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1.
Nat Struct Mol Biol ; 31(4): 701-709, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38589607

RESUMO

Choline is a vital nutrient and a precursor for the biosynthesis of essential metabolites, including acetylcholine (ACh), that play a central role in fetal development, especially in the brain. In cholinergic neurons, the high-affinity choline transporter (CHT1) provides an extraordinarily efficient reuptake mechanism to reutilize choline derived from intrasynaptical ACh hydrolysis and maintain ACh synthesis in the presynapse. Here, we determined structures of human CHT1 in three discrete states: the outward-facing state bound with the competitive inhibitor hemicholinium-3 (HC-3); the inward-facing occluded state bound with the substrate choline; and the inward-facing apo open state. Our structures and functional characterizations elucidate how the inhibitor and substrate are recognized. Moreover, our findings shed light on conformational changes when transitioning from an outward-facing to an inward-facing state and establish a framework for understanding the transport cycle, which relies on the stabilization of the outward-facing state by a short intracellular helix, IH1.


Assuntos
Colina , Proteínas de Membrana Transportadoras , Humanos , Colina/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Transporte Biológico , Acetilcolina/metabolismo
2.
J Agric Food Chem ; 72(13): 7121-7129, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38511275

RESUMO

The dipeptide Tyr-Pro has physiological potential for intact transportability into the brain parenchyma, prevention of cognitive impairment, and an adiponectin receptor 1 (AdipoR1) agonistic effect. The present study aimed to understand the effect of Tyr-Pro on the acetylcholine (ACh) nervous system and its underlying mechanism in NE-4C nerve cells. Concentration-dependent ACh production was induced by stimulation with Tyr-Pro and AdipoRon (an AdipoR1 agonist), along with the expression of AdipoR1 and choline acetyltransferase (ChAT) in NE-4C cells. By knocking down AdipoR1 in the cells, Tyr-Pro promoted ChAT expression, along with the activations of AMPK and ERK 1/2. Tyr-Pro did not alter acetylcholinesterase or ACh receptors, indicating that the dipeptide might operate as an ACh accelerator in nerve cells. This study provides the first evidence that the AdipoR1 agonistic Tyr-Pro is a promising dipeptide responsible for the stimulation of the ACh nervous system by AdipoR1-induced ChAT activation.


Assuntos
Acetilcolina , Acetilcolinesterase , Acetilcolina/farmacologia , Acetilcolina/metabolismo , Acetilcolinesterase/metabolismo , Adiponectina/metabolismo , Dipeptídeos/farmacologia , Dipeptídeos/metabolismo , Neurônios , Proteínas de Transporte
3.
Int J Mol Sci ; 25(5)2024 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-38473838

RESUMO

The occurrence, inhibitory modulation, and trophic effects of GABA have been identified in the peripheral sympathetic nervous system. We have demonstrated that GABA and acetylcholine (ACh) may colocalize in the same axonal varicosities or be segregated into separate ones in the rat superior cervical ganglia (SCG). Neurotransmitter segregation varies with age and the presence of neurotrophic factors. Here, we explored age-dependent changes in the occurrence and segregation of GABA and ACh in rats ranging from 2 weeks old (wo) to 12 months old or older. Using immunohistochemistry, we characterized the expression of L-glutamic acid decarboxylase of 67 kDa (GAD67) and vesicular acetylcholine transporter (VAChT) in the rat SCG at 2, 4, 8, 12 wo and 12 months old or older. Our findings revealed that GAD67 was greater at 2 wo compared with the other ages, whereas VAChT levels were greater at 4 wo than at 12 wo and 12 months old or older. The segregation of these neurotransmitters was more pronounced at 2 and 4 wo. We observed a caudo-rostral gradient of segregation degree at 8 and 12 wo. Data point out that the occurrence and segregation of GABA and ACh exhibit developmental adaptative changes throughout the lifetime of rats. We hypothesize that during the early postnatal period, the increase in GABA and GABA-ACh segregation promotes the release of GABA alone which might play a role in trophic actions.


Assuntos
Acetilcolina , Gânglio Cervical Superior , Ratos , Animais , Acetilcolina/metabolismo , Axônios/metabolismo , Ácido gama-Aminobutírico/metabolismo
4.
Molecules ; 29(5)2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38474455

RESUMO

Leishmania tarentolae (LEXSY) system is an inexpensive and effective expression approach for various research and medical purposes. The stated advantages of this system are the possibility of obtaining the soluble product in the cytoplasm, a high probability of correct protein folding with a full range of post-translational modifications (including uniform glycosylation), and the possibility of expressing multi-subunit proteins. In this paper, a LEXSY expression system has been employed for obtaining the receptor binding domain (RBD) of the spike-protein of the SARS-CoV-2 virus and the homopentameric acetylcholine-binding protein (AChBP) from Lymnaea stagnalis. RBD is actively used to obtain antibodies against the virus and in various scientific studies on the molecular mechanisms of the interaction of the virus with host cell targets. AChBP represents an excellent structural model of the ligand-binding extracellular domain of all subtypes of nicotinic acetylcholine receptors (nAChRs). Both products were obtained in a soluble glycosylated form, and their structural and functional characteristics were compared with those previously described.


