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1.
Biochem Pharmacol ; 223: 116183, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38580167

RESUMO

In this study, we have investigated the pharmacological activity and structural interaction of two novel psychoplastogens, tabernanthalog (TBG) and ibogainalog (IBG) at heterologously-expressed rat (r) and human (h) nicotinic acetylcholine receptors (nAChRs), the rα1ß2γ2L γ-aminobutyric acid type A receptor (GABAAR), and the human voltage-gated N-type calcium channel (CaV2.2 channel). Both compounds inhibited the nAChRs with the following receptor selectivity: α9α10 > α7 > α3ß2 â‰… α3ß4, indicating that ß2/ß4 subunits are relatively less important for their activity. The potencies of TBG and IBG were comparable at hα7 and hα9α10 subtypes, and comparable to their rat counterparts. TBG- and IBG-induced inhibition of rα7 was ACh concentration-independent and voltage-dependent, whereas rα9α10 inhibition was ACh concentration-dependent and voltage-independent, suggesting that they interact with the α7 ion channel pore and α9α10 orthosteric ligand binding site, respectively. These results were supported by molecular docking studies showing that at the α7 model TBG forms stable interactions with luminal rings at 9', 13', and 16', whereas IBG mostly interacts with the extracellular-transmembrane junction. In the α9α10 model, however, these compounds interacted with several residues from the principal (+) and complementary (-) sides in the transmitter binding site. Ibogaminalog (DM506) also interacted with a non-luminal site at α7, and one α9α10 orthosteric site. TBG and IBG inhibited the GABAAR and CaV2.2 channels with 10 to 30-fold lower potencies. In sum, we show that TBG and IBG inhibit the α7 and α9α10 nAChRs by noncompetitive and competitive mechanisms, respectively, and with higher potency than the GABAAR and CaV2.2 channel.


Assuntos
Receptores Nicotínicos , Ratos , Animais , Humanos , Receptores Nicotínicos/metabolismo , Receptores de GABA-A/genética , Receptor Nicotínico de Acetilcolina alfa7/metabolismo , Simulação de Acoplamento Molecular , Ácido gama-Aminobutírico
2.
PLoS One ; 19(4): e0301592, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38635806

RESUMO

Hippocampal interneurons are a very diverse population of cells. Using single-cell quantitative PCR to analyze rat CA1 hippocampal interneurons, we quantified neuronal nicotinic acetylcholine receptor (nAChR) mRNA subunit expression and detailed possible nAChR subtype combinations for the α2, α3, α4, α5, α7, ß2, ß3, and ß4 subunits. We also compared the expression detected in the stratum oriens and the stratum radiatum hippocampal layers. We show that the majority of interneurons in the CA1 of the rat hippocampus contain detectable levels of nAChR subunit mRNA. Our results highlight the complexity of the CA1 nAChR population. Interestingly, the α3 nAChR subunit is one of the highest expressed subunit mRNAs in this population, while the α4 is one of the least likely subunits to be detected in CA1 interneurons. The ß2 nAChR subunit is the highest expressed beta subunit mRNA in these cells. In addition, Pearson's correlation coefficient values are calculated to identify significant differences between the nAChR subunit combinations expressed in the CA1 stratum oriens and the stratum radiatum. Statistical analysis also indicates that there are likely over 100 different nAChR subunit mRNA combinations expressed in rat CA1 interneurons. These results provide a valid avenue for identifying nAChR subtype targets that may be effective hippocampus-specific pharmacological targets.


