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
NOX Isoforms In Diabetes Associated Vascular Injury: Implications For Therapeutic Strategies
Funder
National Health and Medical Research Council
Funding Amount
$441,511.00
Summary
These studies will investigate the role of oxidative stress and enzymes involved in oxidative stress production in diabetes associated blood vessel injury and kidney damage, leading to heart attacks, stroke and kidney failure. We will use unique knockout animal models and novel drug treatments. Ultimately, we aim to develop novel treatments to better treat and prevent diabetes related complications.
NOVEL REGULATORS OF CONNECTIVE TISSUE GROWTH FACTOR EXPRESSION AND BIOACTIVITY IN DIABETIC COMPLICATIONS
Funder
National Health and Medical Research Council
Funding Amount
$235,500.00
Summary
Diabetes mellitus is common in our community. It causes much premature death and loss of quality of life. Recent data from Australian studies show that ~7% of adults over 25 years, and ~20% of people aged over 65 have diabetes, and diabetes in both children and adults is increasing in Australia. A critical problem caused by diabetes, irrespective of its cause, is that blood glucose levels are higher than normal. High blood glucose contributes to much of the damage to body tissues and to the earl ....Diabetes mellitus is common in our community. It causes much premature death and loss of quality of life. Recent data from Australian studies show that ~7% of adults over 25 years, and ~20% of people aged over 65 have diabetes, and diabetes in both children and adults is increasing in Australia. A critical problem caused by diabetes, irrespective of its cause, is that blood glucose levels are higher than normal. High blood glucose contributes to much of the damage to body tissues and to the early death that can occur in diabetes. Unfortunately, given our current treatment methods, in only a small number of patients can glucose levels in the body be consistently controlled into the normal range. How does high blood glucose cause damage to the body and its different tissues? This is a complex process. One way that damage occurs is through an increase in some of the growth factors in the body. In diabetes, high blood glucose can increase the production of some growth factors in an uncontrolled way. In turn, these growth factors then cause tissue damage. One of the growth factors that can be increased by the high glucose in diabetes is called connective tissue growth factor, or CTGF. CTGF can cause scars to form in tissues, and it is increased in diabetes in humans. Through NHMRC sponsored post-doctoral research over the past four years, Dr Twigg has published findings showing pathways by which diabetes causes increases in CTGF, and ways in which CTGF then causes tissue scarring. The current grant proposal presents new data showing further novel pathways by which CTGF is activated by diabetes and ways in which CTGF causes scarring. The pathways involved will be studied in detail in the project. In addition, methods to block CTGF and its harmful effects in diabetes will be developed in this work. By controlling CTGF, it is envisaged that damage to tissues will be reduced, leading to improved quality and quantity of life for people who have diabetes.Read moreRead less
Do Postjunctional Alterations Explain The Effects Of Diabetes On Neurovascular Transmission?
Funder
National Health and Medical Research Council
Funding Amount
$390,886.00
Summary
Diabetes produces disordered skin blood flow that increases risk of skin ulcers and gangrene. The project investigates nervous control of skin blood vessels in diabetes. It is assumed that all affects of diabetes on nerve function are explained by loss of nerves. We hypothesize that some affects of diabetes are due to dysfunction of blood vessels and not to nerve loss. The objective is to identify drug targets to improve blood flow in skin and thereby reduce the risk of skin ulcers and gangrene.
Role Of Growth And Transcription Factors In Tubulointerstitial Injury In Diabetes
Funder
National Health and Medical Research Council
Funding Amount
$454,023.00
Summary
Progressive kidney disease occurs as a result of a range of molecular and cellular pathways. One of the commonest causes of kidney disease is diabetes and this appears to be partly related to increased expression and action of certain growth factors such as CTGF. These factors promote the deposition of scar tissue in the kidney and one of the ways these promote this scarring is to change a cell s behaviour so that it now lays down collagen. This proposal will not only focus on how CTGF promotes ....Progressive kidney disease occurs as a result of a range of molecular and cellular pathways. One of the commonest causes of kidney disease is diabetes and this appears to be partly related to increased expression and action of certain growth factors such as CTGF. These factors promote the deposition of scar tissue in the kidney and one of the ways these promote this scarring is to change a cell s behaviour so that it now lays down collagen. This proposal will not only focus on how CTGF promotes scarring but will explore 2 novel factors called Snail and Slug which can act directly on particular genes such as CTGF to inhibit these deleterious effects. By further characterising these pathways involving Snail, Slug and CTGF in the kidney it will be possible to generate new targets and therapies for various forms of progressive kidney disease including diabetic kidney disease.Read moreRead less
Cytosolic Oxidative Disturbances As A Source Of Mitochondrial Dysfunction In Diabetic Nephropathy
Funder
National Health and Medical Research Council
Funding Amount
$505,786.00
Summary
There is a critical need to identify new therapies for the growing number of patients with diabetic kidney disease. Current medicines only retard progressive disease. Our studies investigate defects in the power houses of the cell, the mitochondria. These defects cause generation of toxic free oxygen radicals which eventually starve the cell of energy production. Therefore, reversal of mitochondrial defects in diabetic kidney disease may be a novel therapeutic target.
