Identification And Characterisation Of A Gene Causing Insulin Hypersecretion In A Mouse Model Of Diabetes Susceptibility
Funder
National Health and Medical Research Council
Funding Amount
$430,320.00
Summary
Diabetes is a disorder primarily characterised by the inability to produce and secrete the pancreatic hormone insulin, which regulates plasma sugar levels. This results in increased sugar levels which cause diabetic complications such as retinopathy and nephropathy. The inability to produce and secrete insulin is due to both defects in function as well as a reduction in pancreatic beta cells. Paradoxically it has been shown that some patients who are at risk of develping diabetes actually secret ....Diabetes is a disorder primarily characterised by the inability to produce and secrete the pancreatic hormone insulin, which regulates plasma sugar levels. This results in increased sugar levels which cause diabetic complications such as retinopathy and nephropathy. The inability to produce and secrete insulin is due to both defects in function as well as a reduction in pancreatic beta cells. Paradoxically it has been shown that some patients who are at risk of develping diabetes actually secrete more insulin than normal. Furthermore it has been suggested that this increase in insulin secretion actually may be associated with the decreased production and secretion of insulin characteristic of diabetes. The DBA-2 mouse is a model of reduced insulin production and secretion when exposed to high sugar levels or diabetes. However we have shown that in the normal non-stressed state DBA-2 mice actually secrete more insulin than normal and that this occurs from a very early age, suggesting that this trait is inherited. We have subsequently performed genetic studies and have identified a segment of DNA containing 10 genes associated with increased insulin secretion in DBA-2 mice. The level of one of these genes we have called Hip1 is increased 5-fold in DBA-2 mice, providing a candidate gene for increased insulin secretion in this model of diabetes susceptibility. However, whether Hip1 is also responsible for reduced insulin production and secretion in the DBA-2 mouse is not known. Therefore the overall hypothesis of this project is that the gene Hip1 which is associated with increased insulin secretion is also responsible for reduced insulin production and secretion when DBA-2 mice are exposed to high sugar or obesity. Determining why Hip1 is increased and whether it results in diabetes in DBA-2 mice may provide a reasonable candidate for the development of therapeutic interventions which may prevent the progression of diabetes in some patients.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
Kallikrein Gene Variants In Prostate Cancer: Analysis Of Gene Regulation And Diagnostic/Prognostic Use
Funder
National Health and Medical Research Council
Funding Amount
$486,801.00
Summary
Prostate cancer is the most common male cancer in Australia. However, early detection through screening programs has proven challenging, and about 30% of the 10,000 new cases diagnosed annually already have advanced disease. Hence, there is a fundamental need for increased basic research in prostate cancer etiology (cause) and tumour biology, and a critical requirement for methods that will assist in earlier detection of the disease and predict progression. A family of proteins called kallikrein ....Prostate cancer is the most common male cancer in Australia. However, early detection through screening programs has proven challenging, and about 30% of the 10,000 new cases diagnosed annually already have advanced disease. Hence, there is a fundamental need for increased basic research in prostate cancer etiology (cause) and tumour biology, and a critical requirement for methods that will assist in earlier detection of the disease and predict progression. A family of proteins called kallikreins (including prostate specific antigen, PSA) are often associated with clinical features of prostate cancer. We will characterise genetic variants (polymorphisms) in kallikrein genes that are consistently over-produced in prostate cancer, and determine whether they cause more protein to be produced in cells grown in the laboratory and in tumour tissue, and-or give rise to different expression products or splice variants. We will use bioinformatics (computer programs) to characterise published kallikrein gene sequences and to examine them for genetic variants that might be related to changes in gene expression or to splice variants. We will then use a case-control study, involving 1200 men with prostate cancer and 1200 healthy men, to determine whether these gene variants are associated with an increased risk of prostate cancer or with clinical aspects of the disease. Finally, we will examine the functional significance of the gene variants. This project represents an important and novel combination of molecular biology with the study of clinical disease at the population level, in the relatively new field of molecular epidemiology. It will clarify the role of kallikrein gene variants in prostate cancer risk and progression. The technologies may ultimately prove useful clinically for diagnosis of prostate cancer or for monitoring of treatment and prognosis, and hopefully will assist in clinical decision-making.Read moreRead less
ERRgamma And Skeletal Muscle: Insights Into Lipid Utilization And Catabolism
Funder
National Health and Medical Research Council
Funding Amount
$357,936.00
Summary
The significance of Nuclear hormone receptors (NRs) in disease is underscored by the range of pharmacopoeia for the treatment of NR-associated disorders (e.g 16% of the top 100 drugs target NRs). ERRgamma receptors are abundantly expressed in skeletal muscle, a major mass periperal tissue that acconts for ~40% of total body weight, and energy expenditure. Muscle is the major site of glucose metabolism and, fatty acid oxidation. Consequently, it has a significant role in insulin sensitivity, the ....The significance of Nuclear hormone receptors (NRs) in disease is underscored by the range of pharmacopoeia for the treatment of NR-associated disorders (e.g 16% of the top 100 drugs target NRs). ERRgamma receptors are abundantly expressed in skeletal muscle, a major mass periperal tissue that acconts for ~40% of total body weight, and energy expenditure. Muscle is the major site of glucose metabolism and, fatty acid oxidation. Consequently, it has a significant role in insulin sensitivity, the blood lipid profile, lipid metabolism and obesity. Understanding the functional role of the orphan ERR receptors in skeletal muscle in the context of inflammation, lipid and energy homeostasis is of paramount importance in further understanding the mechanistic basis of dyslipidemia, chronic inflammation, insulin sensitivity, diabetes and obesity. Identification of novel ERRgamma targets that regulate metabolism in a major mass peripheral tissue, and positively influence the risk factors for cardiovascular disease, provides platforms for potential therapeutic intervention. Cardiovascular disease is the foremost cause of global mortality, and was responsible for >15 million deaths in 2003.Read moreRead less
NR1 Nuclear Hormone Receptors, And Skeletal Muscle Metabolism: Insights Into Dyslipidemia And Metabolic Disease.
