Characterisation Of Erythropoietic Mutants Identified In A Forward Genetic Screen In Mice.
Funder
National Health and Medical Research Council
Funding Amount
$501,902.00
Summary
The human bone marrow is the pivotal organ in the replacement of the vast numbers of blood cells normally consumed each day. One of the cells regenerated by this organ are the red blood cells which are critical for the transport of oxygen to the tissues. This proposal uses genetically altered mice to identify genes that are critical for the production of normal red blood cells. Mice exposed to a chemical that induces random mutations in their genome are bred and pups with abnormal red blood cell ....The human bone marrow is the pivotal organ in the replacement of the vast numbers of blood cells normally consumed each day. One of the cells regenerated by this organ are the red blood cells which are critical for the transport of oxygen to the tissues. This proposal uses genetically altered mice to identify genes that are critical for the production of normal red blood cells. Mice exposed to a chemical that induces random mutations in their genome are bred and pups with abnormal red blood cells are identified. The responsible genetic mutation is identified and the gene is then studied to determine how it influences red blood cell production. The results of these studies provide insights into a variety of human conditions including anemia, thalassemia and sickle cell disease.Read moreRead less
NMR Of Red Cells: Plasma Membrane Oxidoreductase, And Cation Transport
Funder
National Health and Medical Research Council
Funding Amount
$192,388.00
Summary
An interesting paradox exists with respect to the 'central' function of the red blood cell (RBC): it delivers the main oxidising capacity to the body (O2), but it also carries the chemically opposite functionality in its membrane, namely reducing capacity. The reduction of many oxidised proteins and metabolites in blood plasma is mediated by a plasma-membrane oxido-reductase (PMOR). Ascorbic acid (vitamin C) dramatically accelerates this rate of reduction but its precise molecular role is unknow ....An interesting paradox exists with respect to the 'central' function of the red blood cell (RBC): it delivers the main oxidising capacity to the body (O2), but it also carries the chemically opposite functionality in its membrane, namely reducing capacity. The reduction of many oxidised proteins and metabolites in blood plasma is mediated by a plasma-membrane oxido-reductase (PMOR). Ascorbic acid (vitamin C) dramatically accelerates this rate of reduction but its precise molecular role is unknown; neither is the immediate source of the reducing equivalents (electrons) known. Novel, non-invasive, 13C NMR methods have been developed, and others are planned in this project, to study the rate of reduction of Otest? compounds, including 13C-ferricyanide, and reactions of 13C-ascorbate. This will provide a quantitative understanding of the kinetics of the redox reactions in the intact cell. The transfer of negative charges (electrons) from the cell, in the longer term (minutes) inevitably must be matched by the movement of cations (positive charges). The main cation flux is mediated by Na+, K+-ATPase, but various cation exchange pathways are also involved in the total Oionic economy? of the cell. Of special interest will be the calcium-activated K+ (or Gardos) channel. This Oopens? inappropriately in malaria, sickle cell anaemia, and under blood bank storage conditions, and this is thought to be the basis of some of the pathological events in these conditions. The alkali-metal cation exchange pathway ( Na+-Li+) is more activate in the red cells of many patients with hypertension. So, multiple-quantum NMR methods will be used to monitor membrane transport and binding of cations to characterise the kinetics and regulation of the K+-channel, and the Na+-Li+ exchange reactions. The significance will lie in a basic understanding of, and possible 'diagnostic methods' for the biochemical processes that occur in red blood cells in health and disease.Read moreRead less
Determining The Function Of Parasite Proteins At The Membrane Skeleton Of Malaria-infected Red Blood Cells
Funder
National Health and Medical Research Council
Funding Amount
$392,036.00
Summary
Malaria is a serious disease that frequently kills its victim after a bout of high fever and coma. The most vicious form of malaria is caused by a minute parasite called Plasmodium falciparum that lives inside red blood cells. As these parasites grow, they make some dramatic renovations to their red blood cell home that make it become very stiff and sticky. Instead of flowing around the body like normal red blood cells, the infected cells become trapped in small veins and can no longer carry out ....Malaria is a serious disease that frequently kills its victim after a bout of high fever and coma. The most vicious form of malaria is caused by a minute parasite called Plasmodium falciparum that lives inside red blood cells. As these parasites grow, they make some dramatic renovations to their red blood cell home that make it become very stiff and sticky. Instead of flowing around the body like normal red blood cells, the infected cells become trapped in small veins and can no longer carry out their normal job. The ability of the parasite to make red blood cells stiff and sticky is what makes this type of malaria so dangerous, particularly when red cells get stuck in the brain. We plan to look at certain proteins that malaria parasites place on the walls of red blood cells because we think this is what makes them stiff and sticky. We hope this will help with the development of and urgently required ways to cure malaria.Read moreRead less
Novel Strategies In Cancer Cell Invasion In High-density 3D Matrix
Funder
National Health and Medical Research Council
Funding Amount
$60,768.00
Summary
The use of high-density (HD) matrix to study cell invasion sets precedence in mimicking the HD breast tissue condition that pose a real cancer risk. Cell invasion promotes the spread of cancer causing organ failures and death. The aims of this project are to determine the molecular mechanisms and to isolate new regulatory markers of cell invasion into HD matrix. Putative markers will be confirmed by investigating their expression levels in tissue arrays of 195 breast cancer samples.
Elucidation Of Signalling Enzymes Regulating The Small GTPase RhoA
Funder
National Health and Medical Research Council
Funding Amount
$226,320.00
Summary
Many normal and pathological processes in the human body depend on the ability of cells to attach to a biological surface (adhesion), spread out, or move to another site (migration). Examples of biological processes that require such events include the division and arrangement of cells in a developing embryo, or the ability of cancer cells to spread (metastasise). A driving force behind the attachment or movement of cells is their ability to rearrange a scaffolding called the cytoskeleton. The c ....Many normal and pathological processes in the human body depend on the ability of cells to attach to a biological surface (adhesion), spread out, or move to another site (migration). Examples of biological processes that require such events include the division and arrangement of cells in a developing embryo, or the ability of cancer cells to spread (metastasise). A driving force behind the attachment or movement of cells is their ability to rearrange a scaffolding called the cytoskeleton. The cytoskeleton is similar to the skeleton of the human body, in that it acts to maintain cell shape and rigidity. However, it is also actively reorganised to participate in many cellular processes, including cell attachment and movement. By furthering our understanding of how the cytoskeleton is rearranged, this will provide important insights not only into the basics of cell behaviour, but will also have important implications for a number of human disease states. This proposal aims to investigate mechanisms that regulate the reorganisation of the cytoskeleton. It is well established that the rearrangement of this scaffolding, in many different types of cells, is controlled by a family of proteins called the Rho family of small GTPases. One of the members of this family, RhoA, has a specific role in controlling cell attachment, and interestingly, has been implicated in the invasive and metastatic properties of human tumour cells. We have recently identified a protein that is responsible for controlling the activation of RhoA. This proposal aims to further our understanding of how this protein regulates RhoA, and therefore cell attachment and movement. Given that cell attachment and movement are important events contributing to the spread of tumours, this study may provide important insight into alternative approaches of controlling cell movement, and ultimately malignant progression.Read moreRead less