Search Results (241)

Alpha7 nicotinic receptors (α7-nAChRs) are implicated in many neurological disorders, but how they fold and assemble is not well understood. Unlike native α7-nAChRs, α7-5HT3 chimeras fold efficiently in HEK cells and do not require chaperones RIC3 or TMEM35A (NACHO) for proper assembly. We investigated the effects of swapping 5HT3 and α7-receptor protein sequences on α7-5HT3R chimera surface expression in mammalian HEK293 or Bosc23 cells, or chimeric receptor function using Xenopus laevis oocytes with or without chaperones. α7-5HT3Rs, consisting of human α7-nAChRs with mouse 5HT3 transmembrane domains (TMs) express without chaperones as measured by cell surface alpha-bungarotoxin binding. However, when subunit TMs from α7-nAChRs and 5HT3Rs were mixed, chaperones were required. Substituting the SAP motif prior to the α7-nAChR “Latch” tail sequence for the 5HT3 C-terminal decreased expression relative to α7-nAChRs with chaperones. Chaperone effects on L264 and G265 mutations in M2 were also investigated. Some constructs that express well in HEK293 or Bosc23 cells are nonfunctional in oocytes with or without NACHO. Our data do not support direct binding of RIC3 or NACHO to the α7-nAChR TM4 (M4) region; instead, they emphasize the functional importance of the conserved SAP motif. Full article

Neonicotinoid pesticides, including imidacloprid (IMI), are widely used in agriculture and as household insecticides. IMI displays strong affinity for insect nicotinic acetylcholine receptors (nAChRs); however, neonicotinoids still partially bind to mammalian nAChRs. Relatively little is known about how neonicotinoid exposure alters learning, memory or mood, even though nAChRs play a role in these mechanisms. We tested the hypothesis that developmental exposure to IMI impairs performance on memory tasks, and anxiety- and depressive-like behavior. We orally dosed pregnant CD-1 mice from gestation day 10 to birth with vehicle or IMI at 0.5 mg/kg/day or 5.7 mg/kg/day. When exposed animals were adults, we examined cognitive and emotional behaviors and we examined the effect of IMI on α7 and α4 nAChR subunit mRNA expression using qPCR. For both sexes, IMI exposure was associated with impaired striatal-dependent procedural learning task and hippocampal-dependent spatial learning but had no effect on hippocampal-dependent working memory. Males, but not females, displayed increased anxiety-like behavior, with low dose subjects displaying more pronounced effects, suggesting a non-linear dose response. In males, we found lower α7 subunit mRNA expression in the hippocampus and amygdala and lower α4 mRNA expression in the striatum compared to controls. Thus, exposure to IMI during a critical period is associated with disruptions to cognitive and anxiety-like behaviors. Additionally, in males, IMI exposure is associated with reduced expression of nAChR subunits in relevant brain regions. Full article

Highly degraded sterols belonging to the incisterol group have been identified in a large set of microorganisms. The leading product in the family is demethylincisterol A3 (DM-A3), isolated from various fungi and endowed with marked antitumor properties. Since the initial discovery of incisterol from a marine sponge in the 1990s, more than 30 incisterol-type natural products have been identified, essentially from fungi. An overview of these products, their bio-origin, chemical synthesis, and associated pharmacological properties is presented. The series includes diverse incisterol and demethylincisterol derivatives, chaxines, volemolide, different analogues (salimyxins, phellinignincisterols, daedatrin D, inonotoide F, aplykurodinone-1, dendrodoristerol), and a glycoside derivative (xyloneside), all bearing a tetracyclic incisterol framework. An analysis of the anticancer mechanism of the action of DM-A3 underlined the three main components of its activity associated with the (i) inhibition of β-catenin and the Wnt signaling pathway, (ii) inhibition of tyrosine phosphatase SHP2 (IC₅₀ = 6.75 µM) implicated in cancer cell survival and differentiation, and (iii) blockade of α7nAchR activation coupled with inhibition of acetylcholinesterase (IC₅₀ = 11.16 µM). A comprehensive picture of the DM-A3 mechanism of action is discussed, highlighting the uniqueness of the compound as a dual SHP2/AchE inhibitor able to attenuate an inflammatory response through the cholinergic anti-inflammatory pathway. The review shed light on this little-known category of incisterol-type natural products, with the objective of promoting further research into this neglected group of anticancer agents. Full article

