Differential properties of mucous glycoproteins in rat nasal epithelium. A comparison between allergic inflammation and lipopolysaccharide stimulation

Am J Respir Crit Care Med. 2001 Sep 15;164(6):1077-82. doi: 10.1164/ajrccm.164.6.2012058.

Abstract

To examine the differential properties of mucous glycoproteins, we produced hypertrophic and metaplastic changes in goblet cells of rat nasal epithelium by intranasal instillation of ovalbumin (OVA) in OVA-sensitized rats, and by intranasal lipopolysaccharide (LPS) instillation. The epithelial mucosubstance was quantitatively examined by alcian blue-periodic acid-Schiff (AB-PAS) and lectin histochemistry. The newly produced mucin after OVA challenge or LPS instillation contained a high amount of sulfomucin and a low amount of neutral glycoprotein: LPS-induced mucin contained more sulfomucin (70.1% of total) and less neutral glycoprotein (8.6%) than OVA-induced mucin (sulfomucin, 33.6%; neutral glycoprotein, 41.8%; p < 0.01). Four of the lectins stained some of the mucosubstance, indicating the presence of galactose-N-acetylgalactosamine, alpha2,3- and alpha2,6-linked sialic acid-galactose, and fucose residues. After LPS instillation, the reactivity was higher for galactose-N-acetylgalactosamine (64.8% of total) and alpha2,3-linked sialic acid-galactose (75.8%) than after saline instillation (3.5 and 19.1%, respectively) or OVA challenge (5.8 and 32.3%; p < 0.05). OVA challenge did not induce the alteration of terminal sugar residues. A 2-fold increase in mucin mRNA (rat Muc5ac) expression was induced after LPS instillation or OVA challenge, compared with animals treated with saline instillation (p < 0.05). These results indicate that mucin mRNA expression (for peptide backbone) increases similarly after LPS instillation or OVA challenge; however, carbohydrate compositions of newly produced mucin are different between the two groups.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Data Interpretation, Statistical
  • Epithelium / metabolism
  • Epithelium / pathology
  • Epithelium / physiology
  • Goblet Cells / metabolism
  • Goblet Cells / pathology
  • Goblet Cells / physiology*
  • Histocytochemistry
  • Hypersensitivity / pathology
  • Hypersensitivity / physiopathology*
  • Inflammation / pathology
  • Inflammation / physiopathology*
  • Lectins
  • Lipopolysaccharides / administration & dosage*
  • Male
  • Mucins / genetics
  • Mucins / metabolism
  • Mucins / physiology*
  • Mucus / metabolism
  • Mucus / physiology
  • Ovalbumin / administration & dosage
  • RNA, Messenger / analysis
  • Rats
  • Rats, Inbred F344
  • Reverse Transcriptase Polymerase Chain Reaction
  • Sodium Chloride / administration & dosage

Substances

  • Lectins
  • Lipopolysaccharides
  • Mucins
  • RNA, Messenger
  • Sodium Chloride
  • Ovalbumin