SPM biosynthesis during macrophage efferocytosis of apoptotic PMNs is enhanced by PMN MPs. Macrophages were incubated for 5 minutes with PMN MPs before the addition of apoptotic PMNs (7.5 × 105 cells/well). Cells were incubated for 1 hour at 37°C. At the end of the incubation, ice-cold MeOH was added and the products extracted. (A) Representative MRM traces for the identified LMs. (B) Accompanying MS/MS spectra used for identification. (C) Specific bioactive lipid mediator and precursor/pathway markers where: Q1, M-H (parent ion); and Q3, diagnostic ion in the MS-MS (daughter ion) along with mean ± SEM values for each of the mediators identified. Quantification and values obtained after PMN (3 × 105 PMN) and MP (2 × 105 MP) incubations. The detection limit was ∼ 1 pg. *Below limits. (D) D-series resolvins, protectins, and maresins. (E) Lipoxins. (F) Prostaglandins and thromboxanes. (C-F) Results are expressed as mean ± SEM; n = 4 distinct cell preparations. *P < .05 vs macrophage group. **P < .01 vs macrophage group. #P < .05 vs macrophage plus Apo PMN group.
