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1.
Environ Res ; 227: 115724, 2023 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-36948285

RESUMO

Neurotoxic pesticides are a group of chemicals that pose a severe threat to both human health and the environment. These molecules are also known to accumulate in the food chain and persist in the environment, which can lead to long-term exposure and adverse effects on non-target organisms. The detrimental effects of these pesticides on neurotransmitter levels and function can lead to a range of neurological and behavioral symptoms, which are closely associated with neurodegenerative diseases. Hence, the accurate and reliable detection of these neurotoxic pesticides and associated neurotransmitters is essential for clinical applications, such as diagnosis and treatment. Over the past few decades, acetylcholinesterase (AchE) biosensors have emerged as a sensitive and reliable tool for the electrochemical detection of neurotoxic pesticides and acetylcholine. These biosensors can be tailored to utilize the high specificity and sensitivity of AchE, enabling the detection of these chemicals. Additionally, enzyme immobilization and the incorporation of nanoparticles have further improved the detection capabilities of these biosensors. AchE biosensors have shown tremendous potential in various fields, including environmental monitoring, clinical diagnosis, and pesticide residue analysis. This review summarizes the advancements in AchE biosensors for electrochemical detection of neurotoxic pesticides and acetylcholine over the past two decades.


Assuntos
Técnicas Biossensoriais , Resíduos de Praguicidas , Praguicidas , Humanos , Praguicidas/análise , Acetilcolinesterase/análise , Acetilcolinesterase/química , Acetilcolinesterase/metabolismo , Acetilcolina/análise , Resíduos de Praguicidas/análise
2.
Int J Mol Sci ; 23(14)2022 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-35887013

RESUMO

Efavirenz (EFV), an FDA-approved anti-HIV drug, has off-target binding to CYP46A1, the CNS enzyme which converts cholesterol to 24-hydroxycholesterol. At small doses, EFV allosterically activates CYP46A1 in mice and humans and mitigates some of the Alzheimer's disease manifestations in 5XFAD mice, an animal model. Notably, in vitro, all phase 1 EFV hydroxymetabolites activate CYP46A1 as well and bind either to the allosteric site for EFV, neurotransmitters or both. Herein, we treated 5XFAD mice with 8,14-dihydroxyEFV, the binder to the neurotransmitter allosteric site, which elicits the highest CYP46A1 activation in vitro. We found that treated animals of both sexes had activation of CYP46A1 and cholesterol turnover in the brain, decreased content of the amyloid beta 42 peptide, increased levels of acetyl-CoA and acetylcholine, and altered expression of the brain marker proteins. In addition, male mice had improved performance in the Barnes Maze test and increased expression of the acetylcholine-related genes. This work expands our knowledge of the beneficial CYP46A1 activation effects and demonstrates that 8,14-dihydroxyEFV crosses the blood-brain barrier and has therapeutic potential as a CYP46A1 activator.


Assuntos
Acetilcolina , Doença de Alzheimer , Encéfalo , Colesterol 24-Hidroxilase , Acetilcolina/análise , Acetilcolina/metabolismo , Alcinos/metabolismo , Alcinos/farmacologia , Alcinos/uso terapêutico , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/genética , Peptídeos beta-Amiloides/metabolismo , Animais , Benzoxazinas/metabolismo , Benzoxazinas/farmacologia , Benzoxazinas/uso terapêutico , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Colesterol/metabolismo , Colesterol 24-Hidroxilase/genética , Colesterol 24-Hidroxilase/metabolismo , Colesterol 24-Hidroxilase/farmacologia , Ciclopropanos/metabolismo , Ciclopropanos/farmacologia , Ciclopropanos/uso terapêutico , Modelos Animais de Doenças , Feminino , Masculino , Camundongos
3.
Elife ; 112022 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-35856493

