Fig. 5

Temporal profiles of p38 MAPK activity in astroglial and glioma cell lines. a Representative western blots (left) and densitometric analyses (right) of p38 MAPK activation in astroglial (HA) and C6 and IM3 glioma cultures harvested following serum shock at 4-h intervals for 2 days as described in Fig. 1. Graphs on the right depict the average immunoreactive signal of phospho-p38 MAPK (pp38) or total p38 MAPK (p38) normalized to β-actin obtained from 3 independent sets of samples. The pp38 MAPK (black squares) signal was rhythmic in HA cells as confirmed by statistical best fit to a sine wave (p < 0.05; ± SEM). Ratios of pp38/β-actin in C6 and IM3 glioma cultures and of p38/β-actin (gray triangles) signal in all 3 cell lines were arrhythmic as confirmed by statistical best fit to a line (p < 0.05; ± SEM). b Real-time PCR determinations (mean ± SEM) of the relative levels of Bmal1 and Per2 mRNA in HA, C6, and IM3 cultures (n = 3) harvested at 4-h intervals for 2 days as described in Fig. 1. The plotted values correspond to the ratios of Bmal1 or Per2 mRNA signal normalized to Ppia mRNA levels in which the maximal value for each gene was set at 100%. Bmal1 and Per2 mRNA levels were rhythmic in the 3 cell types as confirmed by statistical best fit to a sine wave (p < 0.05; n = 3, ± SEM). Pictures of full gels are shown in Additional file 2