In Vitro and In Vivo Correlation of Hepatic Fraction of Metabolism by P450 in Dogs.

1-Aminobenzotriazole (ABT) has been widely used as a nonspecific mechanism-based inhibitor of cytochrome P450 (P450) enzymes. It is extensively used in preclinical studies to determine the relative contribution of oxidative metabolism mediated by P450 in vitro and in vivo. The aim of present study was to understand the translation of fraction metabolized by P450 in dog hepatocytes to in vivo using ABT, for canagliflozin, known to be cleared by P450-mediated oxidation and UDP-glucuronosyltransferases-mediated glucuronidation, and 3 drug discovery project compounds mainly cleared by hepatic metabolism.

Identification, expression and functional characterization of M4L, a muscarinic acetylcholine M4 receptor splice variant.

Rodent genomic alignment sequences support a 2-exon model for muscarinic M4 receptor. Using this model a novel N-terminal extension was discovered in the human muscarinic acetylcholine M4 receptor. An open reading frame was discovered in the human, mouse and rat with a common ATG (methionine start codon) that extended the N-terminus of the muscarinic acetylcholine M4 receptor subtype by 155 amino acids resulting in a longer variant.

Targeted Blockade of TARP-γ8-Associated AMPA Receptors: Anticonvulsant Activity with the Selective Antagonist LY3130481 (CERC-611).

Background & Objective: 6-[(1S)-1-[1-[5-(2-hydroxyethoxy)-2-pyridyl]pyrazol-3-yl]ethyl]- 3H-1,3-benzothiazol-2-one (LY3130481 or CERC-611) is a selective antagonist of AMPA receptors containing transmembrane AMPA receptor regulatory protein (TARP) γ-8 that is under development for epilepsy. The present study provided a broad inquiry into its anticonvulsant properties. LY3130481 was anticonvulsant in multiple acute seizure provocation models in mice and rats.

Structural Determinants of the γ-8 TARP Dependent AMPA Receptor Antagonist.

The forebrain specific AMPA receptor antagonist, LY3130481/CERC-611, which selectively antagonizes the AMPA receptors associated with TARP γ-8, an auxiliary subunit enriched in the forebrain, has potent antiepileptic activities without motor side effects. We designated the compounds with such activities as γ-8 TARP dependent AMPA receptor antagonists (γ-8 TDAAs). In this work, we further investigated the mechanisms of action using a radiolabeled γ-8 TDAA and ternary structural modeling with mutational validations to characterize the LY3130481 binding to γ-8.

Further Evaluation of Mechanisms Associated with the Antidepressantlike Signature of Scopolamine in Mice.

Background: Conventional antidepressants lack efficacy for many patients (treatmentresistant depression or TRD) and generally take weeks to produce full therapeutic response in others. Emerging data has identified certain drugs such as ketamine as rapidly-acting antidepressants for major depressive disorder and TRD. Scopolamine, a drug used to treat motion sickness and nausea, has also been demonstrated to function as a rapidly-acting antidepressant.

Translational Pharmacology of the Metabotropic Glutamate 2 Receptor-Preferring Agonist LY2812223 in the Animal and Human Brain.

LY2812223 [(1,2,4,5,6)-2-amino-4-(1-1,2,4-triazol-3-ylsulfanyl)bicyclo[3.1.0]hexane-2,6-dicarboxylic acid] was identified via structure-activity studies arising from the potent metabotropic glutamate mGlu2/3 receptor agonist LY354740 [(+)-2-aminobicyclo[3.

Forebrain-selective AMPA-receptor antagonism guided by TARP γ-8 as an antiepileptic mechanism.

Pharmacological manipulation of specific neural circuits to optimize therapeutic index is an unrealized goal in neurology and psychiatry. AMPA receptors are important for excitatory synaptic transmission, and their antagonists are antiepileptic. Although efficacious, AMPA-receptor antagonists, including perampanel (Fycompa), the only approved antagonist for epilepsy, induce dizziness and motor impairment.

Development of a radioligand, [(3)H]LY2119620, to probe the human M(2) and M(4) muscarinic receptor allosteric binding sites.

In this study, we characterized a muscarinic acetylcholine receptor (mAChR) potentiator, LY2119620 (3-amino-5-chloro-N-cyclopropyl-4-methyl-6-[2-(4-methylpiperazin-1-yl)-2-oxoethoxy]thieno[2,3-b]pyridine-2-carboxamide) as a novel probe of the human M2 and M4 allosteric binding sites. Since the discovery of allosteric binding sites on G protein-coupled receptors, compounds targeting these novel sites have been starting to emerge. For example, LY2033298 (3-amino-5-chloro-6-methoxy-4-methyl-thieno(2,3-b)pyridine-2-carboxylic acid cyclopropylamid) and a derivative of this chemical scaffold, VU152100 (3-amino-N-(4-methoxybenzyl)-4,6-dim​ethylthieno[2,3-b]pyridine carboxamide), bind to the human M4 mAChR allosteric pocket.