RESUMO

In the striatum, acetylcholine (ACh) neuron activity is modulated co-incident with dopamine (DA) release in response to unpredicted rewards and reward-predicting cues and both neuromodulators are thought to regulate each other. While this co-regulation has been studied using stimulation studies, the existence of this mutual regulation in vivo during natural behavior is still largely unexplored. One long-standing controversy has been whether striatal DA is responsible for the induction of the cholinergic pause or whether DA D2 receptors (D2Rs) modulate a pause that is induced by other mechanisms. Here, we used genetically encoded sensors in combination with pharmacological and genetic inactivation of D2Rs from cholinergic interneurons (CINs) to simultaneously measure ACh and DA levels after CIN D2R inactivation in mice. We found that CIN D2Rs are not necessary for the initiation of cue-induced decrease in ACh levels. Rather, they prolong the duration of the decrease and inhibit ACh rebound levels. Notably, the change in cue-evoked ACh levels is not associated with altered cue-evoked DA release. Moreover, D2R inactivation strongly decreased the temporal correlation between DA and ACh signals not only at cue presentation but also during the intertrial interval pointing to a general mechanism by which D2Rs coordinate both signals. At the behavioral level D2R antagonism increased the latency to lever press, which was not observed in CIN-selective D2R knock out mice. Press latency correlated with the cue-evoked decrease in ACh levels and artificial inhibition of CINs revealed that longer inhibition shortens the latency to press compared to shorter inhibition. This supports a role of the ACh signal and it's regulation by D2Rs in the motivation to initiate actions.


Assuntos
Acetilcolina , Corpo Estriado , Receptores de Dopamina D2 , Acetilcolina/análise , Acetilcolina/metabolismo , Animais , Colinérgicos , Corpo Estriado/metabolismo , Sinais (Psicologia) , Dopamina , Camundongos , Receptores de Dopamina D2/genética , Receptores de Dopamina D2/metabolismo
4.
J Mater Chem B ; 9(37): 7597-7607, 2021 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-34596205

RESUMO

Enzyme immobilization has been accepted as a powerful technique to solve the drawbacks of free enzymes such as limited activity, stability and recyclability under harsh conditions. Different from the conventional immobilization methods, enzyme immobilization in inorganic hybrid nanoflowers was executed in a biomimetic mineralization manner with the advantages of mild reaction conditions, and thus it was beneficial to obtain ideal biocatalysts with superior characteristics. The key factors influencing the formation of enzyme-based inorganic hybrid nanoflowers were elucidated to obtain a deeper insight into the mechanism for achieving unique morphology and improved properties of immobilized enzymes. To date, immobilized enzymes in inorganic hybrid nanoflowers have been successfully applied in biocatalysis for preparing medical intermediates, biodiesel and biomedical polymers, and solving the environmental or food industrial issues such as the degradation of toxic dyes, pollutants and allergenic proteins. Moreover, they could be used in the development of various biosensors, which provide a promising platform to detect toxic substances in the environment or biomarkers associated with various diseases. We hope that this review will promote the fundamental research and wide applications of immobilized enzymes in inorganic hybrid nanoflowers for expanding biocatalysis and biosensing.


Assuntos
Técnicas Biossensoriais/métodos , Enzimas Imobilizadas/metabolismo , Nanoestruturas/química , Acetilcolina/análise , Biocatálise , Biomarcadores/análise , Doenças do Sistema Nervoso Central/diagnóstico , Poluentes Ambientais/análise , Enzimas Imobilizadas/química , Humanos , Polímeros/química
5.
Anal Biochem ; 632: 114381, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34534543

RESUMO

Acetylcholine (ACh), the major neurotransmitter secreted by cholinergic neurons, is widely found in the peripheral and central nervous systems, and its main function is to complete the transmission of neural signals. When cholinergic neurons are impaired, the synthesis and decomposition of ACh are abnormal and the neural signalling transition is blocked. To some extent, the concentration changes of ACh reflects the occurrence and development of many kinds of nervous system diseases, such as Alzheimer's disease, Parkinson's disease, Myasthenia gravis and so on. Thus, researches of the physiological and pathological roles and the tracking of the concentration changes of ACh in vivo are significant to the prevention and treatment of these diseases. In the paper, the pathophysiological functions and the comprehensive research progress on detection methods of ACh are summarized. Specifically, the latest research and related applications of the optical and electrochemical biosensors are described, and the future development directions and challenges are prospected, which provides a reference for the detection and applications of ACh.


