Disorganization of the cytoskeleton of neurons has major consequences on the transport of
neurotransmitters via the microtubule network. The interaction of cytoskeleton
proteins (actin and
tubulin) was studied in neuronal SK-N-BE cells treated with
tetracosanoic acid (C24:0), which is cytotoxic and increased in
Alzheimer's disease patients. When SK-N-BE cells were treated with C24:0,
mitochondrial dysfunctions and a non-apoptotic mode of cell death were observed. Fluorescence microscopy revealed shrunken cells with perinuclear condensation of actin and
tubulin. Impact of C24:0 on actin-microtubule interaction in human neuronal SK-N-BE cells: evaluation by FRET confocal spectral imaging microscopy after dual staining with
rhodamine-phalloidin and
tubulin tracker green After staining with
rhodamine-phalloidin and with an antibody raised against α-/β-
tubulin, modifications of
F-actin and α-/β-
tubulin levels were detected by flow cytometry. Lower levels of α-
tubulin were found by Western blotting. In C24:0-treated cells, spectral analysis and fluorescence recovery after photobleaching (FRAP) measured by confocal microscopy proved the existence of fluorescence resonance energy transfer (FRET) when actin and
tubulin were stained with
tubulin tracker and
rhodamine-phalloidin demonstrating actin and
tubulin co-localization/interaction. In control cells, no FRET was observed. Our data demonstrate quantitative changes in actin and
tubulin, and modified interactions between actin and
tubulin in SK-N-BE cells treated with C24:0. They also show that FRET confocal imaging microscopy is an interesting method for specifying the impact of cytotoxic compounds on cytoskeleton
proteins.