Figure 4. The PKR upregulates IL-8 expression and secretion.

IL8 mRNA levels were downregulated by PKR knockdown (A). Supernatants of cultured cells were collected, and IL-8 levels were determined by ELISA. Secreted IL-8 was downregulated by PKR knock-down (B). Assays using the IL-8 promoter-luciferase reporter plasmid: IL-8 promoter activities were downregulated by PKR knockdown (C). Mean ± SEM of six replicates. *p<0.05.