ABSTRACT
We report the synthesis and biological evaluation of a series of 7-aryl-1,2,4-triazolo[4,3-a]pyridines with mGlu2 positive allosteric modulator (PAM) activity and affinity. Besides traditional in vitro parameters of potency and affinity, kinetic parameters kon, koff and residence time (RT) were determined. The PAMs showed various kinetic profiles; kon values ranged over 2 orders of magnitude, whereas RT values were within a 10-fold range. Association rate constant kon was linearly correlated to affinity. Evaluation of a short, medium, and long RT compound in a label-free assay indicated a correlation between RT and functional effect. The effects of long RT compound 9 on sleep-wake states indicated long RT was translated into sustained inhibition of rapid eye movement (REM) in vivo. These results show that affinity-only driven selection would have resulted in mGlu2 PAMs with high values for kon but not necessarily optimized RT, which is key to predicting optimal efficacy in vivo.
Subject(s)
Excitatory Amino Acid Agonists/pharmacology , Pyridines/pharmacology , Receptors, Metabotropic Glutamate/agonists , Triazoles/pharmacology , Allosteric Regulation , Animals , CHO Cells , Cricetulus , Excitatory Amino Acid Agonists/chemical synthesis , Kinetics , Piperidines/pharmacology , Pyridines/chemical synthesis , Rats, Sprague-Dawley , Sleep, REM/drug effects , Structure-Activity Relationship , Triazoles/chemical synthesis , TritiumABSTRACT
Positive allosteric modulators of the metabotropic glutamate 2 receptor have generated great interest in the past decade. There is mounting evidence of their potential as therapeutic agents in the treatment of multiple central nervous system disorders. We have previously reported substantial efforts leading to potent and selective mGlu2 PAMs. However, finding compounds with the optimal combination of in vitro potency and good druglike properties has remained elusive, in part because of the hydrophobic nature of the allosteric binding site. Herein, we report on the lead optimization process to overcome the poor solubility inherent to the advanced lead 6. Initial prototypes already showed significant improvements in solubility while retaining good functional activity but displayed new liabilities associated with metabolism and hERG inhibition. Subsequent subtle modifications efficiently addressed those issues leading to the identification of compound 27 (JNJ-46356479). This new lead represents a more balanced profile that offers a significant improvement on the druglike attributes compared to previously reported leads.
Subject(s)
Pyridines/chemistry , Pyridines/pharmacology , Receptors, Metabotropic Glutamate/agonists , Triazoles/chemistry , Triazoles/pharmacology , Administration, Oral , Allosteric Regulation/drug effects , Animals , CHO Cells , Caco-2 Cells , Cricetulus , Dogs , Humans , Male , Models, Molecular , Pyridines/administration & dosage , Pyridines/pharmacokinetics , Rats , Receptors, Metabotropic Glutamate/metabolism , Triazoles/administration & dosage , Triazoles/pharmacokineticsABSTRACT
Herein, we report the structure-activity relationship of a novel series of (2(phenoxymethyl)-6,7-dihydrooxazolo[5,4-c]pyridine-5(4H)-yl(aryl)methanones as potent, selective, and orally bioavailable metabotropic glutamate receptor subtype 5 (mGlu5) positive allosteric modulators (PAMs). On the basis of its robust in vitro potency and in vivo efficacy in multiple preclinical models of multiple domains of schizophrenia, coupled with a good DMPK profile and an acceptable therapeutic window, 17a (VU0409551/JNJ-46778212) was selected as a candidate for further development.
ABSTRACT
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.
ABSTRACT
Current dopamine replacement therapies, in Parkinson's disease (PD), result in aversive side effects and rapid drug dose escalation over time. Therefore, a non-dopaminergic treatment would be an advantageous supplement to lower the dose of dopamine replacement treatment postponing the occurrence of side effects. The noradrenergic system plays an important role in the facilitation or maintenance of the activity of the nigrostriatal dopamine pathways. Here the putative anti-Parkinson effects of the oral selective alpha2C-adrenoceptor antagonist (JNJ27063699 0.1-10mg/kg p.o.) and of vehicle (fruit syrup) were evaluated in the MPTP-marmoset model. Dose-related anti-Parkinson effects were assessed by means of a behavioural rating scale covering parkinsonian symptoms, body weight and body temperature, and two test systems assessing locomotor activity and complex motor skills of hand-eye coordination for controlled movements in MPTP- or saline-pretreated marmosets. JNJ27063699, at the middle and higher doses, consistently improved locomotor activity and hand-eye coordination capabilities, which indicates an improvement in the coordination of motor control -or movements- in MPTP-pretreated monkeys. No additional effects on the parkinsonian symptoms or side effects were observed on other test systems. Overall, the findings link deficit in motor coordination with dysfunctional adrenergic signalling and it suggest that selective alpha2C adrenergic antagonism may contribute to behavioural improvement in the MPTP-monkey model of PD. In multi-drug medication JNJ27063699 might have potential in the treatment of motor deficit in PD.