Assuntos
COVID-19 , Leishmania , Receptores Nicotínicos , Animais , Proteínas de Transporte/metabolismo , Acetilcolina/metabolismo , Lymnaea/metabolismo , SARS-CoV-2/metabolismo , Leishmania/metabolismo , Receptores Nicotínicos/metabolismo
5.
Life Sci ; 343: 122488, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38428573

RESUMO

AIM: The present study evaluated whether topiramate (TPM) treatment during the peripubertal period affects vascular parameters of male rats and whether oxidative stress plays a role in these changes. MAIN METHODS: Rats were treated with TPM (41 mg/kg/day, gavage) or vehicle (CTR group) from the postnatal day (PND) 28 to 50. At PND 51 and 120 the rats were evaluated for: thoracic aorta reactivity to phenylephrine, in the presence (Endo+) or absence of endothelium (Endo-), to acetylcholine and to sodium nitroprusside (SNP), aortic thickness and endothelial nitric oxide synthase (eNOS) expression. In serum were analyzed: the antioxidant capacity by ferric reducing antioxidant power assay; endogenous antioxidant reduced glutathione, and superoxide anion. Results were expressed as mean ± s.e.m., differences when p < 0.05. STATISTICS: Two-way ANOVA (and Tukey's) or Student t-test. KEY FINDINGS: At PND 51, the contraction induced by phenylephrine in Endo+ ring was higher in TPM when compared to CTR. At PND 120, the aortic sensitivity to acetylcholine in TPM rats was reduced in comparison with CTR. The aortic eNOs expression and the aortic thickness were similar between the groups. At PND 51 and 120, TPM group presented a decrease in antioxidants when compared to CTR groups and at PND 120, in TPM group the superoxide anion was increased. SIGNIFICANCE: Taken together, the treatment of rats with TPM during peripubertal period promoted permanent impairment of endothelial function probably mediated by oxidative stress.


Assuntos
Acetilcolina , Antioxidantes , Ratos , Animais , Masculino , Antioxidantes/farmacologia , Antioxidantes/metabolismo , Topiramato/farmacologia , Acetilcolina/metabolismo , Superóxidos/metabolismo , Endotélio Vascular/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Estresse Oxidativo , Aorta Torácica/metabolismo , Fenilefrina/farmacologia , Óxido Nítrico/metabolismo
6.
Philos Trans R Soc Lond B Biol Sci ; 379(1901): 20230075, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38497270

RESUMO

The gut microbiota is crucial for intestinal health, including gastrointestinal (GI) motility. How commensal bacterial species influence GI motility has not been fully elucidated. A major factor of GI motility is the gut contraction promoting the propulsive movement of orally ingested materials. Here, we developed a method to monitor and quantify gut contractions in living Drosophila melanogaster larvae. We found that the culture medium of an isolated strain Lactiplantibacillus plantarum Lsi promoted gut contraction in vivo, which was not observed in Leuconostoc sp. Leui nor Acetobacter persici Ai culture medium. To identify bacteria-derived metabolites, we performed metabolome analysis of the culture media by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Of the 66 metabolites detected, we found that some metabolites changed in a species-specific manner. Among them, acetylcholine was specifically produced by L. plantarum. Feeding exogenous acetylcholine increased the frequency of gut contractions, which was blocked by D-tubocurarine, an inhibitor of nicotinic acetylcholine receptors. In this study, we propose a mechanism by which the gut microbiota influences Drosophila gut motility. This article is part of the theme issue 'Sculpting the microbiome: how host factors determine and respond to microbial colonization'.


