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Localization of Copper-Containing Amine Oxidase Enzymes in the Blood

Authors :
Poulsen, Lars Kærgaard
Pedersen, Lotte Bang
Jensen, Bettina Margrethe
Zatkova, Anna
Poulsen, Lars Kærgaard
Pedersen, Lotte Bang
Jensen, Bettina Margrethe
Zatkova, Anna
Publication Year :
2017

Abstract

Diamine oxidase (DAO) is the main histamine metabolizing enzyme performing its function extracellularly. Its activity can be affected by multiple factors like the presence of enzyme inhibitors, lack of enzyme cofactors or existing intestinal damage. Low DAO activity can lead to histamine accumulation in the organism that may cause detrimental histamine-mediated allergy-like symptoms. Histaminosis describes this state of imbalance between histamine and the capacity of histamine metabolizing enzymes to reduce histamine levels. DAO belongs to the family of copper-containing amine oxidases (AOCs) and is encoded by the AOC1 gene. DAO is expressed mainly by kidney and intestinal epithelial cells. High levels of DAO can be detected in placenta during pregnancy. Eosinophils, Neutrophils and Platelets have been reported to possess histaminase activity, though only very few studies have researched this more. Other AOCs belonging to this family are Retina specific amine oxidase encoded by AOC2 gene and Vascular adhesion protein encoded by AOC3. It is unknown whether the native form of these proteins can metabolize histamine as well and therefore could be contributing to histaminase activity in the circulation as well. In this study we challenged previous findings and tested the presence of AOC1, AOC2 and AOC3 on mRNA and protein levels in the blood, zooming in on different blood cell types step by step. We also analyzed plasma and serum DAO concentrations from various donors and analyzed DAO activity in Platelets. Analysis of DAO concentration is serum and plasma showed that, when the blood was drawn into heparin blood tubes, DAO levels from the same individual were twice as higher as when the blood was drawn into EDTA or serum tubes. We also demonstrated that AOC1 mRNA was mainly contained in Granulocytes, particularly in Eosinophils. Protein analysis showed that Platelets seemed to comprise large amounts of DAO. mRNA analysis of AOC2 and AOC3 demonstrated

Details

Database :
OAIster
Notes :
92 pages, application/pdf, English
Publication Type :
Electronic Resource
Accession number :
edsoai.on1000483504
Document Type :
Electronic Resource