Is Placental Aging The Key To Understanding, Predicting And Preventing Stillbirth?
Funder
National Health and Medical Research Council
Funding Amount
$473,861.00
Summary
Stillbirth occurs in 35 times as many pregnancies as sudden infant death but the causes are unknown. This project will help to develop tests that can predict the risk of stillbirth so that the obstetrician can deliver the baby before it dies. The investigators hypothesise that stillbirth is due to aging of the placenta and that markers of the aging placenta can be detected in the mother’s blood. The project brings together experts in the placenta, aging and obstetric care of high risk pregnancy.
Role Of Transition Metal Ions And Redox Activity In The Development Of Atherosclerotic Plaques
Funder
National Health and Medical Research Council
Funding Amount
$196,018.00
Summary
Metal ions such as iron and copper have been reproted to be present in the lesions present in diseased human arteries and it has been suggested that these metal ions contribute to the development of atherosclerosis (hardening of the arteries) via their ability to catalyse the formation of highly reactive molecualr fragments called free radicals. Though metal ions are known to catalyse such reactions in test-tube experiments, both the presence of metal ions in diseased arteries and their ability ....Metal ions such as iron and copper have been reproted to be present in the lesions present in diseased human arteries and it has been suggested that these metal ions contribute to the development of atherosclerosis (hardening of the arteries) via their ability to catalyse the formation of highly reactive molecualr fragments called free radicals. Though metal ions are known to catalyse such reactions in test-tube experiments, both the presence of metal ions in diseased arteries and their ability to generate free radicals is controversial. This study will employ a novel, minimally-invasive, technique to assess the nature and quantity of metal ions present in well-defined human and animal lesions at different stages of lesion development. The ability of these metal ions to catalyse free radical formation from components present in the artery wall will also be assessed. The release of these metal ions from the artery wall to added organic molecules will be assessed as this might minimise their potential to cause damage, and provide a possible therapeutic strategy. These studies will therefore provide valuable information as to the significance and role of reactive metal ions in the development of human artery disease and the possible prevention, or minimisation, of such processes.Read moreRead less
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
$606,000.00
Summary
Friedreich's ataxia (FA) is due to the lack of a protein known as frataxin. A variety of studies using Baker's yeast and conditional frataxin knockout (KO) mice have shown that deletion of frataxin leads to the accumulation of toxic iron in their mitochondrion. More recently, a variety of studies have shown that FA patients have iron-loading within their mitochondrion. Iron in the highly redox active environment of the mitochondrion could contribute to the generation of cytotoxic radicals that c ....Friedreich's ataxia (FA) is due to the lack of a protein known as frataxin. A variety of studies using Baker's yeast and conditional frataxin knockout (KO) mice have shown that deletion of frataxin leads to the accumulation of toxic iron in their mitochondrion. More recently, a variety of studies have shown that FA patients have iron-loading within their mitochondrion. Iron in the highly redox active environment of the mitochondrion could contribute to the generation of cytotoxic radicals that cause severe damage. Further, cells deficient in frataxin are sensitive to oxidant stress and Fe chelators rescue oxidant-mediated death of cells from FA patients. Indeed, free radical scavengers have shown to be of use in the treatment of this disease. Studies in DR's lab during this NHMRC grant have shown that frataxin is down-regulated by erythroid differentiation or the haem precursor, protoporphyrin IX (BLOOD 2002;99:3813-22). These data indicate a role for frataxin in Fe metabolism and the pathogenesis of FA. In this study we will continue to examine the role of frataxin in the way cells handle Fe using experimental models developed under the current NHMRC grant. These include transfected cell lines with low frataxin expression generated using an expression vector containing anti-sense frataxin cDNA. Further we obtained the frataxin conditional KO mouse and generated a breeding colony. These animals display many of the pathological features of FA and are the best current model of the disease. Indeed, they will be critical for assessing the role of frataxin in Fe metabolism and as a model to test the ability of Fe-binding drugs to prevent the pathology observed. We designed lipid-soluble chelators that can enter the mitochondrion to bind Fe (Biochim Biophys Acta 2001;1536:133-140) and these ligands will be tested to prevent disease progression in the KO mice. This exciting research is crucial for understanding the pathogenesis of FA and in creating new therapies.Read moreRead less
Contribution Of Disturbed Blood Flow And Cerebral Metabolism To White Matter Damage In The Perinatal Brain
Funder
National Health and Medical Research Council
Funding Amount
$369,375.00
Summary
It has been known for some time that the white matter regions of the developing brain are particularly vulnerable to damage. These regions are deep in the brain near the ventricles, and are rich in myelin sheaths wrapped around the nerve fibres running from cell-rich areas in the outer layers of the brain to other regions, and down into the spinal cord. Damage to white matter usually leads to behavioural, learning and motor problems in the newborn infant - in its severest form, seen as cerebral ....It has been known for some time that the white matter regions of the developing brain are particularly vulnerable to damage. These regions are deep in the brain near the ventricles, and are rich in myelin sheaths wrapped around the nerve fibres running from cell-rich areas in the outer layers of the brain to other regions, and down into the spinal cord. Damage to white matter usually leads to behavioural, learning and motor problems in the newborn infant - in its severest form, seen as cerebral palsy. Such outcomes are often associated with the presence of asphyxia and infection during pregnancy, leading to the belief that the damage first arises while the baby is still in utero. In this application we suggest that asphyxia and-or infection during pregnancy cause prolonged disturbances in the regulation of blood flow and integrity of the blood-brain barrier in the developing brain, together with changes in metabolism that result in accumulation of prostaglandins and the toxic hydroxyl radical, leading irreversibly to cell death. If this series of events proves to be true, we have suggested and will test several protocols for protecting the fetal brain, which should be readily translatable to clinical practice.Read moreRead less
THE EFFECT OF STRESS AND ENVIRONMENTAL ENRICHMENT ON DISEASE PROGRESSION IN MESIAL TEMPORAL LOBE EPILEPSY
Funder
National Health and Medical Research Council
Funding Amount
$578,201.00
Summary
Mesial temporal lobe epilepsy, the most common form of drug-resistant epilepsy in adults, is a progressive neurodegenerative condition for which there is currently no effective disease modifying treatment. This proposal will explore whether co-morbid stress accelerates disease progression in MTLE, and whether targeting stress pathways by medical and environmental manipulations can mitigate against this.
