Dynamic Trafficking Of Amino Acid Transporters At Synapses And Their Role In Regulating Neurotransmission
Funder
National Health and Medical Research Council
Funding Amount
$421,219.00
Summary
Brain cells release chemical neurotransmitters to activate their neighbours. The most abundant neurotransmitter is glutamate, which mediates most of the communication in the brain. Following release, this neurotransmitter must be rapidly recycled to prevent levels being depleted and neurotransmission failing. The subject of this grant is to understand what molecules and pathways are used to recycle glutamate in the brain, and how its supply is controlled to sustain continual brain activation.
Examination Of The Molecular Pharmacology Of Anthracyclines Induced Via Their Interaction With Iron
Funder
National Health and Medical Research Council
Funding Amount
$618,401.00
Summary
Anthracyclines are highly effective anti-cancer drugs, but their use is limited by toxic effects on the heart. This is thought to be due to these drugs directly binding iron (Fe). Indeed, we showed that anthracyclines induced marked changes in the way heart cells utilise Fe (DR1-3, 38; Mol. Pharmacol. 2002, 2003, 2004, 2005). We were the first to show that anthracyclines prevent Fe release from the criticial Fe storage protein ferritin. This prevents the use of Fe for vital processes eg. DNA and ....Anthracyclines are highly effective anti-cancer drugs, but their use is limited by toxic effects on the heart. This is thought to be due to these drugs directly binding iron (Fe). Indeed, we showed that anthracyclines induced marked changes in the way heart cells utilise Fe (DR1-3, 38; Mol. Pharmacol. 2002, 2003, 2004, 2005). We were the first to show that anthracyclines prevent Fe release from the criticial Fe storage protein ferritin. This prevents the use of Fe for vital processes eg. DNA and haem synthesis. Hence, this effect probably contributes to the cytotoxic activity of anthracyclines on the heart. We showed that novel drugs developed in my lab that bind Fe called chelators show high activity in animals (DR4) and prevent anthracycline-mediated Fe accumulation in ferritin. Importantly, Fe chelators have been shown to inhibit anthracycline-mediated cardiotoxicity. Indeed, the clinically used cardioprotective agent, ICRF-187, is actually an Fe chelator (5, DR6). However, ICRF-187 is not totally successful in terms of its cardioprotective effects and can cause myelosuppression (5, DR6). While the clinically used chelator, desferrioxamine (DFO), can prevent anthracycline-mediated cardiotoxicity, its poor membrane permeability limits its effectiveness. Our chelators are highly permeable and overcome the disadvantages of DFO (DR4). Thus, they are vital to examine for preventing anthracycline-mediated cardiotoxicity. In this proposal we will examine the changes in Fe metabolism induced by anthracyclines and test the hypothesis that novel Fe chelators may prevent the cardiotoxicity of these agents. We also aim to be the first to assess if preparation of anthracyclines which cannot bind iron prevents their cardiotoxicity. This will be done by preparing metal complexes of these drugs which prevent Fe-binding eg. anthracycline-zinc complexes. These studies are important for the development of less cardiotoxic forms of these very useful anti-tumour agents.Read moreRead less
Understanding The Acute And Cumulative Metabolic Effects Of Prolonged Sitting In Adults
Funder
National Health and Medical Research Council
Funding Amount
$416,597.00
Summary
Sedentary behaviour (sitting time) has been linked to an increased risk of chronic illnesses, including type 2 diabetes and obesity, but recent evidence suggests that light-intensity activity (non-exercise activities of daily living) is associated with reduced risk. These studies will examine whether breaking up sitting time with frequent short periods of activity can overcome the negative effects of prolonged sitting on blood glucose and blood fats in overweight older adults.
Melanotransferrin: A “Missing Link” And A Novel Pharmacological Target For Treatment
Funder
National Health and Medical Research Council
Funding Amount
$613,848.00
Summary
Despite >30 years of research, the precise function of the protein, melanotransferrin (MTf), is unknown. However, we have breakthrough evidence that MTf stimulates WNT signalling as a major driver in cancer progression. We will investigate this hypothesis, which will underpin new cancer therapies. Indeed, we designed a new class of drugs that target the WNT pathway via up-regulating the WNT inhibitor, NDRG1. This drug (DpC) inhibits MTf expression to block tumour cell growth and metastasis.
