European Journal of Pharmacology

We have examined how ibogaine may enhance synaptic plasticity and neural repair. Extracellular efflux analysis showed that ibogaine (3, 10 or 30 M) produced a rapid (<5 minutes) and concentration-dependent suppression of mitochondrial function and glycolysis in mouse cortical neurons. Cell-based imaging demonstrated this metabolic inhibition was preceded by an elevation of the mitochondrial membrane potential and followed by increased mitochondrial reactive oxygen species levels. Like ibogaine, which blocks potassium channels, mitochondrial Kv1.3 channel (mitoKv1.3) inhibitors produce concordant changes over a similar timeframe. Following treatment with ibogaine (3, 10 or 30 M) for 4 hours, a marked concentration-dependent rebound of energy production occurred 20 hours later suggestive of metabolic preconditioning. Indeed, proteomic profiling showed that oral ibogaine (100 mg/kg) administration to female mice produced changes in spinal cord protein abundance indicative of increasing metabolic stress from 0.25-24 hours that resolved by 72 hours. This was accompanied by activation, inhibition and reactivation of synaptic plasticity and neural repair signaling pathways at 0.25, 4-24 and 72 hours, respectively. Hence, by inducing transient metabolic stress, ibogaine may re-open a neurodevelopmental window characterized by enhanced synaptic plasticity and neural repair. Ibogaine binds with high affinity to the sigma-2 receptor. Like mitoKv1-3 inhibitors and sigma-2 receptor ligands, ibogaine transiently elevated AMP-activated protein kinase (0.25 hours) and temporally suppressed mechanistic target of rapamycin and lipid synthesis pathways (0.25-24 hours) implicated in enhanced synaptic plasticity and neural repair. These findings suggest ibogaine rewires and repairs neural circuits by a metabolic preconditioning mechanism, perhaps involving mitoKv1.3 and the sigma-2 receptor.

Allosteric modulation of G protein-coupled receptors (GPCR) is a rapidly advancing area of drug discovery with considerable therapeutic potential. In this study, we used various bioluminescence resonance energy transfer (BRET) assay configurations to investigate the differential activity of LY3154207, a dopamine D1 receptor (D1R)- positive allosteric modulator (PAM), in potentiating D1R-mediated signaling pathways. Our data showed that LY3154207 demonstrated clear bias toward {beta}-arrestin recruitment over G-protein engagement. Among the G-protein subtypes, LY3154207 preferentially potentiated Gs signaling induced by DA. Interestingly, when tested for its effect on the Gs-selective D1R agonist DHX and the Golf-selective agonist TAV, LY3154207 further enhanced the selectivity of these compounds, suggesting a probe-dependent effect. We also studied the structural mechanism underlying this subtype selectivity and found that W123 and R130 in the intracellular loop 2 (ICL2) of D1R were crucial for the activity of LY3154207. Furthermore, the N domain of the G-protein appeared to make minor contributions to this G-protein subtype selectivity of LY3154207. Lastly, our data demonstrated that LY3154207 induced cAMP production in the absence of the orthosteric ligand, indicating that this compound is an ago-PAM.

