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Papers by Guillaume Sandoz

Research paper thumbnail of Two-Pore-Domain Potassium Channel Agonist to Efficiently Treat Migraine

Dataset for the pubilcation "Two-Pore-Domain Potassium Channel Agonist to Efficiently Treat ... more Dataset for the pubilcation "Two-Pore-Domain Potassium Channel Agonist to Efficiently Treat Migraine" the excel files contains all the data obtained for the 4 figures of the publications: -the bahavior in mice -the electrophysiology of primary neuronal culture -Behavior in rats

Research paper thumbnail of Régulation des canaux calcium neuronaux sensibles au potentiel

AIX-MARSEILLE2-BU Méd/Odontol. (130552103) / SudocPARIS-BIUP (751062107) / SudocSudocFranceF

Research paper thumbnail of Heterodimerization within the TREK channel subfamily produces a diverse family of highly regulated potassium channels

Proceedings of the National Academy of Sciences of the United States of America, Mar 28, 2016

Research paper thumbnail of Hijacking of internal calcium dynamics by intracellularly residing rhodopsins

bioRxiv (Cold Spring Harbor Laboratory), May 25, 2023

Research paper thumbnail of Regulation of two-pore-domain potassium TREK channels and their involvement in pain perception and migraine

Neuroscience Letters, Mar 1, 2022

The ability to sense pain signals is closely linked to the activity of ion channels expressed in ... more The ability to sense pain signals is closely linked to the activity of ion channels expressed in nociceptors, the first neurons that transduce noxious stimuli into pain. Among these ion channel, TREK1, TREK2 and TRAAK from the TREK subfamily of the Two-Pore-Domain potassium (K2P) channels, are hyperpolarizing channels that render neurons hypoexcitable. They are regulated by diverse physical and chemical stimuli as well as neurotransmitters through G-protein coupled receptors activation. Here, we review the molecular mechanisms underlying these regulations and their functional relevance in pain and migraine induction.

Research paper thumbnail of Photopharmacological approaches for dissecting potassium channel physiology

Current Opinion in Pharmacology, Apr 1, 2022

Photopharmacology allows for the remote control of ion channels and receptors by the application ... more Photopharmacology allows for the remote control of ion channels and receptors by the application of light-sensitive compounds. Upon irradiation with light these molecules change their configuration, enabling channel modulation with both spatial and temporal resolution. For the control of potassium channel physiology mainly two approaches have evolved. Photoswitchable tethered ligands (PTLs) and freely diffusible photochromic ligands (PCLs), targeting K+ channels, serve to gain insights in neuronal functions of the brain and the heart, whereby the molecules have been refined in the past years with special focus on improving switching characteristics in terms of red-shifted wavelengths and temporal resolution. In this review we provide an overview about the application of these tools in studying potassium channels and neuronal circuit, highlighting recent developments towards future implementations.

Research paper thumbnail of Télécommander l’activité des canaux ioniques endogènes par la lumière

M S-medecine Sciences, Nov 1, 2012

Research paper thumbnail of Migraine and Two-Pore-Domain Potassium Channels

The Neuroscientist, Jul 27, 2020

Research paper thumbnail of A fine-tuned azobenzene for enhanced photopharmacology in vivo

Cell Chemical Biology, 2021

Despite the power of photopharmacology for interrogating signaling proteins, many photopharmacolo... more Despite the power of photopharmacology for interrogating signaling proteins, many photopharmacological systems are limited by their efficiency, speed, or spectral properties. Here, we screen a library of azobenzene photoswitches and identify a urea-substituted "azobenzene-400" core that offers bistable switching between cis and trans with improved kinetics, light sensitivity, and a red-shift. We then focus on the metabotropic glutamate receptors (mGluRs), neuromodulatory receptors that are major pharmacological targets. Synthesis of "BGAG12,400," a photoswitchable orthogonal, remotely tethered ligand (PORTL), enables highly efficient, rapid optical agonism following conjugation to SNAP-tagged mGluR2 and permits robust optical control of mGluR1 and mGluR5 signaling. We then produce fluorophore-conjugated branched PORTLs to enable dual imaging and manipulation of mGluRs and highlight their power in ex vivo slice and in vivo behavioral experiments in the mouse prefrontal cortex. Finally, we demonstrate the generalizability of our strategy by developing an improved soluble, photoswitchable pore blocker for potassium channels.

Research paper thumbnail of Mycolacton: ein Bakterientoxin als zukünftiges Schmerzmittel?

