Urotensin-II In Human Heart: Investigation Of Mechanisms Involved In Cardiac Function
Funder
National Health and Medical Research Council
Funding Amount
$255,990.00
Summary
The normal function of the body is maintained by naturally occurring compounds. Some for example affect the heart, fine tuning it to make it beat faster or slower, or beat with greater or less force when required in different situations in health and disease. We were the first to show just recently that a small protein which occurs naturally in the body, called urotensin-II can affect the way the heart beats. We showed that extremely tiny amounts increase the force of the heart beat. Our finding ....The normal function of the body is maintained by naturally occurring compounds. Some for example affect the heart, fine tuning it to make it beat faster or slower, or beat with greater or less force when required in different situations in health and disease. We were the first to show just recently that a small protein which occurs naturally in the body, called urotensin-II can affect the way the heart beats. We showed that extremely tiny amounts increase the force of the heart beat. Our findings indicate that urotensin-II is the most potent heart stimulator identified to date. In patients with heart failure, short term stimulation of heart contraction is beneficial, supplying the heart and other organs with vital oxygen and nutrients. However, in the long term excessive stimulation causes worsening of the patients condition. Very little is currently known about the way in which urotensin-II alters heart function. The goal of our study is to understand the mechanism involved in urotensin-II mediated effects on the heart. This will involve identifying the location of urotensin-II and its receptors in the heart, and determining what signalling changes occur after the interaction of urotensin-II with its receptors. Urotensin-II must first be cleaved from a larger drug. We will determine where in the heart this cleavage occurs and whether the process is crucial to the ability of urotensin-II to stimulate contraction of the heart. Since stimulators of heart contraction are detrimental to patients with heart failure in the long term, we will determine whether these patients have more urotensin-II in their blood than patients who do not have heart failure. If the levels of urotensin-II are higher in heart failure patients, it may indicate a need to interfere with the interaction of urotensin-II with its receptors.Read moreRead less
Hepatic Fibrogenesis In Paediatric Cholestatic Liver Disease.
Funder
National Health and Medical Research Council
Funding Amount
$254,250.00
Summary
Liver disease in children causes a significant impact on lifespan and quality of life. The commonest causes of liver disease in children are cholestatic, or diseases related to obstruction of bile flow out of the liver. In ways we are only beginning to understand, obstruction of bile flow stimulates liver scar formation which, if untreated, leads to replacement of normal liver tissue and ultimately to failure of the liver. In infants, the most common and serious cholestatic liver disease is bili ....Liver disease in children causes a significant impact on lifespan and quality of life. The commonest causes of liver disease in children are cholestatic, or diseases related to obstruction of bile flow out of the liver. In ways we are only beginning to understand, obstruction of bile flow stimulates liver scar formation which, if untreated, leads to replacement of normal liver tissue and ultimately to failure of the liver. In infants, the most common and serious cholestatic liver disease is biliary atresia. It develops at, or shortly after birth with progressive destruction of the bile ducts, responsible for transporting bile out of the liver. Without early diagnosis and surgery these infants develop progressive liver scarring leading to liver failure and death or liver transplantation within 1-2 years. It is the commonest reason for liver transplantation in children (55-60%) in the Western world. Even with successful surgery, most, if not all patients will come to liver transplantation over the subsequent 25 years because of ongoing, but slower, scar formation. In older children, diseases like cystic fibrosis cause bile duct blockages leading to progressive liver scarring that is slower and unpredictable, contributing to ill health in up to 20% of patients and death from end stage liver disease or liver transplantation in 5%. Using liver tissue from children with these two disorders we have been able to identify the key cells that control the liver scar process, the Hepatic Stellate Cell. We now need to investigate the role of bile constituents on the scar-forming process in these two diseases. We will utilise a well characterised animal model to investigate the influence of bile constituents on cells isolated from this model and apply these findings back to patient samples to determine their role in paediatric cholestatic liver disease. This will help us to better understand the disease process and importantly, develop more effective and earlier treatment.Read moreRead less
Role Of Chemoattractants In Hepatic Stellate Cell Recruitment And Fibrogenesis In Paediatric Cholestatic Liver Disease.
Funder
National Health and Medical Research Council
Funding Amount
$589,175.00
Summary
This project investigates how decreased bile flow in children's liver diseases such as cystic fibrosis and biliary atresia, leads to the release of molecules from the liver which cause recruitment of scar-forming cells. This results in cirrhosis (liver scar) and the necessity for liver transplantation. This project will investigate whether some children are more susceptible to liver scarring due to mutations in genes which cause increased release of these recruitment molecules from the liver.
Assessment Of Oxidant Stress And Mitochondrial Dysfunction In Young Adults With Iron Loading Diseases
Funder
National Health and Medical Research Council
Funding Amount
$601,979.00
Summary
Disorders of iron metabolism are particularly prevalent in Australia and the consequences of excess iron can be severe. Liver disease is frequently associated with iron loading. The commonest form of iron loading can be treated readily, but it is unclear when the first signs of tissue damage occur and thus at what stage treatment should commence. This project will examine in detail the relationship between body iron levels and signs of tissue damage in young subjects with iron loading disease.
