Regulation of cytochrome P450 1A1 on M2 macrophage polarization / 中华危重病急救医学

ABSTRACT

Objective@#To investigate the potential effects of cytochrome P450 1A1 (CYP1A1) in regulating macrophages polarize to M2 type and explore the molecular mechanism.@*Methods@#All trials were completely randomized. ① Experiment 1 6-8 weeks old healthy male C57BL/6J mice were collected, and primary peritoneal cells were extracted, then the cells were divided into phosphate buffered saline (PBS) group and interleukin-4 (IL-4) group. The cells in the IL-4 group were stimulated with 10 mg/L IL-4 (M2 macrophage inducer); and those in the PBS group were given with an equal amount of PBS. The mRNA expressions of intracellular M2 type polarized marker molecules including arginase-1 (Arg-1) and chitinase 3 like protein 1 (YM1) at 2, 4, 6 hours after IL-4 challenge were determined by quantitative reverse transcription-polymerase chain reaction (RT-qPCR). The phosphorylation of tyrosine protein kinase 1/signaling transcriptional and transduced activator 6 (JAK1/STAT6) signaling pathway and protein expressions of CYP1A1 and Arg-1 at 6, 12, 24 hours after IL-4 challenge were determined by Western Blot. ② Experiment 2 RAW264.7 cells with high expression CYP1A1 (CYP1A1/RAW) and their negative control cells (NC/RAW) were cultured in vitro. The cells in logarithmic growth phase were collected, and then they were divided into PBS control group and IL-4 group. The treatment method was the same as experiment 1. The phosphorylations of intracellular JAK1/STAT6 and phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) pathways in different cells at 1 hour and 2 hours after IL-4 challenge were determined by Western Blot. The mRNA and protein expressions of Arg-1 in different cells at 2 hours and 4 hours after IL-4 challenge were determined by RT-qPCR and Western Blot, respectively.@*Results@#① Experiment 1 after IL-4 challenge for 2 hours, the mRNA expressions of Arg-1 and YM1 in the primary peritoneal macrophages of mice were significantly increased as compared with the PBS control group [Arg-1 mRNA (2-ΔΔCt) 1.75±0.82 vs. 1.00±0.21; YM1 mRNA (2-ΔΔCt) 2.58±0.53 vs. 1.00±0.20, both P < 0.05] which indicated that IL-4 induced macrophage to M2 type polarization successfully. Meanwhile, the mRNA expression of CYP1A1 in polarized mouse peritoneal primary macrophages was also elevated as compared with the PBS control group, and peaked at 4 hours [CYP1A1 mRNA (2-ΔΔCt) 2.25±0.69 vs. 1.00±0.17, P < 0.01]. The results indicated that CYP1A1 expression was enhanced when macrophages polarized to M2 type. Compared with the PBS control group, the bands of phosphorylated JAK1 (p-JAK1), phosphorylated STAT6 (p-STAT6), Arg-1 and CYP1A1 were enhanced in primary peritoneal macrophages of mice in the IL-4 group, and reached the peak value at 12 hours then gradually decreased. This result indicated that the phosphorylation of JAK1/STAT6 pathway was enhanced in M2 macrophages with high expression of CYP1A1, and the pathway was activated. ② Experiment 2 after IL-4 challenge for 2 hours, the expression of Arg-1 mRNA in CYP1A1/RAW cells was significantly higher than that in NC/RAW cells (2-ΔΔCt 3.02±0.60 vs. 1.47±0.43, P < 0.05), and the protein band signal was also stronger, and both peaked at 4 hours. This indicated that CYP1A1 could promote the polarization of macrophages to M2. After IL-4 challenge for 2 hours, the expression of p-JAK1 and p-JAK3 protein bands in both cells were significantly enhanced as compared with the PBS control group, but the enhancement of p-STAT6 band in CYP1A1/RAW cells was stronger than that of NC/RAW cells, indicating that CYP1A1 promoted macrophage polarization by promoting phosphorylation of the JAK1/STAT6 pathway. In the meantime, the protein band of Akt, a downstream protein of the PI3K/Akt pathway, in CYP1A1/RAW cells was significantly lower than that of NC/RAW cells, indicating that CYP1A1 did not promote macrophage polarization through this pathway.@*Conclusions@#CYP1A1 promotes the polarization of macrophage to M2 type. The mechanism is related to promoting the phosphorylation of JAK1/STAT6 pathway.