Steroidogenic Factor-1, A Novel Regulator Of Hepatic Stellate Cell Function
Funder
National Health and Medical Research Council
Funding Amount
$589,458.00
Summary
Recently, we have discovered that steroidogenic factor-1, a specialized protein that directs cells to make steroid hormones, is present in cells in the liver called stellate cells. This may play a vital role in how the liver responds to damage and whether the liver will the scar and move on to cirrhosis. Our experiments will determine if this is so and how this system functions. This work will provide a basis for future treatments to improve or prevent cirrhosis in liver disease patients.
Basic Mechanism Of Spontaneous Tolerance Of Liver Allografts In A Rat Model.
Funder
National Health and Medical Research Council
Funding Amount
$374,625.00
Summary
Many thousands of Australians have a failing liver and the only treatment for this is a liver transplant. Liver transplantation is a major life-saving strategy and hundreds of Australians are rescued each year who would otherwise have died. Rejection of the transplant is the major problem affecting these patients. This project investigates an animal model where a transplanted rat liver is not rejected, even though the recipient receives no treatment. Previous studies from our group have shown th ....Many thousands of Australians have a failing liver and the only treatment for this is a liver transplant. Liver transplantation is a major life-saving strategy and hundreds of Australians are rescued each year who would otherwise have died. Rejection of the transplant is the major problem affecting these patients. This project investigates an animal model where a transplanted rat liver is not rejected, even though the recipient receives no treatment. Previous studies from our group have shown that acceptance is due to donor white blood cells transferred with the liver and based on this finding we are developing treatments that can be used in transplant patients. The current application for funding tests another breakthrough that we have recently made, that treatment of the recipient with a substance called interleukin 4 prevents liver acceptance. This finding shows that interleukin 4, which was previously thought to be involved in preventing transplant rejection, is actually involved in stimulating rejection of the liver. It might therefore be possible to prevent rejection by altering the pattern of its expression, for example, by using an antibody to remove it. This application also aims to examine the overall expression of a very large number of genes in liver transplant acceptance compared with rejection. This will use a new technology called gene array analysis to examine expression of at least 5,000 genes to identify those that are increased during liver acceptance. In addition, gene therapy will be used to increase expression of a single gene called IDO that we and others have found to be associated with transplant acceptance. This gene will be expressed in white blood cells of the liver donor after transplantation to promote liver acceptance and prevent rejection. Ultimately it is intended that these findings will be used to prolong the survival of liver transplant patients by revealing new ways to prevent rejection of liver transplants.Read moreRead less
DEVELOPMENT OF CLINICALLY APPLICABLE STRATEGIES TO INDUCE AND MONITOR LONG TERM ACCEPTANCE OF LIVER ALLOGRAFTS
Funder
National Health and Medical Research Council
Funding Amount
$287,036.00
Summary
Liver transplantation is the only therapy for end-stage liver disease and thousands of Australian lives have been saved with this treatment. The major complication of liver transplantation is rejection which leads to loss of about half of the transplanted livers by ten years. Liver transplants in many animal models are not rejected and function normally for the life of the animal. Using one such animal model we have shown that white cells from the donor are responsible for the absence of rejecti ....Liver transplantation is the only therapy for end-stage liver disease and thousands of Australian lives have been saved with this treatment. The major complication of liver transplantation is rejection which leads to loss of about half of the transplanted livers by ten years. Liver transplants in many animal models are not rejected and function normally for the life of the animal. Using one such animal model we have shown that white cells from the donor are responsible for the absence of rejection. Of interest, these cells appear to stimulate a rapid and extreme immune response, which closely resembles rejection. The main difference is that it is quicker and more marked than rejection and then exhausts itself. This observation is unexpected and suggests possibilities for new treatments. Furthermore it questions the effectiveness of our present treatment for rejection of transplanted livers. We have already shown that some kinds of drugs given to prevent rejection in humans actually have the opposite effect in the animal model and prevent long-term acceptance of liver transplants. The aim of this work is to develop in our animal model a better way of treating human liver transplant patients. This will incorporate injection of donor white cells and treatment with drugs which promote the beneficial effects of these cells. We will also develop ways of testing the blood or the liver of the human liver transplant patients early after transplantation to find out whether the patient is accepting the liver or not. This means that we should be able to try this new treatment method in liver transplant patients once it has been optimised in the animal model.Read moreRead less
Function Of The Vitamin D Receptor In Hepatic Non-Parenchymal Cells
Funder
National Health and Medical Research Council
Funding Amount
$509,304.00
Summary
Nuclear receptors are sensors that control many aspects of metabolism, including responses to injury. Our work and has suggested that the Vitamin D Receptor (VDR) may play a vital role in how the liver responds to damage and whether the liver will the scar and move on to cirrhosis. Our experiments will determine if this is so, and in which cells VDR has this role. This work will provide a basis for future treatments to improve or prevent severe liver diseases.
