MPO-deficient neutrophils fail to initiate lipid peroxidation in plasma.
Neutrophils (1 × 106/mL) isolated from healthy and MPO-deficient subjects were incubated at 37°C in HBSS supplemented with DTPA (100 μM, pH 7.0) and fresh human plasma (50%, vol/vol). Cells were activated by the addition of phorbol myristate acetate (PMA, 200 nM) and incubated for 2 hours (Complete System). The contents of 9-H(P)ODE and 9-H(P)ETE formed within endogenous plasma lipids were then determined by LC/ESI/MS/MS as described in “Materials and methods.” Where indicated, human MPO (30 nM) was added to reaction mixtures. Data represent the mean ± SD of triplicate determinations. Each bar within a cluster for a given condition represents results obtained from independent experiments performed with neutrophil preparations from a distinct donor. PMN(MPO+), neutrophils isolated from healthy subjects; PMN(MPO−), neutrophils isolated from MPO-deficient subjects.
