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Oxidized Camkii Promotes Asthma through Activating Mast Cells
Sunday, March 5, 2017: 1:45 PM
Room B314 (Georgia World Congress Center, Building B)
Jingjing Qu, M.D., , , , , ,
Rationale: Oxidation of calmodulin-dependent protein kinase II (ox-CaMKII) by reactive oxygen species (ROS) has been associated with asthma. The contribution of ox-CaMKII to the development of asthma remains to be fully characterized. Here, we tested the effect of ox-CaMKII using oxidant-resistant CaMKII MMVVδ knock in mice (MM-VVδ).

Methods: Ox-CaMKII in cockroach allergens induced allergic inflammation was investigated in mouse model of asthma using MM-VVδ mice. Bone marrow-derived mast cells (BMMCs) from C57BL/6 mice and MM-VVδ mice were tested using OVA. Mast cell activation including β-hexosaminidase, IL-13 secretion, histamine release, and passive cutaneous anaphylaxis (PCA) were quantified.

Results: Compared to wild type (WT), the allergen-challenged MM-VVδ mice displayed a less airway hyper-responsiveness (AHR) and inflammation. These MM-VVδ mice exhibited reduced levels of ROS and diminished recruitment of mast cells to the lungs. OVA-activated bone marrow-derived mast cells (BMMCs) from MM-VVδ showed a significant inhibition of ROS and ox-CaMKII expression. Importantly, OVA-activated MM-VVδ BMMCs had suppressed degranulation, histamine release, leukotriene C4 (LTC4) and IL-13 expression. Adoptive transfer of WT, but not MMVVδ BMMCs, reversed the alleviated AHR and inflammation in allergen-challenged MMVVδ mice. The CaMKII inhibitor KN-93 significantly suppressed IgE-mediated mast cell activation and asthma.

Conclusions: These studies support a critical but previously unrecognized role of ox-CaMKII in mast cells that promotes asthma, and suggest that therapies to reduce ox-CaMKII may be a novel approach for asthma.