Journal Club Schmerzmedizin, 2014

Buruli Ulcer ist eine durch das Bakterium Mycobakterium ulcerans hervorgerufene Krankheit der Hau... more Buruli Ulcer ist eine durch das Bakterium Mycobakterium ulcerans hervorgerufene Krankheit der Haut und Weichteile. Durch das Toxin Mycolacton entstehen dabei grose Gewebeschaden, die zu Beginn der Krankheit keine Schmerzen hervorrufen. Betroffene nehmen daher die Gewebelasionen erst ernst, wenn die Krankheit schon weit fortgeschritten ist. Wissenschaftler um Priscilla Brodin und Laurent Marsollier vom franzosischen Zentrum fur wissenschaftliche Forschung (CNRS) haben nun den molekularen Mechanismus dieser Analgesie aufgedeckt.

Research paper thumbnail of Microfluidic separation of magnetic nanoparticles on an ordered array of magnetized micropillars

Research paper thumbnail of Area-specific development of distinct projection neuron subclasses is regulated by postnatal epigenetic modifications

eLife, 2016

During cortical development, the identity of major classes of long-distance projection neurons is... more During cortical development, the identity of major classes of long-distance projection neurons is established by the expression of molecular determinants, which become gradually restricted and mutually exclusive. However, the mechanisms by which projection neurons acquire their final properties during postnatal stages are still poorly understood. In this study, we show that the number of neurons co-expressing Ctip2 and Satb2, respectively involved in the early specification of subcerebral and callosal projection neurons, progressively increases after birth in the somatosensory cortex. Ctip2/Satb2 postnatal co-localization defines two distinct neuronal subclasses projecting either to the contralateral cortex or to the brainstem suggesting that Ctip2/Satb2 co-expression may refine their properties rather than determine their identity. Gain- and loss-of-function approaches reveal that the transcriptional adaptor Lmo4 drives this maturation program through modulation of epigenetic mecha...

Research paper thumbnail of Télécommander l’activité des canaux ioniques endogènes par la lumière

Research paper thumbnail of MECHANISMS OF SIGNAL TRANSDUCTION-The interaction between the I-II loop and the III-IV loop of Cav2. 1 contributes to voltage-dependent inactivation in a b-dependent manner

Research paper thumbnail of Régulation des canaux calcium neuronaux sensibles au potentiel

AIX-MARSEILLE2-BU Méd/Odontol. (130552103) / SudocPARIS-BIUP (751062107) / SudocSudocFranceF

Research paper thumbnail of Complexes protéiques et perméabilité de la membrane cytoplasmique: exemple du canal TREK

Research paper thumbnail of Remotely control the activity of endogenous ion channels by light

Research paper thumbnail of Two-Pore-Domain Potassium Channel Agonist to Efficiently Treat Migraine

Dataset for the pubilcation "Two-Pore-Domain Potassium Channel Agonist to Efficiently Treat ... more Dataset for the pubilcation "Two-Pore-Domain Potassium Channel Agonist to Efficiently Treat Migraine" the excel files contains all the data obtained for the 4 figures of the publications: -the bahavior in mice -the electrophysiology of primary neuronal culture -Behavior in rats

Research paper thumbnail of A modern ionotropic glutamate receptor with a K+ selectivity signature sequence

Nature Communications, 2011

Glutamate is the major excitatory neurotransmitter in the mammalian central nervous system and ga... more Glutamate is the major excitatory neurotransmitter in the mammalian central nervous system and gates non-selective cation channels. The origins of glutamate receptors are not well understood as they differ structurally and functionally from simple bacterial ligand-gated ion channels. Here we report the discovery of an ionotropic glutamate receptor that combines the typical eukaryotic domain architecture with the 'TXVGYG' signature sequence of the selectivity filter found in K + channels. This receptor exhibits functional properties intermediate between bacterial and eukaryotic glutamate-gated ion channels, suggesting a link in the evolution of ionotropic glutamate receptors.

Research paper thumbnail of Optical probing of a dynamic membrane interaction that regulates the TREK1 channel

Proceedings of the National Academy of Sciences, 2011

TREK channels produce background currents that regulate cell excitability. These channels are sen... more TREK channels produce background currents that regulate cell excitability. These channels are sensitive to a wide variety of stimuli including polyunsaturated fatty acids (PUFAs), phospholipids, mechanical stretch, and intracellular acidification. They are inhibited by neurotransmitters, hormones, and pharmacological agents such as the antidepressant fluoxetine. TREK1 knockout mice have impaired PUFA-mediated neuroprotection to ischemia, reduced sensitivity to volatile anesthetics, altered perception of pain, and a depression-resistant phenotype. Here, we investigate TREK1 regulation by Gq-coupled receptors (GqPCR) and phospholipids. Several reports indicate that the C-terminal domain of TREK1 is a key regulatory domain. We developed a fluorescent-based technique that monitors the plasma membrane association of the C terminus of TREK1 in real time. Our fluorescence and functional experiments link the modulation of TREK1 channel function by internal pH, phospholipid, and GqPCRs to TR...

