Osteal Macrophages As Therapeutic Targets For Fracture Repair
Funder
National Health and Medical Research Council
Funding Amount
$618,015.00
Summary
Fragility fracture associated with osteoporosis is a substantial health problem costing $1.62 billion to treat in 2012 in Australia. There is no approved therapy to improve and accelerate fracture healing to help reduce this increasing health burden. This research will advance understanding of fracture repair in healthy and osteoporotic bone and progress development of a fracture therapy to improve bone repair by promoting specialised immune cells.
Short-term Use Of Intermittent PTH To Accelerate Healing Of Stress Fractures And During Bisphosphonate Treatment.
Funder
National Health and Medical Research Council
Funding Amount
$633,331.00
Summary
Osteoporosis treatments prevent fractures by hindering cells that erode the skeleton. Normally, those cells also repair injuries like stress fractures. Some patients, treated for long periods, can suffer fractures because the treatment slows bone healing. We have an innovative model to test alternative treatments to accelerate stress fracture healing, while osteoporosis treatment continues. This could prevent unusual stress fractures, in patients who still need the bone-sparing effectiveness of ....Osteoporosis treatments prevent fractures by hindering cells that erode the skeleton. Normally, those cells also repair injuries like stress fractures. Some patients, treated for long periods, can suffer fractures because the treatment slows bone healing. We have an innovative model to test alternative treatments to accelerate stress fracture healing, while osteoporosis treatment continues. This could prevent unusual stress fractures, in patients who still need the bone-sparing effectiveness of osteoporosis treatment.Read moreRead less
Role Of The Osteoclast In Endochondral Fracture Repair
Funder
National Health and Medical Research Council
Funding Amount
$310,136.00
Summary
Failure of bone healing leads to significant pain and disability, such that augmentation of fracture repair is a dynamic and important field of study. A full understanding of bone repair is necessary before we can hope to introduce successful therapies. We theorise that by stimulating bone forming cells and inhibiting bone resorbing cells we may be able to provide optimal results. Bone resorbing cells, or osteoclasts, have long been considered essential to the initial stages of bone repair (endo ....Failure of bone healing leads to significant pain and disability, such that augmentation of fracture repair is a dynamic and important field of study. A full understanding of bone repair is necessary before we can hope to introduce successful therapies. We theorise that by stimulating bone forming cells and inhibiting bone resorbing cells we may be able to provide optimal results. Bone resorbing cells, or osteoclasts, have long been considered essential to the initial stages of bone repair (endochondral ossification) during which the early soft cartilaginous callus is replaced by hard mineralised callus. Our preliminary studies lead us to believe that endochondral ossification can indeed proceed without osteoclast activity. If we can safely eliminate osteoclast function early in the early stages of fracture repair, a number of therapeutic options open up for the augmentation of bone healing. The return of osteoclast function is necessary in the long term, so our strategy will also need to take this into account. This study will establish which systems are pivotal in endochondral ossification and therefore which interventions we should explore.Read moreRead less
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.
