1
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Torunoglu ST, Zajda A, Tampio J, Markowicz-Piasecka M, Huttunen KM. Metformin derivatives - Researchers' friends or foes? Biochem Pharmacol 2023; 215:115743. [PMID: 37591450 DOI: 10.1016/j.bcp.2023.115743] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 08/09/2023] [Accepted: 08/09/2023] [Indexed: 08/19/2023]
Abstract
Metformin has been used for ages to treat diabetes mellitus due to its safety profile and low cost. However, metformin has variable pharmacokinetics in patients, and due to its poor oral absorption, the therapeutic doses are relatively high, causing unpleasant gastrointestinal adverse effects. Therefore, novel derivatives of metformin have been synthesized during the past decades. Particularly, after the mid-2000 s, when organic cation transporters were identified as the main metformin carriers, metformin derivatives have been under intensive investigation. Nevertheless, due to the biguanide structure, derivatives of metformin have been challenging to synthesize. Moreover, the mechanisms of metformin's action are not fully understood to date, and since it has multifunctional properties, the interests have switched to re-purposing for other diseases. Indeed, metformin derivatives have been demonstrated in many cases to be more effective than metformin itself and have the potential to be used in different diseases, including several types of cancers and neurodegenerative diseases. On the other hand, the pleiotropic nature of metformin and its derivatives can also create challenges. Not all properties are fit for all diseases. In this review, the history of the development of metformin-like compounds is summarized, and insights into their potential for future drug discovery are discussed.
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Affiliation(s)
- Sema Tuna Torunoglu
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland.
| | - Agnieszka Zajda
- Laboratory of Bioanalysis, Department of Pharmaceutical Chemistry, Drug Analysis and Radiopharmacy, Medical University of Lodz, ul. Muszyńskiego 1, 90-151 Lodz, Poland
| | - Janne Tampio
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland
| | | | - Kristiina M Huttunen
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland.
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2
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Sutherland M, Gordon A, Al-Shammari FOFO, Throup A, Cilia La Corte A, Philippou H, Shnyder SD, Patterson LH, Sheldrake HM. Synthesis and Biological Evaluation of Cyclobutane-Based β3 Integrin Antagonists: A Novel Approach to Targeting Integrins for Cancer Therapy. Cancers (Basel) 2023; 15:4023. [PMID: 37627051 PMCID: PMC10452181 DOI: 10.3390/cancers15164023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 07/25/2023] [Accepted: 08/06/2023] [Indexed: 08/27/2023] Open
Abstract
The Arg-Gly-Asp (RGD)-binding family of integrin receptors, and notably the β3 subfamily, are key to multiple physiological processes involved in tissue development, cancer proliferation, and metastatic dissemination. While there is compelling preclinical evidence that both αvβ3 and αIIbβ3 are important anticancer targets, most integrin antagonists developed to target the β3 integrins are highly selective for αvβ3 or αIIbβ3. We report the design, synthesis, and biological evaluation of a new structural class of ligand-mimetic β3 integrin antagonist. These new antagonists combine a high activity against αvβ3 with a moderate affinity for αIIbβ3, providing the first evidence for a new approach to integrin targeting in cancer.
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Affiliation(s)
- Mark Sutherland
- Institute of Cancer Therapeutics, University of Bradford, Bradford BD7 1DP, UK
| | - Andrew Gordon
- Institute of Cancer Therapeutics, University of Bradford, Bradford BD7 1DP, UK
| | | | - Adam Throup
- Institute of Cancer Therapeutics, University of Bradford, Bradford BD7 1DP, UK
| | - Amy Cilia La Corte
- Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds LS2 9JT, UK
| | - Helen Philippou
- Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds LS2 9JT, UK
| | - Steven D. Shnyder
- Institute of Cancer Therapeutics, University of Bradford, Bradford BD7 1DP, UK
| | | | - Helen M. Sheldrake
- Institute of Cancer Therapeutics, University of Bradford, Bradford BD7 1DP, UK
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3
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Arzani H, Rafii-Tabar H, Ramezani F. The investigation into the effect of the length of RGD peptides and temperature on the interaction with the αIIbβ3 integrin: a molecular dynamic study. J Biomol Struct Dyn 2022; 40:9701-9712. [PMID: 34060983 DOI: 10.1080/07391102.2021.1932602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The tripeptide Arg-Gly-Asp acid (RGD) is a protein sequence in the binding of proteins to cell surfaces, and is involved in various biological processes such as cell adhesion to the extracellular matrix, platelet activation, hemostasis, etc. The C2 domain of the Von Willebrand Factor (VWF), containing the RGD motif, plays an important role in the initial homeostasis process. It binds to the αIIbβ3 integrin and stimulates platelet aggregation. We have investigated, using the molecular Dynamic (MD) simulation method, the effect of the RGD-peptide length, and temperature variation, on the binding to the αIIbβ3 integrin receptor. We examined 10 different structural modes of the αIIbβ3 at three different temperatures; 237 K, 310 K and 318 K. Our findings show that the amino acids that form a binding pocket include Asp224, Tyr234, Ser226, Tyr190, Tyr189, Trp260, Trp262, Asp259, Lys253, Arg214, Asp217, Ser161 and Ala218 and that the ligand-receptor interaction was increased at higher temperatures. It was also found that the increase in the number of ligands' amino acids and their types (% glycine) plays an important role in the stability, conformation, and ligand-receptor interaction.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Hossein Arzani
- Department of Medical Physics and Biomedical Engineering, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hashem Rafii-Tabar
- Department of Medical Physics and Biomedical Engineering, Shahid Beheshti University of Medical Sciences, Tehran, Iran.,The Physics Branch of Iran Academy of Sciences, Tehran, Iran
| | - Fatemeh Ramezani
- Physiology Research Center, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran
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4
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Sandmeier T, Carreira EM. Enantio- and Chemoselective Intramolecular Iridium-Catalyzed O-Allylation of Oximes. Org Lett 2021; 23:2643-2647. [PMID: 33749284 DOI: 10.1021/acs.orglett.1c00559] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A method for the enantio- and chemoselective iridium-catalyzed O-allylation of oximes is described. Kinetic resolution in an intramolecular setting provides enantioenriched oxime ethers and aliphatic allylic alcohols. The synthetic potential of the products generated with this method is showcased by their elaboration into a series of heterocyclic compounds and the formal synthesis of glycoprotein GP IIb-IIIa receptor antagonist (-)-roxifiban. Preliminary mechanistic experiments and computational data shed light on the remarkable chemoselectivity of the reaction.
