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1.
Nat Commun ; 11(1): 1145, 2020 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-32123179

RESUMO

Recent studies show that GPCRs rapidly interconvert between multiple states although our ability to interrogate, monitor and visualize them is limited by a relative lack of suitable tools. We previously reported two nanobodies (Nb39 and Nb6) that stabilize distinct ligand- and efficacy-delimited conformations of the kappa opioid receptor. Here, we demonstrate via X-ray crystallography a nanobody-targeted allosteric binding site by which Nb6 stabilizes a ligand-dependent inactive state. As Nb39 stabilizes an active-like state, we show how these two state-dependent nanobodies can provide real-time reporting of ligand stabilized states in cells in situ. Significantly, we demonstrate that chimeric GPCRs can be created with engineered nanobody binding sites to report ligand-stabilized states. Our results provide both insights regarding potential mechanisms for allosterically modulating KOR with nanobodies and a tool for reporting the real-time, in situ dynamic range of GPCR activity.


Assuntos
Receptores Opioides kappa/química , Receptores Opioides kappa/metabolismo , Anticorpos de Domínio Único/química , Sítio Alostérico , Sítios de Ligação , Técnicas Biossensoriais , Cristalografia por Raios X , AMP Cíclico/metabolismo , Dinorfinas/química , Dinorfinas/farmacologia , Células HEK293 , Humanos , Medições Luminescentes/métodos , Piperazinas/química , Piperazinas/farmacologia , Piperidinas/química , Piperidinas/farmacologia , Conformação Proteica , Pirrolidinas/química , Pirrolidinas/farmacologia , Receptores Acoplados a Proteínas-G/química , Receptores Acoplados a Proteínas-G/metabolismo , Receptores Opioides kappa/agonistas , Receptores Opioides kappa/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Anticorpos de Domínio Único/metabolismo , Tetra-Hidroisoquinolinas/química , Tetra-Hidroisoquinolinas/farmacologia
2.
Genet Test Mol Biomarkers ; 24(1): 17-23, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31940240

RESUMO

Background: Heroin use disorder (HUD) is a complex brain disease that includes multiple phenotypes. Heroin acts primarily as a mu-opioid receptor (OPRM1) agonist. The κ opioid receptor 1 (OPRK1) is critically involved in abstinence and remission. Multiple studies confirm that the OPRM1 and OPRK1 genes are associated with HUD. However, their relationship with the addictive phenotype is still unclear. This study was designed to identify the genetic polymorphisms within OPRM1 and OPRK1 with six HUD phenotypes. Methods: A total of 801 patients with HUD were recruited from the Methadone Maintenance Treatment Program in Xi'an. We identified eight potential functional single nucleotide polymorphisms (SNPs) in the two genes that were genotyped using SNaPshot SNP technology. We then performed a case-control association analysis, investigated particular disease phenotypes, and assessed the extent of epistasis among the variants of the two genes. Results: The OPRK1 rs3802279, rs3802281, and rs963549 genotypes were significantly associated with methadone dosage analyzed by Pearson's chi-square test or binary logistic regression to correct for covariates. The rs3802279 CC, rs3802281 TT, and rs963549 CC genotype carriers required a lower methadone maintenance dose per day. Multifactor dimensionality reduction analysis indicated strong interactions between sex and OPRK1 rs963549. The results of the OPRM1 genotyping did not reveal any associations with the various HUD phenotypes. Conclusion: These findings support an important role of the OPRK1 polymorphism in determining the daily methadone dose and may guide future studies in identifying additional genetic risk factors for HUD.


Assuntos
Dependência de Heroína/genética , Receptores Opioides kappa/genética , Receptores Opioides mu/genética , Adulto , Grupo com Ancestrais do Continente Asiático/genética , Biomarcadores Farmacológicos , Estudos de Casos e Controles , China/epidemiologia , Relação Dose-Resposta a Droga , Feminino , Predisposição Genética para Doença , Genótipo , Haplótipos , Humanos , Masculino , Metadona/farmacologia , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único/genética , Receptores Opioides kappa/metabolismo , Receptores Opioides mu/metabolismo , Transtornos Relacionados ao Uso de Substâncias/genética
3.
Anesth Analg ; 130(1): 248-257, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31166231

RESUMO

BACKGROUND: Persistent use of prescription opioids beyond the period of surgical recovery is a large part of a public health problem linked to the current opioid crisis in the United States. However, few studies have been conducted to examine whether morphine reward is influenced by acute pain and injury. METHODS: In a mouse model of incisional injury and minor trauma, animals underwent conditioning, extinction, and drug-primed reinstatement with morphine to examine the rewarding properties of morphine in the presence of acute incisional injury and drug-induced relapse, respectively. In addition, we sought to determine whether these behaviors were influenced by kappa opioid receptor signaling and measured expression of prodynorphin messenger RNA in the nucleus accumbens and medial prefrontal cortex after conditioning and before reinstatement with morphine and incisional injury. RESULTS: In the presence of incisional injury, we observed enhancement of morphine reward with morphine-conditioned place preference but attenuated morphine-primed reinstatement to reward. This adaptation was not present in animals conditioned 12 days after incisional injury when nociceptive sensitization had resolved; however, they showed enhancement of morphine-primed reinstatement. Prodynorphin expression was greatly enhanced in the nucleus accumbens and medial prefrontal cortex of mice with incisional injury and morphine conditioning and remained elevated up to drug-primed reinstatement. These changes were not observed in mice conditioned 12 days after incisional injury. Further, kappa opioid receptor blockade with norbinaltorphimine before reinstatement reversed the attenuation induced by injury. CONCLUSIONS: These findings suggest enhancement of morphine reward as a result of incisional injury but paradoxically a protective adaptation with incisional injury from drug-induced relapse resulting from kappa opioid receptor activation in the reward circuitry. Remote injury conferred no such protection and appeared to enhance reinstatement.


