title: Reduction of in vitro invasion and in vivo cartilage degradation in a SCID mouse model by loss of function of the fibrinolytic system of rheumatoid arthritis synovial fibroblasts.
abstract: OBJECTIVE
  Urokinase plasminogen activator (uPA), uPA receptor (uPAR), and PA inhibitor 1 (PAI-1) have pivotal roles in the proliferation and invasion of several cell types, including synovial fibroblasts (SFs). The aim of this study was to investigate the possibility of controlling the invasion of rheumatoid arthritis (RA) SFs in vitro and in vivo by inhibiting uPA and uPAR.
  
  
  METHODS
  Normal SFs, SFs from patients with RA, and SFs from patients with psoriatic arthritis (PsA) were used. The levels of uPA, uPAR, and PAI-1 were measured by enzyme-linked immunosorbent assay and reverse transcription-polymerase chain reaction analysis of messenger RNA. The activity of uPA was studied by zymography. Proliferation was measured by cell counting, and cell invasion was measured with a Boyden chamber assembled with Matrigel-coated porous filters. Human cartilage and RA SF implantation in the SCID mouse model of RA were used to study cartilage invasion in vivo.
  
  
  RESULTS
  RA SFs and PsA SFs overexpressed uPAR and as a result were more active than their normal counterparts in terms of both Matrigel invasion and proliferation. This effect was counteracted by a specific inhibitor of uPA enzymatic activity (WX-340) and by uPAR antisense treatment. The use of both WX-340 and uPAR antisense treatment in vitro showed cooperative effects in RA SFs that were more intense than the effects of either treatment alone. Significant inhibition of cartilage invasion was obtained in vivo with uPAR antisense treatment, while uPA inhibition was inefficient, either alone or in combination with antisense treatment.
  
  
  CONCLUSIONS
  The decrease in uPAR expression in RA SFs reduced invasion of human cartilage in vitro and in the SCID mouse model.
authors.affiliation: Department of Experimental Pathology and Oncology, University of Florence and Center for the Study at Molecular and Clinical Level of Chronic, Degenerative, and Neoplastic Diseases to Develop Novel Therapies (DENOTHE), Florence, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Serratì
authors.forename: Francesca
authors.initials: F
authors.lastname: Margheri
authors.forename: Anastasia
authors.initials: A
authors.lastname: Chillà
authors.forename: Elena
authors.initials: E
authors.lastname: Neumann
authors.forename: Ulf
authors.initials: U
authors.lastname: Müller-Ladner
authors.forename: Maurizio
authors.initials: M
authors.lastname: Benucci
authors.forename: Gabriella
authors.initials: G
authors.lastname: Fibbi
authors.forename: Mario
authors.initials: M
authors.lastname: Del Rosso
mesh_terms: D000818:Animals; D001172:Arthritis, Rheumatoid / Q000378:metabolism*; D002358:Cartilage, Articular / Q000378:metabolism*; D002452:Cell Count; D049109:Cell Proliferation; D004195:Disease Models, Animal; D005347:Fibroblasts / Q000378:metabolism*; D006801:Humans; D051379:Mice; D020319:Oligodeoxyribonucleotides, Antisense; D017395:Plasminogen Activator Inhibitor 1 / Q000235:genetics / Q000378:metabolism; D055293:Receptors, Urokinase Plasminogen Activator / Q000235:genetics / Q000378:metabolism; D013583:Synovial Membrane / Q000378:metabolism*; D014568:Urokinase-Type Plasminogen Activator / Q000235:genetics / Q000378:metabolism
chemical_list: D020319:Oligodeoxyribonucleotides, Antisense; D017395:Plasminogen Activator Inhibitor 1; D055293:Receptors, Urokinase Plasminogen Activator; D014568:Urokinase-Type Plasminogen Activator