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1.
Molecules ; 24(11)2019 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-31159491

RESUMO

G protein-coupled receptors (GPCRs) play a key role in many cellular signaling mechanisms, and must select among multiple coupling possibilities in a ligand-specific manner in order to carry out a myriad of functions in diverse cellular contexts. Much has been learned about the molecular mechanisms of ligand-GPCR complexes from Molecular Dynamics (MD) simulations. However, to explore ligand-specific differences in the response of a GPCR to diverse ligands, as is required to understand ligand bias and functional selectivity, necessitates creating very large amounts of data from the needed large-scale simulations. This becomes a Big Data problem for the high dimensionality analysis of the accumulated trajectories. Here we describe a new machine learning (ML) approach to the problem that is based on transforming the analysis of GPCR function-related, ligand-specific differences encoded in the MD simulation trajectories into a representation recognizable by state-of-the-art deep learning object recognition technology. We illustrate this method by applying it to recognize the pharmacological classification of ligands bound to the 5-HT2A and D2 subtypes of class-A GPCRs from the serotonin and dopamine families. The ML-based approach is shown to perform the classification task with high accuracy, and we identify the molecular determinants of the classifications in the context of GPCR structure and function. This study builds a framework for the efficient computational analysis of MD Big Data collected for the purpose of understanding ligand-specific GPCR activity.


Assuntos
Descoberta de Drogas , Ligantes , Aprendizado de Máquina , Relação Quantitativa Estrutura-Atividade , Receptores Acoplados a Proteínas-G , Algoritmos , Sítios de Ligação , Desenho de Drogas , Descoberta de Drogas/métodos , Humanos , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Ligação Proteica , Receptor 5-HT2A de Serotonina/química , Receptor 5-HT2A de Serotonina/metabolismo , Receptores Acoplados a Proteínas-G/química , Receptores Acoplados a Proteínas-G/metabolismo
2.
Drug Test Anal ; 11(7): 990-998, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30845376

RESUMO

Synthetic cathinones (SCs) are ß-keto analogs of amphetamines. Like amphetamines, SCs target monoamine transporters; however, unusual neuropsychiatric symptoms have been associated with abuse of some SCs, suggesting SCs might possess additional pharmacological properties. We performed radioligand competition binding assays to assess the affinities of nine SCs at human 5-HT2A receptors (5-HT2A R) and muscarinic M1 receptors (M1 R) transiently expressed in HEK293 cells. None of the SCs exhibited affinity at M1 R (minimal displacement of [~Kd ] [3 H]scopolamine up to 10 µM). However, two SCs, α-pyrrolidinopropiophenone (α-PPP) and 4-methyl-α-PPP, had low µM Ki values at 5-HT2A R. In 5-HT2A R-phosphoinositide hydrolysis assays, α-PPP and 4-methyl-α-PPP displayed inverse agonist activity. We further assessed the 5-HT2A R functional activity of α-PPP, and observed it competitively antagonized 5-HT2A R signaling stimulated by the 5-HT2 R agonist (±)-2,5-dimethoxy-4-iodoamphetamine (DOI; Kb  = 851 nM). To assess in vivo 5-HT2A R activity, we examined the effects of α-PPP on the DOI-elicited head-twitch response (HTR) in mice. α-PPP dose-dependently blocked the HTR with maximal suppression at 10 mg/kg (P < 0.0001), which is a moderate dose used in studies investigating psychostimulant properties of α-PPP. To corroborate a 5-HT2A R mechanism, we also tested 3,4-methylenedioxy-α-PPP (MDPPP) and 3-bromomethcathinone (3-BMC), SCs that we observed had 5-HT2A R Ki s > 10 µM. Neither MDPPP nor 3-BMC, at 10 mg/kg doses, attenuated the DOI HTR. Our results suggest α-PPP has antagonist interactions at 5-HT2A R in vitro that may translate at physiologically-relevant doses in vivo. Considering 5-HT2A R antagonism has been shown to mitigate effects of psychostimulants, this property may contribute to α-PPPs unpopularity compared to other monoamine transporter inhibitors.


Assuntos
Estimulantes do Sistema Nervoso Central/farmacologia , Propiofenonas/farmacologia , Pirrolidinas/farmacologia , Receptor 5-HT2A de Serotonina/metabolismo , Antagonistas do Receptor 5-HT2 de Serotonina/farmacologia , Alcaloides/química , Alcaloides/farmacologia , Animais , Feminino , Células HEK293 , Humanos , Camundongos
3.
Psychiatr Genet ; 29(3): 79-85, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30789538

RESUMO

OBJECTIVE: We aimed to test the association of polymorphisms in HTR2A, TPH1, and TPH2 genes with attempted suicide in rural China. PARTICIPANTS AND METHODS: On the basis of a case-control study, we recruited 1200 pairs of participants from Shandong Province, China. The blood samples of 712 suicide attempters and 739 nonsuicide attempters were collected finally. We tested seven single nucleotide polymorphisms: rs6313 and rs6311 in HTR2A, rs4537731, rs1800532, and rs1799913 in TPH1, and rs4448731 and rs4641527 in TPH2. RESULTS: In univariate analysis, allele C of rs4537731 was associated negatively with attempted suicide among total and male samples; however, the association was not statistically significant in multivariate analysis after adjusting for other potential confounding factors. No association between other six single nucleotide polymorphisms and attempted suicide was found in the total, male, or female samples. CONCLUSION: This study did not support the effect of these seven serotonergic gene polymorphisms on attempted suicide in rural China.


