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.
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
Novel Actions Of Leptin In Implantation And Placental Function
Funder
National Health and Medical Research Council
Funding Amount
$220,500.00
Summary
The establishment, growth and function of the placenta is of critical importance to the successful maintenance and completion of pregnancy. The placenta is effectively the lifeline of the growing fetus through its supply of nutrients, removal of wastes and coordination of hormone signals that regulate fetal growth and development. Among these signals the hormone leptin, which is produced primarily by fat cells and regulates food intake, has been identified as a crucial player in the control of f ....The establishment, growth and function of the placenta is of critical importance to the successful maintenance and completion of pregnancy. The placenta is effectively the lifeline of the growing fetus through its supply of nutrients, removal of wastes and coordination of hormone signals that regulate fetal growth and development. Among these signals the hormone leptin, which is produced primarily by fat cells and regulates food intake, has been identified as a crucial player in the control of fetal growth. In human pregnancy, the placenta becomes an additional major source of leptin, and this is secreted into the mother and the fetus. Recent work in animal models also indicates that the process of implantation, whereby the embryo embeds itself in the lining of the uterus and establishes a placenta, cannot proceed in the absence of leptin. But how leptin exerts these critical effects on the implantation process and placental function is not known. In this study we will explore several potential actions of leptin in the uterus and placenta, and examine whether the leptin signaling system is aberrant in cases where the fetus does not grow normally. Of particular interest is the possible interaction of leptin with another group of important signaling molecules called the peroxisome proliferator-activated receptors, or PPARs. One of these, PPAR-gamma, plays an indispensable role in the establishment of the placenta, particularly in relation to the formation of blood vessels, a process that is also a target for leptin action. Several lines of evidence, most notably in fat cells, suggest that both PPAR-gamma and leptin regulate common aspects of cell function. Such interactions provide us with important clues as to how leptin and the PPARs could work together to promote the optimal establishment, growth and function of the placenta, and these will be explored in this project.Read moreRead less
Interactions Between Fetal Programming And Postnatal Diet In Development Of The Metabolic Syndrome
Funder
National Health and Medical Research Council
Funding Amount
$445,578.00
Summary
More than 50,000 Australians die annually from cardiovascular disease, accounting for almost 40% of all deaths. Obesity and high blood pressure are both key risk factors for cardiovascular disease, and so it is crucial that we understand the underlying causes of these conditions and how lifestyle changes, such as diet, can prevent them. We now know that several adult-onset diseases, including high blood pressure, obesity and diabetes, are influenced by how well we grow and develop as a fetus. Th ....More than 50,000 Australians die annually from cardiovascular disease, accounting for almost 40% of all deaths. Obesity and high blood pressure are both key risk factors for cardiovascular disease, and so it is crucial that we understand the underlying causes of these conditions and how lifestyle changes, such as diet, can prevent them. We now know that several adult-onset diseases, including high blood pressure, obesity and diabetes, are influenced by how well we grow and develop as a fetus. This effect, known as 'fetal programming', means that if we have a poor environment as a fetus (eg, maternal undernutrition), we are more likely to develop health problems such as high blood pressure many years later. In this study we are interested in how the events in fetal life 'program' these later health problems, and how we might reverse the adverse effects by lifestyle changes after birth. We have developed an animal model in which high blood pressure and problems with fat and muscle function that can lead to obesity and diabetes. These detrimental effects on adult health can be completely prevented in our model by placing offspring on a diet rich in omega-3 fats from the time of birth. These fats are commonly found in fish oil and are well known for their beneficial effects on cardiovascular function. The present proposal will extend these findings by determining whether omega-3 fatty acids can reverse the adverse programming outcomes after they have emerged in adult life. We will also investigate whether fetal programming effects are made even worse by the consumption of excess total dietary fat during development to adulthood, and if this effect can also be overcome by supplementation of the diet with omega-3 fats.Read moreRead less
Interactions Between IGFBP-3 And TGFbeta In The Inhibition Of Breast Cancer Cell Growth
Funder
National Health and Medical Research Council
Funding Amount
$662,970.00
Summary
A protein first identified by our research group, called insulin-like growth factor binding protein-3 or IGFBP-3, has been shown to be a potent inhibitor of the growth of cancer cells. High levels of IGFBP-3 in the bloodstream are associated with a decreased risk of several cancer types, including breast cancer. However, the way in which this protein prevents cancer cells from growing is poorly understood. This project will investigate an entirely novel idea, developed in our laboratory, that th ....A protein first identified by our research group, called insulin-like growth factor binding protein-3 or IGFBP-3, has been shown to be a potent inhibitor of the growth of cancer cells. High levels of IGFBP-3 in the bloodstream are associated with a decreased risk of several cancer types, including breast cancer. However, the way in which this protein prevents cancer cells from growing is poorly understood. This project will investigate an entirely novel idea, developed in our laboratory, that the actions of IGFBP-3 are intimately connected with the actions of another known cell growth inhibitor called transforming growth factor beta (TGFbeta). We have found that these two proteins initiate the same sequence of events leading to growth inhibition in breast cancer cells, and that a receptor protein required for TGFbeta activity is also needed for IGFBP-3 to be inhibitory. Our work has the potential to explain for the first time exactly how IGFBP-3 stops cancer cells from growing. This is important because it is an abundant protein in the body, and understanding how it acts may lead to the development of new approaches to cancer therapy that exploit our findings.Read moreRead less