Assuntos
Drosophila melanogaster , Microbiota , Animais , Acetilcolina/farmacologia , Acetilcolina/metabolismo , Cromatografia Líquida , Espectrometria de Massas em Tandem , Bactérias/metabolismo , Drosophila
7.
Brain Behav Immun ; 118: 408-422, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38461956

RESUMO

Western diet (WD) consumption during early life developmental periods is associated with impaired memory function, particularly for hippocampus (HPC)-dependent processes. We developed an early life WD rodent model associated with long-lasting HPC dysfunction to investigate the neurobiological mechanisms mediating these effects. Rats received either a cafeteria-style WD (ad libitum access to various high-fat/high-sugar foods; CAF) or standard healthy chow (CTL) during the juvenile and adolescent stages (postnatal days 26-56). Behavioral and metabolic assessments were performed both before and after a healthy diet intervention period beginning at early adulthood. Results revealed HPC-dependent contextual episodic memory impairments in CAF rats that persisted despite the healthy diet intervention. Given that dysregulated HPC acetylcholine (ACh) signaling is associated with memory impairments in humans and animal models, we examined protein markers of ACh tone in the dorsal HPC (HPCd) in CAF and CTL rats. Results revealed significantly lower protein levels of vesicular ACh transporter in the HPCd of CAF vs. CTL rats, indicating chronically reduced ACh tone. Using intensity-based ACh sensing fluorescent reporter (iAChSnFr) in vivo fiber photometry targeting the HPCd, we next revealed that ACh release during object-contextual novelty recognition was highly predictive of memory performance and was disrupted in CAF vs. CTL rats. Neuropharmacological results showed that alpha 7 nicotinic ACh receptor agonist infusion in the HPCd during training rescued memory deficits in CAF rats. Overall, these findings reveal a functional connection linking early life WD intake with long-lasting dysregulation of HPC ACh signaling, thereby identifying an underlying mechanism for WD-associated memory impairments.


Assuntos
Acetilcolina , Dieta Ocidental , Humanos , Ratos , Animais , Adolescente , Adulto , Acetilcolina/metabolismo , Memória/fisiologia , Hipocampo/metabolismo , Transdução de Sinais , Transtornos da Memória/metabolismo
8.
Elife ; 132024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38363713

RESUMO

Neurons of the basal forebrain nucleus basalis and posterior substantia innominata (NBM/SIp) comprise the major source of cholinergic input to the basolateral amygdala (BLA). Using a genetically encoded acetylcholine (ACh) sensor in mice, we demonstrate that BLA-projecting cholinergic neurons can 'learn' the association between a naive tone and a foot shock (training) and release ACh in the BLA in response to the conditioned tone 24 hr later (recall). In the NBM/SIp cholinergic neurons express the immediate early gene, Fos following both training and memory recall. Cholinergic neurons that express Fos following memory recall display increased intrinsic excitability. Chemogenetic silencing of these learning-activated cholinergic neurons prevents expression of the defensive behavior to the tone. In contrast, we show that NBM/SIp cholinergic neurons are not activated by an innately threatening stimulus (predator odor). Instead, VP/SIa cholinergic neurons are activated and contribute to defensive behaviors in response to predator odor, an innately threatening stimulus. Taken together, we find that distinct populations of cholinergic neurons are recruited to signal distinct aversive stimuli, demonstrating functionally refined organization of specific types of memory within the cholinergic basal forebrain of mice.


Assuntos
Prosencéfalo Basal , Camundongos , Animais , Prosencéfalo Basal/fisiologia , Neurônios Colinérgicos/fisiologia , Memória/fisiologia , Aprendizagem/fisiologia , Acetilcolina/metabolismo , Colinérgicos
9.
Cell Commun Signal ; 22(1): 118, 2024 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-38347539

RESUMO

BACKGROUND: Disruption of Ca2+ homeostasis after calcium electroporation (CaEP) in tumors has been shown to elicit an enhanced antitumor effect with varying impacts on healthy tissue, such as endothelium. Therefore, our study aimed to determine differences in Ca2+ kinetics and gene expression involved in the regulation of Ca2+ signaling and homeostasis, as well as effects of CaEP on cytoskeleton and adherens junctions of the established endothelial cell lines EA.hy926 and HMEC-1. METHODS: CaEP was performed on EA.hy926 and HMEC-1 cells with increasing Ca2+ concentrations. Viability after CaEP was assessed using Presto Blue, while the effect on cytoskeleton and adherens junctions was evaluated via immunofluorescence staining (F-actin, α-tubulin, VE-cadherin). Differences in intracellular Ca2+ regulation ([Ca2+]i) were determined with spectrofluorometric measurements using Fura-2-AM, exposing cells to DPBS, ionomycin, thapsigargin, ATP, bradykinin, angiotensin II, acetylcholine, LaCl3, and GdCl3. Molecular distinctions were identified by analyzing differentially expressed genes and pathways related to the cytoskeleton and Ca2+ signaling through RNA sequencing. RESULTS: EA.hy926 cells, at increasing Ca2+ concentrations, displayed higher CaEP susceptibility and lower survival than HMEC-1. Immunofluorescence confirmed CaEP-induced, time- and Ca2+-dependent morphological changes in EA.hy926's actin filaments, microtubules, and cell-cell junctions. Spectrofluorometric Ca2+ kinetics showed higher amplitudes in Ca2+ responses in EA.hy926 exposed to buffer, G protein coupled receptor agonists, bradykinin, and angiotensin II compared to HMEC-1. HMEC-1 exhibited significantly higher [Ca2+]i changes after ionomycin exposure, while responses to thapsigargin, ATP, and acetylcholine were similar in both cell lines. ATP without extracellular Ca2+ ions induced a significantly higher [Ca2+]i rise in EA.hy926, suggesting purinergic ionotropic P2X and metabotropic P2Y receptor activation. RNA-sequencing analysis showed significant differences in cytoskeleton- and Ca2+-related gene expression, highlighting upregulation of ORAI2, TRPC1, TRPM2, CNGA3, TRPM6, and downregulation of TRPV4 and TRPC4 in EA.hy926 versus HMEC-1. Moreover, KEGG analysis showed upregulated Ca2+ import and downregulated export genes in EA.hy926. CONCLUSIONS: Our finding show that significant differences in CaEP response and [Ca2+]i regulation exist between EA.hy926 and HMEC-1, which may be attributed to distinct transcriptomic profiles. EA.hy926, compared to HMEC-1, displayed higher susceptibility and sensitivity to [Ca2+]i changes, which may be linked to overexpression of Ca2+-related genes and an inability to mitigate changes in [Ca2+]i. The study offers a bioinformatic basis for selecting EC models based on research objectives.


