Mesenchymal Progenitor Cells And Intervertebral Disc Repair
Funder
National Health and Medical Research Council
Funding Amount
$754,223.00
Summary
Low back pain affects 80% of the general population and is a major social and economic burden thus there is a clear need for effective treatment. Annual direct and indirect costs for low back pain exceeded $100 billion in the USA in 2006. We will use bone marrow derived multipotent progenitor cells in a regenerative strategy to undertake repair of the intervertebral disc in an ovine mechanical destabilisation model which reproduces early degenerative changes similar to those evident in man.
The Role Of Perlecan In Tensional Connective Tissues
Funder
National Health and Medical Research Council
Funding Amount
$605,037.00
Summary
Musculoskeletal diseases affect tension and weight bearing connective tissues which have notoriously poor repair capabilities. These conditions are difficult to treat clinically and surgical repair in many cases does not provide a return to optimal joint function impinging on the quality of life of afflicted individuals and their carers. Our project aims to better understand the structure and function of these tissues in health and disease with a view to improving repair strategies.
Novel Therapeutic Interventions For The Orthopaedic Complications Of Neurofibromatosis Type 1 (NF1).
Funder
National Health and Medical Research Council
Funding Amount
$628,422.00
Summary
Children with the genetic disease NF1 can develop fractures that fail to unite and this can lead to amputation. We have advanced models of NF1-deficient bone cells and fracture healing that we will use to test new pharmaceutical treatments for NF1.
The Role Of V-ATPase Accessory Subunit Ac45 In Osteoclasts
Funder
National Health and Medical Research Council
Funding Amount
$235,500.00
Summary
Osteoclasts are directly related to many lytic bone disorders including osteoporosis, osteoarthritis and Paget's diseases. Development of strategies to control the formation or activities of osteoclasts has been a major focus of bone research. The vacuolar proton pump (V-ATPase) located on the plasma membrane of the osteoclast is responsible for creating a low pH environment critical for bone resorption, and therefore a potential molecular target for the discovery of novel bone antiresorptive ag ....Osteoclasts are directly related to many lytic bone disorders including osteoporosis, osteoarthritis and Paget's diseases. Development of strategies to control the formation or activities of osteoclasts has been a major focus of bone research. The vacuolar proton pump (V-ATPase) located on the plasma membrane of the osteoclast is responsible for creating a low pH environment critical for bone resorption, and therefore a potential molecular target for the discovery of novel bone antiresorptive agents useful for the treatment of lytic bone disorders. The proposed research will give considerable insight into the role of the both V-ATPase accessory subunit Ac45 and V-ATPase complex in osteoclasts. Understanding the molecular and cellular mechanisms by which V-ATPases regulate osteoclast bone resorption will facilitate the development of novel and selective inhibitors for the treatment of lytic bone disorders.Read moreRead less
Molecular Determinants Of Bone Remodelling In The Bone Microenvironment
Funder
National Health and Medical Research Council
Funding Amount
$317,640.00
Summary
There is little information regarding the expression of specific molecules in human bone tissue or their role in skeletal disease. The process of bone remodelling is fundamental for the maintenance of skeletal integrity. Our understanding of the molecular signalling involved in activating bone remodelling is principally derived from tissue culture and animal experiments. We will study human cancellous bone samples donated by patients undergoing surgery, and with the consent of the next-of-kin, t ....There is little information regarding the expression of specific molecules in human bone tissue or their role in skeletal disease. The process of bone remodelling is fundamental for the maintenance of skeletal integrity. Our understanding of the molecular signalling involved in activating bone remodelling is principally derived from tissue culture and animal experiments. We will study human cancellous bone samples donated by patients undergoing surgery, and with the consent of the next-of-kin, taken at autopsy. These molecular and histomorphometric studies will determine whether the understanding derived from tissue culture and animal experiments is consistent with associations demonstrable in the human cancellous bone microenvironment. The elucidation of the molecular signalling in the human bone microenvironment is essential for the effective diagnosis and treatment of bone disease. Recently reported studies have shown very persuasively that fatigue microdamage accumulates in the skeleton and is targeted for repair by remodelling. Our preliminary data shows that microcrack length is positively correlated with IL-11 mRNA gene expression. We will further investigate mRNA gene expression of a number of cytokines involved in bone cell signalling and their association with the level of microdamage in the bone. Using a animal model of controlled bone microdamage induction we will seek to determine the bone remodelling causal relationship between microdamage and cytokine signalling. Furthermore, the cellular and molecular mechanisms that lead to trabecular structures are not well understood. These studies will provide new insight into the processes that determine trabecular structures. This project will investigate these mechanisms and increase our understanding of bone cell function, essential for diagnosis and design of rational treatment for bone diseases.Read moreRead less
