1. DPP-4 enhances M1 polarization and inhibits M2 polarization in macrophages in an ROS-dependent manner.
DPP-4 enhances M1 polarization and inhibits M2 polarization in macrophages in an ROS-dependent manner. A: DPP-4 upregulates LPS-induced M1 marker mRNA expression and increases intracellular ROS production in peritoneal macrophages. B: Linagliptin (Lina) suppresses the increase of DPP-4–induced (500 ng/mL) M1 marker mRNA expression and ROS production by LPS stimulation. C: DPP-4 inhibits IL-4–induced M2 marker mRNA expression and increases ROS in M2-polarized macrophages. D: Linagliptin restores the decrease of DPP-4–induced (500 ng/mL) M2 marker mRNA expression and decreases ROS production in the presence of IL-4. Peritoneal macrophages were isolated and coincubated with LPS (100 ng/mL) or IL-4 (10 ng/mL) and DPP-4 (100–500 ng/mL) or linagliptin (200 nmol/L) for 16 h. n = 6. *P < 0.05, **P < 0.01 vs. control incubations; †P < 0.05, ††P < 0.01 vs. LPS- or IL-4–stimulated incubations; ‡P < 0.05, ‡‡P < 0.01 vs. LPS/IL-4 and DPP-4 and/or linagliptin-stimulated incubations.
Fen Zhuge et al. Diabetes 2016;65:
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