RESUMEN
Metabotropic glutamate receptor 7 (mGlu(7)) has been suggested to be a promising novel target for treatment of a range of disorders, including anxiety, post-traumatic stress disorder, depression, drug abuse, and schizophrenia. Here we characterized a potent and selective mGlu(7) negative allosteric modulator (NAM) (+)-6-(2,4-dimethylphenyl)-2-ethyl-6,7-dihydrobenzo[d]oxazol-4(5H)-one (ADX71743). In vitro, Schild plot analysis and reversibility tests at the target confirmed the NAM properties of the compound and attenuation of L-(+)-2-amino-4-phosphonobutyric acid-induced synaptic depression confirmed activity at the native receptor. The pharmacokinetic analysis of ADX71743 in mice and rats revealed that it is bioavailable after s.c. administration and is brain penetrant (cerebrospinal fluid concentration/total plasma concentration ratio at C(max) = 5.3%). In vivo, ADX71743 (50, 100, 150 mg/kg, s.c.) caused no impairment of locomotor activity in rats and mice or activity on rotarod in mice. ADX71743 had an anxiolytic-like profile in the marble burying and elevated plus maze tests, dose-dependently reducing the number of buried marbles and increasing open arm exploration, respectively. Whereas ADX71743 caused a small reduction in amphetamine-induced hyperactivity in mice, it was inactive in the mouse 2,5-dimethoxy-4-iodoamphetamine-induced head twitch and the rat conditioned avoidance response tests. In addition, the compound was inactive in the mouse forced swim test. These data suggest that ADX71743 is a suitable compound to help unravel the physiologic role of mGlu(7) and to better understand its implication in central nervous system diseases. Our in vivo tests using ADX71743, reported here, suggest that pharmacological inhibition of mGlu(7) is a valid approach for developing novel pharmacotherapies to treat anxiety disorders, but may not be suitable for treatment of depression or psychosis.
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Conducta Animal/efectos de los fármacos , Oxazolona/farmacología , Receptores de Glutamato Metabotrópico/metabolismo , Regulación Alostérica , Anfetamina/farmacología , Animales , Trastornos de Ansiedad/tratamiento farmacológico , Trastornos de Ansiedad/metabolismo , Línea Celular , Emparejamiento Cromosómico/efectos de los fármacos , Trastorno Depresivo/tratamiento farmacológico , Trastorno Depresivo/metabolismo , Femenino , Células HEK293 , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Actividad Motora/efectos de los fármacos , Oxazolona/farmacocinética , Unión Proteica/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Proteínas Recombinantes/farmacologíaRESUMEN
Modulation of the metabotropic glutamate type 2 (mGlu2) receptor is considered a promising target for the treatment of central nervous system diseases such as schizophrenia. Here, we describe the pharmacological properties of the novel mGlu2 receptor positive allosteric modulator (PAM) 3-cyano-1-cyclopropylmethyl-4-(4-phenyl-piperidin-1-yl)-pyridine-2(1H)-one (JNJ-40068782) and its radioligand [(3)H]JNJ-40068782. In guanosine 5'-O-(3-[(35)S]thio)triphosphate binding, JNJ-40068782 produced a leftward and upward shift in the glutamate concentration-effect curve at human recombinant mGlu2 receptors. The EC50 of JNJ-40068782 for potentiation of an EC20-equivalent concentration of glutamate was 143 nM. Although JNJ-40068782 did not affect binding of the orthosteric antagonist [(3)H]2S-2-amino-2-(1S,2S-2-carboxycyclopropyl-1-yl)-3-(xanth-9-yl)propanoic acid (LY-341495), it did potentiate the binding of the agonist [(3)H](2S,2'R,3'R)-2-(2',3'-dicarboxylcyclopropyl)glycine (DCG-IV), demonstrating that it can allosterically affect binding at the agonist recognition site. The binding of [(3)H]JNJ-40068782 to human recombinant mGlu2 receptors in Chinese hamster ovary cells and rat brain receptors was saturable with a KD of â¼10 nM. In rat brain, the anatomic distribution of [(3)H]JNJ-40068782 was consistent with mGlu2 expression previously described and was most abundant in cortex and hippocampus. The ability of structurally unrelated PAMs to displace [(3)H]JNJ-40068782 suggests that PAMs may bind to common determinants within the same site. It is noteworthy that agonists also increased the binding affinity of [(3)H]JNJ-40068782. JNJ-40068782 influenced rat sleep-wake organization by decreasing rapid eye movement sleep with a lowest active dose of 3 mg/kg PO. In mice, JNJ-40068782 reversed phencyclidine-induced hyperlocomotion with an ED50 of 5.7 mg/kg s.c. Collectively, the present data demonstrate that JNJ-40068782 has utility in investigating the potential of mGlu2 modulation for the treatment of diseases characterized by disturbed glutamatergic signaling and highlight the value of [(3)H]JNJ-40068782 in exploring allosteric binding.