Assuntos
Acetilcolina , Cálcio , Cálcio/metabolismo , Acetilcolina/metabolismo , Acetilcolina/farmacologia , Angiotensina II/farmacologia , Bradicinina/farmacologia , Ionomicina/metabolismo , Ionomicina/farmacologia , Tapsigargina/metabolismo , Linhagem Celular , Células Endoteliais/metabolismo , Endotélio Vascular/metabolismo , Perfilação da Expressão Gênica , Eletroporação , Trifosfato de Adenosina/metabolismo
10.
J Agric Food Chem ; 72(9): 4906-4917, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38378185

RESUMO

Gastric parietal cells secrete chloride ions and protons to form hydrochloric acid. Besides endogenous stimulants, e.g., acetylcholine, bitter-tasting food constituents, e.g., caffeine, induce proton secretion via interaction with bitter taste receptors (TAS2Rs), leading to increased cytosolic Ca2+ and cAMP concentrations. We hypothesized TAS2R activation by bitter tastants to result in proton secretion via cellular Na+ influx mediated by transient receptor potential channels (TRP) M4 and M5 in immortalized human parietal HGT-1 cells. Using the food-derived TAS2R agonists caffeine and l-arginine, we demonstrate both bitter compounds to induce a TRPM4/M5-mediated Na+ influx, with EC50 values of 0.65 and 10.38 mM, respectively, that stimulates cellular proton secretion. Functional involvement of TAS2Rs in the caffeine-evoked effect was demonstrated by means of the TAS2R antagonist homoeriodictyol, and stably CRISPR-Cas9-edited TAS2R43ko cells. Building on previous results, these data further support the suitability of HGT-1 cells as a surrogate cell model for taste cells. In addition, TRPM4/M5 mediated a Na+ influx after stimulating HGT-1 cells with the acetylcholine analogue carbachol, indicating an interaction of the digestion-associated cholinergic pathway with a taste-signaling pathway in parietal cells.


Assuntos
Células Parietais Gástricas , Canais de Cátion TRPM , Humanos , Células Parietais Gástricas/metabolismo , Paladar , Cafeína/farmacologia , Cafeína/metabolismo , Prótons , Sódio/metabolismo , Acetilcolina/metabolismo , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Canais de Cátion TRPM/genética , Canais de Cátion TRPM/metabolismo
11.
Vascul Pharmacol ; 154: 107281, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38320678