Mitochondrial Iron Overload And Friedreich's Ataxia: The Role Of Frataxin In Iron And Haem Metabolism
Funder
National Health and Medical Research Council
Funding Amount
$285,990.00
Summary
Friedreich's ataxia (FA) is due to the lack of a protein known as frataxin. Recent studies using Baker's yeast have shown that the deletion of frataxin results in the accumulation of toxic iron in the mitochondrion. More recently, a variety of studies have shown that FA patients have iron loading within their cells. The iron build-up may cause severe damage. At present, the role of frataxin in mammalian mitochondrial iron metabolism is unknown. Our preliminary studies demonstrate that frataxin i ....Friedreich's ataxia (FA) is due to the lack of a protein known as frataxin. Recent studies using Baker's yeast have shown that the deletion of frataxin results in the accumulation of toxic iron in the mitochondrion. More recently, a variety of studies have shown that FA patients have iron loading within their cells. The iron build-up may cause severe damage. At present, the role of frataxin in mammalian mitochondrial iron metabolism is unknown. Our preliminary studies demonstrate that frataxin is down-regulated by either erythroid differentiation or the haem precursor protoporphyrin IX (Becker and Richardson, submitted). These data strongly suggest a role for frataxin in iron metabolism. In the present study we will continue to assess if frataxin plays a role in the way cells handle iron. Using a unique model of mitochondrial iron overload developed in my lab (Richardson et al. (1996) BLOOD 87:3477), we will extensively investigate the iron metabolism of the mitochondrion in order to determine the function of frataxin and its role in Friedreich's ataxia. In addition, we have developed a series of new drugs known as iron chelators that can enter the mitochondrion due to their high lipid solubility (Becker and Richardson 1999 J. Lab. Clin. Med. 134:510). These latter drugs are far more effective than the chelator currently used to treat iron overload, desferrioxamine (DFO). Indeed, our chelators have been designed to result in high iron chelation efficacy but low toxicity (see Becker and Richardson, 1999). This exciting research may be crucial in understanding the development of FA and in creating new therapies such as the use of iron chelators.Read moreRead less
Heparin-induced Thrombocytopenia And Thrombosis: Better Understanding Of Pathogenesis And Improving Diagnosis And Treatment
Funder
National Health and Medical Research Council
Funding Amount
$653,137.00
Summary
Heparin, a widely used drug, can cause an adverse effect which results in a fall of the platelet count and the development of serious thrombosis. This drug complication is mediated by an immune mechanism. This proposal aims to provide a better understanding of the disease mechanism. It also aims to develop a new test that will improve the diagnosis, and to produce a novel drug that will effectively suppress the immune reaction and improve the treatment.
Griseofulvin, A Novel Host-directed Antimalarial Drug
Funder
National Health and Medical Research Council
Funding Amount
$461,551.00
Summary
This grant is for a Phase II clinical trial to test an FDA & TGA approved drug for a new use as an antimalarial drug. The parasite uses an enzyme from the human RBC to help it replicate & early trials show this drug appears to disrupt the life cycle of the parasite. This Phase II clinical trial will test the drug on human subjects, & if successful, the drug will be a new and novel way in which to treat and prevent malarial infections in humans.
A unified model of amino acid homeostasis. This project aims to develop a unified model of amino acid homeostasis in mammalian cells and apply it to brain cells. The model will be underpinned by a mathematical algorithm that allows predicting amino acid levels in the cytosol based on fundamental parameters such as transport and metabolism. This project should provide the significant benefit of enabling the prediction of essential functions such as cell growth and survival.
Roles Of Impaired Apoptosis And Differentiation In Tumourigenesis And Therapy
Funder
National Health and Medical Research Council
Funding Amount
$21,656,910.00
Summary
The ten scientific laboratories in this program have joined forces to investigate two ways in which tumours develop. Both are of particular interest, because they suggest new ways in which cancer might be overcome. Most of our tissues are continually renewed throughout life by production of new cells. Therefore many of the old cells in each tissue must die off to maintain the proper cell numbers. To eliminate cells that are no longer needed or have become damaged, the body has developed a remark ....The ten scientific laboratories in this program have joined forces to investigate two ways in which tumours develop. Both are of particular interest, because they suggest new ways in which cancer might be overcome. Most of our tissues are continually renewed throughout life by production of new cells. Therefore many of the old cells in each tissue must die off to maintain the proper cell numbers. To eliminate cells that are no longer needed or have become damaged, the body has developed a remarkable cell suicide process termed apoptosis. Unfortunately, however, occasionally a random accident to the genes in one of our cells prevents the machinery for apoptosis from being turned on. In that case, the cell will not die when it should and, by continually dividing, it may eventually give rise to a cancer. Since most cancer cells still retain most of the machinery for apoptosis, however, a drug that could switch on this natural cell death machinery would provide a promising new approach to cancer therapy. Identifying and developing such drugs is one major long-term goal of this program. The other focus of our program concerns stem cells. These are rare cells with the remarkable ability to generate an entire tissue. For example, one of our laboratories has identified stem cells that can generate all the cells in the breast. The almost unlimited regenerative capacity of stem cells has a built-in danger. If a stem cell acquires the ability to proliferate excessively, it can go on to form a tumour. Indeed, many cancer researchers now suspect that rare stem cells within a tumour cause its inexorable growth. If tumour growth is maintained by stem cells, it will be essential to develop new forms of therapy that target these rare cancer stem cells rather than merely the bulk of the tumour cells. This is another key long-term goal of our program.Read moreRead less
Targeting An Ion Pump In The Malaria Parasite With Multiple Compound Classes
Funder
National Health and Medical Research Council
Funding Amount
$384,686.00
Summary
Large-scale antimalarial drug screening projects have identified three different classes of compound that kill the malaria parasite at extremely low doses and which hold real promise as next-generation antimalarials. Genetic evidence, as well as preliminary data from our own lab, has led us to the hypothesis that all three compound classes exert their antimalarial effect by blocking a molecular ion pump on the parasite surface. The aim of this study is to test this.