References of "Hanson, Julien"
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See detailThe G Protein-Coupled Receptors Deorphanization Landscape
Laschet, Céline ULiege; Dupuis, Nadine; Hanson, Julien ULiege

in Biochemical Pharmacology (in press)

G protein-coupled receptors (GPCRs) are usually highlighted as being both the largest family of membrane proteins and the most productive source of drug targets. However, most of the GPCRs are ... [more ▼]

G protein-coupled receptors (GPCRs) are usually highlighted as being both the largest family of membrane proteins and the most productive source of drug targets. However, most of the GPCRs are understudied and hence cannot be used immediately for innovative therapeutic strategies. Besides, there are still around 100 orphan receptors, with no described endogenous ligand and no clearly defined function. The race to discover new ligands for these elusive receptors seems to be less intense than before. Here, we present an update of the various strategies employed to assign a function to these receptors and to discover new ligands. We focus on the recent advances in the identification of endogenous ligands with a detailed description of newly deorphanized receptors. Replication being a key parameter in these endeavors, we also discuss the latest controversies about problematic ligand-receptor pairings. In this context, we propose several recommendations in order to strengthen the reporting of new ligand-receptor pairs. [less ▲]

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See detailDifferent contribution of chemokine N-terminal features attest a different ligand binding mode and a bias towards activation of the atypical chemokine receptor ACKR3/CXCR7 compared to CXCR4 and CXCR3
szpakowska, Martyna; Nevins, Amanda M; Meyrath, Max et al

in British Journal of Pharmacology (in press)

Background and purpose Chemokines and their receptors form an intricate interaction and signaling network that plays critical roles in various physiological and pathological cellular processes. The high ... [more ▼]

Background and purpose Chemokines and their receptors form an intricate interaction and signaling network that plays critical roles in various physiological and pathological cellular processes. The high promiscuity and apparent redundancy of this network makes probing individual chemokine/receptor interactions and functional effects, as well as targeting individual receptor axes for therapeutic applications, challenging. Despite poor sequence identity, the N-terminal regions of chemokines, which play a key role in their activity and selectivity, harbor several conserved features. Thus far, little is known regarding the molecular basis of their interactions with conventional vs. atypical chemokine receptors or the conservation of their contributions across chemokine-receptor pairs. Experimental Approach In this study, using a broad panel of chemokine variants and modified peptides derived from the N-terminal region of chemokines CXCL12, CXCL11, and vCCL2, we compare the role of various features in binding and activation of their shared receptors, the two canonical G protein-signaling receptors, CXCR4 and CXCR3, as well as the atypical scavenger receptor CXCR7/ACKR3, which shows exclusively arrestin-dependent activity. Key Results We provide exhaustive molecular insights into the plasticity of the ligand-binding pockets of these receptors, their chemokine binding modes, and their activation mechanisms. We show that, although the chemokine N-terminal region is a critical determinant, neither the most proximal residues nor the N-loop are essential for ACKR3 binding and activation, as opposed to CXCR4 and CXCR3. Conclusion and Implications These results suggest a different interaction mechanism between this atypical receptor and its ligands and illustrates its strong propensity to activation. [less ▲]

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See detail7‐Phenoxy-Substituted 3,4-Dihydro‐2H‐1,2,4-benzothiadiazine 1,1- Dioxides as Positive Allosteric Modulators of α‐Amino-3-hydroxy-5- methyl-4-isoxazolepropionic Acid (AMPA) Receptors with Nanomolar Potency
Goffin, Eric ULiege; Drapier, Thomas ULiege; Probst Larsen, Anja et al

in Journal of Medicinal Chemistry (2018), 61

We report here the synthesis of 7-phenoxy- substituted 3,4-dihydro-2H-1,2,4-benzothiadiazine 1,1-dioxides and their evaluation as AMPA receptor positive allosteric modulators (AMPApams). The impact of ... [more ▼]

