Long-term exposure to carbon nanotubes accelerates systemic aging in mice

The correlation between environmental factors and aging is a growing concern. Epidemiological data have revealed the promoting effect of pollutant exposure on human aging markers, but there is still a lack of research on the aging effects and mechanisms of pollutant exposure. As a widely used carbon-based nanomaterial, there have been a large number of toxicological studies on the biological safety and occupational exposure of carbon nanotubes (CNTs), but there is still a gap in the research on the aging effects of long-term CNTs exposure. In our study, mice were intranasal instillation exposure to CNTs at 5 mg per kilogram body weight per day for 3 months to achieve chronic persistent exposure. Systemic chronic inflammatory response with redox imbalance and significant increase in the number of inflammatory cytokines and leucocytes in the blood of mice was presented. On multi-organ tissues, the expression of aging marker genes, p16^INK4a and p21^Cip1/Waf, and pro-inflammatory senescence-associated secretory phenotype factors genes was significantly up-regulated. The activity of senescence-associated β-galactosidase was enhanced, accompanied by pathological damage and fibrosis. Together, our work is the first study to find that long-term respiratory exposure to CNTs induces systematic aging effects in mice.