Anti-atherosclerotic Effects Of Angiotensin Fragments & Non-AT1 Receptors: Validation As Innovative Therapeutic Targets
Funder
National Health and Medical Research Council
Funding Amount
$512,065.00
Summary
In Australia the largest cause of death is coronary heart disease (CHD) leading to heart attacks or stroke and claiming a staggering 28,000 lives a year. Atherosclerosis is one of the leading causes of cardiovascular disease, with diseased vessels not able to fully dilate and the plaque that has built up inside these vessels impeding blood flow and possibly rupturing, resulting in heart attacks and stroke. One of the major players in the development and progression of atherosclerosis is the horm ....In Australia the largest cause of death is coronary heart disease (CHD) leading to heart attacks or stroke and claiming a staggering 28,000 lives a year. Atherosclerosis is one of the leading causes of cardiovascular disease, with diseased vessels not able to fully dilate and the plaque that has built up inside these vessels impeding blood flow and possibly rupturing, resulting in heart attacks and stroke. One of the major players in the development and progression of atherosclerosis is the hormone, angiotensin II. Angiotensin II has been found to trigger many factors that cause thickening of the vessel wall, inflammation and imbalances in vasodilator capacity (e.g. oxidative stress and endothelial dysfunction), all of which contribute to atherosclerosis. Clinical trials with drugs that inhibit the formation of angiotensin II (ACE inhibitors), or block the action of angiotensin II (angiotensin receptor antagonists), have demonstrated a significant decrease in mortality in patients with high risk for cardiovascular disease. However their mechanism(s) of action are not fully understood as the circulating levels of shorter fragments of angiotensin II (such as Ang IV and Ang (1-7)) are raised in the blood when these drugs are used and may contribute to the protective effects of these drugs. Importantly, we have found that both Ang IV and Ang (1-7) have protective effects in atherosclerotic blood vessels. Therefore, we hypothesise that fragments of angiotensin II (such as Ang IV and others) exert anti-atherogenic effects via distinct binding sites that oppose the effects caused by angiotensin II, and that these may be partly responsible for the cardio-protective effects of the ACE inhibitors and angiotensin receptor antagonists. Thus, information gained in our study will be useful in directing future prescription practices in clinical management of CHD and stroke, and for designing new therapeutic compounds for the management of atherosclerosis.Read moreRead less
Aberrant Oligosaccharide Processing Of Nox2-oxidase As A Mechanism Of Vascular Oxidative Stress In Atherosclerosis
Funder
National Health and Medical Research Council
Funding Amount
$552,565.00
Summary
Excessive production of free radicals by an enzyme called Nox2 may be a cause of artery disease leading to heart attacks and strokes. This study will identify whether the addition of sugarchains to Nox2 causes it to be expressed at the surface of cells allowing the free radicals it produces to exit the cell and cause damage to the blood vessel wall. Charaterising this new pathway of excessive free radical production may pave the way for new diagnostics and treatments for artery disease.
Suppression Of NADPH Oxidase-derived Oxidative Stress By Anti-sense Probes And HDL In Human Vascular Endothelium
Funder
National Health and Medical Research Council
Funding Amount
$455,250.00
Summary
In Australia, coronary heart disease (CHD) causing heart attacks remains the largest cause of death, claiming a staggering 28,000 lives a year. Oxidative stress, resulting from increased production of oxygen free radicals in arteries, is an important cause of CHD, heart attacks and strokes. We seek to understand how such oxyradicals are produced in the key cells that form the lining of all arteries, known as the vascular endothelium. By using novel DNA-type molecules (known as anti-sense) develo ....In Australia, coronary heart disease (CHD) causing heart attacks remains the largest cause of death, claiming a staggering 28,000 lives a year. Oxidative stress, resulting from increased production of oxygen free radicals in arteries, is an important cause of CHD, heart attacks and strokes. We seek to understand how such oxyradicals are produced in the key cells that form the lining of all arteries, known as the vascular endothelium. By using novel DNA-type molecules (known as anti-sense) developed in our laboratory, which block a particular gene causing oxidative stress, we will determine whether this gene is responsible for the formation of oxyradicals in human and mouse cells grown in culture. In addition, we will explore whether this gene is turned on by factors known to be involved in CHD. Finally, we will also investigate whether the good cholesterol known as HDL can act to prevent oxidative stress in human cells, as we discovered it appears to do in living arteries in vivo. If we find it has the same protective effect in endothelium, we will determine how it does this, and which component proteins of the HDL particle are important. This might suggest new treatments to prevent acute events leading to heart attack and stroke, and possibly new applications where damage appears to result from acute oxidative stress, such as in the brain soon after a stroke has occurred. We also have a plan to develop antisense drugs that will target the important gene specifically in the affected endothelium. In addition, we have other specific new drugs that will block this system in arteries. Simultaneously we will be testing the role of this gene in mouse and rabbit models of artery disease, for both our types of drugs might provide valuable new therapeutic agents to target the underlying cause of CHD and not just its symptoms as current drugs do.Read moreRead less
Single-chain Antibodies For Directed Stem Cell Homing And Targeting Of Effector Cells In Vascular Disease
Funder
National Health and Medical Research Council
Funding Amount
$596,677.00
Summary
Regenerative cellular therapy e.g. with adult stem cells is a promising novel medical therapy. However, until now there is no reliable method to direct cells to areas where they are needed. We aim to develop a biotechnological approach based on genetically tailored antibody molecules that will allow cell targeting. As a pilot project we will test whether this approach improves lipid deposition and hardening of arteries.