We report here the synthesis of 7-phenoxy- substituted 3,4-dihydro-2H-1,2,4-benzothiadiazine 1,1-dioxides and their evaluation as AMPA receptor positive allosteric modulators (AMPApams). The impact of substitution on the phenoxy ring and on the nitrogen atom at the 4-position was examined. At GluA2(Q) expressed in HEK293 cells (calcium flux experiment), the most potent compound was 11m (4- cyclopropyl-7-(3-methoxyphenoxy)-3,4-dihydro-2H-1,2,4-ben- zothiadiazine 1,1-dioxide, EC50 = 2.0 nM). The Hill coefficient in the screening and the shape of the dimerization curve in small-angle X-ray scattering (SAXS) experiments using isolated GluA2 ligand-binding domain (GluA2-LBD) are consistent with binding of one molecule of 11m per dimer interface, contrary to most benzothiadiazine dioxides developed to date. This observation was confirmed by the X-ray structure of 11m bound to GluA2-LBD and by NMR. This is the first benzothiadiazine dioxide AMPApam to reach the nanomolar range. [less ▲]

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See detailTargeted mutagenesis of orphan GPCRs of the SREB family
Laschet, Céline ULiege; Dupuis, Nadine ULiege; Geubelle, Pierre ULiege et al

Poster (2017, September)

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See detailActivation of the orphan G protein-coupled receptor GPR27 by surrogate ligands promotes β-arrestin 2 recruitment
Dupuis, Nadine ULiege; Laschet, Céline ULiege; Franssen, Delphine ULiege et al

in Molecular Pharmacology (2017), 91(6), 595-608

G protein-coupled receptors are the most important drug targets for human diseases. An important number of them remain devoid of confirmed ligands. GPR27 is one of these orphan receptors, characterized by ... [more ▼]

G protein-coupled receptors are the most important drug targets for human diseases. An important number of them remain devoid of confirmed ligands. GPR27 is one of these orphan receptors, characterized by a high level of conservation among vertebrates and a predominant expression in the central nervous system. In addition, it has recently been linked to insulin secretion. However, the absence of endogenous or surrogate ligands for GPR27 complicates the examination of its biological function. Our aim was to validate GPR27 signaling pathways and therefore we sought to screen a diversity oriented synthesis library to identify GPR27-specific surrogate agonists. In order to select an optimal screening assay, we investigated GPR27 ligand-independent activity. Both in G protein-mediated pathways and in β-arrestin 2 recruitment, no ligand-independent activity could be measured. However, we observed a recruitment of β-arrestin 2 to a GPR27V2 chimera in the presence of membrane-anchored β-adrenergic receptor kinase 1 (GRK2). Therefore, we optimized a firefly luciferase complementation assay to screen against this chimeric receptor. We identified two compounds (N-[4-(anilinocarbonyl)phenyl]-2,4-dichlorobenzamide (ChemBridge ID5128535) and 2,4-dichloro-N-{4-[(1,3-thiazol-2-ylamino)sulfonyl]phenyl}benzamide (ChemBridge ID5217941)) sharing a N-phenyl-2,4-dichlorobenzamide scaffold, which were selective for GPR27 over its closely related family members GPR85 and GPR173. The specificity of the activity was confirmed with a NanoBiT® β-arrestin 2 assay, imaging of GFP-tagged β-arrestin 2 and PathHunter® β-arrestin 2 Assay. Interestingly, no G protein activation was detected upon activation of GPR27 by these compounds. Our study provides the first selective surrogate agonists for the orphan GPR27. [less ▲]

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See detailDiscovery and pharmacological characterization of succinate receptor (SUCNR1/GPR91) agonists
Geubelle, Pierre ULiege; Gilissen, Julie; Dilly, Sebastien et al

in British Journal of Pharmacology (2017), 174(9), 796-808

Background and Purpose The succinate receptor (SUCNR1 or GPR91) has been described as a metabolic sensor that may be involved in homeostasis. Notwithstanding its implication in important (patho ... [more ▼]

