The Pathogenesis Of Motor Neuron Degeneration Caused By A Triplet Repeat Expansion In The Androgen Receptor Gene.
Funder
National Health and Medical Research Council
Funding Amount
$284,748.00
Summary
Male sex hormones, or androgens, work by binding to a specific receptor, known as the androgen receptor. Androgens have an important and yet poorly understood role in nerve function. Our research is investigating how a genetic mutation in the androgen receptor causes Kennedy?s disease. This is a rare disease, affecting adult males, which causes nerves to die. The nerves which are affected are those supplying our muscles, called motor neurons. This leads to muscle wasting in the face and body. Ot ....Male sex hormones, or androgens, work by binding to a specific receptor, known as the androgen receptor. Androgens have an important and yet poorly understood role in nerve function. Our research is investigating how a genetic mutation in the androgen receptor causes Kennedy?s disease. This is a rare disease, affecting adult males, which causes nerves to die. The nerves which are affected are those supplying our muscles, called motor neurons. This leads to muscle wasting in the face and body. Other symptoms include testicular wasting, reduced fertility and breast tissue enlargement. It is currently not known what causes motor nerves to degenerate in Kennedy?s disease. We are endeavouring to investigate the cause of Kennedy?s disease via the generation of a transgenic mouse carrying this mutation. It is only through a studying transgenic mouse affected by this disease can we begin to understand what is happening to nerves to cause them to die, and importantly, how can we prevent them from dying. These studies will also provide crucial information on the effects of sex hormones on nerves. As there is currently no treatment for Kennedy?s disease, an aim of this project is to investigate how we can treat this disease. This will be the first time that we can systemically test potential treatments and work toward preventing the degeneration of these nerves. Kennedy?s disease is related to a number of other neurodegenerative diseases including Huntington?s disease, which are caused by similar genetic mutations. All of these diseases are caused by degeneration of specific nerve cells. Evidence suggests that there may be similar mechanisms involved in all of these diseases. The results of this study will therefore help us to understand a range of diseases and may eventually lead to the development of therapeutic strategies to prevent their debilitating effects.Read moreRead less
The Role Of Liver Fructose-1,6-phosphatase (FBPase) In Body Weight Regulation
Funder
National Health and Medical Research Council
Funding Amount
$494,718.00
Summary
We have shown that fructose-1,6-bisphosphatase (FBPase), an enzyme important in producing sugar from the liver and one that is connected to Type 2 diabetes, does not cause an increase in sugar production when there is more of the enzyme in mouse livers. It does, however, lower both body weight and the amount of food the mice consume. We therefore hypothesise that liver FBPase is important in controlling body weight in humans and our project aims to find out exactly how and why this happens.
The Role Fructose-1,6-bisphosphatase On The Regulation Of Hepatic Gluconeogenesis
Funder
National Health and Medical Research Council
Funding Amount
$212,485.00
Summary
Type 2 or adult onset diabetes is a disease characterised by high blood sugar that causes damage to the kidneys, eyes and to the circulation and many patients die from heart attack or stroke. There is an increase in the prevalence of diabetes in Australia and a substantial portion of the health budget is utilised by caring for people with diabetes. Determining what exactly causes the increase in blood sugar levels is critical in the treatment of the disease. It is known that the sugar produced a ....Type 2 or adult onset diabetes is a disease characterised by high blood sugar that causes damage to the kidneys, eyes and to the circulation and many patients die from heart attack or stroke. There is an increase in the prevalence of diabetes in Australia and a substantial portion of the health budget is utilised by caring for people with diabetes. Determining what exactly causes the increase in blood sugar levels is critical in the treatment of the