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1.
PLoS One ; 15(6): e0234601, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32589693

RESUMO

Body weight is substantially determined by eating behaviors, which are themselves driven by biological factors interacting with the environment. Previous studies in young children suggest that genetic influences on dopamine function may confer differential susceptibility to the environment in such a way that increases behavioral obesity risk in a lower socioeconomic status (SES) environment but decreases it in a higher SES environment. We aimed to test if this pattern of effect could also be observed in adolescence, another critical period for development in brain and behavior, using a novel measure of predicted expression of the dopamine receptor 4 (DRD4) gene in prefrontal cortex. In a sample of 76 adolescents (37 boys and 39 girls from Baltimore, Maryland/US, aged 14-18y), we estimated individual levels of DRD4 gene expression (PredDRD4) in prefrontal cortex from individual genomic data using PrediXcan, and tested interactions with a composite SES score derived from their annual household income, maternal education, food insecurity, perceived resource availability, and receipt of public assistance. Primary outcomes were snack intake during a multi-item ad libitum meal test, and food-related impulsivity assessed using a food-adapted go/no-go task. A linear regression model adjusted for sex, BMI z-score, and genetic ethnicity demonstrated a PredDRD4 by composite SES score interaction for snack intake (p = 0.009), such that adolescents who had lower PredDRD4 levels exhibited greater snack intake in the lower SES group, but lesser snack intake in the higher SES group. Exploratory analysis revealed a similar pattern for scores on the Perceived Stress Scale (p = 0.001) such that the low PredDRD4 group reported higher stress in the lower SES group, but less stress in the higher SES group, suggesting that PredDRD4 may act in part by affecting perceptions of the environment. These results are consistent with a differential susceptibility model in which genes influencing environmental responsiveness interact with environments varying in obesogenicity to confer behavioral obesity risk in a less favorable environment, but behavioral obesity protection in a favorable one.


Assuntos
Comportamento Alimentar , Receptores de Dopamina D4/metabolismo , Lanches , Adolescente , Baltimore , Feminino , Humanos , Masculino , Obesidade , Córtex Pré-Frontal/metabolismo , Receptores Dopaminérgicos , Receptores de Dopamina D4/fisiologia , Fatores de Risco , Classe Social
2.
Proc Natl Acad Sci U S A ; 117(24): 13771-13782, 2020 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-32487727

RESUMO

The nucleus accumbens (NAc), a central component of the midbrain dopamine reward circuit, exhibits disturbed circadian rhythms in the postmortem brains of depressed patients. We hypothesized that normal mood regulation requires proper circadian timing in the NAc, and that mood disorders are associated with dysfunctions of the NAc cellular circadian clock. In mice exhibiting stress-induced depression-like behavior (helplessness), we found altered circadian clock function and high nighttime expression of the core circadian clock component CRYPTOCHROME (CRY) in the NAc. In the NAc of helpless mice, we found that higher expression of CRY is associated with decreased activation of dopamine 1 receptor-expressing medium spiny neurons (D1R-MSNs). Furthermore, D1R-MSN-specific CRY-knockdown in the NAc reduced susceptibility to stress-induced helplessness and increased NAc neuronal activation at night. Finally, we show that CRY inhibits D1R-induced G protein activation, likely by interacting with the Gs protein. Altered circadian rhythms and CRY expression were also observed in human fibroblasts from major depressive disorder patients. Our data reveal a causal role for CRY in regulating the midbrain dopamine reward system, and provide a mechanistic link between the NAc circadian clock and vulnerability to depression.


Assuntos
Relógios Circadianos , Criptocromos/metabolismo , Depressão/metabolismo , Núcleo Accumbens/metabolismo , Animais , Comportamento Animal , Depressão/genética , Depressão/fisiopatologia , Depressão/psicologia , Dopamina/metabolismo , Feminino , Desamparo Aprendido , Humanos , Masculino , Camundongos , Neurônios/metabolismo , Receptores Dopaminérgicos/genética , Receptores Dopaminérgicos/metabolismo
3.
Proc Natl Acad Sci U S A ; 117(20): 11085-11096, 2020 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-32358191

RESUMO

Glioblastoma (GBM) is the deadliest adult brain cancer, and all patients ultimately succumb to the disease. Radiation therapy (RT) provides survival benefit of 6 mo over surgery alone, but these results have not improved in decades. We report that radiation induces a glioma-initiating cell phenotype, and we have identified trifluoperazine (TFP) as a compound that interferes with this phenotype conversion. TFP causes loss of radiation-induced Nanog mRNA expression, and activation of GSK3 with consecutive posttranslational reduction in p-Akt, Sox2, and ß-catenin protein levels. TFP did not alter the intrinsic radiation sensitivity of glioma-initiating cells (GICs). Continuous treatment with TFP and a single dose of radiation reduced the number of GICs in vivo and prolonged survival in syngeneic and patient-derived orthotopic xenograft (PDOX) mouse models of GBM. Our findings suggest that the combination of a dopamine receptor antagonist with radiation enhances the efficacy of RT in GBM by preventing radiation-induced phenotype conversion of radiosensitive non-GICs into treatment-resistant, induced GICs (iGICs).


