Molecular And Cellular Pathogenesis Of Nonalcoholic Steatohepatitis: Insights From Human Studies
Funder
National Health and Medical Research Council
Funding Amount
$215,500.00
Summary
Nonalcoholic steatohepatitis (NASH) is the commonest cause for liver disease in Australia. On liver biopsy it is characterised by changes similar to that induced by alcohol, but occurs in individuals who consume minimal amounts of alcohol. The risk factors for the development of NASH include obesity, type II diabetes and hyperlipidemia. As the prevalence of obesity and diabetes are rapidly increasing in Australia, it is evident that NASH will become of major public health concern in the future. ....Nonalcoholic steatohepatitis (NASH) is the commonest cause for liver disease in Australia. On liver biopsy it is characterised by changes similar to that induced by alcohol, but occurs in individuals who consume minimal amounts of alcohol. The risk factors for the development of NASH include obesity, type II diabetes and hyperlipidemia. As the prevalence of obesity and diabetes are rapidly increasing in Australia, it is evident that NASH will become of major public health concern in the future. In those that develop liver disease from NASH, a proportion (10-30%) will develop advanced liver scarring leading to significant morbidity and mortality. The overall aim of this proposal is therefore to provide insight into why some people with fatty liver disorders develop NASH and to determine the basis for disease progression in this condition. Over the last decade, work at the Storr Liver Unit in a nutritional animal model of NASH has suggested potential mechanisms for disease progression in NASH. This proposal seeks to determine whether such mechanisms operate in human NASH by conducting studies in a large cohort of well chracterised patients with this disorder. Advances in molecular and cellular biology now permit such studies by anaylsis of small quantities of tissue such as that obtained at the time of liver biopsy. In this proposal we will examine both serum and liver tissue to characterise the role of oxidative stress (the biologic equivalent of rusting), the host immune response, liver cell injury and damage to the metabolic machinery within cells as determinants of diease severity in NASH. It is anticipated that these studies will provide the most comprehensive data to date on the pathogenesis of NASH and should suggest potential therapeutic targets for treating this condition.Read moreRead less
Hepatocyte Replicative Arrest, Hepatic Progenitor Cells And The Ductular Reaction In Hepatic Fibrogenesis
Funder
National Health and Medical Research Council
Funding Amount
$527,683.00
Summary
Chronic liver diseases such as hepatitis C and obesity-related fatty liver can be associated with scarring that eventually results in cirrhosis and liver failure. We are unsure why this scarring occurs, but as hepatitis and fatty liver are becoming more common it is necessary to understand this process so that effective therapies can be developed. This study looks at one possible mechanism to explain the development of liver scarring. We believe that the normal repair mechanisms of the liver lea ....Chronic liver diseases such as hepatitis C and obesity-related fatty liver can be associated with scarring that eventually results in cirrhosis and liver failure. We are unsure why this scarring occurs, but as hepatitis and fatty liver are becoming more common it is necessary to understand this process so that effective therapies can be developed. This study looks at one possible mechanism to explain the development of liver scarring. We believe that the normal repair mechanisms of the liver lead to the production of liver cells to replace those that have died, but in some circumstances also produce small bile ducts that drain bile from the hepatocytes. These small bile ducts may have a previously unsuspected role in stimulating the scar formation. The study will see if the small bile ducts are produced in a range of liver diseases in humans, and will use rodent models to find the factors responsible for stimulating the scarring. When the process is understood more clearly, it could lead to the development of new or more effective therapies to reduce or even reverse liver scarring.Read moreRead less
Host Determinants Of Hepatitis C-associated Liver Disease
Funder
National Health and Medical Research Council
Funding Amount
$610,376.00
Summary
Hepatitis C virus (HCV) infection is a major cause of liver disease and associated deaths in Australia. HCV infection leads to progressive liver failure and may be associated with the development of liver cancer. Currently there are an estimated 220,000 people in Australia living with HCV infection, and by 2020 it is estimated that this number will treble. There is now considerable evidence to indicate that the effect of HCV on the liver is due to ongoing immune activity and the build up of fat ....Hepatitis C virus (HCV) infection is a major cause of liver disease and associated deaths in Australia. HCV infection leads to progressive liver failure and may be associated with the development of liver cancer. Currently there are an estimated 220,000 people in Australia living with HCV infection, and by 2020 it is estimated that this