Assuntos
Dor Aguda/tratamento farmacológico , Comportamento Animal/efeitos dos fármacos , Morfina/farmacologia , Antagonistas de Entorpecentes/farmacologia , Receptores Opioides kappa/agonistas , Recompensa , Ferimentos Penetrantes/tratamento farmacológico , Dor Aguda/metabolismo , Dor Aguda/fisiopatologia , Dor Aguda/psicologia , Animais , Condicionamento Psicológico/efeitos dos fármacos , Modelos Animais de Doenças , Encefalinas/genética , Encefalinas/metabolismo , Extinção Psicológica/efeitos dos fármacos , Masculino , Camundongos Endogâmicos C57BL , Limiar da Dor/efeitos dos fármacos , Precursores de Proteínas/genética , Precursores de Proteínas/metabolismo , Receptores Opioides kappa/metabolismo , Transdução de Sinais , Ferimentos Penetrantes/metabolismo , Ferimentos Penetrantes/fisiopatologia , Ferimentos Penetrantes/psicologia
4.
Dalton Trans ; 48(44): 16476-16492, 2019 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-31599913

RESUMO

Bispidones (3,7-diazabicyclo[3.3.1]nonan-9-one) are bicyclic analogues of the natural antiarrhythmic agent, spartein. They can straightforwardly be obtained from two successive Mannich reactions. Reduction of the ketone gives the corresponding bispidol. Substituted bispidones and bispidols offer a large playground by varying the substituents, the configuration of the carbon atoms in position 2 and 4 as well as the conformation of the bicycle. While chair-boat conformers display a strong affinity for κ-opioid receptors, chair-chair bispidines provide adaptable coordination spheres for transition metal and rare-earth ions. Because of their very rich coordination chemistry, substituted bispidines have emerged in various applications of coordination chemistry, such as catalysis, magnetism and medical imaging.


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes/química , Compostos Bicíclicos Heterocíclicos com Pontes/metabolismo , Complexos de Coordenação/química , Receptores Opioides kappa/química , Receptores Opioides kappa/metabolismo , Animais , Complexos de Coordenação/metabolismo , Humanos , Metais Terras Raras/química , Conformação Molecular , Radioterapia/métodos , Elementos de Transição/química
5.
Amino Acids ; 51(10-12): 1527-1545, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31576456

RESUMO

A new series of N-modified analogues of the VV-hemorphin-5 with aminophosphonate moiety have been synthesized, characterized and investigated for anticonvulsant activity. The novel peptide analogues were prepared by solid-phase peptide synthesis-Fmoc-strategy and were evaluated in the timed intravenous pentylenetetrazole infusion test (ivPTZ) and 6-Hz psychomotor seizure test in mice. The acute neurological toxicity was determined using the rotarod test. The redox potentials at glass carbonic electrode (GC) and the acid/base properties as pKa values of these peptide analogues were compared with the electrochemical behaviour of tyrosine- and tryptophan-containing peptides using different voltamperometric modes. Among the five tested peptide analogues, V3p was the most active against the ivPTZ test with effect comparable to that of the VV-hemorphin-5 (V1) used as a positive control. Dose-dependent elevation of the seizure threshold for myoclonic twitch and generalized clonic seizures was observed after i.c.v. administration of V2p, V4p and V5p as well as for forelimbs tonus in V4p peptides. The peptide analogues V2p-V5p were able to suppress dose-dependent psychomotor seizures in the 6-Hz test. In contrast, the V6p peptide showed either a pro-convulsant effect in the iv PTZ test or was inactive in the 6-Hz test. No changes in motor coordination were noted with the novel peptides. Docking study results suggest that kappa opioid receptor binding could be the mechanism of action of peptide derivatives with anticonvulsant activity. The results suggest that incorporation of aminophosphonate moiety at position 1 of the VV-hemorphin-5 scaffold deserve further evaluation in models of epilepsy and derivatization.


Assuntos
Anticonvulsivantes/síntese química , Anticonvulsivantes/uso terapêutico , Hemoglobinas/síntese química , Hemoglobinas/uso terapêutico , Organofosfonatos/química , Fragmentos de Peptídeos/síntese química , Fragmentos de Peptídeos/uso terapêutico , Animais , Anticonvulsivantes/química , Anticonvulsivantes/metabolismo , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Hemoglobinas/química , Hemoglobinas/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos ICR , Simulação de Acoplamento Molecular , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Receptores Opioides kappa/metabolismo , Convulsões/tratamento farmacológico , Convulsões/metabolismo , Técnicas de Síntese em Fase Sólida , Relação Estrutura-Atividade
6.
Nat Commun ; 10(1): 4037, 2019 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-31492869

RESUMO

Increased body weight is a major factor that interferes with smoking cessation. Nicotine, the main bioactive compound in tobacco, has been demonstrated to have an impact on energy balance, since it affects both feeding and energy expenditure at the central level. Among the central actions of nicotine on body weight, much attention has been focused on its effect on brown adipose tissue (BAT) thermogenesis, though its effect on browning of white adipose tissue (WAT) is unclear. Here, we show that nicotine induces the browning of WAT through a central mechanism and that this effect is dependent on the κ opioid receptor (KOR), specifically in the lateral hypothalamic area (LHA). Consistent with these findings, smokers show higher levels of uncoupling protein 1 (UCP1) expression in WAT, which correlates with smoking status. These data demonstrate that central nicotine-induced modulation of WAT browning may be a target against human obesity.


