Gene Profiling To Develop A Neuroprotective Strategy In A Large Animals Model Of Following Ischaemic Stroke.
Funder
National Health and Medical Research Council
Funding Amount
$359,897.00
Summary
Stroke affects 15 million people worldwide each year. At present, the diagnosis and treatment of stroke is not optimal. The use of gene profiling may provide us with information that could allow us to more accurately identify individuals at risk of stroke, predict stroke outcome and effectively treat stroke patients. In addition, by using a targeted approach to therapy we have the potential to reduce brain swelling and improve outcome following stroke with neuroprotective agents.
Regulation Of Tissue-type Plasminogen Activator Gene Expression In Endothelial Cells And In Transgenic Mice
Funder
National Health and Medical Research Council
Funding Amount
$244,009.00
Summary
Tissue-type plasminogen activator (t-PA) is an enzyme which plays an important role in the removal of blood clots from the circulation. One of the major sites of production of t-PA are endothelial cells which line the blood vessel wall. The rate of t-PA production is greatly influenced by factors released from other cells. One of these factors is tumour necrosis factor (TNF). The t-PA gene is switched off in endothelial cells exposed to TNF. One of the aims of this project is to understand how t ....Tissue-type plasminogen activator (t-PA) is an enzyme which plays an important role in the removal of blood clots from the circulation. One of the major sites of production of t-PA are endothelial cells which line the blood vessel wall. The rate of t-PA production is greatly influenced by factors released from other cells. One of these factors is tumour necrosis factor (TNF). The t-PA gene is switched off in endothelial cells exposed to TNF. One of the aims of this project is to understand how the t-PA gene is suppressed by TNF in human endothelial cells and in transgenic mice. The transgenic mice we have available express the regulatory region of the t-PA gene (called the gene promoter) connected to a reporter gene called LacZ. We will use these animals to visualise the expression pattern of LacZ expression under normal conditions and in mice treated with TNF. The results of these experiments will provide new information as to how the t-PA gene is controlled in cells and in the body.Read moreRead less
Investigation And Modulation Of RANKL-induced Osteoclastogensis, Bone Resorption And Signaling Pathways
Funder
National Health and Medical Research Council
Funding Amount
$33,825.00
Summary
Osteoclasts are exclusively responsible for the degradation of bone matrix. RANKL is a member of a ligand-receptor system which directly regulates osteoclast differentiation and bone resorption. New treatment regime for various bone diseases have been highly sought after for many years. The identification of potential natural compounds that inhibit the formation and function of osteoclasts might serve as a useful tool for such treatment.
Alternate Signalling Pathways Regulating The Human Arachidonate Epoxygenase CYP2J2 In Response To Stress Stimuli
Funder
National Health and Medical Research Council
Funding Amount
$369,000.00
Summary
Hypoxia, or oxygen deprivation, is caused by the decreased supply of blood to cells and is a component of ischaemic injury to the cardiovascular system (e.g. stroke, atherosclerosis) and numerous other organs (e.g. cancer and chemical mediated injury). It is now known that an important group of proteins that switch on specialised target genes in response to hypoxia is Activator-Protein-1 (AP-1). We have found that cytochrome P450 2J2 (CYP2J2), which is an enzyme that forms beneficial fatty acid ....Hypoxia, or oxygen deprivation, is caused by the decreased supply of blood to cells and is a component of ischaemic injury to the cardiovascular system (e.g. stroke, atherosclerosis) and numerous other organs (e.g. cancer and chemical mediated injury). It is now known that an important group of proteins that switch on specialised target genes in response to hypoxia is Activator-Protein-1 (AP-1). We have found that cytochrome P450 2J2 (CYP2J2), which is an enzyme that forms beneficial fatty acid products inside cells, is decreased in hypoxia and that this is due to increased activity of AP-1. We know that similar stressful stimuli can also result in a loss of CYP2J2. Again, AP-1 is involved but we have further evidence for the role of another pathway. This project will explore how these pathways operate individually and together to decrease CYP2J2. Studying the regulation of human genes is difficult because we can not readily monitor their levels in cells in either healthy or sick individuals. So we will make transgenic mouse models to study human CYP2J2 regulation, which will provide information on the human situation. In this project we will identify which factors switch off the CYP2J2 transgene and will analyse the signalling pathways within cells that control this response. The importance of these studies is that they will help us to design pharmacological strategies to prevent the loss of CYP2J2 in cells that are stressed. Such agents may be effective in the treatment of ischaemic injury seen in stroke and atherosclerosis. If we can maintain CYP2J2 levels we may be able to maintain the beneficial fatty acid levels in cells and have a novel therapeutic approach for keeping cells alive.Read moreRead less
Inhibition Of Retinoblastoma Protein Degradation By Interaction With The Serpin PAI-2 Via A Novel Consensus Motif
Funder
National Health and Medical Research Council
Funding Amount
$463,500.00
Summary
Plasminogen activator inhibitor-2 (PAI-2) has previously been shown to inhibit the activity of enzymes outside the cell that are involved in blood clotting and cell migration. We have discovered that this activity is probably not the major role of PAI-2. PAI-2 also has a function inside cells that protect and increases the activity of an important tumour suppressor protein called the retinoblastoma tumour suppressor protein (Rb). Rb is involved in many cellular functions such as, cell death, cel ....Plasminogen activator inhibitor-2 (PAI-2) has previously been shown to inhibit the activity of enzymes outside the cell that are involved in blood clotting and cell migration. We have discovered that this activity is probably not the major role of PAI-2. PAI-2 also has a function inside cells that protect and increases the activity of an important tumour suppressor protein called the retinoblastoma tumour suppressor protein (Rb). Rb is involved in many cellular functions such as, cell death, cell differentiation, cell growth, and most importantly prevention of cancer development. Rb is attacked and destroyed by several viruses which causes cells to become cancerous. This grant seeks to fully understand how PAI-2 protects and interacts with Rb. We have already found a new site on Rb to which PAI-2 binds. This site is also used by other proteins in the cell as well as disease causing virus proteins. Examples of these proteins are BRCA1, a protein involved in breast cancer development, and EBNA6, a protein from Epstein Barr virus that causes glandular fever and tumours. We have also found, and seek to explore further, how PAI-2 reverses the activities of the cervical cancer causing proteins of the human papilloma virus. Although at an early stage, these studies may lead to the development of new therapeutic drugs based on PAI-2 for the treatment of various types cancers or warts caused by HPV. Analysing the activity of PAI-2 inside cells will have implications for understanding much of the confusing scientific literature on PAI-2 and will provide a better comprehension of the role of PAI-2 in inflammation, cell differentiation, wound healing and cancer. For example it has long been known that the presence of PAI-2 in cancerous tumours is linked with a better prognosis, an activity that can now be understood in terms of the PAI-2 interaction with Rb. This new understanding may lead to the development of PAI-2 based prognostic assays for cancer.Read moreRead less
To Understand The Role Of The Plasminogen Activating And Matrix Metalloproteinase Systems In Traumatic Brain Injury
Funder
National Health and Medical Research Council
Funding Amount
$499,321.00
Summary
Tissue-type plasminogen activator (t-PA) is known for its role as a clot dissolving protein. It is present in the brain and following traumatic brain injury (TBI), it can worse brain cell damage. We have established a mouse model of TBI . We will compare brain damage in mice that are deficient in or have high amounts of t-PA. We will also determine whether the recovery rate post-TBI can be improved using specific t-PA blockers. This project may provide new therapies for TBI.