Triclosan induces liver injury in long-life exposed mice via activation of TLR4/NF-κB/NLRP3 pathway

Abstract

Triclosan (TCS) is a widely used synthetic, with broad-spectrum antibacterial properties found in both pharmaceuticals and personal care products. More specifically, it is hepatotoxic in rodents and exhibits differential effects in mice and humans. However, the mechanisms underlying TCS-induced liver toxicity have not been elucidated. This study examined the role of the toll-like receptor 4 (TLR4)/ nuclear factor kappa B (NF-κB)/ nod-like receptor protein 3 (NLRP3) pathway in TCS-exposed liver toxicity by established a long-life TCS-exposed mice liver injury model. The 24 C57BL/6 pregnant mice exposed to TCS (0, 50 and 100 mg/kg) every day during the gestation and nursing period. After weaning, the male mice were left to continue administrate with TCS until 8 weeks of age. Then, mice in each group were sacrificed for investigation. Long-life exposure to TCS resulted in a reduction of body weight in growth mice. TCS exposure caused the increase of serum ALT, AST and ALP. The situation of inflammatory cell infiltration, macrophage recruitment and collagen fiber deposition in TCS-exposed mice liver tissues were performed by histological analysis including hematoxylin-eosin, Masson, Sirius red, and immunohistochemistry staining. Protein expression levels in TLR4/NF-κB/NLRP3 pathway was measured through Western blot, and the NLRP3 inflammasome activation was measured using real-time quantitative PCR (RT-qPCR). The results showed that exposure to TCS elevated TLR4, myeloid differentiation factor 88 (Myd88), TNF receptor associated factor 6 (TRAF6), enhanced NF-κB activation, and affected NLRP3 inflammasome activation in mice liver. Collectively, these findings indicate that long-life exposure to TCS-induced mice by upregulating the TLR4-Myd88-TRAF6 pathway, activating the NF-κB signaling cascade, initiating the NLRP3 inflammasome pathway, and ultimately leading to liver injury, including inflammation, hepatocyte pyroptosis and hepatofibrosis. Henceforth, the TLR4/NF-κB/NLRP3 pathway may now provide a theoretical basis and valuable therapeutic targets for overcoming TCS-induced liver toxicity.

Keywords

• Triclosan
• Long-life exposed model
• TLR4/NF-κB/NLRP3
• Liver injury