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
Using Reward-based Biomarkers To Improve The Early Detection Of Bipolar Disorder In Individuals Seeking Treatment For Depression
Funder
National Health and Medical Research Council
Funding Amount
$366,252.00
Summary
Bipolar disorder is often misdiagnosed as unipolar major depression, which can have disastrous clinical consequences. Emerging evidence indicates that individuals with bipolar disorder show particular dysfunctions within brain regions involved in processing reward. This research will use cutting-edge neuroscience methodologies to investigate reward processing in these two disorders, with the objective of identifying biological markers that help distinguish bipolar from unipolar depression.
Brain Connectivity Imaging Markers To Confirm Diagnosis For Bipolar Vs. Unipolar Depression – A Connectome Approach.
Funder
National Health and Medical Research Council
Funding Amount
$434,369.00
Summary
Differentiating Bipolar disorders from Unipolar Depression is a major clinical challenge. This misdiagnosis hinders optimal clinical care and has many deleterious consequences such self-harm, increased chances of suicide, poor prognosis, and greater health care costs related to this disorder. This project will provide urgently-needed advance in accurate identification of Bipolar disorders using Magnetic Resonance Imaging and remove one of the key obstacles to accurate diagnosis.
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
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.
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
Australian Longitudinal Study Of Heroin Dependence: An 18-20yr Prospective Cohort Study Of Mortality, Abstinence, And Psychiatric And Physical Health Comorbidity
Funder
National Health and Medical Research Council
Funding Amount
$1,210,319.00
Summary
The burden associated with heroin dependence is undeniable. But little is known about the natural history and long-term course of heroin dependence; knowledge that is critical for informing the development of new treatment interventions, health care planning and service delivery. We propose to extend our study of 615 Australians with heroin dependence, recruited in 2001-2002, to 18-20 years follow-up to answer critical questions about the long-term impact of this condition.
Novel nanostructured high energy cathode material. Recently, the demand for rechargeable batteries has exploded due to the enormous increase in the variety and number of miniaturized devices. It is expected that this demand for high capacity rechargeable batteries as energy sources will become even greater in the future. This program is focused to develop novel high performance cathode materials for lithium rechargeable batteries. The outcomes of the project will be of great benefit to develop ....Novel nanostructured high energy cathode material. Recently, the demand for rechargeable batteries has exploded due to the enormous increase in the variety and number of miniaturized devices. It is expected that this demand for high capacity rechargeable batteries as energy sources will become even greater in the future. This program is focused to develop novel high performance cathode materials for lithium rechargeable batteries. The outcomes of the project will be of great benefit to develop new class rechargeable batteries that are economical, lightweight, environmentlly benign and high energy.Read moreRead less