RESUMEN
Depression is one of the most common mental illnesses, affecting almost 300 million people. According to the WHO, depression is one of the world's leading causes of disability and morbidity. People with this illness require both psychological and pharmaceutical treatment because severe depressive episodes often result in suicide. Selective serotonin reuptake inhibitors (SSRI) are widely used antidepressants that target the human serotonin transporter (hSERT). The crystallization of hSERT and the experimental data available allows cost and time-efficient computational tools like virtual screening (VS) to be utilized in the development of therapeutic agents. Here, we synthesized, characterized, and evaluated the biological activity of a novel SSRI analog of paroxetine, rationally designed by applying an artificial neural network-based QSAR model and a molecular docking analysis on hSERT. The analog N-substituted 18a showed higher affinity for the transporter (-10.2 kcal/mol), lower Ki value (1.19 nM) and a safer toxicological profile than paroxetine and was synthesized with a 71% yield. The in vitro cytotoxicity of the analog was evaluated using human glioblastoma (U87 MG), human neuroblastoma (SH SY5Y) and murine fibroblast (L929) cell lines. Also, the hemolytic ability of the compound was assessed on human erythrocytes. Results showed that analog 18a did not exhibit cytotoxic activity on the cell lines used and has no hemolytic activity at any of the concentrations tested, whereas with paroxetine, hemolysis was observed at 2.3, 1.29 y 0.67 mM. Based on these results, it is possible to suggest that analog 18a could be a promising new SSRI candidate for the treatment of this illness.
Asunto(s)
Paroxetina , Inhibidores Selectivos de la Recaptación de Serotonina , Humanos , Ratones , Animales , Paroxetina/uso terapéutico , Simulación del Acoplamiento Molecular , Antidepresivos , Proteínas de Transporte de Serotonina en la Membrana Plasmática/metabolismoRESUMEN
Inflammatory Bowel Disease (IBD) is a chronic gastrointestinal disorder characterized by periods of activity and remission. IBD includes Crohn's disease (CD) and ulcerative colitis (UC), and even though IBD has not been considered as a heritable disease, there are genetic variants associated with increased risk for the disease. 5-Hydroxytriptamine (5-HT), or serotonin, exerts a wide range of gastrointestinal effects under both normal and pathological conditions. Furthermore, Serotonin Transporter (SERT) coded by Solute Carrier Family 6 Member 4 (SLC6A4) gene (located in the 17q11.1-q12 chromosome), possesses genetic variants, such as Serotonin Transporter Gene Variable Number Tandem Repeat in Intron 2 (STin2-VNTR) and Serotonin-Transporter-linked promoter region (5-HTTLPR), which have an influence over the functionality of SERT in the re-uptake and bioavailability of serotonin. The intestinal microbiota is a crucial actor in normal human gut physiology, exerting effects on serotonin, SERT function, and inflammatory processes. As a consequence of abnormal serotonin signaling and SERT function under these inflammatory processes, the use of selective serotonin re-uptake inhibitors (SSRIs) has been seen to improve disease activity and extraintestinal manifestations, such as depression and anxiety. The aim of this study is to integrate scientific data linking the intestinal microbiota as a regulator of gut serotonin signaling and re-uptake, as well as its role in the pathogenesis of IBD. We performed a narrative review, including a literature search in the PubMed database of both review and original articles (no date restriction), as well as information about the SLC6A4 gene and its genetic variants obtained from the Ensembl website. Scientific evidence from in vitro, in vivo, and clinical trials regarding the use of selective serotonin reuptake inhibitors as an adjuvant therapy in patients with IBD is also discussed. A total of 194 articles were used between reviews, in vivo, in vitro studies, and clinical trials.
