Do Synaptic-like Mechanisms Control Insulin Secretion?
Funder
National Health and Medical Research Council
Funding Amount
$593,235.00
Summary
An estimated 415 million people world-wide were diagnosed with diabetes in 2015. One of the causal factors in disease is the dysregulation of insulin secretion. We have developed new techniques to study insulin secretion that has led us to propose a new model for secretory control. This proposal sets out experiments to critically test this model. The outcomes could have wide-reaching impact on understanding and for future treatment and prevention of the diabetes.
How Does Paternal Obesity Influence Offspring Glucose Tolerance?
Funder
National Health and Medical Research Council
Funding Amount
$503,398.00
Summary
Obesity and diabetes are closely related to these conditions in either parent, but how the father contributes is unclear. We have shown that normal females mated with obese fathers consuming high fat diet, produce offspring who develop glucose intolerance and impaired insulin secretion. This work will examine the mechanisms underlying this effect in the rat, testing a novel role for environmental factors in the father on disease in offspring that may be relevant to the growing obesity epidemic.
The Structure And Function Of The Apical Domain In Insulin Secreting Beta Cells.
Funder
National Health and Medical Research Council
Funding Amount
$571,741.00
Summary
Loss of control of insulin secretion is causal in diabetes and therefore its understanding is a key goal to shed light on the disease. We have recently identified a new domain in the insulin secreting cells, called the apical domain. This proposal will define the role of this apical domain in controlling insulin secretion. The outcomes could provide new insights into how diabetes develops and new targets for therapies.
The Preferential Release Of Young Insulin Secretory Granules.
Funder
National Health and Medical Research Council
Funding Amount
$670,005.00
Summary
The aim of this study is to investigate the cause of reduced glucose induced insulin secretion in type 2 diabetes. In pancreatic beta-cells, insulin is packaged and stored in secretory granules (SGs). Upon stimulation, these SGs deliver insulin to the bloodstream. It is known that insulin SGs exist in two functionally distinct pools; and one pool is preferentially secreted upon stimulation. How a cell can differentiate the two SG pools is unclear, and we will address this issue in this project.
Examining The Metabolic And Cognitive Deficits Caused By Insulin Resistance In The Ventral Striatum
Funder
National Health and Medical Research Council
Funding Amount
$400,372.00
Summary
Brain insulin resistance is thought to cause metabolic and cognitive deficits, but the underlying neural mechanisms remain elusive. This project addresses this gap in our knowledge by examining how brain insulin resistance disrupts the metabolic regulation of food intake and the cognitive control of actions. The outcomes will provide new insights in disorders characterised by brain insulin resistance such as obesity and dementia.
Mechanism Of Action Of Sec1p-like Proteins In Membrane Trafficking
Funder
National Health and Medical Research Council
Funding Amount
$234,936.00
Summary
One of the most important evolutionary changes that has occurred is the development of intracellular compartments. All eukaryotic cells possess numerous membrane-encased structures which provide the basis for intracellular specialisation. For example, in order to degrade unwanted components cells have developed degradative enzymes. It is vital for the cell that these enzymes are sequestered away from other cellular components to avoid destruction of valuable molecules. In addition, the cell has ....One of the most important evolutionary changes that has occurred is the development of intracellular compartments. All eukaryotic cells possess numerous membrane-encased structures which provide the basis for intracellular specialisation. For example, in order to degrade unwanted components cells have developed degradative enzymes. It is vital for the cell that these enzymes are sequestered away from other cellular components to avoid destruction of valuable molecules. In addition, the cell has developed a complex assembly line of modifications that are added to proteins in a specific order as they travel to their final destination within the cell. This necessitates the accurate passage of molecules between compartments, a process known as vesicle transport. To orchestrate the complex network of vesicular transport steps between all of the various intracellular compartments it is necessary to employ complex machinery to guide and check that these steps occur with high fidelity. The goal of our research proposal is to define the function of one of the molecules involved in this control process, the so-called Sec1p proteins. The strength of our proposal lies in the diversity of our approach. We intend to explore the molecular advantages of a relatively simple eukaryotic organism, a yeast cell, and apply the findings obtained from this cell to a more complex but highly related vesicular transport process; that of the insulin-regulated movement of a glucose transporter in mammalian fat and muscle cells. While we intend to apply our findings to the treatment of patients with diabetes, it is our ultimate goal to be able to learn more about this fundamental cell biological process so that we can apply our knowledge to understanding many different disease states.Read moreRead less
Understanding Sphingolipid Mediators Of Insulin Resistance
Funder
National Health and Medical Research Council
Funding Amount
$643,447.00
Summary
Sphingolipids are a class of lipid metabolites that have a variety of functions within cells. It has been known for some time that an accumulation of excess lipid, including certain sphingolipids, can adversely impact insulin action and glucose metabolism in cells. In this project we will a combination of strategies to test the hypothesis that the sphingolipid profile can be manipulated to have favourable effects on metabolism.
