Roles Of Interleukins, Chemokines And Circulating Cells In Cardiac Fibrosis
Funder
National Health and Medical Research Council
Funding Amount
$434,134.00
Summary
Cardiac fibrosis is a disease of the heart in which large amounts of collagen are deposited within the heart tissue. This leads to poor heart function and may also lead to sudden death due to arrhythmias (abnormal electrical pulses). This study sets out to define the role of substances called interleukins and special circulating cells called lymphocytes, macrophages and progenitor cells in the development of cardiac fibrosis.
NOVEL CGMP-BASED THERAPIES PREVENT LEFT VENTRICULAR REMODELLING
Funder
National Health and Medical Research Council
Funding Amount
$533,433.00
Summary
Over 300,000 Australians are affected by heart failure. Current drugs for cardiac remodelling (the decline in heart pumping function and changed structure that precede heart failure) slow but not reverse disease progression. We have identified a new, nitrovasodilator-based therapy superior to those currently available. We propose it represents a more effective treatment for reversing abnormalities in both structure and function in the remodelled heart, preventing or delaying heart failure.
Pre-clinical Development Of A Novel Anti-fibrotic, Anti-inflammatory Compound To Treat Diabetic Heart Disease
Funder
National Health and Medical Research Council
Funding Amount
$488,391.00
Summary
Diabetic patients are prone to developing chronic heart failure. In the diabetic heart, scar tissue accumulates within the muscle (fibrosis), impairing function. We have developed a new drug to treat fibrosis in diabetic kidney disease (FT-11), and have approval for pre-clinical development of this drug. We now aim to test whether FT-11 is also effective in reducing fibrosis in the diabetic heart, and whether this can prevent heart failure in an animal model of diabetic heart disease.
The Cardiomyocyte Mineralocorticoid Receptor Plays A Critical Role In Cardiac Disease.
Funder
National Health and Medical Research Council
Funding Amount
$613,477.00
Summary
Drugs that block the mineralocorticoid receptor (MR), which responds to adrenal hormones, protect against heart disease and hypertension. We have shown that this effect is in part due to MR blockade in heart muscle cells. This novel finding is being explored further to understand the precise role of the MR in heart muscle cells in normal physiology and in disease. An understanding of the role of the MR in different tissues will enable development of tissue specific treatments for heart disease.
Anti-apoptotic, Anti-fibrotic, And Positive Inotropic Effects Of Ghrelin And GHRP On Rat And Mouse Cardiac Myocytes
Funder
National Health and Medical Research Council
Funding Amount
$442,530.00
Summary
Growth hormone (GH) is a protein hormone secreted from an endocrine organ, the pituitary gland, below the brain. Synthetic GH-releasing peptides (GHRPs) and endogenous GHRP (ghrelin) possess many other physiological functions in addition to the release of GH. GHRPs have been shown to affect cardiac function in animals and humans through their specific receptors. We recently demonstrated at single cell level that GHRPs increased contraction of cardiac muscle cells and protected them from the prog ....Growth hormone (GH) is a protein hormone secreted from an endocrine organ, the pituitary gland, below the brain. Synthetic GH-releasing peptides (GHRPs) and endogenous GHRP (ghrelin) possess many other physiological functions in addition to the release of GH. GHRPs have been shown to affect cardiac function in animals and humans through their specific receptors. We recently demonstrated at single cell level that GHRPs increased contraction of cardiac muscle cells and protected them from the programmed cell death which occurs in heart failure and myocardial infarction. We also demonstrated that GHRPs protected the heart in chronic heart failure and alleviated functional loss of the heart in experimental heart failure models. Preliminary results now indicate that GHRPs prevent cardiac fibrosis, which accounts for cardiac dysfunction after heart failure and infarction. It is proposed in this project to clarify the mechanism underlying the action of GHRPs in (1) cardiac functional enhancing; (2) anti-cell death; (3) anti-fibrosis effects, in primary cultured rat myocytes in vitro and in cardiac diseased mouse models in vivo. By completing this project, we will be able to (1) better understand the physiological role of ghrelin in the regulation of cardiac function; and (2) clarify the potential for therapeutic use of GHRPs in the treatment of chronic heart failure, a disease affecting 1-2% of the population of Australia, with 5 year mortality rates about 65%.Read moreRead less
Key Role Of Connective Tissue Growth Factor (CTGF) In Familial Cardiomyopathy And Heart Failure
Funder
National Health and Medical Research Council
Funding Amount
$395,051.00
Summary
Familial cardiomyopathies are an important cause of heart failure and sudden death. Understanding the precise mechanisms of how disease develops in cardiomyopathies is an important step for developing new therapeutic and prevention strategies. We plan to investigate the role of connective tissue growth factor (CTGF) , an important protein which causes scar formation in the heart, in cells, mice, and humans predisposed to developing heart disease.
