Search Results (691)

The melon fly, Zeugodacus cucurbitae (Coquillett), is a destructive tephritid pest of cucurbit crops, and neonicotinoids remain important tools for its management. Although neonicotinoids primarily target nicotinic acetylcholine receptors (nAChRs), their possible effects on acetylcholinesterase (AChE)-mediated cholinergic homeostasis in Z. cucurbitae remain poorly understood. In this study, we molecularly characterized the Z. cucurbitae Ache gene and evaluated its expression and functional contribution under dinotefuran, acetamiprid, and thiamethoxam stress. Bioinformatics analyses confirmed conserved cholinesterase features, including the FGESAG catalytic motif, catalytic triad, choline-binding site, oxyanion hole, and conserved disulfide-bond residues. Temporal and tissue-specific expression profiling showed high Ache transcript abundance in eggs, third-instar larvae, and adult heads. Larval exposure to LC₅, LC₂₀, and LC₅₀ concentrations of the three neonicotinoids caused dose- and time-dependent mortality and significantly induced Ache expression, with dinotefuran producing the strongest transcriptional response. Parental exposure also impaired F₁ fecundity, hatchability, larval survival, and adult emergence, with acetamiprid and thiamethoxam causing stronger transgenerational effects than dinotefuran. Oral RNAi significantly increased larval susceptibility upon re-exposure to neonicotinoids after 72 h. These findings indicate that Ache contributes to cholinergic stress response and susceptibility modulation in Z. cucurbitae, supporting its possible potential as an RNAi target for integrated pest management (IPM). However, practical utility at the field level requires further evaluation. Full article

Molecular docking in silico techniques were used to assess the interactions between several drugs used in the treatment of Alzheimer’s disease (AlzD) with neuronal receptors and with tryptophan and glycolytic pathway enzymes. AlzD drugs believed to act by inhibiting acetylcholinesterase (AChE) docked to that enzyme, whereas other drugs did not. No docking was observed to the nicotinic acetylcholine receptor (α-7-nAChR). All the drugs tested docked to the kainic acid receptor for glutamate, whereas donepezil, galantamine, tropisetron and N-acetylcysteine docked to the glutamate-NMDA receptor, but none docked to the glutamate-AMPA receptor. Two compounds docked to GABA receptors. Since the kynurenine pathway of tryptophan metabolism has been linked to AlzD, docking was examined with its various enzymes. Docking to tryptophan-2,3-dioxygenase (TDO2), indoleamine-2,3-dioxygenase-1 (IDO1) and 2-amino-3-carboxymuconic acid-6-semialdehyde decarboxylase was seen with most of the AlzD drugs. Donepezil docked to kynurenine monooxygenase, while rivastigmine, memantine and tropisetron docked to kynurenine aminotransferase-2. There was limited docking to the aryl hydrocarbon receptor and glycolytic enzymes, whereas most drugs docked to phosphoenolpyruvate carboxykinase (PEPCK). Despite their strong docking ability to IDO1 and TDO, none of the compounds tested inhibited their enzyme activity in an assay of kynurenine production. This pilot study highlights the varied pharmacological profile of drugs used in AlzD and suggests that a detailed examination of their functional effects should be considered to assist understanding of their different profiles at on- and off- target sites in human treatment. Full article

Nereistoxin (NTX) and its derivative insecticides cartap and monosultap have been used for decades to control lepidopteran pests by targeting nicotinic acetylcholine receptors (nAChRs). Unlike neonicotinoid agonists that induce excitatory neurotoxicity, nereistoxin insecticides act as antagonists, blocking cholinergic neurotransmission. However, the molecular target and mechanism of action of these compounds remain incompletely understood. Here, we elucidated the mode of action of cartap and monosultap in Drosophila melanogaster through integrated genetic and computational approaches. Bioassays with Drosophila nAChR subunit mutants demonstrated that the α6 subunit is critically required for insecticidal activity of both compounds, with α6 knockout conferring approximately 10-fold resistance to monosultap and 7-fold resistance to cartap. Molecular docking of protonated NTX into an α6 homopentameric channel model revealed a “dual-anchor” blocking mechanism: the protonated amine forms electrostatic interactions with residue Glu267, while the dithiolane ring creates steric hindrance at residue Thr270. Pore diameter measurements showed an optimal binding cavity of 5.96–6.22 Å in the 267–270 region, narrowing dramatically to 1.64 Å at the deep gate (Ser278), explaining how NTX binding physically occludes the channel. Collectively, these results identify α6-containing nAChRs as the primary target of nereistoxin insecticides and provide a structural framework for understanding channel blockade, with important implications for resistance monitoring and the development of next-generation channel-blocking insecticides. Full article