Assuntos
Acetilcolina/análise , Animais , Humanos
6.
Proc Natl Acad Sci U S A ; 118(14)2021 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-33795516

RESUMO

The ability to monitor the release of neurotransmitters during synaptic transmission would significantly impact the diagnosis and treatment of neurological diseases. Here, we present a DNA-based enzymatic nanosensor for quantitative detection of acetylcholine (ACh) in the peripheral nervous system of living mice. ACh nanosensors consist of DNA as a scaffold, acetylcholinesterase as a recognition component, pH-sensitive fluorophores as signal generators, and α-bungarotoxin as a targeting moiety. We demonstrate the utility of the nanosensors in the submandibular ganglia of living mice to sensitively detect ACh ranging from 0.228 to 358 µM. In addition, the sensor response upon electrical stimulation of the efferent nerve is dose dependent, reversible, and we observe a reduction of ∼76% in sensor signal upon pharmacological inhibition of ACh release. Equipped with an advanced imaging processing tool, we further spatially resolve ACh signal propagation on the tissue level. Our platform enables sensitive measurement and mapping of ACh transmission in the peripheral nervous system.


Assuntos
Acetilcolina/metabolismo , Técnicas Biossensoriais/métodos , Gânglios Parassimpáticos/metabolismo , Nanotecnologia/métodos , Acetilcolina/análise , Acetilcolinesterase/química , Acetilcolinesterase/metabolismo , Animais , Bungarotoxinas/farmacologia , Carbocianinas/química , Antagonistas Colinérgicos/farmacologia , DNA/química , Feminino , Corantes Fluorescentes/química , Gânglios Parassimpáticos/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Receptores Colinérgicos/metabolismo
7.
J Vis Exp ; (168)2021 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-33616102

RESUMO

More than 50% of patients with signs and symptoms of myocardial ischemia undergoing coronary angiography have unobstructed coronary arteries. Coronary vasomotor disorders (impaired vasodilatation and/or enhanced vasoconstriction/spasm) represent important functional causes for such a clinical presentation. Although impaired vasodilatation may be assessed with non-invasive techniques such as positron emission tomography or cardiac magnetic resonance imaging, there is currently no reliable non-invasive technique for the diagnosis of coronary spasm available. Thus, invasive diagnostic procedures (IDP) have been developed for the diagnosis of coronary vasomotor disorders including spasm testing as well as assessment of coronary vasodilatation. The identification of the underlying type of disorder (so called endotype) allows the initiation of targeted pharmacological treatments. Despite the fact that such an approach is recommended by the current European Society of Cardiology guidelines for the management of chronic coronary syndromes based on the CorMicA study, comparability of results as well as multicenter trials are currently hampered by major differences in institutional protocols for coronary functional testing. This article describes a comprehensive IDP protocol including intracoronary acetylcholine provocation testing for diagnosis of epicardial/microvascular spasm, followed by Doppler wire-based assessment of coronary flow reserve (CFR) and hyperemic microvascular resistance (HMR) in search of coronary vasodilatory impairment.


Assuntos
Acetilcolina/análise , Adenosina/análise , Vasoespasmo Coronário/diagnóstico , Vasoespasmo Coronário/metabolismo , Feminino , Humanos , Pessoa de Meia-Idade
8.
J Chromatogr Sci ; 59(5): 405-411, 2021 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-33618354

RESUMO

A simple and sensitive method was proposed for choline, carnitine, acetylcarnitine (ACa) and acetylcholine (ACh) separation in feed, blood and urine of animals by using ion chromatography (IC) and detection by tandem mass spectrometry (MS/MS). Analytes were extracted using a mixture of acetonitrile and water, purified by C18 solid-phase extraction columns, separated via IC with an IonPac SCS-1 column and detected by an MS/MS detector by using isotopic internal standards for quantification. The effects of different chromatographic parameters on the separation were also investigated. Under optimal conditions, the recovery was >90%, with the relative standard deviations of <15%. The proposed method was highly reliable for the simultaneous determination of choline, carnitine, ACa and ACh in feed, blood and urine.