Role Of Tissue Ferritin As A Proinflammatory Mediator Of Hepatic Stellate Cell Activation In Hepatic Iron Overload.
Funder
National Health and Medical Research Council
Funding Amount
$574,890.00
Summary
The hepatic stellate cell is responsible for liver scarring (fibrosis) in chronic liver diseases such as the iron overload condition Haemochromatosis. Our research has identified a role for tissue-derived ferritin as a proinflammatory cytokine in hepatic stellate cell biology. This proposal will examine the mechanisms associated with ferritin's proinflammatory action and assess its role in the fibrosis which occurs in Haemochromatosis.
STudy Of Risk Assessment To Reduce Complications In Patients Following Noncardiac SurgerY (STRATIFY)
Funder
National Health and Medical Research Council
Funding Amount
$436,000.00
Summary
Cardiac problems account for many complications in patients undergoing major non-cardiac surgery, and even apparently minor cardiac damage is a marker of high risk for subsequent adverse events. Unfortunately, while money and effort is expended on identifying patients at risk, the appropriate response to this risk is quite unclear. The performance of bypass surgery or balloon angioplasty in order to treat the underlying coronary disease of at-risk patients is used in other situations, and reduce ....Cardiac problems account for many complications in patients undergoing major non-cardiac surgery, and even apparently minor cardiac damage is a marker of high risk for subsequent adverse events. Unfortunately, while money and effort is expended on identifying patients at risk, the appropriate response to this risk is quite unclear. The performance of bypass surgery or balloon angioplasty in order to treat the underlying coronary disease of at-risk patients is used in other situations, and reduces longterm risk. However, in many patients undergoing major noncardiac surgery, this approach may be inappropriately aggressive, as these patients are often elderly, have other diseases that make heart operations more difficult and risky than usual, and in any case may have a reduced life expectancy from the disease necessitating the operation. As the most critical issue is to ensure that patients undergo their surgery uneventfully, an alternative is the use of intensive medical therapy to protect the heart. This multicentre study, based at Brisbane hospitals that perform large numbers of major operations, will follow up patients for complications, and outcome (including quality of life) will be assessed six months after the operation. We will address two important questions about the efficacy and cost of risk reduction strategies. First, in patients at higher levels of risk and with a positive stress test, could a combination of medical therapy designed to protect the heart be as effective as current approaches, which include the performance of bypass surgery or coronary balloon angioplasty? Second, in patients identified as being at some risk - but low risk - are drugs sufficiently effective to avoid the need for further testing to quantify risk? As the population continues to age, the numbers of at risk patients undergoing major surgery will increase, and answers to these questions will provide important information to guide their management.Read moreRead less
Mechanism Of Action Of Sec1p-like Proteins In Membrane Trafficking
Funder
National Health and Medical Research Council
Funding Amount
$234,936.00
Summary
One of the most important evolutionary changes that has occurred is the development of intracellular compartments. All eukaryotic cells possess numerous membrane-encased structures which provide the basis for intracellular specialisation. For example, in order to degrade unwanted components cells have developed degradative enzymes. It is vital for the cell that these enzymes are sequestered away from other cellular components to avoid destruction of valuable molecules. In addition, the cell has ....One of the most important evolutionary changes that has occurred is the development of intracellular compartments. All eukaryotic cells possess numerous membrane-encased structures which provide the basis for intracellular specialisation. For example, in order to degrade unwanted components cells have developed degradative enzymes. It is vital for the cell that these enzymes are sequestered away from other cellular components to avoid destruction of valuable molecules. In addition, the cell has developed a complex assembly line of modifications that are added to proteins in a specific order as they travel to their final destination within the cell. This necessitates the accurate passage of molecules between compartments, a process known as vesicle transport. To orchestrate the complex network of vesicular transport steps between all of the various intracellular compartments it is necessary to employ complex machinery to guide and check that these steps occur with high fidelity. The goal of our research proposal is to define the function of one of the molecules involved in this control process, the so-called Sec1p proteins. The strength of our proposal lies in the diversity of our approach. We intend to explore the molecular advantages of a relatively simple eukaryotic organism, a yeast cell, and apply the findings obtained from this cell to a more complex but highly related vesicular transport process; that of the insulin-regulated movement of a glucose transporter in mammalian fat and muscle cells. While we intend to apply our findings to the treatment of patients with diabetes, it is our ultimate goal to be able to learn more about this fundamental cell biological process so that we can apply our knowledge to understanding many different disease states.Read moreRead less
Enhancing Erythropoietin Therapy In Ischaemia-reperfusion Injury Of Heart And Kidney
Funder
National Health and Medical Research Council
Funding Amount
$361,021.00
Summary
Heart attacks and kidney disease from a lack of blood flow are common causes of morbidity and have poor treatment options. Erythropoietin (epo) is a useful new treatment, but there remain some caveats to its use in humans: eg. it may cause excessive scarring during repair. Use of epo with an anti-inflammatory drug may decrease scarring and provide benefit to long-term health. We plan to carefully define the biomolecular pathways of injury and repair, to better plan this therapy for human use.