Merkel cell carcinoma (MCC) is an aggressive neuroendocrine skin malignancy characterized by high mortality and a rising incidence. Although immune checkpoint inhibitors have significantly improved patient outcomes, many patients exhibit primary or acquired resistance, frequently in the setting of an immunosuppressive tumor microenvironment (TME) enriched for myeloid populations. This review synthesizes current evidence and proposes a testable model in which nicotinic acetylcholine receptor (nAChR) signaling may intersect with tumor-associated macrophage (TAM) biology to reinforce immune exclusion in MCC. Direct MCC-specific evidence currently supports nAChR-subunit expression in tumor tissues and the association of CD163⁺/CD14⁺/S100A8⁺ myeloid populations with resistance to PD-1 pathway blockade; however, functional nAChR signaling in MCC tumor cells, TAMs, or dendritic cells has not yet been demonstrated. We therefore distinguish established MCC observations from mechanistic hypotheses extrapolated from macrophage biology, cholinergic anti-inflammatory signaling, and other cancer models. Within this framework, α7-nAChR signaling on TAMs may activate the cholinergic anti-inflammatory pathway and favor suppressive myeloid states, whereas α3- and α5-containing receptors detected in MCC tumor cells may represent tumor-cell-associated candidates for future mechanistic testing. By integrating evidence on TAM plasticity, spatial immune exclusion, and cholinergic signaling, we propose that the nAChR–macrophage axis is a rational but unproven therapeutic hypothesis that warrants systematic validation in MCC models. Full article

Digger wasps are solitary apoid wasps that excavate ground nests and use venom to paralyze insect prey. Recent phylogenetic analyses suggest that digger wasps belong to an ancient lineage of aculeate Hymenoptera and share an evolutionary ancestry with other venomous hymenopterans, including bees and ants. Although the venoms of ants, bees, and social wasps have been extensively studied, those of digger wasps remain poorly characterized in terms of their composition, molecular diversity, and biological activity. In this study, we investigated the venom of the digger wasp Cerceris japonica using integrated transcriptomic and proteomic analyses. We identified 19 toxin-like proteins and peptides, 14 non-toxin-associated components, and 11 novel peptides and proteins with no detectable similarity to known peptides and proteins. Among these, peptide Cj 2 exhibited insecticidal activity but showed no antimicrobial, hemolytic, or nicotinic acetylcholine receptor-modulating activities. These findings provide new insights into the molecular diversity and biological activities of digger wasp venom, expand our understanding of venom evolution in venomous hymenopterans, and serve as a framework for elucidating the conserved and lineage-specific features of hymenopteran venoms. Full article

Background: Cigarette smoking promotes persistent systemic alterations in COPD, yet the interplay among genetic susceptibility, oxidative stress, immune dysregulation, impaired control of persistent viral replication, and long-term outcomes remains incompletely understood. Methods: We conducted an observational study in 102 patients aged ≥70 years with severe-to-very-severe COPD undergoing pulmonary rehabilitation. Current smokers (n = 38) were compared with never/former smokers (n = 64). Analyses included Chr15q25 genotyping (rs16969968), oxidative stress biomarkers (tail intensity, 8-OHdG, MDA, and bilirubin), hematological and immunological parameters, α7nAChR expression, TTV load as a surrogate marker of immune competence, latent virus prevalence, and five-year survival assessed by multivariable Cox regression. Results: Current smokers exhibited significantly higher DNA damage (tail intensity, p = 0.001; 8-OHdG, p = 0.002), lower bilirubin levels (p = 0.031), increased neutrophil and CD4⁺ T-cell counts (p = 0.031 and p = 0.028, respectively), altered α7nAChR expression on CD4⁺ T cells (p = 0.030), and higher TTV load (p = 0.002) than never/former smokers. The rs16969968 AA genotype was more frequent among current smokers. In survival analyses, an elevated WBC count was independently associated with increased mortality risk (HR 1.12, 95% CI 1.01–1.23; p = 0.035), whereas higher bilirubin levels showed a protective association. TTV load, smoking status, and FEV1 were not independently associated with mortality. Conclusions: In severe-to-very-severe COPD, smoking is associated with a distinct biological profile characterized by enhanced oxidative DNA damage, systemic inflammation, immune remodeling, reduced antioxidant defenses, and impaired control of persistent viral replication. WBC and bilirubin emerged as the biomarkers most consistently associated with long-term outcomes. These findings support integrated biological profiling as a tool for risk stratification and precision-guided rehabilitation in advanced COPD. Full article

