Background: Women are more likely to develop age-related cognitive impairment compared with men of the same age. Pregnancy complications, such as preeclampsia (PE), and menopause may contribute to an elevated risk of cognitive decline with aging in women potentially through an adverse impact on vascular function. PE is associated with a heightened risk of hypertension and large elastic artery stiffness (i.e., aortic and carotid arteries) for several years postpartum. Persistent large artery stiffness may be further amplified in women with a history of PE during the menopause transition, which is marked by an accelerated rate of vascular aging. However, large artery stiffness has not been studied extensively in postmenopausal women with a history of PE. Age-related elevations in large artery stiffness are associated with cognitive decline in middle-aged and older adults however, this relation has not been investigated in young women with a history of PE. Moreover, the degree to which elevated large artery stiffness is amplified and associated with reduced cognitive function among postmenopausal women with a history of PE remains unknown. The purpose of this study was to examine the extent to which large elastic artery stiffness is associated with reductions in cognitive function in premenopausal and postmenopausal women with a history of PE. Methods: Large elastic artery stiffness and domains of cognitive function were assessed in young women one year postpartum (n=18, ages 24-41 yrs.) and postmenopausal women (n=19, ages 52-77 yrs.) thirty-five years postpartum. Aortic stiffness was measured via non-invasive applanation tonometry at the carotid and femoral pulse sites and expressed as carotid-femoral pulse wave velocity (cfPWV). Carotid artery stiffness was quantified as beta-stiffness index (β-stiffness) was measured via ultrasonography and carotid tonometry. Cognitive tests were administered to assess cognitive function in immediate and delayed recall, working memory, processing speed, and executive function. Results: Premenopausal women with a history of PE had higher systolic blood pressure (121 ± 4 vs. 101 ± 3 mmHg, p =0.01) one year postpartum but did not differ significantly from controls in cfPWV (6.2 ± 0.4 vs. 5.1 ± 0.2 m/s, p =0.08), β-stiffness (6.1 ± 0.5 vs. 6.1 ± 0.7 U, p =0.97), or cognitive domains of memory, executive function, or processing speed (all p>0.05). Higher systolic blood pressure was associated with lower executive function (r = -0.53, p = 0.05) in young women one year postpartum. Postmenopausal women with a history of PE did not differ from controls in blood pressure, large artery stiffness, or age-adjusted cognitive domains of memory, executive function, or processing speed (all p>0.05). Large artery stiffness was not associated with cognitive function in premenopausal or postmenopausal women. Conclusions: Young women with a history of PE had elevated systolic pressure one year postpartum, which was associated with reductions in executive function. Large artery stiffness was not elevated or related to cognitive function in postmenopausal women with a history of PE. These preliminary findings suggest that young women with a history of PE are susceptible to reductions in selective cognitive domains related to higher blood pressure, but this effect does not appear to extend into the postmenopausal period.