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Affiliation(s)
- Tobias Sandmeier
- Eidgenössische Technische Hochschule (ETH) Zürich, Building HCI, Vladimir-Prelog-Weg 3, 8093 Zürich, Switzerland
| | - Erick M Carreira
- Eidgenössische Technische Hochschule (ETH) Zürich, Building HCI, Vladimir-Prelog-Weg 3, 8093 Zürich, Switzerland
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5
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Chen J, Gong X, Li J, Li Y, Ma J, Hou C, Zhao G, Yuan W, Zhao B. Carbonyl catalysis enables a biomimetic asymmetric Mannich reaction. Science 2018; 360:1438-1442. [PMID: 29954974 DOI: 10.1126/science.aat4210] [Citation(s) in RCA: 124] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2018] [Accepted: 05/02/2018] [Indexed: 01/01/2023]
Abstract
Chiral amines are widely used as catalysts in asymmetric synthesis to activate carbonyl groups for α-functionalization. Carbonyl catalysis reverses that strategy by using a carbonyl group to activate a primary amine. Inspired by biological carbonyl catalysis, which is exemplified by reactions of pyridoxal-dependent enzymes, we developed an N-quaternized pyridoxal catalyst for the asymmetric Mannich reaction of glycinate with aryl N-diphenylphosphinyl imines. The catalyst exhibits high activity and stereoselectivity, likely enabled by enzyme-like cooperative bifunctional activation of the substrates. Our work demonstrates the catalytic utility of the pyridoxal moiety in asymmetric catalysis.
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Affiliation(s)
- Jianfeng Chen
- The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234, China.,Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041, China
| | - Xing Gong
- The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234, China
| | - Jianyu Li
- The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234, China
| | - Yingkun Li
- The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234, China
| | - Jiguo Ma
- The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234, China
| | - Chengkang Hou
- The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234, China
| | - Guoqing Zhao
- The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234, China
| | - Weicheng Yuan
- Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041, China
| | - Baoguo Zhao
- The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234, China
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6
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Abstract
Antiplatelet therapy displays a critical role in the treatment and prevention of antithrombotic disorders. Many new antiplatelet agents have been developed following the emergence of various clinical limitations of classical antiplatelet drugs. This review covers mainly the recent advances in the development of P2Y12 antagonists and GPIIb/IIIa antagonists. Meanwhile, it summarizes promising approaches to new platelet surface receptors such as prostanoid EP3 receptor, thromboxane A2 prostanoid receptor, protease-activated receptors, GPIb-IX-V receptor and P-selectin. In addition, PI3Kβ, a critical protein at the inside signaling pathway of platelet activation is also mentioned as an important antiplatelet target. Moreover, the development of respective drug candidates is discussed in detail.
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7
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Xie Z, Feng S, Wang Y, Cao C, Huang J, Chen Y, Kong Y, Li Z. Design, synthesis of novel tryptophan derivatives for antiplatelet aggregation activity based on tripeptide pENW (pGlu-Asn-Trp). Eur J Med Chem 2015; 102:363-74. [PMID: 26298494 DOI: 10.1016/j.ejmech.2015.07.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2015] [Revised: 07/06/2015] [Accepted: 07/07/2015] [Indexed: 12/19/2022]
Abstract
pENW, a three mer peptide derived from Agkistrodon acutus Guenther venom, has been found to be an antagonist of the GPIIb/IIIa receptor and shows antiplatelet aggregation activity. Based on pENW and a GPIIb/IIIa inhibitor Tirofiban, a series of tryptophan derivatives were designed, synthesized and evaluated for their antiplatelet aggregation activity induced by ADP. The most potent compound 87 was also tested for the bleeding time and antithrombotic activity in vivo in comparison with Tirofiban. The results indicated that 87 shows similar antiplatelet aggregation activity as Tirofiban to the aggregation of platelet induced by all of the four agonists, but has lower bleeding risk than Tirofiban, representing a promising lead compound for further study.
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Affiliation(s)
- Zhouling Xie
- Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 21009, PR China
| | - Sen Feng
- Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 21009, PR China
| | - Ying Wang
- School of Life Science & Technology, China Pharmaceutical University, 24 Tongjiaxiang, Nanjing 210009, PR China
| | - Chen Cao
- Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 21009, PR China
| | - Jing Huang
- Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 21009, PR China
| | - Yahui Chen
- School of Life Science & Technology, China Pharmaceutical University, 24 Tongjiaxiang, Nanjing 210009, PR China
| | - Yi Kong
- School of Life Science & Technology, China Pharmaceutical University, 24 Tongjiaxiang, Nanjing 210009, PR China.
| | - Zhiyu Li
- Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing 21009, PR China.
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8
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Abstract
This review covers the recent advances in the development of small RGD (Arg-Gly-Asp sequence) containing peptides and their mimetics as potential antithrombotic agents. Glycoprotein IIb/IIIa (GPIIb/IIIa) antagonists include monoclonal antibodies, RGD peptides, peptide hybrids and nonpeptide mimetics. The current trend in the development of nonpeptide mimetics is clearly directed toward orally active and safe antithrombotic drug candidates. But several nonpeptide mimetics, being evaluated for their oral activity in human clinical trials, are currently not approved for clinical use due to poor safety profile. It is expected that newer and more effective nonpeptide mimetics will be developed in the near future.
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9
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Adamson K, Spain E, Prendergast U, Forster RJ, Moran N, Keyes TE. Ligand capture and activation of human platelets at monolayer modified gold surfaces. Biomater Sci 2014; 2:1509-1520. [DOI: 10.1039/c4bm00241e] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The effect of RGD peptides, alkane and PEG in self assembled mixed monolayers on gold on platelet adhesion and activation is explored.
