Mitochondrial Iron Overload And Friedreich's Ataxia: The Role Of Frataxin In Iron And Haem Metabolism
Funder
National Health and Medical Research Council
Funding Amount
$285,990.00
Summary
Friedreich's ataxia (FA) is due to the lack of a protein known as frataxin. Recent studies using Baker's yeast have shown that the deletion of frataxin results in the accumulation of toxic iron in the mitochondrion. More recently, a variety of studies have shown that FA patients have iron loading within their cells. The iron build-up may cause severe damage. At present, the role of frataxin in mammalian mitochondrial iron metabolism is unknown. Our preliminary studies demonstrate that frataxin i ....Friedreich's ataxia (FA) is due to the lack of a protein known as frataxin. Recent studies using Baker's yeast have shown that the deletion of frataxin results in the accumulation of toxic iron in the mitochondrion. More recently, a variety of studies have shown that FA patients have iron loading within their cells. The iron build-up may cause severe damage. At present, the role of frataxin in mammalian mitochondrial iron metabolism is unknown. Our preliminary studies demonstrate that frataxin is down-regulated by either erythroid differentiation or the haem precursor protoporphyrin IX (Becker and Richardson, submitted). These data strongly suggest a role for frataxin in iron metabolism. In the present study we will continue to assess if frataxin plays a role in the way cells handle iron. Using a unique model of mitochondrial iron overload developed in my lab (Richardson et al. (1996) BLOOD 87:3477), we will extensively investigate the iron metabolism of the mitochondrion in order to determine the function of frataxin and its role in Friedreich's ataxia. In addition, we have developed a series of new drugs known as iron chelators that can enter the mitochondrion due to their high lipid solubility (Becker and Richardson 1999 J. Lab. Clin. Med. 134:510). These latter drugs are far more effective than the chelator currently used to treat iron overload, desferrioxamine (DFO). Indeed, our chelators have been designed to result in high iron chelation efficacy but low toxicity (see Becker and Richardson, 1999). This exciting research may be crucial in understanding the development of FA and in creating new therapies such as the use of iron chelators.Read moreRead less
Examining The Metabolic And Cognitive Deficits Caused By Insulin Resistance In The Ventral Striatum
Funder
National Health and Medical Research Council
Funding Amount
$400,372.00
Summary
Brain insulin resistance is thought to cause metabolic and cognitive deficits, but the underlying neural mechanisms remain elusive. This project addresses this gap in our knowledge by examining how brain insulin resistance disrupts the metabolic regulation of food intake and the cognitive control of actions. The outcomes will provide new insights in disorders characterised by brain insulin resistance such as obesity and dementia.
MICROFABRICATED DEVICES: A SIGNIFICANT ADVANCE FOR THE DETECTION AND MOLECULAR ANALYSES OF CIRCULATING CANCER CELLS?
Funder
National Health and Medical Research Council
Funding Amount
$422,107.00
Summary
Using advanced microfabrication concepts, this project aims to develop a platform technology able to capture tumour cells circulating in the blood of cancer patients. Although present only in extremely small numbers, these cells provide invaluable insights into the pathophysiology of the disease and consequently provide vital diagnostic and prognostic information. Molecular analyses of these cancer cells could ultimately enable the design of improved and personalized cancer treatment.
Do Synaptic-like Mechanisms Control Insulin Secretion?
Funder
National Health and Medical Research Council
Funding Amount
$593,235.00
Summary
An estimated 415 million people world-wide were diagnosed with diabetes in 2015. One of the causal factors in disease is the dysregulation of insulin secretion. We have developed new techniques to study insulin secretion that has led us to propose a new model for secretory control. This proposal sets out experiments to critically test this model. The outcomes could have wide-reaching impact on understanding and for future treatment and prevention of the diabetes.
How Does Paternal Obesity Influence Offspring Glucose Tolerance?
Funder
National Health and Medical Research Council
Funding Amount
$503,398.00
Summary
Obesity and diabetes are closely related to these conditions in either parent, but how the father contributes is unclear. We have shown that normal females mated with obese fathers consuming high fat diet, produce offspring who develop glucose intolerance and impaired insulin secretion. This work will examine the mechanisms underlying this effect in the rat, testing a novel role for environmental factors in the father on disease in offspring that may be relevant to the growing obesity epidemic.
Understanding Sphingolipid Mediators Of Insulin Resistance
Funder
National Health and Medical Research Council
Funding Amount
$643,447.00
Summary
Sphingolipids are a class of lipid metabolites that have a variety of functions within cells. It has been known for some time that an accumulation of excess lipid, including certain sphingolipids, can adversely impact insulin action and glucose metabolism in cells. In this project we will a combination of strategies to test the hypothesis that the sphingolipid profile can be manipulated to have favourable effects on metabolism.
The Structure And Function Of The Apical Domain In Insulin Secreting Beta Cells.
Funder
National Health and Medical Research Council
Funding Amount
$571,741.00
Summary
Loss of control of insulin secretion is causal in diabetes and therefore its understanding is a key goal to shed light on the disease. We have recently identified a new domain in the insulin secreting cells, called the apical domain. This proposal will define the role of this apical domain in controlling insulin secretion. The outcomes could provide new insights into how diabetes develops and new targets for therapies.
The Preferential Release Of Young Insulin Secretory Granules.
Funder
National Health and Medical Research Council
Funding Amount
$670,005.00
Summary
The aim of this study is to investigate the cause of reduced glucose induced insulin secretion in type 2 diabetes. In pancreatic beta-cells, insulin is packaged and stored in secretory granules (SGs). Upon stimulation, these SGs deliver insulin to the bloodstream. It is known that insulin SGs exist in two functionally distinct pools; and one pool is preferentially secreted upon stimulation. How a cell can differentiate the two SG pools is unclear, and we will address this issue in this project.
Do The Mitochondrial Sirtuin Enzymes, SIRT3 And SIRT5, Affect Insulin Action In Skeletal Muscle?
Funder
National Health and Medical Research Council
Funding Amount
$92,314.00
Summary
Metabolic disorders such as obesity, insulin resistance and type 2 diabetes are characterised by inappropriate handling of nutrients. Mitochondria are the primary site for nutrient oxidation in cells. Sirtuins such as SIRT3 and SIRT5 are abundant in mitochondria and may affect mitochondrial function and insulin action in skeletal muscle. Understanding the biochemical pathways involved in energy metabolism in skeletal muscle is crucial in the development of therapies for insulin resistance and ty ....Metabolic disorders such as obesity, insulin resistance and type 2 diabetes are characterised by inappropriate handling of nutrients. Mitochondria are the primary site for nutrient oxidation in cells. Sirtuins such as SIRT3 and SIRT5 are abundant in mitochondria and may affect mitochondrial function and insulin action in skeletal muscle. Understanding the biochemical pathways involved in energy metabolism in skeletal muscle is crucial in the development of therapies for insulin resistance and type 2 diabetes.Read moreRead less
De Novo Mutations And The Pathogenesis Of Childhood-onset Autoimmune Disease
Funder
National Health and Medical Research Council
Funding Amount
$1,406,510.00
Summary
This project aims to reveal the gene abnormalities that cause devastating autoimmune diseases to develop in some children, such as Type 1 diabetes, juvenile arthritis and autoimmune destruction of blood cells. The project will use new technologies to identify alterations in the DNA sequence of a child compared to either of their parents, and to test suspicious DNA alterations in laboratory mice in order to understand the gene effects and evaluate new treatments.