Oxidized CaMKII promotes asthma through the activation of mast cells
Jingjing Qu, Danh C. Do, Yufeng Zhou, Elizabeth Luczak, Wayne Mitzner, Mark E. Anderson, Peisong Gao
Jingjing Qu, Danh C. Do, Yufeng Zhou, Elizabeth Luczak, Wayne Mitzner, Mark E. Anderson, Peisong Gao
View: Text | PDF
Research Article Immunology Pulmonology

Oxidized CaMKII promotes asthma through the activation of mast cells

Abstract

Oxidation of calmodulin-dependent protein kinase II (ox-CaMKII) by ROS has been associated with asthma. However, the contribution of ox-CaMKII to the development of asthma remains to be fully characterized. Here, we tested the effect of ox-CaMKII on IgE-mediated mast cell activation in an allergen-induced mouse model of asthma using oxidant-resistant CaMKII MMVVδ knockin (MMVVδ) mice. Compared with WT mice, the allergen-challenged MMVVδ mice displayed less airway hyperresponsiveness (AHR) and inflammation. These MMVVδ mice exhibited reduced levels of ROS and diminished recruitment of mast cells to the lungs. OVA-activated bone marrow–derived mast cells (BMMCs) from MMVVδ mice showed a significant inhibition of ROS and ox-CaMKII expression. ROS generation was dependent on intracellular Ca2+ concentration in BMMCs. Importantly, OVA-activated MMVVδ BMMCs had suppressed degranulation, histamine release, leukotriene C4, 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. 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.

Authors

Jingjing Qu, Danh C. Do, Yufeng Zhou, Elizabeth Luczak, Wayne Mitzner, Mark E. Anderson, Peisong Gao

×

Figure 4

Reduced ROS levels in mast cells of ROS-resistant CaMKII mice.

Options: View larger image (or click on image) Download as PowerPoint
Reduced ROS levels in mast cells of ROS-resistant CaMKII mice. (A) Repre...
(A) Representation of BMMC FACS analysis for the surface markers c-Kit and FcεRI. (B) Representation of images of the colocalization of CaMKII (green) and mitochondria (red) in BMMCs using confocal microscopy. Representative of 2 independent experiments. Scale bar: 10 μm. (C) Experimental setup for IgE-mediated mast cell activation and expression of CaMKII and ROS. BMMCs from WT and MMVVδ mice were sensitized with 1 μg/ml anti-OVA IgE (E-C1) for 16 hours and then stimulated with 10 μg/ml OVA for 30 minutes. (D) Representative immunoblot of ox-CaMKII and total CaMKII (Tot-CaMKII) in OVA-sensitized and challenged BMMCs derived from WT and MMVVδ mice. Various dosages of H2O2 were used as possible controls. One representative immunoblot of three is shown. (E and F) Quantitative data for ox-CaMKII (E) and Tot-CaMKII (F) expression using densitometry from 3 independent Western blots. Mean ± SEM. (G) Levels of intracellular ROS in OVA-sensitized and challenged BMMCs by flow cytometry with CM-H2DCFDA. Mean ± SEM, a single time point from 3 independent experiments. (H) Representative MitoTracker or MitoSOX staining of these OVA-sensitized and challenged WT and MMVVδ BMMCs from 3 independent experiments. Scale bar: 5 μm. (I) Quantitative data for MitoSOX expression in H, as determined by mean fluorescent intensity (MFI). Data represent mean ± SEM, 7–14 high power field view (HFV) per group. Comparisons were made using 2-tailed Student’s t test between OVA-treated WT vs. MMVV. *P < 0.05.