Nineteen previously and newly synthesized amphoteric 8-[(dialkylamino)methyl]-7-hydroxy-4-(2-oxo-2H-chromen-3-yl)-2H-chromen-2-ones were assayed as inhibitors of monoamine oxidases (MAO-A and B) and cholinesterases (AChE and BChE). Five of the tested compounds (2b, 2c, 3c, 5b, and 5c), namely those bearing the less bulky alkyls in the Mannich base 8-CH₂NR₂ (R = Me, Et) and the halogens (Cl, Br) at C6 of the 4-coumarin-3-yl moiety, showed moderate inhibitory potencies toward human MAO-A in the single-digit micromolar range (IC₅₀s from 1.49 to 3.04 µM). In particular, the 6′-Cl derivatives 2b and 5b proved to be reversible competitive inhibitors of human MAO-A with K_i values of 0.272 and 0.326 µM. Among the tested compounds, 3c proved to also be a moderate inhibitor of human AChE (IC₅₀ 4.27 µM). Molecular docking calculations suggested binding modes of the most active compounds to MAO-A and AChE binding sites consistent enough with the experimental data. Chemoinformatic tools suggest for the most active compounds, including the dual MAO-A/AChE inhibitor 3c, full compliance with Lipinski’s rule of five, high probability of gastrointestinal absorption, but low blood–brain barrier (BBB) permeability. While further efforts are required to improve their CNS distribution, herein new phenolic Mannich bases have been identified that may have potential for treating neurodegenerative syndromes. Full article

Background/Objectives: This study evaluated the antifungal, enzyme inhibitory, and anticancer properties of the ethyl acetate (EtOAc) leaves extract of Rubus ulmifolius Schott using in vitro assays and in silico analysis. Methods: Antifungal activity was assessed against five fungal strains by measuring inhibition zones. Enzyme inhibition assays were conducted for acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and urease. Antiproliferative effects were tested against HT-29 colorectal, SK-OV-3 ovarian, and A549 lung cancer cells using the MTT assay. Network pharmacology and molecular docking analyses were performed on major compounds previously identified by GC–MS (gallic acid, caffeic acid, catechin, and fructofuranose) to uncover the potential mechanisms of the plant in colorectal and ovarian cancers. Results: The extract displayed notable antifungal activity, particularly against Penicillium sp., Aspergillus fumigatus, and Candida albicans, with inhibition zones of 22.5 ± 0.7 to 26.8 ± 1.3 mm. Enzyme assays revealed moderate inhibition of AChE (IC₅₀ = 92.94 ± 1.97 µg/mL), weaker activity against BChE (IC₅₀ = 274.93 ± 2.32 µg/mL), and modest inhibition of urease (IC₅₀ = 262.60 ± 1.41 µg/mL). The extract exhibited strong antiproliferative effects against HT-29 and SK-OV-3 cells (IC₅₀ = 2.41 ± 0.13 and 4.63 ± 0.26 µg/mL, respectively), whereas activity against A549 lung cancer cells was limited. Network pharmacology predicted 52 and 44 overlapping target genes between the major compounds and colorectal and ovarian cancers, respectively. Protein–protein interaction networks identified hub genes for each cancer type, with key shared targets including EGFR, ESR1, PTGS2, and STAT3. Molecular docking confirmed favorable binding between these targets and the compounds, particularly catechin, which showed interactions comparable to those of reference inhibitors. Conclusions: These findings suggest that R. ulmifolius may possess multi-target antifungal, neuroprotective, and anticancer potential, warranting further in vitro pharmacological and preclinical validation. Full article

