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Hormetic effects of alcohol in an astroglial cellular model and its proteomics signature
Author(s) -
Khorshidi Fatemeh,
Poljak Anne,
Jayasena Tharusha,
Sachdev Perminder S.
Publication year - 2020
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1002/alz.041665
Subject(s) - hormesis , viability assay , alcohol dehydrogenase , proteomics , toxicity , dna damage , ethanol , lactate dehydrogenase , astrocyte , apoptosis , chemistry , pharmacology , cellular stress response , cell , dna repair , microbiology and biotechnology , biochemistry , oxidative stress , biology , endocrinology , enzyme , dna , fight or flight response , gene , organic chemistry , central nervous system
Background Hormesis or the adaptive stress response is a biphasic dose response to a factor which has a beneficial effect on cells or an organism at low doses while having a toxic effect at higher doses (1). Alcohol has been considered both a cause and protective factor for dementia (2) and arguably has a biphasic effect on brain cells. This study evaluated the dose‐ response relationship of ethanol on astrocytes in vitro , considering the importance of astrocytes in the support, maintenance and repair of neurons and the blood brain barrier (3). Cellular proteomics was performed to examine likely mechanisms underlying the effect. Methods An astrocyte cell line (U‐251) was used, incubating cells with increasing concentrations of ethanol. Cell viability and toxicity were evaluated by MTT (3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide) and LDH (Lactate Dehydrogenase) Assay assays respectively. Proteomic profiling was performed (LC‐MS/MS) to assess differential protein expression in response to ethanol in the hormetic range, and at different timepoints after exposure (12 and 24hrs). Results At low concentrations (0.1% to 1%) ethanol was stimulatory to U‐251 cell growth, and at high doses (5% to 20%) toxic effects were observed, demonstrating a biphasic curve in response to ethanol (Figure 1 & 2). Proteomic evaluation using cells exposed to hormetic doses of ethanol showed significant upregulation of proteins involved in DNA repair and cellular response to stress and DNA damage functions at 12 hours (Figure 3), while at 24 hours protein expression changes mostly related to apoptosis and regulation of reactive oxygen species (Figure 4). Conclusion These results show that at low doses ethanol has a hormetic effect on the U‐251 astrocyte cell line, and a biphasic dose response curve is observed across the full ethanol concentration range. Proteomics profiling suggests that mechanisms of cellular protection within the hormetic range include upregulation of stress response proteins, DNA protection and factors which promote cell growth.