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
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
Heme-oxidised Soluble Guanylyl Cyclase, A Mechanism-based Target For Vascular Diagnostics And Vasoprotective Therapy
Funder
National Health and Medical Research Council
Funding Amount
$524,456.00
Summary
Nitric oxide is produced in the inner lining of blood vessels and maintains blood flow via binding to a specific protein, sGC. In disease, sGC is defective and can be targeted by a novel group of drugs which are more active in diseased versus normal blood vessels. This project will examine the use of these drugs as markers of cardiovascular disease and in the treatment of high cholesterol and may lead to the development of new diagnostic tools and therapies for vascular complications.
Tako-Tsubo Cardiomyopathy: Pathogenesis And Natural History
Funder
National Health and Medical Research Council
Funding Amount
$246,478.00
Summary
Tako-Tsubo cardiomyopathy (TTC): broken heart syndrome is a poorly-understood cause of acute heart failure which usually occurs in post-menopausal women exposed to severe emotional stress. We will investigate the best way to diagnose TTC, identify its molecular causes and impact in the short and long-term on cardiac and blood vessel function. This research potentially should improve the detection and management of TTC, and may point to ways for its prevention.
Role Of Myeloperoxidase In Endothelial Barrier Dysfunction During Inflammation
Funder
National Health and Medical Research Council
Funding Amount
$302,123.00
Summary
The release of the enzyme myeloperoxidase (MPO) within blood vessels is thought to affect their ‘leakiness’ during periods of inflammation, leading to fluid associated swelling (oedema). We propose that MPO produces oxidant chemicals that increase blood vessel leakage. The aim of our work is to study how these chemicals increase vascular leakage by studying the biochemical pathways involved. These studies could lead to new intervention strategies targeting MPO to reduce excessive tissue oedema.
Structural And Drug Discovery Studies Of Oxidative Stress Regulator, Thioredoxin-interacting Protein
Funder
National Health and Medical Research Council
Funding Amount
$288,210.00
Summary
Toxic oxygen molecules known as Reactive Oxygen Species (ROS) are by-product of normal metabolism. The excess of ROS is damaging and is well known to contribute to ageing process and age-related diseases such as cancer, diabetic complications, immune-system decline, and cardiovascular conditions to name a few. The human body possesses several defense systems that protect us from the excess of ROS maintaining a healthy level of ROS. A down-regulator of one of this systems, a protein called TXNIP, ....Toxic oxygen molecules known as Reactive Oxygen Species (ROS) are by-product of normal metabolism. The excess of ROS is damaging and is well known to contribute to ageing process and age-related diseases such as cancer, diabetic complications, immune-system decline, and cardiovascular conditions to name a few. The human body possesses several defense systems that protect us from the excess of ROS maintaining a healthy level of ROS. A down-regulator of one of this systems, a protein called TXNIP, has been recently discovered. The amount of TXNIP is increased in such conditions as high glucose, a first sign of diabetes, and under ischemia, a shortage of blood supply occurring during heart attack. This weakens the anti-oxidant defense systems and makes the organism more vulnerable to ROS exposure. Our team of researchers embarked on structural and functional studies of TXNIP with the purpose to identify small molecules that can interfere with the undesirable action of TXNIP. These molecules might become useful therapeutic agents to counteract weakening organism's ROS defense system caused by TXNIP in many disease conditions such as, cancer, diabetes and cardiac failure.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.