Ellipticine blocks synergistic effects of IL-17A and TNF-α in epithelial cells and alleviates severe acute pancreatitis-associated acute lung injury.

IL-17A combined with TNF-α plays a vital role in inflammatory response and interference of the synergistic effect is an effective strategy for treating inflammatory diseases. Ellipticine, a natural alkaloid, has biological activities on anti-tumor and anti-HIV. However, it is still unknown whether ellipticine can inhibit IL-17A and TNF-α-mediated signaling and has treatment effect on PALI. Here, we reported that ellipticine significantly inhibited the production of pro-inflammatory cytokines and chemokines in pulmonary epithelial cell BEAS-2B treated with IL-17A and TNF-α, but not IL-17A or TNF-α alone. Meanwhile, ellipticine attenuated NF-κB and MAPKs activation in response to IL-17A and TNF-α treatment, inhibited Act1 and TRAF6-mediated NF-κB activation, and blocked the interaction of Act1 with TRAF6. Furthermore, we found that ellipticine significantly alleviated CAE and LPS-induced SAP/PALI. Ellipticine treatment dramatically reduced inflammatory cells infiltration, MPO activity, serum amylase and lipase activity and the protein concentration of BALF. Collectively, our findings indicate that ellipticine inhibits the synergistic effect of IL-17A and TNF-α by targeting on Act1 and TRAF6 interaction and is a potential therapeutic agent for the treatment of SAP/PALI.