251. Inflammatory Stress Causes N-Glycan Processing Deficiency in Ocular Autoimmune Disease
- Author
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Stefano Bonini, Antonio Di Zazzo, Sylvain Lehoux, Inka Brockhausen, Flavio Mantelli, Pablo Argüeso, and Ashley M. Woodward
- Subjects
Adult ,Male ,0301 basic medicine ,Pemphigoid ,Conjunctiva ,Interleukin-1beta ,Pemphigoid, Benign Mucous Membrane ,Golgi Apparatus ,Biology ,N-Acetylglucosaminyltransferases ,Article ,Autoimmune Diseases ,Pathology and Forensic Medicine ,Proinflammatory cytokine ,Cornea ,03 medical and health sciences ,symbols.namesake ,0302 clinical medicine ,Polysaccharides ,Gene expression ,medicine ,Humans ,Aged ,Cell Line, Transformed ,Inflammation ,Autoimmune disease ,Tumor Necrosis Factor-alpha ,Middle Aged ,Golgi apparatus ,medicine.disease ,Pathophysiology ,Cell biology ,030104 developmental biology ,medicine.anatomical_structure ,Cell culture ,symbols ,Female ,030217 neurology & neurosurgery - Abstract
High levels of proinflammatory cytokines have been associated with a loss of tissue function in ocular autoimmune diseases, but the basis for this relationship remains poorly understood. Here we investigate a new role for tumor necrosis factor α in promoting N-glycan-processing deficiency at the surface of the eye through inhibition of N-acetylglucosaminyltransferase expression in the Golgi. Using mass spectrometry, complex-type biantennary oligosaccharides were identified as major N-glycan structures in differentiated human corneal epithelial cells. Remarkably, significant differences were detected between the efficacies of cytokines in regulating the expression of glycogenes involved in the biosynthesis of N-glycans. Tumor necrosis factor α but not IL-1β had a profound effect in suppressing the expression of enzymes involved in the Golgi branching pathway, including N-acetylglucosaminyltransferases 1 and 2, which are required for the formation of biantennary structures. This decrease in gene expression was correlated with a reduction in enzymatic activity and impaired N-glycan branching. Moreover, patients with ocular mucous membrane pemphigoid were characterized by marginal N-acetylglucosaminyltransferase expression and decreased N-glycan branching in the conjunctiva. Together, these data indicate that proinflammatory cytokines differentially influence the expression of N-glycan-processing enzymes in the Golgi and set the stage for future studies to explore the pathophysiology of ocular autoimmune diseases.
- Published
- 2019