Glucocorticoids increase protein carbonylation and mitochondrial dysfunction.

Area of Science:

• Neuroscience
• Cell Biology
• Biochemistry

Background:

• Psychiatric illnesses are linked to prolonged glucocorticoid release, potentially harming neurons.
• Oxidative stress, an imbalance between reactive oxygen species (ROS) and antioxidants, is implicated in psychiatric disorders.
• Mitochondria and NADPH oxidase are key sources of ROS, while antioxidant enzymes like SOD and CAT combat oxidative damage.

Purpose of the Study:

• To investigate the impact of glucocorticoids on oxidative damage in neuronal cells.
• To assess effects on protein carbonylation, mitochondrial function, NADPH oxidase activity, and antioxidant capacity.

Main Methods:

• Rat pheochromocytoma PC12 cells were treated with varying concentrations of corticosterone for 24 hours.
• Assays were performed to measure protein carbonylation, mitochondrial complex I and III activity, NADPH oxidase activity, total antioxidant capacity, and SOD and catalase activity.

Main Results:

• Corticosterone treatment elevated protein carbonylation.
• Mitochondrial complex I activity decreased, while complex III and NADPH oxidase activities remained unchanged.
• Total antioxidant capacity increased at the lowest dose, but SOD activity significantly decreased at the highest dose.
• Catalase activity was unaffected.

Conclusions:

• Glucocorticoids can induce oxidative damage to proteins in neuronal cells.
• Inhibition of mitochondrial complex I and the antioxidant enzyme SOD may contribute to this damage.
• Findings suggest a mechanism linking stress hormone excess to neuronal oxidative stress relevant to psychiatric illnesses.