51
|
Raheem IT, Breslin MJ, Fandozzi C, Fuerst J, Hill N, Huszar S, Kandebo M, Kim SH, Ma B, McGaughey G, Renger JJ, Schreier JD, Sharma S, Smith S, Uslaner J, Yan Y, Coleman PJ, Cox CD. Discovery of tetrahydropyridopyrimidine phosphodiesterase 10A inhibitors for the treatment of schizophrenia. Bioorg Med Chem Lett 2012; 22:5903-8. [PMID: 22892116 DOI: 10.1016/j.bmcl.2012.07.072] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Revised: 07/16/2012] [Accepted: 07/20/2012] [Indexed: 10/28/2022]
Abstract
We describe the discovery of potent and orally bioavailable tetrahydropyridopyrimidine inhibitors of phosphodiesterase 10A by systematic optimization of a novel HTS lead. Lead compound THPP-1 exhibits nanomolar potencies, excellent pharmacokinetic properties, and a clean off-target profile. It displays in vivo target engagement as measured by increased rat striatal cGMP levels upon oral dosing. It shows dose-dependent efficacy in a key pharmacodynamic assay predictive of antipsychotic activity, the psychostimulant-induced rat hyperlocomotion assay. Further, THPP-1 displays significantly fewer preclinical adverse events in assays measuring prolactin secretion, catalepsy, and weight gain, in contrast to the typical and atypical antipsychotics haloperidol and olanzapine.
Collapse
|
52
|
Gotter AL, Webber AL, Coleman PJ, Renger JJ, Winrow CJ. International Union of Basic and Clinical Pharmacology. LXXXVI. Orexin Receptor Function, Nomenclature and Pharmacology. Pharmacol Rev 2012; 64:389-420. [DOI: 10.1124/pr.111.005546] [Citation(s) in RCA: 133] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
|
53
|
Fitzpatrick K, Winrow CJ, Gotter AL, Millstein J, Arbuzova J, Brunner J, Kasarskis A, Vitaterna MH, Renger JJ, Turek FW. Altered sleep and affect in the neurotensin receptor 1 knockout mouse. Sleep 2012; 35:949-56. [PMID: 22754041 DOI: 10.5665/sleep.1958] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
STUDY OBJECTIVE Sleep and mood disorders have long been understood to have strong genetic components, and there is considerable comorbidity of sleep abnormalities and mood disorders, suggesting the involvement of common genetic pathways. Here, we examine a candidate gene implicated in the regulation of both sleep and affective behavior using a knockout mouse model. DESIGN Previously, we identified a quantitative trait locus (QTL) for REM sleep amount, REM sleep bout number, and wake amount in a genetically segregating population of mice. Here, we show that traits mapping to this QTL correlated with an expression QTL for neurotensin receptor 1 (Ntsr1), a receptor for neurotensin, a ligand known to be involved in several psychiatric disorders. We examined sleep as well as behaviors indicative of anxiety and depression in the NTSR1 knockout mouse. MEASUREMENTS AND RESULTS NTSR1 knockouts had a lower percentage of sleep time spent in REM sleep in the dark phase and a larger diurnal variation in REM sleep duration than wild types under baseline conditions. Following sleep deprivation, NTSR1 knockouts exhibited more wake and less NREM rebound sleep. NTSR1 knockouts also showed increased anxious and despair behaviors. CONCLUSIONS Here we illustrate a link between expression of the Ntsr1 gene and sleep traits previously associated with a particular QTL. We also demonstrate a relationship between Ntsr1 and anxiety and despair behaviors. Given the considerable evidence that anxiety and depression are closely linked with abnormalities in sleep, the data presented here provide further evidence that neurotensin and Ntsr1 may be a component of a pathway involved in both sleep and mood disorders.