Asunto(s)
Enfermedades Inflamatorias del Intestino , Serotonina , Humanos , Proteínas de Transporte de Serotonina en la Membrana Plasmática/genética , Disbiosis/genética , Enfermedades Inflamatorias del Intestino/genética , Inhibidores Selectivos de la Recaptación de Serotonina , InmunidadRESUMEN
BACKGROUND: Cardiomyocytes synthesize, utilize and reuptake serotonin, which is involved in the paracrine and autocrine modulation of heart activity and in the pathophysiology of some cardiovascular diseases. OBJECTIVE: To determine the expression of tryptophan-5-hydroxylase (TPH) 1 and 2, serotonin transporter protein (SERT) and serotonergic receptors in hearts with dilated cardiomyopathy (DCM) compared to controls. METHOD: A comparative study was performed in six tissue blocks of the left ventricular free wall (LVWL) and inter-ventricular septum from patients who died of DCM and six who died of no cardiovascular diseases (controls). Five slices from each block were obtained to determine the expression of TPH1 and TPH2, SERT and serotonergic receptors with antibodies specific for immunofluorescence. Immunofluorescence was analyzed by Student's t-test, accepting a significance level of p < 0.05. RESULTS: An increase in TPH1, TPH2, 5-HT2A and 5-HT2B receptors expression were observed in dilated structures compared to controls (p < 0.05). For dilated inter-ventricular septum, the 5-HT4 receptor increased its expression (p < 0.05), and SERT in PLVI compared to controls (p < 0.05). CONCLUSIONS: These results suggest that the increases observed in the expression of TPH, SERT, and serotonergic receptors in hearts with DCM compared to controls could play an important role in the pathophysiology of MCD in humans.
ANTECEDENTES: Los cardiomiocitos sintetizan, utilizan y recapturan serotonina, la cual participa en la modulación parácrina y autócrina de la actividad del corazón y en la fisiopatología de algunas enfermedades cardiovasculares. OBJETIVO: Determinar la expresión de triptófano-5-hidroxilasa (TPH) 1 y 2, transportador de serotonina (SERT) y receptores serotoninérgicos en corazones con miocardiopatía dilatada (MCD) en comparación con controles. MÉTODO: Estudio comparativo en seis bloques de la pared libre del ventrículo izquierdo (PLVI) y del septum interventricular de pacientes fallecidos por MCD y seis que murieron por enfermedades no cardiovasculares. Se obtuvieron cinco cortes de cada bloque para determinar la expresión de TPH1 y TPH2, SERT y receptores serotoninérgicos con anticuerpos específicos por inmunofluorescencia. La inmunofluorescencia fue analizada por la t de Student, aceptando un nivel de significancia de p < 0.05. RESULTADOS: Se observó un aumento en la expresión de TPH1 y TPH2 y en los receptores 5-HT2A y 5-HT2B en las estructuras dilatadas en comparación con las controles (p < 0.05). El receptor 5-HT4 aumentó su expresión en el septum interventricular dilatado (p < 0.05) y el SERT en la PLVI en comparación con los controles (p < 0.05). CONCLUSIONES: Estos resultados sugieren que los aumentos observados en las expresiones de TPH, SERT y receptores serotoninérgicos en corazones con MCD en comparación con controles podrían desempeñar un papel importante en la fisiopatología de la MCD en los humanos.
Asunto(s)
Serotonina , Triptófano , HumanosRESUMEN
Resumen Introducción: Los cardiomiocitos poseen la maquinaria bioquímica capaz de sintetizar, utilizar y recapturar serotonina. Objetivo: Determinar si la miocardiopatía hipertrófica (MCH) induce cambios en la expresión de la triptófano-5-hidroxilasa (TPH) 1 y 2, el transportador de serotonina (SERT) y los receptores serotoninérgicos (RS). Métodos: Estudio transversal de cinco bloques de tejido de corazones con MCH y cinco bloques de corazones de control. Se obtuvieron cinco cortes de la pared libre del ventrículo izquierdo (PLVI) y del septum interventricular (SIV) de cada bloque, para determinar la expresión de TPH1 y TPH2, SERT y RS con anticuerpos por inmunofluorescencia. La inmunofluorescencia fue evaluada mediante t de WELCH, con nivel de significación de p < 0.05. Resultados: La PLVI y el SIV de los corazones con MCH mostraron aumento de la expresión de TPH1 y TPH2, así como de los receptores 5-HT2A y 5-HT2B en comparación con los controles (p < 0.01). El receptor 5-HT4 y SERT aumentaron en el SIV de los corazones con MCH (p < 0.01). Conclusiones: Se demostró aumento de las expresiones de TPH, SERT y RS en los cardiomiocitos de los corazones con MCH en comparación con los controles, lo cual podría participar en la fisiopatología de la MCH en los humanos.
