Enamel matrix derivative promotes superoxide production and chemotaxis but reduces matrix metalloproteinase-8 expression by polymorphonuclear leukocytes.

Background: Polymorphonuclear leukocyte (PMN) is the predominant innate immune cell type activated in acute inflammation. The aim of this study is to determine the impact of enamel matrix derivative (EMD) on superoxide (O2−) generation, chemotaxis, and matrix metalloproteinase-8 (MMP-8) secretion by PMN in vitro to better understand the role of EMD in surgical wound healing.Methods: PMNs were isolated from healthy volunteers (n = 14). O2− generation was measured using a cytochrome c reduction assay. Chemotaxis was measured in a modified Boyden chamber. MMP-8 secretion was analyzed by Western blotting. A relative density method was used to determine the percentage of MMP-8 released from the PMNs in relation to the total cellular MMP-8 content.Results: O2− generation was significantly elevated when PMNs were stimulated with EMD (200 μg/mL) (P <0.01). Secondary stimulation of PMNs with 1 μM N-formyl-methionyl-leucyl-phenylalanine (fMLP) triggered earlier and more sustained O2− generation with EMD. EMD signif...