Publications of Julien Hanson
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See detailβ-arrestin2 recruitment at the β2 adrenergic receptor: a luciferase complementation assay adapted for undergraduate training in pharmacology
Ferraiolo, Mattia; Beckers, Pauline; Marquet, Nicolas et al

in Pharmacology Research and Perspectives (2021), 9(1),

In the context of pharmacology teaching, hands-on activities constitute an essential complement to theoretical lectures. Frequently, these activities consist in exposing fresh animal tissues or even ... [more ▼]

In the context of pharmacology teaching, hands-on activities constitute an essential complement to theoretical lectures. Frequently, these activities consist in exposing fresh animal tissues or even living animals to selected drugs and qualitatively or quantitatively evaluating functional responses. However, technological advancements in pharmacological research and the growing concerns for animal experimentation support the need for innovative and flexible in vitro assays adapted for teaching purposes. We herein report the implementation of a luciferase complementation assay enabling to dynamically monitor β-arrestin2 recruitment at the β2 adrenergic receptor in the framework of pharmacological training at the faculty of Pharmacy and Biomedical Sciences. The assay allowed students to quantitatively characterize the competitive antagonism of propranolol, and to calculate pEC50, pKB and pA2 values after a guided data-analysis session. Moreover, the newly implemented workshop delivered highly reproducible results and were generally appreciated by students. As such, we report that the luciferase complementation-based assay proved to be a straightforward, robust and cost-effective alternative to experiments performed on animal tissues, constituting a useful and flexible tool to enhance and update current hands-on training in the context of pharmacological teaching. [less ▲]

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See detailTHE CONCISE GUIDE TO PHARMACOLOGY 2021/22: G protein-coupled receptors.
Alexander, Stephen Ph; Christopoulos, Arthur; Davenport, Anthony P. et al

in British journal of pharmacology (2021), 178 Suppl 1

The Concise Guide to PHARMACOLOGY 2021/22 is the fifth in this series of biennial publications. The Concise Guide provides concise overviews, mostly in tabular format, of the key properties of nearly 1900 ... [more ▼]

The Concise Guide to PHARMACOLOGY 2021/22 is the fifth in this series of biennial publications. The Concise Guide provides concise overviews, mostly in tabular format, of the key properties of nearly 1900 human drug targets with an emphasis on selective pharmacology (where available), plus links to the open access knowledgebase source of drug targets and their ligands (www.guidetopharmacology.org), which provides more detailed views of target and ligand properties. Although the Concise Guide constitutes over 500 pages, the material presented is substantially reduced compared to information and links presented on the website. It provides a permanent, citable, point-in-time record that will survive database updates. The full contents of this section can be found at http://onlinelibrary.wiley.com/doi/bph.15538. G protein-coupled receptors are one of the six major pharmacological targets into which the Guide is divided, with the others being: ion channels, nuclear hormone receptors, catalytic receptors, enzymes and transporters. These are presented with nomenclature guidance and summary information on the best available pharmacological tools, alongside key references and suggestions for further reading. The landscape format of the Concise Guide is designed to facilitate comparison of related targets from material contemporary to mid-2021, and supersedes data presented in the 2019/20, 2017/18, 2015/16 and 2013/14 Concise Guides and previous Guides to Receptors and Channels. It is produced in close conjunction with the Nomenclature and Standards Committee of the International Union of Basic and Clinical Pharmacology (NC-IUPHAR), therefore, providing official IUPHAR classification and nomenclature for human drug targets, where appropriate. [less ▲]

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See detailGPR101 drives growth hormone hypersecretion and gigantism in mice via constitutive activation of Gs and Gq/11
Abboud, Dayana ULiege; Daly, Adrian ULiege; Dupuis, Nadine ULiege et al

in Nature Communications (2020), 11(1), 4752

Growth hormone (GH) is a key modulator of growth and GH over-secretion can lead to gigantism. One form is X-linked acrogigantism (X-LAG), in which infants develop GH-secreting pituitary tumors over ... [more ▼]

