Analysis Of Calcitonin Receptor Binding And Function
Funder
National Health and Medical Research Council
Funding Amount
$382,821.00
Summary
Receptors form a basic intermediary as the acceptor site for signals that are transmitted between the cells that make up our body. Modulation of receptors, therefore, forms a key target in our ability to treat disease. The largest class of receptors is the superfamily of G protein-coupled receptors (GPCRs), which transmit signals within a cell via proteins called G proteins. GPCRs form between 1 and 5% of the entire repertoire of human genes. One group of GPCRs provide the target for small prote ....Receptors form a basic intermediary as the acceptor site for signals that are transmitted between the cells that make up our body. Modulation of receptors, therefore, forms a key target in our ability to treat disease. The largest class of receptors is the superfamily of G protein-coupled receptors (GPCRs), which transmit signals within a cell via proteins called G proteins. GPCRs form between 1 and 5% of the entire repertoire of human genes. One group of GPCRs provide the target for small protein molecules that cirulate through the body. One such circulating molecule is calcitonin, a peptide that plays an important role in maintaining circulating calcium levels in the body, which is essential for proper maintenance of the skeleton. As a consequence of this action, calcitonin is an important clinically used tool in the treatment of bone disease such as osteoporosis and Paget's disease. Due to the molecular nature of calcitonin and its receptors (and other related receptors) that have a broad, complex mechanism of interaction, we have very little definitive information on how calcitonin interfaces with its receptor to signal to target cells. The current project utilises a novel method of permanently linking calcitonin to its receptor, allowing identification of how the two components come together. Furthermore, the project will explore the functional consequence of naturally occuring genetic variation (genotype) and also examine whether the occurence of specific calcitonin receptor genotype is correlated with disease markers for osteoporosis and obesity. This information provides important fundamentals for understanding how this and related receptors work and the potential for rational design of improved theraupeutic tools.Read moreRead less
Inactivation Of HERG Potassium Channels: Dynamic Changes In The Outer Pore Structure
Funder
National Health and Medical Research Council
Funding Amount
$422,716.00
Summary
Sudden cardiac death, due to disturbances in the normal electrical activity of the heart, is one of the leading causes of death in Australia and its incidence is increasing. Tackling the problem of cardiac arrhythmias is therefore one of the major challenges for cardiology in the 21st century. Two factors are greatly limiting progress in this area, the inability to predict who is most at risk and a paucity of treatment options. To address these problems, we need to better understand the basic me ....Sudden cardiac death, due to disturbances in the normal electrical activity of the heart, is one of the leading causes of death in Australia and its incidence is increasing. Tackling the problem of cardiac arrhythmias is therefore one of the major challenges for cardiology in the 21st century. Two factors are greatly limiting progress in this area, the inability to predict who is most at risk and a paucity of treatment options. To address these problems, we need to better understand the basic mechanisms underlying arrhythmias. The rhythm of the heart beat is controlled by electrical signals mediated by the flow of ions through specialised proteins called ion channels. Of the channels that contribute to cardiac electrical activity, potassium ion channels encoded by the Human ether-a-go-go-related gene (HERG) have been of particular interest for three reasons. Firstly, mutations in HERG are the cause of one third of cases of congenital long QT syndrome, an inherited cause of sudden cardiac death. Secondly, HERG is the molecular target for the vast majority of drugs that cause drug-induced long QT syndrome, the commonest cause of drug-induced arrhythmias and cardiac death. Thirdly, HERG channels have very unusual biophysical properties, which has led to the suggestion that they may act as an endogenous anti-arrhythmic agent . Accordingly, the major objective of the proposed research program is to understand the molecular and structural basis of the unusual properties of HERG channels. We will use a combination of molecular and electrical techiques in conjunction with computer modeling to probe the micoscopic motions in the channel that underly the unusual biophyscial properties of these channels. This work will facilitate a better understanding of how clinically identified mutations in HERG contribute to the increased risk of cardiac arrhythmias. More generally, it will improve our understanding of how cardiac ion channels maintain the normal rhythm of the heart.Read moreRead less
