Research Grants and Fellowships

With the adoption of routine PAP smear screening for dysplasia of the cervix, there has been a dramatic decrease in the incidence and mortality of cervical cancer. Concern exists, however, with the increased morbidity associated with treatments of cervical intraepithelial neoplasia and micro invasive cancer of the cervix, particularly as they relate to increases in preterm labour, preterm premature rupture of the membranes (PPROM) and second trimester pregnancy loss.

Mechanisms by which cervical procedures may cause adverse pregnancy outcomes include an attenuation of mechanical supports relative to the length of the cervix. Alternatively, a possible decrease in mucus production by the cervix may cause a subsequent increase in susceptibility to infection because of the loss of the mucous plug barrier.

Known risk factors for preterm labour include: advancing maternal age, maternal smoking, low socioeconomic status, advancing parity and previous preterm delivery.

The objective of this study is to determine the risk of adverse obstetrical outcomes associated with treatment – namely loop electrosurgical excision procedure (LEEP) and cone biopsy of the cervix - for high grade intraepithelial lesion, carcinoma in situ and micro invasive cancer of the cervix. In addition, we will analyze the risk associated with single and multiple treatments with LEEP and/or cone biopsy.

Adverse pregnancy outcomes to be studied include preterm labour (>37wks,>34wks,>28wks), PPROM and second trimester pregnancy loss. Our analysis will also look at the correlation between cervical cerclage placement for cervical incompetence and the relationship with previous cone biopsy(s)/LEEP procedures. In addition, we will investigate medical assessments (obstetrical triage visits) for threatened preterm labour. Our goal is to perform a multivariable analysis, controlling for known risk factors and confounders in the process.

The human placenta mediates the physiological exchange of gas, nutrients, and waste between mother and fetus. In vitro studies have shown oxygen to be a key regulator of trophoblast differentiation and, thus, of placental development. Early placentation occurs in a relatively hypoxic environment, which supports proliferation of the trophoblast cells. Around 10-12 weeks of gestation, when the placenta opens to the maternal circulation, oxygen levels rapidly increase and promote trophoblast cell invasion of the uterine wall. Impairment of these key cellular events during early placentation, as a result of altered oxygenation and/or impaired oxygen sensing by the trophoblast cells, is thought to have implications in pregnancy-related disorders, such as Preeclampsia (PE) and Intrauterine Growth Restriction (IUGR). PE and IUGR, which are characterized by improper placental development and placental hypoxia, affect 7%-10% of all pregnancies and remain the most common cause of fetal and maternal mortality and morbidity; their etiologies, however, remain an enigma.

In most mammalian systems, Hypoxia Inducible Factor-1 (HIF-1) is the major player involved in sensing low levels of cellular oxygen and eliciting the appropriate adaptive responses. HIF-1 is a transcription factor composed of an inducible -subunit and a constitutive -subunit. Under hypoxic conditions, HIF-1 is stable and promotes the transcription of a variety of genes involved in erythropoiesis, angiogenesis, and glycolysis. Under normoxic conditions, HIF-1is targeted for proteasomal degradation, following proline hydroxylation, by the (oxygen-dependent) prolyl hydroxylases domain (PHD) enzymes. Additionally, in normoxia, Factor Inhibiting HIF-1 (FIH-1), an oxygen-dependent asparginyl hydroxylase, specifically targets and hydroxylates the Asn803 residue located in the C-terminal transactivation domain (C-TAD) of HIF-1. This hydroxylation event, in turn, prevents HIF-1 from recruiting the transcriptional coactivator CBP/p300, and thereby represses its transcriptional activity. Moreover, it has recently been shown that FIH-1 selectively controls the expression of a variety of HIF-1 target genes, further highlighting its intricate role in fine-tuning the HIF-1 machinery.

While numerous studies have investigated specific aspects of HIF-1 regulation, little is known about the mechanisms by which HIF-1 transcriptional activity is regulated in both hypoxia and normoxia. We have recently demonstrated that during human placental development, HIF-1 stability is spatially and temporally regulated by the PHDs and that HIF-1 expression is upregulated in PE. The role of FIH-1 in human placental development and in placental pathologies has never been considered.

As such, the focus of my graduate studies will be to establish the spatial and temporal expression of FIH-1 throughout human placental development and in placental pathologies; to investigate the role of FIH-1 in regulating downstream HIF-1 target genes in the human placenta; and to determine the upstream regulation of FIH-1.

