The Role Of A Novel Extracellular Matrix Protein, WARP, In Cartilage Development, Function And Pathology
Funder
National Health and Medical Research Council
Funding Amount
$482,500.00
Summary
The environment outside all cells is absolutely essential for normal growth and development. In order to undertand many disease and developmental processes it is critical that we acquire a detailed understanding of the various extracellular matrix components and how they interact to form a functional extracellular matrix. We recently discovered a new extracellular matrix protein which we have named WARP for von Willebrand factor A-domain-related protein. Our experiments demonstrate that WARP is ....The environment outside all cells is absolutely essential for normal growth and development. In order to undertand many disease and developmental processes it is critical that we acquire a detailed understanding of the various extracellular matrix components and how they interact to form a functional extracellular matrix. We recently discovered a new extracellular matrix protein which we have named WARP for von Willebrand factor A-domain-related protein. Our experiments demonstrate that WARP is an important constituent of the three-dimensional structure of the extracellular matrix of the articular surface of cartilage. We can show that WARP forms large-scale structures in tissue culture experiments and in extracts from mouse cartilage, and we have some new data which suggests that WARP interacts specifically with collagen II, a large and quantitatively major component of cartilage. We will explore the function of WARP in cartilage and include in vitro experiments that will reveal information about its distribution, tissue forms, and interactions with other extracellular matrix components (PART 1). To define the in vivo role of WARP we will generate a WARP gene knockout mouse (PART 2). These experiments will provide valuable information about the structure of the cartilage in the joint on the surface of bone and in particular the function of WARP in this structure. Since WARP is at the articular cartilage surface we asked whether WARP is lost in cartilage degeneration. In cartilage tissue grown in vitro under conditions that promote cartilage degradation, WARP is fragmented and released from the cartilage surface. We will explore this further in in vitro and in vivo models of cartilage breakdown (PART 3). Thus, in addition to promoting a new understanding of cartilage structure WARP has the exciting potential to become a specific biomarker for arthritis a major joint degenerative disease with high medical and financial cost to the community.Read moreRead less
In Australia osteoarthritis is the leading cause of pain and disability with the majority of individuals displaying radiographic evidence of this condition by age 65. We are developing two novel technologies which use patients' own stem cells to repair damaged cartilage. This project involves both the advancement of these technologies as well as their evaluation using a sheep cartilage repair model. These technologies offer significant promise for those suffering joint pain.
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.
Cartilage Destruction In Arthritis: Mechanism Of Aggrecanase And Matrix Metalloproteinase Action In Vivo And In Vitro
Funder
National Health and Medical Research Council
Funding Amount
$703,180.00
Summary
Arthritis is a disease that causes pain, deformity and disability. The lack of adequate therapies for arthritis is partly a reflection of our limited understanding of the biochemical events involved in disease progression and cartilage destruction. Two distinct families of enzymes are present in cartilage. These are the MMP and the ADAMTS family. These enzyme families are important for cartilage turnover in normal growth and skeletal development. However unregulated enzyme activity resulting in ....Arthritis is a disease that causes pain, deformity and disability. The lack of adequate therapies for arthritis is partly a reflection of our limited understanding of the biochemical events involved in disease progression and cartilage destruction. Two distinct families of enzymes are present in cartilage. These are the MMP and the ADAMTS family. These enzyme families are important for cartilage turnover in normal growth and skeletal development. However unregulated enzyme activity resulting in accelerated cartilage breakdown leads to the pathology recognised as arthritis. While some activities of the MMP and ADAMTS families have been studied in the laboratory, there have been no in vivo studies to determine which family is responsible for cartilage destruction, and which is therefore most appropriate for targeting by drugs. This project will create genetically-modified mice, resistant to either the MMP or the ADAMTS enzymes. The mice will be used in experimental arthritis models to determine which enzymes play the major role in initiating disease, which enzymes are involved in disease progression and which enzymes may be important for repair. In parallel studies, the highly specialised matrix molecule, keratan sulphate, will be studied for its role in cartilage destruction. There is preliminary evidence to suggest that keratan sulphate may be involved in the regulation of ADAMTS activity. The possible direct and indirect modalities of keratan sulphate action will be investigated. The results of this arthritis project will (a) yield new information on the mechanism of disease action; (b) identify targets for the rational design of disease-modifying drugs; (c) elucidate biochemical processes involved in normal skeletal growth and cartilage repair; and (d) provide new in vivo models for testing the efficacy of arthritis therapies.Read moreRead less
Development Of A Smart Arthroscopy System And Prototype Probe For Joint Tissues
Funder
National Health and Medical Research Council
Funding Amount
$230,632.00
Summary
This project relates to the ever growing use of arthroscopy in the management of joint defects. An innovative probe that will combine all the molecular, microstructural and biomechanical characteristics of joint articular cartialge and bone for the purposes of diagnosis, treatment, treatment-related decisions, comparison of the effectiveness of treament methods and post treatment evaluation will be developed. This system will produce spin-offs for artrhoscopy of other soft tissues and bodies.