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Affiliation(s)
- Kellie Adamson
- School of Chemical Sciences
- Dublin City University
- Dublin 9, Ireland
- Department of Molecular and Cellular Therapeutics
- Royal College of Surgeons in Ireland
| | - Elaine Spain
- School of Chemical Sciences
- Dublin City University
- Dublin 9, Ireland
| | - Una Prendergast
- School of Chemical Sciences
- Dublin City University
- Dublin 9, Ireland
| | | | - Niamh Moran
- Department of Molecular and Cellular Therapeutics
- Royal College of Surgeons in Ireland
- Dublin 2, Ireland
| | - Tia E. Keyes
- School of Chemical Sciences
- Dublin City University
- Dublin 9, Ireland
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10
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Bigdeli MA, Halimehjani AZ, Mohammadipour M, Sagharichi P. Preparation of Novel Di-isoxazolines Using Bis(nitrile oxide) 1,3-Dipolar Cycloaddition Methodology. J Heterocycl Chem 2012. [DOI: 10.1002/jhet.856] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Mohammad Ali Bigdeli
- Faculty of Chemistry; Tarbiat Moallem University; 49 Mofateh Street; Tehran; 11365; Iran
| | | | - Mohammad Mohammadipour
- Faculty of Chemistry; Tarbiat Moallem University; 49 Mofateh Street; Tehran; 11365; Iran
| | - Parishad Sagharichi
- Faculty of Chemistry; Tarbiat Moallem University; 49 Mofateh Street; Tehran; 11365; Iran
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11
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Antibodies causing thrombocytopenia in patients treated with RGD-mimetic platelet inhibitors recognize ligand-specific conformers of αIIb/β3 integrin. Blood 2012; 119:6317-25. [PMID: 22490676 DOI: 10.1182/blood-2012-01-406322] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Arginine-glycine-aspartic acid (RGD)-mimetic platelet inhibitors act by occupying the RGD recognition site of α(IIb)/β(3) integrin (GPIIb/IIIa), thereby preventing the activated integrin from reacting with fibrinogen. Thrombocytopenia is a well-known side effect of treatment with this class of drugs and is caused by Abs, often naturally occurring, that recognize α(IIb)/β(3) in a complex with the drug being administered. RGD peptide and RGD-mimetic drugs are known to induce epitopes (ligand-induced binding sites [LIBS]) in α(IIb)/β(3) that are recognized by certain mAbs. It has been speculated, but not shown experimentally, that Abs from patients who develop thrombocytopenia when treated with an RGD-mimetic inhibitor similarly recognize LIBS determinants. We addressed this question by comparing the reactions of patient Abs and LIBS-specific mAbs against α(IIb)/β(3) in a complex with RGD and RGD-mimetic drugs, and by examining the ability of selected non-LIBS mAbs to block binding of patient Abs to the liganded integrin. Findings made provide evidence that the patient Abs recognize subtle, drug-induced structural changes in the integrin head region that are clustered about the RGD recognition site. The target epitopes differ from classic LIBS determinants, however, both in their location and by virtue of being largely drug-specific.
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12
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Target–drug interactions: first principles and their application to drug discovery. Drug Discov Today 2012; 17:10-22. [DOI: 10.1016/j.drudis.2011.06.013] [Citation(s) in RCA: 126] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Revised: 06/07/2011] [Accepted: 06/28/2011] [Indexed: 02/06/2023]
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13
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Minakata S, Okumura S, Nagamachi T, Takeda Y. Generation of Nitrile Oxides from Oximes Using t-BuOI and Their Cycloaddition. Org Lett 2011; 13:2966-9. [DOI: 10.1021/ol2010616] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Satoshi Minakata
- Department of Applied Chemistry and Frontier Research Base for Global Young Researchers, Graduate School of Engineering, Osaka University, Yamadaoka 2-1, Suita, Osaka 565-0871, Japan
| | - Sota Okumura
- Department of Applied Chemistry and Frontier Research Base for Global Young Researchers, Graduate School of Engineering, Osaka University, Yamadaoka 2-1, Suita, Osaka 565-0871, Japan
| | - Toshiki Nagamachi
- Department of Applied Chemistry and Frontier Research Base for Global Young Researchers, Graduate School of Engineering, Osaka University, Yamadaoka 2-1, Suita, Osaka 565-0871, Japan
| | - Youhei Takeda
- Department of Applied Chemistry and Frontier Research Base for Global Young Researchers, Graduate School of Engineering, Osaka University, Yamadaoka 2-1, Suita, Osaka 565-0871, Japan
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14
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Negussie AH, Miller JL, Reddy G, Drake SK, Wood BJ, Dreher MR. Synthesis and in vitro evaluation of cyclic NGR peptide targeted thermally sensitive liposome. J Control Release 2010; 143:265-73. [PMID: 20067811 DOI: 10.1016/j.jconrel.2009.12.031] [Citation(s) in RCA: 118] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2009] [Revised: 12/04/2009] [Accepted: 12/28/2009] [Indexed: 10/20/2022]
Abstract
The Asn-Gly-Arg (NGR) motif in both cyclic and linear form has previously been shown to specifically bind to CD13/aminopeptidase N that is selectively overexpressed in tumor vasculature and some tumor cells. However, previous versions of cyclic NGR used a liable disulfide bridge between cysteine residues that may be problematic for liposome targeting due to disulfide bond formation between adjacent peptides on the liposomal surface. In this study, we report the design, synthesis, and characterization of a novel cyclic NGR-containing peptide, cKNGRE, which does not contain a disulfide bridge. cKNGRE was synthesized in good yield and purity and attached to the fluorescent reporter Oregon Green (cKNGRE-OG) and lysolipid-containing temperature sensitive liposomes (LTSLs). The identity of cKNGRE was verified with NMR and mass spectral techniques. In vitro fluorescence microscopy evaluation of cKNGRE-OG demonstrated binding and active uptake by CD13(+) cancer cells and minimal binding to CD13(-) cancer cells. The cKNGRE-OG ligand displayed 3.6-fold greater affinity for CD13(+) cancer cells than a linear NGR-containing peptide. Affinity for CD13(+) cancer cells was similarly improved 10-fold for both the cyclic and linear NGR when presented in a multivalent fashion on the surface of an LTSL. cKNGRE-targeted LTSLs rapidly released (>75% in <4s) doxorubicin at 41.3 degrees C with minimal release at 37 degrees C. These results demonstrate the ability to synthesize a cKNGRE-targeted temperature sensitive liposome that lacks a disulfide bridge and has sufficient binding affinity for biological applications.
