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See detailThermodynamics and structural analysis of positive allosteric modulation of the ionotropic glutamate receptor GluA2
Krintel, Christian; Frydenvang, Karla; Olsen, Lars et al

in Biochemical Journal (2012), 441

Positive allosteric modulators of the ionotropic glutamate receptor-2 (GluA2) are promising compounds for the treatment of cognitive disorders, e.g. Alzheimer’s disease. These modulators bind within the ... [more ▼]

Positive allosteric modulators of the ionotropic glutamate receptor-2 (GluA2) are promising compounds for the treatment of cognitive disorders, e.g. Alzheimer’s disease. These modulators bind within the dimer interface of the LBD (ligand-binding domain) and stabilize the agonist-bound conformation slowing receptor desensitization and/or deactivation. In the present study, we employ isothermal titration calorimetry to determine binding affinities and thermodynamic details of binding of modulators of GluA2. A mutant of the LBD of GluA2 (LBD-L483Y-N754S) that forms a stable dimer in solution was used. The potent GluA2 modulator BPAM-97 was used as a reference compound. Evidence that BPAM-97 binds in the same pocket as the well-known GluA2 modulator cyclothiazide was obtained from X-ray structures. The LBD-L483Y-N754S:BPAM-97 complex has aKd of 5.6 μM (Δ H = − 4.9 kcal/mol, − T Δ S = − 2.3 kcal/mol; where 1 kcal ≈4.187 kJ). BPAM-97 was used in a displacement assay to determine a Kd of 0.46 mM (Δ H = − 1.2 kcal/mol, − T Δ S = − 3.3 kcal/mol) for the LBD-L483Y-N754S:IDRA-21 complex. The major structural factors increasing the potency of BPAM-97 over IDRA-21 are the increased van der Waals contacts to, primarily, Met496 in GluA2 imposed by the ethyl substituent of BPAM-97. These results add important information on binding affinities and thermodynamic details, and provide a new tool in the development of drugs against cognitive disorders. Key words: binding affinity, crystal structure, ionotropic glutamate receptor, isothermal titration calorimetry, positive allosteric modulator [less ▲]

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See detailBM-573 INHIBITS THE EARLY ATHEROSCLEROTIC LESIONS IN APO-E DEFICIENT MICE BY BLOCKING TP RECEPTORS AND THROMBOXANE SYNTHASE
Cherdon, Céline ULg; Rolin, Stéphanie; Hanson, Julien ULg et al

in Congress of the International Society of Thrombosis and Hemostasis- 57th Annual SSC Meeting (2011, July)

Atherosclerosis is the principal cause of mortality in industrialized countries. Its development is influenced by several mediators of which thromboxane A(2) (TXA(2)) and 8-iso-PGF(2() have recently ... [more ▼]

Atherosclerosis is the principal cause of mortality in industrialized countries. Its development is influenced by several mediators of which thromboxane A(2) (TXA(2)) and 8-iso-PGF(2() have recently received a lot of attention. This study aimed to investigate the effect of a dual thromboxane synthase inhibitor and thromboxane receptor antagonist (BM-573) and ASA on lesion formation in apolipoprotein E-deficient mice. The combination of ASA and BM-573 was also studied. Plasma measurements demonstrated that the treatments did not affect body weight or plasma cholesterol levels. BM-573, but not ASA, significantly decreased atherogenic lesions as demonstrated by macroscopic analysis. Both treatments alone inhibited TXB(2) synthesis but only BM-573 and the combination therapy were able to decrease firstly, plasma levels of soluble intracellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) and secondly, the expression of these proteins in the aortic root of Apo E. These results were confirmed in endothelial cell cultures derived from human saphenous vein endothelial cells (HSVECs). In these cells, BM-573 also prevented the increased mRNA expression of ICAM-1 and VCAM-1 induced by U-46619 and 8-iso-PGF(2(). Our results show that a molecule combining receptor antagonism and thromboxane synthase inhibition is more efficient in delaying atherosclerosis in Apo E(-/-) mice than sole inhibition of TXA(2) formation. [less ▲]

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See detailBM-573 inhibits the development of early atherosclerotic lesions in Apo E deficient mice by blocking TP receptors and thromboxane synthase.
Cherdon, Céline ULg; Rolin, Stephanie; Hanson, Julien ULg et al

in Prostaglandins & Other Lipid Mediators (2011)

Atherosclerosis is the principal cause of mortality in industrialized countries. Its development is influenced by several mediators of which thromboxane A(2) (TXA(2)) and 8-iso-PGF(2() have recently ... [more ▼]

