Temporal And Spatial Regulation Of Caspases In Development And Metamorphosis
Funder
National Health and Medical Research Council
Funding Amount
$473,250.00
Summary
Cell death by a special process called apoptosis is a means of deleting unwanted and harmful cells from the body. Extensive apoptosis occurs during foetal development which is required to get rid of many excess cells produced during the growth of the embryo. Selective apoptosis is also essential for the formation of different tissues and organs in developing foetus. In the adult, apoptosis is required for proper functioning of the immune system, to remove virus infected and cancer cells and in g ....Cell death by a special process called apoptosis is a means of deleting unwanted and harmful cells from the body. Extensive apoptosis occurs during foetal development which is required to get rid of many excess cells produced during the growth of the embryo. Selective apoptosis is also essential for the formation of different tissues and organs in developing foetus. In the adult, apoptosis is required for proper functioning of the immune system, to remove virus infected and cancer cells and in general to maintain the correct number of cells in the body. As such, misregulated apoptosis is associated with the pathogenesis of a wide array of diseases such as autoimmune diseases, many forms of cancer and neurodegenerative disorders (such as Alzheimer's and Parkinson's diseases), heart disease, ischaemia and other conditions. To understand, manage and treat disorders that result from aberrant apoptosis, we need to know at molecular and cellular level, how apoptosis is brought about and how it is regulated. We have been studying these processes in detail for several years. Central to the apoptotic execution of cell death are a group of proteases that target many cellular proteins for specific cleavage. The activation of these proteases is the crucial step in the initiation of apoptosis and therefore each cell has developed complex ways to control this process. In the present proposal, we aim to study regulation of caspases that are involved in developmental apoptosis. Furthermore, we plan to identify proteins that are responsible for the regulation of caspase activation.Read moreRead less
Temporal And Spatial Regulation Of Caspases In Development And Metamorphosis
Funder
National Health and Medical Research Council
Funding Amount
$369,072.00
Summary
Cell death by a special process called apoptosis is a means of deleting unwanted and harmful cells from the body. Extensive apoptosis occurs during foetal development which is required to get rid of many excess cells produced during the growth of the embryo. Selective apoptosis is also essential for the formation of different tissues and organs in developing foetus. In the adult, apoptosis is required for proper functioning of the immune system, to remove virus infected and cancer cells and in g ....Cell death by a special process called apoptosis is a means of deleting unwanted and harmful cells from the body. Extensive apoptosis occurs during foetal development which is required to get rid of many excess cells produced during the growth of the embryo. Selective apoptosis is also essential for the formation of different tissues and organs in developing foetus. In the adult, apoptosis is required for proper functioning of the immune system, to remove virus infected and cancer cells and in general to maintain the correct number of cells in the body. As such, dysregulation of apoptosis is associated with the pathogenesis of a wide array of diseases such as autoimmune diseases, many forms of cancer and neurodegenerative disorders (such as Alzheimer's and Parkinson's diseases), heart disease, ischaemia and other conditions. To understand, manage and treat disorders that result from aberrant apoptosis, we need to know at molecular and cellular level, how apoptosis is brought about and how it is regulated. We have been studying these processes in detail for several years. Central to the apoptotic execution of cell death are a group of proteases that target many cellular proteins for specific cleavage. The activation of these proteases is the crucial step in the initiation of apoptosis and therefore each cell has developed complex ways to control this process. If we understand how these regulatory mechanisms operate, we can then formulate strategies that are targeted towards pathologies involving abnormal apoptosis. Various molecules that are involved in the execution and regulation of apoptosis are potentially excellent targets for therapeutic intervention in a number of disorders and will lead to the development of novel drugs for the treatment and prevention of many pathological conditions. In the present proposal, we aim to study what type of caspases are involved in sculpting of various organs and tissues during development.Read moreRead less