RESUMO

OBJECTIVE: Perivascular adipose tissue (PVAT) function during aging has not been investigated in detail so far and its effect on vasodilation remains to be fully elucidated. The aim of this study was to investigate endothelium-dependent vasodilation of thoracic aorta in a mouse model of accelerated, selective vascular smooth muscle and PVAT aging, induced by SM22α-Cre-driven genetic deletion of the endonuclease ERCC1 (SMC-KO mice) versus healthy littermates (LM). We hypothesized that PVAT enhances vasodilation in LM, possibly through adiponectin secretion, which might be compromised in SMC-KO animals. METHODS: Thoracic aorta was isolated from SMC-KO animals and LM and segments with and without PVAT were mounted in wire myography setups. The endothelium-dependent vasodilation was assessed via acetylcholine dose-response curves and pathway contribution was studied. Moreover, adiponectin secretion was measured after stimulating the aortic segments with PVAT with acetylcholine. RESULTS: Adiponectin, secreted by PVAT, led to increased NO-contribution to endothelium-dependent vasodilation in healthy LM, although this did not increase maximum relaxation due to loss of EDH. Endothelium-dependent vasodilation was decreased in SMC-KO animals due to reduced NO-contribution and complete EDH loss. Despite strong lipodystrophy the PVAT partially compensated for lost vasodilation in SMC-KO. LM PVAT contained acetylcholinesterase that attenuated acetylcholine responses. This was lost in SMC-KO. CONCLUSIONS: PVAT-derived adiponectin is able to partially compensate for age-related decline in NO-mediated vasodilation, even during strong lipodystrophy, in conditions of absence of compensating EDH. In aorta with healthy PVAT acetylcholinesterase modulates vascular tone, but this is lost during aging, further compensating for decreased acetylcholine responsiveness. Thus, preservation of adiponectin levels, through relatively increased production in lipodystrophic PVAT, and reduction of cholinesterase might be regulatory mechanisms of the PVAT to preserve cholinergic vasodilation during aging.


Assuntos
Lipodistrofia , Vasodilatação , Camundongos , Animais , Adiponectina/genética , Acetilcolinesterase/metabolismo , Acetilcolinesterase/farmacologia , Acetilcolina/farmacologia , Acetilcolina/metabolismo , Músculo Liso Vascular/metabolismo , Tecido Adiposo/metabolismo , Envelhecimento , Lipodistrofia/metabolismo
12.
Org Biomol Chem ; 22(8): 1634-1638, 2024 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-38323382

RESUMO

Alzheimer's disease (AD) is characterized by cognitive decline, often attributed to the deficiency of acetylcholine, which can undergo hydrolysis by acetylcholinesterase (AChE) within the biological milieu. Here, we report a supramolecular strategy that takes advantage of confinement effects to inhibit such a hydrolysis process, shedding some light on AD therapy. A water-soluble and bowl-shaped molecule, hexacarboxylated tribenzotriquinacene (TBTQ-C6), was employed to shield acetylcholine (G1) from enzymatic degradation through host-guest binding interactions. Our study revealed highly efficient host-guest interactions with a binding ratio of 1 : 3, resulting in a significant reduction in acetylcholine hydrolysis from 91.1% to 7.4% in the presence of AChE under otherwise identical conditions. Furthermore, TBTQ-C6 showed potential for attenuating the degradation of butyrylcholine (G2) by butyrylcholinesterase (BChE). The broader implications of this study extend to the potential use of molecular containers in various biochemical and pharmacological applications, opening new avenues for research in the field of neurodegenerative diseases.


Assuntos
Doença de Alzheimer , Butirilcolinesterase , Humanos , Butirilcolinesterase/metabolismo , Acetilcolina/metabolismo , Acetilcolina/uso terapêutico , Acetilcolinesterase/metabolismo , Hidrólise , Doença de Alzheimer/tratamento farmacológico , Inibidores da Colinesterase/química , Simulação de Acoplamento Molecular
13.
Eur Biophys J ; 53(1-2): 15-25, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38233601

RESUMO

The α7 nicotinic acetylcholine receptor is a member of the nicotinic acetylcholine receptor family and is composed of five α7 subunits arranged symmetrically around a central pore. It is localized in the central nervous system and immune cells and could be a target for treating Alzheimer's disease and schizophrenia. Acetylcholine is a ligand that opens the channel, although prolonged application rapidly decreases the response. Ivermectin was reported as one of the positive allosteric modulators, since the binding of Ivermectin to the channel enhances acetylcholine-evoked α7 currents. One research has suggested that tilting motions of the nicotinic acetylcholine receptor are responsible for channel opening and activation. To verify this hypothesis applies to α7 nicotinic acetylcholine receptor, we utilized a diffracted X-ray tracking method to monitor the stable twisting and tilting motion of nAChR α7 without a ligand, with acetylcholine, with Ivermectin, and with both of them. The results show that the α7 nicotinic acetylcholine receptor twists counterclockwise with the channel transiently opening, transitioning to a desensitized state in the presence of acetylcholine and clockwise without the channel opening in the presence of Ivermectin. We propose that the conformational transition of ACh-bound nAChR α7 may be due to the collective twisting of the five α7 subunits, resulting in the compression and movement, either downward or upward, of one or more subunits, thus manifesting tilting motions. These tilting motions possibly represent the transition from the resting state to channel opening and potentially to the desensitized state.