Assuntos
Antagonistas de Dopamina/farmacologia , Glioblastoma/metabolismo , Fenótipo , Receptores Dopaminérgicos/efeitos dos fármacos , Trifluoperazina/farmacologia , Animais , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/radioterapia , Modelos Animais de Doenças , Antagonistas de Dopamina/uso terapêutico , Regulação Neoplásica da Expressão Gênica , Glioblastoma/tratamento farmacológico , Glioblastoma/patologia , Glioblastoma/radioterapia , Glioma/tratamento farmacológico , Glioma/metabolismo , Glioma/patologia , Glioma/radioterapia , Quinase 3 da Glicogênio Sintase/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Camundongos SCID , RNA Mensageiro/metabolismo , Tolerância a Radiação , Fatores de Transcrição SOXB1 , Trifluoperazina/uso terapêutico , Ensaios Antitumorais Modelo de Xenoenxerto , beta Catenina
4.
Proc Natl Acad Sci U S A ; 117(17): 9554-9565, 2020 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-32321828

RESUMO

The basal ganglia play an important role in decision making and selection of action primarily based on input from cortex, thalamus, and the dopamine system. Their main input structure, striatum, is central to this process. It consists of two types of projection neurons, together representing 95% of the neurons, and 5% of interneurons, among which are the cholinergic, fast-spiking, and low threshold-spiking subtypes. The membrane properties, soma-dendritic shape, and intrastriatal and extrastriatal synaptic interactions of these neurons are quite well described in the mouse, and therefore they can be simulated in sufficient detail to capture their intrinsic properties, as well as the connectivity. We focus on simulation at the striatal cellular/microcircuit level, in which the molecular/subcellular and systems levels meet. We present a nearly full-scale model of the mouse striatum using available data on synaptic connectivity, cellular morphology, and electrophysiological properties to create a microcircuit mimicking the real network. A striatal volume is populated with reconstructed neuronal morphologies with appropriate cell densities, and then we connect neurons together based on appositions between neurites as possible synapses and constrain them further with available connectivity data. Moreover, we simulate a subset of the striatum involving 10,000 neurons, with input from cortex, thalamus, and the dopamine system, as a proof of principle. Simulation at this biological scale should serve as an invaluable tool to understand the mode of operation of this complex structure. This platform will be updated with new data and expanded to simulate the entire striatum.


Assuntos
Simulação por Computador , Corpo Estriado/fisiologia , Fenômenos Eletrofisiológicos , Modelos Biológicos , Neurônios/fisiologia , Animais , Córtex Cerebral/fisiologia , Corpo Estriado/citologia , Dopamina/metabolismo , Camundongos , Receptores Dopaminérgicos/metabolismo , Tálamo/fisiologia
5.
Clin Interv Aging ; 15: 321-327, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32184581

RESUMO

Objective: Osteoarthritis is the most common type of arthritis and one of the leading causes of job loss and motor disabilities. Recently, the involvement of dopaminergic pathways and dopamine receptor genes has been considered in this disease. Therefore, studying and comparing the expression pattern of these receptor genes can lead to a greater understanding of the pathogenesis of this disease. Methods: In this research, we used the systems biology approach to investigate the role of the dopaminergic pathway in osteoarthritis. Then the gene expression pattern of dopamine receptor genes was examined in an osteoarthritis patientgroup in comparison with healthy individuals by Real-time PCR method. Results: The analysis of the transcriptome dataset of osteoarthritis identified some genes in the dopaminergic pathway and the six most important genes in this disease are in the network with a significant relationship to dopamine receptors which differentially expressed compared to health groups. Statistical analysis of the case control study showed a significant difference (P-value<0.05) in DRD1 and DRD2 family in the patients in comparison to healthy individuals. Discussion: We attained the significant expression pattern of dopamine receptors in the blood of osteoarthritis patients which could be useful to identify new strategies for the diagnosis, management, or treatment of this disease.


Assuntos
Dopamina/metabolismo , Osteoartrite/metabolismo , Receptores Dopaminérgicos/metabolismo , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Receptores de Dopamina D2/metabolismo , Biologia de Sistemas , Transcriptoma
6.
Endocrinology ; 161(4)2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32049280

