Oral Presentation ESA-SRB Conference 2015

Alleviating the effects of acrylamide on the male germ line. (#133)

Aimee L Katen 1 2 3 , Caitlin G Chambers 1 2 3 , Quinn Raw 1 2 3 , Belinda J Nixon 1 2 3 , Simone J Stanger 1 2 3 , Brett Nixon 1 2 3 , Shaun D Roman 1 2 3
  1. The Priority Research Centre for Chemical Biology, The University of Newcastle,, Callaghan, NSW, Australia
  2. School of Environmental & Life Sciences, The University of Newcastle, Callaghan, NSW, Australia
  3. The Priority Research Centre for Reproductive Science, The University of Newcastle, Callaghan, NSW, Australia

Humans are chronically exposed to acrylamide, a toxicant present in foods cooked at temperatures above 120°C. We have chronically administered acrylamide via the drinking water to male mice at doses of 0-2mg/kg bw/day, including doses equivalent to human exposure, for periods up to 12 months (1). Using a modified version of the comet assay we have established that such exposure leads to a time and dose dependent increase in glycidamide adducts in the DNA of spermatocytes of exposed mice (1). Acrylamide is converted to glycidamide solely via the enzyme Cyp2e1(2). Using isolated spermatocytes, treated in vitro, we have prevented both acrylamide and glycidamide induced DNA damage with an inhibitor of Cyp2e1 (resveratrol, 0.1µM) (3).

In the current study we have examined DNA damage in the sperm of mice exposed to acute doses of acrylamide (25mg/kg/day for 5 days i.p.) during spermatogenesis and post-testicular transit.  DNA damage was highest when sperm were exposed during epididymal transit (acrylamide treated 156% of control) or at the pachytene spermatocyte stage (acrylamide treated 185% of control) of spermatogenesis. This correlates with Cyp2e1 expression, as determined by immunohistochemistry. DNA damage could be reduced in vivo with resveratrol cotreatment in a dose dependent manner (10-40mg/kg/day i.p.).

Resveratrol regulates a number of cellular processes in addition to inhibiting Cyp2e1 metabolism of acrylamide (reviewed in 4). To identify a specific Cyp2e1 inhibitor we have modified a Cyp2e1 assay for use in 96 well plates and determined the IC50 for several proposed Cyp2e1 inhibitors including an IC50 of approximately 630µM for resveratrol.  We now have the pipeline in place to identify novel, specific inhibitors of Cyp2e1 with a view to inhibiting the effects of acute exposure to acrylamide and ultimately treating chronic exposure.

  1. Nixon B.J. et al (2012). Toxicological Sciences, 129(1), 135-145.
  2. Ghanayem, B. I., et al, (2005), Toxicol. Sci, 88, 311–8.
  3. Nixon B.J. et al (2014). PLoS One, 9(5), e94904
  4. Katen A. L. & Roman S. D. (2015). Mutation Research - Fundamental and Molecular Mechanisms of Mutagenesis, 777, 91-100.