RESUMO
Hypofunctioning of NMDA receptors, and the resulting shift in the balance between excitation and inhibition, is considered a key process in the pathophysiology of schizophrenia. One important manifestation of this phenomenon is changes in neural oscillations, those above 30 Hz (i.e., gamma-band oscillations), in particular. Although both preclinical and clinical studies observed increased gamma activity following acute administration of NMDA receptor antagonists, the relevance of this phenomenon has been recently questioned given the reduced gamma oscillations typically observed during sensory and cognitive tasks in schizophrenia. However, there is emerging, yet contradictory, evidence for increased spontaneous gamma-band activity (i.e., at rest or under baseline conditions). Here, we use the sub-chronic phencyclidine (PCP) rat model for schizophrenia, which has been argued to model the pathophysiology of schizophrenia more closely than acute NMDA antagonism, to investigate gamma oscillations (30-100 Hz) in the medial prefrontal cortex of anesthetized animals. While baseline gamma oscillations were not affected, oscillations induced by train stimulation of the posterior dorsal CA1 (pdCA1) field of the hippocampus were enhanced in PCP-treated animals (5 mg/kg, twice daily for 7 days, followed by a 7-day washout period). This effect was reversed by pharmacological enhancement of endocannabinoid levels via systemic administration of URB597 (0.3 mg/kg), an inhibitor of the catabolic enzyme of the endocannabinoid anandamide. Intriguingly, the pharmacological blockade of CB1 receptors by AM251 unmasked a reduced gamma oscillatory activity in PCP-treated animals. The findings are consistent with the observed effects of URB597 and AM251 on behavioral deficits reminiscent of the symptoms of schizophrenia and further validate the potential for cannabinoid-based drugs as a treatment for schizophrenia.
Assuntos
Amidoidrolases , Benzamidas , Carbamatos , Fenciclidina , Piperidinas , Esquizofrenia , Animais , Masculino , Ratos , Amidoidrolases/antagonistas & inibidores , Amidoidrolases/metabolismo , Ácidos Araquidônicos/metabolismo , Ácidos Araquidônicos/farmacologia , Benzamidas/farmacologia , Carbamatos/farmacologia , Modelos Animais de Doenças , Endocanabinoides/metabolismo , Antagonistas de Aminoácidos Excitatórios/farmacologia , Antagonistas de Aminoácidos Excitatórios/administração & dosagem , Ritmo Gama/fisiologia , Ritmo Gama/efeitos dos fármacos , Fenciclidina/farmacologia , Piperidinas/farmacologia , Alcamidas Poli-Insaturadas/metabolismo , Alcamidas Poli-Insaturadas/farmacologia , Córtex Pré-Frontal/efeitos dos fármacos , Córtex Pré-Frontal/metabolismo , Córtex Pré-Frontal/fisiopatologia , Pirazóis/farmacologia , Ratos Sprague-Dawley , Esquizofrenia/fisiopatologia , Esquizofrenia/metabolismo , Esquizofrenia/tratamento farmacológicoRESUMO
BACKGROUND: Frontotemporal dementia (FTD) is a heterogeneous group of early onset and progressive neurodegenerative disorders, characterized by degeneration in the frontal and temporal lobes, which causes deterioration in cognition, personality, social behavior and language. Around 45% of the cases are characterized by the presence of aggregates of the RNA-binding protein TDP-43. METHODS: In this study, we have used a murine model of FTD that overexpresses this protein exclusively in the forebrain (under the control of the CaMKIIα promoter) for several biochemical, histological and pharmacological studies focused on the endocannabinoid system. RESULTS: These mice exhibited at postnatal day 90 (PND90) important cognitive deficits, signs of emotional impairment and disinhibited social behaviour, which were, in most of cases, maintained during the first year of life of these animals. Motor activity was apparently normal, but FTD mice exhibited higher mortality. Their MRI imaging analysis and their ex-vivo histopathological evaluation proved changes compatible with atrophy (loss of specific groups of pyramidal neurons: Ctip2- and NeuN-positive cells) and inflammatory events (astroglial and microglial reactivities) in both cortical (medial prefrontal cortex) and subcortical (hippocampus) structures at PND90 and also at PND365. The analysis of the endocannabinoid system in these mice proved a decrease in the hydrolysing enzyme FAAH in the prefrontal cortex and the hippocampus, with an increase in the synthesizing enzyme NAPE-PLD only in the hippocampus, responses that were accompanied by modest elevations in anandamide and related N-acylethanolamines. The potentiation of these elevated levels of anandamide after the pharmacological inactivation of FAAH with URB597 resulted in a general improvement in behaviour, in particular in cognitive deterioration, associated with the preservation of pyramidal neurons of the medial prefrontal cortex and the CA1 layer of the hippocampus, and with the reduction of gliosis in both structures. CONCLUSIONS: Our data confirmed the potential of elevating the endocannabinoid tone as a therapy against TDP-43-induced neuropathology in FTD, limiting glial reactivity, preserving neuronal integrity and improving cognitive, emotional and social deficits.