disease. It is known that the sugar produced and released by the liver is an important contributor to the high blood sugar levels found in patients with diabetes. The main biochemical pathway responsible for this is called gluconeogenesis, a complex arrangement of enzymes, which convert amino acids and fat into sugar. Although it is known that this pathway is overactive in patients with diabetes, the exact reason for this is not clearly understood. The aim of this proposal is to produce a transgenic mouse that has an increase in liver sugar production as a result of an increase in gluconeogenesis, and to study its effects on blood sugar levels. Furthermore, studies will be performed to understand the regulation of this pathway by infusing the transgenic mice with insulin, the hormone that inhibits gluconeogenesis. The mechanism of action of insulin will be determined by the measurement of key enzymes that regulate gluconeogenesis. The significance of this grant is to identify possible sites for the development of new drugs or gene therapy that will lead to a decrease in the production of sugar by the liver. This will lead to better control of blood sugar levels and slow down or even prevent the onset of diabetes complications.Read moreRead less
Mechanisms Of Insulin Resistance And Diabetes Susceptibility
Funder
National Health and Medical Research Council
Funding Amount
$633,783.00
Summary
The two main forms of diabetes - types 1 (T1D) and 2 (T2D) - pose a major problem. It is difficult to identify what causes diabetes. Recently, people at risk of T1D were found to have insulin resistance, a condition thought typical only of T2D. Excitingly, we discovered that the best T1D animal model also shows insulin resistance, and we used it to map important genes. We will now identify these genes. This will help us understand the disease process and to develop better treatments for it.
Osteoporosis is a major health burden resulting from bone fractures in older men and women due to progressive loss of bone and weakening of the skeleton. Although there are currently therapies to reduce bone loss, no current treatment effectively reconstructs lost bone. In this project, which is designed to identify new genes that may in the future be targeted by drugs to reverse osteoporosis, we have identified specific sets of genes that appear to work together to increase bone formation. This ....Osteoporosis is a major health burden resulting from bone fractures in older men and women due to progressive loss of bone and weakening of the skeleton. Although there are currently therapies to reduce bone loss, no current treatment effectively reconstructs lost bone. In this project, which is designed to identify new genes that may in the future be targeted by drugs to reverse osteoporosis, we have identified specific sets of genes that appear to work together to increase bone formation. This proposal is aimed at characterising these genes and the ways in which they work to determine whether they may be good targets for new osteoporosis treatments. We will examine the patterns of these genes in bone. We will also use cell cultures in which bone forming cells develop and function, to determine when the genes are expressed and how they function. We will test the ability of the candidate genes to cause an increase in the amount of bone forming activity in these cell cultures. An increase in bone formation may be caused by an increase in the number bone-forming cells, an increase in the activity of the cells, a decrease in cell death, or a combination of these changes. Each possibility will be tested. This research is important because of the need for new osteoporosis therapies to repair weakened bones. The knowledge resulting from this proposal has the potential to provide an important contribution to skeletal health and thus aged health worldwide.Read moreRead less
This project will test the proposal that rising follicle-stimulating hormone (FSH) levels in ageing females directly accelerate reproductive failure and bone loss , major public health issues due to delayed childbearing and our rising ageing population. We have developed a unique mouse model with elevated FSH levels that cause premature female infertility. We will now use this model to determine the direct effects of high FSH upon ovarian and uterine function, as well as bone loss with age.
