A multivalent lacto-N-fucopentaose III-lysyllysine conjugate decompacts preimplantation mouse embryos, while the free oligosaccharide is ineffective.

Abstract

The carbohydrate chains of glycolipids and glycoproteins at the cell surface are known to undergo many rapid changes during embryogenesis. These developmental changes include (a) alteration of branching structure in lactoseries carbohydrate chains, identified as I/i interconversion (1), (b) modification of terminal chains, responsible for the transition from Ii to ABH or SSEA-1 (reviewed in 2), (c) transition of globoseries antigen expression through pk, p, and Forssman (3), and (d) switching of core structure synthesis from one series to another, such as SSEA-3 ÷ globoseries to SSEA-1 + lactoseries (4). Although these structural changes have been defined clearly using various monoclonal antibodies, their physiological significance is unclear.The appearance of SSEA-1 on the embryo surface after the third cleavage division correlates approximately in time with the onset of compaction (5). During compaction, blastomeres maximize their intercellular contacts and generate a polar distribution of microvilli (6). Identification of SSEA-1 as the X hapten (Gall31 ---* 4[Fucal --0 3]GIcNAcI31 ~ R) (7-9) suggested the possibility of a 3-fucosyl-N-acetyllactosamine recognition system in the early mouse embryo. To test this hypothesis, we have studied the effect of lacto-N-fucopentaose III, its analogues, and their multivalent lysyllysine conjugates on compaction. Materials and Methods Purification of Oligosaccharides.A mixture of lacto-N-fucopentaose (LNFP) I, II, and III was obtained from human milk by the method of Kobata (10). LNFP I, II, and III (unreduced) were separated after acetylation by preparative thin-layer chromatography on HPTLC plates (J. T. Baker Chemical Co., Phiilipsburg, NJ) using a solvent system of butylacetate-acetone-water (25:8:1). After deacetylation, purified pentasaccharides were lyophilized and stored at -20 ° C. Chitotriose (GlcNAcI31 --~ 3GlcNA031 ---, 3GIcNAc) was a gift from Professor Toshiaki Osawa, University of Tokyo.Covalent Attachment of Oligosaccharides to LysyUysine.

Specific glycosphingolipids mediate epithelial-to-mesenchymal transition of human and mouse epithelial cell lines

“…Previous studies from our group and others have demonstrated that glycosphingolipids (GSLs) mediate cell adhesion (12)(13)(14)(15), and they modulate cell growth through their effect on growth factor receptor tyrosine kinases (16)(17)(18)(19)(20). In addition, we have demonstrated that some GSLs, particularly gangliosides, play an essential role in defining cell motility through their interaction with integrins and tetraspanin CD9 or CD82 (21,22).…”

A cloned human cDNA determines expression of a mouse stage-specific embryonic antigen and the Lewis blood group alpha(1,3/1,4)fucosyltransferase.

“…This antigen first appears on the surface of cells at the eight-cell stage of mouse embryogenesis and later becomes restricted to specific cell types during murine development (Solter and Knowles 1978;Pennington et al 1985). Complementary experimental observations by two groups suggest that the SSEA-1 antigen may participate in adhesive events leading up to and involving compaction (Bird and Kimber 1984;Fenderson et al 1984). Although the molecular nature of these processes is undefined, recent biochemical evidence suggests that homotypic carbohydrate-carbohydrate interactions between SSEA-1 molecules may be operative in this context (Eggens et al 1989).…”

“…These patterns are discernible first on the surfaces of preimplantation and early postimplantation embryomc cell aggregates (Bird and Kimber 1984;Fenderson et al 1984;Pennington et al 1985;Fenderson et al 1986;Kimber 1986). In the mature organism, expression of distinct oligosaccharide moieties ultimately becomes restricted to specific cell types (Szulman 1960(Szulman , 1962Watkins 1980;Dodd and Jessel 1985).…”

“…The precise function(s)of such oligosaccharide structures during development is not known. Recent information, however, suggests that these molecules may modulate adhesive events that occur during mammalian embryogenesis (Bird and Kimber 1984;Fenderson et al 1984;Rutishauser et al 1988;Eggens et al 1989;Kojima and Hakomori 1989;Hall et al 1990).…”

Expression of GDP‐l‐Fuc: Gal(β1–4)GlcNAc‐R (Fuc to GlcNAc) α‐1,3‐fucosyltransferase and its Relationship to Glycoprotein Structure in a Human Erythroleukemia Cell Line, HEL

“…Other examples are found at various stages of development. These include the extension or shortening of carbohydrate polymers, such as polysialic acid [3] on the neural cell-adhesion molecule, the presence of fucosyl residues in al-3 linkage to Gal(jI1-4)GlcNAc on glycoconjugates [Fuc(al-3)GlcNAc] associated with particular stages of the embryo [4], the response to the Zucto-N-fucopentaose-I11 complex during compaction of the embryo [5] and the addition of sialic acid residues to a glycoprotein in a-2,6 linkage to galactose during maturation of lymphocytes [6].…”