Molecular Determinants Of Amino Acid-dependent Signalling By The Calcium-sensing Receptor
Funder
National Health and Medical Research Council
Funding Amount
$566,035.00
Summary
Amino acids are the building blocks of proteins and an alternative energy source to carbohydrate and fat. Proteins are major structural components of our bodies. They also fulfil an amazing diversity of cellular and bodily functions acting, for example, as enzymes (biological catalysts), receptors, molecular chaperones and biological machines. Thus, amino acids are key nutrients and the human body has developed mechanisms for tightly regulating cellular responses depending upon their levels in b ....Amino acids are the building blocks of proteins and an alternative energy source to carbohydrate and fat. Proteins are major structural components of our bodies. They also fulfil an amazing diversity of cellular and bodily functions acting, for example, as enzymes (biological catalysts), receptors, molecular chaperones and biological machines. Thus, amino acids are key nutrients and the human body has developed mechanisms for tightly regulating cellular responses depending upon their levels in blood. Identifying amino acid sensing molecules and identifying the mechanisms they use to control cellular responses is thus a key issue in human biology. The applicant identified the calcium-sensing receptor as an amino acid sensor and has shown that this receptor provides a means by which fluctuations in amino acid levels regulate the secretion of the key calcium-regulating hormone, PTH. In the current proposal, the mechanisms that link amino acid activation of the calcium-sensing receptor to its key cellular responses will be determined.Read moreRead less
The proposal focuses on a novel angle explaining how pancreatic beta cells normally match their insulin synthesis, storage and secretion in response to an enhanced demand as occurs during obesity, and how this fails in the progression to Type 2 diabetes. In particular we will expand our discovery that glucose rapidly enhances the synthesis of a novel factor regulating gene transcription. This will generate basic knowledge that will potentially help design of novel therapies for Type 2 diabetes.
Role Of Macrophages In Lipotoxic Beta Cell Failure
Funder
National Health and Medical Research Council
Funding Amount
$612,736.00
Summary
Type 2 diabetes (T2D) affects 7% of Australians and is a major cause of morbidity and mortality. A failure of insulin secretion contributes to T2D, and this is linked to the inability of insulin producing ?-cells to use lipids appropriately (lipotoxicity). Here we will study the role of the immune system and how this inhibits insulin secretion in T2D
Therapeutic Strategies And Screening Methods For PKC Epsilon Antagonists In The Treatment Of Type 2 Diabetes
Funder
National Health and Medical Research Council
Funding Amount
$157,375.00
Summary
Type 2 diabetes is a chronic disease affecting over a million Australians and hundreds of millions of people worldwide. Its prevalence is rising due to several factors such as an increase in caloric intake, the aging of the population, and the common sedentary lifestyle of Western civilization. Type 2 diabetes occurs when the pancreas is unable to produce enough insulin for the body to cope with rising blood glucose levels after a meal, and has been strongly linked to obesity. We have now shown ....Type 2 diabetes is a chronic disease affecting over a million Australians and hundreds of millions of people worldwide. Its prevalence is rising due to several factors such as an increase in caloric intake, the aging of the population, and the common sedentary lifestyle of Western civilization. Type 2 diabetes occurs when the pancreas is unable to produce enough insulin for the body to cope with rising blood glucose levels after a meal, and has been strongly linked to obesity. We have now shown that an enzyme found in the pancreas becomes inappropriately activated under conditions of fat oversupply, and plays an important role in the development of defects in insulin release from the pancreas in response to glucose. Excitingly, we have also shown that inhibition of this enzyme can partly reverse these defects once they have been established. We now intend to further validate this enzyme as a drug target by determining the optimum dosing regimen for the treatment of type 2 diabetes in a mouse model, and testing whether this approach can be used in conjunction with previously-developed drugs which promote insulin action, to improve bood glucose handling better than either treatment alone. This would promote the enzyme as a therapeutic strategy in the treatment of Type 2 diabetes. We also plan to develop a high throuhput screen to identify novel inhibitors of the enzyme, which will further increase the attractiveness of the project to pharmaceutical companies, who are better able to implent full commercialization of our findings.Read moreRead less
Mechanisms Of PKCepsilon-dependent Regulation Of Beta-cell Lipid Metabolism And Insulin Secretion
Funder
National Health and Medical Research Council
Funding Amount
$555,892.00
Summary
Lipid loading of the insulin-producing beta cells of the pancreas contributes to the onset of Type 2 diabetes, but the mechanisms are poorly understood. We have recently established that inhibiting the enzyme PKCe helps restore insulin secretion. By better defining the cellular role of PKCe we will clarify how insulin secretion is disrupted by fatty acids and cholesterol.
Type 2 diabetes is a health crisis in Australia. In this project, we will investigate the mechanisms whereby high glucose and fat impair pancreatic beta-cell function leading to type 2 diabetes. We will establish how endoplasmic reticulum stress and the protein Id1 are linked with loss of beta-cell gene expression and function. The information gained will further our understanding of the basic mechanisms regulating insulin secretion and provide new therapeutic targets for diabetes treatment.
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.
A Solution To The Parathyroid Gland Secretion Problem
Funder
National Health and Medical Research Council
Funding Amount
$508,003.00
Summary
Parathyroid hormone is the master hormone regulator of whole body calcium metabolism and a powerful new treatment for osteoporosis but the mechanism by which its natural secretion is controlled has never been solved. In this project we will apply new insights and advanced technical approaches to resolve this most fundamental question of calcium homeostasis, namely how parathyroid hormone secretion is controlled.