Figure 7

Hypothetical scheme depicting uptake and intracellular signaling induced by MWCNTs leading to induction of COX-2, iNOS, and their respective secreted metabolites in RAW264.7 cells. MWCNTs activate the MEK-ERK signaling cascade, which is required to induce COX-2 and production of PGE₂. MWCNTs also induce iNOS and generation of NO through an ERK1,2-independent mechanism. The MEK inhibitor (U0126) and the iNOS inhibitor (L-NAME) are indicated along with their pharmacologic targets.