Regulation of glucocorticoidreceptor-mRNA in human blood cells by amitriptyline and dexamethasone

146

126

Although gene expression profiles in peripheral blood in major depression are not likely to identify genes directly involved in the pathomechanism of affective disorders, they may serve as biomarkers for this disorder. As previous studies using baseline gene expression profiles have provided mixed results, our approach was to use an in vivo dexamethasone challenge test and to compare glucocorticoid receptor (GR)-mediated changes in gene expression between depressed patients and healthy controls. Whole genome gene expression data (baseline and following GR-stimulation with 1.5 mg dexamethasone p.o.) from two independent cohorts were analyzed to identify gene expression pattern that would predict case and control status using a training (N ¼ 18 cases/18 controls) and a test cohort (N ¼ 11/13). Dexamethasone led to reproducible regulation of 2670 genes in controls and 1151 transcripts in cases. Several genes, including FKBP5 and DUSP1, previously associated with the pathophysiology of major depression, were found to be reliable markers of GR-activation. Using random forest analyses for classification, GR-stimulated gene expression outperformed baseline gene expression as a classifier for case and control status with a correct classification of 79.1 vs 41.6% in the test cohort. GR-stimulated gene expression performed best in dexamethasone non-suppressor patients (88.7% correctly classified with 100% sensitivity), but also correctly classified 77.3% of the suppressor patients (76.7% sensitivity), when using a refined set of 19 genes. Our study suggests that in vivo stimulated gene expression in peripheral blood cells could be a promising molecular marker of altered GR-functioning, an important component of the underlying pathology, in patients suffering from depressive episodes.

Section: Discussionmentioning

confidence: 99%

Dexamethasone Stimulated Gene Expression in Peripheral Blood is a Sensitive Marker for Glucocorticoid Receptor Resistance in Depressed Patients

Menke

Arloth

Pütz

et al. 2012

146

126

“…We have used clomipramine, at 10 mM, for 24 h, as previously described (Pariante et al, 2001a). In vitro treatment with micromolar concentrations of antidepressants for at least 24 h have been previously used in studies that have investigated the in vitro effects of antidepressants on the GR (Pariante et al, 1997(Pariante et al, , 2001aVedder et al, 1999;Budziszewska et al, 2000;Miller et al, 2002;Lai et al, 2003) or on other molecular systems (Chen and Rasenick, 1995;Varga et al, 1996;Szabo et al, 1999;Xia et al, 1999;Maes et al, 1999). Moreover, this concentration resembles the therapeutic plasma and brain levels of tricyclic antidepressants (Hrdina and Dubas, 1981;Glotzbach and Preskorn, 1982).…”

Section: Methodsmentioning

confidence: 99%

“…Therefore, these systems allow the study of molecular effects that are unrelated to the inhibition of catecholamine uptake, the mechanism believed to be crucial in the therapeutic action of antidepressants. Antidepressants increase GR function and GR expression in neuronal cell cultures (Pepin et al, 1989;Okugawa et al, 1999;Hery et al, 2000;Lai et al, 2003), fibroblasts (Pepin et al, 1992;Pariante et al, 1997Pariante et al, , 2001aMiller et al, 2002), and human peripheral blood mononuclear cells (Vedder et al, 1999). However, reduced GR function in vitro by antidepressants has also been described (Pariante et al, 1997(Pariante et al, , 2001aBudziszewska et al, 2000;Miller et al, 2002).…”

Section: Introductionmentioning

confidence: 99%

The Antidepressant Clomipramine Regulates Cortisol Intracellular Concentrations and Glucocorticoid Receptor Expression in Fibroblasts and Rat Primary Neurones

Pariante

Hye

Williamson

et al. 2003

Incubation of LMCAT fibroblasts cells with antidepressants potentiates glucocorticoid receptor (GR)-mediated gene transcription in the presence of cortisol, but not of corticosterone. We have suggested that antidepressants do so by inhibiting the LMCAT cells membrane steroid transporter and thus by increasing cortisol intracellular concentrations. We now confirm and extend this model to primary neuronal cultures. Clomipramine, a tricyclic antidepressant, increased the intracellular accumulation of 3 H-cortisol, but not 3 Hcorticosterone, in LMCAT cells (+80%) and primary rat neurones (+20%). The latter finding is the first demonstration that a membrane steroid transporter is present in neurones. Moreover, verapamil, a membrane steroid transporter inhibitor, reduced the effects of clomipramine on the intracellular accumulation of 3 H-cortisol in LMCAT cells. Finally, clomipramine also decreased GR expression (whole-cell Western blot) in LMCAT cells (50% reduction) and primary rat neurones (80% reduction). This GR downregulation can explain the reduced GR-mediated gene transcription previously described under experimental conditions that do not elicit the effects on the LMCAT cells steroid transporter. This work further supports the hypothesis that membrane steroid transporters regulating the access of glucocorticoids to the brain in vivo are a fundamental target for antidepressant action.

“…Given the well-established effects of antidepressants in enhancing glucocorticoid responsiveness in in vitro studies of neuronal cell cultures (Pepin et al, 1989;Okugawa et al, 1999;Hery et al, 2000;Lai et al, 2003), fibroblasts (Pepin et al, 1992;Pariante et al, 2003a, b;Miller, 2002), and MNL (Vedder et al, 1999) it is challenging to consider the mechanism through which SER administration would result in the opposite effect, that of decreasing glucocorticoid responsiveness in PTSD. One mechanism through which SER and other antidepressants are thought to reverse glucocorticoid resistance associated with GR downregulation, and increased feedback sensitivity, is through their ability to inhibit membrane steroid transporters, in particular, the steroid transporter p-glycoprotein (Weiss et al, 2003;Pariante et al, 2003a, b).…”

Section: Effect Of Sertraline On Glucocorticoid Sensitivity R Yehuda mentioning

confidence: 99%

Effect of Sertraline on Glucocorticoid Sensitivity of Mononuclear Leukocytes in Post-Traumatic Stress Disorder

Yehuda

Yang

Golier

et al. 2005

This study examined the effects of sertraline (SER) on glucocorticoid sensitivity in mononuclear leukocytes (MNL) from eight subjects with current post-traumatic stress disorder (PTSD) and nine comparison subjects. In all, 60 ml of blood was withdrawn by venipuncture at 0800, and MNL were isolated from blood and divided into two portions: the first contained live cells incubated with a series of concentrations of dexamethasone (DEX); the second contained cells incubated with similar concentrations of DEX þ 2 mM SER. Group difference in the concentrations of DEX required to inhibit lysozyme activity by 50% were evaluated under conditions of DEX-only and DEX þ SER using analysis of covariance (ANCOVA). A significant Group Â Condition interaction reflected that SER altered the lysozyme IC 50-DEX in the direction of decreasing sensitivity to glucocorticoids in PTSD while having no uniform effect in cells from comparison subjects. The data provide support for the idea that glucocorticoid receptors might be more responsive to antidepressants in PTSD than in persons without PTSD. Insofar as increased sensitivity to glucocorticoids has been linked with PTSD, the actions of SER on the lysozyme IC 50-DEX suggest that this medication may target a biologic alteration associated with PTSD pathophysiology.