Assuntos
Demência Frontotemporal , Doença de Pick , Masculino , Camundongos , Animais , Demência Frontotemporal/genética , Endocanabinoides/uso terapêutico , Camundongos Transgênicos , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismoRESUMO
The endocannabinoid system (ECS) plays an important role in pain processing and modulation. Since the specific effects of endocannabinoids within the orofacial area are largely unknown, we aimed to determine whether an increase in the endocannabinoid concentration in the cerebrospinal fluid (CSF) caused by the peripheral administration of the FAAH inhibitor URB597 and tooth pulp stimulation would affect the transmission of impulses between the sensory and motor centers localized in the vicinity of the third and fourth cerebral ventricles. The study objectives were evaluated on rats using a method that allowed the recording of the amplitude of evoked tongue jerks (ETJ) in response to noxious tooth pulp stimulation and URB597 treatment. The amplitude of ETJ was a measure of the effect of endocannabinoids on the neural structures. The concentrations of the endocannabinoids tested (AEA and 2-AG) were determined in the CSF, along with the expression of the cannabinoid receptors (CB1 and CB2) in the tissues of the mesencephalon, thalamus, and hypothalamus. We demonstrated that anandamide (AEA), but not 2-arachidonoylglycerol (2-AG), was significantly increased in the CSF after treatment with a FAAH inhibitor, while tooth pulp stimulation had no effect on the AEA and 2-AG concentrations in the CSF. We also found positive correlations between the CSF AEA concentration and cannabinoid receptor type 1 (CB1R) expression in the brain, and between 2-AG and cannabinoid receptor type 2 (CB2R), and negative correlations between the CSF concentration of AEA and brain CB2R expression, and between 2-AG and CB1R. Our study shows that endogenous AEA, which diffuses through the cerebroventricular ependyma into CSF and exerts a modulatory effect mediated by CB1Rs, alters the properties of neurons in the trigeminal sensory nuclei, interneurons, and motoneurons of the hypoglossal nerve. In addition, our findings may be consistent with the emerging concept that AEA and 2-AG have different regulatory mechanisms because they are involved differently in orofacial pain. We also suggest that FAAH inhibition may offer a therapeutic approach to the treatment of orofacial pain.
RESUMO
The complexity of neuropathic pain and its associated comorbidities, including dysautonomia, make it difficult to treat. Overlap of anatomical regions and pharmacology of sympathosensory systems in the central nervous system (CNS) provide targets for novel treatment strategies. The dorsal periaqueductal gray (dPAG) is an integral component of both the descending pain modulation system and the acute stress response and is critically involved in both analgesia and the regulation of sympathetic activity. Local manipulation of the endocannabinoid signaling system holds great promise to provide analgesia without excessive adverse effects and also influence autonomic output. Inhibition of fatty acid amide hydrolase (FAAH) increases brain concentrations of the endocannabinoid N-arachidonoylethanolamine (AEA) and reduces pain-related behaviors in neuropathic pain models. Neuropathic hyperalgesia and reduced sympathetic tone are associated with increased FAAH activity in the dPAG, which suggests the hypothesis that inhibition of FAAH in the dPAG will normalize pain sensation and autonomic function in neuropathic pain. To test this hypothesis, the effects of systemic or intra-dPAG FAAH inhibition on hyperalgesia and dysautonomia developed after spared nerve injury (SNI) were assessed in male and female rats. Administration of the FAAH inhibitor PF-3845 into the dPAG reduces hyperalgesia behavior and the decrease in sympathetic tone induced by SNI. Prior administration of the CB1 receptor antagonist AM281, attenuated the antihyperalgesic and sympathetic effects of FAAH inhibition. No sex differences were identified. These data support an integrative role for AEA/CB1 receptor signaling in the dPAG contributing to the regulation of both hyperalgesia behavior and altered sympathetic tone in neuropathic pain.
Assuntos
Neuralgia , Disautonomias Primárias , Feminino , Masculino , Animais , Ratos , Endocanabinoides/farmacologia , Hiperalgesia/tratamento farmacológico , Substância Cinzenta Periaquedutal/metabolismo , Receptor CB1 de Canabinoide , Amidoidrolases/metabolismo , Neuralgia/tratamento farmacológico , Alcamidas Poli-Insaturadas/uso terapêuticoRESUMO
Early life stress (ELS) increases predisposition to depression. We compared the effects of treatment with the fatty acid amide hydrolase (FAAH) inhibitor URB597, and the selective serotonin reuptake inhibitor paroxetine, on ELS-induced depressive-like behavior and the expression of microRNAs (miRs) associated with depression in the medial prefrontal cortex (mPFC), hippocampal CA1 area, lateral habenula and dorsal raphe in rats. We also examined the mRNA expression of serotonergic (htr1a and slc6a4) and endocannabinoid (cnr1, cnr2 and faah) targets in the mPFC following ELS and pharmacological treatment. Adult males and females exposed to the 'Limited Bedding and Nesting' ELS paradigm demonstrated a depressive-like phenotype and late-adolescence URB597 treatment, but not paroxetine, reversed this phenotype. In the mPFC, ELS downregulated miR-16 in males and miR-135a in females and URB597 treatment restored this effect. In ELS females, the increase in cnr2 and decrease in faah mRNAs in the mPFC were reversed by URB597 treatment. We show for the first time that URB597 reversed ELS-induced mPFC downregulation in specific miRs and stress-related behaviors, suggesting a novel mechanism for the beneficial effects of FAAH inhibition. The differential effects of ELS and URB597 on males and females highlight the importance of developing sex-specific treatment approaches.
