STUDIES TO ELUCIDATE THE EFFECTS OF IRON(III) ON RECOGNITION OF HYALURONATE BY THE CELL SURFACE RECEPTOR CD44

WCU Author/Contributor (non-WCU co-authors, if there are any, appear on document)
Brittania Jane Bintz (Creator)
Institution
Western Carolina University (WCU )
Web Site: http://library.wcu.edu/

Abstract: Iron and the poly-anionic carbohydrate, hyaluronate (HA), have both been implicated as possible contributors to rheumatoid arthritis (RA), an autoimmune disease of unknown etiology. In this work, we hypothesized that in RA patients,iron is bound by HA in such a way as to affect HA binding by the cell surface glycoprotein CD44, a known HA receptor. To test this hypothesis, we developed cell based assays to determine the effects of iron binding to HA on HA binding byCD44. As part of this effort, we prepared biotinylated HA and biotinylated Fecomplexed HA. Mesothelioma cells expressing CD44 were treated with each of these conjugates, and the resulting materials were treated with avidin-fluoresceinand the bound fluorescein was measured using a fluorescence microtiter platereader. We found that Fe (III) decreases the apparent affinity of CD44 receptors on Mesothelioma cells for HA (Observed fluorescence intensity decreased by a factor of ~2). In competition experiments, addition of non-biotinylated Fe complexed HA did not inhibit binding of biotinylated HA. Addition of nonbiotinylated HA, however, appeared to increase the uptake of biotinylated Fe complexed HA. These results suggest that iron(lIl) may crosslink HA molecules,leading to a greater uptake of HA. This crosslinking may influence receptor clustering which is believed to be important to intra-cellular signaling.

Additional Information

Publication
Thesis
Language: English
Date: 2006
Subjects
Rheumatoid arthritis -- Etiology
Carbohydrates -- Metabolism
Iron -- Metabolism

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