Novel Regulators Of Glucose Metabolism And Inflammation In Adipose Tissue Of Females
Funder
National Health and Medical Research Council
Funding Amount
$282,830.00
Summary
Obesity is a common problem which can lead to development of diabetes and heart disease. One of the major mechanisms by which obesity leads to these diseases involves a defect in the ability of insulin to stimulate uptake of glucose into cells. We have found that excess of the sex hormone testosterone in women can contribute to this defect in tissues. This study will investigate why testosterone causes this defect in females and whether this defect can be prevented using existing drug therapies.
Nutrient Dependent Signalling In Bone Via Calcium Sensing Receptors
Funder
National Health and Medical Research Council
Funding Amount
$226,650.00
Summary
Osteoporosis is a major health problem that affects as many as 10% of the Australian Community and costs the health budget millions of dollars each year. A number of key nutritional factors including calcium and dietary protein intake are known to be important in the development of osteoporosis. This proposal will test the hypothesis that human bone cells express a protein which senses calcium and amino acids, the calcium-sensing receptor, and thereby respond to nuritional signals arising from t ....Osteoporosis is a major health problem that affects as many as 10% of the Australian Community and costs the health budget millions of dollars each year. A number of key nutritional factors including calcium and dietary protein intake are known to be important in the development of osteoporosis. This proposal will test the hypothesis that human bone cells express a protein which senses calcium and amino acids, the calcium-sensing receptor, and thereby respond to nuritional signals arising from the presence of calcium ions and amino acids in plasma. Furthermore, we propose that by promoting osteoblast proliferation, maturation and survival, the calcium sensing receptor acts as the key molecular mechanism by which dietary calcium and protein promotes bone formation.These studies have potential to explain relationships between bpne resorptive activity, which raises local calcium concentrations, and bone formation activity and the coupling of bone forming and resorbing activity. These studies have the potential to explain the positive effects of calcium and protein intake on bone mass and may also shed light on the regulation of the coupling between osteoblastic and osteoclastic activityRead moreRead less
Role Of The Growth Hormone Binding Protein As A Transcriptional Activator
Funder
National Health and Medical Research Council
Funding Amount
$387,226.00
Summary
Growth hormone is an important hormone therapeutic for treating dwarfism. Recently, many new therapeutic applications for growth hormone have been discovered, particularly in relation to its role as an anabolic agent. These include post surgery recovery, enhanced bone fracture healing, Crohns disease, dilated cardiomyopathy, infertility and of course, ageing. This proposal examines a novel way that GH could work, that is by sending the extracellular part of its receptor (GHBP) to the nucleus, wh ....Growth hormone is an important hormone therapeutic for treating dwarfism. Recently, many new therapeutic applications for growth hormone have been discovered, particularly in relation to its role as an anabolic agent. These include post surgery recovery, enhanced bone fracture healing, Crohns disease, dilated cardiomyopathy, infertility and of course, ageing. This proposal examines a novel way that GH could work, that is by sending the extracellular part of its receptor (GHBP) to the nucleus, where it can directly activate gene readout. This would have the effect of augmenting the normal action of GH to regulate gene readout. We have exciting preliminary data which makes us think this may be a new mechanism for hormone activation of genes. The level of GHBP in the nucleus is regulated, and if a defect in export of the GHBP occurred, this would lead to accumulation of nuclear GHBP and stimulate cell proliferation. This may be important in cancer cell proliferation, since we find nuclear GHBP in cancers.Read moreRead less
Aldosterone Mediated Cardiac Pathophysiology:The Role Of Corticosteroid Receptors And 11 HSD Isoforms
Funder
National Health and Medical Research Council
Funding Amount
$481,500.00
Summary
Aldosterone a hormone that circulates in blood and is associated with cardiovascular disease. Recently, two clinical trials (RALES, EPHUSUS) demonstrate that if you stop this hormone from acting by giving drugs that inhibit it from binding to the receptor that mediates its response, there is an improvement in the health of heart failure patients. How aldosterone mediates its detrimental effects on heart is largely unknown. Glucocorticoids are another hormone that circulates in blood and can bind ....Aldosterone a hormone that circulates in blood and is associated with cardiovascular disease. Recently, two clinical trials (RALES, EPHUSUS) demonstrate that if you stop this hormone from acting by giving drugs that inhibit it from binding to the receptor that mediates its response, there is an improvement in the health of heart failure patients. How aldosterone mediates its detrimental effects on heart is largely unknown. Glucocorticoids are another hormone that circulates in blood and can bind to the same receptor as aldosterone. In contrast to aldosterone glucocorticoids appear to play a basic maintenance role in heart. Our central hypothesis is that in the healthy heart aldosterone has minimal effects , however, in the diseased heart aldosterone associated pathophysiology is a result of both an increase in the ability of aldosterone to signal to cells and disruption of glucocorticoid signalling. This grant proposal will address how aldosterone and glucocorticoids may directly signal within cardiac cells and how this signalling changes in the diseased heart. In addition, we investigate if enzymes that metabolize glucocortioids and thus render them non-functional play a role in cardiac disease, and if we can reverse the detrimental effects of aldosterone by artificially increasing the production of glucocorticoids in heart. By understanding the mechanisms by which aldosterone promotes cardiac disease, and the role of glucocorticoids and their metabolism in this process will lead to a better understanding of aldosterone induced pathology and thus lead to novel therapeutic targets.Read moreRead less