Assuntos
Comportamento Autodestrutivo/genética , Tentativa de Suicídio/psicologia , Suicídio/psicologia , Adulto , Alelos , Estudos de Casos e Controles , China , Feminino , Frequência do Gene/genética , Estudos de Associação Genética/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único/genética , Receptor 5-HT2A de Serotonina/genética , Receptor 5-HT2A de Serotonina/metabolismo , População Rural , Triptofano Hidroxilase/genética , Triptofano Hidroxilase/metabolismo
4.
Gene ; 694: 93-96, 2019 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-30738094

RESUMO

OBJECTIVES: Tobacco smoking is a complex and multifactorial disease involving both environmental and genetic factors. In the Mexican mestizo population, single-nucleotide polymorphisms (SNPs) associated with cigarette smoking and a greater degree of nicotine addiction have been identified; however, no possible roles have been explored in regard to the age of onset of smoking or in the success of quitting. METHODS: In this study, 151 Mexican mestizo, who smoke cigarettes, were included. They were grouped according to the age at which they started smoking: those who started smoking before 18 years of age (early smokers, ES) and those who started smoking ≥18 years of age (late smokers, LS). In addition, relapse in smoking was evaluated at the first month after the end of treatment. Genetic association was evaluated characterizing 10 SNPs in 4 genes (CHRNA5, CHRNA3, NRXN1, and HTR2A). RESULTS: According to the dominant model of genetic inheritance, rs6313 (CT+TT) of the HTR2A gene was associated (p = 0.0201) with cigarette consumption at early ages (OR = 2.68, CI = 1.18-6.07). When the risk of relapse was analyzed one month after the end of treatment, regardless of the age of onset, the T allele (rs6313) of HTR2A appeared to be a risk factor for relapse (OR = 2.92, 95% CI = 1.06-8.11); the T allele was found more frequently in those who relapsed (50.0%) compared with people who maintained abstinence (25.4%) (p = 0.0332). CONCLUSIONS: Our findings suggest that in Mexican mestizos who smoke cigarettes, the presence of the T allele in rs6313 of the HTR2A gene increases the risk for the early onset of cigarette smoking as well as the risk for relapsing one month after completing smoking cessation treatment.


Assuntos
Fumar Cigarros/genética , Receptor 5-HT2A de Serotonina/genética , Tabagismo/genética , Adolescente , Adulto , Alelos , Feminino , Frequência do Gene/genética , Estudos de Associação Genética , Predisposição Genética para Doença , Variação Genética/genética , Humanos , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Projetos Piloto , Polimorfismo de Nucleotídeo Único/genética , Receptor 5-HT2A de Serotonina/metabolismo , Recidiva , Fatores de Risco , Fumar/efeitos adversos , Abandono do Hábito de Fumar/métodos
5.
Blood ; 133(21): 2325-2337, 2019 05 23.
Artigo em Inglês | MEDLINE | ID: mdl-30755421

RESUMO

Dengue virus (DENV) is the most prevalent vector-borne viral pathogen, infecting millions of patients annually. Thrombocytopenia, a reduction in circulating platelet counts, is the most consistent sign of DENV-induced disease, independent of disease severity. However, the mechanisms leading to DENV-induced thrombocytopenia are unknown. Here, we show that thrombocytopenia is caused by serotonin derived from mast cells (MCs), which are immune cells that are present in the perivascular space and are a major peripheral source of serotonin. We show that during DENV infection, MCs release serotonin, which prompts platelet activation, aggregation, and enhanced phagocytosis, dependent on 5HT2A receptors. MC deficiency in mice or pharmacologic inhibition of MCs reversed thrombocytopenia. Furthermore, reconstitution of MC-deficient mice with wild-type MCs, but not MCs lacking serotonin synthesis resulting from deficiency in the enzyme tryptophan hydroxylase-1, restored the thrombocytopenic phenotype. Exogenous serotonin was also sufficient to overcome the effects of drugs that inhibit platelet activation in vitro and to restore thrombocytopenia in DENV-infected MC-deficient mice. Therapeutic targeting of 5HT2A receptors during DENV infection effectively prevented thrombocytopenia in mice. Similarly, serotonin derived from DENV-activated human MCs led to increased human platelet activation. Thus, MC-derived serotonin is a previously unidentified mechanism of DENV-induced thrombocytopenia and a potential therapeutic target.


Assuntos
Plaquetas/metabolismo , Vírus da Dengue/metabolismo , Dengue/metabolismo , Ativação Plaquetária , Receptor 5-HT2A de Serotonina/metabolismo , Serotonina/metabolismo , Trombocitopenia/metabolismo , Animais , Plaquetas/patologia , Dengue/genética , Dengue/patologia , Feminino , Humanos , Masculino , Mastócitos/patologia , Camundongos , Camundongos Knockout , Receptor 5-HT2A de Serotonina/genética , Serotonina/genética , Trombocitopenia/genética , Trombocitopenia/patologia , Trombocitopenia/virologia
6.
Arch Pharm (Weinheim) ; 352(4): e1800306, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30702760

RESUMO

A series of benzamide derivatives possessing potent dopamine D2 , serotonin 5-HT1A , and 5-HT2A receptor properties were synthesized and evaluated as potential antipsychotics. Among them, 5-(4-(4-(benzo[d]isothiazol-3-yl)piperazin-1-yl)butoxy)-N-cyclopropyl-2-fluorobenzamide (4k) held the best pharmacological profile. It not only exhibited potent and balanced activities for the D2 , 5-HT1A , and 5-HT2A receptors, but was also endowed with low to moderate activities for the 5-HT2C , H1 , and M3 receptors, suggesting a low propensity for inducing weight gain or diabetes. In animal models, compound 4k reduced phencyclidine-induced hyperactivity with a high threshold for catalepsy or muscle relaxation induction. On the basis of its robust in vitro potency and in vivo efficacy in preclinical models of schizophrenia, 4k was selected as a candidate for further development.