Cell death by a special process called apoptosis is a means of deleting unwanted and harmful cells from the body. Extensive apoptosis occurs during foetal development which is required to get rid of many excess cells produced during the growth of the embryo. Selective apoptosis is also essential for the formation of different tissues and organs in developing foetus. In the adult, apoptosis is required for proper functioning of the immune system, to remove virus infected and cancer cells and in g ....Cell death by a special process called apoptosis is a means of deleting unwanted and harmful cells from the body. Extensive apoptosis occurs during foetal development which is required to get rid of many excess cells produced during the growth of the embryo. Selective apoptosis is also essential for the formation of different tissues and organs in developing foetus. In the adult, apoptosis is required for proper functioning of the immune system, to remove virus infected and cancer cells and in general to maintain the correct number of cells in the body. As such, misregulation of apoptosis is associated with the pathogenesis of a wide array of diseases such as autoimmune diseases, many forms of cancer and neurodegenerative disorders (such as Alzheimer's and Parkinson's diseases), heart disease, ischaemia and other conditions. To understand, manage and treat disorders that result from aberrant apoptosis, we need to know at molecular and cellular level, how apoptosis is brought about and how it is regulated. We have been studying these processes in detail for several years. Central to the apoptotic execution of cell death are a group of proteases that target many cellular proteins for specific cleavage. The activation of these proteases is the crucial step in the initiation of apoptosis and therefore each cell has developed complex ways to control this process. If we understand how these regulatory mechanisms operate, we can then formulate strategies that are targeted towards pathologies involving abnormal apoptosis. Various molecules that are involved in the execution and regulation of apoptosis are potentially excellent targets for therapeutic intervention in a number of disorders and will lead to the development of novel drugs for the treatment and prevention of many pathological conditions.Read moreRead less
The Regulation And Role Of Puma And P53 In IL-3 Withdrawal Induced Cell Death
Funder
National Health and Medical Research Council
Funding Amount
$527,683.00
Summary
It is the ultimate fate of most of our cells to die by committing suicide, because they are no longer required, are no longer functioning, or are potentially harmful. This normal physiological process is termed apoptosis . When cell death fails to occur, abnormal cells can accumulate and lead to cancer. Signalling from growth-factors is required for many cell types to survive. When these signals are lost, the cells activate their cell death pathways. It is a hallmark of cancer cells that they ha ....It is the ultimate fate of most of our cells to die by committing suicide, because they are no longer required, are no longer functioning, or are potentially harmful. This normal physiological process is termed apoptosis . When cell death fails to occur, abnormal cells can accumulate and lead to cancer. Signalling from growth-factors is required for many cell types to survive. When these signals are lost, the cells activate their cell death pathways. It is a hallmark of cancer cells that they harbour mutations in cell death genes and their dependence on growth factors for survival is diminished or lost. The genes of the apoptosis pathway function either to promote or inhibit cell death. Some genes in the apoptosis pathway allow apoptosis to proceed rapidly, but do not decide the fate of the cell. Other genes are required for a cell to commit to die, and if they are mutated then a functional cell, that is capable of proliferating, survives. This is a crucial distinction because it is only the genes that decide cell fate that can act as cancer genes, and are valid targets for therapy. We have identified one particular gene, Puma, as an important regulator of cell survival. Without this gene, cells survive longer without growth-factor and, importantly, can proliferate when growth factor is restored. Understanding how this gene functions and is regulated will contribute to our understanding of the gene mutations that lead to cancer and may identify valid targets for cancer therapy. In our model we use growth factor dependent cell lines derived from mice lacking particular genes in the cell death pathway, including Puma. These cells proliferate in the presence of growth factor, and allow us to determine the role of the genes when growth factor is withdrawn. Using this system, we will determine how Puma is able to induce cell death, what other genes are required to regulate this process and how loss of Puma function may contribute to cancer development.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
Mitochondria: Molecular And Cellular Insights Into Their Diverse Contributions To Neuronal Injury
Funder
National Health and Medical Research Council
Funding Amount
$747,927.00
Summary
Mitochondria are components of cells normally providing energy for essential functions and in the energy demanding brain, under stress conditions, mitochondria acts as controllers of cellular decision-making processes leading to neuronal death. Our goal is to understand mitochondrial mechanisms determining how neurones die after various stresses and injury. Using pathological insults relevant to neurological conditions, we shall analyse death molecules and how neurones adapt when threatened.
