The role of N-glycosylation in high glucose-induced upregulation of intercellular adhesion molecule-1 on bovine retinal endothelial cells

Acta Ophthalmol. 2016 Jun;94(4):353-7. doi: 10.1111/aos.13028. Epub 2016 May 6.


Purpose: The development of diabetic retinopathy has been implicated as a consequence of chronic inflammation. Given the role of the intercellular adhesion molecule-1 (ICAM-1) in inflammation, the potential effect of N-glycosylation on the upregulated expression of ICAM-1 at the surface of bovine retinal endothelial cells (BRECs) induced by high glucose concentrations was investigated.

Methods: Gene and protein expression of ICAM-1 in primary BRECs cultured in medium containing increasing concentrations of mannose or glucose in the presence or absence of tunicamycin were studied with reverse transcription-polymerase chain reaction and Western blot analysis, and the expression level of ICAM-1 at the surface of BRECs was examined with an immunofluorescence analysis. A lectin blot assay with PHA-L was performed to explore the level of N-glycans on cell total proteins or immunoprecipitated ICAM-1 from cells treated or untreated with high glucose.

Results: Both the mRNA and protein levels of ICAM-1, as well as the level of ICAM-1 on the cell surface, were significantly upregulated by increasing the concentration of glucose in the culture medium, with a peak concentration of 20 mm. Consistent with these results, a dramatic increase in the N-glycosylation of ICAM-1 in BRECs cultured with a high concentration of glucose was observed, which could be partially attenuated by tunicamycin treatment.

Conclusion: High glucose-induced upregulation of ICAM-1 on the surface of BRECs could be ascribed to the alterations in its N-glycosylation at least in part, indicating that interference with the glycosylation of ICAM-1 may contribute to improving the efficiency of current therapies with diabetic retinopathy.

Keywords: N-glycosylation; high glucose; intercellular adhesion molecule-1.

MeSH terms

  • Animals
  • Blotting, Western
  • Cattle
  • Cells, Cultured
  • Endothelium, Vascular / drug effects*
  • Endothelium, Vascular / metabolism
  • Flow Cytometry
  • Fluorescent Antibody Technique, Indirect
  • Glucose / pharmacology*
  • Glycosylation
  • Intercellular Adhesion Molecule-1 / genetics*
  • Intercellular Adhesion Molecule-1 / metabolism*
  • Polysaccharides / metabolism
  • RNA, Messenger / genetics
  • Real-Time Polymerase Chain Reaction
  • Retinal Vessels / cytology
  • Up-Regulation*


  • Polysaccharides
  • RNA, Messenger
  • Intercellular Adhesion Molecule-1
  • Glucose