To curb viral epidemics and pandemics, antiviral drugs are needed with activity against entire genera or families of viruses. Here, we develop a cell-based multiplex antiviral assay for high-throughput screening against multiple viruses at once, as demonstrated by using three distantly related orthoflaviviruses: dengue, Japanese encephalitis and yellow fever virus. Each virus is tagged with a distinct fluorescent protein, enabling individual monitoring in cell culture through high-content imaging.
View Article and Find Full Text PDFThe CD38-targeting antibody daratumumab has marked activity in multiple myeloma (MM). Natural killer (NK) cells play an important role during daratumumab therapy by mediating antibody-dependent cellular cytotoxicity via their FcγRIII receptor (CD16), but they are also rapidly decreased following initiation of daratumumab treatment. We characterized the NK cell phenotype at baseline and during daratumumab monotherapy by flow cytometry and cytometry by time of flight to assess its impact on response and development of resistance (DARA-ATRA study; NCT02751255).
View Article and Find Full Text PDFWe describe the hit-to-lead exploration of a [1,2,4]triazolo[1,5-]pyrimidine phosphodiesterase 2A (PDE2A) inhibitor arising from high-throughput screening. X-ray crystallography enabled structure-guided design, leading to the identification of preferred substructural components. Further rounds of optimization used relative binding free-energy calculations to prioritize different substituents from the large accessible chemical space.
View Article and Find Full Text PDFCD38-targeted antibody, daratumumab, is approved for the treatment of multiple myeloma (MM). Phase 1/2 studies GEN501/SIRIUS revealed a novel immunomodulatory mechanism of action (MOA) of daratumumab that enhanced the immune response, reducing natural killer (NK) cells without affecting efficacy or safety. We further evaluated daratumumab's effects on immune cells in whole blood samples of relapsed/refractory MM patients from both treatment arms of the phase 3 POLLUX study (lenalidomide/dexamethasone [Rd] or daratumumab plus Rd [D-Rd]) at baseline (D-Rd, 40; Rd, 45) and after 2 months on treatment (D-Rd, 31; Rd, 33) using cytometry by time-of-flight.
View Article and Find Full Text PDFDaratumumab is a CD38-targeted human monoclonal antibody with direct anti-myeloma cell mechanisms of action. Flow cytometry in relapsed and/or refractory multiple myeloma (RRMM) patients treated with daratumumab revealed cytotoxic T-cell expansion and reduction of immune-suppressive populations, suggesting immune modulation as an additional mechanism of action. Here, we performed an in-depth analysis of the effects of daratumumab on immune-cell subpopulations using high-dimensional mass cytometry.
View Article and Find Full Text PDFMass cytometry has emerged as a new state-of-the-art technology that enables in-depth characterization of cellular populations and functions at a single cell resolution. We describe the application of this technology to deeply phenotype the blood and bone marrow components of multiple myeloma patients in a clinical setting. This technology allows for simultaneous quantification of more than 40 markers, overcoming the challenges of traditional fluorescence-based flow cytometry.
View Article and Find Full Text PDFBackground: Phosphodiesterase 10A (PDE10A) is an important regulator of nigrostriatal dopamine (DA) neurotransmission. However, little is known on the effect of alterations in DA neurotransmission on PDE10A availability. Here, we used [F]JNJ42259152 PET to measure changes in PDE10A availability, secondary to pharmacological alterations in DA release and to investigate whether these are D- or D-receptor driven.
View Article and Find Full Text PDFThe cyclic guanosine monophosphate (cGMP) specific phosphodiesterase type 5 (PDE5) plays an important role in various pathologies including pulmonary arterial hypertension and cardiomyopathy. PDE5 represents an important therapeutic and/or prognostic target, but noninvasive assessment of PDE5 expression is lacking. The purpose of this study was to develop and evaluate pyridopyrazinone derivatives labeled with carbon-11 or fluorine-18 as PDE5-specific PET tracers.
