1
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Boncler M, Bartczak K, Rozalski M. Potential for modulation of platelet function via adenosine receptors during inflammation. Br J Pharmacol 2024; 181:547-563. [PMID: 37218380 DOI: 10.1111/bph.16146] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 03/15/2023] [Accepted: 05/15/2023] [Indexed: 05/24/2023] Open
Abstract
Traditionally, platelets are known to play an important role in haemostasis and thrombosis; however, they serve also as important modulators of inflammation and immunity. Platelets secrete adhesion molecules and cytokines, interact with leukocytes and endothelium, and express toll-like receptors involved in a direct interaction with pathogens. Platelets express A2A and A2B subtypes of receptors for adenosine. The activation of these receptors leads to an increase in cAMP concentration in the cytoplasm, thereby resulting in inhibited secretion of pro-inflammatory mediators and reduced cell activation. Therefore, platelet adenosine receptors could be a potential target for inhibiting platelet activation and thus down-regulating inflammation or immunity. The biological effects of adenosine are short-lasting, because the compound is rapidly metabolized; hence, its lability has triggered efforts to synthesize new, longer-lasting adenosine analogues. In this article, we have reviewed the literature regarding the pharmacological potential of adenosine and other agonists of A2A and A2B receptors to affect platelet function during inflammation. LINKED ARTICLES: This article is part of a themed issue on Platelet purinergic receptor and non-thrombotic disease. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.4/issuetoc.
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Affiliation(s)
- Magdalena Boncler
- Department of Haemostasis and Haemostatic Disorders, Chair of Biomedical Sciences, Medical University of Lodz, Lodz, Poland
| | - Kinga Bartczak
- Department of Haemostasis and Haemostatic Disorders, Chair of Biomedical Sciences, Medical University of Lodz, Lodz, Poland
| | - Marcin Rozalski
- Department of Haemostasis and Haemostatic Disorders, Chair of Biomedical Sciences, Medical University of Lodz, Lodz, Poland
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2
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Mehrizi TZ, Kafiabad SA, Eshghi P. Effects and treatment applications of polymeric nanoparticles on improving platelets' storage time: a review of the literature from 2010 to 2020. Blood Res 2021; 56:215-228. [PMID: 34880140 PMCID: PMC8721452 DOI: 10.5045/br.2021.2021094] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Revised: 07/26/2021] [Accepted: 08/25/2021] [Indexed: 12/13/2022] Open
Abstract
Maintaining the quality of platelet products and increasing their storage time are priorities for treatment applications. The formation of platelet storage lesions that limit the storage period and preservation temperature, which can prepare a decent environment for bacterial growth, are the most important challenges that researchers are dealing with in platelet preservation. Nanotechnology is an emerging field of science that has introduced novel solutions to resolve these problems. Here, we reviewed the reported effects of polymeric nanoparticles-including chitosan, dendrimers, polyethylene glycol (PEG), and liposome-on platelets in articles from 2010 to 2020. As a result, we concluded that the presence of dendrimer nanoparticles with a smaller size, negative charge, low molecular weight, and low concentration along with PEGylation can increase the stability and survival of platelets during storage. In addition, PEGylation of platelets can also be a promising approach to improve the quality of platelet bags during storage.
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Affiliation(s)
- Tahereh Zadeh Mehrizi
- Blood Transfusion Research Center, High Institute for Research and Education in Transfusion Medicine, Tehran, Iran
| | - Sedigheh Amini Kafiabad
- Blood Transfusion Research Center, High Institute for Research and Education in Transfusion Medicine, Tehran, Iran
| | - Peyman Eshghi
- Pediatric Congenital Hematologic Disorders Research Center, Shahid Beheshti University of Medical Sciences and Iran Blood Transfusion Organization, Tehran, Iran
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3
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Pineux F, Federico S, Klotz KN, Kachler S, Michiels C, Sturlese M, Prato M, Spalluto G, Moro S, Bonifazi D. Targeting G Protein-Coupled Receptors with Magnetic Carbon Nanotubes: The Case of the A 3 Adenosine Receptor. ChemMedChem 2020; 15:1909-1920. [PMID: 32706529 DOI: 10.1002/cmdc.202000466] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Indexed: 12/14/2022]
Abstract
The A3 adenosine receptor (AR) is a G protein-coupled receptor (GPCR) overexpressed in the membrane of specific cancer cells. Thus, the development of nanosystems targeting this receptor could be a strategy to both treat and diagnose cancer. Iron-filled carbon nanotubes (CNTs) are an optimal platform for theranostic purposes, and the use of a magnetic field can be exploited for cancer magnetic cell sorting and thermal therapy. In this work, we have conjugated an A3 AR ligand on the surface of iron-filled CNTs with the aim of targeting cells overexpressing A3 ARs. In particular, two conjugates bearing PEG linkers of different length were designed. A docking analysis of A3 AR showed that neither CNT nor linker interferes with ligand binding to the receptor; this was confirmed by in vitro preliminary radioligand competition assays on A3 AR. Encouraged by this result, magnetic cell sorting was applied to a mixture of cells overexpressing or not the A3 AR in which our compound displayed indiscriminate binding to all cells. Despite this, it is the first time that a GPCR ligand has been anchored to a magnetic nanosystem, thus it opens the door to new applications for cancer treatment.
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Affiliation(s)
- Florent Pineux
- Department of Chemistry and Namur Research College (NARC), University of Namur, Rue de Bruxelles 61, 5000, Namur, Belgium
| | - Stephanie Federico
- Dipartimento di Scienze Chimiche e Farmaceutiche, Università degli Studi di Trieste, Via L.Giorgeri 1, 34127, Trieste, Italy
| | - Karl-Norbert Klotz
- Institut für Pharmakologie und Toxikologie, Universität Würzburg, Versbacher Straße 9, 97078, Würzburg, Germany
| | - Sonja Kachler
- Institut für Pharmakologie und Toxikologie, Universität Würzburg, Versbacher Straße 9, 97078, Würzburg, Germany
| | - Carine Michiels
- Namur Research Institute for Life Science (NARILIS), Unité de Recherche en Biologie Cellulaire (URBC), University of Namur, 5000, Namur, Belgium
| | - Mattia Sturlese
- Dipartimento di Scienze del Farmaco Molecular Modeling Section (MMS), Università degli Studi di Padova, Via F. Marzolo 5, 35131, Padova, Italy
| | - Maurizio Prato
- Dipartimento di Scienze Chimiche e Farmaceutiche, Università degli Studi di Trieste, Via L.Giorgeri 1, 34127, Trieste, Italy.,Center for Cooperative Research in Biomaterials (CIC biomaGUNE), Basque Research and Technology Alliance (BRTA), Paseo de Miramón 182, 20014, Donostia-San Sebastián, Spain.,Basque Foundation for Science, Ikerbasque, 48013, Bilbao, Spain
| | - Giampiero Spalluto
- Dipartimento di Scienze Chimiche e Farmaceutiche, Università degli Studi di Trieste, Via L.Giorgeri 1, 34127, Trieste, Italy
| | - Stefano Moro
- Dipartimento di Scienze del Farmaco Molecular Modeling Section (MMS), Università degli Studi di Padova, Via F. Marzolo 5, 35131, Padova, Italy
| | - Davide Bonifazi
- Institut für Organische Chemie, Universität Wien, Währinger Str. 38, 1090, Wien, Austria
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4
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Islam N, Gurgel PV, Rojas OJ, Carbonell RG. Use of a Branched Linker for Enhanced Biosensing Properties in IgG Detection from Mixed Chinese Hamster Ovary Cell Cultures. Bioconjug Chem 2019; 30:815-825. [PMID: 30653289 DOI: 10.1021/acs.bioconjchem.8b00918] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Tris(2-aminoethyl)-amine (TREN), a branched amine, was coupled to planar surfaces of alkanethiol self-assembled monolayers (SAMs) to increase the grafting density of IgG-binding peptide (HWRGWV or HWRGWVG) on gold surfaces. One of the three primary amine pendant groups of TREN anchors onto the SAM, while the other two are available for grafting with the C-termini of the peptide. The ellipsometric peptide density on the SAM-branched amine was 1.24 molecules nm-2. The surfaces carrying the peptides were investigated via surface plasmon resonance (SPR) to quantify the adsorption of IgG and showed maximum binding capacity, Qm of 4.45 mg m-2, and dissociation constant, Kd of 8.7 × 10-7 M. Real-time dynamic adsorption data was used to determine adsorption rate constants, ka values, and the values were dependent on IgG concentration. IgG binding from complex mixtures of Chinese hamster ovary supernatant (CHO) was investigated and regeneration studies were carried out. Compared to the unbranched amine-based surfaces, the branched amines increased the overall sensitivity and selectivity for IgG adsorption from complex mixtures. Regeneration of the branched amine-based surfaces was achieved with 0.1 M NaOH, with less than 10% decline in peptide activity after 12 cycles of regeneration-binding.