Preeclampsia is a hypertensive disorder of pregnancy that is diagnosed after the 20th week of gestation. It is defined by the American College of Obstetrics and Gynecology as de novo hypertension of at least 140/90 in a pregnant woman. Proteinuria with the hypertension is sufficient but not required for the diagnosis, especially if a woman displays severe symptoms such as headache, blurry vision, right upper quadrant pain, and low platelet count. Despite significant research, preeclampsia continues to kill 76,000 mothers and 500,000 babies per year worldwide. It causes short and long term consequences such as future metabolic and cardiovascular events for the mother and the child born during a pregnancy affected by preeclampsia. A delay in diagnosis and delayed access to appropriate care is a core cause of the preeclampsia related morbidity and severe mortality worldwide. Despite being in the medical literature since the time of the ancient Greeks, there is currently no significant predictive, preventative, therapeutic, and curative agent for preeclampsia except for an often preterm delivery of the fetus. The complex pathogenesis of preeclampsia has challenged the ability to effectively predict preeclampsia to decrease the delay in this diagnosis. Consequently, an early intervention or triage to higher level obstetric care is hindered. The lack of an early biomarker for preeclampsia also represents a major barrier to treat preeclampsia before major clinical symptoms emerge and the cycle of future cardiovascular risk for mom and baby begins. Novel, very early pregnancy predictive tests for preeclampsia may provide significant clinical utility. Furthermore, a biomarker that is linked with an early pathogenic mechanism in the first trimester development of preeclampsia would reveal a new avenue of early, first trimester intervention to treat and prevent this devastating disease. This work details the search for such a biomarker linked to an early initiator of the molecular pathogenesis of preeclampsia. These microRNA data highlight very important dysregulated mechanisms including immunologic, cell growth, and angiogenic mechanisms. T cells and the role of indoleamine 2,3 dioxygenase (IDO) is important in the early, maternal immune tolerance to the placenta and pregnancy. As poor placentation is a core cause of preeclampsia, a decreased immune tolerance to it is hypothesized to lead to preeclampsia. Furthermore, low IDO activity has been observed in the placentas of preeclamptic pregnancies which may make it a viable biomarker. These IDO-knock out mouse data, demonstrate that chronic IDO deficiency is sufficient to cause some of the core phenotypes of preeclampsia including renal dysfunction, vascular endothelial dysfunction, fetal growth restriction, and a slight increase in systolic blood pressure. This model does not completely phenocopy human preeclampsia. An investigation of early markers that are linked to vascular, immune, and renal abnormalities highlights the vasopressin pathway as a potential biomarker and early initiator of the pathogenesis of preeclampsia. These data demonstrate that copeptin, as a stable marker of vasopressin secretion, is robustly predictive of the development of late pregnancy human preeclampsia, as early as the 6th week of gestation. Furthermore, a mouse model with chronic infusion of vasopressin throughout mouse gestation phenocopies all the essential aspects of human preeclampsia: pregnancy specific hypertension, proteinuria, pathognomonic glomerular endotheliosis, fetal growth restriction, and increased fetal death. Further research must be done to elucidate the immunologic, vascular, and fetal programming phenotypes of this model. This work posits the possibility that the vasopressin pathway may provide new predictive, preventative, therapeutic, and potentially curative modalities for preeclampsia.

Affecting 6-8% of all pregnancies, preeclampsia is the leading cause of maternal morbidity in the western world and is charactensed by hypertension, proteinuria, edema and platelet aggregation. Despite its prevalence and severity, no comprehensive theory or single factor has been suggested to explain the pathophysiology of this multi system disorder of pregnancy, with the only therapies being bed rest, pharmacological symptom management and if necessary early delivery. Oxidative stress plays an important role in the pathophysiology of preeclampsia, resulting from defective trophoblast invasion, reductions in placental perfusion and placental hypoxia/reoxygenation. The inability of endogenous antioxidant systems up regulated in normal pregnancy, to control increased levels of oxidative stress, is suggested as a possible factor in the feed forward generation of reactive oxygen species and placental oxidative stress. That in turn may stimulate increased syncytiotrophoblast apoptosis, endothelial cell activation and the maternal hyper immune response characteristic of preeclampsia. Analysis of the research literature revealed that previous evaluations of placental oxidation and antioxidant enzyme activity in preeclampsia were by no means comprehensive, and exhibited significant inter-study variations. It was the aim of this thesis to clarify the placental oxidative state and the endogenous antioxidant activity of glutathione peroxidase, thioredoxin reductase, thioredoxin and superoxide dismutase in human placentae in an attempt to determine if variations in antioxidant function were due to changes in gene expression or protein oxidation. The findings reported in this thesis indicate the presence of increased levels of oxidative stress in the preeclamptic placenta, associated with significant reductions in antioxidant enzyme capacity. Quantitative real-time PCR analysis of placental samples revealed that deceases in antioxidant capacity in the placenta are more likely to be related to the significant oxidative burden within the tissue rather than reductions in gene expression. A number of animal models exist to investigate components of preeclampsia pathophysiology, however the ability of these models to mimic the oxidative and antioxidant features of preeclampsia remains unclear. The exposure of pregnant rats to N(G)-nitro-L-arginine methyl ester is a widely used model of endothelial cell dysfunction during preeclampsia. It was the aim of this thesis to determine the biochemical characteristics of this model in an attempt to assess its effectiveness in mimicking oxidative changes in the preeclamptic placenta. Although this model is capable of producing a syndiome in rats similar to the disorder in terms of physiology, this is not manifest in terms of placental biochemistry. The importance of selenium in the synthesis of selenobased antioxidants such as glutathione peroxidase and thioredoxin reductase is well documented. Increasing demand for selenium by the developing fetus may be linked to reductions in selenium status during pregnancy. Considering preeclampsia is associated with significant reductions in selenium status it may be hypothesised that reductions in antioxidant function may be linked to selenium inadequacy. The modulation of dietary selenium in pregnant rats was used to determine the importance of selenium during pregnancy and its effect on antioxidant function and placental oxidative stress. The results of this analysis revealed that selenium deficiency causes a pregnancy specific condition similar to preeclampsia. This condition was found to be associated with increased placental oxidative stress and significant reductions in the systemic activity of selenobased antioxidants that could be modified through selenium supplementation. In summary, data obtained in this thesis indicate that placental oxidative stress and reduced antioxidant enzyme activity play a significant role in the pathogenesis of preeclampsia. These studies support the hypothesis that antioxidant sufficiency is crucial in the maintenance of oxidative balance and that antioxidant dysfunction may result in damage to the placenta and the progression of the disease. These novel data further our understanding of the pathophysiology of preeclampsia and provide new insight into the pathogenesis of clinical complications exhibited in this condition, suggesting antioxidant therapy as a possible means for improving the health outcomes of both mother and baby.