Neuropathic pain involves spinal microglial activation and metabolic changes.Forsythoside B (FB) has anti-inflammatory effects, but its role in neuropathic pain and microglial glycolysis remains unclear. We investigated the effects and mechanisms of FB in mice with chronic constriction injury (CCI) and in LPS-stimulated BV2 microglia.FB reduced mechanical allodynia and thermal hyperalgesia in CCI mice. FB also reduced the spinal levels of HIF-1, HK2, PKM2, LDHA, and CD86. It decreased the proportion of IBA1+/CD86+ cells and the levels of IL-1{beta}, IL-6, and TNF-. In LPS20 stimulated BV2 microglia, FB reduced glycolysis-related proteins, proinflammatory markers, and cytokine release. FB also reduced glycolytic activity and partly restored basal mitochondrial respiration. FB did not change Hif1a mRNA levels. However, it Manuscript Click here to access/download;Manuscript;Manuscript.docx increased HIF-1 ubiquitination and promoted its proteasome-dependent degradation. HIF-1 overexpression partly reversed the effects of FB on glycolytic enzymes, CD86 expression, and proinflammatory cytokine production. Immunoprecipitation followed by mass spectrometry and UbiBrowser analysis identified USP7 as a candidate HIF27 1-associated deubiquitinase. Molecular docking and cellular thermal shift assays supported a possible interaction between FB and USP7. FB reduced the association between USP7 and HIF-1. USP7 knockdown produced effects similar to those of FB on HIF-1 ubiquitination and downstream glycolytic and inflammatory responses.Overall, FB alleviated neuropathic pain and reduced proinflammatory microglial responses. These effects may involve the promotion of HIF-1 degradation through modulation of the USP7-HIF-1 regulatory axis.

Autism spectrum disorder (ASD) is a common neurodevelopmental disease with no currently effective treatments. In this study, Xenon (Xe), a noble gas used clinically as an anesthetic and a neuroprotectant, has been investigated for its potential therapeutic effects in ASD. Two genetic ASD mouse models (Mef2c mutant and Shank3-/- mice) were exposed to a low concentration of xenon (25%) mixed with oxygen (30%) and balanced with nitrogen for a single exposure of 30 min or for 10 min per day for 10 days. These Xe exposure paradigms rescued ASD-like behaviors in both male and female mice. The behavioral improvements persisted for up to 10 days following termination of the 10-day exposure paradigm. Mechanistically, Xe reduced glutamic acid decarboxylase expression in the inhibitory neurons (verified with RNAseq) of the paraventricular thalamic nucleus (PVT) and decreased GABA release during social interaction. Targeted infusion of the GABAA receptor agonist muscimol into the PVT abolished the Xe-mediated behavioral improvements. Reduced GABAergic transmission following Xe exposure increased PVT glutamatergic neuronal activity. Chemogenetic inhibition of these neurons eliminated the therapeutic effects of Xe, whereas chemogenetic activation mimicked the Xe-induced behavioral improvements. Furthermore, opto-inhibition of PVT glutamatergic projections to the central amygdala (CeA) blocked Xe-mediated behavioral improvement. Opto-activation of the PVT-CeA glutamatergic circuit reversed ASD-like behaviors. These findings demonstrate that Xe ameliorates ASD-like phenotypes in mouse models by modulating the PVT Glu-CeA circuit, supporting Xe as a novel potential therapy for ASD.

CC10137 is a first-in-class peripherally restricted 2A-adrenergic receptor (2AAR) agonist with broad-spectrum analgesic efficacy and a favorable safety profile. Systematic exploration of the chemical space surrounding first-in-class leads is important for defining series boundaries and guiding continued optimization, but conventional analogue-by-analogue medicinal chemistry samples only a small fraction of the accessible structural space. Here, we used a scaffold-seeded enumeration strategy to expand the chemical space surrounding CC10137 from four SAR-informed seed compounds comprising CC10137 and three closely related structural variants. Application of predefined medicinal chemistry transformation rules in StarDrop generated a virtual library of 16,601,163 unique structures. Morgan fingerprint-based principal component analysis indicated that the library occupied a highly multidimensional structural space involving variation in scaffold substitution, peripheral functional groups, and side-chain composition. A retrospective comparison set of 43 compounds independently designed and experimentally characterized in the earlier CC10137 program represented only approximately 0.00026% of the 16.6-million-member library, yet all 43 were recovered as exact structural matches. Three compounds selected directly from the virtual library retained 2AAR binding affinity and agonist potency below 25 nM. Five representative compounds further showed significant anti-allodynic effects in the in vivo spared nerve injury model, with inhibition rates ranging from 39.3% to 55.7%. These findings support scaffold-seeded computational enumeration as a practical strategy for systematic chemical-space mapping around a first-in-class lead and for identifying additional pharmacologically active structural regions for further optimization.

