H2 inhibits IL-22, alleviates CIAScientific Research

Abstract:

Objective To investigate the therapeutic effect and mechanism of hydrogen (H2) on collagen-induced arthritis (CIA) in mice. Methods DBA/1 mice were randomly divided into normal control group, CIA group and CIA mice treated with H2 group (H2 treated group), with 6 mice in each group. Following the preparation of CIA mouse model, the H2 treated group received H2 inhalation therapy (300 mL/L, 3 hours/d) for 15-60 days. The arthritis score were assessed and HE staining of joint were evaluated by referring to the pathology score; The number of CD4+IL-22+ cells in spleen and joint was observed by flow cytometry and immunohistochemical staining; ELISA was conducted to assess the levels of interleukin 22 (IL-22) in serum and joint; Western blotting was performed to examine the expression of phosphorylated STAT3 (p-STAT3) and phosphorylated NF-κB (p-NF-κB) in joint between the three groups. Results In the CIA group, both the arthritis score and pathology score were higher than control group, while they dropped after H2 treatment. In addition, compared with control group, CIA group showed higher proportion of CD4+IL-22+ cells and higher level of IL-22 which then interestingly decreased after H2 therapy. Besides, the p-STAT3 and p-NF-κB were elevated in CIA mice compared with control group, and H2 treatment significantly inhibited them. Conclusion H2 can reduce the levels of CD4+IL-22+ cells and IL-22, and alleviate arthritis symptoms in CIA mice by inhibiting STAT3/NF-κB pathway.