SURVIVIN IS AN ESSENTIAL MEDIATOR OF ARTHRITIS INTERACTING WITH UROKINASE SIGNALLING.

• ABSTRACT Proto-oncogene survivin has recently been identified as a prognostic marker distinguishing patients with destructive rheumatoid arthritis (RA). In the present material of 132 RA patients and 82 controls the levels of survivin correlated to urokinase (uPA) (r=0.46), a plasminogen activator over expressed in inflamed joints and known to exhibit potent arthritogenic properties. Here we evaluate the functional relationship between these proteins using primary synovial fibroblasts and leukocytes of RA patients, human monocytic (THP-1) and fibroblast (MRC-5) cell lines. Using inhibitors of intracellular signalling we show that uPA and survivin share common transduction pathways being in synovial fibroblasts dependent on the activity of tyrosine kinases, PI3-kinase and MEK. Moreover, uPA production is significantly reduced in fibroblasts if survivin synthesis has been silenced by siRNA. Importantly, silencing of survivin in fibroblasts prevented their invasive growth in knee joints of SCID mice. Interaction of uPA with receptor up regulates survivin expression in leukocytes. In turn, survivin is required for the upregulation of uPA receptor on cell surface. These findings indicate that survivin is an essential mediator of arthritogenic properties of uPA regulating its synthesis in synovial fibroblasts and uPAR expression in leukocytes. Close correlation between survivin and uPA levels in patients with RA supports the importance of this connection for the pathogenesis of arthritis.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Reumatologi och inflammation (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Rheumatology and Autoimmunity (hsv//eng)

Publication and Content Type

ref (subject category)

art (subject category)