Background: Parkinson's disease is a progressive neurodegenerative condition, often associated with motor complications, neuropsychiatric symptoms, and increased care costs in advanced stages. Neuromodulation, especially deep brain stimulation, represents a therapeutic alternative for selected patients. Objective: To characterize the clinical, epidemiological, therapeutic, and economic profile of patients with Parkinson's disease followed at a tertiary center and to estimate the proportion of individuals eligible for neuromodulation. Methods: A cross-sectional descriptive study included 4,060 patients with idiopathic Parkinson disease followed from January 2022 to December 2025. Demographic data, clinical characteristics, functional scales, therapeutic regimen, eligibility criteria for neuromodulation, and cost-effectiveness estimates were analyzed. Comparisons with data from the literature were performed using appropriate statistical tests, considering a significance of p<0.05. Results: The sample was predominantly male, with a median age of 69 years, and a median time of evolution of 8 years. Motor complications occurred in 58.4% of the patients, a frequency higher than that described in general populations. In all, 893 patients were considered eligible for neuromodulation, corresponding to 22.0% of the sample. The economic analysis estimated a reduction in annual costs after neuromodulation, with an average saving of R$ 8,247 per patient/year and an incremental cost-effectiveness ratio of R$ 46,505 per QALY. Conclusion: The study population presented a clinical profile compatible with advanced Parkinson's disease, a high frequency of motor complications and a significant proportion of patients potentially eligible for neuromodulation. The data suggest a possible clinical and economic benefit of the structured incorporation of this therapeutic strategy.

Computational safety evaluation of phytochemical libraries commonly relies on models trained on experimentally tested compounds and applied to much larger and chemically diverse collections. An important but often overlooked question is whether predicted compounds are adequately represented within the experimental chemical space underlying these models. Here, we examined this question for the Indian Medicinal Plants, Phytochemistry and Therapeutics (IMPPAT) database using experimentally characterized datasets for three anti-target endpoints: hERG blockade, cytochrome P450 (CYP) inhibition, and pregnane X receptor (PXR) induction. After structure standardization, 14,956 unique IMPPAT compounds were compared with 8,877 hERG, 4,905 CYP, and 4,138 PXR reference compounds using consensus nearest-neighbor similarity based on Morgan and atom-pair fingerprints. At a Tanimoto similarity threshold of 0.80, only 0.92%, 0.30%, and 0.46% of IMPPAT compounds had close measured analogs in the hERG, CYP, and PXR datasets, respectively. Relative to the internal nearest-neighbor distributions of the reference datasets, a typical IMPPAT compound lay near the 1st percentile, indicating substantial chemical-space separation. Compounds with close experimental analogs also showed distinct molecular characteristics, with descriptor-based logistic regression yielding cross-validated AUC values of 0.77-0.80. Plant-level enrichment was markedly reduced after excluding widely distributed metabolites and was further restricted when the nearest measured analog was required to have pIC50 or pEC50 [&ge;] 5. The remaining signals were concentrated in a limited number of taxa, including Rauvolfia, Sinopodophyllum/Dysosma, Cinchona, and Catharanthus roseus. Overall, most IMPPAT phytochemicals lack close structural representation among currently measured anti-target compounds. Computational safety predictions for these molecules should therefore be interpreted as extrapolations and accompanied by explicit measures of structural support. Absence of a close experimental analog should be regarded as a gap in available evidence rather than evidence of safety.

