Synthesis and SAR of a Library of Cell-Permeable Biotin-R8ERY* Peptidomimetics Inhibiting α4β7 Integrin Mediated Adhesion of TK-1 Cells to MAdCAM-1-Fc

The α4β7 integrin is a well‐known target for the development of drugs against various inflammatory disease states including inflammatory bowel disease, type 1 diabetes, and multiple sclerosis. The β7 subunit contains the cell adhesion regulatory domain (CARD) motif YDRREY within its cytoplasmic domain, which is an effective peptide agent for inhibiting T-cell adhesion. The synthesis of a library of cell-permeable β7 integrin inhibitors based on the shortened biotin-R8ERY (R8 = (l-arginine)8) motif is reported, wherein the tyrosine residue has been modified. The synthesised peptidomimetics were evaluated in a cell adhesion assay and shown to inhibit Mn2+-activated adhesion of mouse TK-1 T-cells to mouse MAdCAM-1. Several analogues exhibited improved activity to that of the tyrosine-containing lead compound 1 (biotin-R8ERY). Specifically, analogues 4, 10, and 22 bearing a 4-chloro, a 4-nitro, and a 3,3-diphenyl substituent showed an increase in activity of approximately two-fold compared with that of the initial lead compound. The six most active compounds of the tested series had IC50’s between 25 and 50 μM.

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Screening for novel cell adhesive regions in bovine Achilles tendon collagen peptides

Biochemistry and Cell Biology ◽

10.1139/bcb-2013-0026 ◽

2014 ◽

Vol 92 (1) ◽

pp. 9-22 ◽

Cited By ~ 6

Author(s):

Pradipta Banerjee ◽

Alka Mehta ◽

C. Shanthi

Keyword(s):

Cell Adhesion ◽

Docking Studies ◽

Exchange Chromatography ◽

Adhesion Assay ◽

Structural Protein ◽

Cell Adherence ◽

Collagen Peptides ◽

Adhesion Ability ◽

A Cell ◽

Hydrophilic Residues

Collagen, a major structural protein of the ECM, is known for its high cell adherence capacity. This study was conducted to identify regions in collagen that harbour such bioactivity. Collagen from tendon was hydrolysed and the peptides fractionated using ion-exchange chromatography (IEC). Isolated peptide fractions were coated onto disposable dishes and screened for cell adherence and proliferative abilities. Active IEC fractions were further purified by chromatography, and two peptides, C2 and E1 with cell adhesion ability, were isolated. A cell adhesion assay done with different amounts of C2 coated onto disposable dishes revealed the maximum adhesion to be 94.6%, compared with 80% for collagen coated dishes and an optimum peptide coating density of 0.507 nmoles per cm2 area of the dish. Growth of cells on C2, collagen, and E1 revealed a similar pattern and a reduction in the doubling time compared with cells grown on uncoated dishes. C2 had a mass of 2.046 kDa with 22 residues, and sequence analysis revealed a higher percentage occurrence of hydrophilic residues compared with other regions in collagen. Docking studies revealed GDDGEA in C2 as the probable site of interaction with integrins α2β1 and α1β1, and stability studies proved C2 to be mostly protease-resistant.

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Dissection of Organizer and Animal Pole Explants from Xenopus laevis Embryos and Assembly of a Cell Adhesion Assay

Journal of Visualized Experiments ◽

10.3791/187 ◽

2007 ◽

Cited By ~ 1

Author(s):

Souichi Ogata ◽

Ken W.Y. Cho

Keyword(s):

Cell Adhesion ◽

Xenopus Laevis ◽

Adhesion Assay ◽

Animal Pole ◽

Cell Adhesion Assay ◽

A Cell ◽

Xenopus Laevis Embryos

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Role of intracellular angiotensin II

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00632.2017 ◽

2018 ◽

Vol 314 (4) ◽

pp. H766-H771 ◽

Cited By ~ 7

Author(s):

Richard N. Re

Keyword(s):

Angiotensin Ii ◽

Protective Factor ◽

Intracellular Space ◽

Neuronal Nuclei ◽

Disease States ◽

Animal Physiology ◽

A Cell

It has become clear that the vasoactive peptide angiotensin II, like other so-called intracrines, can act in the intracellular space. Evidence has accumulated indicating that such angiotensin II activity can be upregulated in disease states and cause pathology. Indeed, other intracrines appear to be involved in disease pathogenesis as well. At the same time, nitric oxide, potentially a cell protective factor, has been shown to be upregulated by intracellular angiotensin II. Recently data have been developed indicating that other potentially protective factors are directly upregulated at neuronal nuclei by angiotensin II. This led to the suggestion that intracellular angiotensin II is cell protective and not pathological. Here, the data on both sides of this issue and a possible resolution are discussed. In summary, there is evidence for both protective and pathological actions of intracellular angiotensin, just as there is abundant evidence derived from whole animal physiology to indicate that angiotensin–driven signaling cascades, including angiotensin II type 2 receptor- and Mas receptor-mediated events, can mitigate the effects of the angiotensin II/angiotensin II type 1 receptor axis (25). This mitigation does not negate the physiological and pathological importance of angiotensin II/angiotensin II type 1 receptor action but does expand our understanding of the workings of both intracellular and extracellular angiotensin II.

