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
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
Thromboxane Receptor Signaling In Endothelial Cells
Funder
National Health and Medical Research Council
Funding Amount
$584,985.00
Summary
Normal organ development and many disease processes, such as cancer and ischemia, 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 short lived lipid derivatives, called eicosanoids. 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.
Vascular Effects Of Exercise Training And Lipid-lowering Therapy At Rest And During Exercise In Hypercholesterolaemia
Funder
National Health and Medical Research Council
Funding Amount
$241,650.00
Summary
The health of the cells which line blood vessels, endothelial cells, is now known to be important in maintaining normal function of the circulation. In patients with elevated blood cholesterol concentration, the function of these cells is abnormal and this is considered to contribute importantly to the blood vessel dysfunction and cardiovascular disease seen in this condition. We have recently demonstrated that drug therapy aimed at decreasing cholesterol concentration in the blood can significa ....The health of the cells which line blood vessels, endothelial cells, is now known to be important in maintaining normal function of the circulation. In patients with elevated blood cholesterol concentration, the function of these cells is abnormal and this is considered to contribute importantly to the blood vessel dysfunction and cardiovascular disease seen in this condition. We have recently demonstrated that drug therapy aimed at decreasing cholesterol concentration in the blood can significantly improve blood vessel function. In other studies we have demonstrated that exercise training improves blood vessel function. The purpose of this research is to determine whether high blood cholesterol impairs exercise capacity by limiting blood flow to exercising muscle. It is also our goal to determine whether exercise training can produce benefit additional to that resulting from lowering cholesterol in those with initially high cholesterol. Blood vessel function will be studied at rest, in response to pharmacological stimulation and during exercise. Vascular function in the forearm will be assessed using synchronised ultrasound (high frequency sound, sonar) and Doppler measures which assess the size of, and flow in, the large artery near the elbow crease. During measurements, procedures are undertaken to alter flow in the arm blood vessels, some depending upon functional ability of the endothelial cells and some independent of those cells. In addition to assessment of blood vessel function, measurements of exercise tolerance will be taken before and after each intervention. By examining the effects of lipid-lowering and exercise training on rest and exercise blood flow responses, this research will help determine the best approach to improving blood vessel function and cardiovascular fitness in patients with high cholesterol.Read moreRead less
Influence Of Flavonoid Structure And Function On Cardiovascular Protection
Funder
National Health and Medical Research Council
Funding Amount
$571,447.00
Summary
The proposed research will further explore the hypothesis that dietary flavonoids can protect against cardiovascular disease. The importance of flavonoid structure for bioactivity needs further study. In addition, metabolic changes to flavonoid structure could have a profound effect on their bioactivity. Therefore, our overall aim is to investigate the effects of individual flavonoids and their metabolites on bioactivity relevant to cardiovascular disease.
Defining The Roles Of NADPH Oxidases In Vascular Remodelling And Arterial Hypertension
Funder
National Health and Medical Research Council
Funding Amount
$401,523.00
Summary
Hypertension (high blood pressure) is a major risk factor for cardiovascular diseases such as heart attacks, heart failure and stroke - the major causes of death world-wide and a huge burden on the Australian health care budget. Oxidative stress, resulting from an imbalance in the production and removal of toxic molecules called free radicals within the blood vessel wall, is a key player in the initiation and progression of these disorders. In the early stages of hypertension, production of free ....Hypertension (high blood pressure) is a major risk factor for cardiovascular diseases such as heart attacks, heart failure and stroke - the major causes of death world-wide and a huge burden on the Australian health care budget. Oxidative stress, resulting from an imbalance in the production and removal of toxic molecules called free radicals within the blood vessel wall, is a key player in the initiation and progression of these disorders. In the early stages of hypertension, production of free radicals only just outweighs their removal, resulting in a mild oxidative stress. However, this is enough to trigger a cascade of downstream events leading to activation of other, normally dormant, free radical generating systems. At these excessive levels, free radicals attack the cells of the artery wall leading to blood vessel dysfunction and ultimately cardiovascular disease. A major source of free radicals in the blood vessel wall are a family of enzymes called NADPH oxidases. It is our hypothesis that upregulation of onr of these enzymes in the early stages of hypertension is the initial trigger for many of the downstream effects that ultimately lead to cardiovascular disease. Our group is uniquely poised to test this hypothesis as we are the only laboratory in the world with access to three different strains of genetically modified mice, each lacking one of the three known isoforms of NADPH oxidase. Identification of the specific isoform of NADPH oxidase involved in free radical production in blood vessels is a critical first step in developing drugs that block vascular free radical production and so remove the molecular link between hypertension and major cardiovascular events.Read moreRead less
Role For Sphingosine Kinase-1 In Endothelial Progenitor Cell Survival And Differentiation.
Funder
National Health and Medical Research Council
Funding Amount
$294,205.00
Summary
Lay description: Collectively, diseases of the vascular system contribute immensely to the burden of health care in Australia. Notably, abnormal blood vessel formation and function (angiogenesis) has been identified as a major cause or contributor to the vascular complications associated with inflammation, cancer, rheumatoid arthritis and diabetes. Endothelial cells are one of the principle cells of blood vessels forming a barrier between the blood and tissues. This project aims to understand th ....Lay description: Collectively, diseases of the vascular system contribute immensely to the burden of health care in Australia. Notably, abnormal blood vessel formation and function (angiogenesis) has been identified as a major cause or contributor to the vascular complications associated with inflammation, cancer, rheumatoid arthritis and diabetes. Endothelial cells are one of the principle cells of blood vessels forming a barrier between the blood and tissues. This project aims to understand the process whereby mature endothelial cells are formed and how replacement of damaged endothelial cells is normally achieved. Stem cell therapy is considered the new frontier for the treatment of many diseases. Understanding how endothelial progenitor cells differentiate to mature endothelial cells and the signals which operate inside the cell may allow therapeutic manipulation of key target moecules in order to limit or control inflammation, tumourigenesis, rheumatoid arthritis and diabetic retinopathy. Our results suggest that one target maybe the enzyme sphingosine kinase.Read moreRead less