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Affiliation(s)
- Ayele H Negussie
- Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD 20892, USA
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15
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Pangburn TO, Petersen MA, Waybrant B, Adil MM, Kokkoli E. Peptide- and aptamer-functionalized nanovectors for targeted delivery of therapeutics. J Biomech Eng 2009; 131:074005. [PMID: 19655996 DOI: 10.1115/1.3160763] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Targeted delivery of therapeutics is an area of vigorous research, and peptide- and aptamer-functionalized nanovectors are a promising class of targeted delivery vehicles. Both peptide- and aptamer-targeting ligands can be readily designed to bind a target selectively with high affinity, and more importantly are molecules accessible by chemical synthesis and relatively compact compared with antibodies and full proteins. The multitude of peptide ligands that have been used for targeted delivery are covered in this review, with discussion of binding selectivity and targeting performance for these peptide sequences where possible. Aptamers are RNA or DNA strands evolutionarily engineered to specifically bind a chosen target. Although use of aptamers in targeted delivery is a relatively new avenue of research, the current state of the field is covered and promises of future advances in this area are highlighted. Liposomes, the classic drug delivery vector, and polymeric nanovectors functionalized with peptide or aptamer binding ligands will be discussed in this review, with the exclusion of other drug delivery vehicles. Targeted delivery of therapeutics, from DNA to classic small molecule drugs to protein therapeutics, by these targeted nanovectors is reviewed with coverage of both in vitro and in vivo deliveries. This is an exciting and dynamic area of research and this review seeks to discuss its broad scope.
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Affiliation(s)
- Todd O Pangburn
- Department of Chemical Engineering, University of Minnesota, Minneapolis, MN 55455, USA
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16
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17
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Convenient synthesis of isoxazolines via tandem isomerization of allyl compounds to vinylic derivatives and 1,3-dipolar cycloaddition of nitrile oxides to the vinylic compounds. Tetrahedron Lett 2008. [DOI: 10.1016/j.tetlet.2008.07.176] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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18
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Zhang JG, Krajden OB, Kainthan RK, Kizhakkedathu JN, Constantinescu I, Brooks DE, Gyongyossy-Issa MIC. Conjugation to Hyperbranched Polyglycerols Improves RGD-Mediated Inhibition of Platelet Function in Vitro. Bioconjug Chem 2008; 19:1241-7. [DOI: 10.1021/bc8000408] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- J. G. Zhang
- Canadian Blood Services, Research & Development, Department of Pathology and Laboratory Medicine, at UBC Centre for Blood Research, 2350 Life Sciences Mall, Vancouver BC
| | - O. B. Krajden
- Canadian Blood Services, Research & Development, Department of Pathology and Laboratory Medicine, at UBC Centre for Blood Research, 2350 Life Sciences Mall, Vancouver BC
| | - R. K. Kainthan
- Canadian Blood Services, Research & Development, Department of Pathology and Laboratory Medicine, at UBC Centre for Blood Research, 2350 Life Sciences Mall, Vancouver BC
| | - J. N. Kizhakkedathu
- Canadian Blood Services, Research & Development, Department of Pathology and Laboratory Medicine, at UBC Centre for Blood Research, 2350 Life Sciences Mall, Vancouver BC
| | - I. Constantinescu
- Canadian Blood Services, Research & Development, Department of Pathology and Laboratory Medicine, at UBC Centre for Blood Research, 2350 Life Sciences Mall, Vancouver BC
| | - D. E. Brooks
- Canadian Blood Services, Research & Development, Department of Pathology and Laboratory Medicine, at UBC Centre for Blood Research, 2350 Life Sciences Mall, Vancouver BC
| | - M. I. C. Gyongyossy-Issa
- Canadian Blood Services, Research & Development, Department of Pathology and Laboratory Medicine, at UBC Centre for Blood Research, 2350 Life Sciences Mall, Vancouver BC
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19
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Hantgan RR, Stahle MC, Horita DA. Entropy Drives Integrin αIIbβ3:Echistatin Binding—Evidence from Surface Plasmon Resonance Spectroscopy. Biochemistry 2008; 47:2884-92. [DOI: 10.1021/bi701877a] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Roy R. Hantgan
- Department of Biochemistry, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, North Carolina 27157-1016
| | - Mary C. Stahle
- Department of Biochemistry, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, North Carolina 27157-1016
| | - David A. Horita
- Department of Biochemistry, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, North Carolina 27157-1016
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20
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Huang G, Zhou Z, Srinivasan R, Penn MS, Kottke-Marchant K, Marchant RE, Gupta AS. Affinity manipulation of surface-conjugated RGD peptide to modulate binding of liposomes to activated platelets. Biomaterials 2008; 29:1676-85. [PMID: 18192005 DOI: 10.1016/j.biomaterials.2007.12.015] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2007] [Accepted: 12/16/2007] [Indexed: 12/21/2022]
Abstract
Platelet adhesion, activation and fibrinogen-mediated aggregation are primary events in vascular thrombosis and occlusion. An injectable delivery system that can carry thrombolytics selectively to the sites of active platelet aggregation has immense potential in minimally invasive targeted therapy of vascular occlusion. To this end we are studying liposomes surface-modified by fibrinogen-mimetic RGD motifs that can selectively target and bind integrin GPIIb-IIIa on activated platelets. Here we report liposome surface-modification with a conformationally constrained high affinity cyclic RGD motif to modulate the GPIIb-IIIa-binding capability of the liposomes. Such affinity enhancement is important for practical in vivo applications to compete with native fibrinogen towards binding GPIIb-IIIa. The platelet-binding of RGD-modified liposomes was studied by fluorescence and scanning electron microscopy, and flow cytometry, in vitro. Binding of RGD-modified liposomes was also tested in vivo in a rat carotid injury model and analyzed ex vivo by fluorescence microscopy. The results from all experiments show that cyclic RGD-liposomes bind activated platelets significantly higher compared to linear RGD-liposomes. Hence, the results establish the feasibility of modulating the platelet-targeting and binding ability of vascularly targeted liposomes by manipulating the affinity of surface-modifying ligands.