Objectif: élaborer un index prédictif de la prééclampsie basé sur les données les plus significatives de lanamnèse, de la clinique, de la biologie et des tests fonctionnels afin didentifier les patientes qui présentent un risque élevé de développer une prééclampsie (PE). Méthodes: Etude cas-contrôle comparant, en dehors de toute grossesse, des patientes ayant présenté, lors dune grossesse antérieure, une prééclampsie (n=101) avec des patientes dont la grossesse a eut un décours strictement normal, à parier pour la gestité, la parité, lâge, lassuétude au tabac et le délai depuis cette grossesse (n=50). Les paramètres analysés sont lanamnèse, lexamen clinique, la biologie sanguine (coagulopathie, trombophilie, hyperhomocystéinémie, vitamines B, marqueurs rénaux et vasculaires); et approches morphologie et fonctionnelle (système cardiovasculaire et rénal). Etude statistique de régressions logistiques a été appliquée à lensemble des données afin de nen dégager que les plus représentatives dans chacune des directions suivies par létude (anamnèse, biologie, épreuve fonctionnelle). Résultats: Lidentification des patientes à haut risque de prééclampsie peut être faite efficacement (88 % de sensibilité et 88 % de spécificité en se basant sur les trois index de risques construits respectivement sur les données anamnestiques et cliniques, sur les données de la biologie et sur les épreuves fonctionnelles. Conclusion: Il ny a actuellement aucun dépistage possible des patientes à risque de prééclampsie en dehors de la grossesse. Cette étude permet lélaboration dun index prédictif de la prééclampsie en préconceptionnel et par la même ouvre les portes à une prévention primaire.

Preeclampsia and molar pregnancy are two devastating placental pathologies characterized by an immature proliferative trophoblast phenotype accompanied by excessive cell death. It is therefore of paramount importance to study the regulation of cell fate in the placenta, to gain a further understanding of the mechanisms that contribute to these diseases. In this dissertation we report that during normal placental development and in preeclampsia, Matador (Mtd), a pro-apoptotic member of the Bcl-2 family, has a dual function in regulating trophoblast cell proliferation and death. Importantly, we reveal a novel role of Mtd-L in promoting cyclin E1 expression and cell cycle progression. Of clinical importance, we also identify that both cyclin E1 and the CDK inhibitor p27, are increased in severe early onset preeclampsia. However, the inhibitory function of p27 in this pathology may be hampered due to its increased phosphorylation at Ser10, resulting in its nuclear export. Of equal importance, data presented demonstrate that placentae from severe early onset preeclampsia display a molecular profile distinct from late onset preeclampsia or intrauterine growth restricted pregnancies. In the final data chapter we demonstrate that Mtd is highly expressed in molar tissue, where it localizes to both apoptotic and proliferative cells. Our data suggests that an abundance of Mtd and cyclin E1 in conjunction with the low level of p27 may contribute to the hyperproliferative nature of the disorder. The body of work in this dissertation uncovers novel insights into the regulation of trophoblast cell fate. Importantly, the impact of Mtd on cyclin E1 to promote G1-S transition is a novel mechanism found to regulate trophoblast cell proliferation in normal and pathological placentation. Equally important is our identification of molecular differences between placental pathologies that may help to differentiate early and late onset preeclampsia, IUGR and molar pregnancy.