Assuntos
Receptores Nicotínicos , Receptor Nicotínico de Acetilcolina alfa7 , Receptor Nicotínico de Acetilcolina alfa7/química , Receptor Nicotínico de Acetilcolina alfa7/metabolismo , Acetilcolina/química , Acetilcolina/metabolismo , Ligantes , Ivermectina/farmacologia , Receptores Nicotínicos/química , Receptores Nicotínicos/metabolismo , Regulação Alostérica
14.
Sci Rep ; 14(1): 46, 2024 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-38168499

RESUMO

Ethanol engages cholinergic signaling and elicits endogenous acetylcholine release. Acetylcholine input to the midbrain originates from the mesopontine tegmentum (MPT), which is composed of the laterodorsal tegmentum (LDT) and the pedunculopontine tegmental nucleus (PPN). We investigated the effect of acute and chronic ethanol administration on cholinergic and glutamatergic neuron activation in the PPN and LDT in male and female mice. We show that ethanol activates neurons of the PPN and not the LDT in male mice. Chronic 15 daily injections of 2 g/kg ethanol induced Fos expression in cholinergic and glutamatergic PPN neurons in male mice, whereas ethanol did not increase cholinergic and glutamatergic neuronal activation in the LDT. A single acute 4 g/kg injection, but not a single 2 g/kg injection, induced cholinergic neuron activation in the male PPN but not the LDT. In contrast, acute or chronic ethanol at either dose or duration had no effect on the activation of cholinergic or glutamatergic neurons in the MPT of female mice. Female mice had higher baseline level of activation in cholinergic neurons compared with males. We also found a population of co-labeled cholinergic and glutamatergic neurons in the PPN and LDT which were highly active in the saline- and ethanol-treated groups in both sexes. These findings illustrate the complex differential effects of ethanol across dose, time point, MPT subregion and sex.


Assuntos
Acetilcolina , Caracteres Sexuais , Feminino , Masculino , Camundongos , Animais , Acetilcolina/metabolismo , Tegmento Mesencefálico/fisiologia , Neurônios Colinérgicos/metabolismo , Colinérgicos/metabolismo
15.
J Mater Chem B ; 12(5): 1149-1167, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38196348

RESUMO

Butyrylcholinesterase (BChE), a member of the human serine hydrolase family, is an essential enzyme for cholinergic neurotransmission as it catalyzes the hydrolysis of acetylcholine. It also plays central roles in apoptosis, lipid metabolism, and xenobiotic detoxification. On the other side, abnormal levels of BChE are directly associated with the formation of pathogenic states such as neurodegenerative diseases, psychiatric and cardiovascular disorders, liver damage, diabetes, and cancer. Thus, selective and sensitive detection of BChE level in living organisms is highly crucial and is of great importance to further understand the roles of BChE in both physiological and pathological processes. However, it is a very complicated task due to the potential interference of acetylcholinesterase (AChE), the other human cholinesterase, as these two enzymes share a very similar substrate scope. To this end, optical imaging probes have attracted immense attention in recent years as they have modular structures, which can be tuned precisely to satisfy high selectivity toward BChE, and at the same time they offer real time and nondestructive imaging opportunities with a high spatial and temporal resolution. Here, we summarize BChE selective imaging probes by discussing the critical milestones achieved during the development process of these molecular sensors over the years. We put a special emphasis on design principles and biological applications of highly promising new generation activity-based probes. We also give a comprehensive outlook for the future of BChE-responsive probes and highlight the ongoing challenges. This collection marks the first review article on BChE-responsive imaging agents.


Assuntos
Acetilcolinesterase , Butirilcolinesterase , Humanos , Butirilcolinesterase/metabolismo , Acetilcolinesterase/metabolismo , Inibidores da Colinesterase/química , Acetilcolina/metabolismo , Imagem Óptica
16.
Life Sci ; 338: 122405, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38176584

RESUMO

AIMS: To evaluate the effects of testosterone on endothelium-dependent vasodilation and oxidative stress in mesenteric resistance arteries. MAIN METHODS: Spontaneously hypertensive rats (SHR), aged 8 to 10 weeks, were divided into four groups: intact (SHAM), intact treated with testosterone (TTO; 3 mg/kg/day) via subcutaneous route (s.c.), intact treated with testosterone and anastrozole [aromatase enzyme inhibitor (TTO + ANA; 0.1 mg/kg/day, s.c.)] and intact treated with testosterone and finasteride [5 α-reductase enzyme inhibitor (TTO + FIN; 5 mg/kg/day, s.c.)] for four weeks. Concentration-response curves to acetylcholine (ACh, 0.1 nmol/L - 10 µmol/L) were obtained in mesenteric resistance arteries previously contracted with phenylephrine (PE, 3 µmol/L), before and after the use of selective inhibitors. Reactive oxygen species (ROS) levels were assessed in the vessels and the endothelium analyzed by scanning electron microscopy. KEY FINDINGS: TTO group showed a lower participation of nitric oxide (NO), increased oxidative stress, and participation of prostanoids and endothelium-dependent hyperpolarization (EDH), possibly to maintain the vasodilator response. Lower participation of NO and prostanoids, combined to an increased participation of EDH, were observed in the TTO + ANA group, in addition to higher levels of ROS and altered endothelial morphology. The vasodilation to ACh was impaired in TTO + FIN, along increased participation of NO, reduction of prostanoids, and greater EDH-dependent vasodilation. SIGNIFICANCE: Testosterone contributes to endothelial vasodilation by enhancing EDH through an increased participation of epoxyeicosatrienoic acids. While the decrease in NO appears to involve the participation of dihydrotestosterone, 17 ß-estradiol seems to stimulate the action of the NO pathway and prostanoids.