Brugada syndrome (BrS) is an inherited arrhythmia disorder with limited drug therapy, quinidine being the principal agent. Loss-of-function variants in SCN5A reduce the cardiac sodium current (INa), but the arrhythmogenic imbalance also depends on the transient outward potassium current (Ito). Here we generated human induced pluripotent stem cell-derived cardioids with right-ventricular identity from a patient carrying an SCN5A frameshift variant (p.A665Gfs*16) and characterised them by patch-clamp and optical mapping. BrS cardioids showed 60% lower peak INa, more than doubled Ito, 38% slower conduction and 76% longer spontaneous cycle length. We then tested AR-788, a benzylaminothiazole-benzimidazole carboxamide of the ARumenamide class. In wild-type (WT) cardiomyocytes AR-788 inhibited Ito concentration-dependently (12%, 30% and 42% at 5, 10 and 20 uM; extrapolated IC50 25.4 uM), and at 10 uM it returned BrS Ito to the level of untreated WT cells (21.71 vs 21.48 pA/pF, p = 0.9716) without reducing INa. It also reduced the rapid delayed-rectifier current (IKr) tail current by 40%, a liability requiring formal proarrhythmia profiling. These data identify AR-788 as an Ito-suppressing member of the ARumenamide class and provide proof of concept that a small molecule can correct the potassium-current excess in a human BrS model.

Background Opioid-free anaesthesia (OFA) has emerged as an alternative to opioid-based anaesthesia (OBA), but its benefit over OBA for postoperative quality of recovery (QoR) remains unclear. To address this question while limiting variability inherent in clinical studies, such as analgesic regimens and patient psychosocial factors, we investigated the effects of OFA versus OBA on postoperative recovery in a controlled preclinical mouse model. Methods Adult male and female C57BL/6J mice underwent laparotomy or sham procedures under isoflurane anaesthesia, and were randomly assigned to saline (control), fentanyl (OBA), or dexmedetomidine (OFA) as intraoperative analgesic adjuncts. All mice received multimodal postoperative analgesia, including carprofen. We adapted a standardised multidimensional recovery model using six behavioural endpoints reflecting human QoR domains: body weight, food intake, locomotor activity, mechanical sensitivity, sucrose preference, and social interaction. These endpoints were assessed on postoperative days 1, 2, 3, and 7. Plasma inflammatory cytokine and brain-derived neurotrophic factor (BDNF) concentrations were also measured in parallel as potential biological correlates of recovery. Results Over the study period, we observed no treatment effect across behavioural endpoints in laparotomised mice, including body weight (P=0.157), food intake (P=0.884), locomotor activity (P=0.864), mechanical sensitivity (P=0.628), sucrose preference (P=0.615), and social interaction (P=0.442). Composite QoR scores did not differ between OFA and OBA groups (P=0.569), with no differences in postoperative circulating inflammatory cytokine or BDNF concentrations. Conclusions Dexmedetomidine-based OFA and fentanyl-based OBA produced similar postoperative behavioural recovery, circulating inflammatory cytokine and BDNF trajectories in laparotomised mice receiving multimodal postoperative analgesia.

Background: Huntington's disease (HD) is an inherited neurodegenerative disorder primarily associated with motor and psychiatric manifestations. No disease-modifying treatment currently exists, with vesicular monoamine transporter type-2 inhibitors (VMAT2i's) being the only FDA-approved therapy for motor features in HD. Previous studies evaluated the antichorea effects of VMAT2i's but did not address its effects on non-choreiform features. Objectives: This study aimed to characterize the effect of VMAT2i's on hyperkinetic, hypokinetic and total hypokinetic subscores of the UHDRS motor assessment in patients with motor-manifest HD from the Enroll-HD research platform. Methods: Data from 622 participants were analyzed. Linear mixed effects models were constructed to compare the rates of change of choreiform and non-choreiform motor scores before and after the initiation of a VMAT2i. We calculated and plotted the direction, magnitude and significance of VMAT2i administration on the rates of change of motor subscores. A similar analysis was performed investigating the effect of antipsychotic medications on motor subscales in HD. Results: VMAT2i's reversed progression of hyperkinesis but significantly increased the rates of change in the hypokinetic and total hypokinetic subscores. Antipsychotics also displayed efficacy in reversing progression of chorea but did not significantly influence progression of hypokinesis. Conclusions: The initiation of VMAT2i's was associated with an improvement in hyperkinesis but was associated with worsening of other motor features of HD. Hypokinesis increases progressively in HD and is correlated with functional impairment and global decline. Therefore, the use of VMAT2i's to treat motor features in HD should be a nuanced decision, considering its multipronged impact.