RESUMO

The ghrelin receptor (GhrR) is known for its strong orexigenic effects in pharmacological doses and has long been considered as a promising target for the treatment of obesity. Several antagonists have been developed to decrease the orexigenic signaling, but none of these have been approved for the treatment of obesity because of adverse effects and lack of efficacy. Heterodimerization and biased signaling are important concepts for G-protein coupled receptor (GPCR) signaling, and the influence of these aspects on the GhrR may be important for feeding behavior and obesity. GhrR has been described to heterodimerize with other GPCRs, such as the dopamine receptors 1 and 2, leading to a modulation of the signaling properties of both dimerization partners. Another complicating factor of GhrR-mediated signaling is its ability to activate several different signaling pathways on ligand stimulation. Importantly, some ligands have shown to be "biased" or "functionally selective," implying that the ligand favors a particular signaling pathway. These unique signaling properties could have a sizeable impact on the physiological functions of the GhrR system. Importantly, heterodimerization may explain why the GhrR is expressed in areas of the brain that are difficult for peptide ligands to access. One possibility is that the purpose of GhrR expression is to modulate the function of other receptors in addition to merely being independently activated. We suggest that a deeper understanding of the signaling properties of the GhrR will facilitate future drug discovery in the areas of obesity and weight management.


Assuntos
Grelina/metabolismo , Receptores de Grelina/metabolismo , Transdução de Sinais/fisiologia , Animais , Humanos , Obesidade/metabolismo , Receptores de Orexina/metabolismo , Multimerização Proteica/fisiologia , Receptores Dopaminérgicos/metabolismo , Receptores de Serotonina/metabolismo
7.
PLoS One ; 15(2): e0229671, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32101569

RESUMO

As in vertebrates, dopaminergic neural systems are key regulators of motor programs in insects, including the fly Drosophila melanogaster. Dopaminergic systems innervate the Mushroom Bodies (MB), an important association area in the insect brain primarily associated to olfactory learning and memory, but that has been also implicated with the execution of motor programs. The main objectives of this work is to assess the idea that dopaminergic systems contribute to the execution of motor programs in Drosophila larvae, and then, to evaluate the contribution of specific dopaminergic receptors expressed in MB to these programs. Our results show that animals bearing a mutation in the dopamine transporter show reduced locomotion, while mutants for the dopaminergic biosynthetic enzymes or the dopamine receptor Dop1R1 exhibit increased locomotion. Pan-neuronal expression of an RNAi for the Dop1R1 confirmed these results. Further studies show that animals expressing the RNAi for Dop1R1 in the entire MB neuronal population or only in the MB γ-lobe forming neurons, exhibit an increased motor output, as well. Interestingly, our results also suggest that other dopaminergic receptors do not contribute to larval motor behavior. Thus, our data support the proposition that CNS dopamine systems innervating MB neurons modulate larval locomotion and that Dop1R1 mediates this effect.


Assuntos
Proteínas de Drosophila/metabolismo , Corpos Pedunculados/metabolismo , Receptores Dopaminérgicos/metabolismo , Animais , Aprendizagem da Esquiva/fisiologia , Condicionamento Clássico , Dopamina/metabolismo , Neurônios Dopaminérgicos/fisiologia , Proteínas de Drosophila/fisiologia , Drosophila melanogaster/metabolismo , Feminino , Regulação da Expressão Gênica/genética , Larva/genética , Larva/metabolismo , Locomoção/fisiologia , Masculino , Memória/fisiologia , Neurônios/metabolismo , Receptores Dopaminérgicos/fisiologia , Olfato/fisiologia
8.
Arch Med Res ; 51(1): 13-20, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-32086104

RESUMO

BACKGROUND: Several studies indicated that antipsychotic treatment response and side effect manifestation can be different due to inter-individual variability in genetic variations. AIM OF THE STUDY: Here we perform a case-control study to explore a potential association between schizophrenia and variants within the antipsychotic drug molecular targets (DRD1, DRD2, DRD3, HTR2A, HTR6) and metabolizing enzymes (CYP2D6, COMT) genes in Armenian population including also analysis of their possible relationship with disease clinical symptoms. METHODS: A total of 18 SNPs was studied in patients with schizophrenia (n = 78) and healthy control subjects (n = 77) using MassARRAY genotyping. RESULTS: We found that two studied genetic variants, namely DRD2 rs4436578*C and HTR2A rs6314*A are underrepresented in the group of patients compared to healthy subjects. After the correction for multiple testing, the rs4436578*C variant remained significant while the rs6314*A reported borderline significance. No significant differences in minor allele frequencies for other studied variants were identified. Also, a relationship between the genotypes and age of onset as well as disease duration has been detected. CONCLUSIONS: The DRD2 rs4436578*C genetic variant might have protective role against schizophrenia, at least in Armenians.


