Vascular And Neuro-glial Dysfunction In Diabetic Retinopathy
Funder
National Health and Medical Research Council
Funding Amount
$481,500.00
Summary
The retina is responsible for sight. Vision occurs by interactions between blood vessels, neurons (cells that transmit electrical signals for vision) and glia (cells that support the retina). In diabetes, high amounts of glucose in blood increases certain factors within retinal cells. These factors slowly cause damage, such that after 15 years of diabetes all patients will have some retinal disease and many will loose sight. Indeed, diabetes is the leading cause of blindness in working people. T ....The retina is responsible for sight. Vision occurs by interactions between blood vessels, neurons (cells that transmit electrical signals for vision) and glia (cells that support the retina). In diabetes, high amounts of glucose in blood increases certain factors within retinal cells. These factors slowly cause damage, such that after 15 years of diabetes all patients will have some retinal disease and many will loose sight. Indeed, diabetes is the leading cause of blindness in working people. The main treatment for diabetic retinal disease is to burn away damaged blood vessels, however, this treatment has problems. Firstly, the burns destroy healthy retina and the disease continues, secondly, the treatment is performed late in the disease and therefore does not prevent the early changes in retinal cells, and thirdly, changes in neurons and glia are often not considered. Therefore, there is an urgent need to understand how blood vessels, neurons and glia interact with each other to threaten vision in diabetes, with the intention of developing safer and more effective treatments. This will be the focus of the current project. Currently, there are no studies that have examined the sequential changes in retinal blood vessels, neurons and glia in diabetes. This is mainly due to the lack of an experimental rodent model that progresses from mild to severe diabetic retinal disease. In 2003, we established such a model in the diabetic Ren-2 rat. In this project the diabetic Ren-2 rat will be used to study retinal cell changes and also to identify the factors that damage these cells. We suggest that angiotensin, bradykinin and VEGF are involved. These factors are present in the normal retina and are increased in diabetes. We will block these factors with specific drugs with the intention of understanding how these factors affect retinal cells in diabetes, and also to develop new drug therapies for the treatment of both early and late diabetic retinal disease.Read moreRead less
Defining Vascular Health And Modifiable Risk Factors Over Time In Childhood.
Funder
National Health and Medical Research Council
Funding Amount
$368,061.00
Summary
Adult heart disease and strokes have their origin in childhood. We will follow healthy children and children with diabetes or obesity over 2 years during puberty when blood vessel disease is detectable. We will define which are the most sensitive markers of blood vessel disease and the continuum of risk factors. This is essential knowledge to best define children at risk and to test clinical and public health interventions.
The Fremantle Diabetes Study Phase II: A Community-based Study Of Diabetes Care, Control, Complications And Cost
Funder
National Health and Medical Research Council
Funding Amount
$1,307,780.00
Summary
In Phase I of the Fremantle Diabetes Study (FDS), valuable and detailed data on a wide range of subjects were obtained from a community-based patient cohort between 1993 and 2001. There is a large body of evidence that the nature and treatment of diabetes in Australia is changing rapidly. In order to provide up to date information to health care providers and government agencies, to confirm observations made in FDS I and to venture into new research areas, Phase II will be conducted.
Aldosterone Inhibition And Diabetic Retinopathy: Treatments And Mechanisms Of Action
Funder
National Health and Medical Research Council
Funding Amount
$511,294.00
Summary
The World Health Organization predicts that by 2030, more than 360 million people will have diabetes. Despite almost all patients developing retinopathy, current treatments do not prevent disease progression. One strategy being evaluated is blockade of a hormone called angiotensin II. We have new evidence that a related system called aldosterone exists in retina and contributes to damage. This project will determine if aldosterone blockade is a potential treatment for diabetic retinopathy.
Characterisation Of Novel AGE Binding Proteins: Implications For Diabetic Vascular Complications.