Assuntos
Tecido Adiposo Marrom/efeitos dos fármacos , Hipotálamo/efeitos dos fármacos , Nicotina/farmacologia , Receptores Opioides kappa/metabolismo , Termogênese/efeitos dos fármacos , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/efeitos dos fármacos , Tecido Adiposo Branco/metabolismo , Adulto , Animais , Peso Corporal/efeitos dos fármacos , Feminino , Estimulantes Ganglionares/administração & dosagem , Estimulantes Ganglionares/farmacologia , Humanos , Hipotálamo/metabolismo , Masculino , Camundongos Knockout , Pessoa de Meia-Idade , Nicotina/administração & dosagem , Ratos Sprague-Dawley , Receptores Opioides kappa/genética , Proteína Desacopladora 1/metabolismo
7.
Internist (Berl) ; 60(8): 814-820, 2019 Aug.
Artigo em Alemão | MEDLINE | ID: mdl-31243493

RESUMO

Chronic pruritus is a symptom of various internal disorders. In contrast to dermatological diseases, pruritus does not present with primary skin alterations in these patients. However, intense scratching my cause secondary skin changes such as abrasion, excoriation, prurigo nodularis, or in rare cases even scarring. The most common internal causes for chronic pruritus are chronic kidney disease, hepatobiliary, and hematological disorders as well as adverse drug reactions. Pruritus is less commonly seen in patients with endocrine or metabolic diseases, malabsorption syndromes, infectious diseases, and solid tumors. The pathogenesis of pruritus in these disorders remains largely elusive, albeit first insights have been gained for uremic and cholestatic pruritus. Antipruritic treatment is therefore symptomatic in most cases and may represent a clinical challenge. The calcium channel blockers gabapentin and pregabalin have the best proven efficacy in chronic kidney disease associated pruritus. In Japan, nalfurafine, a κ-opioid receptor agonist, has been licensed for this indication. UVB light may also attenuate uremic symptoms. In patients suffering from hepatobiliary disorders the sequestrant cholestyramine and the enzyme inducer rifampicin are effective. Furthermore, bezafibrate, the µ­opioid receptor antagonists and, in Japan, nalfurafine may be used to ameliorate cholestatic pruritus. So far, no randomized controlled trials have been performed for chronic itch in other internal disorders. Antipruritic treatment is symptom-based with a focus on the effective therapy of the underlying disease.


Assuntos
Antipruriginosos/uso terapêutico , Doenças do Sistema Digestório/complicações , Doenças Hematológicas/complicações , Prurido/tratamento farmacológico , Prurido/etiologia , Insuficiência Renal Crônica/complicações , Doenças do Sistema Digestório/tratamento farmacológico , Doenças Hematológicas/tratamento farmacológico , Humanos , Receptores Opioides kappa/agonistas , Receptores Opioides kappa/metabolismo , Insuficiência Renal Crônica/tratamento farmacológico , Resultado do Tratamento , Uremia/complicações
8.
Neuropsychopharmacology ; 44(10): 1728-1741, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31141817

RESUMO

Kappa opioid receptor (KOR) agonists show promise in ameliorating disorders, such as addiction and chronic pain, but are limited by dysphoric and aversive side effects. Clinically beneficial effects of KOR agonists (e.g., analgesia) are predominantly mediated by heterotrimeric G protein signaling, whereas ß-arrestin signaling is considered central to their detrimental side effects (e.g., dysphoria/aversion). Here we show that Regulator of G protein Signaling-12 (RGS12), via independent signaling mechanisms, simultaneously attenuates G protein signaling and augments ß-arrestin signaling downstream of KOR, exhibiting considerable selectivity in its actions for KOR over other opioid receptors. We previously reported that RGS12-null mice exhibit increased dopamine transporter-mediated dopamine (DA) uptake in the ventral (vSTR), but not dorsal striatum (dSTR), as well as reduced psychostimulant-induced hyperlocomotion; in the current study, we found that these phenotypes are reversed following KOR antagonism. Fast-scan cyclic voltammetry studies of dopamine (DA) release and reuptake suggest that striatal disruptions to KOR-dependent DAergic neurotransmission in RGS12-null mice are restricted to the nucleus accumbens. In both ventral striatal tissue and transfected cells, RGS12 and KOR are seen to interact within a protein complex. Ventral striatal-specific increases in KOR levels and KOR-induced G protein activation are seen in RGS12-null mice, as well as enhanced sensitivity to KOR agonist-induced hypolocomotion and analgesia-G protein signaling-dependent behaviors; a ventral striatal-specific increase in KOR levels was also observed in ß-arrestin-2-deficient mice, highlighting the importance of ß-arrestin signaling to establishing steady-state KOR levels in this particular brain region. Conversely, RGS12-null mice exhibited attenuated KOR-induced conditioned place aversion (considered a ß-arrestin signaling-dependent behavior), consistent with the augmented KOR-mediated ß-arrestin signaling seen upon RGS12 over-expression. Collectively, our findings highlight a role for RGS12 as a novel, differential regulator of both G protein-dependent and -independent signaling downstream of KOR activation.


