Short-term effects of etifoxine on human gut microbiome in healthy men

Background: Neurosteroids have recently gained in interest as a treatment strategy for affective disorders. Etifoxine is known for its dual mode of action, one of which is to stimulate endogenous neurosteroid synthesis. The gut microbiome has been studied in affective disorders, but it has not been investigated in the context of human etifoxine or neurosteroid interventions. Methods: We performed a crossover study with 36 healthy male volunteers who received etifoxine versus alprazolam and placebo in a balanced Williams design. Participants were randomized into six sequences and went through three 5-day treatments followed by wash-out phases of 9 days. Bacterial compositions in stool samples were determined by high-throughput 16S rRNA amplicon sequencing. Results: Gut microbiome analyses revealed no relevant effects between treatments with respect to alpha and beta diversity. Differential abundance analyses yielded etifoxine treatment as the only effect related to changes in microbial features with reductions of Faecalibacterium duncaniae, Roseburia hominis and Lactobacillus rogosae (i.e., Bacteroides galacturonicus). Conclusion: Here we report on the first human investigation of the gut microbiome with short-term etifoxine intervention. Differences in diversity and compositional structure of the microbiome were more likely due to between- subject effects rather than medication. However, five-day treatment with etifoxine reduced the abundance of a few bacterial species. These species are currently seen as beneficial components of a healthy intestinal microbiome. This reduction in abundances may be related to elevated endogenous neurosteroids

Major Depressive Disorder is Associated with Impaired Mitochondrial Function in Skin Fibroblasts

Mitochondrial malfunction is supposed to be involved in the etiology and pathology of major depressive disorder (MDD). Here, we aimed to identify and characterize the molecular pathomechanisms related to mitochondrial dysfunction in adult human skin fibroblasts, which were derived from MDD patients or non-depressive control subjects. We found that MDD fibroblasts showed significantly impaired mitochondrial functioning: basal and maximal respiration, spare respiratory capacity, non-mitochondrial respiration and adenosine triphosphate (ATP)-related oxygen consumption was lower. Moreover, MDD fibroblasts harbor lower ATP levels and showed hyperpolarized mitochondrial membrane potential. To investigate cellular resilience, we challenged both groups of fibroblasts with hormonal (dexamethasone) or metabolic (galactose) stress for one week, and found that both stressors increased oxygen consumption but lowered ATP content in MDD as well as in non-depressive control fibroblasts. Interestingly, the bioenergetic differences between fibroblasts from MDD or non-depressed subjects, which were observed under non-treated conditions, could not be detected after stress. Our findings support the hypothesis that altered mitochondrial function causes a bioenergetic imbalance, which is associated with the molecular pathophysiology of MDD. The observed alterations in the oxidative phosphorylation system (OXPHOS) and other mitochondria-related properties represent a basis for further investigations of pathophysiological mechanisms and might open new ways to gain insight into antidepressant signaling pathways

Short-term effects of etifoxine on human gut microbiome in healthy men

BackgroundNeurosteroids have recently gained in interest as a treatment strategy for affective disorders. Etifoxine is known for its dual mode of action, one of which is to stimulate endogenous neurosteroid synthesis. The gut microbiome has been studied in affective disorders, but it has not been investigated in the context of human etifoxine or neurosteroid interventions.MethodsWe performed a crossover study with 36 healthy male volunteers who received etifoxine versus alprazolam and placebo in a balanced Williams design. Participants were randomized into six sequences and went through three 5-day treatments followed by wash-out phases of 9 days. Bacterial compositions in stool samples were determined by high-throughput 16S rRNA amplicon sequencing.ResultsGut microbiome analyses revealed no relevant effects between treatments with respect to alpha and beta diversity. Differential abundance analyses yielded etifoxine treatment as the only effect related to changes in microbial features with reductions of Faecalibacterium duncaniae, Roseburia hominis and Lactobacillus rogosae (i.e., Bacteroides galacturonicus).ConclusionHere we report on the first human investigation of the gut microbiome with short-term etifoxine intervention. Differences in diversity and compositional structure of the microbiome were more likely due to between- subject effects rather than medication. However, five-day treatment with etifoxine reduced the abundance of a few bacterial species. These species are currently seen as beneficial components of a healthy intestinal microbiome. This reduction in abundances may be related to elevated endogenous neurosteroids

