Paraoxonase 2 Induces a Phenotypic Switch in Macrophage Polarization Favoring an M2 Anti-Inflammatory State

Figure 4

Direct effect of human PON2 (hPON2) on the inflammatory and anti-inflammatory responses in PON2KO MPM. MPM were harvested from 3-month-old PON2KO male mice. The cells were transfected with pcDNA3.1+ empty plasmid (EP) or with pcDNA3.1+ plasmid containing hPON2 for 4 hours at 37°C. Cells were then washed and cultured with DMEM medium + 10% fetal calf serum for 48 hours. The cells were cultured for additional 12 hours unstimulated and then either M1-activated with IFNγ/LPS or M2-activated with IL-4. IL-6 (a), arginase ΙΙ (b), IL-10 (c), and arginase Ι (d) mRNA expressions were determined by quantitative PCR and results were normalized to GAPDH expression. The inset of (a) shows hPON2 mRNA expression in PON2-deficient MPM transfected with EP and PON2KO MPM transfected with hPON2. Results are expressed as mean ± SD (), , PON2KO MPM versus control MPM; M1 stimulated versus unstimulated, , M1, M2 stimulated versus unstimulated cells.

(a) IL-6 mRNA expression

(b) Arginase II mRNA expression

(c) IL-10 mRNA expression

(d) Arginase I mRNA expression