Intracellular CCL2 content in (A) primary or (B) immortalized PNMEC cultures incubated in the absence (media) or presence of TNFα (10 ng/ml) for 4 h was quantified by cell-based ELISA or immunoblot, respectively. (C, D) Immortalized PNMEC cultures were cultured with (C) 0–100 ng/ml TNFα for 4 h or (D) 0–24 h with 10 ng/ml TNFα, as indicated, and intracellular CCL2 protein was quantified by cell-based ELISA. Data shown are results from 2–3 separate experiments (A, n=12–14 cultures; C, D, n=6–10 cultures). Immunoblot data shown in (B) are from a single experiment performed in duplicate. (A) #, P<0.0001 unpaired Student's t-test; (C) *, P<0.05; ** P<0.01; one-way ANOVA with Dunnett's post-hoc analysis. (D) *, P<0.001; two-way ANOVA with Bonferroni's post-hoc analysis.