Loss of LGR6 is linked with a shift in the lipid mediator profiles and a decrease in ALOX12 levels in neutrophils. (A-B) Neutrophils from participants with the rs74355478 variant in LGR6 (variant group) and controls (control group) were isolated from whole blood and incubated with PBS. After incubation, the supernatant was collected, and lipid mediator concentrations were established using LC-MS/MS–based lipid mediator profiling. (A) PLS-DA analysis of lipid mediator concentrations of neutrophils from the variant and control groups; 2-dimensional score plot with circles representing the 95% confidence regions (top); VIP scores of the lipid mediators with the greatest differences in concentration between the groups (bottom). The P values were calculated using the Hotelling T² test using the first principal component of PLS-DA. (B) Pathway analysis for the differential expression of lipid mediators from the docosahexaenoic acid (DHA), n-3 docosapentaenoic acid (n-3 DPA), eicosapentaenoic acid (EPA), and arachidonic acid (AA) bioactive metabolomes in variant compared with control. Highlighted pathways represent lipid mediators with VIP score >1 in PLS-DA. Red and blue nodes indicate higher or lower concentrations of the lipid mediator, respectively, in the variant group. (C) Ratio of SPM that were found to be differentially expressed in the incubations in panels A-B (ie, VIP >1) to LTB₄ pathway (ie, LTB₄, 20-OH-LTB₄, and 20-COOH-LTB₄). (D-E) Whole blood from participants from the variant and control groups was incubated with antibodies against lineage markers to identify neutrophils (CD16⁺). The expression of lipid mediator biosynthetic enzymes (D) and SPM receptors (E) was evaluated using flow cytometry and fluorescently conjugated antibodies to these proteins; whisker plots representing the number of neutrophils expressing enzymes (D) or receptors (E) (left); bar plots displaying the expression in neutrophils of enzymes (D) or receptors (E) represented as the logarithm (log) of the median fluorescence intensity (MFI; right). Statistical differences between variant and control were determined using the Mann-Whitney test (Student t test for log normalized MFI, after normality check using Shapiro test), and P values are displayed. Results are representative of 3 for variants and 4 for controls (except for COX-2, in which 3 were for controls, due to technical issues). PBS, phosphate-buffered saline.