Atherosclerosis is the principal cause of mortality in industrialized countries. Its development is influenced by several mediators of which thromboxane A(2) (TXA(2)) and 8-iso-PGF(2() have recently received a lot of attention. This study aimed to investigate the effect of a dual thromboxane synthase inhibitor and thromboxane receptor antagonist (BM-573) and ASA on lesion formation in apolipoprotein E-deficient mice. The combination of ASA and BM-573 was also studied. Plasma measurements demonstrated that the treatments did not affect body weight or plasma cholesterol levels. BM-573, but not ASA, significantly decreased atherogenic lesions as demonstrated by macroscopic analysis. Both treatments alone inhibited TXB(2) synthesis but only BM-573 and the combination therapy were able to decrease firstly, plasma levels of soluble intracellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) and secondly, the expression of these proteins in the aortic root of Apo E. These results were confirmed in endothelial cell cultures derived from human saphenous vein endothelial cells (HSVECs). In these cells, BM-573 also prevented the increased mRNA expression of ICAM-1 and VCAM-1 induced by U-46619 and 8-iso-PGF(2(). Our results show that a molecule combining receptor antagonism and thromboxane synthase inhibition is more efficient in delaying atherosclerosis in Apo E(-/-) mice than sole inhibition of TXA(2) formation. [less ▲]

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See detailPyridine Derivatives of Nimesulide as New Promising Anti-inflammatory Agents
Renard, Jean-François ULg; Lecomte, Frédéric ULg; de Leval, Xavier et al

Poster (2011, January)

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See detailMolecular characterization of the AMPA-receptor potentiator S70340 in rat primary cortical culture: Whole-genome expression profiling.
Mourlevat, S.; Galizzi, J. P.; Guigal-Stephan, N. et al

in Neuroscience Research (2011), 70

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See detailNew substituted aryl esters and aryl amides of 3,4-dihydro-2H-1,2,4- benzothiadiazine 1,1-dioxides as positive allosteric modulators of AMPA receptors
Dintilhac, Gaëlle ULg; Arslan, Deniz ULg; Dilly, Sébastien ULg et al

in MedChemComm (2011), 2

AMPA receptor potentiators belonging to 3,4-dihydro-2H-1,2,4-benzothiadiazine 1,1-dioxides have been found to be of great interest as cognitive enhancers. Previous structure–activity relationships have ... [more ▼]

AMPA receptor potentiators belonging to 3,4-dihydro-2H-1,2,4-benzothiadiazine 1,1-dioxides have been found to be of great interest as cognitive enhancers. Previous structure–activity relationships have demonstrated the importance for activity of the nature of the substituent at the 7-position of the heterocycle. This work aims to explore the impact on AMPA potentiation of the introduction of different aryl and aralkyl ester or aryl amide groups at the 7-position. The new synthesized compounds were evaluated as AMPA receptor potentiators by examining their effect on rat brain primary cell cultures on AMPA-evoked membrane depolarisation using fluorescent membrane potential dyes and on imaging-based plate reader. The most potent compound of this series was 2-methylphenyl 4-methyl- 3,4-dihydro-2H-1,2,4-benzothiadiazine-7-carboxylate 1,1-dioxide 16c which provoked a strong potentiation of AMPA current with a potency close to that reported for the best reference compounds of the benzothiadiazine class (i.e cyclothiazide). This work also revealed that only the ortho-substitution of the phenyl group of 1,2,4-benzothiadiazine-7-carboxylate esters provided potent AMPA receptor potentiators opening the way to further chemical exploration. [less ▲]

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See detailModulation of the 6-position of benzopyran derivatives and inhibitory effects on the insulin releasing process
Florence, Xavier; Dilly, Sébastien ULg; De Tullio, Pascal ULg et al

in Bioorganic & Medicinal Chemistry (2011)

The synthesis of different series of 4- and 6-substituted R/S-3,4-dihydro-2,2-dimethyl-2H-1- benzopyrans is described. All of these new benzopyran derivatives were bearing, at the 4- position, a ... [more ▼]

The synthesis of different series of 4- and 6-substituted R/S-3,4-dihydro-2,2-dimethyl-2H-1- benzopyrans is described. All of these new benzopyran derivatives were bearing, at the 4- position, a phenylthiourea moiety substituted on the phenyl ring by a meta or a para-electronwithdrawing group such as Cl or CN. The study aimed at exploring the influence of the nature of the substituent at the 6-position in order to develop new benzopyran-type KATP channel activators exhibiting an improved selectivity towards the insulin secreting cells. The original compounds were examined in vitro on rat pancreatic islets (inhibition of insulin release) as well as on rat aorta rings (vasorelaxant effect) and their activity was compared to that of the reference KATP channel activators (±)-cromakalim, (±)-pinacidil, diazoxide and to previously synthesized cromakalim analogues. Structure–activity relationships indicated that the inhibitory effect on the insulin secreting cells was related to the lipophilicity of the molecules and to the size of the substituent located at the 6-position. A marked inhibitory activity on the insulin secretory process was obtained with molecules bearing a bulky tertbutyloxycarbonylamino group at the 6-position (20-23). The latter compounds were found to have the same efficacy on the pancreatic endocrine tissue than some previously described molecules. Lastly, radioisotopic experiments further identified R/S-N-4-chlorophenyl-N’-(6- tert-butyloxycarbonylamino-3,4-dihydro-2,2-dimethyl-2H-1-benzopyran-4-yl)thiourea (23) as a KATP channel opener. [less ▲]

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