Application of SELDI-TOF mass spectrometry for the identification of differentially expressed proteins by formaldehyde exposure

Abstract

Biomarkers are becoming increasingly important in toxicology and human health because established biomarkers can be utilized in monitoring human exposure to chemicals. Recently, it is generally accepted that a major contributory factor to sick building syndrome (SBS) is the increased use of chemicals such as volatile organic compounds and formaldehyde during either building construction or furnishing materials and consumer products. As formaldehyde is known to have positive correlation with SBS, we profiled differentially expressed proteins by utilizing SELDI-TOF-MS technology in formaldehyde-exposed cell culture and animal model systems. Protein profiling of formaldehyde-treated human tracheal cells, Hs 680, with an anion exchanger chip, Q-10, revealed sixteen differentially expressed proteins which were downregulated by formaldehyde. Sera isolated from formaldehyde-inhaled rats were also subjected to SELDI-TOF-MS on a Q-10 chip, and majority of the differentially expressed proteins were upregulated upon formaldehyde treatment. Intriguingly, a number of quite strongly upregulated proteins were concentrated at the mass range from 30000 to 36000 Da. Furthermore, we identified three potential biomarkers which included two downregulated proteins of 14600 Da and 16700 Da in Hs 680 cells, and an upregulated protein of 33800 Da in rat sera. By partial protein sequencing, these proteins were identified as ribosomal phosphoprotein, large, P2, calmodulin and apolipoprotein E, respectively. Taken together, we provide experimental basis for understanding the toxic mechanism of formaldehyde as well as potential biomarker candidates by applying the powerful SELDI-TOF-MS technology.