Detecting Bioactivity In A Naturally-occurring Aggrecan Fragment
Funder
National Health and Medical Research Council
Funding Amount
$407,634.00
Summary
The dynamic balance of anabolic and catabolic processes in healthy cartilage is disturbed in arthritis, with increased catabolism leading to irreparable cartilage damage. We will study the ability of a naturally-occuring aggrecan fragment to modulate cartilage catabolism. Our in vitro and in vivo experiments suggest that the aggrecan fragment limits cartilage destruction. This study tests our hypothesis that the aggrecan fragment antagonises cartilage damage and promote cartilage repair.
Regulation Of ADAMTS-5 Activity By Keratan Sulphate-binding Exosites
Funder
National Health and Medical Research Council
Funding Amount
$213,342.00
Summary
Arthritis and musculoskeletal conditions are the predominant cause of disability in Australia. The burden of arthritis is felt not only by patients, their families and carers, but also the labour market and the national economy. There is a pressing need to identify new targets for design of inexpensive arthritis therapies. The TNF antagonists have proved effective in managing rheumatoid arthritis (RA), but they are expensive, administered by injection, and in general, only prescribed in Australi ....Arthritis and musculoskeletal conditions are the predominant cause of disability in Australia. The burden of arthritis is felt not only by patients, their families and carers, but also the labour market and the national economy. There is a pressing need to identify new targets for design of inexpensive arthritis therapies. The TNF antagonists have proved effective in managing rheumatoid arthritis (RA), but they are expensive, administered by injection, and in general, only prescribed in Australia for patients who respond poorly to DMARDs. Their long-term efficacy and safety is not yet determined. There are no treatments for osteoarthritis (OA), the disease that occurs more frequently with age and is characterised by destruction of cartilage and aggrecan. New drugs that protect against aggrecan breakdown are urgently needed for OA and they would also be valuable adjunct therapies to the DMARDs for treatment of RA. We have discovered that the major aggrecan-degrading enzyme is ADAMTS-5. ADAMTS-5 is, therefore, a potential target for arthritis therapies. Unfortunately, drugs targeting the active site of ADAMTS-5 are predicted to fail, given the wide tissue distribution of ADAMTS-5, the high level of homology between the active site of ADAMTS enzymes and matrix metalloproteinases (MMPs), and the notorious failure of MMP active site inhibitors in clinical trials. The aim of this project is to determine whether ancillary domains of ADAMTS-5 are a viable alternative target to the active site. We have evidence to suggest that keratan sulphate, which is covalently attached to the aggrecan core protein, can modulate aggrecan cleavage by ADAMTS enzymes. We aim to identify opportunities for developing antagonists that block keratan sulphate binding, or keratan sulphate analogues that block enzyme binding to its substrate. The data will inform the pharmaceutical industry on new directions for modulating aggrecanolysis by ADAMTS-5.Read moreRead less
Chondrocyte Hypertrophy In Development And Disease
Funder
National Health and Medical Research Council
Funding Amount
$360,018.00
Summary
Whereas chondrocyte hypertrophy is a normal feature of skeletal growth, in adult chondrocytes it is associated with osteoarthritis (OA). We propose that collagen II fragments provide signals for hypertrophy in cartilage. The lack of collagen II fragments in our collagenase-resistant mouse provides a unique opportunity to address the role of collagen II fragments in driving cellular hypertrophy. We will identify bioactive collagen II fragments that represent novel targets for OA therapies
A Long Term Follow-up Of The Offspring Cohort: A Controlled Study Of Those At Higher Risk Of Knee Osteoarthritis
Funder
National Health and Medical Research Council
Funding Amount
$238,168.00
Summary
Osteoarthritis is the most common musculoskeletal disorder. Despite this, relatively little is known about how the disease develops. This study will use a powerful technique known as MRI scanning to determine the sequence of changes over 10 years in subjects at higher risk of osteoarthritis (based on their family history) but who do not yet have established disease on radiographs (even though many have symptoms).
Factors That Affect Knee Structure In Healthy Women
Funder
National Health and Medical Research Council
Funding Amount
$199,176.00
Summary
Osteoarthritis (OA) has the largest impact of any chronic disease on burden of disease borne in later life, affecting women more often than men. The importance of OA has been acknowledged by its listing within musculoskeletal disease, the 7th health priority in Australia. It is 4 times as common in women as in men.Treatments which slow or prevent OA progressing are limited, so prevention must play a key role. With increasing disease severity, joint cartilage is lost. We have recently developed a ....Osteoarthritis (OA) has the largest impact of any chronic disease on burden of disease borne in later life, affecting women more often than men. The importance of OA has been acknowledged by its listing within musculoskeletal disease, the 7th health priority in Australia. It is 4 times as common in women as in men.Treatments which slow or prevent OA progressing are limited, so prevention must play a key role. With increasing disease severity, joint cartilage is lost. We have recently developed a method to measure joint cartilage from magnetic resonance imaging (MRI) scans which is able to assess the severity of structural changes in the knee. Using this method will allow us to assess 2 issues: 1) Obesity is the only identified modifiable risk factor for knee OA. However, the mechanism is poorly understood. Weight loss programs may be more effective at reducing the risk of OA if they are combined with programs aimed at maintaining muscle mass. 2) Bone is important in development of Knee OA, but its role is poorly understood. Understanding how bone metabolism relates to risk of knee OA may allow us to prevent disease. Bone is more likely to respond to pharmacological manipulation than cartilage. Thus it may prove a more effective target for intervention than cartilage. The Geelong Osteoporosis Study was begun in 1994 to study bone health in Australian women (urban and rural). Much information relevant to the risk of OA has been collected over the past decade. By performing MRI of the knee now and in 2 years time, we will determine the effect of different measures of obesity and bone metabolism on structural change at the knee which predisposes to OA. Since both of these factors (obesity and bone metabolism) are potentially modifiable, this study may offer new avenues of prevention and therapy in knee OA. This has the potential to promote a better quality of life as people age and to reduce the economic burden of knee OA in the community.Read moreRead less
Does Vitamin D Supplementation Prevent Progression Of Knee Osteoarthritis? A Randomised Controlled Trial
Funder
National Health and Medical Research Council
Funding Amount
$1,016,758.00
Summary
Observational evidence suggests that vitamin D deficiency may have a role in the causes of osteoarthritis (OA) and there are biologically plausible mechanisms to explain this. There is, however, no evidence which shows that intervening with vitamin D supplementation can slow the progression of OA. This study will compare knee OA structural changes in patients receiving vitamin D supplementation with those receiving a placebo. Use of MRI will provide sensitive measures of knee OA changes.
Osteoarthritis (OA) affects approximately 20% of Australians and costs billions each year in joint replacements. Therapies that halt joint destruction in OA are urgently needed. We hypothesise that the little-known gene, vanin -3, is a key regulator of OA disease pathways. Our project will map vanin-3 in the joint and reveal how much vanin-3 contributes to joint destruction in mice. We expect to find a link between vanin-3 and metabolic disorders and identify new targets for therapy.