Assuntos
Catecol O-Metiltransferase/genética , Citocromo P-450 CYP2D6/genética , Polimorfismo de Nucleotídeo Único , Receptores Dopaminérgicos/genética , Receptores de Serotonina/genética , Esquizofrenia/genética , Adulto , Idoso , Antipsicóticos/uso terapêutico , Estudos de Casos e Controles , Dopamina/genética , Dopamina/metabolismo , Feminino , Frequência do Gene , Estudos de Associação Genética , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Redes e Vias Metabólicas/genética , Pessoa de Meia-Idade , Esquizofrenia/tratamento farmacológico , Serotonina/genética , Serotonina/metabolismo , Adulto Jovem
9.
Nat Commun ; 11(1): 912, 2020 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-32060266

RESUMO

Progressive ventricular enlargement, a key feature of several neurologic and psychiatric diseases, is mediated by unknown mechanisms. Here, using murine models of 22q11-deletion syndrome (22q11DS), which is associated with schizophrenia in humans, we found progressive enlargement of lateral and third ventricles and deceleration of ciliary beating on ependymal cells lining the ventricular walls. The cilia-beating deficit observed in brain slices and in vivo is caused by elevated levels of dopamine receptors (Drd1), which are expressed in motile cilia. Haploinsufficiency of the microRNA-processing gene Dgcr8 results in Drd1 elevation, which is brought about by a reduction in Drd1-targeting microRNAs miR-382-3p and miR-674-3p. Replenishing either microRNA in 22q11DS mice normalizes ciliary beating and ventricular size. Knocking down the microRNAs or deleting their seed sites on Drd1 mimicked the cilia-beating and ventricular deficits. These results suggest that the Dgcr8-miR-382-3p/miR-674-3p-Drd1 mechanism contributes to deceleration of ciliary motility and age-dependent ventricular enlargement in 22q11DS.


Assuntos
Ventrículos Cerebrais/metabolismo , Cílios/fisiologia , MicroRNAs/genética , Esquizofrenia/genética , Animais , Deleção Cromossômica , Cílios/genética , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Receptores Dopaminérgicos/genética , Receptores Dopaminérgicos/metabolismo , Esquizofrenia/metabolismo , Esquizofrenia/fisiopatologia
10.
J Agric Food Chem ; 68(8): 2426-2436, 2020 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-32011134

RESUMO

Progressive degeneration of dopaminergic neurons in the substantia nigra is the characteristic feature of Parkinson's disease (PD) and the severity accelerates with aging. Therefore, improving dopamine level or dopamine receptor signaling is a standard approach for PD treatment. Herein, our results demonstrate that bromophenols 2,3,6-tribromo-4,5-dihydroxybenzyl alcohol (1), 2,3,6-tribromo-4,5-dihydroxybenzyl methyl ether (2), and bis-(2,3,6-tribromo-4,5-dihydroxybenzyl) ether (3) from red alga Symphyocladia latiuscula are moderate-selective human monoamine oxidase-A inhibitors and good dopamine D3/D4 receptor agonists. Bromophenol 3 showed a promising D4R agonist effect with a low micromole 50% effective concentration (EC50) value. All of the test ligands were docked against a three-dimensional (3D) model of hD3R and hD4R, and the result demonstrated strong binding through interaction with prime interacting residues-Asp110, Cys114, and His349 on hD3R and Asp115 and Cys119 on hD4R. Overall, the results demonstrated natural bromophenols, especially 1 and 3, from Symphyocladia latiuscula as multitarget ligands for neuroprotection, especially in PD and schizophrenia.


Assuntos
Inibidores da Monoaminoxidase/química , Monoaminoxidase/química , Doenças Neurodegenerativas/enzimologia , Fenóis/química , Extratos Vegetais/química , Receptores Dopaminérgicos/sangue , Rodófitas/química , Humanos , Estrutura Molecular , Monoaminoxidase/metabolismo , Doenças Neurodegenerativas/metabolismo , Receptores Dopaminérgicos/química , Receptores Dopaminérgicos/metabolismo
11.
Psychopharmacology (Berl) ; 237(4): 1131-1145, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31912189

RESUMO

RATIONALE: Current data indicate that the noradrenergic system plays a critical role in neuropathic pain treatment. Notably, drugs that directly affect this system may have curative potential in neuropathy-associated pain. OBJECTIVES: The aim of this study was to evaluate the potential therapeutic efficacy of reboxetine, a potent and selective noradrenaline reuptake inhibitor, on hyperalgesia and allodynia responses in rats with experimental diabetes. Furthermore, mechanistic studies were performed to elucidate the possible mode of actions. METHODS: Experimental diabetes was induced by a single dose of streptozotocin. Mechanical hyperalgesia, mechanical allodynia, thermal hyperalgesia, and thermal allodynia responses in diabetic rats were evaluated by Randall-Selitto, dynamic plantar, Hargreaves, and warm plate tests, respectively. RESULTS: Reboxetine treatment (8 and 16 mg/kg for 2 weeks) demonstrated an effect comparable to that of the reference drug, pregabalin, improving the hyperalgesic and allodynic responses secondary to diabetes mellitus. Pretreatment with phentolamine, metoprolol, SR 59230A, and atropine did not alter the abovementioned effects of reboxetine; however, the administration of α-methyl-para-tyrosine methyl ester, propranolol, ICI-118,551, SCH-23390, sulpiride, and naltrindole significantly inhibited these effects. Moreover, reboxetine did not induce a significant difference in the rat plasma glucose levels. CONCLUSIONS: Our findings indicate that the antihyperalgesic and antiallodynic effects of reboxetine are mediated by the catecholaminergic system; ß2-adrenoceptors; D1-, D2/D3-dopaminergic receptors; and δ-opioid receptors. The results suggest that this analgesic effect of reboxetine, besides its neutral profile on glycemic control, may be advantageous in the pharmacotherapy of diabetic neuropathy-induced pain.


