AIM:To investigate the inhibitory effect of PDE4 inhibitor rolipram on the releases of inflammatory cytokines in mouse macrophages (RAW264.7 cells) induced by myeloid-related protein 8/14 (MRP8/14), and to explore the role of nuclear factor-κB (NF-κB) in this process.METHODS:RAW264.7 cells were treated with MRP8/14.The inflammatory cytokines TNF-α and IL-6 were determined by LiquiChip and qPCR.In contrast, RAW264.7 cells were pretreated with rolipram prior to MRP8/14 exposure.After MRP8/14 challenge, the inflammatory cytokines TNF-α and IL-6 were determined by LiquiChip and qPCR.Moreover, the phosphorylation level of NF-κB P65 was determined by Western blot.The nuclear translocation of NF-κB P65 in RAW264.7 cells was detected by indirect immunofluorescence.RESULTS:The results of LiquiChip and qPCR showed that MRP8/14 enhanced the expression of TNF-α and IL-6 (P<0.01),while pretreatment with rolipram markedly down-regulated the level of inflammatory cytokines induced by MRP8/14 (P<0.05).Meanwhile, MRP8/14 significantly activated the phosphorylation of NF-κB P65, and the protein expression of p65 in the nucleus was increased,while pretreatment with rolipram suppressed the phosphorylation of NF-κB P65 induced by MRP8/14.CONCLUSION:Rolipram may significantly reduce the releases of the inflammatory cytokines induced by MRP8/14 through the NF-κB signaling.