Increased Vulnerability To Stress During Opiate Dependence: Molecular, Anatomical, And Behavioural Correlates
Funder
National Health and Medical Research Council
Funding Amount
$272,640.00
Summary
Heroin addiction is a major health and societal problem in Australia. It is consistently associated with an adverse impact upon individual users, their families, and communities. It is a chronically relapsing condition for which few, if any effective prevention and treatment strategies exist. Moreover, why an individual initiates and maintains heroin taking remains unclear. Stress and negative emotions have a strong impact on heroin use. Stress may drive some individuals to start using heroin, s ....Heroin addiction is a major health and societal problem in Australia. It is consistently associated with an adverse impact upon individual users, their families, and communities. It is a chronically relapsing condition for which few, if any effective prevention and treatment strategies exist. Moreover, why an individual initiates and maintains heroin taking remains unclear. Stress and negative emotions have a strong impact on heroin use. Stress may drive some individuals to start using heroin, stress increases the pleasurable effects of heroin and stress increases the aversive effects of heroin withdrawal. These effects will encourage addiction and discourage addicts from seeking treatment. Stress can also cause an otherwise drug-free individual to relapse to heroin addiction despite having been drug-free for some time. In this project we will study why stress has such a large impact on heroin addicts and heroin addiction. We will test the hypothesis that heroin use actually produces profound alterations in the neural network in the brain which controls responses to stress. This project uses a simple animal model of heroin addiction whereby rats are injected with morphine to study the regulation of several genes which are important in responding to stress. We will also study how this exposure and changes in gene expression alter neurobiological, cardiovascular, and behavioural responses to stress. This project will identify parts of the brain that are altered during heroin addiction, and will also identify why heroin addicts are more vulnerable to stress than the general population. Therefore, this project will help us to identify targets for therapeutic intervention (both psychological and pharmacological) and possibly disrupt the addictive cycle.Read moreRead less
Does Obesity Have The Characteristics Of Addiction?
Funder
National Health and Medical Research Council
Funding Amount
$430,832.00
Summary
The number of overweight or obese people in Australia has increased dramatically in recent years, increasing disease risk. The brain responds to palatable food in ways similar to the response to drugs of addiction, and this may explain why people find it hard to resist palatable food. Our work will explore whether obesity in rats has the characteristics of addiction by examining bingeing, craving, withdrawal and brain circuits in animals chronically exposed to palatable food.
Inhibition Of Fear Memories By Extinction: Neural Substrates.
Funder
National Health and Medical Research Council
Funding Amount
$234,250.00
Summary
Anxiety disorders [e.g., Post Traumatic Stress Disorder (PTSD)] are the most prevalent type of psychopathology in the industrialised world. They are associated with characteristic behavioural (e.g., heightened startle) and autonomic (e.g., cardiovascular) reactions. These disorders are often characterised as an inability to regulate the emotion of fear. Significant progress has been made in understanding the neural and cellular processes involved in the establishment of fear memories, but relati ....Anxiety disorders [e.g., Post Traumatic Stress Disorder (PTSD)] are the most prevalent type of psychopathology in the industrialised world. They are associated with characteristic behavioural (e.g., heightened startle) and autonomic (e.g., cardiovascular) reactions. These disorders are often characterised as an inability to regulate the emotion of fear. Significant progress has been made in understanding the neural and cellular processes involved in the establishment of fear memories, but relatively little is known about the mechanisms by which fear memories can be inhibited or suppressed. Understanding this latter process is a key to the development of effective treatments for anxiety disorders such as PTSD where the patient suffers from persistent, intrusive, unwanted trauma memories. A common experimental procedure for reducing learned fear is to repeatedly expose the subject to a fear-eliciting stimulus but without any aversive outcome. This procedure leads to a progressive loss, or extinction, of the fear reactions elicited by the stimulus. Historically, the extinction of fear was thought to be due to an erasure of the fear memory. However, recent evidence shows that extinction inhibits, rather than erases, the fear memory. Because the fear memories remain intact, some structure(s) in the brain must inhibit activity in the fear pathway. This project uses extinction of conditioned fear reactions in rat subjects to determine the structure(s) in the brain that inhibit fear memories and their behavioural and cardiovascular expression. It brings together the expertise of four well-established researchers and uses a combination of behavioural, physiological, immunohistochemical, tract tracing, and lesion approaches to achieve this aim. The proposed experiments will reveal the structure(s) in the brain that control the inhibition of fear, as well as the site(s) of this inhibition in the fear pathwayRead moreRead less