Abstract Introduction: Cardiomyocytes have a biochemical machinery with the capacity to synthesize, utilize and reuptake serotonin. Objective: To determine whether hypertrophic cardiomyopathy (HCM) induces changes in the expression of tryptophan-5-hydroxylase (TPH) 1 and 2, serotonin transporter (SERT) and serotonergic receptors (SR). Methods: Cross-sectional study of five tissue blocks from hearts with HCM and five controls. Five sections of the left ventricular free wall (LVFW) and interventricular septum (IVS) were obtained from each block to determine the expression of TPH1 and TPH2, SERT and SRs by immunofluorescence with specific antibodies. Immunofluorescence was evaluated by WELCH t-test, with a level of significance of p < 0.05. Results: LVFW and IVS of hearts with HCM showed an increase in the expression of TPH1 and TPH 2 and 5-HT2A and 5-HT2B receptors in comparison with controls (p < 0.01). The 5-HT4 receptor and SERT showed an increase in the IVS of hearts with HCM (p < 0.01). Conclusions: This study demonstrated an increased expression of TPH, SERT and SRs in cardiomyocytes from hearts with HCM in comparison with controls, which could be involved in the pathophysiology of HCM in humans.
RESUMEN
RATIONALE: Serotonin (5-HT) is a monoamine neuromodulator that plays a key role in the organization of the central nervous system. 5-HT alterations may be associated to the emergence of social deficits and psychiatric disorders, including anxiety, depression, and substance abuse disorders. Notably, disruption of the 5-HT system during sensitive periods of development seems to exert long-term consequences, including altered anxiety responses and problematic use of alcohol. OBJECTIVE: We analyzed, in mice, the effects of transient 5-HT depletion at gestation (a developmental stage when medial prefrontal cortex (mPFC) 5-HT levels depend exclusively on placental 5-HT availability) on 5-HT central synthesis and reuptake at weaning. We also explored if 5-HT disruption at the embryonic stage influences behavioral outcomes that may serve as a proxy for autistic- or anxiety-like phenotypes. METHODS: C57/BL6 male and female mice, born from dams treated with a 5-HT synthesis inhibitor (PCPA; 4-Chloro-DL-phenylalanine methyl ester hydrochloride) at gestational days (G)13.5-16.5, were subjected to a behavioral battery that assesses social preference and novelty, compulsive behavior, stereotypies, and ethanol's anti-anxiety effects, at postnatal days (P) 21-28. Afterwards, expression of the genes that encode for 5-HT synthesis (Tph2) and SERT (5-HT transporter) were analyzed in mPFC via real-time RT-PCR. Dopamine 2 receptor (D2R) expression was also analyzed via RT-PCR to further explore possible effects of PCPA on dopaminergic transmission. RESULTS: Transient 5-HT disruption at G13.5-16.5 reduced Tph2 expression of both male and female mice in mPFC at P23. Notably, female mice also exhibited higher SERT expression and reduced D2R expression in mPFC. Mice derived from 5-HT depleted dams displayed heightened compulsive behavior at P21, when compared to control mice. Alcohol anti-anxiety effects at early adolescence (P28) were exhibited by mice derived from 5-HT depleted dams, but not by control counterparts. No social deficits or stereotyped behaviors were observed. CONCLUSION: Transient 5-HT inhibition at gestation resulted in altered expression of genes involved in 5-HT synthesis and reuptake in mPFC at weaning, a period in which the 5-HT system is still developing. These alterations may exert lingering effects, which translate to significant compulsivity and heightened sensitivity to the anxiolytic effects of alcohol at early adolescence.
Asunto(s)
Ansiolíticos , Serotonina , Animales , Ansiolíticos/farmacología , Conducta Animal , Dopamina/metabolismo , Etanol/farmacología , Femenino , Fenclonina/farmacología , Humanos , Masculino , Ratones , Placenta/metabolismo , Embarazo , Piridinolcarbamato , Serotonina/metabolismo , DesteteRESUMEN
Parkinson's disease (PD) is a neurodegenerative disease characterized by motor symptoms and dopaminergic cell loss. A pre-symptomatic phase characterized by non-motor symptoms precedes the onset of motor alterations. Two recent PET studies in human carriers of mutations associated with familial PD demonstrate an early serotonergic commitment-alteration in SERT binding-before any dopaminergic or motor dysfunction, that is, at putative PD pre-symptomatic stages. These findings support the hypothesis that early alterations in the serotonergic system could contribute to the progression of PD, an idea difficult to be tested in humans. Here, we study some components of the serotonergic system during the pre-symptomatic phase in a well-characterized Drosophila PD model, Pink1B9 mutant flies. We detected lower brain serotonin content in Pink1B9 flies, accompanied by reduced activity of SERT before the onset of motor dysfunctions. We also explored the consequences of a brief early manipulation of the serotonergic system in the development of motor symptoms later in aged animals. Feeding young Pink1B9 flies with fluoxetine, a SERT blocker, prevents the loss of dopaminergic neurons and ameliorates motor impairment observed in aged mutant flies. Surprisingly, the same pharmacological manipulation in young control flies results in aged animals exhibiting a PD-like phenotype. Our findings support that an early dysfunction in the serotonergic system precedes and contributes to the onset of the Parkinsonian phenotype in Drosophila.
