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1.
Int J Mol Sci ; 22(16)2021 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-34445564

RESUMO

Niemann-Pick type C (NPC) disease is a wide-spectrum clinical condition classified as a neurovisceral disorder affecting mainly the liver and the brain. It is caused by mutations in one of two genes, NPC1 and NPC2, coding for proteins located in the lysosomes. NPC proteins are deputed to transport cholesterol within lysosomes or between late endosome/lysosome systems and other cellular compartments, such as the endoplasmic reticulum and plasma membrane. The first trait of NPC is the accumulation of unesterified cholesterol and other lipids, like sphingosine and glycosphingolipids, in the late endosomal and lysosomal compartments, which causes the blockade of autophagic flux and the impairment of mitochondrial functions. In the brain, the main consequences of NPC are cerebellar neurodegeneration, neuroinflammation, and myelin defects. This review will focus on myelin defects and the pivotal importance of cholesterol for myelination and will offer an overview of the molecular targets and the pharmacological strategies so far proposed, or an object of clinical trials for NPC. Finally, it will summarize recent data on a new and promising pharmacological perspective involving A2A adenosine receptor stimulation in genetic and pharmacological NPC dysmyelination models.


Assuntos
Agonistas do Receptor A2 de Adenosina/farmacologia , Colesterol/metabolismo , Bainha de Mielina/patologia , Doença de Niemann-Pick Tipo C/patologia , Receptor A2A de Adenosina/metabolismo , Animais , Humanos , Bainha de Mielina/efeitos dos fármacos , Doença de Niemann-Pick Tipo C/tratamento farmacológico , Doença de Niemann-Pick Tipo C/metabolismo
2.
ACS Chem Biol ; 16(6): 991-1002, 2021 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-34048655

RESUMO

Allosteric ligands provide new opportunities to modulate G protein-coupled receptor (GPCR) function and present therapeutic benefits over orthosteric molecules. Negative allosteric modulators (NAMs) can inhibit the activation of a receptor and downstream signal transduction. Screening NAMs for a GPCR target is particularly challenging because of the difficulty in distinguishing NAMs from antagonists bound to the orthosteric site as they both show inhibitory effects in receptor signaling assays. Here we report an affinity mass spectrometry (MS)-based approach tailored to screening potential NAMs of a GPCR target especially from fragment libraries. Compared to regular surface plasmon resonance or NMR-based methods for fragment screening, our approach features a reduction of the protein and compound consumption by 2-4 orders of magnitude and an increase in the data acquisition speed by 2-3 orders of magnitude. Our affinity MS-based fragment screening led to the identification of a new NAM of the adenosine A2A receptor (A2AAR) bearing an unprecedented azetidine moiety predicted to occupy the allosteric sodium binding site. Molecular dynamics simulations, ligand structure-activity relationship (SAR) studies, and in-solution NMR analyses further revealed the unique binding mode and antagonistic property of this compound that differs considerably from HMA (5-(N,N-hexamethylene)amiloride), a well-characterized NAM of A2AAR. Taken together, our work would facilitate fragment-based screening of allosteric modulators, as well as guide the design of novel NAMs acting at the sodium ion pocket of class A GPCRs.


Assuntos
Agonistas do Receptor A2 de Adenosina/farmacologia , Antagonistas do Receptor A2 de Adenosina/farmacologia , Regulação Alostérica/efeitos dos fármacos , Receptor A2A de Adenosina/metabolismo , Sódio/metabolismo , Agonistas do Receptor A2 de Adenosina/química , Antagonistas do Receptor A2 de Adenosina/química , Sítio Alostérico/efeitos dos fármacos , Sítios de Ligação/efeitos dos fármacos , Descoberta de Drogas , Humanos , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Receptor A2A de Adenosina/química
3.
ACS Chem Neurosci ; 12(9): 1606-1620, 2021 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-33856784

RESUMO

Characterizing the structural basis of ligand recognition of adenosine A2A receptor (AA2AR) will facilitate its rational design and development of small molecules with high affinity and selectivity, as well as optimal therapeutic effects for pain, cancers, drug abuse disorders, etc. In the present work, we applied our reported algorithm, molecular complex characterizing system (MCCS), to characterize the binding features of AA2AR based on its reported 3D structures of protein-ligand complexes. First, we compared the binding score to the reported experimental binding affinities of each compound. Then, we calculated an output example of residue energy contribution using MCCS and compared the results with data obtained from MM/GBSA. The consistency in results indicated that MCCS is a powerful, fast, and accurate method. Sequentially, using a receptor-ligand data set of 57 crystallized structures of AA2ARs, we characterized the binding features of the binding pockets in AA2AR, summarized the key residues that distinguish antagonist from agonist, produced heatmaps of residue energy contribution for clustering various statuses of AA2ARs, explored the selectivity between AA2AR and AA1AR, etc. All the information provided new insights into the protein features of AA2AR and will facilitate its rational drug design.


