Anti-Inflammatory Effects of GPR55 Agonists and Antagonists in LPS-Treated BV2 Microglial Cells.

Chronic inflammation is driven by proinflammatory cytokines such as interleukin 6 (IL-6), tumor necrosis factor-α (TNF-α), and chemokines, such as c-c motif chemokine ligand 2 (CCL2), CCL3, C-X-C motif chemokine ligand 2 (CXCL2), and CXCL10. Inflammatory processes of the central nervous system (CNS) play an important role in the pathogenesis of various neurological and psychiatric disorders like Alzheimer's disease, Parkinson's disease, and depression. Therefore, identifying novel anti-inflammatory drugs may be beneficial for treating disorders with a neuroinflammatory background. The G-protein-coupled receptor 55 (GPR55) gained interest due to its role in inflammatory processes and possible involvement in different disorders. This study aims to identify the anti-inflammatory effects of the coumarin-based compound KIT C, acting as an antagonist with inverse agonistic activity at GPR55, in lipopolysaccharide (LPS)-stimulated BV2 microglial cells in comparison to the commercial GPR55 agonist O-1602 and antagonist ML-193. All compounds significantly suppressed IL-6, TNF-α, CCL2, CCL3, CXCL2, and CXCL10 expression and release in LPS-treated BV2 microglial cells. The anti-inflammatory effects of the compounds are partially explained by modulation of the phosphorylation of p38 mitogen-activated protein kinase (MAPK), p42/44 MAPK (ERK 1/2), protein kinase C (PKC) pathways, and the transcription factor nuclear factor (NF)-κB, respectively. Due to its potent anti-inflammatory properties, KIT C is a promising compound for further research and potential use in inflammatory-related disorders.

Anti-Neuroinflammatory Effects of a Macrocyclic Peptide-Peptoid Hybrid in Lipopolysaccharide-Stimulated BV2 Microglial Cells.

Inflammation processes of the central nervous system (CNS) play a vital role in the pathogenesis of several neurological and psychiatric disorders like depression. These processes are characterized by the activation of glia cells, such as microglia. Clinical studies showed a decrease in symptoms associated with the mentioned diseases after the treatment with anti-inflammatory drugs. Therefore, the investigation of novel anti-inflammatory drugs could hold substantial potential in the treatment of disorders with a neuroinflammatory background. In this in vitro study, we report the anti-inflammatory effects of a novel hexacyclic peptide-peptoid hybrid in lipopolysaccharide (LPS)-stimulated BV2 microglial cells. The macrocyclic compound X15856 significantly suppressed Interleukin 6 (IL-6), tumor necrosis factor-α (TNF-α), c-c motif chemokine ligand 2 (CCL2), CCL3, C-X-C motif chemokine ligand 2 (CXCL2), and CXCL10 expression and release in LPS-treated BV2 microglial cells. The anti-inflammatory effects of the compound are partially explained by the modulation of the phosphorylation of p38 mitogen-activated protein kinases (MAPK), p42/44 MAPK (ERK 1/2), protein kinase C (PKC), and the nuclear factor (NF)-κB, respectively. Due to its remarkable anti-inflammatory properties, this compound emerges as an encouraging option for additional research and potential utilization in disorders influenced by inflammation, such as depression.

Functional Selectivity of Coumarin Derivates Acting via GPR55 in Neuroinflammation.

Anti-neuroinflammatory treatment has gained importance in the search for pharmacological treatments of different neurological and psychiatric diseases, such as depression, schizophrenia, Parkinson's disease, and Alzheimer's disease. Clinical studies demonstrate a reduction of the mentioned diseases' symptoms after the administration of anti-inflammatory drugs. Novel coumarin derivates have been shown to elicit anti-neuroinflammatory effects via G-protein coupled receptor GPR55, with possibly reduced side-effects compared to the known anti-inflammatory drugs. In this study, we, therefore, evaluated the anti-inflammatory capacities of the two novel coumarin-based compounds, KIT C and KIT H, in human neuroblastoma cells and primary murine microglia. Both compounds reduced PGE2-concentrations likely via the inhibition of COX-2 synthesis in SK-N-SH cells but only KIT C decreased PGE2-levels in primary microglia. The examination of other pro- and anti-inflammatory parameters showed varying effects of both compounds. Therefore, the differences in the effects of KIT C and KIT H might be explained by functional selectivity as well as tissue- or cell-dependent expression and signal pathways coupled to GPR55. Understanding the role of chemical residues in functional selectivity and specific cell- and tissue-targeting might open new therapeutic options in pharmacological drug development and might improve the treatment of the mentioned diseases by intervening in an early step of their pathogenesis.

