Expression of Glycoconjugates in Normal and Sjögren's Syndrome Labial Glands

Abstract

Glyconjugate expression in formalin-fixed, paraffin-embedded Sjögren's syndrome labial glands (nine cases) was compared with that in normal glands (12 samples) using a wide panel of lectins. Mucous cells expressed mainly mucous-type glycoproteins including sialyl, fucosyl, galactosyl and galactosaminosyl residues, and some N-linked glycoconjugates. Demilunar cells expressed mainly alpha D-mannose, GlcNAc and Gal beta 1.3-GalNAc. Duct cells and cellular glycocalyx expressed O-linked and N-linked residues. Sjögren's syndrome samples showed a statistically significant increase in the expression of GlcNAc. A significantly decreased expression of Gal beta 1,3-GalNAc and alpha D-mannose, residues not usually present in mucous cells, was found (p < 0.05). This suggests that anatomic rather than functional alterations determine mucous cell impairment and the symptoms in Sjögren's syndrome.

The significance of mannan-binding lectin gene alleles in patients with primary Sjo¨gren's syndrome

“…Codon 54 mutation is a risk factor for SLE (5). Although some histological evidence has been presented pointing to the signi® cance of MBL in the development of salivary gland destruction in pSS (6,7), the results have remained controversial at the genetic level (8 ± 10).…”

Glycohistochemical Characteristics of Nasal Polyps From Patients With and Without Cystic Fibrosis

“…A comparison can be made with what is already known in the case of the salivary glands. For example, the terminal sequence Neu5Ac-␣(2,6)-Gal-␤(1,3)-GalNAc is a typical side chain of mucin-type glycoproteins in salivary glands, 30 which secrete salivary mucins with numerous types of terminal sialic acids. 31,32 While the expression of the Neu5Ac-␣(2,6)-Gal-␤(1,3)-GalNAc sequence is typical of the presence of mature mucins, the presence of Gal-␤(1,3)-GalNAc free of sialylation is typical of either immature mucins or IgA, 33 which, in its structure, has 4 O-linked saccharides in the same sequence.…”

“…Sialic acids in saliva act against environmental insult and serve both as lubrication and as a defense against microorganisms. [30][31][32] These sialic acid-dependent properties may also be present in nasal mucosa, but differ according to whether or not the polyposal nasal mucosa is infected by specific pathogens. Interestingly, while an actual receptor for sialylated glycans from P aeruginosa has not yet been defined biochemically, inhibition experiments with SNA intimated that glycans carrying ␣(2,6)linked sialic acids are recognized by P aeruginosa.…”