LPS-Induced G-CSF Expression in Macrophages Is Mediated by ERK2, but Not ERK1
Fig 6
Knockdown of ERK2, but not ERK1, decreases LPS-induced DNase I accessibility of the G-CSF promoter.
THP-1 cells in which either ERK1 or ERK2 was knocked down using shRNA were induced to differentiate into macrophages. After incubation with DMSO or U0126 (10 μM), the cells were incubated with LPS (100 ng/ml) or PBS for 4 h, then nuclei were purified and subjected to DNase I digestion for 5 min. Genomic DNA was then isolated and the amount of undigested DNA within region -624/-450 of the G-CSF promoter (A) or within region -228/-71 of the TNF- α promoter (B) was determined by quantitative real-time PCR and expressed as a percentage of that in cells not treated with LPS and U0126. The results are the mean ± SD for three independent experiments. *p<0.05 compared to the corresponding control.