Assuntos
Amidoidrolases , MicroRNAs , Estresse Psicológico , Animais , Feminino , Masculino , Ratos , Amidoidrolases/antagonistas & inibidores , Amidoidrolases/metabolismo , Benzamidas/farmacologia , Benzamidas/uso terapêutico , Endocanabinoides/metabolismo , MicroRNAs/genética , Estresse Psicológico/genética , Estresse Psicológico/metabolismoRESUMO
Endocannabinoids act as analgesic agents in a number of headache models. However, their effectiveness varies with the route of administration and the type of pain. In this study, we assessed the role of the fatty acid amide hydrolase inhibitor URB597 in an animal model of orofacial pain based on tooth pulp stimulation. More specifically, we assessed the effects of intracerbroventricular (i.c.v.) and intraperitoneal (i.p.) administration of URB597 on the amplitude of evoked tongue jerks (ETJ) in rats. The levels of the investigated mediators anandamide (AEA), 2-arachidonyl glycerol (2-AG), Substance P (SP), calcitonin-gene-related peptide (CGRP), endomorphin-2 (EM-2) and fatty acid amide hydrolase (FAAH) inhibitor by URB597 and receptors cannabinoid type-1 receptors (CB1R), cannabinoid type-2 receptors (CB2R) and µ-opioid receptors (MOR) were determined in the mesencephalon, thalamus and hypothalamus tissues. We have shown that increasing endocannabinoid AEA levels by both central and peripheral inhibition of FAAH inhibitor by URB597 has an antinociceptive effect on the trigemino-hypoglossal reflex mediated by CB1R and influences the activation of the brain areas studied. On the other hand, URB597 had no effect on the concentration of 2-AG in the examined brain structures and caused a significant decrease in CB2R mRNA expression in the hypothalamus only. Tooth pulp stimulation caused in a significant increase in SP, CGRP and EM-2 gene expression in the midbrain, thalamus and hypothalamus. In contrast, URB597 administered peripherally one hour before stimulation decreased the mRNA level of these endogenous neuropeptides in comparison with the control and stimulation in all examined brain structures. Our results show that centrally and peripherally administered URB597 is effective at preventing orofacial pain by inhibiting AEA catabolism and reducing the level of CGRP, SP and EM-2 gene expression and that AEA and 2-AG have different species and model-specific regulatory mechanisms. The data presented in this study may represent a new promising therapeutic target in the treatment of orofacial pain.
Assuntos
Benzamidas , Peptídeo Relacionado com Gene de Calcitonina , Carbamatos , Percepção da Dor , Amidoidrolases/genética , Animais , Benzamidas/farmacologia , Benzamidas/uso terapêutico , Carbamatos/farmacologia , Carbamatos/uso terapêutico , Endocanabinoides/metabolismo , Dor Facial/tratamento farmacológico , Percepção da Dor/efeitos dos fármacos , Alcamidas Poli-Insaturadas/metabolismo , RNA Mensageiro , Ratos , Receptor CB1 de Canabinoide/efeitos dos fármacos , Receptores de Canabinoides/efeitos dos fármacosRESUMO
Parkinson disease (PD) is a progressive neurodegenerative disorder that is often accompanied by motor and psychiatric symptoms. Various approaches have been proposed for the treatment of PD. Here, we investigated the effect of a low dose of fatty acid amide hydrolase inhibitor URB597 (as an enhancer of endocannabinoid anandamide levels), exercise or their combination on some behavior alterations in PD mice lesioned by 6-hydroxydopamine (6-OHDA). The impact of swimming exercise (5×/week for 4 weeks) and URB597 (0.1 mg/kg, 2×/week for 4 weeks) on the anxiety-related behavior (elevated plus maze; EPM), depression-related behavior (tail suspension test; TST), and passive avoidance memory (step-down task) was examined in the sham and male NMRI mouse of PD model. The results show that URB597 prevented memory deficits and elicited antidepressant- and anxiolytic-like effects but did not affect hypolocomotion in the PD mice. However, URB597 did not have a significant effect on the performance of the sham mice in the performed tests. Moreover, swimming training abolished depressive- and anxiogenic-like behaviors and increased locomotion without affecting memory deficits in the PD mice. Meanwhile, swimming decreased immobility time and increased locomotion in the sham mice. Furthermore, URB597 in association with swimming training prevented all deficits induced in the PD mice, while this combination impaired memory and produced the positive effects on depression- and anxiety-related behaviors and locomotion of the sham mice. It is concluded that although URB597 or exercise alone had positive effects on most behavioral tests, their combination improved all parameters in the PD mice.
Assuntos
Doença de Parkinson , Animais , Comportamento Animal , Benzamidas , Carbamatos , Modelos Animais de Doenças , Teste de Labirinto em Cruz Elevado , Elevação dos Membros Posteriores , Masculino , Camundongos , Camundongos Endogâmicos , Oxidopamina/toxicidadeRESUMO
Our study aimed to examine the effects of hypertension and the chronic administration of the fatty acid amide hydrolase (FAAH) inhibitor URB597 on vascular function and the endocannabinoid system in spontaneously hypertensive rats (SHR). Functional studies were performed on small mesenteric G3 arteries (sMA) and aortas isolated from SHR and normotensive Wistar Kyoto rats (WKY) treated with URB597 (1 mg/kg; twice daily for 14 days). In the aortas and sMA of SHR, endocannabinoid levels and cannabinoid CB1 receptor (CB1R) expression were elevated. The CB1R antagonist AM251 diminished the methanandamide-evoked relaxation only in the sMA of SHR and enhanced the vasoconstriction induced by phenylephrine and the thromboxane analog U46619 in sMA in SHR and WKY. In the sMA of SHR, URB597 elevated anandamide levels, improved the endothelium-dependent vasorelaxation to acetylcholine, and in the presence of AM251 reduced the vasoconstriction to phenylephrine and enhanced the vasodilatation to methanandamide, and tended to reduce hypertrophy. In the aortas, URB597 elevated endocannabinoid levels improved the endothelium-dependent vasorelaxation to acetylcholine and decreased CB1R expression. Our study showed that hypertension and chronic administration of URB597 caused local, resistance artery-specific beneficial alterations in the vascular endocannabinoid system, which may bring further advantages for therapeutic application of pharmacological inhibition of FAAH.