Growth hormone (GH) is a key modulator of growth and GH over-secretion can lead to gigantism. One form is X-linked acrogigantism (X-LAG), in which infants develop GH-secreting pituitary tumors over-expressing the orphan G-protein coupled receptor, GPR101. The role of GPR101 in GH secretion remains obscure. We studied GPR101 signaling pathways and their effects in HEK293 and rat pituitary GH3 cell lines, human tumors and in transgenic mice with elevated somatotrope Gpr101 expression driven by the rat Ghrhr promoter (GhrhrGpr101). Here, we report that Gpr101 causes elevated GH/prolactin secretion in transgenic GhrhrGpr101 mice but without hyperplasia/tumorigenesis. We show that GPR101 constitutively activates not only Gs, but also Gq/11 and G12/13, which leads to GH secretion but not proliferation. These signatures of GPR101 signaling, notably PKC activation, are also present in human pituitary tumors with high GPR101 expression. These results underline a role for GPR101 in the regulation of somatotrope axis function. [less ▲]

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See detailNouvelles cibles et perspectives thérapeutiques. Vers une médecine de précision.
Hanson, Julien ULiege

in Revue Médicale de Liège (2020), 75(5-6), 460-465

A therapeutic target can be defined as the biochemical entity by which a drug exerts its beneficial effects. Historically, most drugs have been used without a precise knowledge of their mechanism of ... [more ▼]

A therapeutic target can be defined as the biochemical entity by which a drug exerts its beneficial effects. Historically, most drugs have been used without a precise knowledge of their mechanism of action. The rational drug design for a predefined target has been progressively implemented during the second half of the 20th century. Recent advances in genomics have accelerated the discovery of several targets involved in many pathologies. During the recent period, there has also been a diversification of the types of targets used in therapy. Generally, the proteins modulated by drugs belonged mainly to the families of membrane receptors (receptors coupled to G proteins, ion channels, etc.), nuclear receptors or enzymes. Technological advances in the field of therapeutic antibodies and biotechnologies enabled curative agents to reach previously undruggable targets. In this article, we review these trends and illustrate them by various examples, notably in the field of anticancer drugs, lipid-lowering drugs, gene therapy or antisense therapy. [less ▲]

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See detailTHE CONCISE GUIDE TO PHARMACOLOGY 2019/20: G protein-coupled receptors
Alexander; Christopoulos, A; Davenport, AP et al

in British Journal of Pharmacology (2019), 176(Suppl 1), 21-141

The Concise Guide to PHARMACOLOGY 2019/20 is the fourth in this series of biennial publications. The Concise Guide provides concise overviews of the key properties of nearly 1800 human drug targets with ... [more ▼]

The Concise Guide to PHARMACOLOGY 2019/20 is the fourth in this series of biennial publications. The Concise Guide provides concise overviews of the key properties of nearly 1800 human drug targets with an emphasis on selective pharmacology (where available), plus links to the open access knowledgebase source of drug targets and their ligands (www.guidetopharmacology.org), which provides more detailed views of target and ligand properties. Although the Concise Guide represents approximately 400 pages, the material presented is substantially reduced compared to information and links presented on the website. It provides a permanent, citable, point-in-time record that will survive database updates. The full contents of this section can be found at http://onlinelibrary.wiley.com/doi/10.1111/bph.14748. G protein-coupled receptors are one of the six major pharmacological targets into which the Guide is divided, with the others being: ion channels, nuclear hormone receptors, catalytic receptors, enzymes and transporters. These are presented with nomenclature guidance and summary information on the best available pharmacological tools, alongside key references and suggestions for further reading. The landscape format of the Concise Guide is designed to facilitate comparison of related targets from material contemporary to mid-2019, and supersedes data presented in the 2017/18, 2015/16 and 2013/14 Concise Guides and previous Guides to Receptors and Channels. It is produced in close conjunction with the International Union of Basic and Clinical Pharmacology Committee on Receptor Nomenclature and Drug Classification (NC-IUPHAR), therefore, providing official IUPHAR classification and nomenclature for human drug targets, where appropriate. [less ▲]

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See detailL’expérimentation animale : toujours une nécessité pour la santé animale et humaine
Balthazart, Jacques ULiege; Blanpain, Cédric; Bureau, Fabrice ULiege et al

Article for general public (2019)

Le 1 juillet 2019, « Le Soir » publiait un article relatant la découverte par les chercheurs de l'UCLouvain d'une bactérie pouvant potentiellement contribuer à limiter les risques cardiovasculaires , l ... [more ▼]

