Changes of cytokine profiles during electroconvulsive therapy in patients with major depression.

OBJECTIVES: Electroconvulsive therapy (ECT) is an effective treatment of depression, but its mechanism of action still remains unknown. Some studies emphasize that epileptic seizures result in cerebral production of cytokines, including the cytokine network in association with the pathophysiology of depression. We hypothesized that depressed patients would show a dysregulated profile of peripheral cytokines before and after ECT treatment. METHODS: Fifteen hospitalized subjects with major depressive disorder were recruited. Human cytokine array IV was used to determine the profile of cytokines in the serum during the course of ECT. Positive results of the cytokine assay were verified by reverse transcriptase-polymerase chain reaction. Depressive symptoms were evaluated before and after ECT series. RESULTS: The signal intensity of eotaxin-3 and interleukin (IL)-5 changed statistically significantly between the first ECT and 24 hours after the last ECT. Furthermore, there were significant correlations between the signal intensities of eotaxin-3, bone morphogenetic protein 6, IL-5, and transforming growth factor-ß and the severity of depression. The results of Cytoray assays were confirmed partly by reverse transcriptase-polymerase chain reaction. The changes of tumor necrosis factor ß in pre-post comparison of ECT and the correlation of the Montgomery-Asberg Depression Scale score with tumor necrosis factor ß, IL-5, and bone morphogenetic protein 6 expression could be verified. Only the relative signal intensity of IL-16 correlated significantly with the clinically as well as electroencephalographically measurable seizure duration. CONCLUSION: Electroconvulsive therapy treatment seems to change the expression of various cytokines in relation to changes of affective states such as mood. Therefore, cytokines might play a specific role within the treatment and pathogenesis of affective disorders.

Orexin expression and promoter-methylation in peripheral blood of patients suffering from major depressive disorder.

Orexins are endogenous neuropeptides synthesized in hypothalamic neurones; they play a major role in the regulation of feeding, drinking, endocrine function and sleep/wakefulness that is often disturbed in major depression. The aim of this study was to explore Orexin A expression and promotermethylation in peripheral blood cells of 29 patients (14 male and 15 female patients at three different time points during antidepressive treatment) suffering from major depressive disorder (MDD) by quantitative RT-PCR and bisulfite sequencing. There was a measurable difference between Orexin A expression on admission in comparison to the Orexin mRNA expression in the healthy control group (T=1.53; df=39; p=0.135) that failed to reach statistical significance. An inverse correlation between Orexin A mRNA expression on admission and the HAMD scores at all measurement dates each week over 6 weeks could be detected. A cluster of methylated CPG sites within the promoter region of the Orexin A gene could be identified that was positively correlated with Delta CT values of the mRNA expression 14 days after hospital admission (r=0.625; p=0.072) and 4 weeks afterwards (r=0.582; p=0.1). Considering only the methylation of the 7 CPGs within the CPG island in the promoter 4 weeks after treatment onset a statistically significant relation between the cluster of CPG sites within the island and body weight (r=0.55; p=0.034) as well as BMI (r=0.474; p=0.074) could be detected. Furthermore, this methylation pattern 4 weeks after treatment onset was positively associated with mRNA expression on admission, 2 and 4 weeks afterwards. In sum, these results are an indicator of a link between social stresses, disruptions in energy homeostasis and changes in body weight in relation to depressive disorders that are possibly linked to Orexin dysregulation.