Does Immunosuppression Affect The Post-transplantation Hepatic Fibrogenic Response?
Funder
National Health and Medical Research Council
Funding Amount
$360,000.00
Summary
Liver transplantation is often the only treatment option for patients who progress to end-stage liver disease after initial treatment has failed. Unfortunately, re-emergence of disease is common and patients often develop fibrosis and cirrhosis (scarring of the liver) in the donor organ. In some cases it has been observed that this scarring often develops rapidly, sometimes in a year or less following transplantation. Re-transplantation is often required. This differs from the usual progression ....Liver transplantation is often the only treatment option for patients who progress to end-stage liver disease after initial treatment has failed. Unfortunately, re-emergence of disease is common and patients often develop fibrosis and cirrhosis (scarring of the liver) in the donor organ. In some cases it has been observed that this scarring often develops rapidly, sometimes in a year or less following transplantation. Re-transplantation is often required. This differs from the usual progression of cirrhosis pre-transplant which often takes years or decades to develop. While essential to prevent rejection of the transplanted organ, immunosuppression is not without side effects. To date, few studies have examined the effect of immunosuppressive agents on the development of hepatic fibrosis and the key fibrosis effector cell type, the hepatic stellate cell. These reports have shown that one of the most commonly used immunosuppressant agents (FK-506) may adversely influence fibrosis progression while rapamycin may prevent fibrosis progression. However little is known regarding the mechanisms through which this occurs. We propose to examine the effect of four different immunosuppressants on fibrosis development both in vitro and in vivo to determine whether scar development or scar breakdown pathways are altered post-immunosuppression. If the factors driving the fibrogenesis in the transplanted organ can be elucidated it may then be possible to develop therapeutic strategies to tackle the problem. This may result in a reduced need for re-transplantation which has obvious benefits to the transplant patient but would also reduce the numbers of donor organs required.Read moreRead less
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.
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.
ALCOHOL AND IMPAIRED LIVER REGENERATION: EFFECTS ON MITOGENIC SIGNALING PATHWAYS
Funder
National Health and Medical Research Council
Funding Amount
$365,295.00
Summary
Patients who regularly consume alcohol are slow to recover from liver injury because alcohol poisons the liver's capacity to regenerate itself (grow back). Hence patients with alcohol-induced liver disease have a high mortality and prolonged hospital stays. The applicants have been supported by NHMRC to study how alcohol impairs liver regeneration. They found that the effect is at the level of cell surface receptors for the growth factors that control liver regeneration. Alcohol alters the funct ....Patients who regularly consume alcohol are slow to recover from liver injury because alcohol poisons the liver's capacity to regenerate itself (grow back). Hence patients with alcohol-induced liver disease have a high mortality and prolonged hospital stays. The applicants have been supported by NHMRC to study how alcohol impairs liver regeneration. They found that the effect is at the level of cell surface receptors for the growth factors that control liver regeneration. Alcohol alters the function of these receptors. One major discovery has been that it damages the capacity to generate a rise in calcium within the cell, something that is fundamentally required for any cell to divide and reproduce itself. Thus when a rise in calcium was produced artificially (with chemicals to unlock the internal calcium stores), liver cells from alcohol-fed rats once more responded normally under the influence of growth factors and replicated themselves. The present work isdesigned to find out where this effect of calcium is exerted. The investigators believe that it is related to how other types of signals work, the so-called protein kinase pathways. These are cascades of one protein turning on (activating) the next down the line to ultimately switch on the genes that control cell growth. They will manipulate liver cells from alcohol-fed rats in culture to establish which of these pathways is most affected, and which is the most critical for the control of cell division genes. These studies will greatly advance our understanding about how alcohol impairs liver regeneration. They will give new insight into the control of liver cell growth and division that is such a crucial response of the liver to injury, vital for survival of the liver. This kind of knowledge will open the door for new treatments to be designed that can control liver growth - turn it back on when it has been poisoned, or turn it off when it is inappropriately vigorous and predisposing to liver cancer.Read moreRead less
Role Of Human Amnion Epithelial Cells In Resolving Hepatic Fibrosis
Funder
National Health and Medical Research Council
Funding Amount
$618,755.00
Summary
When the liver is injured repeatedly by viruses and alcohol, it responds through a wound healing process that can lead to extensive scar tissue in the liver (cirrhosis). This condition may require liver transplantation and lifelong use of drugs to prevent the body from rejecting the new organ. To develop an alternate therapy, we will study if substances secreted by amnion cells from the human placenta (afterbirth), which would normally be discarded, can reduce liver scar tissue in mice .
Preconditioning: The Molecular Basis For Protection From Hepatic Ischemia-reperfusion Injury
Funder
National Health and Medical Research Council
Funding Amount
$406,980.00
Summary
When the blood supply to the liver is cut off temporarily (ischemia) and later restored (reperfusion) the liver is damaged by a process called ischemia-reperfusion (IR) injury. This is a major problem during liver surgery and is also an underlying problem in liver transplantation; following storage of a donor liver ready for placing into the recipient it can undergo a similar process called preservation injury. We now understand a lot about how IR comes about, particularly by the formation of da ....When the blood supply to the liver is cut off temporarily (ischemia) and later restored (reperfusion) the liver is damaged by a process called ischemia-reperfusion (IR) injury. This is a major problem during liver surgery and is also an underlying problem in liver transplantation; following storage of a donor liver ready for placing into the recipient it can undergo a similar process called preservation injury. We now understand a lot about how IR comes about, particularly by the formation of damaging oxygen radicals within liver cells to start a process of programmed cell death, but it remains difficult to prevent or treat IR injury. A recent breakthrough has been recognition that subjecting the liver to only a short period (5 or 10 minutes) of ischemia protects against a later period of prolonged ischemia or IR. In the investigator s mouse model, for example, such preconditioning was 60 to 90% protective (depending on the time after IR). This project seeks to understand how preconditioning works to protect the liver against IR injury. Our idea is that preconditioning generates a limited amount of oxygen radicals, and that these turn on signalling pathways in the cell that regulate certain protective genes. Genes that encode antioxidant and other anti-stress pathways are likely to be important, but so are genes that prepare the cell to enter the cell cycle and divide into new cells that regenerate the liver. Conversely, genes that program cell death may be turned off. The outcomes of this research will be to understand the molecular and cellular basis of how preconditioning protects against ischemia-reperfusion injury of the liver. This will allow drug treatments to be devised that, by simulating preconditioning, prevent this common and severe type of liver damage.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
Liver Cell Transplantation For The Treatment Of Liver Based Metabolic Diseases.
Funder
National Health and Medical Research Council
Funding Amount
$444,143.00
Summary
We propose to investigate the role of liver cell transplantation (LCT) for the therapy of inherited liver-based metabolic diseases using a methylmalonic aciduria (MMA) mouse model. LCT provides an exciting alternative to whole organ transplantation. Initially it was considered liver cells would be immunopriviledged. This has not proven to be the case. Immune modulation will be important. We will also examine immune modulation using antibodies to optimise longterm survival of allogeneic cells.