The Role Of Connexin40 In The Pathogenesis Of Atrial Fibrillation Probed By Targeted In Vivo Gene Transfer
Funder
National Health and Medical Research Council
Funding Amount
$529,015.00
Summary
Atrial fibrillation (AF) is a fast and irregular heart rhythm that can predispose sufferers to heart failure and stroke. AF occurs as the result of abnormal electrical conduction in the upper heart chambers. We have found that a protein called Cx40 causes abnormal conduction in heart cells when grown in culture. The aim of this research is to see if AF occurs when Cx40 is increased and prevented when Cx40 is decreased in an AF animal model, potentially defining Cx40 as new therapeutic target.
Characterisation Of A Novel Human Neuromuscular Disease Associated With Deficiency Of The Syntrophins And Dystrobrevin.
Funder
National Health and Medical Research Council
Funding Amount
$284,069.00
Summary
The muscular dystrophies are a group of hereditary muscle diseases which can result in severe and progressive muscle weakness. Children with muscular dystrophy have significant and worsening disabilities; many are unable to walk and, in severe cases, the weakness impairs the muscles of breathing resulting in death at an early age. The more common muscular dystrophies present in early childhood; however some forms of muscular dystrophy are so severe that muscle weakness is obvious at birth, affec ....The muscular dystrophies are a group of hereditary muscle diseases which can result in severe and progressive muscle weakness. Children with muscular dystrophy have significant and worsening disabilities; many are unable to walk and, in severe cases, the weakness impairs the muscles of breathing resulting in death at an early age. The more common muscular dystrophies present in early childhood; however some forms of muscular dystrophy are so severe that muscle weakness is obvious at birth, affected babies are never able to breathe adequately, and die during the first weeks of life. No specific treatment is currently available. Until recently the underlying gene and protein abnormalities resulting in the majority of cases of muscular dystrophy were unknown and hence definitive diagnosis and prenatal diagnosis was not possible. We have recently identified deficiency of a group of muscle proteins, the syntrophins and dystrobrevin, in 15 children with severe weakness, in whom the cause was previously unknown. This group of patients represent the first examples of a novel neuromuscular disorder. We will now identify the disease-causing genetic mutations in these patients and determine how abnormalities in these muscle proteins lead to muscle weakness and degeneration. This research will have immediate application to clinical practice as we will be able to give the childrens' families accurate information about the risk to future offspring and offer prenatal diagnosis. In addition, it will provide new and important information concerning the normal function of human skeletal muscle, which can be used to develop therapies for affected patients.Read moreRead less
Characterisation Of A New Family Of Proteins Involved In Cell Signalling, RNA Metabolism And Cancer
Funder
National Health and Medical Research Council
Funding Amount
$200,880.00
Summary
We have discovered a novel RNA-binding protein (G3BP-2) that is involved in responding to external signals, such as growth factors, at the level of gene expression. Other RNA-binding proteins belonging to the same broad group of proteins are responsible for a host of disease states in mammals including mental retardation, myotonic dystrophy, Huntington?s disease and cancers. Considering the wealth of knowledge accumulated that implicates these proteins to human dysfunction surprisingly few of th ....We have discovered a novel RNA-binding protein (G3BP-2) that is involved in responding to external signals, such as growth factors, at the level of gene expression. Other RNA-binding proteins belonging to the same broad group of proteins are responsible for a host of disease states in mammals including mental retardation, myotonic dystrophy, Huntington?s disease and cancers. Considering the wealth of knowledge accumulated that implicates these proteins to human dysfunction surprisingly few of these RNA-binding proteins have been identified. We have shown that the novel protein discovered in our laboratory is perturbed in cancer and we are interested in characterising its putative role in cancer. The results established in our laboratory so far would indicate that generally, G3BP-2 is expressed in normal tissue and it expression changes in some cancers studied so far. Considering that G3BP-2 lies in a pathway known to be involved in cancer progression it is important to understand what effects the inappropriate expression of G3BP-2 may have on cancer progression and survival. This project is designed to characterise what signals the cell uses to control these proteins and in turn which genes these may effect. In this way we may be able to determine how external signals may effect tumour progression and on what genes this influence is expressed. It would be hoped that this project would increase our understanding of cancer and potentially lead to new diagnostic reagents and therapies in the treatment of cancer.Read moreRead less