Lipid raft integrity affects GABAA receptor, but not NMDA receptor modulation by psychopharmacological compounds

Lipid rafts have been shown to play an important role for G-protein mediated signal transduction and the function of ligand-gated ion channels including their modulation by psychopharmacological compounds. In this study, we investigated the functional significance of the membrane distribution of NMDA and GABAA receptor subunits in relation to the accumulation of the tricyclic antidepressant desipramine (DMI) and the benzodiazepine diazepam (Diaz). In the presence of Triton X-100, which allowed proper separation of the lipid raft marker proteins caveolin-1 and flotillin-1 from the transferrin receptor, all receptor subunits were shifted to the non-raft fractions. In contrast, under detergent-free conditions, NMDA and GABAA receptor subunits were detected both in raft and non-raft fractions. Diaz was enriched in non-raft fractions without Triton X-100 in contrast to DMI, which preferentially accumulated in lipid rafts. Impairment of lipid raft integrity by methyl-β-cyclodextrine (MβCD)-induced cholesterol depletion did not change the inhibitory effect of DMI at the NMDA receptor, whereas it enhanced the potentiating effect of Diaz at the GABAA receptor at non-saturating concentrations of GABA. These results support the hypothesis that the interaction of benzodiazepines with the GABAA receptor likely occurs outside of lipid rafts while the antidepressant DMI acts on ionotropic receptors both within and outside these membrane microdomains

The 18 kDa Translocator Protein (Peripheral Benzodiazepine Receptor) Expression in the Bone of Normal, Osteoprotegerin or Low Calcium Diet Treated Mice

The presence of the translocator protein (TSPO), previously named as the mitochondrial or peripheral benzodiazepine receptor, in bone cells was studied in vitro and in situ using RT-qPCR, and receptor autoradiography using the selective TSPO ligand PK11195

Induced neural progenitor cells and iPS-neurons from major depressive disorder patients show altered bioenergetics and electrophysiological properties

The molecular pathomechanisms of major depressive disorder (MDD) are still not completely understood. Here, we follow the hypothesis, that mitochondria dysfunction which is inevitably associated with bioenergetic disbalance is a risk factor that contributes to the susceptibility of an individual to develop MDD. Thus, we investigated molecular mechanisms related to mitochondrial function in induced neuronal progenitor cells (NPCs) which were reprogrammed from fibroblasts of eight MDD patients and eight non-depressed controls. We found significantly lower maximal respiration rates, altered cytosolic basal calcium levels, and smaller soma size in NPCs derived from MDD patients. These findings are partially consistent with our earlier observations in MDD patient-derived fibroblasts. Furthermore, we differentiated MDD and control NPCs into iPS-neurons and analyzed their passive biophysical and active electrophysiological properties to investigate whether neuronal function can be related to altered mitochondrial activity and bioenergetics. Interestingly, MDD patient-derived iPS-neurons showed significantly lower membrane capacitance, a less hyperpolarized membrane potential, increased Na+ current density and increased spontaneous electrical activity. Our findings indicate that functional differences evident in fibroblasts derived from MDD patients are partially present after reprogramming to induced-NPCs, could relate to altered function of iPS-neurons and thus might be associated with the aetiology of major depressive disorder

Antidepressants increase human hippocampal neurogenesis by activating the glucocorticoid receptor

