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
Understanding Skeletal Development: A Non-proteolytic Mechanism Of Aggrecan Resorption In The Growth Plate
Funder
National Health and Medical Research Council
Funding Amount
$563,044.00
Summary
Bone formation requires resorption of a cartilage template. We challenge the dogma that cartilage resorption is only by PROTEASES, and propose instead that GLYCOSIDASES might also be involved. Aims: Demonstrate that chondrocytes release glycosidases that are important for bone formation. Significance: New information for the design of reconstructive therapies for people with congenital and acquired limb deficiencies or inherited disorders such as arthritis and chondrodysplasias may be gained.
Proteomics Of Arthritis: Exploring Mechanisms Of Cartilage Degradation And Biomarker Identification
Funder
National Health and Medical Research Council
Funding Amount
$592,034.00
Summary
Arthritis is a major clinical and socio-economic problem. Arthritis involves the destruction of cartilage in joints. However, the mechanisms of initiation and progression of cartilage destruction remain poorly understood. Our studies will use new proteomic approaches to identify the changes in protein synthesis and degradation in mouse models of arthritis. This will provide critical information on disease mechanisms and for the development of diagnostic biomarkers and therapeutic approaches
Bone-specific Sclerostin And SIBLING Proteins In Osteoarthritis: Novel Contributions To Cartilage And Bone Pathology
Funder
National Health and Medical Research Council
Funding Amount
$441,058.00
Summary
Arthritis is a major clinical problem and involves the destruction of cartilage in joints. However, the mechanisms of how this cartilage destruction is initiated and progresses remain poorly understood. We recently discovered that that three proteins that play a role in bone are also produced in cartilage and are increased in cartilage during osteoarthritis. We will determine the role of each of these in the disease mechanism to provide new therapeutic and biomarker targets.
Molecular Mechanisms Of Cartilage Degeneration In Osteoarthritis
Funder
National Health and Medical Research Council
Funding Amount
$457,517.00
Summary
Arthritis affects 15% of the entire Australian population and 50% in people over 60. The most common form of joint disease by far is osteoarthritis (OA). One of the central features of OA is the breakdown of the cartilage that covers the ends of bones in joints, and this is a major determinant of the long term outcome and need for joint replacement surgery. There are no current therapies that halt or reverse cartilage breakdown in OA. This is largely due to our incomplete understanding of the mo ....Arthritis affects 15% of the entire Australian population and 50% in people over 60. The most common form of joint disease by far is osteoarthritis (OA). One of the central features of OA is the breakdown of the cartilage that covers the ends of bones in joints, and this is a major determinant of the long term outcome and need for joint replacement surgery. There are no current therapies that halt or reverse cartilage breakdown in OA. This is largely due to our incomplete understanding of the molecular changes and pathways involved in both the onset and progression of cartilage breakdown. Powerful new genomic approaches allow simultaneous screening of changes in a broad profile of genes, particulalrly in humans and mice following complete sequencing of their genomes. By applying this new technology in the earliest stages of cartilage degeneration in OA, the role of novel genes and the pathways involved in the onset of this disease process can be discovered. However, to investigate changes at the initiation of disease, tissue from animal rather than human joints must be used due to the difficulty in obtaining pre-symptomatic human cartilage. In order to maximise the number of genes screened, cartilage from a novel surgically induced model of OA in mice will be used in this study. We have developed micro dissection and linear mRNA amplification methods to overcome inherent problems with tissue availability from this small animal species. Successful completion of these studies will for the first time allow identification of the complex changes that occur in early OA. An important and likely outcome of this research will be identification of novel matrix proteins and regulatory molecules that will provide critical information for the development of new diagnostic and therapeutic approaches to OA.Read moreRead less
The Role Of Suppressor Of Cytokine Signalling-3 (SOCS-3) In Chondrocytes During Development And Disease
Funder
National Health and Medical Research Council
Funding Amount
