RESUMO
Second-generation antipsychotics (SGAs), used as the cornerstone treatment for schizophrenia and other mental disorders, can cause adverse metabolic effects (e.g. obesity and type 2 diabetes). We investigated the effects of SGAs on adipocyte differentiation and metabolism. The presence of therapeutic concentrations of aripiprazole (ARI) or its active metabolite dehydroaripiprazole (DARI) during human adipocyte differentiation impaired adipocyte glucose uptake while the expression of gene markers of fatty acid oxidation were increased. Additionally, the use of a supra-therapeutic concentration of ARI inhibited adipocyte differentiation. Furthermore, olanzapine (OLA), a highly obesogenic SGA, directly increased leptin gene expression but did not affect adipocyte differentiation and metabolism. These molecular insights are novel, and suggest that ARI, but not OLA, may directly act via alterations in adipocyte differentiation and potentially by causing a switch from glucose to lipid utilization in human adipocytes. Additionally, SGAs may effect crosstalk with other organs, such as the brain, to exert their adverse metabolic effects.
Assuntos
Antipsicóticos , Diabetes Mellitus Tipo 2 , Humanos , Antipsicóticos/efeitos adversos , Olanzapina/farmacologia , Olanzapina/metabolismo , Aripiprazol/farmacologia , Aripiprazol/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Piperazinas/metabolismo , Piperazinas/farmacologia , Piperazinas/uso terapêutico , Adipócitos/metabolismoRESUMO
Antipsychotics have been widely accepted as a treatment of choice for psychiatric illnesses such as schizophrenia. While atypical antipsychotics such as aripiprazole are not associated with obesity and diabetes, olanzapine is still widely used based on the anticipation that it is more effective in treating severe schizophrenia than aripiprazole, despite its metabolic side effects. To address metabolic problems, metformin is widely prescribed. Hypothalamic proopiomelanocortin (POMC) neurons have been identified as the main regulator of metabolism and energy expenditure. Although the relation between POMC neurons and metabolic disorders is well established, little is known about the effects of olanzapine and metformin on hypothalamic POMC neurons. In the present study, we investigated the effect of olanzapine and metformin on the hypothalamic POMC neurons in female mice. Olanzapine administration for 5 days significantly decreased Pomc mRNA expression, POMC neuron numbers, POMC projections, and induced leptin resistance before the onset of obesity. It was also observed that coadministration of metformin with olanzapine not only increased POMC neuron numbers and projections but also improved the leptin response of POMC neurons in the olanzapine-treated female mice. These findings suggest that olanzapine-induced hypothalamic POMC neuron abnormality and leptin resistance, which can be ameliorated by metformin administration, are the possible causes of subsequent hyperphagia. [BMB Reports 2022; 55(6): 293-298].
Assuntos
Antipsicóticos , Metformina , Animais , Antipsicóticos/metabolismo , Antipsicóticos/farmacologia , Aripiprazol/metabolismo , Aripiprazol/farmacologia , Feminino , Hipotálamo/metabolismo , Leptina/metabolismo , Metformina/metabolismo , Metformina/farmacologia , Camundongos , Neurônios/metabolismo , Obesidade/tratamento farmacológico , Obesidade/metabolismo , Olanzapina/metabolismo , Olanzapina/farmacologia , Pró-Opiomelanocortina/genética , Pró-Opiomelanocortina/metabolismo , Pró-Opiomelanocortina/farmacologiaRESUMO
BACKGROUND: Antipsychotic drug (APD) treatment has been associated with metabolic abnormalities. Brown adipose tissue (BAT) is the main site of adaptive thermogenesis and secretes various metabolism-improving factors known as batokines. We explored the association of BAT activity with APD treatment and metabolic abnormalities in patients with schizophrenia by measuring the blood levels of bone morphogenetic protein 8b (BMP8b), a batokine secreted by mature BAT. METHODS: BMP8b levels were compared among 50 drug-free, 32 aripiprazole-treated, and 91 clozapine-treated patients with schizophrenia. Regression analysis was used to explore factors, including APD types, that might be associated with BMP8b levels and the potential effect of BMP8b on metabolic syndrome (MS). RESULTS: APD-treated patients had decreased BMP8b levels relative to drug-free patients. The difference still existed after adjustment for body mass index and Brief Psychiatric Rating Scale scores. Among APD-treated group, clozapine was associated with even lower BMP8b levels than the less obesogenic APD, aripiprazole. Furthermore, higher BMP8b levels were associated with lower risks of MS after adjustment for BMI and APD treatment. CONCLUSION: Using drug-free patients as the comparison group to understand the effect of APDs, this is the first study to show APD treatment is associated with reduced BAT activity that is measured by BMP8b levels, with clozapine associated a more significant reduction than aripiprazole treatment. BMP8b might have a beneficial effect against metabolic abnormalities and this effect is independent of APD treatment. Future studies exploring the causal relationship between APD treatment and BMP8b levels and the underlying mechanisms are warranted.
