Regulation Of Bone Formation And Resorption By Osteoblastic EphrinB2/EphB4 Signalling
Funder
National Health and Medical Research Council
Funding Amount
$648,479.00
Summary
Skeletal strength is maintained by balanced cycles of bone resorption and bone formation. Cells that live inside the bone matrix, osteocytes, are thought to co-ordinate this. We have found that two proteins, EphrinB2 and EphB4, exist on the surface of osteocytes and regulate bone formation and resorption. This project investigates how they do this, and whether interfering with or enhancing their signals could be used to increase bone strength in osteoporosis.
Skeletal structure is continually modified throughout life to take into account dietary, hormonal and physical changes. This is brought about by three major cell types which either form bone, destroy bone, or sense mechanical and hormonal influences on the skeleton. My work seeks to understand the way these cells are controlled and how they control each other. In this way, I will identify new ways of treating osteoporosis, arthritis, skeletal birth defects and cancer-induced bone disease.
Mesenchymal Stem Cell Maintenance And Recruitment During Skeletal Repair Are Dependent On EphB-ephrinB Signalling
Funder
National Health and Medical Research Council
Funding Amount
$611,827.00
Summary
There is currently a steady increase in surgical intervention and rehabilitation therapy for bone related fractures due to trauma or osteoporosis as a consequence of an aging population. Bone regeneration involves the coordinated participation of skeletal precursor cells, blood vessels and immune cells recruited from the surrounding tissues. This proposal examines the mechanisms mediating the maintenance and recruitment of skeletal precursor cells to sites of bone damage.
The Role Of Neuronal Hyperactivity And Neurotrophic Factor Signalling In Synaptogenesis, Dendrogenesis And Neuron Death In Motor Neuron Disease
Funder
National Health and Medical Research Council
Funding Amount
$700,331.00
Summary
Using mice with mutant genes causing amyotrophic lateral sclerosis, we will test whether motor neuron hyper-excitability during early development causes excessive synapse and dendrite formation, ultimately leading to neuronal death. We will also test whether activity-dependent secretion of neurotrophic factors and activation of their receptors plays a role in this disease. This will show whether neuronal hyper-activity and neurotrophic factor signaling plays a causal role in this disease.
Molecular And Cellular Changes Following A Cortical Injury: What Role Do They Play In Regeneration?
Funder
National Health and Medical Research Council
Funding Amount
$499,625.00
Summary
Damage to the visual areas of the brain is common after, for example stroke, neurotrauma or hypoxia. The injury often manifests in the form of a scar caused by a specific type of brain cell (astrocyte). This scar acts as a barrier to the cells which transmit information (neurones), preventing re-establishment of connectivity, thus functional recovery. We will see if we can reduce this scar and enhance re-connectivity after injury by blocking some of the molecules that brain cells express.
Defining The Role Of EphA5 In Olfactory Axon Growth, Guidance And Fasciculation
Funder
National Health and Medical Research Council
Funding Amount
$256,320.00
Summary
The olfactory (smell) system is a unique part of the nervous system; nerve cells are generated throughout life and it can regenerate even after injury. It therefore provides an excellent model for examining the growth, development and maintenance of nerve cells. This project will examine the effects on the organisation of the olfactory system when some guidance signals are altered. Information we obtain about how this system develops and regenerates may be useful in treating brain disorders and ....The olfactory (smell) system is a unique part of the nervous system; nerve cells are generated throughout life and it can regenerate even after injury. It therefore provides an excellent model for examining the growth, development and maintenance of nerve cells. This project will examine the effects on the organisation of the olfactory system when some guidance signals are altered. Information we obtain about how this system develops and regenerates may be useful in treating brain disorders and spinal injuries In the current project we will examine the effects of specific nerve cell guidance molecules by generating transgenic mice that produce these molecules only in the olfactory system. We can then determine what changes occur to the nerve cells when these extra molecules are produced. In addition, we will also examine the behaviour of live cells as they are growing. In the past all attempts to understand how nerve cell connections are formed in the olfactory system have used dead tissue that has been permanently preserved. In this project we have the unique opportunity to visualise living nerve cells to enable us to determine how the cells react to the guidance signals. The advantage of this approach is that it allows us to identify important interactions as they occur, rather than attempting to decipher them after they have occurred. An analogy would be watching a football game live and observing how goals were scored and appreciating the performance of individual players versus trying to guess from the final score how the game was played and who the key performers were. The results of these experiments will provide important information on the regeneration of olfactory nerve cells, as well as on the initial growth and targeting of these nerve cells.Read moreRead less
The Role Of The EphA1 In The Normal Epithelial Organs And In Epithelial Tumour Progression.
Funder
National Health and Medical Research Council
Funding Amount
$564,500.00
Summary
The Eph family of proteins were initially found to be important in normal development. In humans this corresponds to the first 12 weeks of pregnancy. In parallel with these studies, other work provided evidence of abnormally high levels of these proteins in a number of human cancers. More recent evidence suggests that these proteins have important roles in the maintenance of normal tissues and in non-malignant diseases. This proposal seeks to understand how one of these proteins (EphA1) works in ....The Eph family of proteins were initially found to be important in normal development. In humans this corresponds to the first 12 weeks of pregnancy. In parallel with these studies, other work provided evidence of abnormally high levels of these proteins in a number of human cancers. More recent evidence suggests that these proteins have important roles in the maintenance of normal tissues and in non-malignant diseases. This proposal seeks to understand how one of these proteins (EphA1) works in the cells which form the skin, liver, kidneys, breast and prostate. These cells also form the lining of the mouth, stomach, bowel and lungs. Understanding how the EphA1 protein and other members of this family cooperate to control the development and maintenance of these organs will allow us to determine whether this protein might be involved in congenital defects and diseases in these organs (such as kidney failure, cirrhosis of the liver and skin diseases). A second main aim of this project is to explore further the observation that Eph proteins are abnormally highly expressed in a wide rangre of human cancers. This abnormal expression is directly correlated with the tumours spreading throughout the body. EphA1 is abnormally highly expressed in cancers of the bowel, lung, breast and prostate. These are the commonest cancers in man and some of the most difficult to treat. The work proposed asks how EphA1 contributes to the development and progression of these cancers. These results will have very direct implications for the development of therapies which target the EphA1 protein.Read moreRead less
The Use Of Soluble Antagonists Of EphA4 In Spinal Cord Injuries
Funder
National Health and Medical Research Council
Funding Amount
$622,361.00
Summary
Permanent and limited recovery of function following spinal cord injury is a direct result of the lack of nerve regrowth through the injury. Our preliminary data suggest that antagonising the effects of EphA4, a protein involved in brain development, leads to substantial functional recovery simultaneous with nerve regrowth. In addition to designing new, more effective blockers of EphA4, we will study the signalling pathways that EphA4 activates to inhibit nerve regrowth.
The Role Of Eph-ephrin Interactions In Mediating Mesenchymal Stem Cell Commitment, Migration And Bone Fracture Repair
Funder
National Health and Medical Research Council
Funding Amount
$579,138.00
Summary
In Australia, there is an increasing incidence of fractures that require surgical intervention and rehabilitation therapy. Fracture healing is a complex process that involves the coordination of different bone and immune cells. Our proposal will identify which cell-cell contact molecules mediate bone cell recruitment and development during normal skeletal growth and bone fracture repair. This study will help advance therapies for fracture repair and diseases of bone loss.