Background and Purpose The succinate receptor (SUCNR1 or GPR91) has been described as a metabolic sensor that may be involved in homeostasis. Notwithstanding its implication in important (patho)physiological processes, the function of SUCNR1 has remained elusive because no pharmacological tools were available. We report on the discovery of the first family of synthetic potent agonists. Experimental Approach We screened a library of succinate analogues and analysed their activity on SUCNR1. In addition, we modelled a pharmacophore and a binding site for the receptor. New agonists were identified based on the information provided by these two approaches. Their activity was studied in various bioassays, including measurement of cAMP levels, [Ca2+]i mobilisation, TGF-α shedding and recruitment of arrestin 3. The in vivo impact of SUCNR1 activation by these new agonists was evaluated on rat blood pressure. Key Results We identified cis-epoxysuccinic acid and cis-1,2-cyclopropanedicarboxylic acid as agonists with an efficacy similar to the one of succinic acid. Interestingly, cis-epoxysuccinic acid was characterized by a 10 to 20 fold higher potency than succinate on the receptor. For example, cis-epoxysuccinic acid reduced cAMP levels with a pEC50 = 5.57 ± 0.02 (EC50 = 2.7 μM) as compared to succinate pEC50 = 4.54 ± 0.08 (EC50 = 29 μM). The rank order of potency of the three agonists was the same in all bioassays tested. In vivo, cis-epoxysuccinic and cis-1,2-cyclopropanedicarboxylic acid increased rat blood pressure to the same extent as succinate did. Conclusions and Implications We provide new agonist tools for SUCNR1 that should facilitate further research on this understudied receptor. [less ▲]

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See detailGPR101 orphan GPCR: a novel cause of growth hormone deregulation
Abboud, Dayana ULiege; Daly, Adrian ULiege; Dupuis, Nadine ULiege et al

Poster (2017, May)

GPR101 is an orphan G-protein coupled receptor with unknown ligand. In 2014, an international study clearly pointed to a strong association between this receptor and the X-linked acrogigantism (X-LAG ... [more ▼]

GPR101 is an orphan G-protein coupled receptor with unknown ligand. In 2014, an international study clearly pointed to a strong association between this receptor and the X-linked acrogigantism (X-LAG) syndrome, which begins in childhood and causes the “tallest giants”. The children (carriers of the GPR101 duplication on the X chromosome) grow abnormally even before they are one year old, secrete phenomenal quantities of growth hormone, and develop pituitary adenomas that do not respond to current therapies. The mechanism by which GPR101 contributes to increased growth hormone secretion is currently not known. Nevertheless, the lack of mechanistic insight into the function of GPR101 precludes its validation as a drug target. This lack of knowledge on GPR101 is the consequence of the paucity of specific pharmacological/research tools currently available. Therefore, we propose to study GPR101 functions and its role in growth hormone regulation. First, we determined the receptor cellular localization. We also deciphered its constitutive signalling pathways by detecting high cAMP levels. We completed our study with an examination of receptor coupling to other pathways and G proteins. Furthermore, we applied targeted mutagenesis to modulate the receptor constitutive activity in order to understand the receptor function at a molecular level. These GPR101 mutants will help us to understand the role of this receptor in GH regulation and/or to treat people suffering from pituitary dysfunction. This information is an absolute prerequisite to link molecular pharmacology of GPR101 with physiological functions. [less ▲]

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See detailChemokine neutralization as an innovative therapeutic strategy for atopic dermatitis
Abboud, Dayana ULiege; Hanson, Julien ULiege

in Drug Discovery Today (2017), 22(4), 702-7011

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See detailPartial filling affinity capillary electrophoresis as a useful tool for fragment-based drug discovery: A proof of concept on thrombin.
Farcas, Elena ULiege; Bouckaert, C.; Servais, Anne-Catherine ULiege et al

in Analytica Chimica Acta (2017), 984

With the emergence of more challenging targets, a relatively new approach, fragment-based drug discovery (FBDD), proved its efficacy and gained increasing importance in the pharmaceutical industry. FBDD ... [more ▼]