Assuntos
Antipsicóticos , Clozapina , Síndrome Metabólica , Esquizofrenia , Tecido Adiposo Marrom/metabolismo , Antipsicóticos/efeitos adversos , Aripiprazol/metabolismo , Aripiprazol/farmacologia , Clozapina/metabolismo , Clozapina/farmacologia , Clozapina/uso terapêutico , Humanos , Síndrome Metabólica/metabolismo , Esquizofrenia/tratamento farmacológico , Esquizofrenia/metabolismo , TermogêneseRESUMO
BACKGROUND: Despite recent progress in understanding the molecular mechanisms regulating aging and lifespan, and the pathways involved being conserved in different species, a full understanding of the aging process has not been reached. In particular, increasing evidence suggests an active role for the nervous system in lifespan regulation, with sensory neurons, as well as serotonin and GABA signaling, having been shown to regulate lifespan in Caenorhabditis elegans (C. elegans). However, the contribution of additional neural factors, and a broad understanding of the role of the nervous system in regulating aging remains to be established. Here, we examine the impact of the dopamine system in regulating aging in C. elegans. RESULTS: We report that mutations of DOP-4, a dopamine D1-like receptor (D1R), and DOP-2, a dopamine D2-like receptor (D2R) oppositely affected lifespan, fast body movement span, reproductive lifespan, and developmental rate in C. elegans. Activation of D2R using aripiprazole, an antipsychotic drug, robustly extended both lifespan and healthspan. Conversely, inhibition of D2R using quetiapine shortened worm lifespan, further supporting the role of dopamine receptors in lifespan regulation. Mechanistically, D2R signaling regulates lifespan through a dietary restriction mechanism mediated by the AAK-2-DAF-16 pathway. The DAG-PKC/PKD pathway links signaling between dopamine receptors and the downstream AAK-2-DAF-16 pathway to transmit longevity signals. CONCLUSIONS: These data demonstrated a novel role of dopamine receptors in lifespan and dietary restriction regulation. The clinically approved antipsychotic aripiprazole holds potential as a novel anti-aging drug.
Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Animais , Aripiprazol/metabolismo , Caenorhabditis elegans/fisiologia , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Dopamina/metabolismo , Fatores de Transcrição Forkhead/metabolismo , Longevidade/genéticaRESUMO
Cholesterol is essential for normal brain function and development. Genetic disruptions of sterol biosynthesis result in intellectual and developmental disabilities. Developing neurons synthesize their own cholesterol, and disruption of this process can occur by both genetic and chemical mechanisms. Many commonly prescribed medications interfere with sterol biosynthesis, including haloperidol, aripiprazole, cariprazine, fluoxetine, trazodone and amiodarone. When used during pregnancy, these compounds might have detrimental effects on the developing brain of the offspring. In particular, inhibition of dehydrocholesterol-reductase 7 (DHCR7), the last enzyme in the biosynthesis pathway, results in accumulation of the immediate cholesterol precursor, 7-dehydrocholesterol (7-DHC). 7-DHC is highly unstable, giving rise to toxic oxysterols; this is particularly pronounced in a mouse model when both the mother and the offspring carry the Dhcr7+/- genotype. Studies of human dermal fibroblasts from individuals who carry DCHR7+/- single allele mutations suggest that the same gene*medication interaction also occurs in humans. The public health relevance of these findings is high, as DHCR7-inhibitors can be considered teratogens, and are commonly used by pregnant women. In addition, sterol biosynthesis inhibiting medications should be used with caution in individuals with mutations in sterol biosynthesis genes. In an age of precision medicine, further research in this area could open opportunities to improve patient and fetal/infant safety by tailoring medication prescriptions according to patient genotype and life stage.
Assuntos
Oxirredutases atuantes sobre Doadores de Grupo CH-CH , Animais , Aripiprazol/metabolismo , Encéfalo/metabolismo , Colesterol , Feminino , Humanos , Camundongos , Neurônios/metabolismo , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/genética , GravidezRESUMO
AIMS/HYPOTHESIS: Second-generation antipsychotic (SGA) drugs have been associated with the development of type 2 diabetes and the metabolic syndrome in patients with schizophrenia. In this study, we aimed to investigate the effects of two different SGA drugs, olanzapine and aripiprazole, on metabolic state and islet function and plasticity. METHODS: We analysed the functional adaptation of beta cells in 12-week-old B6;129 female mice fed an olanzapine- or aripiprazole-supplemented diet (5.5-6.0 mg kg-1 day-1) for 6 months. Glucose and insulin tolerance tests, in vivo glucose-stimulated insulin secretion and indirect calorimetry were performed at the end of the study. The effects of SGAs on beta cell plasticity and islet serotonin levels were assessed by transcriptomic analysis and immunofluorescence. Insulin secretion was assessed by static incubations and Ca2+ fluxes by imaging techniques. RESULTS: Treatment of female mice with olanzapine or aripiprazole for 6 months induced weight gain (p<0.01 and p<0.05, respectively), glucose intolerance (p<0.01) and impaired insulin secretion (p<0.05) vs mice fed a control chow diet. Aripiprazole, but not olanzapine, induced serotonin production in beta cells vs controls, likely by increasing tryptophan hydroxylase 1 (TPH1) expression, and inhibited Ca2+ flux. Of note, aripiprazole increased beta cell size (p<0.05) and mass (p<0.01) vs mice fed a control chow diet, along with activation of mechanistic target of rapamycin complex 1 (mTORC1)/S6 signalling, without preventing beta cell dysfunction. CONCLUSIONS/INTERPRETATION: Both SGAs induced weight gain and beta cell dysfunction, leading to glucose intolerance; however, aripiprazole had a more potent effect in terms of metabolic alterations, which was likely a result of its ability to modulate the serotonergic system. The deleterious metabolic effects of SGAs on islet function should be considered while treating patients as these drugs may increase the risk for development of the metabolic syndrome and diabetes.
