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Characterization of mastoparan-induced histamine release from RBL-2H3 cells
K Mizuno1, N Nakahata, Y Ohizumi
1Department of Pharmaceutical Molecular Biology, Faculty of Pharmaceutical Sciences, Tohoku University, Sendai, Japan.
Abstract:
Mastoparan (5-30 microM), a tetradecapeptide isolated from wasp venom, caused histamine release from RBL-2H3 cells in a concentration- and time-dependent manner. Mastoparan-induced histamine release remained after removing the extracellular Ca2+, whereas the antigen-induced one disappeared. Pertussis toxin did not inhibit mastoparan-induced histamine release from the cells, and mastoparan did not stimulate phosphoinositide hydrolysis. In agreement with the results, RBL-2H3 cells had a small amount of ADP-ribosylation substrates for pertussis toxin. Neomycin (1-5 mM) suppressed mastoparan-induced histamine release and phospholipase D activation. However, butanol slightly inhibited mastoparan-induced histamine release. Moreover, 2,3-diphosphoglycerate inhibited mastoparan-induced phospholipase D activation, but not it's histamine release. On the other hand, mastoparan caused the leakage of lactate dehydrogenase from the cells in a similar concentration range to the histamine release. This leakage was also suppressed by neomycin. These results suggest that mastoparan enhances the membrane permeability, resulting in histamine release in a pertussis toxin-insensitive manner, and that mastoparan-induced phospholipase D activation may not relate to histamine release.
Insights
Mastoparan, a wasp venom peptide, triggers histamine release from cells by increasing membrane permeability. This process is independent of pertussis toxin and phosphoinositide hydrolysis, suggesting a novel mechanism.
Area of Science:
- Immunology
- Cell Biology
- Pharmacology
Background:
- Mastoparan is a tetradecapeptide from wasp venom.
- Mastoparan is known to affect cell membranes.
Purpose of the Study:
- To investigate the mechanism of mastoparan-induced histamine release from RBL-2H3 cells.
- To determine the role of calcium, pertussis toxin, and phospholipase D in mastoparan-induced effects.
Main Methods:
- RBL-2H3 cells were treated with mastoparan.
- Histamine release was measured.
- Extracellular calcium was removed.
- Pertussis toxin and neomycin were used.
- Phospholipase D activation was assessed.
- Lactate dehydrogenase leakage was measured.
Main Results:
- Mastoparan induced histamine release in a concentration- and time-dependent manner.
- Mastoparan-induced histamine release was calcium-independent, unlike antigen-induced release.
- Pertussis toxin did not inhibit mastoparan-induced histamine release.
- Neomycin suppressed both histamine release and phospholipase D activation.
- Mastoparan caused lactate dehydrogenase leakage, indicating membrane damage, which was neomycin-sensitive.
Conclusions:
- Mastoparan enhances cell membrane permeability, leading to histamine release.
- This histamine release mechanism is pertussis toxin-insensitive.
- Mastoparan-induced phospholipase D activation may not be directly linked to histamine release.