Assuntos
Antagonistas do Receptor A2 de Adenosina , Receptor A2A de Adenosina , Adenosina , Agonistas do Receptor A2 de Adenosina/farmacologia , Antagonistas do Receptor A2 de Adenosina/farmacologia , Ligantes , Ligação Proteica , Receptor A2A de Adenosina/metabolismo
4.
Toxicol Appl Pharmacol ; 422: 115460, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-33774062

RESUMO

To explore the protective mechanism of simvastatin in acute lung injury (ALI), the lipopolysaccharide (LPS) induced (5 mg/kg) ALI rat model was used to examine the effects of simvastatin. Following simvastatin treatment, the histopathological evaluation of lung tissues was made using hematoxylin and eosin (H&E) staining. Also, myeloperoxidase (MPO) activity and the levels of tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1ß), and IL-10 were determined by ELISA. Blood gas analyses of arterial blood samples were performed to assess the pulmonary gas exchange. Moreover, the neutrophil count and total protein content were determined in the bronchoalveolar lavage (BAL) fluid. The ratio of wet lung to dry lung (W/D) and the alveolar fluid clearance (AFC) were calculated to estimate the severity of edema. Lastly, the levels of A2BAR, CFTR, claudin4, and claudin18 were also measured by qRT-PCR and Western blotting. Simvastatin treatment, in a dose-related manner, markedly improved the lung histological injury and decreased the levels of TNF-α, IL-1ß, and increased IL-10 in LPS induced ALI. Also, pulmonary neutrophil count was alleviated. Besides, a decreased ratio of W/D lung also confirmed the simvastatin intervention. Notably, simvastatin reduced the levels of A2BAR, CFTR, and claudin18 but upregulated claudin4 in lung tissues. Additionally, treatment with PSB1115, an antagonist of A2BAR, countered the protective effect of simvastatin in ALI. Our study demonstrates that simvastatin has a protective effect against LPS-induced ALI by activating A2BAR and should be exploited as a novel therapeutic target for the treatment of ALI.


Assuntos
Lesão Pulmonar Aguda/prevenção & controle , Agonistas do Receptor A2 de Adenosina/farmacologia , Pulmão/efeitos dos fármacos , Receptor A2B de Adenosina/efeitos dos fármacos , Sinvastatina/farmacologia , Lesão Pulmonar Aguda/induzido quimicamente , Lesão Pulmonar Aguda/metabolismo , Lesão Pulmonar Aguda/patologia , Animais , Claudina-4/metabolismo , Claudinas/metabolismo , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Citocinas/metabolismo , Modelos Animais de Doenças , Mediadores da Inflamação/metabolismo , Lipopolissacarídeos , Pulmão/metabolismo , Pulmão/patologia , Masculino , Infiltração de Neutrófilos/efeitos dos fármacos , Edema Pulmonar/induzido quimicamente , Edema Pulmonar/metabolismo , Edema Pulmonar/patologia , Edema Pulmonar/prevenção & controle , Ratos Sprague-Dawley , Receptor A2B de Adenosina/metabolismo , Transdução de Sinais
5.
PLoS One ; 16(3): e0248689, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33735236

RESUMO

Cerebral ischemia causes tissue death owing to occlusion of the cerebral blood vessels, and cerebral ischemia activates mitogen-activated protein kinase (MAPK) and induces secretion of pro-inflammatory cytokines. Adenosine A2A receptor agonist, polydeoxyribonucleotide (PDRN), suppresses the secretion of pro-inflammatory cytokines and exhibits anti-inflammatory effect. In the current study, the therapeutic effect of PDRN on cerebral ischemia was evaluated using gerbils. For the induction of cerebral ischemia, the common carotid arteries were exposed, and then aneurysm clips were used to occlude the common carotid arteries bilaterally for 7 minutes. In the PDRN-treated groups, the gerbils were injected intraperitoneally with 0.3 mL of saline containing 8 mg/kg PDRN, per a day for 7 days following cerebral ischemia induction. In order to confirm the participation of the adenosine A2A receptor in the effects mediated by PDRN, 8 mg/kg 7-dimethyl-1-propargylxanthine (DMPX), adenosine A2A receptor antagonist, was treated with PDRN. In the current study, induction of ischemia enhanced the levels of pro-inflammatory cytokines and increased phosphorylation of MAPK signaling factors in the hippocampus and basolateral amygdala. However, treatment with PDRN ameliorated short-term memory impairment by suppressing the production of pro-inflammatory cytokines and inactivation of MAPK signaling factors in cerebral ischemia. Furthermore, PDRN treatment enhanced the concentration of cyclic adenosine-3,5'-monophosphate (cAMP) as well as phosphorylation of cAMP response element-binding protein (p-CREB). Co-treatment of DMPX and PDRN attenuated the therapeutic effect of PDRN on cerebral ischemia. Based on these findings, PDRN may be developed as the primary treatment in cerebral ischemia.


Assuntos
Agonistas do Receptor A2 de Adenosina/farmacologia , Isquemia Encefálica/tratamento farmacológico , Transtornos da Memória/tratamento farmacológico , Memória de Curto Prazo/efeitos dos fármacos , Polidesoxirribonucleotídeos/farmacologia , Agonistas do Receptor A2 de Adenosina/uso terapêutico , Antagonistas do Receptor A2 de Adenosina/administração & dosagem , Animais , Isquemia Encefálica/complicações , Isquemia Encefálica/imunologia , AMP Cíclico/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Modelos Animais de Doenças , Gerbillinae , Humanos , Inflamação/tratamento farmacológico , Inflamação/imunologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Transtornos da Memória/imunologia , Fosforilação/efeitos dos fármacos , Polidesoxirribonucleotídeos/uso terapêutico , Receptor A2A de Adenosina/metabolismo
6.
Int J Mol Sci ; 22(4)2021 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-33572077

