Fibroblast function in psoriatic arthritis. II. Increased expression of beta platelet derived growth factor receptors and increased production of growth factor and cytokines

Abstract

Objective: The main objective was to investigate the expression of platelet derived growth factor (PDGF) receptors, and production of growth factors and cytokines from psoriatic skin and synovium derived fibroblasts.

Methods: Fibroblast cultures were established from normal and psoriatic skin and synovium. Confluent cultures of fibroblasts were used for a receptor binding assay for PDGF, and then extracts were run on Western blot. The amount of immunoreactive A and B chain peptides present was determined with specific A or B chain antisera. Production of interleukin 1 beta and PDGF-beta was accomplished by neutralization with the use of commercially available antisera. A functional assay was used to measure transforming growth factor-beta (TGF-beta).

Results: There was an increased expression of the beta PDGF receptor in the psoriatic fibroblasts. Interleukin 1 beta and PDGF-beta production by psoriatic fibroblasts was also increased. However, TGF-beta production was similar in normal and psoriatic fibroblasts.

Conclusion: Our data demonstrate an increased expression of beta PDGF receptor, and production of IL-1 beta and PDGF by psoriatic fibroblasts. The findings provide further support for an active role of this cell line in the pathogenesis of psoriasis and psoriatic arthritis.