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Fármacos actuantes sobre Aminoácidos Excitadores/farmacología , Piperidinas/farmacología , Piridonas/farmacología , Receptores de Glutamato Metabotrópico/efectos de los fármacos , Aminoácidos/metabolismo , Animales , Autorradiografía , Unión Competitiva/efectos de los fármacos , Química Encefálica , Células CHO , Calcio/metabolismo , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Corteza Cerebral/efectos de los fármacos , Corteza Cerebral/metabolismo , Cricetinae , Cricetulus , Ciclopropanos/metabolismo , Agonistas de Aminoácidos Excitadores/metabolismo , Glicina/análogos & derivados , Glicina/metabolismo , Guanosina 5'-O-(3-Tiotrifosfato)/metabolismo , Humanos , Marcaje Isotópico , Ligandos , Masculino , Ratones , Actividad Motora/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Sueño/efectos de los fármacos , Tritio , Xantenos/metabolismoRESUMEN
Allosteric modulators (AMs) are a promising avenue towards safe and selective drugs. AMs can interact selectively with unique domains distinct from the endogenous ligand binding site of receptors, up- or downregulating the response to receptor activation. Emphasis is placed in this article on the latest development in high-sensitivity technologies designed to identify AMs of G-protein coupled receptors. In addition to new pharmacological approaches, encouraging results in the crystal resolution of these targets enable use of more rational approaches to identification and optimization of AMs.
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Descubrimiento de Drogas , Receptores Acoplados a Proteínas G/metabolismo , Regulación Alostérica , Animales , Receptores Acoplados a Proteínas G/químicaRESUMEN
Opioid abuse and overdose have risen to epidemic proportions in the United States. Oxycodone is the most abused prescription opioid. Treatments for opioid use disorder (OUD) seek to reduce vulnerability to relapse by reducing sources of reinforcement to seek drug (i.e., acute drug effects or drug withdrawal/craving). Accumulating evidence that glutamate release elicits drug-seeking behaviors has generated interest in pharmacotherapies targeting the glutamate system. Agonists and positive allosteric modulators of the metabotropic glutamate 2 (mGlu2) receptor decrease glutamate activity, reducing drug taking and seeking. The present study tested whether the mGlu2 receptor positive allosteric modulator ADX106772 reduces oxycodone self-administration and the conditioned reinstatement of oxycodone seeking without affecting behaviors directed toward a highly palatable nondrug reinforcer (sweetened condensed milk). Male Wistar rats were trained to self-administer oxycodone (0.15 mg/kg/infusion, i.v., 12 h/day) or sweetened condensed milk (SCM; diluted 2:1 v/v in H2O, orally, 30 min/day) for 13 days in the presence of a contextual/discriminative stimulus (SD), and the ability of ADX106772 (0, 0.3, 1, 3 and-10 mg/kg, s. c.) to decrease self-administration was tested. The rats then underwent extinction training, during which oxycodone, SCM, and the SD were withheld. After extinction, the ability of ADX106772 to prevent SD-induced conditioned reinstatement of oxycodone and SCM seeking was tested. ADX106772 reduced oxycodone self-administration and conditioned reinstatement without affecting SCM self-administration or conditioned reinstatement. ADX106772 reduced oxycodone taking and seeking and did not affect the motivation for the palatable conventional reinforcer, SCM, suggesting that activating mGlu2 receptors with a positive allosteric modulator is a potential approach for prescription OUD treatment.
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Trastornos Relacionados con Opioides , Receptores de Glutamato Metabotrópico , Ratas , Masculino , Animales , Ratas Wistar , Oxicodona/farmacología , Refuerzo en Psicología , Analgésicos Opioides/farmacología , Trastornos Relacionados con Opioides/tratamiento farmacológico , Autoadministración , Extinción Psicológica , Comportamiento de Búsqueda de DrogasRESUMEN
Parkinson's disease (PD) patients suffer not only from the primary motor symptoms of the disease but also from a range of non-motor symptoms (NMS) that cause disability and low quality of life. Excessive glutamate activity in the basal ganglia resulting from degeneration of the nigrostriatal dopamine pathway has been implicated in the motor symptoms, NMS and dyskinesias in PD patients. In this study, we investigated the effects of a selective mGlu5 negative allosteric modulator (NAM), dipraglurant, in a rodent motor symptoms model of PD, but also in models of anxiety, depression and obsessive-compulsive disorder, all of which are among the most prevalent NMS symptoms. Dipraglurant is rapidly absorbed after oral administration, readily crosses the blood-brain barrier, and exhibits a high correlation between plasma concentration and efficacy in behavioral models. In vivo, dipraglurant dose-dependently reduced haloperidol-induced catalepsy, increased punished licks in the Vogel conflict-drinking model, decreased immobility time in the forced swim test, decreased the number of buried marbles in the marble-burying test, but had no effect on rotarod performance or locomotor activity. These findings suggest that dipraglurant may have benefits to address some of the highly problematic comorbid non-motor symptoms of PD, in addition to its antidyskinetic effect demonstrated in PD-LID patients.