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Affiliation(s)
- Guofeng Huang
- Department of Biomedical Engineering, Case Western Reserve University, Wickenden Building, 10900 Euclid Avenue, Cleveland, OH 44106-7207, USA
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Gangopadhyay AK, Gole GV, Jadhav RD, Lal B. Novel Chiral Auxiliary for Attempted Resolution of Key Roxifiban Intermediate: A Simple Diastereoselective Coupling Approach for the Synthesis of Roxifiban. SYNTHETIC COMMUN 2007. [DOI: 10.1080/00397910701575012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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22
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Mousa SA, Ahmad S. Platelet GPIIb/IIIa antagonist, XV459, in heparin-induced thrombocytopenia. Am J Hematol 2007; 82:276-82. [PMID: 17039513 DOI: 10.1002/ajh.20801] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Heparin-induced thrombocytopenia (HIT) is a serious, immune-related complication of heparin therapy. One of the most severe manifestations of HIT is the development of thromboembolic events, which is based on platelet activation and aggregation caused by HIT-associated antibodies. Therapeutic options for patients with HIT are limited despite advancement toward the development of alternative (nonheparin) anticoagulants, such as direct thrombin inhibitors and indirect anti-factor Xa agents. Platelet GPIIb/IIIa receptor antagonists have been shown to be the final common pathway for platelet aggregation regardless of the use of activator or anticoagulant. In this study, the ability of a novel platelet GPIIb/IIIa antagonist, a free acid form of roxifiban (XV459), to block platelet activation/aggregation in response to highly characterized heparin-PF4 antibody-positive plasma/heparin was examined using light transmittance aggregometry, serotonin release, and (125)I-fibrinogen binding assays to human platelets. XV459 at 20 nM maximally inhibited (P < 0.001) the platelet-activation/aggregation responses as mediated by the HIT antibody-positive plasma (in the presence of therapeutic heparin concentrations). Compared with controls, both HIT antibodies/heparin and TEAC (a mixture of thrombin [0.1 IU/ml], epinephrine [1 microg/ml], arachidonate [0.1 mM], and collagen [10 microml]) resulted in significantly higher levels of fibrinogen binding to human platelets (5-7-fold increase; P < 0.001). Concentration-dependent profiles of XV459 on the mean percent inhibition of (125)I-fibrinogen binding in the presence of HIT antibodies and TEAC were achieved ( approximately 50% inhibition at 10 nM XV459). The platelet GPIIb/IIIa receptor antagonist (XV459) might be of potential benefit in the management of thrombotic thrombocytopenia produced by heparin and/or related glycosaminoglycans.
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Affiliation(s)
- Shaker A Mousa
- Pharmaceutical Research Institute, Albany College of Pharmacy, Albany, New York 12208, USA.
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Copeland RA, Pompliano DL, Meek TD. Drug-target residence time and its implications for lead optimization. Nat Rev Drug Discov 2006; 5:730-9. [PMID: 16888652 DOI: 10.1038/nrd2082] [Citation(s) in RCA: 1027] [Impact Index Per Article: 57.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Much of drug discovery today is predicated on the concept of selective targeting of particular bioactive macromolecules by low-molecular-mass drugs. The binding of drugs to their macromolecular targets is therefore seen as paramount for pharmacological activity. In vitro assessment of drug-target interactions is classically quantified in terms of binding parameters such as IC(50) or K(d). This article presents an alternative perspective on drug optimization in terms of drug-target binary complex residence time, as quantified by the dissociative half-life of the drug-target binary complex. We describe the potential advantages of long residence time in terms of duration of pharmacological effect and target selectivity.
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Affiliation(s)
- Robert A Copeland
- Department of Enzymology and Mechanistic Pharmacology, at GlaxoSmithKline, UP1345, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426, USA.
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24
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Anderluh M, Cesar J, Stefanic P, Kikelj D, Janes D, Murn J, Nadrah K, Tominc M, Addicks E, Giannis A, Stegnar M, Dolenc MS. Design and synthesis of novel platelet fibrinogen receptor antagonists with 2H-1,4-benzoxazine-3(4H)-one scaffold. A systematic study. Eur J Med Chem 2005; 40:25-49. [PMID: 15642407 DOI: 10.1016/j.ejmech.2004.09.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2004] [Revised: 09/01/2004] [Accepted: 09/06/2004] [Indexed: 11/29/2022]
Abstract
New platelet glycoprotein IIb/IIIa (GP IIb/IIIa, integrin alpha(IIb)beta3) antagonists were prepared on a 2H-1,4-benzoxazine-3(4H)-one scaffold. Their anti-aggregatory activities in human platelet rich plasma and their affinity towards alpha(IIb)beta3 and alpha(V)beta3 integrins were assessed. Various substitution positions and side chain variations were studied. In contrast to the generally accepted model, compounds containing ethyl esters as aspartate mimetics were in general more active than the corresponding free acids. We suggest an explanation for the observed behaviour of these new compounds.