Assuntos
Antipsicóticos/farmacologia , Comportamento Animal/efeitos dos fármacos , Benzamidas/farmacologia , Esquizofrenia/tratamento farmacológico , Animais , Antipsicóticos/síntese química , Antipsicóticos/química , Benzamidas/síntese química , Benzamidas/química , Modelos Animais de Doenças , Humanos , Masculino , Camundongos , Camundongos Endogâmicos ICR , Atividade Motora/efeitos dos fármacos , Fenciclidina/toxicidade , Receptor 5-HT1A de Serotonina/efeitos dos fármacos , Receptor 5-HT1A de Serotonina/metabolismo , Receptor 5-HT2A de Serotonina/efeitos dos fármacos , Receptor 5-HT2A de Serotonina/metabolismo , Receptores de Dopamina D2/efeitos dos fármacos , Receptores de Dopamina D2/metabolismo , Esquizofrenia/fisiopatologia , Relação Estrutura-Atividade
7.
Neurochem Int ; 125: 74-81, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30769030

RESUMO

25INBOMe ("25-I", "N-Bomb"), one of new psychoactive substances (NPSs), is being abused for recreational purpose. However, the liability for abuse or dependence has not been systematically studied yet. The objective of the present study was to evaluate rewarding and reinforcing effects of 25INBOMe using conditioned place preference (CPP) and self-administration (SA) paradigms. In addition, ultrasonic vocalizations (USVs) were measured to investigate relationships between USVs and emotional state regarding dependence on psychoactive substances. To understand molecular mechanism involved in its action, dopamine (DA) level changes were analyzed using synaptosomes extracted from the striatal region of the brain. Expression level changes of SGK1 (serum/glucocorticoid regulated kinase 1) and PER2 (period circadian protein homolog 2), two putative biomarkers for drug dependence, were also analyzed. Results showed that 25INBOMe increased both CPP (0.3 mg/kg) and SA (0.03 mg/kg/infusion) and produced higher frequencies in USVs analysis. It also increased DA levels in the striatal region and changed expression levels of SGK1 and PER2. Results of the present study suggest that 25INBOMe might produce rewarding and reinforcing effects, indicating its dependence liability. In addition, frequencies of USV might be associated with emotional state of mice induced by psychoactive substances regarding substance dependence. This is the first systemic preclinical report on the dependence liability of 25INBOMe and the first attempt to introduce a possible relationship between USVs and emotional state of mice regarding substance dependency. Further studies are needed to clarify the mechanism involved in 25INBOMe dependency and determine the usefulness of USV measurement as a method for evaluating dependence liability.


Assuntos
/efeitos dos fármacos , Dimetoxifeniletilamina/análogos & derivados , Recompensa , Transtornos Relacionados ao Uso de Substâncias/metabolismo , Vocalização Animal/efeitos dos fármacos , Animais , Dimetoxifeniletilamina/administração & dosagem , Dimetoxifeniletilamina/metabolismo , Relação Dose-Resposta a Droga , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Ratos , Ratos Sprague-Dawley , Receptor 5-HT2A de Serotonina/metabolismo , Autoadministração , Transtornos Relacionados ao Uso de Substâncias/psicologia , Vocalização Animal/fisiologia
8.
Neuron ; 102(1): 143-158.e7, 2019 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-30770253

RESUMO

In the developing human neocortex, progenitor cells generate diverse cell types prenatally. Progenitor cells and newborn neurons respond to signaling cues, including neurotransmitters. While single-cell RNA sequencing has revealed cellular diversity, physiological heterogeneity has yet to be mapped onto these developing and diverse cell types. By combining measurements of intracellular Ca2+ elevations in response to neurotransmitter receptor agonists and RNA sequencing of the same single cells, we show that Ca2+ responses are cell-type-specific and change dynamically with lineage progression. Physiological response properties predict molecular cell identity and additionally reveal diversity not captured by single-cell transcriptomics. We find that the serotonin receptor HTR2A selectively activates radial glia cells in the developing human, but not mouse, neocortex, and inhibiting HTR2A receptors in human radial glia disrupts the radial glial scaffold. We show highly specific neurotransmitter signaling during neurogenesis in the developing human neocortex and highlight evolutionarily divergent mechanisms of physiological signaling.


Assuntos
Cálcio/metabolismo , Células Ependimogliais/metabolismo , Neocórtex/embriologia , Neurogênese/genética , Receptor 5-HT2A de Serotonina/metabolismo , Animais , Encéfalo/embriologia , Encéfalo/metabolismo , Linhagem da Célula , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento/genética , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Humanos , Camundongos , Neocórtex/citologia , Neocórtex/metabolismo , Neurogênese/fisiologia , Análise de Sequência de RNA , Serotonina/metabolismo , Análise de Célula Única
9.
Nat Struct Mol Biol ; 26(2): 121-128, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30723326

RESUMO

Many drugs target the serotonin 2A receptor (5-HT2AR), including second-generation antipsychotics that also target the dopamine D2 receptor (D2R). These drugs often produce severe side effects due to non-selective binding to other aminergic receptors. Here, we report the structures of human 5-HT2AR in complex with the second-generation antipsychotics risperidone and zotepine. These antipsychotics effectively stabilize the inactive conformation by forming direct contacts with the residues at the bottom of the ligand-binding pocket, the movements of which are important for receptor activation. 5-HT2AR is structurally similar to 5-HT2CR but possesses a unique side-extended cavity near the orthosteric binding site. A docking study and mutagenic studies suggest that a highly 5-HT2AR-selective antagonist binds the side-extended cavity. The conformation of the ligand-binding pocket in 5-HT2AR significantly differs around extracellular loops 1 and 2 from that in D2R. These findings are beneficial for the rational design of safer antipsychotics and 5-HT2AR-selective drugs.


