Abstract

SANTA-GONZALEZ, Gloria A  and  CAMARGO, Mauricio. Antioxidant cellular protection and adaptive response induced by chronic oxidative stimuli. Actu Biol [online]. 2016, vol.38, n.104, pp.71-80. ISSN 0304-3584.  https://doi.org/10.17533/udea.acbi.v38n104a07.

Adaptation is an important mechanism in cells and organisms that allow them to respond to environmental challenges and changing functional demands. To accomplish these requirements, cells integrate modifications at different levels such as gene expression, metabolic activity, cellular functionality and phenotype. The orderly coordination of these changes is fundamental for cells to maintain viability despite a variety of harmful stimuli, such as the case of exceedingly concentrations of reactive oxygen species (ROS). In this study, we tested the hypothesis that chronic and repetitive stimuli with a mild concentration of hydrogen peroxide (H₂O₂) would activate cellular responses, resulting in adaptation. This was done confronting cell cultures to prolonged exposures of H₂O₂ obtained with glucose oxydase (GlucOx) added to the medium to generate a constant concentration of the oxidant (≈ 50 μM); this treatment protocol (1h/d) was extended during seven continuous consecutive days after which the following parameters were evaluated: cell morphology and viability, mitochondrial DNA content, mitochondrial ROS accumulation and antioxidant defense gene expression. These data further support the idea that exposure to continuous and low concentrations of ROS, could act as signaling molecules inducing cellular processes that converged toward adaptation to chronic oxidative stress.

Keywords : adaptation; antioxidant defense; chronic oxidative stress; homeostasis.

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