mRNA Expressional Changes in Rat Livers Exposed to Silver Nanomaterial

PP-29-105 Background/Aims: Toxicogenomics tools combined with bioinfomatics are recognized as powerful and efficient high-through techniques to prioritize the chemicals. The aim of the study is to explore the applicability of this technique in investigating the bioreactivity of nanomaterials via profiling the mRNA expression induced by exposure to nanomaterials. Methods: The citrate capped silver nanomaterial (<20 nm, colloid in the water) was chosen since this material is known to be well dispersed in water. Furthermore, the side effects due to dispersants or capping materials would be minimized since only citrate, the capping material which can be found in the organisms, is used to assist homogenous dispersion. Sprague Dawley rats were exposed to the silver nanomaterial (Ag NM) via oral route using a gavage at the doses of 0, 5, 10, and 20 mg/kg bw for 14 days. The mRNA expressional changes in the rat livers were studied using Rat whole genome 4 × 44 K oligo chips. Results: The functional analyses suggested that Ag NM would induce the changes mRNA expression in the rat liver related to transcription, transport, signal transduction, cell differentiation, immune response. Furthermore, RT-PCR data showed Ag NM would induce up-regulation in CytP450 subfamilies, the oxidative stress related genes and down-regulation in xenobiotics clearance related genes CAR (Constitutive Androstane Receptor) and CCL2 (Chemokine [C-C motif] Ligand 2, MCP-1; Monocyte chemotactic protein) and PPAR-α (Peroxisome Proliferator-Activated Receptor-α). Conclusion: From the results, the genomic technique combined with bioinfomatics could be applicable to investigate the effects of nanomaterials. However, further studies would help to interpret the mRNA expressional changes in predicting any phenotypical changes. Emerging Environmental Problems - Ionizing Radiation, Electromagnetic Field, Stress, Hazardous Wastes