Assuntos
Dopamina/metabolismo , Núcleo Accumbens/metabolismo , Proteínas RGS/genética , Receptores Opioides kappa/metabolismo , Estriado Ventral/metabolismo , beta-Arrestinas/metabolismo , (trans)-Isômero de 3,4-dicloro-N-metil-N-(2-(1-pirrolidinil)-ciclo-hexil)-benzenoacetamida/farmacologia , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Comportamento Animal/efeitos dos fármacos , Ala(2)-MePhe(4)-Gly(5)-Encefalina/farmacologia , Leucina Encefalina-2-Alanina/farmacologia , Feminino , Locomoção/efeitos dos fármacos , Masculino , Camundongos , Camundongos Knockout , Núcleo Accumbens/efeitos dos fármacos , Receptores Opioides kappa/agonistas , Transdução de Sinais , Transmissão Sináptica/efeitos dos fármacos , Estriado Ventral/efeitos dos fármacos
9.
Anesth Analg ; 128(6): 1328-1335, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31094808

RESUMO

BACKGROUND: Opioid dependence is a major public health issue without optimal therapeutics. This study investigates the potential therapeutic effect of dezocine, a nonaddictive opioid, in opioid dependence in rat models. METHODS: Dezocine was administered intraperitoneally to a morphine-dependent rat model to investigate its effect on withdrawal and conditioned place preference (CPP). Effect of dezocine on morphine withdrawal syndrome and CPP was analyzed using 2-way analysis of variance (ANOVA) followed by Tukey's post hoc test. Buprenorphine and vehicle solution containing 20% (v/v) dimethyl sulfoxide were used for positive and negative control, respectively. The astrocytes activation in nucleus accumbens was assessed by immunofluorescence assay of glial fibrillary acidic protein. Effect of dezocine and buprenorphine on the internalization of κ opioid receptor (KOR) was investigated using Neuro2A expressing KOR fused to red fluorescent protein tdTomato (KOR-tdT). Buprenorphine and dezocine were screened against 44 G-protein-coupled receptors, ion channels, and transporter proteins using radioligand-binding assay to compare the molecular targets. RESULTS: The mean withdrawal score was reduced in rats treated with 1.25 mg·kg dezocine compared to vehicle-treated control animals starting from the day 1 (mean difference: 7.8; 95% confidence interval [CI], 6.35-9.25; P < .0001 by 2-way ANOVA). Significance was observed at all treatment days, including day 7 (mean difference: 2.13; 95% CI, 0.68-3.58; P < .001 by 2-way ANOVA). Furthermore, dezocine inhibited the reinstatement of morphine-induced CPP (mean difference: 314; 95% CI, 197.9-430.1; P < .0001 by 2-way ANOVA) compared to the control group. Chronic morphine administration induced astrocytes activation in nucleus accumbens, which was attenuated by dezocine. Dezocine blocked the agonist-induced KOR internalization in vitro, 1 of the mechanisms involved in the downstream signaling and development of opioid dependence. Dezocine had affinity to norepinephrine and serotonin transporters and sigma-1 receptor, whereas buprenorphine showed no activity against these targets. CONCLUSIONS: Dezocine could potentially be used to alleviate opioid dependence. Due to the unique molecular target profile different from buprenorphine, it might have important value in studying the mechanisms of morphine dependence and developing novel therapeutic approaches.


Assuntos
Analgésicos Opioides/efeitos adversos , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Dependência de Morfina/tratamento farmacológico , Morfina/efeitos adversos , Antagonistas de Entorpecentes/farmacologia , Tetra-Hidronaftalenos/farmacologia , Análise de Variância , Animais , Astrócitos/efeitos dos fármacos , Buprenorfina/administração & dosagem , Linhagem Celular , Relação Dose-Resposta a Droga , Imunofluorescência , Proteína Glial Fibrilar Ácida/metabolismo , Masculino , Núcleo Accumbens/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Receptores Opioides kappa/metabolismo
10.
Neuropsychopharmacology ; 44(10): 1714-1719, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-30928993

RESUMO

Kappa opioid receptors (KORs) have been characterized as an aversive system in the brain and implicated in social behavior in preclinical models. This work investigated the effect of social status on the KOR system in humans using positron emission tomography (PET) imaging with the novel KOR agonist radiotracer [11C]EKAP. Eighteen healthy participants (mean age 41.2 ± 9.3) completed the Barratt Simplified Measure of Social Status (BSMSS), an MRI and an [11C]EKAP PET scan on the High Resolution Research Tomograph. Arterial blood sampling and metabolite analysis were conducted to obtain the input function. Regions of interest were based upon an MR template and included the reward/aversion areas of the brain. The multilinear analysis-1 (MA1) method was applied to the regional time-activity curves (TACs) to calculate [11C]EKAP regional volume of distribution (VT). Mixed models and Pearson correlation coefficients were used for body mass index (BMI), gender and age, with age being dropped in subsequent analyses because of nonsignificance. An overall effect of primary ROIs (F7, 112 7.43, p < 0.0001), BSMSS score (F1, 13 7.45, p = 0.02), BMI (F1, 13 23.5, p < 0.001), and gender (F1, 13 23.75, p < 0.001), but not age (F1, 13 1.12, p = 0.35) was observed. Regional [11C]EKAP VT and BSMSS were found to be negatively correlated in the amygdala (r = -0.69, p < 0.01), anterior cingulate cortex (r = -0.56, p = 0.02), caudate (r = -0.66, p < 0.01), frontal cortex (r = -0.52, p = 0.04), hippocampus (r = -0.60, p = 0.01), pallidum (r = -0.59, p = 0.02), putamen (r = -0.62, p = 0.01), and ventral striatum (r = -0.66, p < 0.01). In secondary (non-reward) regions, correlations of [11C]EKAP VT and BSMSS were nonsignificant with the exception of the insula. There was an inverse correlation between social status and KOR levels that was largely specific to the reward/aversion (e.g., saliency) areas of the brain. This finding suggests the KOR system may act as a mediator for the negative effects of social behaviors in humans.


