Liver X Receptor Agonist TO901317 Attenuates Paraquat-Induced Acute Lung Injury through Inhibition of NF-κB and JNKp38 MAPK Signal Pathways

Abstract EN

Paraquat (PQ) is a widely used herbicide with extremely high poisoning mortality mostly from acute lung injury (ALI) or progressive pulmonary fibrosis.

Toxicity mechanisms remain unclear, but a redox cycling process that generates reactive oxygen species (ROS) is involved, as are inflammation and cell apoptosis.

We established an ALI mouse model by intraperitoneal injection of PQ (28 mg/kg) and then investigated the effects of a potent liver X receptor (LXR) agonist, TO901317 (5 or 20 mg/kg), injected intraperitoneally 30 min after PQ administration.

Poisoned mice exhibited severe lung tissue lesions and edema, significant neutrophilic (PMNs) infiltration, and release of the proinflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β).

PQ administration also decreased activity of antioxidases, including superoxide dismutase (SOD), catalase (CAT), and glutathione S-transferases (GSTs), and increased lipid peroxidation as evaluated by malondialdehyde (MDA) levels.

PQ exposure induced upregulation of the proapoptotic gene Bax and downregulation of the antiapoptotic gene Bcl-2, leading to marked cell apoptosis in the lung tissues.

TO901317 treatment reversed all these effects through inhibition of PQ-induced nuclear factor kappa B (NF-κB) and JNK/p38 mitogen-activated protein kinase (MAPK) activation.

The LXR agonist TO901317 had potent antioxidant, anti-inflammatory, and antiapoptotic effects against PQ-induced ALI.