Research paper thumbnail of Two-Pore-Domain Potassium Channel Agonist to Efficiently Treat Migraine

Dataset for the pubilcation "Two-Pore-Domain Potassium Channel Agonist to Efficiently Treat ... more Dataset for the pubilcation "Two-Pore-Domain Potassium Channel Agonist to Efficiently Treat Migraine" the excel files contains all the data obtained for the 4 figures of the publications: -the bahavior in mice -the electrophysiology of primary neuronal culture -Behavior in rats

Research paper thumbnail of Régulation des canaux calcium neuronaux sensibles au potentiel

AIX-MARSEILLE2-BU Méd/Odontol. (130552103) / SudocPARIS-BIUP (751062107) / SudocSudocFranceF

Research paper thumbnail of Heterodimerization within the TREK channel subfamily produces a diverse family of highly regulated potassium channels

Proceedings of the National Academy of Sciences of the United States of America, Mar 28, 2016

Research paper thumbnail of Hijacking of internal calcium dynamics by intracellularly residing rhodopsins

bioRxiv (Cold Spring Harbor Laboratory), May 25, 2023

Research paper thumbnail of Regulation of two-pore-domain potassium TREK channels and their involvement in pain perception and migraine

Neuroscience Letters, Mar 1, 2022

The ability to sense pain signals is closely linked to the activity of ion channels expressed in ... more The ability to sense pain signals is closely linked to the activity of ion channels expressed in nociceptors, the first neurons that transduce noxious stimuli into pain. Among these ion channel, TREK1, TREK2 and TRAAK from the TREK subfamily of the Two-Pore-Domain potassium (K2P) channels, are hyperpolarizing channels that render neurons hypoexcitable. They are regulated by diverse physical and chemical stimuli as well as neurotransmitters through G-protein coupled receptors activation. Here, we review the molecular mechanisms underlying these regulations and their functional relevance in pain and migraine induction.

Research paper thumbnail of Photopharmacological approaches for dissecting potassium channel physiology

Current Opinion in Pharmacology, Apr 1, 2022

Photopharmacology allows for the remote control of ion channels and receptors by the application ... more Photopharmacology allows for the remote control of ion channels and receptors by the application of light-sensitive compounds. Upon irradiation with light these molecules change their configuration, enabling channel modulation with both spatial and temporal resolution. For the control of potassium channel physiology mainly two approaches have evolved. Photoswitchable tethered ligands (PTLs) and freely diffusible photochromic ligands (PCLs), targeting K+ channels, serve to gain insights in neuronal functions of the brain and the heart, whereby the molecules have been refined in the past years with special focus on improving switching characteristics in terms of red-shifted wavelengths and temporal resolution. In this review we provide an overview about the application of these tools in studying potassium channels and neuronal circuit, highlighting recent developments towards future implementations.

Research paper thumbnail of Télécommander l’activité des canaux ioniques endogènes par la lumière

M S-medecine Sciences, Nov 1, 2012

Research paper thumbnail of Migraine and Two-Pore-Domain Potassium Channels

The Neuroscientist, Jul 27, 2020

Research paper thumbnail of A fine-tuned azobenzene for enhanced photopharmacology in vivo

Cell Chemical Biology, 2021

Despite the power of photopharmacology for interrogating signaling proteins, many photopharmacolo... more Despite the power of photopharmacology for interrogating signaling proteins, many photopharmacological systems are limited by their efficiency, speed, or spectral properties. Here, we screen a library of azobenzene photoswitches and identify a urea-substituted "azobenzene-400" core that offers bistable switching between cis and trans with improved kinetics, light sensitivity, and a red-shift. We then focus on the metabotropic glutamate receptors (mGluRs), neuromodulatory receptors that are major pharmacological targets. Synthesis of "BGAG12,400," a photoswitchable orthogonal, remotely tethered ligand (PORTL), enables highly efficient, rapid optical agonism following conjugation to SNAP-tagged mGluR2 and permits robust optical control of mGluR1 and mGluR5 signaling. We then produce fluorophore-conjugated branched PORTLs to enable dual imaging and manipulation of mGluRs and highlight their power in ex vivo slice and in vivo behavioral experiments in the mouse prefrontal cortex. Finally, we demonstrate the generalizability of our strategy by developing an improved soluble, photoswitchable pore blocker for potassium channels.

Research paper thumbnail of Mycolacton: ein Bakterientoxin als zukünftiges Schmerzmittel?

