Functional Effects Of Polymorphic Variation Of The Aromatase (CYP19) Gene On Enzyme Activity:relationship To Disease
Funder
National Health and Medical Research Council
Funding Amount
$237,708.00
Summary
After menopause, oestrogen synthesis changes from an ovarian to an adipose source by concersion of androgens to estrogens, a process catalyzed by aromatase, the product of the CYP19 gene. We will generate mutants of the CYP19 gene that we have previously found in humans by site-directed mutagenesis and observe the effects of these mutants on aromatase function. This research will help with diagnosis and treatment of breast and other cancers and osteoporosis in humans .
An Examination Of The Contribution Of Visceral Adiposity To Insulin Resistance In Humans.
Funder
National Health and Medical Research Council
Funding Amount
$335,800.00
Summary
The worldwide epidemic of Type 2 diabetes is related to major nutritional and activity changes interacting with a genetic predisposition. The two key defects in Type 2 diabetes are a reduced response to insulin (insulin resistance) and relative failure of insulin production. Insulin resistance is the earliest defect and is closely associated with cardiovascular risk. Obesity generates insulin resistance, but intraabdominal (visceral) fat has particular importance. Visceral fat cells are differen ....The worldwide epidemic of Type 2 diabetes is related to major nutritional and activity changes interacting with a genetic predisposition. The two key defects in Type 2 diabetes are a reduced response to insulin (insulin resistance) and relative failure of insulin production. Insulin resistance is the earliest defect and is closely associated with cardiovascular risk. Obesity generates insulin resistance, but intraabdominal (visceral) fat has particular importance. Visceral fat cells are different to other fat cells; they are very metabolically active and 'spill out' fatty acids indiscriminately contributing to insulin resistance in liver and muscle; they also produce hormones which may modify the action of insulin. We will study people undergoing abdominal surgery. Participants will be (1) normal weight and sensitive to insulin, (2) abdominally overweight and insulin resistant, (3) insulin resistant with Type 2 diabetes. We will document abdominal fat, circulating lipid and hormone levels and insulin action. At surgery fat biopsies will be obtained from (a) inside the abdominal cavity, (b) the fat layer under the abdominal skin and (c) fat in the buttock. The activity of a large number of genes in the fat tissue will be assessed in 8 subjects using DNA array (4 each from Groups 1 and 2). Then a small number of genes will be selected on the basis of different activity in visceral fat from buttock fat, and between insulin sensitive and insulin resistant people. The activity of these genes will be determined in all subjects in the 3 groups. We anticipate identifying a few (perhaps 3) genes whose activity is closely associated with insulin resistance and will examine their capability to block insulin action in a series of animal and cellular studies. These studies should identify specific mechanisms by which visceral fat creates insulin resistance. This would be an important step towards prevention and improved medication for Type 2 diabetes.Read moreRead less
The Role Of Muscle Fatty Acid Oxidation In Regulating Intramyocellular Lipid Accumulation.
Funder
National Health and Medical Research Council
Funding Amount
$169,695.00
Summary
Obesity and the subsequent accumulation of fat in muscle leads to reduced insulin action and an increased risk of type 2 diabetes. This project will investigate the metabolic processes that influence fat accumulation and oxidation primarily in skeletal muscle, the tissue responsible for most fuel utilization in the body. This information will help design therapeutic strategies to prevent the development of type 2 diabetes.
Therapeutic Regulation Of Hepatic Steatosis And Lipid Transport In The Metabolic Syndrome
Funder
National Health and Medical Research Council
Funding Amount
$522,435.00
Summary
Obesity is an increasing problem in Australia. Elevated fat levels in the liver and blood are associated with obesity and increased risk for heart disease. In this project, we will demostrate new mechanisms of action of Pioglitazone (an insulin-sensitizing agent) and Omacor (fish oils) that will complement the favourable efect of weight loss in the treatment of elevated blood fats and reduction in risk of heart disease in an important groups of subject in the population.
