Figure 4.

FcεRI-induced COX-2 expression, but not degranulation, is impaired in miR-155 KO BMMCs. Wild-type and miR-155 KO BMMCs were sensitized with anti-DNP-IgE and challenged with multivalent antigen DNP-HSA. (A) Dose-dependent degranulation response of wild-type and miR-155 KO BMMCs after 30 min activation period. Degranulation was determined by β-hexosaminidase release. (B) Leukotriene C4 (LTC₄) biosynthesis after 30 min activation period. (C) Expression of ALOX5 in non-activated wild-type and miR-155 KO BMMCs. Analysis performed was quantitative RT-PCR. (D) Time-course for FcεRI-induced COX-2 expression in wild-type and miR-155 KO BMMCs. Fold change in COX-2 expression was determined by quantitative real-time PCR. The figures represent mean ± SEM of values obtained from independent experiments with 3–6 different BMMC cultures of each genotype from different mice. Significance was determined with Student's t-test. *p < 0.05; **p < 0.01.