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Gao ZG, Chen W, Gao RR, Li J, Tosh DK, Hanover JA, Jacobson KA. Genetic and functional modulation by agonist MRS5698 and allosteric enhancer LUF6000 at the native A 3 adenosine receptor in HL-60 cells. Purinergic Signal 2024:10.1007/s11302-024-09992-z. [PMID: 38416332 DOI: 10.1007/s11302-024-09992-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Accepted: 02/12/2024] [Indexed: 02/29/2024] Open
Abstract
The A3 adenosine receptor (AR) is an important inflammatory and immunological target. However, the underlying mechanisms are not fully understood. Here, we report the gene regulation in HL-60 cells treated acutely with highly selective A3AR agonist MRS5698, positive allosteric modulator (PAM) LUF6000, or both. Both pro- and anti-inflammatory genes, such as IL-1a, IL-1β, and NFκBIZ, are significantly upregulated. During our observations, LUF6000 alone produced a lesser effect, while the MRS5698 + LUF6000 group demonstrated generally greater effects than MRS5698 alone, consistent with allosteric enhancement. The number of genes up- and down-regulated are similar. Pathway analysis highlighted the critical involvement of signaling molecules, including IL-6 and IL-17. Important upstream regulators include IL-1a, IL-1β, TNF-α, NF-κB, etc. PPAR, which modulates eicosanoid metabolism, was highly downregulated by the A3AR agonist. Considering previous pharmacological results and mathematical modeling, LUF6000's small enhancement of genetic upregulation suggested that MRS5698 is a nearly full agonist, which we demonstrated in both cAMP and calcium assays. The smaller effect of LUF6000 on MRS5698 in comparison to its effect on Cl-IB-MECA was shown in both HL-60 cells endogenously expressing the human (h) A3AR and in recombinant hA3AR-expressing CHO cells, consistent with its HL-60 cell genetic regulation patterns. In summary, by using both selective agonists and PAM, we identified genes that are closely relevant to immunity and inflammation to be regulated by A3AR in differentiated HL-60 cells, a cell model of neutrophil function. In addition, we demonstrated the previously uncharacterized allosteric signaling-enhancing effect of LUF6000 in cells endogenously expressing the hA3AR.
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Affiliation(s)
- Zhan-Guo Gao
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, NIDDK, National Institutes of Health, 9000, Rockville Pike, Bethesda, MD, 20892, USA.
| | - Weiping Chen
- Genomics Core, NIDDK, National Institutes of Health, 9000, Rockville Pike, Bethesda, MD, 20892, USA
| | - Ray R Gao
- Genomics Core, NIDDK, National Institutes of Health, 9000, Rockville Pike, Bethesda, MD, 20892, USA
| | - Jonathan Li
- Genomics Core, NIDDK, National Institutes of Health, 9000, Rockville Pike, Bethesda, MD, 20892, USA
| | - Dilip K Tosh
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, NIDDK, National Institutes of Health, 9000, Rockville Pike, Bethesda, MD, 20892, USA
| | - John A Hanover
- Genomics Core, NIDDK, National Institutes of Health, 9000, Rockville Pike, Bethesda, MD, 20892, USA
| | - Kenneth A Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, NIDDK, National Institutes of Health, 9000, Rockville Pike, Bethesda, MD, 20892, USA.
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Fisher CL, Pavan M, Salmaso V, Keyes RF, Wan TC, Pradhan B, Gao ZG, Smith BC, Jacobson KA, Auchampach JA. Extrahelical Binding Site for a 1 H-Imidazo[4,5-c]quinolin-4-amine A 3 Adenosine Receptor Positive Allosteric Modulator on Helix 8 and Distal Portions of Transmembrane Domains 1 and 7. Mol Pharmacol 2024; 105:213-223. [PMID: 38182432 PMCID: PMC10877738 DOI: 10.1124/molpharm.123.000784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 11/27/2023] [Accepted: 12/12/2023] [Indexed: 01/07/2024] Open
Abstract
This study describes the localization and computational prediction of a binding site for the A3 adenosine receptor (A3AR) positive allosteric modulator 2-cyclohexyl-1H-imidazo[4,5-c]quinolin-4-(3,4-dichlorophenyl)amine (LUF6000). The work reveals an extrahelical lipid-facing binding pocket disparate from the orthosteric binding site that encompasses transmembrane domain (TMD) 1, TMD7, and Helix (H) 8, which was predicted by molecular modeling and validated by mutagenesis. According to the model, the nearly planar 1H-imidazo[4,5-c]quinolinamine ring system lies parallel to the transmembrane segments, inserted into an aromatic cage formed by π-π stacking interactions with the side chains of Y2847.55 in TMD7 and Y2938.54 in H8 and by π-NH bonding between Y2847.55 and the exocyclic amine. The 2-cyclohexyl group is positioned "upward" within a small hydrophobic subpocket created by residues in TMDs 1 and 7, while the 3,4-dichlorophenyl group extends toward the lipid interface. An H-bond between the N-1 amine of the heterocycle and the carbonyl of G291.49 further stabilizes the interaction. Molecular dynamics simulations predicted two metastable intermediates, one resembling a pose determined by molecular docking and a second involving transient interactions with Y2938.54; in simulations, each of these intermediates converges into the final bound state. Structure-activity-relationships for replacement of either of the identified exocyclic or endocyclic amines with heteroatoms lacking H-bond donating ability were consistent with the hypothetical pose. Thus, we characterized an allosteric pocket for 1H-imidazo[4,5-c]quinolin-4-amines that is consistent with data generated by orthogonal methods, which will aid in the rational design of improved A3AR positive allosteric modulators. SIGNIFICANCE STATEMENT: Orthosteric A3AR agonists have advanced in clinical trials for inflammatory conditions, liver diseases, and cancer. Thus, the clinical appeal of selective receptor activation could extend to allosteric enhancers, which would induce site- and time-specific activation in the affected tissue. By identifying the allosteric site for known positive allosteric modulators, structure-based drug discovery modalities can be enabled to enhance the pharmacological properties of the 1H-imidazo[4,5-c]quinolin-4-amine class of A3AR positive allosteric modulators.
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Affiliation(s)
- Courtney L Fisher
- Departments of Pharmacology & Toxicology and the Cardiovascular Center (C.L.F., T.C.W., J.A.A.) and Biochemistry and the Program in Chemical Biology (R.F.K., B.C.S.), Medical College of Wisconsin, Milwaukee, Wisconsin; Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland (M.P., V.S., B.P., Z.-G.G., K.A.J.); and Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Padua, Italy (V.S.)
| | - Matteo Pavan
- Departments of Pharmacology & Toxicology and the Cardiovascular Center (C.L.F., T.C.W., J.A.A.) and Biochemistry and the Program in Chemical Biology (R.F.K., B.C.S.), Medical College of Wisconsin, Milwaukee, Wisconsin; Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland (M.P., V.S., B.P., Z.-G.G., K.A.J.); and Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Padua, Italy (V.S.)
| | - Veronica Salmaso
- Departments of Pharmacology & Toxicology and the Cardiovascular Center (C.L.F., T.C.W., J.A.A.) and Biochemistry and the Program in Chemical Biology (R.F.K., B.C.S.), Medical College of Wisconsin, Milwaukee, Wisconsin; Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland (M.P., V.S., B.P., Z.-G.G., K.A.J.); and Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Padua, Italy (V.S.)
| | - Robert F Keyes
- Departments of Pharmacology & Toxicology and the Cardiovascular Center (C.L.F., T.C.W., J.A.A.) and Biochemistry and the Program in Chemical Biology (R.F.K., B.C.S.), Medical College of Wisconsin, Milwaukee, Wisconsin; Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland (M.P., V.S., B.P., Z.-G.G., K.A.J.); and Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Padua, Italy (V.S.)
| | - Tina C Wan
- Departments of Pharmacology & Toxicology and the Cardiovascular Center (C.L.F., T.C.W., J.A.A.) and Biochemistry and the Program in Chemical Biology (R.F.K., B.C.S.), Medical College of Wisconsin, Milwaukee, Wisconsin; Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland (M.P., V.S., B.P., Z.-G.G., K.A.J.); and Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Padua, Italy (V.S.)
| | - Balaram Pradhan
- Departments of Pharmacology & Toxicology and the Cardiovascular Center (C.L.F., T.C.W., J.A.A.) and Biochemistry and the Program in Chemical Biology (R.F.K., B.C.S.), Medical College of Wisconsin, Milwaukee, Wisconsin; Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland (M.P., V.S., B.P., Z.-G.G., K.A.J.); and Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Padua, Italy (V.S.)
| | - Zhan-Guo Gao
- Departments of Pharmacology & Toxicology and the Cardiovascular Center (C.L.F., T.C.W., J.A.A.) and Biochemistry and the Program in Chemical Biology (R.F.K., B.C.S.), Medical College of Wisconsin, Milwaukee, Wisconsin; Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland (M.P., V.S., B.P., Z.-G.G., K.A.J.); and Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Padua, Italy (V.S.)
| | - Brian C Smith
- Departments of Pharmacology & Toxicology and the Cardiovascular Center (C.L.F., T.C.W., J.A.A.) and Biochemistry and the Program in Chemical Biology (R.F.K., B.C.S.), Medical College of Wisconsin, Milwaukee, Wisconsin; Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland (M.P., V.S., B.P., Z.-G.G., K.A.J.); and Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Padua, Italy (V.S.)
| | - Kenneth A Jacobson
- Departments of Pharmacology & Toxicology and the Cardiovascular Center (C.L.F., T.C.W., J.A.A.) and Biochemistry and the Program in Chemical Biology (R.F.K., B.C.S.), Medical College of Wisconsin, Milwaukee, Wisconsin; Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland (M.P., V.S., B.P., Z.-G.G., K.A.J.); and Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Padua, Italy (V.S.)
| | - John A Auchampach
- Departments of Pharmacology & Toxicology and the Cardiovascular Center (C.L.F., T.C.W., J.A.A.) and Biochemistry and the Program in Chemical Biology (R.F.K., B.C.S.), Medical College of Wisconsin, Milwaukee, Wisconsin; Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland (M.P., V.S., B.P., Z.-G.G., K.A.J.); and Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Padua, Italy (V.S.)