Regulation Of Secretion Of The Fungal Virulence Determinant, Phospholipase B
Funder
National Health and Medical Research Council
Funding Amount
$487,500.00
Summary
Serious systemic infections due to fungi have increased dramatically in the past few years, especially in people with poorly functioning immune systems. Treatment of these conditions is problematic because the few drugs which are available are not highly effective, and-or cause significant side-effects. Little is understood of how fungi cause disease, and this problem must be addressed if these infections are to be contained. We have discovered that the enzyme, phospholipase B (PLB), is secreted ....Serious systemic infections due to fungi have increased dramatically in the past few years, especially in people with poorly functioning immune systems. Treatment of these conditions is problematic because the few drugs which are available are not highly effective, and-or cause significant side-effects. Little is understood of how fungi cause disease, and this problem must be addressed if these infections are to be contained. We have discovered that the enzyme, phospholipase B (PLB), is secreted by the disease-causing fungus, Cryptococcus neoformans, and that it is important in enabling the fungus to invade the host's cells and spread around the body from the lungs to the brain, where it can cause meningoencephalitis. PLB is also produced by other disease-causing fungi. The mechanism of PLB secretion is completely unknown. In this project we aim to determine the pathways involved in PLB secretion with the intention of exploiting steps unique to pathogenic fungi, for the future design of new anti-fungal drugs.Read moreRead less
Do The Mitochondrial Sirtuin Enzymes, SIRT3 And SIRT5, Affect Insulin Action In Skeletal Muscle?
Funder
National Health and Medical Research Council
Funding Amount
$92,314.00
Summary
Metabolic disorders such as obesity, insulin resistance and type 2 diabetes are characterised by inappropriate handling of nutrients. Mitochondria are the primary site for nutrient oxidation in cells. Sirtuins such as SIRT3 and SIRT5 are abundant in mitochondria and may affect mitochondrial function and insulin action in skeletal muscle. Understanding the biochemical pathways involved in energy metabolism in skeletal muscle is crucial in the development of therapies for insulin resistance and ty ....Metabolic disorders such as obesity, insulin resistance and type 2 diabetes are characterised by inappropriate handling of nutrients. Mitochondria are the primary site for nutrient oxidation in cells. Sirtuins such as SIRT3 and SIRT5 are abundant in mitochondria and may affect mitochondrial function and insulin action in skeletal muscle. Understanding the biochemical pathways involved in energy metabolism in skeletal muscle is crucial in the development of therapies for insulin resistance and type 2 diabetes.Read moreRead less
De Novo Mutations And The Pathogenesis Of Childhood-onset Autoimmune Disease
Funder
National Health and Medical Research Council
Funding Amount
$1,406,510.00
Summary
This project aims to reveal the gene abnormalities that cause devastating autoimmune diseases to develop in some children, such as Type 1 diabetes, juvenile arthritis and autoimmune destruction of blood cells. The project will use new technologies to identify alterations in the DNA sequence of a child compared to either of their parents, and to test suspicious DNA alterations in laboratory mice in order to understand the gene effects and evaluate new treatments.