Assuntos
Receptores Nicotínicos , Ratos , Animais , RNA Mensageiro/metabolismo , Receptores Nicotínicos/genética , Receptores Nicotínicos/metabolismo , Interneurônios/metabolismo , Neurônios/metabolismo , Hipocampo/metabolismo
3.
Pestic Biochem Physiol ; 200: 105837, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38582599

RESUMO

Susceptibility to insecticides is one of the limiting factors preventing wider adoption of natural enemies to control insect pest populations. Identification and selective breeding of insecticide tolerant strains of commercially used biological control agents (BCAs) is one of the approaches to overcome this constraint. Although a number of beneficial insects have been selected for increased tolerance to insecticides the molecular mechanisms underpinning these shifts in tolerance are not well characterised. Here we investigated the molecular mechanisms of enhanced tolerance of a lab selected strain of Orius laevigatus (Fieber) to the commonly used biopesticide spinosad. Transcriptomic analysis showed that spinosad tolerance is not a result of overexpressed detoxification genes. Molecular analysis of the target site for spinosyns, the nicotinic acetylcholine receptor (nAChR), revealed increased expression of truncated transcripts of the nAChR α6 subunit in the spinosad selected strain, a mechanism of resistance which was described previously in insect pest species. Collectively, our results demonstrate the mechanisms by which some beneficial biological control agents can evolve insecticide tolerance and will inform the development and deployment of insecticide-tolerant natural enemies in integrated pest management strategies.


Assuntos
Inseticidas , Receptores Nicotínicos , Tisanópteros , Animais , Tisanópteros/metabolismo , Inseticidas/toxicidade , Resistência a Inseticidas/genética , Agentes de Controle Biológico/farmacologia , Receptores Nicotínicos/genética , Receptores Nicotínicos/metabolismo , Insetos/genética , Macrolídeos/farmacologia , Combinação de Medicamentos
4.
Commun Biol ; 7(1): 437, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38600247

RESUMO

The ability of the Torpedo nicotinic acetylcholine receptor (nAChR) to undergo agonist-induced conformational transitions requires the presence of cholesterol and/or anionic lipids. Here we use recently solved structures along with multiscale molecular dynamics simulations to examine lipid binding to the nAChR in bilayers that have defined effects on nAChR function. We examine how phosphatidic acid and cholesterol, lipids that support conformational transitions, individually compete for binding with phosphatidylcholine, a lipid that does not. We also examine how the two lipids work synergistically to stabilize an agonist-responsive nAChR. We identify rapidly exchanging lipid binding sites, including both phospholipid sites with a high affinity for phosphatidic acid and promiscuous cholesterol binding sites in the grooves between adjacent transmembrane α-helices. A high affinity cholesterol site is confirmed in the inner leaflet framed by a key tryptophan residue on the MX α-helix. Our data provide insight into the dynamic nature of lipid-nAChR interactions and set the stage for a detailed understanding of the mechanisms by which lipids facilitate nAChR function at the neuromuscular junction.


Assuntos
Receptores Nicotínicos , Animais , Receptores Nicotínicos/metabolismo , Torpedo/metabolismo , Fosfolipídeos , Músculos/metabolismo , Fosfatidilcolinas , Colesterol/metabolismo
5.
Sci Rep ; 14(1): 8291, 2024 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-38594566

RESUMO

Neonicotinoids (NEOs) have been designed to act selectively on insect nicotinic acetylcholine receptors (nAChRs). However, nAChRs are also expressed in vertebrate immune cells, so NEOs may interfere with the immune system in exposed non-target animals. The present study shows that NEOs: imidacloprid and thiacloprid, and their main metabolites: desnitro-imidacloprid and thiacloprid amide, at sub-micromolar concentrations ranging from 2.25 to 20 µM, affect the immune cells of fish. This was found both in primary cultures of leukocytes isolated from the carp head kidney and in the continuous adherent carp monocyte/macrophage cell line. Moreover, the results revealed that the studied pesticides and metabolites generate oxidative stress in carp immune cells and that this is one of the most important mechanisms of neonicotinoid immunotoxicity. Significant increases were observed in the formation of ROS and malondialdehyde (MDA). The antioxidant status alteration was linked with decrease in antioxidant enzyme activity: superoxide dismutase (SOD), catalase (CAT), and non-enzymatic antioxidant glutathione (GSH). Importantly, the metabolites: desnitro-imidacloprid and thiacloprid amide showed significantly higher cytotoxicity towards fish leukocytes than their parent compounds, imidacloprid and thiacloprid, which emphasizes the importance of including intermediate metabolites in toxicology studies.