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Affiliation(s)
- Marko Anderluh
- Faculty of Pharmacy, University of Ljubljana, Askerceva 7, 1000 Ljubljana, Slovenia
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25
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Tanaka KA, Katori N, Kelly AB, Kotze H, Marzec U, Hanson SR. In vivo platelet redistribution and acute transient thrombocytopenia after eptifibatide injection in baboons. Thromb Res 2005; 115:79-87. [PMID: 15567457 DOI: 10.1016/j.thromres.2004.06.044] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2004] [Revised: 06/28/2004] [Accepted: 06/29/2004] [Indexed: 11/25/2022]
Abstract
BACKGROUND The occurrence of thrombocytopenia has been reported during clinical eptifibatide (Integrilin) therapy, but the exact mechanism is not yet established to explain the varied duration and severity of thrombocytopenia associated with glycoprotein (GP) IIb/IIIa inhibitors. We assessed the redistribution of platelets in juvenile baboons during acute transient thrombocytopenia that was observed after eptifibatide injection. METHODS Eptifibatide was administered intravenously to eight baboons by infusion at 20 microg/kg/min or a bolus injection of 10 mg. Platelet distribution was measured with a gamma scintillation camera using 111In-labeled autologous platelets. Platelet function and GP IIb/IIIa receptor inhibition were evaluated using the Plateletworks system. The effects of pretreatment with abciximab (0.4 mg/kg) or human immunoglobulin concentrate (0.75 g/kg) were also investigated. RESULTS Eptifibatide, administered as an infusion or a bolus, caused transient thrombocytopenia with uptake of platelets predominantly by the liver. The recovery of platelet aggregation was associated with the re-entry of platelets from the liver into the systemic circulation. Pretreatment with either abciximab (0.4 mg/kg) or human intravenous immunoglobulin (IVIG, 0.75 g/kg) attenuated eptifibatide-induced thrombocytopenia and the hepatic uptake of radiolabeled platelets. CONCLUSION Acute thrombocytopenia after eptifibatide injection was caused by the transient redistribution of platelets to the liver. Attenuation of the decrease in platelet count and hepatic sequestration by abciximab and IVIG suggests that thrombocytopenia may have been caused by ligand-induced binding site antigen induction and recognition by the reticuloendothelial system.
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Affiliation(s)
- Kenichi A Tanaka
- Department of Anesthesiology, Emory University School of Medicine, 1364 Clifton Rd., NE, 3B South EUH, Atlanta, GA 30322, USA.
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26
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Aguzzi MS, Facchiano F, Ribatti D, Gaeta R, Casadio R, Rossi I, Capogrossi MC, Facchiano A. A novel RGDS-analog inhibits angiogenesis in vitro and in vivo. Biochem Biophys Res Commun 2004; 321:809-14. [PMID: 15358099 DOI: 10.1016/j.bbrc.2004.07.036] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2004] [Indexed: 11/28/2022]
Abstract
In this study the anti-angiogenic action of a novel non-peptide RGDS-analog named RAM was tested in vitro and in vivo. RAM inhibited FGF-2-induced chemotaxis by 80% in an adhesion-independent way. Further, it induced HUVEC-apoptosis in collagen-seeded HUVEC, indicating that such pro-apoptotic effect was adhesion-independent. In vivo studies revealed that RAM inhibited FGF-2 induced angiogenesis by 60% in the mouse Matrigel-assay and in the chicken-egg chorion-allantoic membrane assay. Finally, RAM was markedly more stable in serum as compared to the template RGDS and after 24 h incubation in 100% serum was significantly more active than RGDS. Taken together these results show that RAM exerts anti-chemotactic and pro-apoptotic effects, by an unexpected adhesion-independent mechanism, as we have recently shown for the template RGDS molecule [Blood 103 (2004) 4180], and has in vivo relevant anti-angiogenic properties, with marked stability in serum; therefore, RAM represents a novel promising anti-angiogenic molecule.
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Affiliation(s)
- M S Aguzzi
- Laboratorio di Patologia Vascolare, Istituto Dermopatico della Immacolata, IDI, IRCCS, Rome, Italy
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27
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Mehrotra MM, Heath JA, Smyth MS, Pandey A, Rose JW, Seroogy JM, Volkots DL, Nannizzi-Alaimo L, Park GL, Lambing JL, Hollenbach SJ, Scarborough RM. Discovery of Novel 2,8-Diazaspiro[4.5]decanes as Orally Active Glycoprotein IIb-IIIa Antagonists. J Med Chem 2004; 47:2037-61. [PMID: 15056002 DOI: 10.1021/jm030354b] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In our efforts to develop orally active GPIIb-IIIa antagonists with improved pharmaceutical properties, we have utilized a novel 2,8-diazaspiro[4.5]decane scaffold as a template. We describe here our investigation of a variety of templates including spiropiperidinyl-gamma-lactams, spiropiperidinylimide, spiropiperidinylureas, and spiropiperidinylhydantoins. With the appropriate acidic and basic pharmacophores in place, each template yielded analogues with potent GPIIb-IIIa inhibitory activity. One of the compounds, 59 (CT50787), was also used to demonstrate for the first time the use of a pharmacological agent which is alphaIIbbeta3 specific to display biological activity in a lower species such as mouse and to extend bleeding times. Evaluation of the pharmacokinetic properties of selected compounds from each series in rat, dog, and cynomolgus monkey has led to the identification of 22 (CT51464), a double prodrug, with excellent pharmacokinetic properties. It exhibited good pharmacokinetic profile across species (F% = 33 (Cyno), 73 (dog), 22 (rat); t(1/2)(beta)() = 14.2 h (Cyno), 8.97 h (dog), 1.81 h (rat)). The biologically active form, 23 (CT50728), displayed inhibition of platelet aggregation in platelet rich plasma (PRP) with an IC(50) value of 53 nM in citrate buffer, 110 nM in PPACK anticoagulated PRP, and 4 nM in solid-phase GPIIb-IIIa competition binding assay (ELISA). Both 23 and 22 were stable in human liver microsomes, did not inhibit the P450 3A4 isozyme, and had low protein binding (18.22% for 23) and a desirable log P (0.45 +/- 0.06 for 22, and -0.91 +/- 0.32 for 23). It is predicted that the high oral bioavailability for these compounds in multiple species should translate into lower intra- and intersubject variability in man. The long plasma half-life of the lead is consistent with once or twice daily administration for chronic therapy. Analogue 22 (CT51464) thus appears to be a promising oral GPIIb-IIIa inhibitor with significantly improved pharmacokinetic properties over the previously described clinical candidates and may be found useful in the treatment of arterial occlusive disorders.
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Affiliation(s)
- Mukund M Mehrotra
- Millennium Pharmaceuticals Inc., 256 E. Grand Avenue, South San Francisco, CA 94080, USA.
