The role of the plasminogen activators (PAs), urokinase-PA and tissue-type PA in arthritis [ 2004 - 2006 ]

Research Grant

Researchers: A/Pr Andrew Cook (Principal investigator) ,  Prof John Hamilton ,  Prof Ross Vlahos

Brief description 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.

Funding Amount $AUD 481,500.00

Funding Scheme NHMRC Project Grants

Notes Standard Project Grant