Assuntos
Carpas , Inseticidas , Receptores Nicotínicos , Tiazinas , Animais , Inseticidas/toxicidade , Carpas/metabolismo , Antioxidantes/metabolismo , Neonicotinoides/toxicidade , Nitrocompostos/toxicidade , Estresse Oxidativo , Receptores Nicotínicos/metabolismo , Leucócitos/metabolismo , Amidas
6.
J Environ Sci Health B ; 59(5): 277-284, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38600794

RESUMO

The organophosphate insecticide chlorpyrifos (CPF), an acetylcholinesterase inhibitor, has raised serious concerns about human safety. Apart from inducing synaptic acetylcholine accumulation, CPF could also act at nicotinic acetylcholine receptors, like the α7-isoform (α7-nAChR), which could potentially be harmful to developing brains. Our aims were to use molecular docking to assess the binding interactions between CPF and α7-nAChR through, to test the neurocytotoxic and oxidative effects of very low concentrations of CPF on SH-SY5Y cells, and to hypothesize about the potential mediation of α7-nAChR. Docking analysis showed a significant binding affinity of CPH for the E fragment of the α7-nAChR (ΔGibbs: -5.63 to -6.85 Kcal/mol). According to the MTT- and Trypan Blue-based viability assays, commercial CPF showed concentration- and time-dependent neurotoxic effects at a concentration range (2.5-20 µM), ten-folds lower than those reported to have crucial effects for sheer CPF. A rise of the production of radical oxygen species (ROS) was seen at even lower concentrations (1-2.5 µM) of CPF after 24h. Notably, our docking analysis supports the antagonistic actions of CPF on α7-nAChR that were recently published. In conclusion, while α7-nAChR is responsible for neuronal survival and neurodevelopmental processes, its activity may also mediate the neurotoxicity of CPF.


Assuntos
Clorpirifos , Neuroblastoma , Receptores Nicotínicos , Humanos , Clorpirifos/toxicidade , Simulação de Acoplamento Molecular , Receptor Nicotínico de Acetilcolina alfa7/metabolismo , Acetilcolinesterase/metabolismo , Receptores Nicotínicos/metabolismo
7.
Sci Rep ; 14(1): 9392, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38658769

RESUMO

A series of arecoline derivatives with amino acid moieties were designed and synthesised using an acylamide condensation strategy, taking arecoline as the foundational structure. The insecticidal efficacy of these compounds against Aphis craccivora and Tetranychus cinnabarinus was evaluated. Notably, derivatives 3h and 3i demonstrated superior insecticidal activity compared with arecoline. Additionally, 3h and 3i showed good fungicidal effectiveness against two types of plant fungi. Moreover, molecular docking analyses suggested that 3h and 3i could affect the nervous systems of A. craccivora and T. cinnabarinus by binding to neuronal nicotinic acetylcholine receptors. These findings suggest that compounds 3h and 3i represent promising leads for further development in insecticide and fungicide research.


Assuntos
Aminoácidos , Antifúngicos , Desenho de Fármacos , Inseticidas , Simulação de Acoplamento Molecular , Inseticidas/farmacologia , Inseticidas/síntese química , Inseticidas/química , Animais , Antifúngicos/farmacologia , Antifúngicos/síntese química , Antifúngicos/química , Aminoácidos/química , Afídeos/efeitos dos fármacos , Tetranychidae/efeitos dos fármacos , Relação Estrutura-Atividade , Receptores Nicotínicos/metabolismo , Receptores Nicotínicos/química , Testes de Sensibilidade Microbiana
8.
Cells ; 13(6)2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38534318

