Does Early Overnutrition Differentially Alter Hypothalamic Neuropeptides That Regulate Food Intake In The Rat
Funder
National Health and Medical Research Council
Funding Amount
$346,250.00
Summary
In Australia the incidence of obesity, in particular childhood obesity, is increasing dramatically, and the possible long term consequences of this are of great concern. The brain regulates appetite through a number of chemical transmitters such as neuropeptide Y (NPY) which is present in the brains of mammals and causes increased food intake. The effects of overeating from a young age on these brain transmitters has been largely ignored although this may impact on subsequent eating behaviour. I ....In Australia the incidence of obesity, in particular childhood obesity, is increasing dramatically, and the possible long term consequences of this are of great concern. The brain regulates appetite through a number of chemical transmitters such as neuropeptide Y (NPY) which is present in the brains of mammals and causes increased food intake. The effects of overeating from a young age on these brain transmitters has been largely ignored although this may impact on subsequent eating behaviour. In addition to NPY we will study other transmitters in the brain that have profound effects on appetite, some increasing, and others decreasing, food intake. These may form useful therapeutic targets for new drugs for obesity. Key targets we will study include melanocortins, glucagon-like peptide 1, urocortin, melanin concentrating hormone, agouti related peptide, and NPY. We will determine whether overnutrition from birth to weaning leads to changes in these appetite regulating neurotransmitters in the brain, and monitor the hormonal signals that impact on their activity. We will also determine whether early overnutrition exacerbates the subsequent responses to a high fat diet by comparison with rats made obese as adults. We will measure brain concentrations of the neurotransmitters, the amount released from the brain, and determine whether the feeding responses to injections of these agents is altered in obese animals. We have evidence that these transmitters interact in a co-ordinated fashion to affect feeding; this project will examine whether these interactions are maintained in the various types of obesity. Rats are commonly used for this type of study as the processes regulating feeding are very similar to those in humans and these agents cause similar effects in rats and humans. It is hoped that this information will provide new insight into the way brain adapts to overnutrition, and provide potential treatments for obesity and other feeding disorders.Read moreRead less
Targeting PI3K-regulated MicroRNAs To Treat Heart Failure
Funder
National Health and Medical Research Council
Funding Amount
$532,593.00
Summary
Current therapeutics largely delay heart failure progression rather than regressing it. New therapeutic strategies with the capability of improving function of the failing heart are thus greatly needed. The primary goal of this study is to determine whether novel regulatory genes can enhance cardiac function in a setting of heart failure. Ultimately, technologies that target these genes may lead to innovative pharmacotherapies in the clinical management of heart failure.
The Functional Roles Of ADAMs In The Regulation Of Embryo Implantation.
Funder
National Health and Medical Research Council
Funding Amount
$211,527.00
Summary
The initiation of pregnancy in humans and rodents hinges upon the ability of the embryo to attach to the wall of the uterus and invade into the uterine tissue. This process of embryo implantation is tightly regulated and depends on the secretion of enzymes and regulators of these enzymes. A newly identified family of enzymes which might be important in this process is the ADAMs family. These enzymes have the potential to facilitate both cell attachment and cell invasion and also to activate othe ....The initiation of pregnancy in humans and rodents hinges upon the ability of the embryo to attach to the wall of the uterus and invade into the uterine tissue. This process of embryo implantation is tightly regulated and depends on the secretion of enzymes and regulators of these enzymes. A newly identified family of enzymes which might be important in this process is the ADAMs family. These enzymes have the potential to facilitate both cell attachment and cell invasion and also to activate other enzymes and growth factors. Recent studies in our laboratory have shown the ADAMs to be expressed both at the most invasive time of implantation and when invasion is being down-regulated. This project will examine the role of the ADAMs in embryo implantation facilitating attachment and invasion into the uterus by acting enzymatically on the uterine tissue and by activating other enzymes. It will also determine the role of ADAMs in down-regulating invasion potentially by activating a growth factor, TNF-alpha. Knowledge of this process and particularly its regulation is important for the treatment of pregnancy associated diseases that arise from improper implantation. These include infertility, placenta accreta, choriocarcinoma, miscarriage and pre-eclampsia. Furthermore, an understanding of the regulation of implantation will contribute to the treatment of other conditions associated with cell invasion such as cancer metastasis.Read moreRead less