Hypothesis: FIH-1 plays an important role in regulating the expression of HIF-1 target genes during human placental development. Consequently, disruption of FIH-1 expression and function during early placentation contributes to aberrant expression of HIF-1-dependent genes and, in turn, may predispose the pregnancies to PE and/or IUGR.

Annually, over 500,000 women die due to pregnancy and pregnancy-related causes worldwide, and this number has not changed appreciably in decades. Over 99% of these deaths occur in the developing world. In addition to maternal deaths, there are a far greater number of women and children worldwide who suffer the consequences of unsafe childbirth and a lack of access to emergency obstetrical care; these consequences include such injuries as Obstetric Fistula (OF) and the consequences of mother-to-child transmission of HIV.

Improving maternal care worldwide has been an area of interest for me since I had the opportunity to spend a two-month elective in Uganda after my first year of medical school. Since that time I have taken numerous opportunities to work in developing countries, in particular in Sub Saharan Africa and to participate in clinical care and research.

The Scace/Genesis Award in Global Reproductive Health is allowing me to pursue a Master’s Degree in Public Health (MPH), concentrating in International Health and with an interdisciplinary concentration in Women and Gender Health at Harvard University. This education formalizes my public health skills and training through the teaching of crucial public health and research skills including biostatistics, epidemiology and ethics as well as skills and courses specific to the practice and research of international reproductive health. As part of the MPH program, I will also be writing a thesis which will focus on programming to improve maternal health care in the Eldoret, Kenya area (site of the ASANTE University of Toronto Reproductive Health Partnership) in the context of the new Mother-Baby Hospital, currently under construction.

In the course of pursuing the Master’s Degree in Public Health course of studies at Harvard University, I remain involved in international health work through the University of Toronto Department of Obstetrics and Gynecology, primarily through the ASANTE Reproductive Health Partnership in Eldoret, Kenya.

Current areas of research focus on factors associated with Obstetric Fistula and OF outcomes, evaluating various methods of screening for cervical cancer in resource poor settings and developing and evaluating a training program in essential obstetrical skills for maternal and neonatal health care workers in the region.

The opportunity to spend the year in Boston provides the opportunity for the development of connections and collaborations with other individuals in the Boston academic circles working in global health. Having completed a Master’s Degree in Public Health, the training will greatly benefit future clinical and research work and will also help future trainees at the University of Toronto with an interest in the area of Global Women’s Health.

Ovarian cancer is the leading cause of death of all gynecologic malignancies in the developing world. Despite the advances in chemotherapeutic agents and treatment modalities for patients with ovarian cancer, the mortality rate has not changed significantly over the past twenty years. Studies continue to evaluate varying treatment strategies to improve clinical outcomes in patients with ovarian cancer.

Randomized controlled trials can assess the efficacy of a treatment regimen in selected populations of patients and practitioners, but these studies do not necessarily evaluate the effectiveness of a treatment in the “real-world.” The use of large databases of patients undergoing treatment for ovarian cancer deepens our understanding of the practical effectiveness of a treatment and provides additional information on outcomes that may not be measurable in a randomized controlled trial.

By using the ovarian cancer database at our institution combined with the provincial cancer registry, we plan on studying a number of aspects of clinical health outcomes in this population. We are currently evaluating survival outcomes of patients with less common histologic types of ovarian cancer, such as endometrioid compared to serous tumor pathologies. Our large database contains experience from over twenty years of patient care which allows us to make meaningful comparisons between these cohorts. Future studies will include the role of optimal surgical staging of early stage ovarian cancers in determining adjuvant treatment options, the outcomes associated with neoadjuvant chemotherapy compared to primary surgical debulking, and use of radiation in early stage tumors. The outcomes will be obtained by considering all important prognostic factors, adjusting for these factors by multivariate regression analyses, and incorporating the appropriate use of propensity scores and sensitivity analyses.

This research will continue to generate hypotheses related to possible treatment strategies in ovarian cancer and potentially help to improve the survival outcomes for patients suffering from ovarian cancer.

Intrauterine growth restriction (IUGR), defined as failure of the fetus to achieve its genetically determined growth potential, complicates 4-7% of births and is linked to a 6 to 10 fold increased risk of perinatal mortality. Low placental oxygenation is believed to play a pivotal role in the development of IUGR based on observations indicating increased expression of genes regulated by hypoxia in placentae of IUGR pregnancies.