Assuntos
Antipsicóticos/química , Antipsicóticos/metabolismo , Dibenzotiepinas/química , Dibenzotiepinas/metabolismo , Receptor 5-HT2A de Serotonina/química , Receptor 5-HT2A de Serotonina/metabolismo , Risperidona/química , Risperidona/metabolismo , Humanos , Interações Hidrofóbicas e Hidrofílicas , Estrutura Molecular , Estrutura Secundária de Proteína
10.
Behav Pharmacol ; 30(2 and 3-Spec Issue): 151-162, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30632995

RESUMO

Serotonin, one of the first neurotransmitters to be identified, is an evolutionarily old molecule that is highly conserved across the animal kingdom, and widely used throughout the brain. Despite this, ascribing a specific set of functions to brain serotonin and its receptors has been difficult and controversial. The 2A subtype of serotonin receptors (5-HT2A receptor) is the major excitatory serotonin receptor in the brain and has been linked to the effects of drugs that produce profound sensory and cognitive changes. Numerous studies have shown that this receptor is upregulated by a broad variety of stressors, and have related 5-HT2A receptor function to associative learning. This review proposes that stress, particularly stress related to danger and existential threats, increases the expression and function of 5-HT2A receptors. It is argued that this is a neurobiological adaptation to promote learning and avoidance of danger in the future. Upregulation of 5-HT2A receptors during stressful events forms associations that tune the brain to environmental cues that signal danger. It is speculated that life-threatening situations may activate this system and contribute to the symptoms associated with post-traumatic stress disorder (PTSD). 3,4-Methylenedioxymethamphetamine, which activates 5-HT2A receptors, has been successful in the treatment of PTSD and has recently achieved status as a breakthrough therapy. An argument is presented that 3,4-methylenedioxymethamphetamine may paradoxically act through these same 5-HT2A receptors to ameliorate the symptoms of PTSD. The central thematic contention is that a key role of serotonin may be to function as a stress detection and response system.


Assuntos
Receptor 5-HT2A de Serotonina/metabolismo , Receptor 5-HT2A de Serotonina/fisiologia , Transtornos de Estresse Pós-Traumáticos/metabolismo , 3,4-Metilenodioxianfetamina/análogos & derivados , 3,4-Metilenodioxianfetamina/farmacologia , Animais , Encéfalo/metabolismo , Sinais (Psicologia) , Expressão Gênica , Regulação da Expressão Gênica/fisiologia , Humanos , Aprendizagem , Serotonina/metabolismo , Transtornos de Estresse Pós-Traumáticos/tratamento farmacológico , Transtornos de Estresse Pós-Traumáticos/fisiopatologia , Estresse Fisiológico/fisiologia
11.
Neuropsychopharmacology ; 44(7): 1328-1334, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30685771

RESUMO

The main psychedelic component of magic mushrooms is psilocybin, which shows promise as a treatment for depression and other mental disorders. Psychedelic effects are believed to emerge through stimulation of serotonin 2A receptors (5-HT2ARs) by psilocybin's active metabolite, psilocin. We here report for the first time the relationship between intensity of psychedelic effects, cerebral 5-HT2AR occupancy and plasma levels of psilocin in humans. Eight healthy volunteers underwent positron emission tomography (PET) scans with the 5-HT2AR agonist radioligand [11C]Cimbi-36: one at baseline and one or two additional scans on the same day after a single oral intake of psilocybin (3-30 mg). 5-HT2AR occupancy was calculated as the percent change in cerebral 5-HT2AR binding relative to baseline. Subjective psychedelic intensity and plasma psilocin levels were measured during the scans. Relations between subjective intensity, 5-HT2AR occupancy, and plasma psilocin levels were modeled using non-linear regression. Psilocybin intake resulted in dose-related 5-HT2AR occupancies up to 72%; plasma psilocin levels and 5-HT2AR occupancy conformed to a single-site binding model. Subjective intensity was correlated with both 5-HT2AR occupancy and psilocin levels as well as questionnaire scores. We report for the first time that intake of psilocybin leads to significant 5-HT2AR occupancy in the human brain, and that both psilocin plasma levels and 5-HT2AR occupancy are closely associated with subjective intensity ratings, strongly supporting that stimulation of 5-HT2AR is a key determinant for the psychedelic experience. Important for clinical studies, psilocin time-concentration curves varied but psilocin levels were closely associated with psychedelic experience.


Assuntos
Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Alucinógenos/farmacologia , Psilocibina/sangue , Psilocibina/farmacologia , Receptor 5-HT2A de Serotonina/metabolismo , Adulto , Benzilaminas , Radioisótopos de Carbono , Feminino , Humanos , Masculino , Fenetilaminas , Tomografia por Emissão de Pósitrons , Ligação Proteica , Agonistas do Receptor 5-HT2 de Serotonina/farmacologia
12.
PLoS One ; 14(1): e0209804, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30629611

RESUMO

The last fifteen years have seen the emergence and overflow into the drug scene of "superpotent" N-benzylated phenethylamines belonging to the "NBOMe" series, accompanied by numerous research articles. Although N-benzyl substitution of 5-methoxytryptamine is known to increase its affinity and potency at 5-HT2 receptors associated with psychedelic activity, N-benzylated tryptamines have been studied much less than their phenethylamine analogs. To further our knowledge of the activity of N-benzyltryptamines, we have synthesized a family of tryptamine derivatives and, for comparison, a few 5-methoxytryptamine analogs with many different substitution patterns on the benzyl moiety, and subjected them to in vitro affinity and functional activity assays vs. the human 5-HT2 receptor subtypes. In the binding (radioligand displacement) studies some of these compounds exhibited only modest selectivity for either 5-HT2A or 5-HT2C receptors suggesting that a few of them, with affinities in the 10-100 nanomolar range for 5-HT2A receptors, might presumably be psychedelic. Unexpectedly, their functional (calcium mobilization) assays reflected very different trends. All of these compounds proved to be 5-HT2C receptor full agonists while most of them showed low efficacy at the 5-HT2A subtype. Furthermore, several showed moderate-to-strong preferences for activation of the 5-HT2C subtype at nanomolar concentrations. Thus, although some N-benzyltryptamines might be abuse-liable, others might represent new leads for the development of therapeutics for weight loss, erectile dysfunction, drug abuse, or schizophrenia.