number will treble. There is now considerable evidence to indicate that the effect of HCV on the liver is due to ongoing immune activity and the build up of fat (steatosis) in the liver. This results in the production of biochemical products that lead to tissue damage and to eventual destruction of the liver. Further evidence has recently emerged to suggest that the susceptibility to, and outcome of HCV infection may be influenced by genetic variation in the infected population. The chief investigators on this project have established the best characterised clinical cohort of HCV infected persons worldwide. Further, they have developed considerable expertise in the field of genetics, i.e. the analysis of genes that influence the host's response to an illness. Using this information and expertise, we propose in the present study to analyse in detail the host genetic factors that contribute to variations in the response to HCV, and its correlation with HCV-associated liver damage. This data could allow the development of better patient care strategies and the design of novel therapeutics.Read moreRead less
High blood pressure and heart disease, are a significant health issue affecting more than 25% of the Australian population. We have recently found that a new enzyme called ACE2 involved in cardiovascular regulation is greatly increased in heart tissue following heart attack. Furthermore, we have evidence that this enzyme is released into the blood after a heart attack or as a consequnce of chronic liver injury. The current project aims to expand on our preliminary data and to understand the basi ....High blood pressure and heart disease, are a significant health issue affecting more than 25% of the Australian population. We have recently found that a new enzyme called ACE2 involved in cardiovascular regulation is greatly increased in heart tissue following heart attack. Furthermore, we have evidence that this enzyme is released into the blood after a heart attack or as a consequnce of chronic liver injury. The current project aims to expand on our preliminary data and to understand the basic biology underlying the mechanism of ACE2 secretion in cardiovascular and liver diseases. In addition, the measurement of ACE2 in plasma may provide useful information on prognosis and knowledge of the mechanism underlying ACE2 secretion may define new therapeutic targets to treat and prevent cardiovascular and liver diseaseRead moreRead less
The Role Of MBOAT7 In Hepatic Inflammation: Implications For Therapy
Funder
National Health and Medical Research Council
Funding Amount
$848,340.00
Summary
When a fatty liver progresses to develop inflammation, patients are at-risk of liver-related morbidity and death. Currently, there are no effective therapies. From human studies, we have discovered that a lipid modifying enzyme (MBOAT7) profoundly regulates liver inflammation. In this proposal, we will obtain a detailed understanding of how the activity of this pathway modulates inflammation. We expect to show that MBOAT7 is a novel ‘druggable’ pathway for the treatment of liver inflammation.
MECHANISMS OF DISORDERED HEPATIC LIPID PARTITIONING IN NON-ALCOHOLIC STEATOHEPATITIS
Funder
National Health and Medical Research Council
Funding Amount
$449,591.00
Summary
Fatty liver is the commonest form of liver disease. It is strongly associated with obesity and maturity onset diabetes. The majority of cases of fatty liver disease cause no complications, but when inflammation and liver damage also occur, in the condition of non-alcoholic steatohepatitis or NASH, liver scarring and eventually cirrhosis or liver cancer can result. The reason why some people with fatty liver disease develop NASH and others do not (benign or simple steatosis) is unknown and is the ....Fatty liver is the commonest form of liver disease. It is strongly associated with obesity and maturity onset diabetes. The majority of cases of fatty liver disease cause no complications, but when inflammation and liver damage also occur, in the condition of non-alcoholic steatohepatitis or NASH, liver scarring and eventually cirrhosis or liver cancer can result. The reason why some people with fatty liver disease develop NASH and others do not (benign or simple steatosis) is unknown and is the subject of this research. The studies will be performed in a novel mouse model of obesity and diabetes, the fat aussie mouse, in which all animals develop fatty liver disease after a few months. When fat aussie mice are fed a Macdonald's diet [high in saturated fat] they develop full-blown NASH with liver scarring. Before NASH develops in fat aussie mice, blood levels of adiponectin (a protein produced from fat storage cells) fall. Together with high blood insulin and high blood sugar levels, it is proposed that these changes are what leads to an extraordinarily high build up of fat (lipid) molecules in the liver, to the extent that the fat ultimately damages the liver in a process called lipotoxicity. The planned research will first test whether this hypothesis is correct, and then set about ways to prevent or reverse such a dangerous build up of fats in the liver. Strategies include a high olive oil diet (which is protective in another model of steatohepatitis), correction of blood adiponectin levels, lowering of insulin and blood sugar levels. The anticipated results are a much better understanding of how complications come about in fatty liver disease, and therefore insights into how this disorder can be prevented or reversed in those who are predisposed.Read moreRead less