Endoglin is a cell-surface co-receptor for transforming growth factor (TGF)-ß1 and TGF- ß3 isoforms and is highly expressed in endothelial cells and syncytiotrophoblasts. It has been shown that endoglin plays a key regulatory role in the process of trophoblast differentiation along the invasive pathway. Recent evidence has indicated that in preeclamptic placentae endoglin expression is elevated, and this is associated with high circulatory levels of its soluble form (sENG). It has been hypothesized that sENG may act in concert with soluble VEGF receptor 1 (sFlt1) to induce severe preeclampsia. We have previously reported that TGFß3 expression is regulated by oxygen and is high in pre-eclamptic pregnancies.

The goal of this project is to determine the role of oxygen and TGFß in regulating the expression of endoglin in the human placenta and to characterize endoglin expression in physiological and pathological models of placental hypoxia.

We will examine placentae from different stages of development, knowing that early placentation occurs in poorly oxygenated environment and at 10-12 weeks there is an increase in oxygen tension. In addition, as a pathological model of placental hypoxia we will use placentae of IUGR pregnancies including both IUGR singletons and discordant twins, in which the normal co-twin serves as a control of the IUGR discordant twin. We believe that the pathology in the IUGR discordant twin truly represents a placental disease since both twins are exposed to the same maternal environment.

We believe that findings of this project will introduce new data regarding the regulation of endoglin in the human placenta and will contribute to the understanding of the pathogenesis of IUGR.

Night-time shift work has been identified as a risk factor for several life-threatening pathologies including breast and colon cancer, cardiovascular disease, depression and anxiety disorders, and metabolic abnormalities including obesity and type 2 diabetes. This increased risk is thought to involve recurrent disruption of normal circadian endocrine rhythms triggered by nocturnal lighting. There are more than 11 million shift workers in North America alone who are exposed to nocturnal lighting and routinely subjected to circadian rhythm disruption. Thus development of an effective method to prevent the adverse effects of nocturnal lighting on circadian rhythm disruption would have a tremendous long-term impact on the incidence of diseases that contribute substantially to Canada’s healthcare burden.

The effects of lighting on circadian rhythm entrainment are thought to be mediated by retinal ganglion cells (RGCs) that project to the suprachiasmatic nucleus (SCN) via the retinohypothalamic tract. RGCs are maximally activated by light within the wavelength range of 450-480nm (blue light). We hypothesize that filtration of light in this range can prevent disruption of circadian endocrine rhythms induced by nocturnal light. In preliminary studies using an animal model, filtration of light between 470-480 nm prevented nocturnal light induced disruption of circadian rhythms in melatonin and corticosterone secretion and the expression of core clock genes which regulate biological rhythms. Our initial findings suggest that filtration of low wavelengths from nocturnal light may be a simple, economical approach to reduce the health risks attributed to shift work and nocturnal light exposure. My future studies will investigate normalization of circadian activity rhythms under nocturnal bright light by blocking low wavelengths and to extend our findings in the animal model to humans.

Aim 1: To determine if normalization of nocturnal light-induced changes in endocrine and gene expression extends to normalization of feeding/drinking and locomotor activity. Circadian rhythms are evident in overt activity such as locomotion and feeding and recent evidence suggests that these activity rhythms are maximally affected by low wavelengths of light. Therefore, we will examine if filtering the 470 to 480 nm range from nocturnal lighting can attenuate locomotor activity phase shifts similar to normalizing circadian endocrine rhythms.

Aim 2: To determine the neural and molecular pathway involved in the normalization of endocrine and activity circadian rhythms under filtered nocturnal light. Both endocrine and activity rhythms are regulated by the SCN and the timing of these rhythms is synchronized to the geo-physical light/dark cycle. RGCs project directly onto the SCN via the RHT and activate the SCN by transducing the photic information. Hence, we will examine if the mechanism by which low wavelength optical filters work to normalize circadian rhythms may be through reducing RGC activation leading to reduced SCN activity under nocturnal lighting.

Aim 3: To test whether blocking light wavelengths between 470-480 nm will prevent circadian rhythm alterations in humans exposed to nocturnal lighting. We have already demonstrated that broader range optical filters can be used to normalize melatonin secretion in volunteers exposed to a simulated shift-work environment. We will next examine if filtering only a narrow 10nm bandwidth of optical wavelengths can normalize the rhythms of endocrine markers of metabolism, reproduction and circadian phase along with clock gene expression patterns in humans. Furthermore, psychomotor performance, mood, alertness and fatigue will be determined as neuro-physiologic outcome measures.