Factor inhibiting HIF (FIH) negatively regulates hypoxia inducible factor-1 (HIF-1) transcriptional activity, selectively controlling certain HIF-1 target genes, such as vascular endothelial growth factor (VEGF) and prolyl hydroxylase domain 3 (PHD3), but not others. PHD3 and VEGF are important for placental development and function and are overexpressed in preeclampsia (PE). The purpose of this study was to examine FIH in both normal and pathological human placentae. I hypothesized that FIH regulates VEGF and PHD3 in the placenta and that this rheostat is altered in PE. Results show that FIH suppresses PHD3 and VEGF in JEG-3 cells; this effect was abrogated by FIH gene silencing. Moreover, my data indicate that seven in absentia homologue-1 (Siah-1) targets FIH for degradation in the placenta; this degradation is enhanced in PE and likely contributes to aberrant VEGF and PHD3 expression. Overall, my data suggest an important role for FIH in the pathogenesis of PE.

Background: Some studies have suggested that the risk of preeclampsia in HIV positive pregnant women has increased since the use of HAART became routine. There is also a concern that HIV positive women on HAART have a higher risk of adverse fetal outcomes compared to HIV negative women. Methods: In this matched retrospective cohort study, the risk of preeclampsia and adverse fetal outcomes was examined in 91 HIV positive pregnant women receiving HAART and 273 HIV negative pregnant women. Multivariate logistic regression models were used to adjust for confounding factors. Results: The risk of preeclampsia and preterm birth did not differ significantly between HIV positive and HIV negative women. HIV treated with HAART was an independent predictor for giving birth to a low birthweight baby. Conclusions: HIV positive women on HAART do not have a higher risk of preeclampsia. They do however have a higher risk for lower birthweight infants.

Factor inhibiting HIF (FIH) negatively regulates hypoxia inducible factor-1 (HIF-1) transcriptional activity, selectively controlling certain HIF-1 target genes, such as vascular endothelial growth factor (VEGF) and prolyl hydroxylase domain 3 (PHD3), but not others. PHD3 and VEGF are important for placental development and function and are overexpressed in preeclampsia (PE). The purpose of this study was to examine FIH in both normal and pathological human placentae. I hypothesized that FIH regulates VEGF and PHD3 in the placenta and that this rheostat is altered in PE. Results show that FIH suppresses PHD3 and VEGF in JEG-3 cells; this effect was abrogated by FIH gene silencing. Moreover, my data indicate that seven in absentia homologue-1 (Siah-1) targets FIH for degradation in the placenta; this degradation is enhanced in PE and likely contributes to aberrant VEGF and PHD3 expression. Overall, my data suggest an important role for FIH in the pathogenesis of PE.

Background: Some studies have suggested that the risk of preeclampsia in HIV positive pregnant women has increased since the use of HAART became routine. There is also a concern that HIV positive women on HAART have a higher risk of adverse fetal outcomes compared to HIV negative women. Methods: In this matched retrospective cohort study, the risk of preeclampsia and adverse fetal outcomes was examined in 91 HIV positive pregnant women receiving HAART and 273 HIV negative pregnant women. Multivariate logistic regression models were used to adjust for confounding factors. Results: The risk of preeclampsia and preterm birth did not differ significantly between HIV positive and HIV negative women. HIV treated with HAART was an independent predictor for giving birth to a low birthweight baby. Conclusions: HIV positive women on HAART do not have a higher risk of preeclampsia. They do however have a higher risk for lower birthweight infants.

Die Bedeutung der angiogenen Faktoren „soluble fms-like tyrosine kinase-1“ (sFlt-1) und „placental growth factor“ (PIGF) in der Pathogenese der Präeklampsie (PE) ist in den letzten Jahren hinreichend belegt worden. Bei Patienten mit manifester PE lassen sich dramatisch hohe sFlt-1- bzw. sehr niedrige PlGF-Werte nachweisen. Mittlerweile konnte in Studien die sFlt-1/PlGF-Ratio als sensitiver Parameter ermittelt werden. Ziel der vorliegenden Arbeit ist es, die Zusammenhänge zwischen klinischen Parametern der manifesten Präeklampsie und der sFlt-1/PlGF-Ratio zu spezifizieren. Dabei soll geprüft werden, ob bei manifester PE die Höhe der sFlt-1/PlGF-Ratio vor Entbindung klinische Bedeutung hat und mit Parametern des Schwangerschaftsausgangs in Beziehung steht.