BACKGROUNDAnkylosing spondylitis (AS) is a common inflammatory rheumatic disease which lacks satisfactory treatment so far. Sinomenine (SIN) is an alkaloid and has recently been utilized in treating multiple rheumatic diseases including AS in China, but its exact mechanism remains to be explored. This study investigated the alteration of proteome in peripheral blood mononuclear cells (PBMCs) from AS patients.

METHODSThirty AS patients were enrolled in this study. PBMCs from each AS patient were cultured in medium with or without SIN respectively. Then PBMCs proteins from both groups were separated by two-dimensional electrophoresis (2-DE) and analyzed by mass spectrometry (MS). Two differentially expressed proteins were then chosen to be verified using Western blotting.

RESULTSSeven proteins, including a-synuclein (SNCA), calmodulin (CALM), acidic leucine-rich nuclear phosphoprotein 32 family member A (ANP32A), chloride intracellular channel protein 1 (CLIC1), guanine nucleotide-binding protein G(I)/G(S)/G(T) subunit beta-1 (GNB1), gelsolin (GSN) and histone H2B type 1-M (HISTH2BM) were over-expressed, while coronin- 1A (CORO1A) was under-expressed in the SIN-treated PBMCs. Further bioinformatics search indicated that the changes of SNCA, ANP32A and CLIC1 pertained to apoptosis, while changes of GSN and CORO1A were associated with both apoptosis and inhibition of immunological function. Subsequently GSN and CORO1A were selected to validate by Western blotting and the results were consistent with those of 2-DE.

CONCLUSIONThere were 8 differentially expressed proteins in the SIN-treated PBMCs, which might shed some light on the mechanism of SIN in the treatment of AS.