Significance: The optical filters we have developed could be used as eyewear or applied to light covers or the surface of light bulbs to provide an economical and effective means to prevent circadian rhythm disruption in shift workers, thereby significantly reducing morbidity and mortality in this population.

It has long been known that disturbances of the fetal environment can have profound effects on the development and health of an individual. Studies examining exposure to alcohol, radiation and maternal infections during pregnancy have shown altered development and significant birth defects. The term “programming” is used to describe this, the action of an environmental factor during a sensitive period of development that produces effects that persist throughout life. It is emerging that chronic maternal adversity during pregnancy can have a negative impact on offspring behaviour. Maternal adversity during gestation has been linked to the development of psychiatric disorders, including attention-deficit hyperactivity disorder (ADHD), depression and schizophrenia as well as an increased risk of behavioural and emotional problems in children.

Recent human studies and studies utilizing animals models have shown that maternal adversity is not only linked to altered behaviour but also endocrine function. Indeed these studies have shown that increased maternal anxiety during late pregnancy leads to altered function of the hypothalamo-pituitary-adrenal (HPA) axis in children, which in turn will influence their ability to cope with stress. It has also been proposed that long-term changes in HPA function may lead to altered behaviours through the direct actions of glucocorticoids (stress hormones) on neurotransmitter systems in the brain. For example glucocorticoids are known to influence the forebrain dopaminergic systems that regulate attention and activity, centres directly linked to ADHD in the human.

Aim 1: To determine the effects of chronic maternal adversity on the molecular regulation of systems in the brain that control HPA function and modulate attention and activity levels.

Emerging important evidence from animal experiments indicates that it may be possible to reverse the effects of chronic maternal adversity by enriching/enhancing the quality of the post-natal environment. This may occur by reversing the modification of HPA function or by direct actions on the central dopaminergic system.

Aim 2: To determine the efficacy of environmental enrichment in reversing the endocrine and behavioural effects of chronic maternal adversity and to identify the molecular pathways involved.

Given the emerging literature on the effects of maternal adversity in children, and the rapidly increasing incidence of childhood behavioural disorders such as ADHD, it is imperative we understand the mechanisms by which chronic maternal adversity negatively affects behaviour and endocrine regulation in both juvenile and adult offspring. Once we have this information, we will be in a position to develop therapies for infants and young children exposed to an adverse early environment.

Ovarian Cancer is the number one cause of death among gynecological malignancies and fifth among cancer deaths in women. Advances such as novel chemotherapeutic agents, advanced surgical practice and optimized drug delivery techniques have prolonged the overall survival time in these women, but mortality rates have fluctuated little over the last twenty years.

One of the strategies used to study cancer today is through the use of mass analysis techniques. At the forefront of these techniques is the use of microarrays. Microarrays are platforms that contain information about all of the genes that are turned on or off in specific cancer cells. Determining which genes are turned on in chemotherapy resistant cells for example, would allow researchers to target these genes in order to make them sensitive once again, or to design drugs that might work on alternate gene targets. The advent of array based technology in combination with the completion of the human genome project has enabled researchers to compile tremendous amounts of data on different tumor types. More recently, it has been identified that cancer is more complex than simply a number of genes turned on or off, but rather the answer may lie in collections of genes (metagene signatures) that may be turned on or off together.

The research being performed by our group tackles the problem from several angles. First, specific genes will be sequenced to determine if subtle changes in their sequence combine with specific array patterns identified. The idea here is that whether a group of genes may be turned on or off together might be dependent on subtle changes in these specific genes. The first of these genes we are going to characterize is p53, the most commonly mutated gene in ovarian cancer. The next approach is to use the most up-to-date, sophisticated software to link gene data that has already been collected with groups of genes known to work mechanistically together (i.e. A group of genes that decides whether a cell replicates or not). Finally, once these metagene signatures have been identified, preliminary work will be performed to test cells with drugs against the specific gene collections to determine if a calculable response can be achieved.

Cancer research today has no shortage of data to analyze. The key in the coming years will be to determine how the data fit together creating specific tumor types and their varied characteristics. The research at this institution is at the forefront of this type of analysis and will continue to work at unlocking the key to ovarian cancer genetics.

Multidrug resistance phosphoglycoprotein (Mdr1/P-gp) belongs to a superfamily of ATP-dependent transporters shown to actively transport a wide range of compounds including antiretroviral HIV protease inhibitors, cardiac glycosides, analgesics as well as exogenous and endogenous steroids. The human multidrug resistance gene (MDR1) was first discovered in tumor derived cells, where it was shown to be involved in the development of resistance to chemotherapeutic agents. Subsequently, multidrug resistance genes (mdr1a and mdr1b) have been identified in the mouse and together are believed to functionally resemble MDR1.