An 8-week feeding trial was conducted to investigate the regulatory effects of dietary chitosan oligosaccharide (COS), chlorogenic acid (CGA), and thymopeptide (TH) on the growth performance, antioxidant capacity, and metabolism of juvenile Rhinogobio ventralis. A control group (CON) and three treatment groups (COS, CGA, TH) were established, and the underlying molecular mechanisms were analyzed by transcriptomics and metabolomics. The results showed that dietary supplementation with COS, CGA, and TH significantly improved weight gain rate, specific growth rate, and feed utilization efficiency, with COS exhibiting the strongest growth-promoting effect. COS also significantly increased hepatic catalase and superoxide dismutase activities and decreased malondialdehyde content, indicating a marked antioxidant effect, whereas CGA and TH showed no significant effects on these parameters. Transcriptomic analysis revealed significant differences in gene expression profiles among the groups, with commonly enriched pathways including the FoxO signaling pathway, fatty acid biosynthesis, and nicotinate and nicotinamide metabolism. Metabolomic analysis showed that the three additives significantly reshaped the hepatic metabolic profiles: COS mainly activated anabolic metabolism, CGA predominantly suppressed metabolism, and TH exhibited bidirectional regulation, with bile secretion, neuroactive ligand–receptor interaction, and the Fc epsilon RI signaling pathway commonly enriched in all three groups. Integrative KEGG pathway analysis based on transcriptomic and metabolomic predictions further identified the FoxO signaling pathway and neuroactive ligand–receptor interaction as common targets shared by all three additives. In conclusion, COS, CGA, and TH improve the health status of R. ventralis through differential regulation of immune–metabolic networks. Among them, COS is the most suitable feed additive for growth promotion and antioxidant protection in this species. Full article

Little is known about how nicotinic signalling in human astrocytes may contribute to the functional neurotoxicity of compounds related to tobacco alkaloids and neonicotinoid pesticides. We generated a single-cell Ca²⁺-imaging assay in induced pluripotent stem cell (iPSC)-derived astrocytes, and profiled functional expressions of some neurotoxicologically relevant receptors. Responses to pharmacological tool compounds indicated the expression of nicotinic, muscarinic, purinergic, glutamatergic receptors and voltage-gated Na⁺/Ca²⁺ channels. Closer investigation of the nicotinic system, e.g., using the alpha7 nicotinic acetylcholine receptor (nAChR)-selective positive allosteric modulator PNU-120596 and alpha7-preferring agonist (AR-R17779) demonstrated that Ca²⁺ signals elicited by nicotine and neonicotinoids are dominated by alpha7 nAChRs and depend on the downstream activation of L-type Ca²⁺ channels and tetrodotoxin-sensitive Na⁺ channels. Crosstalk of nAChR activation/desensitization was not observed for the inflammatory response elicited by TNF or for activation of glutamatergic or purinergic signalling. However, pre-stimulation of nAChR by neonicotinoids significantly blunted the response to the neurotransmitter acetylcholine. Comparative experiments in the human neuronal cultures (LUHMES cells) revealed similar potency ranges and pharmacological fingerprints for several neonicotinoids and their human-relevant metabolites descyanothiacloprid and desnitroimidacloprid. The pesticide metabolites showed a high potency, compared with their respective parent compounds. After this basic system characterization, the hitherto data-poor pesticides cycloxaprid and flupyradifurone were comparatively profiled in astrocytic and neuronal test systems. They showed the typical features of alpha7 nAChR agonists. The disruption of cholinergic signalling in astrocytes suggests that neonicotinoids affect not only neurons in human brains. Therefore, future neurotoxicity screening approaches may need to consider astrocyte toxicity. Full article

Fast-channel genetic myasthenic syndromes (FCGMSs) are caused by genetic variants in muscle nicotinic acetylcholine receptor (AChR) subunits that reduce channel open times and impair neuromuscular transmission. Among these, the CHRNE p.P141L variant (εP141L) is associated with particularly severe disease. Here, we characterized a knock-in mouse model harboring the homologous p.P141L variant in Chrne (εP141L)—C57BL/6J-Chrne^em1H/H made by the MRC GEMM program. Homozygous mutant mice fail to thrive, with early lethality (median survival of 16 days), closely recapitulating the severity observed in patients. Despite a preserved neuromuscular junction (NMJ) morphology and robust AChR expression, electrophysiological analyses revealed marked reductions in miniature and evoked endplate potential amplitudes and areas, accompanied by prolonged depolarization kinetics (contrary to expectations for AChR with reduced open times) and increased quantal content, indicative of impaired post-synaptic function with compensatory pre-synaptic adaptation. Notably, disease severity exceeded that of Chrne null mice, likely through competition with more functional g-subunit-containing fetal AChRs. Consistent with this, crossing εP141L mice with CHRNG-expressing mice provided little survival benefit. These findings demonstrate that dysfunctional AChR incorporation is more deleterious than receptor absence and highlight the critical role of subunit composition in sustaining neuromuscular transmission. Pharmacological enhancement of pre-synaptic release with 3,4-diaminopyridine partially improved synaptic parameters. In addition, the AChR-positive allosteric modulator DC-98 modestly improved neurotransmission. Thus, this mouse model provides a faithful platform for mechanistic studies and therapeutic development in FCGMS. Full article

