Shweta Hosakoppal, B.A.
Medicine
Mast cell, aquaporin, allergy, anaphylaxis, histamine
Third Floor, Feinberg Pavilion, Northwestern Memorial Hospital
Mast cells regulate immune responses in part through the release of granules containing mediators, such as histamine, cytokines and proteases. Cross-linking of IgE on FcεRI by antigen results in mast cell activation, a hallmark of allergy and anaphylaxis. Mechanisms that inhibit the activation of these cells might provide novel therapeutic approaches. Using a microarray expression approach, we identified a water channel, Aquaporin 9, that is highly expressed by mast cells, but its role on these cells remained unclear. To investigate this, mast cells were studied after treatment with phloretin, a highly specific chemical inhibitor of Aquaporin 9. Mast cells activated in the presence of phloretin showed significant down-regulation of several cytokines induced by activation, including IL-4, IL-5, IL-6, IL-13 and IL-33. Similarly, degranulation and cell migration were significantly reduced in a dose-dependent manner. Our data suggests that Aquaporin 9 is necessary for mast cell activation and could be a novel target for the treatment of allergies.