Sympathetic Nervous System Activation In Renal Failure. Its Contribution To Pathogenesis And Progression.
Funder
National Health and Medical Research Council
Funding Amount
$490,796.00
Summary
Cardiovascular morbidity and mortality is exceedingly high in patients with chronic renal failure and particularly end stage renal disease. Recent studies suggest that sympathetic activation contributes substantially to the development of hypertension, progression of renal disease and cardiovascular prognosis in these patients. Increased sympathetic nerve firing has been demonstrated in end stage renal disease by the use of clinical microneurography, which has been attributed to uremia-related t ....Cardiovascular morbidity and mortality is exceedingly high in patients with chronic renal failure and particularly end stage renal disease. Recent studies suggest that sympathetic activation contributes substantially to the development of hypertension, progression of renal disease and cardiovascular prognosis in these patients. Increased sympathetic nerve firing has been demonstrated in end stage renal disease by the use of clinical microneurography, which has been attributed to uremia-related toxins. However, renal transplant recipients with excellent graft function and no signs of uremia still exhibit increased sympathetic nerve firing. Most interestingly, bilateral nephrectomized patients have nerve firing rates comparable to that of normal control subjects without renal disease. These data suggest that the diseased kidneys exert excitatory effects on the sympathetic nervous system independent of correction of uremia. The proposed study aims to comprehensively investigate the pattern of sympathetic activation both centrally (microneurography) and regionally (radiotracer dilution methodology) in patients with chronic renal failure and end stage renal disease . The effect of the centrally acting sympatholytic drug rilmenidine on sympathetic activity in the setting of renal disease will be assessed. Patients with ESRD waitlisted for kidney transplantation will be studied before and after transplantation. Some of the transplant recipients will also have undergone uni- or bilateral nephrectomy before transplantation which will enable us to further explore the role of the diseased kidneys in sympathetic activation. The results of this study may prove to have significant implications for treatment and prevention of cardiovascular morbid events frequently associated with renal disease.Read moreRead less
Depression And Risk Of Coronary Heart Disease: A Prospective Study Of Mediating Haemostatic Risk Factors
Funder
National Health and Medical Research Council
Funding Amount
$327,625.00
Summary
Growing evidence suggests that depression, anger and anxiety play a role in causing coronary heart disease (CHD) and complicating the outcome in existing CHD. This may occur by effects of these emotions on promoting blood clotting and the stickiness of platelets - the blood cells responsible for blood clotting. This pilot study will follow a group of people with depression but without CHD and a control group over 8 months to compare how the blood clotting profile changes as depression resolves. ....Growing evidence suggests that depression, anger and anxiety play a role in causing coronary heart disease (CHD) and complicating the outcome in existing CHD. This may occur by effects of these emotions on promoting blood clotting and the stickiness of platelets - the blood cells responsible for blood clotting. This pilot study will follow a group of people with depression but without CHD and a control group over 8 months to compare how the blood clotting profile changes as depression resolves. The potential benefits of this research are a better understanding of the links between the common illnesses of depression and CHD that might improve the prevention and treatment of heart disease.Read moreRead less
Coronary artery disease is the largest single cause of death in Australia, and commonly manifests as heart attack and angina. Congenital heart disease is the most common birth defect. We have identified a gene, Crim1, that is important for heart and coronary artery development. Investigating how this gene functions will lead to a greater understanding of congenital heart disease and may lay the foundation for therapeutics to regenerate damaged hear tissue.
Function Of The S100A1 Ca2+-binding Protein Under Physiological And Pathological Conditions
Funder
National Health and Medical Research Council
Funding Amount
$452,545.00
Summary
The S100A1 protein is one of the most abundant proteins in human heart muscle cells. It binds calcium ions and may play a role in the regulation of heart function. S100A1 levels are reduced in human heart failure, but it is unclear whether this reduction contributes to worsening of the disease. To study this, we have generated a genetically modified mouse strain that cannot make the S100A1 protein. We will use these mice to study how important the protein is for heart function under normal condi ....The S100A1 protein is one of the most abundant proteins in human heart muscle cells. It binds calcium ions and may play a role in the regulation of heart function. S100A1 levels are reduced in human heart failure, but it is unclear whether this reduction contributes to worsening of the disease. To study this, we have generated a genetically modified mouse strain that cannot make the S100A1 protein. We will use these mice to study how important the protein is for heart function under normal conditions, and how it contributes to the development of heart failure. Preliminary data indicate that adult mice with reduced S100A1 protein levels develop a form of heart disease that significantly reduces the efficiency of the pump function of the heart.Read moreRead less
Heart failure (HF) is the most common cause of hospital admission in those over 65y, and has significant morbidity and mortality. We need to develop new strategies to treat HF. Plasma vasopressin (AVP) levels are elevated in HF, and may contribute to adverse outcomes. This proposal will assess the utility of blocking the vasopressin V1 and V2 receptors in a rat model of HF. We shall also measure AVP in humans with HF. The results of this work may result in new approaches to treat HF patients.