Subject(s)
Adrenergic alpha-2 Receptor Antagonists/pharmacology , Antiparkinson Agents/pharmacology , Parkinsonian Disorders/drug therapy , 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine , Administration, Oral , Animals , Body Temperature/drug effects , Body Weight/drug effects , Callithrix , Dose-Response Relationship, Drug , Female , Male , Motor Activity/drug effects , Motor Skills/drug effects , Parkinsonian Disorders/physiopathology , Receptors, Adrenergic, alpha-2/metabolism , Severity of Illness IndexABSTRACT
Advanced leads from a series of 1,2,4-triazolo[4,3-a]pyridines with mGlu2 receptor PAM activity are reported. By modification of the analogous imidazo[1,2-a]pyridine series, the newly reported leads have improved potency, in vitro ADMET, and hERG as well as good in vivo PK profile. The optimization of the series focused on improving metabolic stability while controlling lipophilicity by introducing small modifications to the scaffold substituents. Analysis of this series combined with our previously reported mGlu2 receptor PAMs showed how lipophilic ligand efficiency was improved during the course of the program. Among the best compounds, example 20 (JNJ-42153605) showed a central in vivo efficacy by inhibition of REM sleep state at a dose of 3 mg/kg po in the rat sleep-wake EEG paradigm, a phenomenon shown earlier to be mGlu2 mediated. In mice, compound 20 reversed PCP-induced hyperlocomotion with an ED50 of 5.4 mg/kg sc, indicative of antipsychotic activity.
Subject(s)
Antipsychotic Agents/chemical synthesis , Pyridines/chemical synthesis , Receptors, Metabotropic Glutamate/metabolism , Triazines/chemical synthesis , Allosteric Regulation , Animals , Antipsychotic Agents/pharmacokinetics , Antipsychotic Agents/pharmacology , Blood-Brain Barrier/metabolism , Cell Line , ERG1 Potassium Channel , Electroencephalography , Ether-A-Go-Go Potassium Channels/antagonists & inhibitors , Humans , Hyperkinesis/drug therapy , Male , Mice , Microsomes, Liver/metabolism , Patch-Clamp Techniques , Polysomnography , Pyridines/pharmacokinetics , Pyridines/pharmacology , Rats , Rats, Sprague-Dawley , Sleep/drug effects , Structure-Activity Relationship , Triazines/pharmacokinetics , Triazines/pharmacology , Wakefulness/drug effectsABSTRACT
In rodents 5-hydroxytryptamine type 7 (5-HT(7)) receptor blockade has been shown to be effective in models of depression and to increase the latency to rapid eye movement (REM) sleep and decrease REM duration. In the clinic, the REM sleep reduction observed with many antidepressants may serve as a biomarker. We report here the preclinical and clinical evaluation of a 5-HT(7) receptor antagonist, (3-(4-chlorophenyl)-1,4,5,6,7,8-hexahydro-1-(phenylmethyl)pyrazolo[3,4-d]azepine 2-hydroxy-1,2,3-propanetricarboxylate) (JNJ-18038683). In rodents, JNJ-18038683 increased the latency to REM sleep and decreased REM duration, and this effect was maintained after repeated administration for 7 days. The compound was effective in the mouse tail suspension test. JNJ-18038683 enhanced serotonin transmission, antidepressant-like behavior, and REM sleep suppression induced by citalopram in rodents. In healthy human volunteers JNJ-18038683 prolonged REM latency and reduced REM sleep duration, demonstrating that the effect of 5-HT(7) blockade on REM sleep translated from rodents to humans. Like in rats, JNJ-18038683 enhanced REM sleep suppression induced by citalopram in humans, although a drug-drug interaction could not be ruled out. In a double-blind, active, and placebo-controlled clinical trial in 225 patients suffering from major depressive disorder, neither treatment with pharmacologically active doses of JNJ-18038683 or escitalopram separated from placebo, indicating a failed study lacking assay sensitivity. Post hoc analyses using an enrichment window strategy, where all the efficacy data from sites with an implausible high placebo response [placebo group Montgomery-Åsberg Depression Rating Scale (MADRS) < = 12] and from sites with no placebo response (MADRS > = 28) are removed, there was a clinically meaningful difference between JNJ-18038683 and placebo. Further clinical studies are required to characterize the potential antidepressant efficacy of JNJ-18038683.