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Deng L, Deichert JA, Nguyen S, Young IS, Han C. Synthesis of 3-Functionalized 4-Quinolones from Readily Available Anthranilic Acids. Org Lett 2023; 25:6710-6714. [PMID: 37668573 DOI: 10.1021/acs.orglett.3c02558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/06/2023]
Abstract
We report herein an efficient synthesis of 3-functionalized 4-quinolones, a class of privileged pharmacophores found in numerous biologically and pharmaceutically active compounds. Our synthetic strategy features a telescoped two-step sequence starting from readily available anthranilic acids and functionalized methane derivatives bearing an electron-withdrawing group, such as methyl sulfones, methyl ketones, and acetonitrile. The method delivers good to excellent yields for a variety of structurally diverse substrates, showing good functional group tolerability. We believe that the disclosed method offers a highly efficient and practical entry to functionalized 4-quinolones under mild conditions that is amenable to preparative-scale synthesis.
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Affiliation(s)
- Lin Deng
- Department of Small Molecule Process Chemistry, Genentech, Inc., South San Francisco, California 94080, United States
| | - Julie A Deichert
- Department of Small Molecule Process Chemistry, Genentech, Inc., South San Francisco, California 94080, United States
| | - Sierra Nguyen
- Department of Small Molecule Process Chemistry, Genentech, Inc., South San Francisco, California 94080, United States
| | - Ian S Young
- Department of Small Molecule Process Chemistry, Genentech, Inc., South San Francisco, California 94080, United States
| | - Chong Han
- Department of Small Molecule Process Chemistry, Genentech, Inc., South San Francisco, California 94080, United States
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Gao ZG, Auchampach JA, Jacobson KA. Species dependence of A 3 adenosine receptor pharmacology and function. Purinergic Signal 2023; 19:523-550. [PMID: 36538251 PMCID: PMC9763816 DOI: 10.1007/s11302-022-09910-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 11/26/2022] [Indexed: 12/24/2022] Open
Abstract
Efforts to fully understand pharmacological differences between G protein-coupled receptor (GPCR) species homologues are generally not pursued in detail during the drug development process. To date, many GPCRs that have been successfully targeted are relatively well-conserved across species in amino acid sequence and display minimal variability of biological effects. However, the A3 adenosine receptor (AR), an exciting drug target for a multitude of diseases associated with tissue injury, ischemia, and inflammation, displays as little as 70% sequence identity among mammalian species (e.g., rodent vs. primate) commonly used in drug development. Consequently, the pharmacological properties of synthetic A3AR ligands vary widely, not only in binding affinity, selectivity, and signaling efficacy, but to the extent that some function as agonists in some species and antagonists in others. Numerous heterocyclic antagonists that have nM affinity at the human A3AR are inactive or weakly active at the rat and mouse A3ARs. Positive allosteric modulators, including the imidazo [4,5-c]quinolin-4-amine derivative LUF6000, are only active at human and some larger animal species that have been evaluated (rabbit and dog), but not rodents. A3AR agonists evoke systemic degranulation of rodent, but not human mast cells. The rat A3AR undergoes desensitization faster than the human A3AR, but the human homologue can be completely re-sensitized and recycled back to the cell surface. Thus, comprehensive pharmacological evaluation and awareness of potential A3AR species differences are critical in studies to further understand the basic biological functions of this unique AR subtype. Recombinant A3ARs from eight different species have been pharmacologically characterized thus far. In this review, we describe in detail current knowledge of species differences in genetic identity, G protein-coupling, receptor regulation, and both orthosteric and allosteric A3AR pharmacology.
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Affiliation(s)
- Zhan-Guo Gao
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892-0810, USA.
| | - John A Auchampach
- Department of Pharmacology and Toxicology, and the Cardiovascular Center, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA
| | - Kenneth A Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892-0810, USA.
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5
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Fallot LB, Suresh RR, Fisher CL, Salmaso V, O'Connor RD, Kaufman N, Gao ZG, Auchampach JA, Jacobson KA. Structure-Activity Studies of 1 H-Imidazo[4,5- c]quinolin-4-amine Derivatives as A 3 Adenosine Receptor Positive Allosteric Modulators. J Med Chem 2022; 65:15238-15262. [PMID: 36367749 PMCID: PMC10354740 DOI: 10.1021/acs.jmedchem.2c01170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
We previously reported 1H-imidazo[4,5-c]quinolin-4-amines as A3 adenosine receptor (A3AR) positive allosteric modulators (PAMs). A3AR agonists, but not PAMs, are in clinical trials for inflammatory diseases and liver conditions. We synthesized new analogues to distinguish 2-cyclopropyl antagonist 17 (orthosteric interaction demonstrated by binding and predicted computationally) from PAMs (derivatives with large 2-alkyl/cycloalkyl/bicycloalkyl groups). We predicted PAM binding at a hydrophobic site on the A3AR cytosolic interface. Although having low Caco-2 permeability and high plasma protein binding, hydrophobic 2-cyclohept-4-enyl-N-3,4-dichlorophenyl, MRS7788 18, and 2-heptan-4-yl-N-4-iodophenyl, MRS8054 39, derivatives were orally bioavailable in rat. 2-Heptan-4-yl-N-3,4-dichlorophenyl 14 and 2-cyclononyl-N-3,4-dichlorophenyl 20 derivatives and 39 greatly enhanced Cl-IB-MECA-stimulated [35S]GTPγS binding Emax, with only 12b trending toward decreasing the agonist EC50. A feasible route for radio-iodination at the p-position of a 4-phenylamino substituent suggests a potential radioligand for allosteric site binding. Herein, we advanced an allosteric approach to developing A3AR-activating drugs that are potentially event- and site-specific in action.
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Affiliation(s)
- Lucas B Fallot
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, Maryland 20814, United States
- Department of Chemistry and Life Science, United States Military Academy, 646 Swift Road, West Point, New York 10996, United States
| | - R Rama Suresh
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
| | | | - Veronica Salmaso
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
| | - Robert D O'Connor
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
| | - Noy Kaufman
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
| | - Zhan-Guo Gao
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
| | | | - Kenneth A Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
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Pasquini S, Contri C, Cappello M, Borea PA, Varani K, Vincenzi F. Update on the recent development of allosteric modulators for adenosine receptors and their therapeutic applications. Front Pharmacol 2022; 13:1030895. [PMID: 36278183 PMCID: PMC9581118 DOI: 10.3389/fphar.2022.1030895] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 09/20/2022] [Indexed: 11/13/2022] Open
Abstract
Adenosine receptors (ARs) have been identified as promising therapeutic targets for countless pathological conditions, spanning from inflammatory diseases to central nervous system disorders, from cancer to metabolic diseases, from cardiovascular pathologies to respiratory diseases, and beyond. This extraordinary therapeutic potential is mainly due to the plurality of pathophysiological actions of adenosine and the ubiquitous expression of its receptors. This is, however, a double-edged sword that makes the clinical development of effective ligands with tolerable side effects difficult. Evidence of this is the low number of AR agonists or antagonists that have reached the market. An alternative approach is to target allosteric sites via allosteric modulators, compounds endowed with several advantages over orthosteric ligands. In addition to the typical advantages of allosteric modulators, those acting on ARs could benefit from the fact that adenosine levels are elevated in pathological tissues, thus potentially having negligible effects on normal tissues where adenosine levels are maintained low. Several A1 and various A3AR allosteric modulators have been identified so far, and some of them have been validated in different preclinical settings, achieving promising results. Less fruitful, instead, has been the discovery of A2A and A2BAR allosteric modulators, although the results obtained up to now are encouraging. Collectively, data in the literature suggests that allosteric modulators of ARs could represent valuable pharmacological tools, potentially able to overcome the limitations of orthosteric ligands.
