Regulatory mechanisms in skeletal muscle lipid hydrolysis. The regulation of intramuscular triglyceride (fat) utilisation by human skeletal muscle is largely unknown. Our contention is that the specialized protein enzyme, hormone sensitive lipase (HSL), has a fundamental role in intramuscular triacylglycerol utilisation and is regulated by both intramuscular levels of key metabolites and circulating hormone concentrations. We also propose control points subsequent to HSL activation are important ....Regulatory mechanisms in skeletal muscle lipid hydrolysis. The regulation of intramuscular triglyceride (fat) utilisation by human skeletal muscle is largely unknown. Our contention is that the specialized protein enzyme, hormone sensitive lipase (HSL), has a fundamental role in intramuscular triacylglycerol utilisation and is regulated by both intramuscular levels of key metabolites and circulating hormone concentrations. We also propose control points subsequent to HSL activation are important for triglyceride hydrolysis. Our proposed project examines these factors and will enhance our understanding of the regulation of muscle fat use, thereby leading to potential metabolic strategies (nutritional, pharmacological) that enhance skeletal muscle function at rest and during exercise.Read moreRead less
The role of intracellular calcium in fibre-type specific gene expression in skeletal muscle. Muscles contain different fibre types whose composition can be changed by activity. The aim of this proposal is to identify the intracellular mechanisms which control fibre type. Our hypothesis is that different patterns of intracellular calcium determine the pattern of gene expression which determines fibre type. Understanding how gene expression is regulated is a central issue in biology.
Biological Role of Contraction-Induced Heat Shock Protein Expression. It is well known that mammalian skeletal muscle increases its expression of a group of highly conserved proteins, the heat shock proteins (HSP) in response to repeated contraction. However, the biological role of this expression is unclear. The aim of this project is to determine the biological role of contraction-induced HSP expression. We expect to show that HSP synthesis in response to exercise has three major roles; 1) to ....Biological Role of Contraction-Induced Heat Shock Protein Expression. It is well known that mammalian skeletal muscle increases its expression of a group of highly conserved proteins, the heat shock proteins (HSP) in response to repeated contraction. However, the biological role of this expression is unclear. The aim of this project is to determine the biological role of contraction-induced HSP expression. We expect to show that HSP synthesis in response to exercise has three major roles; 1) to act to repair damaged proteins in recovery from muscle injury 2) to act as a "molecular motor" to translocate proteins from one region of a muscle cell to another and 3) to be released into the circulation in order to act as a central signal to activate immune cells. Such a project will be significant because it will allow for a fundamental understanding as to why these proteins are produced in response to exercise. We expect to enhance our understanding of fundamental cell biology.Read moreRead less
Reducing the fat burden: Identification of novel cellular and molecular targets for alleviating skeletal muscle insulin resistance. Insulin resistance and the associated consequences are a major public health problem in Australia and cost the healthcare system >$1.1 billion/year. Exercise training and thiaziolidinedione (TZD) treatment are therapies that partially ameliorate insulin resistance through distinct and independent mechanisms. However, neither intervention represents a viable long-ter ....Reducing the fat burden: Identification of novel cellular and molecular targets for alleviating skeletal muscle insulin resistance. Insulin resistance and the associated consequences are a major public health problem in Australia and cost the healthcare system >$1.1 billion/year. Exercise training and thiaziolidinedione (TZD) treatment are therapies that partially ameliorate insulin resistance through distinct and independent mechanisms. However, neither intervention represents a viable long-term strategy: exercise training has low compliance, while chronic TZD use is associated with several adverse side effects (edema, weight gain etc.). We will investigate the metabolic, cellular and molecular mechanisms by which these therapies each exert their positive effect on insulin action with the aim of identifying novel targets for future drug interventions. Read moreRead less
Intracellular localisation of insulin signalling proteins in human skeletal muscle following exercise. The metabolic action of insulin in skeletal muscle is enhanced by exercise, but the underlying mechanisms mediating this are unknown. Insulin receptor substrate proteins are key mediators in the intracellular insulin signalling pathway and play a central role in regulating many metabolic events. Our aim is to examine the hypothesis that exercise induces a novel subcellular redistribution of the ....Intracellular localisation of insulin signalling proteins in human skeletal muscle following exercise. The metabolic action of insulin in skeletal muscle is enhanced by exercise, but the underlying mechanisms mediating this are unknown. Insulin receptor substrate proteins are key mediators in the intracellular insulin signalling pathway and play a central role in regulating many metabolic events. Our aim is to examine the hypothesis that exercise induces a novel subcellular redistribution of these insulin receptor substrate proteins in skeletal muscle, such that the metabolic action of insulin is enhanced. Elucidating the mechanisms whereby exercise enhances insulin action underpins the development of new treatments and therapies with the aim of improving skeletal muscle function in health and disease.Read moreRead less
