Abstract: Objective To investigate the regulatory effects of microRN-A-223 on the expression of pro-inflammatory cytokines during the inflammation induced by P.g-LPS in GFs. Methods The expression of microRNA-223 in GFs was interfered by lentiviral transfection, then the optimum concentration of P.g-LPS (800 μg/L) was added to different GFs in which the expressions of microRNA-223 were over expression, suppression of expression and normal expression in vitro. The mRNA levels of tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β), interleukin-6(IL-6), and microRNA-223 were measured by qPCR, and the protein levels of TNF-α, IL-1β, and IL-6 were measured by ELISA. Results When P.g-LPS stimulated GFs to produce inflammatory response, the mRNA levels of microRNA-223 and the mRNA and protein levels of proinflammatory cytokines TNF-α, IL-1β, and IL-6 were significantly higher than those in normal cells. The mRNA and protein levels of proinflammatory cytokines increased with the up-regulation of intracellular microRNA- 223 (P<0.001), and the protein of IL-1β and TNF-α were restrained with the down-regulation of intracellular microRNA-223 (P<0.001). Conclusion When inflammation occurs in gingival fibroblasts, the expression of microRNA-223 increases and the pro-inflammatory cytokines IL-1β, TNF-α and IL-6 are up-regulated, further exacerbating inflammation in cells.

Key words: microRNA-223, porphyromomas gingivalis, human gingival fibroblasts, inflammatory cytokines