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Enfermedad de Parkinson , Humanos , Enfermedad de Parkinson/tratamiento farmacológico , Calidad de Vida , Piridinas/farmacología , Imidazoles/farmacologíaRESUMEN
Activation of G-protein-coupled receptors (GPCRs) results in a variety of cellular responses, such as binding to the same receptor of different ligands that activate distinct downstream cascades. Additional signaling complexity is achieved when two or more receptors are integrated into one signaling unit. Lateral receptor interactions can allosterically modulate the receptor response to a ligand, which creates a mechanism for tissue-specific fine tuning, depending on the cellular receptor coexpression pattern. GPCR homomers or heteromers have been explored widely for GPCR classes A and C but to lesser extent for class B. In the present study, we used bioluminescence resonance energy transfer (BRET) techniques, calcium flux measurements, and microscopy to study receptor interactions within the glucagon receptor family. We found basal BRET interactions for some of the receptor combinations tested that decreased upon ligand binding. A BRET increase was observed exclusively for the gastric inhibitory peptide (GIP) receptor and the glucagon-like peptide 1 (GLP-1) receptor upon binding of GLP-1 that could be reversed with GIP addition. The interactions of GLP-1 receptor and GIP receptor were characterized with BRET donor saturation studies, shift experiments, and tests of glucagon-like ligands. The heteromer displayed specific pharmacological characteristics with respect to GLP-1-induced ß-arrestin recruitment and calcium flux, which suggests a form of allosteric regulation between the receptors. This study provides the first example of ligand-induced heteromer formation in GPCR class B. In the body, the receptors are functionally related and coexpressed in the same cells. The physiological evidence for this heteromerization remains to be determined.
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Péptido 1 Similar al Glucagón/farmacología , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Glucagón/metabolismo , Regulación Alostérica , Secuencia de Aminoácidos , Línea Celular , Endocitosis , Transferencia de Energía , Péptido 1 Similar al Glucagón/química , Humanos , Datos de Secuencia Molecular , Homología de Secuencia de AminoácidoRESUMEN
A series of N-propyl-8-chloro-6-substituted isoquinolones was identified as positive allosteric modulators of metabotropic glutamate receptor 2 (mGluR2 PAM) via high throughput screening (HTS). The subsequent synthesis and initial SAR exploration that led to the identification of compound 28 is described.
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Piridinas/síntesis química , Quinolonas/química , Receptores de Glutamato Metabotrópico/química , Regulación Alostérica , Ensayos Analíticos de Alto Rendimiento , Humanos , Microsomas Hepáticos/metabolismo , Piridinas/química , Piridinas/farmacología , Quinolonas/síntesis química , Quinolonas/farmacología , Receptores de Glutamato Metabotrópico/metabolismo , Relación Estructura-ActividadRESUMEN
Intermittent models of alcohol exposure that mimic human patterns of alcohol consumption produce profound physiological and biochemical changes and induce rapid increases in alcohol self-administration. We used high-density oligonucleotide microarrays to investigate gene expression changes during chronic intermittent alcohol exposure in three brain regions that receive mesocorticolimbic dopaminergic projections and that are believed to be involved in alcohol's reinforcing actions: the medial prefrontal cortex, the nucleus accumbens and the amygdala. An independent replication of the experiment was used for RT-PCR validation of the microarray results. The protein kinase A inhibitor alpha (PKI-alpha, Pkia), a member of the endogenous PKI family implicated in reducing nuclear PKA activity, was found to be increased in all three regions tested. Conversely, we observed a downregulation of the expression of several PKA-regulated transcripts in one or more of the brain regions studied, including the activity and neurotransmitter-regulated early gene (Ania) - 1, -3, -7, -8, the transcription factors Egr1 and NGFI-B (Nr4a1) and the neuropeptide NPY. Reduced expression of PKA-regulated genes in mesocorticolimbic projection areas may have motivational significance in the rapid increase in alcohol self-administration induced by intermittent alcohol exposure.