Prostaglandin G/H Synthase-2 (PGHS-2) Is A Key Regulator Of Skeletal Adaptation And Remodelling
Funder
National Health and Medical Research Council
Funding Amount
$301,018.00
Summary
Knowledge of the biology underlying bone formation is important for developing novel approaches to stimulate new bone formation in skeletal diseases associated with ageing or disability, or for maintenance of new bone around orthopaedic or dental implants. The discovery that a prostaglandin enzyme (PGHS-2) is a key factor in activity-related bone formation and normal bone turnover, as well as a pharmacological target for reducing inflammation, has considerable clinical significance. Specific inh ....Knowledge of the biology underlying bone formation is important for developing novel approaches to stimulate new bone formation in skeletal diseases associated with ageing or disability, or for maintenance of new bone around orthopaedic or dental implants. The discovery that a prostaglandin enzyme (PGHS-2) is a key factor in activity-related bone formation and normal bone turnover, as well as a pharmacological target for reducing inflammation, has considerable clinical significance. Specific inhibition of PGHS-2 by recent anti-inflammatory drugs avoids formation of gastric ulcers, but their influence on normal bone remodelling and fracture repair is not known and must be investigated. Many such inhibitors are in advanced clinical trials, but their effect on bone metabolism has not been published. This project is important because it employs novel experimental models to advance our knowledge of prostaglandin biology in skeletal adaptation, and elucidates important clinical consequences for specific inhibition of PGHS-2 in the skeleton. This project will investigate the regulation of prostaglandin production by PGHS enzymes following mechanical loading in vivo. It will use cell, molecular and histochemical techniques to determine if the genes that regulate the enzymes are influenced by mechanical stimuli, and if they are dependent on other molecules, associated with structural proteins (stress fibres) within the cell. It will investigate if inhibition of PGHS-2 by antiinflammatory drugs or stress-fibre inhibitors, depresses normal bone turnover and healing responses. The outcome of these experiments could indicate new approaches to stimulate bone formation, preserve bone mass, or minimise adverse skeletal effects of anti-inflammatory treatments related to orthopaedic or dental procedures.Read moreRead less
Sclerostin And Dickkopf-1 In Regulation Of Bone Mass
Funder
National Health and Medical Research Council
Funding Amount
$638,581.00
Summary
The WNT pathway is a powerful regulator of bone cell differentiation and bone formation. Two WNT modulators, sclerostin ad Dickkopf 1, are being developed for therapy in bone disease, but critical questions remain unanswered. In this study we use unique genetic mouse models created by the applicants to resolve specific deficiencies surrounding their actions and application as therapies.
NT-3 As An Upstream And Potentially Master Regulator Promoting Bone Fracture Healing
Funder
National Health and Medical Research Council
Funding Amount
$712,857.00
Summary
There is a strong clinical need for cost-effective treatments for delayed healing or non-union bone fractures. Our recent data suggest injury site-derived neurotrophin-3 (NT-3) may be an important overall regulator of bone repair by inducing key factors involved in fracture callus formation and remodelling. This project will address roles and mechanisms of endogenous NT-3 in bone repair and the likelihood of exogenous NT-3 protein in promoting bone healing in clinically relevant fracture models.
Cell Biology Of Stress Fractures: Activation Of Remodelling At Sites Of Non-union
Funder
National Health and Medical Research Council
Funding Amount
$493,817.00
Summary
Stress fractures are debilitating injuries. We characterised a model of stress fractures in rat ulnae, learning that they heal by activated remodelling, that key genes are expressed in a temporal pattern, and that part of the fracture remains un-healed, similar to many clinical cases. Now, we will examine cell localisation of important genes necessary for remodelling, and test the efficacy of different growth factors to activate a healing response in the non-healed section of the fracture.
The Role Of TWIST Family Basic Helix-Loop-Helix Transcription Factors In Bone Cell Commitment, Function And Repair
Funder
National Health and Medical Research Council
Funding Amount
$485,928.00
Summary
In developed countries, projected estimates predict an alarming trend of a two to three fold increase in the number of fractures that require surgical intervention and rehabilitation therapy in the coming decades as a consequence of an aging population. Fracture healing is a complex physiological process that involves the coordinated participation of different bone marrow cells, immune cells and skeletal progenitor cells. Multiple factors regulate interactions between these cell types that influ ....In developed countries, projected estimates predict an alarming trend of a two to three fold increase in the number of fractures that require surgical intervention and rehabilitation therapy in the coming decades as a consequence of an aging population. Fracture healing is a complex physiological process that involves the coordinated participation of different bone marrow cells, immune cells and skeletal progenitor cells. Multiple factors regulate interactions between these cell types that influence the capacity of bone cell progenitors to develop into functional bone forming cells known as osteoblasts. An understanding of the fracture healing is critical for the future advancement of fracture treatment, and for identifying the mechanisms of skeletal growth and repair as well as the causes of aging and disease. This proposal seeks to identify critical regulatory molecules that act to mediate bone cell progenitor recruitment and development during bone fracture repair.Read moreRead less