Assuntos
Antipsicóticos , Diabetes Mellitus Tipo 2 , Ilhotas Pancreáticas , Animais , Antipsicóticos/efeitos adversos , Aripiprazol/metabolismo , Aripiprazol/farmacologia , Diabetes Mellitus Tipo 2/metabolismo , Feminino , Humanos , Ilhotas Pancreáticas/metabolismo , Camundongos , Olanzapina/efeitos adversos , Olanzapina/metabolismoRESUMO
Diretrizes internacionais e nacionais como a FDA (Food and Drug Administration), ICH (International Council for Harmonisation) e ANVISA (Agência Nacional de Vigilância Sanitária) estabelecem a exigência de testes de estabilidade para entender melhor a qualidade de um medicamento. O estudo de estabilidade deve ser realizado usando métodos indicativos de estabilidade que possam qualificar e quantificar os insumos farmacêuticos do medicamento, bem como as impurezas e produtos de degradação nele contidos. O aripiprazol é um antipsicótico atípico de segunda geração aprovado para o tratamento de esquizofrenia, transtorno bipolar, depressão e transtornos do espectro do autismo. Os métodos oficiais descritos nas farmacopeias para avaliar o aripiprazol e suas impurezas utilizam a cromatografia líquida de alta eficiência (HPLC) como técnica principal. Nesta pesquisa, objetivou-se desenvolver um método indicativo de estabilidade por eletroforese capilar de zona (CZE) para o aripiprazol na forma farmacêutica de comprimidos, e identificação dos produtos de degradação por espectrometria de massas. O estudo de degradação forçada e a optimização do método desenvolvido por CZE foram realizados utilizando o conceito de delineamento de experimentos (DoE). A separação do aripiprazol de seus produtos de degradação foi conseguida usando uma coluna capilar de sílica fundida (30,2 cm x 75 µm ID), eletrólito de formiato de amônio 6 mmol/L (pH 3) com 5% de metanol sob um potencial de 15 kV e detecção em 214 nm. A capacidade indicativa de estabilidade do método foi investigada pela análise do aripiprazol após ser submetido a condições de estresse ácido, alcalino, térmico, fotolítico e oxidativo, de acordo com as diretrizes ICH. A oxidação foi a principal via de degradação entre as condições de estresse avaliadas. O aripiprazol foi separado dos seus produtos de degradação oxidativa em tempo de corrida abaixo de 5 minutos. O método por CZE mostrou ser linear na faixa de 60 - 140 µg/mL, R2 = 0,9980, precisão calculada como desvio padrão relativo (DPR) menor que 2% e exatidão calculada como recuperação média de 100,93 ± 0,77%. Os resultados obtidos demonstram que o método por HPLC-RP em modo gradiente, separou o aripiprazol e seus produtos de degradação em um tempo de corrida de 30 minutos. Quatro produtos de degradação foram detectados pelo método LC-MS e o principal produto de degradação oxidativo foi identificado. O aripiprazol mostrou-se suscetível à oxidação no grupo piperazina, gerando principalmente o composto aripiprazol-1-N-óxido
International and national guidelines such as the FDA (Food and Drug Administration), ICH (International Council for Harmonization) and ANVISA (National Health Surveillance Agency) establish the requirement for stability tests to better understand quality of a medicine. The stability study must be carried out using stability indicating methods that can qualify and quantify the pharmaceutical ingredients of the drug, as well as the impurities and degradation products contained therein. Aripiprazole is a second-generation atypic antipsychotic drug approved for the treatment of schizophrenia, bipolar disorder, depression, and autism spectrum disorders. The official method described in the pharmacopoeias to evaluate aripiprazole and its impurities is high performance liquid chromatography (HPLC) as the main technique. In this research, the objective was to develop an indicative method of stability by capillary zone electrophoresis (CZE) for aripiprazole in the pharmaceutical form of tablets, and identification of degradation products by mass spectrometry. The forced degradation study and the optimization of the method developed by CZE were carried out using the concept of design of experiments (DoE). The separation of aripiprazole from its degradation products was achieved using a fused silica capillary column (30,2 cm x 75 µm ID), 6 mmol/L ammonium formate electrolyte (pH 3) with 5% methanol under a potential of 15 kV and detection at 214 nm. The indicative stability of the method was investigated by analyzing