Assuntos
Encéfalo/metabolismo , Receptores Opioides kappa/metabolismo , Classe Social , Adulto , Fatores Etários , Índice de Massa Corporal , Encéfalo/diagnóstico por imagem , Feminino , Voluntários Saudáveis , Humanos , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Tomografia por Emissão de Pósitrons , Fatores Sexuais
11.
J Pharmacol Exp Ther ; 370(1): 1-8, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30975792

RESUMO

The kappa (κ) opioid receptor/dynorphin system modulates depression-like states and anhedonia, as well adaptations to stress and exposure to drugs of abuse. Several relatively short-acting small molecule κ-receptor antagonists have been synthesized, and their behavioral profile has been examined under some conditions. The hypothesis of this study is that pharmacological manipulations of the κ-receptor system will result in changes in ethologically relevant anhedonic-like behaviors in mice. Adult male C57BL/6j mice (n = 6-8) were examined for self-grooming behavior in the splash test (in which robust self-grooming is elicited by spraying the dorsum of the mouse with a sucrose solution). The κ-agonist salvinorin A (0.56-1.8 mg/kg) produced dose-dependent decreases in self-grooming, a marker of anhedonia. The selectivity, potency, and duration of action of two relatively short-acting κ-antagonists, LY2444296 [(S)-3-fluoro-4-(4-((2-(3-fluorophenyl) pyrrolidin-1-yl)methyl)phenoxy)benzamide] and LY2795050 [3-chloro-4-(4-(((2S)-2-pyridin-3-ylpyrrolidin-1-yl)methyl) phenoxy)benzamide], were studied for their effectiveness in preventing grooming deficits caused by salvinorin A (1.8 mg/kg). κ-selective doses of both LY2444296 (0.032-1 mg/kg) and LY2795050 (0.032-0.32 mg/kg) dose- and time-dependently prevented the grooming deficits caused by salvinorin A (1.8 m/kg). We also found that a κ-selective dose of each of these antagonists decreased immobility in the forced swim test, a common test of anti-anhedonia effects. This study shows that the κ-receptor system is involved in an ethologically relevant measure of anhedonia, and that κ-selective doses of these antagonists can produce effects consistent with rapid anti-anhedonia. SIGNIFICANCE STATEMENT: Activation of the κ-opioid receptor system results in grooming deficits in mice, an ethologically relevant marker of anhedonia. Shorter acting κ-antagonists are able to cause effects consistent with rapid antianhedonia.


Assuntos
Asseio Animal/efeitos dos fármacos , Antagonistas de Entorpecentes/farmacologia , Receptores Opioides kappa/agonistas , Receptores Opioides kappa/antagonistas & inibidores , Animais , Relação Dose-Resposta a Droga , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Nociceptividade/efeitos dos fármacos , Oxicodona/antagonistas & inibidores , Oxicodona/farmacologia , Filosofia , Receptores Opioides kappa/metabolismo , Natação
12.
Neuropsychopharmacology ; 44(10): 1720-1727, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31026862

RESUMO

Animal studies indicate that the kappa-opioid receptor/dynorphin system plays an important role in cocaine binges and stress-induced relapse. Our goal was to investigate changes in kappa-opioid receptor (KOR) availability in the human brain using positron emission tomography (PET), before and after a cocaine binge. We also investigated the correlation between KOR and stress-induced cocaine self-administration. PET imaging was performed with the KOR selective agonist [11C]GR103545. Subjects with cocaine-use disorder (CUD) underwent PET scans and performed two types of cocaine self-administration sessions in the laboratory as follows: (1) choice sessions following a cold pressor test, to induce stress, and (2) binge dosing of cocaine. This allowed us investigate the following: (1) the association between KOR binding and a laboratory model of stress-induced relapse and (2) the change in KOR binding following a 3-day cocaine binge, which is thought to represent a change in endogenous dynorphin. A group of matched healthy controls was included to investigate between group differences in KOR availability. A significant association between [11C]GR103545 binding and cocaine self-administration was seen: greater KOR availability was associated with more choices for cocaine. In addition, the 3-day cocaine binge significantly reduced [11C]GR103545 binding by 18% in the striatum and 14% across brain regions. No difference in [11C]GR103545 binding was found between the CUD subjects and matched controls. In the context of previous studies, these findings add to the growing evidence that pharmacotherapies targeting the KOR have the potential to significantly impact treatment development for cocaine-use disorder.


Assuntos
Encéfalo/metabolismo , Transtornos Relacionados ao Uso de Cocaína/metabolismo , Cocaína/administração & dosagem , Receptores Opioides kappa/metabolismo , Adulto , Encéfalo/diagnóstico por imagem , Radioisótopos de Carbono , Estudos de Casos e Controles , Comportamento de Escolha , Fumar Cocaína , Transtornos Relacionados ao Uso de Cocaína/diagnóstico por imagem , Transtornos Relacionados ao Uso de Cocaína/psicologia , Dinorfinas/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Naltrexona/farmacologia , Antagonistas de Entorpecentes/farmacologia , Neostriado/diagnóstico por imagem , Neostriado/metabolismo , Piperazinas , Tomografia por Emissão de Pósitrons , Pirrolidinas , Estresse Psicológico/psicologia
13.
Neuron ; 102(3): 564-573.e6, 2019 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-30878290

RESUMO

Negative affective states affect quality of life for patients suffering from pain. These maladaptive emotional states can lead to involuntary opioid overdose and many neuropsychiatric comorbidities. Uncovering the mechanisms responsible for pain-induced negative affect is critical in addressing these comorbid outcomes. The nucleus accumbens (NAc) shell, which integrates the aversive and rewarding valence of stimuli, exhibits plastic adaptations in the presence of pain. In discrete regions of the NAc, activation of the kappa opioid receptor (KOR) decreases the reinforcing properties of rewards and induces aversive behaviors. Using complementary techniques, we report that in vivo recruitment of NAc shell dynorphin neurons, acting through KOR, is necessary and sufficient to drive pain-induced negative affect. Taken together, our results provide evidence that pain-induced adaptations in the kappa opioid system within the NAc shell represent a functional target for therapeutic intervention that could circumvent pain-induced affective disorders. VIDEO ABSTRACT.


