Figure 2.
Effect of PDGF-BB and EGF on the expression of c-fos and egr-1 mRNA in EGCG-treated VSMCs. Confluent cells in 75-cm2 flasks were precultured in the presence and absence of 50 μM EGCG in serum-free medium for 24 h. Then medium was replaced with serum-free medium without EGCG, and VSMCs were stimulated with 50 ng/ml PDGF-BB and 50 ng/ml EGF for 30 min. Ten micrograms of total RNA were electrophoresed on formaldehyde–agarose gels, blotted onto Hybond N+ membranes, and probed with a 32P-labeled 1.0-kb v-fos cDNA probe that hybridized to the 2.2-kb mRNA of c-fos. The same blot was rehybridized with a 32P-labeled 2.1-kb egr-1 cDNA probe that hybridized to the 3.4-kb egr-1 mRNA and with a 0.77-kb cDNA probe for β-actin mRNA. Arrows show the 28S (4.6 kb), the 18S rRNA (1.8 kb), the 2.2-kb c-fos mRNA, and the 2.0-kb β-actin mRNA.