$348,392.00
Summary
Cytokines are messenger proteins produced and secreted from one cell which then bind to specific receptors on the surface of other cells. After binding, a series of intracellular events occurs, termed signalling, that results in the target cell changing its behaviour. Cytokine signalling, if allowed to proceed unchecked, can result in various disease states. The suppressor of cytokine signalling (SOCS) proteins are key negative regulators of cytokine signalling within the cell. They are induced ....Cytokines are messenger proteins produced and secreted from one cell which then bind to specific receptors on the surface of other cells. After binding, a series of intracellular events occurs, termed signalling, that results in the target cell changing its behaviour. Cytokine signalling, if allowed to proceed unchecked, can result in various disease states. The suppressor of cytokine signalling (SOCS) proteins are key negative regulators of cytokine signalling within the cell. They are induced by a wide range of stimuli, especially from a group called the IL-6 family. We have preliminary data showing that cartilage cells (chondrocytes) normally produce a particular SOCS protein, called SOCS-3. We have also shown that when SOCS-3 production is dysregulated, the chondrocytes undergo excessive proliferation. Normal chondrocyte function is important during skeletal development and diseases such as osteoarthritis are thought to result from abnormal chondrocyte behaviour. It is likely that SOCS-3 has a key role in regulating chondrocyte function. The aim of this proposal is therefore to examine the role of SOCS-3 in chondrocytes, during development and in disease. Much of our understanding of the role of the SOCS proteins comes from the construction of mutant mice that lack a particular SOCS protein. When mutant mice are made that lack SOCS-3 in the whole animal the mice die before birth and so virtually nothing is known about the role of SOCS-3 in chondrocytes and the implications for cartilage in disease states, such as arthritis. To answer this we will create mice that lack SOCS-3 specifically in their chondrocytes. Evaluating the role of SOCS-3 in cartilage development and chondrocyte function during degenerative and inflammatory disease states is potentially of major clinical importance in improving our understanding of arthritis and of cartilage repair.Read moreRead less
Myo1b Bridges The Actin-membrane Interface During Osteoclastic Bone Resorption
Funder
National Health and Medical Research Council
Funding Amount
$429,387.00
Summary
Osteoporosis is a debilitating bone disease which features progressive bone loss. Bone loss (resorption) is driven by the bone resident cell the osteoclast. Identifying molecules that regulate bone resorption by osteoclasts is a crucial first step towards developing new targets for theraputic intervention. This proposal explores the role of Myo1b, a novel protein that appears to facilitate osteoclastic bone resorption and thus represents an attractive new candidate to target bone loss.
Molecular Mechanisms And Therapeutic Effects Of Novel Parthenolide Analogs On Osteolysis
Funder
National Health and Medical Research Council
Funding Amount
$562,815.00
Summary
Rheumatoid arthritis and osteoporosis are common bone diseases with features of bone loss. Drugs that inhibit bone loss are needed for the prevention and treatment of bone diseases. The proposed research explores the potential use of novel herbal inhibitors for the suppression of bone resorbing cells, and their potential as treatments for bone loss.
Furin: Carving-up Vital Substrates For Bone Remodelling And Homeostasis
Funder
National Health and Medical Research Council
Funding Amount
$815,972.00
Summary
Osteoporosis, or porous bone, is a disease characterized by low bone mass and structural deterioration of bone tissue, leading to bone fragility and an increased susceptibility to fractures. It is caused by an imbalance between the cells that are constantly reabsorbing and reforming bone. The proposed project will address furin as a novel regulator of bone remodelling.
Novel Pathways Involving APC And PAR-2 In Cartilage Degradation In Osteoarthritis
Funder
National Health and Medical Research Council
Funding Amount
$448,834.00
Summary
Loss of the cartilage that normally lines the ends of bones is central to joint failure in arthritis and the need for replacement surgery. There are presently no treatments that stop cartilage breakdown in joint disease. This project investigates the role of a new pathway not previously thought to be active in cartilage, in the progressive damage seen in arthritis. Successful completion of these studies may provide a novel new strategy to treat joint disease.