Assuntos
Inibidores da Captação Adrenérgica/uso terapêutico , Neuropatias Diabéticas/tratamento farmacológico , Hiperalgesia/tratamento farmacológico , Neuralgia/tratamento farmacológico , Reboxetina/uso terapêutico , Receptores Opioides delta/metabolismo , Inibidores da Captação Adrenérgica/farmacologia , Animais , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/tratamento farmacológico , Neuropatias Diabéticas/sangue , Neuropatias Diabéticas/induzido quimicamente , Hiperalgesia/sangue , Hiperalgesia/induzido quimicamente , Masculino , Neuralgia/sangue , Neuralgia/induzido quimicamente , Ratos , Ratos Sprague-Dawley , Reboxetina/farmacologia , Receptores Adrenérgicos beta 2/metabolismo , Receptores Dopaminérgicos/metabolismo , Estreptozocina/toxicidade
12.
Insect Biochem Mol Biol ; 116: 103265, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31704156

RESUMO

Animals communicate with each other in aggregating for survival and adaptation. Solitary locusts show an olfactory transition from repulsion to attraction in aggregation. However, the molecular mechanism underlying this transition is less well known. In this study, we explored differentially expressed transcripts (DETs) during locust aggregation and identified that a functional class of general metabolism encompassed the largest number of DETs among all analyzed gene classes. Within this functional class of general metabolism, oxidoreductase mediates synthesis of retinoic acid (RA) from vitamin A and other metabolites derived from carbohydrates. The expression levels of retinaldehyde hydroxylase 1 (raldh1) and retinoid X receptor (rxr), which are two crucial genes for RA synthesis and signaling, were upregulated during 4 h of crowding. Knockdown of raldh1 and rxr by RNA interference (RNAi) in the brains resulted in the loss of olfactory attraction. Moreover, inhibition of RXR by RNAi resulted in downregulated expression of Gna14, a member of the Gα subfamily that transduces signals in G protein-coupled receptor (GPCR) pathways. Abrogating RXR signaling and Gna14 by RNAi knockdown inhibited the function of dopamine receptor 1 (DopR1) and octopamine receptor α1 (OctαR1) in modulating olfactory attraction. RXR signaling is essential for DopR1 and OctαR1 to mediate olfactory attraction. This study showed that RXR signaling mediates attraction by Gα signaling and confirmed a novel link between nuclear receptor RXR and the membrane receptor GPCRs in modulating olfactory attraction.


Assuntos
Locusta migratoria/metabolismo , Feromônios , Receptores X Retinoide/metabolismo , Olfato , Animais , Comportamento Animal/fisiologia , Locusta migratoria/genética , Interferência de RNA , Receptores de Amina Biogênica/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Receptores Dopaminérgicos/metabolismo , Receptores X Retinoide/genética , Transdução de Sinais
13.
Biochim Biophys Acta Biomembr ; 1862(3): 183152, 2020 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-31843475

RESUMO

Dopamine receptors (DRs) are class A G-Protein Coupled Receptors (GPCRs) prevalent in the central nervous system (CNS). These receptors mediate physiological functions ranging from voluntary movement and reward recognition to hormonal regulation and hypertension. Drugs targeting dopaminergic neurotransmission have been employed to treat several neurological and psychiatric disorders, including Parkinson's disease, schizophrenia, Huntington's disease, attention deficit hyperactivity disorder (ADHD), and Tourette's syndrome. In vivo, incorporation of GPCRs into lipid membranes is known to be key to their biological function and, by inference, maintenance of their tertiary structure. A further significant challenge in the structural and biochemical characterization of human DRs is their low levels of expression in mammalian cells. Thus, the purification and enrichment of DRs whilst retaining their structural integrity and function is highly desirable for biophysical studies. A promising new approach is the use of styrene-maleic acid (SMA) copolymer to solubilize GPCRs directly in their native environment, to produce polymer-assembled Lipodisqs (LQs). We have developed a novel methodology to yield detergent-free D1-containing Lipodisqs directly from HEK293f cells expressing wild-type human dopamine receptor 1 (D1). We demonstrate that D1 in the Lipodisq retains activity comparable to that in the native environment and report, for the first time, the affinity constant for the interaction of the peptide neurotransmitter neurotensin (NT) with D1, in the native state.


