The nano-TiO2 exposure can induce hepatic inflammation involving in a JAK–STAT signalling pathway

Abstract

TiO2 nanoparticles (TiO2 NPs) have unique physiochemical properties and thus are widely used in daily life. However, these nanoparticles also have potential toxic effects in humans and animals, and the issue of the security TiO2 NPs has also gained prominence. In this article, mice were administered a gavage instillation of 2.5, 5, or 10 mg/kg body weight TiO2 NPs (5–6 nm) for 90 days. We investigated whether TiO2 NPs activate the JAK–STAT signalling pathway, causing nano-TiO2-induced hepatic toxicity. The results demonstrated that with increasing doses of TiO2 NPs the body weights of the mice body decreased, and the liver index, liver dysfunction, infiltration of inflammatory cells, and hepatocyte apoptosis and necrosis increased. Moreover, liver inflammation was accompanied by increased expression of Janus kinase 2, the signal transducers and activators of transcription 3, interleukin-6, cyclooxygenase-2, neutrophil gelatinase-associated lipocalin, purinergic receptor-7, and epithelial neutrophil-activating protein-78 and decreased expression of suppressors of cytokine signalling-1, peroxisome proliferator-activated receptor-γ, and peroxisome proliferator-activated receptor gamma coactivator-1 alpha. In summary, the activation of the JAK–STAT pathway may be involved in the hepatic inflammation induced by chronic nano-TiO2 toxicity.