AlphaMissense prediction for the evaluation of missense variants in the diagnostic setting of neuromuscular disorders.

Next-generation sequencing has improved diagnostic outcomes for neuromuscular disorders, but interpreting rare missense variants remains challenging. We evaluated AlphaMissense, a recently developed machine learning tool, for predicting missense variant pathogenicity, using 45 (likely) pathogenic variants and 21 variants of uncertain significance from 58 deeply phenotyped patients. AlphaMissense predicted 69% of pathogenic variants correctly, but also classified 62% of variants of uncertain significance as pathogenic.

Selectively counteracting cerebellar adaptations to chronic alcohol exposure reduces acute alcohol withdrawal severity in C57BL6/N mice.

A critical component of Alcohol Use Disorder (AUD) is alcohol (EtOH) withdrawal and consequent aversive withdrawal symptoms that generate negative reinforcement for renewed EtOH consumption to alleviate such symptoms. Here, we simulated human binge EtOH consumption and subsequent acute withdrawal by exposing male and female C57BL6/N mice to EtOH vapor for varying durations (24-72 h). During acute withdrawal, starting 4 h after removal from EtOH vapor, we used patch-clamp recording in cerebellar slices, combined with behavioral analysis of aversive somatic/motor (performance on the accelerating rotorod) and affective/emotional (ultrasonic vocalizations and blood corticosterone) withdrawal symptoms.

Novel pyrazolothienopyridinones as potential GABA receptor modulators.

Unlabelled: The synthesis of novel pyrazolothienopyridinone derivatives as potential GABA receptor modulators was performed and is herein described. A crucial step of the synthesis involving handling unstable aminothiophenes was managed via two different synthetic strategies delivering a set of 8 target compounds.

Supplementary Information: The online version contains supplementary material available at 10.

Novel synthetic procedures for C2 substituted imidazoquinolines as ligands for the α/β-interface of the GABAA-receptor.

Unlabelled: A series of substituted imidazoquinolines, a structurally related chemotype to pyrazoloquinolinones, a well-known class of GABA ligands, was prepared via two synthetic procedures and the efficiency of these procedures were compared. One method relies on classical heterocyclic synthesis, the other one aims at late-stage decoration of a truncated scaffold via direct C-H functionalization. A pharmacological evaluation disclosed that one of the synthesized derivatives showed interesting activity on a α1β3 containing receptor subtype.

Vascular effects of midazolam, flumazenil, and a novel imidazobenzodiazepine MP-III-058 on isolated rat aorta.

Hypotensive influences of benzodiazepines and other GABA receptor ligands, recognized in clinical practice, seem to stem from the existence of "vascular" GABA receptors in peripheral blood vessels, besides any mechanisms in the central and peripheral nervous systems. We aimed to further elucidate the vasodilatatory effects of ligands acting through GABA receptors. Using immunohistochemistry, the rat aortic smooth muscle layer was found to express GABA γ2 and α1-5 subunit proteins.

Search for Novel Therapies for Essential Tremor Based on Positive Modulation of α6-Containing GABA Receptors.

Background: Prior work using GABA receptor subunit knockouts and the harmaline model has indicated that low-dose alcohol, gaboxadol, and ganaxolone suppress tremor via α6βδ GABA receptors. This suggests that drugs specifically enhancing the action of α6βδ or α6βγ2 GABA receptors, both predominantly expressed on cerebellar granule cells, would be effective against tremor. We thus examined three drugs described by studies as selective α6βδ (ketamine) or α6βγ2 (Compound 6, flumazenil) receptor modulators.

Navigating the complex landscape of benzodiazepine- and Z-drug diversity: insights from comprehensive FDA adverse event reporting system analysis and beyond.

Introduction: Medications which target benzodiazepine (BZD) binding sites of GABAA receptors (GABAARs) have been in widespread use since the nineteen-sixties. They carry labels as anxiolytics, hypnotics or antiepileptics. All benzodiazepines and several nonbenzodiazepine Z-drugs share high affinity binding sites on certain subtypes of GABAA receptors, from which they can be displaced by the clinically used antagonist flumazenil.

Pregnenolone sulfate analogues differentially modulate GABA receptor closed/desensitised states.

Background And Purpose: GABA receptors are regulated by numerous classes of allosteric modulators. However, regulation of receptor macroscopic desensitisation remains largely unexplored and may offer new therapeutic opportunities. Here, we report the emerging potential for modulating desensitisation with analogues of the endogenous inhibitory neurosteroid, pregnenolone sulfate.

Cys-loop receptors on cannabinoids: All high?

Endocannabinoids (eCBS) are endogenously derived lipid signaling molecules that serve as tissue hormones and interact with multiple targets, mostly within the endocannabinoid system (ECS). The ECS is a highly conserved regulatory system involved in homeostatic regulation, organ formation, and immunomodulation of chordates. The term "cannabinoid" evolved from the distinctive class of plant compounds found in , an ancient herb, due to their action on CB1 and CB2 receptors.

Novel alpha6 preferring GABA-A receptor ligands based on loreclezole.

The family of GABA-A receptors contains nineteen mammalian subunits from which pentameric, GABA gated anion channels are assembled. The subunit encoded by the GABRA6 gene is highly expressed in the cerebellum and the receptors to which it contributes have recently been demonstrated to be a promising candidate as a novel drug target. Here we examined a series of loreclezole derivatives for potentially selective action at α6β3γ2 receptors with the help of computational methods and functional testing with the two-electrode voltage clamp technique.

