Glutathione is a natural antioxidant, which is known to protect cells in the body from chemical damage. A small part of the glutathione in cells is found in the mitochondria, a structure that is involved in producing the chemical energy needed for normal cell function. The mitochondria are also involved under some circumstances in promoting the death of cells. Although glutathione in general has been well studied, much less attention has been paid to the function of glutathione in mitochondria, ....Glutathione is a natural antioxidant, which is known to protect cells in the body from chemical damage. A small part of the glutathione in cells is found in the mitochondria, a structure that is involved in producing the chemical energy needed for normal cell function. The mitochondria are also involved under some circumstances in promoting the death of cells. Although glutathione in general has been well studied, much less attention has been paid to the function of glutathione in mitochondria, particularly in cells from the brain. Our recent studies indicate that this mitochondrial pool of glutathione is particularly important in limiting the death of cells from the brain when exposed to damaging substances that are increased in some diseases. Thus, the capacity of mitochondrial glutathione to deal with such substances might be a factor in determining the extent of cell loss in the brain, which is an important determinant of symptoms in some of the major neurological diseases. Consistent with this possibility, we have obtained evidence indicating that decreases in glutathione in the mitochondria contribute to the cell death and brain damage that results from a stroke. In our proposed studies, we will investigate the function of mitochondrial glutathione in the two major cell populations from the brain, neurons and astrocytes. We will characterise the protective role of the glutathione and investigate how it enters the mitochondria and what factors influence the amount that is present. This will provide new insights into the function of glutathione in the mitochondria and could also suggest novel approaches for manipulating this antioxidant pool. We will also study models of stroke and some related brain disorders to more directly test the role of this antioxidant in disease and to assess whether manipulating the content of glutathione in the mitochondria has the potential to reduce damage and improve function in these disordersRead moreRead less
Viral Interference With Apoptosis: Defining The Mechanisms And Effects On Viral Pathogenesis
Funder
National Health and Medical Research Council
Funding Amount
$551,328.00
Summary
Apoptosis, or programmed cell death, is an orderly process whereby unwanted or damaged cells are removed from an organism. Deregulation of apoptosis has been implicated in the development of diseases such as cancer and autoimmunity. Therefore, a precise understanding of the mechanisms controlling the initiation of apoptosis has important clinical implications. In addition to removing unwanted cells, apoptosis functions as a defence mechanism to inhibit viral replication. Hence, in order to repli ....Apoptosis, or programmed cell death, is an orderly process whereby unwanted or damaged cells are removed from an organism. Deregulation of apoptosis has been implicated in the development of diseases such as cancer and autoimmunity. Therefore, a precise understanding of the mechanisms controlling the initiation of apoptosis has important clinical implications. In addition to removing unwanted cells, apoptosis functions as a defence mechanism to inhibit viral replication. Hence, in order to replicate efficiently viruses have evolved means to inhibit or interfere with apoptosis. The central aim of this work is to understand how two genes encoded by murine cytomegalovirus (MCMV) inhibit apoptosis and contribute to viral replication. MCMV is used as a model for human CMV (HCMV) infection. The majority of the human population is infected with HCMV which poses no risk to healthy individuals. However, reactivation of HCMV in people who are immunosuppressed such as transplant recipients or AIDS patiens is a significant cause of mortality. The MCMV infection model has provided important insights as to how the immune system controls infection and the mechanisms utilized by viruses to circumvent these processes. The proposed studies will improve our understanding of the processes that regulate viral replication. Understanding how viruses subvert host defence mechanisms will allow us to better understand their role in causing human disease, and thus, will provide key information for the design of improved anti-viral strategies. Importantly, the type of analyses proposed here will also contribute critical insights into the normal processes that control cell survival.Read moreRead less
Cell death by a specialised process known apoptosis is a way of deleting unwanted and harmful cells from the body. As such, aberrant apoptosis is associated with a wide array of diseases including cancer. For example, abnormal levels of proteins that suppress apoptosis or enhance cell survival can result in cancer and often produce resistance to chemotherapy. To understand and treat cancers that result from aberrant apoptosis we need to know at a molecular level how apoptosis is regulated. Centr ....Cell death by a specialised process known apoptosis is a way of deleting unwanted and harmful cells from the body. As such, aberrant apoptosis is associated with a wide array of diseases including cancer. For example, abnormal levels of proteins that suppress apoptosis or enhance cell survival can result in cancer and often produce resistance to chemotherapy. To understand and treat cancers that result from aberrant apoptosis we need to know at a molecular level how apoptosis is regulated. Central to the apoptosis execution are a group of enzymes called caspases that target many cellular proteins for specific cleavage. In this proposal, we will investigate the function of one of the caspases (called caspase-2), in order to better understand its potential role in the apoptosis of cancer cells. A number of recent reports suggest that caspase-2 levels are reduced in many cancer cells. The human caspase-2 gene localizes to a chromosomal region frequently affected- deleted in leukaemia, and caspase-2 levels have been proposed to be predictors of remission and survival in patients with some types of leukaemia. We will study if loss of caspase-2 in cancer cells makes them resistant to killing by drugs and if mice lacking caspase-2 have an increased potential to develop cancer. Understanding caspase-2 function and its regulation is likely to provide new therapeutic opportunities and potential targets for cancer therapy.Read moreRead less
Caspase 8 Apoptotic Signalling Induced By The Inflammasome
Funder
National Health and Medical Research Council
Funding Amount
$603,126.00
Summary
The death of cells of our body can be an active and purposeful process. Programmed death occurs in response to infection or as a defence against cancerous changes. If a virally infected cell can die prior to replication of the virus, this will control the infection. We have investigated cell death in response to DNA found in the cytoplasm of cells, which can be an indication of infection. The novel cell death pathway we are characterising is relevant to defence against infection and tumours.
Only recently has it emerged that our cells have a built-in backup mechanism that instructs cells to die in extreme cases, such as when viruses have hijacked a cell. A misfiring backup mechanism is thought to underlie a number of human diseases, including inflammatory disease. Our investigation will establish a starting point for the development of novel anti-inflammatory drugs.