In our previous study, we demonstrated that a standardized ethanol extract of Perilla frutescens var. acuta (PE) alleviates memory deficits in an Alzheimer’s disease mouse model by inhibiting amyloid β (Aβ) aggregation and promoting its disaggregation. However, the extent to which PE exerts additional cognitive benefits independent of Aβ pathology remained unclear. Here, we aimed to evaluate the effects of PE on synaptic plasticity and learning and memory functions. Male ICR mice were used, and cognitive impairment was induced by scopolamine administration. PE was orally administered at doses determined from previous studies, and cognitive performance was assessed using the passive avoidance, Y-maze, and Morris water maze tests. In parallel, hippocampal slices were employed to examine the effects of PE on synaptic plasticity. PE (100 and 300 μg/mL) significantly enhanced long-term potentiation (LTP) in a concentration-dependent manner without altering basal synaptic transmission. This facilitation of LTP was blocked by scopolamine (1 μM), a muscarinic acetylcholine receptor (mAChR) antagonist, and IEM-1460 (50 μM), a calcium-permeable α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (CP-AMPAR) inhibitor, indicating the involvement of mAChR and CP-AMPAR pathways. In vivo, PE (100, 250, and 500 mg/kg) treatment improved memory performance across all behavioral tasks and upregulated hippocampal synaptic proteins including GluN2B, PSD-95, and CaMKII. Collectively, these results demonstrate that PE ameliorates scopolamine (1 mg/kg)-induced cognitive impairment by enhancing synaptic plasticity, likely through modulation of mAChR, CP-AMPAR, and NMDA receptor signaling. These findings highlight the therapeutic potential of PE for memory deficits associated with cholinergic dysfunction. Full article

Butylparaben (BP), a widely used preservative, was implicated in cognitive impairment, though its neurotoxic mechanisms remain elusive. Basal forebrain cholinergic neurons (BFCN) are selectively lost in dementias, contributing to cognitive decline. To explore different mechanisms related with BFCN loss, we employed BF SN56 cholinergic wild-type or silenced cells for Tau, amyloid-beta precursor protein (βApp), acetylcholinesterase (AChE), or glycogen synthase kinase-3 beta (GSK3β) genes, exposing them to BP (0.1–80 µM) for 1 or 14 days alongside triiodothyronine (T3; 15 nM), N-acetylcysteine (NAC; 1 mM), or recombinant heat shock protein 70 (rHSP70; 30 µM). BP disrupted cholinergic transmission by AChE inhibition and provoked cell death through thyroid hormones (THs) pathway disruption, Aβ/p-Tau protein accumulation, AChE-S overexpression, and oxidative stress (OS). Aβ/p-Tau accumulation was correlated with HSP70 downregulation, OS exacerbation, and GSK3β hyperactivation (for p-Tau). BP-induced OS was mediated by reactive oxygen species (ROS) overproduction and nuclear factor erythroid 2-related factor 2 (NRF2) pathway disruption. All observed effects were contingent upon TH signaling impairment. These findings uncover novel mechanistic links between BP exposure and BFCN neurodegeneration, providing a framework for therapeutic strategies. Full article

Perfluorooctane sulfonamide (PFOSA), the direct precursor to perfluorooctane sulfonate (PFOS), is widely present in the environment. Research has indicated that PFOSA is cardiotoxic and hepatotoxic, but its impact on neurodevelopment remains unclear. In the current study, we observed that exposure of PFOSA caused neurodevelopmental toxicity in zebrafish embryos in a dose-dependent manner, as evidenced by impaired motor abilities and decreased swimming distance. We then demonstrated that PFOSA exposure downregulated the mRNA expression of neurodevelopment-related genes including a1-tubulin, elavl3, ache and dat. Moreover, PFOSA exposure resulted in dose-dependent oxidative stress, which triggers apoptosis in the brains of zebrafish larvae. We further showed that inhibition of the aryl hydrocarbon receptor (AhR) alleviated the oxidative stress and apoptosis induced by PFOSA, thereby counteracting the neurodevelopmental abnormalities in zebrafish larvae. In conclusion, these findings indicate PFOSA causes neurodevelopmental disorders by inducing oxidative stress and apoptosis through the AhR pathway. Full article