Functional Role Of A Novel Coregulator In Metabolism
Funder
National Health and Medical Research Council
Funding Amount
$563,146.00
Summary
Australia is facing a massive epidemic of diabetes and obesity (diabesity). These disorders afflict all age groups, including teenagers, and are a major burden to the health and wealth of Australia. The nuclear receptors and their coregulators are excellent targets for developing new therapeutics to combat these disorders. This grant will evaluate the functional role of SLIRP, a novel nuclear receptor coregulator, in metabolism and could provide new avenues for drug target development.
Comparison Between AICAR And Exercise-induced Stimulation Of Skeletal Muscle AMP-K On Fat/glucose Metabolism In Diabetes
Funder
National Health and Medical Research Council
Funding Amount
$347,036.00
Summary
Background and Rationale: Exercise is important in the life of the diabetic. In well controlled diabetes, the rates of whole body sugar usage and energy production in skeletal muscle (SkM) in response to acute exercise are similar to non-diabetics. However in diabetics, little information is available as to how SkM processes sugar and produces energy during exercise. Insulin controls SkM sugar and energy processing in sedentary subjects. During exercise, these processes are controlled by non-ins ....Background and Rationale: Exercise is important in the life of the diabetic. In well controlled diabetes, the rates of whole body sugar usage and energy production in skeletal muscle (SkM) in response to acute exercise are similar to non-diabetics. However in diabetics, little information is available as to how SkM processes sugar and produces energy during exercise. Insulin controls SkM sugar and energy processing in sedentary subjects. During exercise, these processes are controlled by non-insulin factors. The chemical catalyst AMP activated protein kinase (AMP-K), which has been investigated only in normal exercising rats, is an important alternative regulator of acute sugar processing and energy supply for exercising SkM. No studies of AMP-K activity are available in diabetes. Our studies will focus on i) how important is the stimulation of SkM AMP-K in diabetes to efficient SkM sugar processing and energy production; ii) if the benefits of exercise can be simulated by pharmacological stimulation of AMP-K in sedentary diabetic subjects. We aim to i) compare the metabolic effects of exercise vs pharmacological stimulation of AMP-K in normal and diabetic subjects; ii) define the molecular mechanisms which trigger the AMP-K metabolic responses; iii) determine if the circulating levels of insulin, blood sugar and-or blood fat influence the AMP-K metabolic responses. Likely Outcomes: pharmacological stimulation of AMP-K will improve SkM sugar metabolism, but less so in diabetes. The associated AMP-K stimulation of SkM fat metabolism may blunt the beneficial SkM sugar responses, particularly in diabetes. This information will be used in future drug developments for diabetics which aim to simulate the beneficial AMP-K metabolic effects of exercise.Read moreRead less
Leptin And The Regulation Of Substrate Partitioning
Funder
National Health and Medical Research Council
Funding Amount
$349,876.00
Summary
The prevalence of obesity is increasing with currently 18% of adult Australians being classified as obese. Obesity, particularly abdominal obesity, is associated with high blood lipid levels and blood pressure, and type 2 diabetes. In Australia, the cost of obesity is estimated to be $830 million per year. The ultimate aim of any obesity treatment programme is to reduce body fatness by burning off fat and to prevent further fat storage and so studies which focus on developing strategies to achie ....The prevalence of obesity is increasing with currently 18% of adult Australians being classified as obese. Obesity, particularly abdominal obesity, is associated with high blood lipid levels and blood pressure, and type 2 diabetes. In Australia, the cost of obesity is estimated to be $830 million per year. The ultimate aim of any obesity treatment programme is to reduce body fatness by burning off fat and to prevent further fat storage and so studies which focus on developing strategies to achieve these goals are very important. We have found that subjects who fail to keep weight off after being on a weight-reducing diet are bad fat burners. These people also have low levels of leptin, a hormone made by fat cells which helps to regulate food intake. The first aim of this study is to show that leptin increases the burning of fat by regulating the production and activity of factors which decide whether fat is used for energy or is stored in the body. The second aim is to find ways in which leptin levels can be changed so that fat burning is increased. Some of the ways in which we will change leptin levels are by changing the fat content of the diet, or by drugs, or by giving leptin itself. These studies will be performed in animal models of obesity and will help us to develop strategies for the treatment and prevention of obesity in humans.Read moreRead less