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Encéfalo/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico/fisiología , Etanol/administración & dosificación , Regulación de la Expresión Génica/efectos de los fármacos , Regulación de la Expresión Génica/fisiología , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Amígdala del Cerebelo/metabolismo , Animales , Encéfalo/efectos de los fármacos , Proteínas Portadoras/genética , Células Cultivadas , Esquema de Medicación , Proteína 1 de la Respuesta de Crecimiento Precoz/genética , Etanol/farmacología , Expresión Génica/efectos de los fármacos , Proteínas de Andamiaje Homer , Proteínas Inmediatas-Precoces/genética , Masculino , Factor de Crecimiento Nervioso/genética , Neuropéptido Y/genética , Núcleo Accumbens/metabolismo , Análisis de Secuencia por Matrices de Oligonucleótidos , Corteza Prefrontal/metabolismo , Isoformas de Proteínas/metabolismo , ARN Mensajero/antagonistas & inhibidores , Ratas , Ratas WistarRESUMEN
The activation or the inhibition of G-protein coupled receptors (GPCRs) implicated in the pathophysiology of neurodegenerative disorders is considered as a relevant approach for the treatment of these diseases. The modulation of the relevant GPCRs targets by positive or by negative allosteric modulators appears to be promising, the major challenge remaining the discovery of these molecules. In this review, we highlight the recent development in this field and the therapeutic potential of selected GPCRs allosteric modulators.
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Diseño de Fármacos , Enfermedades Neurodegenerativas/tratamiento farmacológico , Receptores Acoplados a Proteínas G/efectos de los fármacos , Regulación Alostérica/efectos de los fármacos , Animales , Descubrimiento de Drogas/métodos , Humanos , Ligandos , Enfermedades Neurodegenerativas/fisiopatología , Receptores Acoplados a Proteínas G/metabolismoRESUMEN
Positive allosteric modulation of the GABAB receptor is a promising alternative to direct activation of the receptor as a therapeutic approach for treatment of addiction, chronic pain, anxiety, epilepsy, autism, Fragile X syndrome, and psychosis. Here we describe in vitro and in vivo characterization of a novel, potent and selective GABAB positive allosteric modulator (PAM) N-(5-(4-(4-chloro-3-fluorobenzyl)-6-methoxy-3,5-dioxo-4,5-dihydro-1,2,4-triazin-2(3H)-yl)-2-fluorophenyl)acetamide (ADX71441). In vitro, Schild plot and reversibility tests at the target confirmed PAM properties of the compound. In mice and rats ADX71441 is bioavailable after oral administration and is brain penetrant. A single dose of ADX71441 had an anxiolytic-like profile in the mouse marble burying test (minimum effective dose; MED 3 mg/kg) as well as in the elevated plus maze test in mice and rats (both MED 3 mg/kg). Also, in mice, acute administration of ADX71441 reduced visceral pain-associated behaviors in the acetic acid-induced writhing test. ADX71441 dose-dependently reduced time on rotarod in rats (MED 10 mg/kg) indicative of muscle-relaxant qualities. ADX71441 reduced locomotor activity in mice (10 mg/kg) and rats (3 mg/kg) after single dose; however, following sub-chronic administration in mice, 30 mg/kg ADX71441 was associated with normal locomotor activity. While acute administration of ADX71441 reduced body temperature in rats and mice (both MED 10 mg/kg), the effect in the former was transient, rapidly returning to normal levels despite high concentrations of the compound remaining in plasma. Thus, the GABAB PAM ADX71441 represents a valid therapeutic approach for development of novel treatment of anxiety, pain and spasticity.
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Analgésicos/farmacología , Ansiolíticos/farmacología , Ansiedad/tratamiento farmacológico , Proteínas Bacterianas/farmacología , Espasticidad Muscular/tratamiento farmacológico , Dolor/tratamiento farmacológico , Receptores de GABA-B/efectos de los fármacos , Factores de Transcripción/farmacología , Acetamidas , Animales , Proteínas Bacterianas/uso terapéutico , Guanosina 5'-O-(3-Tiotrifosfato)/metabolismo , Células HEK293 , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Actividad Motora/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Receptores de GABA-B/metabolismo , Prueba de Desempeño de Rotación con Aceleración Constante , Factores de Transcripción/uso terapéutico , TriazinasRESUMEN
Several signal transduction pathways have been implicated in the induction of long-term potentiation (LTP), yet the signal transduction mechanisms behind the maintenance-expression phase of LTP are still poorly understood. We investigated the role of phosphatidylinositol 3-kinase (PI3-kinase) in LTP at Schaffer collateral/commissural fiber-CA1 synapses in rat hippocampal slices using biochemical approaches and extracellular electrophysiological recordings. We observed that PI3-kinase activity was induced in the CA1 region during LTP of field EPSPs (fEPSPs) and that two structurally unrelated PI3-kinase inhibitors, LY294002 and wortmannin, abated established LTP, suggesting that PI3-kinase is involved in the maintenance-expression phase of LTP. However, LTP recovered after washout of the reversible PI3-kinase inhibitor LY294002, confirming that LTP maintenance and expression are distinct events and indicating that PI3-kinase activity is required for LTP expression rather than for its maintenance. Interestingly, preincubation with LY294002 did not prevent LTP induction. In fact, if LY294002 was withdrawn 5 min after high-frequency stimulation, an LTP of fEPSP was seen. Last, a voltage-dependent calcium channel-dependent form of LTP in the CA1 could also be reversibly abated by LY294002, raising the possibility that PI3-kinase could be required for the expression of multiple forms of synaptic potentiation.
