Relationship Of The Anabolic And Catabolic Responses In Healing A Critical Sized Defect In Rats
Funder
National Health and Medical Research Council
Funding Amount
$329,750.00
Summary
Delayed bone healing after trauma is a large clinical problem. Figures suggest up to 60,000 fractures result in a delay in healing in Australia per year. Bone healing can also fail to occur in other circumstances, such as after an operation. Research effort into new approaches to solving these problems is clearly justified. We believe that in some situations, bone healing fails due to the body's healing response, the anabolic response, being insufficient. In some other situations, the body's bon ....Delayed bone healing after trauma is a large clinical problem. Figures suggest up to 60,000 fractures result in a delay in healing in Australia per year. Bone healing can also fail to occur in other circumstances, such as after an operation. Research effort into new approaches to solving these problems is clearly justified. We believe that in some situations, bone healing fails due to the body's healing response, the anabolic response, being insufficient. In some other situations, the body's bone resorbing response, the catabolic response, may be too high and prevent healing from occurring. In normal bone healing, there is a balance between the anabolic and catabolic response. In disordered bone healing, these responses are out of balance. Several reasonably new treatments are available which can increase the anabolic response or decrease the catabolic response. We have preliminary results showing that with these agents we can bring these elements into better control, and thus drive bone healing. We have optimised an animal model where both the anabolic and catabolic responses can be controlled. In this project, we explore the optimisation of the timing and magnitude of anabolic and catabolic responses in bone healing.Read moreRead less
Novel Roles For IL-33 In The Maintenance Of Bone Mass And As A Locally Derived Anabolic Factor For Bone
Funder
National Health and Medical Research Council
Funding Amount
$592,574.00
Summary
Over 10% of the population have thin, brittle bones that fracture easily, and is often seen in elderly people. When diagnosed, a fracture has usually already occurred and the bone is already thin. Drugs are available to stop further bone weakening, but building new bone would be best. We have found a protein in bone that reduces bone loss and stimulates bone formation processes. This project seeks to determine how this protein works and how to exploit it to design new bone building therapies.
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 novel successful therapies. We believe that a improved understanding of the origins of the cells involved with bone healing may lead to new surgical, drug and cell-based therapies for the treatment of recalcitrant bone repair. Stem cells originating from the bone marr ....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 novel successful therapies. We believe that a improved understanding of the origins of the cells involved with bone healing may lead to new surgical, drug and cell-based therapies for the treatment of recalcitrant bone repair. Stem cells originating from the bone marrow and periosteum are known to differentiate into mature bone cells and produce bone. However, these tissues are damaged or have poor access to the site of bone injury in many severe open fractures. In these cases, bone repair often initiates in a region adjacent to an opposing muscle. This has led us to speculate that cells from the muscle may directly contribute to bone repair. Published studies, which have be confirmed by our group, have demonstrated the strong potential for muscle-derived progenitor cells (satellite cells) to become bone-like in response to stimuli such as bone morphogenic proteins. To put bone-forming potential of muscle cells in perspective, we plan to expand on these studies and compare mouse satellite cells with mouse bone marrow stem cells. In addition, we plan to use a transgenic mouse whose muscle cells become permanently genetically transformed to stain blue. This mouse will allow us to assess the fate of muscle cells and their contribution to bone formation in ectopic bone formation and fracture repair models. This study will explore on the most basic level the cellular contribution of muscle to bone repair. The results of this research project will significantly influence our therapeutic directions for improving fracture repair in the future.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
Regulation Of Bone Dynamics By Osteal Tissue Macrophages (Osteomacs)
Funder
National Health and Medical Research Council
Funding Amount
$741,095.00
Summary
There is a high demand for effective treatments to rebuild and replace lost bone in fracture repair and osteoporosis. We have described a discrete population of macrophages (classically immune defense cells) within the specialized tissues that line bones. We have shown that these bone tissue macrophages have a novel role in promoting the formation of new bone. This project grant will extend these observations and identify the clinical potential of bone tissue macrophages to treat bone disease.
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