More recently, Mdr1/P-gp has been identified in a number of normal tissues including the intestines, kidney, liver and adrenal where it has been shown to play an important role in limiting absorption and/or facilitating excretion of a wide range of substrates. Tissues with specialized barrier functions such as the blood-brain, blood-testes and blood-placental barriers also express Mdr1/P-gp. Information pertaining to Mdr1/P-gp’s regulation and functional significance in the placenta is minimal.

In most mammals (including human) maternal plasma GC concentrations are 2-10 fold higher than those found in fetal circulation. Fetal protection from high maternal GCs is critical to fetal development. Fetal exposure to GCs of maternal origin is regulated by the placenta. One mechanism controlling fetal exposure to maternally derived GCs is placental 11ß-hydroxysteroid dehydrogenase enzyme type 2 (11ß-HSD2). Recently, the functional importance of Mdr1/P-gp in preventing GC entry into specialized barrier tissues has been demonstrated, such that in the brains of Mdr1/P-gp knockout (KO) animals, a 2-fold increase in GC transfer was observed as compared to wild-type. Similar mechanisms likely operate in other specialized barrier tissues such as the placenta.

We have recently shown high levels Mdr1/P-gp in the syncitial layers of the placenta at mid-gestation, followed by a dramatic decrease in late gestation. Further, our transfer studies have established the importance of placental Mdr1/P-gp in limiting drug transfer of Mdr1/P-gp specific substrates to the developing fetus. These studies also demonstrated a close correlation between placental expression and Mdr1/P-gp function. However, the role of placental Mdr1/P-gp in the prevention of transplacental GC transfer has not been investigated. We now propose a novel model whereby placental Mdr1/P-gp acts in concert with 11ß-HSD2 to protect the fetus from maternally derived GCs. The focus of my doctoral studies is: 1) to determine the role of placental Mdr1/P-gp in fetal protection against maternally derived glucocorticoids (GCs) and 2) to determine whether GCs can modulate expression and/or function of placental Mdr1/P-gp.

Hypothesis: 1) Placental Mdr1/P-gp plays a critical role in protecting the developing fetus from maternally derived GCs. 2) GCs regulate the expression and function of placental Mdr1/P-gp.

Given the potential protective effects of placental Mdr1/P-gp, it is imperative that we understand its function and regulation during pregnancy. This new knowledge will enable the development of improved strategies for fetal protection against the entry of excess GC as well as other drugs and potential teratogens during inappropriate time ‘windows’ of development.

Insulin-like growth factors (IGFs) are essential proteins for stimulating growth during fetal development. IGF levels are mainly regulated by the inhibitory effects of insulin-like growth factor binding protein-1 (IGFBP-1) during fetal life. In humans and animals, high levels of IGFBP-1 leads to low birth weight and are associated with increased incidence of heart disease morbidity and mortality in adulthood. Unfortunately, the effects of IGFBP-1 on fetal heart development and whether such effects lead to long-lasting and adverse consequences on the adult cardiovascular system are unknown.

A mouse model overexpressing IGFBP-1 was created in order to mimic low birth weight in humans. Using this model, our lab has demonstrated enlarged heart to body weight ratio during fetal development, which is commonly observed in human growth restriction. Increase cardiomyocyte size and decreased cardiomyocyte proliferation was also observed. These findings suggest a decrease in total cardiomyocyte count at birth. Because cardiomyocytes largely lose their ability to proliferate shortly after birth in mice (and humans), decreased cardiomyocyte count likely persists into adulthood. Decrease total cardiomyocyte count can explain for the observed impairments in heart structure and function in adulthood. These impairments are likely to increase the risk of acquiring heart diseases.

The next step in this research is to determine the effects of adult heart structural and functional impairments on the mothers’ ability to adapt to the increases in cardiovascular demands that occur during pregnancy. Preliminary studies performed in our lab showed that heart function in the IGFBP-1 overexpressing mice progressively worsen during pregnancy, which is likely to decrease placental perfusion and subsequently decrease maternal-fetal substrate exchange, and therefore further contributes to fetal growth restriction observed in this mouse model. Collectively, these results suggest, not only can elevated levels of IGFBP-1 alter heart development during fetal life and can cause adult heart impairments, it can also impair fetal growth in the next generation by compromising the mother’s ability to support the growing fetus.