PVP-stabilized silver nanoparticles (Ag NPs) were functionalized with sildenafil (Sil), leading to spherical NPs (Ag@Sil NPs) with a size of about 30 nm as observed through transmission electron microscopy and dynamic light scattering. Fourier-transformed IR spectroscopy confirmed the covering of the particles with Sil. The Ag@Sil NPs were incorporated into a 0.1 wt% ointment and tested for the treatment of acute anal fissures in a preliminary medical study involving 50 patients. Typical symptoms such as pain, bleeding, itching, and mass sensation were improved in the intervention group with no adverse effects. Molecular docking showed strong interactions with docking scores slightly above −10 kcal/mol between sildenafil and two different model complexes [Ag–Sil]⁺ for the Ag-bound sildenafil with either piperazine-N- or pyrazole-N-bound Ag⁺ ions and the muscarinic M2 and the nicotinic acetylcholine α3β4 receptor, which are both involved in anal sphincter regulation. All three showed superior binding compared with nitroglycerin and L-arginine. The residue analysis revealed a higher number of relevant interactions for the sildenafil and the two Ag⁺ complexes, compared to nitroglycerin and L-arginine, fully in line with the differences in the docking scores. Full article

Glucagon-like peptide-1 (GLP-1) receptor agonists, originally developed for type 2 diabetes and obesity, have recently attracted interest as potential modulators of addictive behavior. This narrative review summarizes current knowledge on the neurobiological basis, randomized controlled trials, and psychiatric relevance of GLP-1 analogs in substance use disorders. English-language articles available at the time of the search were reviewed between February and April 2026, with emphasis on topics most relevant to psychiatric practice. The literature suggests that GLP-1 signaling influences reward processing, cue reactivity, stress responses, relapse vulnerability, and executive control through actions in the gut–brain axis and mesocorticolimbic circuitry. Early clinical findings are most encouraging in alcohol-related outcomes, including reductions in alcohol cue reactivity, craving, alcohol self-administration, and some measures of heavy drinking, whereas evidence in nicotine dependence is mixed and appears more consistent for limiting post-cessation weight gain than for improving abstinence itself. Evidence for other substance use disorders remains preliminary. Across randomized controlled trials, interpretation is limited by small sample sizes, short follow-up, heterogeneous endpoints, and selective populations. In addition, psychiatric and behavioral safety requires careful attention, particularly regarding rapid weight loss, excessive appetite suppression, restrictive eating, dehydration, and psychological destabilization in vulnerable individuals. At present, GLP-1 receptor agonists should be regarded as promising but unproven adjunctive candidates in addiction psychiatry, warranting further rigorous trials, structured monitoring, and interdisciplinary collaboration. Full article

Chronic neuropathic pain, particularly diabetic neuropathic pain and postherpetic neuralgia, severely impairs patients’ quality of life due to their complex mechanisms and recurrent, long-term nature, making treatment challenging. This study aimed to evaluate the analgesic efficacy of α-conotoxin GeXIVA[1,2], a selective antagonist of the α9α10 nicotinic acetylcholine receptor (nAChR), in rat models of diabetic neuropathic pain and postherpetic neuralgia and investigate its associated physiological and pathological effects. GeXIVA[1,2] was administered continuously for three weeks, with mechanical hypersensitivity assessed through pain sensitivity tests, and behavioral assessments conducted to examine motor coordination and gait. Additionally, neural tissue structure and inflammation were analyzed. The results demonstrated that GeXIVA[1,2] significantly alleviated mechanical hypersensitivity in both diabetic neuropathic pain and postherpetic neuralgia models, with greater efficacy than gabapentin and no signs of tolerance. Behavioral tests indicated no significant effects on motor coordination or gait. Further analysis revealed that GeXIVA[1,2] reduced pro-inflammatory cytokine levels, decreased immune cell infiltration, and promoted repair of damaged nerve fibers. Overall, these findings suggest that GeXIVA[1,2] exerts analgesic effects through anti-inflammatory and neuroprotective mechanisms, providing a potential new therapeutic strategy for diabetic neuropathic pain and postherpetic neuralgia. Full article

