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. 2013 Nov 21:4:251.
doi: 10.3389/fgene.2013.00251. eCollection 2013.

Evaluation of the effects of titanium dioxide nanoparticles on cultured Rana catesbeiana tailfin tissue

S Austin Hammond  1 , Amanda C Carew, Caren C Helbing
Affiliations

Evaluation of the effects of titanium dioxide nanoparticles on cultured Rana catesbeiana tailfin tissue

S Austin Hammond et al. Front Genet. .

Abstract

Nanoparticles (NPs), materials that have one dimension less than 100 nm, are used in manufacturing, health, and food products, and consumer products including cosmetics, clothing, and household appliances. Their utility to industry is derived from their high surface-area-to-volume ratios and physico-chemical properties distinct from their bulk counterparts, but the near-certainty that NPs will be released into the environment raises the possibility that they could present health risks to humans and wildlife. The thyroid hormones (THs), thyroxine, and 3,3',5-triiodothyronine (T3), are involved in development and metabolism in vertebrates including humans and frogs. Many of the processes of anuran metamorphosis are analogous to human post-embryonic development and disruption of TH action can have drastic effects. These shared features make the metamorphosis of anurans an excellent model for screening for endocrine disrupting chemicals (EDCs). We used the cultured tailfin (C-fin) assay to examine the exposure effects of 0.1-10 nM (~8-800 ng/L) of three types of ~20 nm TiO2 NPs (P25, M212, M262) and micron-sized TiO2 (μ TiO2) ±10 nM T3. The actual Ti levels were 40.9-64.7% of the nominal value. Real-time quantitative polymerase chain reaction (QPCR) was used to measure the relative amounts of mRNA transcripts encoding TH-responsive THs receptors (thra and thrb) and Rana larval keratin type I (rlk1), as well as the cellular stress-responsive heat shock protein 30 kDa (hsp30), superoxide dismutase (sod), and catalase (cat). The levels of the TH-responsive transcripts were largely unaffected by any form of TiO2. Some significant effects on stress-related transcripts were observed upon exposure to micron-sized TiO2, P25, and M212 while no effect was observed with M262 exposure. Therefore, the risk of adversely affecting amphibian tissue by disrupting TH-signaling or inducing cellular stress is low for these compounds relative to other previously-tested NPs.

Keywords: amphibian; nanometal; nanoparticle; organ culture; oxidative stress; thyroid hormone; titanium dioxide.

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Figures

Figure 1
Figure 1
Transcript levels of invariant normalizer gene rpl8 in the μ TiO2 and TiO2 NP C-fin assays as indicated by the threshold cycle (Ct) values obtained by QPCR. Bevels indicate increasing concentrations of the indicated compound in the absence or presence of T3. The medians are indicated by solid black lines within the boxes, where the box denotes the 25th and 75th percentiles, and the whiskers indicate the minimum and maximum values that lie within 1.5 box-lengths of the median. Outlier (between 1.5 and 3 box lengths) and extreme values (>3 box lengths) are shown as open circles or asterisks, respectively.
Figure 2
Figure 2
Assessment of the effects of exposure to 0.1, 1.0, and 10 nM μ TiO2, P25, M212, or M262 on thra, thrb, and rlk1 relative transcript levels in R. catesbeiana tailfin biopsies following 48 h exposure to NaOH vehicle or 10 nM T3. Values represent fold-change of steady-state transcript levels relative to each individual's vehicle control baseline as measured by QPCR. Bevels indicate increasing concentrations of the indicated compoundin the absence or presence of T3. Significant response to T3 relative to the vehicle control is indicated by “a” when p ≤ 0.05. thra, thyroid hormone receptor α; thrb, thyroid hormone receptor β ; rlk1, Rana larval keratin type I. See Figure 1 legend for more graph details.
Figure 3
Figure 3
Assessment of the effects of exposure to 0.1, 1.0, and 10 nM μ TiO2, P25, M212, or M262 on hsp30, cat, and sod relative transcript levels in R. catesbeiana tailfin biopsies following 48 h exposure to NaOH vehicle or 10 nM T3. cat, catalase; hsp30, heat shock protein 30; sod, superoxide dismutase. See Figures 1, 2 legends for more graph details. Significance relative to the vehicle control for NPs alone or relative to the T3 only control for the T3-treated plus NP condition is indicated by “b”.
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References

    1. Afaq F., Abidi P., Matin R., Rahman Q. (1998). Cytotoxicity, pro-oxidant effects and antioxidant depletion in rat lung alveolar macrophages exposed to ultrafine titanium dioxide. J. Appl. Toxicol. 18, 307–312 10.1002/(SICI)1099-1263(1998090)18:5<307::AID-JAT508>3.0.CO;2-K - DOI - PubMed
    1. Baan R., Straif K., Grosse Y., Secretan B., El Ghissassi F., Cogliano V. (2006). Carcinogenicity of carbon black, titanium dioxide, and talc. Lancet Oncol. 7, 295–296 10.1016/S1470-2045(06)70651-9 - DOI - PubMed
    1. Baun A., Hartmann N. B., Grieger K. D., Hansen S. F. (2009). Setting the limits for engineered nanoparticles in European surface waters—are current approaches appropriate? J. Environ. Monit. 11, 1774–1781 10.1039/b909730a - DOI - PubMed
    1. Bolis V., Busco C., Ciarletta M., Distasi C., Erriquez J., Fenoglio I., et al. (2012). Hydrophilic/hydrophobic features of TiO2 nanoparticles as a function of crystal phase, surface area and coating, in relation to their potential toxicity in peripheral nervous system. J. Colloid Interface Sci. 369, 28–39 10.1016/j.jcis.2011.11.058 - DOI - PubMed
    1. Cermenati L., Pichat P., Guillard C., Albini A. (1997). Probing the TiO2 photocatalytic mechanisms in water purification by use of quinoline, photo-fenton generated OH. radicals and superoxide dismutase. J. Phys. Chem. B 101, 2650–2658 10.1021/jp962700p - DOI