Mechanisms Of Abnormal Expression Of The IGF2 Gene In Disorders Affectin Foetal Growth
Funder
National Health and Medical Research Council
Funding Amount
$420,872.00
Summary
The IGF2 gene is crucial for foetal growth. Only the copy inherited from the father is active, a phenomenon named parental imprinting. In some children with foetal overgrowth or growth retardation, the deregulation of imprinting of the IGF2 gene during the first days of foetal development will influence subsequent growth and will also have major implications in post-natal and adult life. We will investigate the mechanisms resulting in abnormal imprinting of IGF2 early in development.
Prevention Of Placental Oxidative Stress And Inflammation By Dietary Omega-3 Fatty Acids
Funder
National Health and Medical Research Council
Funding Amount
$547,970.00
Summary
Several pregnancy disorders that result in low birthweight involve aberrant function of the placenta. In this project we will examine one of the key mechanisms underlying placental dysfunction, namely oxidative stress, and determine whether its adverse effects can be limited by supplementation with dietary omega 3 fatty acids. The outcomes of this project will help guide future clinical studies on the possible beneficial effects of omega-3 fatty acids in pregnancy.
P-glycoprotein: A New Player In The Placental Glucocorticoid Barrier
Funder
National Health and Medical Research Council
Funding Amount
$424,711.00
Summary
Adequate growth and development of the fetus are crucial for survival of the newborn. The placenta plays a central role in these processes, providing the fetus with appropriate nutrients and hormonal signals. The placenta also regulates the maternal-fetal passage of hormones, some of which have the capacity to limit fetal growth. These include glucocorticoid hormones from the mother's adrenal gland (eg cortisol) which are normally prevented from passing through the placenta to the fetus due to t ....Adequate growth and development of the fetus are crucial for survival of the newborn. The placenta plays a central role in these processes, providing the fetus with appropriate nutrients and hormonal signals. The placenta also regulates the maternal-fetal passage of hormones, some of which have the capacity to limit fetal growth. These include glucocorticoid hormones from the mother's adrenal gland (eg cortisol) which are normally prevented from passing through the placenta to the fetus due to the 'placental glucocorticoid barrier'. The primary focus of this proposal is the investigation of a potential new contributor to this barrier called P-glycoprotein (P-gp), recently shown to limit access of glucocorticoids to the brain. We propose that because the placenta expresses significant amounts of P-gp, it may help prevent maternal glucocorticoids from reaching the fetus and causing growth retardation. We will determine whether P-gp is a significant contributor to the placental glucocorticoid barrier, and measure how much P-gp is present in normal placentas throughout pregnancy. We will also assess whether there is less P-gp present in placentas of growth-retarded fetuses. Understanding how P-gp affects the passage of glucocorticoids across the placenta could help to treat certain cases of fetal growth retardation.Read moreRead less
MECHANISMS OF ABNORMAL EXPRESSION OF THE IGF2 GENE IN DISORDERS AFFECTING FOETAL GROWTH
Funder
National Health and Medical Research Council
Funding Amount
$560,434.00
Summary
The IGF2 gene is crucial for foetal growth. Only the copy inherited from the father is active, a phenomenon named parental imprinting. In some children with foetal overgrowth or growth retardation, the deregulation of imprinting of the IGF2 gene during the first days of foetal development will influence subsequent growth and will also have major implications in post-natal and adult life. We will investigate the mechanisms resulting in abnormal imprinting of the IGF2 early in development.