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Affiliation(s)
- Nafisa Islam
- Department of Chemical and Biomolecular Engineering , North Carolina State University , Raleigh , North Carolina 27695-7905 , United States.,Department of Chemical Engineering , Bangladesh University of Engineering and Technology , Dhaka 1000 , Bangladesh
| | - Patrick V Gurgel
- Department of Chemical and Biomolecular Engineering , North Carolina State University , Raleigh , North Carolina 27695-7905 , United States.,Prometic Bioseparations , Cambridgeshire , CB23 7AJ , United Kingdom
| | - Orlando J Rojas
- Department of Chemical and Biomolecular Engineering , North Carolina State University , Raleigh , North Carolina 27695-7905 , United States.,Department of Bioproducts and Biosystems, School of Chemical Engineering , Aalto University , Espoo , 00076 , Finland
| | - Ruben G Carbonell
- Department of Chemical and Biomolecular Engineering , North Carolina State University , Raleigh , North Carolina 27695-7905 , United States.,Biomanufacturing Training and Education (BTEC) , North Carolina State University , Raleigh , North Carolina 27606 , United States
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5
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Ma X, Xiong Y, Lee LTO. Application of Nanoparticles for Targeting G Protein-Coupled Receptors. Int J Mol Sci 2018; 19:E2006. [PMID: 29996469 PMCID: PMC6073629 DOI: 10.3390/ijms19072006] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 06/28/2018] [Accepted: 07/04/2018] [Indexed: 01/01/2023] Open
Abstract
Nanoparticles (NPs) have attracted unequivocal attention in recent years due to their potential applications in therapeutics, bio-imaging and material sciences. For drug delivery, NP-based carrier systems offer several advantages over conventional methods. When conjugated with ligands and drugs (or other therapeutic molecules), administrated NPs are able to deliver cargo to targeted sites through ligand-receptor recognition. Such targeted delivery is especially important in cancer therapy. Through this targeted cancer nanotherapy, cancer cells are killed with higher specificity, while the healthy cells are spared. Furthermore, NP drug delivery leads to improved drug load, enhanced drug solubility and stability, and controlled drug release. G protein-coupled receptors (GPCRs) are a superfamily of cell transmembrane receptors. They regulate a plethora of physiological processes through ligand-receptor-binding-induced signaling transduction. With recent evidence unveiling their roles in cancer, GPCR agonists and antagonists have quickly become new targets in cancer therapy. This review focuses on the application of some notable nanomaterials, such as dendrimers, quantum dots, gold nanoparticles, and magnetic nanoparticles, in GPCR-related cancers.
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Affiliation(s)
- Xin Ma
- Centre of Reproduction Development and Aging, Faculty of Health Sciences, University of Macau, Taipa, Macau, China.
| | - Yunfang Xiong
- Centre of Reproduction Development and Aging, Faculty of Health Sciences, University of Macau, Taipa, Macau, China.
| | - Leo Tsz On Lee
- Centre of Reproduction Development and Aging, Faculty of Health Sciences, University of Macau, Taipa, Macau, China.
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6
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Gao X, Yue Q, Liu Y, Fan D, Fan K, Li S, Qian J, Han L, Fang F, Xu F, Geng D, Chen L, Zhou X, Mao Y, Li C. Image-guided chemotherapy with specifically tuned blood brain barrier permeability in glioma margins. Theranostics 2018; 8:3126-3137. [PMID: 29896307 PMCID: PMC5996359 DOI: 10.7150/thno.24784] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2018] [Accepted: 03/05/2018] [Indexed: 11/26/2022] Open
Abstract
Blood-brain barrier (BBB) disruption is frequently observed in the glioma region. However, the tumor uptake of drugs is still too low to meet the threshold of therapeutic purpose. Method: A tumor vasculature-targeted nanoagonist was developed. Glioma targeting specificity of the nanoagonist was evaluated by in vivo optical imaging. BBB permeability at the glioma margin was quantitatively measured by dynamic contrast enhanced magnetic resonance imaging (DCE-MRI). Single-photon emission computed tomography imaging/computed tomography (SPECT/CT) quantitatively determined the glioma uptake of the radiolabeled model drug. T2-weighted MRI monitored the tumor volume. Results: Immunostaining studies demonstrated that the BBB remained partially intact in the invasive margin of patients' gliomas regardless of their malignancies. DCE-MRI showed that vascular permeability in the glioma margin reached its maximum at 45 min post nanoagonist administration. In vivo optical imaging indicated the high glioma targeting specificity of the nanoagonist. SPECT/CT showed the significantly enhanced glioma uptake of the model drug after pre-treatment with the nanoagonist. Image-guided paclitaxel injection after nanoagonist-mediated BBB modulation more efficiently attenuated tumor growth and extended survival than in animal models treated with paclitaxel or temozolomide alone. Conclusion: Thus, image-guided drug delivery following BBB permeability modulation holds promise to enhance the efficacy of chemotherapeutics to glioma.
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7
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Matus MF, Vilos C, Cisterna BA, Fuentes E, Palomo I. Nanotechnology and primary hemostasis: Differential effects of nanoparticles on platelet responses. Vascul Pharmacol 2018; 101:1-8. [DOI: 10.1016/j.vph.2017.11.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 10/12/2017] [Accepted: 11/14/2017] [Indexed: 12/19/2022]
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8
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Simak J, De Paoli S. The effects of nanomaterials on blood coagulation in hemostasis and thrombosis. WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY 2017; 9. [PMID: 28078811 DOI: 10.1002/wnan.1448] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2016] [Revised: 10/19/2016] [Accepted: 11/23/2016] [Indexed: 01/16/2023]
Abstract
The blood coagulation balance in the organism is achieved by the interaction of the blood platelets (PLTs) with the plasma coagulation system (PCS) and the vascular endothelial cells. In healthy organism, these systems prevent thrombosis and, in events of vascular damage, enable blood clotting to stop bleeding. The dysregulation of hemostasis may cause serious thrombotic and/or hemorrhagic pathologies. Numerous engineered nanomaterials are being investigated for biomedical purposes and are unavoidably exposed to the blood. Also, nanomaterials may access vascular system after occupational, environmental, or other types of exposure. Thus, it is essential to evaluate the effects of engineered nanomaterials on hemostasis. This review focuses on investigations of nanomaterial interactions with the blood components involved in blood coagulation: the PCS and PLTs. Particular emphases include the pathophysiology of effects of nanomaterials on the PCS, including the kallikrein-kinin system, and on PLTs. Methods for investigating these interactions are briefly described, and a review of the most important studies on the interactions of nanomaterials with plasma coagulation and platelets is provided. WIREs Nanomed Nanobiotechnol 2017, 9:e1448. doi: 10.1002/wnan.1448 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Jan Simak
- Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD, USA
| | - Silvia De Paoli
- Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD, USA
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9
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Zheng S, Bai YY, Liu Y, Gao X, Li Y, Changyi Y, Wang Y, Chang D, Ju S, Li C. Salvaging brain ischemia by increasing neuroprotectant uptake via nanoagonist mediated blood brain barrier permeability enhancement. Biomaterials 2015; 66:9-20. [PMID: 26188608 DOI: 10.1016/j.biomaterials.2015.07.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2015] [Revised: 07/03/2015] [Accepted: 07/09/2015] [Indexed: 12/28/2022]
Abstract
Ischemic stroke is a leading cause of adult disability and cognitive impairment worldwide. Neuroprotective therapy aims to save neurons by impeding the deleterious ischemic insults. However, the low efficiency of the neuroprotectants crossing blood brain barrier (BBB) prevents their clinical translation. In this work, a nanoagonist (NA) was developed to enhance neuroprotectant uptake by specifically increasing BBB permeability in brain ischemia. This NA first targeted ischemic brain vasculatures, temporarily opened local BBB by activating adenosine 2A receptors, and up-regulated the neuroprotectant uptake in brain ischemia. This NA significantly increased the delivery of superoxide dismutase (SOD), a free radical scavenger, into mouse brain ischemia. The combined treatment of NA/SOD achieved a five-fold ischemic volume reduction rate compared to the animal models treated with SOD alone. Non-invasive magnetic resonance imaging (MRI) confirmed the ischemia targeted BBB opening, increased brain drug delivery efficiency and up-regulated therapeutic response during the combined NA/SOD treatment. Since the inefficient brain drug delivery is a general problem for the treatment of central nervous system (CNS) diseases, this work provides a novel strategy to deliver therapeutics by crossing BBB with high efficiency and targeting specificity.
