Analysis of 2,3,7,8-Tetrachlorodibenzo-p-dioxin-induced Proteome Changes in 5L Rat Hepatoma Cells Reveals Novel Targets of Dioxin Action Including the Mitochondrial Apoptosis Regulator VDAC2

Abstract

As part of a comprehensive survey of the impact of the environmental pollutant and hepatocarcinogen 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on the proteome of hepatic cells, we have performed a high resolution twodimensional gel electrophoresis study on the rat hepatoma cell line 5L. 78 protein species corresponding to 73 different proteins were identified as up-or down-regulated following exposure of the cells to 1 nM TCDD for 8 h. There was an overlap of only nine proteins with those detected as altered by TCDD in our recent study using the non-gel-based isotope-coded protein label method (Sarioglu, H., Brandner, S., Jacobsen, C., Meindl, T., Schmidt, A., Kellermann, J., Lottspeich, F., and Andrae, U. The environmental contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) 1 is the prototype of a class of compounds known as halogenated aromatic hydrocarbons that includes dibenzo-p-dioxins, dibenzofurans, and polychlorinated biphenyls. TCDD has been shown to cause a wide variety of toxic effects and is regarded as the most potent hepatocarcinogen in experimental animals (1). Epidemiological evidence suggests that TCDD is also a human carcinogen (2, 3). The molecular mechanisms underlying the tumorigenic activity of the compound are still largely unknown, which strongly hampers the estimation of the risk to humans associated with dioxin exposure and necessitates further studies aimed at the clarification of these mechanisms. Moreover the multifaceted toxicity of TCDD makes it a very attractive model compound for studies addressing the identification of basic principles associated with the disturbance of cellular homeostasis.

Protein Expression Profiling in the African Clawed Frog Xenopus laevis Tadpoles Exposed to the Polychlorinated Biphenyl Mixture Aroclor 1254

“…However, Aroclor 1254 significantly induced the expression of the glutathione S-transferase Mu1 (GSTM1) gene, which is regulated through the ARE/EpRE (49), in the gills and digestive tract of the abalone Haliotis discus (50). Moreover some studies on rat hepatoma cells have reported that TCDD, whose chemical structure is similar to co-planar PCBs, induced the expression of different proteins in an ARE-dependent manner (51,52). Thus, the up-regulation of antioxidant enzymes such as Prx I with AREcontaining gene promoters is compatible with the hypothesis that PCBs could induce oxidative stress.…”

Release of Bet v 1 from birch pollen from 5 European countries. Results from the HIALINE study

“…The isoform truncated Bet v 1.0101 did increase in expression upon ripening of the pollen, however this minor truncated Bet v 1.0101 isoform represented <5% of total Bet v 1 isoforms. The identity of the spots was confirmed with LC-MS after tryptic digest (Sarioglu et al, 2008), and if possible, by comparison with recombinant proteins. Also, our antibodies did not recognize the hypoallergenic isoform Bet v 1.0401 (Bet v 1 d), similar to a pool of human serum (data not shown) and as reported by others (Friedl-Hajek et al, 1999;Erler et al, 2011).…”

“…Spots were quantified using Proteomweaver software (Definiens, Munich, Germany) and expressed as relative % of the sum of all intensities. Punched spots were identified by tryptic digestion and analysis by mass spectrometry as described by Sarioglu et al (2008).…”

Proteomic Analysis of the Rat Ovary Following Chronic Low-Dose Exposure to 2,3,7,8-Tetrachlorodibenzo-p-Dioxin (TCDD)

“…Some investigators, using two-dimensional gel electrophoresis to determine placental proteins, showed that rat placentas exposed to TCDD were in a hypoxic state at the end of pregnancy (Ishimura et al, 2002). Analysis of the changes in the rat hepatoma cell proteome indicated a mechanism by which TCDD may affect cellular homeostasis and survival (Sarioglu et al, 2008).…”