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Affiliation(s)
- Silvia Pasquini
- Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, Ferrara, Italy
| | - Chiara Contri
- Department of Translational Medicine, University of Ferrara, Ferrara, Italy
| | - Martina Cappello
- Department of Translational Medicine, University of Ferrara, Ferrara, Italy
| | | | - Katia Varani
- Department of Translational Medicine, University of Ferrara, Ferrara, Italy
- *Correspondence: Katia Varani,
| | - Fabrizio Vincenzi
- Department of Translational Medicine, University of Ferrara, Ferrara, Italy
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Fisher CL, Fallot LB, Wan TC, Keyes RF, Suresh RR, Rothwell AC, Gao ZG, McCorvy JD, Smith BC, Jacobson KA, Auchampach JA. Characterization of Dual-Acting A 3 Adenosine Receptor Positive Allosteric Modulators That Preferentially Enhance Adenosine-Induced Gα i3 and Gα oA Isoprotein Activation. ACS Pharmacol Transl Sci 2022; 5:625-641. [PMID: 35983277 PMCID: PMC9380209 DOI: 10.1021/acsptsci.2c00076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Indexed: 12/19/2022]
Abstract
The A3 adenosine receptor (A3AR) is a promising therapeutic target for inflammatory diseases, cancer, and chronic neuropathic pain, with agonists already in advanced clinical trials. Here we report an in-depth comparison of the pharmacological properties and structure-activity relationships of existing and expanded compound libraries of 2-substituted 1H-imidazo[4,5-c]quinolin-4-amine and 4-amino-substituted quinoline derivatives that function as A3AR positive allosteric modulators (PAMs). We also show that our lead compound from each series enhances adenosine-induced A3AR signaling preferentially toward activation of Gαi3 and GαoA isoproteins, which are coexpressed with the A3AR in immune cells and spinal cord neurons. Finally, utilizing an extracellular/intracellular chimeric A3AR approach composed of sequences from a responding (human) and a nonresponding (mouse) species, we provide evidence in support of the idea that the imidazoquinolin-4-amine class of PAMs variably interacts dually with the orthosteric ligand binding site as well as with a separate allosteric site located within the inner/intracellular regions of the receptor. This study has advanced both structural and pharmacological understanding of these two classes of A3AR PAMs, which includes leads for future pharmaceutical development.
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Affiliation(s)
- Courtney L. Fisher
- Department of Pharmacology & Toxicology and the Cardiovascular Center, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, Wisconsin 53226, United States
| | - Lucas B. Fallot
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
- Department of Biochemistry & Molecular Biology, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, Maryland 20814, United States
- Department of Chemistry & Life Science, United States Military Academy, 646 Swift Road, West Point, New York 10996, United States
| | - Tina C. Wan
- Department of Pharmacology & Toxicology and the Cardiovascular Center, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, Wisconsin 53226, United States
| | - Robert F. Keyes
- Department of Biochemistry, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, Wisconsin 53226, United States
| | - R. Rama Suresh
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
| | - Amy C. Rothwell
- Department of Pharmacology & Toxicology and the Cardiovascular Center, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, Wisconsin 53226, United States
| | - Zhan-Guo Gao
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
| | - John D. McCorvy
- Department of Cell Biology, Neurobiology, & Anatomy, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, Wisconsin 53226, United States
| | - Brian C. Smith
- Department of Biochemistry, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, Wisconsin 53226, United States
| | - Kenneth A. Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
| | - John A. Auchampach
- Department of Pharmacology & Toxicology and the Cardiovascular Center, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, Wisconsin 53226, United States
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Itzhak I, Cohen S, Fishman S, Fishman P. A3 adenosine receptor allosteric modulator CF602 reverses erectile dysfunction in a diabetic rat model. Andrologia 2022; 54:e14498. [PMID: 35732294 DOI: 10.1111/and.14498] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 05/08/2022] [Accepted: 05/21/2022] [Indexed: 12/12/2022] Open
Abstract
Adenosine plays a major role in erection by binding to its receptors and activating pathways resulting in increased arterial blood flow and intracavernosal pressure (ICP). CF602, an allosteric modulator of the A3 adenosine receptor (A3AR), increases the binding affinity of the endogenous adenosine to the receptor. We examined the effect of CF602 on resolving erectile dysfunction (ED) in a diabetic ED rat model (streptozotocin-induced diabetic rats that were screened for ED using the apomorphine test). ED was assessed by measuring ICP and main arterial pressure (MAP) during electrostimulation of the cavernosal nerve. A single dose of CF602 or placebo was applied either topically (100 μl from a 100 nM or 500 nM solution) or orally (100, 200 or 500 μg/kg) prior to erectile function assessment. A significant dose-dependent improvement in the ICP:MAP ratio without a change in MAP was recorded with the topical and oral CF602 treatments. A significant increase in smooth muscle:collagen ratio, vascular endothelial growth factor and endothelial nitric oxide synthase was also observed in both administration modes. In conclusion, topical and oral treatment with CF602 significantly improved erectile function, supporting its further evaluation as a treatment for ED.
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Affiliation(s)
| | - Shira Cohen
- Can-Fite BioPharma Ltd., Petah Tikva, Israel
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Km K, Kumar S, Kumar A, Kant R, Chintakunta R. Palladium‐Catalyzed Intramolecular C‐H Heteroarylation to Access Fused Tricyclic Oxazolo[4,5‐c]Quinolines. ASIAN J ORG CHEM 2022. [DOI: 10.1002/ajoc.202200066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Kajol Km
- CSIR-CDRI: Central Drug Research Institute Medicinal & Process Chemistry Division CSIR-CDRI, Lucknow, UP, India 226031 LUCKNOW INDIA
| | - Sujeet Kumar
- CSIR-CDRI: Central Drug Research Institute Medicinal & Process Chemistry Division CSIR-CDRI, Lucknow, UP, India 226031 LUCKNOW INDIA
| | - Amit Kumar
- CSIR-CDRI: Central Drug Research Institute Medicinal & Process Chemistry Division CSIR-CDRI, Lucknow, UP, India 226031 LUCKNOW INDIA
| | - Ruchir Kant
- CSIR-CDRI: Central Drug Research Institute Medicinal & Process Chemistry Division CSIR-CDRI, Lucknow, UP, India 226031 LUCKNOW INDIA
| | - Ramesh Chintakunta
- CSIR-CDRI: Central Drug Research Institute Medicinal and Process Chemistry Division CSIR-CDRI, Lucknow, UP, India 226031 LUCKNOW INDIA
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10
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Affiliation(s)
- Roman S. Malykhin
- N. D. Zelinsky Institute of Organic Chemistry Russian Academy of Sciences Leninsky prospect, 47 Moscow 119991 Russia
- M. V. Lomonosov Moscow State University Department of Chemistry Leninskie gory, 1, str. 3 Moscow 119991 Russian Federation
| | - Alexey Yu. Sukhorukov
- N. D. Zelinsky Institute of Organic Chemistry Russian Academy of Sciences Leninsky prospect, 47 Moscow 119991 Russia
- Plekhanov Russian University of Economics Stremyanny per. 36 Moscow 117997 Russia
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11
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Abstract
G-protein-coupled receptors (GPCRs) have been tractable drug targets for decades with over one-third of currently marketed drugs targeting GPCRs. Of these, the class A GPCR superfamily is highly represented, and continued drug discovery for this family of receptors may provide novel therapeutics for a vast range of diseases. GPCR allosteric modulation is an innovative targeting approach that broadens the available small molecule toolbox and is proving to be a viable drug discovery strategy, as evidenced by recent FDA approvals and clinical trials. Numerous class A GPCR allosteric modulators have been discovered recently, and emerging trends such as the availability of GPCR crystal structures, diverse functional assays, and structure-based computational approaches are improving optimization and development. This Perspective provides an update on allosterically targeted class A GPCRs and their disease indications and the medicinal chemistry approaches toward novel allosteric modulators and highlights emerging trends and opportunities in the field.