Pharmacotherapy, drug-drug interactions and potentially inappropriate medication in depressive disorders.

INTRODUCTION: The aim of this study was to describe the number and type of drugs used to treat depressive disorders in inpatient psychiatry and to analyse the determinants of potential drug-drug interactions (pDDI) and potentially inappropriate medication (PIM). METHODS: Our study was part of a larger pharmacovigilance project funded by the German Innovation Funds. It included all inpatients with a main diagnosis in the group of depressive episodes (F32, ICD-10) or recurrent depressive disorders (F33) discharged from eight psychiatric hospitals in Germany between 1 October 2017 and 30 September 2018 or between 1 January and 31 December 2019. RESULTS: The study included 14,418 inpatient cases. The mean number of drugs per day was 3.7 (psychotropic drugs = 1.7; others = 2.0). Thirty-one percent of cases received at least five drugs simultaneously (polypharmacy). Almost one half of all cases received a combination of multiple antidepressant drugs (24.8%, 95% CI 24.1%-25.5%) or a treatment with antidepressant drugs augmented by antipsychotic drugs (21.9%, 95% CI 21.3%-22.6%). The most frequently used antidepressants were selective serotonin reuptake inhibitors, followed by serotonin and norepinephrine reuptake inhibitors and tetracyclic antidepressants. In multivariate analyses, cases with recurrent depressive disorders and cases with severe depression were more likely to receive a combination of multiple antidepressant drugs (Odds ratio recurrent depressive disorder: 1.56, 95% CI 1.41-1.70, severe depression 1.33, 95% CI 1.18-1.48). The risk of any pDDI and PIM in elderly patients increased substantially with each additional drug (Odds Ratio: pDDI 1.32, 95% CI: 1.27-1.38, PIM 1.18, 95% CI: 1.14-1.22) and severity of disease (Odds Ratio per point on CGI-Scale: pDDI 1.29, 95% CI: 1.11-1.46, PIM 1.27, 95% CI: 1.11-1.44), respectively. CONCLUSION: This study identified potential sources and determinants of safety risks in pharmacotherapy of depressive disorders and provided additional data which were previously unavailable. Most inpatients with depressive disorders receive multiple psychotropic and non-psychotropic drugs and pDDI and PIM are relatively frequent. Patients with a high number of different drugs must be intensively monitored in the management of their individual drug-related risk-benefit profiles.

Polypharmacy and the risk of drug-drug interactions and potentially inappropriate medications in hospital psychiatry.

PURPOSE: The aim of this study was to analyze the epidemiology of polypharmacy in hospital psychiatry. Another aim was to investigate predictors of the number of drugs taken and the associated risks of drug-drug interactions and potentially inappropriate medications in the elderly. METHODS: Daily prescription data were obtained from a pharmacovigilance project sponsored by the Innovations Funds of the German Federal Joint Committee. RESULTS: The study included 47 071 inpatient hospital cases from eight different study centers. The mean number of different drugs during the entire stay was 6.1 (psychotropic drugs = 2.7; others = 3.4). The mean number of drugs per day was 3.8 (psychotropic drugs = 1.6; others = 2.2). One third of cases received at least five different drugs per day on average during their hospital stay (polypharmacy). Fifty-one percent of patients received more than one psychotropic drug simultaneously. Hospital cases with polypharmacy were 18 years older (p < 0.001), more likely to be female (52% vs. 40%, p < 0.001) and had more comorbidities (5 vs. 2, p < 0.001) than hospital cases without polypharmacy. The risks of drug-drug interactions (OR = 3.7; 95% CI = 3.5-3.9) and potentially inappropriate medication use in the elderly (OR = 2.2; CI = 1.9-2.5) substantially increased in patients that received polypharmacy. CONCLUSION: Polypharmacy is frequent in clinical care. The number of used drugs is a proven risk factor of adverse drug reactions due to drug-drug interactions and potentially inappropriate medication use in the elderly. The potential interactions and the specific pharmacokinetics and -dynamics of older patients should always be considered when multiple drugs are used.

Predicting the risk of drug-drug interactions in psychiatric hospitals: a retrospective longitudinal pharmacovigilance study.