Assuntos
Amidoidrolases/efeitos dos fármacos , Amidoidrolases/metabolismo , Benzamidas/farmacologia , Carbamatos/farmacologia , Endocanabinoides/metabolismo , Hipertensão Essencial/metabolismo , Hipertensão Essencial/terapia , Acetilcolina , Animais , Aorta , Ácidos Araquidônicos , Hipertensão/metabolismo , Masculino , Artérias Mesentéricas/efeitos dos fármacos , Nitroprussiato , Alcamidas Poli-Insaturadas , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Receptores de Canabinoides , Vasoconstrição , Vasodilatação/efeitos dos fármacosRESUMO
The ability of endocannabinoid (eCB) to change functional microglial phenotype can be explored as a possible target for therapeutic intervention. Since the inhibition of fatty acid amide hydrolase (FAAH), the main catabolic enzyme of anandamide (AEA), may provide beneficial effects in mice model of Alzheimer's disease (AD)-like pathology, we aimed at determining whether the FAAH inhibitor URB597 might target microglia polarization and alter the cytoskeleton reorganization induced by the amyloid-ß peptide (Aß). The morphological evaluation showed that Aß treatment increased the surface area of BV-2 cells, which acquired a flat and polygonal morphology. URB597 treatment partially rescued the control phenotype of BV-2 cells when co-incubated with Aß. Moreover, URB597 reduced both the increase of Rho protein activation in Aß-treated BV-2 cells and the Aß-induced migration of BV-2 cells, while an increase of Cdc42 protein activation was observed in all samples. URB597 also increased the number of BV-2 cells involved in phagocytosis. URB597 treatment induced the polarization of microglial cells towards an anti-inflammatory phenotype, as demonstrated by the decreased expression of iNOS and pro-inflammatory cytokines along with the parallel increase of Arg-1 and anti-inflammatory cytokines. Taken together, these data suggest that FAAH inhibition promotes cytoskeleton reorganization, regulates phagocytosis and cell migration processes, thus driving microglial polarization towards an anti-inflammatory phenotype.
Assuntos
Amidoidrolases/antagonistas & inibidores , Benzamidas/farmacologia , Carbamatos/farmacologia , Microglia/efeitos dos fármacos , Microglia/metabolismo , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Amidoidrolases/metabolismo , Peptídeos beta-Amiloides/metabolismo , Peptídeos beta-Amiloides/farmacologia , Animais , Ácidos Araquidônicos/metabolismo , Linhagem Celular , Movimento Celular/fisiologia , Polaridade Celular/fisiologia , Citocinas/metabolismo , Citoesqueleto/metabolismo , Modelos Animais de Doenças , Endocanabinoides/metabolismo , Camundongos , Microglia/patologia , Alcamidas Poli-Insaturadas/metabolismoRESUMO
BACKGROUND: Fatty-acid amide hydrolase (FAAH) is an intracellular serine hydrolase that catalyzes the cleavage of endogenous fatty-acid amides, including the endocannabinoid anandamide (AEA). We previously reported that the peripherally restricted FAAH inhibitor URB937, which selectively increases AEA levels outside the central nervous system, reduces hyperalgesia and c-Fos expression in the trigeminal nucleus caudalis (TNC) and the locus coeruleus in an animal model of migraine based on nitroglycerin (NTG) administration. AIM: To further investigate the relevance of FAAH inhibition in the NTG animal model of migraine by testing the effects of the globally active FAAH inhibitor URB597. METHODS: Our experimental approach involved mapping neuronal c-Fos protein expression, measurement of AEA levels in brain areas and in trigeminal ganglia, evaluation of pain-related behavior and quantification of molecular mediators in rats that received URB597 (2â¯mg/kgâ¯i.p.) either before or after NTG administration (10â¯mg/kg, i.p.). RESULTS: Pre-treatment with URB597 significantly reduced c-Fos immunoreactivity in the TNC and inhibited NTG-induced hyperalgesia in the orofacial formalin test. This behavioral response was associated with a decrease in neuronal nitric oxide synthase, calcitonin gene-related peptide and cytokine gene expression levels in central and peripheral structures. Administration of URB597 after NTG had no such effect. CONCLUSIONS: The findings suggest that global FAAH inhibition may offer a therapeutic approach to the prevention, but not the abortive treatment, of migraine attacks. Further studies are needed to elucidate the exact cellular and molecular mechanisms underlying the protective effects of FAAH inhibition.
Assuntos
Amidoidrolases/antagonistas & inibidores , Benzamidas/farmacologia , Carbamatos/farmacologia , Transtornos de Enxaqueca/prevenção & controle , Núcleo Inferior Caudal do Nervo Trigêmeo/efeitos dos fármacos , Animais , Modelos Animais de Doenças , Masculino , Transtornos de Enxaqueca/induzido quimicamente , Transtornos de Enxaqueca/enzimologia , Nitroglicerina/toxicidade , Ratos , Ratos Sprague-Dawley , Vasodilatadores/toxicidadeRESUMO
Hypertension coincides with myocardial alternations in lipid (including sphingolipids) and glucose metabolism. The latest data indicate that accumulation of metabolically active lipids, especially ceramide (CER) and diacylglycerol (DAG) significantly influences intracellular signaling pathways along with inducing insulin resistance. Since, it was demonstrated that the endocannabinoid system (ECS) affects myocardial metabolism it seems to be a relevant tool in alleviating metabolic disturbances within the cardiac muscle due to hypertension. All designed experiments were conducted on the animal model of primary hypertension, i.e., spontaneously hypertensive rat (SHR) with chronic ECS activation by injections of fatty acid amide hydrolase (FAAH) inhibitor-URB597. Lipid analyses were performed using chromatography techniques (gas liquid, thin layer, and high performance liquid chromatography). Colorimetric and immunoenzymatic testes were applied in order to determine plasma concentrations of insulin and glucose. Total myocardial expression of selected proteins was measured by Western blotting and/or immunohistochemistry methods. SHRs exhibited significantly intensified myocardial de novo pathway of CER synthesis as well as DAG accumulation compared to the control Wistar Kyoto rats. Besides, intramyocardial level of potentially cardioprotective sphingolipid, i.e., sphingosine-1-phosphate was considerably decreased in SHRs, whereas URB597 treatment restored the level of this derivative. Unexpectedly, ECS upregulation protected overloaded cardiac muscle against CER and DAG accumulation. Moreover, chronic URB597 treatment improved intramyocardial insulin signaling pathways in both normotensive and hypertensive conditions. It seems that the enhanced ECS triggers protective mechanisms in the heart due to decreasing the level of lipid mediators of insulin resistance.
