Publications by authors named "John C R Randle"

Tethered glycoconjugates of a naphthalene- and piperidine-containing antagonist of the P2Y receptor (PPTN) were synthesized, and their nM receptor binding affinity was determined using a fluorescent tracer in hP2YR-expressing whole CHO cells. The rationale for preparing mono- and disaccharide conjugates of the antagonists was to explore the receptor binding site, which we know recognizes a glucose moiety on the native agonist (UDP-glucose), as well as enhance aqueous solubility and pharmacokinetics, including kidney excretion to potentially counteract sterile inflammation. Glycoconjugates with varied linker length, including PEG chains, were compared in hP2YR binding, suggesting that an optimal affinity (IC, nM) in the piperidine series was achieved for triazolyl -linked glucose conjugates having one (, MRS4872, 3.

View Article and Find Full Text PDF

P2Y receptor (P2YR) is activated by extracellular UDP-glucose, a damage-associated molecular pattern that promotes inflammation in the kidney, lung, fat tissue, and elsewhere. Thus, selective P2YR antagonists are potentially useful for inflammatory and metabolic diseases. The piperidine ring size of potent, competitive P2YR antagonist (4-phenyl-2-naphthoic acid derivative) PPTN was varied from 4- to 8-membered rings, with bridging/functional substitution.

View Article and Find Full Text PDF

High affinity phenyl-piperidine P2YR antagonist (PPTN) was modified with piperidine bridging moieties to probe receptor affinity and hydrophobicity. Various 2-azanorbornane, nortropane, isonortropane, isoquinuclidine, and ring-opened cyclopentylamino derivatives preserved human P2YR affinity (fluorescence binding assay), and their pharmacophoric overlay was compared. Enantiomeric 2-azabicyclo[2.

View Article and Find Full Text PDF
Article Synopsis
  • Researchers modified a known zwitterionic P2YR antagonist by substituting various chemical groups on its structure, focusing on enhancing potency through computational screening.
  • The most effective versions included a piperidine bioisostere and specific modifications that maintained moderate receptor affinity, while certain changes like the aza-scan reduced effectiveness.
  • The study concluded that zwitterionic properties weren't essential for receptor binding, and they explored prodrugs that could create neutral analogues, which showed effectiveness in vivo.
View Article and Find Full Text PDF

Background: 3-Hydroxy-3-methyl-glutaryl coenzyme A reductase inhibitors inhibit HCV replication in vitro. The combination of sertraline and simvastatin has synergistic antiviral activity in vitro, but there are no prior in vivo studies. Our aims were to prospectively assess the antiviral efficacy and safety of this drug combination in chronic hepatitis C (CHC) patients.

View Article and Find Full Text PDF

Variants resistant to compounds specifically targeting HCV are observed in clinical trials. A multi-variant viral dynamic model was developed to quantify the evolution and in vivo fitness of variants in subjects dosed with monotherapy of an HCV protease inhibitor, telaprevir. Variant fitness was estimated using a model in which variants were selected by competition for shared limited replication space.

View Article and Find Full Text PDF

(S)-1-((S)-2-{[1-(4-amino-3-chloro-phenyl)-methanoyl]-amino}-3,3-dimethyl-butanoyl)-pyrrolidine-2-carboxylic acid ((2R,3S)-2-ethoxy-5-oxo-tetrahydro-furan-3-yl)-amide (VX-765) is an orally absorbed prodrug of (S)-3-({1-[(S)-1-((S)-2-{[1-(4-amino-3-chlorophenyl)-methanoyl]-amino}-3,3-dimethyl-butanoyl)-pyrrolidin-2yl]-methanoyl}-amino)-4-oxo-butyric acid (VRT-043198), a potent and selective inhibitor of interleukin-converting enzyme/caspase-1 subfamily caspases. VRT-043198 exhibits 100- to 10,000-fold selectivity against other caspase-3 and -6 to -9. The therapeutic potential of VX-765 was assessed by determining the effects of VRT-043198 on cytokine release by monocytes in vitro and of orally administered VX-765 in several animal models in vivo.

View Article and Find Full Text PDF

Purpose: Cytokines and related inflammatory mediators are rapidly synthesized in the brain during seizures. We previously found that intracerebral administration of interleukin-1 (IL-1)-beta has proconvulsant effects, whereas its endogenous receptor antagonist (IL-1Ra) mediates potent anticonvulsant actions in various models of limbic seizures. In this study, we investigated whether seizures can be effectively inhibited by blocking the brain production of IL-1beta, by using selective inhibitors of interleukin-converting enzyme (ICE/caspase-1) or through caspase-1 gene deletion.

View Article and Find Full Text PDF

Familial cold autoinflammatory syndrome (FCAS) and the related autoinflammatory disorders, Muckle-Wells syndrome and neonatal onset multisystem inflammatory disease, are characterized by mutations in the CIAS1 gene that encodes cryopyrin, an adaptor protein involved in activation of IL-converting enzyme/caspase-1. Mutations in cryopyrin are hypothesized to result in abnormal secretion of caspase-1-dependent proinflammatory cytokines, IL-1beta and IL-18. In this study, we examined cytokine secretion in PBMCs from FCAS patients and found a marked hyperresponsiveness of both IL-1beta and IL-18 secretion to LPS stimulation, but no evidence of increased basal secretion of these cytokines, or alterations in basal or stimulated pro-IL-1beta levels.

View Article and Find Full Text PDF