Targeting Arginase In Peripheral Arterial Occlusive Disease
Funder
National Health and Medical Research Council
Funding Amount
$243,945.00
Summary
Peripheral artery occlusive disease causes narrowing of large peripheral blood vessels which can result in severe pain, gangrene and stroke. Its prevalence is steadily increasing in western countries. This proposal aims to characterize the role of an enzyme (arginase) in PAOD and determine whether it may be a new drug target for treatment of this disease.
The Effect Of CPAP On Erectile And Endothelial Dysfunction In Impotent Men With Obstructive Sleep Apnea
Funder
National Health and Medical Research Council
Funding Amount
$609,559.00
Summary
Erectile dysfunction is common in men with obstructive sleep apnea, due to vascular damage, which leads to heart attack. CPAP is the preferred treatment for patients with OSA because of its well-proven ability to decrease sleepiness and improve blood pressure control. This study will establish if CPAP can also improve erectile and vascular endothelial dysfunction. These results will shed light on the mechanisms that underpin the relationship between OSA and Erectile Dysfunction.
Understanding Local And Regional Determinants Of EDHF And NO Dysfunction In Resistance Arteries In Diabetes
Funder
National Health and Medical Research Council
Funding Amount
$771,295.00
Summary
Diabetes is a serious and increasing health burden worldwide. Most of the sickness and death associated is due to complications arising in the blood vessels. The inner lining of blood vessels in small arteries uses several different mechanisms to ensure proper blood flow, and in diabetes these are impaired. This study will reveal the cellular mechanisms involved and identify pathways for therapeutic intervention to alleviate the debilitating effects of small artery disease.
Normal organ development and many disease processes, such as cancer and tissue damage, depend upon formation of new blood vessels. Our research seeks to identify novel factors regulating blood vessel growth. In this context we have examined the role of proteins that mediate communication between cells, called connexins. By increasing our understanding of the factors affecting blood vessel growth we learn how to create novel therapies to enhance the treatment of ischemic disease and cancer.
Relationship Between Cell-cell Interactions And Disease Severity In Patients With Cerebral Malaria
Funder
National Health and Medical Research Council
Funding Amount
$545,183.00
Summary
Severe malaria is a collection of disease complications that leads to about 2 million deaths each year worldwide. Young children in Africa and young adults in several parts of South-East Asia are particularly affected. Travellers to these regions are also at considerable risk. One of the most dangerous complications of malaria is when the brain becomes affected, which is called cerebral malaria. We still do not understand enough about the changes that link the parasite circulating in the blood w ....Severe malaria is a collection of disease complications that leads to about 2 million deaths each year worldwide. Young children in Africa and young adults in several parts of South-East Asia are particularly affected. Travellers to these regions are also at considerable risk. One of the most dangerous complications of malaria is when the brain becomes affected, which is called cerebral malaria. We still do not understand enough about the changes that link the parasite circulating in the blood with the devastating disturbance of brain function that causes death in some people who develop cerebral malaria. In this project we will investigate some new ideas about how cerebral malaria develops. We will perform a detailed study of brain tissue taken from victims of cerebral malaria and compare the observations with similar ones in children who died of other causes. Then we will work with an experimental model we have developed, in which we put together in culture flasks the various types of cell that are found in the brain lesions in people who die from cerebral malaria. Our aim is to identify some new therapeutic targets for later use in treatment of cerebral malaria patients.Read moreRead less