Asunto(s)
Proteínas de Drosophila , Enfermedades Neurodegenerativas , Enfermedad de Parkinson , Animales , Drosophila/metabolismo , Proteínas de Drosophila/genética , Drosophila melanogaster/metabolismo , Enfermedad de Parkinson/genética , Fenotipo , Proteínas Quinasas/genética , Proteínas Serina-Treonina Quinasas , Proteínas de Transporte de Serotonina en la Membrana Plasmática/genética , Proteínas de Transporte de Serotonina en la Membrana Plasmática/metabolismo , Transmisión SinápticaRESUMEN
INTRODUCTION: Cardiomyocytes have a biochemical machinery with the capacity to synthesize, utilize and reuptake serotonin. OBJECTIVE: To determine whether hypertrophic cardiomyopathy (HCM) induces changes in the expression of tryptophan-5-hydroxylase (TPH) 1 and 2, serotonin transporter (SERT) and serotonergic receptors (SR). METHODS: Cross-sectional study of five tissue blocks from hearts with HCM and five controls. Five sections of the left ventricular free wall (LVFW) and interventricular septum (IVS) were obtained from each block to determine the expression of TPH1 and TPH2, SERT and SRs by immunofluorescence with specific antibodies. Immunofluorescence was evaluated by WELCH t-test, with a level of significance of p < 0.05. RESULTS: LVFW and IVS of hearts with HCM showed an increase in the expression of TPH1 and TPH 2 and 5-HT2A and 5-HT2B receptors in comparison with controls (p < 0.01). The 5-HT4 receptor and SERT showed an increase in the IVS of hearts with HCM (p < 0.01). CONCLUSIONS: This study demonstrated an increased expression of TPH, SERT and SRs in cardiomyocytes from hearts with HCM in comparison with controls, which could be involved in the pathophysiology of HCM in humans.
INTRODUCCIÓN: Los cardiomiocitos poseen la maquinaria bioquímica capaz de sintetizar, utilizar y recapturar serotonina. OBJETIVO: Determinar si la miocardiopatía hipertrófica (MCH) induce cambios en la expresión de la triptófano-5-hidroxilasa (TPH) 1 y 2, el transportador de serotonina (SERT) y los receptores serotoninérgicos (RS). MÉTODOS: Estudio transversal de cinco bloques de tejido de corazones con MCH y cinco bloques de corazones de control. Se obtuvieron cinco cortes de la pared libre del ventrículo izquierdo (PLVI) y del septum interventricular (SIV) de cada bloque, para determinar la expresión de TPH1 y TPH2, SERT y RS con anticuerpos por inmunofluorescencia. La inmunofluorescencia fue evaluada mediante t de WELCH, con nivel de significación de p < 0.05. RESULTADOS: La PLVI y el SIV de los corazones con MCH mostraron aumento de la expresión de TPH1 y TPH2, así como de los receptores 5-HT2A y 5-HT2B en comparación con los controles (p < 0.01). El receptor 5-HT4 y SERT aumentaron en el SIV de los corazones con MCH (p < 0.01). CONCLUSIONES: Se demostró aumento de las expresiones de TPH, SERT y RS en los cardiomiocitos de los corazones con MCH en comparación con los controles, lo cual podría participar en la fisiopatología de la MCH en los humanos.