Background: Erythritol and xylitol, naturally present in fruits and vegetables, are widely used as alternative sweeteners with minimal glycemic and insulinemic effects. Both are also produced endogenously, with elevated plasma concentrations reported in metabolic disorders and cardiovascular disease. Recently, two interventional studies reported enhanced platelet aggregation after acute oral intake of erythritol or xylitol, raising concerns about potential prothrombotic effects. We investigated whether acute exposure to erythritol or xylitol increases platelet reactivity in healthy individuals. Methods: We conducted a randomized, single-blind, crossover study in 14 healthy participants who received erythritol (50 g), xylitol (33.5 g), or water. Platelet aggregation was assessed ex vivo, together with circulating markers of platelet activation (P-selectin), endothelial activation (sVCAM-1), and coagulation (D-dimer), as well as plasma erythritol and xylitol concentrations. Complementary in vitro experiments were performed using platelet-rich plasma from 11 healthy participants exposed to increasing concentrations of erythritol or xylitol, followed by assessment of platelet aggregation. Results: Despite substantial increases in circulating erythritol and xylitol concentrations following oral intake, neither erythritol nor xylitol increased ex vivo platelet aggregation compared with water. Consistently, no relevant changes were observed in P-selectin, sVCAM-1, or D-dimer concentrations. Direct in vitro exposure of platelet-rich plasma to increasing concentrations of erythritol or xylitol likewise did not enhance platelet aggregation. Conclusions: In healthy individuals, acute oral intake of erythritol or xylitol did not increase platelet aggregation or circulating markers of platelet activation, endothelial activation, or coagulation. These findings were supported by in vitro experiments showing no direct effect of erythritol or xylitol on platelet aggregation. Our results do not support an acute platelet-activating effect of erythritol or xylitol under the conditions studied. Registration: URL: https://clinicaltrials.gov/study/NCT04966299; Unique identifier: NCT04966299.

This study aims to identify potential inhibitors of the Ag85C enzyme from Mycobacterium tuberculosis through primary docking, pharmacophore modelling, and ADME/pharmacokinetics analysis. Delamanid and Pretomanid emerged as the top hits in primary docking, demonstrating strong binding affinities and interactions with key active site residues. A robust pharmacophore model was developed, identifying essential features for binding and used to screen 4254 antituberculotic compounds, yielding three promising candidates: F0314-0040, F0398-0505, and F0349-2716. These compounds exhibited high binding affinities in major docking studies. ADME and pharmacokinetics analysis revealed favorable Drug likeness and absorption profiles, supporting their potential as effective antituberculotic agents. The integration of computational methods provided a comprehensive approach for rational drug design.

Hypertriglyceridemia is commonly managed with lipid-lowering drugs such as statins; however, adverse effects, dose intolerance, and financial barriers may limit their use. Therefore, affordable and potentially safer plant-derived alternatives warrant investigation. This study evaluated the lipid-lowering effects of ethanol extracts of Fucus vesiculosus and Phytolacca berry, administered individually or in combination, in mice fed a butter-enriched diet for 12 weeks. Forty-eight mice were randomly assigned to six groups: normal control (Group 1), butter control (Group 2), statin control (Group 3), Fucus vesiculosus extract (Ext-1; Group 4), Phytolacca berry extract (Ext-2; Group 5), and the combined extracts (Group 6). Body weight, organ-to-body-weight ratios, serum lipid parameters, and histopathological changes were assessed. Group 3 showed the lowest final body weight, while Group 6 demonstrated a comparable body-weight trajectory. Organ-to-body-weight ratios varied among groups, with Group 3 generally showing the highest values and Group 6 comparatively lower ratios for several organs. Group 5 had the lowest total cholesterol concentration, followed by Group 3, whereas Group 6 showed cholesterol levels comparable to the normal control and statin groups. Notably, Group 6 exhibited the lowest serum triglyceride concentration (129.9 mg/dL). Histopathological examination revealed relatively mild hepatic alterations and limited vascular plaque formation in Group 6. The combined extracts demonstrated favorable effects on body-weight gain and serum lipid profiles, particularly triglycerides, with comparatively mild histopathological changes. Further mechanistic, dose-response, toxicity, and long-term studies are warranted before clinical application can be considered.