aripiprazole after being subjected to acid, alkali, thermal, photolytic and oxidative stress conditions, according to the ICH guidelines. Oxidation was the main degradation pathway among the stress conditions evaluated. Aripiprazole was separated from its oxidative degradation products at run times below 5 minutes. The CZE method proved to be linear in the range of 60 - 140 µg/mL, R2 = 0,9980, precision calculated as a relative standard deviation (DPR) of less than 2% and accuracy calculated as a mean recovery of 100,93 ± 0,77%. The results obtained demonstrate that the HPLC-RP method in gradient mode separated aripiprazole and its degradation products in a run time of 30 minutes. Four degradation products were detected by the LC-MS method and the main oxidative degradation product was identified. Aripiprazole was shown to be susceptible to oxidation in the piperazine group, generating mainly the compound aripiprazole-1-N-oxide
Assuntos
Espectrometria de Massas/métodos , Preparações Farmacêuticas/análise , Eletroforese Capilar/métodos , Aripiprazol/metabolismo , Estresse Oxidativo , Insumos Farmacêuticos , Otimização de ProcessosRESUMO
The binding of drugs to plasma protein is frequently altered in certain types of renal diseases. We recently reported on the effects of oxidation and uremic toxins on the binding of aripiprazole (ARP) to human serum albumin. In our continuing investigations, we examined the binding of ARP to plasma pooled from patients with chronic renal dysfunction. We examined the issue of the molecular basis for which factors affect the changes in drug binding that accompany renal failure. The study was based on the statistical relationships between ARP albumin binding and biochemical parameters such as the concentrations of oxidized albumin and uremic toxins. The binding of ARP to plasma from chronic renal patients was significantly lower than healthy volunteers. A rational relationship between the ARP binding rate and the concentration of toxins, including indoxyl sulphate (IS) and p-cresyl sulphate (PCS), was found, particularly for IS. Moreover, multiple regression analyses that involved taking other parameters such as PCS or oxidized albumin ratio to IS into account supports the above hypothesis. In conclusion, the limited data reported in this present study indicates that monitoring IS in the blood is a very important determinant in the dosage plan for the administration of site II drugs such as ARP, if the efficacy of the drug in renal disease is to be considered.
Assuntos
Antipsicóticos/metabolismo , Aripiprazol/metabolismo , Proteínas Sanguíneas/metabolismo , Falência Renal Crônica/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Cresóis/metabolismo , Feminino , Humanos , Indicã/metabolismo , Masculino , Ligação Proteica , Estudos Retrospectivos , Albumina Sérica Humana/metabolismo , Ésteres do Ácido Sulfúrico/metabolismo , Adulto JovemRESUMO
Serotonin, or 5-hydroxytryptamine (5-HT), is an important neurotransmitter1,2 that activates the largest subtype family of G-protein-coupled receptors3. Drugs that target 5-HT1A, 5-HT1D, 5-HT1E and other 5-HT receptors are used to treat numerous disorders4. 5-HT receptors have high levels of basal activity and are subject to regulation by lipids, but the structural basis for the lipid regulation and basal activation of these receptors and the pan-agonism of 5-HT remains unclear. Here we report five structures of 5-HT receptor-G-protein complexes: 5-HT1A in the apo state, bound to 5-HT or bound to the antipsychotic drug aripiprazole; 5-HT1D bound to 5-HT; and 5-HT1E in complex with a 5-HT1E- and 5-HT1F-selective agonist, BRL-54443. Notably, the phospholipid phosphatidylinositol 4-phosphate is present at the G-protein-5-HT1A interface, and is able to increase 5-HT1A-mediated G-protein activity. The receptor transmembrane domain is surrounded by cholesterol molecules-particularly in the case of 5-HT1A, in which cholesterol molecules are directly involved in shaping the ligand-binding pocket that determines the specificity for aripiprazol. Within the ligand-binding pocket of apo-5-HT1A are structured water molecules that mimic 5-HT to activate the receptor. Together, our results address a long-standing question of how lipids and water molecules regulate G-protein-coupled receptors, reveal how 5-HT acts as a pan-agonist, and identify the determinants of drug recognition in 5-HT receptors.