The Role Of Angiotensin Converting Enzyme 2 In Diabetic Complications
Funder
National Health and Medical Research Council
Funding Amount
$453,144.00
Summary
Most heart attacks and strokes arise from narrowing of the arteries. This process is regulated by a number of hormonal pathways. One of the most important is the renin angiotensin system. Our group has demonstrated important changes in this pathway which play a pivotal role in regulating the development of atherosclerosis and its response to treatment. It is predicted that these studies will provide critical information to develop innovative treatment strategies for cardiovascular disease.
Growth Factors And Their Effect On MicroRNAs And Transcription Factors In Tubulointerstitial Fibrosis In Diabetes
Funder
National Health and Medical Research Council
Funding Amount
$490,202.00
Summary
A common cause of kidney disease is diabetes and is partly related to increased expression and action of growth factors such as CTGF. These factors promote the deposition of scar tissue in the kidney by acting on a novel class of intracellular regulator molecules called microRNAs, to change the cell's characteristics such that cells begin laying down excess collagen. This proposal will focus on how growth factors act on microRNAs and the role of microRNAs in diabetic kidney disease.
Circulating Low -molecular Weight AGEs In The Development And Progression Of Diabetic Complications
Funder
National Health and Medical Research Council
Funding Amount
$297,523.00
Summary
High levels of sugars seen in patients with diabetes leads to damage of many organs including the heart, the eyes and the kidneys. These high sugars cause damage through a number of mechanisms, one being the formation of advanced glycation end products or AGEs, formed by the irreversible reaction between proteins and glucose. This reaction leads to a change in the shape and function of AGE-modified molecules that progressively contributes to organ damage. AGEs also bind and activate specific rec ....High levels of sugars seen in patients with diabetes leads to damage of many organs including the heart, the eyes and the kidneys. These high sugars cause damage through a number of mechanisms, one being the formation of advanced glycation end products or AGEs, formed by the irreversible reaction between proteins and glucose. This reaction leads to a change in the shape and function of AGE-modified molecules that progressively contributes to organ damage. AGEs also bind and activate specific receptors that promote the damage and scarring of tissue. Where the glucose concentration is high, AGEs accumulate much more quickly. This is one reason why patients with good sugar control do better than those who are unable to control their blood sugars. The importance of this AGE pathway is illustrated by the fact that blocking the formation of AGEs is able to prevent kidney damage in animals with diabetes. In addition, exposure to AGEs can cause diabetes-like changes in the absence of high sugars. Our laboratory is a world leader in the study of the advanced glycation and methods blocking this process. The research proposed will investigate circulating levels of AGEs in experimental animals and patients with diabetes, and correlate them with the development and progression of complications of diabetesRead moreRead less
Normoalbuminuric And Albuminuric Pathways To Renal Insufficiency In Type 2 Diabetes
Funder
National Health and Medical Research Council
Funding Amount
$288,900.00
Summary
Up to one third of patients with type 2 diabetes develop kidney disease (diabetic nephropathy). An increase in protein excretion in the urine (albuminuria) is usually the first sign of kidney disease. Albuminuria usually progresses from normal levels to an intermediate phase (microalbuminuria) lasting 5-10 years and is then followed by overt nephropathy (macroalbuminuria). It has been traditionally believed that onset of a decline in kidney function, measured as glomerular filtration rate, accom ....Up to one third of patients with type 2 diabetes develop kidney disease (diabetic nephropathy). An increase in protein excretion in the urine (albuminuria) is usually the first sign of kidney disease. Albuminuria usually progresses from normal levels to an intermediate phase (microalbuminuria) lasting 5-10 years and is then followed by overt nephropathy (macroalbuminuria). It has been traditionally believed that onset of a decline in kidney function, measured as glomerular filtration rate, accompanies the development of diabetic kidney disease. However, recent studies by our group have shown that about one quarter of patients with type 2 diabetes have impaired kidney function without an increase in albuminuria. This raises the possibility that an alternate non-albuminuric pathway leads to kidney disease in a subgroup of patients with type 2 diabetes. This study will compare kidney structure and function in patients with type 2 diabetes and impaired kidney function with or without increases in albuminuria. The comparison will be accompanied by measurements of the rate of decline in kidney function over 5 years or more, in subjects with or without increases in albuminuria in order to confirm that kidney function may decline independently of albuminuria. The demonstration of alternate mechanisms of renal injury has the potential to identify new targets for the treatment of kidney disease in patients with type 2 diabetes.Read moreRead less