Ogerin, a positive regulator of GPR68, reduces infarct volume and attenuates blood-brain barrier (BBB) leakage post transient middle cerebral artery occlusion (tMCAO). These data support the potential use of Ogerin for ischemic protection. For therapeutic interventions, tissue distribution, kinetics, and brain penetration are important characteristics for a compound. For these reasons, we performed liquid chromatography-mass spectrometry (LC-MS) analysis of Ogerin in mice. At 3 hours following intraperitoneal (IP) injection, liver exhibited highest level of Ogerin among all major organs assessed. We further analyzed time-dependent changes in Ogerin concentration in serum following intravenous delivery. Brain Ogerin level was ~140 ng/g at 2 hour and ~0.06ng/g at 24 hours. The brain-to-serum ratio of Ogerin was ~0.6 at 5 hr. To determine the effect of Ogerin on signaling, we collected samples 24 hours after tMCAO with or without Ogerin delivered and performed Western blotting. Consistent with the diminished level of Ogerin in brain at 24 hour, tMCAO increased similar changes in phosphorylation of PKA substrates and PKC substrates in vehicle- and Ogerin-treated groups. The pharmacokinetic data suggests that Ogerin is effective mainly during acute hours after injection. This finding generates important insights on the design of effective protocol for Ogerin delivery to potentiate GPR68 function in vivo.

HIV infection significantly elevated the odds of cardiovascular diseases, including myocardial fibrosis. We aimed to determine the difference of late gadolinium enhancement (LGE), extracellular volume (ECV), T1, and T2 using cardiac magnetic resonance imaging (CMR) in patients living with HIV (PLWH) and healthy controls. The databases Scopus, Web of Science, Embase, and PubMed were searched systematically using relevant keywords. STATA version 17 was used for meta-analysis using random effect and fixed effect models for heterogeneous and non-heterogeneous analyses. An overall number of 13 studies were included in the current analysis involving 1425 PLWH and 766 healthy controls. PLWH showed significantly higher LGE (OR: 5.47, 95% CI: 1.90-15.64, p<0.001) and ECV (mean difference: 1.46, 95% CI: 0.21-2.71, p=0.02) compared to controls. However, differences in Left Ventricular Ejection Fraction (LVEF) were not significant (mean difference: -1.41, 95% CI: -2.81- -0.01, p=0.05). There were no meaningful disparities in pro B-type natriuretic peptide (BNP) values (mean difference: 8.67, 95% CI: 0.04-17.29, p=0.05) or T2 values (mean difference: 0.91 ms, 95% CI: -1.04-2.86, p=0.36), but T1 values were significantly higher in PLWH (mean difference: 13.78 ms, 95% CI: 9.16-18.40, p<0.001). In meta regression, LGE was correlated with nadir CD4 (z=-3.41, p-value<0.001). In addition, ECV was correlated with white race (Z=-3.97, p-value<0.001), Hepatitis C (Z=-2.08, p-value=0.037), and smoking (Z=2.05, p-value=0.041). HIV is related to a significantly elevated rate of myocardial fibrosis, and factors such as lower nadir CD4, white race, hepatitis C, and smoking were correlated with hepatitis C. Keywords: Myocardial fibrosis, HIV, AIDS, Cardiovascular diseases, Heart failure