Collapse
|
54
|
Smith SM, Uslaner JM, Cox CD, Huszar SL, Cannon CE, Vardigan JD, Eddins D, Toolan DM, Kandebo M, Yao L, Raheem IT, Schreier JD, Breslin MJ, Coleman PJ, Renger JJ. The novel phosphodiesterase 10A inhibitor THPP-1 has antipsychotic-like effects in rat and improves cognition in rat and rhesus monkey. Neuropharmacology 2012; 64:215-23. [PMID: 22750078 DOI: 10.1016/j.neuropharm.2012.06.013] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Revised: 05/14/2012] [Accepted: 06/10/2012] [Indexed: 01/28/2023]
Abstract
Phosphodiesterase 10A (PDE10A) is a novel target for the treatment of schizophrenia that may address multiple symptomatic domains associated with this disorder. PDE10A is highly expressed in the brain and functions to metabolically inactivate the important second messengers cAMP and cGMP. Here we describe effects of a potent and orally bioavailable PDE10A inhibitor [2-(6-chloropyridin-3-yl)-4-(2-methoxyethoxy)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl](imidazo[1,5-a]pyridin-1-yl)methanone] (THPP-1) on striatal signaling pathways, in behavioral tests that predict antipsychotic potential, and assays that measure episodic-like memory in rat and executive function in rhesus monkey. THPP-1 exhibits nanomolar potency on the PDE10A enzyme, demonstrates excellent pharmacokinetic properties in multiple preclinical animal species, and is selective for PDE10A over other PDE families of enzymes. THPP-1 significantly increased phosphorylation of proteins in the striatum involved in synaptic plasticity, including the a-amino-3-hydroxy-5-methylisoxazole-4-proprionic acid receptor (AMPA) GluR1 subunit, extracellular receptor kinase (ERK), and cAMP-response element binding protein (CREB). THPP-1 produced dose-dependent effects in preclinical assays predictive of antipsychotic activity including attenuation of MK-801-induced psychomotor activation and condition avoidance responding in rats. At similar plasma exposures, THPP-1 significantly increased object recognition memory in rat and attenuated a ketamine-induced deficit in the object retrieval detour task in rhesus monkey. These findings suggest that PDE10A inhibitors have the potential to impact multiple symptomatic domains of schizophrenia including positive symptoms and cognitive impairment. This article is part of a Special Issue entitled 'Cognitive Enhancers'.
Collapse
|
55
|
Sun YG, Wu CS, Renger JJ, Uebele VN, Lu HC, Beierlein M. GABAergic synaptic transmission triggers action potentials in thalamic reticular nucleus neurons. J Neurosci 2012; 32:7782-90. [PMID: 22674255 PMCID: PMC3376355 DOI: 10.1523/jneurosci.0839-12.2012] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Revised: 04/04/2012] [Accepted: 04/06/2012] [Indexed: 11/21/2022] Open
Abstract
GABAergic neurons in the thalamic reticular nucleus (TRN) form powerful inhibitory connections with several dorsal thalamic nuclei, thereby controlling attention, sensory processing, and synchronous oscillations in the thalamocortical system. TRN neurons are interconnected by a network of GABAergic synapses, but their properties and their role in shaping TRN neuronal activity are not well understood. Using recording techniques aimed to minimize changes in the intracellular milieu, we show that synaptic GABA(A) receptor activation triggers postsynaptic depolarizations in mouse TRN neurons. Immunohistochemical data indicate that TRN neurons express very low levels of the Cl(-) transporter KCC2. In agreement, perforated-patch recordings show that intracellular Cl(-) levels are high in TRN neurons, resulting in a Cl(-) reversal potential (E(Cl)) significantly depolarized from rest. Additionally, we find that GABA(A) receptor-evoked depolarizations are amplified by the activation of postsynaptic T-type Ca(2+) channels, leading to dendritic Ca(2+) increases and the generation of burst firing in TRN neurons. In turn, GABA-evoked burst firing results in delayed and long-lasting feedforward inhibition in thalamic relay cells. Our results show that GABA-evoked depolarizations can interact with T-type Ca(2+) channels to powerfully control spike generation in TRN neurons.