Assuntos
Afeto/fisiologia , Dinorfinas/metabolismo , Inflamação/metabolismo , Transtornos do Humor/metabolismo , Neurônios/metabolismo , Núcleo Accumbens/metabolismo , Dor/metabolismo , Receptores Opioides kappa/metabolismo , Animais , Inflamação/complicações , Inflamação/psicologia , Camundongos , Transtornos do Humor/etiologia , Transtornos do Humor/psicologia , Inibição Neural , Plasticidade Neuronal , Núcleo Accumbens/citologia , Dor/complicações , Dor/psicologia , Ratos
14.
Behav Pharmacol ; 30(6): 463-470, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-30724802

RESUMO

Pain is a significant public health problem, and assessment of pain-related impairment of behavior is a key clinical indicator and treatment target. Similar to opioids and NSAIDs, dopamine (DA) transporter inhibitors block pain-related depression of intracranial self-stimulation (ICSS) in rats. The primary goal of the present study was to determine if the effects of monoamine uptake inhibitors on pain-related depression of ICSS in rats extend to an assay of pain-related depression of nesting in mice. We hypothesized that the DA transporter-selective uptake inhibitor bupropion would block depression of nesting behavior produced by intraperitoneal injection of lactic acid, whereas selective serotonin transporter-selective citalopram, norepinephrine transporter-selective nisoxetine, and the mixed action selective serotonin transporter/norepinephrine transporter inhibitor milnacipran would be ineffective. Effects of the NSAID ketoprofen were also obtained to facilitate interpretation of the effects of the monoamine uptake inhibitors. Consistent with previous findings, ketoprofen blocked pain-related depression of nesting. In contrast, none of the monoamine uptake inhibitors blocked pain-related depression of nesting, although they all blocked pain-related stimulation of stretching. Unlike findings from studies of pain-related depression of ICSS, these results do not support consideration of DA uptake inhibitors for treatment of pain-related depression of behavior.


Assuntos
Comportamento Animal/efeitos dos fármacos , Comportamento de Nidação/efeitos dos fármacos , Dor/tratamento farmacológico , Analgésicos Opioides/farmacologia , Animais , Bupropiona/farmacologia , Citalopram/farmacologia , Condicionamento Operante/efeitos dos fármacos , Inibidores da Captação de Dopamina/farmacologia , Fluoxetina/análogos & derivados , Fluoxetina/farmacologia , Cetoprofeno/farmacologia , Ácido Láctico/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos ICR , Milnaciprano/farmacologia , Receptores Opioides kappa/metabolismo , Receptores Opioides kappa/fisiologia , Autoestimulação/efeitos dos fármacos
15.
Lipids Health Dis ; 18(1): 52, 2019 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-30764838

RESUMO

BACKGROUND: This study was designed to test the hypothesis that κ-opioid receptor (κ-OR) stimulation reduces palmitate-induced HUVECs apoptosis and to investigate its mechanisms. METHODS: HUVECs were subjected to sodium palmitate, apoptosis and cell viability were determined, HUVECs were treated with specific inhibitors to PI3K, Akt, eNOS and siRNAs targeting κ-OR and Akt. Groups were divided as follows: the control group, the sodium palmitate group, the sodium palmitate+U50,488H (a selective κ-OR agonist) group and the sodium palmitate+U50,488H + nor-BNI (a selective κ-OR antagonist) group. RESULTS: Treatment with sodium palmitate significantly reduced cell viability and increased apoptosis rate which were significantly alleviated by pretreatment with U50,488H, the effect of U50,488H was abolished by nor-BNI. Phosphorylation of Akt and eNOS, as well as NO production were attenuated and accompanied by an increased expression of caspase 3 when HUVECs were subjected to sodium palmitate, and all these changes were restored by pretreatment with U50,488H, the effects of U50,488H were abolished by nor-BNI, and specific inhibitors to PI3K, Akt, eNOS, respectively. SiRNAs targeting κ-OR or Akt abolished the effects of U50,488H on phosphorylation of Akt and eNOS as well as the expressions of caspase 3, Bax and Bcl-2. SiRNAs targeting Akt elicited no effect on the expression of κ-OR. CONCLUSION: This study provides the evidence for the first time that κ-OR stimulation possesses anti-palmitate-induced apoptosis effect, which is mediated by PI3K/Akt/eNOS signaling pathway.


Assuntos
(trans)-Isômero de 3,4-dicloro-N-metil-N-(2-(1-pirrolidinil)-ciclo-hexil)-benzenoacetamida/farmacologia , Apoptose/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Óxido Nítrico Sintase Tipo III/genética , Proteínas Proto-Oncogênicas c-akt/genética , Receptores Opioides kappa/genética , Analgésicos Opioides/farmacologia , Caspase 3/genética , Caspase 3/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Regulação da Expressão Gênica , Células Endoteliais da Veia Umbilical Humana/citologia , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Naltrexona/análogos & derivados , Naltrexona/farmacologia , Antagonistas de Entorpecentes/farmacologia , Óxido Nítrico Sintase Tipo III/antagonistas & inibidores , Óxido Nítrico Sintase Tipo III/metabolismo , Ácido Palmítico/antagonistas & inibidores , Ácido Palmítico/farmacologia , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Fosforilação/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Receptores Opioides kappa/agonistas , Receptores Opioides kappa/antagonistas & inibidores , Receptores Opioides kappa/metabolismo , Transdução de Sinais , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismo
16.
J Med Chem ; 62(2): 561-574, 2019 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-30608693

RESUMO

µ opioid receptor (MOR) agonists have been widely applied for treating moderate to severe pain. However, numerous adverse effects have been associated with their application, including opioid-induced constipation (OIC), respiratory depression, and addiction. On the basis of previous work in our laboratory, NAP, a 6ß- N-4'-pyridyl substituted naltrexamine derivative, was identified as a peripheral MOR antagonist that may be used to treat OIC. To further explore its structure-activity relationship, a new series of NAP derivatives were designed, synthesized, and biologically evaluated. Among these derivatives, NFP and NYP significantly antagonized the antinociception effect of morphine. Whereas NAP acted mainly peripherally, its derivatives NFP and NYP actually can act centrally. Furthermore, NFP produced significantly lesser withdrawal symptoms than naloxone at similar doses. These results suggest that NFP has the potential to be a lead compound to treat opioid abuse and addiction.