Asunto(s)
Cardiomiopatía Hipertrófica , Proteínas de Transporte de Serotonina en la Membrana Plasmática , Triptófano Hidroxilasa , Humanos , Estudios Transversales , Serotonina/metabolismo , Proteínas de Transporte de Serotonina en la Membrana Plasmática/genética , Proteínas de Transporte de Serotonina en la Membrana Plasmática/metabolismo , Triptófano Hidroxilasa/genética , Triptófano Hidroxilasa/metabolismoRESUMEN
A series of 27 compounds of general structure 2,3-dihydro-benzo[1,4]oxazin-4-yl)-2-{4-[3-(1H-3indolyl)-propyl]-1-piperazinyl}-ethanamides, Series I: 7(a-o) and (2-{4-[3-(1H-3-indolyl)-propyl]-1-piperazinyl}-acetylamine)-N-(2-morfolin-4-yl-ethyl)-fluorinated benzamides Series II: 13(a-l) were synthesized and evaluated as novel multitarget ligands towards dopamine D2 receptor, serotonin transporter (SERT), and monoamine oxidase-A (MAO-A) directed to the management of major depressive disorder (MDD). All the assayed compounds showed affinity for SERT in the nanomolar range, with five of them displaying Ki values from 5 to 10 nM. Compounds 7k, Ki = 5.63 ± 0.82 nM, and 13c, Ki = 6.85 ± 0.19 nM, showed the highest potencies. The affinities for D2 ranged from micro to nanomolar, while MAO-A inhibition was more discrete. Nevertheless, compounds 7m and 7n showed affinities for the D2 receptor in the nanomolar range (7n: Ki = 307 ± 6 nM and 7m: Ki = 593 ± 62 nM). Compound 7n was the only derivative displaying comparable affinities for SERT and D2 receptor (D2/SERT ratio = 3.6) and could be considered as a multitarget lead for further optimization. In addition, docking studies aimed to rationalize the molecular interactions and binding modes of the designed compounds in the most relevant protein targets were carried out. Furthermore, in order to obtain information on the structure-activity relationship of the synthesized series, a 3-D-QSAR CoMFA and CoMSIA study was conducted and validated internally and externally (q2 = 0.625, 0.523 for CoMFA and CoMSIA and r2ncv = 0.967, 0.959 for CoMFA and CoMSIA, respectively).
Asunto(s)
Bioensayo/métodos , Receptores de Dopamina D2/metabolismo , Proteínas de Transporte de Serotonina en la Membrana Plasmática/metabolismo , Simulación del Acoplamiento Molecular , Relación Estructura-Actividad Cuantitativa , Receptores de Dopamina D2/genética , Proteínas de Transporte de Serotonina en la Membrana Plasmática/genética , Relación Estructura-ActividadRESUMEN
During the last decade, the one drug-one target strategy has resulted to be inefficient in facing diseases with complex ethiology like Alzheimer's disease and many others. In this context, the multitarget paradigm has emerged as a promising strategy. Based on this consideration, we aim to develop novel molecules as promiscuous ligands acting in two or more targets at the same time. For such purpose, a new series of indolylpropyl-piperazinyl oxoethyl-benzamido piperazines were synthesized and evaluated as multitarget-directed drugs for the serotonin transporter (SERT) and acetylcholinesterase (AChE). The ability to decrease ß-amyloid levels as well as cell toxicity of all compounds were also measured. In vitro results showed that at least four compounds displayed promising activity against SERT and AChE. Compounds 18 and 19 (IC50 = 3.4 and 3.6 µM respectively) exhibited AChE inhibition profile in the same order of magnitude as donepezil (DPZ, IC50 = 2.17 µM), also displaying nanomolar affinity in SERT. Moreover, compounds 17 and 24 displayed high SERT affinities (IC50 = 9.2 and 1.9 nM respectively) similar to the antidepressant citalopram, and significant micromolar AChE activity at the same time. All the bioactive compounds showed a low toxicity profile in the range of concentrations studied. Molecular docking allowed us to rationalize the binding mode of the synthesized compounds in both targets. In addition, we also show that compounds 11 and 25 exhibit significant ß-amyloid lowering activity in a cell-based assay, 11 (50% inhibition, 10 µM) and 25 (35% inhibition, 10 µM). These results suggest that indolylpropyl benzamidopiperazines based compounds constitute promising leads for a multitargeted approach for Alzheimer's disease.