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28
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Naik MU, Naik UP. Calcium-and integrin-binding protein regulates focal adhesion kinase activity during platelet spreading on immobilized fibrinogen. Blood 2003; 102:3629-36. [PMID: 12881299 DOI: 10.1182/blood-2003-05-1703] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Platelet spreading on the subendothelium in response to vascular injury is fundamental to the regulation of physiologic hemostasis. Previously, we have shown that, when bound to glycoprotein IIb (GPIIb), calcium- and integrin-binding protein (CIB) regulates platelet spreading on immobilized fibrinogen (Fg). In this study, we investigated the signaling events that occur downstream of CIB in the absence of signaling that occurs as a result of granular secretion. Using Chinese hamster ovary (CHO) cells as a model, we demonstrate that CIB induces cell migration. Immunofluorescence analysis of CIB localization indicates that endogenous CIB accumulates in areas of focal adhesions, and its overexpression up-regulates the formation of focal adhesion complexes compared with control cells. Immunoprecipitation analysis indicates that CIB associates with focal adhesion kinase (FAK), a key regulator in focal complex formation, and up-regulates its activity. Overexpression of dominant-negative FAK, FRNK, along with CIB in CHO cells completely inhibits CIB-induced cell migration. Further, confirmation of these data in the platelet system indicates that CIB and FAK associate throughout all stages of platelet spreading but only on Fg binding to GPIIb/IIIa. Taken together, our results suggest that CIB regulates platelet spreading through the regulation of FAK activation.
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Affiliation(s)
- Meghna U Naik
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA.
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29
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Lee I, Marchant RE. Molecular interaction studies of hemostasis: fibrinogen ligand-human platelet receptor interactions. Ultramicroscopy 2003; 97:341-52. [PMID: 12801687 DOI: 10.1016/s0304-3991(03)00059-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The interactions between fibrinogen ligands and platelet receptor alpha(IIb)beta(3) were studied under physiological conditions by atomic force microscopy (AFM). Two linear peptide sequences in fibrinogen, RGD and HHLGGAKQAGDV, play central roles in the regulation of hemostasis and thrombosis by facilitating adhesion and aggregation of platelets. In order to measure the interactions (i.e., debonding force), oligopeptides, GSSSGaaa, where aaa is -RGDSPA or -HHLGGAKQAGDV, were synthesized and grafted on to the surface of AFM probe tips. The interaction forces between a peptide-modified AFM probe tip and platelet surface were determined from pN to nN levels using AFM force measurements. Our results show that the zero kinetic off-rate, K(off)(0), for RGDSPA is significantly smaller than that for HHLGGAKQAGDV, under the consideration of flexible receptor surfaces. From our analysis, the K(off)(0), the single molecular binding energy E(b), and the transition state x(b), were extracted from the data, and estimated to be 1.53s(-1), -2.64x10(-20)J and 1.03A for the RGD-alpha(IIb)beta(3) system, and 47.58s(-1), 2.67x10(-20), 1.09A for the HHLGGAKQAGDV-alpha(IIb)beta(3) system, respectively.
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Affiliation(s)
- Imshik Lee
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Eculid Avenue, Wickenden Building, Cleveland, OH 44106-7207, USA
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30
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Murphy J, Wright RS, Gussak I, Williams B, Daly RN, Cain VA, Pieniaszek HJ, Sy SKB, Ebling W, Simonson K, Wilcox RA, Kopecky SL. The use of roxifiban (DMP754), a novel oral platelet glycoprotein IIb/IIIa receptor inhibitor, in patients with stable coronary artery disease. Am J Cardiovasc Drugs 2003; 3:101-12. [PMID: 14727937 DOI: 10.2165/00129784-200303020-00004] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
INTRODUCTION Intravenous platelet glycoprotein (GP) IIb/IIIa receptor inhibitors have a significant beneficial impact on the outcomes of patients undergoing high-risk coronary interventions and in the stabilization of patients with unstable angina pectoris refractory to conventional medical treatment. The role of long-term treatment with oral platelet GP IIb/IIIa receptor inhibitors in patients with coronary artery disease is unproven. This study examined the dose-response effect on inhibition of platelet aggregation by roxifiban (DMP754), a novel oral platelet GP IIb/IIIa receptor inhibitor, and its safety and tolerability in patients with a history of chronic stable angina pectoris. METHODS Ninety-eight patients were randomized to receive either a placebo or 1 of 8 oral dosages of roxifiban. Twenty-two patients were enrolled in multiple-dose regimens, bringing the total study population to 120. The oral dosages were 0.25, 0.5, 0.75, 1, 1.25, 1.5, 2, or 2.5 mg/day for up to 30 days. RESULTS Pharmacodynamic response of roxifiban was clearly dose-dependent. Platelet aggregation inhibition in response to 10 micromol/L slope adenosine diphosphate was sustained throughout the study period (up to 1 month). No serious adverse events, including significant major bleeding events, were associated with roxifiban treatment. Minor bleeding was reported in 5% of participants in the placebo group (1 of 21 cases) versus 26% in the study group (26 of 99 cases). Incidence of minor bleeding associated with roxifiban 2 and 2.5 mg/day was significantly (p < or = 0.05) greater than that with placebo. Adverse events, including gastrointestinal disorders, platelet and clotting disorders, and urinary tract disorders, were observed in 1 of 21 cases (5%) in the placebo group and in 12 of 99 cases (12%) in the study group. Reversible thrombocytopenia without other complications developed in two patients. CONCLUSIONS Roxifiban-induced inhibition of platelet aggregation was dose-dependent and sustained throughout the study period: higher drug dosages correlated with higher levels of platelet inhibition and higher incidence of minor bleeding events. No serious adverse events were observed at any dosage. Thus, roxifiban appears to be a potent oral platelet GP IIb/IIIa receptor inhibitor that is clinically well-tolerated and deserves further study as a new treatment strategy in patients with chronic stable angina pectoris.