A Prospective Study To Identify The Mechanical Causes And Methods For Early Detection Of Knee Osteoarthritis
Funder
National Health and Medical Research Council
Funding Amount
$431,000.00
Summary
Knee osteoarthritis is a great cost to society, financially and in quality of life. Anti-inflammatory drugs are commonly used to treat the symptoms, but many people receive joint replacements to stop pain and improve function. We need to prevent osteoarthritis, but the causes for this common disease are largely unknown. Animal studies have shown two particular mechanical factors that cause osteoarthritis, which are seen in the walking and running, or gait, patterns of some people. We call these ....Knee osteoarthritis is a great cost to society, financially and in quality of life. Anti-inflammatory drugs are commonly used to treat the symptoms, but many people receive joint replacements to stop pain and improve function. We need to prevent osteoarthritis, but the causes for this common disease are largely unknown. Animal studies have shown two particular mechanical factors that cause osteoarthritis, which are seen in the walking and running, or gait, patterns of some people. We call these pathological gait patterns as they impose larger-than-normal forces on the knee's articular surfaces. We measure these knee forces with our new computer knee model coupled with data that we measure in a gait analysis laboratory. These forces may cause knee osteoarthritis in humans, but this is still unknown. Currently there is no simple medical test to detect the early onset of knee osteoarthritis. The bones in the knee are one of the first structures to show osteoarthritic changes. Using our new computerised analysis of high definition X-ray of the knee we can identify subtle differences in the knee due to osteoarthritis. This will be compared with changes to joint assessed using MRI. Osteoarthritis develops slowly in normal people, so to study progression of knee osteoarthritis we need a human population that has a higher risk of developing the disease. Partial meniscectomy in the knee is a common surgery performed to improve knee function in those who have suffered a knee meniscus injury. However, partial meniscectomy patients have a high risk of developing knee osteoarthritis. Therefore, using partial meniscectomy patients we are investigating if pathological gait patterns cause knee osteoarthritis, measuring the development of the disease with our new X-ray methods. With the gait analysis methods we can also identify the movements that characterise these pathological gait patterns so we can formulate rehabilitation programmes to help prevent knee osteoarthritis.Read moreRead less
Intrinsic Bone Qualities In Fragility Fracture Patients: Mass, Microarchitecture, Mineralization And Damage Accumulation
Funder
National Health and Medical Research Council
Funding Amount
$447,027.00
Summary
Osteoporosis drug therapies have been associated with a significant reduction in fragility fracture. Patients receiving osteoporosis drugs, which have different effects on BMD, may have similar reductions in fractures. Furthermore, patients with fragility fractures may have abnormalities in bone structural and material properties. Changes to the process of bone renewal, due to drug therapy, may explain why fracture risk decreases where no detectable change to the structure of bone has been detec ....Osteoporosis drug therapies have been associated with a significant reduction in fragility fracture. Patients receiving osteoporosis drugs, which have different effects on BMD, may have similar reductions in fractures. Furthermore, patients with fragility fractures may have abnormalities in bone structural and material properties. Changes to the process of bone renewal, due to drug therapy, may explain why fracture risk decreases where no detectable change to the structure of bone has been detected. It has also been shown that when bone renewal is suppressed microdamage accumulates in bone tissue, leading to reduced bone toughness. The toughness of bone is of primary importance in relation to fragility fractures, and it has been shown that the fatigue strength and fracture toughness (work to fracture) reduce considerably with age. This proposed study would seek to elucidate the role of bone tissue-level properties in determining bone quality for human subjects: patients with fragility hip fractures on no osteoporosis drugs therapy, hip fracture patients on osteoporosis drugs therapies, and normal age- and sex-matched individuals. Our laboratory has extensive experience in the analysis of the structure of human bone tissue. Recently, we have developed novel and unique techniques to assess bone quality, using micro-CT, backscatter SEM imaging, confocal microscopy and immunohistochemistry. This multifaceted study will identify at the bone tissue-level the structural mechanisms (micro-architecture, mineralisation, and microscopic cracking) that are indicative of the efficacy of fragility fracture drugs. Better understanding of the mechanisms by which bones are less likely to fracture will enable better targeting of osteoporosis drug therapy to individuals at risk of fragility fracture.Read moreRead less
