Figure 5

Effects of actinomycin D and cycloheximide on ET-induced changes in CCL2, CXCL1 and CX3CL1 mRNA levels. (A) Serum-starved astrocytes were treated with 100 nM ET-1 for one (CCL2 and CXCL1) or six (CX3CL1) hours. Actinomycin D (Act-D, 1 μg/mL) or cycloheximide (CHX, 10 μg/mL) was added to the medium 30 minutes before treatment with ET-1. The expression of CCL2, CXCL1 and CX3CL1 mRNA was normalized to G3PDH and expressed as the % of no treatment cultures. Data are the mean ± SEM of 8 to 15 experiments. *P <0.05, **P <0.01 versus no ET-1, ^## P <0.01 versus no inhibitor by one-way ANOVA followed by Fisher’s PLSD test. NS, not significant. (B) Effects of ET-1 on CCL2, CXCL1 and CX3CL1 mRNA expressions in the presence of actinomycin D. Cultured astrocytes were treated with ( open circle) or without (closed circle) 100 nM ET-1 for the time indicated in the presence of 1 μg/mL actinomycin D. Actinomycin D was included in the medium 30 minutes before treatment with ET-1. Data are the mean ± SEM of six experiments. *P <0.05 versus control by one-way ANOVA followed by Fisher’s PLSD test. ANOVA, analysis of variance; ET-1, endothelin-1; G3PDH, glyceraldehyde-3-phosphate dehydrogenase; PLSD, protected least significant difference; SEM, standard error of the mean.