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Affiliation(s)
- Shuyan Zheng
- Key Laboratory of Smart Drug Delivery, Ministry of Education, School of Pharmacy, Fudan University, 826 Zhangheng Rd., Shanghai 201203, China
| | - Ying-Ying Bai
- Jiangsu Key Laboratory of Molecular and Functional Imaging Department of Radiology, Zhongda Hospital, Medical School of Southeast University, 87 Dingjiaqiao Rd., Nanjing 210009, China
| | - Yikang Liu
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, USA
| | - Xihui Gao
- Key Laboratory of Smart Drug Delivery, Ministry of Education, School of Pharmacy, Fudan University, 826 Zhangheng Rd., Shanghai 201203, China
| | - Yan Li
- School of Pharmacy, Shenyang Pharmaceutical University, 103 Wenhua Rd., Shenyang 110016, China
| | - Yinzhi Changyi
- Key Laboratory of Smart Drug Delivery, Ministry of Education, School of Pharmacy, Fudan University, 826 Zhangheng Rd., Shanghai 201203, China
| | - Yuancheng Wang
- Jiangsu Key Laboratory of Molecular and Functional Imaging Department of Radiology, Zhongda Hospital, Medical School of Southeast University, 87 Dingjiaqiao Rd., Nanjing 210009, China
| | - Di Chang
- Jiangsu Key Laboratory of Molecular and Functional Imaging Department of Radiology, Zhongda Hospital, Medical School of Southeast University, 87 Dingjiaqiao Rd., Nanjing 210009, China
| | - Shenghong Ju
- Jiangsu Key Laboratory of Molecular and Functional Imaging Department of Radiology, Zhongda Hospital, Medical School of Southeast University, 87 Dingjiaqiao Rd., Nanjing 210009, China.
| | - Cong Li
- Key Laboratory of Smart Drug Delivery, Ministry of Education, School of Pharmacy, Fudan University, 826 Zhangheng Rd., Shanghai 201203, China.
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10
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Borea PA, Varani K, Vincenzi F, Baraldi PG, Tabrizi MA, Merighi S, Gessi S. The A3 adenosine receptor: history and perspectives. Pharmacol Rev 2015; 67:74-102. [PMID: 25387804 DOI: 10.1124/pr.113.008540] [Citation(s) in RCA: 177] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
By general consensus, the omnipresent purine nucleoside adenosine is considered a major regulator of local tissue function, especially when energy supply fails to meet cellular energy demand. Adenosine mediation involves activation of a family of four G protein-coupled adenosine receptors (ARs): A(1), A(2)A, A(2)B, and A(3). The A(3) adenosine receptor (A(3)AR) is the only adenosine subtype to be overexpressed in inflammatory and cancer cells, thus making it a potential target for therapy. Originally isolated as an orphan receptor, A(3)AR presented a twofold nature under different pathophysiologic conditions: it appeared to be protective/harmful under ischemic conditions, pro/anti-inflammatory, and pro/antitumoral depending on the systems investigated. Until recently, the greatest and most intriguing challenge has been to understand whether, and in which cases, selective A(3) agonists or antagonists would be the best choice. Today, the choice has been made and A(3)AR agonists are now under clinical development for some disorders including rheumatoid arthritis, psoriasis, glaucoma, and hepatocellular carcinoma. More specifically, the interest and relevance of these new agents derives from clinical data demonstrating that A(3)AR agonists are both effective and safe. Thus, it will become apparent in the present review that purine scientists do seem to be getting closer to their goal: the incorporation of adenosine ligands into drugs with the ability to save lives and improve human health.
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Affiliation(s)
- Pier Andrea Borea
- Department of Medical Sciences, Pharmacology Section (P.A.B., K.V., F.V., S.M., S.G.), and Department of Pharmaceutical Sciences, University of Ferrara, Italy (P.G.B., M.A.T.)
| | - Katia Varani
- Department of Medical Sciences, Pharmacology Section (P.A.B., K.V., F.V., S.M., S.G.), and Department of Pharmaceutical Sciences, University of Ferrara, Italy (P.G.B., M.A.T.)
| | - Fabrizio Vincenzi
- Department of Medical Sciences, Pharmacology Section (P.A.B., K.V., F.V., S.M., S.G.), and Department of Pharmaceutical Sciences, University of Ferrara, Italy (P.G.B., M.A.T.)
| | - Pier Giovanni Baraldi
- Department of Medical Sciences, Pharmacology Section (P.A.B., K.V., F.V., S.M., S.G.), and Department of Pharmaceutical Sciences, University of Ferrara, Italy (P.G.B., M.A.T.)
| | - Mojgan Aghazadeh Tabrizi
- Department of Medical Sciences, Pharmacology Section (P.A.B., K.V., F.V., S.M., S.G.), and Department of Pharmaceutical Sciences, University of Ferrara, Italy (P.G.B., M.A.T.)
| | - Stefania Merighi
- Department of Medical Sciences, Pharmacology Section (P.A.B., K.V., F.V., S.M., S.G.), and Department of Pharmaceutical Sciences, University of Ferrara, Italy (P.G.B., M.A.T.)
| | - Stefania Gessi
- Department of Medical Sciences, Pharmacology Section (P.A.B., K.V., F.V., S.M., S.G.), and Department of Pharmaceutical Sciences, University of Ferrara, Italy (P.G.B., M.A.T.)
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11
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Chen JF, Lee CF, Chern Y. Adenosine receptor neurobiology: overview. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2015; 119:1-49. [PMID: 25175959 DOI: 10.1016/b978-0-12-801022-8.00001-5] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Adenosine is a naturally occurring nucleoside that is distributed ubiquitously throughout the body as a metabolic intermediary. In the brain, adenosine functions as an important upstream neuromodulator of a broad spectrum of neurotransmitters, receptors, and signaling pathways. By acting through four G-protein-coupled receptors, adenosine contributes critically to homeostasis and neuromodulatory control of a variety of normal and abnormal brain functions, ranging from synaptic plasticity, to cognition, to sleep, to motor activity to neuroinflammation, and cell death. This review begun with an overview of the gene and genome structure and the expression pattern of adenosine receptors (ARs). We feature several new developments over the past decade in our understanding of AR functions in the brain, with special focus on the identification and characterization of canonical and noncanonical signaling pathways of ARs. We provide an update on functional insights from complementary genetic-knockout and pharmacological studies on the AR control of various brain functions. We also highlight several novel and recent developments of AR neurobiology, including (i) recent breakthrough in high resolution of three-dimension structure of adenosine A2A receptors (A2ARs) in several functional status, (ii) receptor-receptor heterodimerization, (iii) AR function in glial cells, and (iv) the druggability of AR. We concluded the review with the contention that these new developments extend and strengthen the support for A1 and A2ARs in brain as therapeutic targets for neurologic and psychiatric diseases.
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Affiliation(s)
- Jiang-Fan Chen
- Department of Neurology, Boston University School of Medicine, Boston, Massachusetts, USA.
| | - Chien-fei Lee
- Division of Neuroscience, Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Yijuang Chern
- Division of Neuroscience, Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
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12
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Bharatwaj B, Mohammad AK, Dimovski R, Cassio FL, Bazito RC, Conti D, Fu Q, Reineke J, da Rocha SRP. Dendrimer nanocarriers for transport modulation across models of the pulmonary epithelium. Mol Pharm 2015; 12:826-38. [PMID: 25455560 PMCID: PMC4350608 DOI: 10.1021/mp500662z] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
The purpose of this study was to
determine the effect of PEGylation
on the interaction of poly(amidoamine) (PAMAM) dendrimer nanocarriers
(DNCs) with in vitro and in vivo models of the pulmonary epithelium. Generation-3 PAMAM dendrimers
with varying surface densities of PEG 1000 Da were synthesized and
characterized. The results revealed that the apical to basolateral
transport of DNCs across polarized Calu-3 monolayers increases with
an increase in PEG surface density. DNC having the greatest number
of PEG groups (n = 25) on their surface traversed
at a rate 10-fold greater than its non-PEGylated counterpart, in spite
of their larger size. This behavior was attributed to a significant
reduction in charge density upon PEGylation. We also observed that
PEGylation can be used to modulate cellular internalization. The total
uptake of PEG-free DNC into polarized Calu-3 monolayers was 12% (w/w)
vs 2% (w/w) for that with 25 PEGs. Polarization is also shown to be
of great relevance in studying this in vitro model
of the lung epithelium. The rate of absorption of DNCs administered
to mice lungs increased dramatically when conjugated with 25 PEG groups,
thus supporting the in vitro results. The exposure
obtained for the DNC with 25PEG was determined to be very high, with
peak plasma concentrations reaching 5 μg·mL–1 within 3 h. The combined in vitro and in
vivo results shown here demonstrate that PEGylation can be
potentially used to modulate the internalization and transport of
DNCs across the pulmonary epithelium. Modified dendrimers thereby
may serve as a valuable platform that can be tailored to target the
lung tissue for treating local diseases, or the circulation, using
the lung as pathway to the bloodstream, for systemic delivery.
