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The role of N ‐glycosylation in high glucose‐induced upregulation of intercellular adhesion molecule‐1 on bovine retinal endothelial cells
Author(s) -
Liu Kun,
Liu Haiyun,
Zhang Zhihua,
Ye Wen,
Xu Xun
Publication year - 2016
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/aos.13028
Subject(s) - tunicamycin , downregulation and upregulation , intercellular adhesion molecule 1 , western blot , glycosylation , cell adhesion molecule , icam 1 , microbiology and biotechnology , cell adhesion , biology , chemistry , biochemistry , cell , endoplasmic reticulum , unfolded protein response , gene
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 ( BREC s) induced by high glucose concentrations was investigated. Methods Gene and protein expression of ICAM ‐1 in primary BREC s 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 BREC s 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 m m . Consistent with these results, a dramatic increase in the N ‐glycosylation of ICAM ‐1 in BREC s 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 BREC s 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.