Assuntos
Microscopia Crioeletrônica , Ligantes , Lipídeos , Receptores 5-HT1 de Serotonina/metabolismo , Receptores 5-HT1 de Serotonina/ultraestrutura , Apoproteínas/química , Apoproteínas/metabolismo , Apoproteínas/ultraestrutura , Aripiprazol/metabolismo , Aripiprazol/farmacologia , Sítios de Ligação , Colesterol/farmacologia , Proteínas Heterotriméricas de Ligação ao GTP/química , Proteínas Heterotriméricas de Ligação ao GTP/metabolismo , Proteínas Heterotriméricas de Ligação ao GTP/ultraestrutura , Humanos , Modelos Moleculares , Fosfatos de Fosfatidilinositol/química , Fosfatos de Fosfatidilinositol/metabolismo , Fosfatos de Fosfatidilinositol/farmacologia , Receptor 5-HT1A de Serotonina/química , Receptor 5-HT1A de Serotonina/metabolismo , Receptor 5-HT1A de Serotonina/ultraestrutura , Receptores 5-HT1 de Serotonina/química , Agonistas do Receptor 5-HT1 de Serotonina/química , Agonistas do Receptor 5-HT1 de Serotonina/metabolismo , Agonistas do Receptor 5-HT1 de Serotonina/farmacologia , Água/químicaAssuntos
Antipsicóticos/efeitos adversos , Aripiprazol/efeitos adversos , Hiperprolactinemia/induzido quimicamente , Farmacogenética/métodos , Antipsicóticos/metabolismo , Aripiprazol/metabolismo , Humanos , Hiperprolactinemia/genética , Hiperprolactinemia/metabolismo , Farmacogenética/tendências , Receptores Dopaminérgicos/genética , Receptores Dopaminérgicos/metabolismo , Receptores de Serotonina/genética , Receptores de Serotonina/metabolismoRESUMO
Exercise engages signaling networks to control the release of circulating factors beneficial to health. However, the nature of these networks remains undefined. Using high-throughput phosphoproteomics, we quantify 20,249 phosphorylation sites in skeletal muscle-like myotube cells and monitor their responses to a panel of cell stressors targeting aspects of exercise signaling in vivo. Integrating these in-depth phosphoproteomes with the phosphoproteome of acute aerobic exercise in human skeletal muscle suggests that co-administration of ß-adrenergic and calcium agonists would activate complementary signaling relevant to this exercise context. The phosphoproteome of cells treated with this combination reveals a surprising divergence in signaling from the individual treatments. Remarkably, only the combination treatment promotes multisite phosphorylation of SERBP1, a regulator of Serpine1 mRNA stability, a pro-fibrotic secreted protein. Secretome analysis reveals that the combined treatments decrease secretion of SERPINE1 and other deleterious factors. This study provides a framework for dissecting phosphorylation-based signaling relevant to acute exercise.
Assuntos
Exercício Físico/fisiologia , Músculo Esquelético/metabolismo , Fosfoproteínas/metabolismo , Proteínas Quinases/metabolismo , Proteoma/metabolismo , Transdução de Sinais/fisiologia , Estresse Fisiológico/genética , Quinases Proteína-Quinases Ativadas por AMP , Agonistas Adrenérgicos beta/metabolismo , Animais , Aripiprazol/metabolismo , Aripiprazol/farmacologia , Cálcio/agonistas , Cálcio/metabolismo , Interações Medicamentosas , Humanos , Isoproterenol/metabolismo , Isoproterenol/farmacologia , Espectrometria de Massas , Camundongos , Fosfoproteínas/química , Fosforilação , Inibidor 1 de Ativador de Plasminogênio/genética , Inibidor 1 de Ativador de Plasminogênio/metabolismo , Sistemas de Translocação de Proteínas/genética , Sistemas de Translocação de Proteínas/metabolismo , Proteoma/química , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Ratos , Estresse Fisiológico/fisiologia , Tapsigargina/metabolismo , Tapsigargina/farmacologiaRESUMO
We recently reported that aripiprazole binds strongly to human albumin. In continuing our investigations, we investigated the mechanism responsible for the binding and the related interactions of aripiprazole with α1-acid glycoprotein (AGP). The extrinsic Cotton effects for the binding of aripiprazole and its derivatives to AGP were generated, but the magnitudes of the induced circular dichroism intensities did not correlate with those for the binding affinities. It therefore appears that the binding mode of aripiprazole with AGP is somewhat complicated, compared with that of albumin. Isothermal titration calorimetry data obtained for the binding of aripiprazole with AGP were different from that for albumin systems in that the 3 driving reactions, entropy-driven, enthalpy-driven, and the entropy-enthalpy mixed type, were all found for the AGP system, but not albumin. Moreover, the weak binding mode of aripiprazole with the 2 proteins were supported by a molecular docking model analysis. The concentration of albumin in plasma is about 50 times higher than those of AGP, but AGP levels in plasma are increased by about 10 times under inflammatory disease. Therefore, the involvement of these 2 plasma proteins should be considered in more depth for understanding the pharmacokinetics of aripiprazole.