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Affiliation(s)
- Eric A. Wold
- Department of Pharmacology and Toxicology, Chemical Biology Program, University of Texas Medical Branch, Galveston, Texas 77555, United States
- Department of Pharmacology and Toxicology, Center for Addiction Research, University of Texas Medical Branch, Galveston, Texas 77555, United States
| | - Jianping Chen
- Department of Pharmacology and Toxicology, Chemical Biology Program, University of Texas Medical Branch, Galveston, Texas 77555, United States
- Department of Pharmacology and Toxicology, Center for Addiction Research, University of Texas Medical Branch, Galveston, Texas 77555, United States
| | - Kathryn A. Cunningham
- Department of Pharmacology and Toxicology, Chemical Biology Program, University of Texas Medical Branch, Galveston, Texas 77555, United States
- Department of Pharmacology and Toxicology, Center for Addiction Research, University of Texas Medical Branch, Galveston, Texas 77555, United States
| | - Jia Zhou
- Department of Pharmacology and Toxicology, Chemical Biology Program, University of Texas Medical Branch, Galveston, Texas 77555, United States
- Department of Pharmacology and Toxicology, Center for Addiction Research, University of Texas Medical Branch, Galveston, Texas 77555, United States
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12
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Jacobson KA, Merighi S, Varani K, Borea PA, Baraldi S, Tabrizi MA, Romagnoli R, Baraldi PG, Ciancetta A, Tosh DK, Gao ZG, Gessi S. A 3 Adenosine Receptors as Modulators of Inflammation: From Medicinal Chemistry to Therapy. Med Res Rev 2018; 38:1031-1072. [PMID: 28682469 PMCID: PMC5756520 DOI: 10.1002/med.21456] [Citation(s) in RCA: 105] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 05/02/2017] [Accepted: 06/13/2017] [Indexed: 01/09/2023]
Abstract
The A3 adenosine receptor (A3 AR) subtype is a novel, promising therapeutic target for inflammatory diseases, such as rheumatoid arthritis (RA) and psoriasis, as well as liver cancer. A3 AR is coupled to inhibition of adenylyl cyclase and regulation of mitogen-activated protein kinase (MAPK) pathways, leading to modulation of transcription. Furthermore, A3 AR affects functions of almost all immune cells and the proliferation of cancer cells. Numerous A3 AR agonists, partial agonists, antagonists, and allosteric modulators have been reported, and their structure-activity relationships (SARs) have been studied culminating in the development of potent and selective molecules with drug-like characteristics. The efficacy of nucleoside agonists may be suppressed to produce antagonists, by structural modification of the ribose moiety. Diverse classes of heterocycles have been discovered as selective A3 AR blockers, although with large species differences. Thus, as a result of intense basic research efforts, the outlook for development of A3 AR modulators for human therapeutics is encouraging. Two prototypical selective agonists, N6-(3-Iodobenzyl)adenosine-5'-N-methyluronamide (IB-MECA; CF101) and 2-chloro-N6-(3-iodobenzyl)-adenosine-5'-N-methyluronamide (Cl-IB-MECA; CF102), have progressed to advanced clinical trials. They were found safe and well tolerated in all preclinical and human clinical studies and showed promising results, particularly in psoriasis and RA, where the A3 AR is both a promising therapeutic target and a biologically predictive marker, suggesting a personalized medicine approach. Targeting the A3 AR may pave the way for safe and efficacious treatments for patient populations affected by inflammatory diseases, cancer, and other conditions.
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Affiliation(s)
- Kenneth A. Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD20892
| | - Stefania Merighi
- Department of Medical Sciences, Pharmacology Section, University of Ferrara, Via Fossato di Mortara 17/19, 44121 Ferrara, Italy
| | - Katia Varani
- Department of Medical Sciences, Pharmacology Section, University of Ferrara, Via Fossato di Mortara 17/19, 44121 Ferrara, Italy
| | - Pier Andrea Borea
- Department of Medical Sciences, Pharmacology Section, University of Ferrara, Via Fossato di Mortara 17/19, 44121 Ferrara, Italy
| | - Stefania Baraldi
- Department of Pharmaceutical Sciences, University of Ferrara, Via Fossato di Mortara 17, 44121 Ferrara, Italy
| | - Mojgan Aghazadeh Tabrizi
- Department of Pharmaceutical Sciences, University of Ferrara, Via Fossato di Mortara 17, 44121 Ferrara, Italy
| | - Romeo Romagnoli
- Department of Pharmaceutical Sciences, University of Ferrara, Via Fossato di Mortara 17, 44121 Ferrara, Italy
| | - Pier Giovanni Baraldi
- Department of Pharmaceutical Sciences, University of Ferrara, Via Fossato di Mortara 17, 44121 Ferrara, Italy
| | - Antonella Ciancetta
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD20892
| | - Dilip K. Tosh
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD20892
| | - Zhan-Guo Gao
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD20892
| | - Stefania Gessi
- Department of Medical Sciences, Pharmacology Section, University of Ferrara, Via Fossato di Mortara 17/19, 44121 Ferrara, Italy
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13
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Affiliation(s)
- Hélène G. Bazin
- Biomedical & Pharmaceutical Science, University of Montana, 32 Campus Drive #1552, Missoula, MT 59812, USA
| | - Laura S. Bess
- Biomedical & Pharmaceutical Science, University of Montana, 32 Campus Drive #1552, Missoula, MT 59812, USA
| | - Mark T. Livesay
- Biomedical & Pharmaceutical Science, University of Montana, 32 Campus Drive #1552, Missoula, MT 59812, USA
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14
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Du L, Gao ZG, Paoletta S, Wan TC, Gizewski ET, Barbour S, van Veldhoven JPD, IJzerman AP, Jacobson KA, Auchampach JA. Species differences and mechanism of action of A 3 adenosine receptor allosteric modulators. Purinergic Signal 2017; 14:59-71. [PMID: 29170977 DOI: 10.1007/s11302-017-9592-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 11/01/2017] [Indexed: 02/01/2023] Open
Abstract
Activity of the A3 adenosine receptor (AR) allosteric modulators LUF6000 (2-cyclohexyl-N-(3,4-dichlorophenyl)-1H-imidazo [4,5-c]quinolin-4-amine) and LUF6096 (N-{2-[(3,4-dichlorophenyl)amino]quinolin-4-yl}cyclohexanecarbox-amide) was compared at four A3AR species homologs used in preclinical drug development. In guanosine 5'-[γ-[35S]thio]triphosphate ([35S]GTPγS) binding assays with cell membranes isolated from human embryonic kidney cells stably expressing recombinant A3ARs, both modulators substantially enhanced agonist efficacy at human, dog, and rabbit A3ARs but provided only weak activity at mouse A3ARs. For human, dog, and rabbit, both modulators increased the maximal efficacy of the A3AR agonist 2-chloro-N 6-(3-iodobenzyl)adenosine-5'-N-methylcarboxamide as well as adenosine > 2-fold, while slightly reducing potency in human and dog. Based on results from N 6-(4-amino-3-[125I]iodobenzyl)adenosine-5'-N-methylcarboxamide ([125I]I-AB-MECA) binding assays, we hypothesize that potency reduction is explained by an allosterically induced slowing in orthosteric ligand binding kinetics that reduces the rate of formation of ligand-receptor complexes. Mutation of four amino acid residues of the human A3AR to the murine sequence identified the extracellular loop 1 (EL1) region as being important in selectively controlling the allosteric actions of LUF6096 on [125I]I-AB-MECA binding kinetics. Homology modeling suggested interaction between species-variable EL1 and agonist-contacting EL2. These results indicate that A3AR allostery is species-dependent and provide mechanistic insights into this therapeutically promising class of agents.
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Affiliation(s)
- Lili Du
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA
| | - Zhan-Guo Gao
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 200892-0810, USA
| | - Silvia Paoletta
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 200892-0810, USA
| | - Tina C Wan
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA
| | - Elizabeth T Gizewski
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA
| | - Samantha Barbour
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA
| | - Jacobus P D van Veldhoven
- Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research, Leiden University, PO Box 9502, 2300 RA, Leiden, The Netherlands
| | - Adriaan P IJzerman
- Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research, Leiden University, PO Box 9502, 2300 RA, Leiden, The Netherlands
| | - Kenneth A Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 200892-0810, USA
| | - John A Auchampach
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA.
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15
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Sakkal LA, Rajkowski KZ, Armen RS. Prediction of consensus binding mode geometries for related chemical series of positive allosteric modulators of adenosine and muscarinic acetylcholine receptors. J Comput Chem 2017; 38:1209-1228. [PMID: 28130813 PMCID: PMC5403616 DOI: 10.1002/jcc.24728] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2016] [Revised: 11/29/2016] [Accepted: 12/20/2016] [Indexed: 12/13/2022]
Abstract
Following insights from recent crystal structures of the muscarinic acetylcholine receptor, binding modes of Positive Allosteric Modulators (PAMs) were predicted under the assumption that PAMs should bind to the extracellular surface of the active state. A series of well-characterized PAMs for adenosine (A1 R, A2A R, A3 R) and muscarinic acetylcholine (M1 R, M5 R) receptors were modeled using both rigid and flexible receptor CHARMM-based molecular docking. Studies of adenosine receptors investigated the molecular basis of the probe-dependence of PAM activity by modeling in complex with specific agonist radioligands. Consensus binding modes map common pharmacophore features of several chemical series to specific binding interactions. These models provide a rationalization of how PAM binding slows agonist radioligand dissociation kinetics. M1 R PAMs were predicted to bind in the analogous M2 R PAM LY2119620 binding site. The M5 R NAM (ML-375) was predicted to bind in the PAM (ML-380) binding site with a unique induced-fit receptor conformation. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Leon A. Sakkal
- Department of Pharmaceutical Sciences, College of Pharmacy, Thomas Jefferson University, 901 Walnut St. Suite 918. Philadelphia, PA 19170
| | - Kyle Z. Rajkowski
- Department of Pharmaceutical Sciences, College of Pharmacy, Thomas Jefferson University, 901 Walnut St. Suite 918. Philadelphia, PA 19170
| | - Roger S. Armen
- Department of Pharmaceutical Sciences, College of Pharmacy, Thomas Jefferson University, 901 Walnut St. Suite 918. Philadelphia, PA 19170
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16
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Guo D, Heitman LH, IJzerman AP. Kinetic Aspects of the Interaction between Ligand and G Protein-Coupled Receptor: The Case of the Adenosine Receptors. Chem Rev 2016; 117:38-66. [DOI: 10.1021/acs.chemrev.6b00025] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Dong Guo
- Division of Medicinal Chemistry,
Leiden Academic Centre for Drug Research (LACDR), Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Laura H. Heitman
- Division of Medicinal Chemistry,
Leiden Academic Centre for Drug Research (LACDR), Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Adriaan P. IJzerman
- Division of Medicinal Chemistry,
Leiden Academic Centre for Drug Research (LACDR), Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
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17
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Hill SJ, May LT, Kellam B, Woolard J. Allosteric interactions at adenosine A(1) and A(3) receptors: new insights into the role of small molecules and receptor dimerization. Br J Pharmacol 2014; 171:1102-13. [PMID: 24024783 DOI: 10.1111/bph.12345] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 07/09/2013] [Accepted: 07/12/2013] [Indexed: 12/22/2022] Open
Abstract
The purine nucleoside adenosine is present in all cells in tightly regulated concentrations. It is released under a variety of physiological and pathophysiological conditions to facilitate protection and regeneration of tissues. Adenosine acts via specific GPCRs to either stimulate cyclic AMP formation, as exemplified by Gs -protein-coupled adenosine receptors (A2A and A2B ), or inhibit AC activity, in the case of Gi/o -coupled adenosine receptors (A1 and A3 ). Recent advances in our understanding of GPCR structure have provided insights into the conformational changes that occur during receptor activation following binding of agonists to orthosteric (i.e. at the same binding site as an endogenous modulator) and allosteric regulators to allosteric sites (i.e. at a site that is topographically distinct from the endogenous modulator). Binding of drugs to allosteric sites may lead to changes in affinity or efficacy, and affords considerable potential for increased selectivity in new drug development. Herein, we provide an overview of the properties of selective allosteric regulators of the adenosine A1 and A3 receptors, focusing on the impact of receptor dimerization, mechanistic approaches to single-cell ligand-binding kinetics and the effects of A1 - and A3 -receptor allosteric modulators on in vivo pharmacology.