Le 1 juillet 2019, « Le Soir » publiait un article relatant la découverte par les chercheurs de l'UCLouvain d'une bactérie pouvant potentiellement contribuer à limiter les risques cardiovasculaires , l'une des premières causes de décès en Belgique. Cet article soulignait l'importance de la recherche fondamentales et du passage nécessaire par l'expérimentation préclinique (animale) pour développer une application chez l’humain. En réaction, Solange T'Kint, administratrice de l'ASBL S.E.A. - Suppression des Expériences sur l'Animal-, publiait le 2 juillet dans « La Libre » un nouveau pamphlet contre l'expérimentation animale. Mme T Kint avait déjà lancé en aout 2018 une pétition attaquant la découverte3 d'un chercheur de l'ULB sur la dépendance aux drogues réalisée chez la souris , démontrant par là à quel point toute avancée médicale imputable à l'expérimentation animale lui est insupportable. Ici se trouve la réponse de Scientifiques qui pensent indispensable d’informer chacun-e- de manière rigoureuse et de ne jamais laisser diffuser de « fake news » sans réagir. [less ▲]

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See detailThe Distinct Roles of CXCR3 Variants and Their Ligands in the Tumor Microenvironment
Reynders, Nathan; Abboud, Dayana ULiege; Baragli, Alexandra et al

in Cells (2019), 8(6),

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See detailA dynamic and screening-compatible nanoluciferase-based complementation assay enables profiling of individual GPCR-G protein interactions
Laschet, Céline ULiege; Dupuis, Nadine; Hanson, Julien ULiege

in Journal of Biological Chemistry (2019), 294(11), 4079-4090

G protein-coupled receptors (GPCRs) are currently the target of more than 30% of the marketed medicines. However, there is an important medical need for ligands with improved pharmacological activities on ... [more ▼]

G protein-coupled receptors (GPCRs) are currently the target of more than 30% of the marketed medicines. However, there is an important medical need for ligands with improved pharmacological activities on validated drug targets. Moreover, most of these ligands remain poorly characterized, notably because of a lack of pharmacological tools. Thus, there is an important demand for innovative assays that can detect and drive the design of compounds with novel or improved pharmacological properties. In particular, a functional and screening-compatible GPCR-G protein interaction assay is still unavailable. Here, we report on a nanoluciferase-based complementation technique to detect ligands that promote a GPCR-G protein interaction. We demonstrate that our system can be used to profile compounds with regard to the G proteins they activate through a given GPCR. Furthermore, we established a proof of applicability of screening for distinct G proteins on dopamine receptor D2 whose differential coupling to Gαi/o family members has been extensively studied. In a D2-Gαi1 versus D2- Gαo screening, we retrieved five agonists that are currently being used in antiparkinsonian medications. We determined that in this assay, piribedil and pergolide are full agonists for the recruitment of Gαi1 but are partial agonists for Gαo, that the agonist activity of ropinirole is biased in favor of Gαi1 recruitment, and that the agonist activity of apomorphine is biased for Gαo. We proposed that this newly developed assay could be used to develop molecules that selectively modulate a particular G protein pathway. [less ▲]

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See detailLa souris, le patient, et le faux expert. Décryptage d'une mystification.
Bakker, Julie ULiege; Balthazart, Jacques ULiege; Baron, Frédéric ULiege et al

Article for general public (2018)

La recherche sur animaux est actuellement encadrée de façon stricte en Wallonie comme dans toute l'Union Européenne (voir l'article de Marc Vandenheede publié dans le Vif). Cette législation et les ... [more ▼]

La recherche sur animaux est actuellement encadrée de façon stricte en Wallonie comme dans toute l'Union Européenne (voir l'article de Marc Vandenheede publié dans le Vif). Cette législation et les contrôles qui y sont associés induisent de nombreuses contraintes pratiques, des charges administratives et des coûts financiers importants que les chercheurs seraient certainement heureux d'éviter s'il existait une alternative à l'expérimentation animale. [less ▲]

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See detailL'expérimentation animale ne se fait pas en dehors de tout contrôle (OPINION)
Muraille, Eric; de Kerchove d'Exaerde, Alban; Blanpain, Cedric et al

Article for general public (2018)

Proposer de réduire l'expérimentation animale pour raisons morales est louable. Mais ce choix de société ne doit pas être vendu au citoyen en lui laissant croire que la recherche conserverait la même ... [more ▼]