Determinants Of Insulin-like Growth Factor (IGF) Binding And Biological Actions Of IGF Binding Protein-6
Funder
National Health and Medical Research Council
Funding Amount
$399,750.00
Summary
Proteins are complex structures usually consisting of a number of distinct regions. Each of these regions may serve different roles. Insulin-like growth factors (IGFs) are important proteins involved in regulating the growth and other properties of cells. The actions of IGFs are in turn regulated by a family of binding proteins (IGFBPs). The aim of this project is to determine the range of actions of one of these IGFBPs and which parts of this IGFBP are involved in these actions. This may lead t ....Proteins are complex structures usually consisting of a number of distinct regions. Each of these regions may serve different roles. Insulin-like growth factors (IGFs) are important proteins involved in regulating the growth and other properties of cells. The actions of IGFs are in turn regulated by a family of binding proteins (IGFBPs). The aim of this project is to determine the range of actions of one of these IGFBPs and which parts of this IGFBP are involved in these actions. This may lead to new treatments for diseases in which cell growth is disturbed e.g. cancer and diabetes.Read moreRead less
Role Of The Nuclear Growth Hormone Receptor In Cell Proliferation And Function
Funder
National Health and Medical Research Council
Funding Amount
$477,750.00
Summary
In addition to final height, growth hormone regulates many tissues in the body, and through these, regulates metabolism, body composition, vitality and aspects of ageing. However, there is some evidence that GH can also promote cancer, notably colon and blood cell cancers. Our discovery of the receptor for growth hormone in the cell nucleus, notably in many cancers, has led us to investigate the role of the nuclear GH receptor. We have found that targeting this receptor to the nucleus allows the ....In addition to final height, growth hormone regulates many tissues in the body, and through these, regulates metabolism, body composition, vitality and aspects of ageing. However, there is some evidence that GH can also promote cancer, notably colon and blood cell cancers. Our discovery of the receptor for growth hormone in the cell nucleus, notably in many cancers, has led us to investigate the role of the nuclear GH receptor. We have found that targeting this receptor to the nucleus allows the cell to divide without the need for the normal factors which initiate cell division and survival. We have also found that a part of the GH receptor acts as a gene activator, and have identified some of the nuclear proteins which bind to the receptor and make this so. This proposal aims to establish the link between the nuclear GH receptor and cell division, both mechanistically, and in live animals. We also plan to establish if nuclear localizing the receptor artificially results in cancer formation. The outcome would provide an index of risk from current GH therapy, and could lead to a new cancer therapy.Read moreRead less
Role Of IGF Binding Protein-3 (IGFBP-3) And IGFBP-5 As Modulators Of Nuclear Hormone Signalling
Funder
National Health and Medical Research Council
Funding Amount
$465,750.00
Summary
The insulin-like growth factors are small proteins involved in the growth of most tissues. Their actions are regulated by binding to larger proteins (known as IGFBPs) in the bloodstream and outside the cell. However, some IGFBPs are also found inside cells, where they seem to carry out other functions. We believe that two of these binding proteins, IGFBP-3 and IGFBP-5, change the way cells respond to vitamin A and vitamin D. These two vitamins are important in cell growth and in the way certain ....The insulin-like growth factors are small proteins involved in the growth of most tissues. Their actions are regulated by binding to larger proteins (known as IGFBPs) in the bloodstream and outside the cell. However, some IGFBPs are also found inside cells, where they seem to carry out other functions. We believe that two of these binding proteins, IGFBP-3 and IGFBP-5, change the way cells respond to vitamin A and vitamin D. These two vitamins are important in cell growth and in the way certain cells perform specialised functions. In test-tube experiments, IGFBP-3 and IGFBP-5 interact directly with the receptors that regulate the effects of these hormones. If the same thing happens inside the cell, IGFBP-3 and IGFBP-5 could change the way these receptors respond to signals from outside the cell. We will investigate what effect these IGFBPs have in living cells and in whole animals and how this may relate to human disease. If we are able to understand how IGFBP-3 and IGFBP-5 affect the way cells respond to vitamin A and D, then we may be able to develop new ways to treat certain human diseases.Read moreRead less
Pathways Involved In The Insulin-like Growth Factor (IGF)-independent Actions Of IGF Binding Protein-6
Funder
National Health and Medical Research Council
Funding Amount
$550,725.00
Summary
Insulin-like growth factors (IGFs) are important proteins that regulate growth. When not regulated properly, diseases such as cancer can occur. A family of IGF binding proteins regulates IGFs. IGFBPs may inhibit IGFs and we have shown that one of them, IGFBP-6, decreases growth of some experimental cancers. As well as regulating IGFs, some IGFBPs alter cell behaviour independently of IGFs, and we found that IGFBP-6 stimulates cell movement in this way. We will now determine how this happens.