Collapse
|
56
|
Eckle VS, Digruccio MR, Uebele VN, Renger JJ, Todorovic SM. Inhibition of T-type calcium current in rat thalamocortical neurons by isoflurane. Neuropharmacology 2012; 63:266-73. [PMID: 22491022 DOI: 10.1016/j.neuropharm.2012.03.018] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Revised: 02/27/2012] [Accepted: 03/16/2012] [Indexed: 10/28/2022]
Abstract
Thalamocortical (TC) neurons provide the major sensory input to the mammalian somatosensory cortex. Decreased activity of these cells may be pivotal in the ability of general anesthetics to induce loss of consciousness and promote sleep (hypnosis). T-type voltage-gated calcium currents (T-currents) have a key function regulating the cellular excitability of TC neurons and previous studies have indicated that volatile general anesthetics may alter the excitability of these neurons. Using a patch-clamp technique, we investigated the mechanisms whereby isoflurane, a common volatile anesthetic, modulates isolated T-currents and T-current-dependent excitability of native TC neurons in acute brain slices of the rat. In voltage-clamp experiments, we found that isoflurane strongly inhibited peak amplitude of T-current, yielding an IC(50) of 1.1 vol-% at physiological membrane potentials. Ensuing biophysical studies demonstrated that inhibition was more prominent at depolarized membrane potentials as evidenced by hyperpolarizing shifts in channel availability curves. In current-clamp experiments we found that isoflurane decreased the rate of depolarization of low-threshold-calcium spikes (LTCSs) and consequently increased the latency of rebound spike firing at the same concentrations that inhibited isolated T-currents. This effect was mimicked by a novel selective T-channel blocker 3,5-dichloro-N-[1-(2,2-dimethyl-tetrahydro-pyran-4-ylmethyl)-4-fluoro-piperidin-4-ylmethyl]-benzamide (TTA-P2). In contrast, isoflurane and TTA-P2 had minimal effect on resting membrane potential and cell input resistance. We propose that the clinical properties of isoflurane may at least partly be provided by depression of thalamic T-currents.
Collapse
|
57
|
Coleman PJ, Schreier JD, Cox CD, Breslin MJ, Whitman DB, Bogusky MJ, McGaughey GB, Bednar RA, Lemaire W, Doran SM, Fox SV, Garson SL, Gotter AL, Harrell CM, Reiss DR, Cabalu TD, Cui D, Prueksaritanont T, Stevens J, Tannenbaum PL, Ball RG, Stellabott J, Young SD, Hartman GD, Winrow CJ, Renger JJ. Cover Picture: Discovery of [(2R,5R)-5-{[(5-Fluoropyridin-2-yl)oxy]methyl}-2-methylpiperidin-1-yl][5-methyl-2-(pyrimidin-2-yl)phenyl]methanone (MK-6096): A Dual Orexin Receptor Antagonist with Potent Sleep-Promoting Properties (ChemMedChem 3/2012). ChemMedChem 2012. [DOI: 10.1002/cmdc.201290006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
58
|
Coleman PJ, Schreier JD, Cox CD, Breslin MJ, Whitman DB, Bogusky MJ, McGaughey GB, Bednar RA, Lemaire W, Doran SM, Fox SV, Garson SL, Gotter AL, Harrell CM, Reiss DR, Cabalu TD, Cui D, Prueksaritanont T, Stevens J, Tannenbaum PL, Ball RG, Stellabott J, Young SD, Hartman GD, Winrow CJ, Renger JJ. Discovery of [(2R,5R)-5-{[(5-Fluoropyridin-2-yl)oxy]methyl}-2-methylpiperidin-1-yl][5-methyl-2-(pyrimidin-2-yl)phenyl]methanone (MK-6096): A Dual Orexin Receptor Antagonist with Potent Sleep-Promoting Properties. ChemMedChem 2012; 7:415-24, 337. [DOI: 10.1002/cmdc.201200025] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Indexed: 11/09/2022]
|
59
|
Winrow CJ, Gotter AL, Cox CD, Tannenbaum PL, Garson SL, Doran SM, Breslin MJ, Schreier JD, Fox SV, Harrell CM, Stevens J, Reiss DR, Cui D, Coleman PJ, Renger JJ. Pharmacological characterization of MK-6096 – A dual orexin receptor antagonist for insomnia. Neuropharmacology 2012; 62:978-87. [DOI: 10.1016/j.neuropharm.2011.10.003] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Revised: 08/26/2011] [Accepted: 10/04/2011] [Indexed: 01/02/2023]
|
60
|
Gotter AL, Roecker AJ, Hargreaves R, Coleman PJ, Winrow CJ, Renger JJ. Orexin receptors as therapeutic drug targets. PROGRESS IN BRAIN RESEARCH 2012; 198:163-88. [PMID: 22813974 DOI: 10.1016/b978-0-444-59489-1.00010-0] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Orexin (hypocretin) receptor antagonists stand as a model for the development of targeted CNS small-molecule therapeutics. The identification of mutations in the gene for the orexin 2 receptor responsible for canine narcolepsy, the demonstration of a hypersomnolence phenotype in hypocretin knockout mice and the disruption in orexin signaling in narcoleptic patients provides clear genetic proof of concept for targeting orexin-induced arousal for the treatment of insomnia. The full characterization of the genes encoding orexin and its two cognate receptors enabled the