Novel Vasoactive Pathways In Liver Disease; Experimental And Clinical Studies
Funder
National Health and Medical Research Council
Funding Amount
$535,333.00
Summary
Cirrhosis of the liver due to chronic hepatitis and other common liver diseases is now a major cause of illness and death in Australia. This project will examine how a hormone system called the renin angiotensin system contributes to the development of liver damage in these diseases. We will study whether drugs targeting this system can be used to reduce liver scarring and prevent the development of cirrhosis and its complications.
Role Of Nuclear Receptors In Hepatic Injury And Fibrogenesis
Funder
National Health and Medical Research Council
Funding Amount
$443,520.00
Summary
Chronic liver disease is a major cause of death and ill health on a word-wide scale. Several common liver diseases, such as hepatitis B, hepatitis C and non-alcoholic steatohepatitis (fatty liver disease not due to alcohol), are capable of causing protracted liver damage. Irrespective of the cause of injury, the liver has a very narrow way of responding to chronic damage. The most important and insidious of these is hepatic fibrosis (scarring), which, along with liver regeneration, eventually le ....Chronic liver disease is a major cause of death and ill health on a word-wide scale. Several common liver diseases, such as hepatitis B, hepatitis C and non-alcoholic steatohepatitis (fatty liver disease not due to alcohol), are capable of causing protracted liver damage. Irrespective of the cause of injury, the liver has a very narrow way of responding to chronic damage. The most important and insidious of these is hepatic fibrosis (scarring), which, along with liver regeneration, eventually leads to cirrhosis if the injurious process is sufficiently intense and sustained. Liver cirrhosis is the precursor to several undesirable complications of liver disease, most notably primary liver cancer (also called hepatoma), liver failure and severe bleeding from the gut. Therefore, it is not surprising that effective strategies to control liver injury and prevent cirrhosis have been called the holy grail of liver research. To date the only therapies for substantially improving the outcome of patients with chronic liver disease are those that halt or remove the cause of injury. Unfortunately, in many cases it is still not possible to remove or effectively treat the cause of injury. Because of this there is intense interest in therapies that might favourably alter the response of the liver to injury and especially in those that may retard or inhibit scarring and prevent cirrhosis. Nuclear receptors are sensors that control many aspects of the body's metabolism, especially the metabolism of cholesterol and fat. Recently, our work and that of others has suggested that some nuclear receptors may play a vital role in how the liver responds to damage and whether the liver will the scar and move on to cirrhosis. Our experiments will determine if this is so, and which of the several nuclear receptors likely to be involved are the important ones. We will then extend these studies to see if drugs that activate these receptors will improve or prevent severe liver disease.Read moreRead less
Molecular Mechanisms Of Feed-forward Regulation Of Bile Acid Detoxification And Elimination In Cholestasis
Funder
National Health and Medical Research Council
Funding Amount
$334,500.00
Summary
Liver diseases in which there is obstruction to bile flow (cholestatic liver diseases) can lead to liver failure, liver cirrhosis as well as a diminished quality of life. Patients suffer from severe itching which may prove difficult to control. It is thought that may of these adverse effects of obstructed bile flow are due to the retention of a component or bile, called bile acids, within the body. Bile acids are detergent-like compounds formed from cholesterol. Some bile acids are highly toxic ....Liver diseases in which there is obstruction to bile flow (cholestatic liver diseases) can lead to liver failure, liver cirrhosis as well as a diminished quality of life. Patients suffer from severe itching which may prove difficult to control. It is thought that may of these adverse effects of obstructed bile flow are due to the retention of a component or bile, called bile acids, within the body. Bile acids are detergent-like compounds formed from cholesterol. Some bile acids are highly toxic and cause the death of cells within the liver if their concentration becomes too high. Evidence has emerged that the body has control mechanisms to try and combat rising levels of bile acids in cholestatic liver diseases. These control mechanisms are complex and include enzymes from the cytochrome P450 family as well as several specialized transport molecules. In cholestasis these mechanisms promote the removal of bile acids through the urine as well as converting very toxic bile acids to less toxic forms. The present projects builds on discoveries concerning the regulation of cytochrome P450 enzymes made by our group over the last few years, including an in-depth understanding of the way the production of CYP3As is increased by some drugs. We intend to determine in detail how defense mechanisms against toxic bile acids are engaged. In particular, we wish to identify the receptor molecules that 'sense' the rising levels of bile acids that occur in cholestatic liver diseases. An understanding of these issues will allow us to better manage patents with these diseases and develop new strategies for treating cholestatic disorders, for example, development of novel drugs that can influence bile acid detoxification in the liver and other organs.Read moreRead less
Understanding Rapid T-cell Clearance By The Liver: A Critical Step Towards Improved Liver Transplantation.