Assuntos
Aripiprazol/metabolismo , Orosomucoide/metabolismo , Proteínas Sanguíneas/metabolismo , Calorimetria/métodos , Dicroísmo Circular , Humanos , Simulação de Acoplamento Molecular/métodos , Ligação Proteica/fisiologia , Albumina Sérica/metabolismo , Espectrometria de Fluorescência/métodos , TermodinâmicaRESUMO
Partial agonists of the dopamine D2 receptor (D2R) have been developed to treat the symptoms of schizophrenia without causing the side effects elicited by antagonists. The receptor-ligand interactions that determine the intrinsic efficacy of such drugs, however, are poorly understood. Aripiprazole has an extended structure comprising a phenylpiperazine primary pharmacophore and a 1,2,3,4-tetrahydroquinolin-2-one secondary pharmacophore. We combined site-directed mutagenesis, analytical pharmacology, ligand fragments, and molecular dynamics simulations to identify the D2R-aripiprazole interactions that contribute to affinity and efficacy. We reveal that an interaction between the secondary pharmacophore of aripiprazole and a secondary binding pocket defined by residues at the extracellular portions of transmembrane segments 1, 2, and 7 determines the intrinsic efficacy of aripiprazole. Our findings reveal a hitherto unappreciated mechanism for fine-tuning the intrinsic efficacy of D2R agonists.
Assuntos
Antipsicóticos/metabolismo , Aripiprazol/metabolismo , Agonistas de Dopamina/metabolismo , Receptores de Dopamina D2/metabolismo , Antipsicóticos/química , Aripiprazol/química , Sítios de Ligação , Dopamina/química , Dopamina/metabolismo , Agonistas de Dopamina/química , Indóis/química , Indóis/metabolismo , Ligantes , Conformação Molecular , Simulação de Dinâmica Molecular , Mutagênese Sítio-Dirigida , Mutação , Receptores de Dopamina D2/química , Receptores de Dopamina D2/genéticaRESUMO
A simple and sensitive liquid chromatography-tandem mass spectrometry method was developed and validated in human plasma for the simultaneous determination of aripiprazole (ARI) and its metabolite dehydro-aripiprazole (DARI); olanzapine (OLA), risperidone (RIS), paliperidone (PAL), quetiapine (QUE), clozapine (CLO) and caffeine (CAF). CAF is included to the method because it can have an influence on drug metabolism due to competitive inhibition. The above mentioned compounds and their isotope-labeled internal standards were extracted from 200⯵L human plasma samples by both, effective phospholipids-eliminating three-step microelution-solid-phase extraction (µ-SPE) and protein precipitation (PPT) for comparison. A combination of formic acid (0.2%)-acetonitrile (pH 3.0; 65:35, v/v) was used as mobile phase and the chromatogram was run under gradient conditions at a flow rate of 0.6â¯mL/min. Run time lasted 6â¯min, followed by a re-equilibration time of 3â¯min. All analytes were monitored by mass spectrometric detection operating in multiple reaction monitoring mode and the method was validated covering the corresponding therapeutic ranges: 0.18-120â¯ng/mL for ARI, 0.25-80â¯ng/mL for DARI, 1.00-100â¯ng/mL for OLA, 0.70-60â¯ng/mL for RIS, 0.20-30â¯ng/mL for PAL, 0.50-160â¯ng/mL for QUE, 0.50-1000â¯ng/mL for CLO, and finally 1200-3700â¯ng/mL for CAF. The method was validated based on the recommendations of regulatory agencies through tests of precision, accuracy, extraction recovery, identity confirmation, trueness, matrix effect, process efficiency, stability, selectivity, linearity and carry-over effect fulfilling the guideline requirements. Our µ-SPE method results in the elimination of more than 99% of early eluting and more than 92% of late-eluting phospholipids compared to PPT. Additionally, the method was successfully applied for quantifying ARI and OLA plasma concentrations from healthy volunteers.
Assuntos
Antipsicóticos/sangue , Aripiprazol/sangue , Cafeína/sangue , Fosfolipídeos/química , Extração em Fase Sólida , Antipsicóticos/metabolismo , Aripiprazol/metabolismo , Cafeína/metabolismo , Cromatografia Líquida , Humanos , Espectrometria de Massas em TandemRESUMO
Cerebrovascular dysfunction is associated with cognitive impairment in vascular dementia patients. This study aimed to explore augmented improvement of cognition and memory by aripiprazole add-on for cilostazol treatment in vascular dementia model. Male C57BL/6 mice were subjected to BCAS, and spatial probe and memory retention were examined using the Morris water maze (MWM) test. In the present study, the escape latency on the first day after 3rd week was 21.4 ± 4.0 s in sham-operated mice, and 76.3 ± 4.2 s in the vehicle-treated BCAS mice. In the spatial probe tests in the 3rd week, aripiprazole (1 mg/kg/day) showed time-dependently amelioration in spatial learning and memory impairments in contrast to 0.5 mg/kg/day. After treatment with 20 mg/kg/day of cilostazol for 3 weeks, the escape latency significantly decreased to 26.6 ± 5.8 s on the first day and further shortened to 21.6 ± 6.8 s on the fourth day. When the BCAS mice were concurrently treated with 0.5 mg/kg/day aripiprazole plus 20 mg/kg/day of cilostazol for 3 weeks, the escape latency was more shortened from 20.4 ± 1.2 s (1st day) to 14.9 ± 1.7 s on the 4th day of the 3-week trials. Furthermore, decreased spatial memory retention in BCAS mice was significantly alleviated by aripiprazole plus cilostazol cotreatment, indicating the benefit of aripiprazole add-on therapy. In line with these, significantly increased mBDNF and P-CREB levels and reduced apoptosis were identified in the BCAS mouse brain dentate gyrus by cotreatment as contrasted to each monotherapy. These results may provide the synergistic therapeutic avenues for augmented improvement of cognition and memory by cotreatment with aripiprazole plus cilostazol in cases of vascular dementia.