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
Structural And Functional Analyses Of Rat Receptor Activator Of NF-kb Ligand
Funder
National Health and Medical Research Council
Funding Amount
$226,320.00
Summary
Rat RANKL (Xu and Zheng, rat RANKL, AustraliaProvisional Patent PQ3147) has a variety of biological activities including osteoclast differentiation and polarization, and dendritic cell function. Overproduction or increased activity of RANKL can result in excessive osteoclast formation, activation, and bone resorption. This process contributes to many common bone lytic disorders such as osteoporosis, Paget's disease, bone metastatic diseases, arthritis, aseptic bone loosening and non-union of fra ....Rat RANKL (Xu and Zheng, rat RANKL, AustraliaProvisional Patent PQ3147) has a variety of biological activities including osteoclast differentiation and polarization, and dendritic cell function. Overproduction or increased activity of RANKL can result in excessive osteoclast formation, activation, and bone resorption. This process contributes to many common bone lytic disorders such as osteoporosis, Paget's disease, bone metastatic diseases, arthritis, aseptic bone loosening and non-union of fractures. This proposal addresses the important and fundamental issue of RANKL regarding the role of molecular structure on its biological function. We have established that the TNF-like core domain is the functional domain, important for osteoclastogenesis, osteoclast polarisation and protecting against Fas-triggered apoptosis. This proposal will further characterise the mutant forms of the TNF-like core domain of RANKL using site directed mutagenesis and protein truncation analysis, and assess their respective binding activities to OPG and RANK, and their biological activities both in vitro and in vivo. It will lead us into better understanding of the structure-function relationship of RANKL. Ideally, we would like to develop a relative agent for the suppression of osteolysis in orthopaedic related diseases including osteoporosis. Such an optimized molecule could become a potent therapeutic agent that selectively inhibits osteoclast formation and bone resorption.Read moreRead less
Cartilage Destruction In Joint Disease: Studies With ADAMTS-4 And ADAMTS-5 Deficient Mice
Funder
National Health and Medical Research Council
Funding Amount
$540,600.00
Summary
In healthy joints the proteoglycan, aggrecan, gives cartilage compressive resilience to permit weight bearing, but in disease aggrecan is degraded by ADAMTS enzymes. The challenges to the field are to determine which ADAMTS is involved, when these enzymes are active and precisely where they come from. We hypothesise that ADAMTS-4 and-or ADAMTS-5 is involved in cartilage pathology. To test this hypothesis we aim to [1] Generate mice containing mutant ADAMTS-4 and-or -5 in all cells, or [2] in car ....In healthy joints the proteoglycan, aggrecan, gives cartilage compressive resilience to permit weight bearing, but in disease aggrecan is degraded by ADAMTS enzymes. The challenges to the field are to determine which ADAMTS is involved, when these enzymes are active and precisely where they come from. We hypothesise that ADAMTS-4 and-or ADAMTS-5 is involved in cartilage pathology. To test this hypothesis we aim to [1] Generate mice containing mutant ADAMTS-4 and-or -5 in all cells, or [2] in cartilage cells only. [3] Analyse mutant mice for changes in skeletal architecture, changes in ADAMTS mRNA and protein, and changes in aggrecan breakdown products. [4] Assess disease severity in mutant mice in in vivo models of joint disease. We already have mice with ADAMTS-4, or -5, mutated in all tissues and we are generating the double mutants now. We will also generate single and double mutants with dysfunctional enzymes in cartilage only. We will examine skeletal structure by histology and X-ray at all ages and monitor for expression of ADAMTS-1 and -9 to detect any compensatory over-production of other potential 'aggrecanases'. We will also do co-culture experiments in which cartilage and synovial cells from combinations of mutant and control mice will be incubated together to determine whether synovial ADAMTS can penetrate and degrade aggrecan in cartilage. Finally we will induce arthritis in mutant and control mice and monitor them to detect differences in the time of disease onset, the rate of disease progression and overall disease severity. A comparison of whole-mouse with cartilage only mutants in the in vivo models will complement the in vitro co-culture studies and determine whether other joint tissues such as synovium and joint capsule can also produce ADAMTS enzymes that destroy cartilage. This is not known. Together these experiments will reveal if, where and when ADAMTS-4 and-or -5 are active, and whether indeed they are the best targets for drug development.Read moreRead less