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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
2004-10-26
pubmed:abstractText
A large body of evidence now implicates increased leukocyte-endothelial cell adhesion as a key early event in the development of diabetic retinopathy. We recently reported that raised activity of the glycosylating enzyme core 2 beta 1,6-N-acetylglucosaminyltransferase (GlcNAc-T) through protein kinase C (PKC)beta2-dependent phosphorylation plays a fundamental role in increased leukocyte-endothelial cell adhesion and capillary occlusion in retinopathy. In the present study, we demonstrate that following exposure to plasma from diabetic patients, the human promonocytic cell line U937 exhibits a significant elevation in core 2 GlcNAc-T activity and increased adherence to cultured retinal capillary endothelial cells. These effects of diabetic plasma on enzyme activity and cell adhesion, mediated by PKCbeta2-dependent phosphorylation of the core 2 GlcNAc-T protein, were found to be triggered by increased plasma levels of tumor necrosis factor (TNF)-alpha. Levels of enzyme activity in plasma-treated U937 cells were closely dependent on the severity of diabetic retinopathy, with the highest values observed upon treatment with plasma of patients affected by proliferative retinopathy. Furthermore, we noted much higher correlation, as compared with control subjects, between increased values of core 2 GlcNAc-T activity and cell adhesion properties. Based on the prominent role of TNF-alpha in the development of diabetic retinopathy, these observations further validate the significance of core 2 GlcNAc-T in the pathogenesis of capillary occlusion, thereby enhancing the therapeutic potential of specific enzyme inhibitors.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0012-1797
pubmed:author
pubmed:issnType
Print
pubmed:volume
53
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2968-76
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed-meshheading:15504978-Adult, pubmed-meshheading:15504978-Capillaries, pubmed-meshheading:15504978-Cell Adhesion, pubmed-meshheading:15504978-Cells, Cultured, pubmed-meshheading:15504978-Diabetes Mellitus, Type 1, pubmed-meshheading:15504978-Diabetes Mellitus, Type 2, pubmed-meshheading:15504978-Diabetic Retinopathy, pubmed-meshheading:15504978-Endothelium, Vascular, pubmed-meshheading:15504978-Female, pubmed-meshheading:15504978-Humans, pubmed-meshheading:15504978-Leukocytes, pubmed-meshheading:15504978-Male, pubmed-meshheading:15504978-Middle Aged, pubmed-meshheading:15504978-N-Acetylglucosaminyltransferases, pubmed-meshheading:15504978-Protein Kinase C, pubmed-meshheading:15504978-Recombinant Proteins, pubmed-meshheading:15504978-Retinal Vessels, pubmed-meshheading:15504978-Tumor Necrosis Factor-alpha
pubmed:year
2004
pubmed:articleTitle
Tumor necrosis factor-alpha in diabetic plasma increases the activity of core 2 GlcNAc-T and adherence of human leukocytes to retinal endothelial cells: significance of core 2 GlcNAc-T in diabetic retinopathy.
pubmed:affiliation
Centre for Cardiovascular BiologyMedicine, 2nd floor, New Hunt's House, Guy's, King's & St. Thomas' School of Biomedical Sciences, King's College London, London, SE1 1UL, UK.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't