A Novel Mechanism For Intestinal Propulsion: Transit Without Neurons Or Pacemakers
Funder
National Health and Medical Research Council
Funding Amount
$256,973.00
Summary
A significant complication of premature births is that the mechanisms that regulate normal intestinal movements have not yet fully developed. We have recently identified a novel pattern of contraction that is seen predominantly in the colon of mice that have not yet developed either the normal nerve circuits that control gut movement and also lack the pacemaker cells that are intrinsic to the muscle coat. This motor pattern appears to be responsible for the movement of gut content during the dev ....A significant complication of premature births is that the mechanisms that regulate normal intestinal movements have not yet fully developed. We have recently identified a novel pattern of contraction that is seen predominantly in the colon of mice that have not yet developed either the normal nerve circuits that control gut movement and also lack the pacemaker cells that are intrinsic to the muscle coat. This motor pattern appears to be responsible for the movement of gut content during the development and maturation of the nerve circuits that regulate this process in more adult animals. However, the mechanisms responsible for this process have not been identified. This project is directed at identifying these mechanismsRead moreRead less
Protein Partners Of Rapsyn That Regulate Acetylcholine Receptor Clustering
Funder
National Health and Medical Research Council
Funding Amount
$411,000.00
Summary
Spinal nerves control our limb muscles by releasing chemical signals directly onto the surface of muscle fibres that they contact. These chemical signalling contacts are called synapses. They are like the synapses between nerve cells in our brains but easier to study, meaning that we can make more rapid progress in understanding how synapses work. The sensor receptors for chemical signals at the nerve-to-muscle synapse are held in place on the muscle fibre surface by a protein called rapsyn. In ....Spinal nerves control our limb muscles by releasing chemical signals directly onto the surface of muscle fibres that they contact. These chemical signalling contacts are called synapses. They are like the synapses between nerve cells in our brains but easier to study, meaning that we can make more rapid progress in understanding how synapses work. The sensor receptors for chemical signals at the nerve-to-muscle synapse are held in place on the muscle fibre surface by a protein called rapsyn. In turn, rapsyn must be organized by other chemical signals from the nerve, but we don't know exactly how this happens. When the receptors become disorganized at the synapse, in diseases such as Myasthenia Gravis, we lose control of our muscles. This project will employ newly developing techniques of proteomics and genomics to identify new proteins that bind to rapsyn and to test how they work to organize receptors at the synapse. By identifying the proteins that control rapsyn we may be able to develop new treatments for Myasthenia Gravis that restore the function of the synapse with less side effects than current therapies.Read moreRead less
Postsynaptic Signalling Systems That Sustain The Nerve-muscle Synapse
Funder
National Health and Medical Research Council
Funding Amount
$598,041.00
Summary
Neuromuscular junctions (NMJ) are the synapses through which motor nerves control our voluntary muscle cells. This project will investigate the molecular signalling system between nerve and muscle that helps maintain healthy NMJs. Normal ageing involves a progressive decline in muscle strength, often leading to loss of independence in the elderly. We will use a mouse model to test whether a breakdown of the NMJ signalling system contributes to the loss of strength in old age.
The Role Of Connexins In Blood Pressure Regulation: Use Of A Conditional Gene Expression System
Funder
National Health and Medical Research Council
Funding Amount
$583,767.00
Summary
Cell coupling through gap junctions is said to play an important role in regulating blood flow and blood pressure. However data obtained from mice, in which specific gap junctions are deleted, may be compromised by compensatory changes in other junctions. We have validated a new method for rapidly and reversibly altering gap junctions in adult mice with oral sugar. This technique will enable us to directly determine whether interference with cell coupling affects blood flow and blood pressure.