Oral Presentation The Annual Scientific Meeting of the Endocrine Society of Australia and the Society for Reproductive Biology 2014

The role of glycidamide and oxidative adducts in acrylamide induced DNA damage in male germ cells (#108)

Aimee L Katen 1 2 , Belinda J Nixon 1 2 , Simone J Stanger 1 2 , Brett Nixon 1 2 3 , Shaun D Roman 1 2 3
  1. Reproductive Science Group, School of Environmental and Life Sciences, University of Newcastle, Callaghan , New South Wales, Australia
  2. The Priority Research Centres for Reproductive Sciences and Chemical Biology, University of Newcastle, Callaghan, New South Wales, Australia
  3. The Australian Research Council Centre of Excellence in Biotechnology and Development, Callaghan, New South Wales, Australia

Rodent studies of the toxin acrylamide demonstrate that reproductive toxicity from acute exposure particularly affects males. In humans, acrylamide exposure occurs in a chronic manner, with acrylamide produced in a large variety of carbohydrate rich foods cooked at temperatures above 120°C.

We have established an in vitro model system of acrylamide exposure, where the early germ cells, spermatocytes, are isolated from male mice and treated with acrylamide, or its metabolite glycidamide (1 or 0.5µM respectively, 18h). We have shown that metabolism occurs within spermatocytes, which express Cyp2e1, the unique enzyme which catalyses this reaction. Glycidamide has been established as causing most of acrylamide’s toxicity, due to glycidamide’s capacity to adduct directly with the purines of DNA. We have found, using a modified comet assay to assess adducts, that both acrylamide and glycidamide exposure lead to an increase in glycidamide adducts. Interestingly, we also found an increase in oxidative adducts with acrylamide exposure. When the inhibitor resveratrol (0.1µM) was introduced, it prevented the formation of both types of adduct by acting as an antioxidant and by enzyme inhibition (1).

Chronic in vivo acrylamide exposure of male mice to doses relevant to human exposure also results in increased glycidamide adduct formation in spermatocytes as measured by the comet assay (2). Analysis of the oxidative adduct formation using an antibody against 8-hydroxydeoxyguanosine has revealed a time and dose dependent increase in oxidative adduct formation. We have established that resveratrol treatment in vivo is able to reduce this oxidative damage.

Hence, chronic in vivo acrylamide exposure and in vitro exposure generates glycidamide adducts that play the major role in DNA damage, however there is also a contribution by oxidative adduct formation. Resveratrol has been established as an effective dual purpose inhibitor by acting as an antioxidant and an inhibitor of Cyp2e1.

  1. Nixon, B.J., Katen, A.L., Stanger, S.J., Schjenken, J.E., Nixon, B., and Roman, S.D. (2014). Mouse Spermatocytes Express CYP2E1 and Respond to Acrylamide Exposure PLOS ONE 9, doi:10.1371.
  2. Nixon, B.J., Stanger, S.J., Nixon, B., and Roman, S.D. (2012). Chronic exposure to acrylamide induces DNA damage in male germ cells of mice. Tox. Sci 129, 135-145.