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Golla K, Stavropoulos I, Shields DC, Moran N. Peptides derived from cadherin juxtamembrane region inhibit platelet function. ROYAL SOCIETY OPEN SCIENCE 2018; 5:172347. [PMID: 30473799 PMCID: PMC6227957 DOI: 10.1098/rsos.172347] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 09/17/2018] [Indexed: 06/09/2023]
Abstract
The juxtamembrane domains (JMD) of transmembrane proteins are rich in critical peptide sequences that participate in dynamic cell signalling events. Synthetic JMD peptides derived from cadherin cell adhesion proteins have previously been shown to modulate platelet function. In this study, we aimed to develop functional bioactive agents from bioinformatically identified critical peptide sequences. We synthesized overlapping 12-15 amino acid peptides from E- and N-cadherin JMD and assessed their effect on platelet aggregation and platelet ATP secretion. Peptides derived from close to the membrane proximal region inhibit platelet function. Sequential deletion of amino acids from the N- and C-termini of the inhibitory E-cadherin peptides identified the short K756EPLLP763 motif as a critical bioactive sequence. Alanine scanning studies further identified that the di-leucine (LL) motif and positively charged lysine (K) are crucial for peptide activity. Moreover, scrambled peptides failed to show any effect on platelet activity. We conclude that peptides derived from JMD of E-cadherin provide potential lead peptides for the development of anti-thrombotic agents and to enable further understanding of the role of cadherins in platelet function.
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Affiliation(s)
- Kalyan Golla
- Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Ilias Stavropoulos
- UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
- School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
| | - Denis C. Shields
- UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
- School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
| | - Niamh Moran
- Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
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Tzakos AG, Kontogianni VG, Tsoumani M, Kyriakou E, Hwa J, Rodrigues FA, Tselepis AD. Exploration of the antiplatelet activity profile of betulinic acid on human platelets. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2012; 60:6977-83. [PMID: 22720759 PMCID: PMC3676635 DOI: 10.1021/jf3006728] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Betulinic acid, a natural pentacyclic triterpene acid, presents a diverse mode of biological actions including antiretroviral, antibacterial, antimalarial, and anti-inflammatory activities. The potency of betulinic acid as an inhibitor of human platelet activation was evaluated, and its antiplatelet profile against in vitro platelet aggregation, induced by several platelet agonists (adenosine diphosphate, thrombin receptor activator peptide-14, and arachidonic acid), was explored. Flow cytometric analysis was performed to examine the effect of betulinic acid on P-selectin membrane expression and PAC-1 binding to activated platelets. Betulinic acid potently inhibits platelet aggregation and also reduced PAC-1 binding and the membrane expression of P-selectin. Principal component analysis was used to screen, on the chemical property space, for potential common pharmacophores of betulinic acid with approved antithrombotic drugs. A common pharmacophore was defined between the NMR-derived structure of betulinic acid and prostacyclin agonists (PGI2), and the importance of its carboxylate group in its antiplatelet activity was determined. The present results indicate that betulinic acid has potential use as an antithrombotic compound and suggest that the mechanism underlying the antiplatelet effects of betulinic acid is similar to that of the PGI2 receptor agonists, a hypothesis that deserves further investigation.
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Affiliation(s)
- Andreas G. Tzakos
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, GR-45110, Ioannina, Greece
| | - Vassiliki G. Kontogianni
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, GR-45110, Ioannina, Greece
- Yale School of Medicine, Section of Cardiovascular Medicine, 300 George St, Rm 759 New Haven, CT 06511
| | - Maria Tsoumani
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, GR-45110, Ioannina, Greece
- Yale School of Medicine, Section of Cardiovascular Medicine, 300 George St, Rm 759 New Haven, CT 06511
| | - Eleni Kyriakou
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, GR-45110, Ioannina, Greece
| | - John Hwa
- Yale School of Medicine, Section of Cardiovascular Medicine, 300 George St, Rm 759 New Haven, CT 06511
| | - Francisco A. Rodrigues
- Departamento de Matemática Aplicada e Estatística, Instituto de Ciências Matemáticas e de Computação, Universidade de São Paulo-Campus de São Carlos, Caixa Postal 668, 13560-970 São Carlos, SP, Brazil
| | - Alexandros D. Tselepis
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, GR-45110, Ioannina, Greece