Introduction: Mast cells are central effectors of IgE-mediated allergic responses and reside in barrier tissues, where they encounter diverse environmental compounds. How naturally occurring bioactive compounds influence mast cell function under resting versus allergic conditions remains poorly defined. Methods: We compared the effects of cholera toxin, aconitine, and sennoside A on viability, degranulation, and cytokine production in murine bone marrow-derived mast cells. We then examined the acute physiological effects of oral sennoside A in an ovalbumin-induced mouse model of food allergy. Results: None of the compounds reduced mast cell viability at the concentrations tested. Sennoside A, but not cholera toxin or aconitine, induced modest degranulation in resting mast cells without increasing TNF- or IL-6 secretion. In contrast, sennoside A markedly suppressed IgE-dependent antigen-induced degranulation, TNF- and IL-6 secretion, and Il1b expression. Acute oral sennoside A induced dose-dependent diarrhea and hypothermia and increased colonic Tnfa, Il1b, Il33, and Hdc expression. In allergic mice, sennoside A attenuated allergen-induced hypothermia, reduced duodenal Tpsab1 expression, and decreased circulating total IgE, OVA-specific IgE, and OVA-specific IgG1, while increasing Il5 expression. Conclusion: Sennoside A differentially regulates mast cell responses according to activation state and attenuates features of experimental food allergy. These findings identify a previously unrecognized immunomodulatory effect of sennoside A on IgE-driven mast cell activation. However, the mechanisms and the contribution of mast cells to the in vivo phenotype remain to be defined.

Animal studies primarily rely on human monitoring for health and behavioral outcomes. The presence of a human, however, can induce stress and potentially alter experimental results. We sought to answer whether human observation alone is enough to change experimental outcomes and obscure the effect of interest. Our automated home-cage behavioral phenotyping system provided the ideal platform to test this hypothesis. Two cohorts received semaglutide (0.03 mg/kg, intraperitoneally) on separate consecutive days. The first cohort was recorded without inspection after dosing; the second underwent a brief visual health check with no handling. Recordings from the checked cohort on the preceding day, without injection or inspection, provided a matched baseline. A single brief check produced large, time-locked changes across the behavioral repertoire. The changes began before the cage door was opened, indicating a response to experimenter proximity. In addition to adding variance, the semaglutide-treated animals' behavior during observation was more similar to the no-injection baseline than to the semaglutide/no-check reference, transiently erasing the drug phenotype. Brief human observation is therefore not a neutral measurement operation; over the minutes surrounding it, it is a perturbation in itself that is large enough to mask the drug effect it is meant to record.

BackgroundSerotonergic signaling plays an important role in the modulation of absence seizures (ASs), and activation of serotonin 2A receptors (5-HT2ARs) with TCB-2 suppresses spontaneous absence seizures (ASs) in Genetic Absence Epilepsy Rats from Strasbourg (GAERS). Lisuride is a pharmacologically complex serotonergic and dopaminergic ligand with low 5-HT2AR signaling efficacy and a receptor profile distinct from that of TCB-2. We therefore investigated its effects on spontaneous ASs and the contribution of 5-HT2ARs to its actions. MethodsThe effects of systemic lisuride (0.1 and 0.5 mg/kg) on spontaneous ASs were examined in freely moving GAERS over 120 min by quantifying time spent in seizure, mean seizure duration and seizure number. The contribution of 5-HT2ARs was investigated by administering lisuride (0.5 mg/kg) following pretreatment with the selective 5-HT2AR antagonist MDL11,939 (0.5 mg/kg). ResultsLisuride produced marked dose- and time-dependent effects on ASs. At 0.1 mg/kg, lisuride elicited modest pro-absence effect. In contrast, 0.5 mg/kg produced a pronounced biphasic response, with a marked reduction in seizure activity during the first 40 min, followed by rebound increase during the second hour. The early suppression involved reductions in both seizure number and duration, whereas the delayed pro-absence effect was predominantly associated with prolonged ASs. MDL11,939 did not prevent the early seizure suppression but blocked the increase in seizure duration while producing a transient increase in seizure number. ConclusionsLisuride is a dose- and time-dependent bidirectional modulator of ASs in GAERS. The persistence of the profound early anti-absence effect during 5-HT2AR blockade indicates that this response does not require 5-HT2AR activation, whereas the modification of the delayed response by MDL11,939 supports a 5-HT2AR-dependent component in the later phase. These findings distinguish lisuride pharmacologically from TCB-2 and suggest that its biphasic effects arise from the dynamic engagement of multiple receptor mechanisms, potentially including dopaminergic signaling.