RESUMO

Parkinson's disease (PD) is a progressive neurodegenerative disease characterized by resting tremor, bradykinesia, rigidity, and postural instability that also includes non-motor symptoms such as mood dysregulation. Dopamine (DA) is the primary neurotransmitter involved in this disease, but cholinergic imbalance has also been implicated. Current intervention in PD is focused on replenishing central DA, which provides remarkable temporary symptomatic relief but does not address neuronal loss and the progression of the disease. It has been well established that neuronal nicotinic cholinergic receptors (nAChRs) can regulate DA release and that nicotine itself may have neuroprotective effects. Recent studies identified nAChRs in nonneuronal cell types, including glial cells, where they may regulate inflammatory responses. Given the crucial role of neuroinflammation in dopaminergic degeneration and the involvement of microglia and astrocytes in this response, glial nAChRs may provide a novel therapeutic target in the prevention and/or treatment of PD. In this review, following a brief discussion of PD, we focus on the role of glial cells and, specifically, their nAChRs in PD pathology and/or treatment.


Assuntos
Doenças Neurodegenerativas , Doença de Parkinson , Receptores Nicotínicos , Humanos , Doença de Parkinson/metabolismo , Receptores Nicotínicos/metabolismo , Doenças Neurodegenerativas/metabolismo , Nicotina/metabolismo , Dopamina/metabolismo , Astrócitos/metabolismo
9.
Neuropharmacology ; 250: 109927, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38508306

RESUMO

Signaling through nicotinic acetylcholine receptors (nAChRs) plays a role in cocaine reward and reinforcement, suggesting that the cholinergic system could be manipulated with therapeutics to modulate aspects of cocaine use disorder (CUD). We examined the interaction between nAChRs and cocaine reinforcement by expressing a hypersensitive ß2 nAChR subunit (ß2Leu9'Ser) in the ventral tegmental area of male Sprague Dawley rats. Compared to control rats, ß2Leu9'Ser rats acquired (fixed ratio) intravenous cocaine self-administration faster and with greater likelihood. By contrast, ß2Leu9'Ser rats were approximately equivalent to controls in their intake of cocaine on a progressive ratio schedule of reinforcement, suggesting differential effects of cholinergic signaling depending on experimental parameters. Like progressive ratio cocaine SA, ß2Leu9'Ser rats and controls did not differ significantly in food SA assays, including acquisition on a fixed ratio schedule or in progressive ratio sessions. These results highlight the specific role of high-affinity, heteropentameric ß2* (ß2-containing) nAChRs in acquisition of cocaine SA, suggesting that mesolimbic acetylcholine signaling is active during this process.


Assuntos
Cocaína , Receptores Nicotínicos , Ratos , Masculino , Animais , Ratos Sprague-Dawley , Cocaína/farmacologia , Receptores Nicotínicos/metabolismo , Transmissão Sináptica , Colinérgicos , Autoadministração
10.
Chem Biol Interact ; 393: 110957, 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38513929