The Role Of The Plasminogen Activators (PAs), Urokinase-PA And Tissue-type PA In Arthritis
Funder
National Health and Medical Research Council
Funding Amount
$481,500.00
Summary
Many diseases, such as rheumatoid arthritis (RA), are inflammatory by nature. Intra-articular fibrin deposition is an early and persistent hallmark of inflammatory responses, resulting from an altered balance between coagulation (the production of fibrin) and fibrinolysis (the breakdown of fibrin). This fibrin accumulation can have adverse effects in RA, including mediating and-or enhancing inflammation, and contributing to subsequent joint damage. The plasminogen activators (PA), urokinase PA ( ....Many diseases, such as rheumatoid arthritis (RA), are inflammatory by nature. Intra-articular fibrin deposition is an early and persistent hallmark of inflammatory responses, resulting from an altered balance between coagulation (the production of fibrin) and fibrinolysis (the breakdown of fibrin). This fibrin accumulation can have adverse effects in RA, including mediating and-or enhancing inflammation, and contributing to subsequent joint damage. The plasminogen activators (PA), urokinase PA (u-PA) and tissue-type PA (t-PA) convert plasminogen into plasmin which can then breakdown the accumulated fibrin. Their presence in RA patients would therefore be beneficial. However, u-PA is also implicated in cell migration leading to inflammatory cells accumulating in the joint, and cartilage destruction, both of which are detrimental to disease outcome. In the joints of RA patients there are high levels of u-PA and low levels of t-PA. We, and our collaborators, have found that in the absence of t-PA, disease is exacerbated, whilst in the absence of u-PA, the outcome depends on the type of disease, either exacerbating or ameliorating disease. This highlights the different roles u-PA can have. The current proposal aims to determine the role of u-PA in inflammation and arthritis, and whether enhancing t-PA can have beneficial outcomes with respect to disease severity. In addition, we will also study whether intra-articular fibrin deposition can, in fact, drive the inflammatory reaction and cartilage destruction seen in RA. The findings will be important for our understanding of the role of fibrin accumulation in the inflammatory and destructive processes that occur in RA, and the roles of u-PA and t-PA in enhancing and preventing them respectively. Information gained will provide clues for useful strategies for the treatment of human inflammatory diseases, including RA.Read moreRead less
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.
Glycomic Control Of Cartilage Extra Cellular Matrix Turnover
Funder
National Health and Medical Research Council
Funding Amount
$706,289.00
Summary
Small, naturally occurring glycomic molecules control cartilage matrix turnover. We have synthesised small synthetic analogues of the naturally occurring molecules, and demonstrated their ability to regulate signalling pathways. This project will test and mathematical model the synthetic molecules in cell and tissue assays to define their properties and tissue effects, and assess their suitability as a drug delivery system. The results will be an important step towards designing new ways of trea ....Small, naturally occurring glycomic molecules control cartilage matrix turnover. We have synthesised small synthetic analogues of the naturally occurring molecules, and demonstrated their ability to regulate signalling pathways. This project will test and mathematical model the synthetic molecules in cell and tissue assays to define their properties and tissue effects, and assess their suitability as a drug delivery system. The results will be an important step towards designing new ways of treating osteoarthritis and other cartilage diseases.Read moreRead less