Assuntos
Hipertensão , Vasodilatação , Ratos , Animais , Espécies Reativas de Oxigênio/metabolismo , Testosterona/farmacologia , Testosterona/metabolismo , Hipertensão/metabolismo , Ratos Endogâmicos SHR , Inibidores Enzimáticos/farmacologia , Acetilcolina/farmacologia , Acetilcolina/metabolismo , Artérias Mesentéricas , Óxido Nítrico/metabolismo , Prostaglandinas/metabolismo , Endotélio Vascular/metabolismo
17.
Mol Neurobiol ; 61(3): 1363-1382, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37707741

RESUMO

Alzheimer disease is associated with cognitive impairments and neuronal damages. In this study, Scopolamine, a model drug used for the generation of Alzheimer-like symptoms induced cognitive dysfunction in C57BL/6 mice. It also elevated acetylcholine esterase (AcHE) activity, and reduced antioxidant (superoxide dismutase and catalase) activity in cortex tissue. Scop reduced neuronal density and increased pyknotic neurons in hippocampus tissue. In mouse neuroblastoma (Neuro2a) cells, Scop triggered a dose-dependent loss of cell viability and neurite outgrowth reduction. Scop-treated Neuro2a cells showed oxidative stress and reduction in mRNA expression for brain-derived neurotrophic factor (BDNF), nerve growth factor-1 (NGF-1), and Synapsin-1 (SYN-1) genes. Mice treated with Divya-Medha-Vati (DMV), an Ayurvedic polyherbal medicine showed protection against Scop-induced cognitive impairment (Morris Water Maze Escape Latency, and Elevated Plus Maze Transfer Latency). DMV protected against Scop-induced AcHE activity, and loss of antioxidant activities in the mice brain cortex while sustaining neuronal density in the hippocampus region. In the Neuro2a cells, DMV reduced Scop-induced loss of cell viability and neurite outgrowth loss. DMV protected the cells against induction of oxidative stress and promoted mRNA expression of BDNF, NGF-1, and SYN-1 genes. Phytochemical profiling of DMV showed the presence of Withanolide A, Withanolide B, Bacopaside II, Jujubogenin, Apigenin, Gallic acid, Caffeic acid, and Quercetin that are associated with antioxidant and neurostimulatory activities. In conclusion, the study showed that Divya-Medha-Vati was capable of promoting neuronal health and inhibiting Alzheimer-like cognitive dysfunction through enhanced antioxidant activities and modulation of neuronal activities.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Camundongos , Animais , Escopolamina , Acetilcolina/metabolismo , Antioxidantes/metabolismo , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Fator de Crescimento Neural/metabolismo , Neuroproteção , Doença de Alzheimer/metabolismo , Camundongos Endogâmicos C57BL , Estresse Oxidativo , Disfunção Cognitiva/induzido quimicamente , Disfunção Cognitiva/tratamento farmacológico , Disfunção Cognitiva/metabolismo , Transdução de Sinais , Hipocampo/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Aprendizagem em Labirinto , Acetilcolinesterase/metabolismo , Transtornos da Memória/metabolismo
18.
Proteomics ; 24(1-2): e2300151, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37904306

RESUMO

The Cys-loop pentameric ligand-gated ion channels comprise a dynamic group of proteins that have been extensively studied for decades, yielding a wealth of findings at both the structural and functional levels. The nicotinic acetylcholine receptor (nAChR) is no exception, as it is part of this large protein family involved in proper organismal function. Our efforts have successfully produced a highly pure nAChR in detergent complex (nAChR-DC), enabling more robust studies to be conducted on it, including beginning to experiment with high-throughput crystallization. Our homogeneous product has been identified and extensively characterized with 100% identity using Nano Lc MS/MS and MALDI ToF/ToF for each nAChR subunit. Additionally, the N-linked glycans in the Torpedo californica-nAChR (Tc-nAChR) subunits have been identified. To study this, the Tc-nAChR subunits were digested with PNGase F and the released glycans were analyzed by MALDI-ToF. The MS results showed the presence of high-mannose N-glycan in all native Tc-nAChR subunits. Specifically, the oligommanose population Man8-9GlcNac2 with peaks at m/z 1742 and 1904 ([M + Na]+ ions) were observed.


