| First Author | Nam ST | Year | 2017 |
| Journal | Toxicol Appl Pharmacol | Volume | 332 |
| Pages | 25-31 | PubMed ID | 28736076 |
| Mgi Jnum | J:256326 | Mgi Id | MGI:6106213 |
| Doi | 10.1016/j.taap.2017.07.015 | Citation | Nam ST, et al. (2017) Suppression of IgE-mediated mast cell activation and mouse anaphylaxis via inhibition of Syk activation by 8-formyl-7-hydroxy-4-methylcoumarin, 4mu8C. Toxicol Appl Pharmacol 332:25-31 |
| abstractText | Mast cells trigger IgE-mediated allergic reactions by releasing various allergic mediators. 8-Formyl-7-hydroxy-4-methylcoumarin, also called 4mu8C, was originally known as an inositol-requiring enzyme 1 (IRE1) suppressant, but no study has examined its relationship with mast cells and allergic diseases. Therefore, the purpose of this study was to determine whether 4mu8C is effective in suppressing allergic reactions in mast cells and in IgE-mediated allergic animal model. 4mu8C suppressed the degranulation of IgE-mediated mast cells (IC50=3.2muM) and the production of cytokines such as tumor necrosis factor-alpha (TNF-alpha) and interleukin-4 (IL-4) in a dose-dependent manner. 4mu8C also suppressed passive cutaneous anaphylaxis (PCA) in mice (ED50=25.1mg/kg). In an experiment on mast cell signaling pathways stimulated by antigen, the phosphorylation and activation of Syk was decreased by 4mu8C, and phosphorylation of downstream signaling molecules, such as linker for activated T cells (LAT), Akt, and the three MAP kinases, ERK, p38, and JNK, were suppressed. Mechanistic studies showed that 4mu8C inhibited the activity of Lyn and Fyn in vitro. Based on the results of those experiments, the suppressor mechanism of allergic reaction by 4mu8C involved reduced activity of Lyn and Fyn, which is pivotal in an IgE-mediated signaling pathway. In summary, for the first time, this study shows that 4mu8C inhibits Lyn and Fyn, thus suppressing allergic reaction by reducing the degranulation and the production of inflammatory cytokines. This suggests that 4mu8C can be used as a new medicinal candidate to control allergic diseases such as seasonal allergies and atopic dermatitis. |