Background/Objectives: Statins are currently one of the most commonly used cholesterol-lowering drugs. In recent years, in addition to their well-known effects on the cardiovascular system, statins have been shown to exert beneficial effects in the progression of various neuropsychiatric and neurodegenerative diseases. Methods: In this study, the effects of lovastatin on the function of α7-nicotinic acetylcholine (nACh) receptors expressed in rat hippocampus and Xenopus oocytes were investigated. Results: In whole-cell patch clamp studies in hippocampal neurons, 21-day chronic (20 mg/kg), but not acute (20 min), lovastatin treatment caused significant potentiation of choline (a selective agonist for α7 nACh receptors)-induced currents and choline-induced increases in GABA_A receptor-mediated currents. Further studies in Xenopus oocytes expressing human α7-nACh receptors indicated that 72 h pretreatment with lovastatin caused a significant increase in α7-nACh receptor function with an EC₅₀ value of 296 nM. Other statins, such as simvastatin and pravastatin, also potentiated α7-nACh receptors. Potentiation by lovastatin treatment was associated with a significant decrease in oocyte cholesterol content and was diminished by Go6983, an inhibitor of protein kinase C (PKC), suggesting that both decreased cholesterol levels and activation of PKC are involved in statin potentiation of α7-nACh receptors. Conclusions: In conclusion, our findings indicate that chronic lovastatin treatment potentiates the function of α7-nACh receptors in hippocampal neurons and in Xenopus oocytes expressing human α7-nACh receptors and provides important insights that could guide future efforts to design novel drugs targeting α7-nACh receptors. Full article

Acetylcholine (ACh) is an evolutionarily conserved neurotransmitter that is widely distributed in the central and peripheral nervous systems and plays essential roles in multiple physiological processes. This review summarizes the full biological cycle of ACh, including its synthesis, vesicular storage, release, degradation, and reuptake, and discusses the regulatory mechanisms underlying its functions in the nervous system and peripheral organs. Through nicotinic acetylcholine receptors (nAChRs) and muscarinic acetylcholine receptors (mAChRs), ACh is involved in central nervous system functions such as cognition, learning and memory, attention, arousal, reward, and decision-making, as well as peripheral processes including motor control, autonomic regulation, and immune modulation. In addition, ACh plays a pivotal role in the brain–body axis. At the central level, the nervous system regulates peripheral organ function through autonomic and neuroendocrine pathways. At the peripheral level, cholinergic signals derived from the enteric nervous system and immune cells convey information about the body’s internal state to the central nervous system through vagal and other afferent pathways, forming an important bottom-up regulatory network. Collectively, these findings indicate that ACh is not only a classical neurotransmitter but also a key molecular mediator of brain–body communication. A more comprehensive understanding of cholinergic signaling may provide new insights into physiological regulation and the pathogenesis of neurological, psychiatric, cardiovascular, and inflammatory diseases. Full article

Background: Peripheral neuropathy is a common and clinically heterogeneous neurological condition caused by metabolic, inflammatory, toxic, or traumatic factors and is associated with sensory deficits, neuropathic pain, motor impairment, and reduced functional capacity. Management remains challenging and often requires multimodal therapeutic approaches, as pharmacological monotherapy frequently provides incomplete symptom control. Objective: This narrative review explores the conceptual rationale for combining galantamine with iontophoresis and Black Sea brine-based therapy as a potential multimodal strategy for peripheral neuropathy management. Main Findings: Galantamine, a reversible acetylcholinesterase inhibitor and positive allosteric modulator of nicotinic acetylcholine receptors, has demonstrated neuroprotective, neuromodulatory, and anti-inflammatory properties in experimental settings. Iontophoresis may provide a non-invasive method for targeted local drug delivery while reducing systemic exposure. Black Sea brine, widely used in Bulgarian balneological and rehabilitation practice, has been associated with improved circulation, pain reduction, and neuromuscular support. The reviewed evidence suggests biologically plausible complementary mechanisms; however, no direct clinical studies evaluating the combined intervention were identified. Limitations: Current evidence is indirect and derived from separate investigations of galantamine, iontophoresis, and brine-based therapy, as well as heterogeneous historical and regional sources. Therefore, the proposed combination should be considered hypothesis-generating rather than evidence-established. Conclusions: The combination of galantamine, iontophoresis, and Black Sea brine represents a potentially interesting multimodal concept for peripheral neuropathy rehabilitation. Well-designed preclinical and clinical studies are required to determine safety, feasibility, optimal treatment parameters, and therapeutic efficacy. Full article