Glucocorticoid-progesterone Interactions In The Control Of Fetal And Placental Growth
Funder
National Health and Medical Research Council
Funding Amount
$227,036.00
Summary
The growth and function of the placenta is of critical importance to the successful maintenance and completion of human pregnancy. The placenta is effectively the lifeline of the growing fetus through its supply of nutrients, removal of wastes, and coordination of homone signals that regulate fetal growth and development. If the placenta does not perform these functions adequately, the growth rate of the fetus is compromised and can lead to difficulties before and after birth. This project exami ....The growth and function of the placenta is of critical importance to the successful maintenance and completion of human pregnancy. The placenta is effectively the lifeline of the growing fetus through its supply of nutrients, removal of wastes, and coordination of homone signals that regulate fetal growth and development. If the placenta does not perform these functions adequately, the growth rate of the fetus is compromised and can lead to difficulties before and after birth. This project examines how two important steroid hormones, progesterone and glucocorticoids, interact with growth factors in the placenta to control its growth and function. Progesterone is recognized as 'the hormone of pregnancy' as it helps the mother adapt to pregnancy. Progesterone may also affect the placenta by regulating its synthesis and breakdown of other hormones, and the balance between placental cell proliferation and death. These effects of progesterone will be studied in this project. We will also examine how glucocorticoid hormones regulate the growth and function of the placenta. Glucocorticoids are structurally very similar to progesterone, and are secreted by the adrenal gland in increased quantities during pregnancy. Glucocorticoids exert a wide range of effects on the mother, placenta and fetus; indeed, glucocorticoids are recognized clinically as the single-most importnat signal for fetal maturation in late pregnancy. However, too much glucocorticoid retards fetal and placental growth, and in this project we will study how this occurs in the placenta, and how the placenta may protect itself from detrimental effects of glucocorticoids. We will test whether placental growth is restricted by glucocorticoids through their effects on placental growth factor hormones. Overall, these studies could have important implications for the clinical management of pregnancy, particularly in relation to fetal and placental growth.Read moreRead less
Differential Effects On Fetal Growth And Development Of Repeated Fetal Or Maternal Corticosteroid Treatments
Funder
National Health and Medical Research Council
Funding Amount
$356,849.00
Summary
Injections of synthetic hormones (corticosteroids) to women at risk of early preterm birth reduce the rate of respiratory illness and death in the newborn infant. It is standard clinical practice prior to early preterm birth to give corticosteroids by intramuscular injection to the mother. For many women, however, preterm birth does not occur as expected and it has become common practice to give repeated courses of corticosteroids to women in whom the risk of preterm delivery recurs or continues ....Injections of synthetic hormones (corticosteroids) to women at risk of early preterm birth reduce the rate of respiratory illness and death in the newborn infant. It is standard clinical practice prior to early preterm birth to give corticosteroids by intramuscular injection to the mother. For many women, however, preterm birth does not occur as expected and it has become common practice to give repeated courses of corticosteroids to women in whom the risk of preterm delivery recurs or continues. Using the sheep model, we have shown that repeated doses of corticosteroids, given intramuscularly to the mother, are of benefit to newborn lung function, but also reduce the rate of fetal growth and adversely affect brain development. Evidence from the Western Australian Preterm Infant Cohort Study suggests that birthweight in humans is similarly affected by repeated corticosteroids and is followed by behavioral disorders in childhood. Using sheep, we have shown that repeated injections of corticosteroids given directly to the fetus cause no reduction in birthweight although maturation is still enhanced. This finding of a differential effect of corticosteroids by different routes of administration raises several exciting opportunities and questions. First is the possibility that direct fetal treatment may be of use in humans, if current human trials show that repeated doses cause effects similar to those we have seen in sheep. Secondly, the finding challenges our current understanding of how an individual may be programmed for subsequent health or illness by prenatal events. The proposed study will attempt to explain why corticosteroids given to the mother, but not the fetus, restrict fetal growth. Our hypothesis is that these hormones, when given repeatedly to the mother, adversely affect the ability of the placenta to transfer essential nutrients to the fetus. We will test this hypothesis using pregnant sheep in which catheters have been implanted surgically.Read moreRead less
Complement C5a Receptors , Placental Inflammation And Reproductive Impairment.
Funder
National Health and Medical Research Council
Funding Amount
$1,025,229.00
Summary
We are investigating how mothers may have health difficulties during pregnancy, such as high blood pressure, and how this can affect their fetuses' health. There is emerging evidence that an unhealthy placenta during pregnancy can greatly affect fetal development, and it seems that inflammation in the placenta during pregnancy may be a key factor in reducing fetal growth, resulting in low birth weight infants. Our studies are aimed at developing new treatments for this.