Macrophage Derived Platelet Activating Factor Implicated in the Resolution Phase of Gouty Inflammation

Figure 4

Inhibition of endothelial cell activation by platelet activating factor derived from supernatants from MSU crystal stimulated macrophages. Monocytes or macrophages were cultured for 1 and 7 days, respectively, and stimulated with MSU crystals. Collected supernatants were cocultured with human umbilical vein endothelial cells (HUVEC) for 4 hours at a 1 : 2 dilution or 1 : 1 mix, either alone or in the presence of WEB2086 (a PAF receptor antagonist). HUVEC expression of E-Selectin was measured by flow cytometry. WEB2086 was added to supernatant mixtures in culture at 100 μM which relieved the suppression of E-Selectin seen in the 1 : 1 mix condition ( by Student’s paired -test). Relief of E-Selectin suppression by supernatants from day 7 macrophages stimulated with MSU crystals was also observed ( by Student’s paired -test). Results are the mean and SD of 3 experiments. RFI = relative fluorescence intensity. D7 = supernatants from day 7 macrophages, D1 = supernatants from day 1 monocytes, and WEB = WEB2086.