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
Blood clotting is the underlying cause of heart attacks and strokes. We have discovered that the protein, ERp5, is essential for normal blood clotting. Our preliminary findings indicate that ERp5 controls the function of blood platelets in clotting. Our overall aim is to elucidate how ERp5 regulates platelet function. It is crucial that we understand how ERp5 functions in blood clotting if we are to effectively target it in disease.
Thioredoxin Interacting Protein: A Novel Regulator Of Angiogenesis And Impaired Neovascularisation In Diabetes Mellitus
Funder
National Health and Medical Research Council
Funding Amount
$292,639.00
Summary
Heart disease is the leading cause of death and treatment options such as bypass surgery are unsuitable for many sufferers, particularly those with diabetes. This project investigates the regulation of new blood vessel growth through the action of antioxidants and also examines the contribution of adult stem cells to this process. Regulating new blood vessel growth provides a novel means to overcome current problems in the management of both non-diabetic and diabetic patients with heart disease.
PYROXD1 - A Novel Myopathy Disease Gene Identifies A Redox Pathway Essential For Life
Funder
National Health and Medical Research Council
Funding Amount
$1,247,992.00
Summary
An Australian family with a rare myopathy has led to the discovery of a new gene called PYROXD1; a gene that all cells need to survive. PYROXD1 plays a critical role in protecting cells from oxidative stress. We are using patient samples and mouse models to find out what PYROXD1 does that is vital for cell and animal life. We will test whether redox therapies developed for neurodegenerative disorders might help patients with rare neuromuscular disorders, for whom there are no treatment options.
The Physiological Role Of Glutathione-S-Transferase In The Intracellular Storage And Transport Of Nitric Oxide And Its Biomedical Effects
Funder
National Health and Medical Research Council
Funding Amount
$544,839.00
Summary
The aim of this project is to elucidate the mechanisms behind the intracellular regulation of nitrogen monoxide (NO) levels, which has broad implications for understanding NO activity in many processes which have major vital health implications, including the cytotoxic of macrophages and the control of blood pressure.