Assuntos
Bicamadas Lipídicas/química , Receptores de Dopamina D1/isolamento & purificação , Receptores Dopaminérgicos/isolamento & purificação , Linhagem Celular , Detergentes , Células HEK293 , Humanos , Maleatos/química , Lipídeos de Membrana/química , Lipídeos de Membrana/metabolismo , Receptores Dopaminérgicos/metabolismo , Receptores de Dopamina D1/metabolismo , Receptores Acoplados a Proteínas-G/isolamento & purificação , Estirenos/química
14.
Synapse ; 74(1): e22131, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31494966

RESUMO

Mechanisms of synaptic vesicular fusion and neurotransmitter clearance are highly controlled processes whose finely-tuned regulation is critical for neural function. This modulation has been suggested to involve pre-synaptic auto-receptors; however, their underlying mechanisms of action remain unclear. Previous studies with the well-defined C. elegans nervous system have used functional imaging to implicate acid sensing ion channels (ASIC-1) to describe synaptic vesicle fusion dynamics within its eight dopaminergic neurons. Implementing a similar imaging approach with a pH-sensitive fluorescent reporter and fluorescence resonance after photobleaching (FRAP), we analyzed dynamic imaging data collected from individual synaptic termini in live animals. We present evidence that constitutive fusion of neurotransmitter vesicles on dopaminergic synaptic termini is modulated through DOP-2 auto-receptors via a negative feedback loop. Integrating our previous results showing the role of ASIC-1 in a positive feedback loop, we also put forth an updated model for synaptic vesicle fusion in which, along with DAT-1 and ASIC-1, the dopamine auto-receptor DOP-2 lies at a modulatory hub at dopaminergic synapses. Our findings are of potential broader significance as similar mechanisms are likely to be used by auto-receptors for other small molecule neurotransmitters across species.


Assuntos
Autorreceptores/metabolismo , Receptores Dopaminérgicos/metabolismo , Sinapses/metabolismo , Vesículas Sinápticas/metabolismo , Animais , Animais Geneticamente Modificados , Caenorhabditis elegans , Neurônios Dopaminérgicos/metabolismo , Transmissão Sináptica/fisiologia
15.
J Pharmacol Sci ; 142(1): 26-33, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31786058

RESUMO

Cedrol, mainly derived from Juniperus virginiana L. essential oil, has been demonstrated the anxiolytic effect, although its mechanism of action is still not fully established. In the present study, male ICR mice were submitted to the elevated plus maze (EPM) and light-dark box (LDB) tests to investigate the putative mechanism of anxiolytic effect. WAY100635 (5-HT1A receptor antagonist), flumazenil (benzodiazepine receptor antagonist), SCH23390 (dopamine D1 receptor antagonist) or sulpiride (dopamine D2/D3 receptor antagonist) were used in the behavioral experiment to determine the mechanism of action of cedrol. Subsequently, the monoamine neurotransmitter levels were evaluated after behavioral tests. The data suggest that no significant effect in behavioral parameters were observed after sole intraperitoneal (i.p.) injection of antagonists compared to saline group. The anxiolytic effect of cedrol in behavioral procedures was blocked by either WAY100635 or flumazenil. The anxiolytic effect of cedrol (1200 mg/kg) was effectively antagonized by SCH23390 (0.125 mg/kg). Furthermore, cedrol decreased the DA and NE levels in hippocampus, striatum and hypothalamus. The present findings suggest that the dopaminergic system (D1 receptor) rather than serotoninergic or GABAergic system may potentially be involved in the modulation of cedrol-induced anxiolytic-like behaviors in mice.


Assuntos
Ansiolíticos/farmacologia , Ansiedade/tratamento farmacológico , Comportamento Animal/efeitos dos fármacos , Sesquiterpenos Policíclicos/farmacologia , Receptores Dopaminérgicos/metabolismo , Animais , Benzazepinas/farmacologia , Agonistas de Dopamina/farmacologia , Antagonistas de Dopamina/farmacologia , Flumazenil/farmacologia , Regulação da Expressão Gênica , Masculino , Camundongos , Camundongos Endogâmicos ICR , Norepinefrina/metabolismo , Piperazinas/farmacologia , Piridinas/farmacologia , Antagonistas da Serotonina/farmacologia , Sulpirida/farmacologia
16.
Int J Mol Sci ; 20(24)2019 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-31835621