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Affiliation(s)
- Balaji Bharatwaj
- Department of Chemical Engineering and Materials Science, and ‡Department of Pharmaceutical Sciences, Wayne State University , Detroit, Michigan 48202, United States
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13
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Gao X, Qian J, Zheng S, Changyi Y, Zhang J, Ju S, Zhu J, Li C. Overcoming the blood-brain barrier for delivering drugs into the brain by using adenosine receptor nanoagonist. ACS NANO 2014; 8:3678-89. [PMID: 24673594 DOI: 10.1021/nn5003375] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The extremely low permeability of the blood-brain barrier (BBB) poses the greatest impediment in the treatment of central nervous system (CNS) diseases. Recent work indicated that BBB permeability can be up-regulated by activating A2A adenosine receptor (AR), which temporarily increases intercellular spaces between the brain capillary endothelial cells. However, due to transient circulation lifetime of adenosine-based agonists, their capability to enhance brain delivery of drugs, especially macromolecular drugs, is limited. In this work, a series of nanoagonists (NAs) were developed by labeling different copies of A2A AR activating ligands on dendrimers. In vitro transendothelial electrical resistance measurements demonstrated that the NAs increased permeability of the endothelial cell monolayer by compromising the tightness of tight junctions, the key structure that restricts the entry of blood-borne molecules into the brain. In vivo imaging studies indicated the remarkably up-regulated brain uptake of a macromolecular model drug (45 kDa) after intravenous injection of NAs. Autoradiographic imaging showed that the BBB opening time-window can be tuned in a range of 0.5-2.0 h by the NAs labeled with different numbers of AR-activating ligands. By choosing a suitable NA, it is possible to maximize brain drug delivery and minimize the uncontrollable BBB leakage by matching the BBB opening time-window with the pharmacokinetics of a therapeutic agent. The NA-mediated brain drug delivery strategy holds promise for the treatment of CNS diseases with improved therapeutic efficiency and reduced side-effects.
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Affiliation(s)
- Xihui Gao
- Key Laboratory of Smart Drug Delivery, Ministry of Education, School of Pharmacy, Fudan University , 826 Zhangheng Road, Shanghai 201203, China
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Jain V, Bharatam PV. Pharmacoinformatic approaches to understand complexation of dendrimeric nanoparticles with drugs. NANOSCALE 2014; 6:2476-2501. [PMID: 24441940 DOI: 10.1039/c3nr05400d] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Nanoparticle based drug delivery systems are gaining popularity due to their wide spectrum advantages over traditional drug delivery systems; among them, dendrimeric nano-vectors are the most widely explored carriers for pharmaceutical and biomedical applications. The precise mechanism of encapsulation of drug molecules inside the dendritic matrix, delivery of drugs into specific cells, interactions of nano-formulation with biological targets and proteins, etc. present a substantial challenge to the scientific understanding of the subject. Computational methods complement experimental techniques in the design and optimization of drug delivery systems, thus minimizing the investment in drug design and development. Significant progress in computer simulations could facilitate an understanding of the precise mechanism of encapsulation of bioactive molecules and their delivery. This review summarizes the pharmacoinformatic studies spanning from quantum chemical calculations to coarse-grained simulations, aimed at providing better insight into dendrimer-drug interactions and the physicochemical parameters influencing the binding and release mechanism of drugs.
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Affiliation(s)
- Vaibhav Jain
- Department of Medicinal Chemistry, Department of Pharmacoinformatics, National Institute of Pharmaceutical Education and Research, Sector 67, S.A.S. Nagar, Punjab 160 062, India.
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15
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Molecular simulation study of PAMAM dendrimer composite membranes. J Mol Model 2014; 20:2119. [DOI: 10.1007/s00894-014-2119-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Accepted: 12/14/2013] [Indexed: 01/20/2023]
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16
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Ilinskaya AN, Dobrovolskaia MA. Nanoparticles and the blood coagulation system. Part I: benefits of nanotechnology. Nanomedicine (Lond) 2013; 8:773-84. [PMID: 23656264 DOI: 10.2217/nnm.13.48] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Nanotechnology is proven to provide certain benefits in drug delivery by improving solubility, increasing uptake to target sites and changing pharmacokinetics profiles of traditional drugs. Since properties of many materials change tremendously at the nanoscale levels, nanotechnology is also being explored in various industrial applications. As such, nanoparticles are rapidly entering various areas of industry, biology and medicine. The benefits of using nanotechnology for industrial and biomedical applications are often tempered by concerns about the safety of these new materials. One such area of concern includes their effect on the immune system. While nanoparticle interactions with various constituents of the immune system have been reviewed before, little attention was given to nanoparticle effects on the blood coagulation system. Nanoparticle interface with the blood coagulation system may lead to either benefits to the host or adverse reactions. This article reviews recent advances in our understanding of nanoparticle interactions with plasma coagulation factors, platelets, endothelial cells and leukocytes. Part I is focused on desirable interactions between nanoparticles and the coagulation system, and discusses benefits of using nanotechnology to intervene in coagulation disorders. Undesirable interactions posing safety concerns are covered in part II, which will be published in the June issue of Nanomedicine.
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Affiliation(s)
- Anna N Ilinskaya
- Nanotechnology Characterization Laboratory, Advanced Technology Program, SAIC-Frederick Inc., NCI-Frederick, 1050 Boyles Street, Building 469, Frederick, MD 21702, USA
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Ziemba B, Halets I, Shcharbin D, Appelhans D, Voit B, Pieszynski I, Bryszewska M, Klajnert B. Influence of fourth generation poly(propyleneimine) dendrimers on blood cells. J Biomed Mater Res A 2012; 100:2870-80. [DOI: 10.1002/jbm.a.34222] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2012] [Revised: 04/03/2012] [Accepted: 04/05/2012] [Indexed: 02/01/2023]
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18
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Tosh DK, Phan K, Deflorian F, Wei Q, Yoo LS, Gao ZG, Jacobson KA. Click modification in the N6 region of A3 adenosine receptor-selective carbocyclic nucleosides for dendrimeric tethering that preserves pharmacophore recognition. Bioconjug Chem 2012; 23:232-47. [PMID: 22175234 PMCID: PMC3291892 DOI: 10.1021/bc200526c] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Adenosine derivatives were modified with alkynyl groups on N(6) substituents for linkage to carriers using Cu(I)-catalyzed click chemistry. Two parallel series, both containing a rigid North-methanocarba (bicyclo[3.1.0]hexane) ring system in place of ribose, behaved as A(3) adenosine receptor (AR) agonists: (5'-methyluronamides) or partial agonists (4'-truncated). Terminal alkynyl groups on a chain at the 3 position of a N(6)-benzyl group or simply through a N(6)-propargyl group were coupled to azido derivatives, which included both small molecules and G4 (fourth-generation) multivalent poly(amidoamine) (PAMAM) dendrimers, to form 1,2,3-triazolyl linkers. The small molecular triazoles probed the tolerance in A(3)AR binding of distal, sterically bulky groups such as 1-adamantyl. Terminal 4-fluoro-3-nitrophenyl groups anticipated nucleophilic substitution for chain extension and (18)F radiolabeling. N(6)-(4-Fluoro-3-nitrophenyl)-triazolylmethyl derivative 32 displayed a K(i) of 9.1 nM at A(3)AR with ∼1000-fold subtype selectivity. Multivalent conjugates additionally containing click-linked water-solubilizing polyethylene glycol groups potently activated A(3)AR in the 5'-methyluronamide, but not 4' truncated series. N(6)-Benzyl nucleoside conjugate 43 (apparent K(i) 24 nM) maintained binding affinity of the monomer better than a N(6)-triazolylmethyl derivative. Thus, the N(6) region of 5'-methyluronamide derivatives, as modeled in receptor docking, is suitable for functionalization and tethering by click chemistry to achieve high A(3)AR agonist affinity and enhanced selectivity.
