Reducing CVD Risk In The Metabolic Syndrome And Type 2 Diabetes: Novel Approaches To Studies Of Lipoprotein Metabolism
Funder
National Health and Medical Research Council
Funding Amount
$548,669.00
Summary
The incidence of obesity and diabetes is increasing in Australia. With these two conditions comes an increase in cardiovascular disease risk. Elevated blood lipids are an important component of this increased. Weight loss and cholesterol lowering drugs are first line therapies for obesity and diabetes, respectively. Niacin is effective at lowering lipids and raising HDL cholesterol, but the mechanisms responsible for these changes have not been determined.
Factors Controlling Lipid Accumulation In Non-adipose Tissues
Funder
National Health and Medical Research Council
Funding Amount
$463,500.00
Summary
The fat cells of the body are designed to store excess fuel for use when supply from the diet is low, or in situations like exercise, demand is high. Fat also accumulates to some extent in the cells of other tissues types, but in some people the accumulation is excessive. This can have a number of serious effects. In the liver and muscle it can interfere with the ability of insulin to properly regulate the amount of glucose present in the blood, contributing to the development of diabetes. In th ....The fat cells of the body are designed to store excess fuel for use when supply from the diet is low, or in situations like exercise, demand is high. Fat also accumulates to some extent in the cells of other tissues types, but in some people the accumulation is excessive. This can have a number of serious effects. In the liver and muscle it can interfere with the ability of insulin to properly regulate the amount of glucose present in the blood, contributing to the development of diabetes. In the liver, fat accumulation can also lead to cirrhosis and liver failure. Cardiovascular complications, resulting in premature death, are also likely. However despite these devastating consequences it is not clear what the underlying cause of the over-accumulation of fat is not known. In this project we will investigate in detail several aspects of fat metabolism that we think are important in controlling how tissues take up fat from the circulation and whether it is subsequently stored or burnt for energy. We will study the amount of fat that is taken up by different tissues of the body under a range of conditions including fed, and short- and long-term fasting. We will also use drugs to inhibit or promote the amount of fat that is burnt, to see if this changes the rate at which fat is taken up by different tissues. In addition we will accelerate, by genetic manipulation, the rate at which some key enzymes of fat metabolism are produced, to determine their effect on the amount of fat that is stored by different tissue types. Our aim is to determine the metabolic processes that influence fat accumulation in those adversely affected tissues such as liver, heart and skeletal muscle. The identification of the most important processes will contribute significantly to the targeting of therapies aimed at preventing excess fat accumulation and its associated diseases.Read moreRead less
How Important Is Collagen Destruction In Arthritis? A Study With Collagenase-resistant Knockin Mice
Funder
National Health and Medical Research Council
Funding Amount
$529,723.00
Summary
Aggecan and collagen are important structural molecules in cartilage. Together they allow cartilage to bear weight and resist compression. In arthritis, collagen is degraded by collagenases and aggrecan is degraded by aggrecanases. Aggrecan loss is a feature of cartilage disease. Early aggrecan loss is well documented and usually precedes clinical symptoms, suggesting that it is the initiating step in cartilage pathology. Aggrecan loss precedes collagen damage in explant culture, however it is n ....Aggecan and collagen are important structural molecules in cartilage. Together they allow cartilage to bear weight and resist compression. In arthritis, collagen is degraded by collagenases and aggrecan is degraded by aggrecanases. Aggrecan loss is a feature of cartilage disease. Early aggrecan loss is well documented and usually precedes clinical symptoms, suggesting that it is the initiating step in cartilage pathology. Aggrecan loss precedes collagen damage in explant culture, however it is not known whether inhibiting aggrecanases is sufficient to block cartilage damage long-term. In contrast, other studies suggest that aggrecan is only lost after damage to the collagen scaffold. These studies propose that clipping of the collagen scaffold may initiate aggrecan release; with progressive degeneration and collagen clipping, more aggrecan is lost, until ultimately the scaffold is severely damaged and aggrecan is severely depleted. Cartilage can only withstand a limited degree of collagen degradation and any significant damage to the network is widely considered to be irreparable. It is unclear what role aggrecanases and collagenases have in initiating and perpetuating cartilage damage. We have mice with aggrecan resistant to aggrecanases and mice with inactive aggrecanase. We will also create mice with collagen resistant to collagenase. We will use these mice to determine the contribution of collagenases and aggrecanases to the initiation and progression of cartilage damage, in three models of joint disease. We will identify differences in time of disease onset, rate of disease progression and disease severity. The results will show whether one or both activities is important for the initiation and progression of joint disease. This will reveal whether single or combination therapies are required for the management of arthritis. The research will inform the pharmaceutical industry on directions for the development of new drugs to prevent joint disease.Read moreRead less