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
Short-term Effects Of Overfeeding On Metabolic Risk In Humans
Funder
National Health and Medical Research Council
Funding Amount
$417,196.00
Summary
The prevalence of obesity is rapidly increasing in Australia and other parts of the world. Obesity is closely associated with insulin resistance and plays a role in the development of type 2 diabetes. However, the effects of short-term periods of over nutrition in humans remain unclear. In the proposed study, we will investigate the effects of short-term weight gain by high fat feeding in lean subjects, in subjects who are overweight and in subjects who are genetically more likely to develop dia ....The prevalence of obesity is rapidly increasing in Australia and other parts of the world. Obesity is closely associated with insulin resistance and plays a role in the development of type 2 diabetes. However, the effects of short-term periods of over nutrition in humans remain unclear. In the proposed study, we will investigate the effects of short-term weight gain by high fat feeding in lean subjects, in subjects who are overweight and in subjects who are genetically more likely to develop diabetes (due to strong family history). The aims are to distinguish physiological and endocrine characteristics of individuals who store more fat in response to overfeeding. We will identify differences between these individuals and whether they have defects in upregulating machinery involved in fat oxidation and energy production in skeletal muscle that may help them adapt during to energy excess. We will look for changes in type 2 diabetes risk and we will have the potential to identify defects in factors that are involved in this response. We will also re-examine indivudals again after calorie restriction and weight loss. We also plan to confirm the role of the candidate genes involved in fat oxidation that have been identifieid in human studies by in vivo gene transfer technology in rodents. This study will determine whether overweight and lean subjects behave similarly when faced with an overfeeding challenge. We expect that individuals with a genetic predisposition for T2DM will become more IR, due to metabolic inflexibility and a decreased ability to upregulate machinery involved in fatty acid oxidation and mitochondrial function. By characterising the physiological and endocrine responses to overfeeding, we will establish quantifiable markers allowing us to distinguish those at risk and identify new targets for pharmacological or lifestyle intervention.Read moreRead less
Does Loss Of Melanocortin Glucose Sensing Contribute To Obesity Induced Diabetes?
Funder
National Health and Medical Research Council
Funding Amount
$617,531.00
Summary
Diabetes is a failure to properly regulate blood glucose levels. Escalating rates of diabetes are a major health problem. Melanocortin neurons in the brain detect blood sugar levels and usually regulate glucose production and utilization, but in obese animals they do not. We have developed a possible therapeutic, which appears to reverse the glucose insensitivity, and rapidly reduces blood glucose in diabetic mice. This project will determine how melanocortins act to regulate glucose levels
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.