Assuntos
Acetilcolina/análise , Ração Animal/análise , Carnitina/análise , Colina/análise , Cromatografia por Troca Iônica/métodos , Acetilcarnitina/análise , Animais , Limite de Detecção , Modelos Lineares , Reprodutibilidade dos Testes , Espectrometria de Massas em Tandem/métodos
9.
Biotechnol Appl Biochem ; 68(1): 20-29, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31943379

RESUMO

Acetylcholine is a neurotransmitter, which is located at the intersections of the nerve and muscles in the lymph nodes of the internal organs motor systems and in various parts of the central nervous system. A decrease of acetylcholine in brain is associated with Alzheimer's disease. That is why it is an important agent for this disease. In this study, a bienzymatic biosensor system with acetylcholine esterase and choline oxidase was prepared with carbon paste electrode modified with carbon nano Dot-(3-Aminopropyl) triethoxysilane (CDs-APTES) for determination of the amount of acetylcholine. Acetylcholine esterase and choline oxidase enzymes were immobilized onto a modified carbon paste electrode by cross-linking with glutaraldehyde. Determination of acetylcholine was carried out by the oxidation of enzymatically produced H2 O2 at 0.4 V versus Ag/AgCl. The effect of temperature, pH, and substrate concentration on the acetylcholine response of the prepared biosensor was investigated. In addition, the optimum CDs-APTES amount, the linear operating range of the biosensor, and the interference effect were also investigated.


Assuntos
Acetilcolina/análise , Acetilcolinesterase/química , Oxirredutases do Álcool/química , Carbono/química , Neurotransmissores/análise , Eletrodos
10.
J Asthma ; 58(8): 1003-1012, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-32329381

RESUMO

OBJECTIVES: Bronchial asthma can be effectively controlled but not be cured, its etiology and pathogenesis are still unclear, and there are no effective preventive measures. The key characteristic of asthma is chronic airway inflammation, and recent research has found that airway neurogenic inflammation plays an important role in asthma. We previously found that Mycobacterium vaccae nebulization protects against asthma. Therefore, this objective of this study is to explore the effect of M. vaccae nebulization on asthmatic neural mechanisms. METHODS: A total 18 of female Balb/c mice were randomized into normal, asthma control, and M. vaccae nebulization (Neb.group) groups, and mice in the Neb.group were nebulized with M. vaccae one month before the asthmatic model was established. Then, 1 month later, the mice were sensitized and challenged with ovalbumin. Twenty-four hours after the last challenge, mouse airway responsiveness; pulmonary brain-derived neurotropic factor (BDNF), neurofilament-medium length (NF-M, using NF09 antibody), and acetylcholine expression; and nerve growth factor (NGF) mRNA level were determined. RESULTS: We found that the BDNF, NF09, acetylcholine expression, and NGF mRNA level were decreased in the Neb.group compared with levels in the asthma control group. CONCLUSION: M. vaccae nebulization may protected in Balb/c mice against bronchial asthma through neural mechanisms.


Assuntos
Asma/prevenção & controle , Mycobacteriaceae , Acetilcolina/análise , Animais , Asma/metabolismo , Asma/patologia , Fator Neurotrófico Derivado do Encéfalo/análise , Feminino , Pulmão/patologia , Camundongos , Camundongos Endogâmicos BALB C , Fator de Crescimento Neural/análise , Fator de Crescimento Neural/genética
11.
ACS Appl Mater Interfaces ; 12(44): 50039-50051, 2020 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-33084309

RESUMO

The malfunctioning in the release of acetylcholine (ACh+), leading to consequential damages in the neural system, has become an impulsion for the development of numerous progressive transport and detection gadgets. However, several challenges, such as laterality and complexity of transport devices, low precision of amperometric detection systems, and sumptuous, multistaged enzymatic quantification methods, have not yet been overcome. Herein, ionomers, because of their selective ion transporting nature, are chosen as suitable candidates for being implemented into both targeted ACh+ delivery and sensing systems. Based on these two approaches, for the very first time in the literature, the disulfonated poly(arylene ether sulfone) membrane is concurrently (i) used in the mimicry of transduction of the electrical-to-ionic signal in a neural network as "Acetylcholine Pen" (ACh+ Pen) and (ii) operated as a highly sensitive, conductivity-based ACh+ quantifier. Our dual device, being able to operate under an actual action potential of 55 mVbias, shows a strong potential of future applicability in real-time ionic delivery-and-sensing systems.