rapid development of in vitro and ex vivo assays with which to identify lead compound structures and to optimize potency and pharmacokinetic properties. Polysomnographic measures with cross-species translatability capable of measuring the sleep-promoting effects of orexin receptor antagonists from mice to man, and the existence of knockout models not only allow efficacy assessment but also the demonstration of mechanism of action. Focused efforts by a number of groups have identified potent compounds of diverse chemical structure with differential orexin receptor selectivity for either the orexin 1 receptor (OX₁R) or the orexin 2 receptor (OX₂R), or both. This work has yielded tool compounds that, along with genetic models, have been used to specifically define the role these receptors in mediating orexin-induced arousal and vigilance state control. Optimized dual receptor antagonists with favorable pharmacokinetic and safety profiles have now demonstrated efficacy in clinical development and represent a distinct mechanism of action for the treatment of insomnia relative to current standard of care.
Collapse
|
61
|
Renger JJ, Kern JT. Preface to the special issue "Novel pharmaconeurogenetic approaches arising from progress in translational genetics". J Neurogenet 2011; 25:117-9. [PMID: 22074379 DOI: 10.3109/01677063.2011.629355] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
62
|
Bender KJ, Uebele VN, Renger JJ, Trussell LO. Control of firing patterns through modulation of axon initial segment T-type calcium channels. J Physiol 2011; 590:109-18. [PMID: 22063631 DOI: 10.1113/jphysiol.2011.218768] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Spontaneously active neurons typically fire either in a regular pattern or in bursts. While much is known about the subcellular location and biophysical properties of conductances that underlie regular spontaneous activity, less is known about those that underlie bursts. Here, we show that T-type Ca(2+) channels localized to the site of action potential initiation in the axon initial segment play a pivotal role in spontaneous burst generation. In auditory brainstem interneurons, axon initial segment Ca(2+) influx is selectively downregulated by dopaminergic signalling. This regulation has marked effects on spontaneous activity, converting the predominant mode of spontaneous activity from bursts to regular spiking. Thus, the axon initial segment is a key site, and dopamine a key regulator, of spontaneous bursting activity.
Collapse
|
63
|
Millstein J, Winrow CJ, Kasarskis A, Owens JR, Zhou L, Summa KC, Fitzpatrick K, Zhang B, Vitaterna MH, Schadt EE, Renger JJ, Turek FW. Identification of causal genes, networks, and transcriptional regulators of REM sleep and wake. Sleep 2011; 34:1469-77. [PMID: 22043117 DOI: 10.5665/sleep.1378] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
STUDY OBJECTIVE Sleep-wake traits are well-known to be under substantial genetic control, but the specific genes and gene networks underlying primary sleep-wake traits have largely eluded identification using conventional approaches, especially in mammals. Thus, the aim of this study was to use systems genetics and statistical approaches to uncover the genetic networks underlying 2 primary sleep traits in the mouse: 24-h duration of REM sleep and wake. DESIGN Genome-wide RNA expression data from 3 tissues (anterior cortex, hypothalamus, thalamus/midbrain) were used in conjunction with high-density genotyping to identify candidate causal genes and networks mediating the effects of 2 QTL regulating the 24-h duration of REM sleep and one regulating the 24-h duration of wake. SETTING Basic sleep research laboratory. PATIENTS OR PARTICIPANTS Male [C57BL/6J × (BALB/cByJ × C57BL/6J*) F1] N(2) mice (n = 283). INTERVENTIONS None. MEASUREMENTS AND RESULTS The genetic variation of a mouse N2 mapping cross was leveraged against sleep-state phenotypic variation as well as quantitative gene expression measurement in key brain regions using integrative genomics approaches to uncover multiple causal sleep-state regulatory genes, including several surprising novel candidates, which interact as components of networks that modulate REM sleep and wake. In particular, it was discovered that a core network module, consisting of 20 genes, involved in the regulation of REM sleep duration is conserved across the cortex, hypothalamus, and thalamus. A novel application of a formal causal inference test was also used to identify those genes directly regulating sleep via control of expression. CONCLUSION Systems genetics approaches reveal novel candidate genes, complex networks and specific transcriptional regulators of REM sleep and wake duration in mammals.
