Lipid Trafficking At Membrane Contact Sites: The Role Of Oxysterol-Binding Protein-Related Protein 5 And 8 (ORP5 And ORP8)
Funder
National Health and Medical Research Council
Funding Amount
$466,400.00
Summary
Abnormal subcellular lipid distribution is associated with a number of common diseases including cancer, cardiovascular disease, and Alzheimer’s disease. The overall aim of this proposal is to identify and characterize new molecules that regulate the transport of lipids between different cell membranes. Results from the proposed studies will help developing novel therapeutic agents against common human diseases.
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
Matching Supply And Demand: How Does Metabolism Fine-tune Signal Transduction?
Funder
National Health and Medical Research Council
Funding Amount
$316,449.00
Summary
Insulin controls nutrient traffic and disrupting its actions are linked to many diseases: type 2 diabetes, cancer, heart disease. Here, I will test a novel hypothesis that our cells’ metabolic rate, defined by the balance between nutrient supply and energy expenditure, controls how cells respond to insulin. These metabolic regulatory nodes would play a major determinant of many essential functions linked to human health, and thus provide novel therapeutic targets for numerous diseases.
Oxidative Damage and Cell Ageing. This research will benefit Australia by providing a fundamental understanding of how cells age. This will have immediate international impact at the scientific level and will inform strategies to reduce the rate of ageing and alleviation of age-related disorders. In the longer term the research may provide commercial and social outcomes by identifying antioxidant systems that will provide a genuine benefit in reducing ageing.
Identifying The Critical Components Of Growth Factor-mediated Survival Pathways
Funder
National Health and Medical Research Council
Funding Amount
$589,338.00
Summary
The regulation of cell lifespan (cell survival) is controlled by growth factors and lies at the heart of all biological processes. However, little is known of the molecular switches inside cells that either turn survival on or off. We propose to identify and characterize the molecular switches inside cells that control the balance between cell survival and death. Targeting specific components of these switches may provide new approaches for the treatment of cancer and infectious diseases.
Cellular Responses to Oxidative Damage: Cell Aging. The aim of this project is to identify the mechanisms by which oxidative stress and free radical damage cause cell aging. This work will make a significant contribution to our understanding of the aging process in cells by identifying the major reactive oxygen species that contribute to cell aging, which defence systems and antioxidants provide the greatest degree of protection, what damage accumulates as cells age and which genetic systems ar ....Cellular Responses to Oxidative Damage: Cell Aging. The aim of this project is to identify the mechanisms by which oxidative stress and free radical damage cause cell aging. This work will make a significant contribution to our understanding of the aging process in cells by identifying the major reactive oxygen species that contribute to cell aging, which defence systems and antioxidants provide the greatest degree of protection, what damage accumulates as cells age and which genetic systems are activated as during the process.Read moreRead less
Regulation of lipolysis: new players, new paradigms. The way in which fat is broken down is poorly understood. This research will determine how important proteins in fat breakdown are turned on and off. By understanding this relationship, effective pharmaceutical treatments will be developed that will enhance the capacity to burn fat and ultimately reduce the incidence of type 2 diabetes and cardiovascular disease, and ease the associated financial burden on the community and healthcare system. ....Regulation of lipolysis: new players, new paradigms. The way in which fat is broken down is poorly understood. This research will determine how important proteins in fat breakdown are turned on and off. By understanding this relationship, effective pharmaceutical treatments will be developed that will enhance the capacity to burn fat and ultimately reduce the incidence of type 2 diabetes and cardiovascular disease, and ease the associated financial burden on the community and healthcare system. Understanding fat breakdown is also important for developing new processing technologies in the food industry.Read moreRead less
Molecular basis of skeletal muscle lipoapoptosis. High levels of fat in cells are associated with obesity and type 2 diabetes, medical conditions that have increased dramatically in prevalence in Australia. High fat levels in cells also causes cell death. This research will determine the mechanisms by which excessive fat storage leads to cell death and whether this leads to insulin resistance and type 2 diabetes. By understanding this relationship, effective pharmaceutical treatments will be dev ....Molecular basis of skeletal muscle lipoapoptosis. High levels of fat in cells are associated with obesity and type 2 diabetes, medical conditions that have increased dramatically in prevalence in Australia. High fat levels in cells also causes cell death. This research will determine the mechanisms by which excessive fat storage leads to cell death and whether this leads to insulin resistance and type 2 diabetes. By understanding this relationship, effective pharmaceutical treatments will be developed that will ultimately reduce the incidence of type 2 diabetes, and ease the associated financial burden on the community and healthcare system.Read moreRead less
The effect of nitrogen monoxide on intracellular iron metabolism. We discovered that the crucial signalling molecule nitrogen monoxide (NO) mediates iron (Fe) and glutathione (GSH) release by the transporter MRP1 probably as an NO-Fe-GSH complex [DR(2006) PNAS USA 103:7670-5]. During our current ARC grant we have markedly extended these findings by showing that another molecule, GST Pi and MRP1 form part of a coordinated system that stores and transports NO as complexes of Fe and GSH, markedly e ....The effect of nitrogen monoxide on intracellular iron metabolism. We discovered that the crucial signalling molecule nitrogen monoxide (NO) mediates iron (Fe) and glutathione (GSH) release by the transporter MRP1 probably as an NO-Fe-GSH complex [DR(2006) PNAS USA 103:7670-5]. During our current ARC grant we have markedly extended these findings by showing that another molecule, GST Pi and MRP1 form part of a coordinated system that stores and transports NO as complexes of Fe and GSH, markedly extending NO half-life from milliseconds to hours. This has broad implications for understanding NO activity in many processes which have major vital health implications, including tumour cell killing by macrophages and blood pressure control.Read moreRead less
The Effect of Nitrogen Monoxide on Intracellular Iron Metabolism. For the first time, we discovered that nitric oxide (NO) is actively transported from cells by a protein that is known to also transport glutathione (GSH). This is important, as NO was thought to passively diffuse from cells. Active transport overcomes the problems of diffusion which is inefficient and non-targeted. Moreover, NO is released as a complex with iron and GSH which markedly increases its half-life. These findings have ....The Effect of Nitrogen Monoxide on Intracellular Iron Metabolism. For the first time, we discovered that nitric oxide (NO) is actively transported from cells by a protein that is known to also transport glutathione (GSH). This is important, as NO was thought to passively diffuse from cells. Active transport overcomes the problems of diffusion which is inefficient and non-targeted. Moreover, NO is released as a complex with iron and GSH which markedly increases its half-life. These findings have broad implications for understanding the activity of NO in many processes which have major health implications, including tumour cell killing by macrophages, blood pressure etc.Read moreRead less