Publications by authors named "Caterina Virginio"

8 Publications

  • Page 1 of 1

MPX-004 and MPX-007: New Pharmacological Tools to Study the Physiology of NMDA Receptors Containing the GluN2A Subunit.

PLoS One 2016 1;11(2):e0148129. Epub 2016 Feb 1.

Mnemosyne Pharmaceuticals, Inc. (formerly Luc Therapeutics) 400 Technology Square, Cambridge, MA 02139, United States of America.

GluN2A is the most abundant of the GluN2 NMDA receptor subunits in the mammalian CNS. Physiological and genetic evidence implicate GluN2A-containing receptors in susceptibility to autism, schizophrenia, childhood epilepsy and neurodevelopmental disorders such as Rett Syndrome. However, GluN2A-selective pharmacological probes to explore the therapeutic potential of targeting these receptors have been lacking. Here we disclose a novel series of pyrazine-containing GluN2A antagonists exemplified by MPX-004 (5-(((3-chloro-4-fluorophenyl)sulfonamido)methyl)-N-((2-methylthiazol-5-yl)methyl)pyrazine-2-carboxamide) and MPX-007 (5-(((3-fluoro-4-fluorophenyl)sulfonamido)methyl)-N-((2-methylthiazol-5-yl)methyl)methylpyrazine-2-carboxamide). MPX-004 and MPX-007 inhibit GluN2A-containing NMDA receptors expressed in HEK cells with IC50s of 79 nM and 27 nM, respectively. In contrast, at concentrations that completely inhibited GluN2A activity these compounds have no inhibitory effect on GluN2B or GluN2D receptor-mediated responses in similar HEK cell-based assays. Potency and selectivity were confirmed in electrophysiology assays in Xenopus oocytes expressing GluN2A-D receptor subtypes. Maximal concentrations of MPX-004 and MPX-007 inhibited ~30% of the whole-cell current in rat pyramidal neurons in primary culture and MPX-004 inhibited ~60% of the total NMDA receptor-mediated EPSP in rat hippocampal slices. GluN2A-selectivity at native receptors was confirmed by the finding that MPX-004 had no inhibitory effect on NMDA receptor mediated synaptic currents in cortical slices from GRIN2A knock out mice. Thus, MPX-004 and MPX-007 offer highly selective pharmacological tools to probe GluN2A physiology and involvement in neuropsychiatric and developmental disorders.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0148129PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4734667PMC
July 2016

A Novel Modulator of Kv3 Potassium Channels Regulates the Firing of Parvalbumin-Positive Cortical Interneurons.

J Pharmacol Exp Ther 2015 Sep 17;354(3):251-60. Epub 2015 Jun 17.

Autifony s.r.l., Verona, Italy (M.D.R.-S., G.A.); Aptuit s.r.l., Verona, Italy (E.Z., C.M., N.G., R.B., L.A., C.V.); Medicines Research Centre, GlaxoSmithKline S.p.A., Verona, Italy (F.G.); and Autifony Therapeutics Limited, Imperial College Incubator, London, United Kingdom (C.H.L.)

Kv3.1 and Kv3.2 high voltage-activated potassium channels, which display fast activation and deactivation kinetics, are known to make a crucial contribution to the fast-spiking phenotype of certain neurons. Pharmacological experiments show that the blockade of native Kv3 currents with low concentrations of tetraethylammonium or 4-aminopyridine impairs the expression of this firing phenotype. In particular, Kv3 channels are highly expressed by fast-spiking, parvalbumin-positive interneurons in corticolimbic brain circuits, which modulate the synchronization of cortical circuits and the generation of brain rhythms. Here, we describe a novel small molecule, (5R)-5-ethyl-3-(6-{[4-methyl-3-(methyloxy)phenyl]oxy}-3-pyridinyl)-2,4-imidazolidinedione (AUT1), which modulates Kv3.1 and Kv3.2 channels in human recombinant and rodent native neurons. AUT1 increased whole currents mediated by human Kv3.1b and Kv3.2a channels, with a concomitant leftward shift in the voltage dependence of activation. A less potent effect was observed on hKv3.3 currents. In mouse somatosensory cortex slices in vitro, AUT1 rescued the fast-spiking phenotype of parvalbumin-positive-fast-spiking interneurons following an impairment of their firing capacity by blocking a proportion of Kv3 channels with a low concentration of tetraethylammonium. Notably, AUT1 had no effect on interneuron firing when applied alone. Together, these data confirm the role played by Kv3 channels in the regulation of the firing phenotype of somatosensory interneurons and suggest that AUT1 and other Kv3 modulators could represent a new and promising therapeutic approach to the treatment of disorders associated with dysfunction of inhibitory feedback in corticolimbic circuits, such as schizophrenia.
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http://dx.doi.org/10.1124/jpet.115.225748DOI Listing
September 2015

