Fig. 7. HA causes activation of NF-B (p65/p50) in embryonic fibroblasts. (A) MEFs were treated with or without rooster comb HA. Total cell extracts were prepared at the indicated time points and equal amounts of proteins were analysed for NF-B activity by EMSA. Pretreatment with TPCK blocked the appearance of p65/p50. (B) To determine the specificity of binding, a ten- and 100-fold excess of the unlabelled NF-B-binding oligonucleotide or of the AP-1-binding oligonucleotide were used as competitors. The position of the shift produced by the p65/p50 heterodimer is indicated.