Molecular Characterisation Of The Ligand-binding Domain Of The Mineralocorticoid Receptor
Funder
National Health and Medical Research Council
Funding Amount
$215,183.00
Summary
The steroid hormone aldosterone regulates blood pressure by controlling sodium retention. The important role of this hormone in blood pressure control is underlined by the fact that all known monogenetic hypertensive conditions involve aldosterone or sodium reabsorption. Aldosterone works by activating an intracellular 'receptor' protein that in turn switches on specific genes. The products of these genes act to produce sodium retention. Antagonists (blockers) of this receptor are used in the tr ....The steroid hormone aldosterone regulates blood pressure by controlling sodium retention. The important role of this hormone in blood pressure control is underlined by the fact that all known monogenetic hypertensive conditions involve aldosterone or sodium reabsorption. Aldosterone works by activating an intracellular 'receptor' protein that in turn switches on specific genes. The products of these genes act to produce sodium retention. Antagonists (blockers) of this receptor are used in the treatment of hypertension but have undesirable side effects. The design of new, more specific, antagonists has been slow because we do not understand how these drugs bind to the receptor and what effect they have on the protein. How the aldosterone receptor functions is poorly understood. This project aims to investigate the receptor in detail. We are in the process of determining regions of the receptor structure important for hormone binding. This information is vital for the design of new antagonists. The aldosterone receptor is unusual in that it is also activated by cortisol, a steroid hormone involved in stress and inflammation. By examining hormone binding it may be possible to determine if the two steroids activate the receptor in the same way. An understanding of how both natural hormones and synthetic antagonists function is impossible without thorough study of the receptor itself. We intend to examine fundamental aspects of aldosterone receptor function. In particular we wish to identify proteins that interact with the receptor. These proteins either enhance or inhibit the ability of the receptor to switch on genes and are vital to explaining the actions of both natural hormones and synthetic antagonists. Results from these experiments should advance our understanding of the basic biology of aldosterone action and its role in cardiovascular biology, and lead to the design of better receptor antagonists for use in the treatment of hypertension and cardiac fibrosis.Read moreRead less
TARGETING ROS-INDUCED DAMAGE RESCUES THE DIABETIC HEART
Funder
National Health and Medical Research Council
Funding Amount
$487,669.00
Summary
Over 1 million Australians have diabetes. Many of these patients die from cardiovascular disease. We have identified free radicals as a major cause of decreased pumping function and impaired recovery from each heartbeat in the diabetic heart. Stronger antioxidant approaches and-or activation of protective protein pathways is a more effective treatment for reversing impaired function in the diabetic heart, preventing or delaying heart failure in patients with diabetes.
Aldosterone Mediated Cardiac Pathophysiology:The Role Of Corticosteroid Receptors And 11 HSD Isoforms
Funder
National Health and Medical Research Council
Funding Amount
$481,500.00
Summary
Aldosterone a hormone that circulates in blood and is associated with cardiovascular disease. Recently, two clinical trials (RALES, EPHUSUS) demonstrate that if you stop this hormone from acting by giving drugs that inhibit it from binding to the receptor that mediates its response, there is an improvement in the health of heart failure patients. How aldosterone mediates its detrimental effects on heart is largely unknown. Glucocorticoids are another hormone that circulates in blood and can bind ....Aldosterone a hormone that circulates in blood and is associated with cardiovascular disease. Recently, two clinical trials (RALES, EPHUSUS) demonstrate that if you stop this hormone from acting by giving drugs that inhibit it from binding to the receptor that mediates its response, there is an improvement in the health of heart failure patients. How aldosterone mediates its detrimental effects on heart is largely unknown. Glucocorticoids are another hormone that circulates in blood and can bind to the same receptor as aldosterone. In contrast to aldosterone glucocorticoids appear to play a basic maintenance role in heart. Our central hypothesis is that in the healthy heart aldosterone has minimal effects , however, in the diseased heart aldosterone associated pathophysiology is a result of both an increase in the ability of aldosterone to signal to cells and disruption of glucocorticoid signalling. This grant proposal will address how aldosterone and glucocorticoids may directly signal within cardiac cells and how this signalling changes in the diseased heart. In addition, we investigate if enzymes that metabolize glucocortioids and thus render them non-functional play a role in cardiac disease, and if we can reverse the detrimental effects of aldosterone by artificially increasing the production of glucocorticoids in heart. By understanding the mechanisms by which aldosterone promotes cardiac disease, and the role of glucocorticoids and their metabolism in this process will lead to a better understanding of aldosterone induced pathology and thus lead to novel therapeutic targets.Read moreRead less
Cellular Localisation Of Mineralocorticoid Receptor-mediated Vascular Inflammation And Cardiac Fibrosis.
Funder
National Health and Medical Research Council
Funding Amount
$476,264.00
Summary
Cardiovascular disease is a major health and economic burden throughout the world, especially in developed countries and is the leading cause of death and disability in Australia, claiming the lives of over 50,000 Australians each year. Heart failure accounts for many of these deaths and the incidence continues to increase. Two recent large scale clinical trials have shown a 30-35% improvement in patient outcome when a blocker for the mineralocorticoid receptor (MR) is included in current best p ....Cardiovascular disease is a major health and economic burden throughout the world, especially in developed countries and is the leading cause of death and disability in Australia, claiming the lives of over 50,000 Australians each year. Heart failure accounts for many of these deaths and the incidence continues to increase. Two recent large scale clinical trials have shown a 30-35% improvement in patient outcome when a blocker for the mineralocorticoid receptor (MR) is included in current best practice therapy for either heart failure or after a heart attack. The mechanisms underlying these benefits remain to be identified. We have shown that the hormone aldosterone and its receptor, the MR, not only play an important role in the development of high blood pressure but also the progression of cardiac disease. Our most recent studies have shown that blocking the MR not only prevents cardiac fibrosis and vascular damage, but also reverses this process. To understand the mechanisms that translate MR signalling into blood vessel damage and cardiac fibrosis we wish to use mice who have the MR gene inactivated in specific cells only. In this way we can identify those cells critical to the disease process and focus our investigations to these cell types. Understanding the cell specific regulatory mechanisms for the MR may enable the development of heart-specfic blockers of the MR that have minimal, if any side effects.Read moreRead less