RESUMO

Huntington's disease (HD) is an inheritable autosomal-dominant disorder that targets mainly the striatum. 3-Nitropropionic acid (3-NP) induces obvious deleterious behavioral, neurochemical, and histological effects similar to the symptoms of HD. Our study aimed to examine the neuroprotective activity of tropisetron, an alpha-7 neuronal nicotinic acetylcholine receptor (α-7nAChR) agonist, against neurotoxic events associated with 3-NP-induced HD in rats. Forty-eight rats were randomly allocated into four groups. Group I received normal saline, while Groups II, III and IV received 3-NP for 2 weeks. In addition, Group III and IV were treated with tropisetron 1 h after 3-NP administration. Meanwhile, Group IV received methyllycaconitine (MLA), an α-7nAChR antagonist, 30 min before tropisetron administration. Treatment with tropisetron improved motor deficits as confirmed by the behavioral tests and restored normal histopathological features of the striatum. Moreover, tropisetron showed an anti-oxidant activity via increasing the activities of SDH and HO-1 as well as Nrf2 expression along with reducing MDA level. Tropisetron also markedly upregulated the protein expression of p-PI3K and p-Akt which in turn hampered JAK2/NF-κB inflammatory cascade. In addition, tropisetron showed an anti-apoptotic activity through boosting the expression of Bcl-2 and reducing Bax expression and caspase-3 level. Interestingly, all the aforementioned effects of tropisetron were blocked by pre-administration of MLA, which confirms that such neuroprotective effects are mediated via activating of α-7nAChR. In conclusion, tropisetron showed a neuroprotective activity against 3-NP-induced HD via activating PI3K/Akt signaling and suppressing JAK2/NF-κB inflammatory axis. Thus, repositioning of tropisetron could represent a promising therapeutic strategy in management of HD.


Assuntos
Doença de Huntington , Fármacos Neuroprotetores , Receptores Nicotínicos , Animais , Ratos , Receptor Nicotínico de Acetilcolina alfa7/metabolismo , Doença de Huntington/tratamento farmacológico , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , NF-kappa B/metabolismo , Nitrocompostos/toxicidade , Fosfatidilinositol 3-Quinases/metabolismo , Propionatos/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptores Nicotínicos/metabolismo , Transdução de Sinais , Tropizetrona/uso terapêutico
11.
Biochem Biophys Res Commun ; 709: 149825, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38537599

RESUMO

SARS-Cov-2, the virus causing COVID-19, penetrates host target cells via the receptor of angiotensin-converting enzyme 2 (ACE2). Disrupting the virus interaction with ACE2 affords a plausible mechanism for prevention of cell penetration and inhibiting dissemination of the virus. Our studies demonstrate that ACE2 interaction with the receptor binding domain of SARS-Cov-2 spike protein (RBD) can be impaired by modulating the α7 nicotinic acetylcholine receptor (α7 nAChR) contiguous with ACE2. U373 cells of human astrocytoma origin were shown to bind both ACE2-specific antibody and recombinant RBD in Cell-ELISA. ACE2 was found to interact with α7 nAChR in U373 cell lysates studied by Sandwich ELISA. Our studies demonstrate that inhibition of RBD binding to ACE2-expressing U373 cells were defined with α7 nAChR agonists choline and PNU282987, but not a competitive antagonist methyllicaconitine (MLA). Additionally, the type 2 positive allosteric modulator (PAM2) PNU120596 and hydroxyurea (HU) also inhibited the binding. Our studies demonstrate that activation of α7 AChRs has efficacy in inhibiting the SARS-Cov-2 interaction with the ACE2 receptor and in such a way can prevent virus target cell penetration. These studies also help to clarify the consistent efficacy and positive outcomes for utilizing HU in treating COVID-19.


Assuntos
COVID-19 , Receptores Nicotínicos , Humanos , SARS-CoV-2/metabolismo , Receptor Nicotínico de Acetilcolina alfa7/metabolismo , Enzima de Conversão de Angiotensina 2/metabolismo , Glicoproteína da Espícula de Coronavírus/química , Receptores Nicotínicos/metabolismo , Ligação Proteica
12.
ACS Chem Neurosci ; 15(7): 1501-1514, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38511291

