Role of hippocampal TLR4 in neurotoxicity in mice following toluene exposure

• Published in: Neurotoxicology and teratology 2011-09, Vol.33 (5), p.598-602
• Main Authors: Win-Shwe, Tin-Tin, Kunugita, Naoki, Yoshida, Yasuhiro, Fujimaki, Hidekazu
• Format: Article
• Language: English
• Subjects: Administration, Inhalation; Animals; Biological and medical sciences; Chemical and industrial products toxicology. Toxic occupational diseases; Emergency; Gene expression; Gene Expression - drug effects; Gene Expression - genetics; Hippocampus; Hippocampus - drug effects; Hippocampus - metabolism; HSP70 Heat-Shock Proteins - biosynthesis; Hsp70 protein; Hyaluronic Acid - biosynthesis; Male; Medical Education; Medical sciences; Mice; Mice, Inbred C3H; Mice, Mutant Strains; Neurotoxicity; Neurotoxicity Syndromes - genetics; Neurotoxicity Syndromes - metabolism; NF- Kappa B protein; NF-kappa B - biosynthesis; Polymerase chain reaction; Signal transduction; Solvents; Solvents - administration & dosage; Solvents - toxicity; TLR4 protein; Toll-like receptor; Toll-Like Receptor 4 - biosynthesis; Toll-Like Receptor 4 - genetics; Toll-like receptors; Toluene; Toluene - administration & dosage; Toluene - toxicity; Toxicology; Up-Regulation - drug effects
• ISSN: 0892-0362; 1872-9738
• DOI: 10.1016/j.ntt.2011.07.005

Abstract The present study was designed to investigate the possible involvement of TLR4 pathway in the mouse hippocampus following toluene exposure. Male C3H/HeN and C3H/HeJ (TLR4 defective) mice were exposed to 0, 5, 50 or 500 ppm of toluene for 6 weeks. The expressions of TLR4-related signal transduction pathway mRNAs in the hippocampi were examined using real-time RT-PCR and an immunohistochemical analysis. In C3H/HeN mice, the relative mRNA expression levels of TLR4 and NF-κB activating protein were significantly up-regulated in the groups exposed to toluene, but not in the C3H/HeJ mice. Heat shock protein 70, a possible endogenous ligand for TLR4, mRNA was increased in the C3H/HeN mice exposed to toluene. This is the first report to show that TLR4 may have a role in the neurotoxic effects in mice exposed to toluene.