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Agonistic profiles of AMPA receptor (AMPA-R) potentiators may be associated with seizure risk and bell-shaped dose-response effects. Here, we report the pharmacological characteristics of a novel AMPA-R potentiator, TAK-653, which exhibits minimal agonistic properties. TAK-653 bound to the ligand binding domain of recombinant AMPA-R in a glutamate-dependent manner. TAK-653 strictly potentiated a glutamate-induced Ca2+ influx in hGluA1i-expressing CHO cells through structural interference at Ser743 in GluA1. In primary neurons, TAK-653 augmented AMPA-induced Ca2+ influx and AMPA-elicited currents via physiological AMPA-R with little agonistic effects. Interestingly, TAK-653 enhanced electrically evoked AMPA-R-mediated EPSPs more potently than AMPA (agonist) or LY451646 (AMPA-R potentiator with a prominent agonistic effect) in brain slices. Moreover, TAK-653 improved cognition for both working memory and recognition memory, while LY451646 did so only for recognition memory, and AMPA did not improve either. These data suggest that the facilitation of phasic AMPA-R activation by physiologically-released glutamate is the key to enhancing synaptic and cognitive functions, and nonselective activation of resting AMPA-Rs may negatively affect this process. Importantly, TAK-653 had a wide safety margin against convulsion; TAK-653 showed a 419-fold (plasma Cmax) and 1017-fold (AUC plasma) margin in rats. These findings provide insight into a therapeutically important aspect of AMPA-R potentiation. [ABSTRACT FROM AUTHOR]

Agonistic profiles of AMPA receptor (AMPA-R) potentiators may be associated with seizure risk and bell-shaped dose-response effects. Here, we report the pharmacological characteristics of a novel AMPA-R potentiator, TAK-653, which exhibits minimal agonistic properties. TAK-653 bound to the ligand binding domain of recombinant AMPA-R in a glutamate-dependent manner. TAK-653 strictly potentiated a glutamate-induced Ca2+ influx in hGluA1i-expressing CHO cells through structural interference at Ser743 in GluA1. In primary neurons, TAK-653 augmented AMPA-induced Ca2+ influx and AMPA-elicited currents via physiological AMPA-R with little agonistic effects. Interestingly, TAK-653 enhanced electrically evoked AMPA-R-mediated EPSPs more potently than AMPA (agonist) or LY451646 (AMPA-R potentiator with a prominent agonistic effect) in brain slices. Moreover, TAK-653 improved cognition for both working memory and recognition memory, while LY451646 did so only for recognition memory, and AMPA did not improve either. These data suggest that the facilitation of phasic AMPA-R activation by physiologically-released glutamate is the key to enhancing synaptic and cognitive functions, and nonselective activation of resting AMPA-Rs may negatively affect this process. Importantly, TAK-653 had a wide safety margin against convulsion; TAK-653 showed a 419-fold (plasma Cmax) and 1017-fold (AUC plasma) margin in rats. These findings provide insight into a therapeutically important aspect of AMPA-R potentiation. [ABSTRACT FROM AUTHOR]

The platelet-sized particle formation in the human megakaryoblastic leukaemia cell line MEG-01 and its subline MEG-01s was examined. MEG-01 and MEG-01s cells spontaneously released platelet-sized particles into the culture medium, in which the cells occasionally extended cytoplasmic processes similar to those of megakaryocyte proplatelets. Scanning electron microscopic images showed cytoplasmic processes elongated from blebs on the MEG-01 and MEG-01s cell surface and were constricted between segments of platelet size. Immunofluorescence staining with anti-tubulin antibody showed that the cytoplasmic processes contained microtubules that were organized into a ring, which is a characteristic of circulating platelets. Some platelet-sized particles, probably released by ruptures at the sites of the process constriction, were metabolically active in an MTT assay (about 50%). Some particles also expressed the platelet-specific glycoproteins GPIIb, IIIa and GMP-140. Rarely, in response to thrombin, particles underwent a shape change from spherical to a shape with irregular membrane protrusions and fine filopodia, and aggregating with one another. The particles also had increased GMP-140 (P-selectin) expression with the addition of thrombin. These results show the usefulness of the MEG-01 and MEG-01s cell lines for the study of thrombopoiesis. [ABSTRACT FROM AUTHOR]

CCR6 has been implicated in both autoimmune diseases and non-autoimmune diseases. Thus, inhibition of CCR6-dependent cell migration is an attractive strategy for their treatment. An orally available small molecule inhibitor of CCR6 could therefore be a useful biological probe for the pathophysiological studies. Initial SAR study of a hit compound provided potent N -benzenesulfonylpiperidine derivatives that suppressed CCL20-induced Gi signals. By subsequent scaffold morphing of the central ring and further optimization, we identified a novel series of 1,4- trans -1-benzenesulfonyl-4-aminocyclohexanes as potent and selective CCR6 inhibitors with good pharmacokinetic properties. Our compounds showed good correlation between Gi signal inhibitory activity and cell migration inhibitory activity in human CCR6-transfected CHO cells. In addition, representative compound 35 potently inhibited CCR6-dependent cell migration and the increase in ERK phosphorylation in human primary cells. Therefore, the compound could be used effectively as a biological probe against human CCR6. [ABSTRACT FROM AUTHOR]