Assuntos
Aripiprazol/farmacologia , Cognição/efeitos dos fármacos , Memória/efeitos dos fármacos , Animais , Aripiprazol/metabolismo , Encéfalo/fisiopatologia , Isquemia Encefálica/fisiopatologia , Isquemia Encefálica/psicologia , Estenose das Carótidas/fisiopatologia , Cilostazol/metabolismo , Cilostazol/farmacologia , Disfunção Cognitiva/tratamento farmacológico , Demência Vascular/fisiopatologia , Modelos Animais de Doenças , Quimioterapia Combinada , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Fármacos Neuroprotetores/administração & dosagem , Aprendizagem Espacial/efeitos dos fármacosRESUMO
INTRODUCTION: Second generation antipsychotic (AP)s remain the gold-standard treatment for schizophrenia and are widely used on- and off-label for other psychiatric illnesses. However, these agents cause serious metabolic side-effects. The hypothalamus is the primary brain region responsible for whole body energy regulation, and disruptions in energy sensing (e.g. insulin signaling) and inflammation in this brain region have been implicated in the development of insulin resistance and obesity. To elucidate mechanisms by which APs may be causing metabolic dysregulation, we explored whether these agents can directly impact energy sensing and inflammation in hypothalamic neurons. METHODS: The rat hypothalamic neuronal cell line, rHypoE-19, was treated with olanzapine (0.25-100 uM), clozapine (2.5-100 uM) or aripiprazole (5-20 uM). Western blots measured the energy sensing protein AMPK, components of the insulin signaling pathway (AKT, GSK3ß), and components of the MAPK pathway (ERK1/2, JNK, p38). Quantitative real-time PCR was performed to determine changes in the mRNA expression of interleukin (IL)-6, IL-10 and brain derived neurotrophic factor (BDNF). RESULTS: Olanzapine (100 uM) and clozapine (100, 20 uM) significantly increased pERK1/2 and pJNK protein expression, while aripiprazole (20 uM) only increased pJNK. Clozapine (100 uM) and aripiprazole (5 and 20 uM) significantly increased AMPK phosphorylation (an orexigenic energy sensor), and inhibited insulin-induced phosphorylation of AKT. Olanzapine (100 uM) treatment caused a significant increase in IL-6 while aripiprazole (20 uM) significantly decreased IL-10. Olanzapine (100 uM) and aripiprazole (20 uM) increased BDNF expression. CONCLUSIONS: We demonstrate that antipsychotics can directly regulate insulin, energy sensing, and inflammatory pathways in hypothalamic neurons. Increased MAPK activation by all antipsychotics, alongside olanzapine-associated increases in IL-6, and aripiprazole-associated decreases in IL-10, suggests induction of pro-inflammatory pathways. Clozapine and aripiprazole inhibition of insulin-stimulated pAKT and increases in AMPK phosphorylation (an orexigenic energy sensor) suggests impaired insulin action and energy sensing. Conversely, olanzapine and aripiprazole increased BDNF, which would be expected to be metabolically beneficial. Overall, our findings suggest differential effects of antipsychotics on hypothalamic neuroinflammation and energy sensing.