With the emergence of more challenging targets, a relatively new approach, fragment-based drug discovery (FBDD), proved its efficacy and gained increasing importance in the pharmaceutical industry. FBDD identifies low molecular-weight (MW) ligands (fragments) that bind to biologically important macromolecules, then a structure-guided fragment growing or merging approach is performed, contributing to the quality of the lead. However, to select the appropriate fragment to be evolved, sensitive analytical screening methods must be used to measure the affinity in the muM or even mM range. In this particular context, we developed a robust and selective partial filling affinity CE (ACE) method for the direct binding screening of a small fragment library in order to identify new thrombin inhibitors. To demonstrate the accuracy of our assay, the complex dissociation constants of three known thrombin inhibitors, namely benzamidine, p-aminobenzamidine and nafamostat were determined and found to be in good concordance with the previously reported values. Finally, the screening of a small library was performed and demonstrated the high discriminatory power of our method towards weak binders compared to classical spectrophotometric activity assay, proving the interest of our method in the context of FBDD. [less ▲]

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See detailSmall molecule ligands for the orphan GPR27
Dupuis, Nadine ULiege; Franssen, Delphine ULiege; Laschet, Céline ULiege et al

Poster (2016, September 26)

Background G protein-coupled receptors (GPCRs) are involved in many physiological processes and constitute the target of around 30% of marketed therapies. Nonetheless, ~100 human GPCRs have no known ... [more ▼]

Background G protein-coupled receptors (GPCRs) are involved in many physiological processes and constitute the target of around 30% of marketed therapies. Nonetheless, ~100 human GPCRs have no known ligand and are designated as "orphan". This project focuses on GPR27, a rhodopsin-like alpha orphan of the SREB family (Super conserved Receptors Expressed in the Brain), presumably involved in the regulation of insulin secretion [1]. Methods In order to identify small molecules activating GPR27, we developed a firefly luciferase complementation assay (based on [2]) to assess the binding of ß-arrestin2 to the activated GPCR. To increase the affinity for and strengthen the interaction with ß-arrestin2, a GPR27-V2R chimera has been used for library screening. Results Small molecules activating GPR27-V2 have been identified in the DiverSetTM library (ChemBridge). After exclusion of non-specific activities using another unrelated GPCR, two compounds sharing a common scaffold with activity in the low micromolar range were selected for further investigations. We confirmed their agonist profile by performing complete concentration-response curves on our arrestin complementation assay as well as orthogonal assays. These compounds show good specificity being inactive on GPR85-V2 and GPR173-V2 (the two other SREB members). With these original tools, we characterized the recruitment of ß-arrestin2 to activated GPR27 WT. Conclusion We identified small molecule ligands for GPR27 that will serve as valuable tools for studying the pharmacology of GPR27 as well as its physiological roles, for example in insulin secretion. 1 Ku G.M., Pappalardo Z., Luo C.C., German M.S., McManus M.T. An siRNA Screen in Pancreatic Beta Cells Reveals a Role for Gpr27 in Insulin Production. PLoS genetics. 2012, 8, e1002449. 2 Takakura H., Hattori M., Takeuchi M., Ozawa T. Visualization and Quantitative Analysis of G Protein-Coupled Receptor−β-Arrestin Interaction in Single Cells and Specific Organs of Living Mice Using Split Luciferase Complementation. ACS Chem. Biol. 2012, 7, 901−910. [less ▲]

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See detailTargeted mutagenesis of orphan GPCRs of the SREB family
Laschet, Céline ULiege; Dupuis, Nadine ULiege; Soni, Arvind ULiege et al

Poster (2016, September)

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See detailHuman herpesvirus 8-encoded chemokine vCCL2/vMIP-II is an agonist of the atypical chemokine receptor ACKR3/CXCR7
Szpakowska, Martyna; Dupuis, Nadine ULiege; Baragli, Alessandra et al

in Biochemical Pharmacology (2016), 114

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See detailDESIGN OF HIGH-AFFINITY LIGANDS FOR THE BENZOTHIADIAZINE ALLOSTERIC BINDING SITE OF THE AMPA RECEPTORS
Drapier, Thomas ULiege; Geubelle, Pierre ULiege; Bouckaert, Charlotte et al

Poster (2016, May 26)

L-glutamic acid is the major excitatory neurotransmitter in the brain. It exerts its effects through metabotropic and ionotropic receptors. Among the latter, three subtypes have been identified: NMDA ... [more ▼]

