Cytokine Signalling And Insulin Resistance In Obesity.
Funder
National Health and Medical Research Council
Funding Amount
$512,065.00
Summary
Western communities are experiencing an epidemic of obesity that is contributing to diabetes, heart disease, and premature death. This project is investigating why being overweight and obese causes diabetes. Improved understanding about how hormones regulates the body's storage and breakdown of fat and responsiveness to insulin will enable the development of new medicines for the treatment of obesity and the prevention of diabetes.
Macrophages are important cells at the front-line of immunity where one of their main roles is to release anti-bacterial proteins. We will study the macrophage molecules, subcellular organelles and pathways that help to release these proteins to kill bacteria and fight infection. Our studies will identify new cellular targets for boosting immunity and treating inherited diseases with defective macrophage function.
Understanding The Metabolic Consequences Of Impaired AMPKa2 And NNOS� In Skeletal Muscle: Implications For The Metabolic Syndrome
Funder
National Health and Medical Research Council
Funding Amount
$575,527.00
Summary
The inability of muscle to utilise sugar from the blood is a major problem that contributes to obesity and Type 2 diabetes. Since the number of people with these diseases will at least double by 2030, we need to find out what causes this problem. We will examine whether two muscle proteins that are impaired in obesity and Type 2 diabetes are also responsible for impaired sugar utilisation. We think that increasing these muscle proteins will fix the _sugar problem�, and remedy these diseases.
Recycling Endosomes Governing Cell Polarity And Cytokine Secretion.
Funder
National Health and Medical Research Council
Funding Amount
$958,412.00
Summary
Cytokines are chemical messengers released by cells to mount inflammatory responses to fight infections. The timing and direction of cytokine release must be tightly regulated. We investigate the cellular compartments and molecules that control cytokine secretion using sophisticated live cell imaging. Uncontrolled cytokine release is the main cause of ongoing inflammation in arthritis and inflammatory bowel disease and our studies aim to identify cellular targets for new drug development.
Regulating The Secretion Of Inflammatory Cytokines
Funder
National Health and Medical Research Council
Funding Amount
$558,441.00
Summary
Cytokines or chemical messengers released by cells are essential for controlling immune responses but, in excess, they cause Crohn's disease and arthritis. Our research aims to block cytokine release as a novel way to ameliorate disease. We have identified specific cellular proteins, called golgins, that can be targeted to reduce cytokines. Here, characterization of golgin mediated cytokine transport in cells and in a mouse disease model is necessary to translate these findings for human benefit
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
A Novel Lipid Sensitive Kinase And Its Role In Obesity-induced Inflammation And Insulin Resistance.
Funder
National Health and Medical Research Council
Funding Amount
$560,045.00
Summary
It is now apparent that obesity leads to chronic low grade inflammation which results in insulin resistance or pre-diabetes. The mechanisms that link obesity-induced inflammation to insulin resistance are not well understood, but involve lipid oversupply. We have preliminary data identifying that a protein, not known to previously play a role in metabolic diseases, is a critical mediator of lipid-induced inflammation. We will investigate the clinical potential of blocking this protein.
Macrophages are white blood cells that provide front line defence against infection by initiating inflammatory responses by ingesting or phagocytosing microbes and by releasing soluble messengers (cytokines) to recruit other immune cells. These defensive functions require extensive trafficking of proteins within the macrophages. Protein trafficking is orchestrated in part by a family of membrane fusion proteins called SNAREs. By defining the relevant SNAREs, we have recently discovered a much ac ....Macrophages are white blood cells that provide front line defence against infection by initiating inflammatory responses by ingesting or phagocytosing microbes and by releasing soluble messengers (cytokines) to recruit other immune cells. These defensive functions require extensive trafficking of proteins within the macrophages. Protein trafficking is orchestrated in part by a family of membrane fusion proteins called SNAREs. By defining the relevant SNAREs, we have recently discovered a much acclaimed and novel pathway that allows efficient, combined cytokine secretion and phagocytosis in macrophages. Our studies proposed here will now expand on this discovery by comparing the phagocytic process, in terms of SNARE-mediated membrane and cytokine trafficking, for a wide range of microbes, highlighting differences that could provide new avenues for drug development. Moreover, since our strategy of using SNAREs to investigate and map trafficking pathways has proven so successful, we will now launch a major large-scale initiative to study ALL SNARE-mediated trafficking pathways in macrophages using a discovery pipeline of assays, including live cell imaging, we have developed. This will provide valuable information on many SNAREs including those associated with disease, and will elucidate trafficking pathways governing all macrophage actions in immunity, including cytokine secretion and antigen presentation. All of these pathways are highly relevant to current drug targets being used clinically or studied in inflammatory disease and for the development of vaccines.Read moreRead less
Brain Protection: A new therapeutic approach for Multiple Sclerosis In Multiple Sclerosis (MS), the immune system mistakenly attacks the brain. The immune attacks destroy myelin, the protective coat around electrical cables in the brain (demyelination). Current treatments for MS are only partially effective, and work by reducing the number and severity of these attacks. However, MS-related permanent disability in the majority of sufferers is due to the development of progressive MS, and current ....Brain Protection: A new therapeutic approach for Multiple Sclerosis In Multiple Sclerosis (MS), the immune system mistakenly attacks the brain. The immune attacks destroy myelin, the protective coat around electrical cables in the brain (demyelination). Current treatments for MS are only partially effective, and work by reducing the number and severity of these attacks. However, MS-related permanent disability in the majority of sufferers is due to the development of progressive MS, and current therapies do not reduce this progression. It is believed that one major cause of this permanent disability is permanent myelin loss. Interestingly, we have already shown that the growth factor LIF is made by the body during MS-like inflammation, and that it limits damage by directly protecting myelin-producing cells. However, the bodies own LIF production during inflammation is sub-maximal, because myelin protection can be enhanced by giving additional therapeutic LIF. This suggests that (1) The brain produces a defence response to harmful inflammation and that (2) This defence response can be enhanced therapeutically. We therefore want to define exactly how LIF enhances myelin survival. We have measured the response to LIF in myelin-producing cells, and have discovered that it strongly stimulates the production of the small protein galanin. We will now assess if galanin itself protects myelin and myelin-producing cells, and we will test this both in isolated cells and whole animal models. If galanin production is a major mechanism by which the body tries to limit the damage from abnormal inflammation during MS, then medications that mimic the action of galanin (which are already under development for different reasons) could become a major new therapy for Multiple Sclerosis.Read moreRead less
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