Antidepressants increase adult hippocampal neurogenesis in animal models, but the underlying molecular mechanisms are unknown. In this study, we used human hippocampal progenitor cells to investigate the molecular pathways involved in the antidepressant-induced modulation of neurogenesis. Because our previous studies have shown that antidepressants regulate glucocorticoid receptor (GR) function, we specifically tested whether the GR may be involved in the effects of these drugs on neurogenesis. We found that treatment (for 3–10 days) with the antidepressant, sertraline, increased neuronal differentiation via a GR-dependent mechanism. Specifically, sertraline increased both immature, doublecortin (Dcx)-positive neuroblasts (+16%) and mature, microtubulin-associated protein-2 (MAP2)-positive neurons (+26%). This effect was abolished by the GR-antagonist, RU486. Interestingly, progenitor cell proliferation, as investigated by 5′-bromodeoxyuridine (BrdU) incorporation, was only increased when cells were co-treated with sertraline and the GR-agonist, dexamethasone, (+14%) an effect which was also abolished by RU486. Furthermore, the phosphodiesterase type 4 (PDE4)-inhibitor, rolipram, enhanced the effects of sertraline, whereas the protein kinase A (PKA)-inhibitor, H89, suppressed the effects of sertraline. Indeed, sertraline increased GR transactivation, modified GR phosphorylation and increased expression of the GR-regulated cyclin-dependent kinase-2 (CDK2) inhibitors, p27Kip1 and p57Kip2. In conclusion, our data suggest that the antidepressant, sertraline, increases human hippocampal neurogenesis via a GR-dependent mechanism that requires PKA signaling, GR phosphorylation and activation of a specific set of genes. Our data point toward an important role for the GR in the antidepressant-induced modulation of neurogenesis in humans

Simvastatin treatment reduces the cholesterol content of membrane/lipid rafts, implicating the N -methyl-D-aspartate receptor in anxiety: a literature review

ABSTRACT Membrane/lipid rafts (MLRs) are plasmalemmal microdomains that are essential for neuronal signaling and synaptic development/stabilization. Inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme-A reductase (statins) can disable the N-methyl-D-aspartate (NMDA) receptor through disruption of MLRs and, in turn, decrease NMDA-mediated anxiety. This hypothesis will contribute to understanding the critical roles of simvastatin in treating anxiety via the NMDA receptor

Utenti paradossali. Servizio sociale e sex work maschile

Il capitolo vuole sottolineare l’importanza della riflessione dei regimi sessuali all'interno del servizio sociale. Nella prima parte del capitolo vengono evidenziati dei nodi problematici che vanno presi in considerazione quando nel dibattito di servizio sociale si affrontano le tematiche legate a generi e sessualità. Quindi si discute la necessità di appropriate basi conoscitive come prerequisito di pratiche emancipatorie e anti-oppressive. Nella seconda parte vengono evidenziati le principali problematicità con cui deve confrontarsi il servizio sociale nel caso di una popolazione specifica, quella dei sex workers e degli uomini-che-fanno-sesso-con-altri-uomini (Men who have sex with men, Msm), popolazioni disomogenee e di difficile intercettazione che presentano nuove sfide per l’intervento sociale. In questo caso l’analisi evidenzia alcuni dei nodi problematici che caratterizzano questi gruppi specifici che, se trascurati dai servizi e dall’intervento sociale, rischiano di consolidare stereotipi e aumentarne la vulnerabilità sociale. Le conclusioni fanno una sintesi del contributo sottolineando il ruolo centrale della conoscenza critica per la realizzazione di pratiche emancipatorie e anti-opressive.The chapter wants to emphasize the importance of the reflection of sexual regimes within the social service. In the first part of the chapter some problematic issues are highlighted that must be taken into consideration when issues related to gender and sexuality are addressed in the social work debate. Then the need for appropriate knowledge bases is discussed as a prerequisite for emancipatory and anti-oppressive practices. The second part highlights the main problems that social service has to face in the case of a specific population, that of sex workers and men-who-have-sex-with-other-men (Men who have sex with men, Msm ), heterogeneous and difficult to intercept populations that present new challenges for social intervention. In this case, the analysis highlights some of the problematic issues that characterize these specific groups which, if neglected by services and social intervention, risk consolidating stereotypes and increasing their social vulnerability. The conclusions summarize the contribution underlining the central role of critical knowledge for the realization of emancipatory and anti-depressive practices