Figure 3
Amodiaquine inhibits cellular entry of LF.
(a) AQ inhibits LT-mediated caspase-1 activation. RAW264.7 cells were seeded and allowed to adhere overnight and then incubated with 16 μM AQ or DMSO for 1 h before addition of 500 ng/mL PA + LF for 2 h. FLICA was added for a further 1 h and then cells analyzed by fluorescence microscopy. (b) AQ inhibits LT-mediated cleavage of MEK-2. RAW264.7 cells were incubated with AQ or DMSO for 1 h before addition of vehicle control or 1 μg/mL PA + LF for up to 2 h. Cells were lysed and analyzed via immunoblotting with a MEK-2–specific antibody. Tubulin was used as a loading control. (c) FRET data showing fluorescence emission from three reactions, where 5.8 μg/ml LF cleaves fluorescently labeled MAPKK peptide without drugs, in the presence of a known LF inhibitor, 16 μM surfen hydrate, or in the presence of 16 μM AQ. (d and e) AQ protects cells from PA + FP59. RAW264.7 cells were preincubated with a titration of AQ for 1 h, followed by a 6 h intoxication with 500 ng/mL PA + LF (d) or FP59 (e). Cell viability was measured via MTT.