Journal Club Schmerzmedizin, 2014

Buruli Ulcer ist eine durch das Bakterium Mycobakterium ulcerans hervorgerufene Krankheit der Hau... more Buruli Ulcer ist eine durch das Bakterium Mycobakterium ulcerans hervorgerufene Krankheit der Haut und Weichteile. Durch das Toxin Mycolacton entstehen dabei grose Gewebeschaden, die zu Beginn der Krankheit keine Schmerzen hervorrufen. Betroffene nehmen daher die Gewebelasionen erst ernst, wenn die Krankheit schon weit fortgeschritten ist. Wissenschaftler um Priscilla Brodin und Laurent Marsollier vom franzosischen Zentrum fur wissenschaftliche Forschung (CNRS) haben nun den molekularen Mechanismus dieser Analgesie aufgedeckt.

Research paper thumbnail of Microfluidic separation of magnetic nanoparticles on an ordered array of magnetized micropillars

Research paper thumbnail of Area-specific development of distinct projection neuron subclasses is regulated by postnatal epigenetic modifications

eLife, 2016

During cortical development, the identity of major classes of long-distance projection neurons is... more During cortical development, the identity of major classes of long-distance projection neurons is established by the expression of molecular determinants, which become gradually restricted and mutually exclusive. However, the mechanisms by which projection neurons acquire their final properties during postnatal stages are still poorly understood. In this study, we show that the number of neurons co-expressing Ctip2 and Satb2, respectively involved in the early specification of subcerebral and callosal projection neurons, progressively increases after birth in the somatosensory cortex. Ctip2/Satb2 postnatal co-localization defines two distinct neuronal subclasses projecting either to the contralateral cortex or to the brainstem suggesting that Ctip2/Satb2 co-expression may refine their properties rather than determine their identity. Gain- and loss-of-function approaches reveal that the transcriptional adaptor Lmo4 drives this maturation program through modulation of epigenetic mecha...

Research paper thumbnail of Télécommander l’activité des canaux ioniques endogènes par la lumière

Research paper thumbnail of MECHANISMS OF SIGNAL TRANSDUCTION-The interaction between the I-II loop and the III-IV loop of Cav2. 1 contributes to voltage-dependent inactivation in a b-dependent manner

Research paper thumbnail of Régulation des canaux calcium neuronaux sensibles au potentiel

AIX-MARSEILLE2-BU Méd/Odontol. (130552103) / SudocPARIS-BIUP (751062107) / SudocSudocFranceF

Research paper thumbnail of Complexes protéiques et perméabilité de la membrane cytoplasmique: exemple du canal TREK

Research paper thumbnail of Remotely control the activity of endogenous ion channels by light

Research paper thumbnail of Two-Pore-Domain Potassium Channel Agonist to Efficiently Treat Migraine

Dataset for the pubilcation "Two-Pore-Domain Potassium Channel Agonist to Efficiently Treat ... more Dataset for the pubilcation "Two-Pore-Domain Potassium Channel Agonist to Efficiently Treat Migraine" the excel files contains all the data obtained for the 4 figures of the publications: -the bahavior in mice -the electrophysiology of primary neuronal culture -Behavior in rats

Research paper thumbnail of A modern ionotropic glutamate receptor with a K+ selectivity signature sequence

Nature Communications, 2011

Glutamate is the major excitatory neurotransmitter in the mammalian central nervous system and ga... more Glutamate is the major excitatory neurotransmitter in the mammalian central nervous system and gates non-selective cation channels. The origins of glutamate receptors are not well understood as they differ structurally and functionally from simple bacterial ligand-gated ion channels. Here we report the discovery of an ionotropic glutamate receptor that combines the typical eukaryotic domain architecture with the 'TXVGYG' signature sequence of the selectivity filter found in K + channels. This receptor exhibits functional properties intermediate between bacterial and eukaryotic glutamate-gated ion channels, suggesting a link in the evolution of ionotropic glutamate receptors.

Research paper thumbnail of Optical probing of a dynamic membrane interaction that regulates the TREK1 channel

Proceedings of the National Academy of Sciences, 2011

TREK channels produce background currents that regulate cell excitability. These channels are sen... more TREK channels produce background currents that regulate cell excitability. These channels are sensitive to a wide variety of stimuli including polyunsaturated fatty acids (PUFAs), phospholipids, mechanical stretch, and intracellular acidification. They are inhibited by neurotransmitters, hormones, and pharmacological agents such as the antidepressant fluoxetine. TREK1 knockout mice have impaired PUFA-mediated neuroprotection to ischemia, reduced sensitivity to volatile anesthetics, altered perception of pain, and a depression-resistant phenotype. Here, we investigate TREK1 regulation by Gq-coupled receptors (GqPCR) and phospholipids. Several reports indicate that the C-terminal domain of TREK1 is a key regulatory domain. We developed a fluorescent-based technique that monitors the plasma membrane association of the C terminus of TREK1 in real time. Our fluorescence and functional experiments link the modulation of TREK1 channel function by internal pH, phospholipid, and GqPCRs to TR...