Figure 9.

Schematic diagram depicting the possible signaling pathway induced by TMT in BV-2 cells. TMT-induced intracellular ROS may be dominantly generated via NADPH oxidase in BV-2 cells. ROS are then able to activate MAPKs and NF-κB resulting in enhanced production of NO and TNF-α. In this experiment, p38 and JNK MAPK activations occurred earlier than NF-κB, and pretreatment with SB203580 or SP600125 suppressed TMT-induced NF-κB activation. Although the mechanism of MAPK regulation in NF-κB activation is not entirely clear, MAPKs may target various protein kinases relating to NF-κB activation and/or transactivation at NF-κB transcriptional level.