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Hipocampo/fisiología , Potenciación a Largo Plazo/fisiología , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas , Transducción de Señal/fisiología , Androstadienos/farmacología , Animales , Bloqueadores de los Canales de Calcio/farmacología , Canales de Calcio/efectos de los fármacos , Canales de Calcio/metabolismo , Cromonas/farmacología , Estimulación Eléctrica , Activación Enzimática/efectos de los fármacos , Activación Enzimática/fisiología , Inhibidores Enzimáticos/farmacología , Antagonistas de Aminoácidos Excitadores/farmacología , Potenciales Postsinápticos Excitadores/efectos de los fármacos , Potenciales Postsinápticos Excitadores/fisiología , Antagonistas del GABA/farmacología , Hipocampo/citología , Hipocampo/efectos de los fármacos , Técnicas In Vitro , Potenciación a Largo Plazo/efectos de los fármacos , Morfolinas/farmacología , Inhibidores de las Quinasa Fosfoinosítidos-3 , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas c-akt , Ratas , Ratas Wistar , Proteínas Quinasas S6 Ribosómicas/metabolismo , Sinapsis/metabolismo , WortmaninaRESUMEN
Compounds modulating metabotropic glutamate type 2 (mGlu2) receptor activity may have therapeutic benefits in treating psychiatric disorders like schizophrenia and anxiety. The pharmacological and pharmacokinetic properties of a novel mGlu2 receptor-positive allosteric modulator (PAM), 1-butyl-3-chloro-4-(4-phenyl-1-piperidinyl)-2(1H)-pyridinone (JNJ-40411813/ADX71149) are described here. JNJ-40411813 acts as a PAM at the cloned mGlu2 receptor: EC50 = 147 ± 42 nmol/L in a [(35)S]GTPγS binding assay with human metabotropic glutamate type 2 (hmGlu2) CHO cells and EC50 = 64 ± 29 nmol/L in a Ca(2+) mobilization assay with hmGlu2 G α16 cotransfected HEK293 cells. [(35)S]GTPγS autoradiography on rat brain slices confirmed PAM activity of JNJ-40411813 on native mGlu2 receptor. JNJ-40411813 displaced [(3)H]JNJ-40068782 and [(3)H]JNJ-46281222 (mGlu2 receptor PAMs), while it failed to displace [(3)H]LY341495 (a competitive mGlu2/3 receptor antagonist). In rats, JNJ-40411813 showed ex vivo mGlu2 receptor occupancy using [(3)H]JNJ-46281222 with ED50 of 16 mg/kg (p.o.). PK-PD modeling using the same radioligand resulted in an EC50 of 1032 ng/mL. While JNJ-40411813 demonstrated moderate affinity for human 5HT2A receptor in vitro (K b = 1.1 µmol/L), higher than expected 5HT2A occupancy was observed in vivo (in rats, ED50 = 17 mg/kg p.o.) due to a metabolite. JNJ-40411813 dose dependently suppressed REM sleep (LAD, 3 mg/kg p.o.), and promoted and consolidated deep sleep. In fed rats, JNJ-40411813 (10 mg/kg p.o.) was rapidly absorbed (C max 938 ng/mL at 0.5 h) with an absolute oral bioavailability of 31%. Collectively, our data show that JNJ-40411813 is an interesting candidate to explore the therapeutic potential of mGlu2 PAMs, in in vivo rodents experiments as well as in clinical studies.
