Fig. 4.

Time course induction of Egr1 protein expression and Egr-1 DNA-binding activity in human lung fibroblast cells after exposure to CSE. (A) CSE induces Egr-1 expression in a time-dependent manner in NL9 cells. NL9 cells were incubated in the absence (CTL) or in the presence of CSE (50%) and whole-cell lysates were subjected to Western blot analysis. The same membrane was probed with an anti-β-actin antibody to assess equal loading of the gel. (B) Nuclear extracts were assayed for the activity of transcription factor Egr-1 by an ELISA-based TransFactor kit. Significant difference between 1 and 4 h CSE (50%) treatment and CTL is shown (^*, P < 0.05).