Many serious disorders of human pregnancy, including miscarriage, fetal intrauterine growth restriction, and preeclampsia, are believed to be caused by dysfunctional early placental development. It is difficult to use human placentas to understand the root causes of these disorders because placentas become available for study after delivery when the early events that underlie these disorders are long past. However, it is now clear that placental development in mice is remarkably similar to that of humans. Indeed recent studies in genetically-altered mice have shown that the genes important in placental development are very similar between the two species. We are particularly interested in one such gene - GCM1 - which when mutated to inhibit expression, was shown to block placental development. Interestingly this gene is also expressed in the human placenta, and low levels of expression are associated with human fetal growth restriction. However, whether low levels of GCM1 expression is causing the disorder, or is merely correlated, is not known.

The objective of the current study is to use short inhibitory RNA (siRNA) to suppress expression of GCM1 in the placenta to determine whether low levels cause fetal growth restriction. If so, we will then compare the placental pathology in this model with that of human placentas from growth restriction pregnancies. If the placental pathologies are similar, we can use this model to advance our understanding of why the placentas in human pregnancies with fetal growth restriction are inadequately branched and fail to deliver adequate nutrition to support normal fetal growth. If not, we can use this novel approach to investigate the role of other genes known to be critical for normal placental development.

In our studies, we will reduce GCM1 production during early placental development in the embryonic stage in utero by injecting siRNA to GCM1 through fine glass-pulled pipettes positioned under ultrasound guidance using an Ultrasound Biomicroscope. We have preliminary results showing the efficacy of this approach and are ready now to undertake a complete study examining the dose-response relationship between GCM1 expression and fetal and placental growth. We are excited about the next phase of this project because we will study the placenta later in gestation and will for the first time observe the long term consequences of inhibiting, but not abolishing, GCM1 expression in early pregnancy.

These results will allow us to determine how well this model mimics placental defects observed in human placentas from growth-restricted placentas. If similar, our long-term goal would be to use this model to investigate methods to reverse these placental defects thereby improving placental performance and ultimately fetal growth and well-being.

Premature birth is prevalent in today’s society and complicates 7-10% of all pregnancies. It is characterized by initiation of the labour process before 37 weeks of gestation. Preterm birth is associated with up to 85% of neonatal morbidity and mortality and may lead to behavioral and learning problems for the child, as well as emotional and financial challenges for the family. Many studies have been undertaken to explain the underlying mechanisms responsible for preterm birth, hence trying to solve what seems to be one of the biggest challenges in perinatal health care.

It has been shown that the onset of labour is initiated through a signaling pathway originating from the fetus, which stimulates the uterine muscle through increased synthesis and decreased degradation of prostaglandins. 30% of preterm births are infection-mediated, some caused by Bacterial Vaginosis (BV). BV is the result of an alteration in the endogenous vaginal microflora, associated with decreased levels of certain Lactobacillus.

Lactobacillus increases the production of anti-inflammatory cytokines such as IL-4, IL-10, and IL-11, interfering with the cascade leading to preterm births and inhibiting the growth and attachment of organisms causing BV. Regulatory peptide cytokines are key mediators for organizing the interaction between the immune cells such as macrophages and are also responsible for regulating a variety of cell processes. Their production is, therefore, regulated to ensure the homeostasis and effective defense against pathogens. Any failure to maintain homeostasis between the anti- and pro-inflammatory cytokines will lead to inflammatory diseases. It has been shown that BV is also associated with increased growth of harmful bacterias such as Gardnerella, causing an elevated release of pro-inflammatory cytokines such as IL-1ß, IL-2, IL-15, and TNF-a and increased prostaglandin levels. This will in turn lead to increased contractility and preterm birth.

As such, the focus of my graduate work will be on cytokine profile of placental and chorion trophoblast cells with and without lipopolysacchoride and in the presence or absence of Lactobacilli preparations.

Hypothesis: L. rhamnosus GG and GR-1 treated trophoblast cells secrete inhibitory factors that suppress and modulate the expression of pro-inflammatory cytokines and up-regulate the anti-inflammatory ones once activated by LPS. It is hoped that such study would contribute to the long term objective, which is to demonstrate that restoring a vaginal microflora rich in Lactobacilli will interfere with the pathogenesis of BV and the cascade leading to preterm birth.