RESUMEN
JNJ-40411813/ADX71149 (1-butyl-3-chloro-4-(4-phenylpiperidin-1-yl) pyridin-2(1H)-one) is a positive allosteric modulator (PAM) of the mGlu2 receptor, which also displays 5-Hydroxytryptamine (5HT2A) antagonism after administration in rodents due to a rodent-specific metabolite. JNJ-40411813 was compared with the orthosteric mGlu2/3 agonist LY404039 (4-amino-2-thiabicyclo [3.1.0] hexane-4,6-dicarboxylic acid 2,2-dioxide), the selective mGlu2 PAM JNJ-42153605 (3-(cyclopropylmethyl)-7-(4-phenylpiperidin-1-yl)-8-(trifluoromethyl)[1,2,4]triazolo[4,3-a]pyridine) and the 5HT2A antagonist ritanserin in rodent models for antipsychotic activity and potential side effects, attempting to differentiate between the various compounds and mechanisms of action. In mice, JNJ-40411813, JNJ-42153605, and LY404039 inhibited spontaneous locomotion and phencyclidine- and scopolamine-induced but not d-amphetamine-induced hyperlocomotion; the 5HT2A antagonist ritanserin inhibited only spontaneous locomotion and phencyclidine-induced hyperlocomotion. As measured by 2-deoxyglucose uptake, all compounds reversed memantine-induced brain activation in mice. The two mGlu2 PAMs and LY404039, but not ritanserin, inhibited conditioned avoidance behavior in rats. Like ritanserin, the mGlu2 ligands antagonized 2,5-dimethoxy-4-methylamphetamine-induced head twitches in rats. LY404039 but not the mGlu2 PAMs impaired rotarod performance in rats and increased the acoustic startle response in mice. Our results show that although 5HT2A antagonism has effect in some models, mGlu2 receptor activation is sufficient for activity in several animal models of antipsychotic activity. The mGlu2 PAMs mimicked the in vivo pharmacodynamic effects observed with LY404039 except for effects on the rotarod and acoustic startle, suggesting that they produce a primary activity profile similar to that of the mGlu2/3 receptor agonist while they can be differentiated based on their secondary activity profile. The results are discussed in light of clinical data available for some of these molecules, in particular JNJ-40411813.
RESUMEN
BACKGROUND: To examine whether metabotropic glutamate (mGlu) receptors have any role in mechanisms that shape neuronal vulnerability to ischemic damage, we used the 4-vessel occlusion (4-VO) model of transient global ischemia in rats. 4-VO in rats causes a selective death of pyramidal neurons in the hippocampal CA1 region, leaving neurons of the CA3 region relatively spared. We wondered whether changes in the expression of individual mGlu receptor subtypes selectively occur in the vulnerable CA1 region during the development of ischemic damage, and whether post-ischemic treatment with drugs targeting the selected receptor(s) affords neuroprotection. RESULTS: We found that 4-VO caused significantly reduction in the transcript of mGlu2 receptors in the CA1 region at times that preceded the anatomical evidence of neuronal death. Down-regulation of mGlu2 receptors was associated with reduced H3 histone acetylation at the Grm2 promoter. The transcripts of other mGlu receptor subtypes were unchanged in the CA1 region of 4-VO rats. Ischemia did not cause changes in mGlu2 receptor mRNA levels in the resistant CA3 region, which, interestingly, were lower than in the CA1 region. Targeting the mGlu2 receptors with selective pharmacologic ligands had profound effects on ishemic neuronal damage. Post-ischemic oral treatment with the selective mGlu2 receptor NAM (negative allosteric modulator), ADX92639 (30 mg/kg), was highly protective against ischemic neuronal death. In contrast, s.c. administration of the mGlu2 receptor enhancer, LY487379 (30 mg/kg), amplified neuronal damage in the CA1 region and extended the damage to the CA3 region. CONCLUSION: These findings suggest that the mGlu2 receptor is an important player in mechanisms regulating neuronal vulnerability to ischemic damage, and that mGlu2 receptor NAMs are potential candidates in the experimental treatments of disorders characterized by brain hypoperfusion, such as hypovolemic shock and cardiac arrest.
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Isquemia Encefálica/patología , Hipocampo/patología , Neuronas/patología , Neuroprotección , Receptores de Glutamato Metabotrópico/metabolismo , Acetilación/efectos de los fármacos , Regulación Alostérica/efectos de los fármacos , Animales , Temperatura Corporal/efectos de los fármacos , Isquemia Encefálica/metabolismo , Región CA1 Hipocampal/efectos de los fármacos , Región CA1 Hipocampal/patología , Región CA3 Hipocampal/efectos de los fármacos , Región CA3 Hipocampal/patología , Muerte Celular/efectos de los fármacos , Regulación hacia Abajo/efectos de los fármacos , Regulación hacia Abajo/genética , Epigénesis Genética/efectos de los fármacos , Perfilación de la Expresión Génica , Hipocampo/efectos de los fármacos , Histona Desacetilasa 2/metabolismo , Histonas/metabolismo , Ligandos , Masculino , Terapia Molecular Dirigida , Neuronas/efectos de los fármacos , Neuroprotección/efectos de los fármacos , Regiones Promotoras Genéticas/genética , Piridinas/farmacología , Ratas Sprague-Dawley , Receptores de Glutamato Metabotrópico/genética , Sulfonamidas/farmacología , Factores de Tiempo , Regulación hacia Arriba/genéticaRESUMEN
The extracellular signal regulated protein kinases (ERKs), also known as mitogen-activated protein kinases (MAPK) of 42 and 44 kd, play a crucial role in the induction of various forms of neural plasticity. Ethanol induces long-lasting functional changes that are more severe following repeated exposure and may involve intracellular signal transduction mechanisms. Therefore, we investigated the regulation of the ERK signal transduction pathway in models of continuous and intermittent ethanol exposure and withdrawal. Moderate blood alcohol levels (BALs) reduced ERK activation in most of the brain regions studied. Conversely, during withdrawal, activation of ERK was increased in most areas with some regional variations in the levels and kinetics of induction. The most dramatic effects were observed in the amygdala, the cerebellum, the striatum and the hippocampus. In the amygdala and the cerebellum, the activation of ERK observed during withdrawal was significantly higher after intermittent ethanol exposure than after continuous exposure, suggesting the establishment of a form of sensitization to the effects of withdrawal on ERK regulation. Thus the dysregulation of the ERK pathway could contribute to escalation of withdrawal symptoms induced by repeated withdrawal and possibly to the neuroadaptative changes believed to underlie progression towards addiction.
