Peripheral blood GILZ mRNA levels in depression and following electroconvulsive therapy

Abstract

Dysregulation of the hypothalamic-pituitary-adrenocortical (HPA)-axis is commonly observed in patients with depression. The delayed feedback system that mediates inhibition of HPA-axis activation is regulated by glucocorticoid receptors (GRs) found in stress-responsive areas of the brain. Glucocorticoid-induced leucine zipper (GILZ) is a key molecule in glucocorticoid biology and is thought to mediate the downstream anti-inflammatory effects of GRs. Previous reports suggest that GILZ levels are altered in the blood and brains of patients with, and animal models of, depression. However, no study has yet investigated the effects of antidepressant treatment on GILZ. Therefore, our aim was to examine peripheral blood GILZ mRNA levels in patients with depression (n = 88) compared to age- and sex-matched healthy controls (n = 63), and in patients with depression following treatment with a course of electroconvulsive therapy (ECT). We also assessed the relationship between GILZ and mood and clinical outcomes following ECT. GILZ mRNA levels were assessed using qRT-PCR. GILZ levels were found to be significantly lower in patients with depression compared to controls (p < 0.002), and ECT further decreased GILZ levels (p = 0.05). Both of these results survived adjustment for potential covariates. However, we found no association between GILZ and mood scores. Overall, these results suggest that GILZ is involved in the pathophysiology of depression and the peripheral molecular response to ECT.