Increased levels of 5HT2A receptor mRNA expression in peripheral blood mononuclear cells of patients with major depression: correlations with severity and duration of illness
Sammanfattning
Background: Neuroimaging, immunologic, and pharmacologic studies have emphasized the role of 5-
HT2A and 5-HT3A serotonin receptors in the pathophysiology of major depression.
Aim: The aim of this study was to measure the relative expression of 5-HT2A and 5-HT3A receptor
mRNA in peripheral blood mononuclear cells (PBMCs) of patients with major depressive disorder
(MDD).
Method: 5-HT2A and 5-HT3A receptor mRNA expressions were examined in PBMCs of 25 medicationnaïve-patients
with MDD, 25 medication-free MDD patients, and 25 healthy controls. 5-HT2A and 5-
HT3A receptor mRNA expressions were measured using real-time quantitative PCR. This study evaluated
patients’ clinical symptoms using the Hamilton Depression Rating Scale-17 items (HDRS) and the
Beck Depression Inventory (BDI).
Results: Relative 5-HTR2A mRNA expression was significantly higher in PBMCs of all MDD patients when
compared with healthy controls (Z ¼ 3.875, p < 0.05). However, there was no significant difference in
the relative levels of 5-HTR3A mRNA expression in PBMCs of all MDD patients when compared with
healthy controls (Z ¼ 1.328, p > 0.05). MDD patients showed significant correlations between 5-HTR2A
mRNA expression and HDRS scores (rs ¼ 0.902, p < 0.001) and BDI scores (rs ¼ 0.878, p < 0.001).
Conclusion: This study showed that depressed patients, irrespective of treatment, have higher
5-HTR2A mRNA levels in PBMCs than healthy subjects. It also provided evidence that 5-HTR2A mRNA
levels in PBMCs of MDD patients could be associated with the severity of depression and the duration
of the illness.