Insulin-like growth factors (IGFs) are essential regulators of fetal growth and are controlled by the inhibitory effects of IGF binding proteins (IGFBP-1 to 6). IGFBP-1 is the most important regulator of IGFs during fetal and neonatal development. High blood levels of IGFBP-1 during fetal development leads to low birth weight in humans and animals, which consequently leads to significantly increased risk of heart disease morbidity and mortality in adulthood. IGFBP-1 likely plays an important role in heart development. Unfortunately, very little is known about the effects of IGFBP-1 on the fetal heart and whether such effects have long-lasting consequences on the adult cardiovascular system.

In order to mimic low birth weight in humans, a fetal IGFBP-1 overexpressing mouse model was created. A mouse model was chosen because of their low cost, fast reproductive rate, and high genetic and physiologic similarity to humans. Using such model, our lab has demonstrated that IGFBP-1 overexpression during the fetal period alters cardiac development and leads to permanent impairments in cardiac function and anatomy in adulthood. Such impairments are likely to increase risk of acquiring heart diseases.

The long-term goal of this study is to uncover the mechanisms that underlie the correlation between low birth weight and increased incidence of adulthood heart diseases. When such mechanisms are uncovered, heart disease treatments will be able to target fetuses and newborns to prevent adulthood cardiovascular diseases.

During pregnancy, the development of the fetus relies primarily on one organ – the placenta. The role of the placenta is to perform a multiplicity of functions, which in adulthood are accomplished by an extensive network of organs. It acts as a barrier to disease, produces essential hormones and is the primary site of gas and nutrient exchange between the mother and fetus. Abnormalities in placental development or function can therefore be extremely deleterious.

Trophoblast cells are the cells responsible for the formation and function of the placenta. Alteration in the trophoblast cell rheostat with respect to proliferation, differentiation or cell death may therefore lead to the possibility of improper placental function.

Pre-eclampsia and molar pregnancies are two examples of trophoblast related disorders that are associated with improper placentation. Thus far however, the cause of these disorders is not fully understood. Currently both disorders are defined by similar clinical features including hypertension, proteinuria, and edema. Furthermore, both molar and preeclamptic placentae are characterized on the cellular level by an immature, more proliferative, trophoblast phenotype. This has lead many to believe that the study of molecules involved in trophoblast cell cycle and proliferation will provide further understanding of how improper placentation and disease are associated.

Previously, Matador (Mtd), a pro-apoptotic protein, was identified as a key player in the regulation of cell death in reproductive tissue. A specific role of Mtd in placentation has been further supported by the recent discovery by the Caniggia lab of a novel spliced variant of Mtd that is unique to the placenta. Of clinical importance, the level of Mtd was found to be significantly increased in cases of severe early onset pre-eclampsia. Moreover, the expression of Mtd was found to be highly expressed early in gestation when cell death is low and proliferation is high. There is now increasing evidence pointing to the possibility that some proteins involved in cell death may have a dual function and may also play a role in cell cycle control. This has been a recent area of study for the lab and is the basis of my research project.

Hypothesis: Mtd not only regulates cell death, as previously determined, but may also contribute to trophoblast cell proliferation during early placental development.

Epidemiological evidence indicates that poor fetal growth is associated with an increased risk of a number of adult diseases, including cardiovascular disease and depression. The link between fetal growth and disease susceptibility involves the process of fetal programming. This is a process by which a stimulus encountered during critical windows of development can have permanent effects on the structure and/or function of physiological pathways, subsequently leading to pathological consequences in adult life.

Glucocorticoids (GC), the end product of hypothalamic-pituitary-adrenal (HPA) axis activation are postulated to be a primary mediator of fetal programming. Studies have revealed that exposure to GC in utero can produce many of the symptoms observed in adults that had poor prenatal growth, including permanently altered basal and stress-induced HPA axis activity. Chronically elevated levels of endogenous GC in the body can have a number of adverse effects including decreased growth, immuno suppression, and altered cardiovascular and behavioural regulation. Modified regulation of the HPA axis, as occurs in the process of fetal programming, also impairs the ability of the organism to cope with physical and/or psychological stress. Exposure to a stressor during pregnancy results in activation of the maternal HPA axis and consequently an influx of excess endogenous GC of maternal origin to the fetus.

Studies have shown permanent and sex-specific effects on pituitary-adrenal function and stress-related behaviour in offspring whose mothers were exposed to stress during pregnancy in critical windows of fetal brain development. Further, female offspring demonstrated an interaction between programming of the HPA axis, behaviour and stage of the reproductive cycle. The aim of this study is to understand the relationship between an altered maternal environment and modified neuroendocrine and behavioural function in adulthood. Specifically, how a moderate maternal stress during pregnancy affects HPA axis activity and interactions with other physiological pathways, such as the sympathetic nervous system and the hypothalamic-pituitary-gonadal axis. In addition, we will identify how these changes modify anxiety and attention related behaviours in offspring.

