The Relationship between Macrophages Inflammation and Peroxisome Proliferation

Obesity-induced macrophage infiltration into the tissues could lead to chronic low-grade inflammatory or even insulin resistance. Identifying factors that influence the macrophage inflammatory state would thus shed lights on the pathogenesis of insulin resistance. In this study, we investigated the relationship between macrophage inflammatory status and the number of peroxisomes on three sets of systems using techniques including immunofluorescence and Real-time PCR. Results showed that when macrophages polarized to M1 (pro-inflammatory), the number of peroxisome did not change significantly, while macrophages polarized to M2 (anti-inflammatory), the number of peroxisome increased significantly. These unexpected results were also observed when macrophages polarized in the presence of fatty acids. No significant peroxisome proliferation was observed when macrophages polarized to M1-like by the stimulation of saturated fatty acids, yet peroxisome proliferated significantly when macrophages polarized to M2-like by the stimulation of unsaturated fatty acids. The last set of experiments was carried out on Pex3–/– macrophages, where the peroxisome proliferation was restrainedPex3–/– macrophages could still polarize to anti-inflammatory M2/M2-like status, yet without any noticeable peroxisome proliferation. In conclusion, this study indicated that macrophages M1/M1-like polarization does not induce significant peroxisome proliferation, and M2/M2-like polarization could induce peroxisome proliferation under certain conditions.

CSTR: 32200.14.cjcb.2019.07.0013