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The human megakaryocytic cell line UT-7/TPO responds to platelet agonists with intracellular Ca2+elevation and P-selectin expression. Cell Biol Int 2011; 35:537-43. [DOI: 10.1042/cbi20100636] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Dimitriou AA, Stathopoulos P, Mitsios JV, Sakarellos-Daitsiotis M, Goudevenos J, Tsikaris V, Tselepis AD. Inhibition of platelet activation by peptide analogs of the beta(3)-intracellular domain of platelet integrin alpha(IIb)beta(3) conjugated to the cell-penetrating peptide Tat(48-60). Platelets 2010; 20:539-47. [PMID: 19863457 DOI: 10.3109/09537100903324219] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Activation of the platelet integrin-receptor alpha(IIb)beta(3) is the final pathway of platelet aggregation, regardless of the initiating stimulus. Many studies suggest that there are several cytoplasmic proteins such as talin and beta(3)-endonexin that bind to N(744)PLY(747) and N(756)ITY(759) motif of the beta(3) cytoplasmic tail and play the major role in the receptor activation. In this study, we investigated the role of the membrane distal region of human beta(3) cytoplasmic tail and specifically the N(743)NPLYKEA(750) and T(755)NITYRGT(762) sequence that contains an NXXY motif, in platelet aggregation, secretion, alpha(IIb)beta(3) activation (PAC-1 binding) and fibrinogen binding. We synthesized two peptides corresponding to the above sequences as well as their conjugates with the Tat(48-60) cell-penetrating peptide. The capability of conjugates to penetrate the platelet membrane was investigated with confocal laser scanning microscopy using carboxyfluorescein (CF)-labeled peptides. Our results showed that the conjugated with the Tat(48-60) sequence peptides penetrate the platelet membrane and inhibit platelet aggregation in both PRP and washed platelets in a dose-dependent manner. The Tat-beta(3)743-750 conjugate exhibited similar inhibitory activity in PRP and in washed platelets whereas the Tat-beta(3)755-762 conjugate was more potent inhibitor of aggregation in washed platelets than in PRP. Both conjugated peptides were also able to inhibit P-selectin membrane expression as well as PAC-1 and fibrinogen binding to the platelets, the Tat-beta(3)755-762 conjugate being more potent than Tat-beta(3)743-750. The Tat(48-60) peptide and the peptides beta(3)743-750 and beta(3)755-762, which were not conjugated to the Tat(48-60) sequence, did not exhibit any inhibitory effect on the above parameters. In conclusion, the present study shows for the first time that the peptide analogs of the intracellular domain of the beta(3) subunit beta(3)743-750 and beta(3)755-762 conjugated to the cell-penetrating peptide Tat(48-60) are capable of penetrating the platelet membrane and expressing biological activity by inhibiting the activation of alpha(IIb)beta(3), the fibrinogen binding to the activated receptor as well as platelet aggregation. Further studies are necessary to support whether such conjugated peptides may be useful tools for the development of potent antiplatelet agents acting intracellularly through the platelet integrin alpha(IIb)beta(3).
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Affiliation(s)
- Andromaxi A Dimitriou
- Laboratory of Biochemistry, Medical School, University of Ioannina, 45110 Ioannina, Greece
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Provasi D, Murcia M, Coller BS, Filizola M. Targeted molecular dynamics reveals overall common conformational changes upon hybrid domain swing-out in beta3 integrins. Proteins 2009; 77:477-89. [PMID: 19455709 DOI: 10.1002/prot.22463] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The beta3 integrin family members alphaIIbeta3 and alphaVbeta3 signal bidirectionally through long-range allosteric changes, including a transition from a bent unliganded-closed low-affinity state to an extended liganded-open high-affinity state. To obtain an atomic-level description of this transition in an explicit solvent, we carried out targeted molecular dynamics simulations of the headpieces of alphaIIbeta3 and alphaVbeta3 integrins. Although minor differences were observed between these receptors, our results suggest a common transition pathway in which the hybrid domain swing-out is accompanied by conformational changes within the beta3 betaA (I-like) domain that propagate through the alpha7 helix C-terminus, and are followed by the alpha7 helix downward motion and the opening of the beta6-alpha7 loop. Breaking of contact interactions between the beta6-alpha7 loop and the alpha1 helix N-terminus results in helix straightening, internal rearrangements of the specificity determining loop (SDL), movement of the beta1-alpha1 loop toward the metal ion dependent adhesion site (MIDAS), and final changes at the interfaces between the beta3 betaA (I-like) domain and either the hybrid or the alpha beta-propeller domains. Taken together, our results suggest novel testable hypotheses of intradomain and interdomain interactions responsible for beta3 integrin activation.
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Affiliation(s)
- Davide Provasi
- Department of Structural and Chemical Biology, Mount Sinai School of Medicine, New York, NY 10029-6574, USA
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Conformational Studies of the 313-320 and 313-332 Peptide Fragments Derived from the αIIb Subunit of Integrin Receptor with Molecular Dynamics Simulations. Int J Pept Res Ther 2009. [DOI: 10.1007/s10989-009-9187-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Stanica RM, Benaki D, Rodis FI, Mikros E, Tsoukatos D, Tselepis A, Tsikaris V. Structure-activity relationships of αIIb313-320 derived peptide inhibitors of human platelet aggregation. J Pept Sci 2008; 14:1195-202. [DOI: 10.1002/psc.1060] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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