Impact of shear stress on vascular adaptations in humans. Large arteries are important for the delivery of blood and oxygen to organs such as the heart and brain. A primary physiological stimulus which controls the size and function of these crucial arteries is the magnitude of flow or, more accurately, shear force that the inner wall of the artery is exposed to. We have developed novel software which enables non-invasive assessment of arterial wall velocity, diameter and blood flow. We will ass ....Impact of shear stress on vascular adaptations in humans. Large arteries are important for the delivery of blood and oxygen to organs such as the heart and brain. A primary physiological stimulus which controls the size and function of these crucial arteries is the magnitude of flow or, more accurately, shear force that the inner wall of the artery is exposed to. We have developed novel software which enables non-invasive assessment of arterial wall velocity, diameter and blood flow. We will assess the impact of acute and chronic changes in wall flow and shear on arterial size and function. We will also develop new software which measures other aspects of artery wall behaviour. These basic human physiology studies have direct implications for assessment of artery health in humans.Read moreRead less
Single minded 1 in neuron development and satiety signalling. An understanding of how Single minded 1 (SIM1) regulates target genes may allow new pharmaceutical approaches to be designed to combat obesity. As Sim1 belongs to a family of closely related gene regulatory proteins which function in early development and homeostasis, deciphering the molecular control mechanisms of Sim1 may help understand how the related factors function in processes such as angiogenesis, response to low oxygen stres ....Single minded 1 in neuron development and satiety signalling. An understanding of how Single minded 1 (SIM1) regulates target genes may allow new pharmaceutical approaches to be designed to combat obesity. As Sim1 belongs to a family of closely related gene regulatory proteins which function in early development and homeostasis, deciphering the molecular control mechanisms of Sim1 may help understand how the related factors function in processes such as angiogenesis, response to low oxygen stress, invasion of environmental pollutants and autism spectrum diseases. The ability to manipulate these factors would be of great benefit in treating a range of disorders, but a thorough molecular understanding of these factors needs be obtained prior to attempting design of pharmaceuticals.Read moreRead less
Studies on the stereospecific interaction between aldose reductase and inhibitor. There is no therapy specific for treatment of diabetes complications accepted worldwide. The enzyme aldose reductase has shown promising results as a drug target for preventing or delaying the onset of the complications. The structures of human aldose reductase holoenzyme in complex with stereoisomers of the potent inhibitor Fidarestat will be determined at high resolution in order to elucidate the binding modes re ....Studies on the stereospecific interaction between aldose reductase and inhibitor. There is no therapy specific for treatment of diabetes complications accepted worldwide. The enzyme aldose reductase has shown promising results as a drug target for preventing or delaying the onset of the complications. The structures of human aldose reductase holoenzyme in complex with stereoisomers of the potent inhibitor Fidarestat will be determined at high resolution in order to elucidate the binding modes responsible for the differences in their inhibitory potencies. The results may lead to the design of better inhibitors of the enzyme for the treatment of diabetes sufferers, at least until better methods for maintaining metabolic control are developed.Read moreRead less
Structure-based discovery of dipeptidyl peptidase IV inhibitors. Diabetes afflicts approximately 151 million people worldwide, with an estimated increase to 221 million by 2010. To date, no therapy for the treatment of diabetes complications is widely accepted. The enzyme dipeptidyl peptidase IV has shown promising results as a target for the treatment of type 2 diabetes. Structural studies of dipeptidyl peptidase IV in complex with inhibitor will be conducted to elucidate the details of the e ....Structure-based discovery of dipeptidyl peptidase IV inhibitors. Diabetes afflicts approximately 151 million people worldwide, with an estimated increase to 221 million by 2010. To date, no therapy for the treatment of diabetes complications is widely accepted. The enzyme dipeptidyl peptidase IV has shown promising results as a target for the treatment of type 2 diabetes. Structural studies of dipeptidyl peptidase IV in complex with inhibitor will be conducted to elucidate the details of the enzyme-inhibitor interaction. The results will be used to identify the molecular basis of potency and selectivity of dipeptidyl peptidase IV inhibitors and may lead to the discovery of pharmaceutical agents for the treatment of diabetes sufferers.Read moreRead less
Crystallographic studies of aldose and aldehyde reductases. The ability of aldose reductase to reduce the excess glucose that results from the hyperglycaemia of diabetes has been linked to the development of diabetic complications. Recent studies link the lack of a clinically suitable aldose reductase inhibitor to lack of inhibitor selectivity. The structures of the complexes of aldose and aldehyde reductases with various inhibitors should allow us to establish the important aspects of the inh ....Crystallographic studies of aldose and aldehyde reductases. The ability of aldose reductase to reduce the excess glucose that results from the hyperglycaemia of diabetes has been linked to the development of diabetic complications. Recent studies link the lack of a clinically suitable aldose reductase inhibitor to lack of inhibitor selectivity. The structures of the complexes of aldose and aldehyde reductases with various inhibitors should allow us to establish the important aspects of the inhibitor interaction with the residues of the active site. This information will be used in the design of more specific aldose reductase inhibitors.Read moreRead less