Asunto(s)
Acetilcolinesterasa/metabolismo , Enfermedad de Alzheimer/tratamiento farmacológico , Antidepresivos/síntesis química , Inhibidores de la Colinesterasa/síntesis química , Piperazinas/síntesis química , Inhibidores Selectivos de la Recaptación de Serotonina/síntesis química , Proteínas de Transporte de Serotonina en la Membrana Plasmática/metabolismo , Péptidos beta-Amiloides/metabolismo , Animales , Antidepresivos/farmacología , Línea Celular , Inhibidores de la Colinesterasa/farmacología , Donepezilo/química , Diseño de Fármacos , Humanos , Ratones , Simulación del Acoplamiento Molecular , Neuroblastoma , Piperazinas/farmacología , Conformación Proteica , Inhibidores Selectivos de la Recaptación de Serotonina/farmacología , Relación Estructura-ActividadRESUMEN
Anecdotal reports and open-label case studies in humans indicated that the psychedelic alkaloid ibogaine exerts profound antiaddictive effects. Ample preclinical evidence demonstrated the efficacy of ibogaine, and its main metabolite, noribogaine, in substance-use-disorder rodent models. In contrast to addiction research, depression-relevant effects of ibogaine or noribogaine in rodents have not been previously examined. We have recently reported that the acute ibogaine administration induced a long-term increase of brain-derived neurotrophic factor mRNA levels in the rat prefrontal cortex, which led us to hypothesize that ibogaine may elicit antidepressant-like effects in rats. Accordingly, we characterized behavioral effects (dose- and time-dependence) induced by the acute ibogaine and noribogaine administration in rats using the forced swim test (FST, 20 and 40 mg/kg i.p., single injection for each dose). We also examined the correlation between plasma and brain concentrations of ibogaine and noribogaine and the elicited behavioral response. We found that ibogaine and noribogaine induced a dose- and time-dependent antidepressant-like effect without significant changes of animal locomotor activity. Noribogaine's FST effect was short-lived (30 min) and correlated with high brain concentrations (estimated >8 µM of free drug), while the ibogaine's antidepressant-like effect was significant at 3 h. At this time point, both ibogaine and noribogaine were present in rat brain at concentrations that cannot produce the same behavioral outcome on their own (ibogaine â¼0.5 µM, noribogaine â¼2.5 µM). Our data suggests a polypharmacological mechanism underpinning the antidepressant-like effects of ibogaine and noribogaine.
Asunto(s)
Alucinógenos , Ibogaína , Animales , Antidepresivos/farmacología , Alucinógenos/farmacología , Ibogaína/análogos & derivados , Ibogaína/farmacología , Ratas , RoedoresRESUMEN
Serotonin is a biogenic amine that acts as neurotransmitter in different brain regions and is involved in complex behaviors, such as aggression or mood regulation. Thus, this amine is found in defined circuits and activates specific receptors in different target regions. Serotonin actions depend on extracellular levels of this amine, which are regulated by its synthetic enzymes and the plasma membrane transporter, SERT. Serotonin acts also as a neurotrophic signal in ontogeny and in the mature brain, controlling cell proliferation, differentiation, neurogenesis, and neural plasticity. Interestingly, early alterations in serotonergic signaling have been linked to a diversity of neurodevelopmental disorders, including autism spectrum disorder (ASD), attention deficit/hyperactivity disorder (ADHD), or mental illnesses like schizophrenia or depression. It has been proposed that given the complex and numerous actions of serotonin, animal models could better serve to study the complexity of serotonin actions, while providing insights on how hindering serotonergic signaling could contribute to brain disorders. In this mini-review, it will be examined what the general properties of serotonin acting as a neurotransmitter in animals are, and furthermore, whether it is possible that Drosophila could be used to study the contribution of this amine to neurodevelopmental and mental disorders.
RESUMEN
Nicotinic acetylcholine receptors (nAChRs), serotonin transporters (SERT) and dopamine transporters (DAT) represent targets for the development of novel nicotinic derivatives acting as multiligands associated with different health conditions, such as depressive, anxiety and addiction disorders. In the present work, a series of functionalized esters structurally related to acetylcholine and nicotine were synthesized and pharmacologically assayed with respect to these targets. The synthesized compounds were studied in radioligand binding assays at α4ß2 nAChR, h-SERT and h-DAT. SERT experiments showed not radioligand [3H]-paroxetine displacement, but rather an increase in the radioligand binding percentage at the central binding site was observed. Compound 20 showed Ki values of 1.008 ± 0.230 µM for h-DAT and 0.031 ± 0.006 µM for α4ß2 nAChR, and [3H]-paroxetine binding of 191.50% in h-SERT displacement studies, being the only compound displaying triple affinity. Compound 21 displayed Ki values of 0.113 ± 0.037 µM for α4ß2 nAChR and 0.075 ± 0.009 µM for h-DAT acting as a dual ligand. Molecular docking studies on homology models of α4ß2 nAChR, h-DAT and h-SERT suggested potential interactions among the compounds and agonist binding site at the α4/ß2 subunit interfaces of α4ß2 nAChR, central binding site of h-DAT and allosteric modulator effect in h-SERT.
