Disputation
10.02.2011

Molecular mechanisms of methylmercury and PCB 153 neurotoxicity studied by a proteomic approach - Brain proteome responses of Atlantic cod (Gadus morhua)

Karin Berg in Environmental toxicology will defend her PhD-thesis Tuesday February 22nd. Title of the thesis is "Molecular mechanisms of methylmercury and PCB 153 neurotoxicity studied by a proteomic approach - Brain proteome responses of Atlantic cod (Gadus morhua)".

The brain is the most fascinating, sophisticated and complex organ nature has devised. Its integrative role in the nervous system is essential for the ability of animals and humans to survive, thrive and reproduce by appropriate perceptions of and responses to the environment. Hence, adverse effects of toxicants on the brain may have severe and extensive consequences.

Methylmercury (MeHg) and PCB 153 (2,2',4,4',5,5'-hexachlorobiphenyl) are neurotoxic and ubiquitous environmental compounds for which the brain is a major target organ. They bioaccumulate and biomagnify in the aquatic food chains and frequently coexist in fish which is the main source of exposure for humans. The molecular mechanisms underlying the neurotoxicity are not fully understood for either MeHg or PCB 153, and established biomarkers of their neurotoxic effects for use in environmental monitoring are lacking.

All living organisms respond to even the most subtle changes in their environment through changes in the expression of multiple proteins. By simultaneously analyzing the expression of hundreds of proteins, proteomics may be a powerful tool for both elucidation of modes of action of toxiciants and biomarker discovery. The present study demonstrated significant changes in the brain proteome of Atlantic cod (Gadus morhua) exposed to different doses of MeHg and PCB 153. Altered levels of proteins involved in a wide range of functions and processes were found, for example functions essential to neurotransmission, cascades presumably leading to neurodegeneration, apparent neuroprotective mechanisms, and regeneration and repair.

The results indicate a significant overlap in the brain proteome responses to MeHg and PCB 153 exposure, and provide novel clues for further research on MeHg and PCB 153 molecular modes of action in brain. A proper selection of the proteins may also, following validation, be applicable in panels of biomarkers for aquatic environmental monitoring.

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When: Tuesday Februar 22nd 2011 at 11.15

Where: Lite Auditorium, Lauritz Meltzers hus (SV-bygget), Fosswinckels gate 6