Resumen de Increased mitochondrial and cytosolic antioxidant enzymes in manic episodes

Evnur Kahyacı Kılıç, Rugul Köse Çınar, Yasemin Görgülü, Mehmet Bülent Sönmez

• Background and objectives An increasing number of studies have been conducted to investigate the role of oxidative stress in the pathophysiology of bipolar disorder (BD). The aim of our study was to detect the levels of plasma malondialdehyde and the gene expression of antioxidant enzymes in BD patients during manic period and to assess the changes of these markers during the subsequent remission period.

  Methods This study involved 20 drug-free, hospitalized patients with BD type I who met the manic episode diagnostic criteria according to DSM-5, as well as 20 age-sex matched healthy controls. As a marker of lipid damage, malondialdehyde plasma levels were measured by the thiobarbituric acid method; mRNA expression levels of catalase (CAT), glutathione peroxidase (GPx), glutathione synthetase (GS), superoxide dismutase (SOD1) and mitochondrial superoxide dismutase (SOD2) were measured by real-time quantitative PCR from peripheral whole blood samples.

  Results In a manic episode, the expression levels of CAT, GPx, GS and SOD2 were higher in the patients than the healthy controls. With treatment, only the GPx levels decreased significantly. The malondialdehyde and SOD1 levels did not differ between the patients and controls, and in the patient group, they did not differ between the mania and remission periods.

  Conclusion This is the first study that has assessed the mRNA expression levels of antioxidant enzymes in patients with BD type I. The data from this study suggests that there is an increase in the expression of antioxidant enzymes as a response to oxidative stress in BD, and that the gene expression levels of these antioxidant enzymes could be potential biomarkers for manic phase of the disorder.