Hepatic Oxidative Stress, PTPs & STAT Signalling In Obesity
Funder
National Health and Medical Research Council
Funding Amount
$1,086,547.00
Summary
Obesity is increasing at an alarming rate worldwide and is a leading cause of morbidity and mortality. Obesity is causally linked to the development of insulin resistance, a prelude to type 2 diabetes. In this proposal we will define a novel liver centric mechanism by which insulin resistance and oxidative stress may promote the development of morbid obesity, type 2 diabetes and liver disease.
Regulation Of Hypothalamic Insulin & Leptin Signalling By TCPTP
Funder
National Health and Medical Research Council
Funding Amount
$758,504.00
Summary
Insulin & leptin signal in the brain to lower blood glucose, suppress food intake, increase activity & increase energy expenditure. Obesity diminishes the abilities of insulin & leptin to signal. This proposal will determine if the enzyme TCPTP terminates insulin & leptin signaling in the brain. Our studies will provide insight into the molecular causes of obesity & may identify a novel therapeutic target for the treatment of obesity & type 2 diabetes.
Regulation Of Insulin Sensitivity By Reactive Oxygen Species
Funder
National Health and Medical Research Council
Funding Amount
$564,644.00
Summary
In morbid obesity and type 2 diabetes chronic levels of reactive oxygen species (ROS) are detrimental and diminish insulin's ability to maintain normal blood glucose levels. Paradoxically, ROS also promote insulin action by inhibiting enzymes known as protein tyrosine phosphatases (PTPs). This proposal will determine whether the promotion of ROS for the inhibition of PTPs early in the progression of type 2 diabetes may be of therapeutic benefit.
Regulation Of Insulin Signalling & Glucose Homeostasis By Protein Tyrosine Phosphatases
Funder
National Health and Medical Research Council
Funding Amount
$503,776.00
Summary
Type 2 diabetes has reached epidemic proportions afflicting roughly 6% of the adult population in Western society. Although the underlying genetic causes and the associated pathological symptoms are heterogenous, a common feature is high blood glucose due to peripheral insulin resistance. The molecular basis of insulin resistance is believed to be attributable to defects in insulin receptor (IR) signalling. The IR is a protein tyrosine kinase that phosphorylates itself and downstream substrates ....Type 2 diabetes has reached epidemic proportions afflicting roughly 6% of the adult population in Western society. Although the underlying genetic causes and the associated pathological symptoms are heterogenous, a common feature is high blood glucose due to peripheral insulin resistance. The molecular basis of insulin resistance is believed to be attributable to defects in insulin receptor (IR) signalling. The IR is a protein tyrosine kinase that phosphorylates itself and downstream substrates on tyrosine in response to insulin. Protein tyrosine phosphatases (PTPs) that dephosphorylate the IR and its substrates might be important targets for therapeutic intervention in type 2 diabetes; inhibition of specific PTPs may allow for enhanced insulin-induced signalling to alleviate insulin resistance. This proposal will examine the roles of PTPs and in particular TCPTP in IR signalling in vivo. Our studies will shed light on the molecular mechanisms of IR regulation and function and may provide important insights into novel strategies for enhancing insulin sensitivity in type 2 diabetes.Read moreRead less
Factors Regulating The Temporal And Spatial Assembly Of G-protein Coupled Receptor-mediated Arrestin Complexes
Funder
National Health and Medical Research Council
Funding Amount
$472,770.00
Summary
G-protein coupled receptors are proteins that are present at the surface of most cells in the human body. They recognise and bind to specific molecules, such as hormones, the act of which results in a specific signal being transmitted into the cell. This signal alters the function of the cell and so it is critical that it is appropriate, both in type and duration. G-protein coupled receptors and the molecules that activate them provide an essential function within the human body for communicatin ....G-protein coupled receptors are proteins that are present at the surface of most cells in the human body. They recognise and bind to specific molecules, such as hormones, the act of which results in a specific signal being transmitted into the cell. This signal alters the function of the cell and so it is critical that it is appropriate, both in type and duration. G-protein coupled receptors and the molecules that activate them provide an essential function within the human body for communicating between cells, and consequently between organs. They are a major mechanism by which nerve signals are transmitted and hormones regulate bodily functions. They are therefore an important target for pharmaceuticals, with up to 50% of ethical drugs and many drugs of abuse acting upon them. It is critical to understand how these receptors alter cellular function once they receive an appropriate signal, but it is also essential to know how such responses are switched off. Arrestins are proteins within cells that interact with G-protein coupled receptors to 'arrest' their signalling. They desensitise the cell to continuous stimulation, but also act to resensitise the cell to respond to future, separate signals. Recently, they have also been shown to provide alternative mechanisms of altering cellular activity by interacting with other cellular proteins. These interactions greatly increase the potential ways in which a cell can respond once a G-protein coupled receptor is activated. Understanding the resulting complexity is essential if we are to fully exploit the vast therapeutic potential of this important receptor family.Read moreRead less