Assuntos
Endocanabinoides/farmacologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Animais , Biomarcadores , Glicemia/efeitos dos fármacos , Pressão Sanguínea/efeitos dos fármacos , Metabolismo Energético/efeitos dos fármacos , Glucose/metabolismo , Ventrículos do Coração/efeitos dos fármacos , Ventrículos do Coração/metabolismo , Hipertensão/etiologia , Hipertensão/metabolismo , Insulina/metabolismo , Lipídeos/sangue , Redes e Vias Metabólicas/efeitos dos fármacos , Miocárdio/metabolismo , Ratos , Ratos Endogâmicos SHRRESUMO
Hypertension is one of the most common cardiovascular diseases in the world and is associated with oxidative stress. The aim of this study was to examine the effect of the chronic administration of the fatty-acid amide hydrolase inhibitor (URB597-[3-(3-carbamoylphenyl)phenyl]N-cyclohexylcarbamate) to rats with primary (SHRs - spontaneously hypertensive rats) and secondary (DOCA-salt - 11-desoxycorticosterone acetate-salt-induced hypertension) hypertension on the composition and physicochemical properties of erythrocytes membrane. Because changes in membrane composition lead to modifications of electrical charge what may affect cell functions, the levels of following components were determined: four classes of membrane phospholipids (by HPLC - high-performance liquid chromatograph), sialic acid (by resorcinol method), lipid peroxidation product - malondialdehyde (by GCMS - gas chromatography-mass spectrometry). The reduced levels of phospholipids and sialic acid, as well as the increased levels of malonodialdehyde observed in the erythrocyte membrane of rats with primary and secondary hypertension led to a decrease in the negative electrical charge of the membrane. Long-term administration of URB597 to SHRs and DOCA-salt-treated rats partially prevented changes caused by hypertension. Using theoretical equations and the dependence of cell surface charge density as a function of pH, total surface concentrations of acid and base groups and their association constants have been determined. Considering the changes in physicochemical parameters of erythrocyte membranes, URB597 can be considered a potential protective factor for erythrocytes in situations of metabolic changes associated with oxidative stress.
Assuntos
Amidoidrolases/antagonistas & inibidores , Benzamidas/farmacologia , Carbamatos/farmacologia , Membrana Eritrocítica/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Estresse Oxidativo/efeitos dos fármacos , Animais , Modelos Animais de Doenças , Membrana Eritrocítica/química , Membrana Eritrocítica/metabolismo , Hipertensão/sangue , Hipertensão/enzimologia , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Ácido N-Acetilneuramínico/metabolismo , Ratos , Ratos Endogâmicos SHRRESUMO
Activation of cannabinoid CB1 receptors suppresses pathological pain but also produces unwanted side effects, including tolerance and physical dependence. Inhibition of fatty-acid amide hydrolase (FAAH), the major enzyme catalyzing the degradation of anandamide (AEA), an endocannabinoid, and other fatty-acid amides, suppresses pain without unwanted side effects typical of direct CB1 agonists. However, FAAH inhibitors have failed to show efficacy in several clinical trials suggesting that the right partnership of FAAH inhibition and pathology has yet to be identified. We compared efficacy of chronic treatments with a centrally penetrant FAAH inhibitor (URB597), a peripherally restricted FAAH inhibitor (URB937) and an orthosteric pan-cannabinoid agonist (WIN55,212-2) in suppressing neuropathic pain induced by the chemotherapeutic agent paclitaxel. Each FAAH inhibitor suppressed the development of paclitaxel-induced neuropathic pain and reduced the maintenance of already established allodynia with sustained efficacy. Tolerance developed to the anti-allodynic efficacy of WIN55,212-2, but not to that of URB597 or URB937, in each dosing paradigm. Challenge with the CB1 antagonist rimonabant precipitated CB1-dependent withdrawal in paclitaxel-treated mice receiving WIN55,212-2 but not URB597 or URB937. When dosing with either URB597 or URB937 was restricted to the development of neuropathy, paclitaxel-induced allodynia emerged following termination of drug delivery. These observations suggest that both FAAH inhibitors were anti-allodynic rather than curative. Moreover, neither URB597 nor URB937 impeded the ability of paclitaxel to reduce breast (4T1) or ovarian (HeyA8) tumor cell line viability. In fact, URB597 and URB937 alone reduced 4T1 tumor cell line viability, albeit with low potency, and the dose matrix of each combination with paclitaxel was synergistic in reducing 4T1 and HeyA8 tumor cell line viability according to Bliss, Highest Single Agent (HSA) and Loewe additivity models. Both FAAH inhibitors synergized with paclitaxel to reduce 4T1 and HeyA8 tumor cell line viability without reducing viability of non-tumor HEK293 cells. Neither FAAH inhibitor reduced viability of non-tumor HEK293 cells in either the presence or absence of paclitaxel, suggesting that nonspecific cytotoxic effects were not produced by the same treatments. Our results suggest that FAAH inhibitors reduce paclitaxel-induced allodynia without the occurrence of CB1-dependence in vivo and may, in fact, enhance the anti-tumor actions of paclitaxel in vitro.
