The roles of protein kinase Cζ (PKCζ) in tumor necrosis factor α (TNFα)-induced expression of interleukin-1β (IL-8), monocyte chemotactic protein-1 (MCP-1) and adhesion molecule intercellular cell adhesion molecule-1 (ICAM-1) in HaCaT cells. (A–C) The mRNA levels of (A) IL-8, (B) MCP-1 and (C) ICAM-1 in HaCaT cells exposed to TNFα (10 ng/ml) at indicated time points (0, 3, 6, 12, 24, 36 and 48 h) were assessed by RT-qPCR assays. (D–F) RT-qPCR assays showing the effects of PKCζ I (10 µM) or PKCζ-siRNA (100 nM) on the TNFα-induced upregulation of (D) IL-8, (E) MCP-1 and (F) ICAM-1. Bars represent the means ± SD of 3 independent experiments, and normalized to the GAPDH mRNA level with the value in the TNFα-free treatment group set as 1 arbitrarily. *p<0.05 and **p<0.01 vs. the value at 0 h (A–C).