Altered terminal glycosylation and the pathophysiology of CF lung disease.

Altered terminal glycosylation, with increased fucosylation and decreased sialylation, is a hallmark of the cystic fibrosis (CF) glycosylation phenotype. The glycosylation phenotype of CF airway epithelial cells has been modulated by the expression of wtCFTR. Understanding the effects of mutant CFTR on glycosylation may provide further insight into the regulation of glycoconjugate processing as well as new approaches to the therapy of CF.

Alpha1,3fucosyltransferases in cystic fibrosis airway epithelial cells.

Cystic fibrosis (CF) has a glycophenotype of aberrant sialylation and/or fucosylation. The CF glycophenotype is expressed on membrane glycoconjugates of CF airway epithelial cells as increased fucosyl residues in alpha1,3/4 linkage to N-acetyl glucosamine, decreased fucosyl residues in alpha1,2 linkage to galactose and decreased sialic acid. To define the cause of this phenotype, the enzyme activity of alpha1,3fucosyltransferase (FucT) was examined in extracts of CF airway epithelial cells with a variety of low molecular weight substrates.

Terminal glycosylation in cystic fibrosis (CF): a review emphasizing the airway epithelial cell.

Altered terminal glycosylation, with increased fucosylation and decreased sialylation is a hallmark of the cystic fibrosis (CF) glycosylation phenotype. Oligosaccharides purified from the surface membrane glycoconjugates of CF airway epithelial cells have the Lewis x, selectin ligand in terminal positions. This review is focused on the investigations of the glycoconjugates of the CF airway epithelial cell surface.

ST8Sia IV mRNA corresponds with the biosynthesis of alpha2,8sialyl polymers but not oligomers in rat oligodendrocytes.

As oligodendrocytes mature they progress through a series of distinct differentiation steps characterized by the expression of specific markers. One such marker, polysialic acid found on the neural cell adhesion molecule (NCAM), is detected by antibodies and is present on progenitor oligodendrocytes, but is not detected to the same extent on mature oligodendrocytes. Two closely related polysialyltransferases, ST8Sia II (STX) and ST8Sia IV (PST) have been cloned previously and shown to synthesize polysialic acid on NCAM and other glycoproteins.

Activity of fucosyltransferases and altered glycosylation in cystic fibrosis airway epithelial cells.

Cystic fibrosis (CF) glycoconjugates have a glycosylation phenotype of increased fucosylation and/or decreased sialylation when compared with non-CF. A major increase in fucosyl residues linked alpha 1,3 to antennary GlcNAc was observed when surface membrane glycoproteins of CF airway epithelial cells were compared to those of non-CF airway cells. Importantly, the increase in the fucosyl residues was reversed with transfection of CF cells with wild type CFTR cDNA under conditions which brought about a functional correction of the Cl(-) channel defect in the CF cells.