Assuntos
Receptores 5-HT2 de Serotonina/metabolismo , Triptaminas/farmacologia , 5-Metoxitriptamina/análogos & derivados , 5-Metoxitriptamina/farmacologia , Animais , Compostos de Benzil/farmacologia , Células CHO , Cricetulus , Células HeLa , Humanos , Estrutura Molecular , Fenetilaminas , Ensaio Radioligante , Receptor 5-HT2A de Serotonina/metabolismo , Receptor 5-HT2C de Serotonina/metabolismo , Agonistas do Receptor 5-HT2 de Serotonina/farmacologia , Triptaminas/síntese química
13.
Drug Res (Stuttg) ; 69(6): 352-360, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30536257

RESUMO

The main vascular feature in endotoxemia is impaired contractile responses to vasoactive agents. We study the aortic response to 5HT11 A, 5HT1B1D and 5HT2A receptors agonist and antagonist in chronic endotoxemic rats. Intraperitoneal injection of 1 mg/kg lipopolysaccharide for 5 days induced chronic endotoxemia. Control rats received intraperitoneal injection of 1 ml/kg saline for 5 days. Rats divided into 3 groups. In first, DOI2 hydrochloride used as an agonist and sarpogrelate hydrochloride as an antagonist of 5HT2A receptor. In second, (R)-(+)-8-OH-DPAT3 and WAY1001354 used as an agonist and antagonist of 5HT1A receptor respectively. In third, Zolmitriptan used as an agonist and GR127935 hydrochloride as an antagonist of 5HT1B1D receptor. Aorta Isolated for organ bath study. Real time-PCR5 and histopathological study examined receptors gene expression and protein localization. Cumulative 8-OH-DPAT caused relaxation in control aorta (EC506 7.79±21.35 and 8.53±10.74 with and without antagonist), which was enhanced in endotoxemia (EC50 6.35±8.48 and very wide±17.38 with and without antagonist). Cumulative zolmitriptan caused relaxation in control aorta (EC50 very wide±8.65 and 8.38±8.44 with and without antagonist), which was enhanced in endotoxemia (EC50 very wide±9.53 and 8.37±13.49 with and without antagonist). DOI hydrochloride contracted the control aorta (EC50 6.51±7.14 and 5.98±1.65 with and without antagonist), which was converted to relaxation in endotoxemic group (EC50 infinity±80.43 and 7.37±20.28 with and without antagonist). PCR studies revealed enhanced 5HT1A receptor and diminished 5HT1B1D and 5HT2A receptor genes expression, while histopathological studies showed inflamed, damaged endothelium in endotoxemic aorta. Our data supports enhanced vasodilation and impaired vasoconstriction during endotoxemia.


Assuntos
Aorta/efeitos dos fármacos , Endotoxemia/patologia , Vasoconstritores/administração & dosagem , Vasodilatadores/administração & dosagem , Animais , Aorta/fisiopatologia , Modelos Animais de Doenças , Endotoxemia/etiologia , Humanos , Lipopolissacarídeos/toxicidade , Masculino , Ratos , Receptor 5-HT1A de Serotonina/metabolismo , Receptor 5-HT1B de Serotonina/metabolismo , Receptor 5-HT2A de Serotonina/metabolismo , Agonistas do Receptor 5-HT1 de Serotonina/administração & dosagem , Antagonistas do Receptor 5-HT1 de Serotonina/administração & dosagem , Agonistas do Receptor 5-HT2 de Serotonina/administração & dosagem , Antagonistas do Receptor 5-HT2 de Serotonina/administração & dosagem , Vasoconstrição/efeitos dos fármacos , Vasoconstrição/fisiologia , Vasodilatação/efeitos dos fármacos , Vasodilatação/fisiologia
14.
Psychopharmacology (Berl) ; 236(2): 821-830, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30448990

