Hypothalamic Signalling In Cortical And Trabecular Bone Anabolic Activity
Funder
National Health and Medical Research Council
Funding Amount
$472,770.00
Summary
Osteoporosis is a disease associated with an exponential rise in the number of fractures in the elderly. These fractures are so common that around 1 in 3 women and 1in four men will be affected. They cause pain, disability that can be permanent disability and are associated with premature death. Current treatments are able to effectively increase bone strength in osteoporotic patients but can not return bone strength to normal. Some new treatments can restore bone strength to some extent but the ....Osteoporosis is a disease associated with an exponential rise in the number of fractures in the elderly. These fractures are so common that around 1 in 3 women and 1in four men will be affected. They cause pain, disability that can be permanent disability and are associated with premature death. Current treatments are able to effectively increase bone strength in osteoporotic patients but can not return bone strength to normal. Some new treatments can restore bone strength to some extent but these are limited by expense and safety concerns. We have discovered a pathway in the brain that reduces bone formation and by blocking this pathway we can achieve doubling of the amount of bone in key bone sites. This occurs due to a marked increase in the amount of new bone formed. In fact, genetic manipulation of this pathway was able to double the speed at which bone is made by the skeleton. Excitingly, these increases in bone were possible in adult mice, suggesting such changes could be potential therapy for human patients. However, in order to be able to harness this pathway we must understand what molecules within the brain are responsible for the signals that reach the bone. Our proposal aims to identify the nerve signalling molecule(s) and the receptor for these signals within the brain that initiates the increase in bone formation. This project ultimately aims to identify a target for new therapies that could cause this beneficial effect by administration of a simple treatment, preferably by mouth in adult humans.Read moreRead less
The Physiological Role Of Calcitonin And Its Receptor In Bone Cell Metabolism.
Funder
National Health and Medical Research Council
Funding Amount
$496,446.00
Summary
Throughout adult life, bone tissue is continuously remodelled. The two main processes involved in bone remodelling, are bone formation and bone breakdown. Bone formation is controlled by cells known as osteoblasts and bone breakdown is controlled by cells known as osteoclasts. Under normal circumstances these two processes are tightly coupled. Excessive breakdown of bone, causes these two processes to become unbalanced and results in bone loss. This is the basis of many bone diseases such as ost ....Throughout adult life, bone tissue is continuously remodelled. The two main processes involved in bone remodelling, are bone formation and bone breakdown. Bone formation is controlled by cells known as osteoblasts and bone breakdown is controlled by cells known as osteoclasts. Under normal circumstances these two processes are tightly coupled. Excessive breakdown of bone, causes these two processes to become unbalanced and results in bone loss. This is the basis of many bone diseases such as osteoporosis, a condition in which the bones become fragile and therefore more susceptible to fracture. 1 in 2 women and 1 in 3 men aged 70 years and older suffer from osteoporosis in Australia. Despite this, the mechanisms which control osteoclast breakdown of bone are not well understood. Our laboratory is interested in how hormones affect osteoclast action. We plan to examine the role of the hormone calcitonin, an important inhibitor of osteoclastic bone breakdown. This will be achieved by studying transgenic mice in which the receptor, or target, for calcitonin is specifically removed from osteoclasts. This will allow us to precisely determine the role of calcitonin in osteoclast function. Data generated by our research group indicates that calcitonin is also involved in controlling bone formation, however, the way in which calcitonin acts on osteoblasts remains poorly understood. Therefore, studying our transgenic mice will also help clarify the role calcitonin plays in bone formation. Current treatment for osteoporosis involves the administration of drugs which inhibit bone breakdown. This project will increase our understanding of how calcitonin acts to regulate bone breakdown and bone formation and may assist in the design of new therapies for osteoporosis. We believe that this research is of great importance as osteoporosis is becoming more prevalent as the population ages.Read moreRead less
Correction Of Diabetes In An Autoimmune Model Using Insulin-secreting Liver Cells.