The cytokine FL and its receptor, Fms-like tyrosine kinase 3 (FLT3), contribute to chronic pain and to the maladaptive effects of morphine but the intracellular mechanisms underlying these effects remain incompletely understood. Here, we investigated the contribution of the Raf-MEK-ERK pathway to FLT3dependent nociceptive signaling and to the modulation of morphine analgesia. Using HEK293T cells expressing human or mouse FLT3, primary dorsal root ganglion (DRG) neurons, and rodent models, we examined ERK activation, TRPV1 sensitization, and behavioral responses following FLT3 activation by its ligand, FL. FL induced concentration-dependent ERK phosphorylation through FLT3, while pharmacological inhibition of FLT3, Raf, or MEK reduced this response. In primary DRG neurons, MEK inhibition attenuated FLinduced potentiation of capsaicin-evoked calcium responses, supporting a role for MEK-ERK signaling in TRPV1 sensitization. In vivo, intrathecal FL increased ERK phosphorylation in DRGs and induced mechanical hypersensitivity, both of which were reduced by Raf or MEK inhibition. In FLT3/MOR-expressing cells, morphine potentiated FL-induced ERK activation, an effect reduced by naloxone and abolished by FLT3 inhibition. In rats, MEK inhibition prevented the FL-induced reduction of morphine analgesia and subsequent mechanical hypersensitivity. Together, these findings identify Raf-MEK-ERK signaling as an important downstream pathway linking neuronal FLT3 activation to nociceptor sensitization and impaired morphine analgesic efficacy.

Chemobrain, characterized by cognitive dysfunction, has emerged as a significant health concern following cancer treatment. Doxorubicin, an FDA-approved chemotherapeutic agent, is widely used to treat various cancers. However, its adverse effects raise concerns regarding toxicity in non-cancerous cell types. Microglia, the resident immune cells of the brain, play a central role in maintaining neural homeostasis. Despite this, the mechanisms by which microglia become dysfunctional following doxorubicin exposure remain poorly understood. Understanding the transcriptomic alterations induced by doxorubicin in microglia could provide critical insights into mechanisms underlying its neurotoxic effects. In this study, the transcriptomic response of human microglia to doxorubicin using mRNA sequencing combined with bioinformatic analysis was investigated. Exposure to doxorubicin significantly altered microglial morphology, promoting a shift toward a process-bearing phenotype in human HMC3 cells. This phenotypic change was accompanied by elevated levels of DNA damage and was associated with the induction of cellular senescence. At the gene regulation level, the Illumina-based transcriptomic analysis provided 25,834 gene expression profiling in which 5,669 were differentially expressed. The future analyses revealed that 3,431 (upregulated) and 2,238 (downregulated) were differentially expressed under the treatment of doxorubicin. Genes associated with the p53 signaling pathway and inflammatory responses were upregulated, whereas genes involved in translation, DNA replication, and cell-cycle progression were downregulated. This transcriptional dysregulation was accompanied by differential expression of key transcription factors. This study provides transcriptomic evidence elucidating the genotoxic response to doxorubicin in microglial cells, offering mechanistic insights into chemobrain and highlighting key molecular pathways as potential targets for therapeutic intervention.