Collapse
|
64
|
Coburn CA, Luo Y, Cui M, Wang J, Soll R, Dong J, Hu B, Lyon MA, Santarelli VP, Kraus RL, Gregan Y, Wang Y, Fox SV, Binns J, Doran SM, Reiss DR, Tannenbaum PL, Gotter AL, Meinke PT, Renger JJ. Discovery of a Pharmacologically Active Antagonist of the Two-Pore-Domain Potassium Channel K2P9.1 (TASK-3). ChemMedChem 2011; 7:123-33. [DOI: 10.1002/cmdc.201100351] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Indexed: 11/11/2022]
|
65
|
Boehme R, Uebele VN, Renger JJ, Pedroarena C. Rebound excitation triggered by synaptic inhibition in cerebellar nuclear neurons is suppressed by selective T-type calcium channel block. J Neurophysiol 2011; 106:2653-61. [PMID: 21849607 DOI: 10.1152/jn.00612.2011] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Following hyperpolarizing inputs, many neurons respond with an increase in firing rate, a phenomenon known as rebound excitation. Rebound excitation has been proposed as a mechanism to encode and process inhibitory signals and transfer them to target structures. Activation of low-voltage-activated T-type calcium channels and the ensuing low-threshold calcium spikes is one of the mechanisms proposed to support rebound excitation. However, there is still not enough evidence that the hyperpolarization provided by inhibitory inputs, particularly those dependent on chloride ions, is adequate to deinactivate a sufficient number of T-type calcium channels to drive rebound excitation on return to baseline. Here, this issue was investigated in the deep cerebellar nuclear neurons (DCNs), which receive the output of the cerebellar cortex conveyed exclusively by the inhibitory Purkinje cells and are also known to display rebound excitation. Using cerebellar slices and whole cell recordings of large DCNs, we show that a novel piperidine-based compound that selectively antagonizes T-type calcium channel activity, 3,5-dichloro-N-[1-(2,2-dimethyl-tetrahydropyran-4-ylmethyl)-4-fluoro-piperidin-4-ylmethyl]-benzamide (TTA-P2), suppressed rebound excitation elicited by current injection as well as by synaptic inhibition, whereas other electrophysiological properties of large DCNs were unaltered. Furthermore, TTA-P2 suppressed transient high-frequency rebounds found in DCNs with low-threshold spikes as well as the slow rebounds present in DCNs without low-threshold spikes. These findings demonstrate that chloride-dependent synaptic inhibition effectively triggers T-type calcium channel-mediated rebounds and that the latter channels may support slow rebound excitation in neurons without low-threshold spikes.