Subject(s)
Antidepressive Agents/pharmacology , Azepines/pharmacology , Depressive Disorder, Major/drug therapy , Receptors, Serotonin/metabolism , Serotonin Antagonists/pharmacology , Sleep, REM/drug effects , Tricarboxylic Acids/pharmacology , Adolescent , Adult , Animals , Antidepressive Agents/therapeutic use , Azepines/therapeutic use , Cell Line, Transformed , Citalopram/pharmacology , Cohort Studies , Cross-Over Studies , Depressive Disorder, Major/metabolism , Double-Blind Method , Female , HEK293 Cells , Hindlimb Suspension/methods , Humans , Hypothermia/drug therapy , Hypothermia/metabolism , Hypothermia/physiopathology , Male , Mice , Mice, Inbred C57BL , Middle Aged , Rats , Rats, Sprague-Dawley , Serotonin/metabolism , Serotonin Antagonists/therapeutic use , Tricarboxylic Acids/therapeutic use , Young AdultABSTRACT
This paper proposes a modified model averaging approach for linear discriminant analysis. This approach is used in combination with a doubly hierarchical supervised learning analysis and applied to preclinical pharmaco-electroencephalographical data for classification of psychotropic drugs. Classification of a test dataset was highly improved with this method.
Subject(s)
Artificial Intelligence , Drug Evaluation, Preclinical/methods , Electroencephalography/drug effects , Models, Statistical , Psychotropic Drugs/pharmacology , Algorithms , Animals , Discriminant Analysis , Likelihood Functions , Linear Models , Psychotropic Drugs/classification , Rats , Regression Analysis , Selection Bias , Sleep Stages/drug effects , Wakefulness/drug effectsABSTRACT
Phosphodiesterases (PDEs) form a family of enzymes involved in the hydrolysis of cyclic adenosine and guanosine monophosphate (cAMP and cGMP). PDE10A is a member of this family that is almost exclusively expressed in the striatum. Increasing cAMP/cGMP levels via inhibition of PDE10A is under consideration as a novel therapeutic avenue in the discovery of antipsychotics. Papaverine has been used as a pharmacological tool to establish the possible clinical use of PDE10A inhibitors as antipsychotics. Papaverine is known to increase cAMP levels in striatum and to decrease blood pressure, body temperature and locomotor activity after systemic administration. In this study, the effects of papaverine are compared to those of a more specific PDE10A inhibitor MP10. Papaverine raised striatal cAMP levels with hypothermia, hypoactivity and decreased cardiovascular responses. The more selective MP10 had significantly less effects on body temperature and cardiovascular functions, but reduced locomotor activity to a similar extend as papaverine.
Subject(s)
Corpus Striatum/drug effects , Cyclic AMP/metabolism , Papaverine/pharmacology , Phosphodiesterase Inhibitors/pharmacology , Physiological Phenomena/drug effects , Pyrazoles/pharmacology , Quinolines/pharmacology , Animals , Area Under Curve , Blood Pressure/drug effects , Body Temperature/drug effects , Dose-Response Relationship, Drug , Heart Rate/drug effects , Male , Microdialysis/methods , Motor Activity/drug effects , Rats , Rats, Sprague-Dawley , Telemetry/methods , Time FactorsABSTRACT
Wake-promoting drugs are widely used to treat excessive daytime sleepiness. The neuronal pathways involved in wake promotion are multiple and often not well characterized. We tested d-amphetamine, modafinil, and YKP10A, a novel wake-promoting compound, in three inbred strains of mice. The wake duration induced by YKP10A and d-amphetamine depended similarly on genotype, whereas opposite strain differences were observed after modafinil. Electroencephalogram (EEG) analysis during drug-induced wakefulness revealed a transient approximately 2 Hz slowing of theta oscillations and an increase in beta-2 (20-35 Hz) activity only after YKP10A. Gamma activity (35-60 Hz) was induced by all drugs in a drug- and genotype-dependent manner. Brain transcriptome and clustering analyses indicated that the three drugs have both common and specific molecular signatures. The correlation between specific EEG and gene-expression signatures suggests that the neuronal pathways activated to stay awake vary among drugs and genetic background.