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Trastornos Relacionados con Alcohol/enzimología , Encéfalo/efectos de los fármacos , Encéfalo/enzimología , Etanol/administración & dosificación , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Convulsiones por Abstinencia de Alcohol/sangre , Convulsiones por Abstinencia de Alcohol/inducido químicamente , Convulsiones por Abstinencia de Alcohol/enzimología , Trastornos Relacionados con Alcohol/sangre , Animales , Química Encefálica , Enfermedad Crónica , Modelos Animales de Enfermedad , Esquema de Medicación , Etanol/efectos adversos , Etanol/sangre , Especificidad de Órganos , Fosforilación/efectos de los fármacos , Ratas , Ratas Wistar , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiologíaRESUMEN
We previously reported the discovery of 4-aryl-substituted pyridones with mGlu2 PAM activity starting from the HTS hit 5. In this article, we describe a different exploration from 5 that led to the discovery of a novel subseries of phenylpiperidine-substituted pyridones. The optimization strategy involved the introduction of different spacers between the pyridone core and the phenyl ring of 5. The fine tuning of metabolism and hERG followed by differentiation of advanced leads that were identified on the basis of PK profiles and in vivo potency converged on lead compound 36 (JNJ-40411813). Full in vitro and in vivo profiles indicate that 36 displayed an optimal interplay between potency, selectivity, favorable ADMET/PK and cardiovascular safety profile, and central EEG activity. Compound 36 has been investigated in the clinic for schizophrenia and anxious depression disorders.
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Ansiolíticos/química , Antipsicóticos/química , Piperidinas/química , Piridonas/química , Receptores de Glutamato Metabotrópico/metabolismo , Regulación Alostérica , Animales , Ansiolíticos/síntesis química , Ansiolíticos/farmacología , Antipsicóticos/síntesis química , Antipsicóticos/farmacología , Células CHO , Cricetulus , Perros , Canal de Potasio ERG1 , Electroencefalografía , Canales de Potasio Éter-A-Go-Go/fisiología , Células HEK293 , Humanos , Masculino , Técnicas de Placa-Clamp , Piperidinas/síntesis química , Piperidinas/farmacología , Piridonas/síntesis química , Piridonas/farmacología , Ensayo de Unión Radioligante , Ratas Sprague-Dawley , Sueño/efectos de los fármacos , Relación Estructura-Actividad , Vigilia/efectos de los fármacosRESUMEN
The discovery and characterization of compound 48, a selective and in vivo active mGlu2 receptor positive allosteric modulator (PAM), are described. A key to the discovery was the rational exploration of the initial HTS hit 13 guided by an overlay model built with reported mGlu2 receptor PAM chemotypes. The initial weak in vitro activity of the hit 13 was quickly improved, although compounds still had suboptimal druglike properties. Subsequent modulation of the physicochemical properties resulted in compounds having a more balanced profile, combining good potency and in vivo pharmacokinetic properties. Final refinement by addressing cardiovascular safety liabilities led to the discovery of compound 48. Besides good potency, selectivity, and ADME properties, compound 48 displayed robust in vivo activity in a sleep-wake electroencephalogram (sw-EEG) assay consistent with mGlu2 receptor activation, in accordance with previous work from our laboratories.