Collapse
|
66
|
Gotter AL, Santarelli VP, Doran SM, Tannenbaum PL, Kraus RL, Rosahl TW, Meziane H, Montial M, Reiss DR, Wessner K, McCampbell A, Stevens J, Brunner JI, Fox SV, Uebele VN, Bayliss DA, Winrow CJ, Renger JJ. TASK-3 as a potential antidepressant target. Brain Res 2011; 1416:69-79. [PMID: 21885038 DOI: 10.1016/j.brainres.2011.08.021] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Accepted: 08/09/2011] [Indexed: 10/17/2022]
Abstract
Modulation of TASK-3 (Kcnk9) potassium channels affect neurotransmitter release in thalamocortical centers and other sleep-related nuclei having the capacity to regulate arousal cycles and REM sleep changes associated with mood disorders and antidepressant action. Circumstantial evidence from this and previous studies suggest the potential for TASK-3 to be a novel antidepressant therapeutic target; TASK-3 knock-out mice display augmented circadian amplitude and exhibit sleep architecture characterized by suppressed REM activity. Detailed analysis of locomotor activity indicates that the amplitudes of activity bout duration and bout number are augmented in TASK-3 mutants well beyond that seen in wildtypes, findings substantiated by amplitude increases in body temperature and EEG recordings of sleep stage bouts. Polysomnographic analysis of TASK-3 mutants reveals increases in nocturnal active wake and suppressed REM sleep time while increased slow wave sleep typifies the inactive phase, findings that have implications for the cognitive impact of reduced TASK-3 activity. In direct measures of their resistance to despair behavior, TASK-3 knock-outs displayed significant decreases in immobility relative to wildtype controls in both tail suspension and forced swim tests. Treatment of wildtype animals with the antidepressant Fluoxetine markedly reduced REM sleep, while leaving active wake and slow wave sleep relatively intact. Remarkably, these effects were absent in TASK-3 mutants indicating that TASK-3 is either directly involved in the mechanism of this drug's action, or participates in parallel pathways that achieve the same effect. Together, these results support the TASK-3 channel to act as a therapeutic target for antidepressant action.
Collapse
|
67
|
Zhao WQ, Toolan D, Hepler RW, Wolfe AL, Yu Y, Price E, Uebele VN, Schachter JB, Reynolds IJ, Renger JJ, McCampbell A, Ray WJ. High Throughput Monitoring of Amyloid-β42 Assembly into Soluble Oligomers Achieved by Sensitive Conformation State-Dependent Immunoassays. ACTA ACUST UNITED AC 2011; 25:655-69. [PMID: 21483096 DOI: 10.3233/jad-2011-102022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
68
|
Winrow CJ, Gotter AL, Cox CD, Doran SM, Tannenbaum PL, Breslin MJ, Garson SL, Fox SV, Harrell CM, Stevens J, Reiss DR, Cui D, Coleman PJ, Renger JJ. Promotion of sleep by suvorexant-a novel dual orexin receptor antagonist. J Neurogenet 2011; 25:52-61. [PMID: 21473737 DOI: 10.3109/01677063.2011.566953] [Citation(s) in RCA: 197] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Orexins/hypocretins are key neuropeptides responsible for regulating central arousal and reward circuits. Two receptors respond to orexin signaling, orexin 1 receptor (OX(1)R) and orexin 2 receptor (OX(2)R) with partially overlapping nervous system distributions. Genetic studies suggest orexin receptor antagonists could be therapeutic for insomnia and other disorders with disruptions of sleep and wake. Suvorexant (MK-4305) is a potent, selective, and orally bioavailable antagonist of OX(1)R and OX(2)R currently under clinical investigation as a novel therapy for insomnia. Examination of Suvorexant in radioligand binding assays using tissue from transgenic rats expressing the human OX(2)R found nearly full receptor occupancy (>90%) at plasma exposures of 1.1 μM. Dosed orally Suvorexant significantly and dose-dependently reduced locomotor activity and promoted sleep in rats (10, 30, and 100 mg/kg), dogs (1 and 3 mg/kg), and rhesus monkeys (10 mg/kg). Consistent cross-species sleep/wake architecture changes produced by Suvorexant highlight a unique opportunity to develop dual orexin antagonists as a novel therapy for insomnia.