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 special process called apoptosis is a means of deleting unwanted and harmful cells from the body. Extensive apoptosis occurs during foetal development which is required to get rid of many excess cells produced during the growth of the embryo. Selective apoptosis is also essential for the formation of different tissues and organs in developing foetus. In the adult, apoptosis is required for proper functioning of the immune system, to remove virus infected and cancer cells and, in ....Cell death by a special process called apoptosis is a means of deleting unwanted and harmful cells from the body. Extensive apoptosis occurs during foetal development which is required to get rid of many excess cells produced during the growth of the embryo. Selective apoptosis is also essential for the formation of different tissues and organs in developing foetus. In the adult, apoptosis is required for proper functioning of the immune system, to remove virus infected and cancer cells and, in general, to maintain the correct number of cells in the body. As such, misregulation of apoptosis is associated with the pathogenesis of a wide array of diseases. To understand, manage and treat disorders that result from aberrant apoptosis, we need to know at molecular and cellular level, how apoptosis is brought about and how it is regulated. We have been studying these processes in detail for several years. Central to the apoptotic execution of cell death are a group of proteases called caspases, that target many cellular proteins for specific cleavage. The activation of caspases is the crucial step in the initiation of apoptosis and therefore each cell has developed complex ways to control this process. If we understand how these regulatory mechanisms operate, we can then formulate strategies that are targeted towards pathologies involving abnormal apoptosis. In this proposal we will use vinegar fly as a model to study the function of caspases in development. We believe that results from this proposal will have several major benefits. Firstly, they will provide important insight into the mechanisms of developmental apoptosis thereby filling many gaps in our current knowledge. Secondly, the study will endeavour to identify new molecules-pathways that lead to caspase activation. Finally, the proposed studies will shed light on the function of caspases in non-apoptotic pathways.Read moreRead less
Evolutionary Conservation Of Caspase Regulatory Mechanisms
Funder
National Health and Medical Research Council
Funding Amount
$585,215.00
Summary
Apoptosis is a highly controlled process by which metazoans eliminate unwanted and dangerous cells. Dysregulation of apoptosis can contribute to many conditions including cancer, autoimmune and degenerative diseases. To develop therapeutic reagents that promote cell death when it fails to occur, or prevent it from happening inappropriately, it is necessary to understand the mechanisms controlling apoptosis. To date, many of the important insights into mammalian cell death signalling have been in ....Apoptosis is a highly controlled process by which metazoans eliminate unwanted and dangerous cells. Dysregulation of apoptosis can contribute to many conditions including cancer, autoimmune and degenerative diseases. To develop therapeutic reagents that promote cell death when it fails to occur, or prevent it from happening inappropriately, it is necessary to understand the mechanisms controlling apoptosis. To date, many of the important insights into mammalian cell death signalling have been informed by studies of apoptotic pathways in simpler, experimentally tractable model organisms. This project will exploit biochemical approaches and powerful yeast-based tools developed by CI-A to further explore cell death pathways of the nematode Caenorhabditis elegans, and compare these with mammalian apoptosis pathways. Key findings will be verified using genetic approaches. Most apoptotic stimuli ultimately kill mammalian, insect or nematode cells by triggering activation of proteases termed caspases. However, the mechanisms by which caspase activity is regulated appear to differ somewhat between mammals and worms. We will address two general possibilities: either these animals really do differ significantly in the upstream regulation of cell death pathways, or that functional counterparts of key components have not hitherto been identified or fully characterised. Understanding the way in which mammalian apoptosis is regulated will aid in the design of diagnostic and therapeutic reagents for the many diseases in which dysregulation of apoptosis has been implicated. This project seeks to define the extent to which apoptotic regulation is conserved between mammals and nematodes. This knowledge will enable researchers to maximise the utility of nematode cell death models for the further elucidation of mammalian cell death regulatory mechanisms, and to explore how apoptosis can be manipulated for clinical benefit.Read moreRead less
Molecular Mechanisms Of Death In Cells With Defective Apoptotic Pathways
Funder
National Health and Medical Research Council
Funding Amount
$335,065.00
Summary
The body protects itself from cancer by killing any cell that poses a risk of becoming a tumour. The body kills these cells via a carefully orchestrated sequence (or pathway) of events, however many cancer cells have defects in cell death pathways that has permitted them to survive even though they have been told to die. In this proposal we set out a research program to investigate how to kill cancer cells that don't want to die. Various tumour cells have been shown to have increased levels of B ....The body protects itself from cancer by killing any cell that poses a risk of becoming a tumour. The body kills these cells via a carefully orchestrated sequence (or pathway) of events, however many cancer cells have defects in cell death pathways that has permitted them to survive even though they have been told to die. In this proposal we set out a research program to investigate how to kill cancer cells that don't want to die. Various tumour cells have been shown to have increased levels of Bcl-2, a proto-oncogene that blocks cell death induced by diverse stimuli. Cells that over-express Bcl-2 are also resistant to cytotoxic drugs. Understanding how to bypass Bcl-2 (or proteins that block cell death in tumours) will lead to a better understanding of cell death-cell survival and allow us to explore the possibility of tailoring treatment for patients in which specific defects in death pathways have been identified in their cancer cells. Cytotoxic lymphocytes (CL) are cells of the immune system that defend the body from cancer by specifically attacking and killing tumor cells. We have been pioneering studies of CL:tumour interactions in which we can define the morphology and kinetics of critical events in cell death and have shown that CL have the ability to kill target cells that over-express Bcl-2. Following the aims in this proposal, we will understand the mechanisms by which cytotoxic lymphocytes kill target cells that have defects in classical cell death pathways. These studies will therefore define alternative pathways to cell death in the event that a key component of the preferential pathway to cell death is inoperative. Since cytotoxic lymphocytes use a variety of ways to kill their targets and tumors may contain multiple defects in cell death pathways, we will explore which are the key defects, or the combination of multiple defects, in cell death pathways that prevent cytotoxic lymphocyte mediated cell death and permit tumour survival in vivo.Read moreRead less