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Affiliation(s)
- Stephen J Hill
- Cell Signalling Research Group, School of Biomedical Sciences, Medical School, Queen's Medical Centre, University of Nottingham, Nottingham, UK
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18
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Cohen S, Barer F, Bar-Yehuda S, IJzerman AP, Jacobson KA, Fishman P. A₃ adenosine receptor allosteric modulator induces an anti-inflammatory effect: in vivo studies and molecular mechanism of action. Mediators Inflamm 2014; 2014:708746. [PMID: 25374446 DOI: 10.1155/2014/708746] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Accepted: 09/15/2014] [Indexed: 11/24/2022] Open
Abstract
The A3 adenosine receptor (A3AR) is overexpressed in inflammatory cells and in the peripheral blood mononuclear cells of individuals with inflammatory conditions. Agonists to the A3AR are known to induce specific anti-inflammatory effects upon chronic treatment. LUF6000 is an allosteric compound known to modulate the A3AR and render the endogenous ligand adenosine to bind to the receptor with higher affinity. The advantage of allosteric modulators is their capability to target specifically areas where adenosine levels are increased such as inflammatory and tumor sites, whereas normal body cells and tissues are refractory to the allosteric modulators due to low adenosine levels. LUF6000 administration induced anti-inflammatory effect in 3 experimental animal models of rat adjuvant induced arthritis, monoiodoacetate induced osteoarthritis, and concanavalin A induced liver inflammation in mice. The molecular mechanism of action points to deregulation of signaling proteins including PI3K, IKK, IκB, Jak-2, and STAT-1, resulting in decreased levels of NF-κB, known to mediate inflammatory effects. Moreover, LUF6000 induced a slight stimulatory effect on the number of normal white blood cells and neutrophils. The anti-inflammatory effect of LUF6000, mechanism of action, and the differential effects on inflammatory and normal cells position this allosteric modulator as an attractive and unique drug candidate.
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19
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Pandey AK, Sharma R, Singh A, Shukla S, Srivastava K, Puri SK, Kumar B, Chauhan PMS. Synthesis of biologically active pyridoimidazole/imidazobenzothiazole annulated polyheterocycles using cyanuric chloride in water. RSC Adv 2014. [DOI: 10.1039/c4ra03415e] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
An efficient and mild protocol for rapid access to N-fused polyheterocycles via Pictet–Spengler type 6-endo cyclization by cyanuric chloride in aqueous medium has been developed.
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Affiliation(s)
- Anand Kumar Pandey
- Medicinal and Process Chemistry Division
- CSIR-Central Drug Research Institute
- Lucknow, India
| | - Rashmi Sharma
- Medicinal and Process Chemistry Division
- CSIR-Central Drug Research Institute
- Lucknow, India
| | - Awantika Singh
- Sophisticated Analytical Instrument Facility
- CSIR-Central Drug Research Institute
- Lucknow, India
| | - Sanjeev Shukla
- Sophisticated Analytical Instrument Facility
- CSIR-Central Drug Research Institute
- Lucknow, India
| | - Kumkum Srivastava
- Division of Parasitology
- CSIR-Central Drug Research Institute
- Lucknow, India
| | - Sunil K. Puri
- Division of Parasitology
- CSIR-Central Drug Research Institute
- Lucknow, India
| | - Brijesh Kumar
- Sophisticated Analytical Instrument Facility
- CSIR-Central Drug Research Institute
- Lucknow, India
| | - Prem M. S. Chauhan
- Medicinal and Process Chemistry Division
- CSIR-Central Drug Research Institute
- Lucknow, India
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Sun M, Zhang T, Bao W. FeCl3-catalyzed cascade cyclization in one pot: synthesis of ring-fused tetrahydroquinoline derivatives from arylamines and N-substituted lactams. J Org Chem 2013; 78:8155-60. [PMID: 23819553 DOI: 10.1021/jo400979h] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Multiple cross-dehydrogenative-coupling reactions catalyzed by FeCl3 in one pot were developed. Arylamines and N-substituted lactams were reacted, and ring-fused tetrahydroquinoline derivatives were formed by two C-C bonds and one C-N bond formation as well as one C-N bond cleavage. The lactams were also used as solvent.
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Affiliation(s)
- Manman Sun
- Department of Chemistry, Zhejiang University (Xixi Campus), Hangzhou 310028, People's Republic of China
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21
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Müller CE, Schiedel AC, Baqi Y. Allosteric modulators of rhodopsin-like G protein-coupled receptors: opportunities in drug development. Pharmacol Ther 2012; 135:292-315. [PMID: 22728155 DOI: 10.1016/j.pharmthera.2012.06.002] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Accepted: 06/07/2012] [Indexed: 11/21/2022]
Abstract
Rhodopsin-like (class A) G protein-coupled receptors (GPCRs) are one of the most important classes of drug targets. The discovery that these GPCRs can be allosterically modulated by small drug molecules has opened up new opportunities in drug development. It will allow the drugability of "difficult targets", such as GPCRs activated by large (glyco)proteins, or by very polar or highly lipophilic physiological agonists. Receptor subtype selectivity should be more easily achievable with allosteric than with orthosteric ligands. Allosteric modulation will allow a broad spectrum of pharmacological effects largely expanding that of orthosteric ligands. Furthermore, allosteric modulators may show an improved safety profile as compared to orthosteric ligands. Only recently, the explicit search for allosteric modulators has been started for only a few rhodopsin-like GPCRs. The first negative allosteric modulators (allosteric antagonists) of chemokine receptors, maraviroc (CCR5 receptor), used in HIV therapy, and plerixafor (CXCR4 receptor) for stem cell mobilization, have been approved as drugs. The development of allosteric modulators for rhodopsin-like GPCRs as novel drugs is still at an early stage; it appears highly promising.
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Baraldi PG, Preti D, Borea PA, Varani K. Medicinal Chemistry of A3 Adenosine Receptor Modulators: Pharmacological Activities and Therapeutic Implications. J Med Chem 2012; 55:5676-703. [DOI: 10.1021/jm300087j] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Pier Giovanni Baraldi
- Dipartimento
di Scienze Farmaceutiche and ‡Dipartimento di Medicina Clinica e Sperimentale-Sezione
di Farmacologia, Università di Ferrara, 44121 Ferrara, Italy
| | - Delia Preti
- Dipartimento
di Scienze Farmaceutiche and ‡Dipartimento di Medicina Clinica e Sperimentale-Sezione
di Farmacologia, Università di Ferrara, 44121 Ferrara, Italy
| | - Pier Andrea Borea
- Dipartimento
di Scienze Farmaceutiche and ‡Dipartimento di Medicina Clinica e Sperimentale-Sezione
di Farmacologia, Università di Ferrara, 44121 Ferrara, Italy
| | - Katia Varani
- Dipartimento
di Scienze Farmaceutiche and ‡Dipartimento di Medicina Clinica e Sperimentale-Sezione
di Farmacologia, Università di Ferrara, 44121 Ferrara, Italy
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24
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Cheong SL, Federico S, Venkatesan G, Mandel AL, Shao YM, Moro S, Spalluto G, Pastorin G. The A3 adenosine receptor as multifaceted therapeutic target: pharmacology, medicinal chemistry, and in silico approaches. Med Res Rev 2011; 33:235-335. [PMID: 22095687 DOI: 10.1002/med.20254] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Adenosine is an ubiquitous local modulator that regulates various physiological and pathological functions by stimulating four membrane receptors, namely A(1), A(2A), A(2B), and A(3). Among these G protein-coupled receptors, the A(3) subtype is found mainly in the lung, liver, heart, eyes, and brain in our body. It has been associated with cerebroprotection and cardioprotection, as well as modulation of cellular growth upon its selective activation. On the other hand, its inhibition by selective antagonists has been reported to be potentially useful in the treatment of pathological conditions including glaucoma, inflammatory diseases, and cancer. In this review, we focused on the pharmacology and the therapeutic implications of the human (h)A(3) adenosine receptor (AR), together with an overview on the progress of hA(3) AR agonists, antagonists, allosteric modulators, and radioligands, as well as on the recent advances pertaining to the computational approaches (e.g., quantitative structure-activity relationships, homology modeling, molecular docking, and molecular dynamics simulations) applied to the modeling of hA(3) AR and drug design.