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Nitrilos/síntesis química , Piridonas/síntesis química , Receptores de Glutamato Metabotrópico/agonistas , Regulación Alostérica , Animales , Encéfalo/metabolismo , Sinergismo Farmacológico , Canal de Potasio ERG1 , Electroencefalografía , Canales de Potasio Éter-A-Go-Go/fisiología , Células HEK293 , Humanos , Isomerismo , Ratones , Nitrilos/farmacocinética , Nitrilos/farmacología , Técnicas de Placa-Clamp , Piridonas/farmacocinética , Piridonas/farmacología , Ratas , Receptores de Glutamato Metabotrópico/metabolismo , Sueño REM/efectos de los fármacos , Relación Estructura-Actividad , VigiliaRESUMEN
Allosteric modulators of metabotropic glutamate receptors (mGluR) subtypes 1-8 have been shown to offer a valid way to develop small molecule non aminoacid-like therapeutics that can be administered orally and that readily cross the blood-brain barrier. Allosteric modulators of glutamatergic receptors and in particular mGluR5 have emerged as a novel and highly desirable class of compounds for the treatment of central nervous system (CNS) disorders and peripheral disorders. This article provides medicinal chemistry highlights around the chemical classes of potent and highly selective mGluR5 negative allosteric modulators (NAMs) and their therapeutic potential. In addition, it describes the medicinal chemistry approach from the discovery to the clinical candidate selection of a new series of heteroaryl-butynylpyridines targeting mGluR5. The multiparametric optimization of the initial starting point which ended in the selection of potential clinical candidates combining the best pharmacophoric features is presented. The pharmacological properties are reported and support the interest of these agents for new therapeutic approaches. Furthermore, a summary of the diverse mGluR5 Positron Emission Tomography (PET) radioligands is reported.
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Compuestos Heterocíclicos/farmacología , Piridinas/farmacología , Receptores de Glutamato Metabotrópico/antagonistas & inhibidores , Regulación Alostérica/efectos de los fármacos , Química Farmacéutica , Diseño de Fármacos , Compuestos Heterocíclicos/síntesis química , Compuestos Heterocíclicos/química , Tomografía de Emisión de Positrones , Piridinas/síntesis química , Piridinas/química , Receptor del Glutamato Metabotropico 5 , Receptores de Glutamato Metabotrópico/química , Receptores de Glutamato Metabotrópico/metabolismo , Relación Estructura-ActividadRESUMEN
A series of 1,5-disubstituted pyridones was identified as positive allosteric modulators (PAMs) of the metabotropic glutamate receptor 2 (mGluR2) via high throughput screening (HTS). Subsequent SAR exploration led to the identification of several compounds with improved in vitro activity. Lead compound 8 was further profiled and found to attenuate the increase in PCP induced locomotor activity in mice.
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Aminoácidos/farmacología , Compuestos Bicíclicos con Puentes/farmacología , Agonistas de Aminoácidos Excitadores/farmacología , Piridinas/farmacología , Piridonas/farmacología , Receptores de Glutamato Metabotrópico/agonistas , Sulfonamidas/farmacología , Regulación Alostérica , Aminoácidos/química , Animales , Compuestos Bicíclicos con Puentes/química , Evaluación Preclínica de Medicamentos , Estabilidad de Medicamentos , Agonistas de Aminoácidos Excitadores/química , Agonistas de Aminoácidos Excitadores/clasificación , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Ratones , Estructura Molecular , Actividad Motora/efectos de los fármacos , Piridinas/química , Piridonas/química , Piridonas/clasificación , Piridonas/aislamiento & purificación , Proteínas Recombinantes/efectos de los fármacos , Relación Estructura-Actividad , Sulfonamidas/químicaRESUMEN
By using high-density oligonucleotide arrays, we profiled gene expression in reward-related brain regions of rats that developed escalated cocaine intake after extended access to cocaine (6 h per day). Rats allowed restricted daily access to cocaine (only 1 h) that displayed a stable level of cocaine intake and cocaine naive rats were used for controls. Four analysis methods were compared: Affymetrix microarray suite 4 and microarray suite 5, which use perfect-match-minus-mismatch models, and dchip and rma, which use perfect-match-only models to generate expression values. Results were validated by RT-PCR in individual animals from an independent replication of the experiment. A small number of genes was associated with escalated cocaine intake (ESC genes). Unexpectedly, of the brain regions examined [prefrontal cortex, nucleus accumbens, septum, lateral hypothalamus (LH), amygdala, and ventral tegmental area], the LH was the most transcriptionally responsive in escalation of cocaine intake. Most of the ESC genes identified are also expressed during synaptogenesis and synaptic plasticity and include genes that code for several presynaptic and postsynaptic proteins involved in neurotransmission. These results suggest that LH intrinsic circuitry undergoes a structural reorganization during escalation of cocaine use. This remodeling of LH circuitry could contribute to the chronic deficit in reward function that has been hypothesized to drive the transition to drug addiction. Results also support the value of using multiple analysis strategies to identify the most robust changes in gene expression and to compensate for the biases that affect each strategy.