Figure 2.

The calcineurin/NFAT signaling pathway mediates TNFα-induced cyclooxygenase 2 (COX2) expression and prostaglandin E2 (PGE₂) production in C2C12 cells. (A) TNFα stimulated COX2 mRNA and protein expression in a time-dependent manner; (B) TNFα-mediated COX2 expression decreased following inhibition of the calcineurin/NFAT signaling pathway. C2C12 cells pretreated with the calcineurin phosphatase inhibitor FK506 (10 μg/mL) were incubated in the presence or absence of TNFα for 24 h and subjected to RT-PCR analyses; (C) TNFα-induced PGE₂ production was blocked by indomethacin, a COX inhibitor. Treatment with FK506 slightly suppressed TNFα-induced PGE₂ production. C2C12 cells were incubated with FK506 or indomethacin (20 μM) in the presence of TNFα for 24 h and subjected to a PGE₂ parameter assay (* p < 0.05, compared to control; # p < 0.05).