Antagonist Of Corticotrophin Releasing Hormone As Therapeutic Agents For The Prevention Of Premature Birth In Humans
Funder
National Health and Medical Research Council
Funding Amount
$376,650.00
Summary
In developed countries the most common cause of the death of a newborn baby is premature delivery. Pre-term delivery remains the greatest cause of neonatal mortality in the western world and a major consumer of health dollars (approx. $5-7B per year in the US alone). However, a delay in the onset of labour from 20 to 25 weeks has been shown to result in a 55% greater probability of infant survival (550 fewer deaths per 1000). This project will allow: The development of new drugs that will allow ....In developed countries the most common cause of the death of a newborn baby is premature delivery. Pre-term delivery remains the greatest cause of neonatal mortality in the western world and a major consumer of health dollars (approx. $5-7B per year in the US alone). However, a delay in the onset of labour from 20 to 25 weeks has been shown to result in a 55% greater probability of infant survival (550 fewer deaths per 1000). This project will allow: The development of new drugs that will allow the extension of pregnancy term The development of protocols that will in turn reduce neonatal mortality. Additionally we believe that these new agents will be useful in preventing the onset of labour after fetal surgery. Currently there are no effective treatments capable of substantially changing delivery dates. Available therapeutics delay the onset of labour, at best, 24 hours. However, recent exciting results from our laboratories show that rising concentrations of the placental peptide Corticotrophin Releasing Hormone (CRH) are associated with the onset of labour. Further, we have also delayed the onset of labour in pregnant sheep by infusing a relatively insoluble CRH antagonist into the sheep fetus. Labour commenced ONLY AFTER the drug was withdrawn from the mother. This project builds upon an interdisciplinary team: medicinal chemists, molecular modellers, pharmacologists and endocrinologists, to further develop an exciting Australian discovery. Successful completeion of this research will, for the first time, allow the control of pregnancy duration MAXIMISING the benefits to mother and child, reducing mortality and later life morbidities typically associated with premature birth.Read moreRead less
Lipoprotein Metabolism And Mutations Of The APOB Gene Causing Familial Hypobetalipoproteinaemia
Funder
National Health and Medical Research Council
Funding Amount
$396,179.00
Summary
Cardiovascular disease is an increasing problem in Australia, however, the cause of atherosclerosis is incompletely understood. A protein, known as apolipoprotein (apo) B, plays a central role in lipoprotein metabolism. Elevated levels of apoB are characteristic of many forms of hypercholestrolaemia. Familial combined hyperlipidaemia and polygenic hypercholesterolaemia are two common inherited disorders of lipoprotein metabolism that are characterised by elevated apoB levels in the blood and ear ....Cardiovascular disease is an increasing problem in Australia, however, the cause of atherosclerosis is incompletely understood. A protein, known as apolipoprotein (apo) B, plays a central role in lipoprotein metabolism. Elevated levels of apoB are characteristic of many forms of hypercholestrolaemia. Familial combined hyperlipidaemia and polygenic hypercholesterolaemia are two common inherited disorders of lipoprotein metabolism that are characterised by elevated apoB levels in the blood and early atherosclerosis. In contrast, familial hypobetalipoproteinemia is a rare inherited disorder of lipoprotein metabolism characterised by very low levels of cholesterol and apoB in the blood and resistance to atherosclerosis and cardiovascular disease. The focus of this research project is to explore the regulation of apoB metabolism using individuals from unique families with familial hypobetalipoproteinaemia. First, we will determine and characterise the alterations in the APOB gene causing the low cholesterol levels in families with familial hypobetalipoproteinaemia. Second, we will determine if these apoB alterations affect the production and-or clearance of blood fats, or lipoproteins in affected individuals, when compared to controls, by performing metabolic studies. The proposed human in vivo metabolic studies will lead to a better understanding of the mechanism(s) involved in the assembly, secretion, transport, and clearance of plasma apoB-containing lipoproteins. Furthermore, these studies may reveal new protective mechanisms and potentially aid in the development of strategies to suppress over-production of apoB-containing lipoproteins in reciprocal conditions such as familial combined hyperlipidaemia or polygenic hypercholesterolaemia.Read moreRead less
Selectivity And Mode Of Action Of Rho-conopeptide TIA: A Novel Inhibitor Of Alpha1-adrenoceptors.