Assuntos
Amidoidrolases/antagonistas & inibidores , Analgésicos/uso terapêutico , Benzamidas/uso terapêutico , Benzoxazinas/uso terapêutico , Encéfalo/metabolismo , Canabinoides/uso terapêutico , Carbamatos/uso terapêutico , Hiperalgesia/tratamento farmacológico , Morfolinas/uso terapêutico , Naftalenos/uso terapêutico , Neuralgia/tratamento farmacológico , Animais , Antineoplásicos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sinergismo Farmacológico , Tolerância a Medicamentos , Células HEK293 , Humanos , Hiperalgesia/induzido quimicamente , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neuralgia/induzido quimicamente , Paclitaxel , Transtornos Relacionados ao Uso de SubstânciasRESUMO
There is robust evidence indicating that enhancing the endocannabinoid (eCB) tone has therapeutic potential in several brain disorders. The inhibition of eCBs degradation by fatty acid amide hydrolase (FAAH) blockade, is the best-known option to increase N-acyl-ethanolamines-(NAEs)-mediated signaling. Here, we investigated the hypothesis that intranasal delivery is an effective route for different FAAH inhibitors, such as URB597 and PF-04457845. URB597 and PF-04457845 were subchronically administered in C57BL/6 male mice every other day for 20 days for overall 10 drug treatment, and compared for their ability to inhibit FAAH activity by the way of three different routes of administration: intranasal (i.n.), intraperitoneal (i.p.) and oral (p.o.). Lastly, we compared the efficacy of the three routes in terms of URB597-induced increase of NAEs levels in liver and in different brain areas. Results: We show that PF-04457845 potently inhibits FAAH regardless the route selected, and that URB597 was less effective in the brain after p.o. administration while reached similar effects by i.n. and i.p. routes. Intranasal URB597 delivery always increased NAEs levels in brain areas, whereas a parallel increase was not observed in the liver. By showing the efficacy of intranasal FAAH inhibition, we provide evidence that nose-to-brain delivery is a suitable alternative to enhance brain eCB tone for the treatment of neurodegenerative disorders and improve patients' compliance.
Assuntos
Amidoidrolases/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Amidoidrolases/metabolismo , Animais , Benzamidas/administração & dosagem , Benzamidas/farmacologia , Carbamatos/administração & dosagem , Carbamatos/farmacologia , Cerebelo/efeitos dos fármacos , Cerebelo/metabolismo , Endocanabinoides/metabolismo , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Piridazinas/administração & dosagem , Piridazinas/farmacologia , Ureia/administração & dosagem , Ureia/análogos & derivados , Ureia/farmacologiaRESUMO
The insular cortex is an important region of brain involved in the processing of pain and emotion. Recent studies indicate that lesions in the insular cortex induce pain asymbolia and reverse neuropathic pain. Endogenous cannabinoids (endocannabinoids), which have been shown to attenuate pain, are simultaneously degraded by fatty acid amide hydrolase (FAAH) that halts the mechanisms of action. Selective inhibitor URB597 suppresses FAAH activity by conserving endocannabinoids, which reduces pain. The present study examined the analgesic effects of URB597 treatment in the insular cortex of an animal model of neuropathic pain. Under pentobarbital anesthesia, male Sprague-Dawley rats were subjected to nerve injury and cannula implantation. On postoperative day 14, rodents received microinjection of URB597 into the insular cortex. In order to verify the analgesic mechanisms of URB597, cannabinoid 1 receptor (CB1R) antagonist AM251, peroxisome proliferator-activated receptor alpha (PPAR alpha) antagonist GW6471, and transient receptor potential vanilloid 1 (TRPV1) antagonist Iodoresiniferatoxin (I-RTX) were microinjected 15 min prior to URB597 injection. Changes in mechanical allodynia were measured using the von-Frey test. Expressions of CB1R, N-acyl phosphatidylethanolamine phospholipase D (NAPE-PLD), and TRPV1 significantly increased in the neuropathic pain group compared to the sham-operated control group. Mechanical threshold and expression of NAPE-PLD significantly increased in groups treated with 2 nM and 4 nM URB597 compared with the vehicle-injected group. Blockages of CB1R and PPAR alpha diminished the analgesic effects of URB597. Inhibition of TRPV1 did not effectively reduce the effects of URB597 but attenuated expression of NAPE-PLD compared with the URB597-injected group. In addition, optical imaging demonstrated that neuronal activity of the insular cortex was reduced following URB597 treatment. Our results suggest that microinjection of FAAH inhibitor into the insular cortex causes analgesic effects by decreasing neural excitability and increasing signals related to the endogenous cannabinoid pathway in the insular cortex.
