Objective〖WTBZ〗To understand the possible role of some proteins expressed by human synovial fibroblasts (SFs) in the pathogenesis of rheumatoid arthritis.   Methods The expression difference of synovial fibroblast proteins between rheumatoid arthritis (RA) patients and healthy controls was analyzed by 2-DE. The differential expression spots were identified by matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF-MS)

followed by bioinformatics analysis

some of which were validated by Western blot.   Results Using 12% SDS-PAGE following pH 4-7 IPG strips in IEF

averagely 837 and 852 protein spots were detected in RA patients and normal subjects

respectively. Gel image analysis revealed that there were 49 differential protein spots. By peptide mass fingerprinting strategy

we identified 40 protein spots derived from gels of SFs in RA patients among differential spots and 23 valid proteins were obtained. Western blot analysis showed that expressions of Enolase α

Annexin I

Cathepsin D

SOD2

Peroxiredoxin 2 were significantly higher in SFs from RA patients than those from normal subjects

which was consistent with proteome analysis.   Conclusion The differential proteins might be involved in inflammation of synovitis in RA.