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
Development Of Iron Complexes For The Treatment Of FriedreichÍs Ataxia & The Role Of Frataxin In Iron Metabolism
Funder
National Health and Medical Research Council
Funding Amount
$616,143.00
Summary
Friedreich's ataxia (FA) is a neuro- & cardio-degenerative disease where there is an accumulation of toxic iron (Fe) in the mitochondrion. Work from our current NHMRC grant showed iron plays a significant role in FA pathology In fact, the CIs dissected the mechanisms of mitochondrial iron-loading & have published 8 papers in high impact journals with 3 papers in PNAS USA in the last 2 yrs Understanding of this process has led to the design of rationalised drugs for FA This work in this Renewal c ....Friedreich's ataxia (FA) is a neuro- & cardio-degenerative disease where there is an accumulation of toxic iron (Fe) in the mitochondrion. Work from our current NHMRC grant showed iron plays a significant role in FA pathology In fact, the CIs dissected the mechanisms of mitochondrial iron-loading & have published 8 papers in high impact journals with 3 papers in PNAS USA in the last 2 yrs Understanding of this process has led to the design of rationalised drugs for FA This work in this Renewal could lead to novel therapies for FARead moreRead less
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
Investigating The Cellular Response To Iron-Depletion: The Trilogy Of ASK1, Thioredoxin And Ribonucleotide Reductase
Funder
National Health and Medical Research Council
Funding Amount
$552,572.00
Summary
Iron is crucial for many essential biological processes. Recently, we demonstrated that iron-depletion can affects important signalling pathways (e.g., JNK and p38) that play important roles in growth arrest and apoptosis. This study is designed to investigate the cellular and molecular effects of iron depletion which currently remains unclear. The research is crucial for understanding: (1) the effects of iron deficiency and (2) for understanding the effects of iron chelators that are used for t ....Iron is crucial for many essential biological processes. Recently, we demonstrated that iron-depletion can affects important signalling pathways (e.g., JNK and p38) that play important roles in growth arrest and apoptosis. This study is designed to investigate the cellular and molecular effects of iron depletion which currently remains unclear. The research is crucial for understanding: (1) the effects of iron deficiency and (2) for understanding the effects of iron chelators that are used for treating various diseases.Read moreRead less
Pharmacology Of Potential Anti-Tumour Agents: Iron Chelators Of The BpT Class
Funder
National Health and Medical Research Council
Funding Amount
$585,455.00
Summary
Pharmacology of Potential Anti-Tumour Agents: Iron Chelators of the BpT Class Cancer cells have a high iron requirement for DNA synthesis and many clinical trials showed Fe chelators are effective anti-cancer drugs. Their potential to act as anti-tumour agents has been confirmed by the entrance of Triapine into widespread NCI clinical trials. In this NHMRC Renewal, we will perform pharmacological and preclinical studies to promote the development of BpT chelators as novel anti-tumour agents.
Development Of Iron Chelators For The Treatment Of Friedreichs Ataxia And The Role Of Frataxin In Iron Metabolism
Funder
National Health and Medical Research Council
Funding Amount
$550,987.00
Summary
Friedreich's ataxia (FA) is a neuro- and cardio-degenerative disease where there is an accumulation of toxic Fe in the mitochondrion. Excitingly, work from our current NHMRC grant showed iron plays a significant role in FA pathology. Importantly, we developed new drugs (Fe chelators) which rescue the cardiac pathology of FA in an animal model. Studies will now assess if our drugs prevent the neurodegeneration of FA in another animal model. This work could lead to novel therapies for FA.
Role Of Transition Metal Ions And Redox Activity In The Development Of Atherosclerotic Plaques
Funder
National Health and Medical Research Council
Funding Amount
$196,018.00
Summary
Metal ions such as iron and copper have been reproted to be present in the lesions present in diseased human arteries and it has been suggested that these metal ions contribute to the development of atherosclerosis (hardening of the arteries) via their ability to catalyse the formation of highly reactive molecualr fragments called free radicals. Though metal ions are known to catalyse such reactions in test-tube experiments, both the presence of metal ions in diseased arteries and their ability ....Metal ions such as iron and copper have been reproted to be present in the lesions present in diseased human arteries and it has been suggested that these metal ions contribute to the development of atherosclerosis (hardening of the arteries) via their ability to catalyse the formation of highly reactive molecualr fragments called free radicals. Though metal ions are known to catalyse such reactions in test-tube experiments, both the presence of metal ions in diseased arteries and their ability to generate free radicals is controversial. This study will employ a novel, minimally-invasive, technique to assess the nature and quantity of metal ions present in well-defined human and animal lesions at different stages of lesion development. The ability of these metal ions to catalyse free radical formation from components present in the artery wall will also be assessed. The release of these metal ions from the artery wall to added organic molecules will be assessed as this might minimise their potential to cause damage, and provide a possible therapeutic strategy. These studies will therefore provide valuable information as to the significance and role of reactive metal ions in the development of human artery disease and the possible prevention, or minimisation, of such processes.Read moreRead less
Mid-Career Industry Fellowships - Grant ID: IM230100157
Funder
Australian Research Council
Funding Amount
$788,572.00
Summary
Improving Australian iron ore comminution for green steel production. Decarbonisation of the iron ore and steel industry will involve the design of new mineral processing approaches to make the Australian iron ore amenable to green steel production. Energy-efficient ore crushing for optimal ore grades production is key to the development and economics of green steel.