Asunto(s)
Acetilcolina/análogos & derivados , Proteínas de Transporte de Dopamina a través de la Membrana Plasmática/química , Nicotina/análogos & derivados , Receptores Nicotínicos/química , Proteínas de Transporte de Serotonina en la Membrana Plasmática/química , Acetilcolina/agonistas , Acetilcolina/síntesis química , Acetilcolina/química , Regulación Alostérica , Sitios de Unión , Dopamina/química , Agonistas de Dopamina/química , Proteínas de Transporte de Dopamina a través de la Membrana Plasmática/agonistas , Ésteres/química , Células HEK293 , Humanos , Ligandos , Simulación del Acoplamiento Molecular , Nicotina/agonistas , Nicotina/síntesis química , Nicotina/química , Agonistas Nicotínicos/química , Pirrolidinas/química , Ensayo de Unión Radioligante , Proteínas de Transporte de Serotonina en la Membrana Plasmática/agonistas , Relación Estructura-ActividadRESUMEN
The neurotransmitter serotonin (5-HT) acts as an important regulator of the critical neurodevelopmental processes and thus alterations in 5-HT signaling early promotes permanent structural and functional changes in brain. The selective serotonin reuptake inhibitors (SSRIs), as fluoxetine and citalopram, blocking serotonin transporter (SERT) at the presynaptic neuron, which regulates extracellular 5-HT levels. Evidence suggests that the exposure to SSRIs in the neurodevelopmental period may alters 5-HT signaling sensitivity on food intake control. The aim of the present study was to evaluate the effects of neonatal exposure to fluoxetine on molecular and cellular components of the serotonergic system and food intake control in young animals. Methods: The animals were divided according to experimental manipulation, Fluoxetine Group (FG): male pups received application of fluoxetine (10â¯mg/kg, 10⯵L/g) and Saline Group (SG): male pups received saline application (0.9% NaCl, 10⯵L/g), both throughout lactation (PND1-PND21). They evaluated body weight, food intake, SERT gene and protein expression, serotonin content in the hypothalamus. The neonatal exposure to fluoxetine promoted reduction in body weight, disturb the serotonin hypophagic response, and increase the serotonin and SERT hypothalamic in young animals. We conclude that the changes of components of the serotonergic system by neonatal exposure to fluoxetine may be responsible for disturb the inhibitory action of serotonin on food intake.
Asunto(s)
Ingestión de Alimentos/efectos de los fármacos , Fluoxetina/farmacología , Inhibición Neural/efectos de los fármacos , Inhibidores Selectivos de la Recaptación de Serotonina/farmacología , Proteínas de Transporte de Serotonina en la Membrana Plasmática/metabolismo , Serotonina/metabolismo , Transmisión Sináptica/efectos de los fármacos , Factores de Edad , Animales , Animales Recién Nacidos , Peso Corporal/efectos de los fármacos , Citalopram/farmacología , Femenino , Privación de Alimentos , Regulación de la Expresión Génica/efectos de los fármacos , Hipotálamo/citología , Hipotálamo/efectos de los fármacos , Hipotálamo/metabolismo , Masculino , ARN Mensajero/metabolismo , Ratas , Ratas Wistar , Proteínas de Transporte de Serotonina en la Membrana Plasmática/genéticaRESUMEN
A better comprehension on how different molecular components of the serotonergic system contribute to the adequate regulation of behaviors in animals is essential in the interpretation on how they are involved in neuropsychiatric and pathological disorders. It is possible to study these components in "simpler" animal models including the fly Drosophila melanogaster, given that most of the components of the serotonergic system are conserved between vertebrates and invertebrates. Here we decided to advance our understanding on how the serotonin plasma membrane transporter (SERT) contributes to serotonergic neurotransmission and behaviors in Drosophila. In doing this, we characterized for the first time a mutant for Drosophila SERT (dSERT) and additionally used a highly selective serotonin-releasing drug, 4-methylthioamphetamine (4-MTA), whose mechanism of action involves the SERT protein. Our results show that dSERT mutant animals exhibit an increased survival rate in stress conditions, increased basal motor behavior, and decreased levels in an anxiety-related parameter, centrophobism. We also show that 4-MTA increases the negative chemotaxis toward a strong aversive odorant, benzaldehyde. Our neurochemical data suggest that this effect is mediated by dSERT and depends on the 4-MTA-increased release of serotonin in the fly brain. Our in silico data support the idea that these effects are explained by specific interactions between 4-MTA and dSERT. In sum, our neurochemical, in silico, and behavioral analyses demonstrate the critical importance of the serotonergic system and particularly dSERT functioning in modulating several behaviors in Drosophila.
