Ella Ofori

Preventing cervical ripening: the primary mechanism by which progestational agents prevent preterm birth?

OBJECTIVE Recent clinical trials suggest that progestational agents may prevent preterm birth, specifically in women with short cervices. These studies sought to assess novel pathways by which progestational agents (PAs) may modify signal transduction pathways that are involved in cervical ripening. STUDY DESIGN A microarray analysis was performed on pregnant mouse cervix that was exposed to a MPA. Appropriate microarray and cluster analyses were performed. Target genes of interest were investigated in both PA- and inflammation-exposed cervices by quantitative polymerase chain reaction and immunohistochemistry. RESULTS Microarray analysis identified both the previously recognized and novel pathways that are involved in cervical ripening. PAs differentially regulate expression of claudin-2, hyaluronan synthase 2, and lipocalin 2. Claudin expression is significantly decreased by inflammation, which is prevented by PAs. CONCLUSION PAs significantly modulate gene expression in the cervix in the presence and absence of inflammation. The regulation of these pathways, specifically claudin proteins, may be a critical mechanism by which PAs prevent preterm birth, especially in women with premature cervical shortening.

Preterm and Term Cervical Ripening in CD1 Mice (Mus musculus): Similar or Divergent Molecular Mechanisms?

Premature cervical ripening is believed to contribute to preterm birth (PTB). Preterm cervical ripening may be due to an aberrant regulation in timing of the same processes that occur at term, or may result from unique molecular mechanisms. Using mouse models of PTB, this study sought to investigate if the molecular mechanisms that govern cervical ripening were similar between preterm and term. Lipopolysaccharide (LPS) is infused into the uterine horn to create a mouse model of inflammation-induced PTB. For a noninfectious model of PTB, RU486 was administered. Both models result in delivery of pups in 8–24 h. Cervical tissues were collected from these models, as well as throughout gestation. Cervical tissues from E15 (preterm), E15 LPS (preterm inflammation), and E18.5 (term) were used for microarray analysis (n = 18). Additional experiments using gestational time course specimens were performed to confirm microarray results. Specific gene pathways were differentially expressed between the groups. Genes involved in immunity and inflammation were increased in the cervix in inflammation-induced PTB; term labor was not associated with differential expression of immune pathways. Cytokine expression was not increased in cervices during term labor, but was increased in the pospartum period. Epithelial cell differentiation pathway was significantly altered in term, but not preterm, labor. Activation of immune pathways may be sufficient for cervial ripening, but does not appear necessary. Differential expression of the epithelial cell differentiation pathway appears necessary in the process of cervical repair. Our results indicate that the molecular mechanisms governing preterm and term cervical ripening are distinctly different.

Beyond white matter damage: fetal neuronal injury in a mouse model of preterm birth

OBJECTIVE The purpose of this study was to elucidate possible mechanisms of fetal neuronal injury in inflammation-induced preterm birth. STUDY DESIGN With the use of a mouse model of preterm birth, the following primary cultures were prepared from fetal brains: (1) control neurons (CNs), (2) lipopolysaccharide-exposed neurons (LNs), (3) control coculture (CCC) that consisted of neurons and glia, and (4) lipopolysaccharide-exposed coculture (LCC) that consisted of lipopolysaccharide-exposed neurons and glia. CNs and LNs were treated with culture media from CN, LN, CCC, and LCC after 24 hours in vitro. Immunocytochemistry was performed for culture characterization and neuronal morphologic evidence. Quantitative polymerase chain reaction was performed for neuronal differentiation marker, microtubule-associated protein 2, and for cell death mediators, caspases 1, 3, and 9. RESULTS Lipopolysaccharide exposure in vivo did not influence neuronal or glial content in cocultures but decreased the expression of microtubule-associated protein 2 in LNs. Media from LNs and LCCs induced morphologic changes in control neurons that were comparable with LNs. The neuronal damage caused by in vivo exposure (LNs) could not be reversed by media from control groups. CONCLUSION Lipopolysaccharide-induced preterm birth may be responsible for irreversible neuronal injury.

Evaluating the association between all components of the metabolic syndrome and pre-eclampsia.

