Bendadani Carolin, Meinl Walter, Monien Bernhard, Dobbernack Gisela, Florian Simone, Engst Wolfram, Nolden Tobias, Himmelbauer Heinz, Glatt Hansruedi
Department of Nutritional Toxicology, German Institute of Human Nutrition Potsdam-Rehbrücke (DIfE) , Arthur-Scheunert-Allee 114-116, 14558 Nuthetal, Germany.
Chem Res Toxicol. 2014 Jun 16;27(6):1060-9. doi: 10.1021/tx500129g. Epub 2014 May 22.
1-Methylpyrene, a carcinogenic polycyclic aromatic hydrocarbon, forms benzylic DNA adducts, in particular N2-(1-methylpyrenyl)-2'-deoxyguanosine, in mice and rats. It is bioactivated via 1-hydroxymethylpyrene (1-HMP) to electrophilic 1-sulfooxymethylpyrene (1-SMP). In this study, we explored the role of individual mouse sulfotransferase (SULT) forms in this activation. First, we showed that all nine mouse SULTs tested were able to activate 1-HMP to a mutagen in the his- Salmonella typhimurium reversion test. Some activation was even observed with Sult2a3 and Sult5a1, orphan forms for which no substrates were identified hitherto. Subsequently, we used cytosolic preparations from tissues of four mouse lines (wild-type, Sult1a1-, Sult1d1-, and transgenic for human SULT1A1/2) for the activation of 1-HMP in the mutagenicity assay. The most prominent impacts of the genetic SULT status were 96% decrease in hepatic activation by Sult1a1 knockout, 99% decrease in renal activation by Sult1d1 knockout, and 100-fold increase in pulmonary activation by transgenic human SULT1A1/2. Finally, we treated the various mouse lines with 1-HMP (19.3 mg/kg, intraperitoneally), and then determined 1-SMP levels in plasma and DNA adducts in tissues. Transgenic human SULT1A1/2 strongly enhanced 1-SMP plasma levels and DNA adduct formation in the liver, lung, heart, and kidney but not in the colon. Sult1a1 and Sult1d1 knockout reduced plasma 1-SMP levels as well as DNA adduct formation in some tissues (strongest effects: 97% decrease in 1-SMP and 89% decrease in hepatic adducts in Sult1a1- mice). The adduct levels detected in various tissues did not accurately reflect the activation capacity of these tissues determined in vitro, probably due to the distribution of the reactive metabolite 1-SMP via the circulation. In conclusion, we demonstrated that many mouse SULT forms are able to activate 1-HMP. In vivo, we verified a prominent role of Sult1a1 in hepatic and renal adduct formation and a smaller but unambiguous role of Sult1d1, and demonstrated the strong impact of transgenic human SULT1A1/2.
1-甲基芘是一种致癌性多环芳烃，在小鼠和大鼠体内会形成苄基DNA加合物，尤其是N2-(1-甲基芘基)-2'-脱氧鸟苷。它通过1-羟甲基芘（1-HMP）生物活化形成亲电的1-磺氧基甲基芘（1-SMP）。在本研究中，我们探讨了各个小鼠磺基转移酶（SULT）亚型在这种活化过程中的作用。首先，我们发现在鼠伤寒沙门氏菌回复突变试验中，所检测的所有九种小鼠SULT都能够将1-HMP活化为诱变剂。甚至在Sult2a3和Sult5a1（迄今尚未鉴定出底物的孤儿亚型）中也观察到了一些活化作用。随后，我们使用来自四种小鼠品系（野生型、Sult1a1基因敲除型、Sult1d1基因敲除型以及转人类SULT1A1/2基因型）组织的胞质提取物，在致突变性试验中对1-HMP进行活化。SULT基因状态的最显著影响包括：Sult1a1基因敲除使肝脏活化降低96%，Sult1d1基因敲除使肾脏活化降低99%，转人类SULT1A1/2基因使肺部活化增加100倍。最后，我们用1-HMP（19.3mg/kg，腹腔注射）处理各种小鼠品系，然后测定血浆中的1-SMP水平以及组织中的DNA加合物。转人类SULT1A1/2基因强烈提高了肝脏、肺、心脏和肾脏中的1-SMP血浆水平以及DNA加合物形成，但在结肠中未出现这种情况。Sult1a1和Sult1d1基因敲除降低了血浆1-SMP水平以及某些组织中的DNA加合物形成（最显著的影响：Sult1a1基因敲除小鼠中1-SMP降低97%，肝脏加合物降低89%）。在各种组织中检测到的加合物水平并未准确反映这些组织在体外测定的活化能力，这可能是由于活性代谢物1-SMP通过循环进行分布所致。总之，我们证明了许多小鼠SULT亚型能够活化1-HMP。在体内，我们证实了Sult1a1在肝脏和肾脏加合物形成中起主要作用，Sult1d1起较小但明确的作用，并证明了转人类SULT1A1/2基因的强烈影响。