Proposer de réduire l'expérimentation animale pour raisons morales est louable. Mais ce choix de société ne doit pas être vendu au citoyen en lui laissant croire que la recherche conserverait la même qualité ou en serait améliorée. [less ▲]

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See detailTHE CONCISE GUIDE TO PHARMACOLOGY 2017/18: Overview.
Alexander, SP; Kelly, E; Marrion, NV et al

in British Journal of Pharmacology (2017), 174(Suppl 1), 1-16

Abstract The Concise Guide to PHARMACOLOGY 2017/18 is the third in this series of biennial publications. This version provides concise overviews of the key properties of nearly 1800 human drug targets ... [more ▼]

Abstract The Concise Guide to PHARMACOLOGY 2017/18 is the third in this series of biennial publications. This version provides concise overviews of the key properties of nearly 1800 human drug targets with an emphasis on selective pharmacology (where available), plus links to an open access knowledgebase of drug targets and their ligands (www.guidetopharmacology.org), which provides more detailed views of target and ligand properties. Although the Concise Guide represents approximately 400 pages, the material presented is substantially reduced compared to information and links presented on the website. It provides a permanent, citable, point-in-time record that will survive database updates. The full contents of this section can be found at http://onlinelibrary.wiley.com/doi/10.1111/bph.13882/full. In addition to this overview, in which are identified 'Other protein targets' which fall outside of the subsequent categorisation, there are eight areas of focus: G protein-coupled receptors, ligand-gated ion channels, voltage-gated ion channels, other ion channels, nuclear hormone receptors, catalytic receptors, enzymes and transporters. These are presented with nomenclature guidance and summary information on the best available pharmacological tools, alongside key references and suggestions for further reading. The landscape format of the Concise Guide is designed to facilitate comparison of related targets from material contemporary to mid-2017, and supersedes data presented in the 2015/16 and 2013/14 Concise Guides and previous Guides to Receptors and Channels. It is produced in close conjunction with the Nomenclature Committee of the Union of Basic and Clinical Pharmacology (NC-IUPHAR), therefore, providing official IUPHAR classification and nomenclature for human drug targets, where appropriate. [less ▲]

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See detailL’expérimentation animale reste indispensable (OPINION)
Amorim, Christiani; Andris, Fabienne; Arckens, Lut et al

Article for general public (2017)

Trop fréquemment, l’expérimentation animale est présentée comme une pratique archaïque. Elle a bien changé. Et 100 % des patients traités le sont grâce aux concepts et techniques développés grâce à elle.

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

in Pharmacology and 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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See detailMechanism of Nicotinic acid-induced Flushing
Hanson, Julien ULiege

Conference (2011, June 10)

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See detailRole of Keratinocytes GPR109A and COX-2 in Nicotinic Acid and Mono-methyl Fumarate Induced Flushing
Hanson, Julien ULiege; Gille, Andreas; Zwykiel, Sabrina et al

Poster (2010, July 17)

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See detailCardiovascular haemodynamics and ventriculo-arterial coupling in an acute pig model of coronary ischaemia-reperfusion
Lanoye, Lieve; Segers, Patrick; Tchana-Sato, Vincent ULiege et al

in Experimental Physiology (2007), 92(1), 127-137

Although reperfusion after coronary occlusion is mandatory for myocardial salvage, reperfusion may trigger a cascade of harmful events (reperfusion injury) adding to myocardial injury. We investigated ... [more ▼]