A novel series of benzimidazole NR2B-selective NMDA receptor antagonists.

Bioorg Med Chem Lett 2012 Apr 6;22(7):2620-3. Epub 2012 Feb 6.

GlaxoSmithKline R&D, Medicines Research Centre, Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, UK.

A series of novel benzimidazoles are discussed as NR2B-selective N-methyl-d-aspartate (NMDA) receptor antagonists. High throughput screening (HTS) efforts identified a number of potent and selective NR2B antagonists such as 1. Exploration of the substituents around the core of this template identified a number of compounds with high potency for NR2B (pIC(50) >7) and good selectivity against the NR2A subunit (pIC(50) <4.3) as defined by FLIPR-Ca(2+) and radioligand binding studies. These agents offer potential for the development of therapeutics for a range of nervous system disorders including chronic pain, neurodegeneration, migraine and major depression.
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http://dx.doi.org/10.1016/j.bmcl.2012.01.108DOI Listing
April 2012

Synthesis and biological activity of a novel class nicotinic acetylcholine receptors (nAChRs) ligands structurally related to anatoxin-a.

Bioorg Med Chem Lett 2011 Sep 20;21(18):5423-7. Epub 2011 Jul 20.

Department of Pharmaceutical Sciences, University of Ferrara, Via Fossato di Mortara 17/19, 44121 Ferrara, Italy.

The introduction of the isoxazole ring as bioisosteric replacement of the acetyl group of anatoxin-a led to a new series of derivatives binding to nicotinic acetylcholine receptors. Bulkier substitutions than methyl at the 3 position of isoxazole were shown to be detrimental for the activity. The binding potency of the most interesting compounds with α1, α7 and α3β4 receptor subtypes, was, anyway, only at micromolar level. Moreover, differently from known derivatives with pyridine, isoxazole condensed to azabicyclo ring led to no activity.
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http://dx.doi.org/10.1016/j.bmcl.2011.06.127DOI Listing
September 2011

Identification of novel alpha7 nAChR positive allosteric modulators with the use of pharmacophore in silico screening methods.

Bioorg Med Chem Lett 2010 Aug 8;20(15):4561-5. Epub 2010 Jun 8.

GlaxoSmithKline, Molecular Discovery Research, Verona, Italy.

The pharmacophore model of in house potent and selective alpha7 nAChR positive allosteric modulators is reported. The model was used to fish out commercially-available compounds from corporate 3D databases. As a result, novel alpha7 positive modulator chemotypes were identified. A rat full PK profile of a representative compound is also described.
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http://dx.doi.org/10.1016/j.bmcl.2010.06.014DOI Listing
August 2010

Differential inhibition of rat alpha3* and alpha7 nicotinic acetylcholine receptors by tetrandrine and closely related bis-benzylisoquinoline derivatives.

Neurosci Lett 2005 Jun;381(3):299-304

GlaxoSmithKline Medicines Research Centre, Assay Development and Compound Profiling, Via A. Fleming 4, 37135 Verona, Italy.