Objective. Hypothesising that metabolic syndrome may be associated with or useful in the prediction of pre-eclampsia, we investigated the association between all components of metabolic syndrome and C-reactive protein (CRP) in women with and without pre-eclampsia. Methods. A case–control study was performed. Cases had gestational hypertension or pre-eclampsia and controls were term deliveries. Clinical data and maternal serum was collected. The presence of metabolic syndrome (3/5 variables present) and a metabolic score (continuous 0–5) were investigated. Significant associations were evaluated using t-tests, and Pearson chi-square tests of association. Multivariable logistic regression was used to control for confounders. Results. One-hundred and one cases and 267 controls were evaluated. We observed a higher odds of pre-eclampsia when metabolic syndrome was present (AOR = 2.71 [1.1–6.67], p = 0.03). For every one-unit increase in metabolic score, there was a 39% increased odds of pre-eclampsia (AOR = 1.39 [1.06–1.82], p = 0.017). The odds of pre-eclampsia were nearly four times higher when hs- CRP was >8 (AOR = 3.61 [2.14–6.12], p < 0.001). Conclusions. Metabolic syndrome and hs-CRP are associated with pre-eclampsia. Investigation is crucial to determine if these abnormal lipid and inflammatory pathways observed in women with pre-eclampsia are present pre-pregnancy or develop as a result of the disease process of pre-eclampsia. Further investigation is also warranted to determine whether these abnormalities persist post-pregnancy and if so, their contribution to long-term cardiovascular disease.

Inflammation-Induced Preterm Birth in a Murine Model Is Associated with Increases in Fetal Macrophages and Circulating Erythroid Precursors

The presence of intrauterine inflammation has been associated with adverse neurologic outcomes in preterm infants, but the precise mechanisms of fetal brain injury remain unclear. We sought to evaluate inflammatory cell trafficking, fetal organ damage, and molecular regulation in the fetoplacental unit using an established mouse model of preterm birth associated with intrauterine inflammation. Gestational sacs were harvested 6 hours after intrauterine infusion of saline or lipopolysaccharide (LPS). Histologic, immunohistochemical, and molecular investigations were performed to identify target organ damage and the cellular phenotype of inflammatory cells and to quantify circulating inflammatory and hematopoietic mediators within the placental and fetal tissue. There was widespread increase in fetal macrophages in LPS-exposed pups, including within the leptomeninges of the brain, associated with significantly higher of interleukin 6 levels in LPS-exposed pups. Although no specific central nervous system injury (necrosis or apoptosis) was documented, liver hematomas were seen significantly more frequently in LPS-exposed pups. Circulating nucleated fetal erythrocytes were also present more frequently with LPS exposure without significantly higher erythropoietin levels than saline-exposed mice. The presence of increased macrophages, increased circulating interleukin 6 levels, and increased circulating erythroid precursors in LPS-exposed pups suggests that these are significant factors associated with potential target organ damage, such as liver hematomas, associated with intrauterine inflammation and preterm birth. The role of macrophages within the fetal leptomeninges is unclear, but they may play an important role in inflammatory-mediated brain damage, and further investigation of their significance and potential as therapeutic targets is warranted.

Maternal mortality from systemic illness: unraveling the contribution of the immune response.

OBJECTIVE Maternal morbidity and/or mortality (MM) is increased in pyelonephritis and influenza. Alterations in the immune response could account for the increase MM. We sought to determine whether the immune response is functionally different during pregnant and nonpregnant (NP) states. STUDY DESIGN Mouse model of systemic and localized inflammation was used. Maternal serum was assessed for expression of T-helper cell type 1 and 2 cytokines. Maternal spleens were harvested for immunohistochemistry. RESULTS Systemic administration of lipopolysaccharides resulted in no mortality to NP mice compared with 88% in preterm and 100% in term mice. A potent cytokine response was present in both NP and pregnancy. Systemic inflammation in pregnancy results in increased CD8 and CD11c expression in spleens. CONCLUSION Differences in cytokine response to systemic inflammation is unlikley to modulate the increased MM during pregnancy. Altered T-cell and dendritic cell responses in pregnancy may be responsible for the increase in MM.

The use of angiogenic factors in discriminating preeclampsia: are they ready for prime time?

Objectives. We sought to evaluate the association between soluble fms-like tyrosine kinase 1 (sFlt1) and endoglin (ENG) and preeclampsia in an urban population, to develop a discriminatory model, and evaluate the association of these biomarkers with small for gestational age (SGA). Methods. Cases are prospectively identified with preeclampsia. Controls are term patients without preeclampsia. Commercially available ELISAs were used to measure levels of sFlt1, ENG, and placental growth factor (PlGF). Log-transformed levels were compared and multivariable logistic regression analyses were performed to control for confounders. Receiver operating characteristic curves were developed. Results. In cases (n = 86) compared to controls (n = 288), sFlt1 (p = 0.24) levels were no different. However, ENG levels were higher (p < 0.001), and PlGF levels were lower (p < 0.001). Further, levels of sFlt1 had poor discriminatory ability between cases and controls [AUC = 0.56, (0.48–0.63)]. The best model to discriminate between groups included clinical risk factors, ENG, and PlGF [AUC = 0.89, (0.85–0.92)]. Conclusions. Unlike recent reports, this study suggests that sFlt1 may have limited diagnostic utility in predicting preeclampsia, especially term disease.