Asunto(s)
Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Proteínas de Transporte de Serotonina en la Membrana Plasmática/metabolismo , Serotonina/metabolismo , Animales , Conducta Animal/efectos de los fármacos , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Proteínas de Drosophila/genética , Mutación/genética , Serotoninérgicos/metabolismo , Serotoninérgicos/farmacología , Proteínas de Transporte de Serotonina en la Membrana Plasmática/genéticaRESUMEN
The aim of this study was to evaluate the effect of progesterone on the protein expression of α4 subunit of GABA(A) receptor, serotonin transporter (SERT), Akt, Erk, and caspase-3 in the olfactory bulb (OB) of female rats exposed to the forced swimming test (FST). Female rats were injected daily with progesterone (0.4 mg/kg body mass) or vehicle during 2 complete oestrous cycles and exposed to the FST, and the protein expression of GABA(A) receptor α4 subunit, SERT, Akt, Erk, and caspase-3 in the OB were evaluated. Progesterone increased the expression of the α4 subunit in the right OB and decreased its expression in the left OB, although it did not change the expression of other proteins. In summary, our findings indicate that progesterone has an asymmetric modulatory effect on the expression of GABA(A) receptor α4 subunit in the OB. This effect could be related to the antidepressant-like effect of progesterone in female rats.
Asunto(s)
Antidepresivos/farmacología , Expresión Génica/efectos de los fármacos , Bulbo Olfatorio/efectos de los fármacos , Progesterona/farmacología , Receptores de GABA-A/metabolismo , Animales , Relación Dosis-Respuesta a Droga , Femenino , Bulbo Olfatorio/metabolismo , Proteínas de Unión al ARN/metabolismo , Ratas Wistar , Receptores de GABA-A/genética , Transducción de SeñalRESUMEN
The SLC6A4 gene encodes the serotonin transporter SERT. Since the discovery of the role of SLC6A4 polymorphisms on human behavior, there is an increasingly growing wealth of information regarding SLC6A4 gene variants associated with anxiety and mood disorders, as well as their pharmacogenetic implications. In this brief review, the main discoveries on SLC6A4 variants, their functional impact and their suggested roles in neuropsychiatric and neurodevelopmental disorders are discussed.
El gen SLC6A4 codifica el transportador de serotonina SERT. Desde el descubrimiento inicial del rol que tienen polimorfismos de SLC6A4 en el comportamiento humano, hay una creciente cantidad de información acerca de variantes genéticas de SLC6A4 asociadas con trastornos de ansiedad y de estado de ánimo, así como de sus implicancias farmacogenéticas. En esta breve revisión, se discuten los principales descubrimientos de variantes de SLC6A4, su impacto funcional y sus roles sugeridos en enfermedades neuropsiquiátricas y de neurodesarrollo.
Asunto(s)
Humanos , Serotonina , Proteínas de Transporte de Serotonina en la Membrana Plasmática , Enfermedades del Sistema NerviosoRESUMEN
Visceral hypersensitivity plays an important role in motor and sensory abnormalities associated with irritable bowel syndrome, but the underlying mechanisms are not fully understood. The present study was designed to evaluate the expression of the 5-HT4 receptor and the serotonin transporter (SERT) as well as their roles in chronic visceral hypersensitivity using a rat model. Neonatal male Sprague-Dawley rats received intracolonic injections of 0.5% acetic acid (0.3-0.5 mL at different times) between postnatal days 8 and 21 to establish an animal model of visceral hypersensitivity. On day 43, the threshold intensity for a visually identifiable contraction of the abdominal wall and body arching were recorded during rectal distention. Histological evaluation and the myeloperoxidase activity assay were performed to determine the severity of inflammation. The 5-HT4 receptor and SERT expression of the ascending colon were monitored using immunohistochemistry and Western blot analyses; the plasma 5-HT levels were measured using an ELISA method. As expected, transient colonic irritation at the neonatal stage led to visceral hypersensitivity, but no mucosal inflammation was later detected during adulthood. Using this model, we found reduced SERT expression (0.298 ± 0.038 vs 0.634 ± 0.200, P < 0.05) and increased 5-HT4 receptor expression (0.308 ± 0.017 vs 0.298 ± 0.021, P < 0.05). Treatment with fluoxetine (10 mg·kg-1·day-1, days 36-42), tegaserod (1 mg·kg-1·day-1, day 43), or the combination of both, reduced visceral hypersensitivity and plasma 5-HT levels. Fluoxetine treatment increased 5-HT4 receptor expression (0.322 ± 0.020 vs 0.308 ± 0.017, P < 0.01) but not SERT expression (0.219 ± 0.039 vs 0.298 ± 0.038, P = 0.654). These results indicate that both the 5-HT4 receptor and SERT play a role in the pathogenesis of visceral hypersensitivity, and its mechanism may be involved in the local 5-HT level.