New signaling pathways involved in mast cell activation and cell membrane repair

Abstract

RESULTS 54 RESULTS AND DISCUSSION Vacuolin-1-induced changes in mast cells morphology In pilot experiments we determined the effect of vacuolin-1 on mast cell morphology. Incubation of RBL-2H3 cells or BMMCs with 10 μM vacuolin-1 in complete culture media for 3 h resulted in appearance of numerous vacuoles in cytosolic compartment of the cells (Fig 1A-D). Size of the vacuolin-1-treated cells rose (Fig 1E and F) as reflected by mean increase in diameter of RBL-2H3 cells from 14.8 ± 0.2 μm (mean ± S.D., n = 3) to 18.8 ± 0.3 μm, and BMMCs from 14.6 ± 0.2 μm to 17.3 ± 0.2 μm. To decide whether formation of vacuoles depends on specific metabolic pathways we examined cells exposed to various concentrations of pharmacological inhibitors and 10 μM vacuolin-1. Data presented in Table 1 show that most of the drugs tested, including Cl- and/or K+ channel blockers [indanyloxyacetic acid 94 (IAA-94), (dihydroindenyl)oxy/alkanoic acid (DIOA), 5- Nitro-2-(3-phenylpropylamino)-benzoic acid (NPPB), 4,4'-diisothiocyanatostilbene-2,2'- disulphonate (DIDS) and glybenclamide], protein kinase C (PKC) inhibitor (tamoxifen), phosphoinositid-3 kinase (PI3K) inhibitor (wortmannin), Src and Syk family kinase inhibitors (PP2 and piceatannol) and non-muscle myosin (NMM) II ATPase activity inhibitor (blebbistatin)...

RESULTS 54 RESULTS AND DISCUSSION Vacuolin-1-induced changes in mast cells morphology In pilot experiments we determined the effect of vacuolin-1 on mast cell morphology. Incubation of RBL-2H3 cells or BMMCs with 10 μM vacuolin-1 in complete culture media for 3 h resulted in appearance of numerous vacuoles in cytosolic compartment of the cells (Fig 1A-D). Size of the vacuolin-1-treated cells rose (Fig 1E and F) as reflected by mean increase in diameter of RBL-2H3 cells from 14.8 ± 0.2 μm (mean ± S.D., n = 3) to 18.8 ± 0.3 μm, and BMMCs from 14.6 ± 0.2 μm to 17.3 ± 0.2 μm. To decide whether formation of vacuoles depends on specific metabolic pathways we examined cells exposed to various concentrations of pharmacological inhibitors and 10 μM vacuolin-1. Data presented in Table 1 show that most of the drugs tested, including Cl- and/or K+ channel blockers [indanyloxyacetic acid 94 (IAA-94), (dihydroindenyl)oxy/alkanoic acid (DIOA), 5- Nitro-2-(3-phenylpropylamino)-benzoic acid (NPPB), 4,4'-diisothiocyanatostilbene-2,2'- disulphonate (DIDS) and glybenclamide], protein kinase C (PKC) inhibitor (tamoxifen), phosphoinositid-3 kinase (PI3K) inhibitor (wortmannin), Src and Syk family kinase inhibitors (PP2 and piceatannol) and non-muscle myosin (NMM) II ATPase activity inhibitor (blebbistatin)...