Damage To Arterial Extracellular Matrix Induced By Reactive Nitrogen Species And Its Consequences
Funder
National Health and Medical Research Council
Funding Amount
$326,250.00
Summary
It is well established that lipids accumulate in the artery wall during the development of atherosclerosis (hardening of the arteries), and that much of this lipid arises from low-density lipoproteins (LDL). The uptake of cholesterol and lipids from LDL by cells present in the arterial wall is normally tightly regulated and under feedback control, but modification of the LDL particles can result in their recognition by the scavenger receptors of macrophage cells and unregulated accumulation of l ....It is well established that lipids accumulate in the artery wall during the development of atherosclerosis (hardening of the arteries), and that much of this lipid arises from low-density lipoproteins (LDL). The uptake of cholesterol and lipids from LDL by cells present in the arterial wall is normally tightly regulated and under feedback control, but modification of the LDL particles can result in their recognition by the scavenger receptors of macrophage cells and unregulated accumulation of lipids within such cells. The formation of these lipid-laden (foam) cells is a hallmark of atherosclerosis. Whilst this lipid accumulation is undesirable, if the resulting lesions are stable they are of less concern than those that are unstable and prone to rupture. Rupture of lesions and consequent blood clot formation (thrombosis) are a prime cause of sudden heart death and stroke. Despite considerable effort the reasons for plaque rupture are poorly understood. This study will investigate one potential mechanism by which lesions might become destabilised and prone to rupture. We will investigate the role of reactive intermediates in inducing damage to the extracellular matrix. Reactive intermediates are known to be generated by inflammatory cells, and it is well established that these cells are present at elevated levels in lesions. The extracellular matrix is responsible for maintaining the 3-dimensional structure of biological systems including the artery wall, and damage or fragmentation of this material may weaken this scaffolding and make the lesions prone to rupture. We will also examine how such matrix damage affects the behaviour of cells within lesions. A detailed knowledge of which processes are important in lesion rupture is an essential prerequisite to the development of new therapeutic strategies.Read moreRead less
Myeloperoxidase-catalysed Damage To Arterial Extracellular Matrix And Its Consequences
Funder
National Health and Medical Research Council
Funding Amount
$384,750.00
Summary
A heme enzyme (myeloperoxidase) has been shown to be present in the lesions present in diseased human arteries, and it has been reported that this enzyme contributes to the development of arterial disease via its ability to catalyse the formation of highly reactive oxidants. Recent studies have shown that the level of this enzyme correlate strongly with the presence of coronary artery disease, and that this enzyme may play a role in plaque rupture, a leading cause of sudden coronary death. It ha ....A heme enzyme (myeloperoxidase) has been shown to be present in the lesions present in diseased human arteries, and it has been reported that this enzyme contributes to the development of arterial disease via its ability to catalyse the formation of highly reactive oxidants. Recent studies have shown that the level of this enzyme correlate strongly with the presence of coronary artery disease, and that this enzyme may play a role in plaque rupture, a leading cause of sudden coronary death. It has also been reported that elevated levels of metal ions are present in advanced human atherosclerotic lesions. In recent experiments we have shown that products generated by myeloperoxidase can interact with metal ions and superoxide radicals, and that this process results in an exacerbation of damage. This synergism between the oxidants generated by myeloperoxidase and metal ions may explain, at least in part, the complex mixture of products detected in human lesions and be responsible for the weakening of lesion structure and contribute to an enhanced likelihood of plaque rupture. This study will examine the potential effects and mechanisms of damage to extracellular matrix materials from normal arteries and cultured cells We will examine under what circumstances interactions occur and whether these reactions may play a key role in plaque rupture. We will also examine how materials arising from damage to the extracellular matrix may affect the cells whic grow upon this scaffolding, and whether this may be partly responsible for altered behaviour of cells within dveloping atherosclerotic lesions. A detailed knowledge of which processes are important in plaque rupture is an essential pre-requisite to the development of new therapeutic strategies.Read moreRead less
Determinants Of Cardiovascular Health Over The Lifecourse In A Population-based Cohort Study Of Australian Families
Funder
National Health and Medical Research Council
Funding Amount
$92,161.00
Summary
This unique project will examine the heart health of roughly 3500 11-12 year olds in Australia's only nationally-representative children's study. It will then examine factors that may contribute to differing heart disease progression. We will characterise established factors (such as cholesterol, blood pressure and diabetes), as well as measures of infection burden and inflammation to examine the innovative theory that childhood infection and/or its treatment contribute to poorer heart health.