Molecular Regulation Of CRH Gene Expression In The Human Placenta
Funder
National Health and Medical Research Council
Funding Amount
$70,285.00
Summary
Approximately 70% of infant death is a result of premature birth. Preterm delivery occurs in 6-10% of pregnancies, and there has been no reduction in this rate in the last 30 years. This is largely because we remain ignorant of how normal and preterm birth is controlled. Understanding the physiology of human pregnancy is a critical step in the development of ways to detect and prevent preterm birth. Our group has demonstrated a link between production of a hormone (corticotropin releasing hormon ....Approximately 70% of infant death is a result of premature birth. Preterm delivery occurs in 6-10% of pregnancies, and there has been no reduction in this rate in the last 30 years. This is largely because we remain ignorant of how normal and preterm birth is controlled. Understanding the physiology of human pregnancy is a critical step in the development of ways to detect and prevent preterm birth. Our group has demonstrated a link between production of a hormone (corticotropin releasing hormone, CRH) in the placenta and the length of time the baby is carried in the mother. In women who will deliver prematurely the rise in CRH production occurs earlier and more rapidly, while in women who deliver late the rise occurs more slowly. This work has led to the concept of a biological clock that determines the length of time the fetus will be carried by the mother before birth, and in which production of CRH in the placenta plays a central role. We have been studying how the CRH gene is controlled in placental cells. We have discovered some regions in the DNA of the CRH gene which have important roles in controlling how much CRH is made by the placenta. The experiments described in this project will determine the molecular mechanisms that control the production of CRH in the human placenta. This will be done by examining the DNA sequences involved in controlling the CRH gene and by identifying the proteins that actually perform the regulating functions that result in either increased or decreased amounts of CRH being produced by the placenta. This important information will help us better understand how normal and preterm birth is controlled, and from that knowledge new ways to detect and prevent premature birth can be developed.Read moreRead less
Endocrine And Molecular Regulation Of Placental CRH Expression
Funder
National Health and Medical Research Council
Funding Amount
$466,980.00
Summary
Approximately 70% of infant death is associated with premature birth. Preterm birth occurs in 6-10% of pregnancies, and there has been no reduction in the rates of premature birth in the last 30 years. This is largely because we remain ignorant of how normal and abnormal birth is controlled. Understanding the physiology of human pregnancy is a critical step in the development of ways to detect and prevent preterm birth. Our group has demonstrated a link between production of a hormone (corticotr ....Approximately 70% of infant death is associated with premature birth. Preterm birth occurs in 6-10% of pregnancies, and there has been no reduction in the rates of premature birth in the last 30 years. This is largely because we remain ignorant of how normal and abnormal birth is controlled. Understanding the physiology of human pregnancy is a critical step in the development of ways to detect and prevent preterm birth. Our group has demonstrated a link between production of a hormone (corticotrophin releasing hormone, CRH) in the placenta and the length of time the baby is carried in the mother. In women who will deliver prematurely a rise in CRH occurs earlier in the pregnancy and more rapidly, while in women who deliver late the rise occurs more slowly. This work has given rise to the concept of a biological clock that determines the length of time the fetus will be carried by the mother before birth, and in which production of CRH in the placenta plays a central role. We have been studying how the CRH gene is controlled in placental cells. We have discovered some regions in the DNA of the CRH gene which have important roles in controlling how much CRH is made by the placenta. The experiments described in this research project will determine the molecular mechanisms that control the production of CRH in the human placenta. This will be done in two ways: (1) by examining the DNA sequences involved in controlling expression of the CRH gene and (2) by identifying the proteins that actually perform the regulating functions that result in either increased or decreased amounts of CRH being produced by the placenta. This important information will help us better understand how normal and abnormal birth is controlled, and from that knowledge new ways to detect and prevent premature birth can be invented.Read moreRead less
Analysis Of Viral And Cellular Gene Expression During Human Cytomegalovirus Latent Infection Of Hematopoietic Cells
Funder
National Health and Medical Research Council
Funding Amount
$407,545.00
Summary