Diverse neuronal nicotinic acetylcholine receptor (nAChR) subtypes are expressed in hippocampal interneurons. Single-cell analysis of mRNA expression previously revealed prominent co-expression of the α3 and β2 subunits within rat interneurons in the CA1 region. Although the α3 subunit (traditionally expressed together with β4) is usually associated with the peripheral nervous system, its significant co-expression with the β2 subunit in hippocampal interneurons suggests a distinct, potentially novel central nervous system nAChR subtype. We demonstrate that the human α3 and β2 subunits injected into Xenopus laevis oocytes can assemble into at least two functionally distinct subtypes of nAChRs based on different subunit stoichiometries. These subtypes exhibit similar reversal potentials but differ significantly in their desensitization kinetics and acetylcholine (ACh) affinities. The response obtained from a 1:5 α3:β2 mRNA injection ratio shows a higher affinity for ACh and significantly greater desensitization during prolonged ACh application compared to the response obtained from a 5:1 α3:β2 mRNA injection ratio. The identification of distinct functional α3β2 subtypes, characterized by differential desensitization kinetics and ACh affinity, could represent novel targets for the potential development of highly selective cognitive therapeutics for conditions such as Alzheimer’s disease, autism spectrum disorder, and attention deficit hyperactivity disorder, where hippocampal nAChRs are implicated. Full article

Prostate stem cell antigen (PSCA) is a Ly6/uPAR protein that targets neuronal nicotinic acetylcholine receptors (nAChRs). It exists in membrane-tethered and soluble forms, with the latter upregulated in Alzheimer’s disease. We hypothesize that PSCA may be linked to a wider spectrum of neurological diseases and could induce neuroinflammation. Indeed, PSCA expression is significantly upregulated in the brain of patients with multiple sclerosis, Huntington’s disease, Down syndrome, bipolar disorder, and HIV-associated dementia. To investigate PSCA’s structure, pharmacology, and inflammatory function, we produced a correctly folded water-soluble recombinant analog (ws-PSCA). In primary hippocampal neurons and astrocytes, ws-PSCA differently regulates secretion of inflammatory factors and adhesion molecules and induces pro-inflammatory responses by increasing TNFβ secretion. Heteronuclear NMR and ¹⁵N relaxation measurements reveal a classical β-structural three-finger fold with conformationally disordered loops II and III. Positive charge clustering on the molecular surface suggests the functional importance of ionic interactions by these loops. Electrophysiological studies in Xenopus oocytes point on ws-PSCA inhibition of α3β2-, high-, and low-sensitive variants of α4β2- (IC₅₀ ~50, 27, and 15 μM, respectively) but not α4β4-nAChRs, suggesting targeting of the β2 subunit. Ensemble docking and molecular dynamics simulations predict PSCA binding to high-sensitive α4β2-nAChR at α4/β2 and β2/β2 interfaces. Complexes are stabilized by ionic and hydrogen bonds between PSCA’s loops II and III and the primary and complementary receptor subunits, including glycosyl groups. This study gives new structural and functional insights into PSCA’s interaction with molecular targets and provides clues to understand its role in the brain function and mental disorders. Full article