Although reperfusion after coronary occlusion is mandatory for myocardial salvage, reperfusion may trigger a cascade of harmful events (reperfusion injury) adding to myocardial injury. We investigated effects of reperfusion on left ventricular (LV) haemodynamics and ventriculo-arterial (VA) coupling in pigs following acute myocardial ischaemia induced by coronary artery occlusion. Experiments were performed in six animals, with measurements of cardiac and arterial function at baseline, after 60 min of ischaemia (T60) and after 2 (T180) and 4 h of reperfusion (T300). Ventriculo-arterial coupling was assessed using the ventriculo-arterial elastance ratio of paper, as well as using a 'stiffness coupling' and 'temporal coupling' index. Reperfusion following ischaemia (T180 versus T60) induced a progressive decline in cardiovascular function, evidenced by a decrease in mean arterial blood pressure, cardiac output and ejection fraction which was not restored at T300. Although reperfusion also induced an increase in slope of the end-systolic pressure-volume relationship (ESPVR), the ESPVR curve shifted to the right, associated with a depression of contractile function. Histology demonstrated irreversible myocardial damage at T300. The ventriculo-arterial elastance ratio and the 'stiffness coupling' index were unaffected throughout the protocol, but the 'temporal coupling' parameter indicated a relative shift between heart period and the time constant of the arterial system. It is unlikely that these alterations are attributable to ischaemic injury alone. The combination of both the stiffness and temporal coupling index may provide more information when studying ventriculo-arterial coupling than the more commonly used ventricular end-systolic stiffness/effection arterial elastance (E-es/E-a) ratio. [less ▲]

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See detailDesign, synthesis and pharmacological evaluation of sulfonylureas and sulfonycyanoguanidines as thromboxane A2 receptor antagonists. Insights into selectivity between thromboxane A2 receptor isoforms (TPα et TPβ)
Hanson, Julien ULiege

Doctoral thesis (2007)

Thromboxane A2 (TXA2) is an important mediator metabolized from arachidonic acid through the cyclooxygenase pathway, mainly in platelets and macrophages. It is a potent inducer of platelet aggregation and ... [more ▼]

Thromboxane A2 (TXA2) is an important mediator metabolized from arachidonic acid through the cyclooxygenase pathway, mainly in platelets and macrophages. It is a potent inducer of platelet aggregation and smooth muscle contraction. Its overproduction has been detected in pathologies such as stroke, asthma, myocardial infarction or atherosclerosis. The action of TXA2 is mediated by a specific G-protein coupled receptor (TP) of which two alternative spliced isoforms, TPalpha and TPbeta, have been described. The exact role of these two isoforms is not clearly understood. However, recent studies have described their implications in vascular physiology and pathology. The inhibition of the action of TXA2 on platelets and blood vessels would be interesting as original therapies against cardiovascular diseases. Consequently, the design of TP receptor antagonists remains of great interest in cardiovascular medicine. In the laboratory of medicinal chemistry (University of Liège, Belgium), several nitrobenzenesulfonylureas, derived from torasemide (a loop diuretic), have been previously described as TP receptor antagonists. Two compounds, BM573 and BM613 were among the most interesting molecules identified in that previous work. The present project is divided in two parts. First, we have determined the pharmacological properties of BM573 and BM613 as thromboxane synthase inhibitors and TP receptor antagonists, in vitro and in vivo. In our assays, these two compounds were proved to have high affinity for both TPalpha and TPbeta, to be potent antiplatelet agents, to inhibit thromboxane synthase and TP-mediated smooth muscle contraction. Additionally, they significantly reduced the size of the thrombus in a rat model of ferric chloride-induced arterial thrombosis. Consequently, we demonstrated that the TP receptor antagonists BM573 and BM613, belonging to the chemical family of nitrobenzenesulfonylureas, could be regarded as antiplatelet and antithrombotic agents potentially useful in thromboxane-related diseases such as stroke or myocardial infarction. Secondly, given the interesting pharmacological profile of BM573 and BM613, we have designed and synthesized several series of compounds derived from these two agents. We have evaluated the binding properties (affinity) of the first generation (+/- 35 original derivatives) of compounds on either TPalpha or TPbeta, transiently expressed in COS-7 cell lines. Additionally, we have measured the ability of our drugs to inhibit the intracellular calcium mobilization upon TPalpha or TPbeta stimulation. To confirm our results, we also assessed the antiplatelet properties of our drugs by means of determination of inhibition of human platelet aggregation. On the basis of the results obtained with these in vitro assays, we have synthesized and evaluated a second generation of derivatives (+/- 35 original compounds) and improved the selectivity of several original compounds for TP receptor isoforms. The originality of this work was to evaluate a large library of synthetic compounds on both TP receptor isoforms, using specific pharmacological tests. By means of structure-activity relationship studies, we were able to identify chemical groups implicated in selectivity and to propose lead compounds for development of highly specific TPalpha or TPbeta antagonists. Besides, we have identified an in vivo drug candidates for prevention of thrombosis and pathological platelet aggregation. [less ▲]

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