View Article and Find Full Text PDFA novel series of pyrido[4,3-e][1,2,4]triazolo[4,3-a]pyrazines is reported as potent PDE2/PDE10 inhibitors with drug-like properties. Selectivity for PDE2 was obtained by introducing a linear, lipophilic moiety on the meta-position of the phenyl ring pending from the triazole. The SAR and protein flexibility were explored with free energy perturbation calculations.
View Article and Find Full Text PDFThe enzyme phosphodiesterase 10A (PDE10A) regulates the activity of striatal, medium spiny neurons (MSNs), which are divided into a behaviorally stimulating, Gs-coupled D1 receptor-expressing "direct" pathway and a behaviorally suppressant, Gi-coupled D2 receptor-expressing "indirect" pathway. Activating both pathways, PDE10A inhibitors (PDE10AIs) combine functional characteristics of D2 antagonists and D1 agonists. While the effects of PDE10AIs on spontaneous and stimulated behavior have been extensively reported, the present study investigates their effects on suppressed behavior under various conditions of reduced dopaminergic neurotransmission: blockade of D1 receptors with SCH-23390, blockade of D2 receptors with haloperidol, or depletion of dopamine with RO-4-1284 or reserpine.
View Article and Find Full Text PDFWe report the continuation of a focused medicinal chemistry program aimed to further optimize a series of imidazo[1,2-a]pyrazines as a novel class of potent and selective phosphodiesterase 10A (PDE10A) inhibitors. In vitro and in vivo pharmacokinetic and pharmacodynamic evaluation allowed the selection of compound 25a for its assessment in preclinical models of psychosis. The evolution of our medicinal chemistry program, structure-activity relationship (SAR) analysis, as well as a detailed pharmacological profile for optimized lead 25a are described.
View Article and Find Full Text PDFStructure-guided design led to the identification of the novel, potent, and selective phosphodiesterase 2 (PDE2) inhibitor 12. Compound 12 demonstrated a >210-fold selectivity versus PDE10 and PDE11 and was inactive against all other PDE family members up to 10 μM. In vivo evaluation of 12 provided evidence that it is able to engage the target and to increase cGMP levels in relevant brain regions.
View Article and Find Full Text PDFWe report the discovery of a series of imidazo[1,2-a]pyrazine derivatives as novel inhibitors of phosphodiesterase 10A (PDE10A). In a high-throughput screening campaign we identified the imidazopyrazine derivative 1, a PDE10A inhibitor with limited selectivity versus the other phosphodiesterases (PDEs). Subsequent investigation of 1 and replacement of the trimethoxyphenyl group by a (methoxyethyl)pyrazole moiety maintained PDE10A inhibition but enhanced selectivity against the other PDEs.
View Article and Find Full Text PDFThe striatum is the main input structure to the basal ganglia and consists mainly out of medium spiny neurons. The numerous spines on their dendrites render them capable of integrating cortical glutamatergic inputs with a motivational dopaminergic signal that originates in the midbrain. This integrative function is thought to underly attribution of incentive salience, a process that is severely disrupted in schizophrenic patients.
View Article and Find Full Text PDFThe new phosphodiesterase 10A inhibitor (PDE10AI) JNJ-42314415 [3-[6-(2-methoxyethyl)pyridin-3-yl]-2-methyl-8-morpholin-4-ylimidazo[1,2-a]pyrazine] was compared with three reference PDE10AIs and eight dopamine 2 (D(2)) receptor blockers. Despite displaying relatively low PDE10A activity in vitro, JNJ-42314415 was found to be a relatively potent and specific PDE10AI in vivo. The compound was devoid of effects on prolactin release and of receptor interactions associated with other commonly observed adverse effects of available antipsychotics.
View Article and Find Full Text PDFIntroduction: The cyclic guanosine monophosphate (cGMP) specific phosphodiesterase type 5 (PDE5) is considered to play an important role in various etiologies such as pulmonary arterial hypertension (PAH) and chronic heart failure. This PDE5 modulation represents an important prognostic and/or therapeutic target; however, there is currently no method to non-invasively evaluate the PDE5 expression levels in vivo.
Methods: Radiolabeled tracers were prepared by N-alkylation of the corresponding precursors with [(11)C]methyl trifluoromethanesulfonate ([(11)C]CH3OTf) or 2-[(18)F]fluoroethyl trifluoromethanesulfonate ([(18)F]FEtOTf).
