Glutathione is a natural antioxidant, which is known to protect cells in the body from chemical damage. A small part of the glutathione in cells is found in the mitochondria, a structure that is involved in producing the chemical energy needed for normal cell function. The mitochondria are also involved under some circumstances in promoting the death of cells. Although glutathione in general has been well studied, much less attention has been paid to the function of glutathione in mitochondria, ....Glutathione is a natural antioxidant, which is known to protect cells in the body from chemical damage. A small part of the glutathione in cells is found in the mitochondria, a structure that is involved in producing the chemical energy needed for normal cell function. The mitochondria are also involved under some circumstances in promoting the death of cells. Although glutathione in general has been well studied, much less attention has been paid to the function of glutathione in mitochondria, particularly in cells from the brain. Our recent studies indicate that this mitochondrial pool of glutathione is particularly important in limiting the death of cells from the brain when exposed to damaging substances that are increased in some diseases. Thus, the capacity of mitochondrial glutathione to deal with such substances might be a factor in determining the extent of cell loss in the brain, which is an important determinant of symptoms in some of the major neurological diseases. Consistent with this possibility, we have obtained evidence indicating that decreases in glutathione in the mitochondria contribute to the cell death and brain damage that results from a stroke. In our proposed studies, we will investigate the function of mitochondrial glutathione in the two major cell populations from the brain, neurons and astrocytes. We will characterise the protective role of the glutathione and investigate how it enters the mitochondria and what factors influence the amount that is present. This will provide new insights into the function of glutathione in the mitochondria and could also suggest novel approaches for manipulating this antioxidant pool. We will also study models of stroke and some related brain disorders to more directly test the role of this antioxidant in disease and to assess whether manipulating the content of glutathione in the mitochondria has the potential to reduce damage and improve function in these disordersRead moreRead less
Deciphering How PTEN Phosphatase Mediates Excitotoxic Neuronal Death
Funder
National Health and Medical Research Council
Funding Amount
$519,715.00
Summary
In stroke patients, oxygen deprivation indirectly induces massive nerve cell death by activating a cell death-promoting enzyme called PTEN. We aim at unravelling (i) how PTEN is activated by oxygen deprivation, (ii) where the activated PTEN is localised in cells, and (iii) how the activated and optimally localised PTEN induces nerve cell death. The study will benefit development of therapeutic strategies to protect against brain damage in stroke.
Role Of Synaptogenesis In Developmental Motoneuron Cell Death
Funder
National Health and Medical Research Council
Funding Amount
$361,650.00
Summary
Naturally occurring cell death is an important and necessary event that shapes the developing embryo. It occurs in all organs of the developing body. In the nervous system about 50% of all neurons die at a time when they are making contact with one another or with their target organs. The underlying mechanisms that drive programmed neuronal cell death are not known. One possibility is that the formation of neuronal contacts (synapses) with other neurons and target cells determines the fate of a ....Naturally occurring cell death is an important and necessary event that shapes the developing embryo. It occurs in all organs of the developing body. In the nervous system about 50% of all neurons die at a time when they are making contact with one another or with their target organs. The underlying mechanisms that drive programmed neuronal cell death are not known. One possibility is that the formation of neuronal contacts (synapses) with other neurons and target cells determines the fate of a neuron. The connections of motor neurons with muscle during this period of developmental neuronal cell death is the best model to examine this phenomenon. In this grant we are in an exciting position to be able to address what causes neuronal cell death, as we have a number of mice that lack key molecules needed for the formation of specializations that allow neuronal contacts to be made between motor neurons and their muscle, and with other neurons within the spinal cord. By examining the function of motor neurons, counting them and screening for molecular changes in these mice, we will be able to dissect out the mechanism of how a motor neurons' fate is determined during the period of programmed cell death. The outcomes of this research will enable us to understand how the nervous system is shaped during development and will increase our knowledge about the basis of adult neurodegenerative diseases. For example, the pathology of Alzheimer's is characterised by a breakdown in neuronal connections that ultimately result in neuronal death and a loss of thought processes (cognition).Read moreRead less
The Role Of Central And Peripheral Synaptic Activity In The Developmental Death Of Motoneurons.
Funder
National Health and Medical Research Council
Funding Amount
$463,145.00
Summary
Information processing in the nervous system relies on the effective communication between neurons and their target cells which make up our neuronal circuitry. At the centre of all this is the synapse, the specialized contact between a neuron and its target cell, be it another neuron in the brain or a target organ such as skeletal muscle. Our primary goal is to determine how the formation of synaptic connections during development regulates neuronal survival. In this proposal we have focussed on ....Information processing in the nervous system relies on the effective communication between neurons and their target cells which make up our neuronal circuitry. At the centre of all this is the synapse, the specialized contact between a neuron and its target cell, be it another neuron in the brain or a target organ such as skeletal muscle. Our primary goal is to determine how the formation of synaptic connections during development regulates neuronal survival. In this proposal we have focussed on the neuromotor system as it is a well characterised part of the nervous system. During development, 50% of motoneurons die at a time when they are making contact with skeletal muscle, and when contacts onto motoneurons by other neurons are being established. We believe that the formation of effective synaptic contacts onto motoneurons, as well as connections by motoneurons onto muscle are the key regulators of motoneuron survival. We are in a position to be able to address what regulates motoneuron death; as we have a number of mice which lack key molecules needed for the formation of specialisations that allow neuronal contacts to be made between motor neurons and their muscle, and with other neurons within the spinal cord. By examining the function of motoneurons, counting them and screening for molecular changes in these mice, we will be able to dissect out the mechanism of how a motoneurons' fate is determined during developmental motoneuron death. This research could help in developing strategies aimed at improving neuronal connections to improve neuronal viability. Our research will have important implications for our understanding about the basis of adult neuro-degenerative diseases, such as motor neuron disease and Alzheimer's, which are in part characterised by a molecular breakdown in neuronal connections that ultimately result in neuronal death.Read moreRead less
Neuroprotection By Ndfip1 In Brain Injury - Identifying Targets And Understanding Mechanisms
Funder
National Health and Medical Research Council
Funding Amount
$836,225.00
Summary
Brain injury from trauma and motor vehicle accidents is a serious health issue, affecting approximately 30,000 Australians per year. About 10% of the victims suffer serious long term consequences, including mental, physical and behavioural impairment. We have discovered a new brain protein capable of preventing neurons from dying following injury. This grant will improve our understanding of how this protein works, and provide a scientific foundation for devising therapies.