Subject(s)
Brain/drug effects , Central Nervous System Stimulants/pharmacology , Pharmacogenetics , Wakefulness/drug effects , Wakefulness/genetics , Animals , Benzhydryl Compounds/pharmacology , Brain/metabolism , Dextroamphetamine/pharmacology , Dose-Response Relationship, Drug , Electroencephalography/drug effects , Electromyography/methods , Gene Expression Regulation/drug effects , Genotype , Male , Mice , Mice, Inbred Strains , Modafinil , Nerve Tissue Proteins/metabolism , Phenylalanine/analogs & derivatives , Phenylalanine/pharmacology , Proto-Oncogene Proteins c-fos/metabolism , Sleep/drug effects , Species Specificity , Spectrum Analysis , Statistics as Topic , Time FactorsABSTRACT
Compiling pharmacological evidence implicates metabotropic glutamate mGlu(2) receptors in the regulation of emotional states and suggests positive modulators as a novel therapeutic approach of Anxiety/Depression and Schizophrenia. Here, we investigated subcutaneous effects of the metabotropic glutamate mGlu(2/3) agonist (LY354740) on sleep-wake architecture in rat. To confirm the specific effects on rapid eye movement (REM) sleep were mediated via metabotropic glutamate mGlu(2) receptors, we characterized the sleep-wake cycles in metabotropic glutamate mGlu(2) receptor deficient mice (mGlu(2)R(-/-)) and their arousal response to LY354740. We furthermore examined effects on sleep behavior in rats of the positive allosteric modulator, biphenyl-indanone A (BINA) alone and in combination with LY354740 at sub-effective doses. LY354740 (1, 3 and 10 mg/kg) dose-dependently suppressed REM sleep and prolonged its onset latency. Metabotropic glutamate mGlu(2)R(-/-) and their wild type (WT) littermates exhibited similar spontaneous sleep-wake phenotype, while LY354740 (10 mg/kg) significantly affected REM sleep variables in WT but not in the mutant. In rats, BINA (1, 3, 10, 20, 40 mg/kg) dose-dependently suppressed REM sleep, lengthened its onset latency and slightly enhanced passive waking. Additionally, combined treatment elicited a synergistic action on REM sleep variables. Our findings show common changes of REM sleep variables following modulation of metabotropic glutamate mGlu(2) receptor and support an active role of this receptor in the regulation of REM sleep. The synergistic action of BINA on LY354740's effects on sleep pattern implies that positive modulators would tune the endogenous glutamate tone suggesting potential benefit in the treatment of psychiatric disorders, in which REM sleep overdrive is manifested.
Subject(s)
Receptors, Metabotropic Glutamate/metabolism , Sleep/drug effects , Wakefulness/drug effects , Allosteric Regulation , Animals , Biphenyl Compounds/administration & dosage , Biphenyl Compounds/pharmacology , Bridged Bicyclo Compounds/administration & dosage , Bridged Bicyclo Compounds/chemical synthesis , Bridged Bicyclo Compounds/pharmacology , Drug Combinations , Glutamic Acid/metabolism , Indans/administration & dosage , Indans/pharmacology , Mice , Rats , Receptors, Metabotropic Glutamate/agonists , Receptors, Metabotropic Glutamate/deficiency , Sleep, REM/drug effects , Substrate SpecificityABSTRACT
This paper proposes a general and simple procedure that can be applied to establish classification rules for application to multiple-class longitudinal data. The procedure is applied to preclinical pharmaco-electroencephalogram (EEG) studies aiming at characterizing psychotropic drug effects on the basis of spectral EEG analysis. It is a flexible hierarchical supervised learning tool that takes into account the specific nature of the multiple drug classes, as well as the longitudinal aspect of the data. Several variations of this procedure are applied to the EEG data, generally producing comparable results, in particular similar association between the sleeping stages and the psychotropic drug classes.
Subject(s)
Discriminant Analysis , Drug Evaluation, Preclinical/statistics & numerical data , Electroencephalography/statistics & numerical data , Models, Statistical , Psychotropic Drugs/pharmacology , Sleep/drug effects , Wakefulness/drug effects , Animals , Dose-Response Relationship, Drug , Linear Models , Longitudinal Studies , Models, Animal , Psychotropic Drugs/classification , Rats , Reproducibility of Results , Time FactorsABSTRACT
Melanin-concentrating hormone (MCH) is a hypothalamic peptide that centrally regulates food intake, energy balance and emotion. Interestingly, MCH and melanin-concentrating hormone MCH(1) receptors are distributed in brain areas known to regulate vigilance states. Effects of subcutaneous administration of two selective melanin-concentrating hormone MCH(1) receptor antagonists, labeled A and B were examined over a broad dose range (1, 3, 10, 20, 40 mg/kg) on rat sleep-wake architecture. Both compounds have a nanomolar antagonist activity at recombinant human melanin-concentrating hormone MCH(1) receptor (IC(50)=44.1+/-6.1 nM and 26.6+/-5.4 nM, respectively) and potently inhibited the MCH-induced mobilization of [Ca(2+)] (IC(50) 29.1+/-8.1 nM and 10.5+/-4.1 nM, respectively). The selectivity of both compounds was further confirmed on a panel of receptors, transporters and channels. In vivo, both compounds dose-dependently decreased deep sleep primarily by decreasing the mean duration of episodes during the first 4 h post-administration. In parallel, REM sleep and intermediate stage sleep were decreased while active and passive waking increased. Deep sleep and REM sleep onset latencies were significantly prolonged at higher doses. No homeostatic rebound of deep sleep was observed, while a tendency for recovery of REM sleep was found during subsequent dark phase. Together, the results support a role of the melanin-concentrating hormone MCH(1) receptor in the regulation of deep slow-wave sleep-REM sleep cycle. Therapeutic application of melanin-concentrating hormone MCH(1) receptor-inhibiting agents should take into account the significant decreases in deep sleep without recovery as these may interfere with sleep dependent memory consolidation.