Assuntos
Nicotina , Receptores Nicotínicos , Animais , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Acetilcolina/metabolismo , Torpedo/metabolismo , Espectrometria de Massas em Tandem , Receptores Nicotínicos/química , Receptores Nicotínicos/metabolismo
19.
Microcirculation ; 31(1): e12837, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37985248

RESUMO

OBJECTIVE: This study investigated the actions of advanced glycated end-products (AGE), their receptors (RAGE), and NAD(P)H oxidase (Nox) subtypes 1, 2, and 4 on mechanisms of endothelium-dependent dilation of the rat cremaster muscle artery (CMA). METHODS: Immunofluorescence studies were used to examine expression of RAGE in rat arteries. ROS accumulation was measured using luminescence and fluorescence assays. Functional studies were performed using pressure myography. RESULTS: High levels of RAGE expression were shown in the endothelial cells of the CMA, compared with low endothelial expression in middle cerebral and mesenteric arteries and the aorta. Exogenous AGE (in vitro glycated bovine serum albumin) stimulated H2O2 accumulation in CMA, which was prevented by the RAGE antagonist FPS-ZM1, the NAD(P)H oxidase (Nox) inhibitor apocynin and inhibited by the Nox1/4 inhibitor setanaxib, but not the Nox2 inhibitor GSK2795039. In functional studies, AGE inhibited vasodilation of CMA stimulated by acetylcholine, sodium nitroprusside, and the BKCa activator NS1619, but not adenosine-induced dilation. FPS-ZM1, apocynin, and setanaxib prevented the inhibitory effects of AGE on responses to acetylcholine and NS-1619. CONCLUSION: These observations suggest RAGE are constitutively expressed in the endothelium of the rat CMA and may be activated by AGE to stimulate Nox1/4 and ROS formation with resulting inhibition of NO and BKCa-mediated endothelium-dependent dilation.


Assuntos
Acetofenonas , Benzamidas , Células Endoteliais , Endotélio Vascular , NADPH Oxidase 1 , NADPH Oxidase 4 , Animais , Ratos , Acetilcolina/metabolismo , Benzamidas/administração & dosagem , Dilatação , Células Endoteliais/metabolismo , Endotélio Vascular/metabolismo , Peróxido de Hidrogênio/farmacologia , Peróxido de Hidrogênio/metabolismo , Artérias Mesentéricas/metabolismo , Músculo Esquelético/metabolismo , NADPH Oxidases , Espécies Reativas de Oxigênio/metabolismo , Vasodilatação , NADPH Oxidase 4/metabolismo , NADPH Oxidase 1/metabolismo
20.
Rheumatol Int ; 44(1): 1-8, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37814148

RESUMO

The vagus nerve forms intricate neural connections with an extensive number of organs, particularly the digestive system. The vagus nerve has a pivotal role as a fundamental component of the autonomic nervous system, exhibiting an essential effect. It establishes a direct link with the parasympathetic system, consequently eliciting the synaptic release of acetylcholine. Recent studies have revealed the potential anti-inflammatory function of the vagus nerve. The activation of the hypothalamic system through the stimulation of vagal afferents is fundamentally involved in regulating inflammation. This activation process leads to the production of cortisol. The other mechanism, defined as the cholinergic anti-inflammatory pathway, is characterized by the involvement of vagal efferents. These fibers release the neurotransmitter acetylcholine at particular synaptic connections, involving interactions with macrophages and enteric neurons. The mechanism under consideration is ascribed to the α-7-nicotinic acetylcholine receptors. The fusion of acetylcholine receptors is responsible for the restricted secretion of inflammatory mediators by macrophages. A potential mechanism for anti-inflammatory effects involves the stimulation of the sympathetic system through the vagus nerve, leading to the control of immunological responses within the spleen. This article offers an extensive summary of the present knowledge regarding the therapeutic effectiveness of stimulating the vagus nerve in managing inflammatory rheumatic conditions based on the relationship of inflammation with the vagus nerve. Furthermore, the objective is to present alternatives that may be preferred while applying vagus nerve stimulation approaches.


Assuntos
Doenças Reumáticas , Estimulação do Nervo Vago , Humanos , Acetilcolina/metabolismo , Inflamação/terapia , Anti-Inflamatórios , Doenças Reumáticas/terapia
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