Assuntos
Desenho de Fármacos , Morfinanos/química , Receptores Opioides kappa/antagonistas & inibidores , Receptores Opioides mu/antagonistas & inibidores , Analgésicos Opioides/farmacologia , Animais , Sítios de Ligação , Constipação Intestinal/induzido quimicamente , Constipação Intestinal/tratamento farmacológico , Ligantes , Masculino , Camundongos , Conformação Molecular , Simulação de Acoplamento Molecular , Morfinanos/metabolismo , Morfinanos/uso terapêutico , Morfina/farmacologia , Receptores Opioides kappa/genética , Receptores Opioides kappa/metabolismo , Receptores Opioides mu/genética , Receptores Opioides mu/metabolismo , Relação Estrutura-Atividade
17.
Drug Dev Res ; 80(4): 425-437, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30681179

RESUMO

VV-Hemorphin-5 is an endogenous opioid peptide of the Hemorphin family with affinity at opioid receptors. A series of C-amide analogues have been synthesized, based on the structure of VV-Hemorphin-5, modified at position 1 and 7 by the un/natural amino acids (Aa8-Val-Val-Tyr-Pro-Trp-Thr-Gln-NH2 and Val-Val-Tyr-Pro-Trp-Thr-Aa1-NH2 ) using SPPS, Fmoc-chemistry. The peptide derivatives were evaluated for their anticonvulsant activity in three acute seizure tests in male ICR mice, the maximal electroshock (MES), the 6 Hz psychomotor seizure test, and the timed intravenous pentylenetetrazole (ivPTZ) infusion test. Their neurotoxicity was assessed in the rotarod test. Among the tested peptide analogues, V4 showed anticonvulsant activity in the three seizure tests that was comparable to the VV-Hemorphin-5 (V1) used as a positive control. While V5, V6, and V7 peptide derivatives exhibited anticonvulsant activity in the MES and 6 Hz test, they were inactive (V7) or showed pro-convulsant effect (V5 and V6) in the i.v. PTZ test. At a dose of 10 µg/mouse the peptide V2 was effective against clonic seizures induced by PTZ. Motor coordination was not affected by newly developed analogues of VV-Hemorphin-5. Docking study results suggest that kappa opioid receptor binding could be the mechanism of action of peptide derivatives with anticonvulsant activity. The results suggest that incorporation of nonproteinogenic and/or natural amino acids at position 1 and 7 of the VV-Hemorphin-5 scaffold deserve further evaluation in models of epilepsy and derivatization.


Assuntos
Anticonvulsivantes/farmacologia , Hemoglobinas/farmacologia , Peptídeos Opioides/farmacologia , Fragmentos de Peptídeos/farmacologia , Convulsões/tratamento farmacológico , Sequência de Aminoácidos , Animais , Anticonvulsivantes/síntese química , Anticonvulsivantes/química , Eletrochoque , Hemoglobinas/síntese química , Hemoglobinas/química , Masculino , Camundongos Endogâmicos ICR , Simulação de Acoplamento Molecular , Estrutura Molecular , Peptídeos Opioides/síntese química , Peptídeos Opioides/química , Pentilenotetrazol , Fragmentos de Peptídeos/síntese química , Fragmentos de Peptídeos/química , Ligação Proteica , Desempenho Psicomotor/efeitos dos fármacos , Receptores Opioides delta/metabolismo , Receptores Opioides kappa/metabolismo , Relação Estrutura-Atividade
18.
Pain ; 160(4): 824-832, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30681985

RESUMO

Chronic pain is associated with neuroplastic changes in the amygdala that may promote hyper-responsiveness to mechanical and thermal stimuli (allodynia and hyperalgesia) and/or enhance emotional and affective consequences of pain. Stress promotes dynorphin-mediated signaling at the kappa opioid receptor (KOR) in the amygdala and mechanical hypersensitivity in rodent models of functional pain. Here, we tested the hypothesis that KOR circuits in the central nucleus of the amygdala (CeA) undergo neuroplasticity in chronic neuropathic pain resulting in increased sensory and affective pain responses. After spinal nerve ligation (SNL) injury in rats, pretreatment with a long-acting KOR antagonist, nor-binaltorphimine (nor-BNI), subcutaneously or through microinjection into the right CeA, prevented conditioned place preference (CPP) to intravenous gabapentin, suggesting that nor-BNI eliminated the aversiveness of ongoing pain. By contrast, systemic or intra-CeA administration of nor-BNI had no effect on tactile allodynia in SNL animals. Using whole-cell patch-clamp electrophysiology, we found that nor-BNI decreased synaptically evoked spiking of CeA neurons in brain slices from SNL but not sham rats. This effect was mediated through increased inhibitory postsynaptic currents, suggesting tonic disinhibition of CeA output neurons due to increased KOR activity as a possible mechanism promoting ongoing aversive aspects of neuropathic pain. Interestingly, this mechanism is not involved in SNL-induced mechanical allodynia. Kappa opioid receptor antagonists may therefore represent novel therapies for neuropathic pain by targeting aversive aspects of ongoing pain while preserving protective functions of acute pain.