The patch-clamp technique was used to investigate the effects of bis-benzylisoquinoline alkaloids on two of the major neuronal nicotinic acetylcholine receptors (nAChRs), the alpha3-containing nAChR (alpha3*nAChR) endogenously expressed in PC12 cells and the rat alpha7-nAChR heterologously expressed in GH4C1 cells. Tetrandrine and hernandezine reversibly inhibited both receptors displaying half-maximal inhibitory concentrations (IC50) of 8.1 microM and 5.8 microM for alpha3*nAChR and 407.4 nM and 372.2 nM, respectively, for alpha7-nAChR. E6-berbamine completely inhibited the alpha3*nAChR with an IC50 of 5.1 microM, but only partially inhibited the alpha7-nAChR at concentrations up to 30 microM. Tetrandrine inhibition of alpha3*nAChR was functionally non-competitive. All three compounds displaced radiolabelled methyllycaconitine ([3H]-MLA) binding to alpha7-nAChR providing some evidence of competitive antagonism. The results demonstrate that these alkaloids are nAChRs antagonists, with tetrandrine and hernandezine displaying selectivity for one of the major neuronal subtype, the alpha7 nAChR. The different potencies and multiple modes of action on nAChRs may help to better understand the pharmacology of these receptors and to aid in novel drug design.
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http://dx.doi.org/10.1016/j.neulet.2005.02.035DOI Listing
June 2005

The antidepressant fluoxetine blocks the human small conductance calcium-activated potassium channels SK1, SK2 and SK3.

Neurosci Lett 2003 Jul;346(1-2):85-8

GlaxoSmithKline, Medicines Research Centre, Via A Fleming 4, 37135 Verona, Italy.

The effects of fluoxetine (Prozac) on the activity of human small-conductance calcium-activated potassium (SK) channels were investigated utilizing a functional fluorescence assay with bis-(1,3-dibutylbarbituric acid)trimethine oxonol (DiBAC(4)(3)). Fluoxetine blocked SK channels stably expressed in HEK 293 cells in a concentration-dependent manner displaying half-maximal inhibitory concentrations (IC(50)) of 9 microM for hSK1, 7 microM for hSK2 and 20 microM for hSK3. The block of hSK3 channels was confirmed by whole cell patch-clamp recordings of the recombinant cells and human TE 671 cells. Fluoxetine also inhibited [(125)I]apamin binding in a concentration-dependent manner displaying IC(50) values of 63 microM for hSK1, 148 microM for hSK2 and 295 microM for hSK3. These results provide new information concerning the mechanism of therapeutic and/or side effects of one of the most widely used antidepressant drugs.
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http://dx.doi.org/10.1016/s0304-3940(03)00574-3DOI Listing
July 2003

Pharmacological properties of rat alpha 7 nicotinic receptors expressed in native and recombinant cell systems.

Eur J Pharmacol 2002 Jun;445(3):153-61

Systems Research, GlaxoSmithKline Medicines Research Centre, Via A. Fleming 4, 37135, Verona, Italy.

The pharmacological properties of the rat alpha7 nicotinic acetylcholine receptor endogenously expressed in PC12 cells and recombinantly expressed in GH4C1 cells (alpha7-GH4C1 cells) were characterized and compared. Patch-clamp recordings demonstrated that activation by choline and block by methyllycaconitine and dihydro-beta-erythroidine were similar, but block by mecamylamine was different. Whereas in alpha7-GH4C1 cells the inhibition curve for mecamylamine was monophasic (IC(50) of 1.6 microM), it was biphasic in PC12 cells (IC(50) values of 341 nM and 9.6 microM). The same rank order of potency was obtained for various nicotinic agonists, while acetylcholine was 3.7-fold less potent and 1.5-fold more effective in PC12 cells. Dihydro-beta-erythroidine differentially blocked acetylcholine-evoked currents in both systems. Since reverse transcriptase polymerase chain reaction (RT-PCR) experiments revealed expression of alpha3, alpha4, alpha5, alpha7 and beta4 subunits in PC12 cells, whereas GH4C1 cells express only the beta4 subunit, our results suggest that more than one form of alpha7 containing heteromeric nicotinic receptors might be functionally expressed in PC12 cells.
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http://dx.doi.org/10.1016/s0014-2999(02)01750-8DOI Listing
June 2002