RESUMO

Adenosine and dopamine interact antagonistically in living mammals. These interactions are mediated via adenosine A2A and dopamine D2 receptors (R). Stimulation of A2AR inhibits and blockade of A2AR enhances D2R-mediated locomotor activation and goal-directed behavior in rodents. In striatal membrane preparations, adenosine decreases both the affinity and the signal transduction of D2R via its interaction with A2AR. Reciprocal A2AR/D2R interactions occur mainly in striatopallidal GABAergic medium spiny neurons (MSNs) of the indirect pathway that are involved in motor control, and in striatal astrocytes. In the nucleus accumbens, they also take place in MSNs involved in reward-related behavior. A2AR and D2R co-aggregate, co-internalize, and co-desensitize. They are at very close distance in biomembranes and form heteromers. Antagonistic interactions between adenosine and dopamine are (at least partially) caused by allosteric receptor-receptor interactions within A2AR/D2R heteromeric complexes. Such interactions may be exploited in novel strategies for the treatment of Parkinson's disease, schizophrenia, substance abuse, and perhaps also attention deficit-hyperactivity disorder. Little is known about shifting A2AR/D2R heteromer/homodimer equilibria in the brain. Positron emission tomography with suitable ligands may provide in vivo information about receptor crosstalk in the living organism. Some experimental approaches, and strategies for the design of novel imaging agents (e.g., heterobivalent ligands) are proposed in this review.


Assuntos
Imagem Molecular/métodos , Tomografia por Emissão de Pósitrons/métodos , Receptor A2A de Adenosina/metabolismo , Receptores de Dopamina D2/metabolismo , Agonistas do Receptor A2 de Adenosina/farmacologia , Agonistas do Receptor A2 de Adenosina/uso terapêutico , Antagonistas do Receptor A2 de Adenosina/farmacologia , Antagonistas do Receptor A2 de Adenosina/uso terapêutico , Regulação Alostérica/efeitos dos fármacos , Animais , Astrócitos/metabolismo , AMP Cíclico/metabolismo , Modelos Animais de Doenças , Neurônios GABAérgicos/metabolismo , Globo Pálido/citologia , Globo Pálido/diagnóstico por imagem , Globo Pálido/metabolismo , Humanos , Ligantes , Locomoção/efeitos dos fármacos , Locomoção/fisiologia , Camundongos , Núcleo Accumbens/citologia , Núcleo Accumbens/diagnóstico por imagem , Núcleo Accumbens/metabolismo , Doença de Parkinson/diagnóstico , Doença de Parkinson/tratamento farmacológico , Multimerização Proteica/efeitos dos fármacos , Ratos , Recompensa , Esquizofrenia/diagnóstico , Esquizofrenia/tratamento farmacológico , Transtornos Relacionados ao Uso de Substâncias/diagnóstico , Transtornos Relacionados ao Uso de Substâncias/tratamento farmacológico
7.
Neurochem Int ; 145: 104983, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33577869

RESUMO

Improvements in neuronal plasticity are considered to be conducive to recovery from neuropathic pain. Electroacupuncture (EA) is regarded as an effective rehabilitation method for neuropathic pain. However, the effects and potential mechanism associated with EA-induced repair of hyperesthesia are not fully understood. Evidence has suggested that the adenosine A2A receptor (A2AR) and the cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) pathway play an important role in improving neuropathic pain. Here, we examined the function of EA in promoting neuronal plasticity in spinal nerve ligation (SNL) rats. The A2AR antagonist SCH58261, A2AR agonist 2-p-(2-carboxyethyl)phenethylamino-50-N-ethylcarboxamido adenosine HCl (CGS21680) and A2AR siRNA were used to confirm the relationship between A2AR and the cAMP/PKA pathway as well as the effects of A2AR on EA-induced improvements in neurobehavioral state and neuronal plasticity. Mechanical withdrawal threshold (MWT), thermal withdrawal latency (TWL), HE staining, Western blotting, RT-PCR, immunofluorescence, enzyme-linked immunosorbent assay, Nissl staining, silver staining, Golgi-Cox staining and transmission electron microscopy were used to evaluate the changes in neurobehavioral performance, protein expression, neuronal structure and dendrites/synapses. The results showed that EA and CGS21680 improved the behavioral performance, neuronal structure and dendritic/synaptic morphology of SNL rats, consistent with higher expression levels of A2AR, cAMP and PKA. In contrast to the positive effects of EA, SCH58261 inhibited dendritic growth and promoted dendritic spine/synaptic remodeling. In addition, the EA-induced improvement in neuronal plasticity was inhibited by SCH58261 and A2AR siRNA, consistent with lower expression levels of A2AR, cAMP and PKA, and worse behavioral performance. These results indicate that EA suppresses SNL-induced neuropathic pain by improving neuronal plasticity via upregulating the A2AR/cAMP/PKA signaling pathway.


Assuntos
Proteínas Quinases Dependentes de AMP Cíclico/biossíntese , AMP Cíclico/biossíntese , Eletroacupuntura/métodos , Neuralgia/metabolismo , Plasticidade Neuronal/fisiologia , Receptor A2A de Adenosina/biossíntese , Agonistas do Receptor A2 de Adenosina/farmacologia , Antagonistas do Receptor A2 de Adenosina/farmacologia , Animais , Ligadura/efeitos adversos , Masculino , Neuralgia/terapia , Plasticidade Neuronal/efeitos dos fármacos , Medição da Dor/métodos , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Nervos Espinhais/lesões
8.
Neurochem Res ; 46(5): 1081-1091, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33616808