RESUMO

In this study, we delineate the human monoamine oxidase (hMAO) inhibitory potential of natural Diels-Alder type adducts, mulberrofuran G (1), kuwanon G (2), and albanol B (3), from Morus alba root bark to characterize their role in Parkinson's disease (PD) and depression, focusing on their ability to modulate dopaminergic receptors (D1R, D2LR, D3R, and D4R). In hMAO-A inhibition, 1-3 showed mild effects (50% inhibitory concentration (IC50): 54‒114 µM). However, 1 displayed moderate inhibition of the hMAO-B isozyme (IC50: 18.14 ± 1.06 µM) followed by mild inhibition by 2 (IC50: 57.71 ± 2.12 µM) and 3 (IC50: 90.59 ± 1.72 µM). Our kinetic study characterized the inhibition mode, and the in silico docking predicted that the moderate inhibitor 1 would have the lowest binding energy. Similarly, cell-based G protein-coupled receptors (GPCR) functional assays in vector-transfected cells expressing dopamine (DA) receptors characterized 1-3 as D1R/D2LR antagonists and D3R/D4R agonists. The half-maximum effective concentration (EC50) of 1-3 on DA D3R/D4R was 15.13/17.19, 20.18/21.05, and 12.63/‒ µM, respectively. Similarly, 1-3 inhibited 50% of the DA response on D1R/D2LR by 6.13/2.41, 16.48/31.22, and 7.16/18.42 µM, respectively. A computational study revealed low binding energy for the test ligands. Interactions with residues Asp110, Val111, Tyr365, and Phe345 at the D3R receptor and Asp115 and His414 at the D4R receptor explain the high agonist effect. Likewise, Asp187 at D1R and Asp114 at D2LR play a crucial role in the antagonist effects of the ligand binding. Our overall results depict 1-3 from M. alba root bark as good inhibitors of hMAO and potent modulators of DA function as D1R/D2LR antagonists and D3R/D4R agonists. These active constituents in M. alba deserve in-depth study for their potential to manage neurodegenerative disorders (NDs), particularly PD and psychosis.


Assuntos
Inibidores da Monoaminoxidase/farmacologia , Morus/química , Doenças Neurodegenerativas/metabolismo , Extratos Vegetais/farmacologia , Receptores Dopaminérgicos/metabolismo , Benzofuranos/química , Benzofuranos/metabolismo , Benzofuranos/farmacologia , Flavonoides/química , Flavonoides/metabolismo , Flavonoides/farmacologia , Humanos , Modelos Moleculares , Simulação de Acoplamento Molecular , Monoaminoxidase/química , Monoaminoxidase/metabolismo , Inibidores da Monoaminoxidase/química , Doenças Neurodegenerativas/tratamento farmacológico , Casca de Planta/química , Extratos Vegetais/química , Receptores Dopaminérgicos/química , Terpenos/química , Terpenos/farmacologia
17.
Bull Exp Biol Med ; 168(2): 193-198, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31776959

RESUMO

Stimulation of the serotoninergic system (5-hydroxytryptophan, 50 mg/kg; fluoxetine, 3 mg/kg) induced a significant increase in HR and a reduction in the amplitude of all waves of the heart rhythm variability. Stimulation of the dopaminergic system (L-DOPA and amantadine, 20 mg/kg each) resulted in a moderate increase in HR and amplitudes of low-frequency (LF) and very-low-frequency (VLF) waves of the heart rhythm variability. Successive blockade of nicotinic (hexamethonium, 7 mg/kg) and muscarinic cholinergic receptors (atropine, 1 mg/kg) leads to a significant decrease in the variability of cardiointervals (almost to complete levelling) both under control conditions and after stimulation of the neurotransmitter systems. Serotonin receptor blockade (promethazine, 2 mg/kg) did not affect HR, but reduced the amplitude of LF- and VLF-waves. Under conditions of serotoninergic system stimulation, the blockade of serotonin receptors was followed by a significant HR acceleration without changes in heart rhythm variability; blockade of dopamine receptors (sulpiride, 1 mg/kg) induced HR acceleration and increase in the amplitude of LF- and VLF-waves; blockade of dopamine receptors under conditions of dopamine system stimulation was followed by a significant increase in HR and a decrease in the amplitude of all waves of the heart rhythm variability. It can be hypothesized that serotonin- and dopaminergic systems affect the heart rhythm via cardiomyocyte receptors and via modulation of activity of the adrenergic and cholinergic systems. The effects of serotonin- and dopaminergic systems can be considered as synergic in the CNS, and antagonistic at the periphery.


Assuntos
Neurônios Dopaminérgicos/fisiologia , Frequência Cardíaca/efeitos dos fármacos , Neurotransmissores/farmacologia , Receptores de Neurotransmissores/efeitos dos fármacos , Neurônios Serotoninérgicos/fisiologia , Animais , Colina/antagonistas & inibidores , Agonistas de Dopamina/farmacologia , Antagonistas de Dopamina/farmacologia , Neurônios Dopaminérgicos/efeitos dos fármacos , Frequência Cardíaca/fisiologia , Masculino , Agonistas Muscarínicos/farmacologia , Antagonistas Muscarínicos/farmacologia , Ratos , Receptores Dopaminérgicos/metabolismo , Receptores Muscarínicos/metabolismo , Receptores de Serotonina/metabolismo , Neurônios Serotoninérgicos/efeitos dos fármacos , Serotonina/metabolismo , Antagonistas da Serotonina/farmacologia , Agonistas do Receptor de Serotonina/farmacologia
18.
Comput Biol Chem ; 83: 107140, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31715491