Assuntos
Acetilcolina/análise , Polímeros/química , Tamanho da Partícula , Propriedades de Superfície
12.
Anal Chem ; 92(21): 14740-14746, 2020 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-33064457

RESUMO

A handful of bis/tetra-phosphonate calix[4]pyrroles with recognition sites embedding in hydrophobic cavitands were evaluated for the first time as ionophores for polymeric membrane Ach+-selective electrodes. Highly selective potentiometric Ach+ could be achieved over its analogues, especially for Ch+, which differs only by an acetate tail from Ach+. The superior performance of the proposed ISEs might be ascribed to a dual-site binding mode, in which the trimethylammonium head and acetate tail were accommodated by the phosphonate group-bridged aryl walls and the bowl-shaped aromatic cavity, through cation-π/charge-dipole interaction and the convergent four N-H···O hydrogen bonds, respectively. To gain more insight into the performance of the proposed ISEs, the cation-ionophore complex constants in the membrane phase were determined, and the binding affinity trend correlates well with the selectivity pattern. These results suggest that conformational preorganization of the ionophores and complementary weak interactions do change the selectivity of the ionophores. Studies on the influence of the sample solution pH demonstrated that the developed ISEs can be employed in a wide pH range of 4.0-9.6 with a fast response (<60 s), good reversibility, and long lifetime. Optimizing the membrane components, such as ionophores, lipophilic additives, and plasticizers, yielded ISEs, showing Nernstian responses to Ach+ with improved linear ranges and detection limits (a slope of -59.5 mV/dec in the linear range of 1 × 10-6-1 × 10-2 M with a detection limit of 3 × 10-7 M), which led to the success of the determination of Ach+ in spiked urine and milk samples.


Assuntos
Acetilcolina/análise , Éteres Cíclicos/química , Ionóforos/química , Limite de Detecção , Organofosfonatos/química , Potenciometria/instrumentação , Pirróis/química , Resorcinóis/química , Acetilcolina/química , Eletrodos , Ligação de Hidrogênio , Membranas Artificiais
13.
J Med Food ; 23(9): 920-927, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32833554

RESUMO

Cisplatin is a widely used anticancer drug that has adverse effects on gastrointestinal function. Curcumin is a natural polyphenol extracted from the rhizome of turmeric that has a wide range of biological activities. The present study investigated the effects of cisplatin on gastric emptying in mice and examined whether these can be inhibited by curcumin. We found that pretreatment with curcumin (200 mg/kg/day) for 10-30 days partly inhibited the decreases in gastric emptying rate and body weight induced by cisplatin. Furthermore, cisplatin reduced acetylcholine (ACh) concentration and the messenger RNA (mRNA) level of ACh receptor (AChR) as well as acetylcholinesterase activity in the stomach of mice; caused ultrastructural damage to interstitial cells of Cajal (ICC); and altered the expression of c-kit/stem cell factor and the gap junction protein connexin 43 in ICC. Curcumin pretreatment inhibited the effects of cisplatin on ACh indicators and ICC. These results demonstrate that curcumin can protect against cisplatin-induced gastric emptying disorder and thus has therapeutic potential for alleviating this condition in cancer patients receiving cisplatin chemotherapy.