RESUMO

Propofol has shown strong addictive properties in rats and humans. Adenosine A2A receptors (A2AR) in the nucleus accumbens (NAc) modulate dopamine signal and addictive behaviors such as cocaine- and amphetamine-induced self-administration. However, whether A2AR can modulate propofol addiction remains unknown. AAV-shA2AR was intra-NAc injected 3 weeks before the propofol self-administration training to test the impacts of NAc A2AR on establishing the self-administration model with fixed ratio 1 (FR1) schedule. Thereafter, the rats were withdrawal from propofol for 14 days and tested cue-induced reinstatement of propofol seeking behavior on day 15. The propofol withdrawal rats received one of the doses of CGS21680 (A2AR agonist, 2.5-10.0 ng/site), MSX-3 (A2AR antagonist, 5.0-20.0 µg/site) or eticlopride (D2 receptor (D2R) antagonist, 0.75-3.0 µg/site) or vehicle via intra-NAc injection before relapse behavior test. The numbers of active and inactive nose-poke response were recorded. Focal knockdown A2AR by shA2AR did not affect the acquisition of propofol self-administration behavior, but enhance cue-induced reinstatement of propofol self-administration compared with the AAV-shCTRLgroup. Pharmacological activation of the A2AR by CGS21680 (≥ 5.0 ng/site) attenuated cue-induced reinstatement of propofol self-administration behavior. Similarly, pharmacological blockade of D2R by eticlopride (0.75-3.0 µg/site) attenuated propofol seeking behavior. These effects were reversed by the administration of MSX-3 (5.0-20.0 µg/site). The A2AR- and D2R-mediated effects on propofol relapse were not confounded by the learning process, and motor activity as the sucrose self-administration and locomotor activity were not affected by all the treatments. This study provides genetic and pharmacological evidence that NAc A2AR activation suppresses cue-induced propofol relapse in rats, possibly by interacting with D2R.


Assuntos
Núcleo Accumbens/efeitos dos fármacos , Propofol/farmacologia , Receptor A2A de Adenosina/metabolismo , Transtornos Relacionados ao Uso de Substâncias/metabolismo , Adenosina/análogos & derivados , Adenosina/farmacologia , Agonistas do Receptor A2 de Adenosina/farmacologia , Antagonistas do Receptor A2 de Adenosina/farmacologia , Animais , Sinais (Psicologia) , Masculino , Núcleo Accumbens/metabolismo , Fenetilaminas/farmacologia , Propofol/administração & dosagem , RNA Interferente Pequeno/farmacologia , Ratos Sprague-Dawley , Receptor A2A de Adenosina/deficiência , Recidiva , Autoadministração , Xantinas/farmacologia
9.
Structure ; 29(2): 170-176.e3, 2021 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-33238145

RESUMO

In drug design, G protein-coupled receptor (GPCR) partial agonists enable one to fine-tune receptor output between basal and maximal signaling levels. Here, we add to the structural basis for rationalizing and monitoring partial agonism. NMR spectroscopy of partial agonist complexes of the A2A adenosine receptor (A2AAR) revealed conformations of the P-I-F activation motif that are distinctly different from full agonist complexes. At the intracellular surface, different conformations of helix VI observed for partial and full agonist complexes manifest a correlation between the efficacy-related structural rearrangement of this activation motif and intracellular signaling to partner proteins. While comparisons of A2AAR in complexes with partial and full agonists with different methods showed close similarity of the global folds, this NMR study now reveals subtle but distinct local structural differences related to partial agonism.


Assuntos
Agonismo Parcial de Drogas , Receptor A2A de Adenosina/química , Agonistas do Receptor A2 de Adenosina/química , Agonistas do Receptor A2 de Adenosina/farmacologia , Aminopiridinas/química , Aminopiridinas/farmacologia , Sítios de Ligação , Linhagem Celular , Humanos , Imidazóis/química , Imidazóis/farmacologia , Simulação de Dinâmica Molecular , Ligação Proteica , Purinas/química , Purinas/farmacologia , Pirazóis/química , Pirazóis/farmacologia , Receptor A2A de Adenosina/metabolismo
10.
Biochem Pharmacol ; 187: 114370, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33338473

RESUMO

G protein-coupled receptors (GPCRs) are the largest class of membrane proteins with around 800 members in the human genome/proteome. Extracellular signals such as hormones and neurotransmitters regulate various biological processes via GPCRs, with GPCRs being the bodily target of 30-40% of current drugs on the market. Complete identification and understanding of GPCR functionality will provide opportunities for novel drug discovery. Yeast expresses three different endogenous GPCRs regulating pheromone and sugar sensing, with the pheromone pathway offering perspectives for the characterization of heterologous GPCR signaling. Moreover, yeast offers a ''null" background for studies on mammalian GPCRs, including GPCR activation and signaling, ligand identification, and characterization of disease-related mutations. This review focuses on modifications of the yeast pheromone signaling pathway for functional GPCR studies, and on opportunities and usage of the yeast system as a platform for human GPCR studies. Finally, this review discusses in some further detail studies of adenosine receptors heterologously expressed in yeast, and what Geoff Burnstock thought of this approach.


Assuntos
Regulação Fúngica da Expressão Gênica , Receptores Acoplados a Proteínas G/biossíntese , Receptores Purinérgicos P1/biossíntese , Saccharomyces cerevisiae/metabolismo , Agonistas do Receptor A2 de Adenosina/farmacologia , Antagonistas do Receptor A2 de Adenosina/farmacologia , Animais , Humanos , Engenharia de Proteínas/métodos , Agonistas do Receptor Purinérgico P1/farmacologia , Antagonistas de Receptores Purinérgicos P1/farmacologia , Receptores Acoplados a Proteínas G/genética , Receptores Purinérgicos P1/genética , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/genética , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia
11.
J Neurochem ; 156(6): 1020-1032, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-32785947

