The role of resident synovial cells in destructive arthritis

Center of Experimental Rheumatology, University Hospital Zurich and Zurich Center of Integrative Human Physiology, Gloriastrasse 23, CH-8091 Zürich, Switzerland.
Bailli&egrave re s Best Practice and Research in Clinical Rheumatology (Impact Factor: 3.06). 05/2008; 22(2):239-52. DOI: 10.1016/j.berh.2008.01.004
Source: PubMed

ABSTRACT Infiltration by inflammatory cells, thickening of the lining layer, and destructive invasion into cartilage and bone are pathognomic features of the synovium in rheumatoid arthritis (RA). However, the most common cell types at the sites of invasion are resident cells of the joint, in particular synovial fibroblasts. These cells differ from healthy synovial fibroblasts in their morphology, their expression of proto-oncogenes and antiapoptotic molecules, and in their lack of certain tumor suppressor genes. Through their production of proinflammatory cytokines and chemokines mediated by signaling via Toll-like receptors, they are not only effector cells but also active parts of the innate immune system attracting inflammatory immune cells to the synovium. Most importantly, by producing matrix-degrading molecules they contribute strongly to the destructive mechanisms operative in RA.