Role Of Macrophages Residing On The Bone Surface In Bone Renodelling And Repair
Funder
National Health and Medical Research Council
Funding Amount
$54,466.00
Summary
To determine if the F4-80+ macrophages that reside on the bone surface, bone lining macrophages (BLMs) are responsible for the detection of apoptotic osteocyte cells and subsequently initiate bone remodelling in response to bone damage.
Delayed bone healing can be a considerable problem in both children and adults. Up to 10% of fractures fail to heal properly. An advanced understanding of the cellular responses in bone repair and their manipulation could improve the lives of many patients with orthopaedic problems. These studies will advance out knowledge of interventions to promote bone healing which could be translated rapidly into clinical care.
Assessment Of The Properties Of Mesenchymal Stem Cells And Their Role In Skeletal Tissue Repair And Disease
Funder
National Health and Medical Research Council
Funding Amount
$751,854.00
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.
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
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.
Investigation Of COX-2 Regulation Of Bone Turnover And Mechanically Induced Bone Formation By Genetic Overexpression.
Funder
National Health and Medical Research Council
Funding Amount
$440,750.00
Summary
This project is important because it uses novel experimental models to advance our knowledge of prostaglandin biology in normal and pathological bone remodelling, and the response of the skeleton to increased physical activity. We expect that a genetic modification in mice to increase the normal production of key prostaglandin enzymes, cyclooxygenase-2 (COX-2), in bone cells will increase the number of cells that remove bone (osteoclasts), and increase bone loss and the rate of bone turnover whe ....This project is important because it uses novel experimental models to advance our knowledge of prostaglandin biology in normal and pathological bone remodelling, and the response of the skeleton to increased physical activity. We expect that a genetic modification in mice to increase the normal production of key prostaglandin enzymes, cyclooxygenase-2 (COX-2), in bone cells will increase the number of cells that remove bone (osteoclasts), and increase bone loss and the rate of bone turnover when compared to normal mice. We believe this will occur via the effect of prostaglandins on expression of genes that control osteoclast formation. This will be tested by examining the structure of the skeleton, and the expression of certain genes, in transgenic mice at different ages from 2-8 months. These effects may be exacerbated in conditions of increased bone turnover, such as postmenopausal bone loss. This will be tested by examining the bone structure and gene expression in adult mice following removal of their ovaries. Due to the role of COX-2 in adaptation of bone to mechanical loading, we also expect the load-bearing skeleton to be more sensitive to increased weight-bearing activity. We will investigate this hypothesis by applying mechanical loads to the tibiae of mice in a controlled manner and then analysing the bone structure. Knowledge of specific pathways by which bone formation can be stimulated is important for developing novel approaches to induction and augmentation of osteogenesis in skeletal diseases associated with ageing or disability, or for maintenance of new bone around implants. The discovery that COX-2 is a key enzyme in mechanotransduction and osteoclastogenesis in bone, and a pharmacological target for modulating inflammation, has considerable clinical significance. Exploiting this knowledge requires precise knowledge of the role of this enzyme in bone remodelling and adaptation and our experiments will contribute significantly to that knowledgeRead moreRead less
Twist-1 Mediated Regulation Of Multipotential Mesenchymal Stem Cell Self-Renewal And Cell Fate Determination
Funder
National Health and Medical Research Council
Funding Amount
$605,096.00
Summary
In Australia, there is an increasing incidence of fractures and skeletal related problems that require surgical intervention and rehabilitation therapy. These are complex processes that involve the coordination of different bone and immune cells. We will investigate important regulatory molecules that mediate bone-cartilage stem cell recruitment and development during normal skeletal growth and remodelling. This study will help advance therapies for fracture repair and joint deterioration.
The Role Of Muscle And The Application Of Muscle-cell Therapies In Bone Repair
Funder
National Health and Medical Research Council
Funding Amount
$438,936.00
Summary
Muscle is often close to bone and we have found that muscle cells can directly contribute to bone repair. We are examining importance of muscle cells in orthopaedic repair and whether new methods for mobilizing muscle cells can improve healing.
Twist-1 Inhibits MSC Osteoblast Differentiation During Osteoporosis Via Direct Regulation Of The Wnt Signalling Pathway
Funder
National Health and Medical Research Council
Funding Amount
$482,704.00
Summary
There is a predicted dramatic increase in the number of orthopaedic related problems that require surgical intervention and rehabilitation therapy in the coming decade associated with higher incidences of bone diseases as a consequence of an aging population. This proposal seeks to determine whether the transcription factor, Twist-1 plays a central role in regulating the growth and differentiation of skeletal progenitors during bone loss following the onset of osteoporosis.