MECHANISMS OF CEREBROVASCULAR REGULATION IN HEALTH AND DISEASE
Funder
National Health and Medical Research Council
Funding Amount
$216,430.00
Summary
Failure of the cerebral circulation to meet the brain's immediate high nutritive requirements results in stroke in just a few minutes. Stroke continues to be a major cause of death and disability, and this major medical challenge requires urgent and significant research at the basic level to better understand mechanisms of normal, and then abnormal, regulation of cerebral artery function. The project will examine the importance of a novel mechanism in regulating brain blood flow by affecting the ....Failure of the cerebral circulation to meet the brain's immediate high nutritive requirements results in stroke in just a few minutes. Stroke continues to be a major cause of death and disability, and this major medical challenge requires urgent and significant research at the basic level to better understand mechanisms of normal, and then abnormal, regulation of cerebral artery function. The project will examine the importance of a novel mechanism in regulating brain blood flow by affecting the degree of opening of the cerebral arteries. This mechanism involves activation of an enzyme, Rho-kinase, which is present in the wall of blood vessels. The applicants believe that this process plays an important role in the normal, healthy regulation of blood supply to the brain. Moreover, there are strong reasons for us to speculate that the function of this enzyme is abnormally high in two disease states that are associated with an increased risk of stroke - high blood pressure and subarachnoid haemorrhage. We will employ a variety of techniques to assess the importance of Rho-kinase in cerebral artery function in the living body, and also in isolated segments of artery. The results are expected to provide major new insight into mechanisms that regulate brain blood flow, and the knowledge gained here may lead to better therapies to prevent or treat stroke.Read moreRead less
Monitoring cardiovascular risk is a major part of the clinical workload both in general practice and specialty areas, but it is an under-researched area, reflected in a general lack of evidence based guidelines. My research will evaluate how to optimise the monitoring of cardiovascular risk both before and after starting treatment. By maximising clinical benefits for patients and minimising unnecessary resource use, my research will benefit patients, clinicians and the community at large.
Personalised Exercise As Medicine. Optimising The Prescription To Maximise The Benefit
Funder
National Health and Medical Research Council
Funding Amount
$772,490.00
Summary
Humans have never been less physically active than in contemporary Western society. These studies will provide an evidence-basis to address the inactivity epidemic by laying the foundation for personalised and effective exercise prescriptions, to which people are more likely to adhere.
An Implementation Trial Of A Telephone-based Care Management Program For Patients Following Myocardial Infarction
Funder
National Health and Medical Research Council
Funding Amount
$641,656.00
Summary
We are trialling the implementation of an innovative telephone-delivered program for managing people who have had a heart attack. Cardiac rehabilitation programs are generally based in hospitals in Australia and people have to be able to attend the programs when they are offered. Even though such programs have been shown to be very effective in improving outcomes after a heart attack, at least 85% of Australians after a heart attack are either unable to access and-or unable to attend such progra ....We are trialling the implementation of an innovative telephone-delivered program for managing people who have had a heart attack. Cardiac rehabilitation programs are generally based in hospitals in Australia and people have to be able to attend the programs when they are offered. Even though such programs have been shown to be very effective in improving outcomes after a heart attack, at least 85% of Australians after a heart attack are either unable to access and-or unable to attend such programs due to transport and many other barriers. So, there is an urgent need to identify new, effective, and affordable ways of delivering cardiac rehabilitation programs to people after a heart attack. The proposed telephone-delivered program will be particularly appropriate for disadvantaged people, such as those living in rural and remote areas as well as Indigenous Australians, who do not currently have access to hospital-based cardiac rehabilitation programs. People who have had a heart attack will be recruited from three of Brisbane's largest public teaching hospitals, and will then be randomly assigned to the telephone-delivered cardiac rehabilitation program (Care Management Intervention group) or to a control or Usual Care group. The Care Management Intervention group will receive regular telephone calls from a highly qualified 'Care Manager' based at the renowned National Heart Foundation of Australia telephone support service, 'Heartline'. The Care Manager will help people to manage their heart condition and prevent the reoccurrence of further heart problems. People will also be encouraged to make necessary lifestyle and behavioural changes with the assistance of the Care Manager and some Heart Foundation educational and interactive resources to record their progress. We expect that the program or Care Management Intervention group will have better health outcomes than the control or Usual Care group at 6 and 12 months follow up.Read moreRead less
The AMP-activated protein kinase (AMPK) is a metabolic stress-sensing enzyme responsible for matching energy supply to energy demand by the many different cells in our bodies. AMPK is active in the heart, where it may control cardiac function and the response of the heart to disease. It has been difficult to study AMPK in the heart because we lack drugs that block the actions of AMPK. This study will investigate the role of AMPK in the heart using a genetic approach whereby the AMPK enzyme is re ....The AMP-activated protein kinase (AMPK) is a metabolic stress-sensing enzyme responsible for matching energy supply to energy demand by the many different cells in our bodies. AMPK is active in the heart, where it may control cardiac function and the response of the heart to disease. It has been difficult to study AMPK in the heart because we lack drugs that block the actions of AMPK. This study will investigate the role of AMPK in the heart using a genetic approach whereby the AMPK enzyme is rendered inactive (a gene knockout approach). By this approach we will learn how AMPK controls heart function and how drugs that affect AMPK may impact on the heart.Read moreRead less
I am a cardiologist and epidemiologist whose research focus is on large-scale clinical trials and epidemiological research into the prevention of cardiovascular disease, particularly in relation to treatment strategies for acute coronary syndromes, dyslip