Norwegian Institute of Public Health, Division of Environmental Medicine, Department of Chemical Toxicology, 0403 Oslo, Norway.
Mutat Res. 2010 Feb;696(1):55-61. doi: 10.1016/j.mrgentox.2009.12.012. Epub 2009 Dec 22.
The industrial compound and food contaminant acrylamide (AA) is a probable human carcinogen, also known to induce male-mediated reproductive effects in animals. Most data suggest that its metabolite glycidamide (GA) is involved in the observed toxicity. We have investigated in vitro effects of AA/GA in mouse male germ cells (prior to spermatid elongation) and human and mouse peripheral blood lymphocytes, to assess inter-species and cell-type differences in susceptibility, and to explore the nature of the DNA lesion(s) as well as their potential repair. The comet assay was used in combination with the DNA-repair enzymes Fpg and hOGG1 to measure specific DNA lesions. In contrast to AA, GA induced significant levels of DNA lesions (strand breaks and alkali-labile sites) at millimolar concentrations in mouse testicular cells and human peripheral blood lymphocytes (hPBL). Using Fpg, the GA-induced DNA damage was measured at 20-50-fold higher sensitivity, in all cell types investigated. GA-induced DNA damage could not be recognised by hOGG1, suggesting that, based on the known affinities of these repair enzymes, alkylation of guanine is involved, rather than oxidation. Human lymphocytes appeared to be more susceptible to GA-induced lesions than both types of mouse cells. Mouse testicular cells and lymphocytes seemed to respond similarly to GA-induced Fpg-sensitive DNA lesions. The persistence of lesions was explored with cells from mice either proficient or deficient in Ogg1 (mouse 8-oxoguanine DNA glycosylase). Low in vitro repair of GA-induced Fpg-sensitive lesions was observed in primary male germ cells and lymphocytes from both Ogg1(+/+) and Ogg1(-/-) mice. We conclude that there may be differences between mice and humans in AA/GA-induced genotoxicity, and DNA from mouse male germ cells does not appear to be more sensitive to GA than DNA from peripheral blood lymphocytes in vitro. The usefulness of the comet assay in combination with DNA-repair enzymes is demonstrated.
丙烯酰胺（AA）是一种工业化合物和食品污染物，也是一种可能的人类致癌物质，已知可诱导动物的雄性介导的生殖效应。大多数数据表明，其代谢物丙烯醛（GA）参与了观察到的毒性。我们已经研究了 AA/GA 在小鼠精原细胞（在精子伸长之前）和人外周血淋巴细胞中的体外效应，以评估种间和细胞类型的敏感性差异，并探讨 DNA 损伤的性质及其潜在的修复。彗星试验与 DNA 修复酶 Fpg 和 hOGG1 结合使用，以测量特定的 DNA 损伤。与 AA 相反，GA 在毫摩尔浓度下在小鼠睾丸细胞和人外周血淋巴细胞（hPBL）中诱导显著水平的 DNA 损伤（链断裂和碱不稳定位点）。使用 Fpg，在所有研究的细胞类型中，GA 诱导的 DNA 损伤的检测灵敏度提高了 20-50 倍。GA 诱导的 DNA 损伤不能被 hOGG1 识别，这表明，基于这些修复酶的已知亲和力，涉及鸟嘌呤的烷基化，而不是氧化。人外周血淋巴细胞似乎比两种类型的小鼠细胞对 GA 诱导的损伤更敏感。GA 诱导的 Fpg 敏感 DNA 损伤在小鼠睾丸细胞和淋巴细胞中似乎具有相似的反应。用 Ogg1（+/+）和 Ogg1（-/-）小鼠的雄性生殖细胞和淋巴细胞研究了细胞中损伤的持久性。在体外，在 Ogg1（+/+）和 Ogg1（-/-）小鼠的初级精原细胞和淋巴细胞中观察到 GA 诱导的 Fpg 敏感损伤的低修复。我们得出的结论是，AA/GA 诱导的遗传毒性可能存在小鼠和人类之间的差异，并且来自雄性生殖细胞的 DNA 似乎不比来自外周血淋巴细胞的 DNA 对 GA 更敏感。证明了彗星试验与 DNA 修复酶结合使用的有用性。
