Maj Institute of Pharmacology

Selective serotonin reuptake inhibitors (SSRIs) are commonly used to treat depression, but their chronic use is associated with side effects and residual symptoms of depression. Both effects induced by SSRIs are mediated by serotonin receptor-dependent signaling pathways, yet the molecular mechanisms underlying these effects remain unclear. Here, we investigated the impact of chronic and acute activation of the 5-HT7 receptor (5-HT7R) using the selective agonist AGH-194 in male mice. Behavioral assessment revealed that chronic AGH-194 administration induced depressive-like effects in the novelty suppressed feeding test (NSFT), female urine sniffing test (FUST), and novel object location test (NOLT). After acute injection, depressive-like effects were observed only in NSFT. At the molecular level, AGH-194 administration activated matrix metalloproteinase 9 (MMP-9) through a 5-HT7R-Gαs signaling-dependent mechanism. Acute treatment induced transient activation, while chronic treatment led to prolonged enzymatic activity, accompanied by a reduction in the expression of the GluA1 subunit of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) in the hippocampus. At the cellular level, acute but not chronic AGH-194 treatment induced a shift toward more juvenile dendritic spine morphology in the CA1 and dentate gyrus (DG) regions of the hippocampus, along with an increase in dendritic spine density in DG. Electrophysiological recordings demonstrated that acute AGH-194 administration enhanced hippocampal excitability by increasing population spike amplitude in CA1. Chronic AGH-194 treatment further modulated short-term plasticity, increasing both population spike and extracellular field potential paired-pulse ratios (PS-PPR and EPSP-PPR) in CA1, while also enhancing the maximum EPSP slope amplitude. These findings provide novel evidence that chronic 5-HT7R activation can induce depressive-like behaviors in male mice, potentially through sustained MMP-9 activation and alterations in synaptic plasticity. Understanding the molecular and electrophysiological consequences of selective 5-HT7R stimulation may provide insights into receptor-specific mechanisms that could contribute to SSRI-induced side effects, thereby contributing to the development of improved antidepressant strategies.

Abstract Major depressive disorder (MDD) involves dysregulated neuroimmune, metabolic, and oxidative stress (NIMETOX) pathways. Recently, it was shown that NIMETOX pathways should be evaluated in MDD patients stratified for metabolic syndrome (MetS). The current study aims to characterize the metabolic hormone and adipokine profiles of Chinese MDD patients stratified for MetS and to delineate their associations with overall severity of depression (OSOD), suicidal ideation (SI), recurrence of illness (ROI), and physiosomatic symptoms. We enrolled 125 MDD inpatients and 40 healthy controls and measured fasting serum insulin, glucose, glucagon, Glucose-dependent Insulinotropic Polypeptide (GIP), Glucagon-Like Peptide-1 (GLP-1), leptin, secretin, Plasminogen Activator Inhibitor-1 (PAI-1), resistin, ghrelin, and adiponectin, as well as the acute-phase inflammatory (API) response using albumin, transferrin (Tf), and monomeric CRP (mCRP). The results revealed a distinct metabolic hormone and adipokine signature in MDD with significantly lower insulin, glucagon, and PAI-1 levels, alongside an elevated API index (after adjusting for age, MetS, and body mass index). A composite GAP index (ghrelin, adiponectin, PAI-1) correlated negatively with OSOD, SI, ROI, physiosomatic symptoms, and adverse childhood experiences (ACEs). Integrative modeling combining the GAP index, API index, and ACEs achieved an area under the receiver operating characteristic (ROC) curve of 0.864 with an accuracy of 80% for discriminating MDD from controls. In conclusion, the findings delineated that many inpatients with severe MDD suffer from suppressed anabolic hormones and lower adipokine levels coupled with a mild, chronic inflammatory response. The deviations in this “hormonal-immune-metabolic” axis are components of the NIMETOX pathways in MDD and are not associated with MetS.

Abstract During the Holocene, diverse human groups of hunter-gatherers and pastoralists inhabited the Egyptian Western Desert. These Early Holocene populations were attracted by resources associated with numerous temporary lakes ( playas ) and related wetlands, which characterized the Western Desert during wet climatic oscillations at that time. The Gebel Ramlah region, adjacent to Nabta-Kiseiba, is one of the richest areas of Holocene settlement and has been recently investigated. This paper presents the results of research on a unique Early Holocene occupation associated with the so-called El-Ghorab Unit, dated to the 10th millennium BP. Our results interpret the investigated site as a seasonal, short-term hunting station primarily associated with dorcas gazelle hunting, most likely during the early spring season. Despite relatively favorable environmental conditions that allowed for the preservation of animal skeletal remains, there is no evidence of domesticated animals or pottery at the site. The evidence suggests that El-Ghorab Unit societies represent a primarily foraging mode of subsistence.

Alcohol use disorder (AUD) is characterized by pathological motivation to consume alcohol and cognitive inflexibility, leading to excessive alcohol seeking and use. In this study, we investigated the molecular correlates of impaired extinction of alcohol seeking during forced abstinence using a mouse model of AUD in the automated IntelliCage social system. This model distinguished AUD-prone and AUD-resistant animals based on the presence of ≥2 or <2 criteria of AUD, respectively. We used RNA sequencing to identify genes differentially expressed in the hippocampus, a brain region implicated in alcohol motivation, seeking during abstinence, and cognitive inflexibility. Our findings revealed differences in the hippocampal genes linked to the actin cytoskeleton and synaptic function, including cofilin (Cfl), and impaired synaptic transmission in the molecular layer of the hippocampal dentate gyrus (ML-DG) in ≥2 criteria mice as compared to <2 crit animals. To complement this data, we conducted local genetic manipulations in DG. Overexpression of Cfl in the polymorphic layer of the hippocampal dentate gyrus (PoDG) inhibited ML-DG synapses, increased motivation to seek alcohol and sucrose rewards, impaired extinction of seeking, and decreased reward consumption during relapse. Reducing Cfl levels had opposite effects. We also identified three SNPs in the human CFL1 gene (rs369270402, rs2376005, rs36124259) associated with increased AUD risk and found CFL1 mRNA blood levels correlated with alcohol-related hospital admissions. Overall, our study uncovers a novel mechanism linking hippocampal Cfl expression with AUD phenotypes and identifies CFL1 polymorphisms as AUD risk factor in humans.

ABSTRACTThis study aimed to investigate the role of LVV‐hemorphin‐7 (LVV‐H7) in alcohol dependence. LVV‐H7 is a short peptide derived from the cleavage of haemoglobin chains that binds to opioid receptors and plays diverse roles in various physiological and pathological processes. Additionally, LVV‐H7 is cleaved at higher concentrations in the presence of alcohol. We conducted behavioural experiments in animal models and performed proteomic analyses of CNS tissues from alcohol‐addicted rats to identify LVV‐H7 binding partners. Using fluorescent microscopy, we confirmed the blood–brain barrier (BBB) permeability of synthesized LVV‐H7 and its releasing enzyme inhibitor, pepstatin. Our results revealed a dose‐dependent correlation between LVV‐H7 quantities and alcohol levels. Mass spectrometry‐based analyses identified LVV‐H7's protein‐binding targets in CNS tissues of addicted rats and the enzymes responsible for their degradation. These findings highlight the significant role of LVV‐H7 in the mechanisms underlying alcohol dependence and indicate the potential role of hemorphin as a therapeutic target.