Name: Talke Anu Marschall
Diploma / M.Sc degree: Westfälische Wilhelms-Universität Münster, Germany
(August 2013)

PhD Project: Impact of selenium species on methylmercury induced toxic effects in in vitro and in vivo model systems

Abstract of Research Project

Mercury (Hg) species show neurotoxic, nephrotoxic and reprotoxic effects in animal studies and in humans. In Europe main sources of Hg exposure are elemental Hg, organometallic Hg and mercuric Hg. Methyl mercury as the most common organic Hg species in the food chain is taken up via the diet especially from fish. Recently the European Food Safety Authority (EFSA) stated that exposure to methylmercury above the tolerable weekly intake is of concern. The TWI is likely to be exceeded by pregnant women and children in regions with high fish consumption.

Selenium (Se) is a toxic but in low doses essential and ubiquitous metalloid, which has been shown to counteract Hg toxicity in laboratory studies. Several investigations have been carried out already on the molecular mechanisms of Hg detoxification by Se but the mode of action is not fully understood yet.

To get a better understanding of Se antagonizing Hg toxicity, human cell culture models (astrocytes and neurons) and a nematode test system (C. elegans) will be used during my PhD studies. Cellular toxicity and neurodegeneration of Hg in combination with Se will be determined in brain cells and neurons and in C. elegans respectively, to collect information about the ability of Se to change Hg neurotoxicity. Further experiments mimicking the blood-brain-barrier will provide additional information on the influence of Se on the Hg transfer into the brain.