RESUMO

Propofol is the most common intravenous anesthetic agent for induction and maintenance of anesthesia, and has been used clinically for more than 30 years. However, the mechanism by which propofol induces loss of consciousness (LOC) remains largely unknown. The adenosine A2A receptor (A2A R) has been extensively proven to have an effect on physiological sleep. It is, therefore, important to investigate the role of A2A R in the induction of LOC using propofol. In the present study, the administration of the highly selective A2A R agonist (CGS21680) and antagonist (SCH58261) was utilized to investigate the function of A2A R under general anesthesia induced by propofol by means of animal behavior studies, resting-state magnetic resonance imaging and c-Fos immunofluorescence staining approaches. Our results show that CGS21680 significantly prolonged the duration of LOC induced by propofol, increased the c-Fos expression in nucleus accumbens (NAc) and suppressed the functional connectivity of NAc-dorsal raphe nucleus (DR) and NAc-cingulate cortex (CG). However, SCH58261 significantly shortened the duration of LOC induced by propofol, decreased the c-Fos expression in NAc, increased the c-Fos expression in DR, and elevated the functional connectivity of NAc-DR and NAc-CG. Collectively, our findings demonstrate the important roles played by A2A R in the LOC induced by propofol and suggest that the neural circuit between NAc-DR maybe controlled by A2A R in the mechanism of anesthesia induced by propofol.


Assuntos
Anestesia Geral , Anestésicos Intravenosos/farmacologia , Propofol/farmacologia , Receptor A2A de Adenosina/efeitos dos fármacos , Inconsciência/diagnóstico por imagem , Agonistas do Receptor A2 de Adenosina/farmacologia , Antagonistas do Receptor A2 de Adenosina/farmacologia , Animais , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Genes fos/efeitos dos fármacos , Giro do Cíngulo/efeitos dos fármacos , Imageamento por Ressonância Magnética , Núcleo Accumbens/efeitos dos fármacos , Núcleos da Rafe/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Inconsciência/induzido quimicamente
12.
J Immunol Res ; 2020: 8632048, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33299899

RESUMO

Novel coronavirus disease 2019 (COVID-19) causes pulmonary and cardiovascular disorders and has become a worldwide emergency. Myocardial injury can be caused by direct or indirect damage, particularly mediated by a cytokine storm, a disordered immune response that can cause myocarditis, abnormal coagulation, arrhythmia, acute coronary syndrome, and myocardial infarction. The present review focuses on the mechanisms of this viral infection, cardiac biomarkers, consequences, and the possible therapeutic role of purinergic and adenosinergic signalling systems. In particular, we focus on the interaction of the extracellular nucleotide adenosine triphosphate (ATP) with its receptors P2X1, P2X4, P2X7, P2Y1, and P2Y2 and of adenosine (Ado) with A2A and A3 receptors, as well as their roles in host immune responses. We suggest that receptors of purinergic signalling could be ideal candidates for pharmacological targeting to protect against myocardial injury caused by a cytokine storm in COVID-19, in order to reduce systemic inflammatory damage to cells and tissues, preventing the progression of the disease by modulating the immune response and improving patient quality of life.


Assuntos
Trifosfato de Adenosina/metabolismo , COVID-19/imunologia , Doenças Cardiovasculares/virologia , Receptores Purinérgicos/metabolismo , SARS-CoV-2 , Agonistas do Receptor A2 de Adenosina/farmacologia , COVID-19/tratamento farmacológico , COVID-19/metabolismo , Doenças Cardiovasculares/imunologia , Doenças Cardiovasculares/fisiopatologia , Citocinas/metabolismo , Humanos , Isquemia Miocárdica/imunologia , Isquemia Miocárdica/fisiopatologia , Isquemia Miocárdica/virologia , Pandemias , Antagonistas Purinérgicos/farmacologia , Receptor A2A de Adenosina/metabolismo , Receptor A3 de Adenosina/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/imunologia
13.
Int J Mol Sci ; 21(21)2020 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-33114315

RESUMO

Acute liver injury (ALI) causes life-threatening clinical problem, and its underlying etiology includes inflammation and apoptosis. An adenosine A2A receptor agonist, polydeoxyribonucleotide (PDRN), exhibits anti-inflammatory and anti-apoptotic effects by inhibiting the secretion of pro-inflammatory cytokines. In the current study, the protective effect of PDRN against carbon tetrachloride (CCl4)-induced ALI was investigated using mice. For the induction of ALI, mice received intraperitoneal injection of CCl4 twice over seven days. Mice from the PDRN-treated groups received an intraperitoneal injection of 200 µL saline containing PDRN (8 mg/kg), once a day for seven days, starting on day 1 after the first CCl4 injection. In order to confirm that the action of PDRN occurs through the adenosine A2A receptor, 8 mg/kg 3,7-dimethyl-1-propargylxanthine (DMPX), an adenosine A2A receptor antagonist, was treated with PDRN. Administration of CCl4 impaired liver tissue and increased the liver index and histopathologic score. The expression of pro-inflammatory cytokines was increased, and apoptosis was induced by the administration of CCl4. Administration of CCl4 activated nuclear factor-kappa B (NF-κB) and facilitated phosphorylation of signaling factors in mitogen-activated protein kinase (MAPK). In contrast, PDRN treatment suppressed the secretion of pro-inflammatory cytokines and inhibited apoptosis. PDRN treatment inactivated NF-κB and suppressed phosphorylation of signaling factors in MAPK. As a result, liver index and histopathologic score were reduced by PDRN treatment. When PDRN was treated with DMPX, the anti-inflammatory and anti-apoptotic effect of PDRN disappeared. Therefore, PDRN can be used as an effective therapeutic agent for acute liver damage.