Chlorella vulgaris is a nutrient-dense microalga with recognized antioxidant, anti-inflammatory, and metabolic regulatory properties, making it an attractive candidate for functional food applications. In such contexts, both chemical composition and particle size can influence dispersibility, bioactive release, and physiological effects. In this study, two commercial C. vulgaris powders from India (Sample 1) and the UK (Sample 2) were compared with respect to particle size, metabolite composition, and biological activity. Sample 1 exhibited finer particles, while Sample 2 was coarser. GC–MS profiling revealed distinct compositional differences: Sample 1 displayed a higher relative abundance of saturated fatty acids, β-sitosterol, β-amyrin, and glucitol, whereas Sample 2 contained higher levels of unsaturated fatty acids, betulin, salicylic acid, and specific carbohydrates. In vitro assays showed stronger inhibition of albumin denaturation by Sample 1 compared with Sample 2 and prednisolone. Ex vivo tests indicated that both samples induced tonic contraction of gastric smooth muscle through muscarinic acetylcholine receptors (mAChRs) and L-type calcium channels, as evidenced by the marked reduction in responses after atropine and verapamil treatment, with Sample 1 producing a more pronounced effect. Immunohistochemistry further demonstrated broader IL-1β upregulation with Sample 1 and localized nNOS modulation with Sample 2. Overall, the results demonstrate that the interplay between composition and particle size shapes the bioactivity of C. vulgaris, supporting its targeted use in digestive, neuroimmune, and cardiometabolic health. Full article

Background: Multitarget-directed ligands (MTDLs), particularly those combining cholinesterase inhibition with additional mechanisms, are promising candidates for Alzheimer’s disease (AD) therapy. Based on our previous identification of a dual-active coumarin derivative, we designed a new series of 7-alkoxyamino-3-(1,2,3-triazole)-coumarins. Methods: These compounds were synthesized by a new Sonogashira protocol and evaluated for AChE and BChE inhibition, enzymatic kinetics, molecular docking, neurotoxicity in SH-SY5Y cells, neuroprotection against H₂O₂-induced oxidative stress, and additional interactions with H₃R and MAOs. Results: All derivatives inhibited AChE with IC₅₀ values of 4–104 nM, displaying high selectivity over BChE (up to 686-fold). Kinetic and docking studies indicated mixed-type inhibition involving both CAS and PAS. The most potent compounds (1h, 1j, 1k, 1q) were non-neurotoxic up to 50 µM, while 1h and 1k also showed neuroprotective effects at 12.5 µM. Selected derivatives (1b, 1h, 1q) demonstrated multitarget potential, including H₃R affinity (K_i as low as 32 nM for 1b) and MAO inhibition (IC₅₀ of 1688 nM for 1q). Conclusions: This series of coumarin–triazole derivatives combines potent and selective AChE inhibition with neuroprotective and multitarget activities, highlighting their promise as candidates for AD therapy. Full article

Transmitters such as serotonin, dopamine, noradrenaline, and acetylcholine act as regulators or triggers of numerous processes in the early embryo, including in sea urchins. However, the identity of these mechanisms relative to mature nervous systems remains controversial. The aim of this study was to comprehensively characterize the transcriptomic basis of these as well as glutamatergic, GABAergic and histaminergic systems by comparing publicly available RNA-Seq data across four sea urchin species (Mesocentrotus franciscanus, Lytechinus variegatus, Paracentrotus lividus, Strongylocentrotus purpuratus) during early development (egg to early gastrula). Transcript abundance was normalized using the geometric mean of housekeeping genes (GHG) to facilitate comparative analysis and to use the universal significance threshold. We detected mRNA transcripts encoding numerous components (enzymes, receptors, transporters) for all seven transmitter systems from the earliest stages, suggesting a complex signaling potential prior to neurogenesis. The expression of multiple mRNAs of receptors for the same transmitter indirectly supports our earlier notion of the possibility of simultaneous regulation of different processes by this transmitter even in the single-cell embryo. Notably, transcripts for key synthesis enzymes (TPH, DBH) were often low, indicating limited de novo synthesis, while transcripts for degradation enzymes (MAO, AChE) were abundant. Consistent expression across species was observed for specific receptors such as HTR6, D1-like dopamine, β-adrenergic receptors and the α7 subunit of nicotinic AChR. However, the expression profiles of many components, particularly glutamatergic receptors and metabolic enzymes, showed considerable interspecies variability. These findings indicate that multiple transmitter systems are transcriptionally represented early in development, suggesting substantial molecular overlap with mature systems, while the diversity between species points to possible evolutionary plasticity. This comparative transcriptomic dataset provides a basis for targeted functional studies of the role and interactions of these pre-nervous transmitter pathways in orchestrating embryogenesis. Full article