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Affiliation(s)
- Siew Lee Cheong
- Department of Pharmacy, National University of Singapore, 3 Science Drive 2, Singapore 117543, Singapore
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25
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Du L, Gao ZG, Nithipatikom K, Ijzerman AP, Veldhoven JPDV, Jacobson KA, Gross GJ, Auchampach JA. Protection from myocardial ischemia/reperfusion injury by a positive allosteric modulator of the A₃ adenosine receptor. J Pharmacol Exp Ther 2011; 340:210-7. [PMID: 22011434 DOI: 10.1124/jpet.111.187559] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Adenosine is increased in ischemic tissues where it serves a protective role by activating adenosine receptors (ARs), including the A₃ AR subtype. We investigated the effect of N-{2-[(3,4-dichlorophenyl)amino]quinolin-4-yl}cyclohexanecarboxamide (LUF6096), a positive allosteric modulator of the A₃ AR, on infarct size in a barbital-anesthetized dog model of myocardial ischemia/reperfusion injury. Dogs were subjected to 60 min of coronary artery occlusion and 3 h of reperfusion. Infarct size was assessed by macrohistochemical staining. Three experimental groups were included in the study. Groups I and II received two doses of vehicle or LUF6096 (0.5 mg/kg i.v. bolus), one administered before ischemia and the other immediately before reperfusion. Group III received a single dose of LUF6096 (1 mg/kg i.v. bolus) immediately before reperfusion. In preliminary in vitro studies, LUF6096 was found to exert potent enhancing activity (EC₅₀ 114.3 ± 15.9 nM) with the canine A₃ AR in a guanosine 5'-[γ-[³⁵S]thio]triphosphate binding assay. LUF6096 increased the maximal efficacy of the partial A₃ AR agonist 2-chloro-N⁶-(3-iodobenzyl)adenosine-5'-N-methylcarboxamide and the native agonist adenosine more than 2-fold while producing a slight decrease in potency. In the dog studies, administration of LUF6096 had no effect on any hemodynamic parameter measured. Pretreatment with LUF6096 before coronary occlusion and during reperfusion in group II dogs produced a marked reduction in infarct size (∼50% reduction) compared with group I vehicle-treated dogs. An equivalent reduction in infarct size was observed when LUF6096 was administered immediately before reperfusion in group III dogs. This is the first study to demonstrate efficacy of an A₃ AR allosteric enhancer in an in vivo model of infarction.
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Affiliation(s)
- Lili Du
- Department of Pharmacology and the Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
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Karthik Kumar K, Prabu Seenivasan S, Kumar V, Mohan Das T. Synthesis of quinoline coupled [1,2,3]-triazoles as a promising class of anti-tuberculosis agents. Carbohydr Res 2011; 346:2084-90. [DOI: 10.1016/j.carres.2011.06.028] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Revised: 06/01/2011] [Accepted: 06/21/2011] [Indexed: 11/23/2022]
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Gao ZG, Verzijl D, Zweemer A, Ye K, Göblyös A, Ijzerman AP, Jacobson KA. Functionally biased modulation of A(3) adenosine receptor agonist efficacy and potency by imidazoquinolinamine allosteric enhancers. Biochem Pharmacol 2011; 82:658-68. [PMID: 21718691 DOI: 10.1016/j.bcp.2011.06.017] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Revised: 06/13/2011] [Accepted: 06/13/2011] [Indexed: 10/24/2022]
Abstract
Allosteric modulators for the G(i)-coupled A(3) adenosine receptor (AR) are of considerable interest as therapeutic agents and as pharmacological tools to probe various signaling pathways. In this study, we initially characterized the effects of several imidazoquinolinamine allosteric modulators (LUF5999, LUF6000 and LUF6001) on the human A(3) AR stably expressed in CHO cells using a cyclic AMP functional assay. These modulators were found to affect efficacy and potency of the agonist Cl-IB-MECA differently. LUF5999 (2-cyclobutyl derivative) enhanced efficacy but decreased potency. LUF6000 (2-cyclohexyl derivative) enhanced efficacy without affecting potency. LUF6001 (2-H derivative) decreased both efficacy and potency. We further compared the agonist enhancing effects of LUF6000 in several other A(3) AR-mediated events. It was shown that although LUF6000 behaved somewhat differently in various signaling pathways, it was more effective in enhancing the effects of low-efficacy than of high-efficacy agonists. In an assay of cyclic AMP accumulation, LUF6000 enhanced the efficacy of all agonists examined, but in the membrane hyperpolarization assay, it only enhanced the efficacy of partial agonists. In calcium mobilization, LUF6000 did not affect the efficacy of the full agonist NECA but was able to switch the nucleoside antagonist MRS542 into a partial agonist. In translocation of β-arrestin2, the agonist-enhancing effect LUF6000 was not pronounced. In an assay of ERK1/2 phosphorylation LUF6000 did not show any effect on the efficacy of Cl-IB-MECA. The differential effects of LUF6000 on the efficacy and potency of the agonist Cl-IB-MECA in various signaling pathway were interpreted quantitatively using a mathematical model.
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Affiliation(s)
- Zhan-Guo Gao
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0810, USA.
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Fredholm BB, IJzerman AP, Jacobson KA, Linden J, Müller CE. International Union of Basic and Clinical Pharmacology. LXXXI. Nomenclature and classification of adenosine receptors--an update. Pharmacol Rev 2011; 63:1-34. [PMID: 21303899 PMCID: PMC3061413 DOI: 10.1124/pr.110.003285] [Citation(s) in RCA: 1002] [Impact Index Per Article: 77.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
In the 10 years since our previous International Union of Basic and Clinical Pharmacology report on the nomenclature and classification of adenosine receptors, no developments have led to major changes in the recommendations. However, there have been so many other developments that an update is needed. The fact that the structure of one of the adenosine receptors has recently been solved has already led to new ways of in silico screening of ligands. The evidence that adenosine receptors can form homo- and heteromultimers has accumulated, but the functional significance of such complexes remains unclear. The availability of mice with genetic modification of all the adenosine receptors has led to a clarification of the functional roles of adenosine, and to excellent means to study the specificity of drugs. There are also interesting associations between disease and structural variants in one or more of the adenosine receptors. Several new selective agonists and antagonists have become available. They provide improved possibilities for receptor classification. There are also developments hinting at the usefulness of allosteric modulators. Many drugs targeting adenosine receptors are in clinical trials, but the established therapeutic use is still very limited.
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Affiliation(s)
- Bertil B Fredholm
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
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Abstract
Among the purine and pyrimidine receptors, the discovery of small molecular allosteric modulators has been most highly advanced for the A(1) and A(3) adenosine receptors (ARs). These AR modulators have allosteric effects that are structurally separated from the orthosteric effects in SAR studies. The benzoylthiophene derivatives tend to act as allosteric agonists as well as selective positive allosteric modulators (PAMs) of the A(1) AR. A 2-amino-3-aroylthiophene derivative T-62 has been under development as a PAM of the A(1) AR for the treatment of chronic pain. Several structurally distinct classes of allosteric modulators of the human A(3) AR have been reported: 3-(2-pyridinyl)isoquinolines, 2,4-disubstituted quinolines, 1H-imidazo-[4,5-c]quinolin-4-amines, endocannabinoid 2-arachidonylglycerol, and the food dye Brilliant Black BN. Site-directed mutagenesis of A(1) and A(3) ARs has identified residues associated with the allosteric effect, distinct from those that affect orthosteric binding. A few small molecular allosteric modulators have been reported for several of the P2X ligand-gated ion channels and the G protein-coupled P2Y receptor nucleotides. Metal ion modulation of the P2X receptors has been extensively explored. The allosteric approach to modulation of purine and pyrimidine receptors looks promising for development of drugs that are event and site specific in action.