Assuntos
Agonistas do Receptor A2 de Adenosina/administração & dosagem , Tetracloreto de Carbono/efeitos adversos , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , NF-kappa B/metabolismo , Polidesoxirribonucleotídeos/administração & dosagem , Agonistas do Receptor A2 de Adenosina/farmacologia , Animais , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Injeções Intraperitoneais , Masculino , Camundongos , Estresse Oxidativo/efeitos dos fármacos , Fosforilação/efeitos dos fármacos , Polidesoxirribonucleotídeos/farmacologia , Resultado do Tratamento
14.
PLoS One ; 15(9): e0239807, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32998161

RESUMO

Tendinopathy is a degenerative disease in which inflammatory mediators have been found to be sometimes present. The interaction between inflammation and matrix remodeling in human tendon cells (TCs) is supported by the secretion of cytokines such as IL-1ß, IL-6 and IL-33. In this context, it has been demonstrated that pulsed electromagnetic fields (PEMFs) were able to reduce inflammation and promote tendon marker synthesis. The aim of this study was to evaluate the anabolic and anti-inflammatory PEMF-mediated response on TCs in an in vitro model of inflammation. Moreover, since PEMFs enhance the anti-inflammatory efficacy of adenosine through the adenosine receptors (ARs), the study also focused on the role of A2AARs. Human TCs were exposed to PEMFs for 48 hours. After stimulation, A2AAR saturation binding experiments were performed. Along with 48 hours PEMF stimulation, TCs were treated with IL-1ß and A2AAR agonist CGS-21680. IL-1Ra, IL-6, IL-8, IL-10, IL-33, VEGF, TGF-ß1, PGE2 release and SCX, COL1A1, COL3A1, ADORA2A expression were quantified. PEMFs exerted A2AAR modulation on TCs and promoted COL3A1 upregulation and IL-33 secretion. In presence of IL-1ß, TCs showed an upregulation of ADORA2A, SCX and COL3A1 expression and an increase of IL-6, IL-8, PGE2 and VEGF secretion. After PEMF and IL-1ß exposure, IL-33 was upregulated, whereas IL-6, PGE2 and ADORA2A were downregulated. These findings demonstrated that A2AARs have a role in the promotion of the TC anabolic/reparative response to PEMFs and to IL-1ß.


Assuntos
Regulação para Baixo/efeitos da radiação , Campos Eletromagnéticos , Receptor A2A de Adenosina/metabolismo , Tendões/metabolismo , Regulação para Cima/efeitos da radiação , Agonistas do Receptor A2 de Adenosina/farmacologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Células Cultivadas , Colágeno Tipo III/genética , Colágeno Tipo III/metabolismo , Citocinas/genética , Citocinas/metabolismo , Regulação para Baixo/efeitos dos fármacos , Humanos , Interleucina-1beta/farmacologia , Interleucina-33/metabolismo , Interleucina-6/metabolismo , Receptor A2A de Adenosina/química , Receptor A2A de Adenosina/genética , Tendões/citologia , Tendões/efeitos da radiação , Regulação para Cima/efeitos dos fármacos
15.
Neuromolecular Med ; 22(4): 542-556, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32926328

RESUMO

Alzheimer's disease (AD) is a progressive neurodegenerative disorder with loss in memory as one of the cardinal features. 5-N-ethyl carboxamidoadenosine (NECA), an agonist of adenosine-2b receptor, exerts neuroprotective activity against several experimental conditions. Further, NECA activates mitogen-activated protein kinase (MAPK) and also attenuates mitochondrial toxicity in mammalian tissues other than brain. Moreover, there is no report on the role of A2b/MAPK-mediated signaling pathway in Aß-induced mitochondrial toxicity in the brain of the experimental animals. Therefore, the present study evaluated the neuroprotective activity of NECA with or without MAPK inhibitor against Aß-induced cognitive deficit and mitochondrial toxicity in the experimental rodents. Further, the effect of NECA with or without MAPK inhibitor was evaluated on Aß-induced mitochondrial toxicity in the memory-sensitive mice brain regions. Intracerebroventricular (ICV) injection of Aß 1-42 was injected to healthy male mice through Hamilton syringe via polyethylene tube to induce AD-like behavioral manifestations. NECA attenuated Aß-induced cognitive impairments in the rodents. In addition, NECA ameliorated Aß-induced Aß accumulation and cholinergic dysfunction in the selected memory-sensitive mouse HIP, PFC, and AMY. Further, NECA significantly attenuated Aß-induced mitochondrial toxicity in terms of decrease in the mitochondrial function, integrity, and bioenergetics in the brain regions of these animals. However, MAPKI diminished the therapeutic effects of NECA on behavioral, biochemical, and molecular observations in AD-like animals. Therefore, it can be speculated that NECA exhibits neuroprotective activity perhaps through MAPK activation in AD-like rodents. Moreover, A2b-mediated MAPK activation could be a promising target in the management of AD.


Assuntos
Agonistas do Receptor A2 de Adenosina/uso terapêutico , Adenosina-5'-(N-etilcarboxamida)/uso terapêutico , Doença de Alzheimer , Peptídeos beta-Amiloides/toxicidade , Encéfalo/efeitos dos fármacos , Transtornos Cognitivos/tratamento farmacológico , Mitocôndrias/efeitos dos fármacos , Nootrópicos/uso terapêutico , Fragmentos de Peptídeos/toxicidade , Agonistas do Receptor A2 de Adenosina/farmacologia , Adenosina-5'-(N-etilcarboxamida)/farmacologia , Peptídeos beta-Amiloides/administração & dosagem , Animais , Encéfalo/metabolismo , Transtornos Cognitivos/metabolismo , Modelos Animais de Doenças , Donepezila/uso terapêutico , Avaliação Pré-Clínica de Medicamentos , Humanos , Imidazóis/farmacologia , Injeções Intraventriculares , Masculino , Aprendizagem em Labirinto , Camundongos , Mitocôndrias/fisiologia , Teste do Labirinto Aquático de Morris , Nootrópicos/farmacologia , Fragmentos de Peptídeos/administração & dosagem , Piridinas/farmacologia , Distribuição Aleatória , Organismos Livres de Patógenos Específicos
16.
Int J Mol Sci ; 21(18)2020 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-32938013

