disease. PGE(2), macrophage chemotactic protein (MCP)-1, regulated upon activation, normal T cell expressed and secreted (RANTES) and LBP were decreased in the most diseased subset of animals at delivery. Systemic antibody responses to Fusobacterium nucleatum, Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans and Campylobacter rectus were associated most frequently with variations in inflammatory mediator levels. These results provide a profile of systemic inflammatory mediators during ligature-induced periodontitis in pregnant baboons. The relationship of the oral clinical parameters to systemic inflammatory responses is consistent with a contribution to adverse pregnancy outcomes in a subset of the animals.

VITAMIN D AND HUMAN PREGNANCY

At the end of 2007, Time magazine listed the “benefits of vitamin D” as one of its top 10 medical breakthroughs for that year. Since then there has been a remarkable upsurge of interest in vitamin D, with new research advances seemingly published on a weekly basis. In particular, there has been increasing awareness of the variability of vitamin D status in populations across the globe and, significantly, a growing debate about the need for revised parameters for vitamin D supplementation. Although sub-optimal vitamin D is likely to be a widespread problem for 21stcentury societies, it is also clear that some groups are at much greater risk of low vitamin D status. Prominent amongst these are pregnant women and the aim of the following review article will be to discuss this problem in further detail with specific emphasis on its potential physiological and clinical impact.

Changes in placental CRH, urocortins, and CRH-receptor mRNA expression associated with preterm delivery and chorioamnionitis

CONTEXT

The pathogenesis of preterm delivery (PTD) is not clear, although inflammation/infection play a major role. Corticotropin releasing-hormone (CRH) and Urocortins (Ucns) are involved in the pathophysiology of PTD.

OBJECTIVE

This study evaluates trophoblast mRNA expression of CRH, Ucn, Ucn2, Ucn3, and their receptors [CRH-type 1 receptor (CRH-R1), CRH-R2] in infective conditions. To determine whether infection or glucocorticoids contribute to change their placental mRNA expression, the effects of lipopolysaccharide or dexamethasone was evaluated.

DESIGN

Placentas were obtained from spontaneous PTD; premature rupture of membranes (pPROM) and pPROM with chorioamnionitis.

SETTING

Placental specimens were collected from women receiving perinatal care at our Division of Obstetrics and Gynecology.

PATIENTS OR OTHER PARTICIPANTS

Pregnant women delivered preterm were enrolled.

INTERVENTIONS

mRNA expression was evaluated by RT-PCR.

MAIN OUTCOME MEASURE

Because CRH and Ucns are involved in immunological functions we evaluated their involvement in PTD with or without infection.

RESULTS

CRH, Ucn2, and CRH-R1 mRNA expression were higher, while Ucn and CRHR-2 were lower in pPROM with chorioamnionitis than in PTD and pPROM. Ucn3 mRNA expression was lower in pPROM with and without chorioamnionitis than in PTD. The addition of lipopolysaccharide in trophoblast explants decreased Ucn, Ucn3, and CRH-R2 and increased CRH, Ucn2, and CRH-R1 mRNA expression in a dose-dependent manner. Dexamethasone increased CRH and decreased Ucn2 mRNA expression in a dose dependent manner.

CONCLUSIONS

Our findings showed a significant impact of pPROM with chorioamnionitis on placental CRH peptides and receptors, suggesting that placental expression of stress-related pathways is activated in infective process.

Cord blood chemokines differentiate between spontaneous and elective preterm births in singleton pregnancies

BACKGROUND

Signals originating from both maternal and fetal compartments participate in the preterm labor process.

OBJECTIVE

To investigate whether cord blood immunoproteins predict spontaneous preterm labor.

METHODS

Cord blood from 125 very preterm (gestational age <32weeks) singleton infants and 33 term infants was collected after birth and analyzed for 107 immunoproteins on microarrays. Immunoproteins from spontaneous preterm births (SPTB) were compared to immunoproteins from preterm births without labor. The placentas were studied for histology and immunohistochemistry. The data was modeled by classification and regression trees (CART) analysis.

RESULTS

In preterm births, low CCL16 level predicted SPTB with a sensitivity of 94.7%, and specificity of 46.9%. According to logistic regression analysis, low CCL16 (OR 57.9), histologic chorioamnitis (OR 33.6), and high CCL23 (OR 44.6) were independent risk factors of SPTB. Cord blood CCL16 was higher in preterm births without labor and in term births than in SPTBs. CCL16 and its signaling receptor CCR1 were visualized in syncytiotrophoblast and cytotrophoblast cells of placental villi.