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De Amici M, Dallanoce C, Holzgrabe U, Tränkle C, Mohr K. Allosteric ligands for G protein-coupled receptors: a novel strategy with attractive therapeutic opportunities. Med Res Rev 2010; 30:463-549. [PMID: 19557759 DOI: 10.1002/med.20166] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Allosteric receptor ligands bind to a recognition site that is distinct from the binding site of the endogenous messenger molecule. As a consequence, allosteric agents may attach to receptors that are already transmitter-bound. Ternary complex formation opens an avenue to qualitatively new drug actions at G protein-coupled receptors (GPCRs), in particular receptor subtype selective potentiation of endogenous transmitter action. Consequently, suitable exploitation of allosteric recognition sites as alternative molecular targets could pave the way to a drug discovery paradigm different from those aimed at mimicking or blocking the effects of endogenous (orthosteric) receptor activators. The number of allosteric ligands reported to modulate GPCR function is steadily increasing and some have already reached routine clinical use. This review aims at introducing into this fascinating field of drug discovery and at providing an overview about the achievements that have already been made. Various case examples will be discussed in the framework of GPCR classification (family A, B, and C receptors). In addition, the behavior at muscarinic receptors of hybrid derivatives incorporating both an allosteric and an orthosteric fragment in a common molecular skeleton will be illustrated.
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Affiliation(s)
- Marco De Amici
- Department of Pharmaceutical Sciences Pietro Pratesi, University of Milan, via Mangiagalli 25, 20133 Milano, Italy.
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Göblyös A, Ijzerman AP. Allosteric modulation of adenosine receptors. Biochim Biophys Acta 2010; 1808:1309-18. [PMID: 20599682 DOI: 10.1016/j.bbamem.2010.06.013] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2010] [Revised: 06/10/2010] [Accepted: 06/10/2010] [Indexed: 10/19/2022]
Abstract
Allosteric ligands for G protein-coupled receptors (GPCRs) may alter receptor conformations induced by an orthosteric ligand. These modulators can thus fine-tune classical pharmacological responses. In this review we will describe efforts to synthesize and characterize allosteric modulators for one particular GPCR subfamily, the adenosine receptors. There are four subtypes of these receptors: A(1), A(2A), A(2B) and A(3). Allosteric enhancers for the adenosine A(1) receptor may have anti-arrythmic and anti-lipolytic activity. They may also act as analgesics and neuroprotective agents. A(3) allosteric enhancers are thought to be beneficial in ischemic conditions or as antitumor agents. We will summarize recent developments regarding the medicinal chemistry of such compounds. Most data have been and are published about the adenosine A(1) and A(3) receptor, whereas limited or no information is available for the A(2A) and A(2B) receptor, respectively. Receptor mutation studies are also discussed, as they may shed light on the localization of the allosteric binding sites. This article is part of a Special Issue entitled: "Adenosine Receptors".
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Affiliation(s)
- Anikó Göblyös
- Leiden/Amsterdam Center for Drug Research, Division of Medicinal Chemistry, Leiden, The Netherlands
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May LT, Briddon SJ, Hill SJ. Antagonist selective modulation of adenosine A1 and A3 receptor pharmacology by the food dye Brilliant Black BN: evidence for allosteric interactions. Mol Pharmacol 2010; 77:678-86. [PMID: 20086038 DOI: 10.1124/mol.109.063065] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Allosteric binding sites on the adenosine receptor family represent potential therapeutic targets for a number of conditions involving metabolic stress. This study has identified Brilliant Black BN as a novel allosteric modulator of the adenosine A(1) and A(3) receptors. In addition to being a food dye and pharmaceutical excipient, Brilliant Black BN is commonly used within calcium mobilization assays to quench extracellular fluorescence. Brilliant Black BN (5-500 microM) had no significant effect on the calcium mobilization stimulated by the nonselective adenosine receptor agonist 5'-(N-ethylcarboxamido)adenosine in Chinese hamster ovary cells stably transfected with the human adenosine A(1) or A(3) receptor. Likewise, calcium mobilization and radioligand binding assays found that Brilliant Black BN (5-500 microM) did not significantly influence the antagonism mediated by 8-cyclopentyl-1,3-dipropylxanthine (100 nM) at the A(1) receptor. In contrast, the affinity of N-[9-chloro-2-(2-furanyl)[1,2,4]-triazolo[1,5-c]quinazolin-5-yl]benzene acetamide (MRS1220) at the A(3) receptor and xanthine amine congener (XAC) and XAC-X-BY630 at the A(1) and A(3) receptors was significantly decreased in the presence of 500 muM Brilliant Black BN. A reduction in XAC potency at the A(1) and A(3) receptor was achieved within 1 min of Brilliant Black BN addition, despite receptors having been pre-equilibrated with antagonist. Dissociation kinetics of the fluorescent XAC derivative, XAC-X-BY630, revealed that the decrease in affinity is probably due to a significant increase in dissociation rate of the antagonist in the presence of Brilliant Black BN. Taken together, these results suggest that Brilliant Black BN can act allosterically to modify ligand affinity at A(1) and A(3) receptors.
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Affiliation(s)
- L T May
- Institute of Cell Signaling, The University of Nottingham Medical School, Queen's Medical Centre, Nottingham NG7 2UH, UK
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Heitman LH, Narlawar R, de Vries H, Willemsen MN, Wolfram D, Brussee J, Ijzerman AP. Substituted terphenyl compounds as the first class of low molecular weight allosteric inhibitors of the luteinizing hormone receptor. J Med Chem 2009; 52:2036-42. [PMID: 19296599 DOI: 10.1021/jm801561h] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The luteinizing hormone (LH) receptor plays an important role in fertility and certain cancers. The endogenous ligands human chorionic gonadotropin (hCG) and LH bind to the large N terminal domain of the receptor. We recently reported on the first radiolabeled low molecular weight (LMW) agonist for this receptor, [(3)H]Org 43553, which was now used to screen for new LMW ligands. We identified a terphenyl derivative that inhibited [(3)H]Org 43553 binding to the receptor, which led us to synthesize a number of derivatives. The most potent compound of this terphenyl series, 24 (LUF5771), was able to increase the dissociation rate of [(3)H]Org 43553 by 3.3-fold (at 10 muM). In a functional assay, the presence of 24 resulted in a 2- to 3-fold lower potency of both Org 43553 and LH. Thus, the compounds presented in this paper are the first LMW ligands that allosterically inhibit the LH receptor.
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Affiliation(s)
- Laura H Heitman
- Division of Medicinal Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, RA Leiden, The Netherlands
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Kim Y, de Castro S, Gao ZG, Ijzerman AP, Jacobson KA. Novel 2- and 4-substituted 1H-imidazo[4,5-c]quinolin-4-amine derivatives as allosteric modulators of the A3 adenosine receptor. J Med Chem 2009; 52:2098-108. [PMID: 19284749 PMCID: PMC2765805 DOI: 10.1021/jm801659w] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
4-Arylamino and 2- cycloalkyl (including amino substitution) modifications were made in a series of 1H-imidazo[4,5-c]quinolin-4-amine derivatives as allosteric modulators of the human A(3) adenosine receptor (AR). In addition to allosteric modulation of the maximum functional efficacy (in [(35)S]GTPgammaS G protein binding assay) of the A(3)AR agonist Cl-IB-MECA (15), some analogues also weakly inhibited equilibrium radioligand binding at ARs. 4-(3,5-Dichlorophenylamino) (6) or 2-(1-adamantyl) (20) substitution produced allosteric enhancement (twice the maximal agonist efficacy), with minimal inhibition of orthosteric AR binding. 2-(4-Tetrahydropyranyl) substitution abolished allosteric enhancement but preserved inhibition of orthosteric binding. Introduction of nitrogen in the six-membered ring at the 2 position, to improve aqueous solubility and provide a derivatization site, greatly reduced the allosteric enhancement. 2-(4-(Benzoylamino)cyclohexyl) analogues 23 and 24 were weak negative A(3)AR modulators. Thus, consistent with previous findings, the allosteric and orthosteric inhibitory A(3)AR effects in imidazoquinolines are structurally separable, suggesting the possible design of additional derivatives with enhanced positive or negative allosteric A(3)AR activity and improved selectivity in comparison to inhibition of orthosteric binding.