L-glutamic acid is the major excitatory neurotransmitter in the brain. It exerts its effects through metabotropic and ionotropic receptors. Among the latter, three subtypes have been identified: NMDA, AMPA and KA receptors. It is now well established that a deficit in glutamatergic signaling may be responsible for neurological disorders such as mild cognitive impairment, schizophrenia, depression, and ADHD. Enhancement of the signal through positive allosteric modulators of AMPA receptors might be a therapeutic issue for these diseases. These compounds are expected to exert a fine tuning of the signal. Since they require the presence of the endogenous ligand to be active, they are expected to induce less toxicity than agonists. In this context, based on the structure of known allosteric modulators of AMPA receptors such as cyclothiazide and IDRA 21, the Laboratory of Medicinal Chemistry (University of Liège) has developed a series of 1,2,4-benzothiadiazine 1,1-dioxides with high potency as AMPA receptor potentiators. Crystallographic data obtained by the Department of Drug Design and Pharmacology (University of Copenhagen) highlighted those potentiators bind to two contiguous sites at the dimer interface of the ligand binding domain (LBD) of the AMPA receptor1,2. Based on these data, we may expect that the synthesis of dimeric molecules could lead to further improvement in affinity and activity. This assumption was reinforced by docking experiments conducted with virtual examples of dimeric compounds on the GluA2-LBD (collaboration with NAMEDIC). The present work is thus focusing on the preparation of a family of dimeric benzothiadiazine dioxides. Moreover, in collaboration with GIGA-Molecular Pharmacology, we are developing a pharmacological in vitro assay based on the measurement of Ca2+ inflow through a fluorimetric method. This medium-throughput screening will enable the characterization of our new compounds and the validation of our working hypothesis. [less ▲]

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See detailA forskolin free method for measuring cAMP modulation by Gi coupled receptors
Hanson, Julien ULiege

Conference (2016, April 18)

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See detailIdentification of small molecule ligands for the orphan GPCR GPR27
Dupuis, Nadine ULiege; Gilissen, Julie; Derj, Anouar ULiege et al

Poster (2016, January 25)

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See detailTargeted and random mutagenesis of orphan GPCRs of the SREB family
Laschet, Céline ULiege; Dupuis, Nadine ULiege; Derj, Anouar ULiege et al

Poster (2016, January 25)

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See detailGPCRs in immunity: atypical receptors and novel concepts
Hanson, Julien ULiege; Chevigné, Andy

in Biochemical Pharmacology (2016)

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See detailInsight into SUCNR1 (GPR91) structure and function
Gilissen, Julie ULiege; Jouret, François ULiege; Pirotte, Bernard ULiege et al

in Pharmacology & Therapeutics (2016)

SUCNR1 (or GPR91) belongs to the family of G protein-coupled receptors (GPCR), which represents the largest group of membrane proteins in human genome. The majority of marketed drugs targets GPCRs ... [more ▼]

SUCNR1 (or GPR91) belongs to the family of G protein-coupled receptors (GPCR), which represents the largest group of membrane proteins in human genome. The majority of marketed drugs targets GPCRs, directly or indirectly. SUCNR1 has been classified as an orphan receptor until a landmark study paired it with succinate, a citric acid cycle intermediate. According to the current paradigm, succinate triggers SUCNR1 signaling pathways to indicate local stress that may affect cellular metabolism. SUCNR1 implication has been well documented in renin-induced hypertension, ischemia/reperfusion injury, inflammation and immune response, platelet aggregation and retinal angiogenesis. In addition, the SUCNR1-induced increase of blood pressure may contribute to diabetic nephropathy or cardiac hypertrophy. The understanding of SUCNR1 activation, signaling pathways and functions remains largely elusive, which calls for deeper investigations. SUCNR1 shows a high potential as an innovative drug target and is probably an important regulator of basic physiology. In order to achieve the full characterization of this receptor,more specific pharmacological tools such as small-molecules modulators will represent an important asset. In this review, we describe the structural features of SUCNR1, its current ligands and putative binding pocket. We give an exhaustive overview of the known and hypothetical signaling partners of the receptor in different in vitro and in vivo systems. The link between SUCNR1 intracellular pathways and its pathophysiological roles are also extensively discussed. [less ▲]

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