Assuntos
Acetilcolina/análise , Cisplatino/efeitos adversos , Curcumina , Esvaziamento Gástrico/efeitos dos fármacos , Células Intersticiais de Cajal/efeitos dos fármacos , Animais , Peso Corporal/efeitos dos fármacos , Curcumina/farmacologia , Células Intersticiais de Cajal/metabolismo , Camundongos
14.
Anal Bioanal Chem ; 412(18): 4327-4341, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32367293

RESUMO

Acetylcholine (ACh) is a crucial neurotransmitter that is involved in airway constriction. In fact, excessive ACh binding to M3 muscarinic receptor leads to airflow obstruction via smooth muscle contraction. Previous studies have suggested cholinergic malfunction in the pathogenesis of asthma; however, the distribution and abundance of ACh in asthmatic lungs remain unclear because of the challenges of imaging ACh in lung tissue. In this study, we successfully detected and visualised ACh in mouse lung tissue by using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). Here, we applied the ACh imaging method to the two groups of house dust mite-sensitised asthma model mice harbouring different inflammatory levels. The imaging results showed that the lungs of mice had a relatively uniform ACh distribution with some areas of heterogeneity. The lungs of asthma model mice had significantly more ACh than control mice, and the ACh increase was potentiated with intense eosinophil infiltration without acetylcholinesterase deficits. These results indicate that ACh hypersecretion is mediated by an increased infiltration of eosinophils in asthma aggravation. This study provides the first evidence that secreted ACh is elevated with asthma severity in the lungs of asthma model animals by a direct ACh imaging technique with FT-ICR-MS.


Assuntos
Acetilcolina/análise , Asma/patologia , Pulmão/patologia , Espectrometria de Massas/métodos , Animais , Modelos Animais de Doenças , Feminino , Análise de Fourier , Pulmão/química , Camundongos Endogâmicos BALB C
15.
Int J Mol Sci ; 21(3)2020 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-32041338

RESUMO

The effect of cholesterol was investigated on the OCTN1 transport activity measured as [14C]-tetraethylamonium or [3H]-acetylcholine uptake in proteoliposomes reconstituted with native transporter extracted from HeLa cells or the human recombinant OCTN1 over-expressed in E. coli. Removal of cholesterol from the native transporter by MßCD before reconstitution led to impairment of transport activity. A similar activity impairment was observed after treatment of proteoliposomes harboring the recombinant (cholesterol-free) protein by MßCD, suggesting that the lipid mixture used for reconstitution contained some cholesterol. An enzymatic assay revealed the presence of 10 µg cholesterol/mg total lipids corresponding to 1% cholesterol in the phospholipid mixture used for the proteoliposome preparation. On the other way around, the activity of the recombinant OCTN1 was stimulated by adding the cholesterol analogue, CHS to the proteoliposome preparation. Optimal transport activity was detected in the presence of 83 µg CHS/ mg total lipids for both [14C]-tetraethylamonium or [3H]-acetylcholine uptake. Kinetic analysis of transport demonstrated that the stimulation of transport activity by CHS consisted in an increase of the Vmax of transport with no changes of the Km. Altogether, the data suggests a direct interaction of cholesterol with the protein. A further support to this interpretation was given by a docking analysis indicating the interaction of cholesterol with some protein sites corresponding to CARC-CRAC motifs. The observed direct interaction of cholesterol with OCTN1 points to a possible direct influence of cholesterol on tumor cells or on acetylcholine transport in neuronal and non-neuronal cells via OCTN1.


Assuntos
Acetilcolina/análise , Colesterol/farmacologia , Proteínas de Transporte de Cátions Orgânicos/metabolismo , Simportadores/metabolismo , Tetraetilamônio/análise , Acetilcolina/química , Radioisótopos de Carbono/química , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células HeLa , Humanos , Simulação de Acoplamento Molecular , Proteolipídeos/análise , Proteolipídeos/química , Tetraetilamônio/química , Trítio/química
16.
Anal Chem ; 92(4): 3373-3379, 2020 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-31941278

RESUMO

Single-atom nanozymes (SAzymes), as novel nanozymes with atomically dispersed active sites, are of great importance in the development of nanozymes for their high catalytic activities, the maximum utilization efficiency of metal atoms, and the simple model of active sites. Herein, the peroxidase-like SAzymes with high-concentration Cu sites on carbon nanosheets (Cu-N-C) were synthesized through a salt-template strategy. With the densely distributed active Cu atoms (∼5.1 wt %), the Cu-N-C SAzymes exhibit remarkable activity to mimic natural peroxidase. Integrating Cu-N-C SAzymes with natural acetylcholinesterase and choline oxidase, three-enzyme-based cascade reaction system was constructed for the colorimetric detection of acetylcholine and organophosphorus pesticides. This work not only provides a strategy to synthesize SAzymes with abundant active sites but also gives some new insights for robust nanozyme biosensing systems.


