Fig. 4.

Calcium signaling induced by epidemral growth factr (EGF) or hepatocyte growth factor (HGF) is not affected due lipid rafts disorganization. A: confocal images of HepG2 cells loaded with Fluo-4/AM (6 µM) and stimulated with EGF (50 ng/ml). A and D: control (A) and metyl-β-cyclodextrin (MβCD)-treated cells (D) were analyzed. Images were pseudocolored according to the scale shown at bottom. Scale bar = 10 μm. B and E: graphical representation of the fluorescence increase in the nucleus (blue traces) and cytosol (red traces) of a control (B) and an MβCD-treated cell stimulated with EGF (E), pointed with an arrow. C and F: summary of EGF stimulation studies. (control nucleus = 552.3 ± 18%; control cytosol = 444 ± 11%; n = at least 50 cells for each condition). G: confocal images of HepG2 cells loaded with Fluo-4/AM (6 µM) and stimulated with HGF (100 ng/ml). G and J: control (G) and MβCD-treated cells (J) were analyzed. Images were pseudocolored according to the scale shown at bottom. Scale bar = 10 μm. H and K: graphical representation of the fluorescence increase in the nucleus (blue traces) and cytosol (red traces) of a control (H) and an MβCD-treated cell stimulated with HGF (K). I and L: summary of HGF stimulation studies (control nucleus = 589.3 ± 11%; control cytosol = 498 ± 6%; n = at least 50 cells for each condition). Values are means ± SD of the peak Fluo-4 fluorescence acquired during the observation period (expressed as % of baseline) and include the response from 55 control HepG2 cells and 55 MβCD-treated HepG2 cells, for each stimulus. The values indicate the means ± SD. *P < 0.01, difference between groups was statistically significant; ns, not significant. Data were analyzed by one-way ANOVA followed by Bonferroni post tests.