Assuntos
Amidoidrolases/antagonistas & inibidores , Analgésicos/farmacologia , Córtex Cerebral/efeitos dos fármacos , Endocanabinoides/metabolismo , Neuralgia/metabolismo , Amidoidrolases/metabolismo , Animais , Ácidos Araquidônicos/metabolismo , Córtex Cerebral/lesões , Masculino , Neuralgia/fisiopatologia , Ratos Sprague-DawleyRESUMO
BACKGROUND/AIMS: Recent interest in the use of cannabinoids as therapeutic agents has revealed the involvement of the endogenous cannabinoid system (ECS) in the regulation of the cardiovascular system in hypertension. Abnormalities in glucose metabolism and insulin action are commonly detected in hypertensive animals. Thus, potential antihypertensive drugs should be investigated with respect to modulation of glucose homeostasis. Therefore, the aim of the present study was to evaluate the effects of the ECS activation after chronic fatty acid amide hydrolase inhibitor (URB597) administration on plasma glucose and insulin concentrations as well as parameters of myocardial glucose metabolism in the deoxycorticosterone acetate (DOCA)-salt hypertensive rats, an animal model of secondary hypertension. METHODS: Hypertension was induced by DOCA (25mg/kg) injections and addition of 1% NaCl in the drinking water for six weeks. Chronic activation of the ECS was performed by URB597 (1mg/kg) injections for two weeks. We examined fasting plasma levels of insulin (ELISA), glucose and intramyocardial glycogen (colorimetric method). Expressions of glucose transporters (GLUT1, 4) and selected proteins engaged in GLUT translocation as well as glucose metabolism were determined using Western blotting. RESULTS: Hypertension induced hypoinsulinemia with concomitant lack of significant changes in glycemia, reduced intramyocardial glycogen content and increased pyruvate dehydrogenase (PDH) expression in the cardiac muscle. Importantly, chronic URB597 administration in the hypertensive rats increased insulin concentration, elevated plasmalemmal GLUT1 and GLUT4 expression and concomitantly improved myocardial glycogen storage. CONCLUSION: Chronic administration of fatty acid amide hydrolase (FAAH) inhibitor has potential protective properties on myocardial glucose metabolism in hypertension.
Assuntos
Benzamidas/uso terapêutico , Carbamatos/uso terapêutico , Glucose/metabolismo , Hipertensão/patologia , Miocárdio/metabolismo , Animais , Benzamidas/farmacologia , Glicemia/análise , Carbamatos/farmacologia , Acetato de Desoxicorticosterona/toxicidade , Transportador de Glucose Tipo 1/metabolismo , Transportador de Glucose Tipo 4/metabolismo , Glicogênio/análise , Hipertensão/induzido quimicamente , Hipertensão/tratamento farmacológico , Insulina/sangue , Cetona Oxirredutases/metabolismo , Masculino , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Miocárdio/patologia , Fosforilação/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Ratos WistarRESUMO
The interaction between the endocannabinoid and ROS signaling systems has been demonstrated in different organs. Inhibitors of fatty acid amide hydrolase (FAAH), the key enzyme responsible for degradation of the endocannabinoid anandamide, are postulated to possess anti-hypertensive potential. Here, we compared the effects of hypertension and chronic FAAH inhibition by URB597 on the endocannabinoid system and redox balance in spontaneously hypertensive rats (SHR) and hypertensive deoxycorticosterone acetate (DOCA)-salt rats. Enhanced oxidative stress and lipid peroxidation were found in both hypertension models. Hypertension affected cardiac and plasma endocannabinoid systems in a model-dependent manner: anandamide and 2-arachidonoylglycerol levels decreased in SHR and increased in DOCA-salt. Cardiac CB1 receptor expression increased in both models while higher CB2 receptor expression was only in DOCA-salt. URB597 increased endocannabinoid levels in both models but produced the partial reduction of oxidative stress in DOCA-salt but not in SHR. Notably, URB597 decreased antioxidant defense and increased lipid peroxidation products in normotension. Therefore, the therapeutic potential of FAAH inhibitors should be interpreted cautiously.
Assuntos
Endocanabinoides/metabolismo , Coração/fisiopatologia , Hipertensão/fisiopatologia , Miocárdio/metabolismo , Amidoidrolases/antagonistas & inibidores , Amidoidrolases/metabolismo , Animais , Ácidos Araquidônicos/metabolismo , Benzamidas/farmacologia , Carbamatos/farmacologia , Acetato de Desoxicorticosterona , Endocanabinoides/sangue , Glicerídeos/metabolismo , Hipertensão/induzido quimicamente , Hipertensão/genética , Masculino , Oxirredução/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Alcamidas Poli-Insaturadas/metabolismo , Ratos Endogâmicos SHR , Ratos Wistar , Receptor CB1 de Canabinoide/metabolismo , Receptor CB2 de Canabinoide/metabolismoRESUMO
Fatty acid amide hydrolase (FAAH) inhibitor [3-(3-carbamoylphenyl)phenyl] N-cyclohexylcarbamate (URB597) may influence redox balance and blood pressure through the modulation of endocannabinoids levels. Therefore, this study aimed to compare changes in oxidative metabolism and apoptosis in the hearts of rats with spontaneous hypertension (SHR) and secondary hypertension (11-deoxycorticosterone acetate; DOCA-salt rats) treated by URB597 via intraperitoneal injection for 14 days. The results showed that URB597 decreased the activity of NADPH and xanthine oxidases in both groups of rats. Moreover, in the heart of SHR rats, URB597 led to an increase of enzymatic and nonenzymatic antioxidant activity and levels (catalase, vitamin C, glutathione/glutathione disulfide [GSH/GSSG]) and upregulation of the thioredoxin system; however, NRf2 expression was downregulated. The opposite effect in relation to Nrf2 activity and the thioredoxin system was observed in DOCA-salt rats after URB597 administration. Despite improvement in antioxidant parameters, URB597 enhanced oxidative modifications of phospholipids (4-hydroxynonenal and isoprostanes) and proteins (carbonyl groups) in SHR heart, whereas 4-hydroxynonenal and carbonyl groups levels decreased in the heart of DOCA-salt rats. Obtained results suggest that examined lipid mediators are involved in peroxisome proliferator-activated receptors (PPAR)-independent and PPAR-dependent modulation of cardiac inflammatory reactions. Furthermore, decreased expression of pro-apoptotic proteins (Bax and caspase 3 and 9) was observed after URB597 administration in the heart of both groups of hypertensive rats, whereas expression of the antiapoptotic protein (Bcl-2) increased in SHR rats. Long-term administration of URB597 altered cardiac redox status depending on the type of hypertension. URB597 enhanced oxidative metabolism and reduced pro-apoptotic factors in the heart of SHR rats, increasing the probability of heart metabolic disorders occurrence or progression.
