MYOCARDIAL NEOVASCULARIZATION FOR ISCHEMIC HEART DISEASE USING BONE MARROW-DERIVED ANGIOBLASTS
Funder
National Health and Medical Research Council
Funding Amount
$577,400.00
Summary
Congestive heart failure remains a major public health problem. In Western societies heart failure is primarily the consequence of a previous myocardial infarction. We have recently identified certain cells in the bone marrow of adult humans that can cause new blood vessel development in the heart after infarction, protecting the heart muscle cells against death and preventing heart failure. Since the cardiovascular diseases that are most likely to benefit from treatments utilizing adult bone ma ....Congestive heart failure remains a major public health problem. In Western societies heart failure is primarily the consequence of a previous myocardial infarction. We have recently identified certain cells in the bone marrow of adult humans that can cause new blood vessel development in the heart after infarction, protecting the heart muscle cells against death and preventing heart failure. Since the cardiovascular diseases that are most likely to benefit from treatments utilizing adult bone marrow-derived endothelial progenitors, or angioblasts, predominantly affect aging individuals, critical questions that must be addressed are whether advanced age and-or progression of cardiovascular disease reduce the total numbers and-or the functional activity of such cells. In the current proposal we will investigate the relationship between increasing age or progression of ischemic heart disease and changes in the number and in vivo biologic properties of human angioblasts. Patients at various ages and stage of cardiovascular disease will be studied. Angioblast numbers will be quantitated in freshly obtained bone marrow cells. The ability of purified angioblasts to be targeted to the ischemic heart will be studied by labeling the angioblasts with a radioactive tracer and measuring tracer uptake in the heart at various time points after intravenous infusion of the cells. Finally, angioblast functional capacity will be evaluated using standard measurements of heart function before and at various time points after reinfusion of cells into the donor. In Aims 2 and 3 of this proposal we will focus our investigations on the potential use of angioblast therapy for reversal of established chronic heart failure in our animal models. Specifically, we will investigate whether induction of neovascularization results in cardiomyocyte regeneration and explore novel strategies to augment heart muscle regeneration by increasing angioblast trafficking to the damaged myocardium .Read moreRead less
Porphyromonas Gingivalis Cysteine Proteinases In Modulation Of Cell-mediated Immune Response In Periodontitis
Funder
National Health and Medical Research Council
Funding Amount
$228,000.00
Summary
Chronic inflammatory diseases of the tissues supporting the teeth comprise some of the most widespread and common diseases to affect mankind. Recent research has indicated the major contributor to the most common form of destructive periodontal disease is the bacterium Porphyromonas gingivalis. This organism produces powerful enzymes which overcome the body's attempts to neutralise them. It is also known that the destructive phase of the disease is characterised by a change in the behaviour of t ....Chronic inflammatory diseases of the tissues supporting the teeth comprise some of the most widespread and common diseases to affect mankind. Recent research has indicated the major contributor to the most common form of destructive periodontal disease is the bacterium Porphyromonas gingivalis. This organism produces powerful enzymes which overcome the body's attempts to neutralise them. It is also known that the destructive phase of the disease is characterised by a change in the behaviour of the immune system cells which accumulate in the diseased tissues. This is manifest as a loss of protective immunity and replacement by ineffective or even tissue damaging responses. Critical in directing the pattern of behaviour of the immune system cells are the potent messenger molecules or cytokines which pass between cells. We have demonstrated that the bacterial proteinases can destroy a critical messenger molecule that instructs the defensive phagocytic cells to attack bacteria. These cells in return normally send a powerful signal back to the controlling T lymphocyte to amplify the protective signals. Associated bacterial molecules stimulate more secretion of messenger molecules which are paradoxically destroyed by the bacterial enzymes. This could cause chaos in the local tissue environment. Further, the bacterial proteinases can also eliminate some important surface molecules of T lymphocyte that are important in the activation process. The effect of this could produce impairment of T lymphocyte at periodontal sites. The planned research will define how the proteinases modulate T lymphocyte immune response. Further, the relation between the capacity of the bacterial enzymes to disrupt the vascular cells and the progression of periodontitis will also be determined.Read moreRead less
Understanding The Role Of Cell Death In Blood Vessel Regression And Regrowth
Funder
National Health and Medical Research Council
Funding Amount
$468,059.00
Summary
Blood vessels are essential to distribute oxygen and nutrients throughout our bodies, and as such, disruptions to normal blood vessel behaviour can have significant impacts on health. This research is aimed at understanding how blood vessel networks can regrow after damage in order to maintain healthy blood supply to a tissue. This work will be particularly relevant to diseases where blood vessel loss or inappropriate blood vessel growth occur.
How Is Lipoprotein Disposition Influenced By Fenestrae In The Hepatic Sinusoidal Endothelium?
Funder
National Health and Medical Research Council
Funding Amount
$310,500.00
Summary
Understanding lipoprotein metabolism is critical for the prevention of vascular disease. The liver is the main site for lipoprotein metabolism. The initial step in the metabolism of lipoproteins by the liver is their transfer across the liver sinusoidal endothelial cells from the blood to the liver cells. Sinusoidal endothelial cells contain pores called fenestrae that are thought to allow direct passage of large substances and thus filter lipoproteins on the basis of size. We propose to fully d ....Understanding lipoprotein metabolism is critical for the prevention of vascular disease. The liver is the main site for lipoprotein metabolism. The initial step in the metabolism of lipoproteins by the liver is their transfer across the liver sinusoidal endothelial cells from the blood to the liver cells. Sinusoidal endothelial cells contain pores called fenestrae that are thought to allow direct passage of large substances and thus filter lipoproteins on the basis of size. We propose to fully define the role of fenestrae in the ultrafiltration of particles such as lipoproteins and microspheres. This will confirm that ultrafiltration by fenestrae in the liver endothelium is an important biological process akin to filtration by the kidney, and relevant for lipoprotein metabolism. We will determine whether oxidative stress, which generates large gaps in the sinusoidal endothelium, increases the transfer of lipoproteins into the liver. This provides a novel mechanism for fatty liver that follows toxic liver injury, and hence, a therapeutic target for this condition. We will determine whether loss of fenestrae induced by the synthetic non-ionic surfactant, pluronic 407, reduces transfer of lipoproteins. This is an entirely novel mechanism and risk factor for hyperlipidaemia. Finally we will investigate lipoprotein (a) which is a potent risk factor for vascular disease. We will assess with lipoprotein (a), through binding other lipoproteins and increasing their size, impedes their transfer through the fenestrations for subsequent hepatic metabolism. From the basic perspective, these studies will prove that fenestrations in the liver endothelial cell are an ultrafiltration system that is significant for lipoprotein metabolism. From the clinical perspective, the studies will generate novel mechanisms for impaired hepatic metabolism of lipoproteins as well as indicating that fenestrae are a potential target for the development of lipid-lowering pharmacotherapies.Read moreRead less
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.
Role Of Microparticles In Cardiac Ischemia Reperfusion Injury
Funder
National Health and Medical Research Council
Funding Amount
$55,575.00
Summary
Interventional cardiology has reduced the mortality rate associated with heart attack, unfortunately the prevalence of heart failure has subsequently increased, caused in part by reperfusion injury of previously occluded vessels. We aim to identify novel insights into the pathogenesis of IR injury in the heart, as well as the development of new approaches to prevent cardiac damage during cardiac surgery, transplantation, post-angioplasty and coronary artery stenting.
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