Recycling Endosomes Governing Cell Polarity And Cytokine Secretion.
Funder
National Health and Medical Research Council
Funding Amount
$958,412.00
Summary
Cytokines are chemical messengers released by cells to mount inflammatory responses to fight infections. The timing and direction of cytokine release must be tightly regulated. We investigate the cellular compartments and molecules that control cytokine secretion using sophisticated live cell imaging. Uncontrolled cytokine release is the main cause of ongoing inflammation in arthritis and inflammatory bowel disease and our studies aim to identify cellular targets for new drug development.
Physiological Significance Of Cellular Translocation Of The Intestine-specific Homeodomain Protein Cdx2
Funder
National Health and Medical Research Council
Funding Amount
$196,527.00
Summary
Ulcerative colitis and Crohn's disease are debilitating inflammatory diseases of the bowel. Conservative estimates (Australian Crohn's and Colitis Association) suggest that at least 23,000 Australians are affected (>1 in 1000). Ten years after onset, there is an estimated risk of 0.5-1.0% per year of pancolitis patients developing full-blown bowel cancer. Current therapies for colon cancer are not very effective and the median survival for patients with metastatic disease is poor at 7-12 mont ....Ulcerative colitis and Crohn's disease are debilitating inflammatory diseases of the bowel. Conservative estimates (Australian Crohn's and Colitis Association) suggest that at least 23,000 Australians are affected (>1 in 1000). Ten years after onset, there is an estimated risk of 0.5-1.0% per year of pancolitis patients developing full-blown bowel cancer. Current therapies for colon cancer are not very effective and the median survival for patients with metastatic disease is poor at 7-12 months. It is therefore important to increase our understanding of the biology underlying these inflammatory conditions so that more effective treatments may be developed and fewer patients proceed to the cancerous stage. We have recently demonstrated a novel interaction between two proteins that may be relevant to intestinal inflammation. Surprisingly, the two proteins would not normally be expected to coincide with each other because of their different localisations within cells and tissues. The first protein, Cdx2, is only synthesised by intestinal lining cells and normally resides in the nucleus where it activates genes that play a role in the highly specialised absorptive functions of the intestine. The other protein, acrogranin-granulin, is more widely distributed in the body and is generally transported out of cells shortly after it has been made. It has been shown to interact with receptors on epithelial cells and blood cells and promotes their growth. In this proposal we will be investigating whether the complex formed between Cdx2 and granulin is important for normal physiology. Moreover since elevated levels of granulin are associated with inflammation, we aim to determine whether the Cdx2-granulin complex is formed during the active phase of ulcerative colitis and Crohn's disease. Specifically, we will test the hypothesis that the Cdx2-granulin complex plays an important role in repairing the damage caused to the lining of the intestine during inflammation.Read moreRead less
Fluorescence Analysis Of The EGFreceptor Signalling Network
Funder
National Health and Medical Research Council
Funding Amount
$490,750.00
Summary
Receptors are cell-surface molecules that enable the cell to receive chemical messages from the outside environment and transmit these signals to the inside of cell. These messages tell the cells to grow, divide or die. The Epidermal Growth Factor Receptor is linked to a variety of cell signalling pathways that are critical to the normal functioning of cells. Conversely, abberations in Epidermal Growth Factor-mediated cell signalling leads to many types of cancers. A basic understanding of how t ....Receptors are cell-surface molecules that enable the cell to receive chemical messages from the outside environment and transmit these signals to the inside of cell. These messages tell the cells to grow, divide or die. The Epidermal Growth Factor Receptor is linked to a variety of cell signalling pathways that are critical to the normal functioning of cells. Conversely, abberations in Epidermal Growth Factor-mediated cell signalling leads to many types of cancers. A basic understanding of how the receptor is turned off or on is essential to designing drugs that can specifically inhibit its hyperproliferative response. High resolution structures of a key part of the Epidermal Growth Factor Receptor have identified several structural forms of the receptor that are providing valuable clues as to the structural basis for receptor activation. Armed with this information and advanced microscopic imaging technology we are in the unique position to probe receptor activation in living cells. This project seeks to determine which structural form of the receptor is responsible for transmission of cellular messages and how it is impaired in cancerous cells.Read moreRead less
E-cadherin is one of the major proteins responsible for mediating cell-to-cell adhesion in the body. During development, E-cadherin is essential for establishing the cellular architecture of epithelial organs and for maintaining epithelial function in the adult. In this context, E-cadherin acts to establish and maintain the polarity of epithelial cells. E-cadherin is also a powerful tumour suppressor and the loss of E-cadherin expression or function is a primary event in metastasis and cancer in ....E-cadherin is one of the major proteins responsible for mediating cell-to-cell adhesion in the body. During development, E-cadherin is essential for establishing the cellular architecture of epithelial organs and for maintaining epithelial function in the adult. In this context, E-cadherin acts to establish and maintain the polarity of epithelial cells. E-cadherin is also a powerful tumour suppressor and the loss of E-cadherin expression or function is a primary event in metastasis and cancer invasion. Proteins at the surface of epithelial cells must be sorted and trafficked, or transported, to different membrane domains. E-cadherin, for instance, must be trafficked to the lateral domain of cells in order to function in cell-cell adhesion. We recently discovered that cell surface E-cadherin is re-internalized and recycled back to the surface via a pathway that is poised to contribute to the regulation of cell adhesion. Our proposed studies aim to reveal how newly-synthesized E-cadherin and recycling E-cadherin are trafficked, which molecules and which vesicle carriers accomplish this transport. E-cadherin has specific amino acids that act as targeting signals for its sorting and trafficking; we have recently identified one such signal and will now seek the signal responsible for its endocytosis. Using specifically engineered mutants of E-cadherin we will also study other proteins that interact with E-cadherin during its trafficking for sorting and regulation. One of these is polycystin, a protein that is mutated in a common inherited kidney disease. Insights into this disease and normal kidney epithelial function will emerge from this work. A growing understanding of E-cadherin function and regulation is essential for the health of epithelial organs and for controlling and preventing cancer.Read moreRead less