Figure 2.

TNF-α stimulates the release of MMP8 from neutrophilic granulocytes. (a) Biopsies from AI lesions were analyzed by IHC. Staining of myeloperoxidase, an enzyme abundantly expressed in neutrophilic granulocytes, in skin sections counterstained with hematoxylin is shown. Scale bar = 25 μm. (b) Human blood cultures were stimulated with the indicated AI-relevant cytokines or were left unstimulated (control) for 4 h. MMP8 concentrations in cell-free supernatants were quantified by ELISA and demonstrated as percent of control. Data from 5 experiments are shown (mean ± SEM). Significance of differences between control versus stimulation groups was analyzed using the Wilcoxon matched-pairs signed-rank test (two-tailed; ^∗ P < 0.05).