Assuntos
Acetilcolina/análise , Acetilcolinesterase/metabolismo , Oxirredutases do Álcool/metabolismo , Técnicas Biossensoriais , Cobre/metabolismo , Compostos Organofosforados/análise , Praguicidas/análise , Acetilcolina/metabolismo , Acetilcolinesterase/química , Oxirredutases do Álcool/química , Carbono/química , Carbono/metabolismo , Cobre/química , Nanopartículas/química , Nanopartículas/metabolismo , Compostos Organofosforados/metabolismo , Praguicidas/metabolismo
17.
Clin Exp Dermatol ; 45(4): 432-437, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31614011

RESUMO

BACKGROUND: Although during recent years there have been considerable advances in elucidating the mechanisms of psoriasis pathogenesis, its full understanding is still distant. A cholinergic dysfunction has been proposed in the pathophysiology of some inflammatory and autoimmune diseases, including psoriasis. AIM: To determine tissue levels of acetylcholine (ACh) and its muscarinic and nicotinic receptors (mAChR and nAChR) in psoriasis vulgaris lesions in comparison with normal control skin. METHODS: This case-control study included 30 patients with psoriasis vulgaris and 30 controls. A 4-mm punch skin biopsy was taken from the psoriatic plaques of patients and normal skin of controls. ACh level was measured in tissues using the colorimetric method, while mAChR and nAChR gene expression was determined by real-time PCR. RESULTS: The level of ACh was significantly higher in patients (mean ± SD: 5.95 ± 2.69) than in controls (1.12 ± 0.34) (P < 0.001). mAChR and nAChR expressions were significantly higher in patients compared with the controls (P < 0.001). A significant positive correlation was detected between the expression of nAChR in patients and the duration of psoriasis (r = 0.46, P = 0.01), and the body mass index of the patients correlated positively with both nAChR (r = 0.40, P = 0.027) and mAChR expression (r = 0.448, P = 0.013). CONCLUSION: Abnormalities in the cutaneous extraneuronal cholinergic system could be involved in the pathogenesis of psoriasis. The high expression of nAChRs in patients with longer disease durations might represent an attempt by the body to regulate the inflammatory cascade in psoriatic lesions. The high expression of mAChR in psoriatic lesions may provide a link between psoriasis and obesity.


Assuntos
Acetilcolina/análise , Psoríase/metabolismo , Receptores Muscarínicos/metabolismo , Receptores Nicotínicos/metabolismo , Adolescente , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Psoríase/patologia , Receptores Muscarínicos/análise , Receptores Nicotínicos/análise , Adulto Jovem
18.
J Chromatogr A ; 1609: 460506, 2020 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-31526637

RESUMO

A high-performance liquid chromatography-mass spectrometry technique hyphenated on-line with an immobilized enzyme reactor (IMER) was developed by the use of 3 known acetylcholinesterase (AChE) inhibitors (galanthamine, huperzine A and tacrine). This bioanalytical device allows qualitative comparison of the inhibitory strengths of AChE inhibitors. The AChE inhibitory strengths were evaluated and compared by the corresponding acetylcholine peak areas (mass signal) obtained after a chromatographic separation and the elution through the IMER. Only one injection of the analytes is needed to get this comparative analysis. This bioanalytical device was then applied to the extract of a natural plant, Lycoris radiata, which is known to contain AChE inhibitors such as galanthamine and lycoramine. Aside from the demonstration of the inhibitory activity of the two known AChE inhibitors, the AChE inhibitory activity of another compound (dihydro-latifaliumin C) was revealed. This is the first report describing the AChE inhibitory activity of this compound.