RESUMO

NS9283, 3-(3-pyridyl)-5-(3-cyanophenyl)-1,2,4-oxadiazole, is a selective positive allosteric modulator of (α4)3(ß2)2 nicotinic acetylcholine receptors (nAChRs). It has good subtype selective therapeutic potential afforded by its specific binding to the unique α4-α4 subunit interface present in the (α4)3(ß2)2 nAChR. However, there is currently a lack of structure activity relationship (SAR) studies aimed at developing a class of congeners endowed with the same profile of activity that can help consolidate the druggability of the α4-α4 subunit interface. In this study, new NS9283 analogues were designed, synthesized, and characterized for their ability to selectively potentiate the ACh activity at heterologous (α4)3(ß2)2 nAChRs vs nAChR subtypes (α4)2(ß2)3, α5α4ß2, and α7. With few exceptions, all the NS9283 analogues exerted positive modulation of the (α4)3(ß2)2 nAChR ACh-evoked responses. Above all, those modified at the 3-cyanophenyl moiety by replacement with 3-nitrophenyl (4), 4-cyanophenyl (10), and N-formyl-4-piperidinyl (20) showed the same efficacy as NS9283, although with lower potency. Molecular dynamics simulations of NS9283 and some selected analogues highlighted consistency between potentiation activity and pose of the ligand inside the α4-α4 site with the main interaction being with the complementary (-) side and induction of a significant conformational change of the Trp156 residue in the principal (+) side.


Assuntos
Receptores Nicotínicos , Receptores Nicotínicos/metabolismo , Piridinas/farmacologia , Piridinas/química , Membrana Celular/metabolismo , Oxidiazóis/farmacologia
13.
J Physiol Sci ; 74(1): 18, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38491428

RESUMO

The olfactory bulb receives cholinergic basal forebrain inputs as does the neocortex. With a focus on nicotinic acetylcholine receptors (nAChRs), this review article provides an overview and discussion of the following findings: (1) the nAChRs-mediated regulation of regional blood flow in the neocortex and olfactory bulb, (2) the nAChR subtypes that mediate their responses, and (3) their activity in old rats. The activation of the α4ß2-like subtype of nAChRs produces vasodilation in the neocortex, and potentiates olfactory bulb vasodilation induced by olfactory stimulation. The nAChR activity producing neocortical vasodilation was similarly maintained in 2-year-old rats as in adult rats, but was clearly reduced in 3-year-old rats. In contrast, nAChR activity in the olfactory bulb was reduced already in 2-year-old rats. Thus, age-related impairment of α4ß2-like nAChR function may occur earlier in the olfactory bulb than in the neocortex. Given the findings, the vasodilation induced by α4ß2-like nAChR activation may be beneficial for neuroprotection in the neocortex and the olfactory bulb.


Assuntos
Neocórtex , Receptores Nicotínicos , Ratos , Animais , Nicotina/farmacologia , Bulbo Olfatório/metabolismo , Receptores Nicotínicos/metabolismo , Colinérgicos , Neocórtex/metabolismo
14.
Nat Commun ; 15(1): 1939, 2024 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-38431681

RESUMO

The Hydroxycarboxylic acid receptor 2 (HCA2), also known as the niacin receptor or GPR109A, is a prototypical GPCR that plays a central role in the inhibition of lipolytic and atherogenic activities. Its activation also results in vasodilation that is linked to the side-effect of flushing associated with dyslipidemia drugs such as niacin. GPR109A continues to be a target for developing potential therapeutics in dyslipidemia with minimized flushing response. Here, we present cryo-EM structures of the GPR109A in complex with dyslipidemia drugs, niacin or acipimox, non-flushing agonists, MK6892 or GSK256073, and recently approved psoriasis drug, monomethyl fumarate (MMF). These structures elucidate the binding mechanism of agonists, molecular basis of receptor activation, and insights into biased signaling elicited by some of the agonists. The structural framework also allows us to engineer receptor mutants that exhibit G-protein signaling bias, and therefore, our study may help in structure-guided drug discovery efforts targeting this receptor.