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Affiliation(s)
- Dilip K. Tosh
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Khai Phan
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Francesca Deflorian
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Qiang Wei
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Lena S. Yoo
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, 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, Maryland 20892, 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, Maryland 20892, USA
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19
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Chanyshev B, Shainberg A, Isak A, Litinsky A, Chepurko Y, Tosh DK, Phan K, Gao ZG, Hochhauser E, Jacobson KA. Anti-ischemic effects of multivalent dendrimeric A₃ adenosine receptor agonists in cultured cardiomyocytes and in the isolated rat heart. Pharmacol Res 2011; 65:338-46. [PMID: 22154845 DOI: 10.1016/j.phrs.2011.11.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Revised: 11/21/2011] [Accepted: 11/22/2011] [Indexed: 12/28/2022]
Abstract
Adenosine released during myocardial ischemia mediates cardioprotective preconditioning. Multivalent drugs covalently bound to nanocarriers may differ greatly in chemical and biological properties from the corresponding monomeric agents. Here, we conjugated chemically functionalized nucleosides to poly(amidoamine) (PAMAM) dendrimeric polymers and investigated their effects in rat primary cardiac cell cultures and in the isolated heart. Three conjugates of A₃ adenosine receptor (AR) agonists, chain-functionalized at the C2 or N⁶ position, were cardioprotective, with greater potency than monomeric agonist Cl-IB-MECA. Multivalent amide-linked MRS5216 was selective for A₁ and A₃ARs, and triazole-linked MRS5246 and MRS5539 (optionally containing fluorescent label) were A₃AR-selective. The conjugates protected ischemic rat cardiomyocytes, an effect blocked by an A₃AR antagonist MRS1523, and isolated hearts with significantly improved infarct size, rate of pressure product, and rate of contraction and relaxation. Thus, strategically derivatized nucleosides tethered to biocompatible polymeric carriers display enhanced cardioprotective potency via activation of A₃AR on the cardiomyocyte surface.
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Affiliation(s)
- Bella Chanyshev
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
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20
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Enhanced chiral recognition by cyclodextrin dimers. Int J Mol Sci 2011; 12:4637-46. [PMID: 21845101 PMCID: PMC3155374 DOI: 10.3390/ijms12074637] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Revised: 07/07/2011] [Accepted: 07/08/2011] [Indexed: 12/22/2022] Open
Abstract
In this article we investigate the effect of multivalency in chiral recognition. To this end, we measured the host-guest interaction of a β-cyclodextrin dimer with divalent chiral guests. We report the synthesis of carbohydrate-based water soluble chiral guests functionalized with two borneol, menthol, or isopinocampheol units in either (+) or (−) configuration. We determined the interaction of these divalent guests with a β-cyclodextrin dimer using isothermal titration calorimetry. It was found that—in spite of a highly unfavorable conformation—the cyclodextrin dimer binds to guest dimers with an increased enantioselectivity, which clearly reflects the effect of multivalency.
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21
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Kecskés A, Tosh DK, Wei Q, Gao ZG, Jacobson KA. GPCR ligand dendrimer (GLiDe) conjugates: adenosine receptor interactions of a series of multivalent xanthine antagonists. Bioconjug Chem 2011; 22:1115-27. [PMID: 21539392 DOI: 10.1021/bc1005812] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Previously, G protein-coupled receptor (GPCR) agonists were tethered from polyamidoamine (PAMAM) dendrimers to provide high receptor affinity and selectivity. Here, we prepared GPCR ligand--dendrimer (GLiDe) conjugates from a potent adenosine receptor (AR) antagonist; such agents are of interest for treating Parkinson's disease, asthma, and other conditions. Xanthine amine congener (XAC) was appended with an alkyne group on an extended C8 substituent for coupling by Cu(I)-catalyzed click chemistry to azide-derivatized G4 (fourth-generation) PAMAM dendrimers to form triazoles. These conjugates also contained triazole-linked PEG groups (8 or 22 moieties per 64 terminal positions) for increasing water-solubility and optionally prosthetic groups for spectroscopic characterization and affinity labeling. Human AR binding affinity increased progressively with the degree of xanthine substitution to reach K(i) values in the nanomolar range. The order of affinity of each conjugate was hA(2A)AR > hA(3)AR > hA(1)AR, while the corresponding monomer was ranked hA(2A)AR > hA(1)AR ≥ hA(3)AR. The antagonist activity of the most potent conjugate 14 (34 xanthines per dendrimer) was examined at the G(i)-coupled A(1)AR. Conjugate 14 at 100 nM right-shifted the AR agonist concentration--response curve in a cyclic AMP functional assay in a parallel manner, but at 10 nM (lower than its K(i) value), it significantly suppressed the maximal agonist effect in calcium mobilization. This is the first systematic probing of a potent AR antagonist tethered on a dendrimer and its activity as a function of variable loading.
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Affiliation(s)
- Angela Kecskés
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, United States
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22
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Chen JF, Chern Y. Impacts of methylxanthines and adenosine receptors on neurodegeneration: human and experimental studies. Handb Exp Pharmacol 2011:267-310. [PMID: 20859800 DOI: 10.1007/978-3-642-13443-2_10] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Neurodegenerative disorders are some of the most feared illnesses in modern society, with no effective treatments to slow or halt this neurodegeneration. Several decades after the earliest attempt to treat Parkinson's disease using caffeine, tremendous amounts of information regarding the potential beneficial effect of caffeine as well as adenosine drugs on major neurodegenerative disorders have accumulated. In the first part of this review, we provide general background on the adenosine receptor signaling systems by which caffeine and methylxanthine modulate brain activity and their role in relationship to the development and treatment of neurodegenerative disorders. The demonstration of close interaction between adenosine receptor and other G protein coupled receptors and accessory proteins might offer distinct pharmacological properties from adenosine receptor monomers. This is followed by an outline of the major mechanism underlying neuroprotection against neurodegeneration offered by caffeine and adenosine receptor agents. In the second part, we discuss the current understanding of caffeine/methylxantheine and its major target adenosine receptors in development of individual neurodegenerative disorders, including stroke, traumatic brain injury Alzheimer's disease, Parkinson's disease, Huntington's disease and multiple sclerosis. The exciting findings to date include the specific in vivo functions of adenosine receptors revealed by genetic mouse models, the demonstration of a broad spectrum of neuroprotection by chronic treatment of caffeine and adenosine receptor ligands in animal models of neurodegenerative disorders, the encouraging development of several A(2A) receptor selective antagonists which are now in advanced clinical phase III trials for Parkinson's disease. Importantly, increasing body of the human and experimental studies reveals encouraging evidence that regular human consumption of caffeine in fact may have several beneficial effects on neurodegenerative disorders, from motor stimulation to cognitive enhancement to potential neuroprotection. Thus, with regard to neurodegenerative disorders, these potential benefits of methylxanthines, caffeine in particular, strongly argue against the common practice by clinicians to discourage regular human consumption of caffeine in aging populations.
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Affiliation(s)
- Jiang-Fan Chen
- Department of Neurology, Boston University School of Medicine, Boston, MA, USA.
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de Castro S, Maruoka H, Hong K, Kilbey SM, Costanzi S, Hechler B, Brown GG, Gachet C, Harden TK, Jacobson KA. Functionalized congeners of P2Y1 receptor antagonists: 2-alkynyl (N)-methanocarba 2'-deoxyadenosine 3',5'-bisphosphate analogues and conjugation to a polyamidoamine (PAMAM) dendrimer carrier. Bioconjug Chem 2010; 21:1190-205. [PMID: 20565071 DOI: 10.1021/bc900569u] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The P2Y(1) receptor is a prothrombotic G protein-coupled receptor (GPCR) activated by ADP. Preference for the North (N) ring conformation of the ribose moiety of adenine nucleotide 3',5'-bisphosphate antagonists of the P2Y(1) receptor was established by using a ring-constrained methanocarba (a bicyclo[3.1.0]hexane) ring as a ribose substitute. A series of covalently linkable N(6)-methyl-(N)-methanocarba-2'-deoxyadenosine-3',5'-bisphosphates containing extended 2-alkynyl chains was designed, and binding affinity at the human (h) P2Y(1) receptor determined. The chain of these functionalized congeners contained hydrophilic moieties, a reactive substituent, or biotin, linked via an amide. Variation of the chain length and position of an intermediate amide group revealed high affinity of carboxylic congener 8 (K(i) 23 nM) and extended amine congener 15 (K(i) 132 nM), both having a 2-(1-pentynoyl) group. A biotin conjugate 18 containing an extended epsilon-aminocaproyl spacer chain exhibited higher affinity than a shorter biotinylated analogue. Alternatively, click coupling of terminal alkynes of homologous 2-dialkynyl nucleotide derivatives to alkyl azido groups produced triazole derivatives that bound to the P2Y(1) receptor following deprotection of the bisphosphate groups. The preservation of receptor affinity of the functionalized congeners was consistent with new P2Y(1) receptor modeling and ligand docking. Attempted P2Y(1) antagonist conjugation to PAMAM dendrimer carriers by amide formation or palladium-catalyzed reaction between an alkyne on the dendrimer and a 2-iodopurine-derivatized nucleotide was unsuccessful. A dialkynyl intermediate containing the chain length favored in receptor binding was conjugated to an azide-derivatized dendrimer, and the conjugate inhibited ADP-promoted human platelet aggregation. This is the first example of attaching a strategically functionalized P2Y receptor antagonist to a PAMAM dendrimer to produce a multivalent conjugate exhibiting a desired biological effect, i.e., antithrombotic action.
