Effects of corticosteroids and platelet-rich plasma on synoviocytes in IL-1ß-induced inflammatory condition

Corticosteroid injections are used to treat shoulder pain. Platelet-rich plasma (PRP) is known to have anti-inflammatory and anabolic effects, as well as cytoprotective effects against corticosteroids. Thus, this study was to investigate the effects of co-treatment of corticosteroid and PRP on anti-inflammatory and matrix homeostasis of synoviocytes in IL-1ß-induced inflammatory conditions.

Synoviocytes were cultured with 1 ng/mL IL-1β, 1 μM dexamethasone, and 10% (vol/vol) Platelet-poor plasma (PPP), PRP200, PRP1000, and PRP4000 X 10³/μL. Gene expressions of pro-inflammatory and anti-inflammatory cytokines, degradative enzymes, and their inhibitors were evaluated and protein synthesis of degradative enzymes and their inhibitors were also examined.

Corticosteroid modulated anti-inflammatory and pro-inflammatory cytokines, and subsequent PRP treatment did not interfere with the effect of a corticosteroid and modulated the gene expressions of cytokines such as TNF-α and IL-4, which were not regulated by the corticosteroid alone. Gene expressions and protein expressions of degradative enzymes and their inhibitors were suppressed by corticosteroid. Additional PRPs did not alter the gene expression and protein regulated by the corticosteroid and inhibited the gene expression of ADAMTS-5 and protein synthesis of MMP-9 and ADAMTS-5, which were not modulated by the corticosteroid alone.

Corticosteroid regulated the inflammation and synovial homeostasis. When PRP and the corticosteroid were used together, it exhibited synergistic effects on synoviocytes by regulating the parts that were not controlled by corticosteroid alone while not interfering with the effects of the corticosteroid in an inflammatory condition.