Collapse
|
69
|
Tscherter A, David F, Ivanova T, Deleuze C, Renger JJ, Uebele VN, Shin HS, Bal T, Leresche N, Lambert RC. Minimal alterations in T-type calcium channel gating markedly modify physiological firing dynamics. J Physiol 2011; 589:1707-24. [PMID: 21320888 DOI: 10.1113/jphysiol.2010.203836] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
T-type calcium channel isoforms expressed in heterologous systems demonstrate marked differences in the biophysical properties of the resulting calcium currents. Such heterogeneity in gating behaviour not only reflects structural differences but is also observed following the regulation of channel activity by a number of ligands. However, the physiological impact of these differences in gating parameters of the T channels has never been evaluated in situ where the unique interplay between T-type calcium and other intrinsic currents is conserved, and T channel activation can be triggered by synaptic stimulation. Here, using the dynamic clamp technique, artificial T conductances were re-incorporated in thalamic neurons devoid of endogenous T currents to dissect the physiological role of the T current gating diversity on neuronal excitability. We demonstrate that the specific kinetics of the T currents in thalamocortical and nucleus reticularis thalami neurons determine the characteristic firing patterns of these neurons. We show that subtle modifications in T channel gating that are at the limit of the resolution achieved in classical biophysical studies in heterologous expression systems have profound consequences for synaptically evoked firing dynamics in native neurons. Moreover, we demonstrate that the biophysical properties of the T current in the voltage region corresponding to the foot of the activation and inactivation curves drastically condition physiologically evoked burst firing with a high degree of synaptic input specificity.
Collapse
|
70
|
Bergson P, Uebele VN, Renger JJ, Hanck DA. Novel Blockers of T-Type Calcium Channels Modify Gating. Biophys J 2011. [DOI: 10.1016/j.bpj.2010.12.3293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
|
71
|
Reger TS, Yang ZQ, Schlegel KAS, Shu Y, Mattern C, Cube R, Rittle KE, McGaughey GB, Hartman GD, Tang C, Ballard J, Kuo Y, Prueksaritanont T, Nuss CE, Doran SM, Fox SV, Garson SL, Li Y, Kraus RL, Uebele VN, Renger JJ, Barrow JC. Pyridyl amides as potent inhibitors of T-type calcium channels. Bioorg Med Chem Lett 2011; 21:1692-6. [PMID: 21316226 DOI: 10.1016/j.bmcl.2011.01.089] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Revised: 01/19/2011] [Accepted: 01/20/2011] [Indexed: 11/18/2022]
Abstract
A novel series of amide T-type calcium channel antagonists were prepared and evaluated using in vitro and in vivo assays. Optimization of the screening hit 3 led to identification of the potent and selective T-type antagonist 37 that displayed in vivo efficacy in rodent models of epilepsy and sleep.
Collapse
|
72
|
Yang ZQ, Schlegel KAS, Shu Y, Reger TS, Cube R, Mattern C, Coleman PJ, Small J, Hartman GD, Ballard J, Tang C, Kuo Y, Prueksaritanont T, Nuss CE, Doran S, Fox SV, Garson SL, Li Y, Kraus RL, Uebele VN, Taylor AB, Zeng W, Fang W, Chavez-Eng C, Troyer MD, Luk JA, Laethem T, Cook WO, Renger JJ, Barrow JC. Short-acting T-type calcium channel antagonists significantly modify sleep architecture in rodents. ACS Med Chem Lett 2010; 1:504-9. [PMID: 24900239 DOI: 10.1021/ml100170e] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Accepted: 08/18/2010] [Indexed: 01/16/2023] Open
Abstract
A novel phenyl acetamide series of short-acting T-type calcium channel antagonists has been identified and evaluated using in vitro and in vivo assays. Heterocycle substitutions of the 4-position of the phenyl acetamides afforded potent and selective antagonists that exhibited desired short plasma half-lives across preclinical species. Lead compound TTA-A8 emerged as a compound with excellent in vivo efficacy as indicated by its significant modulation of rat sleep architecture in an EEG telemetry model, favorable pharmacokinetic properties, and excellent preclinical safety. TTA-A8 recently progressed into human clinical trials, and in line with our predictions, preliminary studies (n = 12) with a 20 mg oral dose afforded a high C max of 1.82 ± 0.274 μM with an apparent terminal half-life of 3.0 ± 1.1 h.
