1. Titanium Dioxide Nanoparticles Exacerbate Allergic Airway Inflammation via TXNIP Upregulation in a Mouse Model of Asthma.
- Author
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Lim JO, Lee SJ, Kim WI, Pak SW, Moon C, Shin IS, Heo JD, Ko JW, and Kim JC
- Subjects
- Animals, Apoptosis, Asthma blood, Asthma complications, Asthma genetics, Bronchoalveolar Lavage Fluid, Carrier Proteins metabolism, Caspase 3 metabolism, Cell Count, Cell Line, Chemical Phenomena, Cytokines biosynthesis, Cytokines genetics, Cytokines metabolism, Disease Models, Animal, Gene Expression Regulation drug effects, Humans, Hypersensitivity blood, Hypersensitivity complications, Hypersensitivity genetics, Immunoglobulin E blood, Inflammation blood, Inflammation genetics, Inflammation Mediators metabolism, MAP Kinase Kinase Kinase 5 metabolism, Mice, Mucus metabolism, Nanoparticles ultrastructure, Ovalbumin, RNA, Messenger genetics, RNA, Messenger metabolism, Respiratory Hypersensitivity complications, Thioredoxins metabolism, Up-Regulation drug effects, bcl-2-Associated X Protein metabolism, Asthma pathology, Carrier Proteins genetics, Hypersensitivity pathology, Inflammation pathology, Lung pathology, Nanoparticles toxicity, Thioredoxins genetics, Titanium toxicity, Up-Regulation genetics
- Abstract
Titanium dioxide nanoparticles (TiO
2 NPs) are widely used in industrial and medicinal fields and in various consumer products, and their increasing use has led to an increase in the number of toxicity studies; however, studies investigating the underlying toxicity mechanism have been rare. In this study, we evaluated potential toxic effects of TiO2 NPs exposure on lungs as well as the development of asthma through the ovalbumin (OVA)-induced mouse model of asthma. Furthermore, we also investigated the associated toxic mechanism. TiO2 NPs caused pulmonary toxicity by exacerbating the inflammatory response, indicated by an increase in the number and level of inflammatory cells and mediators, respectively. OVA-induced asthma exposed mice to TiO2 NPs led to significant increases in inflammatory mediators, cytokines, and airway hyperresponsiveness compared with those in non-exposed asthmatic mice. This was also accompanied by increased inflammatory cell infiltration and mucus production in the lung tissues. Additionally, TiO2 NPs decreased the expression of B-cell lymphoma 2 (Bcl2) and the expressions of thioredoxin-interacting protein (TXNIP), phospho-apoptosis signal-regulating kinase 1, Bcl2-associated X, and cleaved-caspase 3 were escalated in the lungs of asthmatic mice compared with those in non-exposed asthmatic mice. These responses were consistent with in vitro results obtained using human airway epithelial cells. TiO2 NPs treated cells exhibited an increase in the mRNA and protein expression of interleukin (IL)-1β, IL-6, and tumor necrosis factor-α with an elevation of TXNIP signaling compared to non-treated cells. Moreover, pathophysiological changes induced by TiO2 NP treatment were significantly decreased by TXNIP knockdown in airway epithelial cells. Overall, TiO2 NP exposure induced toxicological changes in the respiratory tract and exacerbated the development of asthma via activation of the TXNIP-apoptosis pathway. These results provide insights into the underlying mechanism of TiO2 NP-mediated respiratory toxicity.- Published
- 2021
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