CONCLUSION

Low umbilical cord blood chemokine CCL16 associates with spontaneous preterm birth. Further studies are required to show whether CCL16 is involved in spontaneous preterm labor or in placental disease necessitating elective preterm delivery.

Characterization of the myometrial transcriptome and biological pathways of spontaneous human labor at term

AIMS

to characterize the transcriptome of human myometrium during spontaneous labor at term.

METHODS

myometrium was obtained from women with (n=19) and without labor (n=20). Illumina HumanHT-12 microarrays were utilized. Moderated t-tests and false discovery rate adjustment of P-values were applied. Real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) was performed for a select set of differentially expressed genes in a separate set of samples. Enzyme-linked immunosorbent assay and Western blot were utilized to confirm differential protein production in a third sample set.

RESULTS

1) Four hundred and seventy-one genes were differentially expressed; 2) gene ontology analysis indicated enrichment of 103 biological processes and 18 molecular functions including: a) inflammatory response; b) cytokine activity; and c) chemokine activity; 3) systems biology pathway analysis using signaling pathway impact analysis indicated six significant pathways: a) cytokine-cytokine receptor interaction; b) Jak-STAT signaling; and c) complement and coagulation cascades; d) NOD-like receptor signaling pathway; e) systemic lupus erythematosus; and f) chemokine signaling pathway; 4) qRT-PCR confirmed over-expression of prostaglandin-endoperoxide synthase-2, heparin binding epidermal growth factor (EGF)-like growth factor, chemokine C-C motif ligand 2 (CCL2/MCP1), leukocyte immunoglobulin-like receptor, subfamily A member 5, interleukin (IL)-8, IL-6, chemokine C-X-C motif ligand 6 (CXCL6/GCP2), nuclear factor of kappa light chain gene enhancer in B-cells inhibitor zeta, suppressor of cytokine signaling 3 (SOCS3) and decreased expression of FK506 binding-protein 5 and aldehyde dehydrogenase in labor; 5) IL-6, CXCL6, CCL2 and SOCS3 protein expression was significantly higher in the term labor group compared to the term not in labor group.

CONCLUSIONS

myometrium of women in spontaneous labor at term is characterized by a stereotypic gene expression pattern consistent with over-expression of the inflammatory response and leukocyte chemotaxis. Differential gene expression identified with microarray was confirmed with qRT-PCR using an independent set of samples. This study represents an unbiased description of the biological processes involved in spontaneous labor at term based on transcriptomics.

Maternal cytokine balance on the third postpartum day is not affected by the mode of delivery after healthy pregnancies

Previous reports have suggested that delivery is associated with the induction of inflammatory cytokines. The present study was designed to investigate whether increased cytokine production was present on postpartum day 3 after a normal pregnancy and whether any changes were associated with the mode of delivery. In total, 33 pregnant women were enrolled; 18 delivered vaginally and 15 underwent an elective caesarean section (C-section). The levels of 17 cytokines and growth hormones were measured at the beginning of delivery or before anaesthesia and on postpartum day 3. While interleukin (IL)-6 and IL-8 levels decreased significantly postpartum, other cytokine concentrations were comparable before and after delivery. Only IL-7 levels were significantly increased in the C-section patients compared with the vaginal birth patients postpartum. In conclusion, there was no risk of a prolonged maternal inflammatory reaction after an uncomplicated vaginal birth or elective C-section, so it is probably not necessary to consider this as an issue when making a decision on the mode of delivery following uncomplicated pregnancy.

Metabolomics in premature labor: a novel approach to identify patients at risk for preterm delivery

OBJECTIVE

Biomarkers for preterm labor (PTL) and delivery can be discovered through the analysis of the transcriptome (transcriptomics) and protein composition (proteomics). Characterization of the global changes in low-molecular weight compounds which constitute the 'metabolic network' of cells (metabolome) is now possible by using a 'metabolomics' approach. Metabolomic profiling has special advantages over transcriptomics and proteomics since the metabolic network is downstream from gene expression and protein synthesis, and thus more closely reflects cell activity at a functional level. This study was conducted to determine if metabolomic profiling of the amniotic fluid can identify women with spontaneous PTL at risk for preterm delivery, regardless of the presence or absence of intraamniotic infection/inflammation (IAI).

