Figure 6

EPO does not act through Egr2 to increase myelin gene expression. (A) EPO induces Egr2 gene expression in CG4-EPOR cells. CG4-EPOR cells were plated in GM, then switched to DM and after 24 h treated with or without EPO 80 ng/mL for 1 h. Egr2 expression was measured by qPCR. Results are expressed as arbitrary units versus no EPO and are the mean ± SD of nine to twelve samples analyzed in duplicate (no EPO, N = 9; EPO, N = 12). ***P< 0.001 versus no EPO by Student t test. (B-C) EPO effect on MOG expression is not blocked by Egr2 silencing. CG4-EPOR cells were differentiated and transfected with siRNA targeting Egr2 or with a negative control siRNA. After 24 h cells were treated with or without EPO 80 ng/mL. Egr2 gene expression was measured 1 h after EPO stimulation (B) and MOG was measured at d 4 of differentiation (C). Results are expressed as arbitrary units versus control cells (no siRNA, no EPO) and are the mean ± SD of four to six samples analyzed in duplicate (panel B, N = 4; panel C, N = 6). ***P< 0.001 versus no EPO; ^§P< 0.001 versus no siRNA; ^#P< 0.001 versus control siRNA; Student t test.