Funder
National Health and Medical Research Council
Funding Amount
$472,500.00
Summary
Type I diabetes mellitus is caused by the autoimmune destruction of the beta cells of the pancreas that secrete insulin. The problems of the chronic complications of diabetes and the lack of donor tissue for transplantation, could theoretically be overcome by engineering from the patient's own cells, an artificial beta cell, i. e. a non-islet cell capable of synthesising, storing and secreting mature insulin in response to metabolic stimuli, such as glucose. The ultimate goal of this technology ....Type I diabetes mellitus is caused by the autoimmune destruction of the beta cells of the pancreas that secrete insulin. The problems of the chronic complications of diabetes and the lack of donor tissue for transplantation, could theoretically be overcome by engineering from the patient's own cells, an artificial beta cell, i. e. a non-islet cell capable of synthesising, storing and secreting mature insulin in response to metabolic stimuli, such as glucose. The ultimate goal of this technology is to deliver the insulin gene directly to a patient's own liver cells which would regulate insulin secretion in response to glucose and other substances that stimulate insulin secretion, controlling blood glucose without the need for immunosuppression. To accomplish this it must be possible to deliver the insulin gene efficiently to primary liver cells (cells derived from an animal's or human's body). Results from our laboratory using a non-pathogenic viral delivery system indicate that we can reverse diabetes in chemically induced diabetic rats by expression of insulin and a beta cell transcription factor NeuroD. The aim of this study is to repeat this in an auto-immune model of diabetes the nonobese diabetic mouse, which mimicks very closely the development of diabetes in humans. We will determine if we can reverse diabetes in these animals and determine if their response to glucose is normal over an extended period of time, with no attack by the factors of the immune system that stimulate the development of diabetes in man. The results from this research proposal should result in the delivery of the insulin gene to large numbers of primary liver cells that will then synthesise, store and secrete insulin in response to glucose. These cells would control blood glucose levels in patients without the need for immunosuppression.Read moreRead less
Androgen Receptor Signalling In Development And Progression Of Prostate Cancer
Funder
National Health and Medical Research Council
Funding Amount
$753,420.00
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 growth and survival, surgical or medical castration results in an initial tumour regression. However, tumours inevitably develop resistance to androgen ablation therapy and regrow. In this study we aim to provide the most comprehensive analysis to date of the role of androgen signalling in the initiation and progression of prostate cancer. This will enable us to identify the most effective means of eliminating androgen-dependent prostate tumours and identify tumours with high metastatic potential. Our studies will indicate whether treatments targeting androgen signalling are a more effective strategy to inhibit prostate cancer growth while minimising undesirable side effects.Read moreRead less
The Role Of The Novel Gene Herpud1 In Insulin Secretion In Type 2 Diabetes
Funder
National Health and Medical Research Council
Funding Amount
$502,370.00
Summary
A reduced ability to secrete insulin is the cause of high blood sugar in type 2 diabetes. This study has identified a gene called Herpud1 that affects insulin secretion. By studying the effects of this gene we are improving our knowledge of the defects that occur in Type 2 diabetes. This has the potential of providing better therapeutic strategies and identifying targets for the developments of better drug development.
How Does Disruption Of Circadian Rhythms Induce Diabetes?
Funder
National Health and Medical Research Council
Funding Amount
$631,782.00
Summary
Increasing evidence suggests that disturbed circadian rhythms initiate and amplify metabolic and cardiovascular disease. The increasing and already high proportion of workers engaged in shiftwork, and increased frequency of disruption of these rhythms in the population more generally, implicate this body system as contributing to the growing epidemic of obesity and diabetes and related disorders in our community and world-wide. While we are now beginning to understand how our rhythms are synchro ....Increasing evidence suggests that disturbed circadian rhythms initiate and amplify metabolic and cardiovascular disease. The increasing and already high proportion of workers engaged in shiftwork, and increased frequency of disruption of these rhythms in the population more generally, implicate this body system as contributing to the growing epidemic of obesity and diabetes and related disorders in our community and world-wide. While we are now beginning to understand how our rhythms are synchronised to night and day, how this rhythmicity is linked to our organs in the normal and common disease states such as diabetes is poorly understood. The discovery of a special set of genes, called clock genes that function in all of the cells in our bodies and strongly influence the function of our organs such as the liver, pancreas and heart has been particularly important. We hypothesise that both environmentally (exogenous) and genetically (endogenous) induced disruption of circadian rhythms causes metabolic dysfunction. This is due to altered central and peripheral clock gene expression rhythms, which in turn alter metabolic rhythms and impair glucose homeostasis. This project aims to determine the impact of disrupted rhythmicity on metabolism with a particular emphasis on the possibility that the disrupted rhythmicity may be a predisposing factor for the development of diabetes.Read moreRead less
An obesity epidemic is evident in first world countries including Australia. Twenty seven percent of men aged 55-64 in this country are obese. Obesity results in increased mortality and morbidity from type 2 diabetes, cardiovascular disease, renal disease and endometrial cancer, among others. Given our flaccid lifestyles, it is imperative that the metabolic processes underlying obesity be fully understood, to allow development of suitable treatment modalities. This proposal seeks to establish an ....An obesity epidemic is evident in first world countries including Australia. Twenty seven percent of men aged 55-64 in this country are obese. Obesity results in increased mortality and morbidity from type 2 diabetes, cardiovascular disease, renal disease and endometrial cancer, among others. Given our flaccid lifestyles, it is imperative that the metabolic processes underlying obesity be fully understood, to allow development of suitable treatment modalities. This proposal seeks to establish an important new element in our understanding of the development of obesity, the transcription factor STAT5. With previous NHMRC support, we developed sophisticated genetically modified mice which lack defined signalling processes initiated by growth hormone, an anti-obesity agent. These studies showed a strong correlation between ability to activate STAT5 and resistance to obesity. There is fragmentary literature evidence to support our hypothesis, which could also explain some of leptins anti-obesity actions. Using mice which lack STAT5, we shall establish a role for STAT5 as an antiobesity agent. The actions of STAT5 are normally blocked by feedback inhibitors referred to as SOCS, discovered by Australians. We shall define which SOCS is the feedback regulator for obesity control, allowing us to develop specific anti-SOCS agents which will act as novel anti-obesity agents.Read moreRead less