Development of selective, fluorescent cannabinoid type 2 receptor ligands based on a 1,8-naphthyridin-2-(1<i>H</i>)-one-3-carboxamide scaffold

Cannabinoid type 2 receptor (CB 2 R) is an attractive target for the treatment of pain and inflammatory disorders. Availability of a selective CB 2 R fluorescent ligand to study CB 2 R expression and localization in healthy and disease conditions would greatly contribute to improving our understanding of this receptor. Herein, we report a series of chromenopyrazole-based CB 2 R fluorescent ligands. The highest affinity fluorescent ligand was Cy5-containing 24 (hCB 2 R pK i = 7.38 ± 0.05), which had 131-fold selectivity over CB 1 R. In a cAMP BRET assay, 24 behaved as a potent CB 2 R inverse agonist. Widefield imaging experiments showed that 24 binds to CB 2 R in live cells with good selectivity and low levels of nonspecific fluorescence. The high affinity, selectivity, and suitable imaging properties of fluorescent ligand 24 make it a valuable tool for studying CB 2 R.

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“…g Data obtained from literature. 17 All data is expressed as mean ± SEM. the concentration range tested.…”

Section: Acs Medicinal Chemistry Lettersmentioning

confidence: 99%

Chromenopyrazole-based High Affinity, Selective Fluorescent Ligands for Cannabinoid Type 2 Receptor

Singh

Oyagawa

Macdonald

et al. 2019

ACS Med. Chem. Lett.

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“…[20][21][22] Several fluorescent ligands targeting CB2R have been reported. [23][24][25][26][27][28][29][30][31][32][33][34][35] However, in our collective experience the published probes perform less than optimally as judged by at least one of the following criteria: modularity of design for multiple applications, selectivity over CB1R, affinity and specificity for CB2R, photophysical properties, and applicability across species, techniques, and cell types. Furthermore, bifunctional probes that require additional manipulations prior to imaging are often incompatible with live cells.…”

Section: Introductionmentioning

confidence: 99%

Development of High-Specificity Fluorescent Probes to Enable Cannabinoid Type 2 Receptor Studies in Living Cells

et al. 2020

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Pharmacological modulation of cannabinoid type 2 receptor (CB2R) holds promise for the treatment of numerous conditions, including inflammatory diseases, autoimmune disorders, pain, and cancer. Despite the significance of this receptor, researchers lack reliable tools to address questions concerning the expression and complex mechanism of CB2R signaling, especially in cell-type and tissue-dependent context. Herein, we report for the first time a versatile ligand platform for the modular design of a collection of highly specific CB2R fluorescent probes, used successfully across applications, species and cell types. These include flow cytometry of endogenously expressing cells, real-time confocal microscopy of mouse splenocytes and human macrophages, as well as FRET-based kinetic and equilibrium binding assays. High CB2R specificity was demonstrated by competition experiments in living cells expressing CB2R at native levels. The probes were effectively applied to FACS analysis of microglial cells derived from a mouse model relevant to Alzheimer's disease and to the detection of CB2R in human breast cancer cells.

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“…The group of Vernall reported a library of 1,8‐naphthyridin‐2‐(1H)‐one‐3‐carboxamide tagged with BODIPY‐X‐630/650 at distinct positions in the presence of linkers of distinct length and chemical composition. Despite one of the candidates displaying high affinity for the CB 2 R (K i =6.33 nM), it lacked specific binding when used as a stain in live cell imaging [158] . The same group expanded the toolbox of CB 2 R fluorescent ligands by assembling amidoaliphatic and PEG‐based linkers with cyanine, BODIPY and rhodamine cores and a N ‐phenylchromenopyrazole pharmacophore.…”

Section: Fluorescent Ligands For Gpcrsmentioning

confidence: 99%

Lighting Up the Plasma Membrane: Development and Applications of Fluorescent Ligands for Transmembrane Proteins

Borgarelli

Klingl

Escamilla-Ayala

et al. 2021

Chemistry A European J

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Despite the fact that transmembrane proteins represent the main therapeutic targets for decades, complete and in‐depth knowledge about their biochemical and pharmacological profiling is not fully available. In this regard, target‐tailored small‐molecule fluorescent ligands are a viable approach to fill in the missing pieces of the puzzle. Such tools, coupled with the ability of high‐precision optical techniques to image with an unprecedented resolution at a single‐molecule level, helped unraveling many of the conundrums related to plasma proteins’ life‐cycle and druggability. Herein, we review the recent progress made during the last two decades in fluorescent ligand design and potential applications in fluorescence microscopy of voltage‐gated ion channels, ligand‐gated ion channels and G‐coupled protein receptors.

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Development of selective, fluorescent cannabinoid type 2 receptor ligands based on a 1,8-naphthyridin-2-(1H)-one-3-carboxamide scaffold

Abstract: High affinity, cannabinoid type 2 receptor selective ligand.

Cited by 17 publications

References 45 publications

Chromenopyrazole-based High Affinity, Selective Fluorescent Ligands for Cannabinoid Type 2 Receptor

Chromenopyrazole-based High Affinity, Selective Fluorescent Ligands for Cannabinoid Type 2 Receptor

Development of High-Specificity Fluorescent Probes to Enable Cannabinoid Type 2 Receptor Studies in Living Cells

Lighting Up the Plasma Membrane: Development and Applications of Fluorescent Ligands for Transmembrane Proteins

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