Toxicological effect of TiO2 nanoparticle-induced myocarditis in mice

Currently, impacts of exposure to TiO2 nanoparticles (NPs) on the cardiovascular system are not well understood. The aim of this study was to investigate whether TiO2 NPs induce myocarditis and its underlying molecular mechanism in the cardiac inflammation in mice. Mice were exposed to TiO2 NPs for 6 months; biochemical parameters of serum and expression of Th1-related and Th2-related cytokines in the heart were investigated. The results showed that TiO2 NP exposure resulted in cardiac lesions coupling with pulmonary inflammation; increases of aspartate aminotransferase (AST), creatine kinase (CK), C-reaction protein (CRP), lactate dehydrogenase (LDH), alpha-hydroxybutyrate dehydrogenase (HBDH), adhesion molecule-1 (ICAM-1), and monocyte chemoattractant protein-1 (MCP-1) levels; and a reduction of nitric oxide (NOx) level in the serum. These were associated with increases of nuclear factor-κB (NF-κB), tumor necrosis factor-α (TNF-α), interleukin (IL)-4, IL-6, transforming growth factor-β (TGF-β), creatine kinase, CRP, adhesion molecule-1, and monocyte chemoattractant protein-1, interferon-γ (IFN-γ), signal transducers and activators of transcription (STAT)1, STAT3, or STAT6, GATA-binding domain-3, GATA-binding domain-4, endothelin-1 expression levels, and T-box expressed in T cells expression level that is the master regulator of pro-inflammatory cytokines and transcription factors in the heart. These findings imply that TiO2 NP exposure may increase the occurrence and development of cardiovascular diseases.