Serum amyloid A (SAA) induces pentraxin 3 (PTX3) production in rheumatoid synoviocytes
Modern Rheumatology, 04/13/2012
Satomura K et al. – The data suggest that SAA plays a role in the proinflammatory and immune responses in rheumatoid synovium by inducing PTX3. The authors provide the first evidence that the acute–phase reactant SAA, which is produced systemically by hepatocytes, perpetuates the rheumatoid inflammatory processes by inducing another proinflammatory molecule, PTX3, locally in rheumatoid synovial tissues.Methods
- PTX3 mRNA expression was examined by reverse transcription polymerase chain reaction, and PTX3 protein was measured by enzyme–linked immunosorbent assay.
- SAA induced PTX3 mRNA and PTX3 protein expression in rheumatoid synoviocytes.
- SAA–induced PTX3 expression was attenuated when rheumatoid synoviocytes were nucleofected with N–formyl peptide receptor ligand–1 (FPRL–1)–specific siRNA, suggesting the involvement of FPRL–1.
- Furthermore, SAA–induced PTX3 expression was inhibited by NF–κB or mitogen–activated protein kinase–specific inhibitors.
- Neither soluble TNF receptor (etanercept) nor recombinant IL–1 receptor antagonist affected PTX3 production by SAA–stimulated synoviocytes, suggesting that SAA directly induces PTX3.