β subunits of GABA receptors form proton-gated chloride channels: Insights into the molecular basis.

Gamma-aminobutyric acid type A receptors (GABARs) are ligand gated channels mediating inhibition in the central nervous system. Here, we identify a so far undescribed function of β-subunit homomers as proton-gated anion channels. Mutation of a single H267A in β3 subunits completely abolishes channel activation by protons.

Unravelling the Turn-On Fluorescence Mechanism of a Fluorescein-Based Probe in GABA Receptors.

GABA (γ-aminobutyric acid type A) receptors are ligand-gated ion channels mediating fast inhibitory transmission in the mammalian brain. Here we report the molecular and electronic mechanism governing the turn-on emission of a fluorescein-based imaging probe able to target the human GABA receptor. Multiscale calculations evidence a drastic conformational change of the probe from folded in solution to extended upon binding to the receptor.

Molecular Mingling: Multimodal Predictions of Ligand Promiscuity in Pentameric Ligand-Gated Ion Channels.

Human pentameric ligand-gated ion channels (pLGICs) comprise nicotinic acetylcholine receptors (nAChRs), 5-hydroxytryptamine type 3 receptors (5-HTRs), zinc-activated channels (ZAC), γ-aminobutyric acid type A receptors (GABARs) and glycine receptors (GlyRs). They are recognized therapeutic targets of some of the most prescribed drugs like general anesthetics, anxiolytics, smoking cessation aids, antiemetics and many more. Currently, approximately 100 experimental structures of pLGICs with ligands bound exist in the protein data bank (PDB).

Unravelling the Turn-On Fluorescence Mechanism of a Fluorescein-Based Probe in GABA Receptors.

GABA (γ-aminobutyric acid type A) receptors are ligand-gated ion channels mediating fast inhibitory transmission in the mammalian brain. Here we report the molecular and electronic mechanism governing the turn-on emission of a fluorescein-based imaging probe able to target the human GABA receptor. Multiscale calculations evidence a drastic conformational change of the probe from folded in solution to extended upon binding to the receptor.

A de novo missense variant in GABRA4 alters receptor function in an epileptic and neurodevelopmental phenotype.

Variants in γ-aminobutyric acid A (GABA ) receptor genes cause different forms of epilepsy and neurodevelopmental disorders. To date, GABRA4, encoding the α4-subunit, has not been associated with a monogenic condition. However, preclinical evidence points toward seizure susceptibility.

Tricyclic antipsychotics and antidepressants can inhibit α5-containing GABA receptors by two distinct mechanisms.

Background And Purpose: Many psychotherapeutic drugs, including clozapine, display polypharmacology and act on GABA receptors. Patients with schizophrenia show alterations in function, structure and molecular composition of the hippocampus, and a recent study demonstrated aberrant levels of hippocampal α5 subunit-containing GABA receptors. The purpose of this study is to investigate the effects of tricyclic compounds on α5 subunit-containing receptor subtypes.

Structure-Guided Computational Methods Predict Multiple Distinct Binding Modes for Pyrazoloquinolinones in GABA Receptors.

Pyrazoloquinolinones (PQs) are a versatile class of GABA receptor ligands. It has been demonstrated that high functional selectivity for certain receptor subtypes can be obtained by specific substitution patterns, but so far, no clear SAR rules emerge from the studies. As is the case for many GABA receptor targeting chemotypes, PQs can interact with distinct binding sites on a given receptor pentamer.

A Benzodiazepine Ligand with Improved GABA Receptor 5-Subunit Selectivity Driven by Interactions with Loop C.

The family of GABA receptors is an important drug target group in the treatment of sleep disorders, anxiety, epileptic seizures, and many others. The most frequent GABA receptor subtype is composed of two -, two -, and one 2-subunit, whereas the nature of the -subunit critically determines the properties of the benzodiazepine binding site of those receptors. Nearly all of the clinically relevant drugs target all GABA receptor subtypes equally.

Two Distinct Populations of α1α6-Containing GABAA-Receptors in Rat Cerebellum.

GABAA receptors are pentameric GABA-gated chloride channels. The existence of 19 different subunits (six α, three β, three γ, δ, ε, θ, π, and three ρ) in mammalian systems gives rise to an enormous theoretical diversity of GABAA receptor subtypes with distinct subunit composition and unique pharmacological properties. These receptors are already now the drug targets of several clinically used compounds, such as benzodiazepines, anesthetics, and many more.

Molecular basis of mood and cognitive adverse events elucidated via a combination of pharmacovigilance data mining and functional enrichment analysis.

Drug-induced Mood- and Cognition-related adverse events (MCAEs) are often only detected during the clinical trial phases of drug development, or even after marketing, thus posing a major safety concern and a challenge for both pharmaceutical companies and clinicians. To fill some gaps in the understanding and elucidate potential biological mechanisms of action frequently associated with MCAEs, we present a unique workflow linking observational population data with the available knowledge at molecular, cellular, and psychopharmacology levels. It is based on statistical analysis of pharmacovigilance reports and subsequent signaling pathway analyses, followed by evidence-based expert manual curation of the outcomes.