title: Monomeric and multimeric blockers of selectins: comparison of in vitro and in vivo activity.
abstract: The potency of the oligosaccharides SiaLe(x), SiaLe(a), HSO(3)Le(x), and HSO(3)Le(a), their conjugates with polyacrylamide (PAA, 40 kD), and other monomeric and polymeric selectin inhibitors has been compared with that of the polysaccharide fucoidan. The following assay systems were used: 1) a 96-well assay based either on the use of recombinant E-, P-, and L-selectins or an analogous assay with natural P-selectin isolated from human platelets; 2) a platelet-based P-selectin cell assay; and 3) a rat model of peritoneal inflammation. IC(50) values for the neoglycoconjugate SiaLe(a)-PAA were 6, 40, and 85 microM for recombinant E-, P-, and L-selectins, respectively; all monomeric inhibitors were about two orders of magnitude weaker. PAA-conjugates, containing as a ligand tyrosine-O-sulfate (sTyr) in addition to one of the sialylated oligosaccharides, were the most potent synthetic blockers in vitro. Compared with fucoidan, the most potent known P- and L-selectin blocker, the bi-ligand glycoconjugate HSO(3)Le(a)-PAA-sTyr displayed similar inhibitory activity in vitro towards L-selectin and about ten times lower activity towards P-selectin. All of the tested synthetic polymers displayed a similar ability to inhibit neutrophil extravasation in the peritonitis model (in vivo) at 10 mg/kg. The data provide evidence that monomeric SiaLe(x) is considerably more effective as a selectin blocker in vivo than in vitro, whereas the opposite is true for fucoidan and the bi-ligand neoglycoconjugate HSO(3)Le(a)-PAA-sTyr.
authors.affiliation: Orekhovich Institute of Biomedical Chemistry, Russian Academy of Medical Sciences, 119121 Moscow, Russia. natalia.ushakova@ibmc.msk.ru
authors.forename: N A
authors.initials: NA
authors.lastname: Ushakova
authors.forename: M E
authors.initials: ME
authors.lastname: Preobrazhenskaya
authors.forename: M I
authors.initials: MI
authors.lastname: Bird
authors.forename: R
authors.initials: R
authors.lastname: Priest
authors.forename: A V
authors.initials: AV
authors.lastname: Semenov
authors.forename: A V
authors.initials: AV
authors.lastname: Mazurov
authors.forename: N E
authors.initials: NE
authors.lastname: Nifantiev
authors.forename: T V
authors.initials: TV
authors.lastname: Pochechueva
authors.forename: O E
authors.initials: OE
authors.lastname: Galanina
authors.forename: N V
authors.initials: NV
authors.lastname: Bovin
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D000208:Acute Disease; D000818:Animals; D019040:E-Selectin / Q000737:chemistry; D005260:Female; D006001:Glycoconjugates / Q000737:chemistry* / Q000494:pharmacology; D006801:Humans; D019041:L-Selectin / Q000737:chemistry; D009504:Neutrophils / Q000276:immunology / Q000473:pathology; D009844:Oligosaccharides / Q000737:chemistry* / Q000494:pharmacology; D019007:P-Selectin / Q000737:chemistry; D010461:Peptones; D010538:Peritonitis / Q000139:chemically induced / Q000188:drug therapy / Q000276:immunology; D011108:Polymers; D011134:Polysaccharides / Q000737:chemistry / Q000494:pharmacology; D051381:Rats; D011994:Recombinant Proteins / Q000737:chemistry / Q000494:pharmacology; D019087:Selectins / Q000378:metabolism*; D000099166:Polyacrylamides
chemical_list: D000180:Acrylic Resins; D019040:E-Selectin; D006001:Glycoconjugates; D019041:L-Selectin; D009844:Oligosaccharides; D019007:P-Selectin; D010461:Peptones; D011108:Polymers; D011134:Polysaccharides; D011994:Recombinant Proteins; D019087:Selectins; D000099166:Polyacrylamides; C007789:fucoidan