OBJECTIVES: The aim was to use routine data available at a patient's admission to the hospital to predict polypharmacy and drug-drug interactions (DDI) and to evaluate the prediction performance with regard to its usefulness to support the efficient management of benefits and risks of drug prescriptions. DESIGN: Retrospective, longitudinal study. SETTING: We used data from a large multicentred pharmacovigilance project carried out in eight psychiatric hospitals in Hesse, Germany. PARTICIPANTS: Inpatient episodes consecutively discharged between 1 October 2017 and 30 September 2018 (year 1) or 1 January 2019 and 31 December 2019 (year 2). OUTCOME MEASURES: The proportion of rightly classified hospital episodes. METHODS: We used gradient boosting to predict respective outcomes. We tested the performance of our final models in unseen patients from another calendar year and separated the study sites used for training from the study sites used for performance testing. RESULTS: A total of 53 909 episodes were included in the study. The models' performance, as measured by the area under the receiver operating characteristic, was 'excellent' (0.83) and 'acceptable' (0.72) compared with common benchmarks for the prediction of polypharmacy and DDI, respectively. Both models were substantially better than a naive prediction based solely on basic diagnostic grouping. CONCLUSION: This study has shown that polypharmacy and DDI can be predicted from routine data at patient admission. These predictions could support an efficient management of benefits and risks of hospital prescriptions, for instance by including pharmaceutical supervision early after admission for patients at risk before pharmacological treatment is established.

Enhanced adenosine A1 receptor and Homer1a expression in hippocampus modulates the resilience to stress-induced depression-like behavior.

Resilience to stress is critical for the development of depression. Enhanced adenosine A1 receptor (A1R) signaling mediates the antidepressant effects of acute sleep deprivation (SD). However, chronic SD causes long-lasting upregulation of brain A1R and increases the risk of depression. To investigate the effects of A1R on mood, we utilized two transgenic mouse lines with inducible A1R overexpression in forebrain neurons. These two lines have identical levels of A1R increase in the cortex, but differ in the transgenic A1R expression in the hippocampus. Switching on the transgene promotes robust antidepressant and anxiolytic effects in both lines. The mice of the line without transgenic A1R overexpression in the hippocampus (A1Hipp-) show very strong resistance towards development of stress-induced chronic depression-like behavior. In contrast, the mice of the line in which A1R upregulation extends to the hippocampus (A1Hipp+), exhibit decreased resilience to depression as compared to A1Hipp-. Similarly, automatic analysis of reward behavior of the two lines reveals that depression resistant A1Hipp-transgenic mice exhibit high sucrose preference, while mice of the vulnerable A1Hipp + line developed stress-induced anhedonic phenotype. The A1Hipp + mice have increased Homer1a expression in hippocampus, correlating with impaired long-term potentiation in the CA1 region, mimicking the stressed mice. Furthermore, virus-mediated overexpression of Homer1a in the hippocampus decreases stress resilience. Taken together our data indicate for first time that increased expression of A1R and Homer1a in the hippocampus modulates the resilience to stress-induced depression and thus might potentially mediate the detrimental effects of chronic sleep restriction on mood.

Work-Time Distribution of Physicians at a German University Hospital.

BACKGROUND: The effective utilization of staff resources is of decisive importance for the adequate, appropriate, and economical delivery of hospital services. The goal of this study was to determine the distribution of working time among doctors in a German university hospital-in particular, in terms of type of activities and time of day. METHODS: The distribution of working time was determined from 14-day samples taken in seven clinical departments of the Medical Center-University of Freiburg. In each 14-day sample, the activities being carried out at multiple, randomly chosen times were recorded. RESULTS: A total of 250 doctors (participation rate: 83%) took part in the study. A total of 20 715 hours of working time was analyzed, representing twelve years of full-time employment. Overall, 46% of working time in the inpatient sector was spent in direct contact with patients, with relevant differences among the participating clinical departments: for instance, the percentage of time taken up by patient contact was 35% in pediatrics and 60% in oral and maxillofacial surgery. Patient contact was highest (over 50% overall) in the period 8 a.m. to 12 noon. CONCLUSION: The amount of working time taken up by activities other than direct patient contact was found to be lower than in previous studies. It remains unclear what distribution of working time is best for patient care and whether it would be possible or desirable to increase the time that doctors spend in direct contact with patients.