Assuntos
Núcleo Central da Amígdala/metabolismo , Inibição Neural/efeitos dos fármacos , Neuralgia/prevenção & controle , Neuralgia/terapia , Receptores Opioides kappa/metabolismo , Transdução de Sinais/fisiologia , Animais , Núcleo Central da Amígdala/patologia , Dor Crônica/terapia , Modelos Animais de Doenças , Hiperalgesia/tratamento farmacológico , Hiperalgesia/etiologia , Técnicas In Vitro , Masculino , Potenciais da Membrana/efeitos dos fármacos , Naltrexona/análogos & derivados , Naltrexona/uso terapêutico , Antagonistas de Entorpecentes/uso terapêutico , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Limiar da Dor/efeitos dos fármacos , Técnicas de Patch-Clamp , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Transmissão Sináptica/efeitos dos fármacos
19.
Am J Addict ; 28(2): 86-91, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30664299

RESUMO

BACKGROUND AND OBJECTIVES: The core pharmacological treatment of Post-Traumatic Stress Disorder (PTSD) is selective serotonin reuptake inhibitors (SSRIs), although remission is only around 30% with them. Many patients will self-treat with opioids and due to the opiate system involvement in dysphoric mood and anxiety/stress responses, it is likely that antagonism of the kappa opioid receptor (KOR) system represents a potential target for treatment of PTSD. The aim of this study is to compare response of PTSD symptoms when antagonizing KOR via buprenorphine/naloxone compared to SSRIs or opioid therapy. METHODS: A retrospective chart review of patients in the MEDVAMC between June 1, 2010 and June 30, 2016 was conducted. Inclusion criteria included patients with a documented diagnosis of PTSD with at least two documented PTSD scores (either PCLC or PC-PTSD). Exclusion criteria included patients not prescribed one of the study medications (ie, buprenorphine, SSRI, or opiate for chronic pain), and patients not on the study medication for at least 30 days. RESULTS: Buprenorphine patients exhibited the lowest final average PTSD score (2.47) and the largest change from baseline (-24.0%) compared to opioids (-16.1%) or SSRIs (1.16%). The average buprenorphine dose was 23.3 mg/day, and the average length of therapy was 860 days. CONCLUSIONS: Buprenorphine may help decrease PTSD symptoms more than SSRIs or opioids alone. Prospective studies are needed to determine whether these effects are reproducible. SCIENTIFIC SIGNIFICANCE: Pharmacotherapy advancements in PTSD treatment have been limited and the kappa opioid receptor system presents a new target that warrants further research. (Am J Addict 2019;XX:1-6).


Assuntos
Buprenorfina/administração & dosagem , Transtornos de Estresse Pós-Traumáticos , Adulto , Analgésicos Opioides/uso terapêutico , Pesquisa Comparativa da Efetividade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Antagonistas de Entorpecentes/administração & dosagem , Receptores Opioides kappa/metabolismo , Estudos Retrospectivos , Inibidores de Captação de Serotonina/uso terapêutico , Transtornos de Estresse Pós-Traumáticos/diagnóstico , Transtornos de Estresse Pós-Traumáticos/tratamento farmacológico , Transtornos de Estresse Pós-Traumáticos/metabolismo , Resultado do Tratamento , Estados Unidos
20.
Behav Brain Res ; 359: 258-265, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30414973

RESUMO

Dynorphin (DYN), and its receptor, the kappa opioid receptor (KOR) are involved in drug seeking and relapse but the mechanisms are poorly understood. One hypothesis is that DYN/KOR activation promotes drug seeking through increased impulsivity, because many stimuli that induce DYN release increase impulsivity. Here, we systematically compare the effects of drugs that activate DYN/KOR on performance on the 5-choice serial reaction time task (5-CSRTT), a test of sustained attention and impulsivity. In Experiment 1, we determined the effects of U50,488 (0, 2.5, 5 mg/kg), yohimbine (0, 1.25, 2.5 mg/kg), and nicotine (0, 0.15, 0.3 mg/kg) on 5-CSRTT performance. In Experiment 2, we determined the effects of alcohol (0, 0.5, 1.0, 1.5 g/kg) on 5-CSRTT performance before and after voluntary, intermittent alcohol exposure. In Experiment 3, we determined the potential role of KOR in the pro-impulsive effects of yohimbine (1.25 mg/kg) and nicotine (0.3 mg/kg) by the prior administration of the KOR antagonist nor-BNI (10 mg/kg). Premature responding, the primary measure of impulsivity, was reduced by U50,488 and alcohol, but these drugs had a general suppressive effect. Yohimbine and nicotine increased premature responding. Yohimbine-, but not nicotine-induced increases in premature responding were blocked by nor-BNI, suggesting that impulsivity induced by yohimbine is KOR dependent. This may suggests a potential role for KOR-mediated increases in impulsivity in yohimbine-induced reinstatement.


Assuntos
Comportamento de Escolha/efeitos dos fármacos , Comportamento Impulsivo/efeitos dos fármacos , Neurotransmissores/farmacologia , Receptores Opioides kappa/metabolismo , Ioimbina/farmacologia , (trans)-Isômero de 3,4-dicloro-N-metil-N-(2-(1-pirrolidinil)-ciclo-hexil)-benzenoacetamida/farmacologia , Animais , Atenção/efeitos dos fármacos , Atenção/fisiologia , Comportamento de Escolha/fisiologia , Relação Dose-Resposta a Droga , Etanol/farmacologia , Comportamento Impulsivo/fisiologia , Masculino , Nicotina/farmacologia , Ratos Long-Evans , Receptores Opioides kappa/antagonistas & inibidores
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