DNA Repair Mechanisms In The Pathogenesis Of Hepatocellular Carcinoma
Funder
National Health and Medical Research Council
Funding Amount
$339,078.00
Summary
Hepatocellular carcinoma (HCC) or cancer originating in the liver ranks 5th in worldwide frequency among tumours, and is the 3rd highest cause of cancer in our region. The incidence is increasing in most countries including Australia, Japan and USA. The overall prognosis is poor, with >80% affected persons dying from this disorder. The risk factors for HCC are well known and include chronic hepatitis B or C virus infection, alcoholism and liver iron accumulation. Despite the vast amount of in ....Hepatocellular carcinoma (HCC) or cancer originating in the liver ranks 5th in worldwide frequency among tumours, and is the 3rd highest cause of cancer in our region. The incidence is increasing in most countries including Australia, Japan and USA. The overall prognosis is poor, with >80% affected persons dying from this disorder. The risk factors for HCC are well known and include chronic hepatitis B or C virus infection, alcoholism and liver iron accumulation. Despite the vast amount of information available regarding these risk factors, the way in which they alter normal liver cells to make them cancerous remains undefined. The majority of liver cancers, regardless of cause, develop in severely scarred, or cirrhotic liver in the presence of chronic liver inflammation. Such an environment causes liver cells, which are usually stable and not dividing, to continue replicating in response to injury; such continued cell division can lead to damaged genetic information in the DNA of these cells. Many cancers are associated with chromosomal damage, including broken ends and deleted genetic material. The main focus of this project to investigate how defective repair of disrupted genetic information contained in DNA of chromosomes in damaged liver cells contributes to the development of liver cancer. Using mice lacking specific genetic information to repair DNA double strand breaks, we plan to investigate whether abnormalities in DNA repair mechanisms in liver cells damaged by diethylnitrosamine (DEN) predisposes liver cells to regenerate abnormally thereby progressing to cancer. We have clues that 7 specific sites in chromosomes where loss of key genes may promote HCC formation. These studies will greatly enhance our understanding of the molecular basis by which HCC develops. The ultimate goal of this research is to develop effective screening and treatment strategies to prevent or interrupt the process of liver cancer development in at-risk individuals.Read moreRead less
Mechanisms Underlying Growth, Lineage Commitment And Differentiation Of Liver Progenitor Cells
Funder
National Health and Medical Research Council
Funding Amount
$535,333.00
Summary
Liver disease is a serious health problem. Viral hepatitis, obesity and alcohol can result in end-stage liver disease. Organ transplant is the only treatment available. A widening gap between organ donations and recipients mandates alternative treatments are developed. Cell transplantation and artificial liver devices are alternatives which can use liver progenitor cells. We will investigate how factors grow and convert them into liver cells for treating liver disease patients.
The Epidemiology And Burden Of Liver Disease In Australia With An Emphasis On Non-alcoholic Fatty Liver Disease.
Funder
National Health and Medical Research Council
Funding Amount
$151,143.00
Summary
Non alcoholic fatty liver disease is now the commonest cause of abnormal liver function in Australia due to its close association with the obesity epidemic. It is likely to become the leading cause of liver failure and liver cancer over the next few decades. Despite this, the prevalence in Australian populations is unknown. The aim of this project is to assess how common this disorder is, the burden it places on the healthcare system and the effectiveness of treatment for liver cancer caused by ....Non alcoholic fatty liver disease is now the commonest cause of abnormal liver function in Australia due to its close association with the obesity epidemic. It is likely to become the leading cause of liver failure and liver cancer over the next few decades. Despite this, the prevalence in Australian populations is unknown. The aim of this project is to assess how common this disorder is, the burden it places on the healthcare system and the effectiveness of treatment for liver cancer caused by advanced non alcoholic fatty liver disease.Read moreRead less
Manganese is an essential trace element for normal health. However in some medical conditions manganese can build up in the brain and cause a Parkinson's like disease called manganism. Experimental evidence suggests that the liver plays an important role in the development of manganism and this project aims to explore the way the liver handles manganese in health and disease. These studies may assist in understanding how manganism develops.