Fig. 6.

P2X₇ nucleotide receptor protein expression is regulated in RA-differentiated SH-SY5Y cells. Human SH-SY5Y neuroblastoma cells were grown to 80% confluency onto cell culture Petri dishes in normal serum. Then, cells were subjected to medium replacement containing b normal serum or d low serum. Both cultures were supplemented with 15 μM RA as described in “Materials and methods” section. Chronic RA treatment was performed by replacing the corresponding medium with fresh medium supplemented with 15 μM RA every 2 days. On the corresponding experimental day, cells were lysed and the P2X₇ nucleotide receptors protein levels were determined by western blot analysis of whole-cell lysates. Non-RA treated cells (undifferentiated cells) under a normal and c low serum content served as controls. P2X₇ nucleotide receptor protein expression was normalized to β-actin protein. Data are the means ± SEM of values from four independent experiments (** P < 0.01 one-way ANOVA). Representative gels are shown