Nerve cell survival is dependent on both growth-promoting factors and factors released by neurotransmission, which can promote recovery in neurodegenerative conditions by overriding cell death pathways. The molecule responsible for activating death pathways in the nervous system is called p75. This project will investigate how p75 results in cell death, how synaptic signals can prevent the activation of the p75 death pathway and whether blocking p75 function can limit neurodegeneration.
Regulation Of Amyloid-beta Production By Glycosphingolipid Synthesis Inhibition
Funder
National Health and Medical Research Council
Funding Amount
$549,925.00
Summary
Alzheimer's disease (AD) prevalence is rising and there is currently no curative treatment. Production of neurotoxic amyloid-beta peptide (Abeta) in the brain is thought to be one causative factor in AD. We have recently discovered a new drug that alters lipid levels in cell membranes and potently inhibits Abeta production by neurons. We will define precisely how this drug works and examine its potential to reduce Abeta accumulation in the brains of mice genetically engineered to mimic AD.
Amyloid Precursor Proteins Novel Role In Alzheimers Disease Through Regulating Neuronal Iron Homeostasis.
Funder
National Health and Medical Research Council
Funding Amount
$949,667.00
Summary
Our group has discovered a novel role of amyloid precursor protein (APP) in cellular iron balance. The smallest form of APP, prevalently found in the brain, is able to convert a damaging iron variety (Fe2+) into the safer Fe3+. Alternative, larger, forms of APP are found to inhibit this effect. This project will establish how APP controls iron homeostasis within brain neuronal cells and how this activity is impaired in disease, thus development a mechanism for diagnostic tests and therapeutics.
How Does The P75 Neurotrophin Receptor Transmit Both Pro-survival And Pro-apoptotic Signals In Neurons?
Funder
National Health and Medical Research Council
Funding Amount
$265,500.00
Summary
Signaling by the two NGF receptors, TrkA and p75, determines the survival or death of sensory neurons and of certain brain neurons involved in memory and learning. The most baffling aspect of these receptors is that in most circumstances they cooperate with each other to maximise the survival of neurons when NGF is present, but in some situations they are opposed to each other. In the latter case, NGF treatment can lead to death, rather than rescue, of neurons. In the last three years we have de ....Signaling by the two NGF receptors, TrkA and p75, determines the survival or death of sensory neurons and of certain brain neurons involved in memory and learning. The most baffling aspect of these receptors is that in most circumstances they cooperate with each other to maximise the survival of neurons when NGF is present, but in some situations they are opposed to each other. In the latter case, NGF treatment can lead to death, rather than rescue, of neurons. In the last three years we have developed novel antisense oligonucleotides which can be used to switch off each receptor separately. These have been, and will continue to be, particularly valuable tools for our research. We have also uncovered a novel way in which the two receptors interact (via a signal transduction molecule known as SHC), which provides us with a competitive edge in this area. We have the expertise and equipment to identify and clone the missing factors that account for the paradoxical interactions between p75 and TrkA. A successful outcome from this project will have important benefits by improving our understanding of the factors controlling neuronal fate, and will help to develop treatments for neurodegenerative diseases.Read moreRead less
Characterisation Of Neural Stem Cells In The Ageing Mammalian Brain
Funder
National Health and Medical Research Council
Funding Amount
$182,411.00
Summary
Due to their relatively recent discovery, little is known about how stem cells in the brain are affected by age. This work will initially focus on understanding how age affects the number of stem cells found in the brain, and how their normal function and regenerative capacity are compromised with increasing age. The second phase of this study will examine how we can slow or even reverse these age-related changes on stem cells by environmental manipulation.
Understanding the biological mechanisms of nerve degeneration is an essential step toward the development of novel therapies for human neurodegenerative conditions such as Parkinson's, Alzheimer's and Huntington's diseases, and for spinal cord injuries. The studies presented in this proposal, using the powerful molecular and genetic tools available for the small nematode worm C. elegans, will provide new insights into the cellular and molecular mechanisms responsible for nerve degeneration.
Identification And Origin Of Neuronal Precursors In The Adult Mouse Hippocampus
Funder
National Health and Medical Research Council
Funding Amount
$284,250.00
Summary
It is now clear that new neurons continue to be generated under normal conditions in at least 2 regions of the adult mammalian brain: the olfactory bulb (smell centre) and the hippocampus (organ responsible for memory and learning). These new neurons replace those lost as part of aging and, as such, are vital to normal brain function. Recently, these results have been extended to show that various insults, such as stroke, can cause the proliferation of precursor cells in the adult brain, which u ....It is now clear that new neurons continue to be generated under normal conditions in at least 2 regions of the adult mammalian brain: the olfactory bulb (smell centre) and the hippocampus (organ responsible for memory and learning). These new neurons replace those lost as part of aging and, as such, are vital to normal brain function. Recently, these results have been extended to show that various insults, such as stroke, can cause the proliferation of precursor cells in the adult brain, which ultimately results in the addition of new nerve cells that go on to repair the pathological damage. Although the production of new nerve cells under normal conditions and following damage is highly significant, we still know surprisingly little about the nature of the precursor population which produces these cells and even less about their regulation. For the most part, this has been due to our inability to identify and isolate the brain stem cell. Thus, over the last 5 years I have adapted cell sorting techniques - which are normally used to separate blood cells to isolate populations of cells from the brains of adult mice. As a result of my work, we are now in the position to sort for a population of stem cells that are known to give rise to new brain cells in the adult olfactory bulb. This work will be extended to identify and characterise the precursor population that resides in the hippocampus. The identification of this hippocampal precursor population will thus provide the foundation for developing new approaches for the treatment of diseases such as strokeRead moreRead less
Role Of ABCA-G Transporters In Neuronal Cholesterol Regulation And Alzheimers Disease
Funder
National Health and Medical Research Council
Funding Amount
$557,582.00
Summary
Alzheimer's disease (AD) prevalence is rising and the contributing factors are poorly understood. Recent research shows that cholesterol regulates the production of neurotoxic amyloid-beta peptide (Abeta). We will study a class of proteins, ABC transporters, that we believe regulate neuronal cholesterol and Abeta metabolism. We will use isolated brain cells, human brain tissue and genetically engineered mice in order to define how cholesterol influences AD and identify new treatment options.
A -induced Cell Death Signalling By The P75 Neurotrophin Receptor.
Funder
National Health and Medical Research Council
Funding Amount
$546,382.00
Summary
The amyloid peptide A is central to the cause of Alzheimer's disease. We have recently found that A can activate the cell death receptor p75NTR which is found in the nerve cells that die in Alzheimer's disease. This project will study whether this death pathway underpins the neuronal death associated with Alzheimer's disease. It will also determine the mechanism by which A activates p75NTR death signalling, and identify biochemical ways to prevent this from occurring.