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
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.
Signalling Through A Bioactive Aggrecan Fragment: What Is The Mechanism?
Funder
National Health and Medical Research Council
Funding Amount
$431,347.00
Summary
Osteoarthritis (OA) affects approximately 20% of Australians. There are no therapies that modify the course of the disease and joint replacement surgery is expensive and invasive. We have discovered that a peptide product of cartilage breakdown (the 32mer) signals cartilage cells to mount an inflammatory and catabolic response. We will determine how the 32mer triggers this response, whether other joint cells are similarly activated and how it can be stopped, with the goal of pursuing new targets ....Osteoarthritis (OA) affects approximately 20% of Australians. There are no therapies that modify the course of the disease and joint replacement surgery is expensive and invasive. We have discovered that a peptide product of cartilage breakdown (the 32mer) signals cartilage cells to mount an inflammatory and catabolic response. We will determine how the 32mer triggers this response, whether other joint cells are similarly activated and how it can be stopped, with the goal of pursuing new targets for therapyRead moreRead less
The Role Of Endogenous Glucocorticoids In Autoimmune Arthritis
Funder
National Health and Medical Research Council
Funding Amount
$693,185.00
Summary
Inflammatory joint diseases affect millions of people worldwide and in most patients these often chronic conditions can not be cured. In an experimental model of arthritis we have found that bone cells can modify the severity of inflammation when certain hormonal signals are blocked. This study will identify the mechanisms underlying these hormonal effects with the aim to find new targets for efficient treatments for arthritis.
Pathobiology Of The Small Leucine Rich Repeat Proteoglycans In Cartilage, Intervertebral Disc And Tendon Degeneration
Funder
National Health and Medical Research Council
Funding Amount
$516,625.00
Summary
Back problems (M$700), OA (M$600), muscle and tendon disorders (M$500) accounted for 60% of musculoskeletal (MSK) health care expenditure in Australia in 1993-1994, were the second most common cause of presentations to a general practitioner, the third leading contributor to health system expenditure (>$3 billion) and accounted for ~300,000 hospital admissions, ~15 million medical services and over 13 million prescriptions. Significant disability due to MSK disease were noted in ~50% of peopl ....Back problems (M$700), OA (M$600), muscle and tendon disorders (M$500) accounted for 60% of musculoskeletal (MSK) health care expenditure in Australia in 1993-1994, were the second most common cause of presentations to a general practitioner, the third leading contributor to health system expenditure (>$3 billion) and accounted for ~300,000 hospital admissions, ~15 million medical services and over 13 million prescriptions. Significant disability due to MSK disease were noted in ~50% of people aged 65 years. Australian census data indicates that ageing trends will result in an increased incidence of MSK conditions as the longevity of the Australian population rises, exerting an ever increasing burden on the healthcare budget. Extreme levels of sporting or physical activity from traumatic loading of joints can lead to excessive loading of collagen fibres in MSK tissues leading to their failure and loss of tissue function. Common end stages of collagen fibre breakdown are preceded by matrix changes which may predispose MSK tissues to enzymatic and mechanical damage. One such change is an increased degradation of a family of small leucine-rich proteoglycans (SLRPs) which modulate the diameter, strength and assembly of collagen fibrils and bind and modify the effects of reparative growth factors and degradative cytokines within connective tissues. Altered synthesis of SLRPs and SLRP fragments have been identified in abnormal intervertebral disc, cartilage and tendon. Very little is known however about how these fragments are generated within these tissues and how they affect growth factor binding or collagen fibril formation. This deficiency will be addressed in our proposed study which will provide novel information on mechanisms of cartilage, intervertebral disc and tendon degeneration and potential therapeutic and diagnostic targets which may be exploited in future studies on the treatment of these musculoskeletal conditions.Read moreRead less