Post Transcriptional Regulation Of Plasminogen Activator Inhibitor Type 2 Gene Expression
Funder
National Health and Medical Research Council
Funding Amount
$318,000.00
Summary
The process of wound healing, cell migration and the spread of cancers requires the recruitment of specialised proteases to the cell surface . These proteases act to degrade other proteins, mainly in the extracellular space, which in turn allows cells to move around, wounds to close, and blood clots to disappear. The plasminogen activating system is one of the enzyme systems involved in these events. One of the proteases that cleaves plasminogen to its active form, plasmin, is urokinase (u-PA) a ....The process of wound healing, cell migration and the spread of cancers requires the recruitment of specialised proteases to the cell surface . These proteases act to degrade other proteins, mainly in the extracellular space, which in turn allows cells to move around, wounds to close, and blood clots to disappear. The plasminogen activating system is one of the enzyme systems involved in these events. One of the proteases that cleaves plasminogen to its active form, plasmin, is urokinase (u-PA) and the activity of u-PA is regulated by its natural inhibitor called plasminogen activator inhibitor type 2 (PAI-2). u-PA is strongly implicated in the progression of metastatic cancer and high levels of PAI-2 relative to u-PA is regularly seen as a positive prognostic indicator for metastatic cancer. In this situation, PAI-2 acts to limit the activity of u-PA thereby restricting the migration potential of the cancer. PAI-2 is unusual because it exists both inside and outside the cell. Outside the cell, PAI-2 acts to inhibit u-PA activity, while inside the cell, PAI-2 also plays a role in the inhibition of cell growth and differentiation. It is therefore important to understand how the production of PAI-2 is regulated in cells. A significant component of PAI-2 regulation occurs post-transcriptionally, particularly at the level of mRNA stability. We have identified some of the proteins that bind to PAI-2 mRNA and influence its longevity in the cell. This project aims to further undertand how these as well as other PAI-2 mRNA binding proteins influence the expression of the PAI-2 gene.Read moreRead less
Post Transcriptional Regulation Of The Plasminogen Activator Inhibitor Type 2 Gene
Funder
National Health and Medical Research Council
Funding Amount
$241,527.00
Summary
The process of wound healing, removal of blood clots, cell migration and the metastatic spread of cancers requires the recruitment of specialised proteases. These proteases act primarily to degrade other proteins, mainly in the extracellular space, which in turn allow cells to move around, wounds to close, and blood clots to disappear. The plasminogen activating system is one of the most important enzyme systems involved in these events. One of the proteases that cleaves plasminogen to its activ ....The process of wound healing, removal of blood clots, cell migration and the metastatic spread of cancers requires the recruitment of specialised proteases. These proteases act primarily to degrade other proteins, mainly in the extracellular space, which in turn allow cells to move around, wounds to close, and blood clots to disappear. The plasminogen activating system is one of the most important enzyme systems involved in these events. One of the proteases that cleaves plasminogen to its active form, plasmin, is urokinase (u-PA). Plasminogen activator inhibitor type 2 (PAI-2) is a serine protease inhibitor that inhibits u-PA activity. The degree of u-PA activity therefore depends on the relative levels of u-PA and PAI-2. In addition to controlling u-PA activity, PAI-2 also influences intracellular events including cell proliferation, differentiation and apoptosis. PAI-2 protein and mRNA levels are substantially modulated by many cytokines and growth factors. This project addresses the molecular mechanisms underlying the regulation of PAI-2 gene expression. We have recently shown that a significant degree of PAI-2 regulation occurs at the level of PAI-2 mRNA stability, and we have identified two regions within the PAI-2 mRNA that play a role in this process. Both regions provide binding sites for cellular proteins. We have identified one of these binding proteins to be HuR, a protein that has recently been shown to control the stability of other mRNAs. The specific aims of this project are firstly, to determine the role of HuR in the control of PAI-2 mRNA stability, and secondly, to clone a characterise the other PAI-2 mRNA binding proteins we have identifed. An understanding of how cells modulate levels of PAI-2 mRNA will significantly add to the broader field of gene regulation and may also provide new clues to influence PAI-2 levels in the body.Read moreRead less
Molecular Mechanisms For The Cell-type Specific Regulation Of The Tissue-type Plasminogen Activator Gene
Funder
National Health and Medical Research Council
Funding Amount
$490,500.00
Summary
Tissue-type plasminogen activator (t-PA) is an important enzyme that is widely known for its ability to remove blood clots. More recently, t-PA has been shown to influence memory development and under pathological conditions can promote neuronal cell death. t-PA is produced by many cells including the endothelial cells that line the blood vessels, fibroblasts, as well as cells within the central nervous system. The t-PA gene is regulated very differently in these cell types and this project will ....Tissue-type plasminogen activator (t-PA) is an important enzyme that is widely known for its ability to remove blood clots. More recently, t-PA has been shown to influence memory development and under pathological conditions can promote neuronal cell death. t-PA is produced by many cells including the endothelial cells that line the blood vessels, fibroblasts, as well as cells within the central nervous system. The t-PA gene is regulated very differently in these cell types and this project will address the mechanisms underlying the cell-type specific regulation of the t-PA gene. Endothelial cells, fibroblasts and neuronal cell cultures will be used to study the regulation of t-PA expression. Information gained will not only add to the understanding of the broader field of gene regulation, but may also provide clues to manipulate the expression of the t-PA gene in different cells.Read moreRead less
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