Human cytomegalovirus (HCMV) is a herpesvirus which infects a majority of the population. HCMV is a significant cause of serious, life-threatening disease in neonates and in people who are immunosuppressed. Transplant recipients such as bone marrow, kidney and heart transplant patients are particularly at risk of developing HCMV disease. Like other herpesviruses, after initial infection HCMV can establish a life-long latent infection. During latency, the virus remains dormant in the human body a ....Human cytomegalovirus (HCMV) is a herpesvirus which infects a majority of the population. HCMV is a significant cause of serious, life-threatening disease in neonates and in people who are immunosuppressed. Transplant recipients such as bone marrow, kidney and heart transplant patients are particularly at risk of developing HCMV disease. Like other herpesviruses, after initial infection HCMV can establish a life-long latent infection. During latency, the virus remains dormant in the human body and no infectious virus is made. However, when conditions are right the virus can awaken (ie reactivate) from its latent state, producing new infectious virus and disease. It is in immunosuppressed individuals such as transplant patients that viral latency and reactivation are of most medical concern, yet viral latency remains very poorly understood. This project has three major components. Firstly, we aim to continue studies which are defining what viral genes are active (ie expressed) during latent infection. Identification of these genes and determination of how they function may have profound implications to our understanding of latency. Secondly, we will examine how human cells are affected when they become latently infected. A new and exciting technology called DNA microarray now makes it possible to examine the expression of many thousands of genes in a single experiment. For the first time, we will be able to determine how the cell changes during latency and reactivation. The study of viral and cellular gene expression during latency may contribute to the development of drugs which interfere with the viruses ability to become latent or reactivate. Thirdly, we have preliminary results which suggest that latent HCMV may actively avoid detection by the immune system. In this project we also aim to determine the mechanism by which the virus interferes with the expression of molecules which are an essential component of our immune system.Read moreRead less
Molecular Mechanisms Of Varicella Zoster Virus Interactions With Key Target Cells
Funder
National Health and Medical Research Council
Funding Amount
$421,650.00
Summary
Varicella zoster virus (VZV) is a herpesvirus which infects up to 90% of the population. VZV causes chickenpox (varicella) predominantly in childhood and shingles (herpes zoster) in middle to old age people. Whilst VZV usually causes relatively mild disease in healthy individuals, VZV still causes significant morbidity in children and adults. VZV causes life-threatening disease in immunocompromised individuals such as patients who are elderly or have HIV disease . Herpes zoster affects many eder ....Varicella zoster virus (VZV) is a herpesvirus which infects up to 90% of the population. VZV causes chickenpox (varicella) predominantly in childhood and shingles (herpes zoster) in middle to old age people. Whilst VZV usually causes relatively mild disease in healthy individuals, VZV still causes significant morbidity in children and adults. VZV causes life-threatening disease in immunocompromised individuals such as patients who are elderly or have HIV disease . Herpes zoster affects many ederly individuals and a major complication is prolonged severe pain or post-herpetic neuralgia (PHN), both severely debilitating and which often requires follow-up medical care for months or years after the initial attack. Despite its significant impact on the community, little is known about the molecular details of how this virus functions. This project aims to improve our understanding of how VZV infection affects specialised human cells in order to make further advances in antiviral therapies as well improve vaccine design for the treatment or prevention of VZV disease and the crippling complication of PHN. This project has four components: (1) We will continue studies which have shown that VZV may actively avoid detection by the immune system. We aim to identify the mechanism and viral genes responsible for interfering with the expression of molecules which are essential for our immune system. (2) We will determine whether VZV infection of specialised immune cells (called dendritic cells) will affect their ability to function and interact with other immune cells (called T cells). (3) We will examine how VZV interacts in human nerve cells (neurons) and whether infected neurons undergo specially programmed cell death (apoptosis). (4) We will examine how different human cells change when they are infected with VZV. A new and exciting technology called DNA microarray now makes it possible to examine the expression of many thousands of genes in one experiment.Read moreRead less
Invasive fungal infections are a serious, escalating health issue. They cause severe disease with high death rates and are very costly to the health system. Current drugs often have suboptimal efficacy and cause side effects. New drugs are needed urgently. Many fungi, including the AIDS-related pathogen, Cryptococcus neoformans, secrete phospholipase B (Plbp) to facilitate infection. We will identify and investigate the Plbp secretion pathway as a novel anti-fungal drug target.