Ethanol-induced oxidative stress in rat astrocytes: role of HSP70.
Ethanol intake is associated with increase in lipid peroxidation and formation of reactive oxygen species in different cerebral areas, in neurons as well as in astrocytes. The latter's integrity is essential for the normal growth of neurons. In previous studies we observed, in different cerebral areas of both acutely and chronically ethanol-treated rats, correlation between ethanol-induced oxidative stress and the increased expression of HSP70 (70 kDa heat shock proteins), chaperonins having a protective and stabilizing effect on stress-induced cell injury. In this study we examined, in vitro, the role of HSP70 on chronically ethanol-treated rat astrocytes by transfection with an anti-HSP70 antisense oligonucleotide. The results show that treatment with ethanol, from 50 to 100 mmol/L, induces a dose-dependent increase in the production of reactive oxygen species and of HSP70 levels, together with an impairment of the respiratory chain activity and a decrease in cell viability. In addition, our data indicate a drastic reduction of cellular metabolism in HSP70-deprived astrocytes, particularly when these cells were also ethanol-treated. In fact, transfection with HSP70 antisense induced moderate oxidative damage in control astrocytes and, consequently, a drastic decrease in the viability of ethanol-treated cells, with the mitochondrial functionality being particularly affected. Our results confirm that heat shock proteins confer a survival advantage to the astrocytes, preventing oxidative damage and nuclear DNA damage as well, and suggest the development of new drugs exerting a cytoprotective role either in physiological, or pathological conditions.
Russo
A
A
Department of Biological Chemistry, Medical Chemistry and Molecular Biology, Faculty of Pharmacy, University of Catania, Italy.
Palumbo
M
M
Scifo
C
C
Cardile
V
V
Barcellona
M L
ML
Renis
M
M
D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002492:Central Nervous System Depressants / Q000494:pharmacology*; D004396:Coloring Agents; D020552:Comet Assay; D000431:Ethanol / Q000494:pharmacology*; D018840:HSP70 Heat-Shock Proteins / Q000032:analysis / Q000378:metabolism*; D015151:Immunoblotting; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008315:Malondialdehyde / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism; D013778:Tetrazolium Salts; D013844:Thiazoles; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
D002492:Central Nervous System Depressants; D004396:Coloring Agents; D018840:HSP70 Heat-Shock Proteins; D017382:Reactive Oxygen Species; D013778:Tetrazolium Salts; D013844:Thiazoles; D017392:Thiobarbituric Acid Reactive Substances; D000431:Ethanol; D008315:Malondialdehyde; D007770:L-Lactate Dehydrogenase; C022616:thiazolyl blue