Title: Comparative study on the response of rat primary astrocytes and microglia to methylmercury toxicity.
Authors: Ni, Mingwei; Li, Xin; Yin, Zhaobao; Sidoryk-Węgrzynowicz, Marta; Jiang, Haiyan; Farina, Marcelo; Rocha, Joao B T; Syversen, Tore; Aschner, Michael
Published In Glia, (2011 May)
Abstract: As the two major glial cell types in the brain, astrocytes and microglia play pivotal but different roles in maintaining optimal brain function. Although both cell types have been implicated as major targets of methylmercury (MeHg), their sensitivities and adaptive responses to this metal can vary given their distinctive properties and physiological functions. This study was carried out to compare the responses of astrocytes and microglia following MeHg treatment, specifically addressing the effects of MeHg on cell viability, reactive oxygen species (ROS) generation and glutathione (GSH) levels, as well as mercury (Hg) uptake and the expression of NF-E2-related factor 2 (Nrf2). Results showed that microglia are more sensitive to MeHg than astrocytes, a finding that is consistent with their higher Hg uptake and lower basal GSH levels. Microglia also demonstrated higher ROS generation compared with astrocytes. Nrf2 and its downstream genes were upregulated in both cell types, but with different kinetics (much faster in microglia). In summary, microglia and astrocytes each exhibit a distinct sensitivity to MeHg, resulting in their differential temporal adaptive responses. These unique sensitivities appear to be dependent on the cellular thiol status of the particular cell type.
PubMed ID: 21351162
MeSH Terms: Analysis of Variance; Animals; Animals, Newborn; Astrocytes/drug effects*; Astrocytes/metabolism; Blotting, Western; Brain/drug effects; Brain/metabolism; Cell Survival/drug effects; Cells, Cultured; Glutathione/metabolism; Heme Oxygenase-1/genetics; Heme Oxygenase-1/metabolism; Immunohistochemistry; Methylmercury Compounds/metabolism; Methylmercury Compounds/pharmacology*; Microglia/drug effects*; Microglia/metabolism; NF-E2-Related Factor 2/genetics; NF-E2-Related Factor 2/metabolism; Oxidative Stress/drug effects; RNA, Messenger/genetics; RNA, Messenger/metabolism; RNA, Small Interfering; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species/metabolism