Beta-arrestin-1 levels: reduced in leukocytes of patients with depression and elevated by antidepressants in rat brain.
ABSTRACT Beta-arrestins play a pivotal role in G protein-coupled receptor desensitization. beta-Arrestins interfere in G protein receptor interaction, thus leading to desensitization of G protein-mediated receptor signaling. G protein receptor signaling and its desensitization were previously implicated in the pathophysiology of mood disorders and in the mechanism of action of antidepressant and mood-stabilizing treatments. The present study aims at quantitatively evaluating beta-arrestin-1 levels in leukocytes of patients with major depression and the effect of antidepressants on beta-arrestin-1 levels in rat brain.
Beta-arrestin-1 measurements were carried out in cortical, hippocampal, and striatal brain regions of rats chronically intragastrically treated with either imipramine, desipramine, or fluvoxamine. Similar measurements were conducted in mononuclear leukocytes of 36 untreated patients with major depression and 32 healthy volunteer subjects. Beta-arrestin-1 levels were evaluated through immunoblot analyses using monoclonal antibodies to beta-arrestin-1.
Beta-arrestin-1 levels were significantly elevated by all three antidepressants in rat cortex and hippocampus, while in the striatum no alterations could be detected. This process became significant within 10 days and took 2-3 weeks to reach maximal increase. Mononuclear leukocytes of patients with depression showed significantly reduced immunoreactive quantities of beta-arrestin-1. The reduction in beta-arrestin-1 levels was significantly correlated with the severity of depressive symptoms.
The findings in the rat study suggest beta-arrestin-1 elevation as a biochemical mechanism for antidepressant-induced receptor down-regulation. The findings in human subjects support the implication of beta-arrestin-1 in the pathophysiology of mood disorders. Beta-arrestin-1 measurements in patients with depression may potentially serve as a biochemical marker for depression.
- SourceAvailable from: Moran Golan[show abstract] [hide abstract]
ABSTRACT: Glial cell line-derived neurotrophic factor (GDNF), essential for neuronal survival, plasticity and development, has been implicated in the mechanism of action of antidepressant drugs (ADs). β-arrestin1, a member of the arrestin protein family, was found to play a role in AD mechanism of action. The present study aimed at evaluating whether the effect of ADs on GDNF in C6 rat glioma cells is exerted through a β-arrestin1-dependent, CREB-interactive pathway. For chronic treatment, C6 rat glioma cells were treated for 3 d with different classes of ADs: imipramine - a non-selective monoamine reuptake inhibitor, citalopram - a serotonin selective reuptake inhibitor (SSRI) or desipramine - a norepinephrine selective reuptake inhibitor (NSRI) and compared to mood stabilizers (lithium and valproic acid) or to the antipsychotic haloperidol. Only ADs significantly elevated β-arrestin1 levels in the cytosol, while reducing phospho-β-arrestin1 levels in the cell nuclear fraction. ADs significantly increased both GDNF expression and release from the cells, but were unable to induce such effects in β-arrestin1 knock-down cells. Chronic AD treatment significantly increased CREB phosphorylation without altering the level of total CREB in the nuclear fraction of the cells. Moreover, treatment with ADs significantly increased β-arrestin1/CREB interaction. These findings support the involvement of β-arrestin1 in the mechanism of action of ADs. We suggest that following AD treatment, β-arrestin1 generates a transcription complex involving CREB essential for GDNF expression and release, thus enhancing GDNF's neuroprotective action that promotes cellular survival and plasticity when the survival and function of neurons is compromised as occurs in major depression.The International Journal of Neuropsychopharmacology 01/2011; 14(10):1289-300. · 5.64 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: Alterations of multiple G protein-mediated signaling pathways are detected in schizophrenia. G protein-coupled receptor kinases (GRKs) and arrestins terminate signaling by G protein-coupled receptors exerting a powerful influence on receptor functions. Modifications of arrestin and/or GRKs expression may contribute to schizophrenia pathology. Cortical expression of arrestins and GRKs was measured postmortem in control and subjects with schizophrenia or schizoaffective disorder. Additionally, arrestin/GRK expression was determined in elderly patients with schizophrenia and age-matched control. Patients with schizophrenia, but not schizoaffective disorder, displayed a reduced concentration of arrestin and GRK mRNAs and GRK3 protein. Arrestins and GRK significantly decreased with age. In elderly patients, GRK6 was reduced, with other GRKs and arrestins unchanged. A reduced cortical concentration of GRKs in schizophrenia (resembling that in aging) may result in altered G protein-dependent signaling, thus contributing to prefrontal deficits in schizophrenia. The data suggest distinct molecular mechanisms underlying schizophrenia and schizoaffective disorder.Neurobiology of Disease 07/2011; 44(2):248-58. · 5.62 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: The biological underpinnings of borderline personality disorder (BPD) and its psychopathology including states of aversive tension and dissociation is poorly understood. Our goal was to examine transcriptional changes associated with states of tension or dissociation within individual patients in a pilot study. Dissociation is not only a critical symptom of BPD but has also been associated with higher risk for self-mutilation and depression. We conducted a whole blood gene expression profile analysis using quantitative PCR in 31 female inpatients with BPD. For each individual, two samples were drawn during a state of high tension and dissociation, while two samples were drawn at non-tension states. There was no association between gene expression and tension states. However, we could show that Interleukin-6 was positively correlated to dissociation scores, whereas Guanine nucleotide-binding protein G(s) subunit alpha isoforms, Mitogen-activated protein kinase 3 and 8, Guanine nucleotide-binding protein G(i) subunit alpha-2, Beta-arrestin-1 and 2, and Cyclic AMP-responsive element-binding protein were negatively correlated to dissociation. Our data point to a potential association of dissociation levels with the expression of genes involved in immune system regulation as well as cellular signalling/second-messenger systems. Major limitations of the study are the the possibly heterogeneous cell proportions in whole blood and the heterogeneous medication.PLoS ONE 01/2013; 8(8):e70787. · 3.73 Impact Factor