Assuntos
Antipsicóticos/farmacologia , Metabolismo Energético/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Animais , Antipsicóticos/metabolismo , Aripiprazol/metabolismo , Aripiprazol/farmacologia , Linhagem Celular , Clozapina/metabolismo , Clozapina/farmacologia , Hipotálamo/efeitos dos fármacos , Hipotálamo/metabolismo , Inflamação/metabolismo , Insulina/metabolismo , Resistência à Insulina/fisiologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/fisiologia , Olanzapina/metabolismo , Olanzapina/farmacologia , Fosforilação/efeitos dos fármacos , Ratos , Esquizofrenia/tratamento farmacológico , Esquizofrenia/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
Mutations in both copies in the gene encoding 7-dehydrocholesterol reductase (DHCR7) cause Smith-Lemli-Opitz Syndrome (SLOS), which is characterized by a toxic elevation in 7-dehydrocholesterol (7-DHC). Aripiprazole (ARI) exposure, independent of genetic mutations, also leads to elevation of 7-DHC. We investigated the combined effect of a single-copy Dhcr7+/- mutation and maternal ARI exposure on the developing offspring brain. We generated a time-pregnant mouse model where WT and Dhcr7+/- embryos were maternally exposed to ARI or vehicle (VEH) from E12 to E19 (5 mg/kg). Levels of cholesterol, its precursors, ARI and its metabolites were measured at P0. We found that ARI and its metabolites were transported across the placenta and reached the brain of offspring. Maternal ARI exposure led to decreased viability of embryos and increased 7-DHC levels, regardless of maternal or offspring Dhcr7 genotype. In addition, Dhcr7+/- pups were more vulnerable to maternal ARI exposure than their WT littermates, and maternal Dhcr7+/- genotype also exacerbated offspring response to ARI treatment. Finally, both 7-DHC levels and 7-DHC/cholesterol ratio is the highest in Dhcr7+/- pups from Dhcr7+/- mothers exposed to ARI, underscoring a potentially dangerous interaction between maternal genotype×embryonic genotype×treatment. Our findings have important clinical implications. SLOS patients should avoid drugs that increase 7-DHC levels such as ARI, trazodone and haloperidol. In addition, treatment with 7-DHC elevating substances might be potentially unsafe for the 1-1.5% of population with single-allele disruptions of the DHCR7 gene. Finally, prenatal and parental genetic testing for DHCR7 should be considered before prescribing sterol-interfering medications during pregnancy.
Assuntos
Aripiprazol/efeitos adversos , Desenvolvimento Embrionário/efeitos dos fármacos , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/metabolismo , Alelos , Animais , Aripiprazol/metabolismo , Colesterol , Modelos Animais de Doenças , Desenvolvimento Embrionário/genética , Feminino , Masculino , Exposição Materna/efeitos adversos , Camundongos , Camundongos Knockout , Mutação , Neurogênese/efeitos dos fármacos , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/genética , Gravidez , Efeitos Tardios da Exposição Pré-Natal , Síndrome de Smith-Lemli-OpitzRESUMO
Previously, we reported on the high-affinity binding of aripiprazole (ARP), an antipsychotic drug, to human albumin and the role of the chlorine atom of ARP on this binding. In this study, we investigated the binding mode of ARP to human albumin in detail using ARP derivatives and several animal-derived albumins. ARP bound strongly to human and dog albumin. The circular dichroism (CD) spectra of ARP bound to human and dog albumin were also similar. Deschloro-ARP bound less strongly to all of the albumin species compared to ARP, and the shapes of CD spectra were similar for all albumin species. CD spectra of dimethyl-ARP, for which chlorine atoms were substituted methyl groups, were quite similar to that of deschloro-ARP. In displacement experiments, competitive binding was observed between ARP and deschloro-ARP. These results suggest that the chlorine atoms in ARP are involved in the binding modes of ARP for human and dog albumins, whereas ARP and deschloro-ARP appear to share the same binding region in site II. The aforementioned results imply that compounds having a chlorine atom bind more strongly to plasma proteins, resulting in a long blood retention time. Therefore, findings reported here may provide the basically useful data for drug design.
Assuntos
Aripiprazol/metabolismo , Cloro/metabolismo , Albumina Sérica Humana/metabolismo , Albumina Sérica/metabolismo , Animais , Sítios de Ligação/fisiologia , Dicroísmo Circular/métodos , Cães , Humanos , Ligação Proteica/fisiologia , Especificidade da EspécieRESUMO
The aim of this study was to design a novel carrier for enhancing the bioavailability of the poorly water-soluble drug, aripiprazole (ARP). Silicosan, the applied carrier, was obtained by chemical interaction between tetraethyl orthosilicate (TEOS) and chitosan HCl. Different ARP-loaded silicosan particles were successfully prepared in absence and presence of one of the following surfactants; Tween 80, Poloxamer 407 and cetyltrimethylammonium bromide (CTAB). The prepared ARP-loaded silicosan particles were thoroughly investigated for their structures using FTIR, XRD, and DSC analysis as well as their particle size, zeta potential, flowability, drug content, and in vitro drug release efficiencies. The prepared ARP-loaded silicosan particles were characterized by amorphous structure, high drug entrapment efficiency and a remarkable improvement in the release of aripiprazole in simulated gastric fluid. SEM and EDX revealed that the morphology and silica atom content in the prepared ARP-loaded silicosan particles were affected by the used surfactant in their formulations. The selected ARP-loaded silicosan particles were subjected to in vivo study using rabbits. The obtained pharmacokinetic results showed that the relative bioavailability for orally administered ARP-loaded silicosan particles (SC-2-CTAB) was 66% higher relative to the oral suspension (AUC0-10h was 16.38 ± 3.21 and 27.23 ± 2.35 ng.h/mL for drug powder and SC-2-CTAB formulation, respectively). The obtained results suggested the unique-structured silicosan particles to be used as successful vehicle for ARP.