Funder
National Health and Medical Research Council
Funding Amount
$210,990.00
Summary
This project will explore a process known as advanced glycation and in particular how this may lead to organ injury in diabetes. Diabetes is characterised by sustained elevation of blood glucose levels which interact with proteins to generate products known as advanced glycation end-products (AGEs). These AGEs bind to other proteins some of which have been isolated and are considered receptors. Our own group has identified a new family of proteins known as ERM proteins which bind to AGEs. This i ....This project will explore a process known as advanced glycation and in particular how this may lead to organ injury in diabetes. Diabetes is characterised by sustained elevation of blood glucose levels which interact with proteins to generate products known as advanced glycation end-products (AGEs). These AGEs bind to other proteins some of which have been isolated and are considered receptors. Our own group has identified a new family of proteins known as ERM proteins which bind to AGEs. This is a highly novel finding which now needs to be examined in more detail. The ERM proteins which include ezrin, radixin and moiesin are found at many sites of diabetic complications including the kidney, retina and blood vessel wall. They have a number of functions including effects on cell adhesion and cell structure. This is important in diabetes where changes in cells including altered structure have been observed. This grant will characterise the interactions between AGEs and ERM proteins at the molecular and cellular level. It will define how AGEs influence cells via interactions with ERM proteins. These studies have the potential to lead to treatments that may modulate the AGE-ERM interactions, thereby retarding or preventing diabetic vascular complications. These complications are of important clinical significance since they are the major cause of morbidity and mortality in the diabetic population. Furthermore, diabetes is a major cause of premature atherosclerosis in our community, diabetic kidney disease is the leading cause of end-stage renal failure in the Western world and diabetic retinopathy (eye disease) is the main cause of blindness in the working age population.Read moreRead less
Hormonal Predictors Of Cardiovascular Outcomes And Mortality In Ageing Men: The Role Of Androgens And The IGF System.
Funder
National Health and Medical Research Council
Funding Amount
$125,035.00
Summary
As men age levels of testosterone and growth hormone fall while ill health increases. We do not know if low hormone levels directly cause heart disease. We will measure testosterone and IGF1, which reflects growth hormone, in 4,200 older men, and relate hormone levels to the future risk of ill health especially heart disease, stroke and large artery blockages. This will clarify whether low hormone levels increase risk of ill health, and the value of studies to test hormone therapy in older men.
Microvascular Complications Of Diabetes - Potential Role Of Regenerative Therapies
Funder
National Health and Medical Research Council
Funding Amount
$32,003.00
Summary
The global burden of diabetes is projected to reach more than 366 million by 2025. According to the AusDiab 2005 study, each year 0.8% of Australians develop diabetes. Diabetes is the leading cause of end-stage kidney disease in Australia. Current treatments slow damage to the kidney, but do not reverse kidney damage. We will explore the potential for adult progenitor cells (endothelial progenitor cells) to reverse damage to the kidney and restore its function.
The Role Of The Endothelium In Insulin's In Vivo Action Upon Skeletal Muscle Metabolism.
Funder
National Health and Medical Research Council
Funding Amount
$451,500.00
Summary
A number of studies using novel techniques developed in association with our USA collaborators, indicate that insulin has a major stimulatory effect on blood flow within muscle in both animals and humans to improve access for itself as well as nutrients such as glucose. As much as 50% of the glucose taken up by muscle in vivo during continual exposure to insulin may be attributed to this effect. Moreover, this haemodynamic effect of insulin in muscle is impaired in a number of animal models and ....A number of studies using novel techniques developed in association with our USA collaborators, indicate that insulin has a major stimulatory effect on blood flow within muscle in both animals and humans to improve access for itself as well as nutrients such as glucose. As much as 50% of the glucose taken up by muscle in vivo during continual exposure to insulin may be attributed to this effect. Moreover, this haemodynamic effect of insulin in muscle is impaired in a number of animal models and in obese humans when insulin mediated muscle glucose uptake is also impaired. What is not known is how insulin mediates this haemodynamic effect of recruiting capillary blood flow. Thus in the present study a number of aspects are to be explored, with particular focus on the cells that line the blood vessels and constitute the capillaries, the so called endothelium. First, we will explore the specific role of the endothelium in insulin's action by using the novel approach of attaching insulin to a large molecule that prevents it leaving the lumen of the blood vessel. This will mean that insulin will be confined to interacting only with insulin receptors on the muscle endothelium. Similarly, non activating anti insulin receptor antibody will be used in the presence of insulin to selectively prevent activation of the endothelial insulin receptors. In addition, we will investigate whether homocysteine, an amino acid found to impair endothelial dependent vasodilatation, impairs the haemodynamic effects of insulin. The impact that normal insulin release after a meal has upon the haemodynamic actions in muscle and the role this has in muscle glucose uptake will also be investigated by using the techniques developed in the first part of the project. Our over riding hypothesis is that the endothelium plays a key role in controlling insulin and possibly glucose access to muscle cells and thus a significant proportion of insulin mediated metabolic events in muscle.Read moreRead less