We hypothesize that prenatal stress will have profound effects on HPA axis function in the adult, but the specific nature and severity of the effect will be dependent on gender and the timing of the stress as well as by interactions with other neuroendocrine pathways. This study will dissect and determine a number of the mechanisms involved in the process of fetal programming, which represents a key link between adverse intrauterine environment and susceptibility to disease in adult life.

Glucocorticoids (GC) such as cortisol are the main product of the stress response. Additionally, synthetic GCs (sGCs) are routinely used to treat pregnant women at risk of preterm labour. This results in elevated levels of glucocorticoids to the fetus during pregnancy.

Studies have shown maternal stress or maternal treatment with sGCs during late gestation has a permanent effect on the stress response in the fetus, as well as in neonatal and adult offspring. However, the consequence for cognitive development of the offspring remains uncertain. Studies have shown a higher incidence of neurodevelopmental abnormalities in children exposed in utero or treated neonatally with glucocorticoids.

Neonatal treatment with glucocorticoids results in deficits in spatial learning and memory. It has also been shown that with this neonatal treatement, long-term potentiation (LTP) in the CA1 subfield of the hippocampus is impaired. Long-term potentiation (LTP), a form of synaptic plasticity involving the strengthening of the post-synaptic response in frequently used synapses, is likely the mechanism underlying learning and memory. LTP in CA1 is dependent on the glutamatergic NMDA receptor and plasticity in this subfield has been correlated with spatial learning and memory.

Further, studies have demonstrated bidirectional effects of glucocorticoid (GR) and mineralocorticoid (MR) receptor activation on LTP. The Matthews lab has recently shown that prenatal exposure to betamethasone, the preferred sGC in North America, can modulate NMDA-R subunit expression in a sex-specific and time-dependent fashion in the fetus. Additionally, animals treated with betamethasone show impaired performance in relearning in the Morris water maze, a test of spatial learning. Currently nothing is known about the effects of prenatal GC exposure on synaptic plasticity of the offspring, though data indicates that there may be detrimental effects if exposure occurs during key times in neurodevelopment.

Hypothesis: Prenatal exposure to glucocorticoids will have an adverse effect on long-term potentiation in the juvenile guinea pig hippocampus. Further, altered trajectory of GR and MR expression will produce changes in the postnatal response to GC and subsequent GR/MR-dependent modulation of LTP.

Epidemiological evidence indicates that poor fetal growth is associated with an increased risk of a number of adult diseases, including hypertension and type 2 diabetes mellitus. The link between fetal growth and disease susceptibility involves the process of fetal programming. This is a process by which a stimulus encountered during critical windows of development can have permanent effects on the structure and/or function of physiological pathways, subsequently leading to pathological consequences in adult life.

Glucocorticoids (GC), the end product of hypothalamo-pituitary-adrenal (HPA) axis activation are postulated to be a primary mediator of fetal programming. Studies have revealed that exposure to GC in utero can produce many of the symptoms observed in adults that had poor prenatal growth, including permanently altered basal and stress-induced HPA axis activity. Chronically elevated levels of endogenous GC in the body can have a number of adverse effects including decreased growth, immunosuppression, and altered cardiovascular and behavioural regulation. Modified regulation of the HPA axis, as occurs in the process of fetal programming, also impairs the ability of the organism to cope with physical and/or psychological stress. Exposure to a stressor during pregnancy results in activation of the maternal HPA axis and consequently an influx of excess endogenous GC of maternal origin to the fetus.

Studies have shown permanent and sex-specific effects on pituitary-adrenal function of offspring exposed to an acute period of nutrient restriction or synthetic GC in utero. The aim of this study is to understand the relationship between an altered maternal environment and modified neuroendocrine and behavioural function in adulthood. Specifically, how a moderate maternal stress during pregnancy affects adrenocortical development and subsequent activity. In addition, we will identify how these changes modify stress-related behaviour, learning and memory.

We hypothesize that prenatal stress will have profound effects on HPA axis function in the adult, but the specific nature and severity of the effect will be dependent on gender and the timing of the stress. This study will dissect and determine a number of the mechanisms involved in the process of fetal neuroendocrine programming, which represents a key link between adverse intrauterine environment and susceptibility to disease in adult life.