STUDY DESIGN

Two retrospective cross-sectional studies were conducted, including three groups of pregnant women with spontaneous PTL and intact membranes: (1) PTL who delivered at term; (2) PTL without IAI who delivered preterm; and (3) PTL with IAI who delivered preterm. The first was an exploratory study that included 16, 19, and 20 patients in groups 1, 2, and 3, respectively. The second study included 40, 33, and 40 patients in groups 1, 2, and 3, respectively. Amniotic fluid metabolic profiling was performed by combining chemical separation (with gas and liquid chromatography) and mass spectrometry. Compounds were identified using authentic standards. The data were analyzed using discriminant analysis for the first study and Random Forest for the second.

RESULTS

(1) In the first study, metabolomic profiling of the amniotic fluid was able to identify patients as belonging to the correct clinical group with an overall 96.3% (53/55) accuracy; 15 of 16 patients with PTL who delivered at term were correctly classified; all patients with PTL without IAI who delivered preterm neonates were correctly identified as such (19/19), while 19/20 patients with PTL and IAI were correctly classified. (2) In the second study, metabolomic profiling was able to identify patients as belonging to the correct clinical group with an accuracy of 88.5% (100/113); 39 of 40 patients with PTL who delivered at term were correctly classified; 29 of 33 patients with PTL without IAI who delivered preterm neonates were correctly classified. Among patients with PTL and IAI, 32/40 were correctly classified. The metabolites responsible for the classification of patients in different clinical groups were identified. A preliminary draft of the human amniotic fluid metabolome was generated and found to contain products of the intermediate metabolism of mammalian cells and xenobiotic compounds (e.g. bacterial products and Salicylamide).

CONCLUSION

Among patients with spontaneous PTL with intact membranes, metabolic profiling of the amniotic fluid can be used to assess the risk of preterm delivery in the presence or absence of infection/inflammation.

Nrf3-deficient mice are not protected against acute lung and adipose tissue damages induced by butylated hydroxytoluene

We found that both wild type and Nrf3 (NF-E2-related factor 3) deficient mice are sensitive to BHT single administration exhibiting respiratory distress and considerably lose body weight following treatment. At time of sacrifice, the BHT-treated Nrf3-/- mice had lost significantly more body weight than their WT counterparts. In the lung, transcript levels of the transcription factors Nrf1, Nrf2 and Nrf3 were differentially regulated by BHT treatment. In addition, genes implicated in adipogenesis were repressed following BHT exposure in the white adipose tissue. Together, our data provide the first evidence that BHT exposure not only affects lung function but also leads to impaired adipogenesis in adipocytes.

Pretreatment with pancaspase inhibitor (Z-VAD-FMK) delays but does not prevent intraperitoneal heat-killed group B Streptococcus-induced preterm delivery in a pregnant mouse model

Caspases and apoptosis are thought to play a role in infection-associated preterm-delivery. We have shown that in vitro treatment with pancaspase inhibitor Z-VAD-FMK protects trophoblasts from microbial antigen-induced apoptosis. Objective. To examine whether in vivo administration of Z-VAD-FMK would prevent infection-induced preterm-delivery. Methods. We injected 14.5 day-pregnant-mice with heat-killed group B streptococcus (HK-GBS). Apoptosis within placentas and membranes was assessed by TUNEL staining. Calpain expression and caspase-3 activation were assessed by immunohistochemistry. Preterm-delivery was defined as expulsion of a fetus within 48 hours after injection. Results. Intrauterine (i.u.) or intraperitoneal (i.p.) HK-GBS injection led to preterm-delivery and induced apoptosis in placentas and membranes at 14 hours. The expression of calpain, a caspase-independent inducer of apoptosis, was increased in placenta. Treatment with the specific caspase inhibitor Z-VAD-FMK (i.p.) prior to HK-GBS (i.p.) delayed but did not prevent preterm-delivery. Conclusion. Caspase-dependent apoptosis appears to play a role in the timing but not the occurrence of GBS-induced preterm delivery in the mouse.

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

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

Possible dual roles for prostacyclin in human pregnancy and labor

During pregnancy, the muscular layer of the uterine wall known as the myometrium, which is composed mainly of smooth muscle cells, is maintained in a state of relative quiescence. A switch from myometrial quiescence to myometrial activation is required to establish uterine contractions during labor. Researchers have long been perplexed by the fact that the major prostaglandin produced by the uterus just prior to labor, prostacyclin, is a smooth muscle relaxant. In this issue of the JCI, Fetalvero et al. provide data that they propose explains this paradox, at least in part (see the related article beginning on page 3966). The authors examined uterine tissue from pregnant women near term and found that prostacyclin stimulation, which raises cAMP levels that were previously thought to affect only myometrial quiescence, can promote myometrial activation over time by increasing the expression of a select group of proteins thought to be indicative of a uterine contractile state.