RESUMO

Dopamine is one of the major neurotransmitters in the brain and body, and regulates a wide variety of functions via its binding with dopamine receptors. Abnormalities in dopamine receptors have also been found to be related to various neurological disorders. For such reason, dopamine receptors are among the key components to understanding the molecular mechanisms of many diseases, they are also the potential drug targets for the treatment of many diseases. Till now, five different dopamine receptors (D1-D5) have been identified in mammals, which are assumed to be evolved from a common ancestor after multiple gene duplication events and functional divergence. Thus, identifying the specific features of each dopamine receptor, will not only provide clues for understanding the functional differences between the receptors, but also help us to design drugs specific for a certain subtype of receptor. In this study, we investigated the functional divergence in dopamine receptors in representative vertebrate species by analyzing their molecular evolution features. Our results showed that the coefficients for type I functional divergence (θI) were significantly greater than 0 for all the pairwise comparisons between the five dopamine receptors, suggesting that type I functional divergence, i.e., altered functional constraints or different evolutionary rates, may have taken place at some amino acids in the receptors. We further identified 84 potential type I functional divergence peptide sites for the pairwise comparisons between the D1-like and D2-like are identified in total. When these sites were mapped to the 3D structure of dopamine receptors, most of them were included in ICL3, M6 and M7 domains. Especially, sixteen of these sites may be the major sites associated with the changes of properties between D1-like and D2-like receptors. These sites provide molecular basis for further studies such as dopamine receptor function exploration and subtype specific drug design and screening.


Assuntos
Evolução Molecular , Receptores Dopaminérgicos/química , Animais , Humanos , Modelos Moleculares , Receptores Dopaminérgicos/metabolismo
19.
Nat Protoc ; 14(12): 3471-3505, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31732722

RESUMO

Multiple aspects of neural activity, from neuronal firing to neuromodulator release and signaling, underlie brain function and ultimately shape animal behavior. The recently developed and constantly growing toolbox of genetically encoded sensors for neural activity, including calcium, voltage, neurotransmitter and neuromodulator sensors, allows precise measurement of these signaling events with high spatial and temporal resolution. Here, we describe the engineering, characterization and application of our recently developed dLight1, a suite of genetically encoded dopamine (DA) sensors based on human inert DA receptors. dLight1 offers high molecular specificity, requisite affinity and kinetics and great sensitivity for measuring DA release in vivo. The detailed workflow described in this protocol can be used to systematically characterize and validate dLight1 in increasingly intact biological systems, from cultured cells to acute brain slices to behaving mice. For tool developers, we focus on characterizing five distinct properties of dLight1: dynamic range, affinity, molecular specificity, kinetics and interaction with endogenous signaling; for end users, we provide comprehensive step-by-step instructions for how to leverage fiber photometry and two-photon imaging to measure dLight1 transients in vivo. The instructions provided in this protocol are designed to help laboratory personnel with a broad range of experience (at the graduate or post-graduate level) to develop and utilize novel neuromodulator sensors in vivo, by using dLight1 as a benchmark.


Assuntos
Neurotransmissores/metabolismo , Optogenética/métodos , Receptores Dopaminérgicos/metabolismo , Animais , Dopamina/metabolismo , Engenharia Genética/métodos , Humanos , Proteínas Luminescentes/genética , Neurônios/metabolismo , Fluxo de Trabalho
20.
Nat Neurosci ; 22(12): 1986-1999, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31719672

RESUMO

The importance of neuronal ensembles, termed engram cells, in storing and retrieving memory is increasingly being appreciated, but less is known about how these engram cells operate within neural circuits. Here we tagged engram cells in the ventral CA1 region of the hippocampus (vCA1) and the core of the nucleus accumbens (AcbC) during cocaine conditioned place preference (CPP) training and show that the vCA1 engram projects preferentially to the AcbC and that the engram circuit from the vCA1 to the AcbC mediates memory recall. Direct activation of the AcbC engram while suppressing the vCA1 engram is sufficient for cocaine CPP. The AcbC engram primarily consists of D1 medium spiny neurons, but not D2 medium spiny neurons. The preferential synaptic strengthening of the vCA1→AcbC engram circuit evoked by cocaine conditioning mediates the retrieval of cocaine CPP memory. Our data suggest that the vCA1 engram stores specific contextual information, while the AcbC D1 engram and its downstream network store both cocaine reward and associated contextual information, providing a potential mechanism by which cocaine CPP memory is stored.


Assuntos
Região CA1 Hipocampal/fisiologia , Cocaína/farmacologia , Condicionamento Psicológico/fisiologia , Rememoração Mental/fisiologia , Núcleo Accumbens/fisiologia , Animais , Comportamento Animal/fisiologia , Clozapina/análogos & derivados , Clozapina/farmacologia , Condicionamento Psicológico/efeitos dos fármacos , Potenciais Pós-Sinápticos Excitadores/fisiologia , Camundongos Transgênicos , Vias Neurais/fisiologia , Optogenética , Receptores Dopaminérgicos/fisiologia
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