Figure 1. Spinal cord injury induces upregulation of expression of E2F1 and its downstream targets.
Analysis of expression of E2F1 and its transcriptional target genes in intact and injured spinal cord were performed by western blotting. A. 5-mm-long segment centered at the injury epicenter was dissected and homogenized in RIPA buffer. Equal amounts of protein were electrophoretically separated on NuPAGE Novex Bis-Tris gradient gels, transferred to nitrocellulose membranes, and blotted with antibodies to E2F1 and CDK1. GAPDH signal served as a loading control. B–C. The signal quantifications for E2F1 (B) and CDK1 (C) using Gel-Pro Analyzer software are displayed. E2F1 and CDK1 expression level was upregulated as early as 15 min and sustained until 3 days after injury. D–E. Cyclin A expression was increased at all time points. F. Bim and c-Myb, downstream targets of E2F1 were upregulated as early as 5 h post-injury and sustained until day 3 after SCI. G–H. Quantification of respective western blots in panel D. N = 4 rats/time point. *P<0.05 vs sham group.