Investigating The Physiological And Clinical Differences In Weight Loss In Obese Subjects With And Without Diabetes.
Funder
National Health and Medical Research Council
Funding Amount
$101,726.00
Summary
Obesity and type 2 diabetes are linked by the production of inflammatory factors in the body. These factors seem to link weight gain, especially around the abdomen, not only with insulin resistance, the precursor to diabetes, but also independently with the development with heart and kidney disease and reduced fertility. This study will investigate the effect of dieting and weight loss on inflammation and the function of the heart and other organs in obese people with and without diabetes.
Protein Tyrosine Phosphatases In The Regulation Of Insulin Receptor Signalling And Glucose Uptake
Funder
National Health and Medical Research Council
Funding Amount
$425,250.00
Summary
The key pathological feature of type II diabetes is the lack of cellular response to normal levels of circulating insulin. Insulin binding to its cell surface transmembrane receptor initiates a cascade of events known as cellular signalling that results in amongst other things in the uptake of glucose. Protein tyrosine phosphatases (PTPs) are key negative regulators of insulin-induced signalling events and their inhibition with broad based chemical inhibitors can mimic several actions of insulin ....The key pathological feature of type II diabetes is the lack of cellular response to normal levels of circulating insulin. Insulin binding to its cell surface transmembrane receptor initiates a cascade of events known as cellular signalling that results in amongst other things in the uptake of glucose. Protein tyrosine phosphatases (PTPs) are key negative regulators of insulin-induced signalling events and their inhibition with broad based chemical inhibitors can mimic several actions of insulin and lower blood glucose levels in both normal and diabetic rats. This proposal will examine the roles of PTPs and in particular TCPTP and PTP1B in insulin receptor-mediated signalling and glucose uptake. Moreover we will explore the role of TCPTP in alternate insulin receptor-independent processes for glucose uptake. Our studies will shed light on processes important for the regulation of glucose uptake. Moreover our studies may lead to the development of drugs capable of inhibiting PTPs such as TCPTP, that may allow for enhanced glucose uptake and have therapeutic use in the treatment of type II diabetes.Read moreRead less
Interactions Between Advanced Glycation And Oxidative Stress In Diabetic Renal And Cardiac Complications
Funder
National Health and Medical Research Council
Funding Amount
$431,700.00
Summary
Kidney and heart disease are serious complications of diabetes. These complications are the major cause of disability and premature death in the western world. Studies from our group and others have shown that diabetic complications appear to be a consequence of a number of different processes. These pathways include a sugar dependent pathway of irreversible interactions between proteins such as collagen and sugar known as advanced glycation. The process of advanced glycation alters the body's a ....Kidney and heart disease are serious complications of diabetes. These complications are the major cause of disability and premature death in the western world. Studies from our group and others have shown that diabetic complications appear to be a consequence of a number of different processes. These pathways include a sugar dependent pathway of irreversible interactions between proteins such as collagen and sugar known as advanced glycation. The process of advanced glycation alters the body's ability to renew these protein, hence causing accelration of the ageing process. In fact, it is estimated that this process occurs almost fifty times faster in diabetes. These sticky complexes accumulate in tissues causing disruption ot the normal tissue structure. Our group has a drug which can act as scissors and cut the sticky sugar off the proteins allowing it to be turned over. Unfortunately this does not fix all of the damage. These AGE molecules are involved in a number of other harmful processes including the production of toxic oxygen derived molecules which are harmful byproducts of diabetes. While these oxygen 'radicals' have been implicated in heart attack and stroke their source has remained a mystery in diabetes. Previously, the only way to remove these molecules was to mop them up with antioxidants such as Vitamin E. Antioxidants work slowly and so some damage is already done before they 'detoxify' these oxygen radicals. We propose to use combinations of medicines to see if we can achieve more effective protection against these processes in experimental diabetes. This may provide new therapies for threatment of kidney and heart disease in diabetes.Read moreRead less
Mineralocorticoid Receptor Co-regulator Recruitment Determines Ligand Specific Signalling.
Funder
National Health and Medical Research Council
Funding Amount
$491,530.00
Summary
Heart disease is a major cause of death and economic burden in Australia and throughout the world. The steroid hormone aldosterone controls salt and water balance,blood pressure and hasa significant role in heart failure. Although drugs that block the aldosterone receptor significantly help patients with heart failure, their use is limited by side effects. This work will identify the profile of proteins that promote aldosterone effects and enable the development of heart-specific blockers.
Lipid Metabolism In The Aromatase Knock-out Mouse (ArKO)
Funder
National Health and Medical Research Council
Funding Amount
$408,055.00
Summary
Studies of humans with natural mutations in aromatase, the enzyme responsible for oestrogen biosynthesis, have revealed a number of unexpected roles for oestrogens in both males and females. These discoveries even challenge the definitions of oestrogens and androgens as we now know them. We have created a mouse model of oestrogen insufficiency by targetted disruption of the aromatase gene. These mice display a number of age dependent phenotypes including both male and female infertility, undermi ....Studies of humans with natural mutations in aromatase, the enzyme responsible for oestrogen biosynthesis, have revealed a number of unexpected roles for oestrogens in both males and females. These discoveries even challenge the definitions of oestrogens and androgens as we now know them. We have created a mouse model of oestrogen insufficiency by targetted disruption of the aromatase gene. These mice display a number of age dependent phenotypes including both male and female infertility, undermineralisation of the bones, intra-abdominal obesity, hypercholesterolaemia and insulin resistance. We are addressing the mechanisms of all of those phenotypes but in the present application we focus on the abnormalities in lipid metabolism. Thus we will seek to understand the increase in adiposity by examining the role of oestrogen in lipid synthesis, oxidation and breakdown in adipose tissue from intra-abdominal sites. We will also examine the role that oestrogen plays in cholesterol uptake, synthesis and catabolism by the liver as well as fatty acid synthesis and oxidation by the liver. These studies will be correlated with whole body parameters such as feeding behaviour, physical activity, energy expenditure, glucose and fat oxidation rates. We will also examine the effect of feeding a high cholesterol or a high fat diet on lipid metabolism in the oestrogen deficient animals, and we will determine the effect of oestradiol and isoflavone replacement on the phenotype. In this way we aim to reach a better understanding of the multiplicity of roles that oestrogens play in the regulation of lipid and cholesterol metabolism in both males and females. The results of such studies will be the development of better strategies to deal with pathologies resulting from disturbances in cholesterol and lipid metabolism.Read moreRead less