Deflazacort modulates the fibrinolytic pattern and reduces uPA-dependent chemioinvasion and proliferation in rheumatoid arthritis synoviocytes.
OBJECTIVE
Extracellular fibrinolysis, controlled by the cell-associated fibrinolytic system (urokinase plasminogen activator, uPA; uPA receptor, uPAR; plasminogen activator inhibitor type-1, PAI-1), is involved in cartilage damage generation and in rheumatoid arthritis (RA) synovitis. Since steroids reduce the rate of radiological progression of RA, we planned to evaluate in healthy and RA synoviocytes the effects of the steroid deflazacort on uPA, uPAR and PAI-1 expression, and subsequent phenotypic modifications in terms of uPA/uPAR-dependent invasion and proliferation.


METHODS
uPA, uPAR and PAI-1 levels were studied by ELISA, RT-PCR (uPAR) and zymography (uPA) in synoviocytes from four RA patients and four healthy controls. Chemoinvasion was assessed by the Boyden chamber invasion assay, using Matrigel as the invasion substrate. Proliferation was evaluated by cell counting. Both invasion and proliferation were measured upon treatment with deflazacort 5 muM with or without parallel stimulation with uPA 500 ng/ml or in the presence of monoclonal anti-uPA and anti-uPAR antibodies.


RESULTS
Invasion and proliferation of RA synoviocytes require a proper functional balance of the fibrinolytic system. Both deflazacort and monoclonal antibodies against uPA and uPAR reduced expression and activity of the system, thus inhibiting invasion and proliferation. In RA synoviocytes, deflazacort induced higher PAI-1 and lower uPA and uPAR levels, as well as a decrease in uPA enzymatic activity. The levels of uPAR mRNA were concomitantly reduced, as was uPA-induced chemoinvasion. All these effects were also shown in controls, though to a lesser extent.


CONCLUSIONS
Deflazacort might control RA synovial proliferation and invasion by differential modulation of single members of the fibrinolytic system.
Department of Internal Medicine, Division of Rheumatology, University of Florence, Viale Pieraccini 18, 50139 Firenze, Italy.
A
A
Del Rosso
M
M
Cinelli
S
S
Guiducci
A
A
Pignone
G
G
Fibbi
F
F
Margheri
A
A
Gabrielli
R
R
Giacomelli
A
A
Coppini
M
M
Del Rosso
M
M
Matucci Cerinic
D000328:Adult; D018501:Antirheumatic Agents / Q000494:pharmacology; D001172:Arthritis, Rheumatoid / Q000473:pathology*; D049109:Cell Proliferation; D002478:Cells, Cultured; D002633:Chemotaxis / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005260:Female; D005342:Fibrinolysis / Q000187:drug effects*; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D017395:Plasminogen Activator Inhibitor 1 / Q000378:metabolism; D011282:Pregnenediones / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism; D055293:Receptors, Urokinase Plasminogen Activator; D013583:Synovial Membrane / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D014568:Urokinase-Type Plasminogen Activator / Q000502:physiology*
D018501:Antirheumatic Agents; C524898:PLAUR protein, human; D017395:Plasminogen Activator Inhibitor 1; D011282:Pregnenediones; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D055293:Receptors, Urokinase Plasminogen Activator; D014568:Urokinase-Type Plasminogen Activator; C021988:deflazacort