Funder
National Health and Medical Research Council
Funding Amount
$412,134.00
Summary
The liver has paradoxical properties: it is the site of effective immune responses to pathogens, but under some circumstances, it is known to induce harmless immune responses. Poor responses can be beneficial in a transplantation setting because, in the absence of immunosuppressive drugs, liver transplants are more readily accepted than other organ allografts. Not only are liver transplants well accepted, they can induce secondary acceptance of kidney or heart grafts from the same donor that wou ....The liver has paradoxical properties: it is the site of effective immune responses to pathogens, but under some circumstances, it is known to induce harmless immune responses. Poor responses can be beneficial in a transplantation setting because, in the absence of immunosuppressive drugs, liver transplants are more readily accepted than other organ allografts. Not only are liver transplants well accepted, they can induce secondary acceptance of kidney or heart grafts from the same donor that would otherwise be rejected. However, this ability of the liver to induce unresponsiveness may allow some viruses to persist, particularly , Hepatitis B and C. Four in every five patients infected with hepatitis C develop a chronic disease due to the inability of the immune system to clear the virus. Although it is known that white blood cells enter the liver and become unresponsive, little is known about the mechanisms that prevent an effective response. The CIA s work has been at the forefront of liver immunology and transplantation by demonstrating that the architecture and vasculature of the liver, and therefore the type of unique cellular interactions taking place within it, are essential to gain an understanding of its unique immunological properties. Using the CIB s unique protocols for solid-organ transplantation in rodents, we will provide evidence for a new mechanism that occurs at very early stages after antigen encounter in the liver. We propose to unravel this mechanism using well characterised transgenic mouse models and advanced analytical technology. We will determine the role of this mechanism in liver transplantation. Our preliminary data point to a very high chance of success. This project will have important implications for transplantation studies and for the development and treatment of food allergies and chronic hepatitis C and other of immune-mediated liver diseases.Read moreRead less
Cholestasis And Hepatocyte Injury In Chronic Liver Disease
Funder
National Health and Medical Research Council
Funding Amount
$615,967.00
Summary
The aim of this project is to understand the consequences of long-term cholestasis or impaired bile excretion/flow on normal liver cells (hepatocytes) and to test whether specific bile acids can cause irreversible damage to hepatocytes leading to their transformation into pre-malignant cells and hepatocellular carcinoma (primary liver cancer). The results from this project will inform new strategies in screening, prevention and treatment of liver cancer in children and adults with cholestasis.
Significance Of Microparticles In The Pathogenesis Of Liver Ischemia Reperfusion Injury
Funder
National Health and Medical Research Council
Funding Amount
$643,958.00
Summary
The overall aim of the project is to investigate the significance of microparticles in liver ischemia reperfusion injury (IRI). IRI causes damage to donor livers stored in preparation for liver transplantation. We postulate that microparticles released from the liver are critical in this form of injury. The expected outcomes are novel insights into liver IRI with the aim of developing new approaches to prevent liver damage during liver surgery, transplantation and shock.