Microparticles stimulate the synthesis of prostaglandin E(2) via induction of cyclooxygenase 2 and microsomal prostaglandin E synthase 1.

Objective: Microparticles are small vesicles that are released from activated or dying cells and that occur abundantly in the synovial fluid of patients with rheumatoid arthritis (RA). The goal of these studies was to elucidate the mechanisms by which microparticles activate synovial fibroblasts to express a proinflammatory phenotype.

Methods: Microparticles from monocytes and T cells were isolated by differential centrifugation.

Imatinib mesylate reduces production of extracellular matrix and prevents development of experimental dermal fibrosis.

Objective: Imatinib mesylate is a clinically well-tolerated small molecule inhibitor that exerts selective, dual inhibition of the transforming growth factor beta (TGFbeta) and platelet-derived growth factor (PDGF) pathways. This study was undertaken to test the potential use of imatinib mesylate as an antifibrotic drug for the treatment of dermal fibrosis in systemic sclerosis (SSc).

Methods: The expression of extracellular matrix (ECM) proteins in SSc and normal dermal fibroblasts was analyzed by real-time polymerase chain reaction, Western blot, and Sircol collagen assay.

Monocyte chemoattractant protein 1 released from glycosaminoglycans mediates its profibrotic effects in systemic sclerosis via the release of interleukin-4 from T cells.

Objective: Monocyte chemoattractant protein 1 (MCP-1; CCL2) has been implicated in the pathogenesis of fibrotic diseases and is up-regulated in patients with systemic sclerosis (SSc). The aim of the present study was to examine the mechanisms by which MCP-1 mediates its profibrotic effects in the setting of SSc.

Methods: The expression of receptors for MCP-1 on dermal fibroblasts was analyzed by real-time polymerase chain reaction and fluorescence-activated cell sorting.