Collapse
|
73
|
Bergson P, Hu T, Uebele VN, Renger JJ, Hanck DA. Novel Blockers of T-type Calcium Channels Modify Gating. Heart Rhythm 2010. [DOI: 10.1016/j.hrthm.2010.09.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
74
|
Suon S, Zhao J, Villarreal SA, Anumula N, Liu M, Carangia LM, Renger JJ, Zerbinatti CV. Systemic treatment with liver X receptor agonists raises apolipoprotein E, cholesterol, and amyloid-β peptides in the cerebral spinal fluid of rats. Mol Neurodegener 2010; 5:44. [PMID: 21034469 PMCID: PMC2988784 DOI: 10.1186/1750-1326-5-44] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2010] [Accepted: 10/29/2010] [Indexed: 11/12/2022] Open
Abstract
Background Apolipoprotein E (apoE) is a major cholesterol transport protein found in association with brain amyloid from Alzheimer's disease (AD) patients and the ε4 allele of apoE is a genetic risk factor for AD. Previous studies have shown that apoE forms a stable complex with amyloid β (Aβ) peptides in vitro and that the state of apoE lipidation influences the fate of brain Aβ, i.e., lipid poor apoE promotes Aβ aggregation/deposition while fully lipidated apoE favors Aβ degradation/clearance. In the brain, apoE levels and apoE lipidation are regulated by the liver X receptors (LXRs). Results We investigated the hypothesis that increased apoE levels and lipidation induced by LXR agonists facilitates Aβ efflux from the brain to the cerebral spinal fluid (CSF). We also examined if the brain expression of major apoE receptors potentially involved in apoE-mediated Aβ clearance was altered by LXR agonists. ApoE, cholesterol, Aβ40, and Aβ42 levels were all significantly elevated in the CSF of rats after only 3 days of treatment with LXR agonists. A significant reduction in soluble brain Aβ40 levels was also detected after 6 days of LXR agonist treatment. Conclusions Our novel findings suggest that central Aβ lowering caused by LXR agonists appears to involve an apoE/cholesterol-mediated transport of Aβ to the CSF and that differences between the apoE isoforms in mediating this clearance pathway may explain why individuals carrying one or two copies of APOE ε4 have increased risk for AD.
Collapse
|
75
|
Uslaner JM, Vardigan JD, Drott JM, Uebele VN, Renger JJ, Lee A, Li Z, Lê AD, Hutson PH. T-type calcium channel antagonism decreases motivation for nicotine and blocks nicotine- and cue-induced reinstatement for a response previously reinforced with nicotine. Biol Psychiatry 2010; 68:712-8. [PMID: 20579972 DOI: 10.1016/j.biopsych.2010.05.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2009] [Revised: 05/03/2010] [Accepted: 05/03/2010] [Indexed: 11/15/2022]
Abstract
BACKGROUND Recent evidence suggests an involvement of T-type calcium channels in the effects of drugs of abuse. METHODS We examined the influence of the novel, potent, and selective T-type calcium channel antagonist [2-(4-cyclopropylphenyl)-N-((1R)-1-{5-[2,2,2-trifluoroethyl]oxo}pyridine-2-yl)ethyl]acetamide] (TTA-A2) (.3, 1, or 3 mg/kg) on motivation for nicotine, as measured by nicotine self-administration on a progressive ratio (PR) schedule, and nicotine- and cue-induced reinstatement for a response previously reinforced with nicotine delivery (n = 11 or 12 Long Evans rats/group). Furthermore, we examined the specificity of the TTA-A2 effects by characterizing its influence on PR responding for food (in the absence or presence of nicotine-potentiated responding), food- versus nicotine-induced cue-potentiated reinstatement for a response previously reinforced by food administration (n = 11 or 12 Wistar Hannover rats/group), and its ability to induce a conditioned place aversion. RESULTS TTA-A2 dose-dependently decreased self-administration of nicotine on a PR schedule and the ability of both nicotine and a cue paired with nicotine to reinstate responding. The effects were specific for nicotine's incentive motivational properties, as TTA-A2 did not influence responding for food on a PR schedule but did attenuate the ability of nicotine to potentiate responding for food. Likewise, TTA-A2 did not alter food-induced cue-potentiated reinstatement for a response previously reinforced by food but did decrease nicotine-induced cue-potentiated reinstatement. Finally, TTA-A2 did not produce an aversive state, as indicated by a lack of ability to induce conditioned place aversion. CONCLUSIONS These data suggest that T-type calcium channel antagonists have potential for alleviating nicotine addiction by selectively decreasing the incentive motivational properties of nicotine.
Collapse
|