RESUMO

Orthotopic liver transplantation (OLT) using allografts from donation after circulatory death (DCD) is potentially associated with compromised clinical outcomes due to ischemia-reperfusion injury (IRI)-induced organ damage and graft-related complications. The aim of this study was to provide in vivo data on the effects of adenosine A2a receptor stimulation in a clinically relevant large animal model of DCD liver transplantation. Cardiac arrest was induced in German Landrace pigs (n = 10; 20-25 kg). After 30 min of warm ischemia, the donor liver was retrieved following a cold flush with 3 L of histidine-tryptophan-ketoglutarate-HTK solution. Animals of the treatment group (n = 5/group) received a standard dose of the selective adenosine receptor agonist CGS 21680 added to the cold flush. All grafts were stored for 4.5 h at 4 °C in HTK-solution before OLT. Hepatocellular injury, apoptosis, protein kinase A-PKA activity, graft microcirculation, liver function, and animal survival were assessed. Compared to untreated livers, adenosine A2a receptor stimulation resulted in improved tissue microcirculation (103% ± 5% vs. 38% ± 4% compared to baseline; p < 0.05), accelerated functional recovery of the graft (indocyanine green-plasma disappearance rate (ICG-PDR) of 75% ± 18% vs. 40% ± 30% after 3 h), increased PKA activity ratio (56% ± 3% vs. 32% ± 3%; p < 0.001 after 1 h), and consequently reduced tissue necrosis and apoptosis. The potent protective effects were clinically manifested in significantly improved survival in the treatment group after 72 h (100% vs. 40%; p = 0.04). The ex vivo administration of adenosine A2a receptor agonist during the back-table flush mitigates IRI-mediated tissue damage and improves functional graft recovery and survival in a large animal model of DCD liver transplantation.


Assuntos
Agonistas do Receptor A2 de Adenosina/farmacologia , Transplante de Fígado/mortalidade , Receptor A2A de Adenosina/metabolismo , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/mortalidade , Adenosina/análogos & derivados , Adenosina/farmacologia , Animais , Modelos Animais de Doenças , Feminino , Glucose/farmacologia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Doadores Vivos , Manitol/farmacologia , Preservação de Órgãos/métodos , Soluções para Preservação de Órgãos/farmacologia , Fenetilaminas/farmacologia , Cloreto de Potássio/farmacologia , Procaína/farmacologia , Traumatismo por Reperfusão/metabolismo , Suínos , Isquemia Quente/métodos
17.
Psychopharmacology (Berl) ; 237(12): 3519-3527, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32772144

RESUMO

RATIONALE AND OBJECTIVE: The adenosine A(2A) receptor forms a mutually inhibitory heteromer with the dopamine D2 receptor, and A(2A) agonists decrease D2 signaling. This study analyzed whether an adenosine A(2A) agonist would alleviate deficits in sensorimotor gating and increases in cyclic-AMP response element binding protein (CREB) in the nucleus accumbens (NAc) in the neonatal quinpirole model of schizophrenia (SZ). METHODS: Male and female Sprague-Dawley rats were neonatally treated with saline (NS) or quinpirole HCl (NQ; 1 mg/kg) from postnatal days (P) 1-21. Animals were raised to P44 and behaviorally tested on auditory sensorimotor gating as measured through prepulse inhibition (PPI) from P44 to P48. Approximately 15 min before each session, animals were given an ip administration of saline or the adenosine A(2A) agonist CGS 21680 (0.03 or 0.09 mg/kg). One day after PPI was complete on P49, animals were administered a locomotor activity test in the open field after saline or CGS 21680 treatment, respectively. On P50, the nucleus accumbens (NAc) was evaluated for CREB protein. RESULTS: NQ-treated rats demonstrated a deficit in PPI that was alleviated to control levels by either dose of CGS 21680. The 0.03 mg/kg dose of CGS 21680 increased startle amplitude in males. The 0.09 mg/kg dose of CGS 21680 resulted in an overall decrease in locomotor activity. NQ treatment significantly increased NAc CREB that was attenuated to control levels by either dose of CGS 21680. CONCLUSIONS: This study revealed that an adenosine A(2A) receptor agonist was effective to alleviate PPI deficits in the NQ model of SZ in both male and female rats.


Assuntos
Agonistas do Receptor A2 de Adenosina/farmacologia , Adenosina/análogos & derivados , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Núcleo Accumbens/efeitos dos fármacos , Fenetilaminas/farmacologia , Inibição Pré-Pulso/efeitos dos fármacos , Receptor A2A de Adenosina/metabolismo , Filtro Sensorial/efeitos dos fármacos , Adenosina/farmacologia , Animais , Animais Recém-Nascidos , Modelos Animais de Doenças , Agonistas de Dopamina/farmacologia , Relação Dose-Resposta a Droga , Feminino , Masculino , Atividade Motora/efeitos dos fármacos , Núcleo Accumbens/metabolismo , Quimpirol/farmacologia , Ratos , Ratos Sprague-Dawley , Receptores de Dopamina D2/metabolismo , Esquizofrenia/tratamento farmacológico , Esquizofrenia/fisiopatologia
18.
Neurosci Lett ; 734: 135108, 2020 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-32497733