A series of phenoxyethylamine derivatives was designed and synthesized to discover potent and selective human α 1D adrenoceptor (α 1D adrenergic receptor; α 1D –AR) antagonists. Compound 7 was taken from our internal compound collection as an attractive starting point and exhibited moderate binding affinity for α 1D –AR and high selectivity against α 1A – and α 1B –ARs. We focused on modifying the 2-methylsulfonylbenzyl group of 7 to discover novel compounds structurally distinct from other reported α 1 –AR antagonists containing the phenoxyethylamine motif. Study of structure activity relationship guided by a targeted ligand-lipophilicity efficiency score led to the discovery of a novel scaffold of 3,4-dihydro-2 H -thiochromene 1,1-dioxide for selective α 1D –AR antagonists. Further optimization studies resulted in the identification of (4 S )- N 4 -[2-(2,5-difluorophenoxy)ethyl]- N 6 -methyl-3,4-dihydro-2 H -thiochromene-4,6-diamine 1,1-dioxide, ( S )– 41 , as a novel, highly potent and selective α 1D –AR antagonist. Herein, we provide details of the structure activity relationship of the phenoxyethylamine analog for the potency and selectivity. [ABSTRACT FROM AUTHOR]

Matrix metalloproteinase-13 (MMP-13), a member of the collagenase family of enzymes, has been implicated to play a key role in the pathology of osteoarthritis. Recently, we have reported the discovery of a series of quinazoline-2-carboxamide based non-zinc-binding MMP-13 selective inhibitors, as exemplified by compound 1 . We then continued our research of a novel class of zinc-binding inhibitors to obtain follow-up compounds with different physicochemical, pharmacokinetic, and biological activity profiles. In order to design selective MMP-13 inhibitors, we adopted a strategy of connecting a zinc-binding group with the quinazoline-2-carboxamide system, a unique S1′ binder, by an appropriate linker. Among synthesized compounds, a triazolone inhibitor 35 exhibited excellent potency (IC 50 = 0.071 nM) and selectivity (greater than 170-fold) over other MMPs (MMP-1, 2, 3, 7, 8, 9, 10, 12, and 14) and tumor necrosis factor-α converting enzyme (TACE). In this article, the design, synthesis, and biological activity of novel zinc-binding MMP-13 inhibitors are described. [ABSTRACT FROM AUTHOR]

5-Chloro-1-(5-chloro-2-(methylsulfonyl)benzyl)-2-imino-1,2-dihydropyridine-3-carboxamide hydrochloride (TAK-259) is a novel, selective, and orally active α 1D adrenoceptor antagonist with anti-urinary frequency effect. A metabolite ( 2 ) of TAK-259 was identified from monkey urine samples. To elucidate the structure of 2 , extraction and purification of the metabolite from TAK-259-treated monkey urine was conducted. Structural analysis of the purified compounds using NMR indicated the compound to be 2-amino-5-chloro-1-[5-chloro-2-(methylsulfonyl)benzyl]-4-oxo-1,4-dihydropyridine-3-carboxamide ( 2a ). An authentic sample of compound 2a was synthesized via regioselective alkylation of 4-methoxypyridin-2-amine. The biological activity of metabolite 2a was also evaluated, and the compound found not to possess affinity toward any known α 1 adrenoceptor subtype. [ABSTRACT FROM AUTHOR]

Matrix metalloproteinase-13 (MMP-13)has been implicated to playa key role in the pathology of osteoarthritis. On the basis of X-raycrystallography, we designed a series of potent MMP-13 selective inhibitorsoptimized to occupy the distinct deep S1′ pocket includingan adjacent branch. Among them, carboxylic acid inhibitor 21kexhibited excellent potency and selectivity for MMP-13 over otherMMPs. An effort to convert compound 21kto the mono sodiumsalt 38was promising in all animal species studied.Moreover, no overt toxicity was observed in a preliminary repeat doseoral toxicity study of compound 21kin rats. A singleoral dose of compound 38significantly reduced degradationproducts (CTX-II) released from articular cartilage into the jointcavity in a rat MIA model in vivo. In this article, we report thediscovery of highly potent, selective, and orally bioavailable MMP-13inhibitors as well as their detailed structure–activity data. [ABSTRACT FROM AUTHOR]

On the basis of X-ray co-crystal structures of matrix metalloproteinase-13 (MMP-13) in complex with its inhibitors, our structure-based drug design (SBDD) strategy was directed to achieving high affinity through optimal protein–ligand interaction with the unique S1″ hydrophobic specificity pocket. This report details the optimization of lead compound 44 to highly potent and selective MMP-13 inhibitors based on fused pyrimidine scaffolds represented by the thienopyrimidin-4-one 26c . Furthermore, we have examined the release of collagen fragments from bovine nasal cartilage in response to a combination of IL-1 and oncostatin M. [ABSTRACT FROM AUTHOR]