LPA generates macrophages in vivo and in humans through a common transcription factor, PPARγ, both in mice and humans. (A) FACS plots showing percentage of CD11b⁺ and F4/80⁺ macrophages elicited in peritoneal and pleural cavities of C57BL/6 mice injected with 3% thioglycollate in the absence or presence of 20 µg LPA. PBS, phosphate-buffered saline. (B) FACS plots showing percentage of CD11b⁺ and F4/80⁺ macrophages elicited in peritoneal and pleural cavities of FVB (FVB-WT) and FVB-ATX-Tg mice injected with 3% thioglycollate. (C) Proportion of peritoneal macrophages positive for F4/80 CD11b in FVB WT and FVB ATX-Tg mice. (D) Heat map showing the expression of surface markers, transcription factors, and cytokine-related genes in monocytes (Mo) and LPA-derived macrophages (LDMa). (E) Quantification of PPARγ mRNA in mouse monocytes and macrophages derived from LPA or M-CSF–treated mouse monocytes for different days. (F) FACS plots showing percentage of CD11b and F4/80 macrophages in monocytes pretreated with different doses of PPARγ inhibitor and cultured in the presence of LPA or M-CSF for 5 days. (G) Quantification of PPARγ in monocytes (control), monocytes treated with LPA, and monocytes pretreated with Akt inhibitor or mTor inhibitor and cultured further in medium supplemented with LPA for 5 days. Rap, rapamycin. (H) Representative phase contrast and Giemsa-stained images of human monocytes cultured in RPMI only (control) and human monocytes cultured in medium with 2.5 µM LPA and 10 ng/mL M-CSF for 7 days. (I-K) Quantification of CD14, CD68, and CD206 mRNA in human monocytes and macrophages derived from human monocytes cultured with different doses of LPA or M-CSF at day 5. (L) FACS plots showing percentage of CD14⁺ and CD68⁺ macrophages in monocytes treated with M-CSF, LPA, or Akt inhibitor (LY294002)-pretreated monocytes cultured in medium with LPA for 5 days. (M) Quantification of PPARγ-relative mRNA in human monocytes and monocytes cultured in medium with LPA or M-CSF for 7 days. (N) FACS plots showing percentage of CD14⁺ and CD68⁺ macrophages in human monocytes cultured with or without PPARγ inhibitor in the presence of LPA for 5 days. Graphs depict mean ± SD of 4 or 5 mice. Data are representative of 2 independent experiments. Error bars represent SD. Scale bars, 100 μm. Student t test was used for all statistical analyses (***P < .001).