Objectives. Research on stem cells indicates their role in the pathogenesis of psychiatric disorders and mechanisms of psychotropic drugs. In this study, we evaluated expression of mRNA markers of neural stem cells (NSCs): nestin, β3-tubulin and vimentin in peripheral blood of patients with bipolar disorder (BD) and assessed the effect of long-term lithium treatment.
Material and methods. Thirty patients with BD were included (fifteen during remission, with illness duration minimum 10 years, never treated with lithium, and 15 treated with lithium for 8–40 years, 16 years on average), and 15 control subjects, matched in terms of sex and age. Assessment of the mRNA was performed using the real-time quantitative reverse transcription PCR procedure.
Results. In BD patients never treated with lithium, the mRNA expression of nestin and β3-tubulin was significantly higher, compared to the control group. In lithium-treated patients, the expression of β3-tubulin was similar to the control group. The mRNA expression of vimentin was higher in lithium-treated BD patients, compared to non-lithium-treated patients and the control group. In the control group, the mRNA expression of nestin and vimentin correlated negatively with the number of CD133+ VSELs (very small embryonic-like stem cells), which was not observed in BD subjects.
Conclusions. The results show a differential mRNA expression of NSCs markers in BD patients and variable effects of long-term lithium treatment on these parameters. Increased levels of nestin and β3-tubulin may indicate excessive regenerative processes occurring in the course of BD, and long-term lithium treatment may inhibit overexpression of β3-tubulin. Elevated mRNA levels of vimentin in lithium-treated patients may be related to neuroprotective properties of this ion.