Funder
National Health and Medical Research Council
Funding Amount
$582,547.00
Summary
The significance of Nuclear hormone receptors (NRs) in disease is underscored by the range of pharmacopoeia for the treatment of NR-associated disorders (e.g 16% of the top 100 drugs target NRs). Orphan NR1 receptors are abundantly expressed in skeletal muscle, a major mass peripheral tissue that accounts for ~40% of total body weight, and energy expenditure. Muscle is the major site of glucose metabolism and, fatty acid oxidation. Furthermore, it is an important regulator of cholesterol homeost ....The significance of Nuclear hormone receptors (NRs) in disease is underscored by the range of pharmacopoeia for the treatment of NR-associated disorders (e.g 16% of the top 100 drugs target NRs). Orphan NR1 receptors are abundantly expressed in skeletal muscle, a major mass peripheral tissue that accounts for ~40% of total body weight, and energy expenditure. Muscle is the major site of glucose metabolism and, fatty acid oxidation. Furthermore, it is an important regulator of cholesterol homeostasis and HDL levels. Consequently, it has a significant role in insulin sensitivity, the blood lipid profile, lipid metabolism and obesity. Understanding the functional role of the orphan NR1 receptors in skeletal muscle in the context of inflammation, lipid and energy homeostasis is of paramount importance in further understanding the mechanistic basis of dyslipidemia, chronic inflammation, insulin sensitivity, diabetes and obesity. Identification of novel NR1 targets that regulate metabolism in a major mass peripheral tissue, and positively influence the risk factors for cardiovascular disease, provides platforms for potential therapeutic intervention. Cardiovascular disease is the foremost cause of global mortality, and was responsible for >15 million deaths in 2003.Read moreRead less
Type 2 Diabetic Renal Complications And Microvascular Injury: Novel Predictors Of Onset And Progression, Mechanisms Of Association With Cardiovascular Disease And The Benefits Of Fenofibrate.
Funder
National Health and Medical Research Council
Funding Amount
$84,448.00
Summary
We will investigate the mechanisms of diabetic complications related to kidney and blood vessel disease, focusing on identifying people at greater risk and ways to improve or prevent these complications. In addition, we will look at how diabetic kidney disease affects non-kidney related problems like heart disease and examine the benefit of fenofibrate on both. This greater understanding will aid further drug development in kidney and cardiovascular diseases.
This study aims to identify naturally occurring genetic variations between men which modify the impact of testosterone, the major male hormone, on men's health and medical care. This study will examine new factors which determine how much any particular man may gain benefit from testosterone exposure such as in muscle and bone development as well as suffer detrimental effects on cardiovascular and prostate diseases. This may clarify some new aspects of how men's health is determined as well as d ....This study aims to identify naturally occurring genetic variations between men which modify the impact of testosterone, the major male hormone, on men's health and medical care. This study will examine new factors which determine how much any particular man may gain benefit from testosterone exposure such as in muscle and bone development as well as suffer detrimental effects on cardiovascular and prostate diseases. This may clarify some new aspects of how men's health is determined as well as developing new, customized medical treatments for men.Read moreRead less
Reversal Of Diabetes In A Humanised Mouse Using A Clinically Applicable Vector System
Funder
National Health and Medical Research Council
Funding Amount
$842,173.00
Summary
Somatic gene therapy is one of the strategies that is being considered to cure Type I diabetes. Specifically, we wish to engineer liver cells to replace beta cell function. The aim of this project is to design a clinically-applicable protocol for the reversal of diabetes using a recombinant adeno-associated vector that delivers genes to human livers with high efficiency showing long term expression without pathogenicity and immunogenicity following a simple intra-peritoneal injection.