The Functional Roles Of ADAMs In The Regulation Of Embryo Implantation.
Funder
National Health and Medical Research Council
Funding Amount
$211,527.00
Summary
The initiation of pregnancy in humans and rodents hinges upon the ability of the embryo to attach to the wall of the uterus and invade into the uterine tissue. This process of embryo implantation is tightly regulated and depends on the secretion of enzymes and regulators of these enzymes. A newly identified family of enzymes which might be important in this process is the ADAMs family. These enzymes have the potential to facilitate both cell attachment and cell invasion and also to activate othe ....The initiation of pregnancy in humans and rodents hinges upon the ability of the embryo to attach to the wall of the uterus and invade into the uterine tissue. This process of embryo implantation is tightly regulated and depends on the secretion of enzymes and regulators of these enzymes. A newly identified family of enzymes which might be important in this process is the ADAMs family. These enzymes have the potential to facilitate both cell attachment and cell invasion and also to activate other enzymes and growth factors. Recent studies in our laboratory have shown the ADAMs to be expressed both at the most invasive time of implantation and when invasion is being down-regulated. This project will examine the role of the ADAMs in embryo implantation facilitating attachment and invasion into the uterus by acting enzymatically on the uterine tissue and by activating other enzymes. It will also determine the role of ADAMs in down-regulating invasion potentially by activating a growth factor, TNF-alpha. Knowledge of this process and particularly its regulation is important for the treatment of pregnancy associated diseases that arise from improper implantation. These include infertility, placenta accreta, choriocarcinoma, miscarriage and pre-eclampsia. Furthermore, an understanding of the regulation of implantation will contribute to the treatment of other conditions associated with cell invasion such as cancer metastasis.Read moreRead less
Modulating Interactions Between TNFalpha And IGF-1 Signaling Pathways To Reduce Necrosis Of Dystrophic Muscle
Funder
National Health and Medical Research Council
Funding Amount
$476,515.00
Summary
Duchene Muscular Dystrophy (DMD) is a lethal childhood disease that affects mainly boys. These experiments will test new highly specific anti-inflammatory drugs for the potential clinical treatment of muscular dystrophies, using the mdx mouse model of human DMD. It is essential that the benefits of such anti-inflammatory drugs are fully evaluated in long term studies in mice. Two of these drugs (Enbrel and Remicade) are already in wide clinical use for inflammatory disorders and present attracti ....Duchene Muscular Dystrophy (DMD) is a lethal childhood disease that affects mainly boys. These experiments will test new highly specific anti-inflammatory drugs for the potential clinical treatment of muscular dystrophies, using the mdx mouse model of human DMD. It is essential that the benefits of such anti-inflammatory drugs are fully evaluated in long term studies in mice. Two of these drugs (Enbrel and Remicade) are already in wide clinical use for inflammatory disorders and present attractive options for treatment of DMD patients due to their high specificity of action and relatively few side effects. We have shown that both of these drugs have a striking protective effect and reduce necrosis of dystrophic muscle in the mdx mouse. The benefits of these drugs (and the mouse equivalent cVIq) is due to blocking the action of the key pro-inflammatory cytokine Tumour Necrosis Factor-alpha (TNFa). However, the precise mechanism by which high levels of TNFa increase necrosis of dystrophic muscle is not clear. There are many possible pathways. Identifying which is the key pathway(s), is of central importance to design and target new drugs to treat such lethal muscle diseases. Such modulation of signalling is a major therapeutic goal. To determine which mechanism of TNFa action is responsible for muscle necrosis, experiments will investigate several signalling pathways using specific inhibitors: the drug Pifithrin to inhibit p53; soluble RAGE to block RAGE (Receptor for Advanced Glycation Endproducts); and specific inhibitory peptides to block JNK (c-Jun N-terminal kinase). The application of these inhibitors (drugs), in mice, as future therapies for muscle diseases is novel. These studies will provide much new information on TNFa related signalling that is highly relevant to the potential treatment of many diseases, including muscle wasting that is a major problem in the ageing population and in disuse atrophy and cachexia.Read moreRead less
The C-type Lectin, Mincle, Is A Macrophage Receptor For Candida Albicans.