Investigation Of The Genetic Basis Of Insulin Hypersecretion In A Mouse Model Of Pancreatic Islet Failure
Funder
National Health and Medical Research Council
Funding Amount
$406,980.00
Summary
Type 2 diabetes is a chronic disease that is associated with blindness, kidney failure, heart attacks and stroke and these are secondary to high blood sugar levels. Thus, determining the cause of high blood sugar levels in type 2 diabetes will lead to better management of the disease and ease the financial burden on the public health system. High blood sugar in type 2 diabetes results from the inability of the body to secrete enough insulin. Insulin is the main hormone that lowers blood sugar le ....Type 2 diabetes is a chronic disease that is associated with blindness, kidney failure, heart attacks and stroke and these are secondary to high blood sugar levels. Thus, determining the cause of high blood sugar levels in type 2 diabetes will lead to better management of the disease and ease the financial burden on the public health system. High blood sugar in type 2 diabetes results from the inability of the body to secrete enough insulin. Insulin is the main hormone that lowers blood sugar levels and is produced by the pancreas. The reason for reduced insulin secretion in type 2 diabetes is not known. Paradoxically, it has been shown that some people who are at an increased risk of developing diabetes (eg people with obesity or a family history of diabetes) secrete more insulin than normal. It is not clear why this is, but a few studies have suggested that reducing insulin secretion in these circumstances can protect the pancreas and preserve its ability to secrete the appropriate amount of insulin. The DBA-2 is a mouse strain that like humans with type 2 diabetes, its pancreas can also fail to secrete the appropriate amount of insulin and under these circumstances becomes diabetic. Furthermore our laboratory has generated evidence that shows that like people who are at risk of diabetes, DBA-2 mice in fact secrete more insulin prior to becoming diabetic. Whether the cause of this increased insulin secretion is linked to the eventual reduction of secretion is not known. The aim of this study is to identify the gene that causes increased insulin secretion in the DBA-2 mouse. Furthermore, genetically manipulated animals will be produced that contain only this gene to determine its effect on insulin secretion. Should the identification of this gene be related to the eventual failure of the pancreas to secrete enough insulin, then it would provide a target for drug therapy to correct insulin levels and therefore reduce blood sugar levels.Read moreRead less
The Mechanisms Of The Anabolic Actions Of Androgens In Bone.
Funder
National Health and Medical Research Council
Funding Amount
$470,960.00
Summary
Androgens (male sex hormones) are one of the few agents that increase bone formation. Androgens act by binding to a specific protein, the androgen receptor (AR). To understand exactly how androgens increase bone formation, we will study mice in which the AR is inactivated only in bone forming cells at specific stages of their development. Understanding the way in which androgens act on bone to increase size and strength will be of great benefit in the design of new treatments for osteoporosis.
Mechanisms Of Hypoglycaemic Damage In Developing Brain- A Protective Role For The Insulin-like Growth Factor System
Funder
National Health and Medical Research Council
Funding Amount
$408,055.00
Summary
The developing brain in the newborn infant or young child is vulnerable to many damaging influences. It is highly dependent on its essential fuel, glucose. Hypoglycemia, or lack of glucose availability, is therefore among the most damaging insults to the young brain, potentially leading to learning difficulties, developmental delay, cerebral palsy or epilepsy. Babies born premature or very small are at risk, as are those exposed to excessive insulin, such as infants of diabetic mothers. Children ....The developing brain in the newborn infant or young child is vulnerable to many damaging influences. It is highly dependent on its essential fuel, glucose. Hypoglycemia, or lack of glucose availability, is therefore among the most damaging insults to the young brain, potentially leading to learning difficulties, developmental delay, cerebral palsy or epilepsy. Babies born premature or very small are at risk, as are those exposed to excessive insulin, such as infants of diabetic mothers. Children with diabetes are also at risk, when their therapy with insulin may at times be excessive, leading to hypoglycaemia and impaired glucose availability for the brain. This proposal is examining at the cellular level the mechanisms involved in loss of brain cells in the face of glucose starvation in these various conditions. We are using several in vitro models where we can grow segments of developing mouse brain or human nerve cells in a dish, compared to studies with mice subjected to low blood glucose (hypoglycemia). After establishing that our laboratory models are representative of the whole animal, we will explore the cellular mechanisms involved in neuronal death following hypoglycaemia, particularly the interaction between the insulin-like growth factor (IGF) and other cell survival genes. We will also examine the possibility that treatment with IGF will reduce the loss of nerves in the brain after an episode of hypoglycemia. This may offer new and effective early treatment for this damaging brain injury in both newborn babies and children with insulin-dependent diabetes.Read moreRead less