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Updated: Jul 17, 2026

Isolation of Peritoneum-derived Mast Cells and Their Functional Characterization with Ca2+-imaging and Degranulation Assays
Published on: July 4, 2018
Increased IgE-dependent mast cell activation and anaphylactic responses in mice lacking the calcium-activated
Rudi Vennekens1, Jenny Olausson, Marcel Meissner
1Laboratory of Ion Channel Research, Division of Physiology, Department of Molecular Cell Biology, Campus Gasthuisberg, O&N1, KU Leuven, Herestraat 49 bus 802, B-3000 Leuven, Belgium. rudi.vennekens@med.kuleuven.be
Abstract:
Mast cells are key effector cells in allergic reactions. Aggregation of the receptor FcepsilonRI in mast cells triggers the influx of calcium (Ca(2+)) and the release of inflammatory mediators. Here we show that transient receptor potential TRPM4 proteins acted as calcium-activated nonselective cation channels and critically determined the driving force for Ca(2+) influx in mast cells. Trpm4(-/-) bone marrow-derived mast cells had more Ca(2+) entry than did TRPM4(+/+) cells after FcepsilonRI stimulation. Consequently, Trpm4(-/-) bone marrow-derived mast cells had augmented degranulation and released more histamine, leukotrienes and tumor necrosis factor. Trpm4(-/-) mice had a more severe IgE-mediated acute passive cutaneous anaphylactic response, whereas late-phase passive cutaneous anaphylaxis was not affected. Our results establish the physiological function of TRPM4 channels as critical regulators of Ca(2+) entry in mast cells.
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