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Pentamidine Is a Specific, Non-Peptide, GPIIb/llla Antagonist

Thrombosis and Haemostasis ◽

10.1055/s-0038-1650305 ◽

1996 ◽

Vol 75 (03) ◽

pp. 503-509 ◽

Cited By ~ 12

Author(s):

Dermot Cox ◽

Toshiaki Aoki ◽

Jiro Seki ◽

Yukio Motoyama ◽

Keizo Yoshida

Keyword(s):

Monoclonal Antibody ◽

Cell Adhesion ◽

Endothelial Cell ◽

Intracellular Ph ◽

Platelet Adhesion ◽

Adhesion Assay ◽

Agonist Peptide ◽

A Cell ◽

Granule Release ◽

Endothelial Cell Adhesion

SummaryPentamidine was previously shown to act on glycoprotein (GP) Ilb/IIIa (Cox et al., Thromb Haemost 1992; 68: 731). In this paper we study the effect of pentamidine on other RGD-dependent receptors. In a cell adhesion assay, pentamidine was 500 times more potent than RGDS at inhibiting platelet adhesion to fibrinogen. While RGDS inhibited platelet adhesion to fibronectin, endothelial cell adhesion to vitronectin or fibronectin, 293 cell adhesion to vitronectin, IMR 32 cell adhesion to fibronectin and C32 cell adhesion to vitronectin; pentamidine failed to inhibit these interactions at doses as high as 1 mM. Resting platelets fixed in the presence of 1 mM RGDS had increased binding of fibrinogen, i.e., RGDS activated GPIMIIa, while pentamidine at 100 ΜM had no effect. Similarly, RGDS induced the binding of an anti-LIBS monoclonal antibody, while pentamidine had no effect. Pentamidine partially, but significantly, inhibited lysosome and a-granule release induced by the thrombin agonist peptide, while RGDS had no effect. Neither pentamidine nor RGDS affected ADP-induced Ca2+ influx. Pentamidine had no effect on ADP-induced intracellular pH changes while RGDS prevented the pH from returning to normal. Thus, pentamidine is a non-peptide GPIIb/IIIa antagonist that is non-activating and is specific for GPIIb/IIIa.

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CCL25 and CCL28 promote α4β7-integrin-dependent adhesion of lymphocytes to MAdCAM-1 under shear flow

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00266.2007 ◽

2008 ◽

Vol 294 (5) ◽

pp. G1257-G1267 ◽

Cited By ~ 41

Author(s):

Alice Miles ◽

Evaggelia Liaskou ◽

Bertus Eksteen ◽

Patricia F. Lalor ◽

David H. Adams

Keyword(s):

Cell Adhesion ◽

Adhesion Molecule ◽

Cell Adhesion Molecule ◽

Human Lymphocytes ◽

Adhesion Assay ◽

Lymphocyte Adhesion ◽

Chemokine Ligand ◽

Inflammatory Bowel ◽

Cell Adhesion Molecule 1

Inflammatory bowel disease is characterized by the recruitment of lymphocytes to the gut via mucosal vessels. Chemokines are believed to trigger α4β1- and α4β7-integrin-mediated adhesion to vascular cell adhesion molecule-1 (VCAM-1) and mucosal addressin cell adhesion molecule-1 (MAdCAM-1) on mucosal vessels, although the contribution of each pathway and the chemokines involved are not well characterized. These interactions occur under conditions of hemodynamic shear, which is critical in determining how lymphocytes integrate chemokine signals to promote transmigration. To define the role of specific chemokines in mediating lymphocyte adhesion to VCAM-1 and MAdCAM-1, we studied the ability of immobilized chemokines to activate adhesion of human lymphocytes in a flow-based adhesion assay. Adhesion to immobilized MAdCAM-1 was α4β7 dependent, with no contribution from α4β1, whereas α4β1 mediated rolling and static adhesion on VCAM-1. Immobilized CC-chemokine ligand (CCL) 25 and CCL28 were both able to trigger α4β7-dependent lymphocyte arrest on MAdCAM-1 under shear, highlighting a potential role for these chemokines in the arrest of lymphocytes on postcapillary venules in the gut. Neither had any effect on adhesion to VCAM-1, suggesting that they selectively trigger α4β7-mediated adhesion. Immobilized CCL21, CCL25, CCL28, and CXC-chemokine ligand (CXCL) 12 all converted rolling adhesion to static arrest on MAdCAM-1 by activating lymphocyte integrins, but only CCL21 and CXCL12 also triggered a motile phenotype characterized by lamelipodia and uropod formation. Thus α4β1/VCAM-1 and α4β7/MAdCAM-1 operate independently to support lymphocyte adhesion from flow, and chemokines may act in concert with one chemokine triggering integrin-mediated arrest and a second chemokine promoting motility and transendothelial migration.

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Efficient synthesis of novel RGD based peptides and the conjugation of the pyrazine moiety to their N-terminus

New Journal of Chemistry ◽

10.1039/c8nj04874f ◽

2019 ◽

Vol 43 (6) ◽

pp. 2702-2709

Author(s):

Fatima Hamdan ◽

Zahra Bigdeli ◽

Saeed Balalaie ◽

Norbert Sewald ◽

Carmela Michalek

Keyword(s):

Cell Adhesion ◽

Adhesion Assay ◽

Efficient Synthesis ◽

Cell Adhesion Assay ◽

N Terminus ◽

A Cell

Novel RGD based peptides (RGDFAKLF and RGDNGRG) were designed and synthesized and were later coupled to the pyrazine moiety at the N-terminus. The IC50 values from the in vitro study of the target peptides using a cell adhesion assay indicated the essential impact of the existence of the pyrazine moiety. Meanwhile, peptide 4 exhibited the best IC50 value.

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