Figure 7. Mice expressing sPLA₂-IIA possess an altered fecal lipidome.

The intestinal and fecal lipid profile of 14-month-old and arthritic 14-week-old male mice housed in the Elite SPF+ animal facility was investigated. (A and B) Lipids were isolated from intestinal samples and identified using high-performance liquid chromatography combined with mass spectrometry. The data distributions for 14-month-old (n = 4) (A) and 14-week-old arthritic mice (n = 9–10) (B) were visualized by principal component analysis (PCA) with 99 % confidence ellipses. (C–F) An untargeted lipidomic analysis was performed using murine fecal samples. Data from 14-month-old (C) and 14-week-old arthritic mice (D) treated or not with antibiotics were visualized by PCA with 99 % confidence ellipses (n = 3–5). (E) Heatmap of the Z scores of the measured lipid classes for each experimental group. (F) Concentration of total fatty acids and lysophospholipids in samples from each mouse group (n = 3–5). (F) Data are presented as mean ± SEM. Statistical analysis included the following: unpaired t test and 1-way ANOVA with Šidák multiple comparisons test. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001.