This fellowship project, with embedded industry experts, aims at better understanding the fragmentation mechanics of Pilbara iron ....Improving Australian iron ore comminution for green steel production. Decarbonisation of the iron ore and steel industry will involve the design of new mineral processing approaches to make the Australian iron ore amenable to green steel production. Energy-efficient ore crushing for optimal ore grades production is key to the development and economics of green steel.
This fellowship project, with embedded industry experts, aims at better understanding the fragmentation mechanics of Pilbara iron ore. It will exploit micro-computed tomography coupled with advanced mechanical testing to offer transformative characterisation methods of ore comminution. The project outcomes will help develop new technologies and optimal production paths to realise a higher-grade iron ore needed for a decarbonised steel industry.
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Data-driven monitoring of raceway dynamics in ironmaking blast furnaces. Raceway dynamics in ironmaking blast furnaces affect operational stability and cost considerably, yet their dynamic behaviour has not been well monitored online. The project aims to develop a data-driven model for monitoring the internal state of gas-solid-powder reacting flow in the raceway and predicting raceway anomalies online. It will be achieved by combining particle-fluid numerical simulations with data processing an ....Data-driven monitoring of raceway dynamics in ironmaking blast furnaces. Raceway dynamics in ironmaking blast furnaces affect operational stability and cost considerably, yet their dynamic behaviour has not been well monitored online. The project aims to develop a data-driven model for monitoring the internal state of gas-solid-powder reacting flow in the raceway and predicting raceway anomalies online. It will be achieved by combining particle-fluid numerical simulations with data processing and reduced-order state observer, supported by lab/plant experiments, and collaborating with two industry partners from coal and steel industries. The project outcomes including codes, models and raceway control strategies can help promote Australian metallurgical coal's global markets and ultimately the Australian economy.Read moreRead less
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
$606,000.00
Summary
Friedreich's ataxia (FA) is due to the lack of a protein known as frataxin. A variety of studies using Baker's yeast and conditional frataxin knockout (KO) mice have shown that deletion of frataxin leads to the accumulation of toxic iron in their mitochondrion. More recently, a variety of studies have shown that FA patients have iron-loading within their mitochondrion. Iron in the highly redox active environment of the mitochondrion could contribute to the generation of cytotoxic radicals that c ....Friedreich's ataxia (FA) is due to the lack of a protein known as frataxin. A variety of studies using Baker's yeast and conditional frataxin knockout (KO) mice have shown that deletion of frataxin leads to the accumulation of toxic iron in their mitochondrion. More recently, a variety of studies have shown that FA patients have iron-loading within their mitochondrion. Iron in the highly redox active environment of the mitochondrion could contribute to the generation of cytotoxic radicals that cause severe damage. Further, cells deficient in frataxin are sensitive to oxidant stress and Fe chelators rescue oxidant-mediated death of cells from FA patients. Indeed, free radical scavengers have shown to be of use in the treatment of this disease. Studies in DR's lab during this NHMRC grant have shown that frataxin is down-regulated by erythroid differentiation or the haem precursor, protoporphyrin IX (BLOOD 2002;99:3813-22). These data indicate a role for frataxin in Fe metabolism and the pathogenesis of FA. In this study we will continue to examine the role of frataxin in the way cells handle Fe using experimental models developed under the current NHMRC grant. These include transfected cell lines with low frataxin expression generated using an expression vector containing anti-sense frataxin cDNA. Further we obtained the frataxin conditional KO mouse and generated a breeding colony. These animals display many of the pathological features of FA and are the best current model of the disease. Indeed, they will be critical for assessing the role of frataxin in Fe metabolism and as a model to test the ability of Fe-binding drugs to prevent the pathology observed. We designed lipid-soluble chelators that can enter the mitochondrion to bind Fe (Biochim Biophys Acta 2001;1536:133-140) and these ligands will be tested to prevent disease progression in the KO mice. This exciting research is crucial for understanding the pathogenesis of FA and in creating new therapies.Read moreRead less