Characterization of the novel positive allosteric modulator, LY2119620, at the muscarinic M(2) and M(4) receptors.

The M(4) receptor is a compelling therapeutic target, as this receptor modulates neural circuits dysregulated in schizophrenia, and there is clinical evidence that muscarinic agonists possess both antipsychotic and procognitive efficacy. Recent efforts have shifted toward allosteric ligands to maximize receptor selectivity and manipulate endogenous cholinergic and dopaminergic signaling. In this study, we present the pharmacological characterization of LY2119620 (3-amino-5-chloro-N-cyclopropyl-4-methyl-6-[2-(4-methylpiperazin-1-yl)-2-oxoethoxy] thieno[2,3-b]pyridine-2-carboxamide), a M(2)/M(4) receptor-selective positive allosteric modulator (PAM), chemically evolved from hits identified through a M4 allosteric functional screen.

LSN2424100: a novel, potent orexin-2 receptor antagonist with selectivity over orexin-1 receptors and activity in an animal model predictive of antidepressant-like efficacy.

We describe a novel, potent and selective orexin-2 (OX2)/hypocretin-2 receptor antagonist with in vivo activity in an animal model predictive of antidepressant-like efficacy. N-biphenyl-2-yl-4-fluoro-N-(1H-imidazol-2-ylmethyl) benzenesulfonamide HCl (LSN2424100) binds with high affinity to recombinant human OX2 receptors (Ki = 4.5 nM), and selectivity over OX1 receptors (Ki = 393 nM).

Pharmacological characterization of LY593093, an M1 muscarinic acetylcholine receptor-selective partial orthosteric agonist.

Alzheimer's disease and schizophrenia are characterized by expression of psychotic, affective, and cognitive symptoms. Currently, there is a lack of adequate treatment for the cognitive symptoms associated with these diseases. Cholinergic signaling and, in particular, M1 muscarinic acetylcholine receptor (m1AChR) signaling have been implicated in the regulation of multiple cognitive domains.

Transmembrane AMPA receptor regulatory proteins and cornichon-2 allosterically regulate AMPA receptor antagonists and potentiators.

AMPA receptors mediate fast excitatory transmission in the brain. Neuronal AMPA receptors comprise GluA pore-forming principal subunits and can associate with multiple modulatory components, including transmembrane AMPA receptor regulatory proteins (TARPs) and CNIHs (cornichons). AMPA receptor potentiators and non-competitive antagonists represent potential targets for a variety of neuropsychiatric disorders.

Co-expression of neuropeptide Y Y1 and Y5 receptors results in heterodimerization and altered functional properties.

Centrally administered neuropeptide Y (NPY) produces anxiolytic and orexigenic effects by interacting with Y1 and Y5 receptors that are colocalized in many brain regions. Therefore, we tested the hypothesis that co-expression of Y1 and Y5 receptors results in heterodimerization, altered pharmacological properties and altered desensitization. To accomplish this, the carboxyl-termini of Y1 and Y5 receptors were fused with Renilla luciferase and green fluorescent protein and the proximity of the tagged receptors assessed using bioluminescent resonance energy transfer.

Neuropeptide Y Y4 receptor homodimers dissociate upon agonist stimulation.

The pancreatic polypeptide-fold family of peptides consists of three 36-amino acid peptides, namely neuropeptide Y (NPY), peptide YY, and pancreatic polypeptide (PP). These peptides regulate important functions, including food intake, circadian rhythms, mood, blood pressure, intestinal secretion, and gut motility, through four receptors: Y1, Y2, Y4, and Y5. Additional receptor subtypes have been proposed based on pharmacology observed in native tissues.

The use of bioluminescence resonance energy transfer 2 to study neuropeptide Y receptor agonist-induced beta-arrestin 2 interaction.

The neuropeptide Y (NPY) family peptides NPY, peptide YY (PYY), and pancreatic polypeptide (PP) bind to four G protein-coupled receptors (GPCRs): Y1, Y2, Y4, and Y5. A key step in the desensitization and internalization of GPCRs is the association of the receptor with beta-arrestins. In the present study, these receptors were analyzed with respect to their ability to interact with GFP2-tagged beta-arrestin 2 using the new bioluminescence resonance energy transfer 2 method.

Neuropeptide Y-Y2 receptors mediate anxiety in the amygdala.

The behavioral effects of direct injection of the neuropeptide Y (NPY) Y2 receptor agonist C2-NPY into the basolateral nucleus of the amygdala (BLA) was assessed in rats utilizing the social interaction test (SI). C2-NPY decreased SI time in a dose-dependent manner with a significant change observed at a dose of 80 pmol/100 nl. The anxiogenic effects produced by intra-amygdalar C2-NPY injections were reversed with intraperitoneal administration of alprazolam (1 mg/kg), a known anxiolytic.