Anti-allergic and anti-inflammatory effects of the Bcl-2 inhibitor ABT-737 on experimental allergic rhinitis models

The anti-cancer agent ABT-737 is designed specifically to inhibit anti-apoptotic proteins of the Bcl-2 family. The development of cancer has long been associated with inflammation. Here, we assess the anti-allergic and anti-inflammatory effects and the underlying molecular mechanisms of ABT-737 on allergic rhinitis (AR) using in vitro and in vivo models. In the in vitro model, the ABT-737 treatment diminished the levels of several inflammatory cytokines in this case vascular endothelial growth factor (VEGF), thymic stromal lymphopoietin (TSLP), interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α) by inhibiting caspase-1 and NF-κB activation in an activated human mast cell line, here HMC-1 cells. These mechanistic observations were validated in ovalbumin-sensitized AR mice. In an AR animal model, ABT-737 significantly diminished clinical symptoms of AR and the levels of AR biomarkers, specifically IgE, histamine, hypoxia-inducible factor-1α, VEGF, TSLP, IL-1β, IL-4, IL-5, IL-6, IL-13, TNF-α, intercellular adhesion molecule-1, and macrophage inflammatory protein-2. In addition, ABT-737 reduced the degree of caspase-1 activity compared to that in AR mice. Simultaneously, ABT-737 diminished the recruitment of mast cells and eosinophils into nasal mucosa tissues compared to the levels in AR mice. In conclusion, we identified new anti-allergic and anti-inflammatory effects of ABT-737. These results imply that ABT-737 can ameliorate allergic inflammatory diseases such as AR.