Synaptic plasticity model of therapeutic sleep deprivation in major depression.

Therapeutic sleep deprivation (SD) is a rapid acting treatment for major depressive disorder (MDD). Within hours, SD leads to a dramatic decrease in depressive symptoms in 50-60% of patients with MDD. Scientifically, therapeutic SD presents a unique paradigm to study the neurobiology of MDD. Yet, up to now, the neurobiological basis of the antidepressant effect, which is most likely different from today's first-line treatments, is not sufficiently understood. This article puts the idea forward that sleep/wake-dependent shifts in synaptic plasticity, i.e., the neural basis of adaptive network function and behavior, represent a critical mechanism of therapeutic SD in MDD. Particularly, this article centers on two major hypotheses of MDD and sleep, the synaptic plasticity hypothesis of MDD and the synaptic homeostasis hypothesis of sleep-wake regulation, and on how they can be integrated into a novel synaptic plasticity model of therapeutic SD in MDD. As a major component, the model proposes that therapeutic SD, by homeostatically enhancing cortical synaptic strength, shifts the initially deficient inducibility of associative synaptic long-term potentiation (LTP) in patients with MDD in a more favorable window of associative plasticity. Research on the molecular effects of SD in animals and humans, including observations in the neurotrophic, adenosinergic, monoaminergic, and glutamatergic system, provides some support for the hypothesis of associative synaptic plasticity facilitation after therapeutic SD in MDD. The model proposes a novel framework for a mechanism of action of therapeutic SD that can be further tested in humans based on non-invasive indices and in animals based on direct studies of synaptic plasticity. Further determining the mechanisms of action of SD might contribute to the development of novel fast acting treatments for MDD, one of the major health problems worldwide.

Increased Signaling via Adenosine A1 Receptors, Sleep Deprivation, Imipramine, and Ketamine Inhibit Depressive-like Behavior via Induction of Homer1a.

Major depressive disorder is among the most commonly diagnosed disabling mental diseases. Several non-pharmacological treatments of depression upregulate adenosine concentration and/or adenosine A1 receptors (A1R) in the brain. To test whether enhanced A1R signaling mediates antidepressant effects, we generated a transgenic mouse with enhanced doxycycline-regulated A1R expression, specifically in forebrain neurons. Upregulating A1R led to pronounced acute and chronic resilience toward depressive-like behavior in various tests. Conversely, A1R knockout mice displayed an increased depressive-like behavior and were resistant to the antidepressant effects of sleep deprivation (SD). Various antidepressant treatments increase homer1a expression in medial prefrontal cortex (mPFC). Specific siRNA knockdown of homer1a in mPFC enhanced depressive-like behavior and prevented the antidepressant effects of A1R upregulation, SD, imipramine, and ketamine treatment. In contrast, viral overexpression of homer1a in the mPFC had antidepressant effects. Thus, increased expression of homer1a is a final common pathway mediating the antidepressant effects of different antidepressant treatments.

Genetically controlled upregulation of adenosine A(1) receptor expression enhances the survival of primary cortical neurons.

Adenosine has a key endogenous neuroprotective role in the brain, predominantly mediated by the adenosine A(1) receptor (A(1)R). This has been mainly explored using pharmacological tools and/or receptor knockout mice strains. It has long been suggested that the neuroprotective effects of A(1)R are increased following receptor upregulation, thus attenuating neuronal damage in pathological conditions. We have previously shown that the neuroprotective and neuromodulatory actions of the cytokines IL-6 and oncostatin M are mediated by induction of neuronal A(1)R expression. In order to investigate the direct effects of A(1)R upregulation in neurons, we have generated a tetracycline-regulated expression system with a bidirectional promoter, directing the simultaneous expression of the mouse A(1)R and GFP/mCherry reporter genes. In a first step, we tested the efficacy of the system in transiently transfected human embryonic kidney 293 cells. In addition, we confirmed the functional integrity of the expressed A(1)R by whole-cell patch clamp recordings. We demonstrated that A(1)R-transfected primary neurons show enhanced survival against N-methyl-D-aspartate-induced excitotoxicity. Pretreatment with an A(1)R-selective agonist additionally strongly decreased neuronal cell death, while an A(1)R antagonist completely abolished the neuroprotective effects of A(1)R upregulation. The presented data provide for the first time direct evidence that the upregulation of A(1)R enhances neuronal survival.