Expression of Sir1-Sir7 Genes in the Course of Recurrent Depressive Disorders

Abstract

Background: The role of sirtuins as a pathogenetic element of some mental disorders is becoming increasingly more common. They participate in many cellular processes, such as ageing, transcription, apoptosis, inflammatory processes, post-translational modification of proteins, gene transcription silencing, activation of DNA repair mechanisms, and regulation of many metabolic processes. The aim of this paper is to verify the statistical hypothesis assuming the difference in expression at the level of mRNA in genes for sirtuins 1-7 between patients with recurrent depressive disorders (rDD) and patients from the control group, and the hypothesis assuming the relation between the expression at the level of mRNA for these genes and clinical variables in the course of recurrent depressive disorders. Subjects and methods: A total of 198 individuals took part in the study (rDD gropup, N=99; control group, N=99). Results: SIR-1 and SIR-6 expression at the mRNA level was significantly higher among the people with rDD as compared to the subjects from the control group. A reversed relationship was observed for SIR-2, SIR-3, SIR-4 and SIR-5. Statistically significant correlations were observed only in the case of SIR-1 and the number of depression episodes (negative relationship), as well as SIR-5 and the severity of depression measured by the Hamilton Depression Rating Scale (positive relationship). Conclusions: Expression at the mRNA level for selected sirtuins is a factor that significantly differentiates people with depressive episodes from healthy ones. SIR-1 and SIR-6 expression at the mRNA level was significantly higher among the people with depression as compared to the subjects from the control group. A reversed relationship (also statistically significant) was observed for SIR-2, SIR-3, SIR-4 and SIR-5.