Assuntos
Amidoidrolases/metabolismo , Benzamidas/administração & dosagem , Carbamatos/administração & dosagem , Coração/efeitos dos fármacos , Hipertensão/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Xantina Oxidase/metabolismo , Animais , Benzamidas/farmacologia , Carbamatos/farmacologia , Acetato de Desoxicorticosterona/efeitos adversos , Modelos Animais de Doenças , Regulação da Expressão Gênica/efeitos dos fármacos , Hipertensão/induzido quimicamente , Hipertensão/classificação , Injeções Intraperitoneais , Masculino , Fator 2 Relacionado a NF-E2 , RatosRESUMO
Exposure to excessive or uncontrolled stress is a major factor associated with various diseases including posttraumatic stress disorder (PTSD). The consequences of exposure to trauma are affected not only by aspects of the event itself, but also by the frequency and severity of trauma reminders. It was suggested that in PTSD, hippocampal-dependent memory is compromised while amygdala-dependent memory is strengthened. Several lines of evidence support the role of the endocannabinoid (eCB) system as a modulator of the stress response. In this study we aimed to examine cannabinoids modulation of the long-term effects (i.e., 1 month) of exposure to a traumatic event on memory and plasticity in the hippocampus and amygdala. Following exposure to the shock and reminders model of PTSD in an inhibitory avoidance light-dark apparatus rats demonstrated: (i) enhanced fear retrieval and impaired inhibitory extinction (Ext), (ii) no long-term potentiation (LTP) in the CA1, (iii) impaired hippocampal-dependent short-term memory in the object location task, (iv) enhanced LTP in the amygdala, and (v) enhanced amygdala-dependent conditioned taste aversion memory. The cannabinoid CB1/2 receptor agonist WIN55-212,2 (0.5mg/kg, i.p.) and the fatty acid amide hydrolase (FAAH) inhibitor URB597 (0.3mg/kg, i.p.), administered 2 hr after shock exposure prevented these opposing effects on hippocampal- and amygdala-dependent processes. Moreover, the effects of WIN55-212,2 and URB597 on Ext and acoustic startle were prevented by co-administration of a low dose of the CB1 receptor antagonist AM251 (0.5mg/kg, i.p.), suggesting that the preventing effects of both drugs are mediated by CB1 receptors. Exposure to shock and reminders increased CB1 receptor levels in the CA1 and basolateral amygdala 1 month after shock exposure and this increase was also prevented by administering WIN55-212,2 or URB597. Taken together, these findings suggest the involvement of the eCB system, and specifically CB1 receptors, in the opposite effects of severe stress on memory and plasticity in the hippocampus and amygdala.
Assuntos
Tonsila do Cerebelo/efeitos dos fármacos , Bromo/farmacologia , Canabinoides/farmacologia , Glutamatos/farmacologia , Hipocampo/efeitos dos fármacos , Magnésio/farmacologia , Receptores de Canabinoides/metabolismo , Transtornos de Estresse Pós-Traumáticos/tratamento farmacológico , Amidoidrolases/antagonistas & inibidores , Amidoidrolases/metabolismo , Tonsila do Cerebelo/patologia , Tonsila do Cerebelo/fisiopatologia , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Aprendizagem da Esquiva/fisiologia , Benzamidas/farmacologia , Benzoxazinas/farmacologia , Moduladores de Receptores de Canabinoides/farmacologia , Carbamatos/farmacologia , Modelos Animais de Doenças , Combinação de Medicamentos , Eletrochoque , Inibidores Enzimáticos/farmacologia , Medo/efeitos dos fármacos , Medo/fisiologia , Hipocampo/patologia , Hipocampo/fisiopatologia , Masculino , Memória/efeitos dos fármacos , Memória/fisiologia , Morfolinas/farmacologia , Naftalenos/farmacologia , Plasticidade Neuronal/efeitos dos fármacos , Plasticidade Neuronal/fisiologia , Piperidinas/farmacologia , Pirazóis/farmacologia , Ratos Sprague-Dawley , Transtornos de Estresse Pós-Traumáticos/patologia , Transtornos de Estresse Pós-Traumáticos/fisiopatologia , Transtornos de Estresse Pós-Traumáticos/psicologiaRESUMO
This study describes the potential of solid lipid nanoparticles and nanostructured lipid carriers as nano-formulations to administer to the central nervous system poorly water soluble drugs. Different neuroactive drugs, i.e. dimethylfumarate, retinyl palmitate, progesterone and the endocannabinoid hydrolysis inhibitor URB597 have been studied. Lipid nanoparticles constituted of tristearin or tristearin in association with gliceryl monoolein were produced. The nanoencapsulation strategy allowed to obtain biocompatible and non-toxic vehicles, able to increase the solubility of the considered neuroactive drugs. To improve URB597 targeting to the brain, stealth nanoparticles were produced modifying the SLN surface with polysorbate 80. A behavioural study was conducted in rats to test the ability of SLN containing URB597 given by intranasal administration to alter behaviours relevant to psychiatric disorders. URB597 maintained its activity after nanoencapsulation, suggesting the possibility to propose this kind of vehicle as alternative to unphysiological mixtures usually employed for animal and clinical studies.