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Affiliation(s)
- Joseph Murphy
- Mayo Alliance for Clinical Trials and Division of Cardiology, Mayo Clinic and Mayo Foundation, Rochester, USA
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31
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Seiffert D, Pedicord DL, Kieras CJ, He B, Stern AM, Billheimer JT. Regulation of clot retraction by glycoprotein IIb/IIIa antagonists. Thromb Res 2002; 108:181-9. [PMID: 12590956 DOI: 10.1016/s0049-3848(02)00395-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Binding of fibrinogen to platelet glycoprotein (GP) IIb/IIIa induces clot retraction. Significant differences among GP IIb/IIIa antagonists were previously noted to inhibit thromboelastography in whole blood specimens. The relationship between efficacy of these agents and inhibition of clot retraction is unclear. Here, we use a plasma-free clot retraction assay to evaluate potency of GP IIb/IIIa antagonists to inhibit clot retraction and modulate platelet signaling, and to address whether these effects are realized in the clinically relevant dose range. The potencies for inhibition of clot retraction and aggregation are similar for antagonists with high affinity for resting platelets and slow off-rates, whereas lower affinity and fast off-rate antagonists are disproportionately less effective in blocking clot retraction. A positive correlation is observed between inhibition of clot retraction and inhibition of tyrosine dephosphorylation across a number of GP IIb/IIIa antagonist pharmacophores. For lower affinity and fast off-rate antagonists, the concentrations required for inhibition of clot retraction clearly exceed the clinical dose range. Site occupancy studies combined with clot retraction experiments addressed whether high affinity and slow off-rate compounds can alter clot retraction during the dosing interval. Binding studies using [3H] Roxifiban, a high affinity GP IIb/IIIa antagonist, indicate that occupancy of >95% of GP IIb/IIIa sites is required to inhibit clot retraction. This level of occupancy is not routinely achieved in the clinic and is not tolerated, at least for chronic therapy. These results suggest that inhibition of clot retraction is not necessary for efficacy of GP IIb/IIIa antagonists.
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Affiliation(s)
- Dietmar Seiffert
- Chemical Enzymology, Experimental Station E400/3255, Bristol-Myers Squibb Company, P.O. Box 80400, Wilmington, DE 19880, USA.
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Acute thrombocytopenia after treatment with tirofiban or eptifibatide is associated with antibodies specific for ligand-occupied GPIIb/IIIa. Blood 2002. [DOI: 10.1182/blood.v100.6.2071] [Citation(s) in RCA: 140] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractAcute thrombocytopenia is a recognized complication of treatment with GPIIb/IIIa inhibitors whose cause is not yet known. We studied 9 patients who developed severe thrombocytopenia (platelets less than 25 × 109/L) within several hours of treatment with the GPIIb/IIIa inhibitors tirofiban (4 patients) and eptifibatide (5 patients). In each patient, acute-phase serum contained a high titer (range, 1:80-1:20 000) IgG antibody that reacted with the glycoprotein IIb/IIIa complex only in the presence of the drug used in treatment. Four patients had been previously treated with the same drug, but 5 had no known prior exposure. Pretreatment serum samples from 2 of the latter patients contained drug-dependent antibodies similar to those identified after treatment. No tirofiban- or eptifibatide-dependent antibodies were found in any of 100 randomly selected healthy blood donors, and only 2 of 23 patients receiving tirofiban or eptifibatide who did not experience significant thrombocytopenia had extremely weak (titer, 1:2) tirofiban-dependent antibodies. In preliminary studies, evidence was obtained that the 9 antibodies recognize multiple target epitopes on GPIIb/IIIa complexed with the inhibitor to which the patient was sensitive, indicating that they cannot all be specific for the drug-binding site. The findings indicate that acute thrombocytopenia after the administration of tirofiban or eptifibatide can be caused by drug-dependent antibodies that are “naturally occurring” or are induced by prior exposure to drug. These antibodies may be human analogs of mouse monoclonal antibodies that recognize ligand-induced binding sites (LIBS) induced in the GPIIb/IIIa heterodimer when it reacts with a ligand-mimetic drug.
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Acute thrombocytopenia after treatment with tirofiban or eptifibatide is associated with antibodies specific for ligand-occupied GPIIb/IIIa. Blood 2002. [DOI: 10.1182/blood.v100.6.2071.h81802002071_2071_2076] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Acute thrombocytopenia is a recognized complication of treatment with GPIIb/IIIa inhibitors whose cause is not yet known. We studied 9 patients who developed severe thrombocytopenia (platelets less than 25 × 109/L) within several hours of treatment with the GPIIb/IIIa inhibitors tirofiban (4 patients) and eptifibatide (5 patients). In each patient, acute-phase serum contained a high titer (range, 1:80-1:20 000) IgG antibody that reacted with the glycoprotein IIb/IIIa complex only in the presence of the drug used in treatment. Four patients had been previously treated with the same drug, but 5 had no known prior exposure. Pretreatment serum samples from 2 of the latter patients contained drug-dependent antibodies similar to those identified after treatment. No tirofiban- or eptifibatide-dependent antibodies were found in any of 100 randomly selected healthy blood donors, and only 2 of 23 patients receiving tirofiban or eptifibatide who did not experience significant thrombocytopenia had extremely weak (titer, 1:2) tirofiban-dependent antibodies. In preliminary studies, evidence was obtained that the 9 antibodies recognize multiple target epitopes on GPIIb/IIIa complexed with the inhibitor to which the patient was sensitive, indicating that they cannot all be specific for the drug-binding site. The findings indicate that acute thrombocytopenia after the administration of tirofiban or eptifibatide can be caused by drug-dependent antibodies that are “naturally occurring” or are induced by prior exposure to drug. These antibodies may be human analogs of mouse monoclonal antibodies that recognize ligand-induced binding sites (LIBS) induced in the GPIIb/IIIa heterodimer when it reacts with a ligand-mimetic drug.
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Zondlo SC, Wang X, Feuerstein GZ. Effects of orally active glycoprotein IIb/IIIa antagonists on platelet CD40 ligand (CD154) expression and platelet-heteroaggregate formation. Thromb Res 2002; 106:35-40. [PMID: 12165287 DOI: 10.1016/s0049-3848(02)00090-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Susan Carr Zondlo
- Cardiovascular Department, Bristol-Myers Squibb Company, Experimental Station, Bldg. 400/3352, Route 141 and Henry Clay Road, 19880, Wilmington, DE, USA
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