Paralipsa gularis (Zeller) has become an increasingly destructive pest in both storage and field ecosystems, particularly affecting maize crops across China. As chemical control methods face limitations due to resistance development and environmental concerns, biological control presents a promising alternative. In this study, we isolated and identified a novel strain of Metarhizium sp. from naturally infected P. gularis larvae collected in Yunnan Province, China. Morphological characterization, along with ITS-rDNA and EF-1α-rDNA sequencing, confirmed the fungus as Metarhizium rileyi. The optimal growth medium for this strain was SMAY, and the optimal conditions were 25 °C under continuous light (L:D = 24:0). Laboratory bioassays showed that the strain exhibited high virulence against P. gularis larvae, with cumulative mortality reaching 82% following infestation with 5 × 10⁸ conidia/mL. Biochemical analyses revealed that fungal infection significantly inhibited the activity of the key antioxidant enzyme SOD in the host, while activities of POD, CAT, and detoxification enzymes (P450, CarE, AChE, and GSTs) were significantly increased. These results indicate that immune responses were triggered, and systemic colonization of the host was achieved. Overall, this native M. rileyi strain demonstrates strong potential as an effective biological control agent. Its ability to overcome insect defenses and induce high mortality supports its integration into pest management programs targeting P. gularis. This work advances the understanding of fungal–insect interactions and contributes to sustainable, environmentally safe strategies for managing a pest of economic importance in agricultural ecosystems. Full article

The present study was motivated by the need to enhance indoor air quality and reduce airborne disease transmission in dense urban environments where high-rise residential buildings face challenges in achieving effective natural ventilation. The problem lies in the lack of scalable and convenient tools to optimize natural ventilation rate, particularly in urban settings with varying building heights. To address this, the scientific technique developed with an innovative metric, the urbanized natural ventilation effectiveness factor (uNVeF), integrates regression analysis of wind direction, velocity, air change rate per hour (ACH), window configurations, and building height to quantify ventilation efficiency. By employing a field measurement methodology, the measurements were conducted across 25 window-opening scenarios in a 13.9 m² residential unit on the 35/F of a Hong Kong public housing building, supplemented by the Hellman Exponential Law with a site-specific friction coefficient (0.2907, R² = 0.9232) to estimate the lower floor natural ventilation rate. The results confirm compliance with Hong Kong’s statutory 1.5 ACH requirement (Practice Note for Authorized Persons, Registered Structural Engineers, and Registered Geotechnical Engineers) and achieving a peak ACH at a uNVeF of 0.953 with 75% window opening. The results also revealed that lower floors can maintain 1.5 ACH with adjusted window configurations. Using the Wells–Riley model, the estimation results indicated significant airborne disease infection risk reductions of 96.1% at 35/F and 93.4% at 1/F compared to the 1.5 ACH baseline which demonstrates a strong correlation between ACH, uNVeF and infection risks. The uNVeF framework offers a practical approach to optimize natural ventilation and provides actionable guidelines, together with future research on the scope of validity to refine this technique for residents and developers. The implications in the building industry include setting up sustainable design standards, enhancing public health resilience, supporting policy frameworks for energy-efficient urban planning, and potentially driving innovation in high-rise residential construction and retrofitting globally. Full article