A Transgenic Analysis Of The Physiologic Roles Of Signalling Domains In The Growth Hormone Receptor
Funder
National Health and Medical Research Council
Funding Amount
$262,500.00
Summary
The key hormone promoting growth postnatally is growth hormone (GH), and it acts through the growth hormone receptor to initiate a variety of signals which regulate gene expression. In addition to its role in growth, GH is an importnat metabolic regulator in starvation. It also appears to play a significant role in the ageing process, since mice lacking the GH receptor live 50% longer than normal mice. Although the signalling systems used by the GH receptor are reasonably well defined in vitro, ....The key hormone promoting growth postnatally is growth hormone (GH), and it acts through the growth hormone receptor to initiate a variety of signals which regulate gene expression. In addition to its role in growth, GH is an importnat metabolic regulator in starvation. It also appears to play a significant role in the ageing process, since mice lacking the GH receptor live 50% longer than normal mice. Although the signalling systems used by the GH receptor are reasonably well defined in vitro, we have no idea which signals are used to control postnatal growth, metabolism and ageing in the live animal. With NHMRC support, we have been creating mice with individual signalling domains of the GH receptor deleted. This proposal aims to use these mice to determine how the GH receptor brings about its actions of promoting postnatal growth, regulating metabolism and altering lifespan. In particular, through the use of gene arrays, we intend to define the key genes regulated in these processes. This would provide potential therapeutic targets for drug development to individually alter these key processes.Read moreRead less
Androgen Receptor Signalling And Progression Of Prostate Cancer
Funder
National Health and Medical Research Council
Funding Amount
$462,750.00
Summary
Prostate cancer is a major health problem in Australia, being the second leading cause of cancer deaths in men. Although there have been improvements in the diagnosis and treatment of prostate cancer, there are no effective treatments for advanced (metastatic) disease that has spread to other parts of the body. Currently, the only therapy for advanced disease involves the reduction in circulating androgens such as testosterone by surgical or medical castration, i.e. androgen ablation. Because pr ....Prostate cancer is a major health problem in Australia, being the second leading cause of cancer deaths in men. Although there have been improvements in the diagnosis and treatment of prostate cancer, there are no effective treatments for advanced (metastatic) disease that has spread to other parts of the body. Currently, the only therapy for advanced disease involves the reduction in circulating androgens such as testosterone by surgical or medical castration, i.e. androgen ablation. Because prostate cells are dependent on testicular androgens for their survival, surgical or medical castration results in an initial tumour regression. However, tumours inevitably develop resistance to current forms of androgen ablation therapy. Inappropriate activation of androgen signalling by non-testicular androgens or other agents may stimulate tumour growth following androgen ablation. In this study, we aim to identify and characterise determinants of the specificity and sensitivity of activation of the androgen receptor, which is the primary mediator of androgen action. Current androgen ablation treatments for prostate cancer only target the availability of androgenic ligands. We propose that it is also necessary to target the androgen receptor itself, because it can be activated by ligands other than testicular androgens. Therefore, we will also evaluate a panel ofagents that target different aspects of the androgen signalling axis, combined with androgen ablation using a cyclical approach to prevent or delay disease progression.Read moreRead less
The Mechanism Of Growth Hormone Receptor Activation
Funder
National Health and Medical Research Council
Funding Amount
$679,500.00
Summary
Growth hormone GH excess or deficit results in considerably shortened lifespan. While cardiovascular disease is a major element in this mortality, GH status has also been linked to kidney disease and diabetic retinopathy. Importantly, GH produced locally in breast cells and prostate cells transform s these cells, creating cancers. We aim to define how GH activates its receptor, to facilitate a GH antagonist which results from understanding how GH activates its cell surface receptor.
L-amino Acid Sensing By The Extracellular Calcium-sensing Receptor: Molecular, Cellular And In Vivo Studies
Funder
National Health and Medical Research Council
Funding Amount
$362,545.00
Summary
Recent work by Dr Conigrave and colleagues demonstrates for the first time that protein and calcium metabolism are linked at the molecular level by the widely distributed calcium-sensing receptor. The project will aim to demonstrate the physiological significance of this finding by testing whether L-amino acids, the building blocks of body protein, exert receptor-dependent control over the secretion and blood levels of hormones that regulate body calcium levels. It will further test the hypothes ....Recent work by Dr Conigrave and colleagues demonstrates for the first time that protein and calcium metabolism are linked at the molecular level by the widely distributed calcium-sensing receptor. The project will aim to demonstrate the physiological significance of this finding by testing whether L-amino acids, the building blocks of body protein, exert receptor-dependent control over the secretion and blood levels of hormones that regulate body calcium levels. It will further test the hypothesis by determining whether amino acids exert receptor-dependent control over the proliferation of bone forming cells and urinary excretion of calcium.Read moreRead less