Assuntos
Inibidores da Colinesterase/análise , Cromatografia Líquida de Alta Pressão/métodos , Enzimas Imobilizadas/análise , Espectrometria de Massas/métodos , Sistemas On-Line , Acetilcolina/análise , Acetilcolinesterase/química , Reatores Biológicos , Galantamina/análise , Limite de Detecção , Lycoris/química , Extratos Vegetais/química , Reprodutibilidade dos Testes
19.
Biosens Bioelectron ; 148: 111796, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31665672

RESUMO

We present a new strategy of Acetylcholinesterease (AchE) immobilization on graphene field-effect transistors (gFETs) for building up Acetylcholine sensors. This method is based on the electrosynthesis of an amino moiety-bearing polymer layer on the graphene channel. The film of the copolymer poly(3-amino-benzylamine-co-aniline) (PABA) does not only provide the suitable electrostatic charge and non-denaturing environment for enzyme immobilization, but it also improves the pH sensitivity of the gFETs (from 40.8 to 56.3 µA/pH unit), probably due to its wider effective pKa distribution. The local pH changes caused by the enzyme-catalyzed hydrolysis produce a shift in the Dirac point of the gFETs to more negative values, which are evidenced as differences in the gFET conductivity and thereby constituted the signal transduction mechanism of the modified transistors. In this way, the constructed biosensors showed a LOD of 2.3 µM and were able to monitor Ach in the range from 5 to 1000 µM in a flow configuration. Moreover, they showed a sensitivity of -26.6 ±â€¯0.7 µA/Ach decade and also exhibited a very low RSD of 2.6%, revealing good device-to-device reproducibility. The biosensors revealed an excellent selectivity to interferences known to be present in the extracellular milieu, and the response to Ach was recovered by 97.5% after the whole set of interferences injected. Finally, the biosensors showed a fast response time, with an average value of 130 s and a good long-term response.


Assuntos
Acetilcolina/análise , Técnicas Biossensoriais/instrumentação , Grafite/química , Polímeros/química , Transistores Eletrônicos , Acetilcolinesterase/química , Compostos de Anilina/química , Benzilaminas/química , Enzimas Imobilizadas/química , Desenho de Equipamento , Oxirredução , Polimerização , Água/análise
20.
Inorg Chem ; 58(15): 9773-9784, 2019 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-31318533

RESUMO

In recent years, transition metal complexes have been developed for catalytical degradation of a phosphate ester bond, particularly in RNA and DNA; however, less consideration has been given for development of complexes for the degradation of a phosphorothioate bond, as they are the foremost used pesticides in the environment and are toxic to human beings. In this context, we have developed copper complexes of benzimidazolium based ligands for catalytical degradation of a series of organophosphates (parathion, paraoxon, methyl-parathion) at ambient conditions. The copper complexes (assigned as N1-N3) were characterized using single X-ray crystallography which revealed that all three complexes are mononuclear and distorted square planner in geometry. Further, the solution state studies of the prepared complexes were carried out using UV-visible absorption, fluorescence spectroscopy, and cyclic voltametry. The complexes N1 and N2 have benzimidazolium ionic liquid as base attached with two 2-mercapto-benzimidazole pods, whereas complex N3 contains a nonionic ligand. The synthesized copper complexes were evaluated for their catalytic activity for degradation of organophosphates. It is interesting that the complex containing the ionic ligand efficiently degrades phosphorothioate pesticides, whereas complex N3 was not found to be appropriate for degradation due to a weaker conversion rate. The organophosphate degradation studies were monitored by recording absorbance spectra of parathion in the presence of catalyst, i.e., copper complexes with respect to time. The parathion was hydrolyzed into para-nitrophenol and diethyl thiophosphate. Moreover, to analyze the inhibition activity of the pesticides toward acetylcholine esterase enzyme in the presence of prepared metal complexes, Ellman's assay was performed and revealed that, within 20 min, the inhibition of acetylcholine esterase enzyme decreases by up to 13%.


Assuntos
Acetilcolina/metabolismo , Esterases/metabolismo , Estruturas Metalorgânicas/química , Praguicidas/química , Praguicidas/toxicidade , Fosfatos/química , Acetilcolina/análise , Benzimidazóis/química , Catálise , Cobre/química , Cristalografia por Raios X , Esterases/análise , Estruturas Metalorgânicas/síntese química , Modelos Moleculares , Estrutura Molecular , Fosfatos/toxicidade
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