RESUMO

BACKGROUND: There is evidence that mGlu2/3 receptors regulate 5-HT2A signaling, interactions that have been theorized to play a role in the antipsychotic-like effects of mGlu2/3 agonists as well as the hallucinogenic effects of 5-HT2A agonists. One approach to unraveling this interaction is through the chronic administration of agonists at the two receptors, which should influence the functional properties of the targeted receptor due to receptor downregulation or desensitization and thereby alter crosstalk between the two receptors. In this study, we investigated whether chronic treatment with the mGlu2/3 agonist LY379268 would alter the behavioral response to a phenethylamine hallucinogen, 25CN-NBOH, which acts as a selective 5-HT2A agonist. METHODS: We first conducted a dose response of 25CN-NBOH (0.1, 0.3, 1, 3, or 10 mg/kg) to confirm the effects on head-twitch response (HTR) and then blockade studies with either the M100907 (0.1 mg/kg) or SB242084 (0.1, 0.3, or 1 mg/kg) to determine the contribution of 5-HT2A and 5-HT2C to 25CN-NBOH-induced HTR, respectively. To determine whether an mGlu2/3 agonist could block 25CN-NBOH-induced HTR, mice were pretreated with vehicle or LY379268 (0.1, 1, or 10 mg/kg) prior to 25CN-NBOH, and HTR was assessed. The effects of chronic LY379268 on 5-HT2A agonist-induced HTR were evaluated by treating mice with either vehicle or LY379268 (10 mg/kg) for 21 days and measuring 25CN-NBOH-induced HTR 48 h after the final LY379268 treatment. The following day (72 h after the final LY379268 treatment), the ability of acute LY379268 to block PCP-induced locomotor activity was assessed. RESULTS: 25CN-NBOH dose-dependently increased the HTR, a 5-HT2A-mediated behavior, in mice. The selective 5-HT2A antagonist M100907 completely blocked the HTR induced by 25CN-NBOH, whereas the selective 5-HT2C antagonist SB242084 had no effect on the HTR. Administration of LY379268 (10 mg/kg SC) attenuated the HTR induced by 1 mg/kg 25CN-NBOH by ~ 50%. Chronic treatment (21 days) with LY379268 also attenuated the HTR response to 25CN-NBOH when tested 48 h after the last dose of LY379268. In locomotor tests, acute LY379268 significantly attenuated PCP-induced locomotor activity in the chronic vehicle treatment group; by contrast, there was only a trend for an overall interaction in the chronic LY379268 group, with LY379268 blocking the locomotor-stimulating effects of PCP only during the last 20 min. CONCLUSIONS: These data are consistent with a functional interaction between mGlu2/3 and 5-HT2A receptors, although the specific mechanism for the interaction is not known. These data support the hypothesis that mGlu2/3 receptors play a prominent role in modulating the behavioral response to 5-HT2A receptor activation.


Assuntos
Agonistas de Aminoácidos Excitatórios/administração & dosagem , Alucinógenos/farmacologia , Fenetilaminas/farmacologia , Receptores de Glutamato Metabotrópico/agonistas , Aminoácidos/administração & dosagem , Animais , Compostos Bicíclicos Heterocíclicos com Pontes/administração & dosagem , Relação Dose-Resposta a Droga , Fluorbenzenos/administração & dosagem , Locomoção/efeitos dos fármacos , Locomoção/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Piperidinas/administração & dosagem , Psicotrópicos/farmacologia , Receptor 5-HT2A de Serotonina/metabolismo , Receptores de Glutamato Metabotrópico/metabolismo , Agonistas do Receptor 5-HT2 de Serotonina/farmacologia , Antagonistas da Serotonina/farmacologia
15.
J Neurophysiol ; 121(1): 105-114, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30281395

RESUMO

Understanding how afferent information is integrated by cortical structures requires identifying the factors shaping excitation and inhibition within their input layers. The input layer of the cerebellar cortex integrates diverse sensorimotor information to enable learned associations that refine the dynamics of movement. Specifically, mossy fiber afferents relay sensorimotor input into the cerebellum to excite granule cells, whose activity is regulated by inhibitory Golgi cells. To test how this integration can be modulated, we have used an acute brain slice preparation from young adult rats and found that encoding of mossy fiber input in the cerebellar granule cell layer can be regulated by serotonin (5-hydroxytryptamine, 5-HT) via a specific action on Golgi cells. We find that 5-HT depolarizes Golgi cells, likely by activating 5-HT2A receptors, but does not directly act on either granule cells or mossy fibers. As a result of Golgi cell depolarization, 5-HT significantly increases tonic inhibition onto both granule cells and Golgi cells. 5-HT-mediated Golgi cell depolarization is not sufficient, however, to alter the probability or timing of mossy fiber-evoked feed-forward inhibition onto granule cells. Together, increased granule cell tonic inhibition paired with normal feed-forward inhibition acts to reduce granule cell spike probability without altering spike timing. Hence, these data provide a circuit mechanism by which 5-HT can reduce granule cell activity without altering temporal representations of mossy fiber input. Such changes in network integration could enable flexible, state-specific suppression of cerebellar sensorimotor input that should not be learned or enable reversal learning for unwanted associations. NEW & NOTEWORTHY Serotonin (5-hydroxytryptamine, 5-HT) regulates synaptic integration at the input stage of cerebellar processing by increasing tonic inhibition of granule cells. This circuit mechanism reduces the probability of granule cell spiking without altering spike timing, thus suppressing cerebellar input without altering its temporal representation in the granule cell layer.


Assuntos
Cerebelo/metabolismo , Inibição Neural/fisiologia , Neurônios/metabolismo , Serotonina/metabolismo , Animais , Cerebelo/efeitos dos fármacos , Masculino , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Inibição Neural/efeitos dos fármacos , Vias Neurais/efeitos dos fármacos , Vias Neurais/metabolismo , Neurônios/efeitos dos fármacos , Técnicas de Patch-Clamp , Ratos Sprague-Dawley , Receptor 5-HT2A de Serotonina/metabolismo , Serotonina/administração & dosagem , Serotoninérgicos/farmacologia , Técnicas de Cultura de Tecidos
16.
Behav Brain Res ; 357-358: 71-81, 2019 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-28736332