Redefining The Role Of Macrophages In Atherosclerosis: Macrophage Subset Role In Plaque Stability
Funder
National Health and Medical Research Council
Funding Amount
$509,190.00
Summary
Vascular disease is a major cause of death and disability through events such as heart attack and stroke. A blood cell, called a macrophage, plays a major detrimental role. However, we have identified the presence of an alternate form of this cell in vascular disease that we propose may play an opposing, beneficial role. We will thus re-define the role of the macrophage in vascular disease and predict that we will be able to demonstrate an alternate healing role. This will provide a new therapeu ....Vascular disease is a major cause of death and disability through events such as heart attack and stroke. A blood cell, called a macrophage, plays a major detrimental role. However, we have identified the presence of an alternate form of this cell in vascular disease that we propose may play an opposing, beneficial role. We will thus re-define the role of the macrophage in vascular disease and predict that we will be able to demonstrate an alternate healing role. This will provide a new therapeutic approach for treatment of atherosclerosis.Read moreRead less
Differences Between Physiological And Pathological Cardiac Hypertrophy Offer New Strategies For Treating Heart Failure
Funder
National Health and Medical Research Council
Funding Amount
$335,473.00
Summary
The heart becomes large both in athletes as well as in patients with heart disease and failure. In the first instance, the large (hypertrophied) heart has normal or even increased pumping ability (function) whereas in the patient with heart disease the function is depressed and the heart may fail. My studies are directed towards finding out what is the difference in these 2 situations and what mechanisms are responsible for making one big heart pump well and the other big heart pump poorly. Spec ....The heart becomes large both in athletes as well as in patients with heart disease and failure. In the first instance, the large (hypertrophied) heart has normal or even increased pumping ability (function) whereas in the patient with heart disease the function is depressed and the heart may fail. My studies are directed towards finding out what is the difference in these 2 situations and what mechanisms are responsible for making one big heart pump well and the other big heart pump poorly. Specifically my project hopes to identify the genes and proteins responsible for the differences. I have already identified one such gene and I now plan to manipulate this gene by overexpressing it in animals (transgenic mice) with heart failure. I predict that overexpression of this gene will improve heart function in models of heart failure. If the hypothesis is correct, activating genes that are activated in the athlete's heart maybe a potential tool for improving heart function, quality of life and life span in patients with heart failure.Read moreRead less
Cardiac-specific Therapy Targeting Hypertrophy And Apoptotis
Funder
National Health and Medical Research Council
Funding Amount
$542,683.00
Summary
We have discovered that certain pathological responses in the heart are mediated by an unusual type of signalling protein. The aim of the proposed studies is to determine whether this unusual signalling mechanism can provide a good target for development of new therapeutic approaches to prevent or treat heart failure.
Transcriptional Regulatory Complexes Associated With Cardiac Hypertrophy
Funder
National Health and Medical Research Council
Funding Amount
$474,517.00
Summary
Following the success in decoding human genome, i.e. DNA sequence, a major task is to understand how the activity of genes with consequent changes in respective proteins. As proteins are an important component for cell structure and function, such changes in quantity and quality of proteins will play a pivotal role to affect disease development and progression. It has been well known that a group of genes are altered (up or down) in the heart under conditions such as heart muscle overgrowth (ie ....Following the success in decoding human genome, i.e. DNA sequence, a major task is to understand how the activity of genes with consequent changes in respective proteins. As proteins are an important component for cell structure and function, such changes in quantity and quality of proteins will play a pivotal role to affect disease development and progression. It has been well known that a group of genes are altered (up or down) in the heart under conditions such as heart muscle overgrowth (ie hypertrophy), aging or of abnormal beating function. The reasons for such altered gene activity remain poorly understood. Although recent studies from research on genetics or cancer have revealed the important role of the DNA and DNA-bound proteins (called histone) in the control of gene activity, this has rarely been studied in the heart. In this project, we will test our hypothesis that DNA-histone structure is a key factor that control gene activities in ageing and diseased heart. This proposal is supported by our recent findings showing that in the hypertrophied heart, such DNA-histone structure did alter in such a way that fits well with alterations in gene activity. We have planned a series of studies to test this hypothesis in a systematic fashion. A number of sophisticated and cutting-edge techniques and experimental models of heart hypertrophy will be used. We will analyse changes in activities of a number of selected genes in the heart and also analyse changes in DNA-histone structures and chemical modifications at particular regions. These changes will then be linked together. We will also explore the possibility of modulating DNA-histone structure, thereby controlling the degree of cardiac hypertrophy. This project is the joint efforts of scientists with substantial experience in research on gene activity and heart diseases, and is highly likely to generate novel information to and hold significant therapeutic potential.Read moreRead less
This project studies the mechanisms involved in rejection of skin and heart grafts using a novel model to track the behaviour of individual graft-reactive white blood cells. We will test two promising new techniques to limit graft rejection: using drugs to inhibit the entry of graft-reactive cells into the graft, and administering cells with the ability to suppress the function of graft-reactive cells. This work will help us to design new therapies to prevent heart graft rejection.