The Role Of The Ras Signalling Molecule, C3G, In The Interaction Of Neural Precursor Cells And Their Environment
Funder
National Health and Medical Research Council
Funding Amount
$319,446.00
Summary
Developmental brain disorders affect 1-3% of the population. The mental retardation disease spectrum includes neuronal migration disorders and neural precursor proliferation disorders. We propose to study a molecular mechanism regulating neuronal migration, survival and proliferation. We have identified a protein, C3G, which is essential for three aspects of nervous system development: (A) C3G limits neural precursor cell proliferation. (B) C3G is essential for neuronal survival. (C) C3G is cruc ....Developmental brain disorders affect 1-3% of the population. The mental retardation disease spectrum includes neuronal migration disorders and neural precursor proliferation disorders. We propose to study a molecular mechanism regulating neuronal migration, survival and proliferation. We have identified a protein, C3G, which is essential for three aspects of nervous system development: (A) C3G limits neural precursor cell proliferation. (B) C3G is essential for neuronal survival. (C) C3G is crucial for neuronal migration. C3G acts in a cascade of proteins, known as the Ras signalling pathway, which transmits signals from the extracellular environment into the cell nucleus to elicit appropriate responses of the cell to cues from the outside. We will identify proteins that, together with C3G, affect the important processes of neural precursor proliferation, and neuron survival and migration. This project will fully characterise a key regulatory mechanism of cellular processes crucial to the development of normal intelligence.Read moreRead less
MITOCHONDRIA, OXIDATIVE STRESS AND NEURONAL APOPTOSIS: BIOCHEMICAL, CELLULAR AND PHARMACOLOGICAL APPROACHES
Funder
National Health and Medical Research Council
Funding Amount
$145,880.00
Summary
Our goal is to understand the detailed process whereby nerve cells die after various stresses and injury. We aim also to develop novel ways of protecting cells against such death. The death of nerve cells plays an important role in a series of neurodegenerative diseases, such as Parkinson's, Huntington's and Motor Neurone Diseases. One prevalent cause of cell death arises from the action of transmitters that normally signal between nerve cells but which, under conditions of stress and injury, ca ....Our goal is to understand the detailed process whereby nerve cells die after various stresses and injury. We aim also to develop novel ways of protecting cells against such death. The death of nerve cells plays an important role in a series of neurodegenerative diseases, such as Parkinson's, Huntington's and Motor Neurone Diseases. One prevalent cause of cell death arises from the action of transmitters that normally signal between nerve cells but which, under conditions of stress and injury, cause overstimulation of the nerve cells leading to death (excitotoxicity). Mitochondria are component of cells normally providing energy for the cell to carry out its various functions; but under stress conditions mitochondria act as controllers in cellular decision-making processes leading to cell death. Moreover, mitochondria are known to play an important role in neurodegenerative diseases, as they are a source of damaging oxygen derivatives called free radicals that cause cell injury. Mitochondria are also involved in death resulting from excitotoxicity. In order to understand the detailed mechanism of the nerve cell death process, we will use cultured nerve cells from the brains of laboratory mice, including both normal mice and those that are models of neurodegenerative disease. Injury leading to death will be induced by analogues of the transmitters that cause excitotoxicity. We will concentrate the those aspects of the death process that involve mitochondria, as this will enable us to test a range of antioxidants that can be expected to lead to new drug treatments for neuronal cell injury. Included in these compounds are novel antioxidants that are targeted to mitochondria. This project brings together the expertise in neuroscience and pharmacology of Professor Beart with the skills in biochemistry of Professor Nagley, particularly in mitochondrial and cell death research, to address this important medical research problem in a multidisciplinary manner.Read moreRead less
Regulation Of P75 Death Signalling: How Neurotransmitter- And Neurotrophic- Signals Determine Cell Survival
Funder
National Health and Medical Research Council
Funding Amount
$292,216.00
Summary
Nerve cell survival is dependent on trophic support in the form of growth factors and synaptic input, both of which promote recovery after nerve injury. The survival pathways activated by growth factors are generally well characterised, whereas survival signals activated by synaptic activity are largely unexplored. This proposal aims to discover how synaptic activity prevents nerve cell death by looking at how synaptic activity inhibits the processes active in dying nerve cells.
Gamma-Secretase Inhibitors As Novel Pharmacological Agents To Target Stroke-induced Brain Injury
Funder
National Health and Medical Research Council
Funding Amount
$441,511.00
Summary
Stroke is the world�s 2nd leading cause of death. In Australia, stroke is the leading cause of serious, long-term disability. Alarmingly, there is a looming stroke epidemic in Australia. There is an urgent need for novel therapies capable of reducing mortality and long-term disability in victims of stroke. We have recently identified gamma-secretase inhibitors (GSIs) as a potent stroke therapy. This project will investigate how GSIs protect against ischaemic stroke at the molecular level.