RESUMO

Zeatin, an adenine-derivative cytokinin has well-established functions in plants. It is also suggested to activate A2A receptors in animals, however, there is limited knowledge of its effects. The main objective of this study is to evaluate the possible effects of zeatin on depression, and our hypothesis is that zeatin might induce an anti-depressant effect via A2A receptor-linked pathways. The forced swim test was used to create a depression-like model on female and male rats. A balanced zeatin isomer mixture (80 % trans-zeatin (tZ), 20 % cis-zeatin (cZ)) was administered intraperitoneally to analyze the effects. Caffeine with a suboptimal dose (2 mg/kg) was used as a known ligand of A2A receptor. Finally, a molecular docking study was also implemented to compare caffeine and tZ in the ligand binding site of A2A receptor. We demonstrate that (1) there is a clear sex-dependent difference in the susceptibility to depression-like symptoms, where female rats in the metestrus phase display higher depressive-like behavior and lower responses to the anti-depressant-like effects of pharmacological applications; (2) 10 mg/kg zeatin exerts an anti-depressant-like effect for both females and males without affecting locomotor activity; (3) 8 mg/kg tZ alone replicates this effect for both sexes, (4) the effect of zeatin is also differential for either sex and (5) the similar effect of caffeine and zeatin implies that the effect might be exerted via A2A receptor mediated pathways. Computational analysis further yielded similar binding patterns for both ligands. In conclusion, zeatin might have a potential therapeutic use in depression, acting via adenosinergic pathways.


Assuntos
Agonistas do Receptor A2 de Adenosina/farmacologia , Antidepressivos/farmacologia , Comportamento Animal/efeitos dos fármacos , Zeatina/farmacologia , Animais , Feminino , Masculino , Atividade Motora/efeitos dos fármacos , Ratos , Ratos Wistar , Caracteres Sexuais
19.
Biomed Res Int ; 2020: 2603873, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32382539

RESUMO

The aim of this study was to explore the effect of adenosine A2A receptor agonists on fracture healing and the regulation of the immunity system after bone fracture. We implanted fibrin gel containing adenosine A2A receptor agonist CGS 21680/inhibitor ZM 241385/saline locally in rat tibial fracture models, finding that the adenosine A2A receptor agonist could promote fracture healing. At the same time, the adenosine A2A receptor agonist decreased the level of IL-6 in blood and the fracture area, increased Treg cells, and decreased Th17 cells in blood of bone fracture rats. Further, tibial fracture rats implanted with the adenosine A2A receptor agonist gel were injected with IL-6. We found that IL-6 could reverse the effect of adenosine A2A receptor agonists on fracture healing and Treg/Th17 cells in blood. Through the above results, we believe that the adenosine A2A receptor agonist can promote fracture healing and regulate Treg/Th17 cells in blood of rats with fractures. These effects are related to IL-6.


Assuntos
Agonistas do Receptor A2 de Adenosina/farmacologia , Adenosina/análogos & derivados , Consolidação da Fratura/efeitos dos fármacos , Interleucina-6/imunologia , Fenetilaminas/farmacologia , Receptor A2A de Adenosina/imunologia , Linfócitos T Reguladores/imunologia , Células Th17/imunologia , Fraturas da Tíbia/imunologia , Adenosina/farmacologia , Animais , Modelos Animais de Doenças , Feminino , Consolidação da Fratura/imunologia , Ratos , Ratos Sprague-Dawley , Linfócitos T Reguladores/patologia , Células Th17/patologia , Fraturas da Tíbia/tratamento farmacológico , Fraturas da Tíbia/patologia
20.
Eur J Pharmacol ; 880: 173126, 2020 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-32348778

RESUMO

In cancer, G protein-coupled receptors (GPCRs) are involved in tumor progression and metastasis. In this study we particularly examined one GPCR, the adenosine A2B receptor. This receptor is activated by high concentrations of its endogenous ligand adenosine, which suppresses the immune response to fight tumor progression. A series of adenosine A2B receptor mutations were retrieved from the Cancer Genome Atlas harboring data from patient samples with different cancer types. The main goal of this work was to investigate the pharmacology of these mutant receptors using a 'single-GPCR-one-G protein' yeast assay technology. Concentration-growth curves were obtained with the full agonist NECA for the wild-type receptor and 15 mutants. Compared to wild-type receptor, the constitutive activity levels in mutant receptors F141L4.61, Y202C5.58 and L310P8.63 were high, while the potency and efficacy of NECA and BAY 60-6583 on Y202C5.58 was lower. A 33- and 26-fold higher constitutive activity on F141L4.61 and L310P8.63 was reduced to wild-type levels in response to the inverse agonist ZM241385. These constitutively active mutants may thus be tumor promoting. Mutant receptors F259S6.60 and Y113F34.53 showed a more than one log-unit decrease in potency. A complete loss of activation was observed in mutant receptors C29R1.54, W130C4.50 and P249L6.50. All mutations were characterized at the structural level, generating hypotheses of their roles on modulating the receptor conformational equilibrium. Taken together, this study is the first to investigate the nature of adenosine A2B receptor cancer mutations and may thus provide insights in mutant receptor function in cancer.


Assuntos
Neoplasias/genética , Receptor A2B de Adenosina/genética , Agonistas do Receptor A2 de Adenosina/farmacologia , Adenosina-5'-(N-etilcarboxamida)/farmacologia , Aminopiridinas/farmacologia , Biologia Computacional , Humanos , Modelos Moleculares , Mutação , Receptor A2B de Adenosina/metabolismo , Saccharomyces cerevisiae/genética
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