Publications by authors named "Nyantsz Wu"

4 Publications

  • Page 1 of 1

High-throughput-compatible assays using a genetically-encoded calcium indicator.

Sci Rep 2019 09 3;9(1):12692. Epub 2019 Sep 3.

Janssen Research & Development, LLC, San Diego, CA, 92121, USA.

Measurement of intracellular calcium in live cells is a key component of a wide range of basic life science research, and crucial for many high-throughput assays used in modern drug discovery. Synthetic calcium indicators have become the industry standard, due their ease of use, high reliability, wide dynamic range, and availability of a large variety of spectral and chemical properties. Genetically-encoded calcium indicators (GECIs) have been optimized to the point where their performance rivals that of synthetic calcium indicators in many applications. Stable expression of a GECI has distinct advantages over synthetic calcium indicators in terms of reagent cost and simplification of the assay process. We generated a clonal cell line constitutively expressing GCaMP6s; high expression of the GECI was driven by coupling to a blasticidin resistance gene with a self-cleaving cis-acting hydrolase element (CHYSEL) 2A peptide. Here, we compared the performance of the GECI GCaMP6s to the synthetic calcium indicator fluo-4 in a variety of assay formats. We demonstrate that the pharmacology of ion channel and GPCR ligands as determined using the two indicators is highly similar, and that GCaMP6s is viable as a direct replacement for a synthetic calcium indicator.
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http://dx.doi.org/10.1038/s41598-019-49070-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6722131PMC
September 2019

Discovery of Imidazo[1,2-]pyrazines and Pyrazolo[1,5-]pyrimidines as TARP γ-8 Selective AMPAR Negative Modulators.

ACS Med Chem Lett 2019 Mar 26;10(3):267-272. Epub 2018 Dec 26.

Janssen Research & Development L.L.C., 3210 Merryfield Row, San Diego, California 92121 United States.

This report discloses the discovery and characterization of imidazo[1,2-]pyrazines and pyrazolo[1,5-]pyrimidines as selective negative modulators of α-amino-3-hydroxy-5-methylisoxazole-4-propionate receptors (AMPARs) associated with transmembrane AMPAR regulatory protein γ-8. Imidazopyrazine was initially identified as a promising γ-8 selective high-throughput screening hit, and subsequent structure-activity relationship optimization yielded subnanomolar, brain penetrant leads. Replacement of the imidazopyrazine core with an isosteric pyrazolopyrimidine scaffold improved microsomal stability and efflux liabilities to provide , JNJ-61432059. Following oral administration, exhibited time- and dose-dependent AMPAR/γ-8 receptor occupancy in mouse hippocampus, which resulted in robust seizure protection in corneal kindling and pentylenetetrazole (PTZ) anticonvulsant models.
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http://dx.doi.org/10.1021/acsmedchemlett.8b00599DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6421542PMC
March 2019

Lead Optimization of 5-Aryl Benzimidazolone- and Oxindole-Based AMPA Receptor Modulators Selective for TARP γ-8.

ACS Med Chem Lett 2018 Aug 13;9(8):821-826. Epub 2018 Jul 13.

Janssen Research & Development L.L.C., 3210 Merryfield Row, San Diego, California 92121, United States.

Glutamate mediates fast excitatory neurotransmission via ionotropic α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors. The trafficking and gating properties of AMPA receptors (AMPARs) can be amplified by transmembrane AMPAR regulatory proteins (TARPs), which are often expressed in localized brain regions. Herein, we describe the discovery, lead optimization, and preclinical characterization of 5-arylbenzimidazolone and oxindole-based negative modulators of AMPARs associated with TARP γ-8, the primary TARP found in hippocampus. High-throughput screen lead was optimized for potency and brain penetration to provide benzimidazolone , JNJ-55511118.1 Replacement of the benzimidazolone core in with an oxindole mitigated reactive metabolite formation and led to the identification of (GluA1/γ-8 pIC = 9.7). Following oral dosing in rats, demonstrated robust target engagement in hippocampus as assessed by autoradiography (ED = 0.6 mg/kg, plasma EC = 9 ng/mL).
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http://dx.doi.org/10.1021/acsmedchemlett.8b00215DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6088354PMC
August 2018

Discovery and Characterization of AMPA Receptor Modulators Selective for TARP-γ8.

J Pharmacol Exp Ther 2016 May 17;357(2):394-414. Epub 2016 Mar 17.

Janssen Research and Development, LLC, Neuroscience Therapeutic Area, San Diego, California (M.P.M., N.W., S.R., M.K.A., B.M.S., C.L., B.L., R.M.W., J.A.M., C.D., S.Y., A.D.W., N.I.C., T.W.L.); and Janssen Research and Development, a Division of Janssen Pharmaceutica NV, Neuroscience Therapeutic Area, Beerse, Belgium (L.V.D., T.S.).

Members of the α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionic acid (AMPA) subtype of ionotropic glutamate receptors mediate the majority of fast synaptic transmission within the mammalian brain and spinal cord, representing attractive targets for therapeutic intervention. Here, we describe novel AMPA receptor modulators that require the presence of the accessory protein CACNG8, also known as transmembrane AMPA receptor regulatory protein γ8 (TARP-γ8). Using calcium flux, radioligand binding, and electrophysiological assays of wild-type and mutant forms of TARP-γ8, we demonstrate that these compounds possess a novel mechanism of action consistent with a partial disruption of the interaction between the TARP and the pore-forming subunit of the channel. One of the molecules, 5-[2-chloro-6-(trifluoromethoxy)phenyl]-1,3-dihydrobenzimidazol-2-one (JNJ-55511118), had excellent pharmacokinetic properties and achieved high receptor occupancy following oral administration. This molecule showed strong, dose-dependent inhibition of neurotransmission within the hippocampus, and a strong anticonvulsant effect. At high levels of receptor occupancy in rodent in vivo models, JNJ-55511118 showed a strong reduction in certain bands on electroencephalogram, transient hyperlocomotion, no motor impairment on rotarod, and a mild impairment in learning and memory. JNJ-55511118 is a novel tool for reversible AMPA receptor inhibition, particularly within the hippocampus, with potential therapeutic utility as an anticonvulsant or neuroprotectant. The existence of a molecule with this mechanism of action demonstrates the possibility of pharmacological targeting of accessory proteins, increasing the potential number of druggable targets.
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http://dx.doi.org/10.1124/jpet.115.231712DOI Listing
May 2016