RESUMO

It has been established that chemical stimulation of the inferior colliculus (IC) of laboratory animals evokes fear-related defensive responses, which are considered panic attack-like behaviours. In addition, there is evidence that defensive reactions provoked by chemical stimulation of midbrain tectum neurons may induce an antinociceptive response. Morphologically, the IC receives projections from other mesencephalic structures, such as the dorsal raphe nucleus (DRN), a region rich in serotonergic neurons that play a critical role in the control of defensive behaviours. Moreover, this monoaminergic brainstem reticular nucleus is suggested to comprise the endogenous pain modulatory system. The aim of the present study was to investigate the role of DRN 5-hydroxytryptamine 2A (5-HT2A) receptors in Wistar rats by local microinjection of R-96544 (a selective antagonist of the 5-HT2A receptor) at doses of 5, 10 or 15 nM on defensive reactions and fear-induced antinociception evoked by chemical stimulation of the central nucleus of the IC with NMDA (6, 9 or 12 nmol). Behavioural responses were analysed for 10 min, and then the nociceptive threshold was measured at 10 min intervals for 70 min. The dose of 12 nmol of NMDA was the most effective in causing panic attack-like defensive behaviours and much higher hypoalgesia. In addition, both effects were attenuated by pretreatment of the DRN with R-96544. These findings suggest the critical participation of DRN 5-HT2A receptors in the modulation of panic attack-like defensive behaviour and unconditioned fear-induced antinociception organised by neurons in the central nucleus of the IC.


Assuntos
Medo/psicologia , Colículos Inferiores/citologia , Neurônios/fisiologia , Nociceptividade/fisiologia , Dor/psicologia , Receptor 5-HT2A de Serotonina/metabolismo , Animais , Modelos Animais de Doenças , Núcleo Dorsal da Rafe , Relação Dose-Resposta a Droga , Agonistas de Aminoácidos Excitatórios/farmacologia , Reação de Congelamento Cataléptica/efeitos dos fármacos , Masculino , N-Metilaspartato/farmacologia , Neurônios/efeitos dos fármacos , Nociceptividade/efeitos dos fármacos , Dor/tratamento farmacológico , Limiar da Dor/efeitos dos fármacos , Limiar da Dor/fisiologia , Pirrolidinas/farmacologia , Ratos , Ratos Wistar , Estatísticas não Paramétricas
17.
Neuropsychopharmacology ; 44(2): 443-454, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30038413

RESUMO

Preclinical findings in rodent models pointed toward activation of metabotropic glutamate 2/3 (mGlu2/3) receptors as a new pharmacological approach to treat psychosis. However, more recent studies failed to show clinical efficacy of mGlu2/3 receptor agonism in schizophrenia patients. We previously proposed that long-term antipsychotic medication restricted the therapeutic effects of these glutamatergic agents. However, little is known about the molecular mechanism underlying the potential repercussion of previous antipsychotic exposure on the therapeutic performance of mGlu2/3 receptor agonists. Here we show that this maladaptive effect of antipsychotic treatment is mediated mostly via histone deacetylase 2 (HDAC2). Chronic treatment with the antipsychotic clozapine led to a decrease in mouse frontal cortex mGlu2 mRNA, an effect that required expression of both HDAC2 and the serotonin 5-HT2A receptor. This transcriptional alteration occurred in association with HDAC2-dependent repressive histone modifications at the mGlu2 promoter. We found that chronic clozapine treatment decreased via HDAC2 the capabilities of the mGlu2/3 receptor agonist LY379268 to activate G-proteins in the frontal cortex of mice. Chronic clozapine treatment blunted the antipsychotic-related behavioral effects of LY379268, an effect that was not observed in HDAC2 knockout mice. More importantly, co-administration of the class I and II HDAC inhibitor SAHA (vorinostat) preserved the antipsychotic profile of LY379268 and frontal cortex mGlu2/3 receptor density in wild-type mice. These findings raise concerns on the design of previous clinical studies with mGlu2/3 agonists, providing the rationale for the development of HDAC2 inhibitors as a new epigenetic-based approach to improve the currently limited response to treatment with glutamatergic antipsychotics.


Assuntos
Antipsicóticos/farmacologia , Clozapina/farmacologia , Lobo Frontal/efeitos dos fármacos , Histona Desacetilase 2/metabolismo , Transtornos Psicóticos/metabolismo , Receptores de Glutamato Metabotrópico/agonistas , Animais , Antipsicóticos/uso terapêutico , Clozapina/uso terapêutico , Modelos Animais de Doenças , Lobo Frontal/metabolismo , Histona Desacetilase 2/genética , Camundongos , Camundongos Knockout , Transtornos Psicóticos/tratamento farmacológico , Receptor 5-HT2A de Serotonina/genética , Receptor 5-HT2A de Serotonina/metabolismo , Receptores de Glutamato Metabotrópico/genética , Receptores de Glutamato Metabotrópico/metabolismo
18.
Behav Brain Res ; 359: 828-835, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30053461

RESUMO

5-Methoxy-α-methyltryptamine (5-MeO-AMT) is a tryptamine derivative that is used recreationally because of its reported hallucinogenic and mood elevating effects. Studies suggest that the psychopharmacological effects of tryptamines involve serotonin receptor 2a (5-HTR2a) activation in the brain. The head-twitch response (HTR) is widely used as a behavioral correlate for assessing 5-HTR2a agonist activity of a drug. Thus, we investigated whether 5-MeO-AMT induces HTR in mice and explored its mechanism of action. 5-MeO-AMT (0.3, 1, 3, 10 mg/kg) was administered once a day for 7 days, and the HTR was measured after 1 day (acute) and 7 days (repeated) of administration. Another cohort of mice was treated with 5-HTR2a antagonist ketanserin (KS) before 5-MeO-AMT administration. We measured 5-HTR2a and 5-HTR2c mRNA levels in the prefrontal cortex of the mice treated acutely or repeatedly with 5-MeO-AMT. We performed western blotting to determine the effects of the drug on the expression of G protein (Gq/11), protein kinase C gamma (PKC-γ), and extracellular signal-regulated kinases 1/2 (ERK1/2), in addition to PKC-γ and ERK1/2 phosphorylation. Additionally, we evaluated potential rewarding and reinforcing effects of 5-MeO-AMT using locomotor sensitization, conditioned place preference (CPP), and self-administration (SA) paradigms. Acute 5-MeO-AMT administration elicited the HTR, while repeated administration resulted in tolerance. KS blocked the 5-MeO-AMT-induced HTR. 5-MeO-AMT increased 5-HTR2a mRNA levels and induced PKC-γ phosphorylation in the prefrontal cortex. 5-MeO-AMT did not induce locomotor sensitization, CPP, or SA. This study shows that 5-MeO-AMT induces HTR through 5-HTR2a activation in the prefrontal cortex, and may have low potential for abuse.