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Affiliation(s)
- Yoonkyung Kim
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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Shukla NM, Kimbrell MR, Malladi SS, David SA. Regioisomerism-dependent TLR7 agonism and antagonism in an imidazoquinoline. Bioorg Med Chem Lett 2009; 19:2211-4. [DOI: 10.1016/j.bmcl.2009.02.100] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2009] [Revised: 02/24/2009] [Accepted: 02/25/2009] [Indexed: 01/22/2023]
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Heitman LH, Göblyös A, Zweemer AM, Bakker R, Mulder-Krieger T, van Veldhoven JPD, de Vries H, Brussee J, IJzerman AP. A Series of 2,4-Disubstituted Quinolines as a New Class of Allosteric Enhancers of the Adenosine A3 Receptor. J Med Chem 2009; 52:926-31. [DOI: 10.1021/jm8014052] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Laura H. Heitman
- Division of Medicinal Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Anikó Göblyös
- Division of Medicinal Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Annelien M. Zweemer
- Division of Medicinal Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Renée Bakker
- Division of Medicinal Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Thea Mulder-Krieger
- Division of Medicinal Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Jacobus P. D. van Veldhoven
- Division of Medicinal Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Henk de Vries
- Division of Medicinal Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Johannes Brussee
- Division of Medicinal Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Adriaan P. IJzerman
- Division of Medicinal Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
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Jacobson KA, Klutz AM, Tosh DK, Ivanov AA, Preti D, Baraldi PG. Medicinal chemistry of the A3 adenosine receptor: agonists, antagonists, and receptor engineering. Handb Exp Pharmacol 2009:123-59. [PMID: 19639281 PMCID: PMC3413728 DOI: 10.1007/978-3-540-89615-9_5] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
A(3) adenosine receptor (A(3)AR) ligands have been modified to optimize their interaction with the A(3)AR. Most of these modifications have been made to the N(6) and C2 positions of adenine as well as the ribose moiety, and using a combination of these substitutions leads to the most efficacious, selective, and potent ligands. A(3)AR agonists such as IB-MECA and Cl-IB-MECA are now advancing into Phase II clinical trials for treatments targeting diseases such as cancer, arthritis, and psoriasis. Also, a wide number of compounds exerting high potency and selectivity in antagonizing the human (h)A(3)AR have been discovered. These molecules are generally characterized by a notable structural diversity, taking into account that aromatic nitrogen-containing monocyclic (thiazoles and thiadiazoles), bicyclic (isoquinoline, quinozalines, (aza)adenines), tricyclic systems (pyrazoloquinolines, triazoloquinoxalines, pyrazolotriazolopyrimidines, triazolopurines, tricyclic xanthines) and nucleoside derivatives have been identified as potent and selective A(3)AR antagonists. Probably due to the "enigmatic" physiological role of A(3)AR, whose activation may produce opposite effects (for example, concerning tissue protection in inflammatory and cancer cells) and may produce effects that are species dependent, only a few molecules have reached preclinical investigation. Indeed, the most advanced A(3)AR antagonists remain in preclinical testing. Among the antagonists described above, compound OT-7999 is expected to enter clinical trials for the treatment of glaucoma, while several thiazole derivatives are in development as antiallergic, antiasthmatic and/or antiinflammatory drugs.
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Affiliation(s)
- Kenneth A Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0810, USA.
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Gao ZG, Ye K, Göblyös A, Ijzerman AP, Jacobson KA. Flexible modulation of agonist efficacy at the human A3 adenosine receptor by the imidazoquinoline allosteric enhancer LUF6000. BMC Pharmacol 2008; 8:20. [PMID: 19077268 PMCID: PMC2625337 DOI: 10.1186/1471-2210-8-20] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2008] [Accepted: 12/12/2008] [Indexed: 02/08/2023] Open
Abstract
Background A series of 1H-imidazo- [4,5-c]quinolin-4-amine derivatives, represented by LUF6000 (N-(3,4-dichloro-phenyl)-2-cyclohexyl-1H-imidazo [4,5-c]quinolin-4-amine), are allosteric modulators of the human A3 adenosine receptor (AR). Here we studied the modulation by LUF6000 of the maximum effect (Emax) of structurally diverse agonists at the A3 AR stably expressed in CHO cells. Results In an assay of [35S]GTPγS binding, the Emax of the A3 AR agonist Cl-IB-MECA at the A3 AR was lower than that of the non-selective AR agonist NECA. LUF6000 exerted an Emax-enhancing effect at a concentration of 0.1 μM or higher, and was shown to increase the Emax of Cl-IB-MECA and other low-efficacy agonists to a larger extent than that of the high-efficacy agonist NECA. Interestingly, LUF6000 converted a nucleoside A3 AR antagonist MRS542, but not a non-nucleoside antagonist MRS1220, into an agonist. LUF6000 alone did not show any effect. Mathematical modeling was performed to explain the differential effects of LUF6000 on agonists with various Emax. A simple explanation for the observation that LUF6000 has a much stronger effect on Cl-IB-MECA than on NECA derived from the mathematical modeling is that NECA has relatively strong intrinsic efficacy, such that the response is already close to the maximum response. Therefore, LUF6000 cannot enhance Emax much further. Conclusion LUF6000 was found to be an allosteric enhancer of Emax of structurally diverse agonists at the A3 AR, being more effective for low-Emax agonists than for high-Emax agonists. LUF6000 was demonstrated to convert an antagonist into an agonist, which represents the first example in G protein-coupled receptors. The observations from the present study are consistent with that predicted by mathematical modeling.
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Affiliation(s)
- Zhan-Guo Gao
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0810, USA.
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Abstract
Allosteric modulators for adenosine receptors may have potential therapeutic advantage over orthosteric ligands. Allosteric enhancers at the adenosine A1 receptor have been linked to antiarrhythmic and antilipolytic activity. They may also have therapeutic potential as analgesics and neuroprotective agents. A3 allosteric enhancers are postulated to be useful against ischemic conditions or as antitumor agents. In this review, we address recent developments regarding the medicinal chemistry of such compounds. Most efforts have been and are directed toward adenosine A1 and A3 receptors, whereas limited or no information is available for A2A and A2B receptors. We also discuss some findings, mostly receptor mutation studies, regarding localization of the allosteric binding sites on the receptors.
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Gao ZG, Jacobson KA. Translocation of arrestin induced by human A(3) adenosine receptor ligands in an engineered cell line: comparison with G protein-dependent pathways. Pharmacol Res 2008; 57:303-11. [PMID: 18424164 DOI: 10.1016/j.phrs.2008.02.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2008] [Revised: 02/29/2008] [Accepted: 02/29/2008] [Indexed: 11/23/2022]
Abstract
Structurally diverse ligands were studied in A(3) adenosine receptor (AR)-mediated beta-arrestin translocation in engineered CHO cells. The agonist potency and efficacy were similar, although not identical, to their G protein signaling. However, differences have also been found. MRS542, MRS1760, and other adenosine derivatives, A(3)AR antagonists in cyclic AMP assays, were partial agonists in beta-arrestin translocation, indicating possible biased agonism. The xanthine 7-riboside DBXRM, a full agonist, was only partially efficacious in beta-arrestin translocation. DBXRM was shown to induce a lesser extent of desensitization compared with IB-MECA. In kinetic studies, MRS3558, a potent and selective A(3)AR agonist, induced beta-arrestin translocation significantly faster than IB-MECA and Cl-IB-MECA. Non-nucleoside antagonists showed similar inhibitory potencies as previously reported. PTX pretreatment completely abolished ERK1/2 activation, but not arrestin translocation. Thus, lead candidates for biased agonists at the A(3)AR have been identified with this arrestin-translocation assay, which promises to be an effective tool for ligand screening.
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Abstract
Adenosine receptors (ARs) are a four-member subfamily of G protein-coupled receptors and are major targets of caffeine and theophylline. There are four subtypes of ARs, designated as A1, A2A, A2B and A3. Selective agonists are now available for all four subtypes. Over a dozen of these selective agonists are now in clinical trials for various conditions, although none has received regulatory approval except for the endogenous AR agonist adenosine itself. A1AR agonists are in clinical trials for cardiac arrhythmias and neuropathic pain. A2AAR agonists are now in trials for myocardial perfusion imaging and as anti-inflammatory agents. A2BAR agonists are under preclinical scrutiny for potential treatment of cardiac ischemia. A3AR agonists are in clinical trials for the treatment of rheumatoid arthritis and colorectal cancer. The present review will mainly cover the agonists that are presently in clinical trials for various conditions and only a brief introduction will be given to major chemical classes of AR agonists presently under investigation.
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Affiliation(s)
- Zhan-Guo Gao
- NIDDK, National Institutes of Health, Molecular Recognition Section, Laboratory of Bioorganic Chemistry, Bldg. 8A, Room B1A-23, 9000 Rockville Pike, Bethesda, Maryland 20892-0810, USA.
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42
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Jacobson KA, Costanzi S, Kim SK, Roh E, Joshi BV, Tchilibon S, Duong HT, Gao ZG. Action of nucleosides and nucleotides at 7 transmembrane-spanning receptors. Nucleosides Nucleotides Nucleic Acids 2007; 25:1425-36. [PMID: 17067963 PMCID: PMC6262823 DOI: 10.1080/15257770600919027] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Ribose ring-constrained nucleosides and nucleotides to act at cell-surface purine recesptors have been designed and synthesized. At the P2Y1 nucleotide receptor and the A3 adenosine receptor (AR) the North envelope conformation of ribose is highly preferred. We have applied mutagenesis and rhodopsin-based homology modeling to the study of purine receptors and used the structural insights gained to assist in the design of novel ligands. Two subgroups of P2Y receptors have been defined, containing different sets of cationic residues for coordinating the phosphate groups. Modeling/mutagenesis of adenosine receptors has focused on determinants of intrinsic efficacy in adenosine derivatives and on a conserved Trp residue (6.48) which is involved in the activation process. The clinical use of adenosine agonists as cytoprotective agents has been limited by the widespread occurrence of ARs, thus, leading to undesirable side effects of exogenously administered adenosine derivatives. In order to overcome the inherent nonselectivity of activating the native receptors, we have introduced the concept of neoceptors. By this strategy, intended for eventual use in gene therapy, the putative ligand binding site of a G protein-coupled receptor is reengineered for activation by synthetic agonists (neoligands) built to have a structural complementarity. Using a rational design process we have identified neoceptor-neoligand pairs which are pharmacologically orthogonal with respect to the native species.
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Affiliation(s)
- Kenneth A Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0810, USA.
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