Assuntos
Dislipidemias , Niacina , Receptores Nicotínicos , Humanos , Niacina/farmacologia , Substituição de Aminoácidos , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Rubor , Receptores Nicotínicos/metabolismo
15.
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
16.
J Agric Food Chem ; 72(11): 5671-5681, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38442746

RESUMO

Neonicotinoids have been widely used to control pests with remarkable effectiveness. Excessive insecticides have led to serious insect resistance. Mutations of the nicotinic acetylcholine receptor (nAChR) are one of the reasons for neonicotinoid resistance conferred in various agricultural pests. Two mutations, V65I and V104I, were found in the nAChR ß1 subunit of two neonicotinoid-resistant aphid populations. However, the specific functions of the two mutations remain unclear. In this study, we cloned and identified four nAChR subunits (α1, α2, α8, and ß1) of thrips and found them to be highly homologous to the nAChR subunits of other insects. Subsequently, we successfully expressed two subtypes nAChR (α1/α2/α8/ß1 and α1/α8/ß1) by coinjecting three cofactors for the first time in thrips, and α1/α8/ß1 showed abundant current rapidly. Acetylcholine, neonicotinoids, and sulfoxaflor exhibited different activation capacities for the two subtypes of nAChRs. Finally, V65I was found to significantly reduce the binding ability of nAChR to neonicotinoids and sulfoxaflor through electrophysiology and computer simulations. V104I caused a decrease in agonist affinity (pEC50) but an increase in the efficacy (Imax) of nAChR against neonicotinoids and reduced the binding ability of nAChR to sulfoxaflor. This study provides theoretical and technical support for studying the molecular mechanisms of neonicotinoid resistance in pests.


Assuntos
Inseticidas , Piridinas , Receptores Nicotínicos , Compostos de Enxofre , Animais , Neonicotinoides/farmacologia , Receptores Nicotínicos/genética , Receptores Nicotínicos/metabolismo , Insetos/metabolismo , Inseticidas/farmacologia , Inseticidas/química , Mutação , Nitrocompostos
17.
Int J Mol Sci ; 25(4)2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38396980

RESUMO

This review summarizes our research on nicotinic acetylcholine receptors in human chromaffin cells. Limited research has been conducted in this field on human tissue, primarily due to the difficulties associated with obtaining human cells. Receptor subtypes were characterized here using molecular biology and electrophysiological patch-clamp techniques. However, the most significant aspect of this study refers to the cross-talk between the two main subtypes identified in these cells, the α7- and α3ß4* subtypes, aiming to avoid their desensitization. The article also reviews other aspects, including the regulation of their expression, function or physical interaction by choline, Ca2+, and tyrosine and serine/threonine phosphatases. Additionally, the influence of sex on their expression is also discussed.


Assuntos
Células Cromafins , Receptores Nicotínicos , Humanos , Receptores Nicotínicos/metabolismo , Colina/metabolismo , Fenômenos Eletrofisiológicos , Células Cromafins/metabolismo
18.
Molecules ; 29(4)2024 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-38398572

RESUMO

Professor Carlos Gutiérrez-Merino, a prominent scientist working in the complex realm of biological membranes, has made significant theoretical and experimental contributions to the field. Contemporaneous with the development of the fluid-mosaic model of Singer and Nicolson, the Förster resonance energy transfer (FRET) approach has become an invaluable tool for studying molecular interactions in membranes, providing structural insights on a scale of 1-10 nm and remaining important alongside evolving perspectives on membrane structures. In the last few decades, Gutiérrez-Merino's work has covered multiple facets in the field of FRET, with his contributions producing significant advances in quantitative membrane biology. His more recent experimental work expanded the ground concepts of FRET to high-resolution cell imaging. Commencing in the late 1980s, a series of collaborations between Gutiérrez-Merino and the authors involved research visits and joint investigations focused on the nicotinic acetylcholine receptor and its relation to membrane lipids, fostering a lasting friendship.