Assuntos
Movimentos da Cabeça/efeitos dos fármacos , Córtex Pré-Frontal/efeitos dos fármacos , Córtex Pré-Frontal/metabolismo , Receptor 5-HT2A de Serotonina/metabolismo , Serotoninérgicos/farmacologia , Serotonina/análogos & derivados , Animais , Condicionamento Operante/efeitos dos fármacos , Relação Dose-Resposta a Droga , Regulação da Expressão Gênica/efeitos dos fármacos , Ketanserina/farmacologia , Locomoção/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , RNA Mensageiro/metabolismo , Receptor 5-HT2A de Serotonina/genética , Autoadministração , Serotonina/farmacologia
19.
Chem Biol Drug Des ; 93(2): 132-138, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30216681

RESUMO

Compounds with activity at serotonin (5-hydroxytryptamine) 5-HT2 and α1 adrenergic receptors have potential for the treatment of central nervous system disorders, drug addiction or overdose. Isolaureline, dicentrine and glaucine enantiomers were synthesized, and their in vitro functional activities at human 5-HT2 and adrenergic α1 receptor subtypes were evaluated. The enantiomers of isolaureline and dicentrine acted as antagonists at 5-HT2 and α1 receptors with (R)-isolaureline showing the greatest potency (pKb  = 8.14 at the 5-HT2C receptor). Both (R)- and (S)-glaucine also antagonized α1 receptors, but they behaved very differently to the other compounds at 5-HT2 receptors: (S)-glaucine acted as a partial agonist at all three 5-HT2 receptor subtypes, whereas (R)-glaucine appeared to act as a positive allosteric modulator at the 5-HT2A receptor.


Assuntos
Aporfinas/química , Receptor 5-HT2A de Serotonina/metabolismo , Receptores Adrenérgicos alfa 1/metabolismo , Serotonina/química , Agonistas de Receptores Adrenérgicos alfa 1/química , Agonistas de Receptores Adrenérgicos alfa 1/metabolismo , Aporfinas/metabolismo , Sítios de Ligação , Células HEK293 , Humanos , Cinética , Simulação de Acoplamento Molecular , Estrutura Terciária de Proteína , Receptor 5-HT2A de Serotonina/química , Receptor 5-HT2A de Serotonina/genética , Receptores Adrenérgicos alfa 1/química , Receptores Adrenérgicos alfa 1/genética , Serotonina/metabolismo , Agonistas do Receptor 5-HT2 de Serotonina/química , Agonistas do Receptor 5-HT2 de Serotonina/metabolismo , Estereoisomerismo , Relação Estrutura-Atividade
20.
Transl Psychiatry ; 8(1): 279, 2018 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-30552318

RESUMO

Serotonin neurotransmitter deficits are reported in suicide, major depressive disorder (MDD) and alcohol use disorder (AUD). To compare pathophysiology in these disorders, we mapped brain serotonin transporter (SERT), 5-HT1A, and 5-HT2A receptor binding throughout prefrontal cortex and in anterior cingulate cortex postmortem. Cases and controls died suddenly minimizing agonal effects and had a postmortem interval ≤24 h to avoid compromised brain integrity. Neuropathology and toxicology confirmed absence of neuropathology and psychotropic medications. For most subjects (167 of 232), a DSM-IV Axis I diagnosis was made by psychological autopsy. Autoradiography was performed in right hemisphere coronal sections at a pre-genual level. Linear model analyses included sex and age with group and Brodmann area as interaction terms. SERT binding was lower in suicides (p = 0.004) independent of sex (females < males, p < 0.0001), however, the lower SERT binding was dependent on MDD diagnosis (p = 0.014). Higher SERT binding was associated with diagnosis of alcoholism (p = 0.012). 5-HT1A binding was greater in suicides (p < 0.001), independent of MDD (p = 0.168). Alcoholism was associated with higher 5-HT1A binding (p < 0.001) but only in suicides (p < 0.001). 5-HT2A binding was greater in suicides (p < 0.001) only when including MDD (p = 0.117) and alcoholism (p = 0.148) in the model. Reported childhood adversity was associated with higher SERT and 5-HT1A binding (p = 0.004) in nonsuicides and higher 5-HT2A binding (p < 0.001). Low SERT and more 5-HT1A and 5-HT2A binding in the neocortex in depressed suicides is dependent on Axis I diagnosis and reported childhood adversity. Findings in alcoholism differed from those in depression and suicide indicating a distinct serotonin system pathophysiology.


Assuntos
Experiências Adversas da Infância , Alcoolismo/metabolismo , Encéfalo/metabolismo , Transtorno Depressivo Maior/metabolismo , Receptor 5-HT1A de Serotonina/metabolismo , Receptor 5-HT2A de Serotonina/metabolismo , Proteínas da Membrana Plasmática de Transporte de Serotonina/metabolismo , Suicídio , Adulto , Autorradiografia , Encéfalo/fisiopatologia , Feminino , Giro do Cíngulo/metabolismo , Giro do Cíngulo/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Córtex Pré-Frontal/metabolismo , Córtex Pré-Frontal/fisiopatologia
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