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Affiliation(s)
- Sonia de Castro
- Molecular Recognition Section and Laboratory of Biological Modeling, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, Maryland, 20892-0810, USA
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24
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Jacobson KA. GPCR ligand-dendrimer (GLiDe) conjugates: future smart drugs? Trends Pharmacol Sci 2010; 31:575-9. [PMID: 20961625 DOI: 10.1016/j.tips.2010.09.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Revised: 09/15/2010] [Accepted: 09/16/2010] [Indexed: 10/18/2022]
Abstract
Unlike nanocarriers that are intended to release their drug cargo at the site of action, biocompatibile polyamidoamine (PAMAM) conjugates are designed to act at cell surface G protein-coupled receptors (GPCRs) without drug release. These multivalent GPCR ligand-dendrimer (GLiDe) conjugates display qualitatively different pharmacological properties in comparison with monomeric drugs. They might be useful as novel tools to study GPCR homodimers and heterodimers as well as higher aggregates. The structure of the conjugate determines the profile of biological activity, receptor selectivity, and physical properties such as water solubility. Prosthetic groups for characterization and imaging of receptors can be introduced without loss of affinity. The feasibility of targeting multiple adenosine and P2Y receptors for synergistic effects has been shown. Testing in vivo will be needed to explore the effects on pharmacokinetics and tissue targeting.
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Affiliation(s)
- Kenneth A Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes, Digestive and Kidney Diseases, NIH, Bethesda, MD 20892, USA.
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Shi Q, Zhong S, Chen Y, Whitaker A. Photo-crosslinking copolymers based polyanhydride and 1G polyamidoamine-methacrylamide as bone tissue engineering: Synthesis, characterization, and in vitro degradation. Polym Degrad Stab 2010. [DOI: 10.1016/j.polymdegradstab.2010.07.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Keene AM, Balasubramanian R, Lloyd J, Shainberg A, Jacobson KA. Multivalent dendrimeric and monomeric adenosine agonists attenuate cell death in HL-1 mouse cardiomyocytes expressing the A(3) receptor. Biochem Pharmacol 2010; 80:188-96. [PMID: 20346920 PMCID: PMC2880883 DOI: 10.1016/j.bcp.2010.03.020] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2010] [Revised: 03/15/2010] [Accepted: 03/16/2010] [Indexed: 11/15/2022]
Abstract
Multivalent dendrimeric conjugates of GPCR ligands may have increased potency or selectivity in comparison to monomeric ligands, a phenomenon that was tested in a model of cytoprotection in mouse HL-1 cardiomyocytes. Quantitative RT-PCR indicated high expression levels of endogenous A(1) and A(2A) adenosine receptors (ARs), but not of A(2B) and A(3)ARs. Activation of the heterologously expressed human A(3)AR in HL-1 cells by AR agonists significantly attenuated cell damage following 4h exposure to H(2)O(2) (750 microM) but not in untransfected cells. The A(3) agonist IB-MECA (EC(50) 3.8 microM) and the non-selective agonist NECA (EC(50) 3.9 microM) protected A(3) AR-transfected cells against H(2)O(2) in a concentration-dependent manner, as determined by lactate dehydrogenase release. A generation 5.5 PAMAM (polyamidoamine) dendrimeric conjugate of a N(6)-chain-functionalized adenosine agonist was synthesized and its mass indicated an average of 60 amide-linked nucleoside moieties out of 256 theoretical attachment sites. It non-selectively activated the A(3)AR to inhibit forskolin-stimulated cAMP formation (IC(50) 66nM) and, similarly, protected A(3)-transfected HL-1 cells from apoptosis-inducing H(2)O(2) with greater potency (IC(50) 35nM) than monomeric nucleosides. Thus, a PAMAM conjugate retained AR binding affinity and displayed greatly enhanced cardioprotective potency.
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Affiliation(s)
- Athena M. Keene
- 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
| | - Ramachandran Balasubramanian
- 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
| | - John Lloyd
- Mass Spectrometry Facility, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0810 USA
| | - Asher Shainberg
- Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Kenneth A. Jacobson
- 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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Das A, Sanjayan GJ, Kecskés M, Yoo L, Gao ZG, Jacobson KA. Nucleoside conjugates of quantum dots for characterization of G protein-coupled receptors: strategies for immobilizing A2A adenosine receptor agonists. J Nanobiotechnology 2010; 8:11. [PMID: 20478037 PMCID: PMC2883535 DOI: 10.1186/1477-3155-8-11] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2010] [Accepted: 05/17/2010] [Indexed: 01/19/2023] Open
Abstract
Background Quantum dots (QDs) are crystalline nanoparticles that are compatible with biological systems to provide a chemically and photochemically stable fluorescent label. New ligand probes with fluorescent reporter groups are needed for detection and characterization of G protein-coupled receptors (GPCRs). Results Synthetic strategies for coupling the A2A adenosine receptor (AR) agonist CGS21680 (2-[4-(2-carboxyethyl)phenylethylamino]-5'-N-ethylcarboxamidoadenosine) to functionalized QDs were explored. Conjugates tethered through amide-linked chains and poly(ethyleneglycol) (PEG) displayed low solubility and lacked receptor affinity. The anchor to the dendron was either through two thiol groups of (R)-thioctic acid or through amide formation to a commercial carboxy-derivatized QD. The most effective approach was to use polyamidoamine (PAMAM) D5 dendrons as multivalent spacer groups, grafted on the QD surface through a thioctic acid moiety. In radioligand binding assays, dendron nucleoside conjugate 11 displayed a moderate affinity at the human A2AAR (Kiapp 1.02 ± 0.15 μM). The QD conjugate of increased water solubility 13, resulting from the anchoring of this dendron derivative, interacted with the receptor with Kiapp of 118 ± 54 nM. The fluorescence emission of 13 occurred at 565 nm, and the presence of the pendant nucleoside did not appreciably quench the fluorescence. Conclusions This is a feasibility study to demonstrate a means of conjugating to a QD a small molecular pharmacophore of a GPCR that is relatively hydrophobic. Further enhancement of affinity by altering the pharmacophore or the linking structures will be needed to make useful affinity probes.
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Affiliation(s)
- Arijit Das
- 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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Tosh DK, Yoo LS, Chinn M, Hong K, Kilbey SM, Barrett MO, Fricks IP, Harden TK, Gao ZG, Jacobson KA. Polyamidoamine (PAMAM) dendrimer conjugates of "clickable" agonists of the A3 adenosine receptor and coactivation of the P2Y14 receptor by a tethered nucleotide. Bioconjug Chem 2010; 21:372-84. [PMID: 20121074 PMCID: PMC2845915 DOI: 10.1021/bc900473v] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
We previously synthesized a series of potent and selective A(3) adenosine receptor (AR) agonists (North-methanocarba nucleoside 5'-uronamides) containing dialkyne groups on extended adenine C2 substituents. We coupled the distal alkyne of a 2-octadiynyl nucleoside by Cu(I)-catalyzed "click" chemistry to azide-derivatized G4 (fourth-generation) PAMAM dendrimers to form triazoles. A(3)AR activation was preserved in these multivalent conjugates, which bound with apparent K(i) of 0.1-0.3 nM. They were substituted with nucleoside moieties, solely or in combination with water-solubilizing carboxylic acid groups derived from hexynoic acid. A comparison with various amide-linked dendrimers showed that triazole-linked conjugates displayed selectivity and enhanced A(3)AR affinity. We prepared a PAMAM dendrimer containing equiproportioned peripheral azido and amino groups for conjugation of multiple ligands. A bifunctional conjugate activated both A(3) and P2Y(14) receptors (via amide-linked uridine-5'-diphosphoglucuronic acid), with selectivity in comparison to other ARs and P2Y receptors. This is the first example of targeting two different GPCRs with the same dendrimer conjugate, which is intended for activation of heteromeric GPCR aggregates. Synergistic effects of activating multiple GPCRs with a single dendrimer conjugate might be useful in disease treatment.
