Chemokines produced by synoviocytes of the subacromial bursa are up-regulated in subacromial inflammation (bursitis) and rotator cuff disease. SDF-1a is an important chemotactic factor in the subacromial bursa that stimulates recruitment of inflammatory cells; however, its mechanism of induction and regulation in the subacromial bursa is unknown. We hypothesised that SDF-1a production in bursal synoviocytes may be induced by local cytokines such as interleukin IL-1β and IL-6. Subacromial bursa specimens were obtained following an institutional review board-approved protocol from patients undergoing shoulder surgery. Bursal specimens were stained with anti-human antibodies to IL-1, IL-6 and SDF-1a by immunohistochemistry and compared to normal and rheumatoid controls. Bursal cells were also isolated from specimens and cultured. Cultured cells were labelled with fluorescent probes and analysed by flow cytometry to determine cell lineage. Early-passaged cells were then treated with cytokines IL-1β and IL-6 and SDF-1a production and expression were measured by ELISA and RT-PCR.Purpose
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