Funder
National Health and Medical Research Council
Funding Amount
$399,300.00
Summary
A major obstacle to the development of safer and more effective treatments for cardivascular diseases and benign prostatic hyperplasia is the inability to find small molecules with sufficient specificity to be safe and effective. The applicant team brings together a unique set of complementary research interests and skills in using conotoxins to define, at the molecular level, how rho-conotoxins act at the alpha1-adrenoceptor, a major drug target for cardiovascualr and related diseases. Rho-cono ....A major obstacle to the development of safer and more effective treatments for cardivascular diseases and benign prostatic hyperplasia is the inability to find small molecules with sufficient specificity to be safe and effective. The applicant team brings together a unique set of complementary research interests and skills in using conotoxins to define, at the molecular level, how rho-conotoxins act at the alpha1-adrenoceptor, a major drug target for cardiovascualr and related diseases. Rho-conotoxins are novel peptide inhibitors of the alpha1-adrenoceptor that appear to act at an undescribed allosteric site. This Project will use rho-conotoxins and analogues to characterise structurally and functionally how and where this class of conopepides act. The structure activity relationship for rho-conotoxins will be established to guide the development of subtype specific inhibitors. Pairwise interactins between the alpha1-adrenoceptorand TIA will be used to dock TIA onto a homolgy model of the alpha1-adrenoceptor. The long-term goal of the project is to develop new and safer treatments for cardiovascular and related disorders.Read moreRead less
Investigation Of Biological Ion Channels: Theoretical Formulation, Computer Simulation And Experimental Verification
Funder
National Health and Medical Research Council
Funding Amount
$677,292.00
Summary
All electrical activities in the brain are regulated by opening and closing of ion channels. Thus, undertanding their mechanisms at a molecular level is a fundamental problem in neurobiology. There are many different types of ion channels, each type fulfilling a different role. For the first time, a group of American scientists have determined the shape of one type of ion channels. Using this newly unveiled information, we propose to build a mathematical theory of ion channels. And then, making ....All electrical activities in the brain are regulated by opening and closing of ion channels. Thus, undertanding their mechanisms at a molecular level is a fundamental problem in neurobiology. There are many different types of ion channels, each type fulfilling a different role. For the first time, a group of American scientists have determined the shape of one type of ion channels. Using this newly unveiled information, we propose to build a mathematical theory of ion channels. And then, making use of a powerful supercomputer, we propose to follow the motion of ions as they move through the channel, study how a channel can select only the correct type of ions to traverse it and determine how many ions a single channel is capable of processing per second. The predictions made by our theory and computer simulations will be checked experimentally. If the predictions and experimental findings do not agree, we will modify the theory and make new predictions.Read moreRead less
Do Rapid Detection & Isolation Of Colonised Patients Reduce MRSA Spread? An Epidemiological, Economic & Modelling Study
Funder
National Health and Medical Research Council
Funding Amount
$354,299.00
Summary
Methicillin-resistant Staphylococcus aureus (MRSA) is the antibiotic resistant form of Golden Staph. It is one of the most common causes of hospital acquired infection. Despite the presence of MRSA for more than 40 years in our hospitals, the most efficient ways of controlling it are still debated. Some experts recommend swabbing all high risk patients for MRSA, isolating those found to be carriers it in single rooms or with other carriers and using special precautions, such as gowns and gloves, ....Methicillin-resistant Staphylococcus aureus (MRSA) is the antibiotic resistant form of Golden Staph. It is one of the most common causes of hospital acquired infection. Despite the presence of MRSA for more than 40 years in our hospitals, the most efficient ways of controlling it are still debated. Some experts recommend swabbing all high risk patients for MRSA, isolating those found to be carriers it in single rooms or with other carriers and using special precautions, such as gowns and gloves, when in contact with these patients. One of the problems with this approach is that it takes 2-3 days to detect MRSA from swabs using the usual culture methods in the microbiology laboratory. This means that there are delays in instituting control measures, which may reduce their effectiveness. We plan to test whether use of isolation and special precautions is better than our current practices in preventing the spread of MRSA from patient to patient in the Royal Melbourne Hospital intensive care unit. Patients will be swabbed several times during their admission to see if they are carrying MRSA. We will use new, rapid laboratory methods that can detect MRSA within hours from these patient specimens. This will mean that if patients are found to be carriers, isolation and special precautions can be implemented early. We will compare how many people get MRSA in the time when we are not using any special precautions with how many get it in the time when we are. We are also going to undertake an economic analysis to see whether, even if these new diagnostic methods are more expensive that standard methods, they may still be worth the cost if we can prevent infections in patients. This study will help infection control practitioners to decide whether patients should be isolated with special precautions if they are MRSA carriers. The results of this study will contribute to better patient outcomes, lower hospital costs and more efficient use of resources.Read moreRead less