Funder
National Health and Medical Research Council
Funding Amount
$465,210.00
Summary
The yeast Candida albicans is an important opportunistic infection that causes both mucosal and disseminated disease in patients whose innate or adaptive immune responses are impaired Infection and proliferation results in fungal colonisation of the tissues, and a variable degree of tissue damage. The latter is determined both by the virulence properties of the organism and by the genetic makeup of the host. This large, extracellular pathogen is eradicated from the body predominantly by acavenge ....The yeast Candida albicans is an important opportunistic infection that causes both mucosal and disseminated disease in patients whose innate or adaptive immune responses are impaired Infection and proliferation results in fungal colonisation of the tissues, and a variable degree of tissue damage. The latter is determined both by the virulence properties of the organism and by the genetic makeup of the host. This large, extracellular pathogen is eradicated from the body predominantly by acavenger (phagocytic) cells, which are also important in determining the severity of the associated tissue lesions. A phagocytic cell that is central to both innate and adaptive immune responses is the macrophage, which not only takes up and kills the yeast, but also is capable of of killing and digesting it, and presenting the components to cells of the adaptive immune system. This project is based on the postulate that the outcome and severity of infection is determined, at least in part, by the early functional response of the macrophage to the overall virulence properties of the yeast. The response is initiated by interactions with cell-surface receptors, and this study will show that a novel macrophage receptor, Mincle, is an important part of the innate immune response to fungal infections. We have shown that it is associated with differences in susceptibility to yeast infections in inbred mouse strains; it can discriminate between different isolates of the yeast; and it initiates the inflammatory signalling cascade. Our project will define the specific role of this receptor in fungal infection. The results will be important in understanding the basic biology of host resistance, and will offer new opportunities for therapeutic intervention by selectively blocking or modifying different activation pathways.Read moreRead less
Mechanisms Underlying The Effects Of TNFalpha In Bone And Haemopoiesis
Funder
National Health and Medical Research Council
Funding Amount
$589,425.00
Summary
Recent studies have identified that bone plays an important role in blood cell production. We have discovered that elevated levels of TNF alpha (which increases with ageing and can negatively impact on health) contributes to a blood cell disorder that can progress to leukaemia. There are also reduced numbers of blood stem cells and bone in this mouse model. In these studies we will determine how TNFalpha contributes to blood and bone defects, which may lead to better treatment of such diseases.
Role Of Transformation And IAPs In Sensitivity Of Cells To TNFalpha
Funder
National Health and Medical Research Council
Funding Amount
$505,786.00
Summary
Current cancer treatments are ineffective and unpleasant for patients. This is because existing cancer treatments target normal as well as cancer cells. New anti-cancer drugs have been designed to encourage cancer cells to kill themselves, by a process called apoptosis, but may still target normal cells. This project aims to discover why cancer cells are susceptible to a novel anti-cancer drug and a natural ligand called TNF but normal cells are not. This will lead to better treatments.
Pathophysiological Significance Of Reverse Signaling Through Membrane TNF
Funder
National Health and Medical Research Council
Funding Amount
$453,055.00
Summary
Cytokines are molecules produced by cells that take part in immune and inflammatory responses. They coordinate the activities of leukocytes and therefore are important in the host response against infections. However, overproduction of some cytokines, particularly tumour necrosis factor, seems to cause the deleterious consequences. Tumour necrosis factor is made by cells, particularly macrophages, T lymphocytes and natural killer cells, in two stages: first, the cytokine is exposed on the surfac ....Cytokines are molecules produced by cells that take part in immune and inflammatory responses. They coordinate the activities of leukocytes and therefore are important in the host response against infections. However, overproduction of some cytokines, particularly tumour necrosis factor, seems to cause the deleterious consequences. Tumour necrosis factor is made by cells, particularly macrophages, T lymphocytes and natural killer cells, in two stages: first, the cytokine is exposed on the surface of the cell and then it is 'clipped off' and released as a smaller, soluble form. In either form it can interact with specific receptors on other cells and, in this way, change the cells' activities. We believe that binding of tumour necrosis factor receptors to the cytokine while it is in its membrane form can also send a message backwards, into the cell bearing the tumour necrosis factor. This process, known as reverse signalling, then changes the activity of this cell. In this project we will investigate this phenomenon in detail. The results will be extremely relevant to new methods of treatment of diseases, that rely either on 'masking' tumour necrosis factor by administering soluble forms of its receptor or on blocking the release of the soluble form of the molecule from the surface of the cell. Our work will enable us to understand the consequences of these approaches more fully. We will also be looking at the role of the membrane form of tumour necrosis factor in a model of infectious disease. Influenza virus is responsible for a great deal of morbidity and mortality around the world. We, and others, have shown, in a mouse model, that some cells in the lungs make tumour necrosis factor during the course of viral pneumonia. Here we will determine whether the membrane form of this cytokine plays a role in clearing virus or causing some of the complications of this disease. This also may have relevance to other inflammatory and infectious disease.Read moreRead less
Apo2L/TRAIL Killing Of Tumour Cells And The Role Of Inhibitor Of Apoptosis Proteins
Funder
National Health and Medical Research Council
Funding Amount
$390,321.00
Summary
Melanomas and Gliomas are tumour types that respond poorly to current treatments. Current treatments are not only sometimes ineffective, but also unpleasant and may cause co-lateral damage. We will test 2 new targetted anti-cancer treatments, that so far appear to have minor side effects in small animal models, on these difficult to treat tumour types to see if and how they kill them. We also want to know whether these independent treatments can work together to kill tumours more effectively. Al ....Melanomas and Gliomas are tumour types that respond poorly to current treatments. Current treatments are not only sometimes ineffective, but also unpleasant and may cause co-lateral damage. We will test 2 new targetted anti-cancer treatments, that so far appear to have minor side effects in small animal models, on these difficult to treat tumour types to see if and how they kill them. We also want to know whether these independent treatments can work together to kill tumours more effectively. Although we will not personally test these drugs in clinical settings, these drugs or similar are currently in preclinical and clinical trials. This means that understanding how these drugs function is of paramount importance and may result in better clinical trials and possibly more rapid acceptance of the use of these drugs in patients.Read moreRead less