Subject(s)
Receptors, Somatostatin/antagonists & inhibitors , Receptors, Somatostatin/metabolism , Sleep Stages/physiology , Animals , CHO Cells , Calcium/metabolism , Cricetinae , Cricetulus , Dose-Response Relationship, Drug , Humans , Inhibitory Concentration 50 , Injections, Subcutaneous , Male , Rats , Rats, Sprague-Dawley , Sleep Stages/drug effects , Sleep, REM/drug effects , Sleep, REM/physiologyABSTRACT
The limitations of blood sampling in pharmacokinetic (PK)/pharmacodynamic (PD) studies in behavioral animal models could in part be overcome by a mixed effects modeling approach. This analysis characterizes and evaluates the population PK of fluvoxamine in rat plasma using nonlinear mixed effects modeling. The model is assessed for its utility in animal behavioral PK/PD studies. In six studies with a different experimental setup, study site and/or sampling design, rats received an intravenous infusion of 1, 3.7 or 7.3mg/kg fluvoxamine. A population three-compartment PK model adequately described the fluvoxamine plasma concentrations. Body weight was included as a covariate and mean population PK parameters for CL, V(1), V(2), Q(2), V(3) and Q(3) were 25.1 ml/min, 256 ml, 721 ml, 30.3 ml/min, 136 ml and 1.0 ml/min, respectively. Inter-individual variability was identified on CL (39.5%), V(1) (43.5%), V(2) (50.1%) and Q(2) (25.7%). A predictive check and bootstrap analysis confirmed the predictive ability, model stability and precision of the parameter estimates. Body weight was identified as a significant covariate of the inter-compartmental clearance Q(2). The pharmacokinetics was independent of factors such as dose, surgery (for instrumentation) and study site. The utility of the model in animal behavioral studies was demonstrated in a PK/PD analysis of the effects on REM sleep in which a sparse PK sampling design was used. By using the pertinent information from the population PK model, individual PK profiles and the PK/PD correlation could be adequately described.
Subject(s)
Behavior, Animal/drug effects , Fluvoxamine , Models, Biological , Selective Serotonin Reuptake Inhibitors , Animals , Fluvoxamine/pharmacokinetics , Fluvoxamine/pharmacology , Infusions, Intravenous , Male , Rats , Rats, Wistar , Selective Serotonin Reuptake Inhibitors/pharmacokinetics , Selective Serotonin Reuptake Inhibitors/pharmacology , Sleep, REM/drug effectsABSTRACT
Chronic neuropathic pain patients often report sleep disturbances such as reduced amount of sleep and excessive daytime tiredness. The aim of this study was to evaluate possible abnormalities in sleep patterns in a widely used animal model of neuropathic pain. Adult male Sprague-Dawley rats were chronically implanted with electrodes for electroencephalogram (EEG) and electromyogram (EMG) registrations to allow continuous 24-h polygraphic recording. Subsequently, a chronic constriction injury (CCI) was inflicted on eight rats in accordance with the CCI model of neuropathic pain and a sham operation was performed on another eight rats. The polygraphic recordings were repeated 13, 27, 55, and 146 days after surgery. Although the CCI animals developed significant mechanical and cold allodynia and heat hyperalgesia, there were no significant differences between the CCI rats and the sham-operated control animals in the spontaneous EEG/EMG in homecage-like conditions. It is concluded that in the chronic phase, this neuropathic pain model does not produce clear sleep disturbances. Such an absence of general suffering from sleep disturbances is advantageous to the CCI model as it makes use of the model more acceptable ethically. Nonetheless, this outcome appears to be in contrast with the clinical situation in neuropathic pain and therefore could also be seen as a disadvantage for the face validity of the CCI model.