The pharmacological effect of the selective PDE10A inhibitor 2-[4-(1-methyl-4-pyridin-4-yl-1H-pyrazol-3-yl)-phenoxymethyl]-quinoline succinic acid (MP-10) on aversively and appetitively motivated behavior in C57BL/6J mice was examined. MP-10 dose-dependently impaired performance on a highly demanding reward schedule during appetitive conditioning. The compound further affected cue-based, but not contextual aversive conditioning.
View Article and Find Full Text PDFThe synthesis, preliminary evaluation and structure-activity relationship (SAR) of a series of 1-aryl-4-methyl[1,2,4]triazolo[4,3-a]quinoxalines as dual phosphodiesterase 2/phosphodiesterase 10 (PDE2/PDE10) inhibitors are described. From this investigation compound 31 was identified, showing good combined potency, acceptable brain uptake and high selectivity for both PDE2 and PDE10 enzymes. Compound 31 was subjected to a microdosing experiment in rats, showing preferential distribution in brain areas where both PDE2 and PDE10 are highly expressed.
View Article and Find Full Text PDFWe have recently reported the phosphodiesterase 10A (PDE10A) inhibitor 2-[4-[1-(2-[(18)F]fluoroethyl)-4-pyridin-4-yl-1H-pyrazol-3-yl]-phenoxymethyl]-quinoline ([(18)F]1a) as a promising candidate for in vivo imaging using positron emission tomography (PET). We now describe the synthesis and biological evaluation of a series of related pyridinyl analogues that exhibit high potency and selectivity as PDE10A inhibitors. The most interesting compounds were injected in rats to measure their levels of PDE10A occupancy through an in vivo occupancy assay.
View Article and Find Full Text PDFPhosphodiesterase 10A (PDE10A) inhibitors have recently been proposed as a new therapy for schizophrenia. The aim of this study was to enhance our understanding of the role of PDE10A inhibitors and potentially identify a clinically useful mechanistic/functional biomarker by using 2-deoxyglucose (2-DG) autoradiography. PDE10A inhibitors papaverine (10 and 40 mg/kg), 6,7-dimethoxy-4-[(3R)-3-(2-quinoxalinyloxy)-1-pyrrolidinyl]quinazoline (PQ-10), (0.
View Article and Find Full Text PDFPhosphodiesterase 10A (PDE10A) hydrolyzes both cAMP and cGMP, and is a key element in the regulation of medium spiny neuron (MSN) activity in the striatum. In the present report, we investigated the effects of targeted disruption of PDE10A on spatial learning and memory as well as aversive and appetitive conditioning in C57BL/6J mice. Because of its putative role in motivational processes and reward learning, we also determined the expression of the immediate early gene zif268 in striatum and anterior cingulate cortex.
View Article and Find Full Text PDFPhosphodiesterases (PDEs) form a family of enzymes involved in the hydrolysis of cyclic adenosine and guanosine monophosphate (cAMP and cGMP). PDE10A is a member of this family that is almost exclusively expressed in the striatum. Increasing cAMP/cGMP levels via inhibition of PDE10A is under consideration as a novel therapeutic avenue in the discovery of antipsychotics.
View Article and Find Full Text PDFCyclic adenosine 3'5'-monophosphate (cAMP) and cyclic guanosine 3'5'-monophosphate (cGMP) serve as second messengers in several cellular pathways within the central nervous system. In various neurological and psychiatric disorders with known deficits in neurotransmission function, CSF levels of cAMP and/or cGMP in patients were studied. Very little information is currently available on cAMP and cGMP levels in CSF of animals.
View Article and Find Full Text PDFA data mining procedure for the rapid scoring of high-throughput screening (HTS) compounds is presented. The method is particularly useful for monitoring the quality of HTS data and tracking outliers in automated pharmaceutical or agrochemical screening, thus providing more complete and thorough structure-activity relationship (SAR) information. The method is based on the utilization of the assumed relationship between the structure of the screened compounds and the biological activity on a given screen expressed on a binary scale.
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