Effects of APELIN-13 on the expression of IL-6, TNF-α, and IFN-γ in rats with experimental autoimmune neuritis

The objective of this paper was to study the effects of PYR-ARG-PRO-ARG-LEU-SER-HIS-YSGLY-PRO-MET-PRO-PHE-OH (APELIN-13) on the expression of inflammatory factors interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ) in rats with experimental autoimmune neuritis (EAN). A total of 30 rats were divided into a control group, an EAN group, and an APELIN-13 group. Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of IL-6, TNF-α, and IFN-γ in rat plasma. Real-time quantitative Polymerase Chain Reaction (PCR) and Western blot were used to detect the protein and mRNA expression of IL-6, TNF-α, and IFN-γ in rat lymph nodes. In the EAN group, the infiltration of various types of inflammatory cells and focal demyelination were observed near the nerve fascicles of sciatic nerves. Compared with the EAN group, the infiltration of inflammatory cells and demyelination in the APELIN-13 group decreased significantly. The levels of plasma IL-6, TNF-α, and IFN-γ in the EAN group were significantly higher than those in the control group (P < 0.05) but significantly lower than those in the APELIN-13 group (P < 0.05). Compared with the control group, the mRNA and protein expression of IL-6, TNF-α, and IFN-γ increased significantly (P < 0.05) in the EAN group but decreased significantly in the APELIN-13 group (P < 0.05). In conclusion, APELIN-13 exerted a protective effect against EAN in rats.