Assuntos
Lipídeos de Membrana , Receptores Nicotínicos , Membrana Celular/metabolismo , Lipídeos de Membrana/química , Transferência Ressonante de Energia de Fluorescência , Membranas/metabolismo , Receptores Nicotínicos/metabolismo
19.
Neurosci Lett ; 824: 137666, 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38331019

RESUMO

Alcohol Use Disorder (AUD) presents a significant and challenging public health concern, marked by a dearth of effective pharmacological treatments. Understanding the neurobiological underpinnings of AUD is of paramount importance for the development of efficacious interventions. The process of addiction entails the acquisition of associative behaviors, prominently engaging the dorsal region of the hippocampus for encoding these associative memories. Nicotinic receptor systems have been implicated in mediating the rewarding effects of ethanol, as well as memory and learning processes. In our current investigation, we delved into the role of α4ß2 nicotinic acetylcholine receptors (nAChRs) within the dorsal hippocampus in the context of ethanol-induced conditioned place preference (CPP), a robust model for scrutinizing the rewarding properties and drug-associated behaviors. To establish CPP, ethanol (2 g/kg) was administered intraperitoneally during a 8-day conditioning phase. Fos immunohistochemistry was employed to assess the involvement of discrete subregions within the dorsal hippocampus in ethanol-induced CPP. Additionally, we probed the influence of α4ß2 nAChRs on CPP via microinjections of a selective nAChR antagonist, dihydro-ß-erythroidine (DHBE, at dosages of 6, 12, and 18 µg/0.5 µL per hemisphere) within the hippocampus. Our results unveiled that ethanol-induced CPP was associated with an increase Fos -positive cells in various subregions of the dorsal hippocampus, including CA1, CA2, CA3, and the dentate gyrus. Intrahippocampal administration of DHBE (at doses of 6 and 18 µg/0.50 µL per hemisphere) effectively blocked ethanol-induced CPP, while leaving locomotor activity unaffected. These findings underscore the critical involvement of the dorsal hippocampus and α4ß2 nAChRs in the acquisition of ethanol-associated learning and reward.


Assuntos
Etanol , Receptores Nicotínicos , Camundongos , Animais , Etanol/farmacologia , Receptores Nicotínicos/metabolismo , Hipocampo/metabolismo , Antagonistas Nicotínicos/farmacologia
20.
Toxins (Basel) ; 16(2)2024 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-38393158

RESUMO

Glioblastoma multiforme (GBM) is the most aggressive type of brain cancer, with a poor prognosis. GBM cells, which develop in the environment of neural tissue, often exploit neurotransmitters and their receptors to promote their own growth and invasion. Nicotinic acetylcholine receptors (nAChRs), which play a crucial role in central nervous system signal transmission, are widely represented in the brain, and GBM cells express several subtypes of nAChRs that are suggested to transmit signals from neurons, promoting tumor invasion and growth. Analysis of published GBM transcriptomes revealed spatial heterogeneity in nAChR subtype expression, and functional nAChRs of α1*, α7, and α9 subtypes are demonstrated in our work on several patient-derived GBM microsphere cultures and on the U87MG GBM cell line using subtype-selective neurotoxins and fluorescent calcium mobilization assay. The U87MG cell line shows reactions to nicotinic agonists similar to those of GBM patient-derived culture. Selective α1*, α7, and α9 nAChR neurotoxins stimulated cell growth in the presence of nicotinic agonists. Several cultivating conditions with varying growth factor content have been proposed and tested. The use of selective neurotoxins confirmed that cell cultures obtained from patients are representative GBM models, but the use of media containing fetal bovine serum can lead to alterations in nAChR expression and functioning.


Assuntos
Glioblastoma , Receptores Nicotínicos , Humanos , Receptores Nicotínicos/genética , Receptores Nicotínicos/metabolismo , Receptor Nicotínico de Acetilcolina alfa7/genética , Receptor Nicotínico de Acetilcolina alfa7/metabolismo , Agonistas Nicotínicos/farmacologia , Proteínas/metabolismo , Peptídeos/farmacologia , Linhagem Celular , Proliferação de Células , Antagonistas Nicotínicos/farmacologia
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