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Affiliation(s)
- Dilip K. Tosh
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892
| | - Lena S. Yoo
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892
| | - Moshe Chinn
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892
| | - Kunlun Hong
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
| | - S. Michael Kilbey
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
| | - Matthew O. Barrett
- Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, NC 27599
| | - Ingrid P. Fricks
- Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, NC 27599
| | - T. Kendall Harden
- Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, NC 27599
| | - 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
| | - Kenneth A. Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892
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Lempens EHM, Helms BA, Bayles AR, Merkx M, Meijer EW. A Versatile, Modular Platform for Multivalent Peptide Ligands Based on a Dendritic Wedge. European J Org Chem 2009. [DOI: 10.1002/ejoc.200901045] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Kim Y, Hechler B, Gao ZG, Gachet C, Jacobson KA. PEGylated dendritic unimolecular micelles as versatile carriers for ligands of G protein-coupled receptors. Bioconjug Chem 2009; 20:1888-98. [PMID: 19785401 DOI: 10.1021/bc9001689] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Despite its widespread application in nanomedicine, poly(ethylene glycol) (PEG) is seldom used for covalent modification of ligands for G protein-coupled receptors (GPCRs) due to potential steric complications. In order to study the influence of PEG chains on the biological activity of GPCR ligands bound to a common macromolecular carrier, we prepared a series of G3 polyamidoamine (PAMAM) dendrimers derivatized with Alexa Fluor 488, varying numbers of PEG(550)/PEG(750)/PEG(2000), and nucleoside moieties derived from the A(2A) adenosine receptor (AR) agonist CGS21680 (2-[4-(2-carboxylethyl)phenylethylamino]-5'-N-ethylcarboxamidoadenosine). These dendrimer conjugates were purified by size exclusion chromatography and characterized by (1)H NMR and MALDI MS. In radioligand binding assays, some PAMAM-PEG conjugates showed enhanced subtype-selectivity at the human A(2A) AR compared to monomeric ligands of comparable affinity. The functional potency was measured in the A(2A) AR-mediated activation of adenylate cyclase and inhibition of ADP-induced platelet aggregation. Interestingly, the dendrimer conjugate 10c bearing 11 PEG(750) chains (out of theoretical 32 amino end groups) and 14 nucleoside moieties was 5-fold more potent in A(2A) AR-mediated stimulation of cyclic AMP formation than 10d with 4 PEG(2000) chains and 21 nucleosides, although the binding affinities of these 2 compounds were similar. Thus, a relatively small (≤10 nm) multivalent ligand 10c modified for water solubility maintained high potency and displayed increased A(2A) AR binding selectivity over the monomeric nucleosides. The current study demonstrates the feasibility of using short PEG chains in the design of carriers that target ligand-receptor interactions.
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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, MD 20892, USA
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van Dongen SFM, de Hoog HPM, Peters RJRW, Nallani M, Nolte RJM, van Hest JCM. Biohybrid Polymer Capsules. Chem Rev 2009; 109:6212-74. [DOI: 10.1021/cr900072y] [Citation(s) in RCA: 357] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Stijn F. M. van Dongen
- Department of Organic Chemistry, Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525AJ Nijmegen, The Netherlands, and Institute of Materials Research & Engineering (IMRE), Research Link 3, Singapore 117602, Singapore
| | - Hans-Peter M. de Hoog
- Department of Organic Chemistry, Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525AJ Nijmegen, The Netherlands, and Institute of Materials Research & Engineering (IMRE), Research Link 3, Singapore 117602, Singapore
| | - Ruud J. R. W. Peters
- Department of Organic Chemistry, Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525AJ Nijmegen, The Netherlands, and Institute of Materials Research & Engineering (IMRE), Research Link 3, Singapore 117602, Singapore
| | - Madhavan Nallani
- Department of Organic Chemistry, Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525AJ Nijmegen, The Netherlands, and Institute of Materials Research & Engineering (IMRE), Research Link 3, Singapore 117602, Singapore
| | - Roeland J. M. Nolte
- Department of Organic Chemistry, Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525AJ Nijmegen, The Netherlands, and Institute of Materials Research & Engineering (IMRE), Research Link 3, Singapore 117602, Singapore
| | - Jan C. M. van Hest
- Department of Organic Chemistry, Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525AJ Nijmegen, The Netherlands, and Institute of Materials Research & Engineering (IMRE), Research Link 3, Singapore 117602, Singapore
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Das A, Zhou Y, Ivanov AA, Carter RL, Harden TK, Jacobson KA. Enhanced potency of nucleotide-dendrimer conjugates as agonists of the P2Y14 receptor: multivalent effect in G protein-coupled receptor recognition. Bioconjug Chem 2009; 20:1650-9. [PMID: 19572637 DOI: 10.1021/bc900206g] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The P2Y(14) receptor is a G protein-coupled receptor activated by uridine-5'-diphosphoglucose and other nucleotide sugars that modulates immune function. Covalent conjugation of P2Y(14) receptor agonists to PAMAM (polyamidoamine) dendrimers enhanced pharmacological activity. Uridine-5'-diphosphoglucuronic acid (UDPGA) and its ethylenediamine adduct were suitable functionalized congeners for coupling to several generations (G2.5-6) of dendrimers (both terminal carboxy and amino). Prosthetic groups, including biotin for avidin complexation, a chelating group for metal complexation (and eventual magnetic resonance imaging), and a fluorescent moiety, also were attached with the eventual goals of molecular detection and characterization of the P2Y(14) receptor. The activities of conjugates were assayed in HEK293 cells stably expressing the human P2Y(14) receptor. A G3 PAMAM conjugate containing 20 bound nucleotide moieties (UDPGA) was 100-fold more potent (EC(50) 2.4 nM) than the native agonist uridine-5'-diphosphoglucose. A molecular model of this conjugate docked in the human P2Y(14) receptor showed that the nucleotide-substituted branches could extend far beyond the dimensions of the receptor and be available for multivalent docking to receptor aggregates. Larger dendrimer carriers and greater loading favored higher potency. A similar conjugate of G6 with 147 out of 256 amino groups substituted with UDPGA displayed an EC(50) value of 0.8 nM. Thus, biological activity was either retained or dramatically enhanced in the multivalent dendrimer conjugates in comparison with monomeric P2Y(14) receptor agonists, depending on size, degree of substitution, terminal functionality, and attached prosthetic groups.
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Affiliation(s)
- Arijit Das
- 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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Jacobson KA. Functionalized congener approach to the design of ligands for G protein-coupled receptors (GPCRs). Bioconjug Chem 2009; 20:1816-35. [PMID: 19405524 DOI: 10.1021/bc9000596] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Functionalized congeners, in which a chemically functionalized chain is incorporated at an insensitive site on a pharmacophore, have been designed from the agonist and antagonist ligands of various G protein-coupled receptors (GPCRs). These chain extensions enable a conjugation strategy for detecting and characterizing GPCR structure and function and pharmacological modulation. The focus in many studies of functionalized congeners has been on two families of GPCRs: those responding to extracellular purines and pyrimidines-i.e., adenosine receptors (ARs) and P2Y nucleotide receptors. Functionalized congeners of small molecule as ligands for other GPCRs and non-G protein coupled receptors have also been designed. For example, among biogenic amine neurotransmitter receptors, muscarinic acetylcholine receptor antagonists and adrenergic receptor ligands have been studied with a functionalized congener approach. Adenosine A(1), A(2A), and A(3) receptor functionalized congeners have yielded macromolecular conjugates, irreversibly binding AR ligands for receptor inactivation and cross-linking, radioactive probes that use prosthetic groups, immobilized ligands for affinity chromatography, and dual-acting ligands that function as binary drugs. Poly(amidoamine) dendrimers have served as nanocarriers for covalently conjugated AR functionalized congeners. Rational methods of ligand design derived from molecular modeling and templates have been included in these studies. Thus, the design of novel ligands, both small molecules and macromolecular conjugates, for studying the chemical and biological properties of GPCRs have been developed with this approach, has provided researchers with a strategy that is more versatile than the classical medicinal chemical approaches.
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Affiliation(s)
- Kenneth A Jacobson
- Molecular Recognition Section, National Institute of Diabetes & Digestive & Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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Abstract
Adenosine acts as a cytoprotective modulator in response to stress to an organ or tissue. Although short-lived in the circulation, it can activate four subtypes of G protein-coupled adenosine receptors (ARs): A(1), A(2A), A(2B), and A(3). The alkylxanthines caffeine and theophylline are the prototypical antagonists of ARs, and their stimulant actions occur primarily through this mechanism. For each of the four AR subtypes, selective agonists and antagonists have been introduced and used to develop new therapeutic drug concepts. ARs are notable among the GPCR family in the number and variety of agonist therapeutic candidates that have been proposed. The selective and potent synthetic AR agonists, which are typically much longer lasting in the body than adenosine, have potential therapeutic applications based on their anti-inflammatory (A(2A) and A(3)), cardioprotective (preconditioning by A(1) and A(3) and postconditioning by A(2B)), cerebroprotective (A(1) and A(3)), and antinociceptive (A(1)) properties. Potent and selective AR antagonists display therapeutic potential as kidney protective (A(1)), antifibrotic (A(2A)), neuroprotective (A(2A)), and antiglaucoma (A(3)) agents. AR agonists for cardiac imaging and positron-emitting AR antagonists are in development for diagnostic applications. Allosteric modulators of A(1) and A(3) ARs have been described. In addition to the use of selective agonists/antagonists as pharmacological tools, mouse strains in which an AR has been genetically deleted have aided in developing novel drug concepts based on the modulation of ARs.
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Affiliation(s)
- Kenneth A Jacobson
- Molecular Recognition Section, Laboratory of Biooorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0810, USA.
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Klutz AM, Gao ZG, Lloyd J, Shainberg A, Jacobson KA. Enhanced A3 adenosine receptor selectivity of multivalent nucleoside-dendrimer conjugates. J Nanobiotechnology 2008; 6:12. [PMID: 18947419 PMCID: PMC2582240 DOI: 10.1186/1477-3155-6-12] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2008] [Accepted: 10/23/2008] [Indexed: 11/18/2022] Open
Abstract
Background An approach to use multivalent dendrimer carriers for delivery of nucleoside signaling molecules to their cell surface G protein-coupled receptors (GPCRs) was recently introduced. Results A known adenosine receptor (AR) agonist was conjugated to polyamidoamine (PAMAM) dendrimer carriers for delivery of the intact covalent conjugate to on the cell surface. Depending on the linking moiety, multivalent conjugates of the N6-chain elongated functionalized congener ADAC (N6-[4-[[[4-[[[(2-aminoethyl)amino]carbonyl]methyl]anilino]carbonyl]methyl]phenyl]-adenosine) achieved unanticipated high selectivity in binding to the cytoprotective human A3 AR, a class A GPCR. The key to this selectivity of > 100-fold in both radioreceptor binding (Ki app = 2.4 nM) and functional assays (EC50 = 1.6 nM in inhibition of adenylate cyclase) was maintaining a free amino group (secondary) in an amide-linked chain. Attachment of neutral amide-linked chains or thiourea-containing chains preserved the moderate affinity and efficacy at the A1 AR subtype, but there was no selectivity for the A3 AR. Since residual amino groups on dendrimers are associated with cytotoxicity, the unreacted terminal positions of this A3 AR-selective G2.5 dendrimer were present as carboxylate groups, which had the further benefit of increasing water-solubility. The A3 AR selective G2.5 dendrimer was also visualized binding the membrane of cells expressing the A3 receptor but did not bind cells that did not express the receptor. Conclusion This is the first example showing that it is feasible to modulate and even enhance the pharmacological profile of a ligand of a GPCR based on conjugation to a nanocarrier and the precise structure of the linking group, which was designed to interact with distal extracellular regions of the 7 transmembrane-spanning receptor. This ligand tool can now be used in pharmacological models of tissue rescue from ischemia and to probe the existence of A3 AR dimers.
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Affiliation(s)
- Athena M Klutz
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland 20892, USA.
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Kim Y, Klutz AM, Jacobson KA. Systematic investigation of polyamidoamine dendrimers surface-modified with poly(ethylene glycol) for drug delivery applications: synthesis, characterization, and evaluation of cytotoxicity. Bioconjug Chem 2008; 19:1660-72. [PMID: 18610944 DOI: 10.1021/bc700483s] [Citation(s) in RCA: 142] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Surface modification of amine-terminated polyamidoamine (PAMAM) dendrimers by poly(ethylene glycol) (PEG) groups generally enhances water-solubility and biocompatibility for drug delivery applications. In order to provide guidelines for designing appropriate dendritic scaffolds, a series of G3 PAMAM-PEG dendrimer conjugates was synthesized by varying the number of PEG attachments and chain length (shorter PEG 550 and PEG 750 and longer PEG 2000). Each conjugate was purified by size exclusion chromatography (SEC) and the molecular weight (MW) was determined by (1)H NMR integration and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). NOESY experiments performed in D 2O on selected structures suggested no penetration of PEG chains to the central PAMAM domain, regardless of chain length and degree of substitution. CHO cell cultures exposed to PAMAM-PEG derivatives (< or =1 microM) showed a relatively high cell viability. Generally, increasing the degree of PEG substitution reduced cytotoxicity. Moreover, compared to G3 PAMAM dendrimers that were N-acetylated to varying degrees, a lower degree of surface substitution with PEG was needed for a similar cell viability. Interestingly, when longer PEG 2000 was fully incorporated on the surface, cell viability was reduced at higher concentrations (32 muM), suggesting increased toxicity potentially by forming intermolecular aggregates. A similar observation was made for anionic carboxylate G5.5 PAMAM dendrimer at the same dendrimer concentration. Our findings suggest that a lower degree of peripheral substitution with shorter PEG chains may suffice for these PAMAM-PEG conjugates to serve as efficient universal scaffolds for drug delivery, particularly valuable in relation to targeting or other ligand-receptor interactions.
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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,
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Kim Y, Klutz AM, Hechler B, Gao ZG, Gachet C, Jacobson KA. Application of the functionalized congener approach to dendrimer-based signaling agents acting through A(2A) adenosine receptors. Purinergic Signal 2008; 5:39-50. [PMID: 18600474 PMCID: PMC2721767 DOI: 10.1007/s11302-008-9113-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2008] [Accepted: 04/30/2008] [Indexed: 11/01/2022] Open
Abstract
As a continued effort to develop multivalent ligands to enhance the pharmacological effects of monomeric drugs, DITC-APEC, a chemically reactive nucleoside A(2A) adenosine receptor (AR) agonist, was employed to derivatize the surface of third-generation (G3) polyamidoamine (PAMAM) dendrimers. The resulting conjugates carried multiple copies of the agonist attached through a thiourea linkage and differed in the number of attachments and in the presence of a fluorophore or additional surface modification. Computer modeling studies suggested that these DITC-APEC-loaded dendrimers extended the overall diameter of the previously reported PAMAM-CGS21680 dendrimer derivatives (Kim et al., Bioconjugate Chem 2008 19:406-411) by ca. 20 A, potentially increasing the conformational flexibility of the appended ligands to achieve optimal geometry for efficient binding at A(2A) ARs. Increased affinity and selectivity in binding in comparison to the CGS21680 conjugate were envisioned, due to the presence of an extended linker, i.e., a dithioureylenephenyl functionality. In vitro radioligand competition experiments showed effective binding of these PAMAM-DITC-APEC dendrimer conjugates at the human A(2A) and A(3) ARs with submicromolar K (i) values and selectivity in comparison to the human A(1) AR. Furthermore, these nucleoside-loaded dendrimers exhibited an A(2A) AR-mediated inhibitory effect on ADP-induced aggregation of human platelets. The present study demonstrates the potential of applying the functionalized congener concept to engineer dendrimer-based multivalent ligands for G protein-coupled receptors.
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Affiliation(s)
- Yoonkyung Kim
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive & Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
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Ivanov AA, Jacobson KA. Molecular modeling of a PAMAM-CGS21680 dendrimer bound to an A2A adenosine receptor homodimer. Bioorg Med Chem Lett 2008; 18:4312-5. [PMID: 18639453 DOI: 10.1016/j.bmcl.2008.06.087] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2008] [Revised: 06/20/2008] [Accepted: 06/25/2008] [Indexed: 01/19/2023]
Abstract
The theoretical possibility of bivalent binding of a dendrimer, covalently appended with multiple copies of a small ligand, to a homodimer of a G protein-coupled receptor was investigated with a molecular modeling approach. A molecular model was constructed of a third generation (G3) poly(amidoamine) (PAMAM) dendrimer condensed with multiple copies of the potent A(2A) adenosine receptor agonist CGS21680. The dendrimer was bound to an A(2A) adenosine receptor homodimer. Two units of the nucleoside CGS21680 could occupy the A(2A) receptor homodimer simultaneously. The binding mode of CGS21680 moieties linked to the PAMAM dendrimer and docked to the A(2A) receptor was found to be similar to the binding mode of a monomeric CGS21680 ligand.
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Affiliation(s)
- Andrei A Ivanov
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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